Expression of RAGE and extracellular matrix induced by transforming growth factor beta 1 in A549 cells

Abstract

Objective To investigate the expressions of receptor for advanced glycation endproducts (RAGE),collagen-Ⅰ,and α-smooth muscle actin (α-SMA) in human A549 cells induced by transforming growth factor beta 1 (TGF-β1).Methods With no TGF-β1-stimulated cells for the control group,human A549 cells were cultured in vitro.Cultured cells were exposed to TGF-β1 with different final concentration (2 μg/L,5 μg/L,10 μg/L) for different time (12 h,24 h,36 h).RAGE mRNA and protein,collagen-Ⅰ and α-SMA in cells were detected at different points after the treatment of TGF-β1 by RT-PCR and Western blotting.Results ①TGF-β1 reduced RAGE mRNA and protein expressions in a dose-and time-dependent manner.②Compared with the control group,RAGE mRNA (0.387±0.088 vs 1.345-±-0.132) and protein expressions (0.174±0.061 vs 1.229±0.112) were significantly reduced (P ＜0.01) in cells exposed to TGF-β1 (5 μg/L) for 24 hours.③The collagen-Ⅰ and α-SMA protein expressions increased after stimulation for 24 hours in 5 μg/L TGF-β1 group.At that point,collagen-Ⅰ and α-SMA protein expressions were 3.1 and 6.7 times of the control group (P ＜0.01).④RAGE expression had a negative correlation with collagen-Ⅰ (r =-0.843,P ＜0.05) and α-SMA protein expression (r =-0.897,P ＜0.05).Conclusions The reduced RAGE,which is negatively correlated with expressions of collagen-Ⅰ and α-SMA proteins in A549 cells exposed to TGF-β1,may be related to the development and progress of pulmonary fibrosis. Key words: Transforming growth factor beta 1; Receptor for advanced glycation end-products; α-smooth muscle actin; Collagen-Ⅰ