記述言語：英語   出版者・発行元：Life Science Alliance  

Mitochondrial transcription factor A, TFAM, is essential for mitochondrial function. We examined the effects of overexpressing the TFAM gene in mice. Two types of transgenic mice were created: TFAM heterozygous (TFAM Tg) and homozygous (TFAM Tg/Tg) mice. TFAM Tg/Tg mice were smaller and leaner notably with longer lifespans. In skeletal muscle, TFAM overexpression changed gene and protein expression in mitochondrial respiratory chain complexes, with down-regulation in complexes 1, 3, and 4 and up-regulation in complexes 2 and 5. The iMPAQT analysis combined with metabolomics was able to clearly separate the metabolomic features of the three types of mice, with increased degradation of fatty acids and branched-chain amino acids and decreased glycolysis in homozygotes. Consistent with these observations, comprehensive gene expression analysis revealed signs of mitochondrial stress, with elevation of genes associated with the integrated and mitochondrial stress responses, including Atf4, Fgf21, and Gdf15. These found that mitohormesis develops and metabolic shifts in skeletal muscle occur as an adaptive strategy.

DOI： 10.26508/lsa.202302498

Web of Science

Scopus

PubMed

担当区分：筆頭著者  

記述言語：英語   出版者・発行元：Nucleic Acids Research  

The 3243A > G in mtDNA is a representative mutation in mitochondrial diseases. Mitochondrial protein synthesis is impaired due to decoding disorder caused by severe reduction of 5-taurinomethyluridine (τm5U) modification of the mutant mt-tRNALeu(UUR) bearing 3243A > G mutation. The 3243A > G heteroplasmy in peripheral blood reportedly decreases exponentially with age. Here, we found three cases with mild respiratory symptoms despite bearing high rate of 3243A > G mutation (>90%) in blood mtDNA. These patients had the 3290T > C haplotypic mutation in addition to 3243A > G pathogenic mutation in mt-tRNALeu(UUR) gene. We generated cybrid cells of these cases to examine the effects of the 3290T > C mutation on mitochondrial function and found that 3290T > C mutation improved mitochondrial translation, formation of respiratory chain complex, and oxygen consumption rate of pathogenic cells associated with 3243A > G mutation. We measured τm5U frequency of mt-tRNALeu(UUR) with 3243A > G mutation in the cybrids by a primer extension method assisted with chemical derivatization of τm5U, showing that hypomodification of τm5U was significantly restored by the 3290T > C haplotypic mutation. We concluded that the 3290T > C is a haplotypic mutation that suppresses respiratory deficiency of mitochondrial disease by restoring hypomodified τm5U in mt-tRNALeu(UUR) with 3243A > G mutation, implying a potential therapeutic measure for mitochondrial disease associated with pathogenic mutations in mt-tRNAs.

DOI： 10.1093/nar/gkad591

Web of Science

Scopus

PubMed

記述言語：英語   出版者・発行元：Cancer Science  

Early detection and long-term monitoring are important for urothelial carcinoma of the bladder (UCB). Urine cytology and existing markers have insufficient diagnostic performance. Here, we examined medium-sized extracellular vesicles (EVs) in urine to identify specific markers for UCB and evaluated their usefulness as diagnostic material. To identify specific markers in urinary EVs derived from UCB, we undertook shotgun proteomics using urine from four UCB patients and four healthy subjects. Next, 29 healthy specimens, 18 noncancer specimens, and 33 UCB specimens, all from men, were analyzed for urinary EVs by flow cytometry to evaluate the diagnostic performance of UCB-specific EVs. Nanoparticle-tracking analysis indicated that the size of EVs extracted from urine was mostly <400 nm. By shotgun proteomics, we detected several proteins characteristic of UCB and found that carcinoembryonic antigen-related adhesion molecule (CEACAM) proteins were increased in patients. Flow cytometric analysis revealed that the degree of expression of CEACAM1, CEACAM5, and CEACAM6 proteins on the surface of EVs varied among patients. Extracellular vesicles expressing CEACAM proteins also expressed mucin 1, suggesting that they were derived from tumorigenic uroepithelial cells. The number of EVs expressing CEACAM1, 5, and 6 proteins was significantly increased in UCB (mean ± SD, 8.6 ± 13%) compared to non-UCB (0.69 ± 0.46) and healthy (0.46 ± 0.34) by flow cytometry. The results of receiver operating characteristic (ROC) analysis showed a good score of area under the ROC curve of 0.907. We identified EVs that specifically express CEACAM proteins in urine and have potential for diagnostic applications. These EVs are potential targets in a new liquid biopsy test for UCB patients.

DOI： 10.1111/cas.15438

Web of Science

Scopus

PubMed

記述言語：英語   出版者・発行元：John Wiley & Sons Australia, Ltd  

膀胱尿路上皮癌(UCB)患者の尿から抽出した細胞外小胞(EV)画分のプロテオミクス解析を行い、特異的な表面抗原となりうるタンパク質の探索を行った。UCB患者4例と健常者4例の尿についてショットガンプロテオミクスを実施し、次に健常者29検体、非癌18検体、UCB 33検体(全て男性)の尿中EVをフローサイトメトリー(FCM)で分析した。ナノ粒子トラッキング解析により、尿から抽出されたEVのサイズは大部分が400nm未満であった。ショットガンプロテオミクスにより、UCB患者でcarcinoembryonic antigen-related adhesion molecule(CEACAM)タンパク質が増加していることを見出した。FCM解析により、EV表面のCEACAM1、CEACAM5、CEACAM6タンパク質の発現の程度は患者によって異なっていた。CEACAMを発現しているEVはムチン1も発現しており、腫瘍形成尿路上皮細胞に由来することが示唆された。FCMによりCEACAM1、5、6タンパク質を発現するEV数は、非UCB(0.69±0.46%)および健常者(0.46±0.34%)に比べてUCB(8.6±13%)で有意に増加していた。ROC曲線下面積は0.907と良好であった。以上より、CEACAMタンパク質を特異的に発現し、診断への応用が期待される尿中EVを同定した。

記述言語：日本語   出版者・発行元：(一社)日本臨床検査医学会  

記述言語：日本語   出版者・発行元：(一社)日本臨床化学会  

マイクロベシクルは細胞膜の出芽により様々な細胞型から生成する小胞で,ヒト体液中に多く存在することからバイオマーカーとして注目を集めている.多くの核酸やミトコンドリアなどのオルガネラを含有し,細胞間で受け渡すことでシグナル伝達にも寄与している.また,ミトコンドリアはATP産生などの役割を果たす一方で,mtDNAは体内で炎症を引き起こす分子としても機能する.そして,マイクロベシクルとmtDNAはともに炎症の際に血液中で数が増加することが報告されている.このような背景を踏まえて,我々は血液中のマイクロベシクルとミトコンドリアに注目し,組織特異的な炎症のバイオマーカー確立を目指して解析を行っている.本稿では,疾患群との比較を見据えて作成した健常人プロファイルについて報告する.(著者抄録)