The Effects Of Vsfatin Gene Overexpression On Insulin Sensitivity, FGF-21, Triglycerid And Cholesterol Metabolism In Rats

Objective: To construct the eukaryotic expression vector of visfatin (pcDNA3.1 (+)-visfatin) and transfect it into normal and high fat-diet rats; To investigate the effect of visfatin gene overexpression on insulin sensitivity, glucose and lipid metabolism and cytokine in these rats.Methods: 1. The recombinant vector (pcDNA3.1 (+)-visfatin) was constructed and transfected into normal and high-fat diet rats. 2. The euglycemic-hyperinsulinemic clamp experiments were performed for evaluation the change of insulin sensitivity. The effect of visfatin was evaluated on plasma glucose, lipid level, and FGF-21. 3. The phosphorylation state of IRS1 in liver, skeletal muscle and adipose tissues were determined by dot-blot. 4. The expression of lipid metabolism related mRNA and protein, such as HMG CoA reductase, SREBP2, PEPCK, SCD1 in liver and ATGL, HSL in adipose tissue, was analyzed by RT-PCR and western blot.Results: 1. Recombinant pcDNA3.1 (+)-visfatin was successfully constructed. 2. Plasma visfatin levels and glucose infusion rates(GIR) were significantly increased of NT and HT rats after 3 days of pcDNA3.1 (+)-visfatin transfection(P<0.01). Plasma fasting insulin were decreased in NT rats(P<0.05). The pIRS1 levels in hepatic, adipose and muscle tissue were significantly increased of NT and HT rats than that of NC rats(P<0.05). Hepatic PPARγmRNA levels of NT and HT rats were significantly higher than that of NC rats(P<0.05 and P<0.01). adipic PPARγmRNA levels of NT rats were significantly increased (P<0.05),and that of HT rats were higher than NC rats but no statistical difference . 3. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) were significantly decreased of NT and HT rats after 3 days of pcDNA3.1 (+)-visfatin transfection(P<0.05). Hepatic SREBP2 mRNA levels of NT and HT rats were significantly higher than that of NC rats(P<0.05). HMG CoA reductase of NT rats were significantly higher than that of NC and HT rats(P<0.05), and there is no statistical difference between NC and HT rats. 4. Adipic ATGL mRNA levels of NT rats were significantly higher than that of NC and HT rats(P<0.05), and that of HT rats were higher than NC rats but no statistical difference . 5.After 3 days of pcDNA3.1 (+)-visfatin transfection plasma FGF-21 were decreased in NT rats,however, FGF-21 were increased in HT rats(P<0.05). The diversity of hepatic FGF-21 mRNA and protein levels was similar to that of plasma FGF-21.Conclusion: 1.The eukaryotic expression vector of pcDNA3.1 (+)-visfatin was successfully constructed. 2. The transfection of pcDNA3.1 (+)-visfatin increase plasma visfatin levels, improve insulin sensitivity and decrease plasma total cholesterol. Visfatin overexpression is effective in increasing the expression of adipic ATGL mRNA and protein levels, and influencing expression of FGF-21.