['Matrix metalloproteinases (MMPs) have a central role in compromising the integrity of the blood-brain barrier (BBB). The role of MMP-12 in brain damage after ischemic stroke remains unknown. The main objective of the current study is to investigate the effect of MMP-12 suppression at an early time point before reperfusion on the BBB damage in rats.', 'Sprague-Dawley rats were subjected to middle cerebral artery occlusion and reperfusion. MMP-12 shRNA-expressing plasmids formulated as nanoparticles were administered at a dose of 1 mg/kg body weight. The involvement of MMP-12 on BBB damage was assessed by performing various techniques, including Evans blue dye extravasation, 2,3,5-triphenyltetrazolium chloride staining, immunoblot, gelatin zymography, and immunofluorescence analysis.', 'MMP-12 is upregulated ≈31-, 47-, and 66-fold in rats subjected 1-, 2-, or 4-hour ischemia, respectively, followed by 1-day reperfusion. MMP-12 suppression protected the BBB integrity by inhibiting the degradation of tight-junction proteins. Either intravenous or intra-arterial delivery of MMP-12 shRNA-expressing plasmid significantly reduced the percent Evans blue dye extravasation and infarct size. Furthermore, MMP-12 suppression reduced the endogenous levels of other proteases, such as tissue-type plasminogen activator and MMP-9, which are also known to be the key players involved in BBB damage.'] Does matrix Metalloproteinase-12 induce Blood-Brain Barrier Damage After Focal Cerebral Ischemia?