UMLS:C0038454 - FACTA Search

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Query: UMLS:C0038454 (stroke)
147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adult rodent brain is capable of generating neuronal progenitor cells in the subventricular zone, and in the dentate gyrus of the hippocampus, throughout the life of the animal. Signals that regulate progenitor cell proliferation, differentiation, and migration are not well known. We report that administration of a nitric oxide donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) aminio]diazen-1-ium-1,2-diolate (DETA/NONOate), to young adult rats significantly increases cell proliferation and migration in the subventricular zone and the dentate gyrus. Treatment with DETA/ NONOate also increases neurogenesis in the dentate gyrus. Furthermore, administration of DETA/NONOate to rats subjected to embolic middle cerebral artery occlusion significantly increases cell proliferation and migration in the subventricular zone and the dentate gyrus, and these rats exhibit significant improvements of neurological outcome during recovery from ischemic stroke. Administration of DETA/NONOate significantly increases cortical levels of guanosine monophosphate both in ischemic and nonischemic rats, supporting the role of nitric oxide in promoting cell proliferation and neurogenesis. Thus, our data indicate that nitric oxide is involved in the regulation of progenitor cells and neurogenesis in the adult brain. This suggests that nitric oxide delivered to the brain well after stroke may have therapeutic benefits.
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PMID:A nitric oxide donor induces neurogenesis and reduces functional deficits after stroke in rats. 1170 66

Pyrroloquinoline quinone (PQQ) is a redox active essential nutrient that can generate or scavenge superoxide depending on its microenvironment. PQQ has been shown previously to be neuroprotective in a rodent stroke model. Here we test whether PQQ interacts with reactive nitrogen species, known to be involved in the pathogenesis of stroke. Using rat forebrain neurons in culture, we determined that the toxicity of SIN-1 was mediated by peroxynitrite and that PQQ could block this toxic action. However, PQQ could not block the toxicity of peroxynitrite itself. Both SIN-1 and peroxynitrite caused ATP depletion, but only SIN-1 evoked ATP depletion was blocked by PQQ. In a cell-free system, PQQ blocked nitration of bovine serum albumin produced by SIN-1, but potentiated peroxynitrite-induced nitration. PQQ was unable to block ATP depletion and cell death induced by NO. donors (DEA/NO, DPT/NO and DETA/NO), indicating that it does not directly interact with nitric oxide, and suggesting that it acts as a superoxide scavenger. PQQ significantly potentiated cGMP accumulation evoked by SIN-1, similar to the effect of superoxide dismutase (SOD). However, unlike SOD, which potentiated neurotoxicity induced by SIN-1, PQQ blocked its toxicity, arguing against the possibility that PQQ functions simply as a SOD mimetic. Indeed, substantially less H2O2 was produced by the incubation of SIN-1 with PQQ, when compared to SOD. These results suggest that PQQ scavenges superoxide without forming toxic levels of H2O2. Therefore, the protective effect of PQQ on stroke might be due, at least in part, to the suppression of peroxynitrite formation.
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PMID:The essential nutrient pyrroloquinoline quinone may act as a neuroprotectant by suppressing peroxynitrite formation. 1238 30

We tested the hypothesis that intravenous infusion of human marrow stromal cells (hMSC) with a nitric oxide donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) aminio] diazen-1-ium-1,2-diolate (DETA/NONOate), enhances angiogenesis, neurogenesis and neurological functional recovery after stroke in rats compared to individual therapy. Experimental groups consist of rats subjected to 2 h of middle cerebral artery occlusion (MCAo) and at 24 h after MCAo intravenous injection of (n=10/group): Group 1: phosphate buffered saline (PBS 1 ml) for control. Group 2: NONOate alone (0.4 mg/kg). Group 3: hMSCs (1 x 10(6)) alone. Group 4: hMSCs (1 x 10(6)) with NONOate (0.4 mg/kg). Functional tests and immunohistochemical staining were performed. Marginal functional recovery after treatment of stroke was found with 1 x 10(6) hMSCs alone (p=0.06) and no benefit was detected with NONOate alone (0.4 mg/kg, p=0.64). However, NONOate+hMSCs in combination significantly induced functional recovery (p<0.05). Treatment using hMSC in combination with NONOate significantly increased vessel perimeter and endothelial cell proliferation compared with hMSC or NONOate alone treatment (p<0.05). Cell proliferation and neurogenesis were assessed with bromodeoxyuridine (BrdU) labeling and immunostaining for cell type-specific markers. Combination treatment promoted increased, BrdU positive cell number in the subventricular zone (SVZ), migrating neuronal doublecortin immunoreactive cells and VEGF and bFGF expression in the ischemic boundary area compared to individual treatment. The functional therapeutic enhancement of combination treatment may be attributed to increased plasticity induced by the combination of a nitric oxide donor and hMSC therapy. These data suggest that pharmacological and cellular therapy may provide an additive therapeutic benefit after stroke.
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PMID:Combination therapy of stroke in rats with a nitric oxide donor and human bone marrow stromal cells enhances angiogenesis and neurogenesis. 1504 60

Inflammatory-activated glia are seen in numerous central nervous system (CNS) pathologies and can kill nearby neurons through the release of cytotoxic mediators. Glia, when activated, can express the inducible isoform of nitric oxide synthase (iNOS) producing high levels of nitric oxide (NO), which can kill neurons in certain conditions. We show, however, that inflammatory activation of glia in a mature culture of cerebellar granule neurons and glia causes little or no neuronal death under normal (21%) oxygen conditions. Similarly, hypoxia (2% oxygen) or low levels of an NO donor (100 microM DETA/NO) caused little or no neuronal death in nonactivated cultures. If inflammatory activation of glia or addition of NO donor was combined with hypoxia, however, extensive neuronal death occurred. Death in both cases was prevented by the N-methyl-D-aspartate (NMDA) receptor blocker MK-801, implying that death was mediated by the glutamate receptor. Low levels of NO were found to increase the apparent K(M) of cellular oxygen consumption for oxygen, probably due to NO-induced inhibition of mitochondrial respiration, in competition with oxygen, at cytochrome oxidase. Necrotic death, induced by hypoxia plus DETA/NO, was increased further by deoxyglucose, an inhibitor of glycolysis, suggesting that necrosis was mediated by energy depletion. Hypoxia was found to be a potent stimulator of microglia proliferation, but this proliferation was not significant in inflammatory-activated cultures. These results suggest that low levels of NO can induce neuronal death under hypoxic conditions, mediated by glutamate after NO inhibition of respiration in competition with oxygen. Brain inflammation can thus sensitize to hypoxia-induced death, which may be important in pathologies such as stroke, neurodegeneration, and brain aging.
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PMID:Nitric oxide from inflammatory-activated glia synergizes with hypoxia to induce neuronal death. 1555 52

Reactive nitrogen and oxygen species (O2*-, H2O2, NO* and ONOO-) have been strongly implicated in the pathophysiology of neurodegenerative and mitochondrial diseases. In the present study, we examined the effects of nitrosative and/or nitrative stress generated by DETA-NO {(Z)-1-[2-aminoethyl-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate}, SIN-1 (3-morpholinosydnonimine hydrochloride) and SNP (sodium nitroprusside) on U87MG glioblastoma cybrids carrying wt (wild-type) and mutant [A3243G (Ala3243-->Gly)] mtDNA (mitochondrial genome) from a patient suffering from MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes). The mutant cybrids had reduced activity of cytochrome c oxidase, significantly lower ATP level and decreased mitochondrial membrane potential. However, endogenous levels of reactive oxygen species were very similar in all cybrids regardless of whether they carried the mtDNA defects or not. Furthermore, the cybrids were insensitive to the nitrosative and/or nitrative stress produced by either DETA-NO or SIN-1 alone. Cytotoxicity, however, was observed in response to SNP treatment and a combination of SIN-1 and glucose-deprivation. The mutant cybrids were significantly more sensitive to these insults compared with the wt controls. Ultrastructural examination of dying cells revealed several characteristic features of autophagic cell death. We concluded that nitrosative and/or nitrative stress alone were insufficient to trigger cytotoxicity in these cells, but cell death was observed with a combination of metabolic and nitrative stress. The vulnerability of the cybrids to these types of injury correlated with the cellular energy status, which were compromised by the MELAS mutation.
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PMID:Effects of nitric oxide donors on cybrids harbouring the mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) A3243G mitochondrial DNA mutation. 1596 53

Chunghyuldan (CHD), a combinatorial drug that has antihyperlipidemic and anti-inflammatory activities, has been shown to improve arterial stiffness and inhibit stroke recurrence in clinical study. To understand the molecular basis of CHD's clinical effects, we explored its effect on cell proliferation and expression of nitric oxide synthase (NOS) and vascular cell adhesion molecule (VCAM-1) in human umbilical vein endothelial cells (HUVECs). Cell number counting and [3H]thymidine incorporation assay demonstrated that nontoxic doses of CHD have an inhibitory effect on DNA synthesis and suppress cell cycle progression of HUVECs. CHD treatment led to a marked induction of NO production through up-regulation of NOS mRNA expression in a dose- and time-dependent manner, whereas it suppressed VCAM-1 expression. CHD inhibition of VCAM-1 expression was totally blocked by pretreatment with the NO synthesis inhibitor L-NMMA, whereas pretreatment with the NO donor DETA-NO further decreased VCAM-1 level in CHD-treated HUVECs, indicating that VCAM-1 regulation by CHD is mediated through increased NO synthesis by CHD. In addition, TNF-alpha-mediated VCAM-1 activation was substantially impeded by CHD treatment. Collectively, our data suggest that anti-inflammatory or anti-hyperlipidemic effects of CHD might be associated with its ability to activate NO production and suppress VCAM-1 expression in human endothelial cells.
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PMID:Chunghyuldan activates NOS mRNA expression and suppresses VCAM-1 mRNA expression in human endothelial cells. 1646 9

Neurogenesis may contribute to functional recovery after neural injury. Nitric oxide donors such as DETA-NONOate promote functional recovery after stroke. However, the mechanisms underlying functional improvement have not been ascertained. We therefore investigated the effects of DETA-NONOate on neural progenitor/stem cell neurospheres derived from the subventricular zone from young and retired breeder rat brain. Subventricular zone cells were dissociated from normal young adult male Wistar rats (2-3 months old) and retired breeder rats (14 months old), treated with or without DETA-NONOate. Subventricular zone neurosphere formation, proliferation, telomerase activity, and Neurogenin 1 mRNA expression were significantly decreased and glial fibrillary acidic protein expression was significantly increased in subventricular zone neurospheres from retired breeder rats compared with young rats. Treatment of neurospheres with DETA-NONOate significantly decreased neurosphere formation and telomerase activity, and promoted neuronal differentiation and neurite outgrowth concomitantly with increased N-cadherin and beta-catenin mRNA expression in both young and old neurospheres. DETA-NONOate selectively increased Neurogenin 1 and decreased glial fibrillary acidic protein mRNA expression in retired breeder neurospheres. N-cadherin significantly increased Neurogenin 1 mRNA expression in young and old neurospheres. Anti-N-cadherin reversed DETA-NONOate-induced neurosphere adhesion, neuronal differentiation, neurite outgrowth, and beta-catenin mRNA expression. Our data indicate that age has a potent effect on the characteristics of subventricular zone neurospheres; neurospheres from young rats show significantly higher formation, proliferation and telomerase activity than older neurospheres. In contrast, older neurospheres exhibit significantly increased glial differentiation than young neurospheres. DETA-NONOate promotes neuronal differentiation and neurite outgrowth in both young and older neurospheres. The molecular mechanisms associated with the DETA-NONOate modulation of neurospheres from young and older animals as well age dependent effects of neurospheres appear to be controlled by N-cadherin and beta-catenin gene expression, which subsequently regulates the neuronal differentiating factor Neurogenin expression in both young and old neural progenitor cells.
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PMID:N-cadherin mediates nitric oxide-induced neurogenesis in young and retired breeder neurospheres. 1658 Jul 82

We tested whether the nitric oxide donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) aminio] diazen-1-ium-1,2-diolate (DETA-NONOate), increases expression of Angiopoietin (Ang1)/Tie2, which may play a role in regulating angiogenesis and vascular integrity after stroke in rats. Wistar rats were subjected to middle cerebral artery occlusion and treated with or without DETA-NONOate. Stroke rats treated with DETA-NONOate show significantly increased Ang1, Tie2 and Occludin expression in the ischemic border compared with control stroke animals (p < 0.05). Consistent with in vivo data, DETA-NONOate promotes capillary tube formation in cultured brain endothelial cells. Neutralizing Ang1 antibody attenuates DETA-NONOate-induced capillary tube formation. The data suggest that the Ang1/Tie2 axis promotes DETA-NONOate-induced angiogenesis and stabilizes of angiogenic vessels after stroke.
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PMID:Nitric oxide regulates Angiopoietin1/Tie2 expression after stroke. 1676 1

Stromal cell-derived factor-1 (SDF1) and its chemokine (CXC motif) receptor 4 (CXCR4), along with matrix metalloproteinases (MMPs), regulate bone marrow stromal cell (BMSC) migration. We tested the hypothesis that a nitric oxide donor, DETA-NONOate, increases endogenous ischemic brain SDF1 and BMSC CXCR4 and MMP9 expression, which promotes BMSC migration into ischemic brain and thereby enhances functional outcome after stroke. C57BL/6J mice were subjected to middle cerebral artery occlusion (MCAo), and 24 hours later, the following were intravenously administered (n = 9 mice per group): (a) phosphate-buffered saline; (b) BMSCs (5 x 10(5)); (c) 0.4 mg/kg DETA-NONOate; (d) combination of CXCR4-inhibition BMSCs with DETA-NONOate; and (e) combination of BMSCs with DETA-NONOate. To elucidate the mechanisms underlying combination-enhanced BMSC migration, transwell cocultures of BMSC with mouse brain endothelial cells (MBECs) or astrocytes were performed. Combination treatment significantly improved functional outcome after stroke compared with BMSC monotherapy and MCAo control, and it increased SDF1 expression in the ischemic brain compared with DETA-NONOate monotherapy and MCAo control. The number of BMSCs in the ischemic brain was significantly increased after combination BMSC with DETA-NONOate treatment compared with monotherapy with BMSCs. The number of engrafted BMSCs was significantly correlated with functional outcome after stroke. DETA-NONOate significantly increased BMSC CXCR4 and MMP9 expression and promoted BMSC adhesion and migration to MBECs and astrocytes compared with nontreatment BMSCs. Inhibition of CXCR4 or MMPs in BMSCs significantly decreased DETA-NONOate-induced BMSC adhesion and migration. Our data demonstrate that DETA-NONOate enhanced the therapeutic potency of BMSCs, possibly via upregulation of SDF1/CXCR4 and MMP pathways, and increased BMSC engraftment into the ischemic brain.
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PMID:Nitric oxide donor upregulation of stromal cell-derived factor-1/chemokine (CXC motif) receptor 4 enhances bone marrow stromal cell migration into ischemic brain after stroke. 1764 Dec 43

Neovascularization may contribute to functional recovery after neural injury. Combination treatment of stroke with a nitric oxide donor, (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1, 2-diolate (DETA-NONOate) and bone marrow stromal cells promotes functional recovery. However, the mechanisms underlying functional improvement have not been elucidated. In this study, we tested the hypothesis that combination treatment upregulates angiopoietin-1 and its receptor Tie2 in the ischemic brain and bone marrow stromal cells, thereby enhancing cerebral neovascularization after stroke. Adult wild type male C57BL/6 mice were i.v. administered PBS, bone marrow stromal cells 5x10(5), DETA-NONOate 0.4 mg/kg or combination DETA-NONOate with bone marrow stromal cells (n=12/group) after middle cerebral artery occlusion. Combination treatment significantly upregulated angiopoietin-1/Tie2 and tight junction protein (occludin) expression, and increased the number, diameter and perimeter of blood vessels in the ischemic brain compared with vehicle control (mean+ or -S.E., P<0.05). In vitro, DETA-NONOate significantly increased angiopoietin-1/Tie2 protein (n=6/group) and Tie2 mRNA (n=3/group) expression in bone marrow stromal cells. DETA-NONOate also significantly increased angiopoietin-1 protein (n=6/group) and mRNA (n=3/group) expression in mouse brain endothelial cells (P<0.05). Angiopoietin-1 mRNA (n=3/group) was significantly increased in mouse brain endothelial cells treated with DETA-NONOate in combination with bone marrow stromal cell-conditioned medium compared with cells treated with bone marrow stromal cell-conditioned medium or DETA-NONOate alone. Mouse brain endothelial cell capillary tube-like formation assays (n=6/group) showed that angiopoietin-1 peptide, the supernatant of bone marrow stromal cells and DETA-NONOate significantly increased capillary tube formation compared with vehicle control. Combination treatment significantly increased capillary tube formation compared with DETA-NONOate treatment alone. Inhibition of angiopoietin-1 significantly attenuated combination treatment-induced tube formation. Our data indicated that combination treatment of stroke with DETA-NONOate and bone marrow stromal cells promotes neovascularization, which is at least partially mediated by upregulation of the angiopoietin-1/Tie2 axis.
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PMID:Treatment of stroke with (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1, 2-diolate and bone marrow stromal cells upregulates angiopoietin-1/Tie2 and enhances neovascularization. 1869 37

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