動脈動中の心臓ライアノジン受容体の異常調節
John A Vest1, Xander H T Wehrens, Steven R Reiken
1Department of Physiology and Cellular Biophysics, Clyde and Helen Wu Center for Molecular Cardiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
Circulation
|April 27, 2005
まとめ
タンパク質キナーゼA (PKA) の高酸化による心臓ライオノジン受容体2 (RyR2) からのサルコプラズマ網膜のカルシウム (Ca2+) 漏れは,心房細動 (AF) に寄与する可能性があります. このRyR2機能障害とカルスタビン2結合の低下は,犬とヒトの両方のAFモデルで観察されました.
科学分野:
- 心血管研究 循環器科の研究
- 分子心臓病学 分子心臓病学
- アリズミーのメカニズム アリズミーのメカニズム
背景:
- サルコプラズマ網膜 (SR) からのカルシウム (Ca2+) 漏れは,心房細動 (AF) のような心房不律に関与しています.
- 心臓のライオノジン受容体 (RyR2) のタンパク質キナーゼA (PKA) ハイパーフォスフォリレーションはSR Ca2+ リークと心室不律を引き起こす可能性がありますが,AFにおけるその役割は不明です.
研究 の 目的:
- 心房細動 (AF) に関するRyR2機能障害の役割を調査する.
- RyR2のPKAリン酸化とAFにおけるcalstabin2結合との関連を検証する.
主な方法:
- 犬とヒトのAFと対照から心房組織を採取した.
- 免疫プレシピテーションと免疫ブロッティングを用いて,RyR2とcalstabin2結合のPKAリン酸化を評価した.
- 平面性脂質二重層における RyR2 チャンネル電流を測定した.
主要な成果:
- AF犬とヒトの両方の心房組織は,RyR2のPKAリン酸化が増加し,calstabin2結合が減少したことを示しました.
- AF犬のRyR2チャネルは,ダイアストール中に開く可能性が高くなり,SR Ca2+の漏れの可能性を示唆しました.
- これらの発見は,AFにおけるRyR2チャネル機能不全を示しています.
結論:
- RyR2 PKAハイパーフォスフォリレーションによって媒介されるSR Ca2+漏れは,AFの開始と維持に寄与する可能性があります.
- RyR2機能障害は,心房細動の潜在的メカニズムである.
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