The Effects of Interleukin-10 on Skeletal Muscle Insulin Resistance and Myogenesis

Sezin Dagdeviren
2016
Skeletal muscle insulin resistance is a major characteristic of obesity and type 2 diabetes. Although obesity-mediated inflammation is causally associated with insulin resistance, the underlying mechanism is unclear. Our lab and others have shown that a chronic low-grade inflammation takes place in skeletal muscles during diet-induced obesity, as evidenced by increased macrophage markers and pro-inflammatory cytokine levels. Interleukin (IL)-10 is a Th2-type cytokine that inhibits the synthesis
more » ... ibits the synthesis and activity of pro-inflammatory cytokines and counteracts the Toll-like receptor-mediated inflammation. Our lab has previously demonstrated the preventive role of IL-10 against insulin resistance. Here, I have analyzed the effects of IL-10 on the skeletal muscle glucose metabolism and myogenesis in three different insulin resistant states (high fat diet-induced, leptin-deficiency-induced and aging-induced). The first model involved long-term (16 weeks) high-fat diet (HFD) feeding that resulted in markedly obese and hyperglycemic mice, representative of obese type 2 diabetic subjects. In mice overexpressing IL-10 specifically in the skeletal muscle (MIL10), we observed improved whole-body and skeletal muscle insulin sensitivity as compared to wild-types after long-term high fat diet feeding. The improved insulin sensitivity in the skeletal muscle was due to increased Akt signaling and decreased muscle inflammation. Leptin is an important adipocyte-derived hormone that is elevated in obesity, and it regulates numerous physiological functions including the energy balance and inflammation. Thus, my second model examined the effects of muscle-specific overexpression of IL-10 on glucose metabolism in the hyperphagic, leptin-deficient ob/ob mice. We detected improved whole-body insulin sensitivity compared to the control mice. My third model examined the effects of increased IL-10 expression using MIL10 mice during aging-induced insulin resistance. In 18-month old MIL10 mice, we found enhanced whole-body and skeletal muscle insu [...]
doi:10.13028/m2qp42 fatcat:2mivjnufbjchzpyutmavgwhypq