Basic fibroblast growth factor regulates expression of growth factors in rat epiphyseal chondrocytes

Chondrocytes produce several local regulatory factors such as basic fibrobl ast growth factor (bFGF), transforming growth factor-beta (TGF-beta) and in sulin-like growth factor-I (IGF-I). In this study, we examined the effect o f bFGF on the expressions of both mRNA and protein of the growth factors sy nthesized by chondrocytes. Treatment of chondrocytes with bFGF (1-100 ng/ml ) stimulated the mRNA expression of bFGF and TGF-beta up to 121-604% and 13 0-220% at 12 h compared with the controls, respectively. On the other hand, the treatment of chondrocytes with bFGF (1-100 ng/ml) suppressed IGF-I mRN A expression to 79-47% at 12 h compared with the controls. An enzyme-linked immunosorbent assay (ELlSA) revealed that the treatment of chondrocytes wi th bFGF (1-100 ng/ml) also enhanced the production of TGF-beta1 proteins in the chondrocytes up to 299-508% at 24 h compared with controls. We conclud e that bFGF influenced the local expression of growth factors by chondrocyt es, suggesting autoregulation of growth factor expression during chondrogen esis. (C) 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.