Functional analysis of nephrotic syndrome caused by TRPC6 gene mutation and new drug development

• Project/Area Number: 17K16262
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Pediatrics
• Research Institution: Kobe University
• Principal Investigator: Nakanishi Keita 神戸大学, 医学研究科, 特命助教 (00793712)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 遺伝性ネフローゼ症候群 / TRPC6 / ミトコンドリア機能異常 / ステロイド抵抗性ネフローゼ症候群 / NGSを用いた遺伝子解析 / ネフローゼ症候群 / TRPC6遺伝子 / 機能解析

Outline of Final Research Achievements

We analyzed Japanese patients diagnosed with steroid resistant nephrotic syndrome by next generation sequencer and detected some kinds of gene defects which were reported as the causative genes of nephrotic syndrome.
For analysis of TRPC6 mutations, Ca influx was performed by transfected the cTRCP6 into human-derived cells. It was confirmed that the increase of intracellular Ca concentration was suppressed with Larixyl Acetate. In the future, we plan to transfect cTRPC6 containing mutations into human-derived cells, and to confirm whether changes in Ca concentration are observed by the introduction of mutations.

Academic Significance and Societal Importance of the Research Achievements

ステロイド抵抗性ネフローゼ症候群に対する次世代シークエンサーを用いた解析結果から、日本における遺伝性ネフローゼ症候群の割合を明らかにすることができた。遺伝性ネフローゼ症候群の中には特別な治療によって腎予後を改善できる遺伝子も含まれており、診断する意義が高いと考えられた。
TRPC6に対する機能解析については、正常のTRPC6遺伝子導入を行ったヒト由来細胞でCa influxを行った結果、Larixyl Acetateによって細胞内Ca濃度上昇が抑制された。Larixyl AcetateがTRPC6遺伝子異常例に対する新薬となる可能性が考えられた。

Research Products

• [Journal Article] Pair analysis and custom array CGH can detect a small copy number variation in COQ6 gene (2018)
  • Author(s): Nakanishi Keita、Okamoto Takayuki、Nozu Kandai、Hara Shigeo、Sato Yasuyuki、Hayashi Asako、Takahashi Toshiyuki、Nagano China、Sakakibara Nana、Horinouchi Tomoko、Fujimura Junya、Minamikawa Shogo、Yamamura Tomohiko、Rossanti Rini、Nagase Hiroaki、Kaito Hiroshi、Ariga Tadashi、Iijima Kazumoto
  • Journal Title: Clinical and Experimental Nephrology Volume: 23 Issue: 5 Pages: 669-675
  • DOI: 10.1007/s10157-018-1682-z
  • NAID: 120006644119
  • Peer Reviewed
• [Presentation] ステロイド抵抗性ネフローゼ症候群における網羅的遺伝子診断体制の構築 (2018)
  • Author(s): 中西啓太、 野津寛大、榊原菜々、長野智那、藤村順也、 堀之内智子、南川将吾、山村智彦、貝藤裕史、島友子、中西浩一、飯島一誠
  • Organizer: 第61回日本腎臓学会学術総会
• [Presentation] An Infantile Nephrotic Syndrome Case Caused by COQ6 Gene Defects Revealed by Pair Analysis and Custom Array CGH (2018)
  • Author(s): Keita Nakanishi, Kandai Nozu, Takayuki Okamoto, Asako Hayashi, Toshiyuki Takahashi, Nana Sakakibara, China Nagano, Junya Fujimura, Tomoko Horinouchi, Shogo Minamikawa, Tomohiko Yamamura, Hiroshi Kaito, Yuko Shima, Koichi Nakanishi, Kazumoto Iijima
  • Organizer: ASN Kidney Week 2018
  • Int'l Joint Research
• [Presentation] The comprehensive gene screening for congenital, infantile, and steroid-resistant nephrotic syndrome in Japan (2018)
  • Author(s): Keita Nakanishi
  • Organizer: ISN FRONTIER 2018
  • Int'l Joint Research
• [Presentation] 先天性ネフローゼ症候群／乳児ネフローゼ症候群およびステロイド抵抗性ネフローゼ症候群における網羅的遺伝子診断体制の構築 (2017)
  • Author(s): 中西 啓太
  • Organizer: 2017年日本小児腎臓病学会学術集会
• [Presentation] The comprehensive gene screening for congenital, infantile, and steroid-resistant nephrotic syndrome in Japan (2017)
  • Author(s): Keita Nakanishi
  • Organizer: ASN Kidney Week 2017
  • Int'l Joint Research
• [Funded Workshop] ASN Kidney Week 2018 (2018)