PMA enhanced the migration and tube formation of human late EPCs by activation of MMP-9 and MMP-2 expression.

(A) Cells were incubated with different doses of PMA for 24 h, and cytotoxicity was measured by cell viability assay. (B, C, D) Cells were incubated with different doses of PMA for 24 h and 10 nM PMA for the indicated time intervals. The enzyme activities and protein levels of MMP-9 and MMP-2 were determined by (B) zymography and (C, D) Western blot analysis. (E) Cells were transfected with either control siRNA or MMP-9 siRNA and then incubated with PMA for 24 h. The levels of MMP-9 activity and protein were determined by zymography and Western blot. (F, G) Late EPCs were transfected with control, MMP-9, and MMP-2 siRNAs and then incubated with PMA for 24 h. The migration and tube formation were measured. Data are expressed as mean ± SEM of three independent experiments. Significant differences between the compared groups are indicated: *P #P < 0.01.