The Mechanism Of ZAG To Alleviate Insulin Resistance By Enhancing Autophagy

Objective:1.To investigate the effect of zinc alpha 2 glycoprotein on the signal substance p-Akt Ser473 and GLUT4,which play a key role in insulin signaling pathway in insulin resistance.2.To investigate the effect of ZAG on the signal substance mTOR,Atg7 and LC3-II,which play a key role in the autophagic signaling pathway in insulin resistance.3.To investigate whether the effect of ZAG on insulin signaling pathway is associated with autophagy.Methods:Induced differentiation of 3T3-L1 preadipocytes into mature fat cells,mature fat cells were divided into control group and insulin resistance group,ZAG group,ZAG+chloroquine group and chloroquine group,the control group cultured in DMEM medium,the other 4 groups containing 1umol/L dexamethasone was cultured for 2 days,to establish the model of insulin resistance,ZAG group add concentration of 25ug/mL ZAG for 24 h,chloroquine group add concentration of 50umol/L chloroquine for 24 h,ZAG+chloroquine group add concentration of 25ug/mL ZAG and concentration of 50umol/L chloroquine for 24 h.Extraction of mRNA and protein from each group of adipocytes,expression of RT-PCR was detected by GLUT4,mTOR,Atg7 groups,LC3-II mRNA,using Western-blotting method to detect the expression of p-AktSer473,GLUT4,mTOR,Atg7,LC3-II protein,and statistics,the correlation.Results:1.The expression of p-Akt Ser473,GLUT4,Atg7 and LC3-II in the control group was significantly higher than that in the insulin resistance group(P < 0.05),and the expression of mTOR in the control group was significantly lower than that in the insulin resistance group(P < 0.05).2.The expressions of p-AktSer473,GLUT4,Atg7 and LC3-II in the ZAG group were significantly higher than that in the insulin resistance group(P < 0.05),and mTOR expression in the ZAG group was significantly lower than that in the insulin resistance group(P < 0.05).3.The expression of p-AktSer473,GLUT4,Atg7 and LC3-II in the chloroquine group was significantly lower than that in the insulin resistance group(P < 0.05),and the expression of mTOR in the chloroquine group was significantly higher than that in the insulin resistance group(P < 0.05).4.The expression of p-AktSer473,GLUT4,Atg7 and LC3-II in the ZAG+chloroquine group was significantly lower than that in the ZAG group(P < 0.05),and the expression of mTOR in the ZAG+ chloroquine group was significantly higher than that in the ZAG group(P < 0.05).Conclusion:1.ZAG can enhance insulin signal transduction and improve insulin resistance in adipocytes.2.inhibition of autophagy pathway may aggravate insulin resistance in adipocytes.3.after inhibition of autophagic pathway,ZAG enhanced insulin signal transduction,and the effect of improving insulin resistance would be weakened.4.ZAG may improve insulin resistance through multiple mechanisms.One of the important mechanisms to reduce insulin resistance is to increase insulin resistance through autophagy pathway.