MMP9 and brain infarction: 1. Significantly reduced the infarct volume 2. Ameliorated brain infarction, significantly improved neurological deficits in locomotor function, inhibited the increased permeability of the blood-brain barrier, the activation of microglia, the expression of TNF-α and iNOS, and suppressed the activity of MMP-9 3. Reduced the blood-brain barrier permeability and inhibited the development of brain edema