8-hydroxy-2--deoxyguanosine and Cerebral-Infarction

The aim of this study was to investigate whether uric acid (UA) might exert neuroprotection via activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and regulating neurotrophic factors in the cerebral cortices after transient focal cerebral ischemia/reperfusion (FCI/R) in rats. UA was intravenously injected through the tail vein (16 mg/kg) 30 min after the onset of reperfusion in rats subjected to middle cerebral artery occlusion for 2 h. Neurological deficit score was performed to analyze neurological function at 24 h after reperfusion. Terminal deoxynucleotidyl transferase-mediated dNTP nick end labeling (TUNEL) staining and hematoxylin and eosin (HE) staining were used to detect histological injury of the cerebral cortex. Malondialdehyde (MDA), the carbonyl groups, and 8-hydroxyl-2'-deoxyguanosine (8-OHdG) levels were employed to evaluate oxidative stress. Nrf2 and its downstream antioxidant protein, heme oxygenase- (HO-) 1,were detected by western blot. Nrf2 DNA-binding activity was observed using an ELISA-based measurement. Expressions of BDNF and NGF were analyzed by immunohistochemistry. Our results showed that UA treatment significantly suppressed FCI/R-induced oxidative stress, accompanied by attenuating neuronal damage, which subsequently decreased the infarct volume and neurological deficit. Further, the treatment of UA activated Nrf2 signaling pathway and upregulated BDNF and NGF expression levels. Interestingly, the aforementioned effects of UA were markedly inhibited by administration of brusatol, an inhibitor of Nrf2. Taken together, the antioxidant and neuroprotective effects afforded by UA treatment involved the modulation of Nrf2-mediated oxidative stress and regulation of BDNF and NGF expression levels. Thus, UA treatment could be of interest to prevent FCI/R injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blotting, Western; Brain Ischemia; Cerebral Infarction; Deoxyguanosine; Enzyme-Linked Immunosorbent Assay; Heme Oxygenase-1; Immunochemistry; In Situ Nick-End Labeling; Male; Malondialdehyde; NF-E2-Related Factor 2; Oxidative Stress; Rats; Rats, Sprague-Dawley; Uric Acid

Remote limb preconditioning (RPC) ameliorates ischemia-induced cerebral infarction and promotes neurological function recovery; however, the mechanism of RPC hasn't been fully understood, which limits its clinical application. The present study aimed at exploring the underlying mechanism of RPC through testing its effects on neuronal oxidative DNA damage and parthanatos in a rat focal cerebral ischemia model. Infarct volume was investigated by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining, and neuronal survival was evaluated by Nissl staining. Oxidative DNA damage was investigated via analyzing the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Besides, terminal deoxynucleotidyl transferase-mediated biotinylated-dUTP nick-end labeling (TUNEL) and DNA laddering were utilized to evaluate neuronal DNA fragmentation. Moreover, we tested whether RPC regulated poly(ADP-ribose) polymer (PAR) and apoptosis inducing factor (AIF) pathway; thus, PAR expression, AIF translocation and AIF/histone H2AX (H2AX) interaction were investigated. The results showed that RPC exerted neuroprotective effects by ameliorating oxidative DNA damage and neuronal parthanatos; additionally, RPC suppressed PAR/AIF pathway through reducing AIF translocation and AIF/H2AX interaction. The present study further exposed neuroprotective mechanism of RPC, and provided new evidence for the research on RPC and ICS.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis Inducing Factor; Brain; Cell Death; Cerebral Infarction; Deoxyguanosine; Disease Models, Animal; DNA Damage; Extremities; Femoral Artery; Histones; Ischemic Preconditioning; Male; Neurons; Neuroprotection; Oxidative Stress; Poly Adenosine Diphosphate Ribose; Random Allocation; Rats, Sprague-Dawley

We evaluated the neuroprotective effects of an anti-oxidative nutrient rich enteral diet (AO diet) that contained rich polyphenols (catechins and proanthocyanidins) and many other anti-oxidative ingredients. Wistar rats were treated with either vehicle, normal AO diet (containing 100kcal/100mL, catechin 38.75mg/100mL and proanthocyanidin 19mg/100mL, 1mL/day), or high AO diet (containing 10 times the polyphenols of the normal AO diet) for 14 days, and were subjected to 90min of transient middle cerebral artery occlusion. The AO diet improved motor function, reduced cerebral infarction volume, and decreased both peroxidative markers such as 4-hydroxynonenal, advanced glycation end products, 8-hydroxy-2-deoxyguanosine and inflammatory markers such as monocyte chemotactic protein-1, ionized calcium-binding adapter molecule-1, and tumor necrosis factor-α. Our study has shown that an AO diet has neuroprotective effects through both anti-oxidative and anti-inflammatory mechanisms, indicating that nutritional control with polyphenols could be useful for patients with acute ischemic stroke.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Oral; Aldehydes; Animals; Antioxidants; Biomarkers; Brain Chemistry; Brain Damage, Chronic; Brain Ischemia; Cerebral Infarction; Deoxyguanosine; Diet; Glycation End Products, Advanced; Infarction, Middle Cerebral Artery; Inflammation; Male; Oxidative Stress; Proanthocyanidins; Rats; Rats, Wistar

Different garlic products reduce the cerebral ischemic damage due to their antioxidant properties. In this work, we investigated the effect of aged garlic extract (AGE) on cyclooxygenase-2 (COX-2) protein levels and activity, and its role as a possible mechanism of neuroprotection in a cerebral ischemia model. Animals were subjected to 1 h of ischemia plus 24 h of reperfusion. AGE (1.2 ml/kg weight, i.p.) was administered at onset of reperfusion. To evaluate the damage induced by cerebral ischemia, the neurological deficit, the infarct area, and the histological alterations were measured. As an oxidative stress marker to deoxyribonucleic acid, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were determined. Finally, as inflammatory markers, TNFα levels and COX-2 protein levels and activity were measured. AGE treatment diminished the neurological alterations (61.6%), the infarct area (54.8%) and the histological damage (37.7%) induced by cerebral ischemia. AGE administration attenuated the increase in 8-OHdG levels (77.8%), in TNFα levels (76.6%), and in COX-2 protein levels (73.6%) and activity (30.7%) induced after 1 h of ischemia plus 24 h of reperfusion. These data suggest that the neuroprotective effect of AGE is associated not only to its antioxidant properties, but also with its capacity to diminish the increase in TNFα levels and COX-2 protein expression and activity. AGE may have the potential to attenuate the cerebral ischemia-induced inflammation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anti-Inflammatory Agents; Antioxidants; Brain Ischemia; Cerebral Infarction; Cyclooxygenase 2; Deoxyguanosine; Garlic; Male; Models, Animal; Oxidative Stress; Plant Extracts; Random Allocation; Rats; Rats, Wistar; Reperfusion; Time Factors; Tumor Necrosis Factor-alpha

The immunosuppressant FK506 (tacrolimus) is neuroprotective in experimental models of cerebral ischemia. However, the precise mechanisms underlying this neuroprotection remain unknown. In the present study, we hypothesized that FK506 treatment could protect rat brain from oxidative injuries through antioxidative and anti-inflammatory pathways after ischemia-reperfusion injury.. Sprague-Dawley rats were subjected to middle cerebral artery occlusion for 120 minutes, followed by reperfusion. Animals received a single injection of FK506 (0·3 mg/kg) or vehicle intravenously at 30 minutes after ischemic induction. Infarct volume and neurological performance were evaluated at 24 hours after reperfusion. Immunohistochemical analysis for 4-hydroxy-2-nonenal (4-HNE), 8-hydroxy-deoxyguanosine (8-OHdG), ionized calcium-binding adapter molecule 1 (Iba-1), and tumor necrosis factor-alpha (TNF-alpha) were conducted at 24 hours after reperfusion.. FK506 significantly reduced infarct volume (61·7%; P=0·01) and improved neurological deficit scores (P<0·05) 24 hours after reperfusion compared to vehicle. In FK506-treated rats, accumulation of 4-HNE (P<0·01) and 8-OHdG (P<0·01) was significantly suppressed in the cerebral cortex 24 hours after reperfusion. In addition, FK506 markedly reduced microglial activation (P<0·01) and TNF-alpha expression (P<0·01).. These results demonstrate that FK506 may have antioxidant as well as anti-inflammatory effects and reduces ischemic damage following cerebral infarction.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Antioxidants; Brain; Calcium-Binding Proteins; Cerebral Infarction; Cerebrovascular Circulation; Deoxyguanosine; Disease Models, Animal; Humans; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Magnetic Resonance Imaging; Male; Microfilament Proteins; Neuroprotective Agents; Oxidative Stress; Rats; Rats, Sprague-Dawley; Tacrolimus; Tumor Necrosis Factor-alpha

We aimed to examine whether thalidomide might inhibit the neuronal damage resulting from focal cerebral ischemia, and if so to explore the neuroprotective mechanism. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion (MCAO) in mice, and thalidomide was intraperitoneally administered a total of three times (at 10 min before, just before, and 1 h after MCAO). Thalidomide significantly reduced (a) the infarct area and volume at 24 and 72 h after MCAO and (b) the neurological score at 72 h after MCAO. Brains were also histochemically assessed for apoptosis and lipid peroxidation using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining and an antibody recognizing 8-hydroxy-2'-deoxyguanosine (8-OHdG), respectively. Thalidomide reduced both the number of TUNEL-positive cells and the oxidative damage. However, post-treatment of thalidomide [20 mg/kg, three times (at just after, 1 h after, 3 h after MCAO)] did not reduce the infarct volume. In an in vitro study, we examined the effects of thalidomide on lipid peroxidation in mouse brain homogenates and on the production of various radical species. Thalidomide inhibited both the lipid peroxidation and the production of H(2)O(2) and O(2).(-) (but not HO(-)) radicals. We also measured the brain concentration of TNF-alpha by ELISA. The TNF-alpha level in the brain was significantly increased at 9-24 h after MCAO. However, thalidomide did not reduce the elevated TNF-alpha level at either 12 or 24 h after MCAO. These findings indicate that thalidomide has neuroprotective effects against ischemic neuronal damage in mice, and that an inhibitory action of thalidomide against oxidative stress may be partly responsible for these neuroprotective effects.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Analysis of Variance; Animals; Blood Pressure; Cell Death; Cells, Cultured; Cerebral Infarction; Deoxyguanosine; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Free Radical Scavengers; Heart Rate; In Situ Nick-End Labeling; In Vitro Techniques; Infarction, Middle Cerebral Artery; Lipid Peroxidation; Male; Mice; Nervous System Diseases; Neuroprotective Agents; Retinal Ganglion Cells; Thalidomide; Time Factors; Tumor Necrosis Factor-alpha

Oxidative stress contributes to post-ischemic brain damage. We assessed the correlation between plasma 8-hydroxy-2'-deoxyguanosine (8-OHdG), as a marker of oxidative DNA damage, and progressive brain damage in rats subjected to transient or permanent ischemia. Male Wistar rats were subjected to permanent- and 0.5-, 1-, 2-h middle cerebral artery occlusion (MCAO). At various times thereafter, the infarct volume, 8-OHdG levels in plasma and brain tissue, DNA fragmentation, and immunohistochemical observations on their brains were recorded and compared. At 12 h after 2-h MCAO-reperfusion, the cortical infarct volume was increased; it peaked at 24 h. DNA degeneration expanded from the caudate putamen into the cortical region at 12 h. 8-OHdG-containing cells in the cortical infarct zone were observed at 12 h, the number of 8-OHdG-positive cells was highest at 24 h and they co-localized with DNA single-strand breaks. Plasma 8-OHdG significantly increased at 12 h, and peaked at 24 h after reperfusion (1.1+/-0.7 ng/ml (mean+/-S.D.); controls 0.3+/-0.1; p<0.01). This increase was in step with increased infarct volume, DNA degradation, and reflected immunohistochemical findings in the cortical region but not the caudate putamen. In the permanent MCAO model, plasma 8-OHdG levels were associated with the brain contents of 8-OHdG. Plasma 8-OHdG and the cortical infarct volume were lower in the 0.5- and 1-h than the 2-h MCAO model. Our findings suggest that 8-OHdG as a peripheral biomarker may be an indicator of oxidative brain damage in acute cerebral infarction.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acute Disease; Animals; Biomarkers; Brain; Cerebral Infarction; Deoxyguanosine; Hypoxia, Brain; Male; Oxidation-Reduction; Oxidative Stress; Rats; Rats, Wistar; Severity of Illness Index