通过两种不同的电压通的Ca2+通道调节人心线粒体Ca2+吸收
Guido Michels1, Ismail F Khan, Jeannette Endres-Becker
1Department of Internal Medicine III, University of Cologne, Cologne, Germany.
Circulation
|April 29, 2009
概括
研究人员在人类心脏中发现了两个新的线粒体通道mCa1和mCa2. 它们在心力衰竭中的功能受损表明它们在心肌病发育和改变细胞代谢中的作用.
科学领域:
- 心脏病学 心脏病学
- 线粒体生物学 线粒体生物学
- 离子通道生理学 离子通道生理学
背景情况:
- 心肌病与细胞内 (Ca2+) 稳态和线粒体功能障碍受损有关.
- 线粒体Ca2+吸收主要归因于Ca2+单载体 (MCU) 和一种非MCU途径,尽管它们的身份仍在争论中.
- 在疾病状态期间,这些通路的功能性变化尚未得到充分理解.
研究的目的:
- 识别和描述人类心脏内线粒体膜中的新型Ca2+选择性通道.
- 在心力衰竭的背景下,研究这些通道的特性和功能变化.
主要方法:
- 补丁电生理学被用来记录Ca2+电流通过线粒体内膜从不失败和失败的人类心脏.
- 评估了对360和红的药理敏感性.
- 评估了精氨酸的激活.
主要成果:
- 两种新的Ca2+选择性通道,mCa1和mCa2,被确定具有明显的电压依赖的关特性.
- mCa1表现出更高的振幅,更短的开口,更低的开放概率和次导状态,并且被360抑制,这表明它是MCU的基础.
- mCa2对360不敏感,但对高度敏感,并且可能代表非MCU通路. 这两个通道都被精子激活.
- 与没有失败的心脏相比,mCa1和mCa2通道的活性在失败的人类心脏中显著下降.
结论:
- 人类线粒体Ca2+吸收由两个不同的道介导,mCa1 (MCU) 和mCa2 (非MCU通道).
- 这些通道在心力衰竭中功能受损,导致Ca2+吸收减少,并可能改变新陈代谢.
- 这些发现阐明了心肌病中线粒体功能障碍背后的新机制.
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