Tendon healing in vitro:: Promotion of collagen gene expression by bFGF with NF-κB gene activation

Purpose: Matrix synthesis of intrasynovial tendon cells and activation of nuclear transcription factors are pivotal to promotion of flexor tendon healing. We investigated the effects of basic fibroblast growth factor (bFGF) on synthesis of type I collagen and activation of nuclear transcription factor kappaB (NF-kappaB) in an in vitro culture model of intrasynovial tenocytes. Method: Tenocytes obtained from explant culture of rabbit intrasynovial tendon segments were treated with bFGF at concentrations of 0, 2, and 10 ng/mL. Expression of type I collagen and NF-kappaB genes was determined by quantitative analysis of products of reverse-transcription polymerase chain reactions. Proliferation of the cells was assessed by incorporation of bromodeoxyuridine into the DNA of the cells. Results: Expression levels of type I collagen and NF-kappaB genes of tenocytes were increased significantly by bFGF. Cell proliferation as indicated by DNA labeling was promoted significantly by bFGF. Expreission of the NF-kappaB gene increase in proliferation rate of tenocytes. Conclusions: Results of this study show that expression of type I collagen and NF-kappaB genes is promoted manifestly by bFGF. The effects were proportionate to in vitro proliferation rates of tenocytes. The study indicated that matrix synthesis of flexor tendons can be promoted by bFGF and that NF-kappaB may play a pivotal role in initiating proliferation and type I synthesis of tenocytes. (C) 2003 by the American Society for Surgery of the Hand.