Activation of MAPKs in IL-1β and/or TNFα stimulated AS/S and IB3-1/S9 cells. Both pair of cell lines were incubated in serum free media for 18 h then stimulated with IL-1β and/or TNFα for the indicated time points. At the indicated time media was removed and cells washed then total cell extracts were prepared which serve to perform western blot to detected phosphorylation and total protein of the MAPKs ERK, p38 and JNK in AS and S cells (A, B, C, D, respectively), and IB3-1 and S9 cells (E, F, G, respectively). Summary graph of data for MAPKs phosphorylation determined by image analysis of densitometry from autoradiographs. Data show mean ± SEM of scan area of pERK, pp38 and pJNK (n = 5 to 8 in each time point and condition) corrected for scan area of β-actin in the same gel lane.