Effects of TGF-ß1 and TGF-ß2 on Proliferation and Matrix Production of Cultured Human Tenon's Capsule Fibroblasts in Pseudoexfoliation and Primary Open-Angle Glaucoma

Abstract

Abstract: : Purpose: Significantly increased aqueous levels of TGF-ß1 (0.1500.04 ng/ml) in pseudoexfoliation (PEX) syndrome/glaucoma and TGF-ß2 (1.90.4 ng/ml) in primary open-angle glaucoma (POAG) may adversely affect the outcome of glaucoma filtration surgery. We therefore investigated the effects of TGF-ß1 and -ß2 on proliferation and extracellular matrix production of cultured Tenon's capsule fibroblasts derived from PEX, POAG, and control patients. Methods: Tenon's capsule fibroblasts obtained from patients with PEX syndrome, PEX glaucoma, POAG, and cataract were cultured and stimulated with TGF-ß1 or TGF-ß2 at concentrations ranging from 0.01 to 20 ng/ml for 1 to 14 days. Cell proliferation was determined with the WST-1 colorimetric assay; extracellular matrix (fibronectin, collagen types I and III) production was assessed by immunoassays. Results: TGF-ß1 and TGF-ß2 stimulated cell proliferation and extracellular matrix production of Tenon's capsule fibroblasts in a characteristic dose-dependent manner. The two isoforms had no significantly different effects on proliferation; they each stimulated cell proliferation with peak activities at 0.1 ng/ml in PEX syndrome and at 1 ng/ml after 2 to 3 days in the other groups. Both isoforms further enhanced the production of fibronectin and collagen with a maximal response obtained at 0.1 ng/ml after 5 days in PEX syndrome/glaucoma and at 1 ng/ml after 5 days in POAG and cataract cultures. Fibronectin synthesis was increased about 5 times, and the level of collagen was elevated factor 10. Whereas both isoforms had a similar effect on matrix production in POAG, TGF-ß1 predominated in PEX syndrome/glaucoma, and TGF-ß2 in the cataract group. Conclusion: These findings indicate that TGF-ß1 and -ß2 in pathophysiologic concentrations are potent stimulators of proliferation and matrix production of human Tenon's capsule fibroblasts, suggesting that both isoforms may significantly influence the conjunctival scarring response after glaucoma filtration surgery. However, TGF-ß1 was more effective in stimulating matrix synthesis in PEX fibroblasts, which could be generally stimulated at lower TGF-ß concentrations than control cells. Anti-TGF-ß1 therapy may be a useful strategy for reducing conjunctival scarring in eyes with PEX glaucoma.

Keywords: 423 growth factors/growth factor receptors • 403 extracellular matrix • 631 wound healing