保存されたエジェクションフラクションによる心不全におけるシノアトリアルノード機能障害のメカニズム
Thassio Mesquita1, Rui Zhang1, Jae Hyung Cho1
1Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (T.M., R.Z., J.H.C., R.Z., Y-N.L., L.S., J.I.G., W.L., E.C.).
Circulation
|December 14, 2021
まとめ
心拍の鈍化反応であるクロノトロプ的無能症は,保存されたエジェクション分数 (HFpEF) による心不全のシナートリアルノード (SAN) 機能障害と関連しています. 構造と機能の内在的なSAN異常は,この制限を駆動し,運動能力に影響します.
科学分野:
- 心臓病科
- 生理学
- 分子生物学
背景:
- シノアトリアルノード (SAN) は心臓の鼓動を調節し,重要なホメオスタティックメカニズムです.
- 慢性不完全症は,心拍数の鈍化であり,心不全で運動能力を制限する.
- HFpEFにおけるクロノトロピク不適格性の背後にあるメカニズムは,ほとんど不明である.
研究 の 目的:
- HFpEFにおけるクロノトロプ的無能性のメカニズムを調査する.
- HFpEFモデルにおける鼻腔節 (SAN) 機能とクロノトロプ的応答を特徴づける.
- HFpEF中にSANの分子と構造の変化を特定する.
主な方法:
- 塩分に敏感なダール・ラットとC57Bl6マウスをHFpEFモデルとして使用し,エジェクション分子が低下したHFの心筋梗塞モデルと共に使用した.
- SAN機能の包括的なin vivo,ex vivo,および単細胞電気生理学的研究を実施した.
- トランスクリプトミア分析のためのRNAシーケンシングを行い,ヒトHFpEF SANの計算モデルを開発した.
主要な成果:
- HFpEFモデルでは,限られたクロノトロピク反応,ベータアドレナジック反応の低下,およびSAN内の先導ペースメーカーが交互に動いていることが示された.
- SANの機能障害には,回復時間が長くなり,イソプロテレノールに対する感受性が低下し,アデノシンによる伝導阻害が示された.
- トランスクリプトミカルプロファイリングは,SANの"膜時計"と"Ca2+時計"のHFpEF関連の変化を特定した.
結論:
- クロノトロプ的無能性とSAN機能障害は,HFpEFと,エジェクション分数の減少したHFの両方で存在します.
- SANの構造と機能の内在的な異常は,HFpEFのクロノトロピク応答の制限の根本的な原因として特定されています.
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