Mitophagy in the Skeletal Muscle Is Suppressed in Spleen Qi Deficiency

Objective: Mitochondrial impairment in the skeletal muscle contributes to useless of limbs in spleen qi deficiency; however the genesis of such impairment is not clear. Herein, PTEN-induced putative kinase 1 (PINK1)-Parkin pathway and mitophagy were studied to explore the machinery of mitochondrial impairment. Methods: 16 male SD rats were randomly divided in the control group and spleen qi deficiency group (model group); transmission electron microscope was used to observe mitochondrial morphology; mitochondrial oxidative phosphorylation was assessed by testing mitochondrial membrane potential (MMP) and levels of ATP and ROS; western blot was used to analyze expressions of PINK1, Parkin, microtubule-associated protein 1 light chain 3-II (LC3-II) and p62. Results: Compared with those in the control group, mitochondria became small, less and scattered, MMP and the ATP level were reduced, the ROS level was elevated, PINK1 expression was decreased, p62 expression was increased, but Parkin and LC3-II expressions were not altered, in the model group. Conclusions: Suppression of mitophagy might be related to the mitochondrial damage in the skeletal muscle when spleen qi deficiency develops.