p38 and Erk1 2 signaling pathways are involved in the secretion of MMP 9 and TNF induced by HKBA and L Omp19 in astrocytes We next investigated whether the specific inhibition of p38 and Erk1 2 MAPK could inhibit MMP 9 produc tion. Therefore, inhibition experiments of the p38 and Erk1 2 MAPK signaling pathways were performed with the specific most inhibitors SB203580 and PD98059, respect ively. Both, p38 and Erk1 2 MAPK pathways partici pated in the production of MMP 9 as elicited by HKBA and Inhibitors,Modulators,Libraries L Omp19. By the zymography or gelatinolytic activ ity test, the production of MMP 9 was significantly inhibited either by p38 or Erk1 2 inhibitors, and was completely abrogated when both inhibitors were used together. This inhibitory effect was reproduced when astrocytes were stimulated with Pam3Cys.

Conversely, inhibition of Jnk1 2 with the specific inhibitor SP600125 had no effect on HKBA induced MMP 9 production. We had previously established that Brucella lipoproteins in duced TNF production by astrocytes. To evaluate whether the increased activation of MAPK p38 and Erk1 2 induced by Inhibitors,Modulators,Libraries stimulation with L Omp19 may be involved in the up regulation of TNF, we also ana lyzed the effect of kinase inhibitors on the production of this cytokine. Paralleling MMP 9 results, inhibition of p38 or Erk1 2, but not Jnk1 2, significantly inhibited TNF secretion from astrocytes as elicited by HKBA and L Omp19, and was completely abolished when both inhibitors were used in combin ation. This indicates that p38 and Erk1 2 MAPK pathways, but not Jnk1 2, could be involved in pathological responses induced by B.

abortus and its li poproteins in astrocytes. TNF induces MMP 9 from B. abortus infected astrocytes Since a concomitant abrogation of B. abortus and L Omp19 induced TNF and MMP 9 production Inhibitors,Modulators,Libraries was ob served when p38 and Erk1 2 pathways were inhibited and considering that TNF is known to induce the production of MMP Inhibitors,Modulators,Libraries 9 by other cell types infected with B. abortus, we decided to investigate the role of TNF in MMP 9 secretion. Astrocytes were pre incubated with an anti TNF neutralizing antibody or its isotype control and then infected with B. abortus or cultured with L Omp19 or HKBA. The secretion of MMP 9 was evaluated by zymography and ELISA after culture. Recombinant TNF was used as control. Incuba tion of astrocytes with anti TNF significantly inhibited the B.

abortus mediated secretion of MMP 9 at the MOI tested. Anti TNF also inhibited significantly the Inhibitors,Modulators,Libraries HKBA and L Omp19 mediated production of MMP 9. The isotype control antibody had no effect on the response in vestigated. As expected, incubation of astrocytes with anti TNF blocked the TNF mediated MMP 9 secre tion. These results indicate meanwhile that in astrocytes the secretion of MMP 9 mediated by B. abortus and its li poproteins depends on TNF.