恩格列净通过自噬-溶酶体途径改善糖尿病肾病小鼠肾组织损伤

Empagliflozin ameliorates renal tissue damage in diabetic nephropathy mice through autophagy-lysosome pathway

目的探讨恩格列净对糖尿病肾病(Diabetic kidney disease,DKD)小鼠肾脏保护作用及自噬-溶酶体通路的影响。方法db/m小鼠作为正常组(Control),db/db小鼠随机分为模型组(Model)、恩格列净组(Empagliflozin)。给药8周,检测小鼠24 h尿蛋白定量(24 h urine protein,24 h-UTP)、血糖(fasting blood glucose,FBG)、糖化血红蛋白(glycosylated hemoglobin,HBA1c)、总胆固醇(total cholesterol,TC)、甘油三脂(triglyceride,TG)、尿素氮(blood urea nitrogen,BUN)、肌酐(creatinine,Scr)、血清肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-1β(interleukin-1β,IL-1β)和单核细胞趋化因子-1(monocyte chemokine-1,MCP-1)水平;Western blot检测肾组织p62、LC3B、Beclin1、Agt7、LAMP1、Bcl-2、caspase-3、Bax蛋白表达;光镜观察肾脏病理变化。结果与Control组比较,Model组小鼠肾小球基底膜增厚,系膜基质增多,囊腔变窄,间质炎性细胞浸润及纤维化(P<0.01);FBG、24 h-UTP、HBA1c、TC、TG、BUN、Scr、TNF-α、IL-1β、MCP-1升高(P<0.01);同时,肾组织LC3B-Ⅱ/LC3B-Ⅰ、Beclin1、LAMP1、Agt7、Bcl-2降低,p62、caspase-3、Bax升高(P<0.01)。恩格列净干预后,小鼠肾脏病理改变减轻;上述指标变化被逆转。结论恩格列净可能通过修复自噬-溶酶体通路,促进自噬底物降解,抑制炎症因子产生,进而抑制细胞凋亡,从而减轻肾脏损伤。

Aim To investigate the effects of empagliflozin on kidney tissue and autophagy-lysosome pathway in diabetic kidney disease(DKD)mice.Methods The db/m group as the control group,the db/db mice were randomly divided into the model group and empagliflozin group.After 8 weeks of administration,the levels of 24 h urine protein(24 h-UTP),fasting blood glucose(FBG),glycosylated hemoglobin(HBA1c),total cholesterol(TC),triglyceride(TG),blood urea nitrogen(BUN),serum creatinine(Scr),tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and monocyte chemoattractant protein-1(MCP-1)were detected.The expression of p62,LC3B,Beclin1,Agt7,LAMP1,Bcl-2,caspase-3 and Bax in kidney tissue was measured by Western blot.The pathological changes of kidney were observed under light microscope.Results Compared with the control group,the model group showed thickening of basement membrane,increased extracellular matrix,interstitial inflammatory cell infiltration and interstitial fibrosis(P<0.01).Moreover,the model group had higher content of FBG,HBA1c,24h-UTP,TC,TG,BUN,Scr,TNF-α,IL-1β,and MCP-1(P<0.01),higher expression of LC3B-Ⅱ/LC3B-Ⅰ,Beclin1,LAMP1,Agt7 and Bcl-2(P<0.01),and lower expression of p62,caspase-3 and Bax in renal tissue(P<0.01)than those in the control group.Compared with the model group,empagliflozin alleviated the pathological injury in kidney(P<0.01),and the changes in the above indicators were reversed.Conclusion By irepairing autophagy-lysosomal pathway in renal tissue,empagliflozin can promote the degradation of autophagy substrates,inhibit the production of inflammatory factors and apoptosis,thereby protecting the kidney.