Effects of TGF-beta on hyaluronan anabolism in fibroblasts derived from the synovial membrane of the rabbit temporomandibular joint

Hyaluronan (HA) synthesis in the synovial membrane is affected by various chemical mediators. It is hypothesized that transforming growth, factor-betal (TGF-beta1) would be a mediator to modulate HA synthesis in cultured synovial membrane fibroblasts of the temporomandibular joint (TMJ). Fibroblasts were extracted from the TMJ synovial membrane of four-week-old Japanese white rabbits. The amount of HA and expression levels of HA synthase (HAS) mRNAs induced by TGF-beta1 treatment were analyzed by means of high-performance liquid chromatography and real-time polymerase chain-reaction, respectively. Both medium and large Amounts of HA were enhanced by the stimulation of TGF-beta1. HAS2 mRNA expression was enhanced 13-fold after six-hour stimulation with TGF-beta1 (10 ng/mL), whereas HAS3 mRNA expression was not, changed significantly. These results suggest that TGF-beta1 enhances the expression of HAS2 mRNA in the TMJ synovial membrane fibroblasts and may contribute to the production of high-molecular-weight HA in the joint fluid.