Role of AT1 receptors and NAD(P)H oxidase in diabetes-aggravated ischemic brain injury

2004 ◽  
Vol 286 (6) ◽  
pp. H2442-H2451 ◽  
Author(s):  
Ikuyo Kusaka ◽  
Gen Kusaka ◽  
Changman Zhou ◽  
Mami Ishikawa ◽  
Anil Nanda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Brain Injury ◽  
Cerebral Ischemia ◽  
Cerebral Infarction ◽  
Focal Cerebral Ischemia ◽  
Lipid Hydroperoxide ◽  
Neurological Deficits ◽  
Sprague Dawley

The objective of the present study was to examine the role of the angiotensin II type 1 receptor (AT1-R) in the diabetes-aggravated oxidative stress and brain injury observed in a rat model of combined diabetes and focal cerebral ischemia. Diabetes was induced by an injection of streptozotoxin (STZ; 55 mg/kg iv) at 8 wk of age. Two weeks after the induction of diabetes, some animals received continuous subcutaneous infusion of the AT1-R antagonist candesartan (0.5 mg·kg−1·day−1) for 14 days. Focal cerebral ischemia, induced by middle cerebral artery occlusion/reperfusion (MCAO), was conducted at 4 wk after STZ injection. Male Sprague-Dawley rats ( n = 189) were divided into five groups: normal control, diabetes, MCAO, diabetes + MCAO, and diabetes + MCAO + candesartan. The major observations were that 1) MCAO produced typical cerebral infarction and neurological deficits at 24 h that were accompanied by elevation of NAD(P)H oxidase gp91phox and p22phox mRNAs, and lipid hydroperoxide production in the ipsilateral hemisphere; 2) diabetes enhanced NAD(P)H oxidase gp91phox and p22phox mRNA expression, potentiated lipid peroxidation, aggravated neurological deficits, and enlarged cerebral infarction; and 3) candesartan reduced the expression of gp91phox and p22phox, decreased lipid peroxidation, lessened cerebral infarction, and improved the neurological outcome. We conclude that diabetes exaggerates the oxidative stress, NAD(P)H oxidase induction, and brain injury induced by focal cerebral ischemia. The diabetes-aggravated brain injury involves AT1-Rs. We have shown for the first time that candesartan reduces brain injury in a combined model of diabetes and cerebral ischemia.

scholarly journals Mito-Tempo prevents nicotine-induced exacerbation of ischemic brain damage

2018 ◽  
Vol 125 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Chun Li ◽  
Hong Sun ◽  
Guodong Xu ◽  
Kimberly D. McCarter ◽  
Jiyu Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Brain Damage ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Neutrophil Infiltration ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Ischemic Brain Damage ◽  
Mitochondrial Oxidative Stress ◽  
Ischemic Brain

Nicotine may contribute to the pathogenesis of cerebrovascular disease via the generation of reactive oxygen species (ROS). Overproduction of ROS leads to brain damage by intensifying postischemic inflammation. Our goal was to determine the effect of Mito-Tempo, a mitochondria-targeted antioxidant, on ischemic brain damage and postischemic inflammation during chronic exposure to nicotine. Male Sprague-Dawley rats were divided into four groups: control, nicotine, Mito-Tempo-treated control, and Mito-Tempo-treated nicotine. Nicotine (2 mg·kg−1·day−1) was administered via an osmotic minipump for 4 wk. Mito-Tempo (0.7 mg·kg−1·day−1ip) was given for 7 days before cerebral ischemia. Transient focal cerebral ischemia was induced by occlusion of the middle cerebral artery for 2 h. Brain damage and inflammation were evaluated after 24 h of reperfusion by measuring infarct volume, expression of adhesion molecules, activity of matrix metalloproteinase, brain edema, microglial activation, and neutrophil infiltration. Nicotine exacerbated infarct volume and worsened neurological deficits. Nicotine did not alter baseline ICAM-1 expression, matrix metallopeptidase-2 activity, microglia activation, or neutrophil infiltration but increased these parameters after cerebral ischemia. Mito-Tempo did not have an effect in control rats but prevented the chronic nicotine-induced augmentation of ischemic brain damage and postischemic inflammation. We suggest that nicotine increases brain damage following cerebral ischemia via an increase in mitochondrial oxidative stress, which, in turn, contributes to postischemic inflammation.NEW & NOTEWORTHY Our findings have important implications for the understanding of mechanisms contributing to increased susceptibility of the brain to damage in smokers and users of nicotine-containing tobacco products.

Dietary genistein and equol (4′, 7 isoflavandiol) reduce oxidative stress and protect rats against focal cerebral ischemia

2010 ◽  
Vol 299 (3) ◽  
pp. R871-R877 ◽  
Author(s):  
Yulin Ma ◽  
Jennifer C. Sullivan ◽  
Derek A. Schreihofer
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Hormone Replacement ◽  
Cerebral Injury ◽  
Female Rats ◽  
Neurological Deficits ◽  
Soy Isoflavone ◽  
Transient Focal Cerebral Ischemia ◽  
The Brain

High soy diets reduce injury in rat models of focal cerebral ischemia and are proposed as alternatives to hormone replacement therapy for postmenopausal women. The present study tests the hypothesis that the major soy isoflavone genistein and the daidzein metabolite equol are neuroprotective in transient focal cerebral ischemia in male and ovariectomized (OVX) female rats by inhibiting oxidative stress. Genistein is the primary circulating soy isoflavone in humans, whereas equol is the primary circulating isoflavone in rats. Male and OVX female Sprague-Dawley rats were fed an isoflavone-reduced diet alone or supplemented with genistein (500 ppm) or equol (250 ppm) for 2 wk prior to 90-min transient middle cerebral artery occlusion followed by reperfusion under isoflurane anesthesia. Indices of oxidative stress were determined 24 h after reperfusion, and cerebral injury was evaluated 3 days after reperfusion. Genistein and equol significantly reduced infarct size in both sexes. Further studies in OVX female rats revealed that this neuroprotection was accompanied by a decrease in NAD(P)H oxidase activity and superoxide levels in the brain. In addition, equol reduced plasma thiobarbituric acid reactive substances, and neurological deficits up to 7 days after injury. There were no significant differences in cerebral blood flow among treatment groups. In conclusion, dietary soy isoflavones are neuroprotective in transient focal cerebral ischemia in male and OVX female rats. These isoflavones may protect the brain via increases in endogenous antioxidant mechanisms and reduced oxidative stress.

scholarly journals Chronic nicotine exposure exacerbates transient focal cerebral ischemia-induced brain injury

2016 ◽  
Vol 120 (3) ◽  
pp. 328-333 ◽  
Author(s):  
Chun Li ◽  
Hong Sun ◽  
Denise M. Arrick ◽  
William G. Mayhan
Keyword(s):  
Cerebral Cortex ◽  
Brain Injury ◽  
Cerebral Ischemia ◽  
Infarct Size ◽  
Focal Cerebral Ischemia ◽  
Neurological Deficits ◽  
Control Group ◽  
Nicotine Exposure ◽  
Chronic Nicotine ◽  
Transient Focal Cerebral Ischemia

Tobacco smoking is a risk factor contributing to the development and progression of ischemic stroke. Among many chemicals in tobacco, nicotine may be a key contributor. We hypothesized that nicotine alters the balance between oxidant and antioxidant networks leading to an increase in brain injury following transient focal cerebral ischemia. Male Sprague-Dawley were treated with nicotine (2 or 4 mg·kg−1·day−1) for 4 wk via an implanted subcutaneous osmotic minipump and subjected to a 2-h middle cerebral artery occlusion (MCAO). Infarct size and neurological deficits were evaluated at 24 h of reperfusion. Superoxide levels were determined by lucigenin-enhanced chemiluminescence. Expression of oxidant and antioxidant proteins was measured using Western blot analysis. We found that chronic nicotine exposure significantly increased infarct size and worsened neurological deficits. In addition, nicotine significantly elevated superoxide levels of cerebral cortex under basal conditions. Transient focal cerebral ischemia produced an increase in superoxide levels of cerebral cortex in control group, but no further increase was found in the nicotine group. Furthermore, chronic nicotine exposure did not alter protein expression of NADPH oxidase but significantly decreased MnSOD and uncoupling protein-2 (UCP-2) in the cerebral cortex and cerebral arteries. Our findings suggest that nicotine-induced exacerbation in brain damage following transient focal cerebral ischemia may be related to a preexisting oxidative stress via decreasing of MnSOD and UCP-2.

scholarly journals The Role of Akt Signaling in Oxidative Stress Mediates NF-κB Activation in Mild Transient Focal Cerebral Ischemia

2008 ◽  
Vol 28 (12) ◽  
pp. 1917-1926 ◽  
Author(s):  
Yun Seon Song ◽  
Purnima Narasimhan ◽  
Gab Seok Kim ◽  
Joo Eun Jung ◽  
Eun-Hee Park ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Signaling Pathway ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Akt Signaling ◽  
Akt Inhibitor ◽  
Akt Phosphorylation ◽  
Transient Focal Cerebral Ischemia

Reactive oxygen species, derived from hypoxia and reoxygenation during transient focal cerebral ischemia (tFCI), are associated with the signaling pathway that leads to neuronal survival or death, depending on the severity and duration of the ischemic insult. The Akt survival signaling pathway is regulated by oxidative stress and is implicated in activation of nuclear factor-κB(NF-κB). Mild cerebral ischemia in mice was used to induce increased levels of Akt phosphorylation in the cortex and striatum. To clarify the role of Akt activation by NF-κB after tFCI, we injected the specific Akt inhibitor IV that inhibits Akt phosphorylation/activation. Inhibition of Akt phosphorylation induced decreases in sequential NF-κB signaling after 30 mins of tFCI at 1 h. Furthermore, the downstream survival signals of the Akt pathway were also decreased. Akt inhibitor IV increased ischemic infarct volume and apoptotic-related DNA fragmentation. Superoxide production in the ischemic brains of mice pretreated with the Akt inhibitor was higher than in vehicle-treated mice. In addition, those pretreated mice showed a reduction of approximately 33% in copper/zinc-superoxide dismutase expression. We propose that Akt signaling exerts its neuroprotective role by NF-κB activation in oxidative cerebral ischemia in mice.

scholarly journals Pretreatment with Shuanghe-Tang Extract Attenuates Postischemic Brain Injury and Edema in a Mouse Model of Stroke: An Analysis of Medicinal Herbs Listed in Dongui Bogam

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Min Jae Kim ◽  
Seo-Yeon Lee ◽  
Ji Young Hwang ◽  
Hyunha Kim ◽  
Ki-Tae Ha ◽  
...  
Keyword(s):  
Brain Injury ◽  
Cerebral Ischemia ◽  
Mouse Model ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Immunohistochemical Analysis ◽  
Medicinal Herbs ◽  
Neurological Deficits ◽  
Dependent Manner

Aim. Although stroke is among the leading causes of death and long-term disability, there are few effective treatments for limiting the severity of neurological sequelae. We evaluated the effects of 29 medicinal herbs listed in the Pung chapter of the 17th century Korean medical text Dongui Bogam on stroke symptoms in a mouse model of cerebral ischemia. Methods. Focal cerebral ischemia was induced via photothrombosis. Infarct volume, brain edema, and neurological deficits were evaluated. Immunofluorescence staining for tight junction proteins and aquaporin 4 (AQP4) was performed following ischemic injury. Results. Based on our initial findings, we examined the effects of two prescriptions in which the candidate herbs comprised more than 60% of the total formula: Shuanghe-tang and Zengsunsiwu-tang. Pretreatment with Shuanghe-tang significantly reduced infarct volume, decreased blood-brain barrier (BBB) breakdown, attenuated edema, and improved neurological and motor functions in a dose-dependent manner (30, 100, and 300 mg/kg), while no such effects were observed in mice pretreated with Zengsunsiwu-tang. Immunohistochemical analysis revealed significant increases in ipsilateral occludin and zonula occludens 1 (ZO-1) expression in Shuanghe-tang-pretreated mice, as well as increased AQP4 immunofluorescence. Conclusions. These results indicate that Shuanghe-tang may protect against brain injury and promote recovery of neurological function following ischemia.

scholarly journals Role of Neutrophils in Exacerbation of Brain Injury After Focal Cerebral Ischemia in Hyperlipidemic Mice

Stroke ◽  
2015 ◽  
Vol 46 (10) ◽  
pp. 2916-2925 ◽  
Author(s):  
Josephine Herz ◽  
Pascal Sabellek ◽  
Thomas E. Lane ◽  
Matthias Gunzer ◽  
Dirk M. Hermann ◽  
...  
Keyword(s):  
Brain Injury ◽  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia

Deferoxamine-induced attenuation of brain edema and neurological deficits in a rat model of intracerebral hemorrhage

2003 ◽  
Vol 15 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Takehiro Nakamura ◽  
Richard F. Keep ◽  
Ya Hua ◽  
Timothy Schallert ◽  
Julian T. Hoff ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Brain Injury ◽  
Intracerebral Hemorrhage ◽  
Brain Edema ◽  
Iron Chelator ◽  
Iron Accumulation ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Autologous Whole Blood ◽  
The Right

Object In the authors' previous studies they found that brain iron accumulation and oxidative stress contribute to secondary brain damage after intracerebral hemorrhage (ICH). In the present study they investigated whether deferoxamine, an iron chelator, can reduce ICH-induced brain injury. Methods Male Sprague–Dawley rats received an infusion of 100 μl of autologous whole blood into the right basal ganglia and were killed 1, 3, or 7 days thereafter. Iron distribution was examined histochemically (enhanced Perl reaction). The effects of deferoxamine on ICH-induced brain injury were examined by measuring brain edema and neurological deficits. Apurinic/apyrimidinic endonuclease/redox effector factor–1 (APE/Ref-1), a repair mechanism for DNA oxidative damage, was quantitated by Western blot analysis. Iron accumulation was observed in the perihematoma zone beginning 1 day after ICH. Deferoxamine attenuated brain edema, neurological deficits, and ICH-induced changes in APE/Ref-1. Conclusions Deferoxamine and other iron chelators may be potential therapeutic agents for treating ICH. They may act by reducing the oxidative stress caused by the release of iron from the hematoma.

Neuroprotective effect of peroxynitrite decomposition catalyst and poly(adenosine diphosphate—ribose) polymerase inhibitor alone and in combination in rats with focal ischemia

2004 ◽  
Vol 101 (4) ◽  
pp. 669-675 ◽  
Author(s):  
Shyam S. Sharma ◽  
Shankar Munusamy ◽  
Meenakshisundaram Thiyagarajan ◽  
Chaman L. Kaul
Keyword(s):  
Cerebral Ischemia ◽  
Cerebral Infarction ◽  
Focal Cerebral Ischemia ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Parp Inhibitor ◽  
Adenosine Diphosphate ◽  
Neurological Deficits ◽  
Content Type ◽  
Fine Print

Object. The authors evaluated the neuroprotective effect of 5,10,15,20-tetrakis(N-methyl-4′-pyridyl)porphyrinatoiron(III) (FeTMPyP), a peroxynitrite decomposition catalyst, and 1,5-isoquinolinediol (ISO), a poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitor, alone and in combination in rats with focal cerebral ischemia induced by middle cerebral artery occlusion (MCAO). Methods. Male Sprague—Dawley rats were subjected to 2 hours of MCAO followed by 22 hours of reperfusion. Cerebral infarction and neurological deficits were estimated after ischemia. Intraperitoneal injections of FeTMPyP (1 and 2 mg/kg) and ISO (0.05 and 0.1 mg/kg) were administered alone or in combination in ischemic animals. The PARP activity in vehicle- and drug-treated groups was estimated using anti—poly(ADP-ribose) antibody in immunofluorescence and immunoblotting studies. Two hours of MCAO and 22 hours of reperfusion produced significant cerebral infarction and neurological deficits. Treatment with FeTMPyP (1 and 2 mg/kg) and ISO (0.05 and 0.1 mg/kg) produced a significant reduction in cerebral infarction and neurological deficits. Combination therapy (2 mg/kg FeTMPyP and 0.1 mg/kg ISO) enhanced the inhibition of ischemic volume (77.81 ± 0.86%) compared with monotherapies (FeTMPyP 54.07 ± 5.6% and ISO 53.06 ± 3.88%). Immunoblotting and immunofluorescence studies showed PARP activation after ischemia, which was reduced by drug treatment. Conclusions. Neuroprotection observed with FeTMPyP and ISO alone and in combination may be attributed to inhibition of the peroxynitrite—PARP cascade of cerebral ischemia/reperfusion injury.

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