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中別府 雄作(なかべっぷ ゆうさく) データ更新日:2019.06.06

教授 /  生体防御医学研究所 個体機能制御学部門 脳機能制御学分野


主な研究テーマ
活性酸素による脳機能障害とその防御機構の解明
キーワード:活性酸素、核酸、8-オキソグアニン、MTH1、OGG1、MUTYH、ミクリグリア、アルツハイマー病
2017.04~2020.03.
アルツハイマー病の遺伝的危険因子の解明とそのメカニズムの解明
キーワード:認知症、遺伝子発現プロファイリング、剖検脳、動物モデル、iPS細胞
2008.04.
fosB遺伝子の選択的スプライシング産物による脳機能制御機構の解明
キーワード:選択的スプライシング、転写制御、神経新生、気分障害、てんかん
2011.04.
環境ストレスによるヌクレオチドプールの恒常性破綻の分子病態と制御機構の解明
キーワード:損傷、ヌクレオチドプール、DNA、RNA
2010.04~2015.03.
活性酸素による生体障害とその防御機構の解明
キーワード:酸化的DNA損傷、酸化ヌクレオチド、ゲノム障害、ミトコンドリア、突然変異、細胞死、ガレクチンー1、シグナル伝達、前初期転写因子 、発がん、脳の老化、免疫不全
2003.12.
活性酸素による脳・神経細胞の障害とその防御機構
キーワード:酸化的DNA損傷、酸化ヌクレオチド、ゲノム障害、ミトコンドリア、突然変異、細胞死、脳の老化、前初期転写因子
1998.12~2003.11.
従事しているプロジェクト研究
活性酸素による脳機能障害とその防御機構の解明
2017.06~2017.06, 代表者:中別府雄作, 九州大学.
ヒト酸化プリンヌクレオシド三リン酸分解酵素MTH1の阻害剤の探索
2014.08~2017.03, 代表者:中別府雄作, 九州大学, 九州大学.
大規模ゲノム疫学共同研究による認知症の危険因子および防御因子の解明
2013.04~2016.03, 代表者:清原裕, 九州大学大学院医学研究院, 九州大学大学院医学研究院
わが国では高齢人口の急増とともに認知症患者が増え、大きな医療・社会問題となっている。認知症の予防対策を講じるには地域住民中の認知症の実態を把握し、その危険因子を明らかにする必要がある。しかし、現在のところ認知症の危険因子はほとんど解明されていないのが実状である。本プロジェクトでは、わが国で進行中の主な認知症の疫学研究を統合し、それに認知症の高リスク群の脳卒中患者および糖尿病患者のコホート研究を加えて大規模ゲノム疫学共同研究を組織し、以下の解析を行う。
福岡県久山町では、1985年から65歳以上の高齢住民を対象に、世界で最も精度の高い認知症の疫学調査(久山町研究)が進行中である。また、同町では2002年より生活習慣病のゲノム疫学研究が継続され、その基盤が整備されている。本研究では、老年期認知症の疫学調査において、アルツハイマー病(AD)をはじめとする認知症の有病率・発症率の時代的変化を明らかにし、その危険因子および防御因子を包括的な健診項目の中より解明する。そしてゲノム解析およびマイクロアレイ解析によってADの遺伝的危険因子を特定する。また血管性認知症(VaD)のリスクが高い脳卒中患者とADのリスクが高い糖尿病患者を対象にした大規模疾患コホートの解析と久山町の一般住民の追跡データを合わせた解析により、短期間に認知症の危険因子・防御因子を明らかにする。さらに認知症の疫学研究を行っている国立大学系の研究グループから構成されるコンソーシアムを組織し、全国の5つの地域住民における軽度認知障害および認知症のデータベースを統合してデータバンクを形成する。そしてデータを一元的に管理するシステムを構築し、既存データから共通項目を選びこれを説明変数としてADの危険因子を特定する。本プロジェクトの成果は、日本人の認知症の危険因子・防御因子を明らかにし、さらに予防手段の確立を通して国民の保健・医療・福祉の向上をもたらし、とくに高齢者医療費の削減につながると期待される。本研究は、各対象者からインフォームドコンセントを取得した上で、当該の倫理指針に基づき遂行される。
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環境ストレスによるヌクレオチドプールの恒常性破綻の分子病態と制御機構の解明
2010.04~2015.03, 代表者:中別府雄作, 九州大学生体防御医学研究所, 九州大学生体防御医学研究所
DNA および RNA の前駆体であるヌクレオチドは放射線や生体内外の環境ストレスにより多様な 化学修飾を受けるが,その放射線生物影響における意義は不明で,早急に解決すべき課題である。 本研究では、環境ストレスによる修飾ヌクレオチドの生成が引き起こす生体障害を「ヌクレオチ ドプールの恒常性の破綻」としてとらえ以下の5つのアプローチで多様な放射線生物応答の制御機構を明らかにする。
[1]放射線照射により生じる修飾ヌクレオチドを 同定し,in vivo での活性酸素や一酸化窒素,金 属等の存在による生成への影響を明らかにする。
[2]細胞外に放出・分泌される修飾ヌクレオチド 等の細胞影響を明らかにし,Bystander effects のメディエータとしての機能と作用機序を解明 する。
[3]修飾ヌクレオチド分解酵素を網羅的に探索 し、基質特異性,放射線による発現制御と分子機 序を解明し,その欠損と高発現が放射線生物影響 にどのように関わるか明らかにする。
[4]DNA 中の修飾ヌクレオチド修復酵素を網羅的 に探索し,その機能と放射線生物影響への関わりを明らかにする。
[5]神経変性の病態モデルマウスへの放射線照射の影響をヌクレオチドプールの恒常性,ゲノム DNA 障害と遊離の修飾ヌクレオチドによる細胞機能制御に注目して明らかにする。.
アルツハイマー病の危険因子の解明と予防に関する大規模ゲノム疫学研究
2008.04~2013.03, 代表者:清原裕, 九州大学大学院医学研究院, 九州大学大学院医学研究院
本研究では、福岡県久山町における老年期認知症のゲノム疫学調査において、地域住民におけるアルツハイマー病(AD)の実態を明らかにし、その危険因子・防御因子を包括的な健診成績の中より明らかにするとともに、その遺伝的危険因子を特定する。さらに、食事・運動の介入試験を行い、ADの予防手段の確立を図る。その成果は、国民の保健・医療・福祉の向上をもたらし、とくに高齢者医療費の削減につながると期待される。.
グローバルCOEプログラム「個体恒常性を担う細胞運命の決定とその破綻」
2007.06~2012.03, 代表者:藤木幸夫, 九州大学大学院システム生命科学府, 九州大学大学院システム生命科学府、医学系学府、
本プログラムは、平成14年度より5年間、九州大学において遂行された、21世紀COEプログラム「統合生命科学 – ポストゲノム時代の生命高次機能の探究」(代表:藤木幸夫)の成果と個体恒常性の概念を融合・発展させ、「個体恒常性を担う細胞運命決定のメカニズム解明と幹細胞生物学として医療応用の基盤構築」に関する新しい世界最高水準の教育研究拠点を形成することを目的としている。
個体は発生期において細胞が指数関数的に増殖するが、ある時点でその増殖は停止し、あるものは機能分化を遂げ、あるものは老化・死に至る。その中で幹細胞と呼ばれる一群の集団は再び増殖する能力を有している。この細胞運命の決定を通じて発生・分化・再生のバランスを統合的に制御することが個体恒常性の維持に重要だと考えられるが、その制御メカニズムの本質には未だ謎が多く残されている。しかしながら、この制御機構の破綻は発癌など疾病に直結し、その解明は生物学的な側面だけでなく、医学的にも早急になされるべき課題である。今までの生命科学は、分子・細胞レベルの基本原理を主軸とし発展してきたが、現時点での知識では臓器・個体の高次機能レベルを理解するためにはまだまだ大きな乖離が存在するのは多くの生命科学者が感じているところである。21世紀の生命科学は個体恒常性を守護する根本原理を明らかにすることが主軸になると考えられ、本研究拠点構想はまさにその第一歩を踏み出そうとするものであり、今後の生命科学を発展させる上での必要性は非常に高いものとなっている。.
脳梗塞感受性遺伝子研究成果の活用・実用化
2006.08~2009.07, 代表者:清原裕, 九州大学大学院医学研究院, 九州大学大学院医学研究院
脳神経疾患の原因遺伝子の多くが同定され、神経疾患の脳科学はポストゲノムの時代を迎えたといえる。脳の発生は遺伝的にプログラミングされているが、発達期の脳においてはもっともダイナミックに脳と環境との相互作用が起こる。しかし、発達期における脳と環境の相互作用の研究は緒についたばかりである。今日、統合失調症や自閉症は脳の発達の異常が、そのべースにあることが認識されつつある。たとえば、ミクロのレベルでは、統合失調症のうち一部の遺伝性のタイプの原因遺伝子は、ニューロン突起伸長に深く関与した分子であることが明らかにされてきている。一方、脳損傷時の再生・修復過程には、発達と同様な分子機構が用いられており、脳の発達に重要なニューロン突起伸長因子は脳損傷時の修復においても重要な機能を担っている。従来、脳疾患は退行過程のみから研究が行われてきたが、発達と修復の共通性からみた脳疾患の研究は新たな視点を提供すると考えられる。他方、マクロのレベルでは、乳幼児にも使用できる非侵襲的脳機能計測法、たとえば事象関連電位(ERP)、機能的MRI (fMRI)、近赤外脳機能イメージング法(NIRS)が開発され、脳の機能発達の客観的解析が可能となった。これらと心理・教育・臨床医学データを比較・検討することにより、脳の定型発達、脳損傷時のニューラルネットワークの可塑性、および発達と修復の共通性の解析が可能となる。そこで、われわれは、マクロレベルの行動脳科学や非侵襲的脳機能解析からミクロレベルのニューラルネットワーク形成まで集約的に発達脳科学を研究する世界にも類をみない研究組織を構築し、発達と修復の共通性に焦点をあてた研究を行う。.
ポストゲノム発達脳科学の創生とその研究・教育基盤の構築〔九州大学 P and P、タイプB)
2005.04~2007.03, 代表者:吉良潤一, 九州大学大学院医学研究院, 九州大学大学院医学研究院
脳神経疾患の原因遺伝子の多くが同定され、神経疾患の脳科学はポストゲノムの時代を迎えたといえる。脳の発生は遺伝的にプログラミングされているが、発達期の脳においてはもっともダイナミックに脳と環境との相互作用が起こる。しかし、発達期における脳と環境の相互作用の研究は緒についたばかりである。今日、統合失調症や自閉症は脳の発達の異常が、そのべースにあることが認識されつつある。たとえば、ミクロのレベルでは、統合失調症のうち一部の遺伝性のタイプの原因遺伝子は、ニューロン突起伸長に深く関与した分子であることが明らかにされてきている。一方、脳損傷時の再生・修復過程には、発達と同様な分子機構が用いられており、脳の発達に重要なニューロン突起伸長因子は脳損傷時の修復においても重要な機能を担っている。従来、脳疾患は退行過程のみから研究が行われてきたが、発達と修復の共通性からみた脳疾患の研究は新たな視点を提供すると考えられる。他方、マクロのレベルでは、乳幼児にも使用できる非侵襲的脳機能計測法、たとえば事象関連電位(ERP)、機能的MRI (fMRI)、近赤外脳機能イメージング法(NIRS)が開発され、脳の機能発達の客観的解析が可能となった。これらと心理・教育・臨床医学データを比較・検討することにより、脳の定型発達、脳損傷時のニューラルネットワークの可塑性、および発達と修復の共通性の解析が可能となる。そこで、われわれは、マクロレベルの行動脳科学や非侵襲的脳機能解析からミクロレベルのニューラルネットワーク形成まで集約的に発達脳科学を研究する世界にも類をみない研究組織を構築し、発達と修復の共通性に焦点をあてた研究を行う。.
統合生命科学(平成14年度21世紀COEプログラム)
2002.04~2007.03, 代表者:藤木幸夫, 九州大学理学研究院生物科学部門, 九州大学理学府、医学府分子生命科学専攻、生体防御医学研究所
近年の生命科学の爆発的な進歩は、「ゲノム」という設計図から「細胞」、「個体」、さらには「集団」に至るまで種々のレベルにおける広範な生命現象を、共通の概念で論じることを可能にした。われわれは生命現象のメカニズムを解き明かすとき、各レベルでの詳細な研究にとどまることなく、ゲノムから集団に至るまでの多くのレベルで「統合」的に理解することを求められるようになりつつある。

しかしながら現在の日本の大学では、生命科学の専門家は複数の異なる組織に配置されて、相互交流による統合的な生命科学研究やその発展が阻害されているのが現状である。このことは研究面だけでなく、教育面でも今後ますます深刻な影響を与えるであろう。われわれ九州大学は、本拠点メンバーによる現在までの高いレベルの研究・教育の実績に基づき、世界的な生命科学研究拠点を創出すると共に、全レベルでの統合的な生命科学を志向する人材を育成・輩出することを、将来の大きな目標としている。また対欧米のみならず、アジアへの玄関口である福岡という地の利を意識、活用した国際性豊かな研究教育拠点としても大きく展開をはかる。

そのためには、まず現在の研究院等に所属する生命科学研究者の再編と新たな統合が必要であり、これをゲノム、細胞、個体、集団の4つの機能領域に再編する。これは単に類似の研究者を寄せ集めて再編した独立の組織ではなく、各々の間で綿密な交流と連携が行えるようにしなければ、上記目的は達成できない。そのために共通基盤に基づく「統合」的な研究体制と教育体制の確立が重要であり、これを推進するために上記4領域の上位に各領域の代表及び国内外からの学識者による「統合生命科学COE会議」を設置し、統合的研究基盤インフラの構築、横断的な研究交流の推進、インタラクティブな教育方法の確立などを目指す。すなわち、平易に表現すれば今まで各個バラバラに存在していた4つの「ゲノム」、「細胞」、「個体」、「集団」という餅に、「統合」という名の串を通して「統合生命科学」という団子を作り上げ、もって広い視野に立つ先進的な研究者・教育者を連帯させて世界的な研究拠点を構築し、将来の人材を育成することを目的とする。.
ゲノム疫学に基づくEBMデータベースの開発とテーラーメイド医療の実現(文部科学省:21世紀型革新的先端ライフサイエンス技術開発プロジェクト)
2002.04~2004.03, 代表者:清原 裕, 九州大学医学部附属病院第二内科, 九州大学医学部附属病院第二内科
 日本人の平均的集団である久山町住民を対象に、環境要因とともに日本人の健康状態の表現型と遺伝型の双方の情報を兼ね備えたデータベースを構築する。これに、別のプロジェクトで創設される疾患感受性遺伝子のゲノム疫学データベースを結合し、患者個々人の特性に応じて生活習慣病の発症を一定の確率で予測しうるデータベースシステムを構築する。このシステムの活用によって、種々のリスクレベルに応じて生活習慣の改善を促すための基本原理を見いだし、より効果的・定量的な生活習慣病の予防法を構築するとともに、質の高いテーラーメイド医療の実現を目指す。.
日本人の動脈硬化に関する先端的研究〔九州大学 P and P、タイプA)
2001.04~2004.03, 代表者:竹下彰・居石克夫, 九州大学大学院医学研究院, 九州大学大学院医学研究院
1.「日本人の動脈硬化」の疫学的・病理学的研究
2.「日本人の動脈硬化」の発症に下にょする遺伝子同定とその生体機能の解析
3.「日本人の動脈硬化」に対する新しい治療法の開発.
遺伝子操作マウス樹立の支援システムの構築〔九州大学 P and P、タイプB)
2000.04~2002.03, 代表者:續輝久, 九州大学大学院医学研究院, 九州大学大学院医学研究院
本研究では、21世紀の「ゲノム科学」の時代に、九州大学が研究資源としての遺伝子操作マウスを戦略的に開発し積極的に活用するためのコア・ユニット設立へ向けて、コラボ・ステーションに設置された「機能病態解析システム室」と連携した基盤作りに取り組んだ。.
研究業績
主要著書
1. Nakabeppu Y, Neurodegeneration caused by accumulation of an oxidized base lesion, 8-oxoguanine, in nuclear and mitochondrial DNA: from animal models to human diseases, in The Base Excision Repair Pathway – Molecular Mechanisms and Role in Disease Development and Therapeutic Design–, edited by David M Wilson III., World Scientific, Chapter 14, pp.523-556, 2017.01, [URL].
2. 中別府 雄作, 神経変性疾患と酸化ストレス、酸化ストレスの医学(吉川 敏一監修、 内藤 裕二、豊國 伸哉 編集)
, 診断と治療社, p217-227, 2014.09.
3. Oka, S., Ohno, M., and Nakabeppu, Y., Construction and characterization of a cell line deficient in repair of mitochondrial, but not nuclear, oxidative DNA damage. In Mitochondrial DNA, Methods and Protocols, (J.A. Stuart, ed.), Humana Press, New York, Methods Mol Biol 544: 251-264., 2009.07.
4. Ohno, M., Oka, S., and Nakabeppu, Y. , Quantitative analysis of oxidized guanine, 8-oxoguanine, in mitochondrial DNA by immunofluorescence method. In Mitochondrial DNA, Methods and Protocols, (J.A. Stuart, ed.), Humana Press, New York, Methods Mol Biol 544: 199-212, 2009.07.
5. Nakabeppu, Y., Behmanesh, M., Yamaguchi, H., Yoshimura, D., and Sakumi, K., Prevention of the mutagenecity and cytotoxicity of oxidized purine nucleotides, In Oxidative Damage to Nucleic Acids, (M. D. Evans, and M. S. Cooke, eds. ), Molecular Biology Intelligence Unit. Springer, New York, NY, USA, Chapter 3, p40-53., 2007.07, [URL].
6. Nakabeppu, Y., Maki, H., and Sekiguchi, M. , DNA Replication and Transcription: In Genomics and Genetics: From Molecular Details to Analysis and Techniques (Meyers, R.A. ed.), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany., Vol. 1: pp. 47-73, 2007.02.
主要原著論文
1. Naoki Haruyama, Kunihiko Sakumi, Atsuhisa Katogi, Daisuke Tsuchimoto, Gabriele De Luca, Margherita Bignami, and Yusaku Nakabeppu, 8-Oxoguanine accumulation in aged female brain impairs neurogenesis in the dentate gyrus and major island of Calleja, causing sexually dimorphic phenotypes, Progress in Neurobiology, https://doi.org/10.1016/j.pneurobio.2019.04.002, in press, 2019.04, [URL], In mammals, including humans, MTH1 with 8-oxo-dGTPase and OGG1 with 8-oxoguanine DNA glycosylase minimize 8-oxoguanine accumulation in genomic DNA. We investigated age-related alterations in behavior, 8-oxoguanine levels, and neurogenesis in the brains of Mth1/Ogg1-double knockout (TO-DKO), Ogg1-knockout, and human MTH1-transgenic (hMTH1-Tg) mice. Spontaneous locomotor activity was significantly decreased in wild-type mice with age, and females consistently exhibited higher locomotor activity than males. This decrease was significantly suppressed in female but not male TO-DKO mice and markedly enhanced in female hMTH1-Tg mice. Long-term memory retrieval was impaired in middle-aged female TO-DKO mice. 8-Oxoguanine accumulation significantly increased in nuclear DNA, particularly in the dentate gyrus (DG), subventricular zone (SVZ) and major island of Calleja (ICjM) in middle-aged female TO-DKO mice. In middle-aged female TO-DKO mice, neurogenesis was severely impaired in SVZ and DG, accompanied by ICjM and DG atrophy. Conversely, expression of hMTH1 efficiently suppressed 8-oxoguanine accumulation in both SVZ and DG with hypertrophy of ICjM. These findings indicate that newborn neurons from SVZ maintain ICjM in the adult brain, and increased accumulation of 8-oxoguanine in nuclear DNA of neural progenitors in females is caused by 8-oxo-dGTP incorporation during proliferation, causing depletion of neural progenitors, altered behavior, and cognitive function changes with age.
2. Akira Sakurada, Koji Miyanishi, Shingo Tanaka, Masanori Sato, Hiroki Sakamoto, Yutaka Kawano, Kohichi Takada, Yusaku Nakabeppu, Masayoshi Kobune, Junji Kato, An Intronic Single Nucleotide Polymorphism in the MUTYH Gene Is Associated with Increased Risk for HCV-induced Hepatocellular carcinoma, Free Radic Biol Med, 10.1016/j.freeradbiomed.2018.09.010, 129, 88-96, 2018.12, [URL].
3. Erika Castillo, Julio Leon, Guianfranco Mazzei, Nona Abolhassani, Naoki Haruyama, Takashi Saito, Takaomi Saido, Masaaki Hokama, Toru Iwaki, Tomoyuki Ohara, Toshiharu Ninomiya, Yutaka Kiyohara, Kunihiko Sakumi, Frank M LaFerla, Yusaku Nakabeppu, Comparative profiling of cortical gene expression in Alzheimer's disease patients and mouse models demonstrates a link between amyloidosis and neuroinflammation, Scientific Reports, 10.1038/s41598-017-17999-3, 7, 1, 17762, 2017.12, [URL], Alzheimer’s disease (AD) is the most common form of dementia, characterized by accumulation of amyloid β (Aβ) and neurofibrillary tangles. Oxidative stress and inflammation are considered to play an important role in the development and progression of AD. However, the extent to which these events contribute to the Aβ pathologies remains unclear. We performed inter-species comparative gene expression profiling between AD patient brains and the App NL-G-F/NL-G-F and 3xTg-AD-H mouse models. Genes commonly altered in App NL-G-F/NL-G-F and human AD cortices correlated with the inflammatory response or immunological disease. Among them, expression of AD-related genes (C4a/C4b, Cd74, Ctss, Gfap, Nfe2l2, Phyhd1, S100b, Tf, Tgfbr2, and Vim) was increased in the App NL-G-F/NL-G-F cortex as Aβ amyloidosis progressed with exacerbated gliosis, while genes commonly altered in the 3xTg-AD-H and human AD cortices correlated with neurological disease. The App NL-G-F/NL-G-F cortex also had altered expression of genes (Abi3, Apoe, Bin2, Cd33, Ctsc, Dock2, Fcer1g, Frmd6, Hck, Inpp5D, Ly86, Plcg2, Trem2, Tyrobp) defined as risk factors for AD by genome-wide association study or identified as genetic nodes in late-onset AD. These results suggest a strong correlation between cortical Aβ amyloidosis and the neuroinflammatory response and provide a better understanding of the involvement of gender effects in the development of AD..
4. Marco Seifermann, Alexander Ulges, Tobias Bopp, Svetlana Melcea, Andrea Schafer, Sugako Oka, Yusaku Nakabeppu, Arne Klungland, Christof Niehrs, Bernd Epe, Role of the DNA repair glycosylase OGG1 in the activation of murine splenocytes., DNA repair, 10.1016/j.dnarep.2017.08.005, 58, 13-20, 2017.08, [URL].
5. Vladimir Vartanian, Jana Tumova, Pawel Dobrzyn, Yusaku Nakabeppu, R. Stephen Lloyd, Harini Sampath, 8-oxoguanine DNA glycosylase (OGG1) deficiency elicits coordinated changes in lipid and mitochondrial metabolism in muscle, PLos One, 10.1371/journal.pone.0181687, 12, 7, e0181687, 2017.07, [URL].
6. Shinji Asada, Eiko Ohta, Yoriko Akimoto, ABOLHASSANI NONA, Daisuke Tsuchimoto, Yusaku Nakabeppu, 2-Oxoadenosine induces cytotoxicity through intracellular accumulation of 2-oxo-ATP and depletion of ATP but not via the p38 MAPK pathway, Scientific Reports, 10.1038/s41598-017-06636-8, 7, 1, 6528, 2017.07, [URL].
7. Nona Abolhassani, Julio Leon, Zijing Sheng, Sugako Oka, Hideomi Hamasaki, Toru Iwaki, Yusaku Nakabeppu, Molecular pathophysiology of impaired glucose metabolism, mitochondrial dysfunction, and oxidative DNA damage in Alzheimer's disease brain, Mech Ageing Dev, 10.1016/j.mad.2016.05.005, 161, 95-104, 2017.01, [URL], In normal brain, neurons in the cortex and hippocampus produce insulin, which modulates glucose metabolism and cognitive functions. It has been shown that insulin resistance impairs glucose metabolism and mitochondrial function, thus increasing production of reactive oxygen species. Recent progress in Alzheimer's disease (AD) research revealed that insulin production and signaling are severely impaired in AD brain, thereby resulting in mitochondrial dysfunction and increased oxidative stress. Among possible oxidative DNA lesions, 8-oxoguanine (8-oxoG) is highly accumulated in the brain of AD patients. Previously we have shown that incorporating 8-oxoG in nuclear and mitochondrial DNA promotes MUTYH (adenine DNA glycosylase) dependent neurodegeneration. Moreover, cortical neurons prepared from MTH1 (8-oxo-dGTPase)/OGG1 (8-oxoG DNA glycosylase)-double deficient adult mouse brains is shown to exhibit significantly poor neuritogenesis in vitro with increased 8-oxoG accumulation in mitochondrial DNA in the absence of antioxidants. Therefore, 8-oxoG can be considered involved in the neurodegenerative process in AD brain. In mild cognitive impairment, mitochondrial dysfunction and oxidative damage may induce synaptic dysfunction due to energy failures in neurons thus resulting in impaired cognitive function. If such abnormality lasts long, it can lead to vicious cycles of oxidative damage, which may then trigger the neurodegenerative process seen in Alzheimer type dementia..
8. Michel Massaad, Jia Zhou, Daisuke Tsuchimoto, Janet Chou, Haifa Jabara, Erin Janssen, Salome Glauzy, Brennan G. Olson, Henner Morbach, Toshiro Ohsumi, Klaus SchmitzAbe, Markianos Kyriacos, Jennifer Kane, Kumiko Torisu, Yusaku Nakabeppu, Luigi D. Notarangelo, Eliane Chouery, André Megarbane, Peter B. Kang, Deficiency of the base excision repair enzyme NEIL3 is associated with increased lymphocyte apoptosis, autoantibodies and predisposition to autoimmunity, J Clin Invest, 10.1172/JCI85647., 126, 11, 4219-4236, 2016.11, [URL], Alterations in the apoptosis of immune cells have been associated with autoimmunity. Here, we have identified a homozygous missense mutation in the gene encoding the base excision repair enzyme Nei endonuclease VIII-like 3 (NEIL3) that abolished enzymatic activity in 3 siblings from a consanguineous family. The NEIL3 mutation was associated with fatal recurrent infections, severe autoimmunity, hypogammaglobulinemia, and impaired B cell function in these individuals. The same homozygous NEIL3 mutation was also identified in an asymptomatic individual who exhibited elevated levels of serum autoantibodies and defective peripheral B cell tolerance, but normal B cell function. Further analysis of the patients revealed an absence of LPS-responsive beige-like anchor (LRBA) protein expression, a known cause of immunodeficiency. We next examined the contribution of NEIL3 to the maintenance of self-tolerance in Neil3-/- mice. Although Neil3-/- mice displayed normal B cell function, they exhibited elevated serum levels of autoantibodies and developed nephritis following treatment with poly(I:C) to mimic microbial stimulation. In Neil3-/- mice, splenic T and B cells as well as germinal center B cells from Peyer's patches showed marked increases in apoptosis and cell death, indicating the potential release of self-antigens that favor autoimmunity. These findings demonstrate that deficiency in NEIL3 is associated with increased lymphocyte apoptosis, autoantibodies, and predisposition to autoimmunity..
9. Sugako Oka, Julio Leon, Kunihiko Sakumi, Tomomi Ide, Dongchon Kang, Frank M LaFerla, Yusaku Nakabeppu, Human mitochondrial transcriptional factor A breaks the mitochondria-mediated vicious cycle in Alzheimer’s disease, Sci Rep, 10.1038/srep37889, 6, 37889, 2016.11, [URL], In the mitochondria-mediated vicious cycle of Alzheimer's disease (AD), intracellular amyloid β (Aβ) induces mitochondrial dysfunction and reactive oxygen species, which further accelerate Aβ accumulation. This vicious cycle is thought to play a pivotal role in the development of AD, although the molecular mechanism remains unclear. Here, we examined the effects of human mitochondrial transcriptional factor A (hTFAM) on the pathology of a mouse model of AD (3xTg-AD), because TFAM is known to protect mitochondria from oxidative stress through maintenance of mitochondrial DNA (mtDNA). Expression of hTFAM significantly improved cognitive function, reducing accumulation of both 8-oxoguanine, an oxidized form of guanine, in mtDNA and intracellular Aβ in 3xTg-AD mice and increasing expression of transthyretin, known to inhibit Aβ aggregation. Next, we found that AD model neurons derived from human induced pluripotent stem cells carrying a mutant PSEN1 (P117L) gene, exhibited mitochondrial dysfunction, accumulation of 8-oxoguanine and single-strand breaks in mtDNA, and impaired neuritogenesis with a decreased expression of transthyretin, which is known to be downregulated by oxidative stress. Extracellular treatment with recombinant hTFAM effectively suppressed these deleterious outcomes. Moreover, the treatment increased expression of transthyretin, accompanied by reduction of intracellular Aβ. These results provide new insights into potential novel therapeutic targets..
10. Kumiko Torisu, Xueli Zhang, Mari Nonak, Takahide Kaji, Daisuke Tsuchimoto, Kosuke Kajitani, SAKUMI Kunihiko, Torisu Takehiro, Kazuhiro Chida, Katsuo Sueishi, Michiaki Kubo, Jun Hata, Kitazono T, Yutaka Kiyohara, Yusaku Nakabeppu, PKCη deficiency improves lipid metabolism and atherosclerosis in apolipoprotein E-deficient mice, Genes to Cells, 10.1111/gtc.12402, 21, 10, 1030-1048, 2016.10, [URL].
11. Yasuto Yoneshima, Nona Abolhassani, Teruaki Iyama, Kunihiko Sakumi, Naoko Shiomi, Masahiko Mori, Tadahiro Shiomi, Tetsuo Noda, Daisuke Tsuchimoto, Yusaku Nakabeppu, Deoxyinosine triphosphate induces MLH1/PMS2- and p53-dependent cell growth arrest and DNA instability in mammalian cells, Sci Rep, 10.1038/srep32849, 6, 32849, 2016.09, [URL].
12. Shunji Nakatake, Yusuke Murakami, Yasuhiro Ikeda, Noriko Morioka, Takashi Tachibana, Kohta Fujiwara, Noriko Yoshida, Shoji Notomi, Toshio Hisatomi, Shigeo Yoshida, Tatsuro Ishibashi, Yusaku Nakabeppu, Koh-Hei Sonoda, MUTYH promotes oxidative microglial activation and inherited retinal degeneration, JCI Insight, 10.1172/jci.insight.87781, 1, 15, e87781, 2016.09, [URL].
13. Julio Leon, Kunihiko Sakumi, Erika Castillo, Zijing Sheng, Sugako Oka, Yusaku Nakabeppu, 8-Oxoguanine accumulation in mitochondrial DNA causes mitochondrial dysfunction and impairs neuritogenesis in cultured adult mouse cortical neurons under oxidative conditions., Sci Rep, 10.1038/srep22086, 6, 22086, 2016.02, [URL].
14. Bjorge, Monica D, Hildrestrand, Gunn A, Scheffler, Katja, Suganthan, Rajikala, Rolseth, Veslemoy, Kusnierczyk, Anna, Rowe, Alexander D, Vagbo, Cathrine B, Vetlesen, Susanne, Eide, Lars, Slupphaug, Geir, Nakabeppu, Yusaku, Bredy, Timothy W, Klungland, Arne, Bjoras, Magnar, Synergistic Actions of Ogg1 and Mutyh DNA Glycosylases Modulate Anxiety-like Behavior in Mice, Cell Reports, 10.1016/j.celrep.2015.12.001, 13, 12, 2671-2678, 2015.12.
15. Yuko Kobayakawa, Kunihiko Sakumi, Kosuke Kajitani, Toshihiko Kadoya, Hidenori Horie, Jun-ichi Kira, Yusaku Nakabeppu, Galectin-1 deficiency improves axonal swelling of motor neurons in SOD1G93A transgenic mice, Neuropathol Appl Neurobiol, 10.1111/nan.12123, 41, 2, 227-244, 2015.02, [URL].
16. Sugako Oka, Julio Leon, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, MUTYH, an adenine DNA glycosylase, mediates p53 tumor suppression via PARP-dependent cell death, Oncogenesis, 10.1038/oncsis.2014.35, 3, e121, 2014.10, [URL].
17. Masaaki Hokama, Sugako Oka, Julio Leon, Toshiharu Ninomiya, HIROYUKI HONDA, Kensuke Sasaki, Toru Iwaki, Tomoyuki Ohara, Tomio Sasaki, Frank M. LaFerla, Yutaka Kiyohara, Yusaku Nakabeppu, Altered expression of diabetes-related genes in Alzheimer’s disease brains: The Hisayama study, Cereb Cortex, 10.1093/cercor/bht101, 24, 9, 2476-2488, 2014.09, [URL], Diabetes mellitus (DM) is considered to be a risk factor for dementia including Alzheimer's disease (AD). However, the molecular mechanism underlying this risk is not well understood. We examined gene expression profiles in postmortem human brains donated for the Hisayama study. Three-way analysis of variance of microarray data from frontal cortex, temporal cortex, and hippocampus was performed with the presence/absence of AD and vascular dementia, and sex, as factors. Comparative analyses of expression changes in the brains of AD patients and a mouse model of AD were also performed. Relevant changes in gene expression identified by microarray analysis were validated by quantitative real-time reverse-transcription polymerase chain reaction and western blotting. The hippocampi of AD brains showed the most significant alteration in gene expression profile. Genes involved in noninsulin-dependent DM and obesity were significantly altered in both AD brains and the AD mouse model, as were genes related to psychiatric disorders and AD. The alterations in the expression profiles of DM-related genes in AD brains were independent of peripheral DM-related abnormalities. These results indicate that altered expression of genes related to DM in AD brains is a result of AD pathology, which may thereby be exacerbated by peripheral insulin resistance or DM..
18. Hiroko Nomaru, Kunihiko Sakumi, Atsuhisa Katogi, Yoshinori N Ohnishi, Kosuke Kajitani, Daisuke Tsuchimoto, Eric J. Nestler, Yusaku Nakabeppu, Fosb gene products contribute to excitotoxic microglial activation by regulating the expression of complement C5a receptors in microglia, Glia, 10.1002/glia.22680., 62, 8, 1284-1298, 2014.08, [URL].
19. Hideomi Hamasaki, Hiroyuki Honda, Satoshi O Suzuki, Masaaki Hokama, Yutaka Kiyohara, Yusaku Nakabeppu, Toru Iwaki, Down-regulation of MET in hippocampal neurons of Alzheimer's disease brains, Neuropathology, 10.1111/neup.12095, 34, 3, 284-290, 2014.06, [URL].
20. Mizuki Ohno, Kunihiko Sakumi, Ryutaro Fukumura, Masato Furuichi, Yuki Iwasaki, Masaaki Hokama, Toshimichi Ikemura, Teruhisa Tsuzuki, Yoichi Gondo, Yusaku Nakabeppu, 8-oxoguanine causes spontaneous de novo germline mutations in mice, Sci Rep, 10.1038/srep04689, 4, 4689, 2014.04, [URL].
21. Hideo Tsuji, Hiroko Ishii-Ohba, Tadahiro Shiomi, Naoko Shiomi, Takanori Katsube, Masahiko Mori, Mitsuru Nenoi, Ohno Mizuki, Daisuke Yoshimura, Sugako OKa, Yusaku Nakabeppu, Kouichi Tasumi, Masahiro Muto, Toshikiko Sada, Nature of nontargeted radiation effects observed during fractionated irradiation-induced thymic lymphomagenesis in mice, J Radiat Res, 10.1093/jrr/rrs128, 54, 3, 453-466, PMID: 23297316, 2013.05.
22. Noriko Yutsudo, Takkashi Kamada, Kosuke Kajitani, Hiroko Nomaru, Atsuhisa Katogi, Yoko H Ohnishi, Yoshinori N Ohnisi, Kei-ichiro Takase, Hiroshu Shugeto, SAKUMI Kunihiko, Yusaku Nakabeppu, fosB-null mice display impaired adult hippocampal neurogenesis and spontaneous epilepsy with depressive behavior, Neuropsychopharmacology, doi:10.1038/npp.2012.260, 38, 5, 895-906, 2013.04, [URL].
23. Harini Sampath, Vladimir Vartanian, M. Rick Rollins, Kunihiko Sakumi, Yusaku Nakabeppu, R. Stephen Lloyd, 8-Oxoguanine DNA Glycosylase (OGG1) Deficiency Increases Susceptibility to Obesity and Metabolic Dysfunction, PLoS ONE, 10.1371/journal.pone.0051697, 7, 12, e51697, 2012.12, [URL].
24. Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Abolhassani Nona, Nomaru Hiroko, Kunihiko Sakumi, Yamada Hidetaka, Yusaku Nakabeppu, 8-Oxoguanine causes neurodegeneration during MUTYH-mediated DNA base excision repair, J Clin Invest, 10.1172/JCI65053, 122, 12, 4344-4361, 2012.12, [URL].
25. Murakami Y, Ikeda Y, Yoshida N, Notomi S, Hisatomi T, Oka S, De Luca G, Yonemitsu Y, Bignami M, Nakabeppu Y, Ishibashi T., MutT Homolog-1 Attenuates Oxidative DNA Damage and Delays Photoreceptor Cell Death in Inherited Retinal Degeneration, Am J Pathol, doi: 10.1016/j.ajpath.2012.06.026, 181, 4, 1378-1386, 2012.10.
26. Ohnishi YN, Ohnishi YH, Hokama M, Nomaru H, Yamazaki K, Tominaga Y, Sakumi K, Nestler EJ, Nakabeppu Y, FosB is essential for the enhancement of stress tolerance and antagonizes locomotor sensitization by ΔFosB, Biological Psychiatry, 186, 4, 1943-1950, 2011.09.
27. Iwama E, Tsuchimoto D, Iyama T, Sakumi K, Nakagawara A, Takayama K, Nakanishi Y, Nakabeppu Y., Cancer-Related PRUNE2 Protein Is Associated with Nucleotides and Is Highly Expressed in Mature Nerve Tissues, J Mol Neurosci, 10.1007/s12031-010-9490-2, 44, 2, 103-114, 2011.06, [URL].
28. Iyama T, Abolhassani N, Tsuchimoto D, Nonaka M, Nakabeppu Y., NUDT16 is a (deoxy)inosine diphosphatase, and its deficiency induces accumulation of single-strand breaks in nuclear DNA and growth arrest, Nucleic Acids Research, 38, 14, 4834-4843, 2010.06.
29. Abolhassani, N, Iyama, T, Tsuchimoto, D, Sakumi, K, Ohno, M, Behmanesh, M, Nakabeppu, Y., NUDT16 and ITPA play a dual protective role in maintaining chromosome stability and cell growth by eliminating dIDP/IDP and dITP/ITP from nucleotide pools in mammals, Nucleic Acids Research, 38, 9, 2891-2903, 2010.05.
30. Martin SA, McCabe N, Mullarkey M, Cummins R, Burgess DJ, Nakabeppu Y, Oka S, Kay E, Lord CJ, Ashworth A. , DNA polymerases as potential therapeutic targets for cancers deficient in the DNA mismatch repair proteins MSH2 or MLH1, Cancer Cell, 17, 3, 1235-1248, 2010.03.
31. Behmanesh, M., Sakumi, K., Abolhassani, N., Toyokuni, S., Oka, S., Ohnishi, Y., Tsuchimoto, D., and Nakabeppu, Y. , ITPase-deficient mice show growth retardation and die before weaning, Cell Death Differ, 16, 10, 1315-1322, 2009.10.
32. Kyota Fujita, Toshihiro Seike, Noriko Yutsudo, Mizuki Ohno, Hidetaka Yamada, Hiroo Yamaguchi, Kunihiko Sakumi, Yukiko Yamakawa, Mizuho A. Kido, Atsushi Takaki, Toshihiko Katafuchi, Yoshinori Tanaka, Yusaku Nakabeppu, Mami Noda , Hydrogen in Drinking Water Reduces Dopaminergic Neuronal Loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine Mouse Model of Parkinson’s Disease, PLoS ONE, 4, 9, e7247, 2009.09.
33. Kajitani, K., Nomaru, H., Ifuku, M., Yutsudo, N., Dan, Y., Miura, T., Tsuchimoto, D., Sakumi, K., Kadoya, T., Horie, H., Poirier, F., Noda, M. and Nakabeppu, Y., Galectin-1 promotes basal and kainate-induced proliferation of neural progenitors in the dentate gyrus of adult mouse hippocampus, Cell Death Differ, 16, 3, 417-427, 2009.03.
34. Nonaka, M., Tsuchimoto, D., Sakumi, K. and Nakabeppu, Y., Mouse RS21-C6 is a mammalian 2’-deoxycytidine 5’-triphosphate pyrophosphohydrolase, preferring 5-iodocytosine, FEBS J, 276, 6, 1654-1666, 2009.03.
35. Nakane, H., Hirota, S., Brooks, P. J., Nakabeppu, Y., Nakatsu, Y., Nishimune, Y., Iino, A., and Tanaka, K. , Impaired spermatogenesis and elevated spontaneous tumorigenesis in xeroderma pigmentosum group A gene (Xpa)-deficient mice. , DNA Repair, 7, 12, 1938-1950, 2008.12.
36. Ohnishi YN, Sakumi K, Yamazaki K, Ohnishi YH, Miura T, Tominaga Y, Nakabeppu Y., Antagonistic regulation of cell-matrix adhesion by FosB and ΔFosB/Δ2ΔFosB encoded by alternatively spliced forms of fosB transcripts., Mol Biol Cell, 19(11): 4717-4729, 2008.11.
37. Dan Y, Ohta Y, Tsuchimoto D, Ohno M, Ide Y, Sami M, Kanda T, Sakumi K, Nakabeppu Y., Altered gene expression profiles and higher frequency of spontaneous DNA strand breaks in APEX2-null thymus., DNA Repair, 7 (9): 1437-1454, 2008.09.
38. Yanaru-Fujisawa R, Matsumoto T, Ushijima Y, Esaki M, Hirahashi M, Gushima M, Yao T, Nakabeppu Y, Iida M., Genomic and functional analyses of MUTYH in Japanese patients with adenomatous polyposis., Clin Genet, 73(6):545-553, 2008.06.
39. Ichikawa J, Tsuchimoto D, Oka S, Ohno M, Furuichi M, Sakumi K, Nakabeppu Y., Oxidation of mitochondrial deoxynucleotide pools by exposure to sodium nitroprusside induces cell death., DNA Repair, 7(3):418-430, 2008.03.
40. Oka S, Ohno M, Tsuchimoto D, Sakumi K, Furuichi M, Nakabeppu Y., Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs., EMBO Journal., 27(2):421-432., 2008.01.
41. Sakamoto K, Tominaga Y, Yamauchi K, Nakatsu Y, Sakumi K, Yoshiyama K, Egashira A, Kura S, Yao T, Tsuneyoshi M, Maki H, Nakabeppu Y, Tsuzuki T., MUTYH-null mice are susceptible to spontaneous and oxidative stress induced intestinal tumorigenesis., Cancer Research, 67(14):6599-6604. , 2007.07.
42. Kuraoka I, Suzuki K, Ito S, Hayashida M, Kwei JS, Ikegami T, Handa H, Nakabeppu Y, Tanaka K., RNA polymerase II bypasses 8-oxoguanine in the presence of transcription elongation factor TFIIS., DNA Repair, 6, 6, 841-851, 2007.06.
43. Ohtsubo T, Ohya Y, Nakamura Y, Kansui Y, Furuichi M, Matsumura K, Fujii K, Iida M, Nakabeppu Y., Accumulation of 8-oxo-deoxyguanosine in cardiovascular tissues with the development of hypertension., DNA Repair, 6, 6, 760-769, 2007.06.
44. Nakamura T, Kitaguchi Y, Miyazawa M, Kamiya H, Toma S, Ikemizu S, Shirakawa M, Nakabeppu Y, Yamagata Y., Crystallization and preliminary X-ray analysis of human MTH1 complexed with two oxidized nucleotides, 8-oxo-dGMP and 2-oxo-dATP., Acta Crystallograph Sect F Struct Biol Cryst Commun., 62(Pt 12):1283-1285, 2006.12.
45. Kamiya H, Cadena-Amaro C, Dugue L, Yakushiji H, Minakawa N, Matsuda A, Pochet S, Nakabeppu Y, Harashima H., Recognition of Nucleotide Analogs Containing the 7,8-Dihydro-8-oxo Structure by the Human MTH1 Protein., J. Biochem., 140(6):843-849, 2006.12.
46. Akatsuka S, Aung TT, Dutta KK, Jiang L, Lee WH, Liu YT, Onuki J, Shirase T, Yamasaki K, Ochi H, Naito Y, Yoshikawa T, Kasai H, Tominaga Y, Sakumi K, Nakabeppu Y, Kawai Y, Uchida K, Yamasaki A, Tsuruyama T, Yamada Y, Toyokuni S., Contrasting genome-wide distribution of 8-hydroxyguanine and acrolein-modified adenine during oxidative stress-induced renal carcinogenesis., Am. J. Pathol., 169(4):1328-1342, 2006.10.
47. Arai T, Fukae J, Hatano T, Kubo S, Ohtsubo T, Nakabeppu Y, Mori H, Mizuno Y, Hattori N., Up-regulation of hMUTYH, a DNA repair enzyme, in the mitochondria of substantia nigra in Parkinson's disease., Acta Neuropathol, 112(2):139-145., 2006.08.
48. Sakai Y, Oda H, Yoshimura D, Furuichi M, Kang D, Iwai S, Hara T, Nakabeppu Y., The GT to GC single nucleotide polymorphism at the beginning of an alternative exon 2C of human MTH1 gene confers an amino terminal extension that functions as a mitochondrial targeting signal., J. Mol. Med., 4(8):660-670, 2006.08.
49. Arima, H., Kiyohara Y., Tanizaki Y., Nakabeppu Y., Kubo M., Kato I., Sueishi K., Tsuneyoshi M., Fujishima M. and Iida M, Angiotensin I-converting enzyme gene polymorphism modifies the smoking-cancer association: the Hisayama Study., Europ. J. Cancer Prev., 5(3):196-201, 2006.06.
50. Ohno M, Miura T, Furuichi M, Tominaga Y, Tsuchimoto D, Sakumi K, Nakabeppu Y., A genome-wide distribution of 8-oxoguanine correlates with the preferred regions for recombination and single nucleotide polymorphism in the human genome., Genome Res., 6(5):567-575, 2006.05.
51. Yamaguchi, H., Kajitani K., Dan Y., Furuichi M., Ohno M., Sakumi K., Kang D. and Nakabeppu Y., MTH1, an oxidized purine nucleoside triphosphatase, protects the dopamine neurons from oxidative damage in nucleic acids caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine., Cell Death Differ, 13(4):551-563, 2006.04.
52. Kajitani, K., Yamaguchi H., Dan Y., Furuichi M., Kang D. and Nakabeppu Y., MTH1, an oxidized purine nucleoside triphosphatase, suppresses the accumulation of oxidative damage of nucleic acids in the hippocampal microglia during kainate-induced excitotoxicity., J. Neurosci., 26(6):1688-1698, 2006.02.
53. Torisu, K., Tsuchimoto D., Ohnishi Y. and Nakabeppu Y., Hematopoietic tissue-specific expression of mouse Neil3 for endonuclease VIII-like protein., J. Biochem., 10.1093/jb/mvi168, 138, 6, 763-772, 138(6):763-772, 2005.12.
54. Kurushima, H., Ohno M., Miura T., Nakamura T. Y., Horie H., Kadoya T., Ooboshi H., Kitazono T., Ibayashi S., Iida M. and Nakabeppu Y., Selective induction of ΔFosB in the brain after transient forebrain ischemia accompanied by an increased expression of galectin-1, and the implication of ΔFosB and galectin-1 in neuroprotection and neurogenesis., Cell Death Differ, 10.1038/sj.cdd.4401648, 12, 8, 1078-1096, 12 (8):1078-1096., 2005.08.
55. Kunisada, M., Sakumi K., Tominaga Y., Budiyanto A., Ueda M., Ichihashi M., Nakabeppu Y. and Nishigori C., 8-Oxoguanine Formation Induced by Chronic UVB Exposure Makes Ogg1 Knockout Mice Susceptible to Skin Carcinogenesis., Cancer Res, 10.1158/0008-5472.CAN-05-0724, 65, 14, 6006-6010, 65 (14):6006-10., 2005.07.
56. Campalans, A., Marsin S., Nakabeppu Y., O'Connor T R., Boiteux S. and Radicella J. P., XRCC1 interactions with multiple DNA glycosylases: A model for its recruitment to base excision repair., DNA Repair, 10.1016/j.dnarep.2005.04.014, 4, 7, 826-835, 4 (7):826-35., 2005.07.
57. Fukae, J., Takanashi M., Kubo S.-i., Nishioka K.-i., Nakabeppu Y., Mori H., Mizuno Y. and Hattori N., Expression of 8-oxoguanine DNA glycosylase (OGG1) in Parkinson's disease and related neurodegenerative disorders., Acta Neurophathologica, 10.1007/s00401-004-0937-9, 109, 3, 256-262, 109 (3):256-262., 2005.03.
58. Behmanesh, M., Sakumi K., Tsuchimoto D., Torisu K., Ohnishi-Honda Y., Derrick E R. and Nakabeppu Y., Characterization of the structure and expression of mouse Itpa gene and its related sequences in the mouse genome., DNA Research, 10.1093/dnares/12.1.39, 12, 1, 39-51, 12 (1):29-41., 2005.02.
59. Ushijima, Y., Y. Tominaga, T. Miura, Daisuke Tsuchimoto, K. Sakumi, and Y. Nakabeppu., A functional analysis of the DNA glycosylase activity of mouse MUTYH protein excising 2-hydroxyadenine opposite guanine in DNA., Nucleic Acids Res., 10.1093/nar/gki214, 33, 2, 672-682, 33(2):672-682., 2005.01.
60. Robertson, G. S., C. J. Lee, K. Sridhar, Y. Nakabeppu, M. Cheng, Y.-M. Wang, and M. G. Caron., Clozapine-, but not haloperidol-, induced increases in deltaFosB-like immunoreactivity is completely blocked in the striatum of mice lacking D3 dopamine receptors, Eur. J. Neurosci., 10.1111/j.1460-9568.2004.03774.x, 20, 11, 3189-3194, 20(11):3189-3194., 2004.12.
61. Keiji Hashimoto, Yusaku Nakabeppu, Masaaki Moriya, Futile short-patch DNA base excision repair of adenine:8-oxoguanine mispair, Nucleic Acids Res., 10.1093/nar/gkh909, 32, 19, 5928-5934, 32(19):5928-5234, 2004.11.
62. T. Miura, M. Takahashi, H. Horie, H. Kurushima, D. Tsuchimoto, K. Sakumi, Y. Nakabeppu, Galectin-1beta, a natural monomeric form of galectin-1 lacking its six amino-terminal residues promotes axonal regeneration but not cell death., Cell Death and Differentiation, 10.1038/sj.cdd.4401462, 11, 10, 1076-1083, 11(10):1076-1083, 2004.10.
63. Masaki Mishima, Yasunari Sakai, Noriyuki Itoh, Hiroyuki Kamiya, Masato Furuichi, Masayuki Takahashi, Yuriko Yamagata, Shigenori Iwai, Yusaku Nakabeppu, Masahiro Shirakawa, Structure of human MTH1, a Nudix family hydrolase that selectively degrades oxidized purine nucleoside triphosphates., J. Biol. Chem., 10.1074/jbc.M402393200, 279, 32, 33806-33815, 279(32):33806-33815, 2004.08.
64. Yohei Tominaga, Yasuhiro Ushijima, Daisuke Tsuchimoto, Masaki Mishima, Masahiro Shirakawa, Seiki Hirano, Kunihiko Sakumi, Yusaku Nakabeppu., MUTYH prevents OGG1 or APEX1 from inappropriately processing its substrate or reaction product with its C-terminal domain., Nucleic Acids Res., 10.1093/nar/gkh642, 32, 10, 3198-3211, 32 (10):3198-3211, 2004.06.
65. Kimura, Y., S. Oda, A. Egashira, Y. Kakeji, H. Baba, Y. Nakabeppu, and Y. Maehara., A variant form of hMTH1, a human homologue of mutT E. coli mutator gene, correlates with somatic mutation in p53 tumour suppressor gene in gastric cancer patients., J. Med. Genet., 10.1136/jmg.2003.013268, 41, 5, 41 (5): e57, 2004.05.
66. Iida, T., Furuta, A., Nakabeppu, Y., and Iwaki, T., Defense mechanism to oxidative DNA damage in glial cells., Neuropathol., 10.1111/j.1440-1789.2003.00540.x, 24, 2, 125-130, 24 (2): 125-130, 2004.05.
67. Kamiya, H., H. Yakushiji, L. Dugue, M. Tanimoto, S. Pochet, Y. Nakabeppu, H. Harashima., Probing the substrate recognition mechanism of the human MTH1 protein by nucleotide analogs., J. Mol. Biol., 10.1016/j.jmb.2003.12.060, 336, 4, 843-850, 336 (4): 843-850, 2004.02.
68. Ichinoe, A., M. Behmanesh, Y. Tominaga, Y. Ushijima, S. Hirano, Y. Sakai, D. Tsuchimoto, K. Sakumi, N. Wake, Y. Nakabeppu., Identification and characterization of two forms of mouse MUTYH proteins encoded by alternatively spliced transcripts., Nucleic Acids Res., 10.1093/nar/gkh214, 32, 2, 477-487, 32(2):477-487, 2004.01.
69. Russo, M. T., M. F. Blasi, F. Chiera, P. Fortini, P. Degan, P. Macpherson, M. Furuichi, Y. Nakabeppu, P. Karran, G. Aquilina, and M. Bignami., The oxidized Deoxynucleotide Triphosphate Pool is a Significant Contributor to Genetic Instability in Mismatch Repair-Deficient Cells., Mol. Cell Biol., 10.1128/MCB.24.1.465-474.2004, 24, 1, 465-474, 24: 465-474., 2004.01.
70. Xu, P., K. Yoshioka, D. Yoshimura, Y. Tominaga, T. Nishioka, M. Ito, and Y. Nakabeppu., In vitro development of mouse embryonic stem cells lacking JSAP1 scaffold protein revealed its requirement during early embryonic neurogenesis., J. Biol. Chem., 10.1074/jbc.M307888200, 278, 48, 48422-48433, 278:48422-48433, 2003.11.
71. Hirano, S., Y. Tominaga, A. Ichinoe, Y. Ushijima, D. Tsuchimoto, Y. Honda-Ohnishi, T. Ohtsubo, K. Sakumi, and Y. Nakabeppu., Mutator phenotype of MUTYH-null mouse embryonic stem cells., J. Biol. Chem., 10.1074/jbc.C300316200, 278, 40, 38121-38124, 278:38121-38124, 2003.10.
72. Yoshimura, D., K. Sakumi, M. Ohno, Y. Sakai, M. Furuichi, S. Iwai, and Y. Nakabeppu., An oxidized purine nucleoside triphosphatase, MTH1 suppresses cell death caused by oxidative stress., J. Biol. Chem., 278:37965-37973, 2003.09.
73. Tahara, K., D. Tsuchimoto, Y. Tominaga, S. Asoh, S. Ohta, M. Kitagawa, H. Horie, T. Kadoya, and Y. Nakabeppu., ΔFosB but not FosB Induces Delayed Apoptosis Independent of Cell Proliferation in the Rat1a Embryo Cell Line., Cell Death Diff., 10.1038/sj.cdd.4401173, 10, 5, 496-507, 10:496-507, 2003.04.
74. Yamazaki, K., T. Aso, Y. Ohnishi, M. Ohno, K. Tamura, T. Shuin, S. Kitajima, and Y. Nakabeppu., Mammalian elongin A is not essential for cell viability but required for proper cell-cycle progression with limited alteration of gene expression., J. Biol. Chem., 10.1074/jbc.C300047200, 278, 15, 13585-13589, 278:13585-13589, 2003.04.
75. Sakumi, K., Y. Tominaga, M. Furuichi, P. Xu, T. Tsuzuki, M. Sekiguchi, and Y. Nakabeppu., Ogg1 Knockout-associated Lung Tumorigenesis and Its Suppression by Mth1 Gene Disruption., Cancer Res., 63, 5, 902-905, 63:902-905, 2003.03.
76. Tsuruya, K., M. Furuichi, Y. Tominaga, M. Shinozaki, M. Tokumoto, T. Yoshimitsu, K. Fukuda, H. Kanai, H. Hirakata, M. Iida, and Y. Nakabeppu., Accumulation of 8-oxoguanine in the cellular DNA and the alteration of the OGG1 expression during ischemia-reperfusion injury in the rat kidney., DNA Repair, 10.1016/S1568-7864(02)00214-8, 2, 2, 211-229, 2:211-229, 2003.02.
77. Ide, Y., D. Tsuchimoto, Y. Tominaga, Y. Iwamoto, and Y. Nakabeppu., Characterization of the genomic structure and expression of the mouse Apex2 gene., Genomics, 10.1016/S0888-7543(02)00009-5, 81, 1, 47-57, 81:47-57, 2003.01.
78. Takahashi, M., F. Maraboeuf, Y. Sakai, H. Yakushiji, M. Mishima, M. Shirakawa, S. Iwai, H. Hayakawa, M. Sekiguchi, and Y. Nakabeppu., Role of tryptophan residues in the recognition of mutagenic oxidized nucleotides by human antimutator MTH1 protein., J. Mol. Biol., 10.1016/S0022-2836(02)00163-8, 319, 1, 129-139, 319:129-139, 2002.05.
79. Nishioka, T., K. Sakumi, T. Miura, K. Tahara, H. Horie, T. Kadoya, and Y. Nakabeppu., fosB gene products trigger cell proliferation and morphological alteration with an increased expression of a novel processed form of galectin-1 in the rat 3Y1 embryo cell line., J. Biochem., 131, 5, 653-661, 131:653-661, 2002.05.
80. Kikuchi, H., A. Furuta, K. Nishioka, S. O. Suzuki, Y. Nakabeppu, and T. Iwaki., Impairment of mitochondrial DNA repair enzymes against accumulation of 8-oxo-guanine in the spinal motor neurons of amyotrophic lateral sclerosis., Acta Neuropathol., 10.1007/s00404-001-0480-x, 103, 4, 408-414, 103:408-414, 2002.04.
81. Sakai, Y., M. Furuichi, M. Takahashi, M. Mishima, S. Iwai, M. Shirakawa, and Y. Nakabeppu., A molecular basis for the selective recognition of 2-hydroxy-dATP and 8-Oxo-dGTP by human MTH1., J. Biol. Chem., 10.1074/jbc.M110566200, 277, 10, 8579-8587, 277:8579-8587, 2002.03.
82. Hayashi, H., Y. Tominaga, S. Hirano, A. E. McKenna, Y. Nakabeppu, and Y. Matsumoto., Replication-Associated Repair of Adenine:8-Oxoguanine Mispairs by MYH., Current Biol., 10.1016/S0960-9822(02)00686-3, 12, 4, 335-339, 12:335-339, 2002.02.
83. Fujikawa, K., H. Yakushiji, Y. Nakabeppu, T. Suzuki, M. Masuda, H. Ohshima, and H. Kasai., 8-Chloro-dGTP, a hypochlorous acid-modified nucleotide, is hydrolyzed by hMTH1, the human MutT homolog., FEBS Lett., 10.1016/S0014-5793(02)02240-8, 512, 1-3, 149-151, 512:149-151, 2002.02.
84. Iida, T., A. Furuta, K. Nishioka, Y. Nakabeppu, and T. Iwaki., Expression of 8-oxoguanine DNA glycosylase is reduced and associated with neurofibrillary tangles in Alzheimer's disease brain., Acta Neuropathol., 103, 1, 20-25, 103:20-25, 2002.01.
85. Tsuzuki, T., A. Egashira, H. Igarashi, T. Iwakuma, Y. Nakatsuru, Y. Tominaga, H. Kawate, K. Nakao, K. Nakamura, F. Ide, S. Kura, Y. Nakabeppu, M. Katsuki, T. Ishikawa, and M. Sekiguchi., Spontaneous tumorigenesis in mice defective in the MTH1 gene encoding 8-oxo-dGTPase., Proc. Natl. Acad. Sci. U. S. A., 10.1073/pnas.191086798, 98, 20, 11456-11461, 98:11456-11461, 2001.09.
86. Furuta, A., T. Iida, Y. Nakabeppu, and T. Iwaki., Expression of hMTH1 in the hippocampi of control and Alzheimer's disease., Neuroreport, 10.1097/00001756-200109170-00028, 12, 13, 2895-2899, 12:2895-2899, 2001.09.
87. Jaiswal, M., N. F. LaRusso, K. Nishioka, Y. Nakabeppu, and G. J. Gores., Human Ogg1, a protein involved in the repair of 8-oxoguanine, is inhibited by nitric oxide., Cancer Res., 61, 17, 6388-6393, 61:6388-6393, 2001.09.
88. Kasprzak, K. S., Y. Nakabeppu, T. Kakuma, Y. Sakai, K. Tsuruya, M. Sekiguchi, J. M. Ward, B. A. Diwan, K. Nagashima, and B. H. Kasprzak., Intracellular Distribution of the Antimutagenic Enzyme MTH1 in the Liver, Kidney, and Testis of F344 Rats and its Modulation by Cadmium., Exp. Toxico. Pathol., 10.1078/0940-2993-00201, 53, 5, 325-335, 53:325-336, 2001.07.
89. Tsuchimoto, D., Y. Sakai, K. Sakumi, K. Nishioka, M. Sasaki, T. Fujiwara, and Y. Nakabeppu., Human APE2 protein is mostly localized in the nuclei and to some extent in the mitochondria, while nuclear APE2 is partly associated with proliferating cell nuclear antigen., Nucleic Acids Res., 10.1093/nar/29.11.2349, 29, 11, 2349-2360, 29:2349-2360., 2001.06.
90. Iida, T., A. Furuta, M. Kawashima, J. Nishida, Y. Nakabeppu, and T. Iwaki., Accumulation of 8-oxo-2'-deoxyguanosine and increased expression of hMTH1 protein in brain tumors., Neuro-oncol., 10.1215/15228517-3-2-73, 3, 2, 73-81, 3:73-81, 2001.04.
91. Rodriguez, J. J., D. R. Garcia, Y. Nakabeppu, and V. M. Pickel., Enhancement of laminar FosB expression in frontal cortex of rats receiving long chronic clozapine administration., Exp. Neurol., 10.1006/exnr.2000.7612, 168, 2, 392-401, 168:392-401, 2001.04.
92. Rodriguez, J. J., D. R. Garcia, Y. Nakabeppu, and V. M. Pickel., FosB in rat striatum: normal regional distribution and enhanced expression after 6-month haloperidol administration., Synapse, 10.1002/1098-2396(200102)39:2<122::AID-SYN3>3.0.CO;2-R, 39, 2, 122-132, 39:122-132, 2001.02.
93. Fujikawa, K., H. Kamiya, H. Yakushiji, Y. Nakabeppu, and H. Kasai., Human MTH1 protein hydrolyzes the oxidized ribonucleotide, 2-hydroxy-ATP., Nucleic Acids Res., 10.1093/nar/29.2.449, 29, 2, 449-454, 29:449-454., 2001.01.
94. Shimokawa, H., Y. Fujii, M. Furuichi, M. Sekiguchi, and Y. Nakabeppu., Functional significance of conserved residues in the phosphohydrolase module of Escherichia coli MutT protein., Nucleic Acids Res., 10.1093/nar/28.17.3240, 28, 17, 3240-3249, 28:3240-3249, 2000.09.
95. Miyako, K., C. Takamatsu, S. Umeda, T. Tajiri, M. Furuichi, Y. Nakabeppu, M. Sekiguchi, N. Hamasaki, K. Takeshige, and D. Kang., Accumulation of adenine DNA glycosylase-sensitive sites in human mitochondrial DNA., J. Biol. Chem., 10.1074/jbc.275.16.12326, 275, 16, 12326-12330, 275:12326-12330, 2000.04.
96. Fujii, Y., H. Shimokawa, M. Sekiguchi, and Y. Nakabeppu., Functional significance of the conserved residues for the 23-residue module among MTH1 and MutT family proteins., J. Biol. Chem., 10.1074/jbc.274.53.38251, 274, 53, 38251-38259, 274:38251-38259, 1999.12.
97. Shimura-Miura, H., N. Hattori, D. Kang, K. Miyako, Y. Nakabeppu, and Y. Mizuno., Increased 8-oxo-dGTPase in the mitochondria of substantia nigral neurons in Parkinson's disease., Ann. Neurol., 10.1002/1531-8249(199912)46:6<920::AID-ANA17>3.0.CO;2-R, 46, 6, 920-924, 46:920-924, 1999.11.
98. Oda, H., A. Taketomi, R. Maruyama, R. Itoh, K. Nishioka, H. Yakushiji, T. Suzuki, M. Sekiguchi, and Y. Nakabeppu., Multi-forms of human MTH1 polypeptides produced by alternative translation initiation and single nucleotide polymorphism., Nucleic Acids Res., 10.1093/nar/27.22.4335, 27, 22, 4335-4343, 27:4335-4343, 1999.11.
99. Fujikawa, K., H. Kamiya, H. Yakushiji, Y. Fujii, Y. Nakabeppu, and H. Kasai., The oxidized forms of dATP are substrates for the human MutT homologue, the hMTH1 protein., J. Biol. Chem., 10.1074/jbc.274.26.18201, 274, 26, 18201-18205, 274:18201-18205., 1999.06.
100. Nishioka, K., T. Ohtsubo, H. Oda, T. Fujiwara, D. Kang, K. Sugimachi, and Y. Nakabeppu., Expression and differential intracellular localization of two major forms of human 8-oxoguanine DNA glycosylase encoded by alternatively spliced OGG1 mRNAs., Mol. Biol. Cell, 10, 5, 1637-1652, 10:1637-1652., 1999.05.
主要総説, 論評, 解説, 書評, 報告書等
1. 酒井 康成、赤峰 晢、奥園 清香、瀬戸山 大樹、山元 裕之、康 東天、中別府 雄作、大賀 正一, てんかん性脳症に関与する収束的分子シグナルの解明, てんかん治療研究振興財団,  研究年報 29巻:25-30, 2018.09, [URL].
2. Yusaku Nakabeppu, Eiko Ohta, Nona Abolhassani, MTH1 as a nucleotide pool sanitizing enzyme: friend or foe?, Radic Biol Med, 107, 151-158., doi: 10.1016/j.freeradbiomed.2016.11.002., 2017.06, [URL].
3. 中別府 雄作, ゲノムに蓄積した8-oxoguanine に起因する病態とその防御機構 -発がんから神経変性まで-, 基礎老化研究 40 (3) 23-31, 査読あり, 2016.09,  8-oxoguanine は代表的な酸化塩基であるが、これまで自然突然変異の主要な原因として研究が進められてきた。細胞ゲノムへの8-oxoguanine の蓄積はヌクレオチドプールに生じた8-oxo-dGTP を分解するMTH1(MutT homolog-1) とDNA 中のcytosine に対合した8-oxoguanine を切り出すOGG1(8-oxoguanine DNA glycosylase)、鋳型DNA 中の8-oxoguanine に挿入されたadenine を切り出すMUTYH(MutY homolog)の3つの酵素によって低いレベルに保たれている。MTH1、OGG1、MUTYH 欠損マウスの解析から、8-oxoguanine の核ゲノムとミトコンドリアゲノムへの蓄積はMUTYH によって開始される塩基除去修復反応に依存して、2つの独立した細胞死の経路を活性化することが明らかになった。MUTYH に依存した細胞死はがん抑制機構の1つとして機能するだけでなく、ミトコンドリア機能障害による神経細胞死とミクログリオーシスを介して神経変性疾患の発症に関与する.
4. 中別府 雄作, 酸化ストレスによる核ゲノム恒常性破綻の分子病態, 医学のあゆみ 254:368−374, 2015.08.
5. 土本 大介, 中別府 雄作, 酸化的DNA損傷と防御機構, 別冊・医学のあゆみ 「レドックスUPDATE–ストレス制御の臨床医学・健康科学」(監修:平家俊男、淀井淳司)(医歯薬出版株式会社), p50-53:監修:平家俊男、淀井淳司, 2015.07.
6. 中別府 雄作, アルツハイマー病におけるインスリン産生低下とミトコンドリア機能不全, 細胞工学 Vol. 34, No. 4, 389-391 2015, 2015.04.
7. 中別府 雄作, アルツハイマー病は脳の糖尿病!?, NHK きょうの健康 通巻325号 94-97, 2015.04.
8. Arikuni Uchimura, Yuichiro Hara, Yoichi Gondo, Yusaku Nakabeppu, International Symposium on “Germline Mutagenesis and Biodiversification”, Genes Genet. Syst., Genes Genet Syst. 2014;89(2):93-95., 2014.09.
9. Yusaku Nakabeppu, 脳内酸化ストレス, 分子精神医学 Vol. 14, No. 3, 200-201, 2014, 2014.07, [URL].
10. Yusaku Nakabeppu, Cellular Levels of 8-Oxoguanine in either DNA or the Nucleotide Pool Play Pivotal Roles in Carcinogenesis and Survival of Cancer Cells, Int J Mol Sci. 2014, 15(7):12543-12557. doi: 10.3390/ijms150712543., 2014.07, [URL], 8-Oxoguanine, a major oxidized base lesion formed by reactive oxygen species, causes G to T transversion mutations or leads to cell death in mammals if it accumulates in DNA. 8-Oxoguanine can originate as 8-oxo-dGTP, formed in the nucleotide pool, or by direct oxidation of the DNA guanine base. MTH1, also known as NUDT1, with 8-oxo-dGTP hydrolyzing activity, 8-oxoguanine DNA glycosylase (OGG1) an 8-oxoG DNA glycosylase, and MutY homolog (MUTYH) with adenine DNA glycosylase activity, minimize the accumulation of 8-oxoG in DNA; deficiencies in these enzymes increase spontaneous and induced tumorigenesis susceptibility. However, different tissue types have different tumorigenesis susceptibilities. These can be reversed by combined deficiencies in the defense systems, because cell death induced by accumulation of 8-oxoG in DNA is dependent on MUTYH, which can be suppressed by MTH1 and OGG1. In cancer cells encountering high oxidative stress levels, a high level of 8-oxo-dGTP accumulates in the nucleotide pool, and cells therefore express increased levels of MTH1 in order to eliminate 8-oxo-dGTP. Suppression of MTH1 may be an efficient strategy for killing cancer cells; however, because MTH1 and OGG1 protect normal tissues from oxidative-stress-induced cell death, it is important that MTH1 inhibition does not increase the risk of healthy tissue degeneration. .
11. Yusaku Nakabeppu, 核酸の酸化損傷に起因する神経変性の分子機序, 医学のあゆみ Vol. 27 (9), p. 961-968, 2013.11, 多くの神経変性疾患では,核酸塩基の中で最も酸化されやすいグアニンの主要な酸化体である8-オキソグアニン(8-oxoG)が多量に蓄積することから,8-oxoGが神経変性に関与する可能性が示唆されていた。我々はハンチントン病や網膜色素変性症のモデルマウスの解析から,8-oxoGが神経変性を引き起こす分子機序を明らかにした。酸化ストレス下の細胞ではDNA中のグアニンよりヌクレオチドプール中のdGTPがより酸化されやすく,生じた8-oxo-dGTPは複製に伴ってゲノムDNAに取り込まれる。神経細胞では主にミトコンドリアDNAに,一方ミクログリアでは核DNAに8-oxoGが蓄積する。次の複製でDNA中の8-oxoGに対して取り込まれたアデニンはMUTYHで切り出されるが,その修復過程で一本鎖切断が過剰に生成される。その結果,ミトコンドリアDNAの分解や核内でのPARPの活性化を介して2つの異なるプログラム細胞死が起動され,神経変性が進行する。.
12. Fujita K, Yamafuji M., Yusaku Nakabeppu, MAMI NODA, Therapeutic approach to neurodegenerative diseases by medical gases: focusing on redox signaling and related antioxidant enzymes, Oxid Med Cell Longev. 2012:324256. , doi: 10.1155/2012/324256. , 2012.07.
13. 作見 邦彦, 土本 大介, 中別府 雄作, ニトロソ化ストレスによるイノシン三リン酸の生成と細胞応答, 細胞工学 Vol. 31: 175-180, 2012.01.
14. Oka S, Nakabeppu Y., DNA glycosylase encoded by MUTYH functions as a molecular switch for programmed cell death under oxidative stress to suppress tumorigenesis, Cancer Sci. 2011;102(4):677-682. , 2011.04.
15. Kyota Fujita, Yusaku Nakabeppu, and Mami Noda, Therapeutic Effects of Hydrogen in Animal Models of Parkinson’s Disease, Parkinsons Dis. 2011:307875, 2011.04.
16. Ihara H, Sawa T, Nakabeppu Y, Akaike T., Nucleotides function as endogenous chemical sensors for oxidative stress signaling, J Clin Biochem Nutr. 2011;48(1):33-39, 2011.01.
17. Nakabeppu Y., Oka S., Sheng Z., Tsuchimoto D., Sakumi K. , Programmed cell death triggered by nucleotide pool damage and its prevention by MutT homolog-1 (MTH1) with oxidized purine nucleoside triphosphatase. , Mutation Research, 2010.06.
18. Tsuchimoto D., Iyama T., Nonaka M., Abolhassani N., Ohta E., Sakumi K., Nakabeppu Y., A comprehensive screening system for damaged nucleotide-binding proteins., Mutation Research, 2010.06.
19. Sakumi K., Abolhassani N., Behmanesh M., Iyama T., Tsuchimoto D., Nakabeppu Y., ITPA protein, an enzyme that eliminates deaminated purine nucleoside triphosphates in cells., Mutation Research, 2010.06.
20. 中別府雄作, ミトコンドリアのデオキシリボヌクレオチドプールの酸化と細胞死, 医学のあゆみ, Vol. 232-N0.6: 681-689, 2010.02.
21. 中別府雄作, AIF, Medical Tribune ことばのカルテ, VOL.42 NO.48: p.46, 2009.11.
22. 中別府雄作, 塩基除去修復酵素MUTYHに依存したプログラム細胞死と発癌抑制機構, 実験医学 増刊, Vol. 27, N0.15: 135-139, 2009.09.
23. 岡素雅子,中別府雄作, 核およびミトコンドリアDNAの酸化損傷によって引き起こされる2つの独立した細胞死の経路, 実験医学26巻9号1376-1379., 2008.09.
24. Yusaku Nakabeppu, Daisuke Tsuchimoto, Hiroo Yamaguchi and Kunihiko Sakumi, Oxidative Damage in Nucleic Acids and Parkinson's Disease, Journal of Neuroscience Research, 85(5):919-934. , 2007.04.
25. Yusaku Nakabeppua, Kosuke Kajitani, Katsumi Sakamoto, Hiroo Yamaguchi, Daisuke Tsuchimoto, MTH1, an oxidized purine nucleoside triphosphatase, prevents the cytotoxicity and neurotoxicity of oxidized purine nucleotides, DNA Repair, Vol. 5(7): 761-772, 2006.07.
26. Nakabeppu Y., Sakumi K., Sakamoto K., Tsuchimoto D., Tsuzuki T., Nakatsu Y., Mutagenesis and carcinogenesis caused by the oxidation of nucleic acids., Biol. Chem., Vol. 387: 373-379., 2006.04.
主要学会発表等
1. 土本 大介, 古賀 祐一郎, 林 良憲, アボルハッサニ ノナ, 米嶋 康臣, 中西 博, 豊國 伸哉, 中別府 雄作, ITPA欠損によるヒトてんかん性脳症のモデルとしての神経幹細胞特異的Itpaノックアウトマウス, 平成30年度先端モデル動物支援プラットフォーム成果発表会, 2019.01.
2. 土本 大介、古賀 祐一郎、林 良憲、Nona Abolhassani、米嶋 康臣、中西 博、中別府 雄作,  ITPA欠損によるヒトてんかん性脳症のモデルとしての神経幹細胞特異的Itpaノックアウトマウス, 第41回日本分子生物学会年会, 2018.11.
3. Daisuke Tsuchimoto, Yuichiro Koga, Yoshinori Hayashi, Nona Abolhassani, Yasuto Yoneshima, Hiroshi Nakanishi, Yusaku Nakabeppu, Neural stem cell-specific Itpa knockout mouse as a model of human ITPA deficiency, The 13th International Symposium of the Institute Network for Biomedical Sciences joint with the 3rd Symposium of the Inter-University Research Network for Trans-Omics Medicine & the 28th Hot Spring Harbor Symposium, 2018.10.
4. Yusaku Nakabeppu, Sugako Oka, Julio Leon, Nona Abolhassani, Tomomi Ide, Dongchon Kang, Molecular pathophysiology of insulin depletion, mitochondrial dysfunction, and oxidative stress in Alzheimer's disease brain, The 30th International Conference of the Korean Society for Molecular and Cellular Biology, 2018.09, In normal brain, some neurons in the cortex and hippocampus produce insulin, which modulates glucose metabolism and cognitive functions. Recent progress in Alzheimer’s disease (AD) research revealed that insulin production and signaling are severely impaired in AD brain, thereby resulting in mitochondrial dysfunction and increased oxidative stress. Here, we examined the effects of transgenic expression of human mitochondrial transcriptional factor A (hTFAM) on the pathology of a mouse model of AD (3xTg-AD), because TFAM is known to protect mitochondria from oxidative stress through maintenance of mitochondrial DNA. Expression of hTFAM significantly improved cognitive function, reducing accumulation of both 8-oxoguanine, an oxidized form of guanine, in mitochondrial DNA and intracellular A in 3xTg-AD mice and increasing expression of transthyretin, known to inhibit A aggregation. Next, we found that AD model neurons derived from human induced pluripotent stem cells carrying a mutant PSEN1P117L gene, exhibited mitochondrial dysfunction, accumulation of 8-oxoguanine and single-strand breaks in mitochondrial DNA, and impaired neuritogenesis with a decreased expression of transthyretin. Extracellular treatment with recombinant hTFAM effectively suppressed these deleterious outcomes. Moreover, the treatment increased expression of transthyretin, accompanied by reduction of intracellular A. These results provide new insights into potential novel therapeutic targets..
5. 中別府雄作, 活性酸素によるゲノム損傷に起因する機能障害とその防御機構の解明, 日本遺伝学会第90回大会, 2018.09.
6. 中別府雄作, 活性酸素による核酸の酸化と脳の老化, 第16回 レドックス・ライフイノベーション シンポジウム, 2018.08, 活性酸素(ROS)は、ミトコンドリアにおける電子伝達系をはじめとする代謝経路の副産物として生成されるだけでなく、生体防御、神経伝達、血管拡張およびシグナル伝達などに必須な分子としても産生される。そのため、脂質、タンパク質、核酸などの細胞を構成する生体分子は、ROSによって酸化される危険性に常に曝されている。加齢に伴いさまざまな生体分子の酸化体が蓄積すると、多様な細胞機能障害を引き起こすため変性疾患や発がんにつながると考えられている。
 細胞内のさまざまな生体分子の中でもDNAやその前駆体ヌクレオチドの酸化は、突然変異やプログラム細胞死の原因となることが明らかになってきた。生殖細胞系列の突然変異は遺伝的多型や遺伝性疾患の原因となり、体細胞における突然変異は発がんの原因となる。一方、DNA損傷を高度に蓄積した細胞はその修復過程に依存して細胞死に陥り、変性疾患の原因となる。
 DNA中の主要な酸化塩基、8-オキソグアニン(8-oxoG)は、ヌクレオチドプール中のdGTPの酸化型である8-oxo-dGTPのDNAへの取り込み、あるいはDNA中のグアニン塩基の直接酸化に由来する。ヒトや動物のゲノムDNAに蓄積した8-oxoGは、老化に伴うがんや神経変性の原因となるが、8-oxo-dGTP分解活性を有するMTH1、8-oxoG DNAグリコシラーゼ活性を有するOGG1およびアデニンDNAグリコシラーゼを有するMutYホモログ(MUTYH)の作用によってそのレベルは低く保たれている。
我々は、MTH1とOGG1の二重欠損マウスが老化に伴い行動異常や記憶障害を呈することを見出した。このような障害は特にメスマウスで顕著に認められ、剖検脳の病理解析から海馬歯状回と側脳室下帯に存在する新生神経細胞に8-oxoGが特異的に蓄積し、新生神経細胞の減少を引き起こしていることが明らかになった。ヒトMTH1を発現するトランスジェニックマウスではこのような障害が野生型マウスよりも低く抑えられていたことから、神経前駆細胞のヌクレオチドプール中に蓄積した8-oxo-dGTPがDNA複製に際して取り込まれ、その結果新生神経細胞の障害を引き起こすことが示唆された。

参考文献
Nakabeppu Y. Neurodegeneration caused by accumulation of an oxidized base lesion, 8-oxoguanine, in nuclear and mitochondrial DNA: from animal models to human diseases. In The Base Excision Repair Pathway: Molecular Mechanisms and Role in Disease Development and Therapeutic Design, edited by Wilson III DM. World Scientific Publishing, p. 523-556, 2017..
7. Naoki Haruyama, Kunihiko Sakumi, Atsuhisa Katogi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Accumulation of 8-oxoguanine in nuclear genome of neural progenitors in aged mouse brain causes atrophy of major island of Calleja resulting in locomotor hyperactivity, The 41st Annual Meeting of The Japan Neuroscience Society, 2018.07.
8. Daisuke Tsuchimoto, Yuichiro Koga, Yoshinori Hayashi, Nona Abolhassani, Yasuto Yoneshima, Hiroshi Nakanishi, Yusaku Nakabeppu, Neural stem cell-specific Itpa knockout mouse as a model of human ITPA deficiency, The 41st Annual Meeting of The Japan Neuroscience Society, 2018.07.
9. Nona Abolhassani, Ryohei Ikegami, Naoki Haruyama, Guianfranco Mazzei, Takashi Saito, Takaomi C Saido, Yusaku Nakabeppu, Long-term exposure to high-fat diet significantly exacerbated cognitive deficit in aged AppNL-F/NL-F knock-in mouse model of Alzheimer´s disease along with persistent impaired glucose tolerance, The 41st Annual Meeting of The Japan Neuroscience Society, 2018.07.
10. Yusaku Nakabeppu, Nona Abolhassani, Eiko Ohta, Zijing Sheng, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, Oxidative DNA damage and Repair in Cancer and Aging, The 14th Japan - Korea Joint Symposium on Cancer and Ageing Research, 2018.06.
11. 中別府 雄作, アルツハイマー病を脳の糖尿病として捉える, 知の拠点セミナー, 2018.04, [URL].
12. Yusaku Nakabeppu, Sugako Oka, Julio Leon, Nona Abolhassani, Tomomi Ide, Dongchon Kang, Protection of mitochondrial DNA from oxidative damage effectively blocks the mitochondria-mediated vicious cycle of Alzheimer's disease, Consortium of Biological Sciences 2017, 2017.12.
13. Guianfranco Mazzei, Kunihiko Sakumi, Yusaku Nakabeppu, Impaired hippocampal neurogenesis in APP mouse model of Alzheimer disease., Third International meeting in Bioscience, Young Peruvian Scientist Network, 2017.12.
14. 本名 嶺治, 鈴木 諭, 濱﨑 英臣, 本田 裕之, 北川 玲華, 司城 昌大, 前田 教寿, Nona Abolhassani, 中別府 雄作, 岩城 徹, ラット脳発生およびヒト筋萎縮性側索硬化症におけるCRYMの発現変化, 2017年度生命科学系学会合同年次大会, 2017.12.
15. 作見 邦彦, 大野 みずき, 中別府 雄作, 遺伝性疾患自然発症モデル動物としてのmutator mouse, 2017年度生命科学系学会合同年次大会, 2017.12.
16. 春山 直樹, 作見 邦彦, 加藤木 敦央, 土本 大介, 中別府 雄作, 側坐核・カレハ島の新生GABAニューロンへの8-オキソグアニンの蓄積は加齢マウスの多動の原因となる, 2017年度生命科学系学会合同年次大会, 2017.12.
17. Yusaku Nakabeppu, Naoki Haruyama, Guianfranco Mazzei, Ryouhei Ikegami, Nona Abolhassani, Molecular Pathophysiology of Impaired Glucose Metabolism, Mitochondrial Dysfunction, and Oxidative DNA Damage in Alzheimer's Disease Brain, The 5th Annual World Congress of Geriatrics and Gerontology 2017, 2017.12.
18. Naoki Haruyama, Kunihiko Sakumi, Atsuhisa Katogi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Accumulation of 8-oxoguanine in the nuclei of newly-generated GABAergic neurons in the nucleus accumbens and islands of Calleja contributes to locomotor hyperactivity in aged mice., The 27th Hot Spring Harbor International Symposium, 2017.10, Mammals including humans possess 8-oxo-2’-deoxyguanosine triphosphatase (8-oxo-dGTPase) encoded by MTH1 gene and 8-oxoguanine DNA glycosylase encoded by OGG1 gene, thus minimizing accumulation of 8-oxoguanine in genomic DNA. We investigated correlation between levels of 8-oxoguanine in mouse brains and their locomotor activities during aging from 10 weeks (young), 36 weeks (middle-aged) to 81 weeks (old ) of age, using Mth1/Ogg1-double knockout (TO-DKO) and human MTH1-transgenic (hMTH1-Tg) mice.
First, we found strong nuclear 8-oxoguanine immunoreactivity in hippocampal dentate gyrus and subventricular zone (SVZ), where adult neurogenesis occurs, and in the shell of the nucleus accumbens (NAccSh), especially in middle-aged TO-DKO brains. Among them, the major islands of Calleja (ICj) located in NAccSh, into which a separate mass of cells, referred to as the "ventral migratory mass" migrates from the SVZ to supply newborn GABAergic neurons postnatally, exhibited prominent 8-oxoguanine immunoreactivity. Four weeks after bromodeoxyuridine (BrdU) injection (i. p.), there were significant reduction in number of BrdU-labeled newborn cells in NAccSh + ICj of TO-DKO brains in comparison with wild-type controls. In addition, the number of neurons and volume of ICj were significantly decreased in middle-aged TO-DKO, compared with wild-type mice.
In behavior analyses, we found middle-aged and old TO-DKO, but not young mice were hyperactive in a familiar environment in comparison with wild-type controls. Conversely, middle-aged and old hMTH1-Tg mice were hypoactive. Moreover, the locomotor activities of mice were significantly correlated with both levels of nuclear 8-oxoguanine in NAccSh + ICj and numbers of neurons in ICj.
We concluded that accumulation of nuclear 8-oxoguanine in post-mitotic NAccSh and ICj neurons in the aged mice is a consequence of 8-oxo-dGTP incorporation into the nuclear genomes of neuronal progenitors during their proliferation, thus resulting in their depletion during aging, probably because nuclear 8-oxoguanine is known to induce apoptosis through the process of base excision repair..
19. Naoki Haruyama, Atsuhisa Katogi, Kunihiko Sakumi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Nuclear accumulation of 8-oxoguanine in nucleus accumbens neurons contributes to age-related locomotor hyperactivity in Mth1/Ogg1-double knockout mice.
, 九州大学教育改革シンポジウム2017, 2017.07, Mammals possess 8-oxo-dGTPase encoded by MTH1 gene and 8-oxoguanine DNA glycosylase encoded by OGG1 gene, thus minimizing accumulation of 8-oxoguanine in genomic DNA. Middle-aged and old Mth1/Ogg1-double knockout (TO-DKO) mice were hyperactive in a familiar environment. These abnormal behaviors were correlated with nuclear accumulation of 8-oxoguanine in neurons of the nucleus accumbens shell (NAccSh) and the islands of Calleja (ICj). In the aged TO-DKO brain, the nuclear 8-oxoguanine was detected predominantly in immature neurons present in NAccSh, ICj, and subventricular zone. Number of ΔFOSB-positive neurons is significantly increased in the nucleus accumbens core, suggesting hyperdopaminergic state in NAccCo. .
20. 中別府 雄作, アルツハイマー病脳におけるインスリン産生・応答系の破綻とミトコンドリア機能障害, 医療薬学フォーラム 2017/第25回クリニカルファーマシーシンポジウム, 2017.07.
21. 中別府 雄作, アルツハイマー病脳におけるミトコンドリア機能障害と炎症応答に起因する酸化ストレスの分子病態, 第59回日本老年医学会学術集会, 2017.06.
22. Yusaku Nakabeppu, Oxidative DNA damage and repair in Alzheimer’s disease brain, 6th US-Japan DNA Repair Meeting, 2017.05.
23. 中別府 雄作, アルツハイマー病脳におけるインスリン枯渇とミトコンドリア機能不全に起因する酸化ストレスの分子病態, 第13回レドックス・ライフイノベーションシンポジウム, 2017.03, [URL].
24. 土本 大介, 古賀 祐一郎, 米嶋 康臣, 浅田 真司, 作見 邦彦, 中別府 雄作, イノシン三リン酸分解酵素ITPA欠損症のモデルマウス作製と解析, 平成28年度「先端モデル動物支援プラットフォーム成果発表会」, 2017.02.
25. Yusaku Nakabeppu, Oxidative DNA damage and repair in carcinogenesis and neurodegeneration, International Symposium on Immune Diversity and Cancer Therapy Kobe 2017, 2017.01, [URL], 8-oxoguanine, the most common oxidized base, has been characterized as a natural cause of mutagenesis. Levels of 8-oxoguanine in genomes are maintained very low by coordinated actions of MTH1 hydrolyzing 8-oxo-dGTP formed in nucleotide pool, OGG1 excising 8-oxoguanine opposite cytosine in DNA, and MUTYH excising adenine inserted opposite 8-oxoguanine in template DNA. Studies with mutant mice lacking MTH1, OGG1 and MUTYH, revealed that accumulation of 8-oxoguanine in nuclear genome causes increased occurrence of spontaneous somatic or germline mutations, mainly G to T transversions. The somatic mutations result in carcinogenesis or accelerated aging, and the germline mutations cause genetic alterations of phenotypes and are transmitted to the offspring. Among the three genes, MUTYH exhibits the strongest tumor suppression, probably through induction of p53-dependent cell death. While, we have shown that 8-oxoguanine accumulation in nuclear or mitochondrial DNA in brains under oxidative conditions is highly associated with neurodegeneration, and that MTH1 and OGG1 protect brains by preventing the 8-oxoguanine accumulation, while MUTYH accelerates neurodegeneration. Isolated neurons from wild-type and MTH1/OGG1-deficient mice exhibited efficient neuritogenesis in the presence of antioxidants, however, in the absence of antioxidants MTH1/OGG1-deficient neurons increased 8-oxoguanine accumulation in their mitochondrial DNA, and exhibited significantly poor neuritogenesis, indicating that MUTYH induces neuronal dysfunction when 8-oxogianine accumulated in mitochondrial DNA in neurons. Oxidative stress markedly activated microglia isolated from wild-type but not MUTYH-deficient brains, and only the former significantly induced neuronal death in co-culture experiments. These results indicate that MUTYH induces neuronal dysfunction and microglial activation, independently, and thus accelerates neurodegeneration. These results indicate that MUTYH plays pivotal roles in neuro-inflammatory responses in brain.

References
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[2] Sheng, Z., Oka, S., Tsuchimoto, D., Abolhassani, N., Nomaru, H., Sakumi, K., Yamada, H., Nakabeppu, Y., 8-Oxoguanine causes neurodegeneration during MUTYH-mediated DNA base excision repair, J Clin Invest 122 (2012) 4344-4361.
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26. Ohno Mizuki, Kunihiko Sakumi, Yusaku Nakabeppu, Regulation of base substitution mutagenesis and chromosome recombination induced by 8-oxoguanine accumulated in the genome, The 39th Annual Meeting of the Molecular Biology Society of Japan, 2016.12.
27. Guianfranco Mazzei, Erika Castillo, Kunihiko Sakumi, Takashi Saito, Takaomi Saido, Yusaku Nakabeppu, Impaired hippocampal neurogenesis in App-knock-in model mice of Alzheimer’s disease, The 39th Annual Meeting of the Molecular Biology Society of Japan, 2016.12.
28. 土本 大介, 米嶋 康臣, 古賀 祐一郎, Nona Abolhassani, 猪山 輝昭, 浅田 真司, 作見 邦彦, 塩見 尚子, 森 雅彦, 塩見 忠博, 野田 哲生, 中別府 雄作, イノシン三リン酸分解酵素ITPA欠損の哺乳動物細胞およびマウス中枢神経系への影響の解析, 第39回日本分子生物学会年会, 2016.12.
29. 岡 素雅子, 盛 子敬, フリオ レオン, 土本 大介, 作見 邦彦, 中別府 雄作, アルツハイマー病進展における核あるいはミトコンドリアDNA中に蓄積した8-oxoguanineの役割, 第39回日本分子生物学会年会, 2016.12.
30. 鷹野 典子, 大野 みずき, 中津 可道, 中別府 雄作, 續 輝久, Mutyh欠損マウスにおける酸化ストレスによる消化管腫瘍発生頻度上昇と特異的体細胞変異シグニチャーの解析, 第39回日本分子生物学会年会, 2016.12.
31. 加藤木 敦央, 大西 克典, 作見 邦彦, 中別府 雄作, マウス脳におけるFOSBアイソフォームによる遺伝子発現調節機構の解析, 第39回日本分子生物学会年会, 2016.11.
32. Erika Castillo, Julio Leon, Nona Abolhassani, Guianfranco Mazzei, Kunihiko Sakumi, Takashi Saito, Takaomi Saido, Yusaku Nakabeppu, Comparative gene expression profiling of triple-transgenic 3xTg-AD and APP-knock-in model mice of Alzheimer’s disease, The 46th Annual Meeting of Society for Neuroscience, 2016.11, Alzheimer’s disease (AD) is the major type of senile dementia, but there is no successful treatment until now due to its complexity. To better understand the molecular mechanisms underlying AD pathology, several mouse models have been developed to mimic the main neuropathological hallmarks. In the present study, we performed a comparative gene expression profiling of two different AD model mice: the classical triple-transgenic model mice 3xTg-AD which carry two mutated human transgenes, APP (KM670/671NL) and MAPT (P301L) driven by exogenous Thy1.2 promoter with a knock-in mutation of Psen1 (M146V) that promotes formation of plaques and tangles; and the recently established AD model mice APP NL-G-F with three pathogenic App knock-in mutations (Swedish KM670/671NL, Arctic E693G and Iberian I716F) that promote aggressive amyloidosis under the control of endogenous App promoter. We prepared total RNA from cortex of 12-month-old male mice of each AD model and control, obtained their gene expression profiles using microarray technology and performed a comparative analysis. In both AD models, we observed no significant reduction in expression levels of neuronal markers, but genes involved in neuroprotection (Fos, Nr4a1, Nr4a2, Nr4a3, Egr2) were commonly downregulated. Among 306 significantly altered genes in the 3xTg-AD cortex (fold change < -1.2 or > 1.2, ANOVA p < 0.05), we found genes related to neurological diseases (21), metabolic disorders (21) and immune response (17). In contrast, among 257 altered genes in the APP NL-G-F cortex, the most significantly upregulated genes encode proteins involved in the inflammatory (18) and immune (18) responses (top 5: Cst7, Clec7a, Ccl3l3, Lilrb4), accompanied by a significant upregulation of astrocyte markers (Aqp4, Gfap, S100b) and genes encoding complement components (C1qa, C1qb, C1qc, Tyrobp), as well as alterations in genes related to neurological disease (18) and lipid metabolism (13). The results observed in APP NL-G-F mice suggest that amyloidosis induced by endogenous expression of pathogenic APP protein may cause strong inflammatory/immune responses that would play important roles in AD pathogenesis. Recent reports highlight the contribution of astrocytic activation to neuroinflamation in AD, however the mechanism involved is still unclear. To delineate the astrocytic activation by endogenous β-amyloid, we are now examining the gene expression profiles, biochemical and physiological properties of cultured astrocytes isolated from adult APP NL-G-F..
33. 司城 昌大, 濱﨑 英臣, 本田 裕之, 鈴木 諭, Nona Abolhassani, 中別府 雄作, 岩城 徹, ヒト海馬におけるAlzheimer病理変化とAE-binding protein 1発現様式, 第57回日本神経病理学会, 2016.06.
34. Shunji Nakatake, Yusuke Murakami, Yasuhiso Ikeda, Kota Fujiwara, Takashi Tachibana, Toshio Hisatomi, Shigeo Yoshida, Tatsuro Ishibashi, Yusaku Nakabeppu, Koh -hei Sonoda, Oxidative DNA Damage in Microglia Exacerbates Retinal Inflammation and Degeneration through MUTYH-mediated Base Excision Repair in a Mouse Model of Retinitis Pigmentosa, ARVO 2016 Annual Meeting, 2016.05.
35. 中別府 雄作, アルツハイマー病における脳内糖代謝制御の破綻とそのメカニズム, 第8回 Saga – Diabetes And Lipid Metabolism, 2016.02.
36. Sugako Oka, Nona Abolhassani, Julio Leon, Masaaki Hokama, Masahiro Shijo, Hideomi Hamasaki, Toru Iwaki, Yutaka Kiyohara, Tomomi Ide, Dongchon Kang, Yusaku Nakabeppu, Molecular pathophysiology of insulin depletion, mitochondrial dysfunction and oxidative stress in Alzheimer's disease brain, The 11th International Symposium on Geriatrics and Gerontology, 2016.02, Comparative analyses of gene expression profiles in brains of sporadic Alzheimer’s disease (SAD) patients donated for Hisayama study and a mouse model of AD (3xTg-AD) revealed that genes involved in noninsulin-dependent diabetes mellitus (DM) and obesity were significantly altered in AD brains, as were genes related to psychiatric disorders and AD. Neuronal expression of MET, receptor for HGF known to cooperatively regulate hepatic insulin-signaling and glucose metabolism, and PCSK1, essential for proinsulin processing, was significantly decreased in SAD hippocampi. Expression of AEBP1, known to bind IB and activate NF-B, was highly increased in SAD hippocampal neurons. The alterations in the expression profiles of DM-related genes in SAD were independent of peripheral DM-related abnormalities. These results indicate that altered expression of genes related to DM in SAD brains is a result of AD pathology, which may thereby be exacerbated by peripheral insulin resistance or DM.
The expression profiles also revealed mitochondrial dysfunction and increased oxidative stress in AD brain. Transgenic expression of human TFAM (hTFAM), mitochondrial transcription factor A in 3xTg-AD mice significantly ameliorated mitochondrial dysfunction and oxidative stress resulting in improved cognitive dysfunction and AD pathology. hTFAM expression significantly reduced mitochondrial accumulation of 8-oxoguanine (8-oxoG) in 3xTg-AD brains. In order to evaluate whether 8-oxoG contributes to neurodegeneration in AD, we introduced MTH1 and OGG1 deficiencies, the former hydrolyzes 8-oxo-dGTP and the latter excise 8-oxoG in DNA, thus minimizing 8-oxoG accumulation in DNA, into the 3xTg-AD mice. The 3xTg-AD mice with MTH1/OGG1 deficiencies exhibited severe cognitive dysfunction and neurodegeneration with increased mitochondrial accumulation of 8-oxoG. In contrast, human MTH1 expression in 3xTg-AD mice improved cognitive dysfunction and AD pathology. We previously reported that expression of MTH1 and OGG1 proteins is significantly decreased in SAD brains, thus suggesting that increased 8-oxoG accumulation in mitochondrial DNA exacerbates neurodegeneration in SAD brains..
37. 岡 素雅子, フリオ レオン, 土本 大介, 作見 邦彦, 中別府 雄作, Cell death induced by MUTYH-initiated base excision repair plays a role in p53-mediated tumor suppression, 平成 27 年度「個体レベルでのがん研究支援活動」 ワークショッフ, 2016.02.
38. Nona Abolhassani, Masaaki Hokama, Daisuke Saitou, Mikita Suyama, Toru Iwaki, Yutaka Kiyohara, Yusaku Nakabeppu, Characterization of transcript variants expressed in Alzheimer’s disease brain with human transcriptome array and deep RNA sequencing analyses: The Hisayama Study, 2nd Zing Neurodegeneration Conference, 2015.12.
39. Yoriko Akimoto, Nona Abolhassani, Erika Castillo, Daisuke Tsuchimoto, Yusaku Nakabeppu, Comprehensive analyses of X-ray irradiation-induced modification of purine nucleosides, 第38回 日本分子生物学会年会・第88回日本生化学会 合同大会(BMB2015), 2015.12, Radiation can cause various chemical modifications on nucleotides by free radicals produced during radiolysis of water molecules. Modified nucleotides are known to cause various biological effects such as mutagenesis and cell death, however, it is largely unknown whether those contribute to the radiation-induced biological effects. Guanine is known to be most susceptive to oxidation. In the present study, we thus comprehensively analyzed modification of purine nucleosides caused by X-ray irradiation. Using HPLC-PDA and LC-MS/MS systems, various forms of modified purine nucleosides in free purine nucleosides, and to a lesser extent DNA solution, in vitro, were identified in quantitative manners, and some of them were confirmed in cellular nucleotide pools after X-ray irradiation. We also examined dependencies of their yields on both X-ray doses and nucleoside concentrations, in vitro. We found that 8-oxo-adenosine, 8-oxo-2’-deoxyadenosine, 2-hydroxyadenosine, 2-hydroxy-2’-deoxyadenosine, inosine and 2’-deoxyinosine were generated by X-ray irradiation in a dose dependent manner. Since yields of 8-oxo-guanosine and 8-oxo-2’-deoxyguanosine (8-oxo-[d]Guo) were saturated at higher doses of X-rays, we then examined that effects of X-ray irradiation on 8-oxo-[d]Guo. We found that 8-oxo-[d]Guo were further modified through the indirect effect of X-ray irradiation. We identified ion pairs for hyperoxidized products of 8-oxo-guanine from 8-oxo-[d]Guo exposed to X-rays. In addition, we detected several unknown modified nucleosides, which can be distinguished as nucleosides with modified bases or with modified sugars based on UV and mass spectrometry analyses..
40. 森岡 紀子, 能丸 寛子, Julio Leon, 加藤木 敦央, 作見 邦彦, 中別府 雄作, AP-1転写因子を構成するFosb遺伝子産物による補体受容体遺伝子C5ar1発現制御機構の解析, 第38回 日本分子生物学会年会・第88回日本生化学会 合同大会(BMB2015), 2015.12, 補体系は細菌感染初期に活性化する免疫システムの一種であるが、脳内においても発現し、独自の役割を担っている。C5AR1は補体系の最終産物C5aの受容体であり、脳内ではニューロン、ミクログリア、アストロサイトなどで発現している。特に脳内の免疫担当細胞であるミクログリアについては、アルツハイマー病モデルマウスや脊椎損傷モデルマウスにおいてC5ar1の発現を上昇させる事が知られている。C5AR1の阻害剤投与によってこれらの病態の進行が抑制されることから、C5ar1を発現するミクログリアが神経炎症を進行させていることが示唆されてきたが、一方でミクログリアにおけるC5ar1の発現制御機構はほとんど明らかになっていなかった。
当研究室では近年、マウスミクログリアにおいてAP-1転写因子ファミリーの一員であるFosbがC5ar1の発現を制御している事を発見した。そこで今回、我々はさらにFosb遺伝子産物によるC5ar1発現制御機構を解析した。ミクログリア系のマウス培養細胞であるMG6を用いたレポーターアッセイにおいて、C5ar1の翻訳開始点から592 bp 以内にFOSBに応答してC5ar1の発現を上昇させる領域が存在することを見出した。一方、神経炎症にはミクログリアだけではなく体循環系から流入してきた単球由来のマクロファージも関与していることが知られている。我々はFosb遺伝子産物によるC5ar1発現制御が、単球/マクロファージにおいても行われているか調べた。その結果、Fosb遺伝子産物をもたないFosb-nullマウス由来の腹腔マクロファージでは、ミクログリアと同様にC5ar1の発現が有意に減少している事がわかった。また、マクロファージ由来のマウス培養細胞RAW264.7細胞を用いたプロモーター解析によって、マクロファージでのFosbによるC5ar1発現調節はミクログリアと共通である可能性が高いことがわかった。現在、成体マウスから単離培養したミクログリアを用いて、さらに詳細なC5ar1発現制御機構の解析を進めているので、あわせて報告する。
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41. Sugako Oka, Julio Leon, Atsuhisa Katogi, Kunihiko Sakumi, Dongchon Kang, Tomomi de, Yusaku Nakabeppu, Expression of human mitochondrial transcriptional factor A (hTFAM) breaks the vicious circle of oxidative stress and amyloid β accumulation in triple-transgenic mouse model of Alzheimer’s disease, 第38回 日本分子生物学会年会・第88回日本生化学会 合同大会(BMB2015), 2015.12, Alzheimer's disease (AD) is an age-related neurodegenerative disorder pathologically characterized by amyloid plaques and neurofibrillary tangles. Accumulation of Amyloid β (Aβ) in cytoplasm induces mitochondrial dysfunction and ROS production. Oxidative stress accompanying aging is known to accelerate the intracellular Aβ accumulation, thus the vicious circle is considered to have a pivotal role for developing AD, however, the molecular mechanism remains unclear. In the present study, we examined effects of human mitochondrial transcriptional factor A (hTFAM) on the pathology of a triple-transgenic mouse model of AD (3xTg-AD) harboring PS1M146V, APP(Swe), and tauP301L transgenes, because TFAM is known to protect mitochondria from oxidative stress through maintenance of mitochondrial DNA (mtDNA). hTFAM expression markedly suppressed both accumulation of 8-oxoguanine, an oxidized form of guanine, in the mtDNA and Aβ in cerebral cortices and hippocampi observed in 3xTg-AD mice. 3xTg-AD mice expressing hTFAM exhibited significant improvement of learning and memory deficit. Microarray analysis revealed that the expression of the gene encoding transthyretin, which is known to bind Aβ and inhibit its aggregation, was increased in hippocampi of 3xTg-AD mice expressing hTFAM. Moreover, we found that Alzheimer’s disease model human neurons derived from iPS cells to which a mutant (P117L) copy of PSEN1 gene was introduced, showed mitochondrial dysfunction as well as build-up of single-strand breaks (SSBs) in mtDNA. Treatment of recombinant hTFAM suppressed the build-up of SSBs and improved mitochondrial function. These results provide the new insight into the molecular mechanisms of AD pathology and possible new therapeutic strategies for AD..
42. 司城 昌大, 濱崎 英臣, 本田 裕之, 鈴木 諭, 中別府 雄作, 岩城 徹, アルツハイマー病脳における遺伝子発現変化が引き起こす糖代謝障害と酸化ストレス, 第38回 日本分子生物学会年会・第88回日本生化学会 合同大会(BMB2015), 2015.12, AE-binding protein 1 (AEBP1)は脂肪細胞分化制御や、マクロファージでのNF-κB経路亢進による炎症反応促進を行う。中枢神経系での機能は不明だが、剖検脳を用いた網羅的発現解析にて、Alzheimer病(AD)群の海馬でAEBP1 mRNA発現が亢進していた。そこで本研究では、ヒト脳組織におけるAEBP1の蛋白発現変化及びAD病理変化との関連について免疫組織化学的に検討した。対象は2014年7月から後ろ向きに連続抽出した久山町研究剖検症例(AD群22例、非AD群38例)の、海馬を含む側頭葉内側部のホルマリン固定パラフィン包埋標本を用いた。HE染色及びAEBP1、アミロイドβ蛋白(Aβ)、リン酸化タウ(p-tau)に対する免疫染色を行い、AEBP1発現細胞の同定ならびに両群間の発現変化を評価した。その結果、AEBP1は主に海馬などの大脳辺縁系錐体細胞に構成的に発現しており、非AD群ではCA4領域からCA2領域に錐体細胞の強陽性所見が得られ、CA1領域から海馬台・海馬傍回にかけて次第に染色性が低下する傾向にあった。対してAD群ではCA1領域から海馬台での錐体細胞の染色性が上昇し、一部でNF-κB核内移行が組織学的に確認された。さらにAβ蛋白凝集物である老人斑と一致してAEBP1染色性を認め、老人斑の変性神経突起内にAEBP1が局在する所見が得られた。またp-tau蛋白凝集物である神経原線維変化(tangle)を有する錐体細胞ではAEBP1染色性は低下するが、未凝集のp-tauを有する錐体細胞(pretangle)ではAEBP1染色性は上昇する傾向にあった。神経細胞でのNF-κB急性過剰発現は神経細胞死を誘導する一方で、構成的発現は抗アポトーシス作用・シナプス可塑性に寄与し、ADに対しては神経保護作用が主体とされる。またミクログリアでのNF-κB経路亢進は炎症反応を介して神経細胞死を誘導する。海馬錐体細胞のAEBP1構成的発現、及びAD病理変化や前駆病変と一致する神経細胞を主体とした発現亢進は、Aβ・p-tauを起点とした神経細胞障害に対してAEBP1は神経細胞内でのNF-κB経路亢進を介して神経保護的に作用する可能性がある。.
43. 本名 嶺治, 濱崎 英臣, 司城 昌大, 中別府 雄作, 岩城 徹, ヒト脳におけるCRYMの発現とAlzheimer病理変化との関連, 第38回 日本分子生物学会年会・第88回日本生化学会 合同大会(BMB2015), 2015.12, 久山町研究の剖検脳を用いた網羅的発現解析により、mu-crystallyn(CRYM)のmRNAがAlzheimer病(AD)の海馬において著明に減少することが見出された。そこで本研究ではCRYMに対する抗体を用いて免疫組織化学染色を行い、まず正常脳内の発現様式を明らかにし、AD脳内での発現変化を検討した。対象はAD脳5症例、非AD脳11症例で、全脳各部位のホルマリン固定パラフィン包埋標本を用いた。また、海馬を含む側頭葉内側部については、AD脳17症例、非AD脳25症例の標本を検討した。HE染色、Klüver-Barrera染色およびCRYMに対する免疫染色を行い、CRYMの発現細胞の同定、並びに対照群とAD間における発現変化を評価した。免疫染色の結果、全ての症例で大脳新皮質では皮質全層のニューロピルが淡く染色され、第5層の大型錐体細胞の胞体が強く陽性所見を示した。第3層の錐体細胞が弱陽性に染色される症例も多く見られた。大脳基底核では尾状核の小型神経細胞のほとんど全てが陽性所見を示し、一方、被殻では小型神経細胞が部分的に小集団を成して陽性を示しており、striosome構造に関連している可能性が示された。淡蒼球の神経細胞は陰性であった。海馬では、海馬台、CA1、歯状回に陽性細胞が多く見られたが、CA4は陽性細胞に乏しかった。小脳では分子層のニューロピルのみが陽性であった。脳幹諸核での発現は乏しかった。AD症例群は海馬錐体細胞におけるCRYM発現低下が見られたが、症例間での差が大きかった。老人斑との関連はみられず、神経原線維変化が出現した神経細胞ではCRYMの発現が低下しているものが多かった。
CRYMは、NADPH依存性甲状腺ホルモン結合蛋白であり、ヒト脳、神経系の細胞において発現し、神経保護作用を持っていると報告されている。本研究において、層状壊死により脱落しやすい大脳新皮質第3、5層や虚血に弱い海馬CA1領域の大型錐体細胞で発現していることは、もともとストレスに弱い細胞を保護する役割を持っている可能性があることと、AD症例でCRYMのmRNAが減少したことから、海馬のCRYM発現の減少傾向と関連している可能性が示唆された。
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44. 土本 大介, 古賀 祐一郎, 米嶋 康臣, 浅田 真司, 中別府 雄作, イノシン三リン酸分解酵素ITPAの組織特異的欠損マウス作成と解析, 第38回 日本分子生物学会年会・第88回日本生化学会 合同大会(BMB2015), 2015.12, (デオキシ)イノシン三リン酸([d]ITP)は(デオキシ)アデノシン三リン酸の酸化的脱アミノ化体である.哺乳動物ではイノシン三リン酸分解酵素(ITPA)が[d]ITPを一リン酸型へと分解することによりその蓄積を防いでいる.以前に我々はITPA欠損マウスを作製したが,ITPA欠損マウスは発育遅延と心機能異常などを示しながら生後2週間以内に死亡することを報告した.今回,マウスの各組織におけるITPA欠損の影響を詳細に解析するために組織特異的ITPA欠損マウスを作製した.Itpa遺伝子のexon 5の上流と下流にloxP配列を挿入したItpaflox アリルを持つItpa(+/flox)マウスを作成した.カリフォルニア大学デービス校よりItpafloxアリル作製用ターゲティングベクターを入手したが、同ベクターはItpa exon 2, 3, 4, を欠失していたため,予めC57BL/6Nマウス由来胚性幹細胞JM8A3由来の同領域を導入したターゲティングベクターを構築し、JM8A3細胞に導入した.樹立したItpa(+/flox)マウスは,まず全身FLPeリコンビナーゼ発現マウス(RBRC 01834)と交配を行い,ネオマイシン耐性カセットを除去した.次に肝細胞特異的CREリコンビナーゼ発現マウス(Alb-cre; Jackson 003574)と交配を行い,Itpa(+/flox)/Alb-creマウスを得た.更に同遺伝子型のマウス同士を交配することでItpa(flox/flox)/Alb-creマウスを得た.同マウスは生存可能であり,肝臓特異的なITPAタンパク質の大幅な減少とItpa exon 5の欠失をウェスタンブロットとゲノムDNAのPCRにより確認した.現在,このマウスについて病理学的解析などを進めている.また,他の組織におけるITPA欠損の影響解析のためのマウス交配も進行中であり,その結果も合わせて報告したい..
45. 岡 素雅子, フリオ レオン, 土本 大介, 作見 邦彦, 中別府 雄作, MUTYHによる塩基除去修復過程に依存して誘導される細胞死はp53の発がん抑制機構の1つとして機能する, 第44回 日本環境変異学会, 2015.11, 発がんの過程においては、突然変異の蓄積のみならず細胞死の回避が重要な役割をもつ。私たちはこれまでに、核あるいはミトコンドリアDNAに蓄積した酸化塩基8-oxoguanineがそれぞれpoly-ADP ribose polymerase(PARP)あるいはカルパイン依存性細胞死を引き起こし、いずれもadenine DNA glycosylase(MUTYH)により生じるDNA一本鎖切断の蓄積という共通のシグナルに依存することを明らかにした。今回、私たちは、野生型p53を持つヒトがん細胞株は酸化ストレス感受性を示し、p53が核DNAに蓄積した8-oxoguanineにより起動されるMUTYH-PARP経路に依存して細胞死を誘導することを見出した。一方MUTYHのノックダウンは酸化ストレス抵抗性をもたらすが、この抵抗性はミスマッチ修復酵素MLH1のノックダウンでキャンセルされた。さらにMUTYH遺伝子の発現がp53に依存すること、その調節領域と制御機構を明らかにした。以上の結果は、MUTYHがp53による発がん抑制のメディエータとして機能することを示唆している。.
46. 作見 邦彦, 大野 みずき, 古市 正人, 續 輝久, 中別府 雄作, 生殖細胞自然突然変異の新規発生と変異アリールの伝達, 第44回 日本環境変異学会, 2015.11, ヒト集団中における生殖細胞突然変異の頻度は1.2 x 10-8 mutation/base/generationと報告されている。しかしその発生機構に関して,我々の知識は十分とは言えない。我々は 「8-オキソグアニンが生殖細胞突然変異の原因のひとつである」 という仮説をたてMth1, Ogg1, Mutyh triple KOマウスを用いて検証を行い,生殖細胞系列への8-オキソグアニンの蓄積に伴って G-T トランスバージョン変異が新規に発生し,メンデルの法則に従って子孫へ伝達されることを見いだして報告した(大野らJEMS2012,2013)。今回,このマウスに発生した個々の突然変異を祖先に遡って追跡することで,有性生殖における自然突然変異の新規発生と変異アリールの伝達,固定化および消失の現象を同定することができたので報告する。また,涙腺腫瘍等が家族性に発生し子孫に伝わっていることが明らかになった。受精卵から始まる配偶子形成過程でゲノムDNA上に存在する8-オキソグアニンが,次世代に伝達される突然変異の原因になっていると考えられる。.
47. Julio Leon, Kunihiko Sakumi, Sugako Oka, Erika Castillo, Yusaku Nakabeppu, 8-Oxoguanine accumulated in mitochondrial DNA disturbs neuritic regeneration of cultured adult mouse cortical neurons under conditions of oxidative stress, 45th Annual Meeting of Society for Neuroscience, 2015.10.
48. Shunji Nakatake, Yusuke Murakami, Yasuhiro Ikeda, Noriko Yoshida, Takashi Tachibana, Toshio Hisatomi, Yusaku Nakabeppu, Tatsuro Ishibashi, MUTYH, a Base Excision Repair Enzyme against Oxidative DNA Damage, Induces Single-strand Break Formation and Mediates Photoreceptor Cell Death in a Mouse Model of Retinitis Pigmentosa, The 8th Joint Meeting of Japan-China-Korea Ophthalmologists, 2015.10.
49. Kunihiko Sakumi, Mizuki Ohno, Masato Furuichi, Teruhisa Tsuzuki, Yusaku Nakabeppu, 8-oxoguanine causes spontaneous de novo germline mutations in mice, 第74回日本癌学会学術総会, 2015.10, Spontaneous germline mutations lead new familial tumor pedigrees. However, the cause and mechanism remain unclear. 8-guanine (8-oxoG) is a candidate molecule that causes germline mutations, because it makes DNA more prone to mutation and constantly generated by reactive oxygen species in vivo. We have shown that endogenous 8-oxoG caused de nova spontaneous and heritable G to T mutations in mice, which occurred at different stages in the germ cell lineage and were distributed throughout chromosomes. Using exome analyses covering 40.9 Mb of mouse transcribed regions, we found increased frequencies of G to T mutations at a rate of 2 x 10-7 mutations/base/generation in offspring of Mthl/Oggl /Mutyh triple
knockout (TOY-KO) mice, which accumulate 8-oxoG in the nuclear DNA of gonadal cells. The roles of MTH1, OGG1, and MUTYH are specific for the prevention of 8-oxoG-induced mutation, and 99% of the mutations observed in TOY-KO mice were G to transversions caused by 8-oxoG; therefore, we concluded that 8-oxoG is a causative molecule for spontaneous and inheritable mutations of the germ lineage cells..
50. 中別府 雄作, アルツハイマー病脳における糖代謝障害とミトコンドリア機能不全, 第7回西播磨ブレインサイエンス研究会, 2015.08.
51. 中別府 雄作, 岡 素雅子, 盛 子敬, 大野 みずき, 土本 大介, 作見 邦彦, 活性酸素によるDNA損傷が引起こすさまざまな生命現象: 突然変異から神経変性まで, 第17回 日本進化学会年大会, 2015.08, 生物にとって、その遺伝情報を担うゲノムDNAを細胞から細胞へ、親から子へと正確に伝え維持することは最も基本的な生物学的機能であるが、ゲノム情報はその複製過程で生じる突然変異により変化する可能性がある。突然変異、すなわちゲノムの可変性は、生物にとって2つの大きな意義を持っている。ゲノムの変化は生物種の多様性には不可欠であり、突然変異は生物進化の原動力となる。一方で、ゲノムの変化は個体の存続や子孫の維持の破綻の原因ともなる。ゲノムDNAやその前駆体であるヌクレオチドは、酸素呼吸の過程で必然的に発生する活性酸素や生体防御のために生体が能動的に産生する活性酸素によって酸化される危険に常に曝されている。活性酸素に曝されたDNAやヌクレオチドは様々な酸化的化学修飾を受けるが、このような酸化損傷は修復・除去されないと突然変異を引き起こすことで先天性異常やがん化の原因となり、あるいは細胞死を引き起こすことで多くの変性疾患の原因となることが明らかになってきた。本シンポジウムでは、活性酸素による核酸の酸化に起因する「突然変異」と「細胞死」の生物学的帰着について、我々のこれまでの研究成果を紹介する。.
52. Mizuki Ohno, Noriko Takano, Kunihiko Sakumi, Ryutaro Fukumura, Yuki Iwasaki, Toshimichi Ikemura, Yoichi Gondo, Yusaku Nakabeppu, Yoshimichi Nakatsu, Teruhisa Tsuzuki, The role of MUTYH in the oxidative stress-induced mutagenesis and tumorigenesis in the mouse intestine, The Zing conference on “Genomic Integrity", 2015.08, Germline mutation (GM) generates genetic diversity, and is regarded as a driving force of molecular evolution. Besides, spontaneously occurring somatic mutations (SMs) increase the cancer risk.
To clarify the common cause of spontaneous SMs and GMs in mammals, we focused on the role of oxidative DNA damage and its repair system. 8-Oxoguanine (8-oxoG), a major oxidized form of guanine, is a potent pre-mutagenic lesion that causes G:C to T:A transversions. MUTYH, OGG1, and MTH1 are key enzymes that prevent this mutagenesis. Previously, we showed that oxidative stress dramatically increases SMs and tumor incidence in the intestines of Mutyh-deficient mice.
To assess the influence of 8-oxoG on spontaneous GMs, Mth1, Ogg, and Mutyh triple-knockout (TOY-KO) mice were generated and maintained by intragenerational crosses. In this mouse line, we observed an increased tumor incidence, shortened life span, and reduced litter size. Notably, congenital phenotypic abnormalities were frequently observed in the offspring. This was an expected consequence of the high GM rate. Based on a whole-exome sequencing analysis, we detected an 18-fold increase in the GM rate relative to that of wild-type mice. Most of the GMs detected in TOY-KO mice were G:C to T:A transversions. These data indicate that the 8-oxoG content and the repair system influence the rate of G to T transversions not only in somatic cells but also in germline cells.
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53. Nona Abolhassani, Masaaki Hokama, Daisuke Saitou, Mikita Suyama, Toru Iwaki, Yutaka Kiyohara, Yusaku Nakabeppu, Characterization of transcript variants expressed in Alzheimer´s disease brains with human transcriptome array and deep RNA sequencing analyses: The Hisayama Study, The 38th Annual Meeting of the Japan Neuroscience Society, 2015.07, To identify molecular pathological alterations in Alzheimer´s disease (AD) brains, we had previously performed comparative gene expression profiling with GeneChip Human Gene Array using RNAs prepared from postmortem human brains donated for the Hisayama study. The hippocampi of AD brains showed the most significant alteration in gene expression profile. Genes involved in noninsulin–dependent diabetes mellitus and obesity were significantly altered in both AD brains and the AD mouse model, as were genes related to psychiatric disorders and AD (Hokama M. et al., Cerebral Cortex, 2014). Recently it has been shown that transcript variants of some genes are associated with AD. In the present study, in order to obtain a comprehensive view of the transcriptome in AD, we applied a high throughput GeneChip Human Transcriptome Array (HTA) to the hippocampal RNAs. HTA enables us to identify expression changes at the exon and sub-exon levels, taking into account the diversity of transcript isoforms generated by alternative transcription initiation and splicing. We thus discovered significant altered expression profiles of transcript variants in various genes such as RGS4, PRKCB, MET, PCSK1 and GABRA1, in addition to confirming the significantly altered expression profile found in the previous study. But in particular microarray probes cover small regions and not a full transcript structure. To determine the full structure of transcripts whose change is associated with AD, we also performed deep RNA sequencing using same samples. We will present the altered expression profiles in AD brains revealed by these analyses..
54. Julio Jesus Leon Incio, Kunihiko Sakumi, Sugako Oka, Erika Castillo, Yusaku Nakabeppu, Cortical neurons isolated from adult Mth1/Ogg1-double-knockout mouse exhibit impaired neurite regeneration under conditions of oxidative stress, The 38th Annual Meeting of the Japan Neuroscience Society, 2015.07, Oxidative damage and mitochondrial dysfunction are known to play pivotal roles in aging and neurodegenerative diseases, such as Alzheimer´s disease (AD). AD brains accumulate increased level oxidized base lesions such as 8-oxoguanine (8-oxoG) in both nuclear and mitochondrial DNAs as well as in RNA. MTH1 with an 8-oxo-dGTPase activity hydrolyzes 8-oxo-dGTP to 8-oxodGMP and pyrophosphate in nucleotide pools, while OGG1 with an 8-oxoG DNA glycosylase activity excises 8-oxoG paired with cytosine in DNA, thereby maintaining low levels of 8-oxoG in the cellular DNAs. Our group has reported that Mth1/Ogg1-double knockout (Mth1/Ogg1-DKO) mice are highly vulnerable to 3-nitropropionic acid-induced striatal degeneration with increased accumulation of 8-oxoG in mitochondrial DNA of striatal neurons in comparison to wild-type mice. In the present study, we compared the efficiency of neurite regeneration of adult cortical neurons isolated from adult wild-type and Mth1/Ogg1-DKO brains. We cultured cortical neurons isolated from 15-19 week-old mice and maintained them in medium supplemented with B27 with or without antioxidants for 48h. Regenerating neurites were identified by MAP2-immunofluorescence with confocal imaging. Neuronal populations were classified according to the following criteria: stage 1 neurons lacking neurites, stage 2 with one or more minor neurites, and stage 3 with one neurite at least twice as long as any other. We found similar distributions of cortical neurons isolated from both Mth1/Ogg1-DKO and wild-type mice maintained in medium supplemented with B27 containing antioxidants; about 10% in stage 1, 15 to 20% in stage 2, and 60% in stage 3. However, we found that when the neurons were maintained in medium supplemented with B27 lacking antioxidant, neurons isolated from Mth1/Ogg1-DKO brains exhibited significantly less population in stage 3 (20%), compared to those isolated from wild-type brain (60% in stage 3). Moreover, Mth1/Ogg1-DKO neurons were approximately 50% in stage 2 and 25% in stage 1, while wild-type neurons were about 25% in stage 2 and less than 10% in stage 1. We are now analyzing whether the impaired neurite regeneration in Mth1/Ogg1-DKO neurons is due to mitochondrial dysfunction associated with the accumulation of 8-oxoG in mitochondrial DNA..
55. Atsuhisa Katogi, Hiroko Nomaru, Yoshinori N. Ohnishi, Kunihiko Sakumi, Yusaku Nakabeppu, Characterization of Fosb gene products expressed in various Fosb mutant mice, The 38th Annual Meeting of the Japan Neuroscience Society, 2015.07, Fosb gene products compose AP-1 transcription factors and regulate expression of various genes related to neuronal function. Fosb gene produces two forms of mature transcripts, Fosb and ΔFosb mRNAs because it has an intron-like sequence in exon 4, which allows alternative splicing. Fosb mRNA encodes full-length FOSB and vFOSB, while ΔFosb mRNA encodes ΔFOSB and Δ2ΔFOSB. Δ2ΔFOSB is a product of alternative initiation of translation from Met79 codon in the ΔFosb mRNA. vFOSB is also likely to be a product of an alternative initiation of translation of Fosb mRNA. We have established Fosb-null mice and Fosbd/d mutant mice, the latter expressing only ΔFOSB and Δ2ΔFOSB. Recently, we also established FosbF/F mutant mice expressing only Fosb mRNA. In the present study, we characterized the Fosb gene products expressed in each Fosb mutant mice by 2-D electrophoresis followed by western blotting. We found multiple spots representing FOSB, vFOSB, ΔFOSB and Δ2ΔFOSB, respectively, and we thus considered possible post-translational modifications of each Fosb gene product. Although some of the spots were disappeared after phosphatase treatment, there were still multiple spots remained, suggesting that each Fosb gene product is post-translationally modified in various manners including phosphorylation. We thus analyzed Fosb gene products by mass spectrometry in order to identify post-translational modifications of each Fosb gene product..
56. Kosuke Kajitani, Yusaku Nakabeppu, Yoshihiko Kadoya, Hidenori Horie, Characterization of galectin-1-positive cells in the mouse hippocampus: the relevance of galectin-1 to interneurons, The 38th Annual Meeting of the Japan Neuroscience Society, 2015.07, Galectin-1 (gal-1) is one of several well-studied proteins from the galectin family. It is a 14.5 kDa glycoprotein with a single carbohydrate-binding domain. To examine the distribution and properties of gal-1 in the mouse hippocampus, we performed immunohistochemistry using an anti-gal-1 antibody. We found that most gal-1-positive cells showed both NeuN and β-tubulin III (Tuj-1) immunoreactivity (NeuN: 93%, β-tubulin III: 88%). Furthermore, we determined that 77% of gal-1-positive cells in the mouse hippocampus expressed somatostatin. Additionally, 79% expressed GAD67, 34% expressed parvalbumin, 5% expressed calretinin, 2% expressed calbindin, and 31% expressed neuropeptide Y.
In order to examine whether gal-1 influences the number of interneurons in the mouse hippocampus, we next compared the number of interneuron marker-expressing cells between gal-1 knockout (KO) and wild-type (WT) mice by using stereological counting techniques. We counted the number of somatostatin-, parvalbumin-, and GAD67-positive cells in the hippocampi of both gal-1 KO and WT mice. However, no significant differences were found.
These results indicate that gal-1 is expressed in interneurons that express β-tubulin III, and that it may be a novel marker for interneuron subpopulations in the hippocampus; however, gal-1 does not affect the number of interneurons in the adult mouse hippocampus..
57. Zijing Sheng, Yusaku Nakabeppu, Cranial irradiation causes hippocampal degeneration through accumulation of 8-oxoguanine in mitochondrial DNA in neurons, The 38th Annual Meeting of the Japan Neuroscience Society, 2015.07, 8-Oxoguanine (8-oxoG) is one of the major oxidative base lesions in DNA, and is highly mutagenic because it can pair with adenine as well as cytosine. To counteract oxidative damage to nucleic acids, MTH1 hydrolyzes oxidized purine nucleoside triphosphates, thus sanitizing nucleotide pools. OGG1, an 8-oxoguanine DNA glycosylase, prevents buildup of 8-oxoguanine in both nuclear and mitochondrial genomes.
It has been shown that cranial irradiation during the treatment of malignancies induces cognitive impairments, and oxidative DNA damage has been inferred to be involved in this process. However, the underlying mechanisms responsible for radiation-induced cognitive deficits are largely unknown.
In the present study, we first found that cranial irradiation of Ogg1/Mth1-double knockout (DKO) mice decreased their locomotor activities in open field test, and cognitive impairments were observed in passive avoidance test. We then demonstrated that cranial irradiation caused severe degeneration of hippocampal axons and loss of synapses in the Ogg1/Mth1-DKO mice in comparison to wild-type mice. Furthermore, we confirmed that 8-oxoG accumulated in mitochondrial DNA was significantly increased in both neuronal soma and axons in the Ogg1/Mth1-DKO mice.
Our results indicate that MTH1 and OGG1 play pivotal roles for neuroprotection under cranial irradiation, especially by maintaining mitochondrial DNA integrity in hippocampal neurons, thus providing new mechanistic insights into the cognitive impairments induced by cranial irradiation..
58. Sugako Oka, Julio Leon, Nona Abolhassani, Masaaki Hokama, Toru Iwaki, Yutaka Kiyohara, Dongchon Kang, Yusaku Nakabeppu, Interspecies comparative gene expression profiling revealed impaired insulin production and insulin signaling in Alzheimer's disease brains: The Hisayama Study , The 2015 Alzheimer's Disease Congress, 2015.06, To identify molecular pathological alterations in Alzheimer’s disease (AD) brains, we performed interspecies comparative microarray analyses using RNA prepared from postmortem human brain tissues donated for the Hisayama study, and hippocampal RNAs from the triple-transgenic mouse model of AD (3xTg-AD). We found altered expression of genes involved in insulin production, insulin signaling and mitochondrial function in AD brains. Mitochondrial dysfunction is considered to have a pivotal role for developing AD, we further examined effects of human mitochondrial transcriptional factor A (hTFAM) transgene, which plays important roles to maintain mitochondrial homeostasis, on the pathology of 3xTg-AD mice..
59. Yusaku Nakabeppu, Oxidation of nucleic acids and control mechanisms of spontaneous mutagenesis and tumorigenesis in mammals, The CRUK/MRC Oxford Institute for Radiation Oncology 2015 Seminar Series , 2015.06, For living organisms, the most fundamental biological function is maintaining the integrity of their genomic DNAs harboring the genetic information and transmitting them precisely from cell to cell, as well as from parents to their offspring. The genomic DNA and its precursor nucleotides are always in danger of oxidation by reactive oxygen species (ROS) which are generated both as byproducts of oxidative metabolism and as a consequence of exposure to pathogens, ionizing radiation, chemicals and other environmental factors. Increased accumulation of oxidized bases in genomic DNAs of somatic cells may cause mutations resulting in cancer, while non-lethal mutations in germ lineage cells may cause genetic disorders or result in genetic polymorphisms in populations of sexually reproductive organisms and are thus regarded as a driving force of evolution. Among the four nucleobases, guanine is the most susceptible to oxidation, and its simple oxidized form, 8-oxoguanine (8-oxoG), is one of the major oxidation products in DNA or nucleotides. It is well known that 8-oxoG is a pre-mutagenic lesion because it can pair with adenine as well as cytosine during DNA replication, and causes G to T or A to C base substitutions. To counteract mutagenic potential of 8-oxoG, human and rodents are equipped with three distinct enzymes, MTH1, OGG1 and MUTYH. MTH1 hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP and pyrophosphate, thus avoiding incorporation of 8-oxoG into DNA. OGG1 and MUTYH are DNA glycosylases excising 8-oxoG opposite cytosine and adenine opposite 8-oxoG in DNA, respectively. To evaluate the influence of 8-oxoG on genetic diversity in mammals, we established mutant mice lacking these three genes, and examined levels of 8-oxoG accumulation in their genomes and spontaneous occurrence of heritable mutations. In comparison to wild-type mice, Mth1/Ogg1/Mutyh triple knockout (TOY-TKO) mice accumulated 2 to 4-fold increased levels of 8-oxoG in the nuclear DNA of gonadal cells. Using exome analyses covering 40.9 Mb of mouse transcribed regions, we found increased frequencies of G to T mutations in offspring of TOY-TKO mice at a rate of 2 × 10-7 mutations/base/generation, which is about 200-fold higher incidence found in normal human population. By tracing each mutated allele in the pedigree, we reproduced the appearance, transmission, fixation and disappearance of the spontaneously generated mutations in TOY-TKO mice. Moreover, we found that accumulation of 8-oxoG in the genome of gonadal cells increase meiotic chromosome recombination, thus further enhancing the genomic diversity. Finally, we demonstrated that MUTYH, adenine DNA glycosylase, whose expression is dependent on p53, induces cell death when 8-oxoG highly accumulated in the genomes, thus mediating p53 tumor suppression.

References:
1. Oka, S., Leon, J., Tsuchimoto, D., Sakumi, K. and Nakabeppu, Y. (2014) MUTYH, an adenine DNA glycosylase, mediates p53 tumor suppression via PARP-dependent cell death. Oncogenesis, 3, e121.
2. Ohno, M., Sakumi, K., Fukumura, R., Furuichi, M., Iwasaki, Y., Hokama, M., Ikemura, T., Tsuzuki, T., Gondo, Y. & Nakabeppu, Y. (2014) 8-oxoguanine causes spontaneous de novo germline mutations in mice. Sci Rep 4: 4689.
3. Sheng, Z., Oka, S., Tsuchimoto, D., Abolhassani, N., Nomaru, H., Sakumi, K., Yamada, H. & Nakabeppu, Y. (2012) 8-Oxoguanine causes neurodegeneration during MUTYH-mediated DNA base excision repair. J Clin Invest 122, 4344-4361.
4. Oka, S., Ohno, M., Tsuchimoto, D., Sakumi, K., Furuichi, M. and Nakabeppu, Y. (2008) Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs. EMBO J, 27, 421-432.
5. Ohno, M., Miura, T., Furuichi, M., Tominaga, Y., Tsuchimoto, D., Sakumi, K. and Nakabeppu, Y. (2006) A genome-wide distribution of 8-oxoguanine correlates with the preferred regions for recombination and single nucleotide polymorphism in the human genome. Genome Res, 16, 567-575.
5. Sakumi, K., Tominaga, Y., Furuichi, M., Xu, P., Tsuzuki, T., Sekiguchi, M. and Nakabeppu, Y. (2003) Ogg1 knockout-associated lung tumorigenesis and its suppression by Mth1 gene disruption. Cancer Res, 63, 902-905.
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60. 中別府 雄作, アルツハイマー病脳における遺伝子発現の変化と酸化ストレス, 第68回日本酸化ストレス学会学術集会, 2015.06,  脳・神経組織は,その機能,すなわち「神経興奮と神経伝導に関連したイオンの能動輸送」の維持に膨大なエネルギーを必要とする。成人脳の重量は全体重の2%前後であるが、脳機能を維持するには安静時に全身で消費するエネルギーの20%程度が必要とされることからも、脳機能を維持する上でエネルギー供給がいかに重要か、一目瞭然である。生体はグルコースの代謝で得られるATPを主要なエネルギーとして利用するが,そのほとんどがミトコンドリアでの酸素呼吸に依存して合成される
 通常、グルコースは解糖系でピルビン酸まで代謝された後,ミトコンドリアのTCAサイクルに入り,電子伝達系と共役した酸化的リン酸化により高エネルギー化合物であるATPに変換される。ミトコンドリア電子伝達系の複合体I〜IVの間では電子が受け渡され,その時の酸化還元電位差によるエネルギーがATPに変換されるが,この電子伝達系から電子の一部が漏出して酸素分子に直接付加されるとスーパーオキシドを生じる。生理的な条件下においてミトコンドリアでの酸素呼吸により消費される酸素の数%がスーパーオキシドをはじめとする活性酸素に転換されることが明らかにされている。脳組織は他の組織の10倍以上の酸素を消費することから,活性酸素の生成も非常に高いと考えられている。
 アルツハイマー病やパーキンソン病などの老化に伴い発症頻度が増加する神経変性疾患の主要な原因の1つとして酸化ストレスが注目されている。多くの神経変性疾患患者の剖検脳の解析から,脳組織に脂質やタンパク質の酸化体に加えて核酸塩基の中で最も酸化されやすいグアニンの酸化体である8-オキソグアニンが多量に蓄積することが報告されており,神経変性が酸化ストレスをともなうことを示す根拠と考えられている。
 本講演では,アルツハイマー病に注目し,九州大学久山町研究における剖検脳と動物モデルを用いた解析結果を紹介しながら、認知機能障害や神経変性に至る過程に酸化ストレスがどのように関与するのかを考えてみたい。

1. Hokama, M., Oka, S., Leon, J., Ninomiya, T., Honda, H., Sasaki, K., Iwaki, T., Ohara, T., Sasaki, T., LaFerla, F.M., et al. Altered expression of diabetes-related genes in Alzheimer's disease brains: the hisayama study. Cereb Cortex. 2014;24(9):2476-2488.
2. Hamasaki, H., Honda, H., Suzuki, S.O., Hokama, M., Kiyohara, Y., Nakabeppu, Y., and Iwaki, T. Down-regulation of MET in hippocampal neurons of Alzheimer's disease brains. Neuropathology. 2014;34(3):284-290.
3. 中別府雄作,2014,神経変性疾患と酸化ストレス.「酸化ストレスの医学」(吉川 敏一監修,内藤 裕二,豊國 伸哉 編集),pp. 217-227,診断と治療社.
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61. 中別府 雄作, 岡 素雅子, Julio Leon, Nona Abolhassani, 外間 正朗, 岩城 徹, 清原 裕, 井手 友美, Dongchon Kang, アルツハイマー病脳におけるミトコンドリア機能不全とインスリン抵抗性の分子病態, 第56回日本神経病理学会総会学術研究会, 2015.06.
62. Yusaku Nakabeppu, Sugako Oka, Zijing Sheng, Kunihiko Sakumi, MUTYH-dependent programmed cell death triggered by 8-oxoguanine and its implication in tumor suppression and neurodegeneration, 15th International Congress of Radition Research: ICRR2015, 2015.05.
63. Sugako Oka, Ohno Mizuki, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs, BIT’8th, Annual World Cancer Congress-2015, 2015.05.
64. Shunji Nakatake, Yusuke Murakami, Yasuhiro Ikeda, Noriko Yoshida, Takashi Tachibana, Toshio Hisatomi, Yusaku Nakabeppu, Tatsuro Ishibashi, MUTYH, a Base Excision Repair Enzyme against Oxidative DNA Damage, Induces Single-strand Break Formation and Mediates Photoreceptor Cell Death in a Mouse Model of Retinitis Pigmentosa, The Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) 2015, 2015.05.
65. 大平 明弘, 海津 幸子, 奥野 勉, 中別府 雄作, DNA塩基除去修復欠損マウスにおける網膜光障害, 第119回日本眼科学会総会, 2015.04.
66. 中武 俊二, 村上 祐介, 池田 康博, 吉田 倫子, 立花 崇, 久富 智朗, 中別府 雄作, 石橋 達郎, 網膜色素変性の視細胞死におけるゲノムの酸化損傷とMUYTHの役割, 第119回日本眼科学会総会, 2015.04.
67. Sugako Oka, Julio Leon, Nona Abolhassani, Masaaki Hokama, Toru Iwaki, Yutaka Kiyohara, Dongchon Kang, Yusaku Nakabeppu, Interspecies comparative gene expression profiling revealed impaired insulin production and insulin signaling accompanied by mitochondrial dysfunction in Alzheimer's disease brains: The Hisayama Study, 第88回薬理学会年会, 2015.03.
68. Sugako Oka, Julio Leon, Masaaki Hokama, Toru Iwaki, Yutaka Kiyohara, Dongchon Kang, Yusaku Nakabeppu, Impaired insulin production/signaling accompanied by mitochondrial dysfunction and oxidative stress in Alzheimer's disease brains, Progress 100: Kyushu-U and Stanford-U Joint Research and Education Program:First Symposium: From Genes to Human Diseases, 2015.03.
69. 中別府 雄作, アルツハイマー病脳における遺伝子発現変化が引き起こす糖代謝障害と酸化ストレス, 東京都総合医学研究所セミナー, 2015.02,  脳・神経組織は,その機能,すなわち「神経興奮と神経伝導に関連したイオンの能動輸送」の維持に膨大なエネルギーを必要とする。成人脳の重量は全体重の2%前後であるが、脳機能を維持するには安静時に全身で消費するエネルギーの20%程度が必要とされることからも、脳機能を維持する上でエネルギー供給がいかに重要か、一目瞭然である。生体はグルコースの代謝で得られるATPを主要なエネルギーとして利用するが,そのほとんどがミトコンドリアでの酸素呼吸に依存して合成される
 通常、グルコースは解糖系でピルビン酸まで代謝された後,ミトコンドリアのTCAサイクルに入り,電子伝達系と共役した酸化的リン酸化により高エネルギー化合物であるATPに変換される。ミトコンドリア電子伝達系の複合体I〜IVの間では電子が受け渡され,その時の酸化還元電位差によるエネルギーがATPに変換されるが,この電子伝達系から電子の一部が漏出して酸素分子に直接付加されるとスーパーオキシドを生じる。生理的な条件下においてミトコンドリアでの酸素呼吸により消費される酸素の数%がスーパーオキシドをはじめとする活性酸素に転換されることが明らかにされている。脳組織は他の組織の10倍以上の酸素を消費することから,活性酸素の生成も非常に高いと考えられている。
 アルツハイマー病やパーキンソン病などの老化に伴い発症頻度が増加する神経変性疾患の主要な原因の1つとして酸化ストレスが注目されている。多くの神経変性疾患患者の剖検脳の解析から,脳組織に脂質やタンパク質の酸化体に加えて核酸塩基の中で最も酸化されやすいグアニンの酸化体である8-オキソグアニンが多量に蓄積することが報告されており,神経変性が酸化ストレスをともなうことを示す根拠と考えられている。
 本セミナーでは,アルツハイマー病に注目し,九州大学久山町研究における剖検脳と動物モデル、iPS細胞由来神経細胞における解析の結果を紹介しながら、認知機能障害や神経変性に至る過程に酸化ストレスがどのように関与するのかを考えてみたい。
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70. Yusaku Nakabeppu, Sugako Oka, Julio Leon, Nona Abolhassani, Masaaki Hokama, Toru Iwaki, Yutaka Kiyohara, Dongchon Kang, Impaired insulin production and insulin signaling accompanied by mitochondrial dysfunction in Alzheimer's disease brains: The Hisayama Study, 包括型脳科学研究推進支援ネットワーク 冬のシンポジウム, 2014.12, To identify molecular pathological alterations in Alzheimer’s disease (AD) brains, we performed interspecies comparative microarray analyses using RNA prepared from postmortem human brain tissues donated for the Hisayama study, and hippocampal RNAs from the triple-transgenic mouse model of AD (3xTg-AD). The hippocampi of AD brains showed the most significant alteration in gene expression profile. Genes involved in noninsulin-dependent diabetes mellitus (DM) and obesity were significantly altered in both AD brains and the AD mouse model, as were genes related to psychiatric disorders and AD. The altered expression profiles in AD brains were independent of peripheral DM-related abnormalities. Moreover, the altered gene expression profiles in AD brains indicate mitochondrial dysfunction and increased ROS production supporting that mitochondrial dysfunction is considered to have a pivotal role for developing AD.
We thus further examined effects of human mitochondrial transcriptional factor A (hTFAM) transgene on the pathology of 3xTg-AD mice. TFAM is now known to contribute not only in transcription of mitochondrial DNA but also maintenance of mitochondrial DNA, and thus protecting mitochondria from oxidative stress. In the Morris Water Maze test, 13-month-old 3xTg-AD hemizygous mice carrying hemizygous hTFAM transgene exhibited significant improvement of learning and memory deficit compared to 3xTg-AD hemizygous mice. Accumulation of Aβ was markedly decreased in cerebral cortices and hippocampi of the 3xTg-AD/hTFAM mice. Moreover, 3xTg-AD/hTFAM mice exhibited much less accumulation of 8-oxo-dG, an oxidative stress marker, in cerebral cortices and hippocampi in comparison to 3xTg-AD mice which accumulated higher level of 8-oxo-dG. To clarify the mechanism of improvement of AD phenotype by hTFAM, we are currently performing gene expression profiling using hippocampal RNA prepared from these animals. These results will provide the new insight to understand the molecular mechanisms of AD pathology and possible new strategies for the therapy of AD..
71. 岡 素雅子, Julio Leon, 加藤木 敦央, 作見 邦彦, 井手 友美, 康 東天, 中別府 雄作, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in Alzheimer’s disease model mice, 第14回 日本ミトコンドリア学会 年会, 2014.12.
72. 森岡 紀子, 能丸 寛子, 作見 邦彦, 土本 大介, 中別府 雄作, Fosb遺伝子産物はマクロファージにおける補体C5a受容体遺伝子、C5ar1とC5ar2の発現を制御する, 第37回日本分子生物学会年会, 2014.11.
73. Atsuhisa Katogi, Hiroko Nomaru, Yoshinori N. Ohnishi, Kunihiko Sakumi, Yusaku Nakabeppu, Analysis of FosbF/F mice expressing only FOSB and vFOSB, 第37回日本分子生物学会年会, 2014.11.
74. Sugako Oka, Julio Leon, Atsuhisa Katogi, Erika Castillo, Nona Abolhassani, Kunihiko Sakumi, Tomomi Ide, Dongchon Kang, Yusaku Nakabeppu, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in Alzheimer’s disease model mice, 第37回日本分子生物学会年会, 2014.11.
75. 土本 大介, 米嶋 康臣, Nona Abolhassani, 猪山 輝昭, 作見 邦彦, 塩見 尚子, 森 雅彦, 塩見 忠博, 野田哲生, 中別府 雄作, デオキシイノシン三リン酸の蓄積はミスマッチ修復タンパク質MLH1に依存した細胞周期の遅延をもたらす, 第37回日本分子生物学会年会, 2014.11.
76. Nona Abolhassani, Massaki Hokama, Toru Iwaki, Yutaka Kiyohara, Yusaku Nakabeppu, Characterization of transcript variants expressed in Alzheimer’s disease brains with human transcriptome array and deep RNA sequencing analyses: The Hisayama Study, 第37回日本分子生物学会年会, 2014.11.
77. 岡 素雅子, 盛 子敬, 作見 邦彦, 中別府 雄作, ほ乳動物ゲノムにおける8-オキソグアニンの修復プロセッシングと細胞運命, 第37回日本分子生物学会年会, 2014.11.
78. 秋本 頼子, Nona Abolhassani, Erika Castillo, 岡 素雅子, 土本 大介, 作見 邦彦, 中別府 雄作, 放射線照射によって生成される損傷プリンヌクレオシドの同定と定量, 第37回日本分子生物学会年会, 2014.11.
79. 作見 邦彦, 大野 みずき, 福村 龍太郎, 権藤 洋一, 岩﨑 裕貴, 池村 淑道, 續 輝久, 中別府 雄作, 8-oxoguanine に起因するde novo germline mutation の解析, 第37回日本分子生物学会, 2014.11.
80. Yusaku Nakabeppu, Mizuki Ohno, Sugako Oka, Zijing Sheng, Kunihiko Sakumi, Control mechanisms of genetic diversity and programed cell death induced by 8-oxoguanine in mammals, 9th 3R (Replication, Repair, recombination) symposium, 2014.11, Among the four nucleobases, guanine is the most susceptible to oxidation, and its simple oxidized form, 8-oxoguanine (8-oxoG), is one of the major oxidation products in DNA or nucleotides. It is well known that 8-oxoG is a pre-mutagenic lesion because it can pair with adenine as well as cytosine during DNA replication, and causes G to T or A to C base substitutions. To counteract mutagenic potential of 8-oxoG, human and rodents are equipped with three distinct enzymes, MTH1, OGG1 and MUTYH. MTH1 hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP and pyrophosphate, thus avoiding incorporation of 8-oxoG into DNA. OGG1 and MUTYH are DNA glycosylases excising 8-oxoG opposite cytosine and adenine opposite 8-oxoG in DNA, respectively.
To evaluate the influence of 8-oxoG on genetic diversity in mammals, we established mutant mice lacking these three genes, and examined levels of 8-oxoG accumulation in their genomes and spontaneous occurrence of heritable mutations. In comparison to wild-type mice, Mth1/Ogg1/Mutyh triple knockout (TOY-TKO) mice accumulated 2 to 4-fold increased levels of 8-oxoG in the nuclear DNA of gonadal cells. Using exome analyses covering 40.9 Mb of mouse transcribed regions, we found increased frequencies of G to T mutations in offspring of TOY-TKO mice at a rate of 2 × 10-7 mutations/base/generation, which is about 200-fold higher incidence found in normal human population. By tracing each mutated allele in the pedigree, we reproduced the appearance, transmission, fixation and disappearance of the spontaneously generated mutations in TOY-TKO mice. Moreover, accumulation of 8-oxoG in the genome of gonadal cells increase meiotic chromosome recombination, thus further enhancing the genomic diversity.
We also found that excessive accumulation of 8-oxoG in nuclear or mitochondrial genomes induces cell death, which is involved in cancer suppression or neurodegeneration, and that the cell death is mediated by MUTYH-initiated base excision repair of adenine inserted opposite 8-oxoG during replication.

References:
Ohno, M., Sakumi, K., Fukumura, R., Furuichi, M., Iwasaki, Y., Hokama, M., Ikemura, T., Tsuzuki, T., Gondo, Y. & Nakabeppu, Y. (2014) 8-oxoguanine causes spontaneous de novo germline mutations in mice. Sci Rep 4, 4689.
Nakabeppu, Y. (2014) Cellular Levels of 8-Oxoguanine in either DNA or the Nucleotide Pool Play Pivotal Roles in Carcinogenesis and Survival of Cancer Cells. Int J Mol Sci 15, 12543-12557.
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81. Michel J. Massaad, Daisuke Tsuchimoto, Janet Chou, Toshiro Ohsumi, Jia Zhou, Haifa Jabara, Jennifer Kane, Klaus Schmitz, Markianos Kyriacos, Kumiko Torisu, Yusaku Nakabeppu, Peter Kang, Eliane Choueiry, Andre Megarbane, Masayuki Mizui, George Tsokos, Waleed El-Herz, Luigi Notarangelo, Susan Wallace, Raif S. Geha, THE HUMAN NEI ENDONUCLEASE VIII-LIKE 3 (NEIL3) IS A NOVEL GENE ASSOCIATED WITH THE DEVELOPMENT OF AUTO-ANTIBODIES , 16th Biennial Meeting of the European Society for Immunodeficiency, 2014.10, We identified the genetic cause of a combined immunodeficiency in a consanguineous family with history of severe recurrent infections, autoimmunity, chronic diarrhea, and death.
The patients had normal numbers of T/B cells and normal T cell function. However, B cell proliferation and immunoglobulin production were decreased. Furthermore, the patients had high levels of serum auto-antibodies. Whole genome sequencing (WGS) identified a mutation in a highly conserved residue in the base excision repair enzyme NEIL3. The mutation does not affect protein expression but abolishes enzymatic activity. To determine the effect of loss of NEIL3 function, we studied Neil3-/- mice. Neil3-/- mice had no overt immune defect, however, they had high levels of serum auto-antibodies, and developed autoimmune kidney damage following treatment with the TLR3 ligand polyI:C. We later identified an unrelated asymptomatic individual with the same mutation in NEIL3, and found that she had high levels of serum auto-antibodies. LRBA lies in the same region of homozygosity as NEIL3. Further analysis of the WGS data identified a homozygous duplication of exons 49-53 of LRBA. We confirmed this duplication at the level of mRNA/cDNA, and showed that it resulted in loss of LRBA expression.
We identified NEIL3 as a novel gene associated with the development of auto-antibodies. While the mutations in both NEIL3 and LRBA contribute to the patient’s autoimmunity, the infections and colitis are likely due to the mutation in LRBA. This mutation would have been missed by whole exome sequencing, underlining the importance of WGS for the detection of disease-causing structural variations.
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82. Teruhisa Tsuzuki, Mizuki Ohno, Noriko Takano, Kenichi Taguchi, Yusaku Nakabeppu, Yasunobu Aoki, Takehiko Nohmi, Yoshimichi Nakatsu, Oxidative stress-induced intestinal tumors in Mutyh-deficient mice treated with low doses of potassium bromate, 5th US-Japan DNA Repair Meeting, 2014.10, Reactive oxygen species (ROS) are generated in vivo by the exposure of chemicals and ionizing radiation. ROS induce oxidative DNA damages that cause mutagenesis and tumorigenesis in mammals. The antimutagenic activity against oxidative DNA damage appears to be a factor that determines the susceptibility for tumorigenesis among individuals. MUTYH is an enzyme, adenine DNA glycosylase that can remove adenine incorporated opposite to 8-oxo-guanine during DNA replication, and is suppressing the spontaneous mutation. Previously we have established an experimental system for oxidative DNA damage-induced tumorigenesis in the gastrointestinal tract in Mutyh-deficient mice.
To assess the dose-dependent relation between the level of oxidative stress and tumor incidence we performed oxidative stress-induced intestinal tumorigenesis experiments using Mutyh-deficient mice as well as the wild-type mice as a control. Mice were divided into five groups and were received the different doses of potassium bromate; 0, 0.05, 0.1, 0.15, 0.2%, in drinking water for sixteen weeks. No tumor was developed in Mutyh-deficient mice untreated or treated at the dose of 0.05%, whereas a number of tumors were observed in small intestine of all the mice treated at the dose of 0.1% or higher. The average number of tumor per mouse was 8.8, 41.6, 61.8 at the dose of 0.1%, 0.15%, 0.2%, respectively. In contrast, the average number of tumor per mouse was only 0.9 when 0.2% solution, the highest dose applied, was given to wild-type mice. These results suggest that the intestinal tumorigenesis correlates to the level of oxidative stress in Mutyh-deficient mice.
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83. Yusaku Nakabeppu, Sugako Oka, Zijing Sheng, Kunihiko Sakumi, MUTYH-dependent programed cell death induced by 8-oxoguanine accumulated in cellular DNAs and its implication in tumorigenesis and neruodegeneration, 5th US-Japan DNA Repair Meeting, 2014.10, 8-Oxoguanine, a major oxidized base lesion formed by reactive oxygen species, can pair with adenine as well as cytosine in DNA, thus resulting in G to T transversion mutation or cell death in mammals, if it accumulates in DNA. 8-Oxoguanine can originate as 8-oxo-dGTP, formed in the nucleotide pool, or by direct oxidation of the DNA guanine base. MTH1 with 8-oxo-dGTP hydrolyzing activity, 8-oxoguanine DNA glycosylase (OGG1) an 8-oxoG DNA glycosylase, and MutY homolog (MUTYH) with adenine DNA glycosylase activity, minimize the accumulation of 8-oxoG in DNA: deficiencies in these enzymes increase susceptibility to spontaneous and induced tumorigenesis. As expected, the triple-knockout mice of all three genes exhibit extremely increased incidences of spontaneous tumors in various tissues with significantly shortened life span. Interestingly, Mth1/Ogg1-double knockout mice are rather resistant to such spontaneous tumorigenesis. We found that 8-oxoguanine accumulated in cellular DNAs induces programed cell death dependent on MUTYH-initiated base excision repair. Moreover, we demonstrated that excessive accumulation of 8-oxoG in nuclear or mitochondrial DNAs in brain tissue induces neurodegeneration in which MUTYH plays an essential role..
84. 大野 みずき, 鷹野 典子, 佐々木 史子, 田口 健一, 中別府 雄作, 中津 可道, 續 輝久, 酸化ストレス誘発突然変異と消化管がんの解析, 日本放射線影響学会第57回大会, 2014.10, 放射線をはじめ様々な外的要因により生体内で発生した活性酸素種は、核DNAを損傷して突然変異を引き起こし、発がんの誘発要因になると予測される。近年家族性大腸がんの原因遺伝子としてMUTYHが同定された。MUTYHタンパク質はアデニンDNAグリコシラーゼで、DNA複製の過程で鋳型鎖上の酸化型グアニン(8−オキソグアニン)に対してアデニンが取り込まれて誤塩基対が形成された際にアデニンを切り出す活性を有し、自然突然変異の抑制に寄与している。我々はこれまでにMutyh遺伝子欠損マウスでは、加齢により消化管腫瘍の発生頻度が上昇することを見いだし、酸化DNA損傷は消化管がんの誘発要因であり、MUTYHはその抑制に大きく寄与していることを報告している。さらに酸化剤(臭素酸カリウム)を飲水投与することで酸化ストレスを負荷し、Mutyh遺伝子欠損マウスに短期間で消化管がんを誘発する実験系を確立している。
今回は酸化ストレス・ゲノム変異・発がんの関連を解析する目的で、酸化剤投与量を段階的に調整し、腫瘍発生以前の消化管細胞群における突然変異頻度およびそのスペクトル、腫瘍形成頻度および病理学的解析を行った。その結果、Mutyh遺伝子欠損マウスの消化管に発生した腫瘍数および突然変異頻度が酸化剤投与量に依存して増加する傾向(量—反応関係)を認めた。また酸化剤投与により生じた突然変異はG→Tの一塩基置換が最も多く、8−オキソグアニンに起因するものであった。以上の結果よりMUTYHが酸化ストレス誘発消化管がんの抑制に重要な働きをしている事が明らかとなった。
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85. 外間 正朗, 岡 素雅子, Julio Leon, 二宮 利治, 本田 裕之, 佐々木 健介, 岩城 徹, 小原 知之, 清原 裕, 中別府 雄作, アルツハイマー病脳における糖尿病関連遺伝子の発現異常とその意義:久山町研究, 第56回歯科基礎医学会学術大会, 2014.09, 世界では認知症患者は2000万人に上り、この数は高齢者人口の急速な増加により2040年までには8000万人を超えると予想されている。全認知症とアルツハイマー病 (AD)の日本の高齢者における割合は、ここ20年間で特に75歳以上で顕著に増加してきた。このため、認知症、特にADに対して効果的な予防戦略を立てることが重要となってきた。この目的を達成するためには、高齢者におけるADを含む認知症の危険因子を理解することが重要である。これまでの研究で、認知症、特にADの発症におけるインスリンと糖代謝の影響が示されている。久山町研究においても、高インスリン血症と高血糖が老人班の形成と強い相関性を持つ事が明らかになっている。
 我々は、AD脳における分子病態を遺伝子発現の変化に注目して明らかにするために、久山町研究に献体された方の死後脳とADモデルマウスの海馬における遺伝子発現プロファイルの比較解析を行った。死後脳の前頭皮質、側頭皮質、海馬から得られたマイクロアレイデータについてAD、脳血管性認知症 (VD)、性別の3要因について分散分析を行ったところ,AD患者の海馬において最も顕著な遺伝子発現プロファイルの変化を認めた。同様の遺伝子発現プロファイルの変化は側頭葉と前頭葉でも認められた。この遺伝子発現プロファイルの変化の程度は,AD特異的な病理変化の程度と平行して海馬>側頭葉>前頭葉の順であった。AD患者とADモデルマウスの海馬における発現変化を比較解析したところ,精神疾患とADに関連する遺伝子群に加えてインスリン産生とインスリン・シグナリングに関与する遺伝子群の発現変化が共通に認められた。このようなAD患者の脳における遺伝子発現プロファイルの変化は末梢の糖尿病や糖代謝障害とは無関係であった。以上の結果は、ADに特有の病態が脳におけるインスリン産生低下とインスリン・シグナリングの異常をもたらすことを意味しており,末梢のインスリン抵抗性や糖尿病はこのようなAD脳におけるインスリン・シグナリングの異常を増悪させる可能性が示唆される。
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86. 鷹野 典子, 大野 みずき, 中別府 雄作, 中津 可道, 續 輝久, Mutyh欠損マウスにおける酸化ストレス誘発発がんおよび突然変異の解析, 日本遺伝学会 第86回大会, 2014.09.
87. 作見 邦彦, 大野 みずき, 福村 龍太郎, 権藤 洋一, 岩﨑 裕貴, 池村 淑道, 續 輝久, 中別府 雄作, DNA酸化損傷修復欠損マウスの継代実験で捉えられた遺伝現象, 日本遺伝学会 第86回大会, 2014.09.
88. 岡 素雅子, 盛 子敬, 中別府 雄作, MUTYHによって開始される塩基除去修復に依存した2つの独立したプログラム細胞死の経路, 日本遺伝学会 第86回大会, 2014.09.
89. Taikai Inoue, Akio Matsumoto, Megumi Yamafuji, Tomoko Tachibana, Yusaku Nakabeppu, Haruaki Nakaya, Mami Noda, Stomach-brain interaction induced by molecular hydrogen in Parkinson’s disease model animal , 第37回日本神経科学大会, 2014.09.
90. Atsuhisa Katogi, Hiroko nomaru, Yoshinori N. Ohnishi, Kunihiko Sakumi, Yusaku Nakabeppu, Analysis of FosbF/F mice expressing only FOSB and vFOSB but not ΔFOSB and Δ2ΔFOSB, 第37回日本神経科学大会, 2014.09, Activator protein-1 (AP-1) transcription factor is composed of JUN family proteins and FOS family proteins. Among Fos family genes, only Fosb gene produces two forms of mature transcripts, Fosb and ΔFosb mRNAs by alternative splicing. By alternative translation initiation, the former encodes full-length FOSB and vFOSB, while the latter encodes ΔFOSB and Δ2ΔFOSB both of which lack the C-terminal 101 amino acids of FOSB. We previously reported that Fosb-null mice show anxiety-like behavior, depressive-like behavior and adult-onset epilepsy, while Fosbd/d mutant mice expressing only ΔFOSB and Δ2ΔFOSB do not show such abnormal behaviors. However, it is still unclear whether FOSB and/or vFOSB have some roles in these abnormal behaviors. To further understand how FOSB and/or ΔFOSB regulate such behaviors, we established FosbF/F mice expressing only full-length Fosb mRNA. By western blotting, we confirmed that only FOSB and vFOSB proteins, which are not detected in Fosbd/d and Fosb-null mice, are detected in whole cell extracts prepared from FosbF/F mouse brains. We next performed a series of behavioral tests including open-field test, elevated plus maze test, repeated forced swim test and home-cage activity measurement. In elevated plus maze test, FosbF/F mice exhibited significantly decreased time spent on an open arm compared with wild-type littermates, as observed in Fosb-null mice. However, the immobility time during forced swim test and spontaneous locomotor activity were not changed compared with wild-type littermates. Moreover, FosbF/F mice did not exhibit adult-onset epilepsy. In summary, FosbF/F mice exhibited anxiety-like behavior, as seen in Fosb-null mice, but not depressive-like behavior nor adult-onset epilepsy. We thus concluded that FOSB and/or vFOSB are enough to suppress depressive-like behavior and adult-onset epilepsy, but not enough to suppress anxiety-like behavior.
91. Zijing Sheng, Yusaku Nakabeppu, Mechanism by which 8-oxoguanine causes dopaminergic neurodegeneration in aged mice, 第37回日本神経科学大会, 2014.09, 8-Oxoguanine, a major oxidized base lesion, has been inferred to be involved in the neurodegenerative diseases. To counteract oxidative damage to nucleic acids, MTH1 hydrolyzes oxidized purine nucleoside triphosphates, thus sanitizing nucleotide pools. OGG1, an 8-oxoguanine DNA glycosylase, prevents buildup of 8-oxoguanine in both nuclear and mitochondrial genomes. Our previous studies showed that MTH1-deficient young mice exhibited a greater accumulation of 8-oxoguanine after MPTP administration (Yamaguchi et al., Cell Death Differ, 2006). Aging is a risk factor for the development and progression of Parkinson’s disease (PD), however, the mechanism by which 8-oxoguanine causes dopamine neurodegeneration in aged mice, has yet to be clarified.
In the present study, first, we observed that expression of MTH1 and OGG1 is abundantly detected in substantia nigra. Then, double-immunodetection with neuronal markers revealed that dopaminergic neurons co-express both MTH1 and OGG1. Furthermore, we show that the MPTP-treated mutant mice lacking MTH1 and OGG1exhibit abnormal behavior compared to wild-type mice. These results strongly suggest that MTH1 and OGG1 contribute to the maintenance of genomic integrity in dopaminergic neurons, and play an important role in PD pathogenesis.
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92. Hiroko Nomaru, Kunihiko Sakumi, Atsuhisa Katogi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Fosb gene products contribute to excitotoxic microglial activation by regulating the expression of complement C5a receptors in microglia, 第37回日本神経科学大会, 2014.09, The Fosb gene encodes subunits of the activator protein-1 transcription factor complex. Two mature mRNAs, Fosb and ΔFosb,encoding full-length FOSB and ΔFOSB proteins respectively, are formed by alternative splicing of FosbmRNA. Fosb products are expressed in several brain regions. Moreover, Fosb-null mice exhibit depressive-like behaviors and adult-onset spontaneous epilepsy, demonstrating important roles in neurological and psychiatric disorders. Study ofFosb products has focused almost exclusively on neurons; their function in glial cells remains to be explored. In this study, we found that microglia express equivalent levels of Fosb and ΔFosb mRNAs to hippocampal neurons and, using microarray analysis, we identified six microglial genes whose expression is dependent on Fosb products. Of these genes, we focused on C5ar1 and C5ar2, which encode receptors for complement C5a. In isolated Fosb-null microglia, chemotactic responsiveness toward the truncated form of C5a was significantly lower than that in wild-type cells. Fosb-null mice were significantly resistant to kainate-induced seizures compared with wild-type mice. C5ar1 mRNA levels and C5aR1 immunoreactivity were increased in wild-type hippocampus 24 hours after kainate administration; however, such induction was significantly reduced in Fosb-null hippocampus. Furthermore, microglial activation after kainate administration was significantly diminished in Fosb-null hippocampus, as shown by significant reductions in CD68 immunoreactivity, morphological change and reduced levels of Il6 and Tnf mRNAs, although no change in the number of Iba-1-positive cells was observed. These findings demonstrate that, under excitotoxicity, Fosb products contribute to a neuroinflammatory response in the hippocampus through regulation of microglial C5ar1 and C5ar2 expression. .
93. 海津 幸子, 奥野 勉, 中別府 雄作, 大平 明弘, DNA塩基除去修復欠損マウスにおける網膜光障害, 第25回眼科酸化ストレス研究会, 2014.07, <目的>活性酸素によるDNAやヌクレオチドの酸化で最も高頻度に生じる酸化塩基「8-オキソグアニン」と「2-ヒドロキシアデニン」の修復・排除には,酸化プリンヌクレオシド三リン酸分解酵素 (MTH1), 8-オキソグアニンDNAグリコシラーゼ (OGG1), アデニン/2-ヒドロキシアデニンDNAグリコシラーゼ(MUTYH)の3つの酵素が不可欠である。OGG1, MUTYHの単独欠損マウス,Ogg1とMUTYHおよびOgg1とMTH1の二重欠損マウスを用い,これらの酵素の欠損がマウスの網膜光障害に対してどのような影響を与えるか調べた。
<方法>OGG1ノックアウト(KO)マウス,Mutyh KOマウス,Ogg1/Mth1 ダブル(D)KOマウス,およびOgg1/Mutyh DKOマウス(いずれも雌雄混合)を使用した。コントロール群としては野生型マウスであるC57BL6/J(日本クレア)を使用した。マウスは明期12時間(約30ルクス),暗期12時間の環境で飼育した後,約6~7週齢の段階で実験に供した。照射光の波長は350~385 nm とし、網膜への照射エネルギー量が75 J/cm2となるように照射時間を調節した。また,照射は麻酔下で行い,左眼のみに照射を行った。右眼は対照眼として遮蔽して光が当たらないようにした。照射後1週間目に網膜電図(ERG)の測定を行い,網膜の機能評価を行った。ERGを測定した後、眼球を摘出して厚さ4μmのパラフィン切片を作成してHE染色を行った。視神経乳頭を中心に上下10ヶ所の外顆粒層(ONL)の厚さを測定(ImageJ 1.32, National Institute of Health, Bethesda, MD)して網膜の構造を評価した。
<結果>Mutyh KO群のa-waveは未照射眼と比較して有意差が無く,また,a-waveとb-wave共にコントロール群であるC57BL6/J群よりも振幅の減弱が有意に少なかった。外顆粒層(ONL)は光照射によって全ての群で薄くなっていた。特に,視神経乳頭に近い部分で顕著であり、下方よりも上方でONLが薄くなっていた。しかし,Mutyh KO群では下方ではONLの厚さは対照眼とほぼ同程度に維持されており,上方の菲薄化も他の群と比較すると軽度であった。
<結論>MUTYH KO群では、完全ではないものの網膜光障害が抑制されており,網膜光障害の発生にMutyhが深く関与している事が明らかとなった。
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94. 岡 素雅子, 康 東天, 中別府 雄作, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in a mouse model of Alzheimer's disease, 変異機構研究会 第27回夏の学校, 2014.06.
95. Yusaku Nakabeppu, Mizuki Ohno, Ryutaro Fukumura, Yuki Iwasaki, Toshimichi Ikemura, Yoichi Gondo, Kunihiko Sakumi, Oxidation of nucleic acids and control mechanisms of genetic diversity in mammals, International Symposium on Germline Mutagenesis and Biodiversification, 2014.03, For living organisms, the most fundamental biological function is maintaining the integrity of their genomic DNAs harboring the genetic information and transmitting them precisely from cell to cell, as well as from parents to their offspring. The genomic DNA and its precursor nucleotides are always in danger of oxidation by reactive oxygen species (ROS) which are generated both as byproducts of oxidative metabolism and as a consequence of exposure to pathogens, ionizing radiation, chemicals and other environmental factors. Increased accumulation of oxidized bases in genomic DNAs of somatic cells may cause mutations resulting in cancer, while non-lethal mutations in germ lineage cells may cause genetic disorders or result in genetic polymorphisms in populations of sexually reproductive organisms and are thus regarded as a driving force of evolution. Among the four nucleobases, guanine is the most susceptible to oxidation, and its simple oxidized form, 8-oxoguanine (8-oxoG), is one of the major oxidation products in DNA or nucleotides. It is well known that 8-oxoG is a pre-mutagenic lesion because it can pair with adenine as well as cytosine during DNA replication, and causes G to T or A to C base substitutions. To counteract mutagenic potential of 8-oxoG, human and rodents are equipped with three distinct enzymes, MTH1, OGG1 and MUTYH. MTH1 hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP and pyrophosphate, thus avoiding incorporation of 8-oxoG into DNA. OGG1 and MUTYH are DNA glycosylases excising 8-oxoG opposite cytosine and adenine opposite 8-oxoG in DNA, respectively. To evaluate the influence of 8-oxoG on genetic diversity in mammals, we established mutant mice lacking these three genes, and examined levels of 8-oxoG accumulation in their genomes and spontaneous occurrence of heritable mutations. In comparison to wild-type mice, Mth1/Ogg1/Mutyh triple knockout (TOY-TKO) mice accumulated 2 to 4-fold increased levels of 8-oxoG in the nuclear DNA of gonadal cells. Using exome analyses covering 40.9 Mb of mouse transcribed regions, we found increased frequencies of G to T mutations in offspring of TOY-TKO mice at a rate of 2 × 10-7 mutations/base/generation, which is about 200-fold higher incidence found in normal human population. By tracing each mutated allele in the pedigree, we reproduced the appearance, transmission, fixation and disappearance of the spontaneously generated mutations in TOY-TKO mice. Moreover, we found that accumulation of 8-oxoG in the genome of gonadal cells increase meiotic chromosome recombination, thus further enhancing the genomic diversity.
References:
1. Ohno, M., Miura, T., Furuichi, M., Tominaga, Y., Tsuchimoto, D., Sakumi, K., and Nakabeppu, Y. (2006). A genome-wide distribution of 8-oxoguanine correlates with the preferred regions for recombination and single nucleotide polymorphism in the human genome. Genome Res 16: 567-575.
2. Nakabeppu, Y., Sakumi, K., Sakamoto, K., Tsuchimoto, D., Tsuzuki, T., and Nakatsu, Y. (2006). Mutagenesis and carcinogenesis caused by the oxidation of nucleic acids. Biological Chemistry 387: 373-379..
96. Zijing Sheng, Sugako Oka, Yasuhiro Ikeda, Margherita Bignami, Yusaku nakabeppu, 8-oxo-dGTP generated in nucleotide pools is a major cause of neurodegeneration under oxidative stress, International symposium "New Frontier of Molecular Neuropathology 2014", 2014.03, Mitochondrial dysfunction and microglial activation are involved in neurodegeneration, and are related to oxidative stress. Activation of calpain, PARP and AIF is known to be involved in various neurodegenerative diseases such as Alzheimer’s disease in which 8-oxoguanine, a major oxidized lesion in DNA, is accumulated in cellular DNA. We demonstrated that accumulation of 8-oxoguanine in mitochondrial DNA of neurons causes calpain-dependent neuronal loss, while its accumulation in nuclear DNA of microglia causes PARP-dependent activation of AIF, resulting in microgliosis. Moreover, we demonstrated that 8-oxoguanine in cellular DNA is primarily derived from 8-oxo-dGTP generated in nucleotide pools under oxidative stress..
97. 大野 みずき, 作見 邦彦, 福村 龍太郎, 岩崎 裕貴, 池村 淑道, 續 輝久, 権藤 洋一, 中別府 雄作, 8-Oxoguanine causes spontaneous de novo germline mutations : a study from the mutator mouse line, SMBE Satellite Meeting / NIG International Symposium: The Causes of Genome Evolution, 2014.03, Spontaneous germline mutation (GM) generates genetic variation and is regarded as a driving force of molecular evolution. Elucidation of the causes and mechanisms of spontaneous GM may bring us closer to a better understanding of genome evolution in mammal.
We focus on the oxidative DNA lesions as an endogenous cause of spontaneous GM in mammals. Among the four bases, guanine is the most susceptible to oxidation, and 8-oxoguanine (8-oxoG) is a major form of oxidized guanine, which is spontaneously and constantly generated by reactive oxygen species in vivo. 8-OxoG is known as a potent pre-mutagenic lesion, because it can pair with adenine as well as cytosine during DNA replication and cause a G:C to T:A transversion mutation. In E. coli, inactivation of any of the genes; MutM, MutT, and MutY, in the system for preventing 8-oxoG-induced mutation leads to a mutator phenotype.
To assess the contribution of 8-oxoG in de novo spontaneous GM in mouse, we generated Mth1/Ogg1/ Mutyh triple knockout (TOY-KO) mouse deficient in 8-oxoG-induced mutation avoidance system. To expect the accumulation of GMs in the progeny, TOY-KO mice were maintained by the intragenerational cross until generation eighth. In this mouse line, we found higher tumor incidence and shorter life span than the control. Moreover, as generation proceeded, we observed the decreased litter size and increased frequency of congenital phenotypic abnormality. By whole exome sequencing analysis, we successfully detected accumulated GMs in the offspring’s genome, which occurred in the mice in ancestral generations.
It's notable that most of mutations were G to T transversion, which were caused by 8-oxoG. The mutation rate per generation was increased approximately 18-fold in this mutator mouse line. These results suggest that 8-oxoG potentially induces de novo spontaneous GMs, and its repair system is effectively suppressing those mutations in wild-type animals to maintain their genome and phenotype stable.
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98. Hiroko Nomaru, Kunihiko Sakumi, Atsuhisa Katogi, Yoshinori N Ohnishisi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Microglial activation by Fosb Gene, International Symposium between Kyushu University Post-Global Centers of Excellence Program and School of Biomedical Sciences, Monash University, Melbourne, Australia, 2014.02, The Fosb gene encodes subunits of the activator protein-1 transcription factor complex. Two types of mature mRNA, Fosb and ∆Fosb encoding full-length FOSB and ∆FOSB proteins, respectively, are formed by alternative splicing of the Fosb gene. Fosb products are expressed in several brain regions. Moreover, Fosb-null mice exhibit depressive-like behaviors and altered seizure activity, demonstrating their important roles in neurological and psychiatric disorders. Study of Fosb products has focused almost on neurons; their function in glial cells remains to be explored. In this study, we found that microglia express equivalent levels of Fosb and ∆Fosb mRNAs as hippocampal neurons, and identified six microglial genes whose expression is dependent on Fosb products using microarray analysis. Of these genes, we focused on C5ar1 and C5ar2, which encode receptors for complement C5a. In isolated Fosb-null microglia, chemotactic responsiveness toward the truncated form of C5a and levels of C5ar1 and C5ar2 mRNAs were significantly lower than those in wild-type. Fosb-null mice were significantly resistant to kainate-induced seizures compared with wild-type. Twenty-four hours after kainate administration, C5ar1 mRNA levels were increased more than eightfold, with increased C5aR1 immunoreactivity, in wild-type hippocampus; however, such induction was significantly diminished in Fosb-null hippocampus. Furthermore, microglial activation after kainate administration was significantly diminished in Fosb-null hippocampus. These findings demonstrate that Fosb products are required for inducing a neuroinflammatory response in hippocampus through the regulation of C5ar1 and C5ar2 expression in microglia..
99. Yasuto Yoneshima, Daisuke Tsuchimoto, Nona Abolhassani, Teruaki Iyama, Kunihiko SakumiI, Naoko Shiomi, Masahiko Mori, Tadahiro Shiomi, Yusaku Nakabeppu, Accumulation of deoxyinosine triphosphate induces mismatch repair-dependent cell growth arrest and instability of genomic DNA, International Symposium between Kyushu University Post-Global Centers of Excellence Program and School of Biomedical Sciences, Monash University, Melbourne, Australia, 2014.02, DNA damage is known to cause genome instability or cellular dysfunction, thus resulting in various disorders. We have demonstrated that damaged nucleotides generated in nucleotide pools, which are incorporated into DNA through DNA replication, are major sources of DNA damage. To minimize incorporation of damaged nucleotides into DNA, organisms are equipped with specific enzymes hydrolyzing such deleterious nucleotides. Deoxyinosine triphosphate (dITP) is a damaged nucleotide generated by oxidative deamination of dATP. We previously reported that inosine triphosphatase (ITPA) and nudix (nucleoside diphosphate linked moiety X)-type motif 16 (NUDT16) hydrolyze dITP or dIDP to dIMP in mammalian cells, and their deficiency causes cell growth arrest (1, 2). In the present study, we analyzed roles of repair systems for DNA containing deoxyinosine (dI) in the cell growth arrest caused by deficiency in ITPA or NUDT16. We found that knock-down of MLH1, an essential gene for DNA mismatch repair (MMR) system, efficiently suppressed the cell growth arrest and the accumulation of single-strand breaks caused by knock-down of NUDT16 in HeLa MR cells. Although MLH1-deficient HCT116 cells did not show any abnormal growth after knock-down of ITPA, H414 cells, which were established by knock-in of wild-type MLH1 allele into the HCT116 cells, again exhibited cell growth arrest after knock-down of ITPA, accompanied by increased single-stranded DNA breaks. We then performed electrophoresis gel mobility shift assay using double-stranded oligo-DNA containing dI and nuclear extract of HeLa MR or H414 cells. Only oligo-DNA containing dI:deoxyguanosine (dG) pair showed a shifted band, which was specifically disappeared in the presence of anti-MSH6 antibody. In summary, these results suggest that MMR complex may recognize dI:dG pairs in DNA, which are generated by replication-dependent incorporation of dITP accumulated in the nucleotide pool, and subsequently incise DNA during the repair process, thus inducing cell growth arrest.

(References)
(1) N. Abolhassani, Nucleic Acids Res. (2010) 38, p2891-2903
(2) T. Iyama, Nucleic Acids Res. (2010) 38, p4834-4843.
100. 中別府 雄作, 大野 みずき, 作見 邦彦, Oxidation of nucleic acids by reactive oxygen species and control mechanisms of genetic diversity in mammals, International Symposium between Kyushu University Post-Global Centers of Excellence Program and School of Biomedical Sciences, Monash University, 2014.02, For living organisms, the most fundamental biological function is maintaining the integrity of their genomic DNAs harboring the genetic information and transmitting them precisely from cell to cell, as well as from parents to their offspring. The genomic DNA and its precursor nucleotides are always in danger of oxidation by reactive oxygen species (ROS) which are generated both as byproducts of oxidative metabolism and as a consequence of exposure to pathogens, ionizing radiation, chemicals and other environmental factors. Increased accumulation of oxidized bases in genomic DNAs of somatic cells may cause mutations resulting in cancer, while non-lethal mutations in germ lineage cells may cause genetic disorders or result in genetic polymorphisms in populations of sexually reproductive organisms and are thus regarded as a driving force of evolution.
Among the four nucleobases, guanine is the most susceptible to oxidation, and its simple oxidized form, 8-oxoguanine (8-oxoG), is one of the major oxidation products in DNA or nucleotides. It is well known that 8-oxoG is a pre-mutagenic lesion because it can pair with adenine as well as cytosine during DNA replication, and causes G to T or A to C base substitutions. To counteract mutagenic potential of 8-oxoG, human and rodents are equipped with three distinct enzymes, MTH1, OGG1 and MUTYH. MTH1 hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP and pyrophosphate, thus avoiding incorporation of 8-oxoG into DNA. OGG1 and MUTYH are DNA glycosylases excising 8-oxoG opposite cytosine and adenine opposite 8-oxoG in DNA, respectively.
To evaluate the influence of 8-oxoG on genetic diversity in mammals, we established mutant mice lacking these three genes, and examined levels of 8-oxoG accumulation in their genomes and spontaneous occurrence of heritable mutations. In comparison to wild-type mice, Mth1/Ogg1/Mutyh triple knockout (TOY-TKO) mice accumulated 2 to 4-fold increased levels of 8-oxoG in the nuclear DNA of gonadal cells. Using exome analyses covering 40.9 Mb of mouse transcribed regions, we found increased frequencies of G to T mutations in offspring of TOY-TKO mice at a rate of 2 × 10-7 mutations/base/generation, which is about 200-fold higher incidence found in normal human population. By tracing each mutated allele in the pedigree, we reproduced the appearance, transmission, fixation and disappearance of the spontaneously generated mutations in TOY-TKO mice. Moreover, we found that accumulation of 8-oxoG in the genome of gonadal cells increase meiotic chromosome recombination, thus further enhancing the genomic diversity.

(References)
(1) Ohno, M., Miura, T., Furuichi, M., Tominaga, Y., Tsuchimoto, D., Sakumi, K., and Nakabeppu, Y. (2006). A genome-wide distribution of 8-oxoguanine correlates with the preferred regions for recombination and single nucleotide polymorphism in the human genome. Genome Res 16: 567-575.
(2) Nakabeppu, Y., Sakumi, K., Sakamoto, K., Tsuchimoto, D., Tsuzuki, T., and Nakatsu, Y. (2006). Mutagenesis and carcinogenesis caused by the oxidation of nucleic acids. Biological chemistry 387: 373-379..
101. Masaaki Hokama, Sugako Oka, Julio Leon, Toshiharu Ninomiya, Hiroyuki Honda, Kensuke Sasaki, Toru Iwaki, Tomoyuki Ohara, Yutaka Kiyohara, Yusaku Nakabeppu, アルツハイマー病脳における糖尿病関連遺伝子の発現異常:久山町研究, 第18回 日本神経精神医学会, 2013.12, 世界では認知症患者は2000万人に上り、この数は高齢者人口の急速な増加により2040年までには8000万人を超えると予想されている。全認知症とアルツハイマー病 (AD)の日本の高齢者における割合は、ここ20年間で特に75歳以上で顕著に増加してきた。このため、認知症、特にADに対して効果的な予防戦略を立てることが重要となってきた。この目的を達成するためには、高齢者におけるADを含む認知症の危険因子を理解することが重要である。これまでの研究で、認知症、特にADの発症におけるインスリンと糖代謝の影響が示されている。久山町研究においても、高インスリン血症と高血糖が老人班の形成と強い相関性を持つ事が明らかになっている。
 我々は、AD脳における分子病態を遺伝子発現の変化に注目して明らかにするために、久山町研究に献体された方の死後脳とADモデルマウスの海馬における遺伝子発現プロファイルの比較解析を行った。死後脳の前頭皮質、側頭皮質、海馬から得られたマイクロアレイデータについてAD、脳血管性認知症 (VD)、性別の3要因について分散分析を行ったところ,AD患者の海馬において最も顕著な遺伝子発現プロファイルの変化を認めた。同様の遺伝子発現プロファイルの変化は側頭葉と前頭葉でも認められた。この遺伝子発現プロファイルの変化の程度は,AD特異的な病理変化の程度と平行して海馬>側頭葉>前頭葉の順であった。AD患者とADモデルマウスの海馬における発現変化を比較解析したところ,精神疾患とADに関連する遺伝子群に加えてインスリン産生とインスリンシグナリングに関与する遺伝子群の発現変化が共通に認められた。このようなAD患者の脳における遺伝子発現プロファイルの変化は末梢の糖尿病や糖代謝障害とは無関係であった。以上の結果は、ADに特有の病態が脳におけるインスリン産生低下とインスリンシグナリングの異常をもたらすことを意味しており,末梢のインスリン抵抗性や糖尿病はこのようなAD脳におけるインスリンシグナリングの異常を増悪させる可能性が示唆される。
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102. 能丸 寛子, 作見 邦彦, 加藤木 敦央, 大西 克典, 梶谷 康介, 土本 大介, Eric J. Nestler, 中別府 雄作, Fosb遺伝子産物は補体C5aレセプターの遺伝子発現を制御することにより、ミクログリアの活性化に寄与している, 第36回日本分子生物学会, 2013.12.
103. 大野 みずき, 中津 可道, 中別府 雄作, 續 輝久, 酸化DNA損傷と消化管がん, 第36回日本分子生物学会, 2013.12.
104. 岡 素雅子, Julio Leon, 外間 正朗, 加藤木 敦央, 作見 邦彦, 井手 友美, Dongchon Kang, 中別府 雄作, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in Alzheimer's disease model mice, 第36回日本分子生物学会, 2013.12.
105. 米嶋 康臣, 土本 大介, 外間 正朗, Nona Abolhassani, 猪山 輝昭, 作見 邦彦, 塩見 尚子, 森 雅彦, 塩見 忠博, 中別府 雄作, デオキシイノシン三リン酸の蓄積はミスマッチ修復機構に依存した細胞増殖抑制とゲノム不安定性を引き起こす, 第36回日本分子生物学会, 2013.12.
106. Erika Castillo, Julio Leon, 秋本 頼子, 作見 邦彦, 岡 素雅子, 土本 大介, 中別府 雄作, Cytotoxic effects of X-ray irradiation on proliferating and differentiated human neuroblastoma cell line SH-SY5Y, and their modulation by BDNF and inhibitors for CDK5 and calpains, 第36回日本分子生物学会, 2013.12.
107. Hiroko Nomaru, Kunihiko Sakumi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Fosb gene products regulate expression of C5ar1 and C5l2 genes and microglial activation, The 43rd annual meeting of the Society for Neuroscience, 2013.11.
108. Yuko Kobayakawa, Kunihiko Sakumi, Yusaku Nakabeppu, Dual effects of Galectin-1 in amyotrophic lateral screlosis, The 43rd annual meeting of the Society for Neuroscience, 2013.11.
109. Sugako Oka, Julio Leon, Masaaki Hokama, Atsuhisa Katogi, Kunihiko Sakumi, Dongchon Kang, Yusaku Nakabeppu, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in Alzheimer’s disease model mice, International Symposium on Mitochondria 2013(第13回日本ミトコンドリア学会), 2013.11.
110. Zijing Sheng, Sugako Oka, Yusaku Nakabeppu, MUTYH-dependent neurodegeneration initiated by mitochondrial accumulation of 8-oxoguanine in neurons is efficiently suppressed by MTH1 and OGG1., 10th Conference of the Asian Society of Mitochondrial Research and Medicine (ASMRM) , 2013.11, Oxidative stress is considered to be important in the etiology of several neurodegenerative disorders, and it has been shown that levels of 8-oxoguanine (8-oxoG), one of the major oxidation products in DNA and nucleotides which can pair with adenine as well as cytosine, are significantly increased in mitochondrial DNA as well as nuclear DNA in the brains of patients with Parkinson’s disease (PD), Alzheimer’s disease (AD) and Huntington’s disease (HD) in comparison to control brains. Mammalian cells are equipped with elaborate means of minimizing accumulation of 8-oxoG in DNA. 8-Oxo-2’-deoxyguanosine triphosphatase (8-oxo-dGTPase) encoded by MTH1 hydrolyzes 8-oxo-dGTP to 8-oxo-dGMP and pyrophosphate in nucleotide pools, thereby avoiding incorporation of 8-oxo-dGMP into DNA. 8-OxoG DNA glycosylase encoded by OGG1 excises 8-oxoG paired with cytosine in DNA, while adenine DNA glycosylase encoded by MUTYH removes the adenine inserted opposite 8-oxoG in template DNA during DNA replication, thus preventing mutagenesis. Expression levels of MTH1, OGG1 and MUTYH are also significantly altered in the brains of such patients, suggesting that their altered expression along with accumulation of 8-oxoG in brain cause neurodegeneration; however, how 8-oxoG and these enzymes are associated with the neurodegenerative process is poorly understood.
Here, we show that the mitochondrial inhibitor 3-nitropropionic acid(3-NP)-treated mutant mice lacking MTH1 and/or OGG1 exhibit severe striatal neurodegeneration, while mutant mice lacking both OGG1 and MUTYH are resistant to the neurodegeneration. 8-OxoG accumulated in mitochondrial DNA of neurons caused calpain-dependent neuronal loss, while delayed nuclear 8-oxoG accumulation in microglia caused poly (ADP-ribose) polymerase-dependent activation of apoptosis-inducing factor, thus exacerbating microgliosis. These separate signaling pathways were initiated by accumulation of single-strand breaks (SSBs) in each type of DNA caused by MUTYH. These results demonstrate that 8-oxoG accumulated in nuclear and mitochondrial DNA is differentially involved in neurodegeneration.
Overexpression of human MTH1 in mouse striatum efficiently abrogates 3-NP-induced striatal degeneration accompanied by effective suppression of 8-oxoG accumulation in the striatum. Mth1/Ogg1-DKO mice exhibited the highest susceptibility to the 3-NP-induced striatal degeneration with the highest levels of 8-oxoG in striatal DNAs. These findings indicate that the major source of 8-oxoG accumulated in DNA are 8-oxo-dGTP generated in nucleotide pool; the former is repaired by OGG1 and the latter is hydrolyzed by MTH1. DNA replication is essential for accumulation of 8-oxoG in the respective DNA, and moreover, insertion of adenine opposite 8-oxoG also depends on replication. Neurons are postmitotic and only mitochondrial DNA but not nuclear DNA is always replicated in neurons in order to support energy essential for maintenance of neuronal functions. 8-OxoG is therefore dominantly accumulated in mitochondrial DNA of neurons under oxidative stress, resulting in SSBs accumulation in mitochondrial DNA during MUTYH-initiated base excision repair (BER) of adenine inserted opposite 8-oxoG. While microglia is mitotic, thus 8-oxoG and SSBs accumulated in nuclear DNA dependent on its replication and MUTYH-initiated BER. Thus, replication of the respective DNAs in neurons and microglia determines which of the two separate signaling pathways must be activated upon accumulation of 8-oxoG under oxidative stress.
We now propose that MUTYH-initiated BER may represent a common mechanism shared among various neurodegenerative diseases. Suppression of MUTYH together with inhibition of calpain and PARP in brain may thus be an efficient strategy for protecting brain under conditions of oxidative stress.

Keywords: oxidative damage, nucleotide pool, base excision repair, Huntington’s disease model

Acknowledgements: This work was supported by grants from JSPS KAKENHI Grant numbers 18300124, 19390114, 22221004, and 22501014.
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111. 續 輝久, 大野 みずき, 中津 可道, 中別府 雄作, Oxidative stress-induced tumorigenesis in the small intestine of Mutyh-deficient mice: the effect of low-level exposure, 第72回 日本癌学会学術総会, 2013.10.
112. 岡 素雅子, 中別府 雄作, MUTYH, an adenine DNA glycosylase, mediates p53 tumor suppression via caspase-independent cell death pathway, 第72回 日本癌学会学術総会, 2013.10.
113. 中別府 雄作, 大野 みずき, 作見 邦彦, 活性酸素による核酸の酸化と哺乳動物における遺伝子多様性の制御機構, 日本遺伝学会 第85回大会, 2013.09, 生物にとって、その遺伝情報を担うゲノムDNAを細胞から細胞へ、親から子へと正確に伝え維持することは最も基本的な生物学的機能である。ゲノムDNAやその前駆体であるヌクレオチドは、酸素呼吸の副産物や微生物感染時の殺菌分子として生成される活性酸素に常時曝されており、様々な酸化的化学修飾を受ける。酸化ヌクレオチドはヌクレオチドプールから排除されないとゲノムDNAに蓄積するが、修復系が機能することで常に低いレベルに保たれている。本ワークショップでは、核酸の酸化が哺乳動物の遺伝子多様性にどのように関わるのか、酸化プリンヌクレオチド分解酵素(MTH1)と塩基除去修復酵素(OGG1とMUTYH)に注目して議論する。.
114. 作見 邦彦, 大野 みずき, 福村 龍太郎, 権藤 洋一, 岩崎 裕貴, 池村 淑道, 續 輝久, 中別府 雄作, 酸化DNA 損傷に起因するde novo germline mutationの解析 (II), 日本遺伝学会 第85回大会, 2013.09, 我々は,生殖系列の細胞において8-oxoguanineが修復されずに蓄積すると世代を超えて伝わる突然変異(生殖細胞突然変異)の発生頻度が上昇することを明らかにした(前演題)。この変異は外来の変異原によって誘導されるのではなく,細胞自身が保有する原因によって生じる突然変異であり,自然突然変異に分類される。この変異の発生と伝達の様式を家系図上で解析することで生殖細胞突然変異が発生する時期を推定した。生殖細胞突然変異は体細胞突然変異の一種であり,発生の初期,あるいは生殖細胞に分化が決定したあとなど,さまざまな時期に発生していると考えられる。.
115. 大野 みずき, 作見 邦彦, 福村 龍太郎, 権藤 洋一, 岩崎 裕貴, 池村 淑道, 續 輝久, 中別府 雄作, 酸化DNA 損傷に起因するde novo germline mutationの解析 , 日本遺伝学会 第85回大会, 2013.09, 生殖細胞系列に生じた突然変異は次世代以降に伝わる可能性があり遺伝的多様性を増しゲノム進化の原動力になっている。我々は酸化DNA損傷が生殖細胞系列の自然突然変異に及ぼす影響を解析する目的で、その修復に関与する遺伝子群の欠損マウスを作製し世代内交配により各世代で生じた変異を蓄積させた家系を作製した。世代の進んだ個体を選択して全エクソーム解析を行いこの家系で生じた変異を解析したところ、突然変異頻度は野生型に比較して約18倍に上昇していた。この結果は酸化DNA損傷は通常の生活環境下でも恒常的に発生しており、その修復機構が機能することで生殖細胞系列の突然変異頻度を低下させていることが示された。.
116. 中別府 雄作, SOD1G93AトランスジェニックALSモデルマウスにおけるgalectin-1の発現, 包括的脳科学研究推進支援ネットワーク 平成25 年度 夏のワークショップ, 2013.09, 筋萎縮性側索硬化症(ALS)患者の剖検例において脊髄運動神経の腫大部にニューロフィラメントの凝集体とともにガラクトース結合レクチンの1つであるgalectin-1の過剰な蓄積が報告されている。Galectin-1は還元的な環境下ではホモダイマーとして細胞増殖,細胞接着,腫瘍転移,T細胞のアポトーシス誘導に関わるが,酸化的な環境下ではシステイン残基の酸化によりモノマーの酸化型Galectin-1に変換される。酸化型galectin-1は神経の軸索再生を促進する活性を有し、ALSモデルマウスへの長期投与により運動神経変性を抑制することが報告されているが,内在性のgalectin-1がALSの発症にどのように関わるのかこれまで全く報告がない。
 我々は,転写因子をコードするfosB遺伝子の研究を進める過程でgalectin-1の発現がfosBの下流で制御されることを見出し,fosBによる細胞増殖やアポトーシス誘導にgalectin-1が関わることを報告し,さらにアミノ末端の6アミノ酸を欠くバリアントgalectin-1βの存在を報告した。Galectin-1βは酸化還元状態に関わらずモノマーで存在し,全長の酸化型galectin-1αと同等の神経軸索再生能を有する。さらに,ラットとマウス脳における発現解析から,galectin-1は海馬歯状回の神経前駆細胞とアストロサイトに発現し,ストレス下に誘導される海馬歯状回における神経新生を促進的に制御することを明らかにした。
 今回我々は、ALSの発症におけるgalectin-1の関与を明らかにする目的で,SOD1G93Aトランスジェニックマウスにおけるgalectin-1の発現と局在を解析し,以下の事実を見出した。
① SOD1G93Aトランスジェニックマウスでは,運動機能失調の発症以前より脊髄運動神経軸索の腫大部にgalectin-1がニューロフィラメントとともに過剰に蓄積した凝集体からなるニューロスフェロイド(axonal spheroid)が確認された。この知見は,ALS患者の脊髄運動神経のニューロスフェロイドに認められるgalectin-1の過剰蓄積が,SOD1G93AトランスジェニックALSモデルマウスで再現されるALSに普遍的な病理変化であることを世界で初めて明らかにしたものである。
② 運動神経変性の進行期には軸索周囲に増生したアストロサイトにgalectin-1の高発現を認めた。
 現在、SOD1G93Aトランスジェニックマウスにおけるgalectin-1欠損の影響を詳細に解析を進めている。.
117. 中別府 雄作, 外間 正朗, 岡 素雅子, Julio Leon, 二宮 利治, 本田 裕之, 佐々木 健介, 岩城 徹, 小原 知之, Frank M. LaFerla, 清原 裕, Altered Expression of Diabetes-Related Genes in Alzheimer's Disease Brains: The Hisayama Study, 包括的脳科学研究推進支援ネットワーク 平成25 年度 夏のワークショップ, 2013.08, Diabetes mellitus (DM) is considered to be a risk factor for dementia including Alzheimer's disease (AD). However, the molecular mechanism underlying this risk is not well understood. We examined gene expression profiles in postmortem human brains donated for the Hisayama study. Three-way analysis of variance of microarray data from frontal cortex, temporal cortex, and hippocampus was performed with the presence/absence of AD and vascular dementia, and sex, as factors. Comparative analyses of expression changes in the brains of AD patients and a mouse model of AD were also performed. Relevant changes in gene expression identified by microarray analysis were validated by quantitative real-time reverse-transcription polymerase chain reaction and western blotting. The hippocampi of AD brains showed the most significant alteration in gene expression profile. Genes involved in noninsulin-dependent DM and obesity were significantly altered in both AD brains and the AD mouse model, as were genes related to psychiatric disorders and AD. The alterations in the expression profiles of DM-related genes in AD brains were independent of peripheral DM-related abnormalities. These results indicate that altered expression of genes related to DM in AD brains is a result of AD pathology, which may thereby be exacerbated by peripheral insulin resistance or DM..
118. Sugako Oka, Dongchon Kang, Yusaku Nakabeppu, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in Alzheimer’s disease model mice, 2013 Alzheimer's Association International Conference, 2013.07, Mitochondrial dysfunction are is considered to have a pivotal role for developing Alzheimer's disease (AD). It has been reported that amyloid β (Aβ) accumulated in cytoplasm induce mitochondrial dysfunction and ROS production by interacting with amyloid Aβ-binding alcohol dehydrogenase, mitochondrial matrix components. We It previously has been reported that 8-oxoguanine (8-oxoG), one of the major oxidation products in DNA/RNA and nucleotides, accumulates in mitochondrial DNA of AD brain neurons. Oxidative DNA damage especially in mitochondrial DNA can lead to synaptic dysfunction and neuronal cell deathloss, and synaptic dysfunction, and thereby may causecausing neurodegenation. In the present study, we examined the effects of human mitochondrial transcriptional factor A (hTFAM) overexpressiontransgene on the pathology of AD a mouse model of AD mice (3xTg-AD) harboring PS1M146V, APP(Swe), and tauP301L transgenes. TFAM is now known to contribute not only in the replication transcription of mitochondrial DNA but also its maintenance of mitochondrial DNA, and thus protecting DNA mitochondria from oxidative stress. In the Morris Water Maze test, 13-month-old 3xTg-AD hemizygous mice carrying hemizygous hTFAM transgeneTg mice exhibited significantly improvement of learning and memory deficit compared to 3xTgAD hemizygous mice without the hTFAM transgene. Accumulation of Aβ was markedly decreased in cerebral cortices and hippocampi of the 3xTg-AD/hTFAM hemizygous mice. The expression of hTFAM suppressed the increase of the signal against anti-8-oxoG observed in cerebral cortex, hippocampi of 3xTgAD mice. Moreover, 3xTg-AD/hTFAM hemizygous mice exhibited much less 8-oxo-dG immunoreactivity in cerebral cortices and hippocampi in comparison to 3xTgAD hemizygous mice which accumulated higher level of 8-oxo-dG in axonal mitochondria. To clarify the mechanism of improvement of AD phenotype by hTFAM, we are currently performing gene expression profiling using hippocampal RNA prepared from these animals. These results will provide the new insight to understand the molecular mechanisms of AD pathology and possible new strategies for the therapy of AD..
119. Yoriko Akimoto, Sugako Oka, Julio Leon, Yusaku Nakabeppu, Quantitative detection of oxidative DNA damage in brains of the triple transgenic Alzheimer’s disease mouse model, 2013 Alzheimer's Association International Conference, 2013.07, Modified nucleotides are known to cause various biological effects (e.g. cancer, neurodegenerative diseases). 8-oxo-guanine and 8-oxo-adenine are major oxidized products of guanine and adenine, respectively. These modified nucleobases can lead to mutations, altered protein synthesis, or cell death. 8-oxo-guanine is known to pair with adenine and cytosine, thus causing GC to TA or AT to CG transversion mutations. 8-oxo-adenine can form a base pair with cytosine or guanine, thereby it may cause AT to GC transition and AT to CG transversion mutation, respectively. It has been reported that these major oxidized lesions are highly accumulated in the postmortem brain tissues of Alzheimer’s disease patients. In the present study, we focused on the accumulation of 8-oxo-deoxyadenosine and 8-oxo-deoxyguanosine in brains of the triple-transgenic Alzheimer’s disease mouse model (3xTg-AD). Prior to the quantification, we prepared and purified 13C, 15N-labeled 8-oxo-deoxyadenosine as an internal control. We previously found that 8-oxo-deoxyadenosine was effectively generated by X-ray irradiation. 13C, 15N-labeled deoxyadenosine was exposed to X-rays and then 13C, 15N-labeled 8-oxo-deoxyadenosine was separated and purified by HPLC. DNA samples were prepared from hippocampi, cerebral cortices, cerebelli, brain stems and striata of over 100-weeks old non-transgenic control mice and 3xTg-AD homozygous (3xTg-AD-H) mice harboring PS1M146V, APP(Swe), and tauP301L transgenes. The absolute levels of 8-oxo-deoxyadenosine and 8-oxo-deoxyguanosine in each brain region were determined by LC-MS/MS analysis using the stable isotope-labeled internal standards. These results will provide the new insight to understand the mechanisms in the pathogenesis of the Alzheimer’s disease with a mouse model. .
120. 中別府 雄作, 岡 素雅子, SHENG ZIJING, 土本 大介, 作見 邦彦, 核酸損傷と生体防御, 第124回 日本生体防御学会学術集会, 2013.07, 生物にとって,その遺伝情報を担うゲノムDNAを細胞から細胞へ,親から子へと正確に伝え維持することは最も基本的な生物学的機能である。しかしながら,ゲノムDNAやその前駆体であるヌクレオチドは,酸素呼吸の副産物,さらに生体防御あるいはシグナル分子として生体が生成する活性酸素および活性窒素などの活性分子種によって化学修飾を受ける危険に常に曝されている。活性分子種に曝されたDNAやヌクレオチドプール中には酸化,脱アミノ化,ニトロ化など多様な化学修飾を受けたヌクレオチドが生じるが,このような修飾ヌクレオチドは修復・除去されないと突然変異を引き起こすことで細胞のがん化の原因となり,あるいは細胞死をひき起こすことで多くの変性疾患の原因となる。ヒトを始めとする哺乳動物の細胞では,その主要な遺伝情報を格納している核に加えてミトコンドリアもゲノムDNAを持つ。ミトコンドリアは生命活動に不可欠なエネルギーを酸素呼吸により産生するが,ミトコンドリアの呼吸鎖を構成する電子伝達系から漏出した電子は酸素を還元してスーパーオキシドを生成する。スーパーオキシドからは過酸化水素やヒドロキシラジカルなどより反応性の高い活性酸素が生じるため,ミトコンドリアは常に酸化ストレスに曝されている。
 我々はこれまで,ヌクレオチドの修飾体やゲノムDNA中に蓄積した修飾塩基に注目し,そのゲノムDNAへの蓄積を防御する酵素系の研究を進めてきた。その過程で,活性分子種はDNA中の塩基よりも遊離のヌクレオチドの塩基に作用しやすく,様々な修飾ヌクレオチドを生体内で生成することを明らかにした。大腸菌からヒトに至るまでほとんどの生物は,ヌクレオチドプール中で生成された修飾ヌクレオシド三リン酸を積極的に分解・排除するヌクレオチドプール浄化酵素系を備えて,ゲノムDNAやRNAへの異常塩基の蓄積を防いでいる。一方で,このような修飾ヌクレオチドがDNAポリメラーゼの作用でゲノムDNAに取り込まれたり,DNA中の塩基が活性分子種で直接修飾されて生じたゲノムDNA中の修飾塩基は,多様なDNA損傷修復酵素系の働きで除去され常に低いレベルに保たれている。
 遺伝子改変マウスを用いた研究から,ヌクレオチドプール浄化酵素あるいはDNA損傷修復酵素の欠損は自然突然変異率の上昇と自然発がん頻度の上昇をもたらすことが明らかになり,ヒトゲノムの解析からこれらの修復遺伝子の多型や変異と高発がん家系の関係も解明されつつある。我々は,このような遺伝子改変マウスと細胞を用いた解析から,ヌクレオチドプールに蓄積した修飾ヌクレオチドはゲノムDNAに蓄積して突然変異の原因となるだけでなく,細胞内の代謝系やシグナル伝達系などに作用して様々な細胞機能障害をもたらすことを見出した。また,ゲノムDNAに取り込まれた修飾塩基もDNA損傷修復酵素系の働きを介して,細胞増殖の阻害や細胞死を引き起こすことが明らかになった。
 本講演では,突然変異と細胞死,さらに発がんから心不全,神経変性などの個体レベルでの生体障害の発生と抑制に活性分子種による核酸の損傷とその防御機構がどのように関わっているのか,我々の最近の研究成果をもとに紹介する。.
121. 中別府 雄作, 活性分子種による核酸の化学修飾に起因する病態とその防御機構, 老化促進モデルマウス(SAM)研究協議会 第28回 研究発表会, 2013.07, 生物にとって、その遺伝情報を担うゲノムDNAを細胞から細胞へ、親から子へと正確に伝え維持することは最も基本的な生物学的機能である。しかしながら、ゲノムDNAやその前駆体であるヌクレオチドは、酸素呼吸の副産物、さらに生体防御あるいはシグナル分子として生体が生成する活性酸素および活性窒素などの活性分子種によって化学修飾される危険に常に曝されている。活性分子種に曝されたDNAやヌクレオチドプール中には種々の塩基あるいはヌクレオチドの酸化、脱アミノ化、ニトロ化など多様な化学修飾体が生じるが、このような化学修飾体は修復・除去されないと突然変異を引き起こすことで細胞のがん化の原因となり、あるいは細胞死をひき起こすことで多くの変性疾患の原因となる。ヒトを始めとする哺乳動物の細胞では、その主要な遺伝情報を格納している核に加えてミトコンドリアもゲノムDNAを持つ。ミトコンドリアは生命活動に不可欠なエネルギーを酸素呼吸により産生するが、ミトコンドリアの呼吸鎖を構成する電子伝達系から漏出した電子は酸素を還元してスーパーオキシドを生成する。スーパーオキシドからは過酸化水素やヒドロキシラジカルなどより反応性の高い活性酸素が生じるため、ミトコンドリアは常に酸化ストレスに曝されている。
 我々はDNAやヌクレオチドの化学修飾体が引き起こす細胞障害とそれに対する防御機構の解析を進める中で、ゲノムDNA中に蓄積した8-オキソグアニンが突然変異と発がんの原因となるだけでなく、プログラム細胞死を誘導することを見出し、その分子機構の解明を進めてきた。核あるいはミトコンドリアのゲノムDNA中に蓄積した8-オキソグアニンはシグナル分子として特異的なセンサー分子で認識され、様々なエフェクター分子の制御を介してそれぞれ独立した細胞死のプログラムを起動する。我々は最近、このような細胞死のプログムが、神経変性や網膜色素変性に関わることを明らかにした。本講演では8-オキソグアニンのゲノム蓄積に起因する様々な病態とその防御機構について、我々のこれまでの研究成果を紹介する。.
122. Hiroko Nomaru, Kunihiko Sakumi, Noriko Yutsudo, Daisuke Tsuchimoto, Yusaku Nakabeppu, Comprehensive analysis of gene expression regulated by Fosb gene in brain-derived cells, Neuro2013 Joint Conference of: The 36th annual Meeting of the Japan Neuroscience Society The 56th Annual Meeting of the Japanese Society for Neurochemistry The 23rd Annual Meeting of Japanese Neural Network Society, 2013.06, Fosb gene produces two mature transcripts, Fosb and ΔFosb mRNAs by alternative splicing, thus encoding multiple subunits of AP-1 (activator protein-1) transcription factors. ΔFOSB and Δ2ΔFOSB proteins encoded by ΔFosb mRNA lack the C-terminal 101 amino acids of FOSB protein encoded by the Fosb mRNA. It is likely that the Fosb gene products, FOSB, ΔFOSB and Δ2ΔFOSB may differentially modulate the expression of various AP-1 targets. The expression of Fosb is weakly detected in throughout normal brain, especially cerebral cortex and hippocampus, and is highly inducible in response to various brain stimuli. We recently found that Fosb-null mice exhibit depressive behavior and adult-onset epilepsy, while Fosbd/d mutant mice expressing only ΔFOSB and Δ2ΔFOSB exhibit increased locomotor activity.In the present study, we isolated neurons, astrocytes and microglia from cortex and hippocampus and compared the expression levels of Fosb and ΔFosb mRNAs. We found that expression levels of Fosb and ΔFosb mRNAs vary according to types of cells. We then compared gene expression profiles in microglia and astrocytes isolated from wild-type, Fosb-null and Fosbd/d mutant mice by microarray analyses. Among the three mouse lines, 8 genes exhibit significantly different expression levels with fold changes greater than 1.5 in microglia, while expression levels of 24 genes are significantly different in astrocytes. It is noteworthy that only Ercc2 exhibits significantly decreased expression in both microglia and astrocytes derived from Fosb-null and Fosbd/d mutant mice in comparison to wild-type mice. Expression levels of 4 genes including C5ar and Gpr77, C5a receptor genes, were significantly decreased in Fosb-null and Fosbd/d microglia but not in Fosb-null and Fosbd/d astrocyte. In summary, Fosb gene products differentially modulate the expression of their targets in different cell types. .
123. Yuko Kobayakawa, Kunihiko Sakumi, Yusaku Nakabeppu, Dual effects of Galectin-1 in amyotrophic lateral sclerosis, Neuro2013 Joint Conference of: The 36th annual Meeting of the Japan Neuroscience Society The 56th Annual Meeting of the Japanese Society for Neurochemistry The 23rd Annual Meeting of Japanese Neural Network Society, 2013.06, Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease which shows progressive muscle weakness associated with degeneration of motor neurons. Its molecular mechanism is still largely unclear. Galectin-1, a member of the β-galactoside-binding lectin family, expresses in various tissues and has multiple functions such as cell proliferation, cell adhesion, tumor metastasis and apoptosis of activated T cell. It has been shown that reduced form of Galectin-1 exists as a homodimer while its oxidized form exists as a monomer, and each form exerts different effects on cells. The oxidized Galectin-1 is known to promote the axonal regeneration after axotomy of peripheral nerve.
It has been reported that Galectin-1 is accumulated in axonal spheroids of spinal cord, in both sporadic and SOD1 mutant familial ALS patients. Additionally, the oxidized Galectin-1 has been shown to be neuroprotective in a mutant SOD1-Tg mouse model of ALS. We thus examined roles of Galectin-1 in the pathogenesis of ALS by cross-breeding the ALS model mice (SOD1G93A) with Galectin-1 null mice (Lgals1-/-).
First, we elucidated the expression pattern of Galectin-1 in SOD1G93A mice. Galectin-1 is accumulated in axonal spheroids long before disease onset. While after the onset, astrocytes around axons of motor neurons express high level of Galectin-1. We then evaluated effects of Galectin-1 knockout in the SOD1G93A mice. SOD1G93A/Lgals1-/- mice exhibit significantly delayed onset of motor dysfunction in comparison to SOD1G93A/Lgals1+/+ mice. However, disease progression was accelerated in SOD1G93A/Lgals1-/- mice after the onset of motor dysfunction, and there was no difference in survival curve between SOD1G93A/Lgals1-/- mice and SOD1G93A/Lgals1+/+ mice.We thus suggest that Galectin-1 accumulated in the axons of motor neurons promotes neuronal degeneration, however, Galectin-1 expressed in astrocytes at the symptomatic stage is neuroprotective. .
124. Zijing Sheng, Yusaku Nakabeppu, Expression of the defense enzymes MTH1, OGG1 and MUTYH against oxidative damage in nucleic acids in the mouse brain, Neuro2013 Joint Conference of: The 36th annual Meeting of the Japan Neuroscience Society The 56th Annual Meeting of the Japanese Society for Neurochemistry The 23rd Annual Meeting of Japanese Neural Network Society, 2013.06, Oxidative DNA damage has been inferred to be involved in the neurodegenerative diseases as well as brain aging. To counteract oxidative damage to nucleic acids, human and rodents are equipped with three defense enzymes, MTH1, OGG1 and MUTYH. MTH1 hydrolyzes oxidized purine nucleoside triphosphates to the monophosphates, thus sanitizing nucleotide pools. OGG1, an 8-oxoguanine DNA glycosylase, prevents buildup of 8-oxoguanine in both nuclear and mitochondrial genomes. MUTYH, an adenine DNA glycosylase, excises adenine opposite 8-oxoguanine and 2-hydroxyadenine opposite guanine. Using knockout mice of each gene, we have shown that MTH1, OGG1, or MUTYH play different roles in various brain regions such as hippocampus, striatum or substantia nigra under increased oxidative stress (Sheng et al., J Clin Invest, 2012; Yamaguchi et al., Cell Death Differ, 2006). However, their expression and distribution in the mouse brain have yet to be inestigated in detail. In the present study, the expression of MTH1, OGG1 and MUTYH proteins in the mouse brain was examined immunohistochemically with light microscopy (LM), laser scanning confocal microscopy (LSCM) and electron microscopy (EM) . First, we observed that expression of MTH1, OGG1 or MUTYH is abundantly detected in various brain regions, including the striatum, hippocampus, and substantia nigra. LSCM confirmed that various neuronal marker-positive cells express MTH1, OGG1 or MUTYH, respectively. Furthermore, EM revealed that immunogold particles for MTH1, OGG1 or MUTYH, are detected in nuclei, cytoplasm, and mitochondria of neurons, respectively. These results strongly suggest that these defense enzymes contribute to the maintenance of nuclear and mitochondrial genomic integrities in neurons, thus may play important roles in protection of brains from oxidative stress. Our results provide important morphological bases for further understanding of functions of these enzymes in the mouse brain..
125. Yoriko Akimoto, Sugako Oka, Yusaku Nakabeppu, Quantitative detection of oxidative DNA damage in brains of the triple transgenic Alzheimer's disease mouse model, Neuro2013 Joint Conference of: The 36th annual Meeting of the Japan Neuroscience Society The 56th Annual Meeting of the Japanese Society for Neurochemistry The 23rd Annual Meeting of Japanese Neural Network Society, 2013.06, Modified nucleotides are known to cause various biological effects (e.g. cancer, neurodegenerative diseases). 8-oxo-guanine and 8-oxo-adenine are major oxidization products of guanine and adenine, respectively. These modified nucleobases can lead to mutations, altered protein synthesis, or cell death. 8-oxo-guanine is known to pair with adenine and cytosine, thus causing GC to TA or AT to CG transversion mutations. 8-oxo-adenine can form a base pair with cytosine or guanine, thereby it may cause AT to GC transition and AT to CG transversion mutation, respectively. It has been reported that these major oxidized lesions are highly accumulated in the postmortem brain tissues of Alzheimer's disease patients. In the present study, we focused on the accumulation of 8-oxo-deoxyadenosine and 8-oxo-deoxyguanosine in brains of the triple-transgenic Alzheimer's disease mouse model (3xTg-AD). Prior to the quantification, we prepared and purified 13C, 15N-labeled 8-oxo-deoxyadenosine as an internal control. We previously found that 8-oxo-deoxyadenosine was effectively generated by X-ray irradiation. 13C, 15N-labeled deoxyadenosine was exposed to X-rays and then 13C, 15N-labeled 8-oxo-deoxyadenosine was separated and purified by HPLC. DNA samples were prepared from hippocampi, cerebral cortices, cerebelli, brain stems and striata of non-transgenic control mice and 3xTg-AD homozygous (3xTg-AD-H) mice harboring PS1M146V, APP(Swe), and tauP301L transgenes,.The absolute levels of 8-oxo-deoxyadenosine and 8-oxo-deoxyguanosine in each brain region were determined by LC-MS/MS analysis using the stable isotope-labeled internal standards..
126. Noriko Yutsudo, Takashi Kamada, Kosuke Kajitani, Hiroko Nomaru, Atsuhisa Katogi, Yoko H. Ohnishi, Yoshinori N. Ohnishi, Kei-ichiro Takase, SAKUMI Kunihiko, Hiroshi Shigeto, Yusaku Nakabeppu, fosB-null mice display impaired adult hippocampal neurogenesis and spontaneous epilepsy with depressive behavior, Neuro2013 Joint Conference of: The 36th annual Meeting of the Japan Neuroscience Society The 56th Annual Meeting of the Japanese Society for Neurochemistry The 23rd Annual Meeting of Japanese Neural Network Society, 2013.06, Patients with epilepsy are at high risk for major depression relative to the general population, and both disorders are associated with changes in adult hippocampal neurogenesis, although the mechanisms underlying disease onset remain unknown. The expression of ΔFosB protein, an alternative splice product of the immediate early gene fosB is known to be induced in neural progenitor cells within the subventricular zone of the lateral ventricles and subgranular zone of the hippocampus following transient forebrain ischemia in the rat brain, and adenovirus-mediated ΔFosB expression can promote neural stem cell proliferation. We recently found that fosB-null mice show increased depressive-like behaviors, thus suggesting impaired neurogenesis in fosB-null mice. We analyzed neurogenesis in the hippocampal dentate gyrus of fosB-null and fosBd/d mice expressing ΔFosB but not FosB, the other alternative splice product of the fosB gene, in comparison with wild-type mice using stereological counting methods, as well as neuropathology, behaviors and gene expression profiles. fosB-null mice but not fosBd/d mice displayed impaired neurogenesis in the adult hippocampus and spontaneous epilepsy. Microarray analysis revealed that genes related to neurogenesis, depression and epilepsy are altered in the hippocampus of fosB-null mice. We therefore concluded that the fosB-null mouse is the first animal model providing a genetic and molecular basis for the comorbidity between depression and epilepsy with abnormal neurogenesis, all of which are caused by loss of a single gene, fosB..
127. Sugako Oka, Dongchon Kang, Yusaku Nakabeppu, Expression of human mitochondrial transcriptional factor A (hTFAM) improves cognitive function in Alzheimer's disease model mice, Neuro2013 Joint Conference of: The 36th annual Meeting of the Japan Neuroscience Society The 56th Annual Meeting of the Japanese Society for Neurochemistry The 23rd Annual Meeting of Japanese Neural Network Society, 2013.06, Mitochondrial dysfunction is considered to have a pivotal role for developing Alzheimer's disease (AD). It has been reported that amyloid β (Aβ) accumulated in cytoplasm induce mitochondrial dysfunction and ROS production by interacting with Aβ-binding alcohol dehydrogenase, mitochondrial matrix components. It has been reported that 8-oxoguanine (8-oxoG), one of the major oxidation products in DNA/RNA and nucleotides, accumulates in AD brain. Oxidative DNA damage especially in mitochondrial DNA can lead to synaptic dysfunction and neuronal loss, and thereby causing neurodegenation. In the present study, we examined effects of human mitochondrial transcriptional factor A (hTFAM) transgene on the pathology of a mouse model of AD (3xTg-AD) harboring PS1M146V, APP(Swe), and tauP301L transgenes. TFAM is now known to contribute not only in transcription of mitochondrial DNA but also maintenance of mitochondrial DNA, and thus protecting mitochondria from oxidative stress. In the Morris Water Maze test, 13-month-old 3xTg-AD hemizygous mice carrying hemizygous hTFAM transgene exhibited significant improvement of learning and memory deficit compared to 3xTgAD hemizygous mice without the hTFAM transgene. Accumulation of Aβ was markedly decreased in cerebral cortices and hippocampi of the 3xTg-AD/hTFAM hemizygous mice. Moreover, 3xTg-AD/hTFAM hemizygous mice exhibited much less 8-oxo-dG immunoreactivity in cerebral cortices and hippocampi in comparison to 3xTgAD hemizygous mice which accumulated higher level of 8-oxo-dG in axonal mitochondria. To clarify the mechanism of improvement of AD phenotype by hTFAM, we are currently performing gene expression profiling using hippocampal RNA prepared from these animals. These results will provide the new insight to understand the molecular mechanisms of AD pathology and possible new strategies for the therapy of AD..
128. Yusaku Nakabeppu, Quality Control of Nucleotide Pools is Essential for Cellular Homeostasis, Invited seminar at Institute of Molecular Cancer Research University of Zurich, Switzerland, 2013.04.
129. Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, 8-Oxoguanine in brain causes complex neurodegeneration through DNA repair, Gordon research conference on Oxidative Stress & Disease, 2013.04, 8-Oxoguanine (8-oxoG), a common DNA lesion caused by reactive oxygen species, is associated with carcinogenesis and neurodegeneration. Although the mechanism by which 8-oxoG causes carcinogenesis is well understood, the mechanism by which it causes neurodegeneration is unknown. Here, we report that neurodegeneration is triggered by an adenine-DNA glycosylase (MUTYH)-mediated excision repair of 8-oxoG-paired adenine. Mutant mice lacking 8-oxo-2’-deoxyguanosine triphosphatase (MTH1) and/or 8-oxoguanine DNA glycosylase (OGG1) exhibited severe striatal neurodegeneration, whereas mutant mice lacking MUTYH or OGG1/MUTYH were resistant to neurodegeneration under conditions of oxidative stress. These results indicate that OGG1 and MTH1 are protective, while MUTYH promotes neurodegeneration. We observed that 8-oxoG accumulated in the mitochondrial DNA of neurons and caused calpain-dependent neuronal loss, while delayed nuclear accumulation of 8-oxoG in microglia resulted in poly (ADP-ribose) polymerase (PARP)-dependent activation of apoptosis-inducing factor (AIF) and exacerbated microgliosis. These results revealed that neurodegeneration is a complex process caused by 8-oxoG accumulation in the genomes of neurons and microglia. Different signaling pathways were triggered by the accumulation of single-strand breaks in each type of DNA generated during base excision repair initiated by MUTYH, suggesting that suppression of MUTYH may protect the brain under conditions of oxidative stress..
130. Yusaku Nakabeppu, Zijing Sheng, Sugako Oka, Oxidative damage in brain genomes and neuroprotective mechanisms, 第90回日本生理学会大会, 2013.03, 8-Oxoguanine (8-OxoG), a major oxidized base lesion produced by reactive oxygen species, is associated with various pathological conditions including carcinogenesis and neurodegenerative disorders such as Parkinson’s disease and Alzheimer’s disease. Although the mechanism by which 8-oxoG causes carcinogenesis is well understood, the mechanism by which it causes neurodegeneration is unknown. We recently demonstrated that excision repair of adenine inserted opposite 8-oxoG by adenine DNA glycosylase encoded by Mutyh triggers complex neurodegeneration under oxidative stress. Mutant mice lacking 8-oxo-dGTPase encoded by Mth1 and/or 8-oxoG DNA glycosylase encoded by Ogg1 exhibited severe neurodegeneration, whereas mutant mice lacking Mutyh or Ogg1/Mutyh were resistant to neurodegeneration when mitochondrial neurotoxin, 3-nitropropionic acid was administered. These results indicate that OGG1 and MTH1 protect brain while MUTYH promotes neurodegeneration under oxidative stress. 8-OxoG accumulated in mitochondrial DNA of neurons and caused calpain-dependent neuronal loss, while delayed nuclear accumulation of 8-oxoG in microglia resulted in PARP-dependent activation of apoptosis-inducing factor and exacerbated microgliosis. These results reveal that neurodegeneration under oxidative stress is a complex process caused by 8-oxoG accumulation in the genomes of neurons and microglia in the brain. Different signaling pathways were triggered by the accumulation of single-strand breaks in each type of DNA generated during base excision repair initiated by MUTYH..
131. 中別府 雄作, 活性分子種による核酸の化学修飾に起因する病態とその防御機構, 山口大学遺伝子実験施設セミナー , 2013.03.
132. Yusaku Nakabeppu, Quality Control of Nucleotide Pools is Essential for Cellular Homeostasis, Invited seminar at Istituto Superiore di Sanitá, Roma, Italy, 2013.03.
133. Julio Leon, Masaaki Hokama, Sugako Oka, Kunihiko Sakumi, Daisuke Tsuchimoto, Erika Castillo, Yusaku Nakabeppu, Cross-talk between insulin and other growth factors signaling regulate their neuroprotective functions, 11th International Conference on Alzheimer's & Parkinson's Diseases, 2013.03.
134. Yusaku Nakabeppu, Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi , Striatal degeneration initiated by a mitochondrial toxin, 3-nitropropionic acid is dependent on MUTYH-initiated base excision repair of 8-oxoguanine-paired adenine, 11th International Conference on Alzheimer's & Parkinson's Diseases, 2013.03.
135. Kunihiko Sakumi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Control mechanism to maintain the low level of deoxyinosine in DNA, Keystone Symposium on Genomic Instability and DNA Repair (X6), 2013.03.
136. 中別府 雄作, 活性分子種による核酸の化学修飾と生体応答, 長崎大学がんゲノム不安定性研究拠点(NRGIC) 平成24年度第59回大学院セミナー, 2013.01.
137. Yusaku Nakabeppu, Neurodegeneration caused by two distinct signaling pathways dependent on 8-oxoguanine and MUTYH-initiated base excision repair, The 2012 International Symposium on “Signaling Functions of Reactive Oxygen Species”, Grants-in-Aid for Scientific Research on Innovative Areas (Research in a Proposed Research Area), MEXT, Japan, 2012.12, 8-Oxoguanine (8-OxoG), a major oxidized base lesion produced by reactive oxygen species, is associated with various pathological conditions including carcinogenesis and neurodegenerative disorders such as Parkinson’s disease, Huntington’s disease and Alzheimer’s disease. Although the mechanism by which 8-oxoG causes carcinogenesis is well understood, the mechanism by which it causes neurodegeneration is unknown. We recently demonstrated that excision repair of adenine inserted opposite 8-oxoG by adenine DNA glycosylase encoded by Mutyh triggers complex neurodegeneration under oxidative stress. Mutant mice lacking 8-oxo-dGTPase encoded by Mth1 and/or 8-oxoG DNA glycosylase encoded by Ogg1 exhibited severe neurodegeneration, whereas mutant mice lacking Mutyh or Ogg1/Mutyh were resistant to neurodegeneration when mitochondrial neurotoxin, 3-nitropropionic acid was administered. These results indicate that OGG1 and MTH1 protect brain while MUTYH promotes neurodegeneration under oxidative stress. 8-OxoG accumulated in mitochondrial DNA of neurons and caused calpain-dependent neuronal loss, while delayed nuclear accumulation of 8-oxoG in microglia resulted in PARP-dependent activation of apoptosis-inducing factor and exacerbated microgliosis. These results reveal that neurodegeneration under oxidative stress is a complex process caused by 8-oxoG accumulation in the genomes of neurons and microglia in the brain. Different signaling pathways were triggered by the accumulation of single-strand breaks in each type of DNA generated during base excision repair initiated by MUTYH, suggesting that suppression of MUTYH may protect the brain under conditions of oxidative stress..
138. 小早川 優子, 作見 邦彦, 中別府 雄作, 筋萎縮性側索硬化症におけるGalectin-1の病態への関与, 第35回日本分子生物学会年会, 2012.12, 筋萎縮性側索硬化症(amyotrophic lateral sclerosis, ALS)は、運動神経の変性により進行性に全身の筋力が低下し、死に至る神経変性疾患である。その病態には、酸化ストレス、グルタミン酸毒性、軸索輸送障害、ミトコンドリア障害、小胞体ストレスなどが関与することが知られているが、全容は未だ明らかでない。一方Galectin-1は、多くの組織に発現し、細胞増殖、細胞接着、腫瘍転移、T細胞のアポトーシスなどに関与する多機能な分子である。これまでに、弧発性および家族性ALS患者剖検例において、脊髄運動神経のaxonal spheroidにGalectin-1の蓄積を認めることが報告されている。また酸化型Galectin-1は、末梢神経損傷モデルにおいて軸索再生を促進することが知られており、ALSモデルマウスにおいても、酸化型Galectin-1の投与が運動神経変性を抑制したとの報告がある。以上のことからGalectin-1がALSの病態に何らかの関与をすることが考えられるが、その機序は明らかでない。
今回我々は、ALSモデルマウスである変異SOD1 Tgマウス(SOD1G93A)を用い、Galectin-1の病態への関与を検討した。SOD1G93Aマウスでは、発症以前より腫大した運動神経軸索内にGalectin-1が蓄積し、進行期には運動神経軸索周囲のアストロサイトにGalectin-1の発現を認めた。さらにSOD1G93AマウスにおけるGalectin-1 KOの効果を観察したところ、Galectin-1 KOによりSOD1G93Aマウスの筋力低下の出現が遅れた。一方、死亡率の改善は得られなかった。以上より、病初期に運動神経軸索内に蓄積したGalectin-1は運動神経変性を促進するが、進行期におけるアストロサイトでのGalectin-1の発現は、運動神経変性に対し保護的に働いている可能性を考えた。.
139. 能丸寛子、作見邦彦、土本大介、中別府雄作, fosB遺伝子産物によるアナフィラトキシンC5a走化性受容体遺伝子 C5arとGpr77の発現制御機構の解析, 第35回日本分子生物学会年会, 2012.12, 転写因子AP-1(Activator Protein-1) はJun familyとFos familyのタンパク質によって構成されている。fosB遺伝子はFos familyの中で唯一alternative splicingによってfosB mRNAと∆fosB mRNAの2つのmature mRNAをコードする。fosB遺伝子産物の標的遺伝子としてCox-2やMmp-2などが報告されているが、FosBとΔFosBによる遺伝子発現制御機構の全貌は明らかになっていない。現在、fosB遺伝子を完全に欠損するfosB-nullマウスとΔfosB mRNA のみを産生するfosBd/dマウスを樹立している。本研究では、脳組織における免疫担当細胞であるmicrogliaにおいて野生型, fosB-null, fosBd/dマウスから初代培養法によりmicrogliaを単離しfosB遺伝子産物により発現が制御される遺伝子をmicroarrayにより探索した。Fold change≦1.5, ANOVA p<0.05で解析したところ、8遺伝子の発現が変化していることがわかった。このうち、補体C5aの受容体をコードするC5arとGpr77 遺伝子の発現レベルが同様に変化していることからこの2つの遺伝子に注目して解析を行った。野生型microgliaと比較すると、これら2つのmRNAはどちらもfosB-nullとfosBd/d microgliaで減少しており、FosBにより発現が制御されていることが示唆される。このFosB依存性の発現はマウス腹腔マクロファージやRaw blue cell lineでも同様に確認され、C5arとGpr77の発現はマクロファージとミクログリアでfosB遺伝子産物によって同様に制御されていることがわかった。また、ChIP assayにより、C5ar, Gpr77遺伝子のそれぞれの上流にFosB結合領域が存在することが確認された。.
140. 大野 みずき、作見 邦彦、福村 龍太郎、権藤 洋一、田口健一、續輝久、中別府 雄作, 酸化損傷塩基の修復機構を欠損するマウス家系の解析, 第35回日本分子生物学会年会, 2012.12, 放射線や化学物質などの外的要因、あるいは細胞内でのエネルギー産生の副産物としても生じる活性酸素種によってゲノムDNAは恒常的に酸化ストレスに曝されている。グアニンの酸化体である8-オキソグアニン(8-oxoG)はシトシンだけでなくアデニンとも誤対合を形成し塩基置換を引き起こすことが知られているが、大腸菌からヒトまで多くの生物は8-oxoGの影響を効率よく軽減するシステムを有している。マウスではMth1はヌクレオチドプール中の酸化プリンヌクレオチドを分解することでDNA複製の際の8-oxo-dGTPの取り込みを抑制し、Ogg1はシトシンに対合した8-oxoGを除去することでゲノム中に8-oxoGが蓄積することを抑制し、さらにMutyhは鋳型鎖の8-oxoGに対して取り込まれたアデニンを除去することで誤対合の形成を抑制しており、これら3つの経路が協調して働くことで8-oxoGに起因する突然変異の発生頻度を低く抑えている。それぞれの遺伝子の単独欠損マウスは通常の飼育環境下では劇的な表現型を示さないことから、1つの経路が破綻したことによる影響は残りの経路の働きによりオフセットされていると考えられた。そこで今回はほ乳類の体細胞ゲノムおよび生殖細胞ゲノムでの8-oxoGの影響を解析する目的で、Ogg1, Mth1, Muyth三重遺伝子欠損マウスを樹立し家系内交配による繁殖維持を行った。これらのマウスは短命で早期に多臓器発がんを認めた。また出生直後の死亡率が高く二分脊椎などの先天異常も多く認められた。さらに常染色体優性あるいは劣性遺伝形式で種々の変異表現型が出現した。このことは、Ogg1, Mth1, Muythの欠損が体細胞だけでなく生殖細胞ゲノムでの突然変異率を上昇させた結果であると考えられた。家系内の世代の異なるマウス由来のゲノム配列を解析した結果も併せて報告する。.
141. Sugako Oka, Masaaki Hokama, Julio Leon, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Obesity and altered expression of genes related to diabetes mellitus in a transgenic mouse model of Alzheimer's disease, 第35回日本分子生物学会年会, 2012.12, Diabetes mellitus (DM) is considered to be a risk factor for developing Alzheimer's disease (AD). It has been reported that induction of DM in AD model mouse accelerates AD neuropathology and memory dysfunction. Contrary to this, mouse models of AD are likely to be more susceptible to insulin resistance. The relationship between AD and DM is not entirely clear. In this study, we performed gene expression profiling using RNA prepared from the hippocampi of 14-month-old 3xTg-AD homozygous (3xTg-AD-H) mice harboring PS1M146V, APP(Swe), and tauP301L transgenes in comparison to non-Tg. We found that expression of genes relevant to genetic disorders (62 genes) are altered and these genes are subcategorized as genes relevant to bipolar disorder, non-insulin-dependent DM, coronary artery disease, AD, Parkinson’s disease, obesity and others. Among them, expression level of Pcsk, encoding protein convertase subtilisin/kexin type 1, which is essential for proinsulin processing, was significantly decreased. Pcsk1 was placed upstream of insulin in the network along with Ide, encoding insulin degrading enzyme, whose expression was significantly increased. In 15-month old non-Tg brains, PCSK1 immunoreactivity was found in most neurons in the cerebral cortex, hypothalamus and CA2, CA3 hippocampal subregions. In contrast, the expression level was significantly diminished in 3xTg-AD-H brains. Moreover, the mice exhibited increased food intake and obesity on a standard diet. These findings indicate that obesity as well as altered expression of genes related to DM is likely to be a result of AD pathology, which may thereby be exacerbated by peripheral insulin resistance or DM..
142. 大野 みずき、作見 邦彦、福村 龍太郎、権藤 洋一、續輝久、中別府 雄作, 酸化損傷塩基の修復機構は生殖細胞ゲノム変異を抑制し同系交配によるマウスの表現型の安定性に寄与する, 日本環境変異学会第41回大会, 2012.11, 放射線や化学物質などの外的要因、あるいは細胞内でのエネルギー産生の副産物としても生じる活性酸素種によってゲノムDNAは恒常的に酸化ストレスに曝されている。グアニンの酸化体である8-オキソグアニン(8-oxoG)はシトシンだけでなくアデニンとも誤対合を形成し塩基置換を引き起こすことが知られている。我々はほ乳類の生殖細胞ゲノムでの8-oxoGの影響を解析する目的で、Ogg1, Mth1, Muyth三重遺伝子欠損マウスを樹立し家系内交配による繁殖維持を行った。これらのマウスは短命で早期に多臓器発がんを認めた。また出生直後の死亡率が高く二分脊椎などの先天異常も多く認められた。さらに常染色体優性あるいは劣性遺伝形式で種々の変異表現型が出現した。このことは、Ogg1, Mth1, Muythの欠損が体細胞だけでなく生殖細胞ゲノムでの突然変異率を上昇させた結果であると考えられた。家系内の世代の異なるマウス由来のゲノム配列を解析した結果も併せて報告する。.
143. Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi and Yusaku Nakabeppu, 8-Oxoguanine causes complex neurodegeneration in a MUTYH-dependent manner, which can be efficiently suppressed by MTH1 and/or OGG1, The 8th 3R Symposium (International Symposium on DNA Replication, Recombination and Repair), 2012.11, 8-Oxoguanine (8-OxoG), a major oxidized base lesion, is associated with various pathological conditions including carcinogenesis and neurodegeneration. The mechanism by which 8-oxoG causes neurodegeneration remains elusive, although the mutagenic pathway resulting in carcinogenesis is well understood. We report here that excision repair of adenine inserted opposite 8-oxoG by adenine DNA glycosylase encoded by Mutyh triggers complex neurodegeneration. Mutant mice lacking 8-oxo-dGTPase encoded by Mth1 and/or 8-oxoG DNA glycosylase encoded by Ogg1 exhibit severe striatal neurodegeneration, whereas mutant mice lacking Mutyh or Ogg1/Mutyh are resistant to neurodegeneration under conditions of oxidative stress. These results indicate that OGG1 and MTH1 can protect brain while MUTYH promotes neurodegeneration. 8-OxoG accumulated in mitochondrial DNA of neurons caused calpain-dependent neuronal loss, while delayed nuclear accumulation of 8-oxoG in microglia resulted in PARP-dependent activation of apoptosis-inducing factor, thus exacerbating microgliosis. These results reveal that neurodegeneration is a complex process caused by 8-oxoG accumulation in the genomes of neurons and microglia in the brain. Different signaling pathways were triggered by the accumulation of single-strand breaks in each type of DNA generated during base excision repair initiated by MUTYH..
144. Eiko Ohta, Kunihiko Sakumi, Daisuke Tsuchimoto, Yuka Takiguchi, Yusaku Nakabeppu, 2-OH-ATP as a signal molecule for the oxidative stress in mammalian cells, The 8th 3R Symposium (International Symposium on DNA Replication, Recombination and Repair), 2012.11, 2-Hydroxyl-adenosine triphosphate (2-OH-ATP) is one of oxidized forms of ATP generated under oxidative conditions. MTH1 protein, which is encoded by the Mth1 (Nudt1) gene in mouse and possesses an oxidized purine nucleoside triphosphatase activity, most efficiently hydrolyses 2-OH-ATP among known substrates. We have reported that 2-OH-ATP causes a growth arrest of the Mth1-deficient cells. We hypothesize that 2-OH-ATP acts as a signal molecule under the oxidative stress in mammalian cells. In this scenario, ATP, a most abundant nucleotide in cell, functions as a sensor molecule. Using affymetrix GeneChip® Mouse Gene 1.0 ST Array, we demonstrated that 2-OH-adenosine (2-OH-Ado, a precursor of 2-OH-ATP) alters gene expression profile in the Mth1–deficient cells, and the expression of human MTH1 protein suppresses these alterations caused by 2-OH-Ado. Among the genes affected by 2-OH-Ado, we focus on the Ccne genes (genes for cyclin E). By quantitative PCR analysis, we observed that the level of Ccne2 mRNA started to decrease 1.5 hr after 2-OH-Ado administration, and reached about 10% level of the control after 6 hr. The decrease occurred in a p38 MAPK-dependent manner, because it was suppressed by SB203580, an inhibitor of p38 MAPK. The signaling pathway from 2-OH-ATP to the decreased expression of of Ccne mRNA and cell growth arrest is still under investigation. Because ATP is the most abundant nucleotide in cell, and is required for many kinds of biological processes, a contamination of the modified ATP molecule, such as 2-OH-ATP, may result in an alteration of normal cellular processes. 2-OH-ATP is a good candidate for the signal molecule transmitting the intracellular oxidative stress to the p38-MAPK pathway, and thus causing the cell cycle arrest at G1-S boundary, which guarantees a better condition for DNA replication. .
145. Yoriko Akimoto, Yusaku Nakabeppu, Identification and quantification of radiation-induced modified purine nucleosides, The 8th 3R Symposium (International Symposium on DNA Replication, Recombination and Repair), 2012.11, The radiotherapy is widely used as the effective treatment for malignant tumors. For effective radiotherapy, it is an important principle to induce selective death of neoplastic cells, however, it is also essential to consider effects of radiation on normal cells. It has been considered that DNA double-strand breaks are the most important damage resulting in severe radiation injury during the radiotherapy. On the other hand, effects of radiation on nucleotide pools, which supply precursor nucleotides during DNA and RNA synthesis, have not been considered yet, even though radiation can cause various chemical modifications on the nucleotides by radicals produced during radiolysis of water molecules. Modified nucleotides are known to cause various biological effects (e.g. cancer, neurodegenerative diseases), however, it is largely unknown whether those are involved in exerting the radiation-induced biological effects. In the present study, we focused on the effects of X-ray irradiation on purine nucleosides. We identified and quantified radiation-induced modified purine nucleosides using HPLC-PDA (photodiode array detector) and LC-MS/MS methods, and examined dependencies on both X-ray doses and nucleoside concentrations. In addition to known oxidized purine nucleosides, we found many unknown modified nucleosides after X-ray irradiation. We also irradiated DNA solution, which was extracted from mouse liver, and quantified modified nucleosides. We found that free nucleosides were more susceptible to X-ray induced oxidation than were nucleosides in DNA. These results indicate that nucleotide pools are significantly susceptible to X-ray-induced modification, and may be more important targets of radiation than DNA itself..
146. Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi and Yusaku Nakabeppu, 8-Oxoguanine in brain causes complex neurodegeneration through DNA repair, The 9th ASMRM and Chinese Mit'2012, 2012.11.
147. Mizuki Ohno, Kunihiko Sakumi, Teruhisa Tsuzuki, Yusaku Nakabeppu , INFLUENCE OF 8-OXOGUANINE ON MITOTIC AND MEIOTIC CHROMOSOME, The 10th International Symposium on Chromosomal Aberrations, 2012.10, Oxidative stress-induced DNA damage can be a cause of genomic instability. Among the four nucleobases, guanine is the most susceptible to oxidation, and its simple oxidized form, 8-oxoguanine (8-oxoG), is one of the major oxidation products in DNA or nucleotides. It is well known that 8-oxoG is a pre-mutagenic lesion because it can pair with adenine as well as cytosine during DNA replication, and causes a G:C to T:A base substitution. Escherichia coli strains lacking repair activities of 8-oxoG exhibit mutator phenotype and the mice lacking OGG1 (8-oxoG DNA glycosylase, excising 8-oxoG opposite cytosine in DNA) exhibit the accumulation of 8-oxoG in the genome (Sakumi et al, Cancer Res. 2003). However the influence on chromosome aberration of 8-oxoG still remained to be defined..
148. 中別府 雄作、土本 大介、盛 子敬、岡 素雅子、作見 邦彦, 活性酸素による核酸の修飾とゲノム応答の遺伝学, 日本遺伝学会第84回大会, 2012.09.
149. 作見 邦彦、土本 大介、中別府 雄作, 哺乳動物のITP 分解酵素とエンドヌクレアーゼV, 日本遺伝学会第84回大会, 2012.09.
150. 秋本 頼子、中別府 雄作, 放射線照射によって生成されるプリンヌクレオシドの修飾体の同定と定量, 日本遺伝学会第84回大会, 2012.09.
151. Julio Leon, Masaaki Hokama, Sugako Oka, Erika Castillo, Kunihiko Sakumi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Cooperative neuroprotection by insulin and neurotrophic factors, 日本遺伝学会第84回大会, 2012.09.
152. Sugako Oka, Masaaki Hokama, Julio Leon, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Alzheimer’s disease mouse model exhibits altered expression of genes related to diabetes-mellitus with obesity, 日本遺伝学会第84回大会, 2012.09.
153. Erika Castillo, Julio Leon, Yoriko Akimoto, Yasuto Yoneshima, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Cytotoxic eff ects of X-ray irradiation on proliferative and differentiated human neuroblastoma cell line, SH-SY5Y, and modulation by neurotrophic factors and CDK5 inhibitor, 日本遺伝学会第84回大会, 2012.09.
154. 能丸 寛子、作見 邦彦、土本 大介、中別府 雄作, fosB 遺伝子産物によるアナフィラトキシンC5a 走化性受容体遺伝子C5ar とGpr77 の発現制御機構の解析, 日本遺伝学会第84回大会, 2012.09.
155. 大野 みずき、作見 邦彦、福村 龍太郎、権藤 洋一、續輝久、中別府 雄作, 8- オキソグアニンの修復機構を欠損するマウスは、生殖細胞ゲノム中の突然変異頻度の 上昇と遺伝性の変異形質を呈する, 日本遺伝学会第84回大会, 2012.09.
156. 小早川 優子、作見 邦彦、中別府 雄作, 変異SOD1トランスジェニックマウスを用いた、筋萎縮性側索硬化症におけるガレクチン1の病態への関与の検討, 日本遺伝学会第84回大会, 2012.09.
157. 盛 子敬、岡 素雅子、土本 大介、作見 邦彦、中別府 雄作, 酸化ストレスは MUTYH による塩基除去 修復経路を介してcalpain/PARP 依存 性の神経変性を引き起こす, 日本遺伝学会第84回大会, 2012.09.
158. 作見 邦彦、 中別府 雄作, DNA中のデオキシイノシン量を制御するメカニズム, 第71回日本癌学会学術総会, 2012.09.
159. Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Base excision repair by MUTYH initiates calpain/PARP-dependent neurodegeneration under oxidative stress, 第35回日本神経科学大会, 2012.09.
160. Julio Leon, Masaaki Hokama, Sugako Oka, Kunihiko Sakumi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Synergistic interaction between insulin and other growth factors modulates their neuroprotective functions, 第35回日本神経科学大会, 2012.09.
161. Hiroko Nomaru, Noriko Yutsudo, Yusaku Nakabeppu, Comprehensive analysis of gene expression regulated by fosB gene in neuron and glia, 第35回日本神経科学大会, 2012.09.
162. Sugako Oka, Masaaki Hokama, Julio Leon, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Obesity and altered expression of genes related to Diabetes-mellitus in Alzheimer’s disease mouse model , 第35回日本神経科学大会, 2012.09.
163. Yusaku Nakabeppu, Altered expression of diabetes-related genes in Alzheimer's disease brains, 11th Surugadai International Symposium, 2012.07.
164. 岡 素雅子、レオン フリオ、土本 大介、作見 邦彦、中別府 雄作, MUTYHはp53による発がん抑制のメディエータである, 第35回日本がん疫学・分子疫学研究会総会, 2012.07.
165. 秋本 頼子、中別府 雄作, 放射線照射によって生成される修飾ヌクレオシドの解析, 第35回日本がん疫学・分子疫学研究会総会, 2012.07.
166. Nona Abolhassani, Teruaki Iyama, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Leona D Samson, Mechanism of genome instability triggered by deoxyinosine nucleotides, 7th Annual CEHS Poster Session, 2012.05.
167. Yusaku Nakabeppu, Quality control in the nucleotide pools is essential for cellular homeostasis, Invited seminar at Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 2012.04.
168. Yusaku Nakabeppu, Quality control in the nucleotide pools is essential for cellular homeostasis, Invited seminar at National Institute of Environmental Health Science, NIH, 2012.04.
169. Daisuke Tsuchimoto, Teruaki Iyama, Nona Abolhassani, Yasuto Yoneshima, Kunihiko Sakumi, Naoko Shiomi, Masahiko Mori, Tadahiro Shiomi, Tetsuo Noda and Yusaku Nakabeppu, Mechanism of genome instability triggered by deoxyinosine nucleotides and defense systems in mammalian cells, 4th US-JAPAN DNA REPAIR MEETING, 2012.04.
170. Yusaku Nakabeppu, 8-Oxoguanine, a spontaneously oxidized guanine base, promotes somatic and meiotic recombination, thus contributing to carcinogenesis and genomic diversity, Invited seminar at Laboratory of Molecular Biology, National Heart, Lung, and Blood Institute, NIH, 2012.04.
171. Nomaru H, Yutsudo N, Hokoma M, Nakabeppu Y., Comprehensive analysis of gene expression regulated by fosB gene in neuron and glia, The munich Life Science Symposium for Young Scientist 2012, 2012.03.
172. Noriko Yutsudo, Takashi Kamada, Hiroko Nomaru, Yoko H. Ohnishi, Yoshinori N. Ohnishi, Kosuke Kajitani, Kunihiko Sakumi, Hiroshi Shigeto, Yusaku Nakabeppu, Mice lacking fosB display impaired adult hippocampal neurogenesis and spontaneous epilepsy, The 21st Hot spring Harbor Symposium jointly with 8th Global COE International Symposium, Young Investigators Presentation, 2012.01.
173. 太田 詠子, 土本 大介, 作見 邦彦, 瀧口 友香, 中別府 雄作, 酸化ヌクレオチド2-OH-ATP による細胞死の制御機構, 第34回日本分子生物学会年会, 2011.12.
174. Daisuke Tsuchimoto, Teruaki Iyama, Nona Abolhassani, Yasuto Yoneshima, Kunihiko Sakumi, Naoko Shiomi, Masahiko Mori, Tadahiro Shiomi, Yusaku Nakabeppu, Mechanism of genome instability triggered by deoxyinosine nucleotides and defense systems in mammalian cells, 第34回日本分子生物学会年会, 2011.12.
175. 岡 素雅子,レオン フリオ,作見 邦彦,土本 大介,中別府 雄作, MUTYH はp53 による発がん抑制のメディエータである, 第34回日本分子生物学会年会, 2011.12.
176. Julio Leon, Masaaki Hokama, Sugako Oka, Erika Castillo, Kunihiko Sakumi, Daisuke Tsuchimoto, Yusaku Nakabeppu, Roles of insulin in survival and proliferation of SH-SY5Y neuroblastoma cells under neuronal differentiation, 第34回日本分子生物学会年会, 2011.12.
177. 岡 素雅子、フリオ レオン、作見 邦彦、土本 大介、中別府 雄作, MUTYHはp53による発がん抑制のメディエータである, 第40回日本環境変異原学会シンポジウム, 2011.11.
178. 中別府 雄作, アルツハイマー病の分子機構〜遺伝子発現機構からのアプローチ, Hisayama Study Conference 2011, 2011.11.
179. 盛 子敬,岡 素雅子,土本 大介,作見 邦彦,中別府 雄作, 酸化ストレスはDNA修復酵素MUTYHに依存して神経変性を引き起こす, 第4回 Kyushu CVD Conference, 2011.11.
180. M. Hokama, T. Iwaki, K. Sasaki, Y. Kiyohara, T. Sasaki, Y. Nakabeppu, Gene expression profiling of postmortem brains of patients with Alzheimer’s disease pathology: The Hisayama Study, 41st Annual meeting of Society for Neuroscience, 2011.11.
181. H. Nomaru, N. Yutsudo, M. Hokoma, Y. Nakabeppu, Comprehensive analysis of gene expression regulated by fosB gene in neuron and glia, 41st Annual meeting of Society for Neuroscience, 2011.11.
182. Nona Abolhassani, Yusaku Nakabeppu, The biological significance of ITPA protein and its substrates, ITP and dITP in mouse, DNA Repair and Mutagenesis (DRAM) Seminar Season at Center for Environmental Health Sciences, 2011.10.
183. 外間 政朗, 岩城 徹, 清原 裕, 佐々木 富男,中別府 雄作, 剖検脳マイクロアレイ解析による脳疾患遺伝子発現プロファイリング, 脳神経外科学会第70回学術総会, 2011.10.
184. 大野 みずき,作見 邦彦,古市 正人,中西 恵美,續 輝久,中別府 雄作, 8-Oxoguanine はDNA 鎖切断を誘発することで減数分裂期の相同染色体組換え頻度を上昇させる, 日本遺伝学会第83回大会, 2011.09.
185. 土本 大介,猪山 輝昭,アボルハッサニ ノナ,米嶋 康臣,作見 邦彦,中別府 雄作, ほ乳動物細胞におけるデオキシイノシンヌクレオチドによるゲノム不安定化とその防御機構, 日本遺伝学会第83回大会, 2011.09.
186. 中別府 雄作, 活性分子種による核酸の化学修飾と生体応答, 日本植物学会 第75回大会, 2011.09.
187. 湯通堂 紀子,鎌田 崇嗣,能丸 寛子,大西(本田) 陽子,大西 克典,梶谷 康介,作見 邦彦,重藤 寛史,中別府 雄作, ΔFosB/Δ2ΔFosB は成体海馬神経前駆細胞の増殖制御とてんかん自然発症の抑制に働く, 第34回日本神経科学大会, 2011.09.
188. 盛 子敬,中別府 雄作, マウス黒質における核酸の酸化損傷防御酵素群、MTH1, OGG1, MUTYHの領域特異的な発現, 第34回日本神経科学大会, 2011.09.
189. 能丸 寛子,大西 克典,外間 政朗,湯通堂 紀子,中別府 雄作, 脳内細胞におけるfosBによる遺伝子プロファイルの網羅的解析, 第34回日本神経科学大会, 2011.09.
190. 中別府雄作、猪山輝昭、岡素雅子、盛子敬、作見邦彦、土本大介, 活性分子種による核酸の化学修飾と生体応答, 第2回 Molecular Cardiovascular Conference Ⅱ, 2011.09.
191. Yusaku Nakabeppu, 8-Oxoguanine, a spontaneously oxidized guanine base, promotes somatic and meiotic recombination, thus contributing to carcinogenesis and genomic diversity, The 5th Biennial Meeting of Society for Free Radical Research-Asia (SFRR-Asia) and 8th Conference of Asian Society for Mitochondrial Research and Medicine (ASMRM), 2011.09.
192. Noriko Yutsudo, Takashi Kamada, Hiroko Nomaru, Yoko H. Ohnishi, Yoshinori N. Ohnishi, Kosuke Kajitani, Kunihiko Sakumi, Hiroshi Shigeto, Yusaku Nakabeppu, Fosb products regulate proliferation of adult hippocampal neural progenitor cells and suppress spontaneous epileptic seizures, 2011 International Summer Conference for Neurons and Brain Disease,, 2011.08.
193. Noriko Yutsudo, Takashi Kamada, Hiroko Nomaru, Yoko H. Ohnishi, Yoshinori N. Ohnishi, Kosuke Kajitani, Kunihiko Sakumi, Hiroshi Shigeto, Yusaku Nakabeppu, ΔFosB and/or Δ2ΔFosB regulate proliferation of adult hippocampal neural progenitor cells and suppress spontaneous epileptic seizures, Neurogenesis 2011, 2011.06.
194. Sugako Oka, Yusaku Nakabeppu, MUTYH-initiated base excision repair triggers two distinct cell death pathways by monitoring 8-oxoguanine in nuclear and mitochondrial DNAs, Keystone Symposia on Stem Cells, Cancer and Metastasis, 2011.03.
195. Teruaki Iyama, Nona Abolhassani, Daisuke Tsuchimoto and Yusaku Nakabeppu, NUDT16 is a (deoxy)inosine diphosphatase, and its deficiency induces accumulation of single-strand breaks in nuclear DNA and growth arrest, 6th Global-COE Young Investigators Forum, 2011.02.
196. Hiroko Nomaru, Yoshinori N Ohnishi, Masaaki Hokoma, Noriko Yutsudo and Yusaku Nakabeppu, Comprehensive analysis of gene expression profiles in brain regulated by fosB gene, 6th Global-COE Young Investigators Forum, 2011.02.
197. 作見 邦彦, 大野 みずき, 田口 健一, 外間 政朗, 中別府 雄作, Ogg1,Mth1,Mutyh triple knockout mouseの樹立と解析, 平成22年度「個体レベルでの発がん研究支援活動」ワークショップ −個体レベル研究のワークショップ(個体レベルの癌研究の魅力:培養細胞と臨床研究をつなぐマトリクス)−, 2011.02.
198. Teruaki Iyama, Nona Abolhassani, Daisuke Tsuchimoto and Yusaku Nakabeppu, NUDT16 is a (deoxy)inosine diphosphatase, and its deficiency induces accumulation of single-strand breaks in nuclear DNA and growth arrest, Keystone Symposia on Genomic Instability and DNA Repair, 2011.02.
199. Yusaku Nakabeppu, Molecular mechanisms for oxidative DNA damage-induced neurodegeneration, The 7th Conference of Asian Society for Mitochondrial Research and Medicine (ASMRM) , 2010.12.
200. 岡 素雅子、フリオ レオン、中別府 雄作, MUTYHはp53による発がん抑制のメディエータである, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
201. 稲里みゆき、古賀由香里、橋川智恵、中村照也、池水信二、中別府 雄作、山縣ゆり子, ヒトMTH1の幅広い基質特異性発現機構の解明, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
202. 土本 大介、猪山 輝昭、アボルハッサニ ノナ、野中 麻里、中別府 雄作, NUDT16は(デオキシ)イノシン二リン酸分解酵素であり、その欠損は核DNAの一本鎖切断の蓄積と増殖抑制をもたらす, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
203. 太田詠子、土本大介、作見邦彦、中別府雄作, 酸化ヌクレオチド2-OH-ATPによる細胞死の制御機構, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
204. 大野みずき、作見邦彦、續輝久、中別府雄作, 8-oxoguanineはDNA 鎖切断を誘発することで減数分裂期の相同染色体組換え頻度を上昇させる, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
205. Kunihiko Sakumi, Nona Abolhassani, Mehrdad Behmanesh, Teruaki Iyama, Daisuke Tsuchimoto, Yusaku Nakabeppu, The biological significance of ITPA protein and its substrates, ITP and dITP in mouse, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
206. 中別府雄作、Nona Abolhassani、猪山輝昭、太田詠子、盛子敬、岡素雅子、土本大介、作見邦彦, 環境ストレスによるヌクレオチドプールの恒常性破綻に起因するゲノム障害とその防御機構, BMB2010 (第33回日本分子生物学会年会・第83回日本生化学会大会 合同大会), 2010.12.
207. 中別府雄作, 活性酸素による核酸の損傷と神経変性の機序, 第3回 Kyushu CVD Conference, 2010.11.
208. Yusaku Nakabeppu, Nona Abolhassani, Teruaki Iyama, Zijing Sheng, Sugako Oka, Kunihiko Sakumi and Daisuke Tsuchimoto, Quality control in the purine nucleotide pools is essential for maintaining genomic integrity in mammals, The 7th 3R (Replication, Recombination and Repair) Symposium, 2010.10.
209. Zijing Sheng, Sugako Oka, Daisuke Tsuchimoto, Kunihiko Sakumi and Yusaku Nakabeppu, Mitochondrial toxin, 3-nitropropionic acid induces striatal degeneration through the two distinct MUTYH-dependent cell death pathways, The 7th 3R (Replication, Recombination and Repair) Symposium, 2010.10.
210. Sugako Oka, Zijing Sheng, Yusaku Nakabeppu, MUTYH-initiated base excision repair triggers two distinct cell death pathways by monitoring 8-oxoguanine in nuclear and mitochondrial DNAs, The 7th 3R (Replication, Recombination and Repair) Symposium, 2010.10.
211. Nona Abolhassani, Teruaki Iyama, Daisuke Tsuchimoto, Kunihiko Sakumi, Mizuki Ohno, Mehrdad Behmanesh, Yusaku Nakabeppu, NUDT16 and ITPA play a dual protective role in maintaining chromosome stability and cell growth by eliminating dIDP/IDP and dITP/ITP from nucleotide pools in mammals, The 7th 3R (Replication, Recombination and Repair) Symposium, 2010.10.
212. Teruaki Iyama, Nona Abolhassani, Daisuke Tsuchimoto, Mari Nonaka and Yusaku Nakabeppu, NUDT16 is a (deoxy)inosine diphosphatase, and its deficiency induces accumulation of single-strand breaks in nuclear DNA and growth arrest, The 7th 3R (Replication, Recombination and Repair) Symposium, 2010.10.
213. 岡素雅子、中別府雄作, MUTYHはp53による発がん抑制のメディエータである, 第69回日本癌学会学術総会, 2010.09.
214. Nona Abolhassani, Teruaki Iyama, Daisuke Tsuchimoto, Kunihiko Sakumi, Yusaku Nakabeppu, Deoxyinosine incorporated into DNA under ITPA deficiency, 日本遺伝学会第82回大会, 2010.09.
215. 中別府雄作、猪山輝昭、Nona Abolhassani、太田詠子、盛子敬、岡素雅子、作見邦彦、土本大介, 環境ストレスによるヌクレオチドプールの恒常性破綻の分子病態, 日本遺伝学会第82回大会, 2010.09.
216. 湯通堂 紀子, 鎌田 崇嗣, 大西(本田) 陽子, 大西 克典, 梶谷 康介, 作見 邦彦, 重藤 寛史, 中別府 雄作, fosB欠損マウスは成体海馬における神経新生の低下を示し,てんかんを自然発症する, 第33回日本神経科学大会, 2010.09.
217. 盛 子敬, 中別府 雄作, ミトコンドリア型MUTYHに依存した線条体変性, 第33回日本神経科学大会, 2010.09.
218. Daisuke Tsuchimoto, Eiko Ohta, Nona Abolhassani, Teruaki Iyama, Mari Nonaka, Mehrdad Behmanesh, Kunihiko Sakumi and Yusaku Nakabeppu, Quality control in the purine nucleotide pools is essential for cellular homeostasis, L.I.G.G.S’ Seminar at University of Leicester, 2010.07.
219. Zijing Sheng, Sugako Oka, Yusaku Nakabeppu, Base excision repair-mediated programmed cell death and neurodegeneration, 3rd International Genome Dynamics in Neurosciences Conference “DNA Repair and Neurological disease”, 2010.07.
220. 中別府 雄作, 活性分子種による核酸の化学修飾と生体応答, 第51回日本生化学会 中国・四国支部例会シンポジウム, 2010.05.
221. Nona Abolhassani, Teruaki Iyama, Daisuke Tsuchimoto, Kunihiko Sakumi, Mizuki Ohno, Mehrdad Behmanesh, Yusaku Nakabeppu, NUDT16 and ITPA play a dual protective role in maintaining chromosome stability and cell growth by eliminating dIDP/IDP and dITP/ITP from nucleotide pools in mammals, Gordon Research Conference on DNA Damage, Mutation and Cancer, 2010.03.
222. Daisuke Tsuchimoto, Eiko Ohta, Nona Abolhassani, Teruaki Iyama, Mari Nonaka, Mehrdad Behmanesh, Kunihiko Sakumi and Yusaku Nakabeppu, Quality control in the purine nucleotide pools is essential for cellular homeostasis, 5th GCOE International Symposium on Cell Cycle and Differentiation, 2010.02.
223. Teruaki Iyama, Nona Abolhassani, Daisuke Tsuchimoto, Mari Nonaka, and Yusaku Nakabeppu, NUDT16 is a (deoxy)inosine diphosphatase, and its deficiency induces nuclear accumulation of single-stranded DNA with growth arrest, 5th GCOE International Symposium on Cell Cycle and Differentiation, 2010.02.
224. Sugako Oka, Yusaku Nakabeppu, MUTYH, a molecular switch for programmed cell death and tumor suppression, AACR-JCA 8th Joint Conference, Cancer Genomics, Epigenomics, and the Development of Novel Therapeutics, 2010.02.
225. 中別府雄作, 核酸の酸化がもたらす生体障害とその防御機構 , 第26回臨床フリーラジカル会議 , 2010.01.
226. 鳥巣久美子、張学礼、野中麻里、中別府雄作, 脳梗塞感受性遺伝子Prkchの欠損はApoe遺伝子欠損マウスにおける高脂血症と動脈硬化を改善する, 第2回 Kyushu CVD Conference, 2010.01.
227. Nona Abolhassani, Teruaki Iyama, Daisuke Tsuchimoto, Kunihiko Sakumi, Mizuki Ohno, Mehrdad Behmanesh, Yusaku Nakabeppu, An increased expression of NUDT16 with IDP/dIDP hydrolyzing activity in immortalized ITPA-null mouse embryonic fibroblasts suppresses ITPA-deficient phenotypes, 第33回日本分子生物学会年会/第83回日本生化学会大会, 2009.12.
228. Teruaki Iyama, Daisuke Tsuchimoto, Nona Abolhassani, Yusaku Nakabeppu, Human NUDT16 is a novel nucleotide pool sanitizing enzyme hydrolyzing (deoxy)inosine diphosphate to (deoxy)inosine monophosphate, 第33回日本分子生物学会年会/第83回日本生化学会大会, 2009.12.
229. Sugako Oka, Julio Leon, Yusaku Nakabeppu, MUTYH is a potential mediator of p53 tumor suppression, 第33回日本分子生物学会年会/第83回日本生化学会大会, 2009.12.
230. Kumiko Torisu, Mari Nonaka, Zhang Xulei, Takahide Kaji, Takehiro Torisu, Reiko Tanaka, Yoshikazu Miwa, Michiaki Kubo, Kazuhiro Chida, Katsuo Sueishi, Mitsuo Iida, Yutaka Kiyohara, Yusaku Nakabeppu, Disruption of Prkch gene for protein kinase C η efficiently attenuates atherosclerosis in mice, 第33回日本分子生物学会年会/第83回日本生化学会大会, 2009.12.
231. Teruaki Iyama, Daisuke Tsuchimoto, Nona Abolhassani, Yusaku Nakabeppu, Human NUDT16 is a novel nucleotide pool sanitizing enzyme hydrolyzing (deoxy)inosine diphosphate to (deoxy)inosine monophosphate, 49th ASCB Annual Meeting , 2009.12.
232. Yusaku Nakabeppu, Sugako Oka, Zijing Sheng, Daisuke Tsuchimoto, Kunihiko Sakumi, Base excision repair-mediated programmed cell death responsible for tumor suppression and neurodegeneration, 4th International Workshop on Cell Regulations in Division and Arrest, 2009.12.
233. 中別府雄作, 核酸の酸化と細胞死のシグナル伝達, 大阪大学 蛋白質研究所 セミナー, 2009.11.
234. 大野みずき、作見邦彦、古市正人、續輝久、中別府雄作, 酸化的DNA損傷と生殖細胞ゲノム変異, 日本環境変異原学会 第38回大会, 2009.11.
235. 大野みずき、作見邦彦、古市正人、續輝久、中別府雄作, 酸化的DNA損傷と生殖細胞ゲノム変異, 日本放射線影響学会第52回大会, 2009.11.
236. Sugako Oka, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, and Yusaku Nakabeppu, MUTYH, A MOLECULAR SWITCH FOR PROGRAMMED CELL DEATH AND TUMOR SUPPRESSION, The Fortieth International Symposium of The Princess Takamatsu Cancer Research Fund, 2009.11.
237. Noriko YUTSUDO, Takashi KAMADA, Yoko HONDA-OHNISHI, Yoshinori OHNISHI, Kosuke KAJITANI, Kunihiko SAKUMI, Hiroshi SHIGETO, Yusaku NAKABEPPU, Poor proliferation of neural progenitors in the dentate gyrus of hippocampus in adult fosB-null mice exhibiting increased susceptibility for spontaneous epileptic seizures, Kyushu Brain Days 2009, International Student Symposium, 2009.11.
238. 土本大介、猪山輝昭、アボルハッサニ・ノナ、中別府雄作, ヒトNUDT16は(デオキシ)イノシン二リン酸を(デオキシ)イノシン一リン酸に加水分解する新規ヌクレオチドプール浄化酵素である, 第20回複製・組換え・修復ワークショップ, 2009.11.
239. Kunihiko Sakumi, Mizuki Ohno, Ken-ichi Taguchi, Masaaki Hokama, Yoshimichi Nakatsu, Teruhisa Tsuzuki, Yusaku Nakabeppu, Production and analysis of the Ogg1, Mth1, Mutyh triple knockout mouse strain, 第68回日本癌学会学術総会, 2009.10.
240. Sugako Oka, Yusaku Nakabeppu, MUTYH is a potential mediator of p53 tumor suppression, 第68回日本癌学会学術総会, 2009.10.
241. Noriko Yutsudo, Takashi Kamada, Yoko Honda-Ohnishi, Yoshinori Ohnishi, Kosuke, Kajitani, Kunihiko Sakumi, Hiroshi Shigeto, Yusaku Nakabeppu, Poor proliferation of neural progenitors in the dentate gyrus of hippocampus in adult fosB-null mice exhibiting increased susceptibility for spontaneous epileptic seizures, 第32回日本神経科学会大会, 2009.09.
242. Sheng Zijing, Hidetaka Yamada, Yusaku Nakabeppu, Mitochondrial toxin, 3-nitropropionic acid induces MUTYH-dependent striatal degeneration, 第32回日本神経科学会大会, 2009.09.
243. Daisuke Tsuchimoto, Eiji Iwama, Teruaki Iyama, Yusaku Nakabeppu, Identification of the full-length form of Prune2, a neuroblastoma-related protein, 第32回日本神経科学会大会, 2009.09.
244. 大野みずき、作見邦彦、古市正人、續輝久、中別府雄作, 酸化損傷塩基の修復能を欠損するマウスにおける継世代的影響の解析, 日本遺伝学会第81回大会, 2009.09.
245. Yusaku Nakabeppu, Oxidative damage in nucleic acids and mitochondrial dysfunction, SFRR International Summer School 2009 in Japan, 2009.09.
246. Yusaku Nakabeppu, Eiko Ohta, Junji Ichikawa, Daisuke Tsuchimoto, Programmed cell death triggered by nucleotide pool damage, The 10th International Conference on Environmental Mutagens (ICEM), 2009.08.
247. Zijing Sheng, Sugako Oka, Yusaku Nakabeppu, MUTYH-dependent cell death and neurodegeneration, The 2nd Erling Seeberg symposium on DNA repair, 2009.06.
248. 太田 詠子,土本 大介,中別府 雄作, 酸化ヌクレオチドによるシグナル伝達, 第62回日本酸化ストレス学会学術集会, 2009.06.
249. Noriko YUTSUDO, Takashi KAMADA, Yoko HONDA-OHNISHI, Yoshinori OHNISHI, Kosuke KAJITANI, Kunihiko SAKUMI, Hiroshi SHIGETO, Yusaku NAKABEPPU, Poor proliferation of neural progenitors in the dentate gyrus of hippocampus in adult fosB-null mice exhibiting increased susceptibility for spontaneous epileptic seizures, Neurogenesis 2009 “Hippocamal neurogenesis: its implication in neural functions and mental diseases”, 2009.06.
250. Teruhisa Tsuzuki, Jingshu Piao, Takuro Isoda, Kunihiko Sakumi, Yusaku Nakabeppu, and Yoshimichi Nakatsu, Oxidative Stress-Induced Tumorigenesis in the Small Intestine of Various DNA Repair-Deficient Mice, The 3rd ASM Conference on DNA Repair and Mutagenesis: From Molecular Structure to Human Disease, 2009.05.
251. Mizuki Ohno, Masato Furuichi, Kunihiko Sakumi, Yusaku Nakabeppu, 8-Oxoguanine promotes base substitution and homologous recombination in mammalian germ cells, The 3rd ASM Conference on DNA Repair and Mutagenesis: From Molecular Structure to Human Disease, 2009.05.
252. Kunihiko Sakumi, Nona Abolhassani, Sugako Oka, Shinya Toyokuni, Mehrdad Behmanesh, Yusaku Nakabeppu, Characterization of ITPase knockout mouse, The 3rd ASM Conference on DNA Repair and Mutagenesis: From Molecular Structure to Human Disease, 2009.05.
253. Yusaku Nakabeppu, Oxidative damage in brain genome and neuroprotection , The 11th Meeting of Hirosaki International Forum of Medical Science Emerging Frontiers in Brain Research -Crossroads of metabolic regulation,stress response and disease, 2009.03.
254. 中別府雄作, 核酸の酸化とプログラム細胞死, レドックス170委員会第20回研究会“レドックス研究とケミカルバイオロジー”, 2009.03.
255. Yusaku Nakabeppu, MUTYH, a molecular switch for programmed cell death under oxidative stress-friend or foe?, The 3rd Global COE International Symposium on Stem Cells and Regenerative Medicine, 2009.02.
256. 中別府雄作 , Galectin-1はマウス成体海馬歯状回における神経新生を促進する, 第2回 九州大学グローバルCOEプログラム 「個体恒常性を担う細胞運命の決定とその破綻」事業推進担当者発表会, 2009.02.
257. Yusaku Nakabeppu , Oxidative genomic damage in brain and neuroprotection, The Joint Symposium of the 4th International Symposium of Institutes Network and Osaka University Global COE (Frontier Biomedical Science Underlying Organelle Network Biology) Symposium , 2009.02.
258. 中別府雄作,盛子敬,岡素雅子, ミトコンドリア毒3-ニトロプロピオン酸は8-オキソグアニンの蓄積を伴うMUTYH依存性の線条体変性を誘発するが,MTH1とOGG1 により抑制される, 第8回日本ミトコンドリア学会年会, 2008.12.
259. 中別府雄作 , Overview of programmed cell death and oxidative stress, 第8回日本ミトコンドリア学会年会, 2008.12.
260. 中別府雄作, 活性酸素によるゲノム障害とその防御機構, 第3回放射線防護研究センターシンポジウム(独立行政法人放射線医学総合研究所) 「生き物はどのようにして放射線に立ち向かうか-DNA損傷応答と適応応答-」, 2008.12.
261. 太田詠子,土本大介,大野みずき,作見邦彦,中別府雄作, 哺乳動物細胞における2-OH-ATPの生物学的影響, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
262. 大野みずき,作見邦彦,古市正人,中別府雄作, OGG1/MTH1/MUTYH三重欠損マウスは遺伝性の異常形質を頻発するミューテータ・フェノタイプを示す, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
263. 土本大介,吉田菜桜子,中別府雄作, 新規損傷ヌクレオチド浄化酵素ITPBP2の同定と機能解析, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
264. 外間政朗,大野みずき,作見邦彦,佐々木富男, 中別府雄作, Ogg1, Mth1, Mutyh の3重遺伝子欠損マウス系統のミュテーター・フェノタイプに起因した遺伝性水頭症, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
265. H. Nomaru, K. Kajitani, M. Ifuku, N. Yutsudo, Y. Dan, T. Miura, D. Tsuchimoto, K. Sakumi, T. Kadoya, H. Horie, F. Poirier, M. Noda and Y. Nakabeppu, Galectin-1 promotes basal and kainate-induced proliferationof neural progenitors in the dentate gyrus of adult mouse hippocampus, Berlin Brain Days: 5th International PhD Symposium, 2008.12.
266. Kyota Fujita, Toshihiro Seike, Yukiko Yamakawa, Mizuki Ohno, Hiroo Yamaguchi, Hidetaka Yamada, Toshihiko Katafuchi, Atsushi Takaki, Mizuho Kido, Yusaku Nakabeppu and Mami Noda, Protective effects of hydrogen in drinking water in a mouse model of Parkinson’s disease, Berlin Brain Days: 5th International PhD Symposium, 2008.12.
267. 岩間映二, 土本大介, 中別府雄作, 新規cAMP phosphodiesteraseの同定と癌転移に関与する可能性の検討, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
268. 岡素雅子,大野みずき, 土本大介, 作見邦彦, 中別府雄作, 核とミトコンドリアDNAへの8-oxoguanine の同時蓄積によって起動されるプログラム細胞死, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
269. Abolhassani Nona, Kunihiko Sakumi, Mizuki Ohno, Daisuke Tsuchimoto, Mehrdad Behmanesh, Yusaku Nakabeppu, Novel pathway for hydrolysis of inosine nucleotides detected in immortalized ITPA-null mouse embryo fibroblasts, BMB2008(第31回日本分子生物学会年会・第81回日本生化学会大会 合同大会), 2008.12.
270. Mizuki Ohno and Yusaku Nakabeppu, 8-Oxoguanine is a major cause for the genome instability and diversity through enhancing the somatic and meiotic recombination, 日本環境変異原学会第37回大会, 2008.12.
271. Zijing Sheng, Sugako Oka and Yusaku Nakabeppu, The mitochondrial toxin, 3-nitropropionic acid induces MUTYH-dependent striatal neurodegeneration with accumulation of 8-oxoguanine which is effectively suppressed by OGG1 and MTH1, The 5th ASMRM and Chinese Mit’2008, 2008.11.
272. 岡素雅子,大野みずき,土本大介,作見邦彦,古市正人,中別府雄作, MUTYHは核とミトコンドリアDNA中の8-オキソグアニンの制御により2つの異なる細胞死経路を引き起こす, 第67回日本癌学会学術総会, 2008.10.
273. Mizuki Ohno and Yusaku Nakabeppu, 8-Oxoguanine, a major form of spontaneously oxidized guanine base, promotes genome diversity through enhancing chromosome recombination, The 6th 3R (Replication, recombination, repair) Symposim 2008, 2008.10.
274. Yoshimichi Nakatsu, Jingshu Piao, Takuro Isoda, Kunihiko Sakumi, Yusaku Nakabeppu, Teruhisa Tsuzuki, Potassium Bromate-Induced Tumorigenesis in the Small Intestine of Various DNA Repair-Deficient Mice, The 6th 3R (Replication, recombination, repair) Symposim 2008, 2008.10.
275. 藤田 慶大、清家 稔博、山川 裕希子、大野 みずき、山口 浩雄、山田 英孝、高木 厚司、城戸 瑞穂、中別府 雄作、野田 百美, 水素水はパーキンソン病モデルマウスにおいてドパミン神経細胞死を抑制する, 第59回西日本生理学会, 2008.10.
276. Kyota Fujita, Toshihiro Seike, Yukiko Yamakawa, Mizuki Ohno, Hiroo Yamaguchi, Hideyuki Yamada, Atsushi Takaki, Mizuho Kido, Yusaku Nakabeppu and Mami Noda, Hydrogen in drinking water reduces dopaminergic neuronal loss in a mouse model of Parkinson’s Disease, 第51回日本神経化学会, 2008.09.
277. 大野みずき、作見邦彦、中別府雄作, 8-オキソグアニンは染色体組換えを促進し、ゲノム多様性の原因となる, 日本遺伝学会第80回大会, 2008.09.
278. 大野みずき、作見邦彦、古市正人,中別府雄作, Ogg1/Mth1/Mutyh三重遺伝子欠損マウスは遺伝性の異常形質を頻発するミューテータ・フェノタイプを示す, 日本遺伝学会第80回大会, 2008.09.
279. 中別府雄作, 活性酸素によるゲノム障害とその防御機構 −発がんと神経変性の分子病態−, 第27回分子病理学研究会, 2008.08.
280. Mizuki Ohno, Masato Furuichi, Kunihiko Sakumi, Yusaku Nakabeppu, 8-Oxoguanine promotes genetic diversity through enhancing meiotic recombination, XX International Congress of Genetics, 2008.07.
281. Noriko Yutsudo, Yoko Honda-Ohnishi, Yoshinori Ohnishi, Kunihiko Sakumi, Yusaku Nakabeppu, ΔFosB promotes neurogensis in the dentate gyrus of mouse hippocampus, 第31回日本神経科学会大会, 2008.07.
282. Sheng Zijing, Hidetaka Yamada, Yusaku Nakabeppu, OGG1 and MTH1 effectively suppress accumulation of 8-oxoguanine in striatal medium spiny neurons and their degeneration induced by mitochondrial toxin, 3-nitropropionic acid, 第31回日本神経科学会大会, 2008.07.
283. Hiroko Nomaru, Kosuke Kajitani, Masataka Ifuku, Toshihiko Kadoya, Hidenori Horie, Françoise Poirier, Mami Noda, Kunihiko Sakumi, Yusaku Nakabeppu, Galectin-1 expressed in astrocytes promotes neurogenesis in the mouse hippocampus after brain damage caused by excitotoxicity., 第31回日本神経科学会大会, 2008.07.
284. 中別府雄作、市川淳二、岡素雅子、大野みずき、太田詠子、土本大介、作見邦彦, ミトコンドリアヌクレオチドプールの酸化に起因する細胞死とその防御機構, 第61回日本酸化ストレス学会, 2008.06.
285. Junji Ichikawa, Daisuke Tsuchimoto, Sugako Oka, Mizuki Ohno, Kunihiko Sakumi, Yusaku Nakabeppu, Oxidation of mitochondrial deoxynucleotide pools induces mitochondrial degeneration and cell death, The 7th European Meeting on Mitochondrial Pathology, 2008.06.
286. Sugako Oka, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, Masato Furuichi and Yusaku Nakabeppu, Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs, The 7th European Meeting on Mitochondrial Pathology, 2008.06.
287. 大野みずき、作見邦彦、中別府雄作, 8-オキソグアニンは染色体組換えを誘発する, がん予防大会2008福岡(第9回日本がん分子疫学研究会、第15回日本がん予防学会、第31回日本がん疫学研究会合同大会), 2008.05.
288. 朴晶淑、中津可道、磯田拓郎、續輝久、作見邦彦、中別府雄作, Msh2遺伝子欠損マウスにおける酸化ストレス誘発小腸腫瘍の解析, がん予防大会2008福岡(第9回日本がん分子疫学研究会、第15回日本がん予防学会、第31回日本がん疫学研究会合同大会), 2008.05.
289. 中津可道、朴晶淑、磯田拓郎、續輝久、作見邦彦、中別府雄作, DNA修復関連遺伝子欠損マウスにおける酸化ストレス誘発消化管発がん, がん予防大会2008福岡(第9回日本がん分子疫学研究会、第15回日本がん予防学会、第31回日本がん疫学研究会合同大会), 2008.05.
290. Sugako Oka, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, Masato Furuichi and Yusaku Nakabeppu, Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs, The Joint Symposium of the 3rd International Symposium of Institutes Network and Hot Spring Harbor-Global COE Symposium, 2008.02.
291. Junji Ichikawa, Daisuke Tsuchimoto, Sugako Oka, Mizuki Ohno, Kunihiko Sakumi, Yusaku Nakabeppu, Nitric oxide induces cell death through oxidation of mitochondrial deoxynucleotide pools, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 2007.12.
292. 岡素雅子,大野みずき,土本大介,作見邦彦,古市正人,中別府雄作, 核とミトコンドリアゲノムに蓄積した8-オキソグアニンは異なる2つの経路により細胞死を誘導する, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 2007.12.
293. 太田詠子,大野みずき,土本大介,作見邦彦,中別府雄作, 哺乳動物細胞における2-OH-ATPの生物学的影響, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 2007.12.
294. 野中麻里,土本大介,太田詠子,作見邦彦,中別府雄作, ITP結合タンパク質ITPBP1の生化学的特性の解析, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 2007.12.
295. 大野みずき、作見邦彦、中別府雄作, ゲノムに蓄積した8-オキソグアンンは染色体組換えを誘発する, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 2007.12.
296. Nona Abolhassani, Kunihiko Sakumi, Mizuki Ohno, Mehrdada Behmanesh, Yusaku Nakabeppu, ITPA-deficient mouse embryonic fibroblasts exhibit chromosomal aberrations, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 2007.12.
297. Yutsudo, N., Honda-Ohnishi, Y., Ohnishi, Y., Nakabeppu, Y. , ΔFosB promotes neurogenesis in the dentate gyrus of mouse hippocampus after brain damage caused by excitotoxicity., The 37th annual meeting of the Society for Neuroscience, 2007.11.
298. Yusaku Nakabeppu, Disruption of Defense Mechanisms Against Oxidative Damage in Nucleic Acids and the Affect of Polyphenols, 3rd International Conference on Polyphenol and Health, 2007.11.
299. Sugako Oka, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, Masato Furuichi, and Yusaku Nakabeppu, Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs, Japan-Finland Joint Meeting on Mitochondria, 2007.10.
300. Yusaku Nakabeppu, Defenses against damage in nucleotide pools and the suppression of carcinogenesis, neurodegeneration and heart failure, 38th Annual Meeting of the Environmental Mutagen Society, 2007.10.
301. Sugako Oka, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, Masato Furuichi, and Yusaku Nakabeppu, Two distinct pathways of cell death triggered by oxidative damage to nuclear and mitochondrial DNAs, Nordic Region Workshop on Mitochondria (Scandomit 07), 2007.10.
302. Zijing Sheng, Hidetaka Yamada, Yusaku Nakabeppu, Oxidative damage in nucleic acids in Huntington's disease model, 第30回日本神経科学大会・第50回日本神経化学会大会・第17回日本神経回路学会大会 合同学会, 2007.09.
303. Noriko Yutsudo, Yoko Honda-Ohnishi, Yoshinori Ohnishi, Yusaku Nakabeppu, ΔFosB promotes neurogenesis in the dentate gyrus of mouse hippocampus after brain damage caused by excitotoxicity, 第30回日本神経科学大会・第50回日本神経化学会大会・第17回日本神経回路学会大会 合同学会, 2007.09.
304. Kosuke Kajitani, Toshihiko Kadoya, Hidenori Horie, Francoise Poirier, Yusaku Nakabeppu, Galectin-1 promotes neurogenesis in the dentate gyrus of mouse hippocampus after brain damage caused by excitotoxicity, 第30回日本神経科学大会・第50回日本神経化学会大会・第17回日本神経回路学会大会 合同学会, 2007.09.
305. Nona Abolhassani, Kunihiko Sakumi, Mizuki Ohno, Mehrdad Behmanesh, Yusaku Nakabeppu, Analyses of ITPA-deficient mouse and embryonic fibroblasts, The 19th annual meeting on Mouse Molecular Genetics, 2007.09.
306. 大野みずき、作見邦彦、中別府雄作, 8-オキソグアニンのゲノム蓄積は相同染色体組換えを促進し遺伝的多様性を生み出す原動力となる, 第9回日本進化学会大会, 2007.09.
307. 大野みずき、作見邦彦、中別府雄作, 酸化塩基、8-オキソグアニンのゲノム蓄積は染色体組換えを促進する, 日本遺伝学会第79回大会, 2007.09.
308. Y. Nakabeppu, N. Yutsudo, H. Kurushima, K. Kajitani, Y.H. Ohnishi and Y.N. Ohnishi., Mice that express only ΔFosB display a hyperactive phenotype accompanied by increased neurogenesis and resistance to excitotoxicity, 30th Annual Meeting of the Canadian College of Neuropsychopharmacology (CCNP), 2007.06.
309. Yusaku Nakabeppu, Cell death caused by 8-oxoguanine, 3rd Japan-US DNA Repair Meeting, 2007.05.
310. Sugako Oka, Mizuki Ohno, Daisuke Tsuchimoto, Kunihiko Sakumi, Masato Furuichi, and Yusaku Nakabeppu, MUTYH MEDIATES TWO DISTINCT CELL DEATH PATHWAYS BY MONITORING BUILDUP OF 8-OXOGUANINE IN NUCLEAR AND MITOCHONDRIAL GENOMES, 4th Meeting of Asian Society for Mitochondrial Research and Medicine, 2007.02.
311. 土本 大介, 野中 麻里,太田 詠子, 作見 邦彦, 中別府 雄作, ATP固定化樹脂を用いた損傷ヌクレオチド結合タンパク質の探索, 日本分子生物学会2006フォーラム, 2006.12.
312. 段 由規彦,梶谷 康介,湯通堂 紀子,作見 邦彦,土本 大介,伊東 健, 山本 雅之,中別府 雄作, 転写因子Nrf2はカイニン酸誘発興奮毒性への脳応答を制御する, 日本分子生物学会2006フォーラム, 2006.12.
313. 太田 詠子,大野 みずき,土本 大介,作見 邦彦,中別府 雄作, 哺乳動物細胞における2-OH-ATPおよび8-oxo-GTPの生物学的影響, 日本分子生物学会2006フォーラム, 2006.12.
314. 作見 邦彦, ベーマネシュ マーダッド, 岡 素雅子, 豊國 伸 哉, 土本 大介, 中別府 雄作, ITPase欠損と心臓の異常, 日本分子生物学会2006フォーラム, 2006.12.
315. 市川 淳二, 土本 大介, 大野 みずき, 岡 素雅子, 中別府 雄作, MTH1は、一酸化窒素に起因する酸化ストレスが誘発する細胞死を,ミトコンドリアゲノムへの酸化ヌクレオチドの取り込みを抑制する事で効率良く抑制する, 第6回日本ミトコンドリア学会年会, 2006.12.
316. Yoko H. Ohnishi, Yoshinori N. Ohnishi, Hitoshi Ishibashi, Kei Eto, Kunihiko Sakumi, Mami Noda, Yusaku Nakabeppu, FosB and deltaFosB determine susceptibility to excitotoxicity induced by kainate, The 36th annual meeting of the Society for Neuroscience, 2006.10.
317. Yoshinori N. Ohnishi, Yoko H. Ohnishi, Hideaki Kurushima, Kunihiko Ssakumi, Yusaku Nakabeppu, Increased expression of ΔFosB causes hyperlocomotor activity and fearless behavior, and to which FosB efficiently counteracts and also attenuates ΔFosB-independent exploratory behavior., The 36th annual meeting of the Society for Neuroscience, 2006.10.
318. 大野 みずき, 三浦智史, 中別府 雄作, ヒトゲノムに及ぼす8-オキソグアニンの影響, 日本遺伝学会第78回大会, 2006.09.
319. 中別府 雄作, 8-オキソグアニンとヒトゲノムの多様性, 日本遺伝学会第78回大会, 2006.09.
320. 中別府雄作, ヌクレオチドプール浄化機構の生物学的意義, 日本放射線影響学会第49回大会, 2006.09.
321. 大野 みずき, 三浦智史, 中別府 雄作, 8-オキソグアニンはゲノム進化の原動力か?, 日本進化学会2006年大会, 2006.08.
322. 中別府雄作, 核酸の酸化による生体障害とその防御機構ー発がんから神経変性までー, 第17回中国四国生体ラジカル研究会, 2006.07.
323. Yusaku Nakabeppu, ITPase is a quality controller of the ATP pool, 20th IUBMB International Congress of Biochemistry and Molecular Biology, and 11th FAOBMB Congress, Satellite Symposium on Frontiers in Redox Sciences, 2006.06.
特許出願・取得
特許出願件数  0件
特許登録件数  2件
学会活動
所属学会名
日本がん疫学・分子疫学研究会
日本分子生物学会
日本神経科学会
日本生化学会
日本ミトコンドリア学会
日本遺伝学会
日本癌学会
Asian Society of Mitochondrial Research and Medicine
Society for Neuroscience
American Society for Microbiology
American Society for Biochemistry and Molecular Biology
学協会役員等への就任
2013.10~2016.12, 日本遺伝学会, 幹事.
2011.11~2015.10, 日本ミトコンドリア学会, 理事.
2011.01~2016.12, 日本癌学会, 評議員.
2010.01~2013.03, 日本がん疫学・分子疫学研究会, 幹事.
2009.01~2010.12, 日本遺伝学会, 評議員.
2008.01~2010.12, 日本酸化ストレス学会, 評議員.
2008.01~2010.12, 日本癌学会, 評議員.
2004.01~2008.12, 日本生化学会, JB編集委員.
2005.01, 日本ミトコンドリア学会, 評議員.
2003.04~2006.03, 日本遺伝学会, 評議員.
2000.01~2009.12, 日本がん分子疫学研究会, 幹事.
2002.01~2004.12, 日本ミトコンドリア研究会, 評議員.
学会大会・会議・シンポジウム等における役割
2015.09.24~2015.09.26, 日本遺伝学会 第87回大会, 座長(Chairmanship).
2015.07.28~2015.07.31, 第38回日本神経科学大会, 座長(Chairmanship).
2014.11.25~2014.11.27, 第37回日本分子生物学会, 座長(Chairmanship).
2014.09.17~2014.09.19, 日本遺伝学会 第86回大会, 座長(Chairmanship).
2014.09.08~2014.09.10, 3rd International Conference and Exhibition on Neurology & Therapeutics, Organizing Comittee Member.
2013.11.04~2013.11.05, 10th Conference of the Asian Society of Mitochondrial Research and Medicine (ASMRM2013), 座長(Chairmanship).
2013.10.03~2013.10.05, 第72回日本癌学会 学術総会, 座長(Chairmanship).
2013.06.20~2013.06.23, 第36回日本神経科学大会, 座長(Chairmanship).
2013.03.21~2014.03.22, International Symposium on “Germline Mutagenesis and Biodiversification”, Advisory board member.
2012.09.24~2012.09.26, 日本遺伝学会第84回大会, 大会委員長.
2012.09.19~2012.09.21, 第71回日本癌学会学術総会, 座長(Chairmanship).
2012.09.18~2012.09.21, 第35回日本神経科学大会, 座長(Chairmanship).
2011.12.13~2012.12.16, 第34回日本分子生物学会年会, 座長(Chairmanship).
2011.10.03~2011.10.05, 第70回日本癌学会学術総会, 座長(Chairmanship).
2011.09.20~2011.09.22, 日本遺伝学会第83回大会, 座長(Chairmanship).
2010.09.22~2010.09.24, 第69回日本癌学会学術総会, 座長(Chairmanship).
2010.09.20~2010.09.22, 日本遺伝学会第82回大会, 座長(Chairmanship).
2009.11.07~2009.11.09, Kyushu Brain Days 2009, International Student Symposium , 座長(Chairmanship).
2009.09.16~2009.09.17, 日本遺伝学会第81回大会, 座長(Chairmanship).
2008.10.28~2008.10.30, 第67回日本癌学会学術総会, 座長(Chairmanship).
2008.09.03~2008.09.05, 日本遺伝学会第80回大会, ワークショップ世話人.
2008.09.03~2008.09.05, 日本遺伝学会第80回大会, 座長(Chairmanship).
2008.06.19~2008.06.20, 第61回日本酸化ストレス学会, 座長(Chairmanship).
2008.05.22~2008.05.23, がん予防大会2008福岡(第9回日本がん分子疫学研究会、第15回日本がん予防学会、第31回日本がん疫学研究会合同学術大会), 日本がん分子疫学研究会学術委員長.
2007.12~2007.12.19, 第7回日本ミトコンドリア学会年会, 座長(Chairmanship).
2007.12~2007.12.19, 第30回日本分子生物学会年会・第80回日本生化学会大会 合同大会, 座長(Chairmanship).
2007.02~2007.02.19, 4th Meeting of Asian Society for Mitochondrial Research and Medicine, 座長(Chairmanship).
2006.09~2006.09.19, 第65回日本癌学会学術総会, 座長(Chairmanship).
2005.12~2005.12.19, 第28回日本分子生物学会年会, 座長(Chairmanship).
2005.09~2005.09.19, 9th International Conference on Environmental Mutagens, 座長(Chairmanship).
2005.09~2005.09.19, 第48 回日本神経化学会大会, 座長(Chairmanship).
2005.07~2005.07.19, 研究所ネットワーク国際シンポジウム, 座長(Chairmanship).
2014.11.25~2014.11.27, 第37回日本分子生物学会, ワークショップ・オーガナイザー.
2014.09.17~2014.09.19, 日本遺伝学会 第86回大会, ワークショップ・オーガナイザー.
2014.03.21~2014.03.22, International Symposium on "Germline Mutagenesis and Biodiversification", Advisory board member.
2012.09.24~2012.09.26, 日本遺伝学会第84回大会, 大会委員長.
2011.08.31~2011.09.04, 8th Meeting of Asian Society for Mitochondrial Research and Medicine, ASMRM Officer, Local Organizer.
2010.12.16~2010.12.18, 7th Meeting of Asian Society for Mitochondrial Research and Medicine, ASMRM Council Member.
2008.11.07~2008.11.09, 5th Meeting of Asian Society for Mitochondrial Research and Medicine, International Scientific Committee.
2008.05.22~2008.05.23, がん予防大会2008福岡 (第9回日本がん分子疫学研究会・第15回日本がん予防学会・第31回日本がん疫学研究会合同学術大会), 学術会長.
2008.02~2008.02.19, 第3回研究所ネットワーク国際シンポジウム/第17回生体防御医学研究所ホットスプリングハーバーシンポジウム/グローバルCOE「理医連携」シンポジウム合同シンポジウム, 企画委員長.
2007.02.01~2007.02.19, 4th Meeting of Asian Society for Mitochondrial Research and Medicine, International Advisor.
2005.12.07~2005.12.09, 第28回日本分子生物学会年会, 組織委員.
2005.09.28~2005.09.30, 第48 回日本神経化学会大会, プログラム委員.
2005.07.01~2005.07.30, 研究所ネットワーク国際シンポジウム, 企画委員.
学会誌・雑誌・著書の編集への参加状況
2013.01~2018.12, Cancer Science, 国際, 編集委員.
2012.01~2014.03, ISRN Biochemistry, 国際, 査読委員.
2010.04, Genes and Genetic Systems, 国際, 編集委員.
2010.01, Genes to Cells, 国際, 編集委員.
2002.01, DNA Repair, 国際, 査読委員.
2004.01~2008.12, Journal of Biochemistry, 国際, 編集委員.
学術論文等の審査
年度 外国語雑誌査読論文数 日本語雑誌査読論文数 国際会議録査読論文数 国内会議録査読論文数 合計
2017年度 24  24 
2016年度 26  26 
2015年度 32  36 
2014年度 26  26 
2013年度 31  31 
2012年度 26  26 
2011年度 31  31 
2010年度 28  29 
2009年度 14  16 
2008年度 29  29 
2007年度 17  17 
2006年度 23  23 
2005年度
2004年度 22  22 
2004年度 10  10 
2002年度
2001年度
2000年度
その他の研究活動
海外渡航状況, 海外での教育研究歴
Johns Hopkins University, UnitedStatesofAmerica, 1987.09~1991.08.
外国人研究者等の受入れ状況
2017.06~2017.08, 1ヶ月以上, Peru, 外国政府・外国研究機関・国際機関.
2018.04~2019.03, 1ヶ月以上, China, .
2014.06~2019.03, 1ヶ月以上, Iran, .
2015.04~2018.03, 1ヶ月以上, China, .
2015.05~2015.08, 1ヶ月以上, Peru, 外国政府・外国研究機関・国際機関.
2013.06~2013.09, 1ヶ月以上, Iran, 日本学術振興会.
2011.05~2015.03, 1ヶ月以上, ヌクレオチドプール研究センター, China, 学内資金.
2010.04~2011.03, 1ヶ月以上, 財団法人 長寿科学振興財団, Iran, 民間・財団.
2009.09~2010.03, 1ヶ月以上, China, Shenzhen Center for Diseases control and prevention.
2007.10~2011.03, 1ヶ月以上, China, 文部科学省.
2007.04~2009.03, 1ヶ月以上, China, 民間・財団.
2005.10~2007.09, 1ヶ月以上, China, 日本学術振興会.
2000.10~2004.03, 1ヶ月以上, China, 科学技術振興事業団.
1998.10~2000.09, 1ヶ月以上, China, 日本学術振興会.
受賞
2018年度 日本遺伝学会木原賞, 日本遺伝学会, 2018.09.
平成28年度上原生命科学財団研究助成金, 公益財団法人 上原生命科学財団, 2017.03.
第40回 三菱財団自然科学研究助成, 財団法人 三菱財団, 2009.07.
昭和シェル石油環境研究成果賞, 財団法人 昭和シェル石油環境研究助成財団, 2006.09.
昭和シェル石油環境研究助成金, 財団法人 昭和シェル石油環境研究助成財団, 1997.09.
日本癌学会奨励賞受賞, 日本癌学会, 1994.09.
研究資金
科学研究費補助金の採択状況(文部科学省、日本学術振興会)
2017年度~2019年度, 基盤研究(A), 代表, 活性酸素による脳機能障害とその防御機構の解明.
2015年度~2017年度, 基盤研究(C), 分担, Pten変異マウスを用いた新しいてんかん病理・治療モデルの確立.
2014年度~2016年度, 基盤研究(C), 連携, 8-オキソグアニンが引き起こすドパミン神経変性の分子機序の解明.
2014年度~2016年度, 基盤研究(C), 分担, ヒストンメチル化酵素PR-set7の関わる細胞機能と発癌の解析 .
2015年度~2016年度, 萌芽研究, 代表, 慢性腎不全が誘発する脳機能障害における核酸の酸化損傷とその防御機構の関与の解明.
2013年度~2015年度, 基盤研究(C), 分担, TFAM発現を用いたアルツハイマー病におけるインスリンシグナル破綻機構の解明.
2010年度~2014年度, 基盤研究(S), 代表, 環境ストレスによるヌクレオチドプールの恒常性破綻の分子病態と制御機構の解明.
2013年度~2014年度, 新学術領域研究, 代表, Galectin-1による筋萎縮性側索硬化症の発症と進行の二面的制御.
2011年度~2013年度, 基盤研究(C), 分担, ヒストンH4リジン20のメチル化を介した染色体機能の解析 .
2011年度~2013年度, 基盤研究(C), 分担, DNA塩基除去修復欠損マウスを用いた網膜光障害の分子病態解明.
2010年度~2012年度, 基盤研究(A), 代表, 環境ストレスによるヌクレオチドプールの恒常性破綻の分子病態と制御機構の解明.
2010年度~2012年度, 基盤研究(C), 分担, p53によるDNA修復遺伝子MUTYHの発現制御と細胞死における役割の解明.
2011年度~2012年度, 挑戦的萌芽研究, 代表, fosB遺伝子の選択的スプライシング産物による脳機能制御機構の解明.
2007年度~2009年度, 基盤研究(B), 連携, マウスを用いたDNAおよび遊離ヌクレオチドの品質管理機構欠損の分子病態解析.
2008年度~2009年度, 特定領域研究, 代表, 活性酸素によるゲノム障害とがん細胞死.
2005年度~2007年度, 特別研究員奨励費, 代表, 酸化的DNA損傷によるドパミン神経変性とその防御機構の研究.
2006年度~2007年度, 特定領域研究, 代表, 酸化的ストレスによる細胞死と消化管がん抑制機構におけるMUTYHの働き.
2006年度~2007年度, 基盤研究(B), 代表, 脳・神経細胞の維持における核酸の酸化損傷防御機構の役割.
2004年度~2006年度, 基盤研究(B), 分担, 遺伝子改変マウスをモデルとしたDNA塩基除去修復欠損の分子病態解明.
2005年度~2005年度, 特定領域研究, 代表, 酸化的ストレスによる細胞死と消化管がん抑制機構におけるMUTYHの働き.
2004年度~2004年度, 特定領域研究, 代表, ゲノム多型及び遺伝病の成因としての自然DNA酸化損傷とその修復機構の破綻.
1999年度~2001年度, 基盤研究(B), 代表, フリーラジカルによる細胞傷害に対する防御機構の研究.
2003年度~2003年度, 特定領域研究, 代表, ヒト癌におけるMTH1発現亢進の意義の解明とMTH1の発現・機能抑制法の開発.
1998年度~2000年度, 基盤研究(B), 代表, 脳・神経細胞の維持における活性酸素によるDNA傷害の修復機構の役割.
科学研究費補助金の採択状況(文部科学省、日本学術振興会以外)
2013年度~2015年度, 厚生労働科学研究費補助金 (厚生労働省), 分担, 大規模ゲノム疫学共同研究による認知症の危険因子および防御因子の解明.
2008年度~2012年度, 厚生労働科学研究費補助金 (厚生労働省), 分担, アルツハイマ-病の危険因子の解明と予防に関する大規模ゲノム疫学研究.
2003年度~2005年度, 厚生労働科学研究費補助金 (厚生労働省), 分担, アンジオテンシン変換酵素遺伝子多型と脳・心血管病の関係に関する疫学調査:久山町研究.
日本学術振興会への採択状況(科学研究費補助金以外)
1998年度~2000年度, 外国人特別研究員, 代表, 活性酸素によるDNA傷害に対する防御機構の生物学的意義.
競争的資金(受託研究を含む)の採択状況
2016年度~2017年度, 上原記念生命科学財団 平成28年度 研究助成金 , 代表, 酸化ストレスによるミクログリア活性化機構の解明.
2014年度~2016年度, 独立行政法人医薬基盤研究所 創薬支援ネットワーク, 代表, ヒト酸化プリンヌクレオシド三リン酸分解酵素MTH1の阻害剤の探索.
2009年度~2009年度, 三菱財団自然科学研究助成, 代表, 「DNA修復酵素MUTYHに依存した細胞死の制御機構と生物学的意義の解明」.
1999年度~2003年度, 戦略的創造研究推進事業(CREST), 代表, 活性酸素による脳・神経細胞の障害とその防御機構.
共同研究、受託研究(競争的資金を除く)の受入状況
2006.08~2016.07, 分担, 脳梗塞感受性遺伝子研究成果の活用・実用化.
2006.08~2009.07, 分担, 脳梗塞感受性遺伝子研究成果の活用・実用化.
2004.04~2005.03, 代表, ポリフェノール素材のDNAの酸化障害に与える影響,及び関連遺伝子に関する共同研究.
寄附金の受入状況
2009年度, Dr. Jianhui Yuan (Shenzhen Center for Disease Control and Prevention, P.R. China)
, 奨学寄付金,研究課題:The interaction of oxidative DNA damage repair genes.
2007年度, アサヒビール, 奨学寄付金.
2006年度, 昭和シェル石油環境研究助成財団, 奨学寄付金.
2006年度, アサヒビール株式会社, 奨学寄付金.
2005年度, アサヒビール株式会社, 奨学寄付金.
学内資金・基金等への採択状況
2014年度~2014年度, 九州大学教育研究プログラム・研究拠点形成プロジェクト(特別枠), 代表, アルツハイマー病脳における核酸の酸化損傷による神経変性の機序と防御機構の解明.
2008年度~2009年度, 九州大学教育研究プログラム・研究拠点形成プロジェクト(Cタイプ), 分担, 新規大学院教育プログラム:大学院生による国際シンポジウム「九州ブレイン・デイズ」の開催.
2005年度~2006年度, 九州大学教育研究プログラム・研究拠点形成プログラム(Bタイプ), 分担, ポストゲノム発達脳科学の創生とその研究・教育基盤の構築.
2002年度~2004年度, 九州大学教育研究プログラム・研究拠点形成プログラム(Aタイプ), 分担, 日本人の動脈硬化に関する先端的研究.
2001年度~2002年度, 九州大学教育研究プログラム・研究拠点形成プログラム(Bタイプ), 分担, 遺伝子操作マウス樹立の支援システムの構築.
1998年度~1999年度, 九州大学教育研究プログラム・研究拠点形成プログラム(Bタイプ), 代表, 活性酸素の生体内動態と生体傷害・生体防御に関する研究.
1997年度~1999年度, 九州大学教育研究プログラム・研究拠点形成プログラム(Aタイプ), 分担, 多元的アプローチによる生命現象の解明と応用.

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pure2017年10月2日から、「九州大学研究者情報」を補完するデータベースとして、Elsevier社の「Pure」による研究業績の公開を開始しました。
 
 
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