ABSTRACT. The present study identified the proteins that are differentially expressed during ischemic brain injury. Adult male rats were performed a middle cerebral artery occlusion (MCAO) to induce cerebral ischemia, and brains were collected at 24 hr after MCAO. Protein analysis was performed on the cerebral cortex using two-dimensional gel electrophoresis. Protein spots with a greater than 3 fold change in intensity between the sham and MCAO groups were identified by mass spectrometry. Among these proteins, 60 kDa heat shock protein, dehydropyrimidinase-related protein 2, t-complex protein 1, and Rho GDP dissociation inhibitor levels were significantly increased in MCAO group compared to those of the sham group. In contrast, thioredoxin, peroxiredoxin-2, stathmin, ubiquitin carboxyterminal hydrolase L1, guanine nucleotide-binding protein , pyridoxal-5'-phosphate phosphatase, and apoplipoprotein A-I levels were significantly decreased in MCAO group. These results suggest that cerebral ischemia induces neuronal cells death by changing expression levels of several proteins. Neurodegenerative disorders including Alzheimer's disease, Parkinson's disease and stroke are a major cause of adult disability and mortality. Among these disorders, stroke is a serious cerebrovascular disorder and the most common cause of death. A previous study demonstrated that cerebral ischemia in an experimental stroke model involves apoptotic and survival signaling pathways and leads to neuronal cells death [24]. Oxidative stress, metabolic compromise, and mitochondrial dysfunction may trigger neuronal apoptosis in neurodegenerative disorders [17]. The mechanisms of neuronal cell death are very complex and vague. At present, little is known about the changes in protein expression in damaged brain region during ischemic injury. The purpose of this study was to investigate these changes in expression in the cerebral cortex following ischemic brain injury.
MATERIALS AND METHODSExperimental animals: Male Sprague-Dawley rats (225-250 g, n=40) were purchased from Samtako Co. (Animal Breeding Center, Osan, Korea) and were randomly divided into two groups, sham-operated group and middle cerebral artery occlusion (MCAO)-operated group (n=20 per group). Animals were maintained under controlled temperature (25C) and lighting (14L:10D), and allowed free access to food and water. All animal experiments were carried out in accordance with the Guide for care and use of laboratory animals, and use of Gyeongsang National University.Middle cerebral artery occlusion: The MCAO model was prepared following the previously described method of intra-luminal vascular occlusion [16]. Animals were anesthetized with sodium pentobarbital (100 mg/kg). The right common carotid artery, internal carotid artery, and external carotid artery were exposed through a midline cervical incision. A 4/0 monofilament nylon was inserted from the external carotid artery into the lumen of the internal carotid artery until it obstructed the origin of the middle cerebral artery. At ...