转化生长因子β1及其信号转导分子Smad 2在病变肾小球中的表达及其意义

目的 探讨转化生长因子β1（TGF-β1）及其信号转导分子Smad2在肾小球肾炎中的表达及其意义。方法 以11例肾小球轻微病变为对照组,对各种不同组织学类型的IgA肾病40例、膜性肾炎10例、硬化性肾炎11例的肾穿刺活检标本,分别行原位分子杂交检测肾小球Smad2mRNA的表达和免疫组织化学ABC方法观察TGF-β1、IV型胶原及纤维蛋白在肾小球中的染色强度,并对其检测结果作图像分析处理。结果 除轻微病变型IgA肾病的Smad2mRNA表达外,其他病理类型肾炎中病变肾小球TGF-β1蛋白和Smad2mRNA的表达均高于对照组,且两者在肾小球中的表达与IV型胶原、纤连蛋白在肾小球中的沉积呈正相关。结论 TGF-β1及其信号转导分子Smad2可能参与了病变肾小球细胞外基质的过量积聚,在肾小球硬化过程中起重要作用。

The expressions of TGF-beta1 and Smad 2 mRNA on diseased glomeruli and their significance in the development of glomerulosclerosis

OBJECTIVE: To explore the expressions of transforming growth factor-beta1 (TGF-beta1) and its signaling transduction molecule Smad 2 and their significance in the development of glomerulosclerosis. METHODS: Using in situ hybridization and immunohistochemistry to detect Smad 2 mRNA expression and TGF-beta1, collagen IV, fibronectin expression in renal biopsies from 61 cases with a spectrum of glomerulonephritis including IgA nephropathy (40 cases), membranous glomerulonephritis (10 cases) and sclerosing glomerulonephritis (11 cases), compared with 11 cases of glomerular mild lesion with image analysis system. RESULTS: With the exception of Smad 2 mRNA expression in mild type IgA nephropathy, all other types of diseased glomeruli showed increased expression of both TGF-beta1 and Smad 2 mRNA when compared with the 11 cases of mild glomerular lesions. The expressions of glomerular TGF-beta1 and Smad 2 mRNA positively correlated with collagen IV and fibronectin deposition in the glomeruli. CONCLUSIONS: TGF-beta1 and Smad 2 may be involved in the excessive deposition of glomerular extracellular matrix and play an important role in the development of glomerulosclerosis.