The role of MAPKs on MMP-9 expression and chrysin-inhibited MMP-9 expression by blocking JNK/c-Jun and ERK/c-Fos pathway in AGS cells.

Cells pretreated with a concentration of 50μM PD98059 (PD), 50μM SP600125 (SP) or 20 μM SB203580 (SB) for 1 h were incubated with 100 nM PMA for 4 h. After incubation, MMP-9 mRNA in the cell lysates was determined by RT-PCR. # P<0.05 versus control; * P<0.05 versus only PMA (A). Expression vectors encoding a dominant negative mutant MEK (K97M), mutant JNK (TAM67), or mutant p38 MAPK (mP38) were co-transfected with pGL4-MMP-9 promoter constructs into AGS cells. After incubation with 100 nM PMA for 4 h, luciferase activity was determined using a luminometer. The data represents the mean ± SD from triplicate measurements. # P<0.05 versus control; * P<0.05 versus only PMA (B). Expression pMCL empty vector, encoding a dominant negative mutant MEK (K97M) or mutant JNK (TAM67) was co-transfected with pGL3-AP-1 luciferase construct into AGS cells. After incubation with 100 nM PMA for 4 h, luciferase activity was determined using a luminometer. The data represents the mean ± SD from triplicate measurements. # P<0.05 versus control; * P<0.05 versus only PMA (C). AGS cells pretreated with 50 μM PD98059, 50 μM SP600125, and 20 μM SB203580 were incubated with 100 nM PMA, and cell lysates were analyzed for the phosphorylated c-Jun and phosphorylated c-Fos by western blot analysis. # P<0.05 versus control; * P<0.05 versus only PMA (D). AGS cells pretreated with indicated concentration of chrysin were incubated with 100 nM PMA, and cell lysates were analyzed for the phosphorylated JNK1/2 and phosphorylated p42/44 by western blot analysis. # P<0.05 versus control; * P<0.05 versus only PMA (E and F).