Electrical coupling and plasticity of the mitochondrial network
Electrical coupling and plasticity of the mitochondrial network
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DOI：
10.1054/ceca.2000.0177
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发表时间：
2000-11-01
期刊：
影响因子：
4
通讯作者：
Ichas, F
中科院分区：
文献类型：
--
作者：
De Giorgi, F;Lartigue, L;Ichas, F
动力学荧光成像和电位探针四甲基罗丹明甲酯（TMRM）被用来诱发和检测活细胞中单个线粒体的膜电位（Δ psi（m））的变化。作为优先TMRM在线粒体中的积累和TMRM光活化的组合效应，个体细胞器显示由局部活性氧（ROS）介导的线粒体渗透性转换孔（PTP）门控引起的急剧瞬时去极化。在COS-7细胞中，PTP的这种定向重复门控引起随机Delta psi（m），在单个细胞器的水平上闪烁，但也在线粒体群体的整个亚群中引起显著的同步Delta psi（m）转换，表明存在潜在的电耦合线粒体网络。在单个细胞中，这个网络可以包括多达65%的总线粒体群体，并表现出高度的可塑性与线粒体单位自发连接和断开连接的结构在几秒钟内。这些结果表明，在静息细胞中，线粒体网络是一个动态的质子传导结构，能够交换和协调PTP产生的电信号。(C)2000年哈考特出版社有限公司
Kinetic fluorescence imaging and the potentiometric probe tetramethyl rhodamine methyl ester (TMRM) were used to evoke and detect changes in membrane potential (Delta psi (m)) of individual mitochondria in living cells. As a combined effect of preferential TMRM accumulation in mitochondria, and of TMRM photoactivation, individual organelles displayed sharp transient depolarizations caused by local reactive oxygen species (ROS)-mediated gatings of the mitochondrial permeability transition pore (PTP). In COS-7 cells, such directed repetitive gatings of the PTP gave rise to stochastic Delta psi (m), flickering at the level of individual organelles, but also to prominent synchronous Delta psi (m) transitions in whole subgroups of the mitochondrial population, indicative of the existence of an underlying electrically coupled mitochondrial network. In single cells, this network could comprise as much as 65% of the total mitochondrial population, and exhibited a high plasticity with mitochondrial units spontaneously connecting to and disconnecting from the coupled structure within seconds. These results indicate that in resting cells, the mitochondrial network is a dynamic proton-conducting structure capable to commute and coordinate electrical signals generated by the PTP. (C) 2000 Harcourt Publishers Ltd.