在心脏衰竭中节功能障碍的机制
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
概括
慢性无能症,即心率减弱的反应,与心脏衰竭中阴耳节 (SAN) 功能障碍有关. 结构和功能的内在SAN异常导致这种限制,影响运动能力.
科学领域:
- 心脏病学
- 生理学
- 分子生物学
背景情况:
- 鼻腔节点 (SAN) 调节心率,这是一个关键的平衡机制.
- 慢性无能,心率减弱反应,限制心力衰竭的运动能力与保存的射出分数 (HFpEF).
- 在HFpEF中,慢性无能性背后的机制在很大程度上是未知的.
研究的目的:
- 调查HFpEF中慢性无能性的机制.
- 在HFpEF模型中描述鼻腔节点 (SAN) 功能和时间反应.
- 在HFpEF期间识别SAN的分子和结构变化.
主要方法:
- 用达尔对盐敏感的老鼠和C57Bl6小鼠作为HFpEF模型,以及减少喷射分数的心肌梗塞模型.
- 对SAN功能进行了全面的体内,体外和单细胞电生理学研究.
- 进行了转录组分析的RNA测序,并开发了人类HFpEF SAN的计算模型.
主要成果:
- 在HFpEF模型中表现出有限的慢性反应,受损的β-上腺素反应,以及SAN内的交替主导心脏起器.
- SAN功能障碍包括延长恢复时间,降低对异二醇的敏感性,以及通过腺挑战显示的导电阻塞.
- 转录基因分析在SAN的"膜时钟"和"Ca2+时钟"中发现了与HFpEF相关的改变.
结论:
- 在HFpEF和减少喷射分数的HF模型中存在慢性无能和SAN功能障碍.
- 在HFpEF中,SAN结构和功能的内在异常被确定为慢性反应限制的根本原因.
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