Hedgehog信号通路在百草枯致肺上皮间质转化过程中的作用

The role of hedgehog signaling pathway in the process of paraquat-induced pulmonary epithelium transformation

目的肺纤维化是百草枯(Paraquat,PQ)病死率极高的主要原因,目前PQ中毒所致肺纤维化的分子机制尚未阐明,且临床上缺少有效的治疗药物或方法,阻碍了PQ中毒患者的存活和预后。肺上皮间质转化在纤维化形成过程中发挥重要作用,我们拟阐明PQ-肺上皮间质转化发生发展的分子机制。方法Ⅱ型肺泡上皮细胞株RLE-6TN经转化生长因子β1(TGF-β1)-siRNA沉默TGF-β1基因后再进行PQ处理,Western blotting检测细胞中上皮间质转化标志性蛋白的表达水平;RLE-6TN细胞经GANT61(Hedgehog信号通路阻断剂)处理后Western blotting检测细胞上皮间质性蛋白;Q-PCR和Western blotting检测Hedgehog信号通路阻断对TGF-β1的mRNA水平和蛋白水平的影响。结果 siRNA沉默TGF-β1基因后,再进PQ处理24h,肺上皮细胞发生上皮间质转化程度减弱;GANT61阻断Hedgehog通路后,抑制了PQ所致的细胞上皮间质转化;阻断Hedgehog通路可抑制PQ对TGF-β1mRNA和蛋白表达的上调。结论TGF-β1在PQ中毒所致肺纤维化上皮间质转化发生和发展过程中发挥正向调控作用,并有可能是Hedgehog通路调节PQ-肺上皮间质转化发生发展的作用靶点。Hedgehog信号通路与TGF-β1之间的调节关系可能成为治疗PQ中毒所致肺纤维化新的理论依据。

Objective To clarify the molecular mechanism of the development of pulmonary epithelium transformation.Methods RLE-6 TN cells（Hedgehog signaling pathway blocker）were treated with Paraquat after siRNA silencing TGF-β1 gene,and the expression of epithelial marker and interstitial marker protein were detected by Western Blotting test.And the effect of Hedgehog signaling pathway on mRNA levels and protein levels of TGF-β1 were detected by Q-PCR and Western Blotting test.Results Knockdown of TGF-β1 inhibited Paraquat-induced pulmonary epithelium transformation in RLE-6 TN cells.Western Blotting showed that after the treatment of Paraquat and GANT61,the degree of Paraquat-induced pulmonary epithelium transformation decreased.The Hedgehog signaling pathway blocked the expression of mRNA and protein of TGF-β1.Conclusions We speculated that TGF-β1 plays a positive regulatory role in the occurrence and development of pulmonary epithelium transformation,and it may be the target of the Hedgehog pathway regulating the development of epithelium transformation.The regulation relationship between Hedgehog signaling pathway and TGF-β1 may be a new theoretical basis for the treatment of pulmonary fibrosis caused by Paraquat poisoning.