脂聚糖诱导的败血症会损害小鼠鼻腔节点中的M2R-GIRK信号传递
Niroj Shrestha1, Klaus Zorn-Pauly1, Pietro Mesirca2,3
1Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical Physics and Biophysics, Medical University of Graz, 8010 Graz, Austria.
概括
败血症通过破坏肌肉受体2-G蛋白激活的内向校正通道信号传递在鼻腔节点中,损害了心率变化 (HRV). 这种分子机制降低了心率,并在败血症中损害了副交感反应.
科学领域:
- 心血管生理学心血管生理学
- 分子心脏病学分子心脏病学
- 败血症病理生理学病理生理学
背景情况:
- 败血症是一种全球性卫生危机,死亡率高,通常与心率变化 (HRV) 的受损有关.
- 败血症中的HRV降低与对寄生交感刺激的心脏反应和相关,但在鼻腔节点 (SAN) 的潜在分子机制仍然不清楚.
研究的目的:
- 调查在败血症期间SAN中偏交感信号受损的分子机制.
- 确定肌性受体2-G蛋白激活向内纠正通道 (M2R-GIRK) 信号在败血症引起的心脏功能障碍中的作用.
主要方法:
- 利用脂多糖诱导性败血症的小鼠模型.
- 使用心电图,Ca2+成像,电生理学和蛋白质测试.
- 分析了小鼠SAN组织和人类右心房附属体.
主要成果:
- 败血症显著减弱了SAN细胞中的副交感反应,包括IKACh激活和减少Ca2+调动.
- 在败血症小鼠和人类患者的SAN组织中观察到M2R,GIRK1和GIRK4离子通道组件的减少表达.
- 这些功能缺陷并非由常见的促炎细胞因子调解.
结论:
- 损坏的M2R-GIRK信号传递是导致败血症SAN功能障碍和HRV异常的关键分子机制.
- 这一途径代表了管理与败血症相关的心脏并发症的潜在治疗标.
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