IL-1β induces MMP-9 expression and SIRCs migration.

(A) Cells were incubated with IL-1β for the indicated times. The conditioned media were subjected to determine MMP-9 expression by gelatin zymography. The cell lysates were analyzed by Western blot using an anti-GAPDH antibody. (B) Cells were incubated with 1.5 ng/ml IL-1β for the indicated time intervals. The cell viability was measured by MTT assay. (C, D) Cells were incubated with IL-1β for the indicated time intervals. The mRNA levels and promoter activity of MMP-9 were determined by RT-PCR and promoter assay, respectively. (E) Cells were pretreated with 10 µM MMP2/9 inhibitor (MMP2/9 i) for 1 h, and then incubated with IL-1β for 24 h. SIRCs migration was observed. Data are expressed as mean±S.E.M. of three independent experiments. ^*P<0.05; ^#P<0.01, as compared with the exposed to vehicle alone.