Figure 3.
Schematic diagram of the neurovascular unit that comprises neurons, microvessels (endothelium), astrocytes, and pericytes that reside within the basement membrane. Neurons and microvessels communicate through astrocytes (updated from del Zoppo GJ, 2006 and other sources). There is spatiotemporal change of MMP-9 expression within the neurovascular unit after ischemic stroke. In the acute phase (within 24h), MMP-9 is mainly derived from brain endothelial cells and infiltrating leukocytes (especially neutrophils). In the late phase, MMP-9 is mainly secreted by astrocytes and neurons. Updated from Zlokovic BV, 2006 and other sources.