miR-17 Influences TGF-β1 Induced Pulmonary Fibrosis by Regulating Autophagy
Objective To investigate the effect of miR-17 on autophagy and fibrosis in transforming growth factor-β1(TGF-β1)induced pulmonary fibrosis cell models in vitro.Methods Human embryonic lung fibroblast HFL1 cells were induced with recombinant human TGF-β1 protein,and the pulmonary fibrosis cell model was established.CCK-8 was used to detect the cell activity,and the hydroxyproline(Hyp)content in the cell supernatant was detected by ELISA kit.The cells were divided into control group,model group,3-methyladenine(3-MA)group,miR-17 inhibitor group and miR-17 inhibitor+3-MA group.Cell proliferation was detected by CCK-8,cell apoptosis was detected by flow cytometry,and the expressions of mitochondrial auto-phagy associated proteins LC3-Ⅱ and p62,fibrosis markers α-SMA and collagen Ⅰ protein were detected by Western blot-ting.Results HFL1 cell activity increased after TGF-β1 induction(P<0.01),the content of Hyp in cell supernatant was in-creased(P<0.01),in vitro pulmonary fibrosis cell model was constructed successfully.Compared with the control group,the cell viability of model group was significantly increased(P<0.01),the apoptosis rate was significantly decreased(P<0.01),LC3-Ⅱ protein expression level was significantly decreased(P<0.01),the protein expression levels of p62,α-SMA and collagenⅠ were significantly increased(all P<0.01).Compared with the model group,cell viability of miR-17 inhibitor group was sig-nificantly decreased(P<0.01),the apoptosis rate was significantly increased(P<0.01),LC3-Ⅱ protein expression level was significantly increased(P<0.01),the protein expression levels of p62,α-SMA and collagen Ⅰ were significantly decreased(all P<0.01).Cell viability of miR-17 inhibitor+3-MA group was significantly decreased compared with 3-MA inhibitor group(P<0.01),the apoptosis rate was significantly increased(P<0.01),LC3-Ⅱ protein expression level was significantly increased(P<0.01),the protein expression levels of p62,α-SMA and collagen Ⅰ were significantly decreased(all P<0.01).Conclusion Inhi-bition of miR-17 can inhibit TGF-β1-induced pulmonary fibrosis through activation of autophagy.