Relationship Between Suppressor Of Cytokine Signaling-3 And Interleukin-6 & Insulin Resistance

Objective Insulin resistance is the common soil of metabolic disorders. Inflammation appears to play an important role in the mechanism of insulin resistance and may be the mediator to develop to metabolic disorder syndrome. IL-6,as one of the proinflammatory cytokine, is indicated to be the central mediator of Acute Phase Response(APR) and sensitive marker of sub-clinical inflammation. A two-to threefold elevation of circulating IL-6 has been observed in insulin resistance patients. It is positively associated with hyperglycemia, insulin resistance and type 2 diabetes mellitus. It is also known to predict the development of cardiovascular disease. Suppressor of cytokine signaling-3(SOCS-3) is a crucial member of recently discovered SOCS family. It is one of the key regulators of many cytokine signaling, including IL-6.In this study, we detected the level of IL-6 and S0CS-3mRNA and aimed to discuss the relationship between S0CS-3mRNA and IL-6 & insulin resistance in rats.Method Twenty-four common male Wistar rats were randomly divided into 3 groups after weighting: group A were given high fat and sugar diet; group B were injected with IL-6 and control group C. They are feed in standard condition for six weeks and free of drinking and eating. All rats were killed after fasting 12h and recorded weight of body in the end. FBG and FINS were measured and insulin resistance value (HOMA-IR) was assessed by homeostasis mode assessment. Liver expression of S0CS-3mRNA was detected by RT-PCR. The level of IL-6 was detected by ELISA.Results Compare to controls, rats in high fat and sugar group are obesity and significantly gain weight. The level of IL-6 and liver expression of S0CS-3mRNA are significantly higher than that in control (p<0.01). After injection of recombinant rat IL-6, both IL-6 and S0CS-3mRNA are increased, but only the latter is significant (p<0.05).Correlation analyze indicate that the expression of SOCS-3mRNA positivelycorrelated with plasma IL-6 level. And partial correlation further discover the relationship between SOCS-3mRNA,IL-6, A W and HOMA-IR(p<0.05).Conclusion The level of IL-6 increased in the condition of insulin resistance and can up-regulate S0CS-3mRNA. High expression of SOCS-3 mRNA positively correlated with insulin resistance and may contribute to one of the mechanisms of insulin resistance.