血小板生成素抑制TGFβ1诱导的肺成纤维细胞向肌成纤维细胞转化的研究

Effects of thrombopoietin on TGFβ1-induced myofibroblast transdifferentiation in human lung fibroblasts

目的:探讨血小板生成素处理对TGFβ1介导的肺成纤维细胞向肌成纤维细胞转化的影响。方法:CCK8法测定血小板生成素及TGFβ1组合处理后细胞生长的抑制率,采用荧光实时定量PCR及免疫荧光染色分别检测不同处理组细胞αSMA、COL1A2基因及蛋白的表达水平,应用免疫荧光染色检测细胞增殖相关蛋白Ki-67的表达水平,应用荧光实时定量PCR检测HO-1基因的表达水平。结果:TGFβ1处理能够诱导肺成纤维细胞分化为肌成纤维细胞,细胞形态发生显著变化且增殖速度提高,肌成纤维细胞标志基因/蛋白αSMA及COL1A2的表达水平随诱导时间延长显著提高(P<0.01)。在TGFβ1处理同时添加血小板生成素(TPO),αSMA、COL1A2基因和蛋白的表达水平均显著下调(P<0.01)。此外,TPO显著抑制TGFβ1诱导的细胞增殖,且增殖相关蛋白Ki-67的表达水平较TGFβ1处理组显著降低(P<0.05)。此外,发现TGFβ1处理导致HO-1的表达水平下降,而添加TPO能够挽救该基因的表达水平(P<0.05)。结论:血小板生成素能够抑制TGFβ1诱导的肺成纤维细胞向肌成纤维细胞的转化,这一发现对肺纤维化的对症治疗具有潜在的应用价值。

Objective:To investigate the effects of thrombopoietin(TPO)on proliferation and collagen synthesis in pulmonary fibro-blasts induced by TGFβ1.Methods:Cultured human embryonic lung fibroblasts(HFLs)were treated with recombinant human TGF-β1 to induce myofibroblast differentiation.Different concentrations of recombinant human TPO were applied individually or in combina-tion.Cell proliferation rate was determined using the CCK8 assay.Q-PCR and immunofluorescence assay were employed to examine the mRNA and protein expression ofα-smooth muscle actin(αSMA)and type I collagen(COL1)A2.Results:TGFβ1 treatment induced HFL transdifferentiation to myofibroblasts was determined by the expression ofαSMA,a myofibroblast-specific marker.Cell prolifera-tion increased during the induction.COL1 gene and protein expression were upregulated by TGFβ1 induction(P<0.05).The TGFβ1-in-duced mRNA and protein expression ofαSMA and COL1A2 was decreased by TPO treatment(P<0.05),as determined by reverse tran-scription quantitative polymerase chain reaction and immunofluorescence analysis,respectively.The inhibitory rate showed a dose de-pendent effect within a certain TPO concentration range.The CCK8 assay demonstrated that TPO downregulated the TGFβ1-induced proliferation(P<0.05).Furthermore,the expression of heme oxygenase-1(HO-1)was downregulated in TGFβ1-induced lung fibro-blasts,and these effects were attenuated by TPO administration(P<0.05).Conclusions:TPO can inhibit the TGFβ1-induced prolifera-tion and differentiation of human lung fibroblasts.These effects may be mediated in part by HO-1-related signaling pathways.