Activities and protein expression of MMP-9 andMMP-2. Liver samples obtained from the 4 groups of mice were analyzed for the (A) MMP-9 and MMP-2 activity and (B) MMP-9 and MMP-2 protein expression. The quantified results of MMP-9/MMP-2, MMP-9/actin, and MMP-2/actin ratio were shown in the lower panels, respectively. *, # and ¥ indicate significant differences as compared to the PBS, IgG, or B19-NS1 group, respectively. Similar results were obtained in three independent experiments.