慢性肾脏病患者肾组织蛋白酶B的表达及意义

目的 探讨慢性肾脏病患者肾组织蛋白酶B(cathepsin B，CB)的表达及其与肾组织纤维化的关系。方法 采用免疫组织化学SP法和计算机图像分析系统检测肾组织CB、IV型胶原的表达情况，并以体视学多能目镜测试系统对肾活检组织病理切 片进行形态计量，计算硬化肾小球比率及病变肾小管肾间质比率。结果 CB在近曲小管表达最高，在肾小球和肾小管其他部位表达较少。轻度纤维化组和中度纤维化组CB的表达明显低于无纤维化组。CB表达与Ⅳ型胶原表达、病变肾小管肾间质比率及硬化肾小球比率呈显著负相关。结论 CB主要在肾近曲小管表达，其表达成少是细胞外基质(extracellular matrtx，ECM)降解减少的原因之一，参与肾组织纤维化的发生机制。

The expression and its significance of cathepsin B in patients with chronic renal disease

Objective To elucidate localization of cathepsin B in human kidney and its role in the genesis of renal fibrosis. Methods The expression of cathepsin B and type IV collagen in the renal biopsy specimens was analysed using computer image analysis system on the immunohistochemical stained section. The relationship between the expression of cathepsin B and the degree of glomerulosclerosis and tubulointerstitial injury was analysed.Results The cathepsin B expression was strong in renal proximal tubule. The cathepsin B expression was significantly decreased in light and middle fibrosis groups compared with that in no fibrosis group ( P <0.05). The cathepsin B expression was significantly negatively correlated with type IV collagen and the degree of glomerulosclerosis and tubulointerstitial injury ( P <0.05). Conclusion The cathepsin B was located in the proximal tubule. The decreased expression of cathepsin B resulted in the over deposition of extracellular matrix (ECM) in some degree, which might contribute to the forming of renal fibrosis.