Effects And Mechanism Of Zinc Alpha2 Glycoprotein On Lipid Metabolism In C57 Mouse Primary Hepatic Cells Induced By Palmitic Acid

Objective: To investigate the effects and mechanism of Zinc alpha2 glycoprotein on lipid metabolism in mouse primary hepatocytes induced by palmitic acid.Methods: 1.Isolation and culture of mouse primary hepatocytes(MPH).2.The cultured MPHs were treated with PA at concentrations of 0.4mM in serum-free conditions for 24 hours.Then,rAAV2-ZAG and rAAV2-EGFP were transfected into PA induced fatty MPHs for 48 hours.Intracellular lipid accumulation was examined by Oil Red O staining and the triglyceride measurement kit.The protein level of Adiponectin,liver metabolic nuclear receptors,fatty acids synthesis genes and β-oxidation genes were detected by Western blot.3.The MPHs were treated with PA at concentrations of 0.4mM for 24 hours,then the PA-induced fat MPHs were treated with 1mM ETO for 8 hours.Finally,the MPHs were treated with ZAG recombinant protein for another 24 hours,then enzyme-linked immunoassay was used to detect the cellular triglyceride(TG)and β-hydroxybutyrate.Results:1.An improved method to isolate and culture mice hepatocytes was successfully established.2.Intracellular triglyceride level was significantly decreased and little lipid droplet stained red by Oil Red O was found in rAAV2-ZAG transfected group compared with the control group in the presence of PA.3.The protein level of Adiponectin,FXR,PPARα,CPT1 A were dramatically up-regulated,while,the protein level of SREBP-1c,LXR,FAS,ACC were dramatically down-regulated in rAAV2-ZAG transfected group compared with the control group in the presence of PA(P<0.01).4.When the ETO didn’t exist,ZAG could prominently decrease the PA-induced cellular TG content(a decrease of 32.2%,P<0.01),while increase the cellular β-hydroxybutyrate(a increase of 44.1%,P<0.01).In the presence of ETO,ZAG could slightly decrease the PA-induced cellular TG content(a decrease of 10.7%,P<0.05),however,the cellular β-hydroxybutyrate content didn’t change any more.Conclusion:ZAG alleviates palmitic acid-induced intracellular lipid accumulation mainly by promotng lipolysis in mouse primary hepatocytes.