| Objective:To investigate the mechanism of dapagliflozin in regulating renal oxidative stress caused by insulin resistance,we used high-fat-induced obese mice by not only comparing glucose and lipid metabolism indexes but slso detecting the expression of proteins involved in Nrf2-related pathway in kidney after treated with dapagliflozin or not.(1)Effects of dapagliflozin on glycolipid metabolism in obese mice were systematically studied by establishing the high-fat-diet induced model.(2)Levels of oxidases in plasma and kidney tissue were determined to evaluate the effect of dapagliflozin on oxidative stress in obese mice.(3)To explore the effect of dapagliflozin on the expression of PGC-1α,Keap1 and Nrf2 in kidney and the mechanism of improving renal oxidative stress.Methods:Totally 24 robust male C57BL/6 mice aged 7-8 weeks were selected.All mice were raised in a sterile environment with temperature of 23-27℃ and humidity of 45-55%in separate cages.Mice were fed with standard pellet feed and were free to drink purified water.The experiment began after 1 week’s adaptive feeding.Then the 24 mice were randomly distributed into normal control(NC)group,obesity control(OC)group and dapagliflozin group.NC group was fed with standard pellet,while the other mice were fed a high fat pellet for 16 weeks later to establish obese mice model.The intervention group were given dapagliflozin 10mg/(kg·d)by gavage for 21 consecutive days.Equal volumes of 0.9%sodium chloride injection were injected intraperitoneally in NC and OC groups.During administration,level of body mass and fasting plasma glucose of each group were recorded according to the experimental arrangement,and glucose tolerance test and insulin tolerance test were conducted.After 21 days of intervention,serum insulin and lipid concentrations were detected using ELISA kit.Meanwhile,the contents of SOD,MDA,CAT and GSH-Px in mice plasma and kidney tissues were determined by ELISA.Real-time PCR and Western blot were adopted to analysis the mRNA and protein expression of PGC-lα,Keap1 and Nrf2 in kidney.Results:(1)In comparison with the model control mice,weight and fat mass of dapagliflozin mice decreased after 21 days of treatment(P<0.05),indicating that dapagliflozin could inhibit fat accumulation and reduce body weight of obese group.(2)In comparison with the obese control group,blood glucose concentrations and serum insulin levels of mice in dapagliflozin group decreased(P<0.05),glucose tolerance and insulin tolerance were significantly improved(P<0.05),indicating that dapagliflozin could increase insuline sensitivity.(3)In comparison with the obese group,serum triglycerides and total cholesterol of dapagliflozin group were lower(P<0.05),indicating that dapagliflozin could improve systemic lipid metabolism.(4)In comparison with the obese mice,SOD,CAT and GSH-Px in plasma of mice in dapagliflozin group were increased(P<0.05),while MDA was decreased(P<0.05),indicating that dapagliflozin could improve the oxidative stress state of obese mice.(5)In comparison with the obese mice,SOD,CAT and GSH-Px in kidney tissue of dapagliflozin group were increased(P<0.05),while MDA was decreased(P<0.05),indicating that dapagliflozin could reduce oxidative stress level in kidney tissue.(6)Compared with the obese group,PGC-1α mRNA and protein levels of dapagliflozin kidney were increased(P<0.05),Keapl mRNA and protein were decreased(P<0.05),while protein Nrf2 were increased(P<0.05),indicating that dapagliflozin could regulate renal PGC-1qq and Keap1/Nrf2 pathway.Conclusion:Dapagliflozin could improve glycolipid metabolism of obese mice induced by high-fat-diet,reduce their body mass and improve insulin resistance.Meanwhile,dapagliflozin could improve the higher oxidative stress of plasma and kidney tissue in obese mice.Through molecular level detection,we found dapagliflozin could regulate renal PGC-1α and Keapl/Nrf2 pathway,through which dapagliflozin may combat renal oxidative stress and achieve renal protection. |
PDF Full Text Request