慢性移植肾肾病肾组织中转化生长因子β_1、金属蛋白酶2、金属蛋白酶组织抑制剂1的表达及意义

Expression and significance of transforming growth factor-beta 1,matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-1 in the renal tissue of patients with chronic allograft nephropathy

背景:相关实验表明,转化生长因子β1、金属蛋白酶2和金属蛋白酶组织抑制剂1在慢性移植肾肾病中发挥着重要作用,但发病机制尚不十分明确。目的:探讨转化生长因子β1、金属蛋白酶2和金属蛋白酶组织抑制剂1在慢性移植肾肾病患者肾组织及正常肾组织中的表达及意义。设计、时间及地点:细胞组织形态对照观察实验,于2008-06/10在福建漳州解放军第一七五医院病理实验室完成。材料:24例慢性移植肾肾病患者的移植肾组织,10例正常肾组织做对照。方法:34例参试者肾组织标本均进行免疫组织化学染色:常规甲醛固定,石蜡包埋,切成厚3μm的切片,正常非免疫性血清封闭,依次加一抗、二抗及SP复合物,DAB显色,苏木精复染,透明封固。主要观察指标:免疫组织化学染色观察34例肾组织标本的转化生长因子β1、金属蛋白酶2和金属蛋白酶组织抑制剂1的表达情况,并分析3者间及与慢性移植肾肾病病理分级之间的相互关系。结果:定性分析:在移植肾肾病的肾组织中转化生长因子β1、金属蛋白酶2和金属蛋白酶组织抑制剂1在肾小管上皮细胞胞浆和胞膜多呈强阳性表达。定量分析:转化生长因子β1、金属蛋白酶组织抑制剂1、金属蛋白酶2在正常组和慢性移植肾肾病组间的表达有显著差异(P<0.01),且转化生长因子β1、金属蛋白酶组织抑制剂1的表达随慢性移植肾肾病的病理分级的增加而增加,而金属蛋白酶2则略有下降趋势。同时转化生长因子β1和金属蛋白酶组织抑制剂1的表达之间呈正相关(r=0.651,P<0.05)。结论:转化生长因子β1、金属蛋白酶2、金属蛋白酶组织抑制剂1的表达异常是慢性移植肾肾病的重要表现,转化生长因子β1可能通过上调金属蛋白酶组织抑制剂1的表达从而抑制细胞外基质的降解引起移植肾纤维化。

BACKGROUND： Previous experiments have shown that transforming growth factor-β1 （TGF-β1）, matrix metalloproteinase-2 （MMP-2） and tissue inhibitor of metalloproteinase-1 （TIMP-1） play an important role in chronic allograft nephropathy, but the mechanisms remains unclear. OBJECTIVE： To investigate the expression and significance of TGF-β1, MMP-2 and TIMP-1 in the renal tissues of chronic allograft nephropathy and normal renal tissues. DESIGN, TIME AND SETTING： A histological and morphological control observational experiment of cytology was performed at Pathological Laboratory of the 175lh hospital from June to October 2008. PARTICIPANTS： The transplanted renal tissues extracted from 24 patients with chronic allograft nephropathy were used in the experiment, and the normal renal tissues in 10 patients were assigned as controls. METHODS： Immunohistochemical staining was performed in all the renal tissues. All the renal tissues were fixed with formaldehyde and embedded by paraffin wax. Then the sections were prepared with a thickness of 3 μm, and were then closed with normal non-immune serum. Subsequently, the sections were incubated as follows： primary antibody, secondary antibody, streptavidin peroxidase complex, and diaminobenzidine （DAB）, followed by HE counterstaining. The sections were cleared and coverslipped. MAIN OUTCOME MEASURES： The expressions of TGF-β1, MMP-2 and TIMP-1 in the renal tissues were observed by immunohistochemical staining. The relationships among TGF-β1, MMP-2 and TIMP-1, as well as between them and the grade of chronic allograft nephropathy were analyzed. RESULTS： Qualitative analysis： The TGF-β1, MMP-2 and TIMP-1 showed strongly positive expressions in the cytoplasm and membrane of renal tubular epithelial cells in transplanted renal tissues. Quantitative analysis： There were significant differences in expression of TGF-β1, MMP-2 and TIMP-1 between in transplanted renal tissues and in normal renal tissues （P〈 0.01）. As the grade of chronic allograft nephropathy increasing, the expressions of TGF-β1 and TIMP-1 increased, while the expression of MMP-2 had a slight decreasing tendency. There was a positive correlation between the expressions of TIMP-1 and TGF-β1 （r =0.651, P 〈 0.05）. CONCLUSIONS： Abnormal expressions of TGF-β1, MMP-2 and TIMP-1 are important manifestations of chronic allograft nephropathy. TGF-β1 has a fibrogenic action by indirectly inhibiting extracellular matrix degradation via upregulation of TIMP-1.