Effects of transforming growth factor-β2 on human Tenon fibroblasts transformation and scarring after glaucoma filtration surgery / 中华实验眼科杂志

ABSTRACT

Background Research showed that transforming growth factor-β2 (TGF-β2) promotes scar formation.But its mechanism in scarring after glaucoma filtration surgery is worthy of studying.Objective This study was to investigate the effect of TGF-β2 on myofibroblast transition of human Tenon fibroblasts (HTFs) and scarring after glaucoma filtration surgery.Methods Tenon capsular tissue was obtained from 3 patients with strabismus during the surgery and was incubated in DMEM with 10％ fetal bovine serum (FBS).The cells were collected and passaged in the free-serum medium for 24 hours,and then 1,2,5,10,20 μg/L TGF-β2 was added into the medium respectively,to induce the transformation of HTFs,and 2 μg/L or 5 μg/L TGF-β2 was used to treat the HTFs for 6,24,48 and 72 hours.The control group was not treated with TGF-β2.The expressions of α-smooth muscle actin (α-SMA) and phosphorylation of the signaling proteins (pSmad2) in HTFs were detected by Western blot assay.The expressions of α-SMA and F-actin were located by cell immunofluorescine technique under the confocal immunofluorescence microscopy.Cell contractility was determined by collagen gel contraction assays.This study was approved by Ethic Committee of Institute of Surgery Research of Daping Hospital,and informed consent was obtained from each patient or custodian initial of the study.Results The expression of α-SMA protein in the HTFs was increased significantly after the treatment of TGF-β2 in comparison with the control group and reached a peak at 24-48 hours.The α-SMA expression was gradually weakened in the 10 μg/L TGF-β2 groups.Little of α-SMA and F-actin were expressed in the control group.However,strong staining for α-SMA and F-actin were observed in the 1,2 and 5 μg/L TGF-β2 groups and then the staining weakened at the concentration of 10 μg/L.In addition,pSmad2 showed a stronger expression in the 2 μg/L TGF-β2 group than that in the PBS group and FBS group,with the strongest expression in 30 minutes through 2 hours.The untreated gel contracted (78.00±3.13)％ from its initial size,and contraction in the 1,2,5,10 μg/L TGF-β2 group were (63.88±1.78)％,(20.69±0.65)％,(19.49-±0.54)％,(16.24±0.84) ％,respectively,TGF-β2 increased HTFs contraction significantly (Fgroup =859.400,P =0.000).Conclusions TGF-β2 can induce transdifferentiation of Tenon fibroblast into myofibroblast and increase cell contractility,with a concentration-dependent and time-dependent pattern to an extent.It may be the mechanism of scar formation after glaucoma filter surgery.