肾淋巴循环障碍致肾小管间质纤维化及对转化生长因子β1和Smad2/3表达的影响

目的 探讨肾淋巴循环障碍对大鼠肾小管间质纤维化的作用及其与TGF-β1、Smad2/3表达变化的关系。 方法 雄性Wistar大鼠48只，随机分为淋巴循环障碍模型组和假手术对照组各24只。分别在术后1、2、4、8周每组各处死6只。测定尿蛋白量（24 h）和Scr。PAS和Masson染色观察肾组织病理改变。用实时PCR检测TGF-β1、Smad2/3、I型胶原（ColⅠ）mRNA的表达量。用免疫组化和（或）Western 印迹方法检测肾组织ColⅠ、TGF-β1、Smad2/3和磷酸化Smad2/3（p-Smad2/3）的蛋白表达量及主要表达部位。 结果 模型组大鼠尿蛋白显著增加，随着时间推移肾功能逐渐减退，并出现明显的组织病理改变，小管间质损伤指数明显高于对照组（P < 0.05或P < 0.01），并随时间延长而逐渐加重。肾组织中ColⅠ、TGF-β1、Smad2/3、p-Smad2/3的蛋白和（或）基因表达水平也明显增高（P < 0.01），且主要表达在肾小管上皮细胞及肾间质。 结论 肾淋巴循环障碍可导致大鼠肾脏功能及小管间质的损害，并随着时间的延长而加重。其作用机制可能与激活TGF-β-Smad途径，导致肾小管间质纤维化有关。

Effect of renal lymph circulation disorder on tubulointerstitial fibrosis and the expression of TGF-β1 and Smad2/3

Objective 　To investigate the influence of renal lymph circulation disorder on renal tubulointerstitial fibrosis and the expression of TGF-β1/Smad2/3 in rat kidney. Methods 　Forty-eight male Wistar rats were randomly divided into two groups, twenty-four rats in each group: (1)control group: sham operation; (2)model group: renal lymph ligation. Six rats in each group were sacrificed at week 1, 2, 4 and 8 respectively after operation. The renal tissue was examined by PAS and Masson stain. The sites and expressions levels of type I collagen(Col I),TGF-β1, Smad2/3, phosphorylated-Smad 2/3 (p-Smad2/3) protein were examined by immunohistochemical staining and/or Western blot. Real-time PCR was applied to determine the mRNA expression of Col I， TGF-β1, Smad2 and Smad3. Results 　Renal disfunction and tubulointerstitial fibrosis were found in model group, and the tubulointerstitial lesion was remarkably aggravated in week 8 compared with control group（P<0.05）. Expression levels of Col I， TGF-β1, Smad2/3, p-Smad2/3 protein and/or mRNA were significantly increased during 1～8 weeks after operation. Immunohistochemical staining indicated that these proteins were mainly expressed in renal tubulointerstitium. Conclusions Disorder of renal lymph circulation can damage renal structure, especially lead to tubulointerstitial fibrosis. The possible mechanism is the activation of TGF-β/Smad signaling pathway. The high expression levels of Smad2, Smad3, and TGF-β1 protein may be the major cause leading to tubulointerstitial fibrosis.