Effect of all-trans-retinoic acid on the proliferation and expression ofα-SMA in human embryonic lung fibroblasts

AIM:To investigate the effects of all-trans-retinoic acid(ATRA)on the proliferation and differentiation of transforming growth factorβ_1(TGF-β_1)-stimulated human embryonic lung fibroblasts(HFL-I). METHODS:The HFL-I cells were cultured in vitro and were pretreated with ATRA for 3 days at the concentrations of 0.1μmol/L,1μmol/L and 10μmol/L.The proliferation of HFL-1 cells was detected by MTT method.The mRNA expression ofα-smooth muscle actin(α-SMA)in HFL-I cells stimulated with TGF-β_1 for 0 h,6 h,12 h,24 h,48 h and 72 h was detected by RT-PCR and the protein expression ofα-SMA at the time points of 1,3 and 5 days was detected by Western blotting.The mRNA expression ofα-SMA in HFL-I cells pretreated with different concentrations of ATRA for 24 h was detected the by RT-PCR and the protein expression at time point of 3rd day was detected by Western blotting.RESULTS:Different concentration of ATRA inhibited the proliferation of HFL-I in a dose-dependent manner (P0.05).Both mRNA and protein expression ofα-SMA in HFL-I cells pretreated with TGF-β_1 was up-regulated (P0.05).ATRA down-regulated the mRNA and protein expression ofα-SMA induced by TGF-β_1 in a dose-dependent manner(P0.05).CONCLUSION:ATRA inhibits the proliferation and TGF-β_1-stimulated differentiation in HFL-I cells by down-regulating the mRNA and protein expression ofα-SMA.