Oxidation of Ryanodine Receptor (RyR) and Calmodulin enhance Ca release and pathologically alter RyR structure and Calmodulin affinity

• Project/Area Number: 26670403
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Cardiovascular medicine
• Research Institution: Yamaguchi University
• Principal Investigator: ODA Tetsuro 山口大学, 医学部附属病院, 助教 (40569290)
• Co-Investigator(Kenkyū-buntansha): YAMAMOTO Takeshi 山口大学, 大学院医学系研究科, 准教授 (50363122)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 分子心臓学 / リアノジン受容体 / 酸化ストレス / カルモジュリン / ドメイン連関障害 / ダントロレン

Outline of Final Research Achievements

Oxidative stress contribute to cardiac ryanodine receptor (RyR2) dysfunction in heart failure (HF). However, effects of oxidative stress on RyR2 conformation and leak in myocytes are poorly understood. We used fluorescent CaM, FKBP12.6, and domain-peptide biosensor (F-DPc10) to measure (1) RyR2 activation by hydrogen peroxide (H2O2)-induced oxidation, (2) RyR2 conformation change caused by oxidation, (3) CaM-RyR2 and FK506-binding protein (FKBP12.6)-RyR2 interaction upon oxidation, and (4) whether dantrolene affects 1-3. H2O2 significantly increased the frequency of Ca2+ sparks and dantrolene almost completely blocked this effect. H2O2 significantly reduced CaM-RyR2 binding, but had no effect on FKBP12.6-RyR2 binding. Dantrolene restored CaM-RyR2 binding but had no effect on oxidation levels. H2O2 also accelerated F-DPc10-RyR2 association while dantrolene slowed it. Thus, H2O2 causes conformational changes, and dantrolene reverses these RyR2 effects.

Research Products

• [Journal Article] Oxidation of Ryanodine Receptor (RyR) and Calmodulin enhance Ca release and pathologically alter RyR structure and Calmodulin affinity (2015)
  • Author(s): Tetsuro Oda, Yi Yang, Hitoshi Uchinoumi, David D. Thomas, Ye Chen-Izu, Takayoshi Kato, Takeshi Yamamoto, Masafumi Yano, Razvan L. Cornea, Donald M. Bers
  • Journal Title: Journal of Molecular and Cellular Cardiology Volume: 85 Pages: 240-248
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] In cardiomyocytes, dantrolene can correct defective domain interaction caused by oxidation, and restore calmodulin binding affinity in RyR2 (2015)
  • Author(s): 小田 哲郎
  • Organizer: 日本循環器学会
  • Place of Presentation: 大阪 (大阪国際会議場）
  • Year and Date: 2015-04-24 – 2015-04-26