摘要目的 明确糖尿病肾病小鼠模型中肾小管上皮细胞-间充质转化(epithelial mesenchymal transition,EMT)中高迁移率核小体结合蛋白1(high mobility group nucleosome binding domain 1,HMGN1)表达水平的变化,并探讨HMGN1在肾脏纤维化中的作用.方法 20只C57BL/6小鼠随机分成对照组、模型组、贝那普利组和胰岛素组.药物干预8周后处死小鼠取血、尿和肾组织样本,分别检测常规生理、生化指标;使用HE、天狼星红染色法检测肾脏结构及纤维化情况;使用免疫组化、原位杂交法检测肾组织中HMGN1、CD68、F4/80、α平滑肌肌动蛋白(α-SMA)、E钙黏蛋白(E-cadherin)的蛋白及mRNA表达水平.结果 模型组血糖、肾脏指数、尿蛋白肌酐比均明显高于正常组.模型组中,HE染色显示肾小球肥大、肾小管间质炎性细胞浸润;天狼星红染色显示肾组织内胶原纤维蛋白沉积;且HMGN1蛋白及mRNA表达水平增高,CD68、F4/80阳性细胞数增加,α-SMA蛋白表达增高,E-cadherin蛋白表达降低(均P<0.05).贝那普利干预后上述指标未见明显改善.胰岛素干预后,CD68阳性细胞数、α-SMA蛋白表达水平较模型组降低,E-cadherin蛋白表达水平较模型组增高(均P<0.05).相关性分析显示,HMGN1表达水平与CD68、F4/80、α-SMA、E-cadherin、胶原纤维蛋白相关,而CD68和F4/80蛋白水平分别与α-SMA、胶原纤维蛋白、血糖相关(均P<0.05).结论 HMGN1参与糖尿病肾病纤维化进展,其相关机制可能与诱导巨噬细胞相关的EMT过程有关.

abstractsObjective This study aimed to investigate the renal expression change of high mobility of nucleosome binding protein 1 ( HMGN1) in epithelia-mesenchymal transition ( EMT) process, and to study the effect of HMGN1 on renal fibrosis in the diabetic nephropathy mice model. Methods 20 C57BL/6 mice were randomly divided into control group, model group, benazepril group, and insulin group. After 8 weeks of drug intervention, blood, urine and kidney tissue samples were taken from mice. The routine physiological and biochemical indexes were detected. Renal structure and fibrosis were detected by HE and Sirius red staining, respectively. Immunohistochemistry and in situ hybridization were used to investigate the protein and mRNA expression levels of HMGN1, CD68, F4/80,α-smooth muscle actin (α-SMA) , and E-cadherin in renal tissue. Results Blood glucose, renal index, and urinary albumin to creatinine ratio ( UACR) were significantly higher in the model group than those in the normal group. In the model group, HE staining showed glomerular hypertrophy and interstitial inflammatory cell infiltration, and Sirius red showed collagen deposition in the renal tissue. Compared with normal group, HMGN1, CD68, F4/80 positive cell counts andα-SMA protein expression were all increased, while E-cadherin protein expression was downregulated in the model group ( all P<0.05) . The above indexes were not improved significantly in the benazepril group. And after intervention of insulin, the expression levels of CD68 positive cell count andα-SMA protein were decreased and the expression levels of E-cadherin protein were increased compared with the model group ( all P<0.05) . The correlation analysis showed that the level of HMGN1 was correlated with CD68, F4/80, α-SMA, E-cadherin and collagen protein, while CD68 and f4/80 were correlated withα-SMA, collagen protein and blood glucose, respectively ( all P<0. 05 ) . Conclusion HMGN1 is involved in the progression of diabetic nephropathy fibrosis, and its underlying mechanism might be related to the macrophage-mediated EMT process.