Effect of Cytokines on Regulation of the Production of Transforming Growth Factor Beta-1 in Cultured Human Tenon's Capsule Fibroblasts

Abstract

Purpose

Transforming growth factor-β1 (TGF-β1) is thought to play a pivotal role in the regulation of the wound healing process after glaucoma filtering surgery. The aim of the present study was to investigate whether platelet-derived growth factor isoforms (PDGF-AA, PDGF-BB), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), in-terleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) modulate the production of latent and/or active TGF-β1 by cultured human Tenon's capsule fibroblasts (HTF).

Methods

Human Tenon's capsule fibroblasts were seeded at two different densities (30 cells/mm² and 150 cells/mm²) and stimulated for five days with PDGF-AA, PDGF-BB, bFGF, EGF, IL-1β and TGF-β1. Control cells were treated with serum-free medium (WM/F12). The concentrations of latent and active TGF-β1 in the medium were determined using an immunoassay before and after activation of TGF-β1 by transient acidification.

Results

The concentration of latent TGF-β1 in conditioned media from HTF seeded at high density (150 cells/mm²) significantly increased after stimulation with 5 ng/ml TGF-β1 (151.5 ± 41.7 pg/ml) or 10 ng/ml IL-1β (45.7 ± 8.1 pg/ml). The concentration of active TGF-β1 in conditioned media also significantly increased after stimulation of HTF with 5 ng/ml TGF-β1 (48.4 ± 27.5 pg/ml).

Conclusions

The present results indicate that TGF-β1 is the most potent inducer of its own synthesis in HTF. Activation of an autocrine TGF-β1 loop may play a role in the wound healing response after glaucoma filtering surgery.