电针调控PI3K/AKT/FoxO1信号通路改善2型糖尿病大鼠肝脏糖异生的机制研究OA

Objective To investigate the regulatory effects of electroacupuncture(EA)intervention on the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/forkhead box transcription factor O1(FoxO1)signaling pathway and gluconeogenic function in liver tissue of type 2 diabetes mellitus(T2DM)model rats,so as to elucidate the possible mechanisms underlying EA improvement of blood glucose levels.Methods Male SD rats were fed with a high-fat diet combined with intraperitoneal injection of streptozotocin to establish T2DM model.The rats were randomly divided into model,EA,and EA+LY294002 groups,with 10 rats in each group;another 10 age-matched SD rats were selected as the control group.Rats in the EA group received EA intervention at"Zusanli"(ST36)and"Neiting"(ST44)as well as acupuncture at"Weiwanxiashu"(EX-B3),once daily for 15 min each time,6 times a week,for 4 consecutive weeks.The EA+LY294002 group received intraperitoneal injection of the PI3K inhibitor LY294002(10 mg/kg)in addition to the EA treatment once daily,with the same intervention period with the EA group.Random blood glucose was measured using a glucometer;body weight was measured with an electronic balance;HE staining was used to observe pathological changes in liver tissue;real-time quantitative PCR was used to detect the mRNA expression levels of PI3K,AKT,FoxO1,phosphoenolpyruvate carboxykinase(PEPCK),and glucose-6-phosphatase(G6Pase);Western blot was used to detect the protein expression levels of PI3K,p-PI3K,AKT,p-AKT,FoxO1,PEPCK,and G6Pase.Results After treatment,compared with the control group,the model group showed significantly elevated random blood glucose levels(P<0.01),decreased body weight(P<0.01),severe liver tissue damage with enlarged hepatocytes and numerous fatty vacuoles,decreased mRNA expression levels of PI3K and AKT and reduced p-PI3K/PI3K and p-AKT/AKT protein expression ratios(P<0.01,P<0.05),and increased mRNA and protein expression levels of FoxO1,PEPCK,and G6Pase(P<0.01)in liver tissue.Compared with the model group,the EA group showed significantly decreased random blood glucose(P<0.01),increased body weight(P<0.01),improved liver pathological injury with reduced hepatocyte size and attenuated steatosis,significantly increased mRNA expression levels of PI3K and AKT and elevated p-PI3K/PI3K and p-AKT/AKT protein expression ratios(P<0.01),and decreased mRNA and protein expression levels of FoxO1,PEPCK,and G6Pase(P<0.01)in liver tissue.Compared with the EA group,the EA+LY294002 group showed elevated random blood glucose(P<0.01),decreased body weight(P<0.05),aggravated liver tissue injury,decreased mRNA expression levels of PI3K and AKT and reduced p-AKT/AKT protein expression ratio(P<0.01,P<0.05),and increased mRNA and protein expression levels of FoxO1,PEPCK,and G6Pase(P<0.01,P<0.05)in liver tissue.Conclusion EA at EX-B3,ST36,and ST44 can significantly reduce blood glucose levels,increase body weight,and improve liver injury in T2DM rats.The underlying mechanism may involve activation of the hepatic PI3K/AKT/FoxO1 signaling pathway,which suppresses the expression of the downstream gluconeogenic key enzymes PEPCK and G6Pase,thereby reducing hepatic glucose output.