miR-25表达对糖尿病肾病形成调控的分子机制研究

Study on the molecular mechanism of miR-25 expression in the regulation of diabetic nephropathy

目的 探讨microRNA-25（miR-25）表达调控糖尿病肾病（diabetic nephropathy,DN）形成的分子机制.方法 分别采用链脲佐菌素和高糖诱导法构建糖尿病肾病模型（Dia组）小鼠和模型HK-2细胞,采用荧光定量PCR检测正常小鼠（Con组）和Dia组小鼠肾脏质量指数（LVWI）和肾脏miR-25、DAB2IP、P38-MAPK、P-AKT mRNA表达水平,并检测HK-2细胞miR-25、DAB2IP、P38-MAPK、P-AKT mRNA表达水平.采用miR-25 mimics在HK-2细胞中过表达miR-25,采用Western blot技术检测DAB2IP、P38-MAPK、P-AKT蛋白表达水平.结果 Dia组小鼠建模全部成功.Dia组小鼠肾脏质量指数、P38-MAPK、P-AKT、DAB2IP mRNA相对表达水平显著高于Con组,肾脏miR-25相对表达水平显著低于Con组（P＜0.05）.模型组HK-2细胞miR-25相对表达水平显著低于正常HK-2细胞（P＜0.05）,模型组HK-2细胞P38-MAPK、P-AKT、DAB2IP mRNA相对表达水平均显著高于正常HK-2细胞（P＜0.05）.用miR-25 mimics转染HK-2细胞和模型HK-2细胞,Western blot结果显示模型HK-2细胞中P-AKT和P38-MAPK表达显著下调（P＜0.05）.结论 miR-25高表达可抑制P-AKT和P38-MAPK表达,可能通过JNK信号通路促进DN的发生.

Objective To investigate the molecular mechanism of microRNA-25 （miR-25） expression in the regulation of diabetic nephropathy （DN） formation.Methods Diabetic nephropathy model （Dia group）mice and model HK-2 cells were induced by streptozotocin and high glucose induction method,respectively.Fluorescence quantitative PCR was used to detect the quality of kidney in normal mice （Con group） and Dia group mice.LVWI and the expression levels of miR-25,DAB2IP,P38-MAPK,and P-AKT mRNA in kidneys,and the expression levels of miR-25,DAB2IP,P38-MAPK,and P-AKT mRNA in HK-2 cells were detected.MiR-25 mimics were used to overexpress miR-25 in HK-2 cells,and Western blot was used to detect the expression of DAB2IP,P38-MAPK,and P-AKT protein.Results All mice in the Dia group were successfully modeled.The renal mass index,relative expression of P38-MAPK,P-AKT,and DAB2IP mRNA of Dia group were significantly higher than those of Con group,the relative expression of miR-25 in the kidney was significantly lower than that of Con group （P〈0.05）.The relative expression level of miR-25 in HK-2 cells of model group was significantly lower than that of normal HK-2 cells （P〈0.05）,the relative expression levels of P38-MAPK,P-AKT,and DAB2IP mRNA in HK-2 cells of model group were significantly higher than those of normal HK-2 cells （P〈0.05）.After HK-2 cells and model HK-2 cells were transfected with miR-25 mimics,Western blot results showed that the expression of P-AKT and P38-MAPK in model HK-2 cells significantly down-regulated （P〈0.05）.Conclusion High expression of miR-25 can inhibit the expression of P-AKT and P38-MAPK,and may promote the occurrence of DN through the JNK signaling pathway.