Figure 5  Western blot analysis of MMP9 protein level. (a) Western blot showed that protein level of MMP9 was elevated in astrocytes after scratch and was significantly higher in group KO TBI than in group WT TBI. (b) Quantitative analysis of western blot result showed that relative protein level of MMP9 was higher in astrocytes after scratch (P < 0.01). Such elevation was much severe in group KO TBI than in group WT TBI (P < 0.01). (*P < 0.01, compared with sham counterpart; # P < 0.01, compared with WT TBI).