YY1对肺泡Ⅰ型上皮细胞纤维化的调控研究

The role of YY1 during fibrosis in alveolar type Ⅰ epithelial cells and the related mechanisms

目的研究核转录因子YinYang1(YY1)对肺泡Ⅰ型上皮细胞的调控功能及作用机制。方法比较不同肺泡上皮细胞和肺癌细胞中纤维化标志物分子和YY1的表达;通过CCK8增殖实验检测YY1对R3/1细胞增殖的影响;通过YY1过表达以及特异敲低技术,检测TGF-β1刺激R3/1细胞后纤维化标志物分子的表达;通过Western印迹法检测YY1影响NF-κB质核转移的作用。结果纤维化标志物分子α-sma和vimentin在R3/1细胞中特异高表达,与A549细胞相比,YY1在R3/1细胞中低表达; YY1显著抑制R3/1细胞增殖;过表达YY1降低TGF-β1诱导R3/1细胞中的α-sma和vimentin的表达,敲低YY1能够进一步促进TGF-β1诱导的α-sma高表达;在R3/1细胞中过表达YY1抑制TGF-β1诱导的NF-κB细胞核蛋白增加。结论 YY1在R3/1细胞中能够抑制TGF-β1诱导的NF-κB从细胞质到细胞核的转移,进而抑制了其对纤维化基因的转录激活。

Objective To investigate the effects of nuclear transcription factor YY1 on alveolar typeⅠepithelial cells（typeⅠAEC） and its mechanisms. Methods The expression of fibrosis markers and YY1were compared in different types of alveolar epithelial cells and lung cancer cells. The effect of YY1 ontype Ⅰ AEC R3 / 1 cell proliferation was examined by CCK8 assay. The expression of fibrosis markerswas determined by Western blotting and qRT-PCR in R3 / 1 cells with over-expressed or knockdownedYY1 and TGF-β 1. The expression of NF-κB protein in the cytoplasm and the nucleus was alsodetected by Western blot in R3 / 1 cells transfected with TGF-β and YY1 plasmid. Results Comparedwith type Ⅱ AEC A549 cells, the expression of fibrotic markers α-sma and vimentin was significantlyhigher and the expression of YY1 was significantly lower in R3 / 1 cells. Over-expression of YY1reduced α-sma mRNA and protein expression in R3 / 1 cells after TGF-β1 treatment, while YY1knockdown promoted the α-sma induction in TGF-β treated R3 / 1 cells. Overexpression of YY1reduced the expression of nuclear protein of NF-κB, which was induced by TGF-β1 in R3 / 1 cells.Conclusion YY1 can inhibit the relocalization of NF-κB from the cytoplasm to the nucleus inducedby TGF-β1 in R3 / 1 cells, which is associated with the inhibition of transcriptional activation offibrosis-related genes.