Abstract
Matrix metalloproteinases (MMPs) cleave almost all components of the extracellular matrix (ECM) and cause acute neurovascular disruption and parenchymal destruction. Previously, MMPs inhibition was considered to be a therapeutic strategy in early stages of ischemia. This study was designed to investigate whether early MMPs inhibition could promote the recovery of cerebral ischemia. Male Sprague-Dawley rats underwent right middle cerebral artery occlusion (MCAO) for 1 h and reperfusion. The rats were divided into three groups: sham + vehicle (S + V) group, MCAO + vehicle (M + V) group, and MCAO + GM6001 (M + G) group. Infarct volume was assessed by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and the expression of GFAP, IBA1, p-ERK, ERK, and MMP9 were evaluated by Western blot and immunofluorescence staining on 1, 4, 7, and 14 days after MCAO. Neuronal apoptosis was assessed by Fluoro-Jade C staining. The results showed that MMPs inhibition significantly increased the infarct volume and the expressions of GFAP and IBA1 in the M + V group were much higher than those in the M + G group; whereas the expression of p-ERK was upregulated in both the M + V and M + G groups. These findings suggest that MMPs promote the activation and migration of astrocytes and microglia to form protected zone in the penumbra and lessen the infarct volume after cerebral ischemic stroke.