Adiponectin Inhibits Atherosclerosis By Regulating The Level Of Autophagy In Macrophages

Background and Objective: Adiponectin(APN)has been confirmed its role in protecting vascular endothelial cells,anti-atherosclerosis,and adjusting the action of insulin resistance[2].The aim of this study is to explore the effect of adiponectin on the macrophage autophagy and to reveal its new mechanism of anti-atherosclerosis,providing a new target for the treatment of AS.Methods: The human THP-1 cell lines were cultured in vitro,divided into three groups,control group,oxidized low density lipoprotein(ox-LDL)group and ox-LDL + APN group.The cytotoxicity of ox-LDL was measured by CCK-8.The expression of cellular proteins before and after APN was detected by western blot.The ultrastructure of macrophages was observed by transmission electron microscopy.And we used Annexin V/PI staining to evaluate the apoptosis of macrophages.Results: CCK-8 results showed that the survival rate of macrophages decreased significantly with ox-LDL concentration increasing(P ? 0.05).Western blot results showed that the expression of intracellular autophagy marker LC3 II was significantly increased after ox-LDL treatment,which is showing a concentration-and time-dependent manner.The highest level of autophagy was observed when ox-LDL concentration was 30 mg / L and incubation time was 6 h(P?0.05).The expression of LC3 II in macrophages of ox-LDL + APN group was significantly lower than that of ox-LDL-treated group,transmission electron microscopy results also showed that the formation of autophagosomes in macrophages was significantly reduced in ox-LDL + APN group compared with ox-LDL group(P?0.05).The results of Annexin V/PI staining showed that APN could inhibit the early apoptosis of macrophages induced by ox-LDL,and the inhibitory effect of APN on apoptosis was independent of autophagy.Conclusion: Ox-LDL could increase the level of autophagy in macrophages.APN may play the role of anti-AS by reducing autophagy level in macrophages.