Fig. 4
From: Mitochondrial transfer/transplantation: an emerging therapeutic approach for multiple diseases
The putative mechanism by which cells engulf and internalize exogenous mitochondria. Exogenous mitochondria enter the cell via actin-dependent endocytosis or macropinocytosis and then form endosomes or macropinosomes. A small portion of exogenous mitochondria bind to lysosomes and are degraded; a large portion of exogenous mitochondria escape from endosomes, macropinosomes or lysosomes and fuse with endogenous mitochondria, which is mediated by MFN1/2 and OPA1