Recombinant human MFG-E8 attenuates cerebral ischemic injury: Its role in anti-inflammation and anti-apoptosis

Abstract

Excessive inflammation and apoptosis contribute to the pathogenesis of ischemic stroke. MFG-E8 is a 66-kDa glycoprotein that has shown tissue protection in various models of organ injury. However, the potential role of MFG-E8 in cerebral ischemia has not been investigated. We found that levels of MFG-E8 protein in the brain were reduced at 24 h after cerebral ischemia. To assess the potential role of MFG-E8 in cerebral ischemia, adult male Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO). At 1 h post-stroke onset, an intravenous administration of 1 ml saline as vehicle or 160 μg/kg BW recombinant human MFG-E8 (rhMFG-E8) as treatment was given. The optimal dose of rhMFG-E8 was obtained from previous dose-response organ protection in rat sepsis studies. Neurological scores were determined at 24 h and 48 h post-MCAO. Rats were sacrificed thereafter and brains rapidly removed and analyzed for infarct size, histopathology, and markers of inflammation and apoptosis. Compared with saline vehicle, rhMFG-E8 treatment led to significant decreases in sensorimotor and vestibulomotor deficits, and infarct size at 24 h and 48 h post-MCAO. Measures associated with improved outcome included reduced microglial inflammatory cytokine secretion, adhesion molecules and neutrophil influx, cleaved caspase-3, and upregulation of peroxisome proliferator activated receptor-γ (PPAR-γ), and Bcl-2/Bax ratio leading to decreased apoptosis. Thus, rhMFG-E8 treatment is neuroprotective against cerebral ischemia through suppression of inflammation and apoptosis. © 2011 Elsevier Ltd. All rights reserved.