研究者業績

永岡 唯宏

ナガオカ タダヒロ  (Tadahiro Nagaoka)

基本情報

所属
藤田医科大学 医科学研究センター 助教
学位
博士(工学)(岡山大学)

研究者番号
70634864
ORCID ID
 https://orcid.org/0000-0002-9391-0243
J-GLOBAL ID
200901003678735202
researchmap会員ID
5000082906

外部リンク

脊椎動物の発生過程で神経管形成に重要な役割を果たす平面内細胞極性因子の生化学的な解析により、神経管形成機構と神経管形成異常で起こる難病「二分脊椎症」の病態解明を目指しています。中でも、蛋白質間相互作用や蛋白質修飾、特にユビキチン化に興味を持っています。

論文

 35
  • Tadahiro Nagaoka, Tatsuya Katsuno, Kyoka Fujimura, Kunihiro Tsuchida, Masashi Kishi
    Scientific reports 13(1) 3905-3905 2023年3月8日  査読有り
    Although the core constituents of the Wnt/planar cell polarity (PCP) signaling have been extensively studied, their downstream molecules and protein-protein interactions have not yet been fully elucidated. Here, we show genetic and molecular evidence that the PCP factor, Vangl2, functionally interacts with the cell-cell adhesion molecule, N-cadherin (also known as Cdh2), for typical PCP-dependent neural development. Vangl2 and N-cadherin physically interact in the neural plates undergoing convergent extension. Unlike monogenic heterozygotes, digenic heterozygous mice with Vangl2 and Cdh2 mutants exhibited defects in neural tube closure and cochlear hair cell orientation. Despite this genetic interaction, neuroepithelial cells derived from the digenic heterozygotes did not show additive changes from the monogenic heterozygotes of Vangl2 in the RhoA-ROCK-Mypt1 and c-Jun N-terminal kinase (JNK)-Jun pathways of Wnt/PCP signaling. Thus, cooperation between Vangl2 and N-cadherin is at least partly via direct molecular interaction; it is essential for the planar polarized development of neural tissues but not significantly associated with RhoA or JNK pathways.
  • Riuko Ohashi, Hajime Umezu, Ayako Sato, Tatsuya Abé, Shuhei Kondo, Kenji Daigo, Seijiro Sato, Norikazu Hara, Akinori Miyashita, Takeshi Ikeuchi, Teiichi Motoyama, Masashi Kishi, Tadahiro Nagaoka, Keiko Horiuchi, Atsushi Shiga, Shujiro Okuda, Tomoki Sekiya, Aya Ohtsubo, Kosuke Ichikawa, Hiroshi Kagamu, Toshiaki Kikuchi, Satoshi Watanabe, Jun-Ichi Tanuma, Peter Schraml, Takao Hamakubo, Masanori Tsuchida, Yoichi Ajioka
    Cells 9(11) 2020年11月3日  査読有り
    Ribosomal RNA (rRNA), the most abundant non-coding RNA species, is a major component of the ribosome. Impaired ribosome biogenesis causes the dysfunction of protein synthesis and diseases called "ribosomopathies," including genetic disorders with cancer risk. However, the potential role of rRNA gene (rDNA) alterations in cancer is unknown. We investigated germline and somatic single-nucleotide variants (SNVs) in the rDNA promoter region (positions -248 to +100, relative to the transcription start site) in 82 lung adenocarcinomas (LUAC). Twenty-nine tumors (35.4%) carried germline SNVs, and eight tumors (9.8%) harbored somatic SNVs. Interestingly, the presence of germline SNVs between positions +1 and +100 (n = 12; 14.6%) was associated with significantly shorter recurrence-free survival (RFS) and overall survival (OS) by univariate analysis (p < 0.05, respectively), and was an independent prognostic factor for RFS and OS by multivariate analysis. LUAC cell line PC9, carrying rDNA promoter SNV at position +49, showed significantly higher ribosome biogenesis than H1650 cells without SNV. Upon nucleolar stress induced by actinomycin D, PC9 retained significantly higher ribosome biogenesis than H1650. These results highlight the possible functional role of SNVs at specific sites of the rDNA promoter region in ribosome biogenesis, the progression of LUAC, and their potential prognostic value.
  • Tadahiro Nagaoka, Mikio Furuse, Toshihisa Ohtsuka, Kunihiro Tsuchida, Masashi Kishi
    Scientific reports 9(1) 2912-2912 2019年2月27日  査読有り
    The PET and LIM domain-containing protein, Prickle, plays a key role in planar cell polarity (PCP) in Drosophila. It has been reported that mutations in the PRICKLE2 gene, which encodes one of the human orthologues of Prickle, are associated with human diseases such as epilepsy and autism spectrum disorder. To develop preventive and therapeutic strategies for these intractable diseases, we studied the regulation of Prickle2 protein levels in transfected HEK293T cells. Prickle2 levels were negatively regulated by a physical interaction with another PCP protein, Van Gogh-like 2 (Vangl2). The Vangl2-mediated reduction in Prickle2 levels was, at least in part, relieved by proteasome inhibitors or by functional inhibition of the Cullin-1 E3 ubiquitin ligase. Furthermore, the expression of Vangl2 enhanced the polyubiquitination of Prickle2. This ubiquitination was partially blocked by co-expression of a ubiquitin mutant, which cannot be polymerised through their Lys48 residue to induce target proteins toward proteasomal degradation. Together, these results suggest that Prickle2 is polyubiquitinated by the Vangl2 interaction in a Cullin-1-dependent manner to limit its expression levels. This regulation may play a role in the local and temporal fine-tuning of Prickle protein levels during PCP signal-dependent cellular behaviours.
  • Tadahiro Nagaoka, Masashi Kishi
    NEUROSCIENCE LETTERS 612 251-255 2016年1月  査読有り
    The excitatory postsynaptic region of the vertebrate hippocampus is usually compartmentalized into the postsynaptic density (PSD) and N-cadherin-rich domain, which is important for synaptic adhesion. However, the molecular mechanisms underlying the compartment formation are unknown. In the present report, we show that the planar cell polarity (PCP) protein Van Gogh-like 2 (Vangl2) plays a role in this regionalization. In cultured rat hippocampal neurons that were subjected to Vangl2 expression silencing, the formed clusters of PSD-95, one of the major scaffolding proteins in PSD, tended to overlap with those of N-cadherin. Further, in the dendrites of these neurons, the immunofluorescence of PSD-95 was to some extent diffused, without a significant change in the total signal. Because Vangl2 physically interacts with both PSD-95 and N-cadherin in vivo, these results suggest that a PCP-related direct molecular mechanism underlies the horizontal polarization of the postsynaptic regions. (c) 2015 Elsevier Ireland Ltd. All rights reserved.
  • Tadahiro Nagaoka, Katsuhiko Tabuchi, Masashi Kishi
    SCIENTIFIC REPORTS 5 12916 2015年8月  査読有り
    Postsynaptic density-95/Discs large/Zonula occludens-1 (PDZ) domain-mediated protein interactions play pivotal roles in various molecular biological events, including protein localisation, assembly, and signal transduction. Although the vertebrate regulator of planar cell polarity Van Gogh-like 2 (Vangl2) was recently described as a postsynaptic molecule with a PDZ-binding motif, the role of its PDZ interaction at the synapse is unknown. In this report, we demonstrate that the PDZ interaction was dispensable for the normal cluster formation of Vangl2 and not absolutely required for the synapse-associated localisation of Vangl2 in cultured hippocampal neurons. We further showed that the synaptic localisation of Vangl2 was categorised into two types: overlapping co-localisation with postsynaptic density (PSD)-95 or highly correlated but complementary pattern of association with PSD-95. Only the former was significantly sensitive to deletion of the PDZ-binding motif. In addition, the PDZ interaction enhanced the protein interactions between PSD-95 and Prickle2, which is another planar cell polarity factor that is localised at the postsynaptic density. Taken together with our recent report that the density of PSD-95 clusters was reduced in Vangl2-silenced neurons, these results suggest that Vangl2 determines the complex formation and clustering of postsynaptic molecules for synaptogenesis in mammalian brains.

MISC

 5

講演・口頭発表等

 12

担当経験のある科目(授業)

 8
  • 2021年1月 - 現在
    医学研究演習  (藤田医科大学)
  • 2020年5月 - 現在
    生命科学特論I  (藤田医科大学 大学院医学研究科修士課程)
  • 2018年4月 - 現在
    卒業研究  (藤田医科大学 医療科学部)
  • 2022年10月 - 2024年3月
    解剖生理学実験  (中京学院大学 短期大学部健康栄養学科)
  • 2022年4月 - 2023年8月
    解剖生理学A  (中京学院大学 短期大学部健康栄養学科)
  • 2020年10月 - 2022年8月
    解剖学実験  (中京学院大学 短期大学部)
  • 2020年4月 - 2022年3月
    解剖学  (中京学院大学 短期大学部)
  • 2004年4月 - 2005年10月
    生物学  (岡山労災看護専門学校)

共同研究・競争的資金等の研究課題

 8

社会貢献活動

 2

教育内容・方法の工夫(授業評価等を含む)

 3
  • 件名
    大学院医学研究科 修士課程 生命科学特論I
    開始年月日
    2020/05/11
  • 件名
    医療科学部 臨床検査学科 卒業論文指導
    開始年月日
    2019/06/10
    終了年月日
    2019/10/15
  • 件名
    医療科学部 臨床工学科 卒業論文指導
    開始年月日
    2018/04/09

その他教育活動上特記すべき事項

 2
  • 件名
    アセンブリII 皆でサイエンス・カフェを企画・運営してみよう!
    開始年月日
    2020/05/18
    終了年月日
    2020/06/29
  • 件名
    アセンブリI ランニング班
    開始年月日
    2018/05/14
    終了年月日
    2019/11/25