Prdx6 Prevents Diabetic Myopathy by Improving Skeletal Muscle Cell Differentiation

Diabetes mellitus is characterized by a state of hyperglycemia resulting from altered insulin secretion by pancreatic beta cell, insulin action or both. This pathological condition is frequently associated with muscle mass loss, a condition defined as sarcopenia, and diabetic myopathy, represented by an impairment of the regenerative power of muscle fiber and by an altered differentiation of progenitor cells. Oxidative stress has been identified as the main cause of muscular alterations typical of diabetic patients. We showed that Peroxiredoxin 6 (Prdx6), a relatively new antioxidant enzyme belonging from the Peroxiredoxin family, has a central role in glucose homeostasis by exerting a potent antioxidant role. Based on these results, in the present study we aimed to verify whether Prdx6 modulates the association between diabetes and the progression of myopathy and sarcopenia. Firstly, we evaluated the gene expression of the main factors involved in the differentiation of myogenic muscle cells such as MyoD and Myogenin in murine knockout models for Prdx6 (Prdx6-/-). We observed significant decreased levels of both genes in Prdx6-/- mice compared to controls, suggesting an impairment of the regenerative potential of muscle fibers. These data were, also, confirmed by using in vitro cell model of murine myoblasts (C2C7) knockdown for Prdx6. Moreover, in the murine models, the process of muscle atrophy was studied by evaluating the gene expression of MuRF1 and Atrogin-1 that finely regulate protein degradation at skeletal muscle level. According to our hypothesis, the expression levels of both enzymes were significantly increased confirming the presence of muscle atrophy. Our study, for the first time, highlights a fundamental role of Prdx6 in the preservation of muscle mass, suggesting how Prdx6 can be considered a potential therapeutic target for diabetic myopathy and sarcopenia. However, further studies are needed in order to understand the molecular mechanism underlying this phenomenon.