Preliminary Study On The Regulatory Role And Mechanism Of MiR-486 In Idiopathic Pulmonary Interstitial Fibrosis Under Hypoxia

Objective: The purpose of this study was to investigate the expression level of mi R-486 in human embryonic lung fibroblasts treated with different hypoxia time,and to explore the regulatory role and mechanism of mi R-486 in idiopathic pulmonary interstitial fibrosis.Methods: 1.Human embryonic lung fibroblasts(MRC5 cells)were cultured and subcultured,and treated with different hypoxic time(0h,6h,12 h,24h,48h).q RT-PCR was used to detect the expression of mi R-486,fibronectin FN and α-vascular Smooth muscle actin α-SMA.2.MRC5 cells were transfected with overexpressed and silenced mi R-486 lentivirus,and the expression levels of FN,α-SMA,Collagen I andⅢ were detected after overexpression/silencing of mi R-486.3.Double luciferase reporter assay was used to detect whether fibroblast growth factor 9(FGF9)was the target gene of mi R-486.The MRC5 cells were silenced with FGF9,and the expression of related genes was detected by q RT-PCR and Western blot.Results:1.With the prolongation of hypoxia,the expression of mi R-486 was gradually decreased,while the expression of FN,α-SMA and other idiopathic pulmonary interstitial fibrosis related genes was gradually increased,and the differences were significant statistically(P<0.05).2.Overexpression of mi R-486 could inhibit the expression of genes related to idiopathic pulmonary interstitial fibrosis,such as FN,α-SMA,Collagen I,Ⅲ,etc,while the above results were opposite when mi R-486 was silenced.3.Dual luciferase reporter gene assay detected that FGF9 was the target gene of mi R-486,and the expression of FGF9 decreased after overexpression of mi R-486 at protein level or mi RNA level,while increased after silencing of mi R-486.4.After silencing FGF9,the expressions of FGF9,FN,α-SMA,Collagen I,Ⅲ and other genes related to pulmonary interstitial fibrosis decreased.Conclusion: 1.Hypoxia is involved in the pathogenesis of idiopathic pulmonary interstitial fibrosis by down-regulating mi R-486 and up-regulating FN and α-SMA.2.mi R-486 is a micro RNA associated with hypoxia,and participates in the pathogenesis of IPF by regulating FN,α-SMA,Collagen Ⅰ、Ⅲ.3.FGF9 is the target gene of mi R-486,which regulates the pathogenesis of IPF by targeting FGF9.