Kissing and nanotunneling mediate intermitochondrial communication in the heart

• DOI: 10.1073/pnas.1300741110
• Publication Date: 2013-02-06T06:48:25Z
• Authors: Xiaohu Huang; Lei Sun; Shuangxi Ji; Ting Zhao; Wanrui Zhang; Jiejia Xu; Jue Zhang; Yanru Wang; Xianhua Wang; Clara Franzini-Ar...; Ming Zheng; Heping Cheng
• Keywords: Mitochondrial matrix

Mitochondria in many types of cells are dynamically interconnected through constant fusion and fission, allowing for exchange mitochondrial contents repair damaged mitochondria. However, constrained by the myofibril lattice, ∼6,000 mitochondria adult mammalian cardiomyocyte display little motility, it is unclear how, if at all, they communicate with each other. By means target-expressing photoactivatable green fluorescent protein (PAGFP) matrix or on outer membrane, we demonstrated that local PAGFP signal propagated over entire population cardiomyocytes a time scale ∼10 h. Two elemental steps intermitochondrial communications were manifested as either sudden transfer between pair adjacent (i.e., “kissing”) dynamic nanotubular tunnel “nanotunneling”) nonadjacent The average content index (fractional exchange) was around 0.5; rate kissing 1‰ s −1 per pair, nanotunneling about 14 times smaller. Electron microscopy revealed extensive intimate contacts elongated protrusions, providing structural basis nanotunneling, respectively. We propose that, otherwise static form one continuous network to share signals.