General Education

中島 昭

ナカシマ アキラ  (Nakashima Akira)

基本情報

所属
藤田医科大学 医学部 医学科 生理化学 教授
医学教育企画室(兼務) 副室長
学位
博士(医学)(藤田保健衛生大学)

通称等の別名
ナカシマアキラ
J-GLOBAL ID
200901085737243854
researchmap会員ID
1000102599

研究キーワード

 3

論文

 52
  • Yu Kodani, Miho Kawata, Hidetaka Suga, Takatoshi Kasai, Chikafumi Ozone, Mayu Sakakibara, Atsushi Kuwahara, Shiori Taga, Hiroshi Arima, Toshiki Kameyama, Kanako Saito, Akira Nakashima, Hiroshi Nagasaki
    Frontiers in Endocrinology 13 941166-941166 2022年7月12日  査読有り
    Human stem cell-derived organoid culture enables the in vitro analysis of the cellular function in three-dimensional aggregates mimicking native organs, and also provides a valuable source of specific cell types in the human body. We previously established organoid models of the hypothalamic-pituitary (HP) complex using human pluripotent stem cells. Although the models are suitable for investigating developmental and functional HP interactions, we consider that isolated pituitary cells are also useful for basic and translational research on the pituitary gland, such as stem cell biology and regenerative medicine. To develop a method for the purification of pituitary cells in HP organoids, we performed surface marker profiling of organoid cells derived from human induced pluripotent stem cells (iPSCs). Screening of 332 human cell surface markers and a subsequent immunohistochemical analysis identified epithelial cell adhesion molecule (EpCAM) as a surface marker of anterior pituitary cells, as well as their ectodermal precursors. EpCAM was not expressed on hypothalamic lineages; thus, anterior pituitary cells were successfully enriched by magnetic separation of EpCAM+ cells from iPSC-derived HP organoids. The enriched pituitary population contained functional corticotrophs and their progenitors; the former responded normally to a corticotropin-releasing hormone stimulus. Our findings would extend the applicability of organoid culture as a novel source of human anterior pituitary cells, including stem/progenitor cells and their endocrine descendants.
  • Yu Kodani, Miho Kawata, Hidetaka Suga, Yoko S Kaneko, Akira Nakashima, Toshiki Kameyama, Kanako Saito, Hiroshi Nagasaki
    eNeuro 2022年4月18日  
    Hypothalamic melanin-concentrating hormone (MCH) neurons are important regulators of multiple physiological processes, such as sleep, feeding, and memory. Despite the increasing interest in their neuronal functions, the molecular mechanism underlying MCH neuron development remains poorly understood. We report that a three-dimensional culture of mouse embryonic stem cells (mESCs) can generate hypothalamic-like tissues containing MCH-positive neurons, which reproduce morphologic maturation, neuronal connectivity, and neuropeptide/neurotransmitter phenotype of native MCH neurons. Using this in vitro system, we demonstrate that Hedgehog (Hh) signaling serves to produce major neurochemical subtypes of MCH neurons characterized by the presence or absence of cocaine- and amphetamine-regulated transcript (CART). Without exogenous Hh signals, mESCs initially differentiated into dorsal hypothalamic/prethalamic progenitors and finally into MCH+CART+ neurons through a specific intermediate progenitor state. Conversely, activation of the Hh pathway specified ventral hypothalamic progenitors that generate both MCH+CART- and MCH+CART+ neurons. These results suggest that in vivo MCH neurons may originate from multiple cell lineages that arise through early dorsoventral patterning of the hypothalamus. Additionally, we found that Hh signaling supports the differentiation of mESCs into orexin/hypocretin neurons, a well-defined cell group intermingled with MCH neurons in the lateral hypothalamic area (LHA). The present study highlights and improves the utility of mESC culture in the analysis of the developmental programs of specific hypothalamic cell types.Significance StatementA growing body of literature has revealed the importance of hypothalamic melanin-concentrating hormone (MCH) neurons in energy homeostasis and the cognitive function, but their developmental biology remains relatively unknown. To establish a new approach for addressing this issue, we tested the ability of an in vitro differentiation system of mouse embryonic stem cells (mESCs) to recapitulate the development of MCH neurons. The mESC culture robustly generated MCH-positive neurons resembling native neurons in several aspects and provided evidence that Hedgehog (Hh) signaling is a key factor to produce neurochemical subtypes of MCH neurons. Our results demonstrate the suitability of mESC culture as a platform to study the molecular mechanisms underlying the development of MCH neurons and possibly of other hypothalamic cell types.
  • Miho Kawata, Yu Kodani, Mahito Ohkuma, Ei-Ichi Miyachi, Yoko S Kaneko, Akira Nakashima, Hidetaka Suga, Toshiki Kameyama, Kanako Saito, Hiroshi Nagasaki
    PloS one 17(11) e0276694 2022年  
    The hypothalamus is comprised of heterogenous cell populations and includes highly complex neural circuits that regulate the autonomic nerve system. Its dysfunction therefore results in severe endocrine disorders. Although recent experiments have been conducted for in vitro organogenesis of hypothalamic neurons from embryonic stem (ES) or induced pluripotent stem (iPS) cells, whether these stem cell-derived hypothalamic neurons can be useful for regenerative medicine remains unclear. We therefore performed orthotopic transplantation of mouse ES cell (mESC)-derived hypothalamic neurons into adult mouse brains. We generated electrophysiologically functional hypothalamic neurons from mESCs and transplanted them into the supraoptic nucleus of mice. Grafts extended their axons along hypothalamic nerve bundles in host brain, and some of them even projected into the posterior pituitary (PPit), which consists of distal axons of the magnocellular neurons located in hypothalamic supraoptic and paraventricular nuclei. The axonal projections to the PPit were not observed when the mESC-derived hypothalamic neurons were ectopically transplanted into the substantia nigra reticular part. These findings suggest that our stem cell-based orthotopic transplantation approach might contribute to the establishment of regenerative medicine for hypothalamic and pituitary disorders.
  • Akira Nakashima, Hisateru Yamaguchi, Mii Kondo, Takahiro Furumura, Yu Kodani, Yoko S Kaneko, Miho Kawata, Hiroshi Nagasaki, Toshiharu Nagatsu, Akira Ota
    Journal of neural transmission (Vienna, Austria : 1996) 2020年8月10日  査読有り
    5'-Nucleotidase domain-containing protein 2 (NT5DC2) has been revealed by genome-wide association studies (GWAS) as a gene implicated in neuropsychiatric disorders related to the abnormality of dopamine (DA) activity in the brain. Based on its amino acid sequence, NT5DC2 is assumed to be a member of the family of haloacid dehalogenase-type phosphatases; although there is no information about its function and structural conformation. We recently reported that NT5DC2 binds to tyrosine hydroxylase (TH) and that the down-regulation of NT5DC2 tended to increase DA synthesis. In this study, we investigated whether NT5DC2 could regulate the catalytic activity of TH, which converts tyrosine to DOPA, because the phosphorylation level of TH, controlled by protein kinases and phosphatases, is well known to regulate its catalytic activity. The down-regulation of NT5DC2 by siRNA increased mainly DOPA synthesis by TH in PC12D cells, although this down-regulation tended to increase the conversion of DOPA to DA by aromatic L-amino acid decarboxylase. The increased DOPA synthesis should be attributed to the catalytic activity of TH controlled by its phosphorylation, because Western blot analysis revealed that the down-regulation of NT5DC2 tended to increase the level of TH phosphorylated at its Ser residues, but not that of the TH protein. Moreover, the induction of kinase activity by forskolin markedly potentiated the phosphorylation of TH at its Ser40 in PC12D cells having down-regulated NT5DC2. Immunocytochemical analysis of PC12D cells demonstrated that NT5DC2, TH protein, and TH phosphorylated at its Ser40 were predominantly localized in the cytoplasm and that the localization of NT5DC2 and TH proteins partially overlapped. Collectively, our results indicate that NT5DC2 could work to inhibit the DOPA synthesis by decreasing the phosphorylation of TH at its Ser40. We propose that NT5DC2 might decrease this phosphorylation of TH by promoting dephosphorylation or by inhibiting kinase activity.
  • Nakashima A, Yamaguchi H, Kodani Y, Kaneko YS, Kawata M, Nagasaki H, Nagatsu T, Ota A
    Biochemical and biophysical research communications 516(4) 1060-1065 2019年9月  査読有り

MISC

 34

書籍等出版物

 7

講演・口頭発表等

 28

担当経験のある科目(授業)

 6

共同研究・競争的資金等の研究課題

 7

教育内容・方法の工夫(授業評価等を含む)

 1
  • 件名
    生理学授業へのe-learningによる自己学習システムの導入
    開始年月日
    2011/01
    終了年月日
    2011/03
    概要
    e-learning教材「一歩一歩学ぶ生命科学」をmoodleシステムに組み込み、生理学講義受講前の学生に自己学習をさせることにより生理学講義の理解を助けるシステムを構築した。

作成した教科書、教材、参考書

 1
  • 件名
    新訂・生理学実習書、日本生理学会教育委員会編/ 編集委員/ 南江堂
    終了年月日
    2013/10
    概要
    生理学実習を行うための教員・学生のための実習書を作成した(分担編集)

教育方法・教育実践に関する発表、講演等

 2
  • 件名
    生理学授業へのe-learningによる自己学習システムの導入事例の報告
    終了年月日
    2011/10
    概要
    第43回藤田医学会で報告した。
  • 件名
    学生指導で注意していること(藤田保健衛生大学・医学部・指導教員懇談会・講演)
    終了年月日
    2012/07
    概要
    指導教員に対する学生の指導方法について

その他教育活動上特記すべき事項

 2
  • 件名
    学内医学教育ワークショップの開催(第27回〜57回、計30回)
    開始年月日
    2008/04
    終了年月日
    2015/09
    概要
    医学教育企画室による学内教員向けワークショップの開催と運営(試験問題の作り方、ポートフォリオ導入、PBLテュータトレーニングなど)
  • 件名
    基礎統合実習の開催(2005年・第1回〜2015年・第11回、学外活動)
    開始年月日
    2005/08
    終了年月日
    2015/08
    概要
    生理学・病理学・生化学など基礎医学系全ての知識を基にして、学生が自ら考えた仮設を実験で検証する「真実を探求」することを目的とした実習を全国の医学生を集めて開催