Figure 2

HKBA and L-Omp19 induce MMP-9 secretion from astrocytes. Astrocytes were stimulated with HKBA (from 10⁶ to 10⁹ bacteria/ml), B. abortus (Ba) LPS (Ba , 1,000 ng/ml), lipidated Omp19 (L-Omp19, from 10 to 1,000 ng/ml) or unlipidated Omp19 (U-Omp19, 1,000 ng/ml). MMP-9 production was determined by zymography (A, C) and ELISA (D) at 48 hours post stimulation. For MMP activities, culture supernatants were incubated with a fluorescein-conjugated gelatin substrate that produces highly fluorescent peptides when gelatin is digested (B, E). PMA (50 ng/ml) and Pam₃Cys (50 ng/ml) were used as positive controls. Bars express the mean ± SEM of duplicates. Data shown are from a representative experiment of four performed. ***P < 0.001; **P < 0.01 versus non-stimulated (NS) astrocytes.