Studies On The Mechanism Of Lung Fibrosis Inhibition Of Mutant Ectodomain Of FGF Receptor In Primary Type ? Alveolar Epithelial Cells

This study mainly focused on the inhibitory machanism of msFGFR2c(The 252 mutant-type soluble ectodomain of fibroblast growth factor recptor-2IIIc,ms FGFR2c)on pulmonary fibrosisin in vitro and in vivo.Firstly,we explore the role of FGF(Fibroblast growth factor,FGF)signaling on pulmonary fibrotic process in vitro.The protein expression was identified by Western blot,AEC?(Type II alveolar epithelial cells,AEC?)expression of N-Cadherin,CTGF(Connective tissue growth factor,CTGF)and ?-SMA(Alpha-smooth muscle actin,?-SMA)was significantly increased after induction of the fibroblasts MRC-5 conditional medium(Here in after referred as Medium).Trans-well tests showed that Anti-CTGF and msFGFR2c could inhibit the migration of AEC? cells induced by Medium.The expression level of TGF-?(Transforming growth factor-?,TGF-?)and FGF-2 was detected by ELISA(Enzyme linked-immuno-sorbent assay,ELISA),results showed that TGF-? and FGF-2 was up-regulated in Medium.These results suggested that TGF-? and FGF-2 played important roles in lung fibrosis.The protein expression of FGF-2 was identified by ELISA,FGF-2 expression was up-regulated after TGF-? induction.RT-PCR results showed that TGF-? and CTGF induced isoform switching of fibroblast growth factor receptors,causing the cells become to isoform of FGFR2 c.Since isoform of FGFR2 c is one of the most suitable receptor for FGF-2,therefore FGF-2 can act on AEC? cells and involved in the fibrotic process.The protein expression of ?-SMA was identified by Western Blot,?-SMA expression was down-regulated after addition of msFGFR2 c to TGF-?-treated cells.These results indicated that FGF-2 might be involved in TGF-?-induced fibrosis by an autocrine,which can be inhibited by msFGFR2 c.Secondly,we explore the role of msFGFR2 c on pulmonary fibrotic process in vivo.In vivo: Pulmonary fibrosis model of C57 BL / 6 miceinduced by bleomycin was established,results of the body weight of mice,HE staining(Hematoxylin-eosin staining,HE)and Massion staining indicated that FGFR2 c could significantly inhibit pulmonary fibrosis.FGF signaling pathway was involved in the mechanisms of pulmonary fibrosis.