BMP-7对TGF-β_1诱导人肾小管上皮细胞外基质表达的影响

目的观察骨形态发生蛋白-7(BMP-7)对TGF-β1诱导人近端肾小管上皮细胞(HK-2)细胞外基质(ECM)成分表达的影响,以探讨其延缓肾间质纤维化病变的作用机制。方法将体外培养的HK-2细胞分为空白对照组,3μg.L-1TGF-β1组,BMP-7组,TGF-β1加不同浓度BMP-7组。免疫荧光检测FN的表达;RT-PCR和Western blot分别检测FN、ColⅠα1mRNA及蛋白的表达。结果免疫荧光检测结果显示,3μg.L-1TGF-β1刺激HK-2细胞48h后,FN表达明显增强;加入200μg.L-1BMP-7干预后荧光明显减弱。RT-PCR和Western blot结果显示,TGF-β1刺激HK-2细胞48h后,FN、ColⅠα1mRNA及蛋白表达均明显高于对照组(P<0.01);BMP-7(100～400μg.L-1)可在mRNA及蛋白水平呈剂量依赖性下调TGF-β1诱导的FN、ColⅠα1的表达。结论BMP-7能抑制TGF-β1诱导的HK-2细胞FN、ColⅠα1的合成。表明BMP-7抑制肾小管间质纤维化的进展、改善肾功能的作用,部分是通过抑制肾小管上皮细胞分泌细胞外基质实现的。

Effects of BMP-7 on the expression of extracellular matrix in human renal proximal epithelial cells induced by TGF-β1

Aim To investigate the effects of bone morphogenic protein(BMP)-7 on the expression of extracelluar matrix components(ColⅠand FN)in human renal proximal tubular cells(HK-2)induced by transforming growth factor-β1(TGF-β1),and to explore the inhibition of BMP-7 on renal interstitial fibrosis.Methods HK-2 cells were treated with TGF-β1,BMP-7,or a combination of both for 48 h.The expression of FN was assessed by indirect immunofluorescence.RT-PCR and Western blot were used to determine the mRNA and protein expression of FN and ColⅠα1.Results Indirect immunofluorescence staining showed that FN staining in 3 μg·L-1 TGF-β1 group was considerably stronger than that in control group.By an addition of 200 μg·L-1 BMP-7,the expression of FN was significantly inhibited.RT-PCR and Western blot showed the mRNA and protein expression of FN and ColⅠα1 were up-regulated by TGF-β1 after 48 hours significantly(P<0.01).BMP-7 dramatically down-regulated the expression of FN and ColⅠα1 induced by TGF-β1 in a dose-dependent manner both in mRNA and protein levels.Conclusions BMP-7 has the role to inhibit the overproduction of FN and ColⅠα1 induced by TGF-β1.BMP-7 exerts its antifibrotic effect partially through blocking the TGF-β1-induced accumulation of ECM in human renal tubular epithelial cells.