Mitochondria transplant therapy improves regeneration and restoration of injured skeletal muscle

Background Injection of exogenous mitochondria has been shown to improve the ischaemia‐damaged myocardium, but the effect of mitochondrial transplant therapy (MTT) to restore skeletal muscle mass and function has not been tested following neuromuscular injury. Therefore, we tested the hypothesis that MTT would improve the restoration of muscle function after injury. Methods BaCl2 was injected into the gastrocnemius muscle of one limb of 8–12‐week‐old C57BL/6 mice to induce damage without injury to the resident stem cells. The contralateral gastrocnemius muscle was injected with phosphate‐buffered saline (PBS) and served as the non‐injured intra‐animal control. Mitochondria were isolated from donor mice. Donor mitochondria were suspended in PBS or PBS without mitochondria (sham treatment) and injected into the tail vein of BaCl2 injured mice 24 h after the initial injury. Muscle repair was examined 7, 14 and 21 days after injury. Results MTT did not increase systemic inflammation in mice. Muscle mass 7 days following injury was 21.9 ± 2.1% and 17.4 ± 1.9% lower (P