mocetinostat and Stroke

Chronic kidney disease (CKD) is associated with high cardiovascular risk and mortality. Myeloperoxidase (MPO) has been linked to adverse events in patients with mild-moderate CKD. We sought to investigate whether MPO levels are associated with adverse outcomes in patients with CKD. We studied participants with mild to moderate CKD in the prospective chronic renal insufficiency cohort (CRIC). We followed patients for incident heart failure (HF), death, and composite outcome (myocardial infarction, incident peripheral arterial disease, cerebrovascular accident and death). A total of 3872 patients were included (2702 without CVD, 1170 with CVD). After multiple adjustments, doubling of MPO in patients with prior CAD was associated with risk of HF (HR 1.15 [1.01-1.30], P = 0.032) and mortality (HR 1.16 [1.05-1.30], P = 0.005), and composite outcome of MI, PAD, CVA and death (HR 1.12 [1.01-1.25], P = 0.031). In this cohort of patients with mild to moderate CKD and CAD, MPO levels are independently associated with incident HF, all-cause mortality, and a composite outcome.

Topics: Coronary Artery Disease; Heart Failure; Humans; Peroxidase; Prospective Studies; Renal Insufficiency, Chronic; Risk Factors; Stroke

Breakdown of the blood-brain barrier (BBB) is a key step associated with ischemic stroke and its increased permeability causes extravasation of plasma proteins and circulating leukocytes. Polymorphonuclear neutrophil (PMN) proteases may participate in BBB breakdown. We investigated the role of PMNs in ischemic conditions by testing their effects on a model of BBB in vitro, under oxygen-glucose deprivation (OGD) to mimic ischemia, supplemented or not with high-density lipoproteins (HDLs) to assess their potential protective effects. Human cerebral endothelial cells cultured on transwells were incubated for 4 hours under OGD conditions with or without PMNs and supplemented or not with HDLs or alpha-1 antitrypsin (AAT, an elastase inhibitor). The integrity of the BBB was then assessed and the effect of HDLs on PMN-induced proteolysis of extracellular matrix proteins was evaluated. The release of myeloperoxidase and matrix metalloproteinase 9 (MMP-9) by PMNs was quantified. Polymorphonuclear neutrophils significantly increased BBB permeability under OGD conditions via proteolysis of extracellular matrix proteins. This was associated with PMN degranulation. Addition of HDLs or AAT limited the proteolysis and associated increased permeability by inhibiting PMN activation. Our results suggest a deleterious, elastase-mediated role of activated PMNs under OGD conditions leading to BBB disruption that could be inhibited by HDLs.

Topics: Blood-Brain Barrier; Brain Ischemia; Cell Line; Coculture Techniques; Endothelial Cells; Extracellular Matrix Proteins; Female; Humans; Lipoproteins, HDL; Male; Matrix Metalloproteinase 9; Neutrophils; Peroxidase; Proteolysis; Stroke

The causality between myeloperoxidase (MPO) and cardiovascular disease still remains unclear. We performed a two-sample Mendelian randomization (MR) study to estimate the potential causal effect of MPO on the risks of ischemic stroke, ischemic stroke subtypes, heart failure (HF), and atrial fibrillation (AF).. Seventeen independent single-nucleotide polymorphisms associated with MPO levels were identified as instrumental variables from a European-descent genome-wide association study. Summary-level data on ischemic stroke originated from the Multiancestry Genome-wide Association Study of Stroke Consortium with 440 328 European individuals. We used the inverse-variance weighted method to assess the potential causality of plasma MPO with ischemic stroke and its subtypes in the main analysis. Genetically determined higher plasma MPO concentration was significantly associated with increased risks of ischemic stroke (odds ratio [OR] per standard deviation [SD] increase, 1.05; 95% confidence interval [CI], 1.02-1.09; P = 0.002) and cardioembolic stroke (CES) (OR per SD increase, 1.10; 95% CI, 1.03-1.18; P = 0.005), but was not associated with risks of large artery stroke or small vessel stroke. In the secondary analysis, MPO was associated with a high risk of HF (OR per SD increase, 1.05; 95% CI, 1.02-1.07; P = 0.001) and AF (OR per SD increase, 1.04; 95% CI, 1.01-1.07; P = 0.004). MR-Egger regression showed no directional pleiotropy for all associations, and the sensitivity analyses further confirmed these findings.. High plasma MPO levels were potentially associated with increased risks of ischemic stroke, CES, HF, and AF, suggesting that MPO plays an important role in the development of cardiovascular disease.

Topics: Atrial Fibrillation; Genome-Wide Association Study; Heart Failure; Humans; Ischemic Stroke; Mendelian Randomization Analysis; Peroxidase; Polymorphism, Single Nucleotide; Stroke

To explore the value of serum lipoprotein-associated phospholipase A2（Lp-PLA2）combined with myeloperoxidase（MPO）for the diagnosis of large artery atherosclerosis(LAA) cerebral infarction.. Baseline data were collected from patients with first-ever acute cerebral infarction, serum Lp-PLA2 and MPO levels were measured. The etiology of cerebral infarction was classified according to the Chinese Ischemic Stroke Subtype Classification Standard. The risk factors associated with LAA cerebral infarction were identified by univariate and multivariate regression analysis. The diagnostic value of serum Lp-PLA2 and MPO for LAA cerebral infarction was assessed by the area under the receiver-operating characteristic (ROC) curve.. Overall 368 patients were involved, 148 patients (40.22 %) were LAA. The serum La-PLA2 and MPO levels were higher in the LAA group than those in non-LAA group (23.06 ± 3.39 ng/mL versus 17.48 ± 3.26 ng/mL; 93.60 ± 9.58 ng/mL versus 75.98 ± 15.53 ng/mL; P < 0.001 for both). Multivariate analysis showed that elevated levels of serum Lp-PLA2 (OR 1.742, 95 %CI 1.499-2.025; P < 0.001) and MPO (OR 1.060, 95 % CI 1.026-1.096; P = 0.001) were the independent risk factors of LAA cerebral infarction. The area under curve of the serum Lp-PLA2 combined with MPO for the diagnosis of LAA cerebral infarction was 0.896 [0.866 ∼ 0.927] (P < 0.001).. Serum Lp-PLA2 combined with MPO could be valued as a predictor of acute cerebral infarction caused by large artery atherosclerosis.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Arteries; Atherosclerosis; Biomarkers; Brain Ischemia; Cerebral Infarction; Humans; Peroxidase; Risk Factors; Stroke

During the COVID-19 pandemic, vaccination is the most important countermeasure. Pharmacovigilance concerns however emerged with very rare, but potentially disastrous thrombotic complications following vaccination with ChAdOx1. Platelet factor-4 antibody mediated vaccine-induced immune thrombotic thrombocytopenia (VITT) was described as an underlying mechanism of these thrombotic events. Recent work moreover suggests that mechanisms of immunothrombosis including neutrophil extracellular trap (NET) formation might be critical for thrombogenesis during VITT. In this study, we investigated blood and thrombus specimens of a female patient who suffered severe stroke due to VITT after vaccination with ChAdOx1 in comparison to 13 control stroke patients with similar clinical characteristics. We analyzed cerebral thrombi using histological examination, staining of complement factors, NET-markers, DNase and LL-37. In blood samples at the hyper-acute phase of stroke and 7 days later, we determined cell-free DNA, myeloperoxidase-histone complexes, DNase activity, myeloperoxidase activity, LL-37 and inflammatory cytokines. NET markers were identified in thrombi of all patients. Interestingly, the thrombus of the VITT-patient exclusively revealed complement factors and high amounts of DNase and LL-37. High DNase activity was also measured in blood, implying a disturbed NET-regulation. Furthermore, serum of the VITT-patient inhibited reactive oxygen species-dependent NET-release by phorbol-myristate-acetate to a lesser degree compared to controls, indicating either less efficient NET-inhibition or enhanced NET-induction in the blood of the VITT-patient. Additionally, the changes in specific cytokines over time were emphasized in the VITT-patient as well. In conclusion, insufficient resolution of NETs, e.g. by endogenous DNases or protection of NETs against degradation by embedded factors like the antimicrobial peptide LL-37 might thus be an important factor in the pathology of VITT besides increased NET-formation. On the basis of these findings, we discuss the potential implications of the mechanisms of disturbed NETs-degradation for diagnostic and therapeutic approaches in VITT-related thrombogenesis, other auto-immune disorders and beyond.

Topics: COVID-19; Deoxyribonuclease I; Deoxyribonucleases; Extracellular Traps; Female; Humans; Neutrophils; Pandemics; Peroxidase; Platelet Factor 4; Purpura, Thrombocytopenic, Idiopathic; Stroke; Thrombocytopenia; Thrombosis; Vaccines

Stroke is the second leading cause of death worldwide. Patients who have a stroke are susceptible to many gastrointestinal (GI) complications, such as dysphagia, GI bleeding, and fecal incontinence. However, there are few studies focusing on the GI tract after stroke. The current study is to investigate the changes of intestinal structure and function in mice after ischemic stroke. Ischemic stroke was made as a disease model in mice, in which brain and ileal tissues were collected for experiments on the 1

Topics: Actins; Animals; Apoptosis; Blotting, Western; Claudin-1; Inflammation; Intestines; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Neuroglia; Occludin; Peroxidase; Stroke; Zonula Occludens-1 Protein

Dysregulation of the oxidant-antioxidant system contributes to the pathogenesis of cerebral stroke (CS). Epigenetic changes of redox homeostasis genes, such as glutamate-cysteine ligase (GCLM), glutathione-S-transferase-P1 (GSTP1), thioredoxin reductase 1 (TXNRD1), and myeloperoxidase (MPO), may be biomarkers of CS. In this study, we assessed the association of DNA methylation levels of these genes with CS and clinical features of CS. We quantitatively analyzed DNA methylation patterns in the promoter or regulatory regions of 4 genes (GCLM, GSTP1, TXNRD1, and MPO) in peripheral blood leukocytes of 59 patients with CS in the acute phase and in 83 relatively healthy individuals (controls) without cardiovascular and cerebrovascular diseases. We found that in both groups, the methylation level of CpG sites in genes TXNRD1 and GSTP1 was ≤ 5%. Lower methylation levels were registered at a CpG site (chr1:94,374,293, GRCh37 [hg19]) in GCLM in patients with ischemic stroke compared with the control group (9% [7%; 11.6%] (median and interquartile range) versus 14.7% [10.4%; 23%], respectively, p < 0.05). In the leukocytes of patients with CS, the methylation level of CpG sites in the analyzed region of MPO (chr17:56,356,470, GRCh3 [hg19]) on average was significantly lower (23.5% [19.3%; 26.7%]) than that in the control group (35.6% [30.4%; 42.6%], p < 0.05). We also found increased methylation of MPO in smokers with CS (27.2% [23.5%; 31.1%]) compared with nonsmokers with CS (21.7% [18.1%; 24.8%]). Thus, hypomethylation of CpG sites in GCLM and MPO in blood leukocytes is associated with CS in the acute phase.

Topics: Biomarkers; DNA Methylation; Female; Glutamate-Cysteine Ligase; Glutathione S-Transferase pi; Humans; Leukocytes; Male; Middle Aged; Peroxidase; Smoking; Stroke; Thioredoxin Reductase 1

Because of their prothrombotic and neuroinflammatory effects, neutrophils and neutrophil extracellular traps (NETs) represent interesting therapeutic targets for spontaneous intracerebral haemorrhage (sICH). We investigated the presence, spatial and temporal distribution of NETs in a human sICH post-mortem study.. From 2005 to 2019, all sICH patients who came to autopsy within the first month after stroke were included and grouped according to the timing of death: 72 h, 4-7 days, 8-15 days and >15 days after ICH onset. Paraffin-embedded tissue was extracted from four strategic areas: haematoma, peri-haematomal area, ipsilateral surrounding brain tissue and a control contralateral area. Myeloperoxidase and histone H3 citrulline were immunolabelled to detect neutrophils and NETs respectively.. Neutrophils were present in the brains of the 14 cases (4 men, median age: 78 years) and NETs were found in 7/14 cases. Both neutrophils and NETs were detected within the haematoma but also in the surrounding tissue. The appearance of neutrophils and NETs was time-dependent, following a two-wave pattern: during the first 72 h and between 8 and 15 days after ICH onset. Qualitative examination showed that neutrophils and NETs were mainly located around dense fibrin fibres within the haematoma.. These observations provide evidence for NETs infiltration in the brain of patients who die from sICH. NETs might interact with early haemostasis within the haematoma core, and with the surrounding neuroinflammatory response. These findings open research perspectives for NETs in the treatment of sICH injuries.

Topics: Brain; Cerebral Hemorrhage; Extracellular Traps; Hematoma; Humans; Neutrophils; Peroxidase; Stroke

In acute cerebral ischemia, circulating neutrophil count and neutrophil-to-lymphocyte ratio (NLR) are positively associated with stroke severity and worse outcomes. Mediators of this effect are unknown. We aimed to investigate (1) the relationship between plasma matrix metalloproteinase-9 (MMP-9) and myeloperoxidase (MPO) concentrations with stroke severity and outcome and (2) MMP-9 and MPO release after ex vivo stimulation of neutrophils by recombinant tissue plasminogen activator (rtPA).. We analyzed data collected in 255 patients with supratentorial cerebral infarcts recruited within 48 hours of symptoms onset irrespective of rtPA treatment. The endpoints were excellent outcome (modified Rankin Scale score 0-1), symptomatic intracerebral hemorrhage (European Cooperative Acute Stroke Study-II definition), and death at 3 months. The role of rtPA treatment on peripheral neutrophil degranulation was investigated in 18 patients within 4.5 hours and after 72 hours.. Neutrophil counts, NLR, and MPO plasma concentrations, but not MMP-9, were positively correlated with stroke severity. Higher neutrophil counts and NLR were independently associated with worse outcomes and higher mortality rates at month 3. Higher MPO plasma concentrations, but not MMP-9, were associated with worse outcome. Neutrophil-derived MMP-9, after ex vivo rtPA stimulation, but not MPO, were higher after 72 hours in patients treated by IV rtPA but not associated with hemorrhagic transformation.. Neutrophil counts, NLR, and MPO plasma concentrations are associated with worse outcome in patients with acute cerebral ischemia, in contrast to MMP-9. Further investigations are needed to deepen our knowledge on MPO's role in the deleterious effect of neutrophils because it could represent a potential therapeutic target.

Topics: Aged; Biomarkers; Cohort Studies; Female; Humans; Lymphocyte Count; Male; Matrix Metalloproteinase 9; Middle Aged; Neutrophils; Peroxidase; Recovery of Function; Stroke

Myeloperoxidase (MPO) is an important oxidative enzyme participating in different stages of cardiovascular disease and predicts prognosis. Little is known about its role in acute cerebrovascular events and carotid plaque vulnerability. In this study, the aim was to assess plasma MPO levels in acute stroke patients and their correlation to stroke severity and stroke outcome.. Plasma MPO levels were assessed in patients presenting with acute brain ischaemia within 36 h of symptom onset (n = 144, mean age 64.7 ± 11.6 years, 67% men) and in patients with moderate-to-severe carotid stenosis undergoing carotid artery stenting (n = 51, mean age 66.3 ± 8.4 years, 75% men). Patients presenting with acute brain ischaemia were assessed serially for stroke severity and disability.. Plasma MPO concentrations (ng/ml) were associated with interleukin-6 (r = 0.38, P < 0.0001) and gender (median interquartile range) of 68.6 (49.8-107.0) vs. 59.7 (42.7-85.5) in women vs. men (P = 0.02). In acute brain ischaemia, MPO concentrations were associated with non-lacunar subtype (bottom, middle and top tertiles 37.5%, 71.7% and 71.7% respectively; P = 0.001), with stroke severity (baseline National Institutes of Health Stroke Scale score > 10, bottom, middle and top tertiles 6.3%, vs. 41.7% and 31.3%, respectively; P < 0.006) as well as with stroke severity at days 1-2, days 4-5 and at discharge (P < 0.05 for all), but less with disability at discharge (modified Rankin Scale score ≥ 2, 41.7% vs. 60.4% and 58.7% for the bottom, middle and top tertiles, respectively; P = 0.096).. Amongst patients with acute brain ischaemia, plasma MPO concentrations were associated with stroke severity and non-lacunar subtype, but not with long-term functional disability.

Topics: Aged; Brain Ischemia; Carotid Stenosis; Female; Humans; Male; Middle Aged; Peroxidase; Plasma; Stroke; Treatment Outcome

Stroke is devastating with a limited choice of intervention. Many pharmacological entities are available but none of them have evolved successfully in counteracting the multifaceted molecular alterations following stroke. Myeloperoxidase (MPO) has been reported to play an important role in neuroinflammation following neurodegenerative diseases. Therefore, using it as a therapeutic target may be a strategy to confer neuroprotection in stroke. Trigonelline (TG), a plant alkaloid has shown neuroprotective effects in the past. Here we explore its neuroprotective effects and its role in glutathione mediated MPO inhibition in ischemic stroke.. An in silico study was performed to confirm effective TG and MPO interaction. An in vitro evaluation of toxicity with biochemical estimations was performed. Further, in vivo studies were undertaken where rats were treated with 25, 50 and 100 mg/kg TG or standard MPO inhibiting drug4‑Aminobenzoic hydrazide (4‑ABH) at 60 min prior, post immediate and an hour post 90 min of middle cerebral artery occlusion (MCAo) followed by 24 h reperfusion. Rats were evaluated for neurodeficit and motor function tests. Brains were further harvested for infarct size evaluation, biochemical analysis, and western blot experiments.. TG at 100 mg/kg dose i.p. administered immediately post ischemia confers neuroprotection by reducing cerebral infarct with improvement in motor and neurodeficit scores. Furthermore, elevated nitrite and MDA levels were also found to be reduced in brain regions in the treated group. TG also potentiated intrinsic antioxidant status and markedly inhibited reduced glutathione mediated myeloperoxidase expression in the cortical brain region.. TG confers neuroprotection by reduced glutathione mediated myeloperoxidase inhibition in ischemic stroke.

Topics: Alkaloids; Aniline Compounds; Animals; Antioxidants; Blotting, Western; Brain Ischemia; Cerebral Infarction; Disease Models, Animal; Dose-Response Relationship, Drug; Glutathione; Male; Neuroprotective Agents; Peroxidase; Rats; Rats, Sprague-Dawley; Stroke

Topics: Antibodies; Antibodies, Antineutrophil Cytoplasmic; Brain; Disease Progression; Dysarthria; Eosinophilia; Facial Paralysis; Fatal Outcome; Humans; Hypesthesia; Magnetic Resonance Imaging; Male; Microscopic Polyangiitis; Middle Aged; Muscle Weakness; Peroxidase; Proteinuria; Smokers; Stroke

High-density lipoprotein (HDL) has important anti-atherogenic functions, including antioxidant effects. However, it is unclear whether the antioxidative activity of HDL is associated with the severity and outcome of acute ischemic stroke. We aimed to evaluate this association.. We prospectively studied 199 consecutive patients admitted with acute ischemic stroke and followed them up until discharge. We measured HDL antioxidant capacity, HDL-associated paraoxonase-1 (PON1) activity and HDL-associated myeloperoxidase (MPO) levels. Severe stroke was defined as National Institutes of Health Stroke Scale (NIHSS) at admission ≥5. Dependency was defined as modified Rankin scale at discharge between 2 and 5.. Patients with severe stroke had lower HDL antioxidant capacity, higher MPO levels and higher MPO/PON1 ratio. Independent risk factors for severe stroke were female gender (RR 2.80, 95% CI 1.37-5.70, p = 0.005), glucose levels (RR 1.01, 95% CI 1.0-1.02, p < 0.01) and HDL antioxidant capacity (RR 1.03, 95% CI 1.01-1.06, p < 0.05). Patients who were dependent at discharge had lower HDL antioxidant capacity, higher MPO levels and higher MPO/PON1 ratio. Independent predictors of dependency at discharge were lack of lipid-lowering treatment (RR 6.86, 95% CI 1.83-25.67, p < 0.005) and NIHSS (RR 1.56, 95% CI 1.29-1.88, p < 0.0001). The HDL antioxidant capacity did not differ between patients who died during hospitalization and those who were discharged. The only independent predictor of in-hospital mortality was NIHSS (RR 1.16, 95% CI 1.06-1.27, p < 0.005).. Impaired antioxidative activity of HDL is associated with more severe acute ischemic stroke and might also predict a worse functional outcome in these patients.

Topics: Aged; Aged, 80 and over; Antioxidants; Aryldialkylphosphatase; Blood Glucose; Brain Ischemia; Female; Hospital Mortality; Humans; Lipoproteins, HDL; Male; Middle Aged; Peroxidase; Predictive Value of Tests; Prospective Studies; Risk Factors; Sex Factors; Stroke; Treatment Outcome

Recent studies suggest that myeloperoxidase (MPO)-dependent oxidative stress plays a significant role in brain injury in stroke patients. We previously showed that

Topics: Animals; Apoptosis; Brain; Cell Differentiation; Cell Proliferation; Disease Models, Animal; Enzyme Inhibitors; Male; Mice; Mice, Inbred C57BL; Microglia; Neural Stem Cells; Neurons; Neutrophils; Oligopeptides; Oxidative Stress; Peroxidase; Stroke; Wnt Signaling Pathway

Matrix metalloproteinase (MMP)-8 and myeloperoxidase (MPO) may contribute to cerebral damage in acute ischemic stroke. We tested the hypothesis that levels of MPO, MMP-8 and the ratio between MMP-8 and its regulator, tissue inhibitor of metalloproteinase (TIMP-1), are increased in acute ischemic stroke and its etiologic subgroups and they correlate with stroke severity.. In a cross-sectional case-control study, serum concentrations of MMP-8, MPO and TIMP-1 were assessed within 24 h after admission in 470 first-ever ischemic stroke patients and 809 age- and sex-matched controls, randomly selected from the population. Odds ratios (OR) per decade of log transformed dependent variables were calculated and adjusted for age, sex and vascular risk factors.. Levels of MMP-8 (OR 4.9; 95% CI 3.4-7.2), MMP-8/TIMP-1 ratio (3.0; 2.2-4.1) and MPO (6.6; 4.0-11.0) were independently associated with ischemic stroke. MMP-8 levels differed between etiologic stroke subgroups (p = 0.019, ANOVA), with higher levels in cardioembolic stroke and stroke due to large vessel disease, and lower levels in microangiopathic stroke. MMP-8, MMP-8/TIMP-1 ratio and MPO (p < 0.001) concentrations showed positive associations with stroke severity independent of stroke etiology.. Concentrations of serum neutrophil markers are increased after ischemic stroke and associate with stroke severity and etiology. The value of these biomarkers in diagnostics and prognostics is worth being evaluated.

Topics: Aged; Biomarkers; Brain Ischemia; Case-Control Studies; Cross-Sectional Studies; Female; Humans; Inflammation Mediators; Male; Matrix Metalloproteinase 8; Middle Aged; Neutrophils; Peroxidase; Severity of Illness Index; Stroke; Time Factors; Tissue Inhibitor of Metalloproteinase-1; Up-Regulation

Stroke induces immune alterations such as impaired oxidative burst and reduced release of neutrophil extracellular traps (NETs). We hypothesised that key enzymes of these defence mechanisms may be altered in ischaemic stroke. Therefore, we analysed the intra- and extracellular amounts of myeloperoxidase (MPO) and neutrophil elastase (NE) in patient sera and granulocytes and monocytes. Because the autonomous nervous system is thought to mediate stroke-induced immune alterations, we also studied the influence of stress hormones and acetylcholine on MPO and NE. Rapid recanalization by recombinant tissue plasminogen activator (r-tPA) is the only available treatment for ischaemic stroke besides thrombectomy, and its influence on antibacterial defence mechanisms of granulocytes and monocytes were addressed here.. Ex vivo: Intracellular and serum MPO and NE were measured on days 0, 1, 3 and 5 post-stroke by either flow cytometry or enzyme-linked immunosorbent assay (ELISA) and compared to controls. In vitro: Blood from healthy donors was incubated with catecholamines, dexamethasone and acetylcholine, and the percentage of NET-producing cells and the area covered by NETs were quantified immunohistochemically. Intra- and extracellular MPO and NE were quantified by flow cytometry or ELISA. Blood samples from healthy donors were incubated with r-tPA, and oxidative burst, phagocytosis, NETosis, cytokine release, MPO and NE were quantified by flow cytometry, ELISA and microscopy.. MPO was reduced in granulocytes but increased in sera obtained from stroke patients compared to controls. NE was not altered intracellularly but was elevated in patient sera. The percentage of NET-producing neutrophils was decreased by stress hormones and increased by acetylcholine. Neither intracellular MPO nor NE was altered by hormone treatment; however, adrenaline and acetylcholine induced NE release. r-tPA led to reduced phagocytosis and oxidative burst in granulocytes and monocytes in vitro. NETosis, MPO release and cytokines were not altered, whereas NE release was enhanced by r-tPA.. Intracellular reduction of MPO might be responsible for reduced NETosis in stroke patients. The impact of enhanced MPO and NE serum levels in stroke patients should be addressed in future studies. r-tPA impaired antibacterial defence function in vitro. Therefore, patients who undergo unsuccessful recanalization therapy might be at higher risk for infection, which should be analysed in future investigations. Immune alterations due to r-tPA effects in stroke patients should also be investigated.

Topics: Acetylcholine; Aged; Aged, 80 and over; Anti-Bacterial Agents; Antigens, CD; Brain Ischemia; Cytokines; Dose-Response Relationship, Drug; Extracellular Fluid; Extracellular Traps; Female; Granulocytes; Humans; Leukocyte Elastase; Male; Middle Aged; Neurotransmitter Agents; Peroxidase; Phagocytes; Stroke; Tissue Plasminogen Activator

Primary intracerebral haemorrhage and lacunar ischaemic stroke are acute manifestations of progressive cerebral microvascular disease. Current paradigms suggest atherosclerosis is a chronic, dynamic, inflammatory condition precipitated in response to endothelial injury from various environmental challenges. Myeloperoxidase plays a central role in initiation and progression of vascular inflammation, but prior studies linking myeloperoxidase with stroke risk have been inconclusive. We hypothesized that genetic determinants of myeloperoxidase levels influence the development of vascular instability, leading to increased primary intracerebral haemorrhage and lacunar stroke risk. We used a discovery cohort of 1409 primary intracerebral haemorrhage cases and 1624 controls from three studies, an extension cohort of 12 577 ischaemic stroke cases and 25 643 controls from NINDS-SiGN, and a validation cohort of 10 307 ischaemic stroke cases and 29 326 controls from METASTROKE Consortium with genome-wide genotyping to test this hypothesis. A genetic risk score reflecting elevated myeloperoxidase levels was constructed from 15 common single nucleotide polymorphisms identified from prior genome-wide studies of circulating myeloperoxidase levels (P < 5 × 10-6). This genetic risk score was used as the independent variable in multivariable regression models for association with primary intracerebral haemorrhage and ischaemic stroke subtypes. We used fixed effects meta-analyses to pool estimates across studies. We also used Cox regression models in a prospective cohort of 174 primary intracerebral haemorrhage survivors for association with intracerebral haemorrhage recurrence. We present effects of myeloperoxidase elevating single nucleotide polymorphisms on stroke risk per risk allele, corresponding to a one allele increase in the myeloperoxidase increasing genetic risk score. Genetic determinants of elevated circulating myeloperoxidase levels were associated with both primary intracerebral haemorrhage risk (odds ratio, 1.07, P = 0.04) and recurrent intracerebral haemorrhage risk (hazards ratio, 1.45, P = 0.006). In analysis of ischaemic stroke subtypes, the myeloperoxidase increasing genetic risk score was strongly associated with lacunar subtype only (odds ratio, 1.05, P = 0.0012). These results, demonstrating that common genetic variants that increase myeloperoxidase levels increase risk of primary intracerebral haemorrhage and lacunar stroke, directly implicate the my

Topics: Aged; Aged, 80 and over; Case-Control Studies; Cerebral Hemorrhage; Cohort Studies; Databases, Factual; Female; Genome-Wide Association Study; Humans; Male; Middle Aged; Peroxidase; Risk Factors; Statistics, Nonparametric; Stroke

To investigate the roles of the oxidative stress related-genes ALOX5, ALOX5AP and MPO in ischemic stroke susceptibility in the Han Chinese population.. A total of 351 ischemic stroke patients and 417 controls were recruited. The ALOX5 rs10900213, ALOX5AP rs4293222 and MPO rs2107545 gene polymorphisms were genotyped.. We identified that rs2107545 of MPO gene was significantly associated with ischemic stroke susceptibility after adjusting for covariates. Furthermore, we also considered the likely complexity of oxidative stress and inflammatory process in stroke by assessing the combined effects of multiple genes. Generalized multifactor dimensionality reduction (GMDR) analysis revealed that the combination of ALOX5 rs10900213, ALOX5AP rs4293222 and MPO rs2107545 was significantly associated with increased risk of ischemic stroke (P=0.0040, OR (95% CI) =1.991 (1.241 to 3.195)). Additionally, the MPO rs2107545 genotype was significantly associated with clinical outcomes at 6 months after discharge from the hospital.. Our study revealed that epistatic interaction among the ALOX5, ALOX5AP and MPO genes played a significant role in vulnerability to ischemic stroke. Furthermore, these results also suggest that the rs2107545 of MPO gene can be used as a biomarker for the susceptibility and prognosis of ischemic stroke patients.

Topics: 5-Lipoxygenase-Activating Proteins; Aged; Arachidonate 5-Lipoxygenase; Asian People; Brain Ischemia; Case-Control Studies; China; Female; Genotype; Humans; Male; Middle Aged; Oxidative Stress; Peroxidase; Polymorphism, Single Nucleotide; Stroke

Established risk factors do not fully identify patients at risk for recurrent stroke. The SPARCL trial (Stroke Prevention by Aggressive Reduction in Cholesterol Levels) evaluated the effect of atorvastatin on stroke risk in patients with a recent stroke or transient ischemic attack and no known coronary heart disease. This analysis explored the relationships between 13 plasma biomarkers assessed at trial enrollment and the occurrence of outcome strokes.. We conducted a case-cohort study of 2176 participants; 562 had outcome strokes and 1614 were selected randomly from those without outcome strokes. Time to stroke was evaluated by Cox proportional hazards models.. There was no association between time to stroke and lipoprotein-associated phospholipase A. Osteopontin, neopterin, and myeloperoxidase were independently associated with the risk of recurrent stroke and improved risk classification when added to a clinical risk algorithm.. URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00147602.

Topics: Aged; Anticholesteremic Agents; Biomarkers; Cohort Studies; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Ischemic Attack, Transient; Male; Middle Aged; Neopterin; Osteopontin; Peroxidase; Prognosis; Recurrence; Risk Factors; ROC Curve; Stroke

Cyclosporine A (CsA) is known as a neuroprotective agent against cerebral ischemia/reperfusion (I/R) in animal models. However, the significant therapeutic effects of CsA have been observed in high systemic doses or manipulating the blood-brain barrier, resulting in systemic side effects and toxicity. As the liposome nanocarriers have been developed for efficient delivery of peptide and proteins, liposomal CsA (Lipo-CsA) could improve cerebral (I/R) injuries. In this study, the liposomal CsA formulation (CsA at dose of 2.5 mg/kg) was prepared to assess the brain injury outcomes in 90 min middle cerebral artery occlusion (MCAO) stroke model followed by 48 h reperfusion in treating rats. Five minutes after induction of cerebral ischemia in rats, intravenous (iv) administration of Lipo-CsA significantly (P < 0.001) recovered the infarct size, the brain edema, and the neurological activities compared to corresponding control groups following 48 h I/R. In addition, after 48 h cerebral I/R, Lipo-CsA potentially (P < 0.001) inhibited the inflammation responses including MPO activity and tumor necrosis factor-alpha level in comparison to other groups. In conclusion, the results indicate that the low dose of CsA in liposomal formulation is more effective compared to higher dose of free form of CsA in treatment of ischemic brain in rats.

Topics: Animals; Brain Ischemia; Cyclosporine; Disease Models, Animal; Infarction, Middle Cerebral Artery; Inflammation; Liposomes; Male; Nanoparticles; Neuroprotective Agents; Peroxidase; Rats; Rats, Wistar; Reperfusion Injury; Stroke; Time Factors; Tumor Necrosis Factor-alpha

Atherosclerosis (AS) is the primary pathological result of obesity. Vulnerable AS plaques cause fatal clinical end points such as myocardial infarction and stroke. To prevent this, improvements in early diagnosis and treatment are essential. Because vulnerable AS plaques are frequently nonstenotic, they are preclinically undetectable using conventional imaging. Levels of blood lipids, C-reactive protein, and interleukin-6 are increased, but are insufficient to indicate the process of critical perpetuation before the end points present. More specific biomarkers (e.g. troponin, copetin, natriuretic peptides, growth differentiation factor-15, or soluble ST2) indicate the acute coronary syndrome or cardiac insufficiency, but not a critical destabilization of AS lesions in coronary or carotid arteries. Thus, valuable time (months to years) that could be used to treat the patient is wasted. An improved management of this dilemma may involve better detection of variations in degrees of immune inflammation in plaques by using new biomarkers in blood and/or within the lesion (molecular imaging). Macrophage and T-cell polarization, and innate and adaptive immune responses (e.g. Toll-like receptors) are involved in this critical process. New biomarkers in these mechanisms include pentraxin 3, calprotectins S100A8/S100A9, myeloperoxidase, adiponectin, interleukins, and chemokines. These proteins may also be candidates for molecular imaging using nuclear (magnetic resonance) imaging tools. Nevertheless, the main challenge remains: which asymptomatic individual should be screened? At which time interval? Intense interdisciplinary research in laboratory medicine (biomarkers), nanomedicine (nanoparticle development), and radiology (molecular imaging) will hopefully address these questions.

Topics: Adiponectin; Atherosclerosis; Biomarkers; C-Reactive Protein; Cholesterol; Cytokines; Humans; Inflammation; Inflammation Mediators; Leukocyte L1 Antigen Complex; Myocardial Infarction; Peroxidase; Risk Factors; Serum Amyloid P-Component; Stroke

According to literature, the inflammatory response and platelets are associated with coronary heart disease mortality. In this study, we examine if similar relationships exist after acute cerebral infarctions.. Between 2005 and 2007, individuals (n = 61) hospitalized with acute stroke were investigated 2.1 ± .3 (SD) days after hospital admission. After 9.3 ± .7 (SD) years, 29 patients (age 79 ± 8 [SD]; 12 women) had died. They were compared with survivors (age 69 ± 9 [SD]; 9 women) with respect to inflammatory parameters and platelet features such as activity and reactivity.. Inflammation and platelets at the acute event do not forecast long-term survival of stroke sufferers.

Topics: Aged; Aged, 80 and over; Blood Platelets; C-Reactive Protein; Cytokines; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation; Male; Middle Aged; Neutrophils; Peroxidase; Retrospective Studies; Stroke

Cerebral ischemia is a common disease and one of the most common causes of death and disability worldwide. The lack of glucose and oxygen in neuronal tissue leads to a series of inflammatory events, culminating in neuronal death. Eriodictyol is a flavonoid isolated from the Chinese herb Dracocephalum rupestre that has been proven to have anti-inflammatory properties.. Thus, the present study was designed to explore whether eriodictyol has neuroprotective effects against the neuronal damage, motor and memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) in mice.. Animals were orally treated with eriodictyol (1, 2 and 4mg/kg) or vehicle (saline) 30min before pMCAO, 2h after, and then once daily for the following five days.. The parameters studied were neuronal viability, brain infarcted area; sensorimotor deficits; exploratory activity; working and aversive memory; myeloperoxidase (MPO) activity; TNFα, iNOS and GFAP immunoreactivity.. The treatment with eriodictyol prevented neuronal death, reduced infarct area and improved neurological and memory deficits induced by brain ischemia. The increase of MPO activity and TNF-α, iNOS and GFAP expression were also reduced by eriodictyol treatment.. These findings demonstrate that eriodictyol exhibit promising neuroprotection effects against the permanent focal ischemia cerebral injury in the mice experimental model and the underlying mechanisms might be mediated through inhibition of neuroinflammation.

Topics: Animals; Astrocytes; Brain; Brain Ischemia; Cell Survival; Disease Models, Animal; Encephalitis; Exploratory Behavior; Flavanones; Locomotion; Male; Memory, Short-Term; Mice; Neurons; Neuroprotective Agents; Nitric Oxide Synthase Type II; Peroxidase; Stroke; Tumor Necrosis Factor-alpha

Among children with arterial ischemic stroke (AIS), those with arteriopathy have the highest recurrence risk. We hypothesized that arteriopathy progression is an inflammatory process and that inflammatory biomarkers would predict recurrent AIS.. In an international study of childhood AIS, we selected cases classified into 1 of the 3 most common childhood AIS causes: definite arteriopathic (n=103), cardioembolic (n=55), or idiopathic (n=78). We measured serum concentrations of high-sensitivity C-reactive protein, serum amyloid A, myeloperoxidase, and tumor necrosis factor-α. We used linear regression to compare analyte concentrations across the subtypes and Cox proportional hazards models to determine predictors of recurrent AIS.. Median age at index stroke was 8.2 years (interquartile range, 3.6-14.3); serum samples were collected at median 5.5 days post stroke (interquartile range, 3-10 days). In adjusted models (including age, infarct volume, and time to sample collection) with idiopathic as the reference, the cardioembolic (but not arteriopathic) group had higher concentrations of high-sensitivity C-reactive protein and myeloperoxidase, whereas both cardioembolic and arteriopathic groups had higher serum amyloid A. In the arteriopathic (but not cardioembolic) group, higher high-sensitivity C-reactive protein and serum amyloid A predicted recurrent AIS. Children with progressive arteriopathies on follow-up imaging had higher recurrence rates, and a trend toward higher high-sensitivity C-reactive protein and serum amyloid A, compared with children with stable or improved arteriopathies.. Among children with AIS, specific inflammatory biomarkers correlate with cause and-in the arteriopathy group-risk of stroke recurrence. Interventions targeting inflammation should be considered for pediatric secondary stroke prevention trials.

Topics: Adolescent; Biomarkers; Brain Ischemia; C-Reactive Protein; Cerebral Arterial Diseases; Child; Child, Preschool; Female; Humans; Male; Peroxidase; Recurrence; Risk Factors; Serum Amyloid A Protein; Stroke; Tumor Necrosis Factor-alpha

The relationship between inflammation and neurogenesis in stroke is currently not well understood. Focal ischemia enhances cell proliferation and neurogenesis in the neurogenic regions, including the subventricular zone (SVZ), dentate gyrus, as well as the non-neurogenic striatum, and cortex in the ischemic hemisphere. Myeloperoxidase (MPO) is a potent oxidizing enzyme secreted during inflammation by activated leukocytes, and its enzymatic activity is highly elevated after stroke. In this study, we investigated whether the inhibition of MPO activity by a specific irreversible inhibitor, 4-aminobenzoic acid hydrazide (ABAH) (MPO

Topics: 4-Aminobenzoic Acid; Acetylation; Animals; Brain-Derived Neurotrophic Factor; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; DNA-Binding Proteins; Enzyme Inhibitors; Histones; Infarction, Middle Cerebral Artery; Lateral Ventricles; Male; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Neostriatum; Nerve Tissue Proteins; Neurogenesis; Nuclear Proteins; Peroxidase; Receptors, CXCR4; Recovery of Function; Stroke

HDL-cholesterol concentration is a reliable negative risk factor for acute cerebral infarction (ACI). Beyond quantitative aspects, our aim was to determine whether lipoprotein profiles and HDL functionality were altered at the acute phase of ischemic stroke.. Blood was taken from ACI patients within 4.5 h of symptom onset. Lipoproteins were separated by electrophoresis for determination of particle size. HDLs were isolated from plasma of patients (n = 10) and controls (n = 10) by ultracentrifugation. The relative amounts of paraoxonase 1 (PON1), α1antitrypsin (AAT) and myeloperoxidase (MPO) were determined by Western blot. HDL functional assays were performed on human-brain endothelial cells stimulated with TNFα.. Stroke patients had higher proportion of large HDL particles relative to controls (37.8 ± 11.8 vs. 28.4 ± 6.6, p = 0.04). HDLs from patients contained significantly less ApoA1 (1.63 ± 0.42 vs. 2.54 ± 0.71 mg/mL, p = 0.0026) and PON1 (4598 ± 1921 vs. 6598 ± 1127 AU, p = 0.01) than those from controls, whereas MPO and AAT were more abundant in HDLs isolated from ACI patients (respectively 3657 ± 1457 vs. 2012 ± 1234 and 3347 ± 917 vs. 2472 ± 470 AU, p = 0.014 and p = 0.015). HDLs reduced the expression of VCAM1, MCP1 and MMP3 mRNA induced by TNFα in blood-brain barrier endothelial cells. HDLs from patients were less effective in inhibiting TNFα-induced transcription of these genes (respectively 38.6 vs. 55.6% for VCAM1, p = 0.047, 44 vs. 48.1% for MCP1, p = 0.015 and 70 vs. 74% for MMP3, p = 0.024).. ACI may be associated with a modified distribution of HDL particles (increased proportion of large particles) and HDL-binding proteins, resulting in an inappropriate protection of endothelial cells under ischemic conditions.

Topics: Adult; Aged; Aged, 80 and over; alpha 1-Antitrypsin; Apolipoprotein A-I; Aryldialkylphosphatase; Brain Infarction; Brain Ischemia; Case-Control Studies; Electrophoresis; Endothelium, Vascular; Female; Humans; Inflammation; Lipoproteins, HDL; Male; Middle Aged; Particle Size; Peroxidase; RNA, Messenger; Stroke; Tumor Necrosis Factor-alpha

Few effective treatment options exist for stroke beyond the hyperacute period. Radical generation and myeloperoxidase (MPO) have been implicated in stroke. We investigated whether pharmacologic reduction or gene deletion of this highly oxidative enzyme reduces infarct propagation and improves outcome in the transient middle cerebral artery occlusion mouse model (MCAO). Mice were treated with 4-aminobenzoic acid hydrazide (ABAH), a specific irreversible MPO inhibitor. Three treatment regimens were used: (1) daily throughout the 21-day observational period, (2) during the acute stage (first 24 hours), or (3) during the subacute stage (daily starting on day 2). We found elevated MPO activity in ipsilateral brain 3 to 21 days after ischemia. 4-Aminobenzoic acid hydrazide reduced enzyme activity by 30% to 40% and final lesion volume by 60% (P<0.01). The MPO-knockout (KO) mice subjected to MCAO also showed a similar reduction in the final lesion volume (P<0.01). The ABAH treatment or MPO-KO mice also improved neurobehavioral outcome (P<0.001) and survival (P=0.01), but ABAH had no additional beneficial effects in MPO-KO mice, confirming specificity of ABAH. Interestingly, inhibiting MPO activity during the subacute stage recapitulated most of the therapeutic benefit of continuous MPO inhibition, suggesting that MPO-targeted therapies could be useful when given after 24 hours of stroke onset.

Topics: Animals; Brain; Disease Models, Animal; Enzyme Inhibitors; Magnetic Resonance Imaging; Mice; Mice, Inbred C57BL; Mice, Knockout; Peroxidase; Stroke

To develop an economic model to estimate the change in the number of events and costs of non-fatal myocardial infarction (MI) and non-fatal ischemic stroke (IS) as a result of implementing routine risk-stratification with a multiple inflammatory biomarker approach.. Reductions in the numbers of non-fatal MI and non-fatal IS events and in related per-member-per-month (PMPM) and 5-year costs (excluding test costs) due to biomarker testing were modeled for a US health plan with one million beneficiaries. Inputs for the model included literature-based MI and IS incidence rates, healthcare costs associated with MI and IS, laboratory results of biomarker testing, MI and IS hazard ratios related to biomarker levels, patient monitoring and intervention costs and use/costs of preventative pharmacotherapy. Preventative pharmacotherapy inputs were based on an analysis of pharmacy claims data. Costs savings (2013 USD) were assessed for patients undergoing biomarker testing compared to the standard of care. Data from MDVIP and Cleveland Heart Lab supported two critical inputs: (1) treatment success rates and (2) the population distribution of biomarker testing. Incidence rates, hazard ratios, and other healthcare costs were obtained from the literature.. For a health plan with one million members, an estimated 21,104 MI and 22,589 IS events occurred in a 5-year period. Routine biomarker testing among a sub-group of beneficiaries ≥35 years old reduced non-fatal MI and IS events by 2039 and 1869, respectively, yielding cost savings of over $187 million over 5 years ($3.13 PMPM), excluding test costs. Results were sensitive to changes in treatment response rates. Nonetheless, cost savings were observed for all input values.. This study suggests that health plans can realize substantial cost savings by preventing non-fatal MI and IS events after implementation of routine biomarker testing. Five-year cost savings before test costs could exceed $3.13 PMPM.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Adult; Age Factors; Aged; Aged, 80 and over; Biomarkers; C-Reactive Protein; Cardiovascular Agents; Cardiovascular Diseases; Costs and Cost Analysis; Female; Hematologic Tests; Humans; Insurance Claim Review; Male; Middle Aged; Models, Econometric; Myocardial Infarction; Peroxidase; Risk Assessment; Risk Factors; Stroke; United States

To investigate the effect of neurogenic neuroprotection conferred by cerebellar fastigial nucleus stimulation (FNS) and the role of PPARγ-mediated inflammation in a rat model of cerebral ischemia reperfusion.. After a continuous 1 hour fastigial nucleus electric stimulation, the male Sprague Dawley (SD) rats were given middle cerebral artery occlusion (MCAO) for 1, 3, 6, 9, 12 and 15 hours undergoing reperfusion with intravenous recombinant tissue plasminogen activator (rt-PA), while the control group received without FNS. After 72 h of reperfusion, the neurological deficits, infarct volume and brain edema were evaluated. The brain tissue in ischemic penumbra was determined the myeloperoxidase (MPO) activity by a spectrophotometer and expression of PPARγ was measured by Rt-PCR and Western blotting.. Our findings showed that FNS group had significantly reduced infarct volume and brain edema, and improved neurological deficits compared with the control group, especially in 6 h and 9 h reperfusion subgroups (p<0.05). The expression levels of PPARγ increased gradually and the peak may be before and after 9 h reperfusion, the 3 h, 6 h, 9 h, 12 h and 15 h reperfusion subgroups were higher than each control group (p<0.05). The MPO activity of 6 h, 12 h and 15 h reperfusion subgroups were higher than each control group (p<0.05).. The neuroprotective effects of FNS have been shown to prolong the therapeutic window in cerebral ischemia/reperfusion, which might be related to the PPARγ mediated-inflammation in penumbral region.

Topics: Animals; Brain; Brain Edema; Brain Ischemia; Cerebellar Nuclei; Electric Stimulation; Fibrinolysis; Fibrinolytic Agents; Infarction, Middle Cerebral Artery; Inflammation; Male; Neuroprotective Agents; Peroxidase; PPAR gamma; Rats; Rats, Sprague-Dawley; Reperfusion; Stroke; Tissue Plasminogen Activator

The aim of this study was to examine the level of myeloperoxidase (MPO) measured before specific treatment in patients presenting to the Emergency Department with acute ischemic stroke and its correlation to mortality and the severity of the stroke.. The study was carried out on 55 patients with a confirmed diagnosis of ischemic stroke, and on 44 healthy control group. Before specific intervention, serum samples were taken to measure levels of MPO. The medical records, demographic, clinical, laboratory and neuro-imaging data were noted.  The National Institutes of Health Stroke Scale was used to determine the severity of the stroke.. A total of 55 patients, of whom 32 (58.2%) were male, who had presented within 24 hours of the onset of symptoms of acute ischemic stroke were included in the study. Fifteen of these patients (27.2%), of whom five were women, died. There was a statistically significant difference in the serum MPO levels of patients who survived and those who died. When the patients were grouped as high or normal in terms of plasma MPO levels, a significant correlation was found between MPO level, cortical + subcortical stroke location and strokes with a lesion diameter of more than 4 cm. In the high MPO group, Troponin T and CRP levels were significantly higher than those of the normal MPO group.. The level of myeloperoxidase in the serum of acute ischemic stroke patients rises and there is a correlation between myeloperoxidase level and prognosis.

Topics: Acute Disease; Aged; Case-Control Studies; Female; Humans; Male; Middle Aged; Peroxidase; Prognosis; Stroke; Troponin T

Periodontitis is a common infectious disease associated with increased risk for ischemic stroke though presently unclear mechanisms. In a case-control study, we investigated salivary levels of four periodontal pathogens, as well as systemic and local inflammatory markers. The population comprised 98 patients with acute ischemic stroke (mean ± SD, 68.2 ± 9.7 yrs; 45.9% women) and 100 healthy controls (69.1 ± 5.2 yrs; 47.0% women). Patients were more often edentulous and had fewer teeth than controls (13.8 ± 10.8 versus 16.6 ± 10.1). After adjusting for stroke risk factors and number of teeth, controls had higher saliva matrix metalloproteinase-8 (MMP-8), myeloperoxidase (MPO), IL-1β, Aggregatibacter actinomycetemcomitans, and serum LPS activity levels. Patients had higher serum MMP-8 and MPO, and they were more often qPCR-positive for A. actinomycetemcomitans (37.9% versus 19.0%) and for ≥3 periodontopathic species combined (50.0% versus 33.0%). We conclude that controls more often had evidence of current periodontal infection with higher periodontal pathogen amount, endotoxemia, local inflammation and tissue destruction. Stroke patients more often had evidence of end-stage periodontitis with edentulism and missing teeth. They were more often carriers of several periodontopathic pathogens in saliva, especially A. actinomycetemcomitans. Additionally, inflammatory burden may contribute to high systemic inflammation associated with elevated stroke susceptibility.

Topics: Aged; Aggregatibacter actinomycetemcomitans; Biomarkers; Brain Ischemia; Case-Control Studies; Female; Humans; Inflammation; Interleukin-1beta; Male; Matrix Metalloproteinase 8; Mouth, Edentulous; Periodontitis; Peroxidase; Porphyromonas gingivalis; Risk Factors; Saliva; Stroke

Evidence indicates that angiotensin II type 2 receptors (AT2R) exert cerebroprotective actions during stroke. A selective non-peptide AT2R agonist, Compound 21 (C21), has been shown to exert beneficial effects in models of cardiac and renal disease, as well as hemorrhagic stroke. Here, we hypothesize that C21 may exert beneficial effects against cerebral damage and neurological deficits produced by ischemic stroke. We determined the effects of central and peripheral administration of C21 on the cerebral damage and neurological deficits in rats elicited by endothelin-1 induced middle cerebral artery occlusion (MCAO), a model of cerebral ischemia. Rats infused centrally (intracerebroventricular) with C21 before endothelin-1 induced MCAO exhibited significant reductions in cerebral infarct size and the neurological deficits produced by cerebral ischemia. Similar cerebroprotection was obtained in rats injected systemically (intraperitoneal) with C21 either before or after endothelin-1 induced MCAO. The protective effects of C21 were reversed by central administration of an AT2R inhibitor, PD123319. While C21 did not alter cerebral blood flow at the doses used here, peripheral post-stroke administration of this agent significantly attenuated the MCAO-induced increases in inducible nitric oxide synthase, chemokine (C-C) motif ligand 2 and C-C chemokine receptor type 2 mRNAs in the cerebral cortex, indicating that the cerebroprotective action is associated with an anti-inflammatory effect. These results strengthen the view that AT2R agonists may have potential therapeutic value in ischemic stroke, and provide the first evidence of cerebroprotection induced by systemic post stroke administration of a selective AT2R agonist.

Topics: Angiotensin II Type 2 Receptor Blockers; Animals; Brain Infarction; Brain Ischemia; CD11b Antigen; Cerebrovascular Circulation; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Glial Fibrillary Acidic Protein; Imidazoles; Male; Nitric Oxide Synthase Type II; Peroxidase; Pyridines; Rats; Rats, Sprague-Dawley; Stroke; Sulfonamides; Thiophenes; Time Factors

A 73-year-old man was admitted to our hospital because of a decrease in spontaneity. His medical history included two stroke episodes, probably related to hypertension. Brain MRI on admission demonstrated acute infarction in the right caudate nucleus and left putamen. Intravenous infusion of a low molecular-weight heparin added to oral antiplatelets was started. Following admission, he developed a low grade fever and severe inflammatory reaction. The focus of infection was not evident, and none of the antibiotics tried were effective. Ten days after admission, he developed right hemiparesis, and an additional brain MRI showed new multiple infarctions. We also determined the presence of a high MPO-ANCA titer (57 EU), and we diagnosed the patient's condition to be ANCA-associated vasculitis (AAV). Steroid therapy improved his inflammatory reaction and stroke recurrence was not observed. We suggest that vasculitis should be considered as a potential risk factor for repeated small infarctions with fever of unknown origin, especially those of perforating artery territories.

Topics: Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Anticoagulants; Biomarkers; Fever of Unknown Origin; Heparin; Humans; Magnetic Resonance Imaging; Male; Methylprednisolone; Peroxidase; Prednisolone; Pulse Therapy, Drug; Recurrence; Risk Factors; Stroke; Warfarin

Young stroke patients constitute 15%-30% of all stroke patients in India as against 3.0%-8.5% reported from the West. The mechanisms for stroke in the young may include unconventional risk factors such as infections. We aimed to investigate the role (if any) of Chlamydia pneumoniae antibodies in young patients with acute ischemic stroke (AIS). Several proinflammatory cytokines and biomarkers are released early after the onset of brain ischemia. We assessed the role of heat shock protein (hsp) 65, neopterin, and myeloperoxidase upregulation after AIS in predicting stroke severity. We also assessed relationship of upregulated inflammatory biomarkers with C pneumoniae antibody titres (IgG, IgA, and IgM).. Eighty acute stroke patients and healthy age- and sex-matched controls were recruited. Blood samples were drawn within 1 week from the onset of stroke. Detection of IgA, IgG, and IgM antibodies to C pneumoniae was done with a validated microimmunofluorescence technique from 5 mL of serum in all subjects. Inflammatory biomarkers such as neopterin, myeloperoxidase and hsp 65 were estimated with sandwich enzyme linked immunosorbent assay (ELISA) method.. hsp 65 and neopterin were significantly elevated in all stroke patients with respect to healthy controls (odds ratio [OR], 4.9; 95% confidence interval [CI], 23.5-67.8; P = .001 and OR, 4.4; 95% CI, 2.08-9.4; P = .04, respectively). Eighty-one percent of cases were seropositive for IgA versus 32% of controls (P = .003), and IgG was positive in 52.7% versus 17.3% of controls (P = .05). Myeloperoxidase levels were similar in patients and controls. Correlation and multiple regression indicated a high level of predictability and sensitivity of hsp 65 to IgA. C. pneumoniae antibody titres when all other variables were constant (F [4,90] = -6.8, P = .001). Patients with high NIHSS scores (>15) had elevated levels of hsp 65 (mean, 13.2 ng/mL) suggesting correlation with stroke severity.. The study demonstrated high levels of hsp 65 and neopterin levels in AIS correlated to significantly elevated IgA titres of C pneumoniae. Elevated levels of hsp 65 were associated with stroke severity.

Topics: Adolescent; Adult; Antibodies, Bacterial; Biomarkers; Brain Ischemia; Case-Control Studies; Chlamydia Infections; Chlamydophila pneumoniae; Female; Heat-Shock Proteins; Humans; Immunoglobulins; India; Inflammation; Male; Middle Aged; Neopterin; Peroxidase; Risk Factors; Stroke; Young Adult

Ischemic stroke may result from transient or permanent reductions of regional cerebral blood flow. Polymorphonuclear neutrophils have been described as the earliest inflammatory cells to arrive in ischemic tissue. CXCR1/2 receptors are involved in the recruitment of these cells. However, the contribution of these chemokine receptors during transient brain ischemia in mice remains poorly understood. In this work, we investigated the effects of reparixin, an allosteric antagonist of CXCR1/2 receptors, in a model of middle cerebral artery occlusion and reperfusion in mice.. C57BL/6J male mice treated with reparixin or vehicle were subjected to a middle cerebral artery occlusion procedure 1 h after the treatment. Ninety minutes after ischemia induction, the monofilament that prevented blood flow was removed. Twenty-four hours after the reperfusion procedure, behavioral changes, including motor signs, were analyzed with the SmithKline/Harwell/lmperial College/Royal Hospital/Phenotype Assessment (SHIRPA) battery. The animals were sacrificed, and brain tissue was removed for histological and biochemical analyses. Histological sections were stained with hematoxylin and eosin, neutrophil infiltration was estimated by myeloperoxidase activity and the inflammatory cytokine IL-iβ was measured by ELISA.. Pre-treatment with reparixin reduced the motor deficits observed in this model of ischemia and reperfusion. Myeloperoxidase activity and IL-iβ were reduced in the reparixin-treated group. Histological analysis revealed that ischemic injury was also attenuated by reparixin pre-treatment.. Our results suggest that the blockade of the CXCR1/2 receptors by reparixin promotes neuroprotective effects by reducing the levels of polymorphonuclear infiltration in the brain and the tissue damage associated with middle cerebral artery occlusion and reperfusion.

Topics: Animals; Brain Injuries; Brain Ischemia; Enzyme-Linked Immunosorbent Assay; Male; Mice; Mice, Inbred C57BL; Neuroprotective Agents; Peroxidase; Receptors, Interleukin-8A; Receptors, Interleukin-8B; Reproducibility of Results; Stroke; Sulfonamides; Time Factors; Treatment Outcome

Several clinically available cardiac biomarkers have established their prognostic value in patients with acute coronary syndromes. However, their relative prognostic significance in stable subjects has not been prospectively validated, either individually or in combination. The aim of this study was to evaluate the extent to which B-type natriuretic peptide, myeloperoxidase, and high-sensitivity C-reactive protein alone or together could be prognostic biomarkers in 3,635 consecutive stable patients without acute coronary syndrome who underwent elective diagnostic coronary angiography. After adjusting for traditional risk factors and renal function, each of the markers monitored was a significant predictor of incident major adverse cardiovascular events (death, nonfatal myocardial infarction, and stroke) over 3 years. A cardiac biomarker score based on the sum total of "positive" biomarkers provided independent prediction of future risk for incident major adverse cardiovascular events at 3 years (hazard ratio [HR] 7.61, 95% confidence interval [CI] 4.98 to 11.65, p <0.001), even after adjusted for traditional risk factors (HR 6.11, 95% CI 3.98 to 9.38, p <0.001). A positive cardiac biomarker score remained a strong and independent predictor of 3-year risk for major adverse cardiovascular events among those with normal glycemic control (HR 4.24, 95% CI 1.96 to 9.18, p <0.001), those with prediabetes (HR 7.62, 95% CI 3.87 to 15.01, p <0.001), and those with diabetes (HR 5.61, 95% CI 2.55 to 12.33, p <0.001), as well as within subjects without significant angiographic evidence of coronary artery disease (HR 10.82, 95% CI 3.82 to 30.6, p <0.001). In conclusion, an integrated assessment of cardiac biomarkers may provide independent prognostic value for long-term adverse clinical events in stable cardiac patients.

Topics: Biomarkers; Blood Glucose; C-Reactive Protein; Cause of Death; Coronary Angiography; Coronary Artery Disease; Female; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Myocardial Infarction; Natriuretic Peptide, Brain; Ohio; Peroxidase; Predictive Value of Tests; Prognosis; Prospective Studies; Risk Assessment; Risk Factors; Stroke; Survival Rate; Troponin I

We aimed at challenging the prognostic accuracies of myeloperoxidase (MPO) and antibodies anti-apolipoprotein A-1 (anti-apoA-1 IgG), alone or in combination, for major adverse cardiovascular events (MACE) prediction, one year after carotid endarterectomy (CEA). In this prospective single centre study, 178 patients undergoing elective CEA were included. Serum anti-apoA-1 IgG and MPO were assessed by enzyme-linked immunosorbent assay prior to the surgery. Post-hoc determination of the MPO cut-off was performed by receiver operating characteristics (ROC) analyses. MACE was defined by the occurrence of fatal or non-fatal acute coronary syndromes or stroke during one year follow-up. Prognostic accuracy of anti-apoA-1 IgG was assessed by ROC curve analyses, survival analyses and reclassification statistics. During follow-up, 5% (9/178) of patients presented a MACE, and 29% (52/178) were positive for anti-apoA-1 IgG. Patients with MACE had higher median MPO and anti-apoA-1 IgG levels at admission (p=0.01), but no difference for the 10-year global Framingham risk score (FRS) was observed (p=0.22). ROC analyses indicated that both MPO and anti-apoA-1 IgG were significant predictors of subsequent MACE (area under the curve [AUC]: 0.75, 95% confidence interval [95%CI]: 0.61-0.89, p=0.01; and 0.74, 95%CI: 0.59-90; p=0.01), but combining anti-apoA-1 IgG positivity and MPO>857 ng/ml displayed the best predictive accuracy (AUC: 0.78, 95%CI: 0.65-0.91; p=0.007). It was associated with a poorer MACE-free survival (98.2% vs. 57.1%; p<0.001, LogRank), with a positive likelihood ratio of 13.67, and provided incremental predictive ability over FRS. In conclusion, combining the assessment of anti-apoA-1 IgG and MPO appears as a promising risk stratification tool in patients with severe carotid stenosis.

Topics: Acute Coronary Syndrome; Aged; Aged, 80 and over; Apolipoprotein A-I; Area Under Curve; Autoantibodies; Biomarkers; C-Reactive Protein; Carotid Stenosis; Endarterectomy, Carotid; Female; Humans; Kaplan-Meier Estimate; Likelihood Functions; Logistic Models; Male; Middle Aged; Odds Ratio; Peroxidase; Prospective Studies; Risk Factors; ROC Curve; Severity of Illness Index; Stroke; Switzerland; Time Factors; Treatment Outcome

Myeloperoxidase (MPO) concentrations predict adverse clinical outcomes in the setting of acute coronary syndromes and heart failure, but the prognostic role of MPO in stable patients with known atherosclerotic burden is unclear.. We examined plasma MPO concentrations and their relationship with prevalent significant coronary artery disease (defined as >50% stenosis in any coronary vessel) and incident major adverse cardiovascular events (MACEs), including death, myocardial infarction, and stroke, in a 3-year prospective follow-up study of 1895 patients undergoing elective coronary angiography.. The median plasma MPO concentration was 101 pmol/L (interquartile range 68-187 pmol/L). Patients with plasma MPO concentrations >322 pmol/L (14.6% of population) had increased risk of developing future MACEs [hazard ratio (HR) 1.78, 95% CI 1.33-2.37, P < 0.001], and MPO as a single variable predictor of MACE showed an area under the ROC curve of 0.67. After adjusting for traditional cardiac risk factors, creatinine clearance, B-type natriuretic peptide, and high-sensitivity C-reactive protein (hsCRP), increased MPO concentrations remained significantly associated with incident MACEs over the ensuing 3-year period (HR 1.71; 95% CI 1.27-2.30, P < 0.001). In patients with increased hsCRP, MPO ≤322 pmol/L was associated with lower event rates than observed with MPO >322 pmol/L.. Plasma MPO concentrations provide independent prognostic value for the prediction of long-term incident MACEs in a stable, medically managed patient population with coronary artery disease. In individuals with increased hsCRP concentrations, we observed lower risk of incident MACEs when concomitant MPO concentrations were low vs when MPO concentrations were high.

Topics: Biomarkers; C-Reactive Protein; Coronary Stenosis; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Infarction; Peroxidase; Predictive Value of Tests; Prognosis; Prospective Studies; Reference Values; Risk; ROC Curve; Stroke

There is substantial evidence that inflammation within the central nervous system contributes to stroke risk and recovery. Inflammatory conditions increase stroke risk, and the inflammatory response is of major importance in recovery and healing processes after stroke. We investigated the role of inflammatory genes IL1B, IL6, MPO, and TNF in stroke susceptibility and recovery in a population sample of 672 patients and 530 controls, adjusting for demographic, clinical and lifestyle risk factors, and stroke severity parameters. We also considered the likely complexity of inflammatory mechanisms in stroke, by assessing the combined effects of multiple genes. Two interleukin 6 (IL6) and one myeloperoxidase (MPO) single-nucleotide polymorphisms were significantly associated with stroke risk (0.022<(corrected)P<0.042), highlighting gene variants of low to moderate effect in stroke risk. An epistatic interaction between the IL6 and MPO genes was also identified in association with stroke susceptibility (P=0.031 after 1,000 permutations). In a subset of 546 patients, one IL6 haplotype was associated with stroke outcome at 3 months ((corrected)P=0.024), an intriguing finding warranting further validation. Our findings support the association of the IL6 gene and present novel evidence for the involvement of MPO in stroke susceptibility, suggesting a modulation of stroke risk by main gene effects, clinical and lifestyle factors, and gene-gene interactions.

Topics: Aged; Case-Control Studies; Epistasis, Genetic; Female; Genetic Predisposition to Disease; Humans; Inflammation; Interleukin-6; Male; Middle Aged; Peroxidase; Polymorphism, Single Nucleotide; Recovery of Function; Risk Factors; Stroke

Tropisetron is widely used to counteract chemotherapy-induced emesis. Evidence obtained from human and animal studies shows that tropisetron possesses anti-inflammatory properties. In this study, we assessed the effect of tropisetron on brain damage in a rat thromboembolic model of stroke. Stroke was rendered in rats by introduction of an autologous clot into the middle cerebral artery (MCA). Tropisetron (1 or 3mg/kg); m-chlorophenylbiguanide (mCPBG), a selective 5-HT(3) receptor agonist (15 mg/kg); tropisetron (3mg/kg) plus mCPBG (15 mg/kg); granisetron (3mg/kg); tacrolimus (1mg/kg); or tacrolimus (1mg/kg) plus tropisetron (3mg/kg) were administered intraperitoneally 1h prior to embolization. Behavioral scores and infarct volume as well as myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-α) level were determined in the ipsilateral cortex 4h and 48 h following stroke induction. Forty-eight hours after embolization, tropisetron (1 or 3mg/kg), tropisetron (3mg/kg) plus mCPBG (15 mg/kg), tacrolimus (1mg/kg), or tacrolimus (1mg/kg) plus tropisetron (3mg/kg) significantly curtailed brain infarction, improved behavioral scores, diminished elevated tissue MPO activity, and reduced TNF-α levels compared to control group (n=6; P<0.05). mCPBG or granisetron had no effect on the mentioned parameters. Tropisetron attenuates brain damage after a thromboembolic event. Beneficial effects of tropisetron in this setting are receptor independent.

Topics: Analysis of Variance; Animals; Biguanides; Blood Gas Analysis; Brain Edema; Brain Infarction; Brain Injuries; Cerebral Cortex; Disease Models, Animal; Dose-Response Relationship, Drug; Immunosuppressive Agents; Indoles; Ischemia; Male; Nervous System Diseases; Peroxidase; Rats; Rats, Wistar; Seizures; Serotonin Antagonists; Stroke; Tacrolimus; Tropisetron; Tumor Necrosis Factor-alpha

Animal models of transient ischemia suggest that oxygen-derived free radicals produced on reperfusion of ischemic brain could constitute the main cause of reperfusion injury. We aimed to determine the presence and role of lipid peroxidation and protein oxidation-related molecules after tissue plasminogen activator-induced recanalization in human stroke.. A total of 160 patients with strokes involving the middle cerebral artery and treated with tissue plasminogen activator and 60 healthy controls were included. Blood samples, transcranial Doppler recordings, and National Institutes of Health Stroke Scale scores were obtained at baseline (pretreatment), 1 hour and 2 hours after tissue plasminogen activator bolus, and 12 hours and 24 hours after stroke onset. The main lipid peroxidation end-product malondialdehyde, advanced oxidation protein products, and plasma concentrations of myeloperoxidase were assessed.. At baseline, all oxidative stress biomarkers were higher than in control subjects (P<0.01 for all comparisons). Malondialdehyde remained high compared with controls during the study period, whereas myeloperoxidase concentrations were significantly raised at baseline, 1 hour after tissue plasminogen activator administration, and 12 hours after stroke onset. Malondialdehyde concentrations correlated with stroke severity and were associated with outcome and with hemorrhagic complications. Regarding recanalization, among those patients with middle cerebral artery recanalization by the end of tissue plasminogen activator infusion (44%) or anytime thereafter, no peaking of any of the studied molecules could be identified.. Our study showed that systemic oxidative damage to lipids and proteins had already occurred at baseline in stroke. In contrast to animal studies, a relationship between free radical-mediated oxidative damage to lipids or proteins and reperfusion injury after arterial recanalization could not be established.

Topics: Aged; Animals; Biomarkers; Cerebral Hemorrhage; Female; Fibrinolytic Agents; Humans; Male; Malondialdehyde; Oxidative Stress; Peroxidase; Reactive Oxygen Species; Reperfusion; Stroke; Thrombolytic Therapy; Tissue Plasminogen Activator

Myeloperoxidase (MPO) is a glycoprotein released by activated polymorphonuclear neutrophils, which takes part in the defence of the organism through production of hypochlorous acid (HOCl), a potent oxidant. MPO has a role in pathogenesis of atherosclerosis. The aim of the study was to evaluate the time course of MPO plasma levels in the early stage of ischemic stroke. The study included 78 patients with acute ischemic stroke, 46 females and 32 males, mean age 74.3 +/- 6.8 years. Blood samples for MPO measurement were taken within 24 hours after the onset of ischemic stroke. Seventy-two patients served as matched controls 43 females and 29 males, mean age 71.3 +/- 6.4 years. MPO was measured in plasma using the Abbott Architect platform (Abbott Diagnostics Inc., Abbott Parck IL). Comparisons between patients and controls and patients group were expressed as relative risk with its 95% confidence interval (RR [95% CI]), where a lower limit > 1.0 was considered significant. All p values were determined by Fischer's exact test. A value of p < 0.05 was considered statistically significant. Mean plasma MPO level was in patients with acute ischemic stroke 583 +/- 48 pmol/L. Seventy-one patients out of seventy-eight patients with ischemic stroke presented mean plasma MPO levels greater than the upper of normal (425 +/- 36 pmol/L, p < 0.0001, (RR 8.188, [95% CI 4.038 to 16.600]). Twelve controls presented mean plasma MPO level greater than the upper of normal. In conclusion, plasma MPO levels were statistically significantly higher in patients after ischemic stroke as compared to controls. MPO has been associated with acute ischemic stroke but its direct role in its pathogenesis has not been established. MPO could be proposed as a potential prognostic marker of such lesions rather than a marker of diagnosis. MPO is a new biomarker and a possible future therapeutic target.

Topics: Aged; Aged, 80 and over; Biomarkers; Brain Ischemia; Case-Control Studies; Cohort Studies; Female; Humans; Male; Peroxidase; Risk Factors; Stroke; Time Factors

Recently, we reported a neuroprotective effect for Hawthorn (Crataegus oxyacantha) ethanolic extract in middle cerebral artery occlusion-(MCAO) induced stroke in rats. The present study sheds more light on the extract's mechanism of neuroprotection, especially its immunomodulatory effect.. After 15 days of treatment with Hawthorn extract [100 mg/kg, pretreatment (oral)], male Sprague Dawley rats underwent transient MCAO for 75 mins followed by reperfusion (either 3 or 24 hrs). We measured pro-inflammatory cytokines (IL-1β, TNF-α, IL-6), ICAM-1, IL-10 and pSTAT-3 expression in the brain by appropriate methods. We also looked at the cytotoxic T cell sub-population among leukocytes (FACS) and inflammatory cell activation and recruitment in brain (using a myeloperoxidase activity assay) after ischemia and reperfusion (I/R). Apoptosis (TUNEL), and Bcl-xL- and Foxp3- (T(reg) marker) positive cells in the ipsilateral hemisphere of the brain were analyzed separately using immunofluorescence.. Our results indicate that occlusion followed by 3 hrs of reperfusion increased pro-inflammatory cytokine and ICAM-1 gene expressions in the ipsilateral hemisphere, and that Hawthorn pre-treatment significantly (p ≤ 0.01) lowered these levels. Furthermore, such pre-treatment was able to increase IL-10 levels and Foxp3-positive cells in brain after 24 hrs of reperfusion. The increase in cytotoxic T cell population in vehicle rats after 24 hrs of reperfusion was decreased by at least 40% with Hawthorn pretreatment. In addition, there was a decrease in inflammatory cell activation and infiltration in pretreated brain. Hawthorn pretreatment elevated pSTAT-3 levels in brain after I/R. We also observed an increase in Bcl-xL-positive cells, which in turn may have influenced the reduction in TUNEL-positive cells compared to vehicle-treated brain.. In summary, Hawthorn extract helped alleviate pro-inflammatory immune responses associated with I/R-induced injury, boosted IL-10 levels, and increased Foxp3-positive T(regs) in the brain, which may have aided in suppression of activated inflammatory cells. Such treatment also minimizes apoptotic cell death by influencing STAT-3 phosphorylation and Bcl-xL expression in the brain. Taken together, the immunomodulatory effect of Hawthorn extract may play a critical role in the neuroprotection observed in this MCAO-induced stroke model.

Topics: Adult; Animals; bcl-X Protein; Brain; Crataegus; Cytokines; Disease Models, Animal; Encephalitis; Humans; Immunologic Factors; Infarction, Middle Cerebral Artery; Intercellular Adhesion Molecule-1; Interleukin-10; Male; Neuroprotective Agents; Peroxidase; Plant Extracts; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; STAT3 Transcription Factor; Stroke

Stress is known to be one of the risk factors of stroke, but only a few experimental studies have examined the possible mechanisms by which prior stress may affect stroke outcome. In stroke patients, infections impede neurological recovery and increase morbidity as well as mortality. We previously reported that stress induces a bacterial translocation and that prior immobilization stress worsens experimental stroke outcome through mechanisms that involve inflammatory mediators such as release of proinflammatory cytokines and enzyme activation. We now investigate whether bacterial translocation from the intestinal flora of rats with stress before experimental ischemia is involved in stroke outcome. We used an experimental paradigm consisting of exposure of Fischer rats to repeated immobilization sessions before permanent middle cerebral artery occlusion (MCAO). The presence of bacteria and the levels and expression of different mediators involved in the bacterial translocation were analyzed. Our results indicate that stress before stroke is related to the presence of bacteria in different organs (mesenteric nodes, spleen, liver, and lung) after MCAO and increases inflammatory colonic parameters (such as cyclooxygenase-2, inducible nitric oxide synthase, and myeloperoxidase), but decreases colonic immunoglobulin A, and these results are correlated with colonic inflammation and bacterial translocation. Understanding the implication of bacterial translocation during stress-induced stroke worsening is of great potential clinical relevance, given the high incidence of infections after severe stroke and their main role in mortality and morbidity in stroke patients.

Topics: Animals; Anti-Bacterial Agents; Bacterial Translocation; Colitis; Colon; Corticosterone; Cyclooxygenase 2; Disease Models, Animal; Immunoglobulin A; Infarction, Middle Cerebral Artery; Lung; Lymph Nodes; Male; Nitric Oxide Synthase Type II; Penicillin G; Permeability; Peroxidase; Rats; Rats, Inbred F344; Restraint, Physical; Risk Factors; Spleen; Stress, Psychological; Stroke

Inflammation can extend ischemic brain injury and adversely affect outcome in experimental animal models. A key difficulty in translating animal studies to humans is the lack of a definitive method to confirm and track inflammation in the brain in vivo. Myeloperoxidase (MPO), a key inflammatory enzyme secreted by activated neutrophils and macrophages/microglia, can generate highly reactive oxygen species to cause additional damage in cerebral ischemia. We report here that a functional, enzyme-activatable MRI agent can accurately track the oxidative activity of MPO noninvasively in stroke in living animals. We found that MPO is widely distributed in ischemic tissues, correlates positively with infarct size, and is detected even 3 weeks postinfarction. The peak level of MPO activity, determined by activation of the MPO-sensing agent in vivo and confirmed by MPO activity and quantitative RT-PCR assays, occurred on day 3 after ischemia. Both neutrophils and macrophages/microglia contribute to secrete MPO in the ischemic brain, although neutrophils peak earlier (days 1-3) whereas macrophages/microglia are most abundant later (days 3-7). In contrast to the conventional MRI agent diethylenetriamine-pentatacetate gadolinium, which reports blood-brain barrier disruption, MPO imaging is able to additionally track MPO activity and confirm inflammation on the molecular level in vivo, information that was previously only possible to obtain on ex vivo brain sections and impossible to assess in living human patients. Our findings could allow efficient noninvasive serial screening of therapies targeting inflammation and the use of MPO imaging as an imaging biomarker to risk-stratify patients.

Topics: Animals; Disease Models, Animal; Gadolinium DTPA; Inflammation; Magnetic Resonance Imaging; Mice; Mice, Inbred C57BL; Peroxidase; Stroke

The prognostic role of inflammation in peripheral arterial disease (PAD) remains to be conclusively established. Accordingly, in these patients we investigated the impact of myeloperoxidase (MPOx) and C-reactive protein on the incidence of myocardial infarction and stroke.. Of 156 PAD patients, 10 had a myocardial infarction and seven a stroke, during follow-up. We used the receiver operating characteristic curve analysis and the bootstrap approach to identify the MPOx, C-reactive protein, and ankle brachial index (ABI) threshold levels that provided the best cut-off to predict the outcome. For MPOx a cut-off > or =183.7 pM was independently associated with a poor outcome (HR = 6.80, 95% CI 1.20-38.69, P = 0.031). The result remained unmodified when MPOx was used as a continuous variable (HR = 1.03, 95% CI 1.01-1.05, P = 0.031). Conversely, C-reactive protein was not a prognostic determinant in our series (HR = 0.88, 95% CI 0.60-1.29, P = 0.514). Kaplan-Meier curves for the four groups of patients delineated according to ABI and MPOx values identified using the bootstrap approach showed that the addition of MPOx measurement to ABI improved the ability to identify patients at risk for myocardial infarction and stroke.. In PAD, MPOx, but not C-reactive protein, predicts an increased risk of major cardiovascular events, and adds to the prognostic value of ABI, currently the most powerful prognostic indicator in these patients.

Topics: Aged; Blood Pressure; C-Reactive Protein; Epidemiologic Methods; Female; Humans; Male; Myocardial Infarction; Peripheral Vascular Diseases; Peroxidase; Prognosis; Stroke

Psychological stress causes an inflammatory response in the brain and is able to exacerbate brain damage caused by experimental stroke. We previously reported that subacute immobilization stress in mice worsens stroke outcome through mechanisms that involve inflammatory mechanisms, such as accumulation of oxidative/nitrosative mediators and expression of inducible nitric oxide synthase and cyclooxygenase-2 in the brain. Some of these inflammatory mediators could be regulated by innate immunity, the activation of which takes place in the brain and produces an inflammatory response mediated by toll-like receptors (TLRs). Recently, we described the implications of TLR4 in ischemic injury, but the role of TLR4 in stress has not yet been examined. We therefore investigated whether inflammation produced by immobilization stress differs in mice that lack a functional TLR4 signaling pathway.. We used an experimental paradigm consisting of the exposure of mice to repeated immobilization sessions (1 hour daily for 7 days) before permanent middle cerebral artery occlusion.. We found that TLR4-deficient mice subjected to subacute stress had a better behavioral condition compared with normal mice (C3H/HeN) and that this effect was associated with a minor inflammatory response (cyclooxygenase-2 and inducible nitric oxide synthase expression) and lipid peroxidation (malondialdehyde levels) in brain tissue. Furthermore, previous exposure to stress was followed by a smaller infarct volume after permanent middle cerebral artery occlusion in TLR4-deficient mice than in mice that express TLR4 normally.. Our results indicate that TLR4 is involved in the inflammatory response after subacute stress and its exacerbating effect on stroke. These data implicate the effects of innate immunity on inflammation and damage in the brain after stroke.

Topics: Animals; Behavior, Animal; Brain Ischemia; Corticosterone; Cyclooxygenase 2; Encephalitis; Gene Expression; Male; Mice; Mice, Inbred C3H; Mice, Mutant Strains; Neuroimmunomodulation; Nitric Oxide Synthase Type II; Peroxidase; Recovery of Function; Restraint, Physical; Signal Transduction; Stress, Psychological; Stroke; Toll-Like Receptor 4

The rewarming phase after therapeutic hypothermia in cerebral ischemia appears crucial as rapid rewarming may lead to rebound phenomena and enhance deleterious ischemic effects. We hypothesized that slow and controlled rewarming after moderate hypothermia is superior to fast rewarming in rats subjected to 90 min temporary middle cerebral artery occlusion (tMCAO). Two experiments were designed: (i) 34 rats were randomly assigned to either normothermic treatment, to hypothermia (33 degrees C) with rapid rewarming within 20 min, or to hypothermia with slow rewarming within 2 h after 4 h of hypothermia starting 2 h after tMCAO. Infarct size, neuroscore, myeloperoxidase and aquaporin 4 (AQP4) positive cells were assessed on day 5 after tMCAO. (ii) In 15 rats, striatal cerebral microdialysis was performed from 1.5 h before until 8 h after tMCAO. Total infarct volume was largest in the normothermic group (89.9+/-16.8 mm(3)) followed by the fast rewarming group (69.2+/-12.6 mm(3)), and a significantly smaller infarct volume in the slow rewarming group (41.1+/-6.6 mm(3), p<0.05). Neurological functions improved in both hypothermia groups at day 5 after tMCAO (Neuroscore median 2.5 in normothermia vs. 1.5 in both hypothermia groups) though without any difference between slowly and fast rewarmed animals. Periinfarct expression of AQP4 was less prominent in slowly rewarmed animals as was the count of MPO-positive cells in subcortical regions. Glutamate release was significantly higher at 4 distinct time points in the control group. Slow rewarming after a period of hypothermia is superior to fast rewarming. It may blunt deleterious rebound effects such as overexpression of AQP4, sustain anti-inflammatory mechanisms and thereby preserve the neuroprotection delivered by hypothermia.

Topics: Animals; Aquaporin 4; Arterial Occlusive Diseases; Cerebral Infarction; Corpus Striatum; Glutamic Acid; Hypothermia, Induced; Immunohistochemistry; Male; Microdialysis; Middle Cerebral Artery; Nervous System; Peroxidase; Rats; Rats, Wistar; Rewarming; Stroke; Time Factors

Neuroinflammation is one of the events occurring after acute brain injuries. The aim of the present report was to characterize a rat model to study acute neuroinflammation on the histopathological, biochemical and functional outcomes. Lipopolysaccharide (LPS), known as a strong immunostimulant, was directly injected into the hippocampus. The spatiotemporal evolution of inducible NOS (iNOS) and cell death was studied from 6 h to 7 days. A perfect time course correlation was observed between iNOS immunoreactivity and iNOS activity showing an acute, expansive and transient iNOS induction in the hippocampus with a peak at 24 h. It was associated with a marked increase in NO metabolite (NO(x)) levels, and a high level of myeloperoxidase (MPO) activity. This inflammation precedes a massive cellular loss including at least neurons and astrocytes, and a drop of constitutive NOS activity, restrictive to the ipsilateral hippocampus from 48 h after LPS injection. Moreover, sensorimotor function impairment occurred from 24 h to 7 days with a maximum at 24 h post-LPS injection. Therefore, we characterized an in vivo model of acute neuroinflammation and neurodegeneration, in relation with a neurological deficit, which may be a powerful tool for mechanistic studies and for further evaluation of the potential neuroprotective agents.

Topics: Animals; Astrocytes; Brain Injuries; Disease Models, Animal; Encephalitis; Hippocampus; Inflammation Mediators; Lipopolysaccharides; Male; Movement Disorders; Nerve Degeneration; Neurons; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peroxidase; Rats; Rats, Sprague-Dawley; Sensation Disorders; Stroke; Time Factors; Up-Regulation

Expression of matrix metalloproteinases (MMPs), proteolytic enzymes that degrade extracellular proteins, is altered after ischemia/reperfusion injury and may contribute to blood-brain barrier (BBB) breakdown. Neutrophils, a source of reactive oxygen species and MMP-9, infiltrate damaged tissue 6 to 24 hours after ischemia and have also been implicated in delayed secondary tissue damage. Here we examined the spatial-temporal relation between MMP-9 expression and neutrophil infiltration after stroke.. Knockout mice containing 50% manganese superoxide dismutase activity (SOD2-KOs), which are more susceptible to ischemic damage than wild-type (WT) littermates, underwent quantitative antigen (MMP-9, myeloperoxidase) immunohistochemistry (24 and 72 hours) analysis and protein expression by Western blotting (6, 12, 24, 48, and 72 hours) after transient focal cerebral ischemia. BBB breakdown was determined by Evans blue extravasation.. There was a clear spatial relation between MMP-9 expression and Evans blue extravasation. MMP-9-positive cell and vessel counts for SOD2-KOs (72 hours) were significantly different from SOD2-KO (24 hours, P=0.004), WT (24 hours, P=0.01), and WT (72 hours, P=0.007) mice. In contrast, MMP-9-positive neutrophil counts were comparatively low and did not differ by time or animal type. MMP-9 expression was biphasic in SOD2-KOs but not in WT littermates, with a significant increase observed 6 to 12 hours after ischemic insult and again at 48 to 72 hours. SOD2-KOs showed increased MMP-9 expression compared with WT littermates at all time points studied (P< or =0.05).. In this model, neutrophils are not the primary source of MMP-9 protein and thus are unlikely the key contributor to BBB breakdown observed in SOD2-KOs.

Topics: Animals; Blotting, Western; Brain Ischemia; Cell Movement; Evans Blue; Extravasation of Diagnostic and Therapeutic Materials; Immunohistochemistry; Matrix Metalloproteinase 9; Mice; Mice, Knockout; Neutrophil Infiltration; Neutrophils; Peroxidase; Stroke

We evaluated the neuroprotective effect of UK-279,276 (also referred to as recombinant neutrophil inhibitory factor), a selective CD11b/CD18 antagonist, in combination with thrombolytic therapy on focal cerebral ischemia.. Male Wistar rats (n=88) were subjected to embolic middle cerebral artery occlusion. Animals were randomly assigned to the following groups (n=11 in each group): vehicle treatment alone at 2 or 4 hours, UK-279,276 treatment alone at 2 or 4 hours, recombinant human tissue plasminogen activator (rhtPA) treatment alone at 2 or 4 hours, or the combination of UK-279,276 and rhtPA at 2 or 4 hours. Infarct volume, neurological function, hemorrhagic transformation, neutrophil accumulation, and parenchymal fibrin deposition were measured 7 days after middle cerebral artery occlusion.. Treatment with UK-279,276 significantly (P<0.05) improved neurological severity scores, an index of neurological functional deficit, but had no effect on infarct volume compared with vehicle-treated animals. Treatment with rhtPA alone at 2 but not 4 hours significantly (P<0.05) reduced infarct volume and improved neurological function compared with vehicle-treated animals. Combination treatment with UK-279,276 and rhtPA at 2 or 4 hours significantly (P<0.01) reduced infarct volume and enhanced recovery of neurological function compared with control. Neutrophil accumulation and fibrin deposition in the brain parenchyma of combination-treated rats at 2 and 4 hours after stroke were significantly reduced (P<0.05) compared with corresponding vehicle-treated control groups. The neuroprotective effect of the combined treatments was superior to the additive effects from each treatment of rhtPA or UK-279,276 alone.. These data suggest that the combination treatment with UK-279,276 and rhtPA may extend the window of thrombolytic therapy for the acute treatment of stroke.

Topics: Animals; Body Weight; Brain; CD11b Antigen; Cerebral Hemorrhage; Disease Models, Animal; Fibrin; Glycoproteins; Helminth Proteins; Humans; Infarction, Middle Cerebral Artery; Intracranial Embolism; Male; Membrane Proteins; Neurologic Examination; Neuroprotective Agents; Peroxidase; Rats; Rats, Wistar; Recombinant Proteins; Severity of Illness Index; Stroke; Tissue Plasminogen Activator

Myeloperoxidase (MPO) has been shown to contribute to several diseases and more particularly to atherosclerosis through excessive ROS production via the MPO/H(2)O(2)/Cl(-) oxidation system. The aim of this study was to determine whether there is an association between MPO polymorphisms and brain infarction (BI), one of the main consequences of atherosclerosis. We investigated MPO G-463A and G-129A polymorphisms in 450 patients with BI confirmed by magnetic resonance imaging (MRI) and 450 controls of the GENIC (Génétique de l'Infarctus Cérébral) Study. Genotype determination of MPO was performed by polymerase chain reaction and allele-specific oligonucleotide hybridization (ASO). Genotype distributions for each of both MPO polymorphisms were found to be similar between cases and controls overall, and according to etiologic subtypes or gender. The frequency of the A allele of the G-463A polymorphism was 22% (95% confidence interval, 19.4 to 24.9) and the frequency of the A allele of the G-129A polymorphism was 6.8% (95% confidence interval, 5.3 to 8.6). The odds ratio (OR) for BI in carriers of the A allele of the G-129A polymorphism was 0.92 (95% confidence interval, 0.61 to 1.39), and the OR for BI in carriers of the A allele of the G-463A polymorphism was 1.15 (95% confidence interval, 0.88 to 1.52). No association between the main risk factors for BI such as hypertension, cholesterol, diabetes and MPO polymorphisms was found. In analyses restricted to cases, we identified an association between the A allele of the G-129A polymorphism and the size of the brain infarct (P=0.01). Furthermore, the A allele of the G-463A polymorphism was associated with a poorer functional short-term outcome as evaluated by the Rankin score (P=0.02). In conclusion, MPO polymorphisms were associated with the extent of brain damage and the functional outcome rather than with the risk of developing a BI.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Base Sequence; Brain Infarction; Case-Control Studies; Cohort Studies; Female; France; Genetic Predisposition to Disease; Genotype; Humans; Logistic Models; Magnetic Resonance Imaging; Male; Middle Aged; Molecular Sequence Data; Odds Ratio; Peroxidase; Polymerase Chain Reaction; Polymorphism, Genetic; Probability; Prognosis; Risk Assessment; Severity of Illness Index; Stroke; Survival Rate

Enlimomab, a murine monoclonal anti-human intercellular adhesion molecule (ICAM)-1 antibody, had a negative outcome in a multicenter acute-stroke trial. We did a bedside-to-bench study in standardized rat stroke models to explore mechanisms for these untoward results.. After focal brain ischemia in Wistar rats and spontaneously hypertensive rats (SHR), we administered murine anti-rat ICAM-1 antibody (1A29), subclass-matched murine immunoglobulin (IgG1), or vehicle intravenously. To examine whether rat anti-mouse antibodies were generated against the mouse protein and whether these were deleterious, we sensitized Wistar rats with 1A29 or vehicle 7 days before surgery. Infarct volume, tissue myeloperoxidase activity, neutrophil CD11b expression, and microvascular E-selectin, P-selectin, and ICAM-1 expression were examined 48 hours after surgery. Complement activation was serially assessed for 2 hours after a single injection of either 1A29 or vehicle.. 1A29 treatment did not significantly reduce infarct size in either strain. 1A29 sensitization augmented infarct size and generated rat anti-mouse antibodies. Although 1A29 inhibited neutrophil trafficking shown by reduction in brain myeloperoxidase activity, circulating neutrophils were activated and displayed CD11b upregulation. Complement was activated in 1A29-sensitized Wistar rats and 1A29-treated SHR. E-selectin (SHR), endothelial P-selectin (Wistar and SHR), and ICAM-1 (SHR) were upregulated in animals treated with 1A29.. Administration to rats of a murine antibody preparation against ICAM-1, 1A29, elicits the production of host antibodies against the protein, activation of circulating neutrophils, complement activation, and sustained microvascular activation. These observations provide several possible mechanisms for central nervous system-related clinical deterioration that occurred when Enlimomab was given in acute ischemic stroke.

Topics: Animals; Antibodies, Monoclonal; Body Weight; Brain; Brain Infarction; Brain Ischemia; Cerebrovascular Circulation; Clinical Trials as Topic; Complement C3a; Flow Cytometry; Humans; Immunohistochemistry; Intercellular Adhesion Molecule-1; Isoantibodies; Laser-Doppler Flowmetry; Leukocyte Count; Mice; Peroxidase; Rats; Rats, Inbred SHR; Rats, Wistar; Selectins; Stroke