YY1对肺泡Ⅰ型上皮细胞纤维化的调控研究

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 type Ⅰ epithelial cells(type Ⅰ AEC) and its mechanisms. Methods The expression of fibrosis markers and YY1 were compared in different types of alveolar epithelial cells and lung cancer cells. The effect of YY1 on type Ⅰ AEC R3/1 cell proliferation was examined by CCK8 assay. The expression of fibrosis markers was determined by Western blotting and qRT-PCR in R3/1 cells with over-expressed or knockdowned YY1 and TGF-β 1. The expression of NF-κB protein in the cytoplasm and the nucleus was also detected by Western blot in R3/1 cells transfected with TGF-β and YY1 plasmid. Results Compared with type Ⅱ AEC A549 cells, the expression of fibrotic markers α-sma and vimentin was significantly higher and the expression of YY1 was significantly lower in R3/1 cells. Over-expression of YY1 reduced α-sma mRNA and protein expression in R3/1 cells after TGF-β1 treatment, while YY1 knockdown promoted the α-sma induction in TGF-β treated R3/1 cells. Overexpression of YY1 reduced 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 induced by TGF-β1 in R3/1 cells, which is associated with the inhibition of transcriptional activation of fibrosis-related genes