TNF alpha contributes for attenuating both Y(397)FAK and Y(416)Src phosphorylations in osteoblasts

ObjectiveOur poor understanding of how inflammatory mediators can affect osteoblast behavior led us to investigate the tumor necrosis factor (TNF)-induced focal adhesion kinase (FAK) and Src phosphorylation.Material and MethodsMC3T3-E1 pre-osteoblast cells were harvested at specific time points after either TNF treatment or RAW267 stimulated conditioned medium, and thereafter cell extracts were prepared for Immunoblotting assay. ELISA detected TNF content at conditioned medium. Tumor necrosis factor--neutralizing antibodies also were used.ResultsIt was possible to show that TNF provokes attenuation at Y-phosphorylation of both FAK (at Y-397) and Src (at Y-416) proteins (PConclusionsAltogether, these results suggest that LPS-stimulated macrophage mediators attenuate both FAK and Src activations in osteoblast, suggesting a novel role for TNF on osteoblast performance.