Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/1873-3468.12881

Language：English   Publishing type：Research paper (scientific journal)  

Arginine methylation is a post-translational modification which is catalyzed by protein arginine methyltransferases (PRMTs). Here, we report that PRMT1 is highly expressed in neural stem/precursor cells (NS/PCs) of mouse embryos, and knockdown of PRMT1 in NS/PCs suppresses the generation of astrocytes. The luciferase assay demonstrated that knockdown of PRMT1 inhibits activation of the promoter of a typical astrocytic marker gene, glial fibrillary acidic protein (Gfap), in NS/PCs. The transcription factor signal transducer and activator of transcription 3 (STAT3) is known to generally be critical for astrocytic differentiation of NS/PCs. We found that PRMT1 methylates arginine residue(s) of STAT3 to regulate its activity positively, resulting in the promotion of astrocytic differentiation of NS/PCs.

DOI： 10.1111/jnc.14123.

Language：English  

DOI： 10.1038/nsmb.2990

Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cmet.2010.10.005

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学　百年講堂   Country：Japan  

Event date： 2021.5

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

The choroid plexus (ChP), located in each brain ventricles, produces cerebrospinal fluid (CSF) and secretes various cytokines and growth factors into the CSF. Although several studies have reported that CSF serves as a niche for NSCs regulating neurogenesis, little is known about the aging changes. Since the ChP is sensitive to peripheral body signals, and gates immune cells to brain, disruption of ChP function and CSF composition are common to neurological disorders, such as multiple sclerosis, ischemia and Alzheimer`s disease. Despite these essential roles, remarkably little is known for the molecular mechanisms governing these functions of the ChP. Herein, we performed mRNA-seq analyses together with small RNA-seq of the ChP in the lateral ventricle using young (3-4 months) and aged (21-24 months) mice, and identified several sets of differentially expressed mRNA/miRNA. Global analysis of expressed genes in the lateral ventricle ChP cells revealed that the most overrepresented gene ontology terms in the aged mice are related to the inflammatory response. Indeed, single cell RNA-seq analysis clearly revealed that some population of aged ChP cells express higher level of chemokines such as Cxcl12/13 that linked to immune cell recruitment. In addition to the inflammatory response, several sets of ChP-expressed miRNA seemed to directly regulate NSCs proliferation. Taken together, our findings shed new light on the function of the ChP, and will facilitate future studies to design active and healthy brain barrier system.

Event date： 2020.2

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Santa Fe   Country：United States  

Although neural stem cells (NSCs) produce new neurons even in adulthood, neurogenesis decreases in the brain with aging, and little is known about the underlying mechanisms. Several studies have reported that cerebrospinal fluid (CSF), which is primarily produced by the choroid plexus (ChP) in ventricles, serves as a niche for NSCs. ChP is a highly vascularized epithelial tissue constituting blood-CSF barrier and secretes various cytokines and growth factors into the CSF. We have recently performed mRNA-seq analyses together with small RNA-seq of the ChP in the lateral ventricle (LVChP) using young (3-4 months) and aged (21-24 months) mice, and identified several sets of differentially expressed mRNA/miRNA. Global analysis of expressed genes in the LVChP revealed that the most overrepresented gene ontology terms in the aged mice are related to the inflammatory response. Indeed, single cell RNA-seq analysis clearly revealed that some population of LVChP cells express higher level of chemokines such as Cxcl12/13 in aged mice. In addition to the inflammatory response, several sets of LVChP-expressed miRNA seemed to directly regulate NSCs proliferation. Taken together, our findings strongly suggest the potential of ChP in neural stem cells regulation and brain functions.

Event date： 2017.9

Language：English  

Country：Spain  

Event date： 2017.1

Language：English  

Venue：Olympic Valley   Country：United States  

Event date： 2015.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：神戸   Country：Japan  

Choroid Plexus as the key regulator for development, maturation, and aging of the central nervous system

Event date： 2013.9

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：パシフィコ横浜   Country：Japan  

脊椎動物における生物時計の発振では、bHLH/PAS型の転写因子であるCLOCKとBMAL1のヘテロ2量体が、時計遺伝子であるperiodやcryptochromeのプロモーター領域に結合することで転写が活性化される。これらの遺伝子産物であるPERおよびCRYは、CLOCK-BMAL1に直接作用し転写活性を抑制するため、自らの転写へのネガティブフィードバック機構が成立する。遺伝子の転写制御には、ヒストンタンパク質の修飾によるクロマチンリモデリングが密接に関与するが、近年、生物時計の発振においても、数多くの報告がされている。我々はまず、時計遺伝子プロモーター領域におけるヒストンH3K4のトリメチル化修飾に概日性のリズムがあること、またこのメチル化修飾のリズムが、ヒストンH3のアセチル化修飾と同調して生じることを発見した。さらに、ヒストンH3K4に特異的なメチル基転移酵素であるMLL1（mixed lineage leukemia 1）が、CLOCK-BMAL1と時間依存的に相互作用することを見出した。この時間依存的な相互作用により、　MLL1はCLOCK-BMAL1と伴に標的遺伝子のプロモーターへとリクルートされ、その領域でのヒストンH3K4のトリメチル化修飾を行う。この結果生じるクロマチン構造変化は、MLL1-pol II・CLOCK-BMAL1を含む転写関連因子群のプロモーターへの結合を安定化させ、標的遺伝子の転写活性を促進することを明らかにした。すなわち、MLL1はクロマチンリモデリングにより、時計発振に必須な転写因子がDNAに結合するための場の制御を行う。本講演では、堅調に概日性の周期を刻むため生物が獲得した、さまざまなエピジェネティック制御について紹介する。

Event date： 2013.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：国立京都国際会館   Country：Japan  

Oxygen (O2) is a substrate for energy production and deeply involved in the regulations of cellular metabolism. Although standard cell culture systems are exposed to the environmental O2 level of 21% (normoxia), actual O2 concentration in both developing and adult brains is 1-8% (hypoxia). Accumulating studies have revealed that O2 and its signal transduction pathways control cell proliferation, differentiation, and morphogenesis during the development of various tissues. The mammalian brain cortex comprises deep- and upper-layer neurons (layer V-VI and II-IV, respectively) and glial cells including astrocytes. All these cells are sequentially generated from common multipotent neural stem cells (NSCs) in this order during development. Therefore, NSCs at midgestation produce neither upper-layer neuron nor astrocyte, but mainly differentiate into deep-layer neurons. In addition, it is generally known that this NSC’s property change can be recapitulated in the embryonic stem (ES) cell culture systems. Recently, we have shown that the acquisition of astrogenic potential by NSCs is delayed in standard in vitro culture compared to those in vivo, while, in vitro culture under hypoxic condition can restore this impairment. Herein, we further analyze the impact of O2 levels during corticogenesis, i.e. deep- and upper-layer neuron production of NSCs. Mouse ES cells were cultured and induced to neural differentiation under normoxic or hypoxic condition, and the differentiation was evaluated by quantitative PCR and immunocytochemistry. We found that the expression of upper-layer specific neuronal genes in hypoxia culture appeared earlier than that in normoxia. Thus, it is conceivable that O2 levels contribute to appropriate scheduling of not only neuron-glia fate switching but also neuronal subtype specification throughout development.

Event date： 2024.4

Language：English   Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

The adult hippocampus harbors a pool of neural stem cells (NSCs) that the source of life-long neurogenesis and plasticity, and their behavior are regulated by extrinsic cues arising from their surroundings. However, this tight regulation of NSCs disturbed with age, resulting in a decline in adult neurogenesis, which contributes to the progressive deterioration of hippocampus-related cognitive function. Several studies have demonstrated that cerebrospinal fluid (CSF), which is primarily produced by the choroid plexus (ChP) in the ventricles and plays fundamental roles as a niche for NSCs, especially during development. ChP is a highly vascularized epithelial tissue constituting blood-CSF barrier and secretes various growth factors into the CSF. By performing RNAseq analysis, we have recently found that gene sets of the microRNA (miRNA) biogenesis and the exosomal secretion pathways are remarkably downregulated in the aged ChP. In agreement with these findings, small RNAseq analysis exposed that hundreds of ChP expressed mature miRNAs were downregulated in aged mice. Since miRNAs are loaded into the extracellular vesicles and function in trans, we explored miRNAs which have function in NSCs. We first directly overexpressed these ChP-expressed miRNAs in NSCs and found that some enhanced NSCs’ proliferation. Then, we evaluate functions of these miRNAs in vivo, by using adeno-associated virus, which is known to preferentially infect ChP epithelial cells when injected into the lateral ventricle. When we knocked-down these miRNAs in the ChP, decrease in the amount of target miRNAs in CSF was consistently observed. We found that some of these miRNAs regulate NSCs’ behavior, affecting neurogenesis and spatial memory. Our findings suggest that the expression change of miRNAs in the ChP affects NSCs’ regulation during brain aging, and ChP-derived miRNAs can be potential therapeutic targets for age-associated brain disorders such as dementia and Alzheimer’s disease.

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2019.12

Language：English  

Venue：福岡   Country：Japan  

Neural stem cells (NSCs) are self-renewing, multipotent cells that generate neurons and glial cells such as astrocytes and oligodendrocytes. During brain development, tight regulation of neurogenesis to astrogenesis switching of NSCs is critical to generate a balanced number of each neural cell type for proper brain functions. Accumulating evidence has indicated that a complex array of epigenetic modifications control the timing of neuronal and astrocytic differentiation of NSCs, however, molecular mechanisms of NSC fate decision is still far from a complete understanding.
Bone morphogenetic proteins (BMPs) are one group of well-characterized factors to induce astrocytic differentiation of NSCs. Nevertheless, we have recently found that BMPs induce neuronal differentiation of NSCs which were isolated from embryonic day 11 (E11). To elucidate molecular mechanism underlying developmental stage dependent change of NSCs fate in response to BMPs, we have performed genome-wide mapping of SMADs target genes in E11 and E14 of NSCs. RNA-seq and ChIP-seq analyses revealed that within this short developmental time period, SMADs dramatically change their targets, for example, SMADs specifically bound to the promoters of proneural genes, Neurog1 and Dlx2 in E11 but not in E14 NSCs. Conversely, SMADs binding on a typical astrocyte marker glial fibrillary acidic protein promoter was observed only in E14 NSCs. Mapping of these stage-specific SMADs binding regions with whole-genome bisulfite sequencing and ATAC-seq data, we identified several novel epigenetically regulated regions, which may contribute to the developmental stage-dependent alteration in the preference of NSC’s fate choice.

Event date： 2018.6 - 2021.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：九州大学　百年講堂   Country：Japan  

In the developing mouse brain, the three major cell types, i.e., neurons and two glial cells (astrocytes and oligodendrocytes) are generated from common multipotent neural stem cells (NSCs). In this process, tight regulation of neurogenesis to astrogenesis switching of NSCs is critical to generate a balanced number of each neural cell type for proper brain functions. Accumulating evidence has indicated that a complex array of epigenetic modifications control the timing of neuronal and astrocytic differentiation of NSCs, however, molecular mechanisms of NSC fate decision is still far from complete understanding.
Bone morphogenetic proteins (BMPs) are one group of well-characterized factors to induce astrocytic differentiation of NSCs obtained from mouse forebrain at relatively late-gestational stages (e.g., E14 and later). Nevertheless, we have recently found that BMPs induce neuronal differentiation of NSCs at mid-gestational stages (e.g., E11). To elucidate molecular mechanism underlying this developmental stage dependent change of NSCs fate in response to BMPs, we have performed genome-wide analyses of gene expression (RNA-seq), P-SMAD binding sites (ChIP-seq), and chromatin accessibility (ATAC-seq) in E11 and E14 NSCs. Comprehensive analyses revealed that within this short developmental time period, SMAD target genes were altered dramatically, contributing to the developmental stage-dependent alteration in the preference of NSC’s fate choice.

Event date： 2018.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Nagoya City University   Country：Japan  

Event date： 2014.3

Language：Japanese  

Venue：大阪大学　吹田キャンパス   Country：Japan  

Language：English  

Venue：Santa Fe   Country：United States