Institute of Biology and Molecular Genetics (IBGM), Department of Biochemistry and Molecular Biology and Physiology, Faculty of Medicine, University of Valladolid and CSIC, Ramón y Cajal, 7, E-47005 Valladolid, Spain.
Int J Mol Sci. 2020 Nov 16;21(22):8622. doi: 10.3390/ijms21228622.
Mitochondrial [Ca] plays an important role in the regulation of mitochondrial function, controlling ATP production and apoptosis triggered by mitochondrial Ca overload. This regulation depends on Ca entry into the mitochondria during cell activation processes, which is thought to occur through the mitochondrial Ca uniporter (MCU). Here, we have studied the mitochondrial Ca dynamics in control and MCU-defective worms in vivo, by using worms expressing mitochondrially-targeted YC3.60 yellow cameleon in pharynx muscle. Our data show that the small mitochondrial Ca oscillations that occur during normal physiological activity of the pharynx were very similar in both control and MCU-defective worms, except for some kinetic differences that could mostly be explained by changes in neuronal stimulation of the pharynx. However, direct pharynx muscle stimulation with carbachol triggered a large and prolonged increase in mitochondrial [Ca] that was much larger in control worms than in MCU-defective worms. This suggests that MCU is necessary for the fast mitochondrial Ca uptake induced by large cell stimulations. However, low-amplitude mitochondrial Ca oscillations occurring under more physiological conditions are independent of the MCU and use a different Ca pathway.
线粒体 [Ca] 在调节线粒体功能中起着重要作用，控制着由线粒体 Ca 过载触发的 ATP 产生和细胞凋亡。这种调节依赖于细胞激活过程中线粒体 Ca 的内流，据认为这是通过线粒体 Ca 单向转运蛋白 (MCU) 实现的。在这里，我们通过使用在咽肌中表达靶向线粒体的 YC3.60 黄色荧光蛋白的线虫，研究了体内对照和 MCU 缺陷线虫中线粒体 Ca 动力学。我们的数据表明，在咽正常生理活动期间发生的小线粒体 Ca 振荡在对照和 MCU 缺陷线虫中非常相似，除了一些动力学差异，这些差异主要可以通过神经元对咽的刺激变化来解释。然而，用 carbachol 直接刺激咽肌会引发线粒体 [Ca] 的大量且持续增加，在对照线虫中比在 MCU 缺陷线虫中要大得多。这表明 MCU 对于大细胞刺激诱导的快速线粒体 Ca 摄取是必要的。然而，在更生理条件下发生的低幅度线粒体 Ca 振荡独立于 MCU，并使用不同的 Ca 途径。
