Supernatants from Bru cella infected astrocytes produced selleck chemicals Veliparib gelatin breakdown when assayed in fluid phase under native conditions in which MMP TIMP complexes are not dissociated, as occurs during gel electrophoresis. Thus, this assay demon strated the presence of a net gelatinase activity in these su pernatants, suggesting that the MMP 9 induction detected in Brucella infected astrocytes may truly contribute Inhibitors,Modulators,Libraries to col lagen degradation in brain parenchyma. MMP 2, the other main metalloproteinase with gelatinase activity, has been implicated in the pathology associated with CNS infec tions. Thus, we also investigated the up regulation of both, MMP 2 and MMP 9 in astrocytes. However, under our experimental conditions B. abortus infection of astro cytes did not alter the expression of MMP 2.

The production of MMP 9 was not dependent Inhibitors,Modulators,Libraries on bac terial viability, since it was also induced by exposure to heat killed B. abortus, suggesting that it was elic ited by a structural bacterial component. We established that the structural element responsible of such response was not B. abortus LPS. B. abortus possesses lipoproteins and studies conducted in our laboratory have demon strated that B. abortus lipoproteins can elicit inflammatory mediators and MMP 9 from other cell types. Thus, we hypothesized that B. abortus lipoproteins could be the structural components involved in the observed Inhibitors,Modulators,Libraries phenomenon. L Omp19, a prototypical B. abortus lipo protein, induced the secretion of MMP 9 from astrocytes in a dose dependent fashion. U Omp19 had no effect, demonstrating that acylation of Omp19 is required for its biological activity.

Not only L Omp19 but also Pam3Cys was able Inhibitors,Modulators,Libraries to induce MMP 9. Since all brucellar lipoproteins likely share the Pam3Cys modification, this entails that any lipoprotein should be able to exert this effect. As the B. abortus genome contains no less than 80 genes encod ing putative lipoproteins, many of which were shown to be expressed in the outer membrane of the bacterium, one can envision that the local concentration of Bru cella lipoproteins in confined Inhibitors,Modulators,Libraries tissue spaces within the brain may be sufficient to exert their biological effects. In this context, we can hypothesize that any surface exposed Brucella lipoprotein may be relevant beyond in vitro as says and not one lipoprotein but selleck Carfilzomib rather a combination of them may contribute to MMP 9 secretion elicited by B. abortus within the brain. Of note, although both L Omp 19 and B. abortus produce increases in MMP 9 from astrocytes, the concentration produced by L Omp 19 is considerable higher than that produced by B. abortus. The reasons for this difference are unknown but may relate to the different bioavailability of L Omp19 when used as a highly purified ligand.