Matrix metalloproteinases in cerebral ischemia.

Matrix metalloproteinases (MMPs) are involved in the pathophysiology of several central nervous system diseases that share common pathogeneses, such as disruption of the blood-brain barrier (BBB), neuroinflammation, oxidative stress, and remodeling of the extracellular matrix (ECM). In early ischemic injury, MMPs participate in disruption of the BBB by digesting the basal lamina of capillaries and ECM, leading to vasogenic edema and hemorrhagic transformation. However, ECM degradation and remodeling are essential for tissue recovery, with MMPs having a key role as modulators of homeostasis between neuronal death and tissue regeneration. Thus, MMPs may be a double-edged sword that has a deleterious or beneficial role depending on the stage of brain injury.