节拍锁定的ATP微域在鼻腔节点中映射了Ca2+计时的能量层次和区域节拍器作用
Manuel F Muñoz1, Collin Matsumoto1, Paula Rhana1
1Department of Physiology & Membrane Biology, School of Medicine, University of California, Davis, USA.
bioRxiv : the preprint server for biology
|September 2, 2025
概括
节节拍细胞表现出每次节拍的ATP调节,不同的代谢微域与心率协调能量供应. 这种钟控制氧化酸化,影响细胞功能和心律.
科学领域:
- 心脏电生理学
- 线粒体新陈代谢
- 细胞生理学
背景情况:
- 鼻腔 (SA) 节点心脏起器细胞通过合电压和振荡器产生心跳.
- 这些细胞中腺三酸盐 (ATP) 供应的节拍调节仍不清楚.
- 了解能量动态对于SA节点功能和心率控制至关重要.
研究的目的:
- 在SA节点节拍细胞中研究节拍解析的ATP动态.
- 阐明Ca2+和ATP生成之间的关系.
- 了解SA节点内的代谢异质性的空间组织和功能影响.
主要方法:
- 使用基因编码传感器实时监测未损坏的小鼠SA节点和分离的肌细胞中的细胞和线粒体ATP.
- 使用药理剂 (伊瓦布拉丁,塔西加丁,FCCP) 来探测Ca2+时钟对ATP产生的影响.
- 在完整的SA节点内分析了ATP表型的空间分布.
主要成果:
- 细胞质ATP呈现与Ca2+过渡物同步的短暂增加,观察到明显的高和低增益表型.
- 线粒体ATP流显示了两种模式:模式-1 (增长) 和模式-2 (下降),与Ca2+负载和细胞发射率相关.
- 这些表型在SA节点内的独特空间定位与心率,线粒体体积和毛细体密度的梯度并行.
结论:
- 上游的Ca2+时钟调节SA结节肌细胞中的节拍锁定氧化酸化.
- 节拍锁定的代谢微域统一了血管结构,线粒体组织和Ca2+信号,以匹配能量供应和兴奋性.
- 代谢异质性有助于SA节点内的功能专业化,影响速率控制和带宽.
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