RESUMO
AIM:To investigate whether the protective effect of adiponectin on glucose and lipid metabolism is achieved through down-regulating major histocompatibility complex classⅡ( MHCⅡ) in the adipose tissue.METHODS:Adiponectin knockout ( KO) mice and C57BL/6 ( WT) mice were fed with high-fat diet and standard diet for 24 weeks, re-spectively.The body weight, fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insu-lin resistance (HOMA-IR), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol ( HDL-C) , hepatic histology, and classⅡtrans-activator ( CIITA) , histocompatibility 2 class II antigen E beta (H2-Eb1) and cluster of differentiation 74 (CD74) mRNA and MHC II protein levels in adipose tissue were measured at sacrifice.siRNA targeting MHC II and overexpression vector was used in 3T3-L1 cells to explore the effect of adiponectin on the protein level of MHCⅡ.RESULTS:The levels of body weight, FBG, FINS, HOMA-IR, TC, TG, LDL-C, hepatic steatosis, CIITA, H2-Eb1 and CD74 mRNA expression, and MHCⅡ protein expression in the KO mice were higher than those in the WT mice that fed with high-fat diet or standard diet.In 3T3-L1 cells, inhibition of adiponectin reversed MHC II protein level induced by specific siRNA.The expression of MHC II in adipocytes decreased after adiponectin was overexpressed.CONCLUSION: Adiponectin improves glucose and lipid metabolism through sup-pressing the expression of MHCⅡin the adipose tissue.