MMP9 and brain ischemia: MMP-9 is also upregulated in rodent models of cerebral ischemia, hemorrhage and trauma [13-15] and after its activation by proteases and ROS [16,17] can disrupt the blood brain barrier (BBB), a disruption that leads to extravasation of blood proteins, to brain edema, to cerebral hypoperfusion, and ultimately to neuronal damage [18-20].