Inhibition of TGF-β-Induced Collagen Production in Rabbit Flexors Tendons

Purpose: Postoperative adhesions frequently compromise the success of flexor tendon repair. Manipulation of growth factors responsible for scar formation may be a method of decreasing adhesion formation. Transforming growth factor beta (TGF-β) is a key cytokine in the pathogenesis of tissue fibrosis. The purpose of this study was to examine the effectiveness of TGF-β neutralizing antibody in blocking TGF-β-induced collagen I production in rabbit flexor tendons in vitro. Methods: Sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes were obtained from rabbit flexor tendons. Each cell culture was supplemented with 1 ng/mL of TGF-β along with increasing doses of TGF-β neutralizing antibody (0.1-2.0 μg/mL). Collagen I production was measured by enzyme-linked immunoabsorbent assay and TGF-β bioactivity was measured by the luciferase assay. Results were compared with TGF-β alone and unsupplemented controls. Results: The addition of neutralizing antibody significantly reduced TGF-β-induced collagen I production in a dose-dependent manner in all 3 cell cultures. TGF-β bioactivity was also reduced by its neutralizing antibody. Conclusions: This study shows that TGF-β inhibition through its neutralizing antibody was effective in cultured flexor tendon cells. The results encourage further experiments that use such agents to modulate flexor tendon wound healing in in vivo models in the hope of eventually blocking the effect of TGF-β on flexor tendons clinically.