Effect of nerve growth factor on cultured human chondrocytes

Nerve growth factor (NGF) is involved in several joint diseases. It participates in nociception and neurogenic inflammation and its concentrations increase in synovial fluid and tissue from arthritis. However, data about its role in articular cartilage are scant and conflicting. This study analysed effects of different NGF concentrations on cultured human chondrocytes by evaluating cell proliferation, cell phenotype, and gene expression. The MTT test excluded an influence on cell viability. Alcian blue and S100 staining demonstrated that NGF may induce de-differentiation of the chondrocyte phenotype. Real-time PCR showed that NGF did not influence gene expression of type I, II and XI collagen, TGF-β, IGF-1 and metalloproteinase (MMP)-13, while it reduced the expression of MMP-3. These findings show that NGF may have uncertain effects in human chondrocytes. Further investigations by wider gene expression and protein synthesis analyses are required to determine how chondrocytes may be influenced by NGF.