Tumor necrosis factor α induced activation and increased tyrosine phosphorylation of mitogen activated protein (MAP) kinase in rheumatoid synovial fibroblasts

Objective To determine whether TNF α activates MAPK in rheumatoid synovial fibroblasts.Methods Cultured rheumatoid synovial fibroblasts were stimulated with exogenous TNF α,and then Western blot analysis of cell lysates was made.Results Multiple protein kinases were phosphorylated upon TNF α treatment.Induction of MAPK phosphorylation was time and dose dependent.Conclusion MAPK is likely to represent an important component in the cascade of signals that link TNF receptors to various TNF α elicited cellular responses in rheumatoid synovial fibroblasts.