目的 研究转化生长因子-β 1 (transforming growth factor beta-1 ,TGF-β 1 ) 诱导的肾间质成纤维细胞(NRK-49F) 发生表型转化时基质金属降解酶MMP-9 及其抑制因子TIMP-1 表达的变化及对分泌纤维连接蛋白(fibronectin,FN) 的影响。 方法 以不同浓度hTGF-β 1 (0 ng/ml 、0.5 ng/ml、1 ng/ml、2 ng/ml、5 ng/ml、10 ng/ml) 刺激NRK-49F 细胞48 h,分别应用ELISA法检测细胞上清FN 的浓度,免疫荧光检测细胞表型标记物α-SMA、Vimentin 的表达,Western blot、Northern blotting 方法检测MMP-9、TIMP-1 的基因及蛋白质表达。 结果 0.5 ~ 10 ng/ml TGF- β 1 随刺激浓度增高NRK-49F 细胞表达α-SMA明显增多、Vimentin 明显减少,细胞上清中FN 的含量显著增加(P < 0.05 或P < 0.01) ;同时,TGF-β 1 浓度> 2 ng/ml 时显著上调TIMP-1 mRNA 及蛋白表达水平(P < 0.05 或P < 0.01) ;以上效应均呈浓度依赖性,但对细胞MMP-9 mRNA 及蛋白表达无明显影响(P > 0.05)。 结论 TGF- β 1 能诱导肾间质成纤维细胞活化,使FN 的分泌增多,该作用可能与TGF-β 1 上调了TIMP-1 基因及蛋白质水平,进而减少细胞外基质(extracellular matrix,ECM) 的降解有关。
Objective To study the changes on MMP-9 and TMP-1 expression when renal interstitial fibroblast cells (NRK-49F) occurred phenotypic transform induced by transforming growth factor beta-1 (TGF- β 1 ), and its effects on the secretion of fibronectin (FN). Methods Renal interstitial fibroblast cells (NRK-49F) of rats were stimulated by hTGF- β 1 at different concentrations of 0 ng/ml, 0.5 ng/ml, 1 ng/ml, 2 ng/ml, 5ng/ml, 10 ng/ml. Immune fluorescence was used to measure the expression of cell phenotype sign α -SMA and Vimentin, and ELISA was used to detect the concentration of FN in supernatant, while Western Blot and Northern Blotting technique was used to measure the expression of MMP-9 and TIMP-1. Results TGF- β 1 at the concentration of 0.5 ng/ml - 10 ng/ml induced the expression of α -SMA which represented myofibroblast appearance, with increasing concentration of TGF- β 1 , the expression of α -SMA gradually increased and Vimentin decreased significantly, furthermore FN secretion were driven up greatly (P 〈 0.05 or P 〈 0.01), while TGF- β 1 at the concentration of 2 ng/ml markly drove up the expression of TIMP-1 mRNA and protein(P 〈 0.05 or P 〈 0.01) , those effects showed concentration-dependent form. However, TGF- β 1 at above concentration had no remarkable effect on MMP-9 mRNA and protein expression (P 〉 0.05). Conclusion TGF- β 1 can induce renal interstitial fibroblast activation to be myofibroblast, and promote fibronectin secretion, whose effects may be related to up-regulation of TIMP-1 expression so as to restrain ECM decompounded.