Updated on 2025/11/10

All information, except for affiliations, is reprinted from the information registered on researchmap.

写真a

 
Kazuyuki Ohbo
 
Organization
Graduate School of Medicine Department of Medicine Histology and Cell Biology Professor
School of Medicine Medical Course
Title
Professor
Homepage
http://www-user.yokohama-cu.ac.jp/~finemorp/
External link

Research Interests

  • regenerative medicine

  • 自己複製

  • 幹細胞

  • lung development

  • Germ cell development

  • Epigenetics

  • self-renew

  • Stem cell

  • エピジェネティクス

Research Areas

  • Life Science / Medical biochemistry

  • Life Science / System genome science

  • Life Science / Anatomy

  • Life Science / Genome biology

Professional Memberships

  • JAPANESE SOCIETY OF DEVELOPMENTAL BIOLOGISTS

    　 More details

  • THE JAPANESE ASSOCIATION OF ANATOMISTS

    　 More details

  • JAPAN SOCIETY OF HISTOCHEMISTRY AND CYTOCHEMISTRY

    　 More details

Papers

  • Abnormal H3K27me3 underlies degenerative spermatogonial stem cells in cryptorchid testis

    Kazushige Kuroha, Ivana Dočkal, Uroš Radović, Kuniko Nakajima, Ikue Hoshi, Shion Matsuda, Noriko Kojitani, Kazuyuki Ohbo, Shin-ichi Tomizawa

    Development   2025.1

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：The Company of Biologists  

    Cryptorchidism is the most frequent congenital defect in newborn males characterized by the absence of the testis from the scrotum. Approximately 90% of patients with untreated bilateral cryptorchidism exhibit azoospermia due to defective spermatogenesis in the affected testis. While abnormal spermatogonial stem cell maintenance or differentiation is suggested to cause germ cell degeneration in the cryptorchid testis, underlying molecular mechanisms remain unclear. Here we profiled spermatogonial epigenetic landscapes using surgically induced cryptorchid testis in the mouse. We show that cryptorchidism leads to alterations in local, but not global H3K27me3 and H3K9me3 in undifferentiated spermatogonia. Of these, the loss of H3K27me3 was correlated with activation of developmental and proapoptotic pathway genes that are repressed by the polycomb machinery in germ cells. Cryptorchid spermatogonia exhibit the increase of H3K27me3 demethylases KDM6A and KMD6B. Furthermore, we reveal that an increased temperature leads to Kdm6a/b upregulation in germline stem cells cultured in vitro. Thus, our study suggests that temperature-dependent histone demethylation may induce mRNA dysregulation due to the partial loss of H3K27me3 in spermatogonia.

    DOI： 10.1242/dev.204239

    researchmap

  • Spatial and temporal expression analysis of BMP signal modifiers, Smoc1 and Smoc2, from postnatal to adult developmental stages in the mouse testis Reviewed

    Michio Ono, Kuniko Nakajima, Shin-ichi Tomizawa, Takayuki Shirakawa, Ippei Okada, Hirotomo Saitsu, Naomichi Matsumoto, Kazuyuki Ohbo

    Gene Expression Patterns   2024.12

    　More details

    Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1016/j.gep.2024.119383

    researchmap

  • A non-canonical bivalent gene Wfdc15a controls spermatogenic protease and immune homeostasis. Reviewed International journal

    Shin-Ichi Tomizawa, Rachel Fellows, Michio Ono, Kazushige Kuroha, Ivana Dočkal, Yuki Kobayashi, Keisuke Minamizawa, Koji Natsume, Kuniko Nakajima, Ikue Hoshi, Shion Matsuda, Masahide Seki, Yutaka Suzuki, Kazushi Aoto, Hirotomo Saitsu, Kazuyuki Ohbo

    Development (Cambridge, England)   2024.9

    　More details

    Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    Male infertility can be caused by chromosomal abnormalities, mutations, and epigenetic defects. Epigenetic modifiers pre-program hundreds of spermatogenic genes in spermatogonial stem cells (SSCs) for expression later in spermatids, but it remains mostly unclear whether and how those genes are involved in fertility. Here, we report that Wfdc15a, a WFDC family protease inhibitor pre-programmed by KMT2B, is essential for spermatogenesis. We found that Wfdc15a is a non-canonical bivalent gene carrying both H3K4me3 and facultative H3K9me3 in SSCs but is later activated along with the loss of H3K9me3 and acquisition of H3K27ac during meiosis. We show that Wfdc15a deficiency causes defective spermiogenesis at the beginning of spermatid elongation. Notably, depletion of Wfdc15a causes substantial disturbance of the testicular protease-antiprotease network and leads to an orchitis-like inflammatory response associated with TNFa expression in round spermatids. Together, our results reveal a unique epigenetic program regulating innate immunity crucial for fertility.

    DOI： 10.1242/dev.202834

    PubMed

    researchmap

  • A behind-the-scenes role of BDNF in the survival and differentiation of spermatogonia. Reviewed International journal

    Shin-Ichi Tomizawa, Kazushige Kuroha, Michio Ono, Kuniko Nakajima, Kazuyuki Ohbo

    Asian journal of andrology   2024.8

    　More details

    Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    Mouse spermatogenesis entails the maintenance and self-renewal of spermatogonial stem cells (SSCs), which require a complex web-like signaling network transduced by various cytokines. Although brain-derived neurotrophic factor (BDNF) is expressed in Sertoli cells in the testis, and its receptor tropomyosin receptor kinase B (TrkB) is expressed in the spermatogonial population containing SSCs, potential functions of BDNF for spermatogenesis have not been uncovered. Here, we generate BDNF conditional knockout mice and find that BDNF is dispensable for in vivo spermatogenesis and fertility. However, in vitro, we reveal that BDNF-deficient germline stem cells (GSCs) exhibit growth potential not only in the absence of glial cell line-derived neurotrophic factor (GDNF), a master regulator for GSC proliferation, but also in the absence of other factors, including epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and insulin. GSCs grown without these factors are prone to differentiation, yet they maintain expression of promyelocytic leukemia zinc finger (Plzf), an undifferentiated spermatogonial marker. Inhibition of phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and Src pathways all interfere with the growth of BDNF-deficient GSCs. Thus, our findings suggest a role for BDNF in maintaining the undifferentiated state of spermatogonia, particularly in situations where there is a shortage of growth factors.

    DOI： 10.4103/aja202457

    PubMed

    researchmap

  • Father-to-offspring transmission of extremely long NOTCH2NLC repeat expansions with contractions: genetic and epigenetic profiling with long-read sequencing Reviewed International journal

    Hiromi Fukuda, Daisuke Yamaguchi, Kristofor Nyquist, Yasushi Yabuki, Satoko Miyatake, Yuri Uchiyama, Kohei Hamanaka, Ken Saida, Eriko Koshimizu, Naomi Tsuchida, Atsushi Fujita, Satomi Mitsuhashi, Kazuyuki Ohbo, Yuki Satake, Jun Sone, Hiroshi Doi, Keisuke Morihara, Tomoko Okamoto, Yuji Takahashi, Aaron M. Wenger, Norifumi Shioda, Fumiaki Tanaka, Naomichi Matsumoto, Takeshi Mizuguchi

    Clinical Epigenetics   13 ( 1 )   204 - 204   2021.12

    　More details

    Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

    <title>Abstract</title><sec>
    <title>Background</title>
    GGC repeat expansions in <italic>NOTCH2NLC</italic> are associated with neuronal intranuclear inclusion disease. Very recently, asymptomatic carriers with <italic>NOTCH2NLC</italic> repeat expansions were reported. In these asymptomatic individuals, the CpG island in <italic>NOTCH2NLC</italic> is hypermethylated, suggesting that two factors repeat length and DNA methylation status should be considered to evaluate pathogenicity. Long-read sequencing can be used to simultaneously profile genomic and epigenomic alterations. We analyzed four sporadic cases with <italic>NOTCH2NLC</italic> repeat expansion and their phenotypically normal parents. The native genomic DNA that retains base modification was sequenced on a per-trio basis using both PacBio and Oxford Nanopore long-read sequencing technologies. A custom workflow was developed to evaluate DNA modifications. With these two technologies combined, long-range DNA methylation information was integrated with complete repeat DNA sequences to investigate the genetic origins of expanded GGC repeats in these sporadic cases.


    </sec><sec>
    <title>Results</title>
    In all four families, asymptomatic fathers had longer expansions (median: 522, 390, 528 and 650 repeats) compared with their affected offspring (median: 93, 117, 162 and 140 repeats, respectively). These expansions are much longer than the disease-causing range previously reported (in general, 41–300 repeats). Repeat lengths were extremely variable in the father, suggesting somatic mosaicism. Instability is more frequent in alleles with uninterrupted pure GGCs. Single molecule epigenetic analysis revealed complex DNA methylation patterns and epigenetic heterogeneity. We identified an aberrant gain-of-methylation region (2.2 kb in size beyond the CpG island and GGC repeats) in asymptomatic fathers. This methylated region was unmethylated in the normal allele with bilateral transitional zones with both methylated and unmethylated CpG dinucleotides, which may be protected from methylation to ensure <italic>NOTCH2NLC</italic> expression.


    </sec><sec>
    <title>Conclusions</title>
    We clearly demonstrate that the four sporadic <italic>NOTCH2NLC</italic>-related cases are derived from the paternal GGC repeat contraction associated with demethylation. The entire genetic and epigenetic landscape of the <italic>NOTCH2NLC</italic> region was uncovered using the custom workflow of long-read sequence data, demonstrating the utility of this method for revealing epigenetic/mutational changes in repetitive elements, which are difficult to characterize by conventional short-read/bisulfite sequencing methods. Our approach should be useful for biomedical research, aiding the discovery of DNA methylation abnormalities through the entire genome.


    </sec>

    DOI： 10.1186/s13148-021-01192-5

    PubMed

    researchmap

    Other Link： https://link.springer.com/article/10.1186/s13148-021-01192-5/fulltext.html

  • Maintenance DNA methylation in pre-meiotic germ cells regulates meiotic prophase by facilitating homologous chromosome pairing Reviewed

    Yuki Takada, Ruken Yaman-Deveci, Takayuki Shirakawa, Jafar Sharif, Shin-ichi Tomizawa, Fumihito Miura, Takashi Ito, Michio Ono, Kuniko Nakajima, Yoko Koseki, Fuyuko Shiotani, Kei-ichiro Ishiguro, Kazuyuki Ohbo, Haruhiko Koseki

    Development   148 ( 10 )   2021.5

    　More details

    Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Company of Biologists  

    <title>ABSTRACT</title>
    Heterochromatin-related epigenetic mechanisms, such as DNA methylation, facilitate pairing of homologous chromosomes during the meiotic prophase of mammalian spermatogenesis. In pro-spermatogonia, de novo DNA methylation plays a key role in completing meiotic prophase and initiating meiotic division. However, the role of maintenance DNA methylation in the regulation of meiosis, especially in the adult, is not well understood. Here, we reveal that NP95 (also known as UHRF1) and DNMT1 – two essential proteins for maintenance DNA methylation – are co-expressed in spermatogonia and are necessary for meiosis in male germ cells. We find that Np95- or Dnmt1-deficient spermatocytes exhibit spermatogenic defects characterized by synaptic failure during meiotic prophase. In addition, assembly of pericentric heterochromatin clusters in early meiotic prophase, a phenomenon that is required for subsequent pairing of homologous chromosomes, is disrupted in both mutants. Based on these observations, we propose that DNA methylation, established in pre-meiotic spermatogonia, regulates synapsis of homologous chromosomes and, in turn, quality control of male germ cells. Maintenance DNA methylation, therefore, plays a role in ensuring faithful transmission of both genetic and epigenetic information to offspring.

    DOI： 10.1242/dev.194605

    researchmap

  • Tsga8 is required for spermatid morphogenesis and male fertility in mice. Reviewed International journal

    Yuki Kobayashi, Shin-Ichi Tomizawa, Michio Ono, Kazushige Kuroha, Keisuke Minamizawa, Koji Natsume, Selma Dizdarević, Ivana Dočkal, Hiromitsu Tanaka, Tatsukata Kawagoe, Masahide Seki, Yutaka Suzuki, Narumi Ogonuki, Kimiko Inoue, Shogo Matoba, Konstantinos Anastassiadis, Nobuhisa Mizuki, Atsuo Ogura, Kazuyuki Ohbo

    Development (Cambridge, England)   148 ( 8 )   2021.3

    　More details

    Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    During spermatogenesis, intricate gene expression is coordinately regulated by epigenetic modifiers, which are required for differentiation of spermatogonial stem cells (SSCs) contained among undifferentiated spermatogonia. We previously found that KMT2B conveys H3K4me3 at bivalent and monovalent promoters in undifferentiated spermatogonia. Because these genes are expressed late in spermatogenesis or during embryogenesis, we expect that many of them are potentially programmed by KMT2B for future expression. Here, we show that one of the genes targeted by KMT2B, Tsga8, plays an essential role in spermatid morphogenesis. Loss of Tsga8 in mice leads to male infertility associated with abnormal chromosomal distribution in round spermatids, malformation of elongating spermatid heads and spermiation failure. Tsga8 depletion leads to dysregulation of thousands of genes, including the X chromosome genes that are reactivated in spermatids, and insufficient nuclear condensation accompanied by reductions of TNP1 and PRM1, key factors for histone-to-protamine transition. Intracytoplasmic sperm injection (ICSI) of spermatids rescued the infertility phenotype, suggesting competency of the spermatid genome for fertilization. Thus, Tsga8 is a KMT2B target that is vitally necessary for spermiogenesis and fertility.

    DOI： 10.1242/dev.196212

    PubMed

    researchmap

  • Human epididymis protein 4 is a new biomarker to predict the prognosis of progressive fibrosing interstitial lung disease. Reviewed International journal

    Naoki Nishiyama, Masahiro Masuo, Yoshihisa Nukui, Tomoya Tateishi, Mitsuhiro Kishino, Ukihide Tateishi, Kaori Morota, Kazuyuki Ohbo, Yasunari Miyazaki

    Respiratory investigation   59 ( 1 )   90 - 98   2021.1

    　More details

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

    BACKGROUND: The clinical course and prognosis of progressive fibrosing interstitial lung diseases (PF-ILDs) vary between individuals. Notably, predictive serum biomarkers for disease management are needed. Serum human epididymis protein 4 (HE4) is reportedly elevated in patients with idiopathic pulmonary fibrosis (IPF); however, its clinical utility remains unknown. We evaluated the potential of serum HE4 as a biomarker for patients with PF-ILD. METHODS: Serum HE4 was measured in a retrospective study consisting of 34 patients with PF-ILD and 40 healthy volunteers. The relationship between serum HE4 levels and clinical parameters or prognosis was investigated. To validate the significance of results obtained, a prospective observational study was performed in 37 patients presenting PF-ILD and 40 control patients without PF-ILD. RESULTS: Serum HE4 levels were higher in patients with PF-ILD than in healthy volunteers (P < 0.01). Moreover, serum HE4 levels correlated with the extent of honeycombing on chest high-resolution computed tomography (r = 0.41, P = 0.015). In multivariate analysis using the Cox proportional hazard model, higher HE4 levels (>238 pmol/L) were associated with an elevated mortality risk; hazard ratio (HR) 7.27, 95% CI 1.56-34.0, P = 0.01 in the derivation cohort; HR 44.3, 95% CI 4.19-468, P < 0.01 in validation cohort. CONCLUSIONS: Serum HE4 levels may serve as a new diagnostic and prognostic biomarker for patients with PF-ILD.

    DOI： 10.1016/j.resinv.2020.08.002

    PubMed

    researchmap

  • Gain-of-Function MN1 Truncation Variants Cause a Recognizable Syndrome with Craniofacial and Brain Abnormalities. Reviewed International journal

    Noriko Miyake, Hidehisa Takahashi, Kazuyuki Nakamura, Bertrand Isidor, Yoko Hiraki, Eriko Koshimizu, Masaaki Shiina, Kazunori Sasaki, Hidefumi Suzuki, Ryota Abe, Yayoi Kimura, Tomoko Akiyama, Shin-Ichi Tomizawa, Tomonori Hirose, Kohei Hamanaka, Satoko Miyatake, Satomi Mitsuhashi, Takeshi Mizuguchi, Atsushi Takata, Kazuyuki Obo, Mitsuhiro Kato, Kazuhiro Ogata, Naomichi Matsumoto

    American journal of human genetics   106 ( 1 )   13 - 25   2020.1

    　More details

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

    MN1 was originally identified as a tumor-suppressor gene. Knockout mouse studies have suggested that Mn1 is associated with craniofacial development. However, no MN1-related phenotypes have been established in humans. Here, we report on three individuals who have de novo MN1 variants that lead to a protein lacking the carboxyl (C) terminus and who presented with severe developmental delay, craniofacial abnormalities with specific facial features, and structural abnormalities in the brain. An in vitro study revealed that the deletion of the C-terminal region led to increased protein stability, an inhibitory effect on cell proliferation, and enhanced MN1 aggregation in nuclei compared to what occurred in the wild type, suggesting that a gain-of-function mechanism is involved in this disease. Considering that C-terminal deletion increases the fraction of intrinsically disordered regions of MN1, it is possible that altered phase separation could be involved in the mechanism underlying the disease. Our data indicate that MN1 participates in transcriptional regulation of target genes through interaction with the transcription factors PBX1, PKNOX1, and ZBTB24 and that mutant MN1 impairs the binding with ZBTB24 and RING1, which is an E3 ubiquitin ligase. On the basis of our findings, we propose the model that C-terminal deletion interferes with MN1's interaction molecules related to the ubiquitin-mediated proteasome pathway, including RING1, and increases the amount of the mutant protein; this increase leads to the dysregulation of MN1 target genes by inhibiting rapid MN1 protein turnover.

    DOI： 10.1016/j.ajhg.2019.11.011

    PubMed

    researchmap

  • Lack of whey acidic protein (WAP) four-disulfide core domain protease inhibitor 2 (WFDC2) causes neonatal death from respiratory failure in mice. Reviewed International journal

    Kuniko Nakajima, Michio Ono, Uroš Radović, Selma Dizdarević, Shin-Ichi Tomizawa, Kazushige Kuroha, Go Nagamatsu, Ikue Hoshi, Risa Matsunaga, Takayuki Shirakawa, Takeyuki Kurosawa, Yasunari Miyazaki, Masahide Seki, Yutaka Suzuki, Haruhiko Koseki, Masataka Nakamura, Toshio Suda, Kazuyuki Ohbo

    Disease models & mechanisms   12 ( 11 )   2019.11

    　More details

    Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    Respiratory failure is a life-threatening problem for pre-term and term infants, yet many causes remain unknown. Here, we present evidence that whey acidic protein (WAP) four-disulfide core domain protease inhibitor 2 (Wfdc2), a protease inhibitor previously unrecognized in respiratory disease, may be a causal factor in infant respiratory failure. Wfdc2 transcripts are detected in the embryonic lung and analysis of a Wfdc2-GFP knock-in mouse line shows that both basal and club cells, and type II alveolar epithelial cells (AECIIs), express Wfdc2 neonatally. Wfdc2-null-mutant mice display progressive atelectasis after birth with a lethal phenotype. Mutant lungs have multiple defects, including impaired cilia and the absence of mature club cells from the tracheo-bronchial airways, and malformed lamellar bodies in AECIIs. RNA sequencing shows significant activation of a pro-inflammatory pathway, but with low-quantity infiltration of mononuclear cells in the lung. These data demonstrate that Wfdc2 function is vitally important for lung aeration at birth and that gene deficiency likely causes failure of the lung mucosal barrier.

    DOI： 10.1242/dmm.040139

    PubMed

    researchmap

  • Kmt2b conveys monovalent and bivalent H3K4me3 in mouse spermatogonial stem cells at germline and embryonic promoters. Reviewed International journal

    Shin-Ichi Tomizawa, Yuki Kobayashi, Takayuki Shirakawa, Kumiko Watanabe, Keita Mizoguchi, Ikue Hoshi, Kuniko Nakajima, Jun Nakabayashi, Sukhdeep Singh, Andreas Dahl, Dimitra Alexopoulou, Masahide Seki, Yutaka Suzuki, Hélène Royo, Antoine H F M Peters, Konstantinos Anastassiadis, A Francis Stewart, Kazuyuki Ohbo

    Development (Cambridge, England)   145 ( 23 )   2018.11

    　More details

    Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

    The mammalian male germline is sustained by a pool of spermatogonial stem cells (SSCs) that can transmit both genetic and epigenetic information to offspring. However, the mechanisms underlying epigenetic transmission remain unclear. The histone methyltransferase Kmt2b is highly expressed in SSCs and is required for the SSC-to-progenitor transition. At the stem-cell stage, Kmt2b catalyzes H3K4me3 at bivalent H3K27me3-marked promoters as well as at promoters of a new class of genes lacking H3K27me3, which we call monovalent. Monovalent genes are mainly activated in late spermatogenesis, whereas most bivalent genes are mainly not expressed until embryonic development. These data suggest that SSCs are epigenetically primed by Kmt2b in two distinguishable ways for the upregulation of gene expression both during the spermatogenic program and through the male germline into the embryo. Because Kmt2b is also the major H3K4 methyltransferase for bivalent promoters in embryonic stem cells, we also propose that Kmt2b has the capacity to prime stem cells epigenetically.

    DOI： 10.1242/dev.169102

    PubMed

    researchmap

  • EPC1/TIP60-Mediated Histone Acetylation Facilitates Spermiogenesis in Mice Reviewed

    Yixin Dong, Kyo-ichi Isono, Kazuyuki Ohbo, Takaho A. Endo, Osamu Ohara, Mamiko Maekawa, Yoshiro Toyama, Chizuru Ito, Kiyotaka Toshimori, Kristian Helin, Narumi Ogonuki, Kimiko Inoue, Atsuo Ogura, Kazutsune Yamagata, Issay Kitabayashi, Haruhiko Koseki

    MOLECULAR AND CELLULAR BIOLOGY   37 ( 19 )   2017.10

    　More details

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

    DOI： 10.1128/MCB.00082-17

    Web of Science

    PubMed

    researchmap

  • DNA methylation and gene expression dynamics during spermatogonial stem cell differentiation in the early postnatal mouse testis Reviewed

    Naoki Kubo, Hidehiro Toh, Kenjiro Shirane, Takayuki Shirakawa, Hisato Kobayashi, Tetsuya Sato, Hidetoshi Sone, Yasuyuki Sato, Shin-ichi Tomizawa, Yoshinori Tsurusaki, Hiroki Shibata, Hirotomo Saitsu, Yutaka Suzuki, Naomichi Matsumoto, Mikita Suyama, Tomohiro Kono, Kazuyuki Ohbo, Hiroyuki Sasaki

    BMC GENOMICS   16   624   2015.8

    　More details

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

    DOI： 10.1186/s12864-015-1833-5

    Web of Science

    PubMed

    researchmap

  • RNA Binding Protein Nanos2 Organizes Post-transcriptional Buffering System to Retain Primitive State of Mouse Spermatogonial Stem Cells Reviewed

    Zhi Zhou, Takayuki Shirakawa, Kazuyuki Ohbo, Aiko Sada, Quan Wu, Kazuteru Hasegawa, Rie Saba, Yumiko Saga

    DEVELOPMENTAL CELL   34 ( 1 )   96 - 107   2015.7

    　More details

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

    DOI： 10.1016/j.devcel.2015.05.014

    Web of Science

    PubMed

    researchmap

  • Epigenetic regulation in stem cell development, cell fate conversion, and reprogramming Reviewed

    Kazuyuki Ohbo, Shin-Ichi Tomizawa

    Biomolecular Concepts   6 ( 1 )   1 - 9   2015.3

    　More details

    Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：De Gruyter Mouton  

    DOI： 10.1515/bmc-2014-0036

    Scopus

    PubMed

    researchmap

  • Stem cell epigenetics: Insights from studies on embryonic, induced pluripotent, and germline stem cells. Reviewed

    Tomizawa, S, Shirakawa, T, Ohbo, K

    Curr Pathobiol Rep   2   1 - 9   2014

    　More details

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

    researchmap

  • An epigenetic switch is crucial for spermatogonia to exit the undifferentiated state toward a Kit-positive identity Reviewed

    Takayuki Shirakawa, Ruken Yaman-Deveci, Shin-Ichi Tomizawa, Yoshito Kamizato, Kuniko Nakajima, Hidetoshi Sone, Yasuyuki Sato, Jafar Sharif, Akio Yamashita, Yuki Takada-Horisawa, Shosei Yoshida, Kiyoe Ura, Masahiro Muto, Haruhiko Koseki, Toshio Suda, Kazuyuki Ohbo

    Development (Cambridge)   140 ( 17 )   3565 - 3576   2013.9

    　More details

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

    DOI： 10.1242/dev.094045

    Scopus

    PubMed

    J-GLOBAL

    researchmap

  • Serum level of HE4 is closely associated with pulmonary adenocarcinoma progression Reviewed

    Shin-ichi Yamashita, Keita Tokuishi, Toshihiko Moroga, Satoshi Yamamoto, Kazuyuki Ohbo, So Miyahara, Yasuhiro Yoshida, Jun Yanagisawa, Daisuke Hamatake, Masafumi Hiratsuka, Yasuteru Yoshinaga, Takeshi Shiraishi, Akinori Iwasaki, Katsunobu Kawahara

    TUMOR BIOLOGY   33 ( 6 )   2365 - 2370   2012.12

    　More details

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

    DOI： 10.1007/s13277-012-0499-8

    Web of Science

    PubMed

    researchmap

  • Splice variant HE4-V3 expression is associated with favorable prognosis in pulmonary adenocarcinoma Reviewed

    Keita Tokuishi, Shin-ichi Yamashita, Kazuyuki Ohbo, Katsunobu Kawahara

    TUMOR BIOLOGY   33 ( 1 )   103 - 109   2012.2

    　More details

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

    DOI： 10.1007/s13277-011-0252-8

    Web of Science

    PubMed

    J-GLOBAL

    researchmap

  • HP1 gamma links histone methylation marks to meiotic synapsis in mice Reviewed

    Yuki Takada, Chie Naruse, Yael Costa, Takayuki Shirakawa, Makoto Tachibana, Jafar Sharif, Fuyuko Kezuka-Shiotani, Dai Kakiuchi, Hiroshi Masumoto, Yo-ichi Shinkai, Kazuyuki Ohbo, Antoine H. F. M. Peters, James M. A. Turner, Masahide Asano, Haruhiko Koseki

    DEVELOPMENT   138 ( 19 )   4207 - 4217   2011.10

    　More details

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

    DOI： 10.1242/dev.064444

    Web of Science

    PubMed

    J-GLOBAL

    researchmap

  • Enhancer of Polycomb 1 is essential for spermiogenesis by regulating histone hyperacetylation status Reviewed

    Dong Yixin, Takada Yuki, Isono Kyo-ichi, Ohbo Kazuyuki, Ogonuki Narumi, Ogura Atsuo, Inoue Kimiko, Toyama Yoshiro, Maekawa Mamiko, Toshimori Kiyotaka, Koseki Haruhiko

    DIFFERENTIATION   80   S29 - S30   2010.11

    　More details

  • The histone 3 lysine 4 methyltransferase, Mll2, is only required briefly in development and spermatogenesis Reviewed

    Stefan Glaser, Sandra Lubitz, Kate L. Loveland, Kazu Ohbo, Lorraine Robb, Frieder Schwenk, Jost Seibler, Daniela Roellig, Andrea Kranz, Konstantinos Anastassiadis, A. Francis Stewart

    EPIGENETICS & CHROMATIN   2 ( 2 )   5   2009.4

    　More details

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

    DOI： 10.1186/1756-8935-2-5

    Web of Science

    researchmap

  • Progress of In Vitro Culture Systems of Spermatogonia

    Ohbo Kazuyuki, Ogawa Takehiko

    Journal of Mammalian Ova Research   26 ( 4 )   178 - 182   2009

    　More details

    Language：Japanese   Publisher：JAPANESE SOCIETY OF OVA RESEARCH  

    Mammalian spermatogenesis is a classic adult stem cell system. Identification of a crucial self renewal factor, glial cell line derived neurotrophic factor (GDNF), has provided new opportunities in cell culture systems of testicular cells. Spermatogonia can be maintained for years in culture with GDNF. Transplantation experiments of cultured spermatogonia have shown that they are able to reconstitute all the germ cells with proper programming in the testes, suggesting that the stem cell population of spermatogonia is maintained <i>in vitro</i> for at least, a couple years. Recently, it has also been reported that cultured spermatogonia have the potency to convert to multi-potent stem cells. The rapid progress of <i>in vitro</i> culture systems of spermatogonia makes it possible to apply the culture systems not only to the study of male infertility but also to regenerative medicine.<br>

    DOI： 10.1274/jmor.26.178

    researchmap

  • A CTX family cell adhesion molecule, JAM4, is expressed in stem cell and progenitor cell populations of both male germ cell and hematopoietic cell lineages Reviewed

    Go Nagamatsu, Masako Ohmura, Takuo Mizukami, Isao Hamaguchi, Susumu Hirabayashi, Shosei Yoshida, Yutaka Hata, Toshio Suda, Kazuyuki Ohbo

    MOLECULAR AND CELLULAR BIOLOGY   26 ( 22 )   8498 - 8506   2006.11

    　More details

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

    DOI： 10.1128/MCB.01502-06

    Web of Science

    PubMed

    researchmap

  • The first round of mouse spermatogenesis is a distinctive program that lacks the self-renewing spermatogonia stage Reviewed

    S Yoshida, M Sukeno, T Nakagawa, K Ohbo, G Nagamatsu, T Suda, Y Nabeshima

    DEVELOPMENT   133 ( 8 )   1495 - 1505   2006.4

    　More details

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

    DOI： 10.1242/dev.02316

    Web of Science

    PubMed

    J-GLOBAL

    researchmap

  • Loss of Tie2 receptor compromises embryonic stem cell-derived endothelial but not hematopoietic cell survival Reviewed

    Hamaguchi, I, T Morisada, M Azuma, K Murakami, M Kuramitsu, T Mizukami, K Ohbo, K Yamaguchi, Y Oike, DJ Dumont, T Suda

    BLOOD   107 ( 3 )   1207 - 1213   2006.2

    　More details

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

    DOI： 10.1182/blood-2005-05-1823

    Web of Science

    researchmap

  • The niche for spermatogonial stem cells in the mammalian testis Reviewed

    T Ogawa, M Ohmura, K Ohbo

    INTERNATIONAL JOURNAL OF HEMATOLOGY   82 ( 5 )   381 - 388   2005.12

    　More details

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

    DOI： 10.1532/IJH97.05088

    Web of Science

    PubMed

    researchmap

  • Spatial analysis of germ stem cell development in Oct-4/EGFP transgenic mice Reviewed

    M Ohmura, S Yoshida, Y Ide, G Nagamatsu, T Suda, K Ohbo

    ARCHIVES OF HISTOLOGY AND CYTOLOGY   67 ( 4 )   285 - 296   2004.11

    　More details

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

    Web of Science

    PubMed

    researchmap

  • Derivation and morphological characterization of mouse spermatogonial stem cell lines Reviewed

    T Ogawa, M Ohmura, Y Tamura, K Kita, K Ohbo, T Suda, Y Kubota

    ARCHIVES OF HISTOLOGY AND CYTOLOGY   67 ( 4 )   297 - 306   2004.11

    　More details

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

    Web of Science

    PubMed

    researchmap

  • Cell adhesion to ephrinb2 is induced by EphB4 independently of its kinase activity Reviewed

    H Sakamoto, XQ Zhang, S Suenobu, K Ohbo, M Ogawa, T Suda

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   321 ( 3 )   681 - 687   2004.8

    　More details

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

    DOI： 10.1016/j.bbrc.2004.07.016

    Web of Science

    PubMed

    researchmap

  • Neurogenin3 delineates the earliest stages of spermatogenesis in the mouse testis Reviewed

    S Yoshida, A Takakura, K Ohbo, K Abe, J Wakabayashi, M Yamamoto, T Suda, Y Nabeshima

    DEVELOPMENTAL BIOLOGY   269 ( 2 )   447 - 458   2004.5

    　More details

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

    DOI： 10.1016/j.ydbio.2004.01.036

    Web of Science

    PubMed

    researchmap

  • Identification and characterization of stem cells in prepubertal spermatogenesis in mice Reviewed

    K Ohbo, S Yoshida, M Ohmura, O Ohneda, T Ogawa, H Tsuchiya, T Kuwana, J Kehler, K Abe, HR Scholer, T Suda

    DEVELOPMENTAL BIOLOGY   258 ( 1 )   209 - 225   2003.6

    　More details

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

    DOI： 10.1016/S0012-1606(03)00111-8

    Web of Science

    PubMed

    researchmap

  • Expression and function of NJ-1 surface antigen in megakaryopoiesis Reviewed

    H Tang, XQ Zhang, T Naruse, K Ohbo, T Suda

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   292 ( 3 )   667 - 674   2002.4

    　More details

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

    DOI： 10.1006/bbrc.2002.6721

    Web of Science

    PubMed

    researchmap

  • Sgn1, a basic helix-loop-helix transcription factor delineates the salivary gland duct cell lineage in mice Reviewed

    S Yoshida, K Ohbo, A Takakura, H Takebayashi, T Okada, K Abe, Y Nabeshima

    DEVELOPMENTAL BIOLOGY   240 ( 2 )   517 - 530   2001.12

    　More details

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

    DOI： 10.1006/dbio.2001.0473

    Web of Science

    researchmap

  • Germline-specific expression of the Oct-4/green fluorescent protein (GFP) transgene in mice Reviewed

    T Yoshimizu, N Sugiyama, M De Felice, Y Il Yeom, K Ohbo, K Masuko, M Obinata, K Abe, HR Scholer, Y Matsui

    DEVELOPMENT GROWTH & DIFFERENTIATION   41 ( 6 )   675 - 684   1999.12

    　More details

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

    Web of Science

    researchmap

  • Synergism with germ line transcription factor Oct-4: Viral oncoproteins share the ability to mimic a stem cell-specific activity Reviewed

    A Brehm, K Ohbo, W Zwerschke, Botquin, V, P Jansen-Durr, HR Scholer

    MOLECULAR AND CELLULAR BIOLOGY   19 ( 4 )   2635 - 2643   1999.4

    　More details

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

    Web of Science

    researchmap

  • Cerebrospinal fluid interleukin 6 in amyotrophic lateral sclerosis: immunological parameter and comparison with inflammatory and non-inflammatory central nervous system diseases Reviewed

    T Sekizawa, H Openshaw, K Ohbo, K Sugamura, Y Itoyama, JC Niland

    JOURNAL OF THE NEUROLOGICAL SCIENCES   154 ( 2 )   194 - 199   1998.2

    　More details

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

    Web of Science

    researchmap

  • Lymphohaematopoietic abnormalities and systemic lymphoproliferative disorder in interleukin-2 receptor gamma chain-deficient mice Reviewed

    M Ikebe, K Miyakawa, K Takahashi, K Ohbo, M Nakamura, K Sugamura, T Suda, K Yamamura, K Tomita

    INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY   78 ( 3 )   133 - 148   1997.6

    　More details

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

    Web of Science

    researchmap

  • The carboxy-terminal transactivation domain of Oct-4 acquires cell specificity through the POU domain Reviewed

    A Brehm, K Ohbo, H Scholer

    MOLECULAR AND CELLULAR BIOLOGY   17 ( 1 )   154 - 162   1997.1

    　More details

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

    Web of Science

    researchmap

  • Demonstration of a cross-talk between IL-2 and IL-5 in phosphorylation of IL-2 and IL-5 receptor beta chains Reviewed

    K Ohbo, H Asao, T Kouro, M Nakamura, S Takaki, Y Kikuchi, K Hirokawa, A Tominaga, K Takatsu, K Sugamura

    INTERNATIONAL IMMUNOLOGY   8 ( 6 )   951 - 960   1996.6

    　More details

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

    Web of Science

    researchmap

  • Germline regulatory element of Oct-4 specific for the totipotent cycle of embryonal cells Reviewed

    YI Yeom, G Fuhrmann, CE Ovitt, A Brehm, K Ohbo, M Gross, K Hubner, HR Scholer

    DEVELOPMENT   122 ( 3 )   881 - 894   1996.3

    　More details

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

    Web of Science

    researchmap

  • Modulation of hematopoiesis in mice with a truncated mutant of the interleukin-2 receptor gamma chain Reviewed

    K Ohbo, T Suda, M Hashiyama, A Mantani, M Ikebe, K Miyakawa, M Moriyama, M Nakamura, M Katsuki, K Takahashi, K Yamamura, K Sugamura

    BLOOD   87 ( 3 )   956 - 967   1996.2

    　More details

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

    Web of Science

    researchmap

  • Retinoic acid-mediated down-regulation of Oct3/4 coincides with the loss of promoter occupancy in vivo Reviewed

    S Minucci, Botquin, V, YI Yeom, A Dey, Sylvester, I, DJ Zand, K Ohbo, K Ozato, HR Scholer

    EMBO JOURNAL   15 ( 4 )   888 - 899   1996.2

    　More details

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

    Web of Science

    researchmap

  • FUNCTIONAL-ANALYSIS OF THE HUMAN INTERLEUKIN-2 RECEPTOR-GAMMA CHAIN GENE PROMOTER Reviewed

    K OHBO, N TAKASAWA, N ISHII, N TANAKA, M NAKAMURA, K SUGAMURA

    JOURNAL OF BIOLOGICAL CHEMISTRY   270 ( 13 )   7479 - 7486   1995.3

    　More details

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

    Web of Science

    researchmap

  • PHYSICAL ASSOCIATION OF JAK1 AND JAK2 TYROSINE KINASES WITH THE INTERLEUKIN-2 RECEPTOR-BETA AND GAMMA-CHAINS Reviewed

    N TANAKA, H ASAO, K OHBO, N ISHII, T TAKESHITA, M NAKAMURA, H SASAKI, K SUGAMURA

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   91 ( 15 )   7271 - 7275   1994.7

    　More details

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

    Web of Science

    researchmap

  • THE IL-2/IL-2 RECEPTOR SYSTEM - INVOLVEMENT OF A NOVEL RECEPTOR SUBUNIT, GAMMA-CHAIN, IN GROWTH SIGNAL TRANSDUCTION Reviewed

    K SUGAMURA, T TAKESHITA, H ASAO, S KUMAKI, K OHBO, K OHTANI, M NAKAMURA

    TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE   168 ( 2 )   231 - 237   1992.10

    　More details

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

    Web of Science

    researchmap

  • MONOCLONAL-ANTIBODIES DEFINING DISTINCT EPITOPES OF THE HUMAN IL-2 RECEPTOR BETA-CHAIN AND THEIR DIFFERENTIAL-EFFECTS ON IL-2 RESPONSES Reviewed

    K OHBO, T TAKESHITA, H ASAO, Y KURAHAYASHI, K TADA, H MORI, M HATAKEYAMA, T TANIGUCHI, K SUGAMURA

    JOURNAL OF IMMUNOLOGICAL METHODS   142 ( 1 )   61 - 72   1991.8

    　More details

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

    Web of Science

    researchmap

  • INTERLEUKIN-6 IN CEREBROSPINAL-FLUID OF HTLV-I-ASSOCIATED MYELOPATHY Reviewed

    K OHBO, K SUGAMURA, T SEKIZAWA, K KOGURE

    NEUROLOGY   41 ( 4 )   594 - 595   1991.4

    　More details

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

    Web of Science

    researchmap

  • MOLECULAR-CLONING AND CHARACTERIZATION OF A NOVEL GLYCOPROTEIN, GP34, THAT IS SPECIFICALLY INDUCED BY THE HUMAN T-CELL LEUKEMIA-VIRUS TYPE-I TRANSACTIVATOR P40TAX Reviewed

    S MIURA, K OHTANI, N NUMATA, M NIKI, K OHBO, Y INA, T GOJOBORI, Y TANAKA, H TOZAWA, M NAKAMURA, K SUGAMURA

    MOLECULAR AND CELLULAR BIOLOGY   11 ( 3 )   1313 - 1325   1991.3

    　More details

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

    Web of Science

    researchmap

  • ESTABLISHMENT OF A CYCLIC ADENOSINE MONOPHOSPHATE-DEPENDENT GROWING HUMAN T-CELL LINE DERIVED FROM AN INTERLEUKIN-2-DEPENDENT CELL-LINE Reviewed

    T TAKESHITA, K OHBO, M NAKAMURA, Y GOTO, K SUGAMURA

    JOURNAL OF CELLULAR PHYSIOLOGY   145 ( 2 )   238 - 243   1990.11

    　More details

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

    Web of Science

    researchmap

  • IL-2-induced signal transduction: Involvement of tyrosine kinase and IL-2 receptor γ chain Reviewed

    K. Sugamura, T. Takeshita, H. Asao, S. Kumaki, K. Ohbo, K. Ohtani, M. Nakamura

    Lymphokine Research   9 ( 4 )   539 - 542   1990

    　More details

    Language：English   Publishing type：Research paper (international conference proceedings)  

    Scopus

    PubMed

    researchmap

  • IL-2 receptor subunit, p75: Direct demonstration of its IL-2 binding ability by using a novel monoclonal antibody Reviewed

    Jun Suzuki, Toshikazu Takeshita, Kazuyuki Ohbo, Hironobu Asao, Keiya Tada, Kazuo Sugamura

    International Immunology   1 ( 4 )   373 - 377   1989.9

    　More details

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

    DOI： 10.1093/intimm/1.4.373

    Scopus

    PubMed

    researchmap

▼display all

MISC

  • 精子幹細胞分化を制御するエピジェネティックな機構の解析

    大保和之, 南澤恵佑, 尾野道男, 中島久仁子, FELLOWS Rachel, 富澤信一

    日本解剖学会総会・全国学術集会抄録集(CD-ROM)   129th   2024

    　More details

  • Role of a novel protease inhibitor for spermatogenesis and immune homeostasis

    富澤信一, FELLOWS Rachel, 尾野道男, 黒羽一誠, DOCKAL Ivana, 南澤恵佑, 鈴木穣, 才津浩智, 大保和之

    日本解剖学会総会・全国学術集会抄録集(CD-ROM)   128th   2023

    　More details

  • Cryptorchidism induces abnormal epigenetic and transcriptional signatures in spermatogonia

    尾野道男, DOCKAL Ivana, RADOVIC Uros, 大保和之, 富澤信一

    日本解剖学会総会・全国学術集会抄録集(CD-ROM)   128th   2023

    　More details

  • WFDCファミリーに属するプロテアーゼインヒビターWFDC2の発現及び機能解析

    林亜葵, 中島久仁子, 尾野道男, 富澤信一, 大保和之

    日本解剖学会総会・全国学術集会抄録集(CD-ROM)   127th   2022

    　More details

  • Regulation of male germ cell development through KMT2B-dependent epigenetic programming

    富澤信一, 小林裕貴, FELLOWS Rachel, 尾野道男, 黒羽一誠, 田中宏光, 河越龍方, 才津浩智, 鈴木穣, 水木信久, 小倉淳郎, 大保和之

    日本解剖学会総会・全国学術集会抄録集(CD-ROM)   127th   2022

    　More details

  • 精子幹細胞分化系列におけるエピジェネティックおよびトランスクリプトームの解析

    富澤信一, 小林裕貴, PETERS Antoine H.F.M., ANASTASSIADIS Konstantinos, STEWART A Francis, 関真秀, 鈴木穣, CLARK Stephen, KELSEY Gavin, 大保和之

    日本分子生物学会年会プログラム・要旨集(Web)   42nd   2019

    　More details

  • エピジェネティックな機構を介した精子発生制御メカニズムの解析

    小林裕貴, 尾野道男, 溝口敬太, 夏目幸治, 富澤信一, 河越龍方, 水木信久, 小倉淳郎, 大保和之

    日本解剖学会総会・全国学術集会講演プログラム・抄録集   124th   2019

    　More details

  • エピジェネティックなエンハンサーマーカーからみた精子幹細胞

    大保和之, 富澤信一

    日本遺伝学会大会プログラム・予稿集   91st   2019

    　More details

  • Kmt2b(H3K4メチル化酵素)遺伝子欠損マウスにおける精細管の微細形態

    尾野道男, 小林裕貴, 富澤信一, 大保和之

    日本解剖学会総会・全国学術集会講演プログラム・抄録集   123rd   2018

    　More details

  • 尾部欠損及び鈎状突起の低形成と三葉化を示した1例

    川村飛翔, 渡辺武俊, 藤本優, 加藤伸忠, 大庭千佳, 祖父江瑤子, 氏赳人, 羽鳥尚寛, 富澤信一, 尾野道男, 鳥本いづみ, 吉田敬一郎, 宮木孝昌, 大保和之

    日本解剖学会総会・全国学術集会講演プログラム・抄録集   121st   2016

    　More details

  • 腎臓において,過剰動脈および回転異常を呈した一例

    荻窪まどか, 長谷川広大, 後藤希実, 張田佳代, 松沼まり, 氏赳人, 羽鳥尚寛, 富澤信一, 尾野道男, 鳥本いづみ, 吉田敬一郎, 宮木孝昌, 大保和之

    日本解剖学会総会・全国学術集会講演プログラム・抄録集   121st   2016

    　More details

  • 新生仔マウスの精原幹細胞の形成と分化における全ゲノムDNAメチル化およびトランスクリプトーム解析

    久保 直樹, 藤 英博, 白根 健次郎, 白川 峰征, 小林 久人, 佐藤 哲也, 曾根 秀利, 佐藤 康人, 富澤 信一, 鶴崎 美徳, 柴田 弘紀, 才津 浩智, 鈴木 穣, 松本 直通, 須山 幹太, 河野 友宏, 大保 和之, 佐々木 裕之

    日本生化学会大会・日本分子生物学会年会合同大会講演要旨集   88回・38回   [1P0606] - [1P0606]   2015.12

    　More details

    Language：English   Publisher：(公社)日本生化学会  

    researchmap

  • エピジェネティクスの視点から見た精原幹細胞分化

    OBO KAZUYUKI

    日本生殖医学会雑誌   60 ( 1/2 )   89   2015.4

    　More details

    Language：Japanese  

    J-GLOBAL

    researchmap

  • 核内微細形態変化とエピジェネティックな変化の精巣幹細胞分化における役割

    富澤信一, 白川峰征, 大保和之

    日本解剖学会総会・全国学術集会講演プログラム・抄録集   119th   2014

    　More details

  • 生殖細胞からみた幹細胞の分化制御システム

    OBO KAZUYUKI

    横浜医学   64 ( 1 )   13 - 19   2013.1

    　More details

  • マウス新生仔期の精原幹細胞の分化におけるメチローム変動

    久保直樹, 藤英博, 白根健次郎, 白根健次郎, 白川峰征, 神里亮人, 曾根秀利, 佐藤康人, 鶴崎美徳, 富澤信一, 柴田弘紀, 才津浩智, 松本直通, 大保和之, 佐々木裕之, 佐々木裕之

    日本分子生物学会年会プログラム・要旨集(Web)   36th   2013

    　More details

  • HE4 EXPRESSION IS ASSOCIATED WITH WORSE PROGNOSIS IN PULMONARY ADENOCARCINOMA

    Shin-Ichi Yamashita, Keita Tokuishi, Toshihiko Moroga, Takafumi Hashimoto, Mirei Kamei, Shuji Suehiro, Kiyoshi Ono, Satoshi Yamamoto, Masao Chujo, Kazuyuki Ohbo, Katsunobu Kawahara

    JOURNAL OF THORACIC ONCOLOGY   6 ( 6 )   S972 - S973   2011.6

    　More details

    Language：English   Publishing type：Research paper, summary (international conference)  

    Web of Science

    researchmap

  • マウス精子形成の初期における幹細胞システムと組織構築の成立

    吉田 松生, 助野 真美子, 中川 俊徳, 大保 和之, 須田 年生, 鍋島 陽一

    日本発生生物学会大会講演要旨集   38回   145 - 145   2005.5

    　More details

    Language：Japanese   Publisher：日本発生生物学会  

    researchmap

  • The interleukin-2 receptor gamma chain: its role in the multiple cytokine receptor complexes and T cell development in XSCID. (Annu Rev Immunol)

    SUGAMURA K, ASAO H, KONDO M, TANAKA N, ISHII N, OHBO K, NAKAMURA M, TAKESHITA T

    Annu Rev Immunol   14   179 - 205   1996

    　More details

  • HTLV-I INFECTION AND IL-2 RECEPTOR EXPRESSION

    M NAKAMURA, K OHBO, N TAKASAWA, K SUGAMURA

    AIDS RESEARCH AND HUMAN RETROVIRUSES   10 ( 4 )   449 - 449   1994.4

    　More details

    Language：English   Publishing type：Research paper, summary (international conference)  

    Web of Science

    researchmap

▼display all

Presentations

  • Kmt2b（H3K4メチル化酵素）遺伝子欠損マウスにおける精細管の微細形態

    尾野道男, 小林裕貴, 富澤信一, 大保和之

    第123回日本解剖学会総会・全国学術総会  2018.3 

    　More details

    Event date： 2018.3

    researchmap

  • エピジェネティクスの視点から見た精原幹細胞分化

    大保 和之

    第60回日本生殖医学会 シンポジウム 1『生殖細胞の産生制御機構』  2015.4 

    　More details

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

    researchmap

  • 精子幹細胞分化に関わるゲノム修飾機構の解析

    大保 和之

    第57回日本組織細胞化学会総会・学術集会 シンポジウム4 配偶子形成・受精・着床の最先端研究  2016.9 

    　More details

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

    researchmap

  • WAP-type four-disulfide core (WFDC) domain family分子群の肺における分子機能について

    大保 和之

    第56回日本呼吸器学会学術講演会サテライトシンポジウム  2016.4 

    　More details

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

    researchmap

  • Role of a mammalian histone H3K4me3 methyltransferase Kmt2b for spermatogonial stem cell differentiation and migration

    Kobayashi Y., Tomizawa SI, Ono M., Ohbo K.

    2018.3 

    　More details

  • ヒストンメチル化酵素による精巣幹細胞分化制御とその意味

    大保 和之

    第122回日本解剖学会総会・全国学術集会 シンポジウム9 精子形成研究のUpdate  2017.3 

    　More details

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

    researchmap

  • Regulation of spermatogenesis by Kmt2b-dependent epigenome in spermatogonial stem cells.

    Kobayashi Y., Tomizawa S., Ono M., Kuroha K., Kawagoe T., Seki M., Suzuki Y., Ogonuki N., Inoue K., Matoba S., Mizuki N., Ogura A., Ohbo K.

    2021.3 

    　More details

  • WFDCファミリーに属するプロテアーゼイン日ビターWFDC2の発現及び機能解析

    林亜葵, 中島久仁子, 尾野道男, 富澤信一, 大保和之

    第126回日本解剖学会総会・全国学術総会  2021.3 

    　More details

  • Role of a novel protease inhibitor for spermatogenesis and immune homeostasis

    2023.3 

    　More details

  • Cryptorchidism induces abnormal epigenetic and transcriptional signatures in spermatogonia

    2023.3 

    　More details

  • 精子幹細胞におけるプライミング機構により制御されているWfdc15aの精子形成における役割

    大保和之

    日本遺伝学95回大会  2023.9 

    　More details

  • Spermatogonial chromatin priming for spermiogenic and post-fertilization development

    2023.6 

    　More details

  • 精子幹細胞分化を制御するエピジェネティックな機構の解析

    大保和之, 南澤恵佑, 尾野道男, 中島久仁子, Rachel Fellows, 富澤信一

    第129回日本解剖学会総会・全国学術総会  2024.3 

    　More details

  • エピジェネティックチェックポイントの精子幹細胞分化における意義について Invited

    大保和之

    第４回有性生殖研究会  2024.3 

    　More details

  • 「DNAメチル化を介した、精巣幹細胞から前駆細胞への運命制御機構

    大保 和之

    第111回日本解剖学会総会・全国学術集会 シンポジウム  2006.3 

    　More details

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

    researchmap

  • 精巣幹細胞特異的発現分子により可視化された幹細胞のゲノム修飾動態

    大保 和之

    第114回日本解剖学会総会・全国学術集会 シンポジウム“生殖系細胞の機能発現とイメージング”  2009.3 

    　More details

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

    researchmap

  • DNAメチル化を介した、精巣幹細胞から前駆細胞への運命決定制御機構の解析

    平成１８年度文部科学省 特定領域研究 生殖細胞の発生プロセス・再プログラム化とエピジェネティクス 公開シンポジウム  2006 

    　More details

  • Changing of chromatin architecture at the transition from stem cells to progenitor cells in testis.

    Cold Spring Harbor Laboratory Meeting on Germ Cells  2006 

    　More details

    Presentation type：Poster presentation  

    researchmap

  • Lack of whey-four disulphide core (WFDC2) protease inhibitor causes neonatal death from respiratory failure in mice

    2020.3 

    　More details

  • エピジェネティックな機構を介した精子発生制御メカニズムの解析

    小林裕貴, 尾野道男, 溝口敬太, 夏目幸治, 富澤信一, 河越龍方, 水木信久, 小倉淳郎, 大保和之

    第124回日本解剖学会総会・全国学術総会  2019.3 

    　More details

  • An epigenetic switch is crucial for spermatogonia to transition from a stem cell to a progenitor identity Invited International conference

    OHBO Kazuyuki

    Gordon Research Conferences Germinal Stem Cell Biology  2013.7 

    　More details

    Language：English   Presentation type：Oral presentation (invited, special)  

    researchmap

  • Analysis of the difference of chromatin architecture between stem cells and progenitor cells in the testes.

    EMBO Conference on Chromatin and Epigenetics  2007 

    　More details

    Presentation type：Poster presentation  

    researchmap

  • ゲノム修飾からみた成体精巣幹細胞分化機構

    大保 和之

    第121回日本解剖学会総会・全国学術集会 シンポジウム“精巣研究の最前線”  2016.3 

    　More details

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

    researchmap

▼display all

Research Projects

  • Effects of paternal histone modification integrated in undifferentiated spermatogonial during early embryogenesis

    Grant number：22H04677  2022.4 - 2024.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    　 More details

    Grant amount：\8320000 （ Direct Cost: \6400000 、 Indirect Cost：\1920000 ）

    researchmap

  • Effects of histone modification primed in spermatogonia stem cells on the next generation totipotency program

    Grant number：20H05370  2020.4 - 2022.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    　 More details

    Grant amount：\7800000 （ Direct Cost: \6000000 、 Indirect Cost：\1800000 ）

    researchmap

  • Analysis of epigenome infertiity mechanism by the state-of-art single cell and ultrtrace histone modification methods

    Grant number：19KK0183  2019.10 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))

    　 More details

    Grant amount：\18460000 （ Direct Cost: \14200000 、 Indirect Cost：\4260000 ）

    researchmap

  • Identification and dynamic analysis of true stem cells in testicular stem cells using the latest single cell analysis method

    Grant number：19K07250  2019.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    　 More details

    Grant amount：\4420000 （ Direct Cost: \3400000 、 Indirect Cost：\1020000 ）

    researchmap

  • International joint research on gamete formation through the cutting-edge analysis system

    Grant number：15K21736  2015.11 - 2018.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    Kobayashi Satoru, MATSUI YASUHISA, YOSHIZAKI GORO, OBATA YAYOI

    　 More details

    Grant amount：\35100000 （ Direct Cost: \27000000 、 Indirect Cost：\8100000 ）

    International joint research was performed, based on the research supported by Grant-in-Aid for Scientific Research on Innovation Area "Mechanisms regulating gamete formation in animals", which aimed to find the regulatory mechanisms of primordial germ cell (PGC) formation and gamete stem cell (GSC) function in animals. This international joint research consisted of constructing an in vitro live-imaging system for spermatogenesis, developing the method to analyze epigenetic regulation of spermatogenesis, and encouraging and supporting tight interaction with oversea researchers through international meetings. This research grant enabled us to establish a novel world-leading research community.

    researchmap

  • Mechanisms regulating gamete formation in animals

    Grant number：25114001  2013.6 - 2018.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    Kobayashi Satoru, OHBO KAZUYUKI, OBATA YAYOI

    　 More details

    Grant amount：\71370000 （ Direct Cost: \54900000 、 Indirect Cost：\16470000 ）

    The Grant-in-Aid for Scientific Research on Innovation Area "Mechanisms regulating gamete formation in animals" aimed to find the regulatory mechanisms of primordial germ cell (PGC) formation and gamete stem cell (GSC) function in diverse animal species. To accomplish this purpose, the researchers using unique organisms, and with different backgrounds, such as in vivo and in vitro analysis, cooperated with each other. This committee encouraged and supported tight interactions within the researchers to establish a novel world-leading research community.

    researchmap

  • Regulatory Mechanism of Gamete Stem Cells

    Grant number：20116001  2008.11 - 2014.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    YOSHIDA Shosei, KOBAYASHI Satoru, YOSHIZAKI Goro, KOBAYASHI Kazuya, NIKI Yuzo, OGAWA Takehiko, OHBO Kazuyuki, ASAOKA Miho

    　 More details

    Grant amount：\53300000 （ Direct Cost: \41000000 、 Indirect Cost：\12300000 ）

    researchmap

  • Regulatory mechanism of mouse GSC/niche system and in vitro spermatogenesis

    Grant number：20116005  2008 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

    OGAWA Takehiko, OHBO Kazuyuki

    　 More details

    Grant amount：\171210000 （ Direct Cost: \131700000 、 Indirect Cost：\39510000 ）

    We succeeded to produce mouse sperm from spermatogonial stem cells (SSCs) in vitro. We adopted an organ culture method, and found that serum replacement was effective to induce complete spermatogenesis in our system. When cultured SSCs were transplanted into the seminiferous tubules of extracted host testes, they also differentiated into sperm in the cultured testis tissues. In addition, we demonstrated that an infertile model mouse, Sl/Sl^d mutant, can be treated with the explantation of their testis tissues.

    researchmap

  • DNAメチル化を介した、精巣幹細胞から前駆細胞への運命決定制御機構の解析

    Grant number：18051014  2006 - 2007

    日本学術振興会  科学研究費助成事業  特定領域研究

    大保 和之

    　 More details

    Grant amount：\5000000 （ Direct Cost: \5000000 ）

    これまで、他の組織幹細胞と同じように、精巣の幹細胞も、より未分化な細胞に発現している分子などを検索し、これを指標に幹細胞の同定、純化を行う試みが成されてきた。その結果、Oct4,Neurogenin3,PLZFなどの新たな分子マーカーが明らかになった。一方、昨今の急速な方法論の進展により、高次の遺伝子発現制御の視点から、クロマチンの様々な修飾を認識する抗体が次々に樹立され、さらにはクロマチン免疫沈降法などにより、より詳細な解析が可能となった。本研究では、この2つの成果を融合し、精巣幹細胞に特徴的クロマチン修飾構造があるか否か、あるとしたらどのようなものであるかを明らかにする研究である。
    主にNeurogenin3を指標とした解析によれば、精巣の幹細胞は比較的低メチル化を示し、denovoのDNAメチル基転移酵素を発現しない細胞集団であることがわかってきた。また、H3Me2K9といった抑制性のヒストン修飾も認められなかった。一方、ポリコム遺伝子群が修飾するH3Me3K27といった修飾は、分化度に関わらず変化が無かった。ゲノム局所における、これら修飾の変化を検証するために、クロマチン免疫沈降法を用いて、主にc-Kit遺伝子周辺を検索したところ、c-Kitを発現する以前からクロマチンはオープンになっているとともに、発現の必要がない遺伝子の発現調節領域には、H3Me3K27の修飾が強く認められた。
    このように、精巣幹細胞に特徴あるクロマチン修飾が認められることが明らかとなった。今後、これらの修飾の変化を手がかりに、ゲノムワイドで検証を行う必要があると考えられる。さらには、その修飾がもたらす幹細胞活性に対する影響の生物学的意義についても、さらなる解析が必要であると考えられた。

    researchmap

  • Transdifferentiation of hematopoietic stem cells and endothelial progenitors

    Grant number：14207042  2002 - 2004

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    OIKE Yuichi, HIRAO Atsushi, OHBO Kazuyuki

    　 More details

    Grant amount：\50960000 （ Direct Cost: \39200000 、 Indirect Cost：\11760000 ）

    In this project, we try to clarify the differentiation pathway to hematopoietic stem cells (HSCs) and vascular endothelial cells from common progenitor cells or hemangioblasts. Hemogenic endothelial cells were defined in dorsal aorta in embryos, while hemangioblasts were not clarified yet at a clonal level in adult bone marrow. Both HSCs and endothelial cells express common surface molecules, CD31, CD34, Flk-1 and Tie2, which is a receptor for angiopoietins (Angs).
    1)We have demonstrated that Tie2-positive HSCs adhere to Ang-1-producing osteoblasts, and that this signal is critical for maintaining the quiescent stem cells (Cell, 2004).
    2)Angiopoietin-like proteins (Angptl) 1 and 2 synergistically show the anti-apoptotic effects on vascular endothelial cells using a Morpholino in Zebrafish.
    3)Surprisingly, Angplt 6 is involved in the energy metabolism as well as angiogenesis. Angptl 6 KO mice show the obesity, while Tg mice show some resistance to obesity and diabetes (Nat.Med.2005).

    researchmap

  • Differentiation of Mesenchymal Stem Cells in Bone Marrow

    Grant number：12557082  2000 - 2002

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    SUDA Toshio, HIRAO Atsushi, OHBO Kazuyuki, OIKE Yuichi

    　 More details

    Grant amount：\13200000 （ Direct Cost: \13200000 ）

    We studied the linkage among osteogenesis, angiogenesis and hematopoiesis in bone marrow formation. Interaction between osteoclasts and osteoblasts is indispensable to form bone and bone cavity as hematopoietic tissues. RANK/RANKL provided new insights into the osteoclast differentiation pathway. We have established a pure osteoclast culture system by isolating precursor cells and cultured in the presence of M-CSF and soluble RANKL. This system revealed that differentiation of osteoclasts is anchorage-dependent and that osteoclastogenesis is completely inhibited by GM-CSF and switched to dendritic cell differentiation by suppression of c-Fos expression. On the other hand, we purified mesenchymal stem cells from perichondrial cells and characterized their differentiation. We show that chondrocytes inhibited the growth of vascular endothelial cells. Eph-ephrin signaling might be involved in the invasion of vascular cells. Now, we are trying to isolate osteoclast-specific molecules by DNA subtraction method between osteoclasts and macrophages derived from common precursor cells. Since these two types of cells express quite similar molecules, osteoclast-specific molecules are enriched. These osteoclast-specific molecules are targets to regulate the osteoclast function.

    researchmap

  • マウス生殖細胞で機能する転写因子および細胞表面レセプターの系統的解析

    Grant number：12206048  2000

    日本学術振興会  科学研究費助成事業  特定領域研究(C)

    吉田 松生, 大保 和之

    　 More details

    <背景と目的>
    マウス精原細胞を通して、生殖細胞の本質に迫ることを目指す。精原細胞は、精巣内で減数分裂に入る前の細胞で、「全能性」、「減数分裂の制御」、「インプリンティング」といった重要な細胞機能を担う。精原細胞の一部は精子形成の「幹細胞」として機能する。しかし、ここで機能する分子の知見は非常に少ない。本研究では、生殖細胞特異的にGFPを発現するトランスジェニック・マウスからセル・ソーティングを行うことにより、少数の精原細胞を高度に純化し、cDNAライブラリーを構築した。これを用いて、精原細胞に発現する転写因子及び細胞表面タンパク質、分泌タンパク質を網羅的に検索した。
    <検討結果>
    転写因子の検索は、転写のco-activatorであるCBP、およびbasic helix-loop-helix型転写因子の共通の結合因子であるE12をbaitとした酵母two-hybrid法を用いた。前者のスクリーニングでは、転写制御に関わると考えられる因子を多数得ている。うちいくつかは生殖細胞に高く発現していた。後者の実験の結果6つのbHLH因子を同定した。ここには非常に未分化な精原細胞に限局して発現する因子、減数分裂の前後に発現する因子が含まれていた。いずれも新規の知見である。
    同一のcDNAより、Signal Sequence Trap法により細胞表面タンパク質や分泌タンパク質の検索を行った。解析が進行中であるが、現在までに367クローンを単離し、塩基配列の決定により46の既知及び未知の分子を同定した。
    <考察>
    本研究で得られた因子が特異的な転写制御複合体を作る可能性、幹細胞や減数分裂の制御を行う可能性が示された。やはり同定されつつある受容体を含む細胞表面分子や分泌因子を介したシグナルが、これら核内因子と機能的連関を持つことにより生殖細胞機能を制御する全体像が明かとなることが期待される。

    researchmap

  • IDENTIFICATION OF DISEASE GENE USING BAC TRANSGENIC MICE

    Grant number：11694296  1999 - 2000

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B).

    YAMAMURA Kenichi, OHBO Kazuyuki, ARAKI Kimi, ABE Kuniya

    　 More details

    Grant amount：\6300000 （ Direct Cost: \6300000 ）

    Chromosome should be replicated without any loss of DNA at the end of chromosome and each one chromosome should be separated into daughter cells while cell division. To accomplish this process, at least three elements, replication origin, telomere, and centromere, are required. In yeast and E.coli, these elements are well characterized and are already cloned. Using these elements, it is now possible to construct artificial chromosome such as yeast artificial chromosome (YAC) or bacterial artificial chromosome (BAC). These artificial chromosomes can be used for isolating a large fragment of DNA spanning to a few hundreds of kb in BAC and a few magabase in YAC.As YAC is quite unstable, use of BAC is becoming more popular. We have tried to establish a method to produce transgenic mice by microinjecting BAC into fertilized eggs. We found that isolation of BAC can be done by pulse field gel electrophoresis, removal of agarose gel fraction containing BAC with about 100 to 200 kb DNA, and digestion of agarose with agarase. The optimum concentration of BAC DNA for microinjection was 1 to 1.5 ng/μl. Although the number of live born mice is lower than that in injection with normal DNA, the overall efficiency of transgenic production was the same and 10 to 60 % of live mice were transgenic. As BAC9 of about 165kb size seems to contain whole qkI gene, we injected these BAC9 and established two lines of transgenic mice. These mice were mated with quaking mice to produce transgenic mice with quaking background. These transgenic mice did not develop quaking phenotype. BAC containing T gene could also rescue the T phenotype. These results clearly suggest that BAC transgenesis can be a powerful tool to test whether the BAC used for transgenesis contains a candidate gene.

    researchmap

  • Study of mechanism of X-licombined immunodeficiency caused by mutations of the IL-2 receptor gamma chain

    Grant number：06404025  1994 - 1996

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    SUGAMURA Kazuo, KASAI Noriyuki, KONNO Tasuke, ASAO Hironobu

    　 More details

    Grant amount：\32900000 （ Direct Cost: \32900000 ）

    Human X-linked severe immunodeficiency (XSCID) is caused by mutations of the common cytokine receptor gamma chain (gammac chain) gene. In this research project, the functional significance of the gammac chain in interacellular signal transduction has been investigated. Consequently, it has been demonstrated that Jak3 tyrosine kinase is associated with the gammac chain, and Jakl is assicuated with the beta chain of IL-2 receptor and alpha chains of IL-4, IL-7 and IL-9 receptor via the box1 regions included in their cytoplasmic domains. Using box1 mutants of the IL-2 receptor beta chain, Jak1 was revealed to be dispensable for cell growth signal transduction mediated by IL-2, whereas Jak3 has been shown to be essential for such signal transduction. We have identified and molecularly cloned a novel signal transducing adaptor molecule named STAM.STAM was revealed to contain an SH3 domain and ITAM (Immunoreceptor tyrosine-based activation motif) region, which are essential for signal tansduction downstream of Jak3. We also generated mice lacking the gammac chain function caused by its mutation. The gammac chain-knockout mice should be a useful model for development of gene-therapy for human XSCID.

    researchmap

  • ジーンターゲッティングによるXSCIDモデルマウスの作出

    Grant number：06770237  1994

    日本学術振興会  科学研究費助成事業  奨励研究(A)

    大保 和之

    　 More details

    Grant amount：\900000 （ Direct Cost: \900000 ）

    1.相同染色体組換え
    昨年度までに作製したマウスインターロイキン2受容体γ鎖のターゲッティングベクターを、ES細胞株、E14-1細胞及びCCE細胞にそれぞれ導入し、サザンブロット法でスクリーニングして、相同染色体組換えを起こしたクローンを得た。これら、クローンよりキメラマウスを作出し、さらにC57BL/6マウスとの交配により得られたマウスをスクリーニングし、組換え体が次世代に伝わっていることを確認した。
    2.表現型の解析
    C57BL/6マウスと継代交配することによりγ鎖のノックアウトマウスを得た。ノックアウトマウスは、胎児致死することなく発育する。表現型を検索した結果、胸腺はとくに皮質が萎縮しており、細胞数は8週令で正常マウスの50分の1であった。特に、CD4+CD8+T細胞、及びCD4-CD8+T細胞が著名に減少していた。CD4+CD8-T細胞は減少しているものの比較的保たれていた。脾臓は正常の大きさであったが、白脾臓の構造がくずれており脾臓内のsIgM陽性B細胞は著名に減少していた。表面抗原の解析からProB細胞からPreB細胞への分化の阻害が認められた。マクロファージは増加していた。骨髄の細胞数はほぼ正常で、構成細胞は脾臓と同様な傾向が認められた。興味深い点として血液幹細胞分画の増加とコロニー形成能が著名に亢進していた。
    3.今後の展開
    今回得られたノックアウトマウスに再度γ鎖を再導入しレスキュー実験を行う。導入するγ鎖には、様々な部分欠失γ鎖遺伝子を用い、再導入された部分欠失遺伝子の欠失部分と、再導入により回復するマウスの表現型をそれぞれ比較することにより、γ鎖の機能ドメインをin vivoで検討する。

    researchmap

  • Tリンパ球特異的チロシンキナーゼItkの細胞増殖分化における役割

    Grant number：06281202  1994

    日本学術振興会  科学研究費助成事業  重点領域研究

    中村 正孝, 大保 和之, 竹下 敏一

    　 More details

    Grant amount：\3300000 （ Direct Cost: \3300000 ）

    ItkはT細胞に特異的に発現しているチロシンキナーゼで、その機能、特にT細胞の増殖分化での役割の解明が待たれている。Itkの機能を解明するために、まず、Itkに対する抗体を樹立した。抗原として、大腸菌で産生したGSTとヒトItkN末端の融合蛋白を用い、ヒトItkに対する単クロン抗体(TUK35)を作成した。本抗体はItkを免疫沈降することができるばかりでなく、ウエスタンブロットでもItkを検出できる。どのような刺激によりItkが活性化されるか調べるために、T細胞を種々の刺激で活性した後、Itkのチロシンリン酸を検討した。抗TCR/CD3あるいはCD28抗体で刺激すると、刺激後早期にItkのチロシンリン酸化が認められた。さらに、抗体による免疫沈降物のなかにFynが含まれており、ItkとFynが細胞内で会合していることが示唆された。転写促進因子として知られるHTLV‐1Taxが、Itkの発現を転写レベルで促進することを証明した。
    機能的なIL‐2受容体は少なくともα鎖、β鎖、γ鎖の3種類のサブユニットより成る。IL‐2によるT細胞増殖に関与するチロシンキナーゼを同定するため、IL‐2受容体に含まれるチロシンキナーゼを検討した。抗β鎖抗体による免疫沈降物中にJAK1チロシンキナーゼ分子が含まれ、抗γ鎖抗体の免疫沈降物にJAK3が含まれていることを見い出した。これらの検出はIL‐2に依存しない。また、IL‐2刺激により、JAK1、JAK3ともチロシンリン酸化され、IL‐2刺激によりこれらのチロシンキナーゼが活性化されるものと考えられる。さらに、β鎖、γ鎖のサブユニットの変異体を用いた実験から、JAK1との会合、活性化にはβ鎖のセリン領域が、JAK3との会合、活性化にはγ鎖のSH2様領域が必要であることも明らかにした。

    researchmap

▼display all