Regulation Of MiRNA-29b On Epithelial-to-mesenchymal Transition In Pulmonary Fibrosis And Its Mechanism

Objective:To investigate the regulation and mechanism of miR-29 b on epithelial-mesenchymal transformation in pulmonary fibrosis.Methods:Cell culture:1.TGF-?1 was used as an inducer to induce fibrosis in A549 cells.2.miR-29b-3p agomir/antagomir was transfected into TGF-?1-induced A549 cells.After 24 hours of co-culture,ELISA and qRT-PCR were used to detect the expression of TGF-?1/Smad3?E-cad??-SMA?Col1A1 protein and its mRNAand miR-29b-3p in extracellular fluid and cells.Clinical research:The population was divided into Iidiopathic pulmonary fibrosis group(IPF)?control group.The expression of TGF-?1/Smad3?E-cad??-SMA?Col1A1 protein and its mRNA and miR-29b-3p were detected by ELISA and qRT-PCR.Results:Cell culture: 1.Compared with TGF-?1 group,the expression of TGF-?1/Smad3??-SMA ? Col1A1 protein and mRNA were increased(P<0.05),the expression of miR-29b-3p ? E-cad protein and its mRNA were significantly decreased(P<0.05).2.miR-29b-3p agomir can increase the expression of miR-29b-3p?E-cad and inhibite the expression of TGF-?1/Smad3 ? Col1A1(P<0.05).3.miR-29b-3p antagomir can inhibite the expression of mRNA and protein of miR-29b-3p?E-cad,promoted the expression of TGF-?1/Smad3?Col1A1(P<0.05).Clinical research: Compared with the control group,the protein and mRNA expressions of TGF-?1/Smad3 ? ?-SMA and Col1A1 were increased in IPF patients(P<0.05),the expression of E-cad protein ? mRNA and miR-29b-3p were significantly decreased(P<0.05).Conclusion:Cell culture:miR-29b-3p may regulate the process of pulmonary fibrosis throughthe TGF-?1/Smad3 pathway.Col1A1 and E-cad may be downstream genes of this pathway.Clinical research: The expression of miR-29 b in blood of patients with IPF is decreased,and may be involved in the development of IPF through TGF-?1/Smad3-mediated epithelial-mesenchymal transition.By comprehensive analysis,in vitro and clinical research have shown that low expression of miR-29 b leads to up-regulation of TGF-?1/Smad3 pathway,which in turn mediates epithelial-mesenchymal transition,which may be one of the important pathogenesis of IPF.Activation of miR-29 b may inhibit the development of IPF.