目的:研究甲基莲心碱(Nef)对糖尿病肾病(DN)的影响,并基于miRNA调控理论探讨Nef在DN中的作用机制。
方法:构建DN小鼠模型并用Nef处理。血清肌酐(Crea),通过试剂盒测量小鼠的血尿素(UREA)和尿白蛋白,通过苏木精-伊红染色和Masson染色观察肾脏组织病理学改变和纤维化。肾组织超氧化物歧化酶(SOD),采用酶联免疫吸附试验(ELISA)检测丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)活性。采用蛋白质印迹法检测肾组织中核因子E2相关因子2(Nrf2)/血红素加氧酶1(HO-1)信号通路相关蛋白的表达。定量逆转录-聚合酶链反应(qRT-PCR)检测肾组织中miR-17-5p的表达。随后,通过人肾小球系膜细胞(HMC)的高糖培养构建了DN体外模型,细胞用miR-17-5p模拟物转染和/或用Nef处理,我们使用qRT-PCR检测细胞miR-17的表达,流式细胞术检测细胞凋亡,ELISA检测细胞SOD,MDA,和GSH-Px活动,蛋白质印迹法检测Nrf2/HO-1信号通路相关蛋白的表达,和双荧光素酶报告基因检测来验证Nrf2与miR-17-5p的靶向关系。
结果:服用Nef可显著降低血糖水平,Crea,UREA和miR-17-5p的表达,改善肾脏组织病理学和纤维化,显著降低MDA水平,SOD和GSH-Px活性升高,并激活了DN小鼠肾组织中Nrf2的表达。Nrf2是miR-17-5p的转录后靶标。在用miR-17-5p模拟物转染的HMC中,Nrf2的mRNA和蛋白水平被显著抑制。此外,miR-17-5p过表达和Nef干预导致高糖诱导的HMC细胞凋亡和MDA水平显著增加,HO-1和Nrf2蛋白表达显著降低。
结论:总的来说,这些结果表明Nef对DN有改善作用,其机制可能是通过miR-17-5p/Nrf2途径实现的。
OBJECTIVE: To investigate the effect of Neferine (Nef) on diabetic nephropathy (DN) and to explore the mechanism of Nef in DN based on miRNA regulation theory.
METHODS: A DN mouse model was constructed and treated with Nef. Serum creatinine (Crea), blood urea (UREA) and urinary albumin were measured in mice by kits, and renal histopathological changes and fibrosis were observed by hematoxylin-eosin staining and Masson staining. Renal tissue superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) activities were measured by enzyme-linked immunosorbent assay (ELISA). Western blotting was used to detect the expression of nuclear factor E2-related factor 2 (Nrf2)/ heme oxygenase 1 (HO-1) signaling pathway-related proteins in kidney tissues. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-17-5p in kidney tissues. Subsequently, a DN in vitro model was constructed by high glucose culture of human mesangial cells (HMCs), cells were transfected with miR-17-5p mimic and/or treated with Nef, and we used qRT-PCR to detect cellular miR-17 expression, flow cytometry to detect apoptosis, ELISAs to detect cellular SOD, MDA, and GSH-Px activities, Western blots to detect Nrf2/HO-1 signaling pathway-related protein expression, and dual luciferase reporter gene assays to verify the targeting relationship between Nrf2 and miR-17-5p.
RESULTS: Administration of Nef significantly reduced the levels of blood glucose, Crea, and UREA and the expression of miR-17-5p, improved renal histopathology and fibrosis, significantly reduced MDA levels, elevated SOD and GSH-Px activities, and activated Nrf2 expression in kidney tissues from mice with DN. Nrf2 is a post-transcriptional target of miR-17-5p. In HMCs transfected with miR-17-5p mimics, the mRNA and protein levels of Nrf2 were significantly suppressed. Furthermore, miR-17-5p overexpression and Nef intervention resulted in a significant increase in high glucose-induced apoptosis and MDA levels in HMCs and a significant decrease in the protein expression of HO-1 and Nrf2.
CONCLUSIONS: Collectively, these results indicate that Nef has an ameliorative effect on DN, and the mechanism may be through the miR-17-5p/Nrf2 pathway.