Effect Of ALK5 Inhibitor On TGF-?1-induced Retinal Pigment Epithelial Cell Fibrosis

ObjectiveTo investigate the transformation effect of transforming growth factor beta1?TGF-?₁?of human retinal pigment epithelium?hRPE?cells into fibroblasts and the intervention effect of inhibitor?SB-431542?of activated receptor kinase 5?ALK5?on them.MethodshRPE cells were cultured in vitro and randomly divided into four groups:control group;TGF-?₁ treatment group;TGF-?₁+SB-431542 treatment group;SB-431542 treatment group.In the control group,no treatment was performed.However,the other three groups were treated for 24 hours with a concentration of 10?g/L TGF-?₁,10?g/L TGF-?₁+30?mol/L SB-431542 and 30?mol/L SB-431542.The proliferation rates of hRPE cells were detected by MTT assay in each group.The migration of RPE cells was observed in each group at 0h,12h and 24h after treatment by scratch test.The distribution and expression of ALK5 protein were detected by immunofluorescence assay in each group.Protein expression of ALK5,vascular endothelial growth factor?VEGF?,alpha smooth muscle actin??-SMA?,collagen type??Sol??,and fibronectin?FS?in each group was performed by western blot.ResultsSompared with the control group,10?g/L TGF-?₁ changed the appearance of RPE cells,which showed a fibroblast-like appearance after 24h of action on RPE cells,and significantly promoted the proliferation and migration of RPE cells.In addition,the proliferation rate of RPE cells was?1.33±0.08?times that of the control group.After treatment with 30?mol/L SB-431542 for 24h,the proliferation rate of RPE cells was?67.77±6.78?%in the 10?g/L TGF-?₁ treated group.After treatment with TGF-?₁ for 24h,protein expressions of ALK5,VEGF,?-SMA,Sol?and FS increased significantly,which was?3.69±0.37?times,?1.76±0.05?times,?2.58±0.18?times,?1.86±0.11?times,?1.74±0.08?times,respectively.SB-431542 reversed the protein expressions of ALK5,VEGF,?-SMA,Sol?and FS induced by TGF-?₁,which presented?67.73±5.15?%,?71.71±3.50?%,?79.87±0.05?%,?63.59±3.16?%,?83.07±2.31?%respectively,compared with TGF-?₁ treatment group with statistically significant differences?all P<0.05?.ConclusionsTGF-?₁ can promote RPE cells migration,fibroblasts transformation,and significantly increase protein expressions of ALK5,VEGF,?-SMA,Sol?and FS of RPE cells;SB-431542 can inhibit the fibrosis of RPE cells by inhibiting the effects of TGF-?₁.