Adiponectin activates AMP-activated protein kinase via LKB1 pathway

Abstract

Objective To explore whether adiponectin activates AMP-activated protein kinase(AMPK) via LKB1 pathway or not in skeletal muscle and liver tissues.Methods Male Sprague-Dawley rats ( n =28 ) were divided into normal control diet( NC,n =15 ) and high-fat diet( HF,n =13 ) groups.After 16 weeks feeding,fasting blood free fatty acids( FFA ),triglyceride( TG ),total cholesterol( TC ),fasting plasma glucose( FPG ),fasting insulin(FINS),and adiponectin were determined.The protein levels of AMPKα,phosphorylated AMPKα ( p-AMPK ),and LKB1 in the skeletal muscle and liver tissues were analyzed with Western blot.Cultured primary skeletal muscle cells and hepatic cells were incubated with aditonectin and radicicol.The expression of AMPKα,p-AMPKα,and LKB1 inthese cells were analyzed with immunofluorescence method.Results Compared with NC group,body weight,FFA,TG,FPG,and FINS in rats of HF group were significantly higher( all P＜0.05 ) while serum adiponeetin level was lower( P＜0.05 ).The levels of AMPKα phosphorylation and LKB1 expression in the skeletal muscle and liver tissues of HF group were lower than those in NC group. In primary skeletal muscle cells and hepatic cells,adiponectin significantly increased the levels of AMPKα phosphorylation and LKB1 expression ( all P＜ 0.05 ),which were decreased by radicicol ( P＜0.05 ).Conclusion Adiponectin may activate AMPK via LKB1 pathway in skeletal muscle and liver tissues of rats. Key words: Adiponectin; LKB1 ; AMP-activated protein kinase