Mitochondria are morphologically and functionally heterogeneous within cells
Mitochondria are morphologically and functionally heterogeneous within cells
复制标题
DOI：
10.1093/emboj/21.7.1616
复制
发表时间：
2002-04-02
期刊：
影响因子：
11.4
通讯作者：
Bootman, MD
中科院分区：
文献类型：
--
作者：
Collins, TJ;Berridge, MJ;Bootman, MD
我们研究了线粒体在单个完整细胞内是否代表形态连续和功能同质的实体。线粒体的物理连续性通过线粒体靶向的DsRed1或钙黄蛋白的三维荧光重建来确定。HeLa、PAEC、COS-7、HUVEC、肝细胞、皮质星形胶质细胞和神经元细胞的线粒体均呈非均匀分布，大小不一。核周位置的线粒体比细胞外周位置的线粒体聚集更密集，在细胞外周可以清楚地看到单个分离的线粒体。利用光漂白后的荧光恢复，我们观察到DsRed1和钙黄蛋白在单个线粒体的基质中高度移动，并且细胞内的线粒体不是连续的。线粒体没有电偶联，因为只有单个线粒体在负载tmre的细胞照射后才观察到去极化。观察了单细胞线粒体在膜电位、激素诱发的胞质钙信号的隔离和通透性过渡孔打开时间等方面的功能异质性，以响应叔丁基过氧化氢。我们的数据表明，单个细胞内的线粒体在形态上是异质的和不连接的，这使得它们具有不同的功能特性。
We investigated whether mitochondria represent morphologically continuous and functionally homogenous entities within single intact cells. Physical continuity of mitochondria was determined by three-dimensional reconstruction of fluorescence from mitochondrially targeted DsRed1 or calcein. The mitochondria of HeLa, PAEC, COS-7, HUVEC, hepatocytes, cortical astrocytes and neuronal cells all displayed heterogeneous distributions and were of varying sizes. There was a denser aggregation of mitochondria in perinuclear positions than in the cell periphery, where individual isolated mitochondria could be seen clearly. Using fluorescence-recovery after photobleaching, we observed that DsRed1 and calcein were highly mobile within the matrix of individual mitochondria, and that mitochondria within a cell were not lumenally continuous. Mitochondria were not electrically coupled, since only individual mitochondria were observed to depolarize following irradiation of TMRE-loaded cells. Functional heterogeneity of mitochondria in single cells was observed with respect to membrane potential, sequestration of hormonally evoked cytosolic calcium signals and timing of permeability transition pore opening in response to tert-butyl hydroperoxide. Our data indicate that mitochondria within individual cells are morphologically heterogeneous and unconnected, allowing them to have distinct functional properties.