Mitochondria transfer from myocytes to endothelial cells promotes angiogenesis in skeletal muscle

Skeletal muscle and vascular health are closely interconnected, yet the mechanisms underlying their crosstalk remain poorly understood. This study investigates the role of mitochondria transfer from myocytes to endothelial cells. Using in vitro 2D and 3D coculture systems, combined with protein-level and functional analyses, we show that mitochondria are transferred via extracellular vesicles in a Rab7-dependent and cellular connection-independent manner. Connexin 43 (CX43) inhibition downregulating Growth-Associated Protein 43 (GAP43) but enhances mitochondria transfer, accompanied by increasing Rab7. Transferred mitochondria promote endothelial cells proliferation, migration, ATP production, and angiogenesis, which could be the key processes in preserving vascular integrity and muscle function. Our study indicated that the aging-associated decline in CX43 and mitochondrial quality exacerbates muscle atrophy by facilitating the transfer of dysfunctional mitochondria. These findings uncover a novel mechanism of muscle-vessel communication and highlight mitochondria transfer as a potential therapeutic target for aging-related muscular and vascular deterioration. New and Noteworthy. Mitochondria transfer is a way for cell communication. However, mitochondria transfer between myocyte and endothelial cell remains unknown. Here, we demonstrates that mitochondria transfer occurs between myocytes and endothelial cells. Interestingly, inhibition of CX43 leads to a decrease in GAP43 expression, while simultaneously upregulating Rab7 and enhancing mitochondria transfer from myocytes to endothelial cells. Furthermore, we reveal that Rab7-induced mechanism mediates the transfer of both functional and impaired mitochondria from myocytes to endothelial cells.