CLDN5 and ischemic stroke: Increased expression and activity of several matrix metalloproteases (MMPs; e.g., MMP2 and MMP9) after ischemic stroke contributes to acute BBB damage by cleaving the extracellular domains of several adherens (VE-Cadherin) and tight (Claudin-5, Occludin) junction proteins in BECs (reviewed in [18, 19]).