MMP9 and ischemic stroke: Implantation of MSCs and/or EPCs could aid in the reconstruction of astrocytic end-feet and tight junctions, via the secretion of proangiogenic growth factors, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF-2), and transforming growth factor-beta (TGF-β), attenuation of immune cell infiltration, MMP9 downregulation, and VEGF-A signaling pathway modulation effects, to restore the integrity of BBB and the functional recovery of the cerebral vasculature at the acute phase of ischemic stroke [60–62].