The Research Of The Effects And Mechanisms Of ZAG On Insulin Resistance Of Adipocytes By P-AKT/GLUT4 Signal Pathway

Objective:To investigate the effect of Zinc-alpha2-glycoprotein(ZAG)on 3T3-L1 adipocytes and to understand its possible mechanism based on P-AKT/GLUT4 signal pathway.Methods:After subculturing 3T3-L1 adipocytes for five generations,differentiated them into mature cells and observed intracellular lipid droplets by oil red O staining.The cells were randomly assigned to normal saline and dexamethasone injection for 48 h,respectively,which were blank control group(N group)and insulin resistance model group(IR group),IR group was treated with ZAG for 24 h as ZAG group.ELISA method measured the levels of tumor necrosis factor-a(TNF-a)and interleukin 6(IL-6)in cell culture medium;Western Blotting method determined the protein expression levels of adiponectin,leptin,phosphorylation of serine/threonine kinase Western Blotting(P-AKT),glucose transporter 4(GLUT4).The relative expression levels of adiponectin,leptin,TNF-?,IL-6,AKT and GLUT4 were measured by RT-PCR in m RNA.Results:(1)Expression levels of adiponectin and leptin in protein and m RNA:IR group is lower than N group of adiponectin(p<0.05);Compared with IR group,the relative expression of adiponectin protein and m RNA increased in ZAG group(p<0.05),relative expression of leptin protein and m RNA decreased(p<0.05).(2)Cells supernatant levels and m RNA's expression levels of TNF-? and IL-6:IR group is higher than N of TNF alpha and IL-6(p<0.05);Compared with IR group,TNF-? and IL-6's cell supernatant levels and the relative expression of m RNA decreased in ZAG group(p<0.05).(3)P-AKT protein and AKT m RNA expression level:IR group is lower than N group(p<0.05);Compared with IR group,the relative expression of P-AKT protein and AKT m RNA increased in ZAG group(p<0.05).(4)GLUT4 protein and m RNA expression level:IR group is lower than group N(p<0.05);Compared with IR group,the expression of GLUT4 protein and m RNA increased in ZAG group(p<0.05).Conclusion:ZAG increase adiponectin expression and decrease the expression level of leptin,TNF-? and IL-6 in 3T3-L1 adipocytes.Therefore,ZAG can improve insulin resistance of adipocytes.It may be related to the improvement of GLUT4 expression through P-AKT/GLUT4 signaling pathway.