Objective:To investigate the regulation effect of endogenous nicotinamide phosphoribosyl transferase (Nampt) on the Vimentin expression of glomerular cells in high concentration glucose,and to clarify the mechanism of formation of diabetic kidney inflammation fibrosis.Methods:The C57/BL6 diabetic mice were selected and the kidney tissues were collected,and the wild C57/L86 mice were used as control group;the pathological section and tissue fluorescence staining were performed.The expression and location of endogenous Nampt and Vimentin in the glomerular cells were detected by immuno-focused technology.The HBZY-1 cells were randomly divided into 4 groups:low concentration of glucose (LG,0.56 mmol · L-1) control group,high concentration glucose (HG,200 mmol · L-1) group,HG +-FK866 group and HG+nicotinamide mononucleotide (NMN) group.In HG group,the cells were treated with FK866 (10 μmol · L-1) and NMN (1 mmol · L-1) for 24 h after cultured with HG for 5 d.The expression levels of Nampt,Vimentin,nuclear factor-kappa B p65 (NF-κBp65) and sirtuin type 1 (Sirt1) were detected by immunofluorescence and Western blotting methods.The expression levels of Nampt and Vimentin were detected by RT-PCR and Western blotting methods.Results:The shape and size of glomerulus had obvious atrophy of the mice in severe diabetic group compared with normal C57/BL6 mice group.The expression level of Vimentin in glomerular cells was increased with the increasing of endogenous Nampt (P＜0.01).When the HBZY-1 cells were cultured in HG condition,the exprssion levels of Nampt,Vimentin and NF-kB p65 were obviously increased while the Sirt1 expression levels was significantly decreased compared with control group (P＜ 0.01).The expression levels of Nampt,Vimentin and NF-κB p65 in glomerular cells in HG+FK866 HG+ NMN groups were singnificartyly decreased compared with control group (P＜0.01).Conclusion:The endogenous Nampt over-expression in glomerular cells can enhance the expression of Vimentin under high concentration of glucose stress through NF-κBp65 and Sirt1 signal pathway.%目的:探讨高浓度葡萄糖条件下肾小球系膜细胞过度表达的内源性烟酰胺磷酸核糖转移酶(Nampt)对波形蛋白(Vimentin)表达的调控作用,阐明糖尿病并发肾脏炎症纤维化的形成机制.方法:取患严重自发性糖尿病的C57/BL6小鼠肾脏,以野生型C57/L86小鼠作为对照组,行病理切片和组织荧光染色,应用免疫共聚焦方法检测肾小球系膜细胞中内源性Nampt和Vimentin表达及定位;肾小球膜HBZY-1细胞随机分为4组,即0.56mmol·L-1低浓度葡萄糖(LG)对照组、200 mmol·L-1高浓度葡萄糖(HG)处理组、HG+ FK866组和HG+NMN组;高浓度葡萄糖干预5d后,分别施加FK866(10 μmol·L-1)和NMN(1 mmol·L-1)作用24 h后,通过免疫荧光和免疫印迹法检测细胞内源性Nampt、Vimentin、核因子κB p65 (NF-κBp65)和依赖于烟酰胺腺嘌呤二核苷酸(NAD+)的组蛋白去乙酰化酶1 (Sirtl)表达水平;应用RT-PCR和免疫印迹等方法检测细胞Nampt和Vimentin表达水平.结果:与野生型C57/BL6小鼠组比较,严重糖尿病组小鼠肾小球明显萎缩,肾小球细胞内Vimentin表达水平随内源性Nampt表达水平升高而增加(P＜0.01);与0.56 mmol·L-1低浓度葡萄糖对照组比较,高浓度葡萄糖冲击细胞Nampt、NF-κBp65和Vimentin表达水平明显升高(P＜0.01),Sirt1表达水平明显降低(P＜0.01).HG+FK866和HG+NMN组肾小球系膜细胞中Nampt、Vimentin和NF-κBp65表达水平均较对照组明显降低(P＜0.01).结论:高浓度葡萄糖冲击条件下肾小球系膜细胞过度表达的内源性Nampt能够通过NF-κBp65和Sirt1信号通路促进Vimentin表达.
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