Effect of cytokines on regulation of the production of transforming growthfactor beta-1 in cultured human Tenon's capsule fibroblasts

PURPOSE. Transforming growth factor-beta 1 (TGF-beta 1) is thought to play a pivotal role in the regulation of the wound healing process after glaucom a filtering surgery. The aim of the present study was to investigate whethe r platelet-derived growth factor isoforms (PDGF-AA, PDGF-BB), basic fibrobl ast growth factor (bFGF), epidermal growth factor (EGF), interleukin-1 beta (IL-1 beta) and transforming growth factor-beta 1 (TGF-beta 1) modulate th e production of latent and/or active TGF-beta 1 by cultured human Tenon's c apsule fibroblasts (HTF). METHODS. Human Tenon's capsule fibroblasts were seeded at two different den sities (30 cells/mm(2) and 150 cells/mm(2)) and stimulated for five days wi th PDGF-AA, PDGF-BB, bFGF, EGF, IL-1 beta and TGF-beta 1. Control cells wer e treated with serum-free medium (WM/F12). The concentrations of latent and active TGF-beta 1 in the medium were determined using an immunoassay befor e and after activation of TGF-beta 1 by transient acidification. RESULTS. The concentration of latent TGF-beta 1 in conditioned media from H TF seeded at high density (150 cells/mm(2)) significantly increased after s timulation with 5 ng/ml TGF-beta 1 (151.5 +/- 41.7 pg/ml) or 10 ng/ml IL-1 beta (45.7 +/- 8.1 pg/ml). The concentration of active TGF-beta 1 in condit ioned media also significantly increased after stimulation of HTF with 5 ng /ml TGF-beta 1 (48.4 +/- 27.5 pg/ml). CONCLUSIONS. The present results indicate that TGF-beta 1 is the most poten t inducer of its own synthesis in HTF. Activation of an autocrine TGF-beta 1 loop may play a role in the wound healing response after glaucoma filteri ng surgery.