Triptolide inhibits TGF-β-induced matrix contraction and fibronectin production mediated by human Tenon fibroblasts

AIM: To determine if triptolide influences the contractility and fibronectin production in human Tenon fibroblasts (HTFs). METHODS: HTFs were cultured in type I collagen gels with or without transforming growth factor beta (TGF-beta) and/or triptolide. The diameter of the collagen gel was used to measure contraction. Immunoblot analysis was used to quantify myosin light chain (MLC) phosphorylation and integrin expression. Laser confocal fluorescence microscopy was used to monitor the formation of actin stress fibers. Fibronectin production was measured with an enzyme immunoassay. RESULTS: Triptolide inhibition of contraction in TGF-beta-induced collagen gel mediated by HTFs was dose dependent and statistically significant at 3 nmol/L (P<0.05) and maximal at 30 nmol/L and significantly time dependent at 2d (P<0.05). Triptolide reduced TGF-beta-induced expression of integrins alpha 5 and beta 1, phosphorylation of MLC, and formation of stress fibers in HTFs. Furthermore, the inhibition of triptolide on the attenuated TGF-beta-induced production of fibronectin by HTFs was concentration-dependent and significant at 1 nmol/L (P<0.05) and maximal at 30 nmol/L. CONCLUSION: Triptolide suppress the contractility of the immune HTFs induced by TGF-beta and the production of fibronectin by these cells. It is promising that triptolide treatment may possibly inhibit scar formation after glaucoma filtration surgery.