Matrix metalloproteinase-9 deficiency has no effect on glial scar formation after transient focal cerebral ischemia in mouse

Glial scar formation was investigated in wild-type and MMP-9 deficient mice during a period of 21 days after 45 min of focal cerebral ischemia by intraluminal thread occlusion of the middle cerebral artery. The results showed no differences in the kinetics of activation of microglia, oligodendrocyte precursors and reactive astrocytes and showed only a slight difference in the pattern of macrophage infiltration. These results suggest that a specific targeting of MMP-9, as a mean to prevent ischemia-induced blood–brain barrier disruption, would have no significant effects on the recruitment of cells involved in glial scar formation.