ABSTRACT
Abstract Purpose: To evaluate histopathological and ultrastructural changes and expression of proteins related to apoptosis CASPASE 3 and XIAP after experimental induction of temporary focal cerebral ischemia (90 minutes) due to obstruction of the middle cerebral artery in alcoholism model. Methods: Forty adult Wistar rats were used, subdivided into 5 experimental groups: control group (C); Sham group (S); Ischemic group (I); Alcoholic group (A); and Ischemic and Alcoholized group (I+A): animals submitted to the same treatment of group A and after four weeks were submitted to focal cerebral ischemia during 90 minutes, followed by reperfusion of 48 hours. Were processed for histopathological analysis and immunohistochemistry (for the protein expression of CASPASE -3 and XIAP). Results: Greater histopathological changes were observed in the animals of groups I and I+A in the three areas analyzed. The neuronal loss was higher in the medial striatum region of the animals of groups I and I + A. The protein expression of CASPASE -3 was higher than that of XIAP in the groups I and I + A for both proteins. Conclusion: The expression of XIAP was slightly higher where the histopathological changes and expression of CASPASE -3 was less evident.
Subject(s)
Animals , Male , Ischemic Attack, Transient/pathology , Alcoholism/pathology , Inhibitor of Apoptosis Proteins/analysis , Caspase 3/analysis , Time Factors , Immunohistochemistry , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Random Allocation , Ischemic Attack, Transient/metabolism , Rats, Wistar , Apoptosis , Middle Cerebral Artery , Microscopy, Electron, Transmission , Alcoholism/metabolism , Edema , Electromyography/methods , Mitochondria/pathologyABSTRACT
Abstract Purpose: To investigate whether the neuroprotective effect of TSA on cerebral ischemia reperfusion injury is mediated by the activation of Akt/GSK-3β signaling pathway. Methods: Mice were randomly divided into four groups (n=15): sham group (S); ischemia reperfusion group (IR); ischemia reperfusion and pretreated with TSA group (IR+T); ischemia reperfusion and pretreated with TSA and LY294002 group (IR+T+L). The model of cerebral ischemia reperfusion was established by 1h of MCAO following 24h of reperfusion. TSA (5mg/kg) was intraperitoneally given for 3 days before MCAO, Akt inhibitor, LY294002 (15 nmol/kg) was injected by tail vein 30 min before the MCAO. Results: TSA significantly increased the expression of p-Akt, p-GSK-3β proteins and the levels of SOD, Bcl-2, reduced the infarct volume and the levels of MDA, ROS, TNF-α, IL-1β, Bax, Caspase-3, TUNEL and attenuated neurological deficit in mice with transient MCAO, LY294002 weakened such effect of TSA dramatically. Conclusions: TSA could significantly decrease the neurological deficit and reduce the cerebral infarct volume, oxidative stress, inflammation, as well as apoptosis during cerebral ischemia reperfusion injury, which was achieved by activation of the Akt/GSK-3β signaling pathway.
Subject(s)
Animals , Male , Rats , Signal Transduction/drug effects , Ischemic Attack, Transient/metabolism , Neuroprotective Agents/pharmacology , Glycogen Synthase Kinase 3/drug effects , Proto-Oncogene Proteins c-akt/drug effects , Histone Deacetylase Inhibitors/pharmacology , Signal Transduction/physiology , Ischemic Attack, Transient/physiopathology , Glycogen Synthase Kinase 3/metabolism , Disease Models, Animal , Mice, Inbred BALB CABSTRACT
Several studies have demonstrated that ischemic preconditioning increases superoxide dismutase activity, but it is unclear how ischemic preconditioning affects events downstream of hydrogen peroxide production during subsequent severe ischemia and reperfusion in the hippocampus. To answer this question, we investigated whether ischemic preconditioning in the hippocampal CA1 region increases the activities of antioxidant enzymes glutathione peroxidase and catalase, resulting in a decrease in the level of hydroxyl radicals during subsequent severe ischemia-reperfusion. Transient forebrain ischemia was induced by four-vessel occlusion in rats. Ischemic preconditioning for 3 min or a sham operation was performed and a 15-min severe ischemia was induced three days later. Ischemic preconditioning preserved the CA1 hippocampal neurons following severe ischemia. The concentration of 2,3-dihydroxybenzoic acid, an indicator of hydroxyl radical, was measured using in vivo microdialysis technique combined with HPLC. The ischemia-induced increase in the ratio of 2,3-dihydroxybenzoic acid concentration relative to baseline did not differ significantly between preconditioned and control groups. On the other hand, activities of the antioxidant enzymes glutathione peroxidase-1 and catalase were significantly increased at 3 days after ischemic preconditioning in the hippocampus. Our results suggest that, in preconditioned rats, while hydrogen peroxide is generated from severe ischemia, the activity of catalase and glutathione peroxidase-1 is correspondingly increased to eliminate the excessive hydrogen peroxide. However, our results show that the enhanced activity of these antioxidant enzymes in preconditioned rats is not sufficient to decrease hydroxyl radical levels during subsequent severe ischemia-reperfusion.
Subject(s)
Animals , Male , Rats , Antioxidants/metabolism , Catalase/metabolism , Enzyme Activation , Glutathione Peroxidase/metabolism , Hippocampus/blood supply , Hydrogen Peroxide/metabolism , Hydroxybenzoates/metabolism , Hydroxyl Radical/metabolism , Ischemic Attack, Transient/metabolism , Ischemic Preconditioning , Prosencephalon , Rats, Sprague-Dawley , Reperfusion Injury/metabolismABSTRACT
Neurogenesis can be induced by pathological conditions such as cerebral ischemia. However the molecular mechanisms or modulating reagents of the reactive neurogenesis after the cerebral ischemia are poorly characterized. Retinoic acid (RA) has been shown to increase neurogenesis by enhancing the proliferation and neuronal differentiation of forebrain neuroblasts. Here, we examined whether RA can modulate the reactive neurogenesis after the cerebral ischemia. In contrast to our expectation, RA treatment decreased the reactive neurogenesis in subventricular zone (SVZ), subgranular zone (SGZ) and penumbral region. Furthermore, RA treatment also decreased the angiogenesis and gliosis in penumbral region.
Subject(s)
Animals , Male , Rats , Brain/blood supply , Cell Differentiation , Cell Proliferation , Ischemic Attack, Transient/metabolism , Neovascularization, Pathologic , Neuroglia/pathology , Neurons/pathology , Rats, Sprague-Dawley , Tretinoin/pharmacologyABSTRACT
The expression of c-fos protein was examined by means of immunocytochemistry in the rat brain following incomplete ischaemia, to elucidate the molecular mechanisms of post-ischaemic neuronal death and of the modulated neurotransmission of surviving neurons. Incomplete ischaemia was produced by permanent unilateral or bilateral common carotid artery (CCA) occlusion. After 1 h of unilateral occlusion, the level of c-fos protein-like nuclear immunoreactivity increased in cortical neurons ipsilateral to the insult, especially in cingulate and piriform cortices. The reactivity peaked at 3-6 h, and was undetectable after 3 days. A number of scattered immunostained neurons in the ipsilateral subiculum, CA 1 and dentate gyrus became visible after 1 day. The effect reached a peak between 1-3 days, then returned to basal levels by 7 days. Bilateral CCA occlusion showed a similar distribution of immunoreactivity, but on both hemispheres. Immunoreactive neurons were more numerous and intensely stained but more transient. The induction of c-fos was completely blocked or reduced by treatment with MK-801. Our results suggest that c-fos expression after CCA occlusion is NMDA receptor mediated, and that it has a specific role in neurons after ischaemic insult.