Oxidative stress in the context of acute cerebrovascular stroke

Determination of oxidative stress level and some antioxidant activities in refractory epilepsy patients

The aim of this study was to determine the levels of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) in patients with refractory epilepsy. Serum superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) levels were determined using the spectrophotometer method. Refractory epilepsy patients' serum superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) levels were statistically significant compared to the healthy control group (p < 0.05). In conclusion, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) levels may play an important role in the etiopathogenesis of refractory epilepsy. This study was the first to investigate some parameters in refractory epilepsy disease.

Total oxidant/antioxidant status, copper and zinc levels in acute ischemic stroke patients after mechanical thrombectomy

BACKGROUND AND PURPOSE

We aimed to identify the relationship of total antioxidant status, total oxidant status, and copper (Cu) and zinc (Zn) situations with the short-term prognostic and stroke severity in acute ischemic stroke cases who were successfully recanalized by mechanical thrombectomy.

METHODS

A study of 36 acute ischemic stroke patients and 22 controls were prospectively studied. Tube samples were attained at admission and 24 h after recanalization. In patients who were successfully recanalized (thrombolysis in cerebral infarction ≥ 2b), a 3-month modified Rankin scale (mRS) score of 0-2 was considered a good prognosis, and a score of 3-6 was considered a poor prognosis.

RESULTS

Admission Cu levels were significantly higher in the poor prognosis group (p = 0.031). In the multivariate logistic regression analysis, Cu was not associated with poor prognosis (p = 0.357). Cu and Zn levels were lower in the patients group compared to controls (p = 0.014 and p = 0.010, respectively). There was no correlation between National Institute of Health Stroke Scale and biomarkers (p > 0.05). The temporal variation of biomarkers did not differ significantly between the good prognosis and poor prognosis groups (p interaction > 0.05).

CONCLUSIONS

High admission Cu levels were associated with poor prognosis, but this association was limited. In addition, Cu and Zn levels were statistically lower in patients. There was no relationship between total antioxidant/oxidant status and short-term prognosis or stroke severity.

The Role of Potential Oxidative Biomarkers in the Prognosis of Acute Ischemic Stroke and the Exploration of Antioxidants as Possible Preventive and Treatment Options

Ischemic strokes occur when the blood supply to a part of the brain is interrupted or reduced due to arterial blockage, and it often leads to damage to brain cells or death. According to a myriad of experimental studies, oxidative stress is an important pathophysiological mechanism of ischemic stroke. In this narrative review, we aimed to identify how the alterations of oxidative stress biomarkers could suggest a severity-reflecting diagnosis of ischemic stroke and how these interactions may provide new molecular targets for neuroprotective therapies. We performed an eligibility criteria-based search on three main scientific databases. We found that patients with acute ischemic stroke are characterized by increased oxidative stress markers levels, such as the total antioxidant capacity, F2-isoprostanes, hydroxynonenal, total and perchloric acid oxygen radical absorbance capacity (ORACTOT and ORACPCA), malondialdehyde (MDA), myeloperoxidase, and urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine. Thus, acute ischemic stroke is causing significant oxidative stress and associated molecular and cellular damage. The assessment of these molecular markers could be useful in diagnosing ischemic stroke, finding its causes, predicting its severity and outcomes, reducing its impact on the cellular structures of the brain, and guiding preventive treatment towards antioxidant-based therapy as novel therapeutic alternatives.

In Mild and Moderate Acute Ischemic Stroke, Increased Lipid Peroxidation and Lowered Antioxidant Defenses Are Strongly Associated with Disabilities and Final Stroke Core Volume

In acute ischemic stroke (AIS), there are no data on whether oxidative stress biomarkers have effects above and beyond known risk factors and measurements of stroke volume. This study was conducted in 122 mild-moderate AIS patients and 40 controls and assessed the modified ranking scale (mRS) at baseline, and 3 and 6 months later. We measured lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced oxidation protein products, paraoxonase 1 (PON1) activities and PON1 Q192R genotypes, high density lipoprotein cholesterol (HDL), sulfhydryl (-SH) groups), and diffusion-weighted imaging (DWI) stroke volume and fluid-attenuated inversion recovery (FLAIR) signal intensity. We found that (a) AIS is characterized by lower chloromethyl acetate CMPAase PON1 activity, HDL and -SH groups and increased LOOH and neurotoxicity (a composite of LOOH, inflammatory markers and glycated hemoglobin); (b) oxidative and antioxidant biomarkers strongly and independently predict mRS scores 3 and 6 months later, DWI stroke volume and FLAIR signal intensity; and (c) the PON1 Q192R variant has multiple effects on stroke outcomes that are mediated by its effects on antioxidant defenses and lipid peroxidation. Lipid peroxidation and lowered -SH and PON1-HDL activity are drug targets to prevent AIS and consequent neurodegenerative processes and increased oxidative reperfusion mediators due to ischemia-reperfusion injury.

A Systematic Review of Body Fluids Biomarkers Associated With Early Neurological Deterioration Following Acute Ischemic Stroke

Biomarkers are objectively measured biological properties of normal and pathological processes. Early neurological deterioration (END) refers to the deterioration of neurological function in a short time after the onset of acute ischemic stroke (AIS) and is associated with adverse outcomes. Although multiple biomarkers have been found to predict END, there are currently no suitable biomarkers to be applied in routine stroke care. According to the Preferred Reporting Items for Systematic Review standards, we present a systematic review, concentrating on body fluids biomarkers that have shown potential to be transferred into clinical practice. We also describe newly reported body fluids biomarkers that can supply different insights into the mechanism of END. In our review, 40 scientific papers were included. Depending on the various mechanisms, sources or physicochemical characteristics of body fluids biomarkers, we classified related biomarkers as inflammation, protease, coagulation, metabolism, oxidative stress, and excitatory neurotoxicity. The body fluids biomarkers whose related articles are limited or mechanisms are unknown are categorized as other biomarkers. The inflammation-related biomarkers, such as neutrophil-to-lymphocyte ratio and hypersensitive C-reactive protein, play a crucial role among the mentioned biomarkers. Considering the vast heterogeneity of stroke progression, using a single body fluids biomarker may not accurately predict the risk of stroke progression, and it is necessary to combine multiple biomarkers (panels, scores, or indices) to improve their capacity to estimate END.

Propagation of age‐related diseases due to the changes of lipid peroxide and antioxidant levels in elderly people: A narrative review

Background and Aims

Lipid peroxidation end products are the major culprit for inducing chronic diseases in elderly people. Along with the elevated level of lipid peroxide biomarkers, there is a significant disruption of antioxidants balance, which combinedly propagate the diseases of elderly people. The aim of the present review is to bridge the connection of changes in lipid peroxides biomarkers and antioxidants level with age‐associated diseases in elderly people.

Methods

This narrative review was performed following a comprehensive search for suitable articles in multiple online databases, including PubMed, Google Scholar, EMBASE, Web of Science, Cochrane Library, and ScienceDirect using selected search terms. The most appropriate literature was included based on the selection criteria.

Results

From the review, it is found that many age‐related diseases propagated with an increased level of the end products of lipid peroxide and reduced levels of antioxidants in elderly people. When the end products of lipid peroxidation increase in the body, it creates oxidative stress, which ultimately leads to many complicated diseases, including cancers, cardiovascular and neurogenic diseases, and many other chronic inflammatory diseases. The oxidative stress induced by peroxidation can be assessed by different lipid peroxide end products such as malondialdehyde, oxidized low‐density lipoprotein, isoprostanes, neuroprostanes, lipoperoxides, oxysterols (7‐ketocholesterol, 7β‐hydroxycholesterol), and many more.

Conclusions

This study definitively answers the correlation between the changes in lipid peroxides and antioxidants level and age‐related diseases. Our narrative article recommends future investigations for elucidating the mechanisms rigorously to establish a compact correlation.

Integrated Analysis of the Cecal Microbiome and Plasma Metabolomics to Explore NaoMaiTong and Its Potential Role in Changing the Intestinal Flora and Their Metabolites in Ischemic Stroke

Ischemic stroke (IS), as a leading cause of disability worldwide, affects intestinal bacterial communities and their metabolites, while recent discoveries have highlighted the importance of the intestinal microflora in the development of IS. Systematic investigations of complex intestinal bacterial communities and their metabolites during ischemic brain injury contribute to elucidate the promising therapeutic targets for IS. However, the associations between intestinal microbiota and related circulating metabolic processes in IS remained unclear. Hence, to identify the changed microflora and their metabolites in IS of NaoMaiTong (NMT), an effective clinical medication, we established the middle cerebral artery occlusion/reperfusion (MCAO/R) model using conventionalized and pseudo-germ-free (PGF) rats. Subsequently, we systematically screen the microflora and related metabolites changing in IS via an integrated approach of cecal 16S rRNA sequencing combined with plasma metabolomics. We found that NMT relied on intestinal flora to improve stroke outcome in conventionalized rats while the protection of NMT was reduced in PGF rats. Total 35 differential bacterial genera and 26 differential microbial metabolites were regulated by NMT. Furthermore, L-asparagine and indoleacetaldehyde were significantly negatively correlated with Lachnospiraceae_UCG.001 and significantly positively correlated with Lachnoclostridium. Indoleacetaldehyde also presented a negative correlation with Lactobacillus and Bifidobacterium. 2-Hydroxybutyric acid was strongly negatively correlated with Ruminococcus, Lachnospiraceae_UCG.001 and Lachnospiraceae_UCG.006. Creatinine was strongly negatively correlated with Akkermansia. In summary, the research provided insights into the intricate interaction between intestinal microbiota and metabolism of NMT in IS. We identified above differential bacteria and differential endogenous metabolites which could be as prebiotic and probiotic substances that can influence prognosis in stroke and have potential to be used as novel therapeutic targets or exogenous drug supplements.

Deep Sequencing of the Rat MCAO Cortexes Reveals Crucial circRNAs Involved in Early Stroke Events and Their Regulatory Networks

Circular RNAs (circRNAs) are highly enriched in the central nervous system and significantly involved in a range of brain-related physiological and pathological processes. Ischemic stroke is a complex disorder caused by multiple factors; however, whether brain-derived circRNAs participate in the complex regulatory networks involved in stroke pathogenesis remains unknown. Here, we successfully constructed a cerebral ischemia-injury model of middle cerebral artery occlusion (MCAO) in male Sprague-Dawley rats. Preliminary qualitative and quantitative analyses of poststroke cortical circRNAs were performed through deep sequencing, and RT-PCR and qRT-PCR were used for validation. Of the 24,858 circRNAs expressed in the rat cerebral cortex, 294 circRNAs were differentially expressed in the ipsilateral cerebral cortex between the MCAO and sham rat groups. Cluster, GO, and KEGG analyses showed enrichments of these circRNAs and their host genes in numerous biological processes and pathways closely related to stroke. We selected 106 of the 294 circRNAs and constructed a circRNA-miRNA-mRNA interaction network comprising 577 sponge miRNAs and 696 target mRNAs. In total, 15 key potential circRNAs were predicted to be involved in the posttranscriptional regulation of a series of downstream target genes, which are widely implicated in poststroke processes, such as oxidative stress, apoptosis, inflammatory response, and nerve regeneration, through the competing endogenous RNA mechanism. Thus, circRNAs appear to be involved in multilevel actions that regulate the vast network of multiple mechanisms and events that occur after a stroke. These results provide novel insights into the complex pathophysiological mechanisms of stroke.

Hyperhomocysteinemia and Ischemic Stroke: A Potential Dose-Response Association-A Systematic Review and Meta-analysis

Background and Purpose  Previous studies suggest an association between increased homocysteine (Hcy) and risk of ischemic stroke. Yet, it remains unknown whether a dose-response association exists between Hcy levels and risk of ischemic stroke. Methods  Systematic literature searches were performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were studies investigating ischemic stroke risk in an adult population with measured Hcy levels. We computed odds ratios (ORs) for a 5 µmol/L increase in Hcy levels using a random effects meta-analysis. Results  In total, 108 studies met the inclusion criteria of which 22 were rated as high-quality studies, and 20 studies included a dose-response analysis. Hcy levels were analyzed either as a continuous or categorical variable. The majority of the studies found an increased risk of ischemic stroke when comparing the highest-to-lowest Hcy strata. A graded association was observed over the Hcy strata, indicating a dose-response association, with the most apparent effect when Hcy levels exceeded approximately 15 µmol/L. No studies explored a potential nonlinear association between Hcy levels and ischemic stroke. Six studies were included in a meta-analysis, showing an OR of 1.43 (95% confidence interval [CI]: 1.28-1.61) per 5 µmol/L increase in Hcy levels. Conclusion  This review and meta-analysis indicate a dose-response association between Hcy levels and ischemic stroke. An evident increase in effect measures was observed when Hcy levels exceeded 15 µmol/L, indicating a nonlinear association between ischemic stroke and Hcy levels. This nonlinear association warrants further study. This study is registered with clinical trial ( https://www.crd.york.ac.uk/prospero/ ; unique identifier: CRD42019130371).

Systemic administration of sunflower oil exerts neuroprotection in a mouse model of transient focal cerebral ischaemia

OBJECTIVES

Natural products are valuable sources of nutraceuticals for the prevention or treatment of ischemic stroke, a major cause of death and severe disability worldwide. Among the mechanisms implicated in cerebral ischemia-reperfusion damage, oxidative stress exerts a pivotal role in disease progression. Given the high antioxidant potential of most components of sunflower oil, we have explored its effects on ischemic brain injury produced in the mouse by transient occlusion of the middle cerebral artery (MCAo).

KEY FINDINGS

Intraperitoneal (i.p.) administration of sunflower oil at doses of 3 ml/kg (48 h, 24 h and 1 h before MCAo) significantly reduced brain infarct volume and oedema assessed 24 h after the insult. This neuroprotective treatment schedule also prevented the elevation of brain lipid peroxidation produced by MCAo-reperfusion injury. By contrast, doses of 0.03 ml/kg of sunflower oil resulted ineffective on both cerebral damage and lipid peroxidation. Although sunflower oil did not affect serum levels of Diacron-reactive oxygen metabolites (d-ROMs), both 0.03 and 3 ml/kg dosing regimens resulted in the preservation of serum biological antioxidant potential (BAP) that was otherwise dramatically reduced 24 h after MCAo.

CONCLUSIONS

Sunflower oil represents a promising source of neuroprotective extracts/compounds that can be exploited for the prevention and/or treatment of cerebral ischemia.

Design, synthesis, and biological evaluation of novel stachydrine derivatives as potent neuroprotective agents for cerebral ischemic stroke

Stachydrine is a natural product with multiple protective biological activities, including those involved in preventing cancer, ischemia, and cardiovascular disease. However, its use has been limited by low bioavailability and unsatisfactory efficacy. To address this problem, a series of stachydrine derivatives (A1/A2/A3/A4/B1/B2/B3/B4) were designed and synthesized, and biological studies were carried out in vitro and in vivo. When compared with stachydrine, Compound B1 exhibited better neuroprotective effects in vitro, and significantly reduced infarction size in the model of the middle cerebral artery occlusion rat model. Therefore, Compound B1 was selected for further research on ischemic stroke. Graphical abstract.

Intra-arterial anti-oxidant power negatively correlates with white matter injury, and oxidative stress positively correlates with disability in daily activities

Oxidative stress influences many kinds of diseases. Our hypothesis is that oxidative stress and antioxidant potentials correlate with cognitive function, activities of daily life and white matter injury. (UMIN-CTR R000016770) Thirty-two consecutive patients participated to this study after informed consent. A routine biochemical analysis, modified-Rankin Scale (m-RS), revised Hasegawa Dementia Scale (HDS-R), Mini-Mental State Examination (MMSE) and fluid-attenuated-inversion-recovery imaging (FLAIR) were performed before admission. Derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were measured photometrically using arterial blood. Statistical analyses were done by analysis variance or logistic regression analysis. Median age was 72 (IQR: 64.3 -- 75.8). The d-ROMS were 367 ± 55.4, and BAP was 1967 ± 284. HDS-R and m-RS deteriorated with d-ROMs elevation (p < 0.05). Uric acid and creatinine decreased with d-ROMs elevation (p < 0.05). Both periventricular hyperintensity grade and deep and subcortical white matter hyperintensity grade worsened with BAP reduction (p < 0.05). Oxidative stress correlates negatively with cognitive function and activities of daily life. Low antioxidative potentials correlate with aggravation of white matter injury. We should control both oxidative stress and antioxidative potential to maintain healthy lives.

Homocysteine might increase the risk of recurrence in patients presenting with primary cerebral infarction

PURPOSE

Although hyperhomocysteinemia (Hhcy) is a risk factor for cerebral infarction, its effect on recurrent cerebral infarction is less-defined. We aimed to investigate the association of Hhcy and increased risk of recurrent cerebral infarct.

MATERIALS AND METHODS

From 2011 to 2013, we recruited 231 primary cerebral infarct patients that were divided to a Hhcy group (n = 105) and a control group (n = 126) according to plasma homocysteinemia (Hcy) levels exceeding 15 μmol/L. In this prospective study, risk factors such as gender, age, blood lipid and glucose levels, history of diabetes, high blood pressure, smoking habits and plasma Hhcy levels were determined. A three-year follow-up compared differences in cerebral infarction recurrence rates. Statistical analyses identified whether plasma Hhcy levels were an independent risk factor for recurrent cerebral infarction.

RESULTS

Triglyceride and low-density lipoprotein (LDL) levels in the Hhcy group were significantly higher than controls, and cerebral infarct recurrence rates in the Hhcy group exceeded control subject rates through the three-year follow-up (p = .021, p = .036 and p = .025). Cox proportional hazards modeling showed that elevated Hhcy levels (hazard ratio [HR] = 3.062, p < .001), increased age (HR = 1.069, p < .01), circulating triglyceride levels (HR = 1.686, p = .048), and relative National Institutes of Health Stroke (NIHSS) score (HR = 1.068, p = .016) were risk factors for recurrent cerebral infarction.

CONCLUSIONS

Level of Hhcy was a risk factor for recurrent cerebral infarction. Further, particular demographic and clinical outcomes including age, relative NIHSS scores, and circulating triglyceride levels were markedly associated with the occurrence of cerebral infarction.

Biomarker for Ischemic Stroke Using Metabolome: A Clinician Perspective

Finding ischemic stroke biomarker is highly desirable because it can improve diagnosis even before a patient arrives to the hospital. Metabolome is one of new technologies that help to find biomarkers. Most metabolome-related ischemic stroke studies were done in Asia and had exploratory designs. Although failed to find specific biomarkers, they discovered several important metabolite-stroke associations which belong to three pathophysiological mechanisms: Excitotoxicity with activation of glutamate, resulting in the increase of glutamate derivatives proline and pyroglutamate; Oxidative stress with production of free radicals and perturbed concentrations of uric acid, matrix metalloproteinase-9, branch-chained amino acids, sphingolipids, homocysteine, asymmetric dimethylarginine, nitric oxide and folate cycle metabolites; and Stroke mediated inflammation, affecting phospholipid metabolism with perturbed levels of lysophosphatidylethanolamine and lysophosphatidylcholine. The discovered metabolite-stroke associations need further evaluation in prospective, high-quality studies with patients matched for age, risk factors, and medications.

Determination of the Predictive Value of Serum Bilirubin in Patients with Ischemic Stroke: A Prospective Descriptive Analytical Study

Purpose: In all types of ischemic stroke, especially in the acute phase, excessive oxidative stress causes structural and functional damage to the brain. This may play a major role in the pathophysiology of the brain damage. Higher serum levels of bilirubin have therapeutic effects in oxidative stress-induced stroke. Nevertheless, role of increased serum levels of bilirubin in the acute phase of ischemic stroke is ccontroversial.

Methods: This study was a cross-sectional prospective descriptive study conducted in the Emergency Department (ED) of Imam Reza hospital, Tabriz University of Medical Sciences, Tabriz, Iran, throughout six months. 275 ischemic stroke patients were evaluated based on their brain CT scan infarct size, NIHSS, MRS, and serum levels of bilirubin. Later, data were analyzed using SPSS software.

Results: Results: Total, direct and indirect bilirubin levels were significantly higher in expired patients (p < 0.0001). Total (p< 0.0001), direct (p< 0.0001) and indirect (p< 0.0001) bilirubin levels, NIHSS score (p< 0.0001), and ischemic area (p< 0.0001) significantly predicted the outcome in these patients.

Conclusion: Total, direct and indirect bilirubin levels was significantly associated with mortality in the acute phase of ischemic stroke patients.

Hyperacute changes in blood mRNA expression profiles of rats after middle cerebral artery occlusion: Towards a stroke time signature

Stroke evolution is a highly dynamic but variable disease which makes clinical decision making difficult. Biomarker discovery programs intended to aid clinical decision making have however largely ignored the rapidity of stroke evolution. We have used gene array technology to determine blood mRNA expression changes over the first day after stroke in rats. Blood samples were collected from 8 male spontaneously hypertensive rats at 0, 1, 2, 3, 6 and 24h post stroke induction by middle cerebral artery occlusion. RNA was extracted from whole blood stabilized in PAXgene tubes and mRNA expression was detected by oligonucleotide Affymetrix microarray. Using a pairwise comparison model, 1932 genes were identified to vary significantly over time (p≤0.5x10^-7) within 24h after stroke. Some of the top20 most changed genes are already known to be relevant to the ischemic stroke physiopathology (e.g. Il-1R, Nos2, Prok2). Cluster analysis showed multiple stereotyped and time dependent profiles of gene expression. Direction and rate of change of expression for some profiles varied dramatically during these 24h. Profiles with potential clinical utility including hyper acute or acute transient upregulation (with expression peaking from 2 to 6h after stroke and normalisation by 24h) were identified. We found that blood gene expression varies rapidly and stereotypically after stroke in rats. Previous researchers have often missed the optimum time for biomarker measurement. Temporally overlapping profiles have the potential to provide a biological “stroke clock” able to tell the clinician how far an individual stroke has evolved.

Serum Coenzyme Q10 Is Associated with Clinical Neurological Outcomes in Acute Stroke Patients

Disruption of prooxidant-antioxidant balance may lead to oxidative stress which is known as a mechanism contributing to ischemic stroke. Coenzyme Q10 (CoQ10) is an endogenous antioxidant that could be effective in preventing oxidative stress. However, the contribution of serum levels of CoQ10 in clinical neurological outcomes following ischemic stroke has not been clearly established. This study aims at measuring serum concentration of CoQ10 along with major indicators of antioxidant and oxidant among patients within 24 h after onset of the stroke symptoms, and investigating their relation with the clinical status of patients. Serum levels of CoQ10, superoxide dismutase (SOD), and malondialdehyde (MDA) were measured in 76 patients and 34 healthy individuals. Severity of the neurological deficit, functional disability, and cognitive status in ischemic subjects were respectively studied with the National Institutes of Health stroke scale (NIHSS), modified Rankin Scale (MRS), and Mini-Mental State Examination (MMSE). Stroke patients had significantly lower serum level of CoQ10 and SOD as compared to controls (27.34 ± 35.40 ng/ml, 18.58 ± 0.76 μ/ml, respectively; p < 0.05), whereas the serum MDA level was significantly higher (38.02 ± 2.61 μm, p < 0.05). A significant negative correlation was detected between the serum CoQ10 level and scores of NIHSS and MRS. A similar association was discerned between the SOD level and the neurological deficit score. The serum MDA level was also found to be strongly correlated with all three neurological scales. These findings suggest that the serum level of CoQ10 like other antioxidant and oxidant markers can significantly change early after ischemic stroke and they are substantially associated with clinical neurological outcomes.

Correlation of Serum Nitric Oxide (NO) with Glasgow Coma Scale (GCS) in Acute Ischemic Stroke Patient: A Study in North India

Nitric oxide (NO) is one of the key players in the pathogenesis of ischemic stroke. Limited reports are available about the serum level of NO and their correlation with Glasgow Coma Scale (GCS) score in acute (<24 h) ischemic stroke (AIS) patients. A hospital based, cross sectional study was done in North Indian population to find out correlation of serum NO and GCS in AIS patients. 50 patients of AIS and 25 healthy controls were chosen for the study. Serum NO level was measured by ELISA and GCS scores were assessed by a neurologist. Pearson correlation coefficients were analyzed to look for the relationship between NO and GCS. Statistically highly significant elevation in mean serum NO level was observed in cases as compared to controls (p < 0.01). A negative correlation of NO levels with neurological score of GCS r (48) = -0.144, p > 0.05 was seen. This indicates oxidative stress in acute ischemic stroke may be the result of imbalance in oxidant/antioxidant homeostasis.

Oxidative Stress Biomarkers of Brain Damage: Hyperacute Plasma F2-Isoprostane Predicts Infarct Growth in Stroke

BACKGROUND AND PURPOSE

Oxidative stress is an early response to cerebral ischemia and is likely to play an important role in the pathogenesis of cerebral ischemic injury. We sought to evaluate whether hyperacute plasma concentrations of biomarkers of oxidative stress, inflammation, and tissue damage predict infarct growth (IG).

METHODS

We prospectively measured plasma F2-isoprostane (F2-isoP), urinary 8-oxo-7,8-dihydro-2'-deoxyguoanosine, plasma oxygen radical absorbance capacity assay, high sensitivity C reactive protein, and matrix metalloproteinase 2 and 9 in consecutive patients with acute ischemic stroke presenting within 9 hours of symptom onset. Patients with baseline diffusion-weighted magnetic resonance imaging and follow-up diffusion-weighted imaging or computed tomographic scan were included to evaluate the final infarct volume. Baseline diffusion-weighted imaging volume and final infarct volume were analyzed using semiautomated volumetric method. IG volume was defined as the difference between final infarct volume and baseline diffusion-weighted imaging volume.

RESULTS

A total of 220 acute ischemic stroke subjects were included in the final analysis. One hundred seventy of these had IG. Baseline F2-isoP significantly correlated with IG volume (Spearman ρ=0.20; P=0.005) and final infarct volume (Spearman ρ=0.19; P=0.009). In a multivariate binary logistic regression model, baseline F2-isoP emerged as an independent predictor of the occurrence of IG (odds ratio, 2.57; 95% confidence interval, 1.37-4.83; P=0.007). In a multivariate linear regression model, baseline F2-isoP was independently associated with IG volume (B, 0.38; 95% confidence interval, 0.04-0.72; P=0.03).

CONCLUSIONS

Elevated hyperacute plasma F2-isoP concentrations independently predict the occurrence of IG and IG volume in patients with acute ischemic stroke. If validated in future studies, measuring plasma F2-isoP might be helpful in the acute setting to stratify patients with acute ischemic stroke for relative severity of ischemic injury and expected progression.

Testosterone May Hold Therapeutic Promise for the Treatment of Ischemic Stroke in Aging: A Closer Look at Laboratory Findings

Male sex is more prone to cerebrovascular disorders, yet the exact role of androgens in cerebral ischemia remains unclear. Here we reviewed current understanding of testosterone (TES) neuroprotective activity against ischemic stroke and mechanisms underlying these effects in aging. TES may exert a neuroprotective effect in aging through pathways including inhibition of oxidant molecules production, enhancing the enzymatic antioxidant capacity of the brain and modulation of apoptotic cell death. Given this, a better understanding of the neuroprotective roles of TES may propose an effective therapeutic strategy to improve the quality of life and decrease androgen-related cerebrovascular problems in the aging men.

Inhibition of Myeloperoxidase by N-Acetyl Lysyltyrosylcysteine Amide Reduces Oxidative Stress-Mediated Inflammation, Neuronal Damage, and Neural Stem Cell Injury in a Murine Model of Stroke

Recent studies suggest that myeloperoxidase (MPO)-dependent oxidative stress plays a significant role in brain injury in stroke patients. We previously showed that N-acetyl lysyltyrosylcysteine amide (KYC), a novel MPO inhibitor, significantly decreased infarct size, blood-brain barrier leakage, infiltration of myeloid cells, loss of neurons, and apoptosis in the brains of middle cerebral artery occlusion (MCAO) mice. Inhibition of MPO also noticeably reduced neurologic severity scores of MCAO mice. Thus, our data support the idea that MPO-dependent oxidative stress plays a detrimental role in tissue injury in ischemic stroke. However, the mechanisms of MPO-induced injury in stroke are still largely unknown. Here, we present new evidence showing that KYC treatment greatly reduced inflammation by decreasing the number of proinflammatory M1 microglial cells and N1 neutrophils in the brains of MCAO mice. KYC also markedly reduced the expression of high-mobility group box 1, receptor for advanced glycation end products, and nuclear factor-κB in the brains of MCAO mice. Both neurons and neural stem cells (NSCs) were oxidatively injured by MPO-dependent oxidative stress in MCAO mice. Inhibiting MPO-dependent oxidative stress with KYC significantly reduced oxidative injury and apoptosis in neurons and NSCs. KYC treatment also protected transplanted exogenous NSCs in the brains of MCAO mice. Thus, our studies suggest that MPO-dependent oxidative stress directly injures brain tissues by oxidizing neurons and NSCs and increasing inflammation during stroke. Inhibition of MPO activity with KYC preserves neuronal function and helps the brain recover from injury after stroke.

Arctic ground squirrel resist peroxynitrite-mediated cell death in response to oxygen glucose deprivation

Cerebral ischemia-reperfusion (I/R) injury initiates a cascade of events, generating nitric oxide (NO) and superoxide(O₂^•-) to form peroxynitrite (ONOO^-), a potent oxidant. Arctic ground squirrels (AGS; Urocitellus parryii) show high tolerance to I/R injury. However, the underlying mechanism remains elusive. We hypothesize that tolerance to I/R modeled in an acute hippocampal slice preparation in AGS is modulated by reduced oxidative and nitrative stress. Hippocampal slices (400µm) from rat and AGS were subjected to oxygen glucose deprivation (OGD) using a novel microperfusion technique. Slices were exposed to NO, O₂^.- donors with and without OGD; pretreatment with inhibitors of NO, O₂^.- and ONOO^- followed by OGD. Perfusates collected every 15min were analyzed for LDH release, a marker of cell death. 3-nitrotyrosine (3NT) and 4-hydroxynonenal (4HNE) were measured to assess oxidative and nitrative stress. Results show that NO/O₂^.- alone is not sufficient to cause ischemic-like cell death, but with OGD enhances cell death more in rat than in AGS. A NOS inhibitor, SOD mimetic and ONOO^- inhibitor attenuates OGD injury in rat but has no effect in AGS. Rats also show a higher level of 3NT and 4HNE with OGD than AGS suggesting the greater level of injury in rat is via formation of ONOO^-.

Intra-arterial oxidative stress correlates negatively with cognitive function and positively with postoperative ischemic lesions in carotid artery stenosis stenting

BACKGROUND AND PURPOSE

Carotid plaque contains biologically active substances released into the blood during carotid artery stenting (CAS). The main purpose of this prospective study was to analyse sequential changes in oxidative stress during CAS and their relationship to clinical factors.

METHODS

Twenty-two consecutive CAS procedures were performed between May 2014 and April 2016. Arterial blood was collected four times: (1) after the sheath insertion without edaravone; (2) pre-angioplasty with edaravone from the carotid artery; (3) after post-stenting angioplasty from an occluded carotid artery; and (4) before sheath removal. Derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were measured photometrically. The relationship between d-ROMs or BAP and preoperatively investigated biochemical parameters, cognitive function, and number of diffusion-weighted image (DWI) high spot lesions was analysed using one-way ANOVA and the Tukey-Kramer HSD test.

RESULTS

The d-ROM values for CAS were 355±58.8 Carratelli Units at sheath insertion, 315±57.2 after edaravone infusion, 328±56.8 after post-stenting angioplasty, and 315±53.0 just before sheath removal. The d-ROM values were reduced significantly after edaravone infusion (P<0.05). The BAP at sheath insertion was reduced significantly according to age (P<0.05). The d-ROMs at sheath insertion correlated negatively with the dementia scale and positively with the post-CAS DWI high spots (1.00±1.07; P<0.05). Other biochemical parameters did not correlate with the d-ROM values or BAP.

CONCLUSION

Oxidative stress is correlated negatively with cognitive function and positively with postoperative ischemic lesions. Antioxidant potential decreases with ageing.

Live or let die: Neuroprotective and anti-cancer effects of nutraceutical antioxidants

Diet sources are closely involved in the pathogenesis of diverse neuropsychiatric disorders and cancers, in addition to inherited factors. Currently, natural products or nutraceuticals (commonly called medical foods) are increasingly employed for adjunctive therapy of these patients. However, the potential molecular mechanisms of the nutrient efficacy remain elusive. In this review, we summarized the neuroprotective and anti-cancer mechanisms of nutraceuticals. It was concluded that the nutraceuticals exerted neuroprotection and suppressed tumor growth possibly through the differential modulations of redox homeostasis. In addition, the balance between reactive oxygen species (ROS) production and ROS elimination was manipulated by multiple molecular mechanisms, including cell signaling pathways, inflammation, transcriptional regulation and epigenetic modulation, which were involved in the therapeutic potential of nutraceutical antioxidants against neurological diseases and cancers. We specifically proposed that ROS scavenging was integral in the neuroprotective potential of nutraceuticals, while alternation of ROS level (either increase or decrease) or disruption of redox homeostasis (ROS addiction) constituted the anti-cancer property of these compounds. We also hypothesized that ROS-associated ferroptosis, a novel type of lipid ROS-dependent regulatory cell death, was likely to be a critical mechanism for the nutraceutical antioxidants. Targeting ferroptosis is advantageous to develop new nutraceuticals with more effective and lower adverse reactions for curing patients with neuropsychiatric diseases or carcinomas.

Preventive and therapeutic effect of brozopine on stroke in Dahl Salt-sensitive hypertensive rats

Our aim was to explore the preventive and therapeutic effects of sodium (±)-5-bromo-2-(α-hydroxypentyl) benzoate (brand name: brozopine, BZP) on stroke in Dahl Salt-sensitive (Dahl-SS) hypertensive rats. Dahl-SS rats were fed a high-salt diet to observe the effect of BZP on blood pressure, and brain, heart, and kidney tissues. Additionally, the incidence of stroke was recorded according to the neurological score. The relative mechanisms investigated included anti-oxidative effects and anti-platelet aggregation. BZP reduced the incidence of stroke, neuronal necrosis in the brain, and cell swelling and inflammatory infiltration in the kidney. Its mechanisms were related to the increased activities of gluthatione peroxidase and catalase and the decreased level of plasma nitric oxide. BZP inhibited arachidonic acid (AA) - induced platelet aggregation (IC₅₀: 12µM) rather than that of adenosine diphosphate (ADP) - and/or thrombin-induced platelet aggregation in vitro. Interestingly, BZP inhibited ADP-, thrombin-, or AA-induced platelet aggregation and elevated the level of AMP-activated protein kinase, cyclic guanosine monophosphate, and vasodilator-stimulated-phosphoprotein, and attenuated ATP contents and mitogen-activated protein kinase levels in platelet and inhibited thrombus formation in a carotid artery thrombosis model, dose-dependently, in Dahl-SS hypertensive-induced stroke rats. In conclusion, BZP can have therapeutic and preventive effects on stroke in Dahl-SS hypertensive rats, the mechanisms of which may be related to anti-oxidant, anti-platelet aggregation and anti-thrombus formation.

Incretin hormones regulate microglia oxidative stress, survival and expression of trophic factors

The incretin hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) are primarily known for their metabolic function in the periphery. GLP-1 and GIP are secreted by intestinal endocrine cells in response to ingested nutrients. Both GLP-1 and GIP stimulate the production and release of insulin from pancreatic β cells as well as exhibit several growth-regulating effects on peripheral tissues. GLP-1 and GIP are also present in the brain, where they provide modulatory and anti-apoptotic signals to neurons. However, very limited information is available regarding the effects of these hormones on glia, the immune and supporting cells of the brain. Therefore, we set out to resolve whether primary human microglia and astrocytes, two subtypes of glial cells, express the GLP-1 receptor (GLP-1R) and GIP receptor (GIPR), which are necessary to detect and respond to GLP-1 and GIP, respectively. We further tested whether these hormones, similar to their effects on neuronal cells, have growth-regulating, antioxidant and anti-apoptotic effects on microglia. We show for the first time expression of the GLP-1R and the GIPR by primary human microglia and astrocytes. We demonstrate that GLP-1 and GIP reduce apoptotic death of murine BV-2 microglia through the binding and activation of the GLP-1R and GIPR, respectively, with subsequent activation of the protein kinase A (PKA) pathway. Moreover, we reveal that incretins upregulate BV-2 microglia expression of brain derived neurotrophic factor (BDNF), glial cell-line derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in a phosphoinositide 3-kinase (PI3K)- and PKA-dependent manner. We also show that incretins reduce oxidative stress in BV-2 microglia by inhibiting the accumulation of intracellular reactive oxygen species (ROS) and release of nitric oxide (NO), as well as by increasing the expression of the antioxidant glutathione peroxidase 1 (GPx1) and superoxide dismutase 1 (SOD1). We confirm these results by demonstrating that GLP-1 and GIP also inhibit apoptosis of primary murine microglia, and upregulate expression of BDNF by primary murine microglia. These results indicate that GLP-1 and GIP affect several critical homeostatic functions of microglia, and could therefore be tested as a novel therapeutic treatment option for brain disorders that are characterized by increased oxidative stress and microglial degeneration.

Dynamic thiol-disulfide homeostasis in acute ischemic stroke patients

Dynamic thiol-disulfide homeostasis plays a critical role in the cellular protection provided by antioxidation. The aim of this study was to investigate whether there is a change in thiol-disulfide homeostasis in acute ischemic stroke patients. Patients diagnosed with acute ischemic stroke that had undergone magnetic resonance diffusion-weighted imaging within the first 24 h were prospectively included in this study. The thiol, disulfide, and total thiol levels were measured during the first 24 and 72 h, and the National Institutes of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), and Barthel Index (BI) of the patients were recorded. Overall, the relationships between the thiol-disulfide levels of the patients and the infarct volumes, NIHSS, mRS, and BI scores were investigated. In this study, 54 patients and 53 healthy controls were included. The mean of the native thiol levels in the stroke group was 356.572 ± 61.659 μmol/L (min/max 228.00/546.40), while it was 415.453 ± 39.436 μmol/L (min/max 323.50/488.70) in the control group (p < 0.001). A negative, significant correlation was observed between the infarct volumes and native thiol levels (ρ = -0.378; p = 0.005), and the disulfide levels were similar between the groups (Z = 0.774; p = 0.439). Significant difference was found between the thiol levels of the mild and moderate-severe NIHSS groups (p = 0.026). The changes in the thiol levels under oxidative stress may be associated with the severity of the stroke. Substitution of thiol deficiency and correction of thiol-disulfide imbalance may be beneficial in ischemic stroke.

Effect of L-pGlu-(1-benzyl)-l-His-l-Pro-NH2 against in-vitro and in-vivo models of cerebral ischemia and associated neurological disorders

Central nervous system plays a vital role in regulation of most of biological functions which are abnormally affected in various disorders including cerebral ischemia, Alzheimer's and Parkinson's (AD and PD) worldwide. Cerebral stroke is an extremely fatal and one of the least comprehensible neurological disorders due to limited availability of prospective clinical approaches and therapeutics. Since, some endogenous peptides like thyrotropin-releasing hormone have shown substantial neuroprotective potential, hence present study evaluates the newer thyrotropin-releasing hormone (TRH) analogue L-pGlu-(1-benzyl)-l-His-l-Pro-NH₂ for its neuroprotective effects against oxygen glucose deprivation (OGD), glutamate and H₂O₂ induced injury in pheochromocytoma cell lines (PC-12 cells) and in-vivo ischemic injury in mice. Additionally, the treatment was further analyzed with respect to models of AD and PD in mice. Cerebral ischemia was induced by clamping both bilateral common carotid arteries for ten minutes. Treatment was administered to the mice five minute after restoration of blood supply to brain. Consequential changes in neurobehavioural, biochemical and histological parameters were assessed after a week. L-pGlu-(1-benzyl)-l-His-l-Pro-NH₂ showed significant reduction in glutamate, H₂O₂ and OGD -induced cell death in concentration and time dependent manner. Moreover, L-pGlu-(1-benzyl)-l-His-l-Pro-NH₂ resulted in a substantial reduction in CA1 (Cornus Ammonis 1) hippocampal neuronal cell death, inflammatory cytokines, TNF-α, IL-6 and oxidative stress in hippocampus. In addition, L-pGlu-(1-benzyl)-l-His-l-Pro-NH₂ was found to be protective in two acute models of AD and PD as well these findings demonstrate the neuroprotective potential of L-pGlu-(1-benzyl)-l-His-l-Pro-NH₂ in cerebral ischemia and other diseases, which may be mediated through reduction of excitotoxicity, oxidative stress and inflammation.

Oxidative Stress Markers and Their Dynamic Changes in Patients after Acute Ischemic Stroke

We have focused on determining the range of oxidative stress biomarkers and their dynamic changes in patients at different time points after the acute ischemic stroke (AIS). 82 patients with AIS were involved in our study and were tested: within 24 h from the onset of the attack (group A); at 7-day follow-up (group B); and at 3-month follow-up (group C). 81 gender and age matched volunteers were used as controls. Stroke patients in group A had significantly higher concentrations of plasma lipid peroxides and urine 8-isoprostanes when compared with controls. Protein carbonyls were not significantly different in any experimental group compared to controls. Antioxidant capacity of plasma was increased only in experimental group C. Activities of superoxide dismutase and catalase were elevated in all three experimental AIS groups compared to controls. Paraoxonase activity was reduced in groups A and B and unchanged in group C when compared to controls. Glutathione peroxide activity was elevated only in group A. Our results suggest that free radical damage is the highest within 24 h after the attack. During the next 3 months oxidative damage to lipids caused by free radicals is reduced due to activated antioxidant system.

Fractions of Total Plasma Homocysteine in Patients with Ischemic Stroke Before the Age of 55 Years

The mechanism responsible for the association between elevated circulating homocysteine levels and ischemic stroke remains unclear. Therefore, the authors assessed total plasma homocysteine (tHcy) and its fractions (free [fHcy] and protein-bound [bHcy] homocysteine) in patients with ischemic stroke before the age of 55 years. Fifty patients (23 men, mean age 46.8 ±7.6 years) with ischemic stroke or transient ischemic attacks, with symptoms lasting <72 hours were enrolled. In this group: 32 (64%) patients had hypertension; 12 (24%), ischemic heart disease (IHD); and 20 (40%), type 2 diabetes mellitus (DM). The control group consisted of 30 matched healthy individuals (17 men, mean age 44.6 ±6.2 years). The tHcy, fHcy, and bHcy levels were determined by high-performance liquid chromatography. tHcy and its fractions did not differ significantly between patients and controls. However, stroke patients with hypertension had significantly higher concentrations of tHcy and bHcy compared to stroke patients without hypertension (tHcy 13.0 ±3.3 vs 10.7 ±3.2 µmol/L, p<0.05; bHcy 9.7 ±2.6 vs 7.8 ±2.3 µmol/L, p<0.01, respectively); fHcy was borderline significant: 3.1 (1.5-6.5) vs 2.5 (1.8-5.3) µmol/L, p=0.05. The presence of IHD, DM, hyperlipoproteinemia, clinical subtypes of stroke, smoking, and family history of stroke did not influence these parameters. In the group of 50 patients, tHcy correlated with mean systolic blood pressure (BP) ( r =0.3, p<0.05) and bHcy correlated with mean systolic and mean diastolic BP ( r =0.3, p<0.05). These findings suggest an association between hypertension and redox status of Hcy in patients with ischemic stroke before the age of 55 years. This observation supports the hypothesis that elevated BP may contribute to Hcy-related vascular injury.

Notch signaling in cerebrovascular diseases (Review)

The Notch signaling pathway is a crucial regulator of numerous fundamental cellular processes. Increasing evidence suggests that Notch signaling is involved in inflammation and oxidative stress, and thus in the progress of cerebrovascular diseases. In addition, Notch signaling in cerebrovascular diseases is associated with apoptosis, angiogenesis and the function of blood-brain barrier. Despite the contradictory results obtained to date as to whether Notch signaling is harmful or beneficial, the regulation of Notch signaling may provide a novel strategy for the treatment of cerebrovascular diseases.

The Differences in the Cellular and Plasma Antioxidative Capacity Between Transient and Defined Focal Brain Ischemia: Does it Suggest Supporting Time-Dependent Neuroprotection Therapy?

There are many opened questions about the precocious role of oxidative stress in the physiopathology of the early stage of transitory ischemic attack (TIA) and defined focal brain ischemia, as well as about its correlation with clinical severity, short-lasting and clinical outcome prediction in these conditions. The study evaluates the values of glutathione (GSH), glutathione peroxidase, and superoxide dismutase (SOD) in hemolysates and total thiol content (-SH), advanced oxidation protein products (AOPP), SOD, and malondialdehyde (MDA) in plasma, in TIA and stroke patients in the early stage of their neurological onset. The results are interpreted in view of the potential relationship between tested parameters and clinical severity and clinical outcome prediction. Better hemolysates' and total antioxidant profile with higher values of AOPP were observed in TIA compared to stroke patients (p < 0.05). The stroke patients with initially better clinical presentation showed better antioxidant profile with lower values of AOPP (p < 0.05). In TIA patients, this was observed for GSH, -SH content, and AOPP (p < 0.05), which correlated with a short risk for stroke occurrence in this group (p < 0.01). Beyond MDA values, all tested parameters showed correlation with clinical outcome in stroke patients (p < 0.05). The measurement of oxidative stress in TIA and stroke patients would be important for identifying patients' subgroups which might receive supporting therapy providing better neurological recovery and clinical outcome. That approach might give us an additional view of a short-lasting risk of stroke occurrence after TIA, and its clinical outcome and prognosis.

Plasma Oxidants and Antioxidants in Acute Ischaemic Stroke

Plasma levels of the oxidants xanthine oxidase, nitric oxide and malondialdehyde and the antioxidants superoxide dismutase, glutathione peroxidase and glutathione reductase, together with total superoxide scavenger activity and non-enzymatic superoxide scavenger activity, were determined in 19 patients with acute ischaemic stroke and 20 controls. Compared with controls, superoxide dismutase, total superoxide scavenger activity, glutathione peroxidase and glutathione reductase activities were significantly lower, and nitric oxide and malondialdehyde levels significantly higher, in acute stroke patients. Xanthine oxidase showed a slight but non-significant increase in stroke patients compared with controls. There was no significant difference in non-enzymatic superoxide scavenger activity between the two groups. There was a positive correlation between glutathione reductase levels and Glasgow Coma Scale scores, and a negative correlation between malondialdehyde levels and non-enzymatic superoxide scavenger activity. These findings suggest that oxidative stress in patients with acute ischaemic stroke may be the result of an imbalance in oxidant/antioxidant homeostasis.

Inhibition of myeloperoxidase oxidant production by N-acetyl lysyltyrosylcysteine amide reduces brain damage in a murine model of stroke

BACKGROUND

Oxidative stress plays an important and causal role in the mechanisms by which ischemia/reperfusion (I/R) injury increases brain damage after stroke. Accordingly, reducing oxidative stress has been proposed as a therapeutic strategy for limiting damage in the brain after stroke. Myeloperoxidase (MPO) is a highly potent oxidative enzyme that is capable of inducing both oxidative and nitrosative stress in vivo.

METHODS

To determine if and the extent to which MPO-generated oxidants contribute to brain I/R injury, we treated mice subjected to middle cerebral artery occlusion (MCAO) with N-acetyl lysyltyrosylcysteine amide (KYC), a novel, specific and non-toxic inhibitor of MPO. Behavioral testing, ischemic damage, blood-brain-barrier disruption, apoptosis, neutrophils infiltration, microglia/macrophage activation, and MPO oxidation were analyzed within a 7-day period after MCAO.

RESULTS

Our studies show that KYC treatment significantly reduces neurological severity scores, infarct size, IgG extravasation, neutrophil infiltration, loss of neurons, apoptosis, and microglia/macrophage activation in the brains of MCAO mice. Immunofluorescence studies show that KYC treatment reduces the formation of chlorotyrosine (ClTyr), a fingerprint biomarker of MPO oxidation, nitrotyrosine (NO2Tyr), and 4-hydroxynonenal (4HNE) in MCAO mice. All oxidative products colocalized with MPO in the infarcted brains, suggesting that MPO-generated oxidants are involved in forming the oxidative products.

CONCLUSIONS

MPO-generated oxidants play detrimental roles in causing brain damage after stroke which is effectively reduced by KYC.

Thioredoxin as a marker for severity and prognosis of aneurysmal subarachnoid hemorrhage

OBJECTIVE

Circulating levels of thioredoxin (Trx), a potent anti-oxidant that modulates inflammation, cell growth and apoptosis, are increased in various critical care conditions. The purpose of this study was to establish the relationship between serum Trx levels and prognosis of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

An enzyme-linked immunosorbent assay measurement of Trx was performed in serum from 132 patients and 132 healthy volunteers. Clinical outcomes included 6-month mortality and unfavorable outcome (Glasgow outcome scale score of 1-3).

RESULTS

The serum Trx levels were significantly higher in patients than in controls (23.4±12.2 ng/mL vs.8.5±4.0 ng/mL, P<0.001) and had close relation to the World Federation of Neurological Surgeons (WFNS) scores (r=0.461, P<0.001) and modified Fisher scores (r=0.459, P<0.001). Trx was an independent predictor for 6-month mortality (Odds ratio, 1.386; 95% confidence interval, 1.015-2.161; P<0.001) and 6-month unfavorable outcome (Odds ratio, 1.297; 95% confidence interval, 1.012-2.002; P<0.001). Based on receiver operating characteristic curve, TRX had similar prognostic value compared with WFNS scores and modified Fisher scores and also significantly improved their prognostic value for 6-month unfavorable outcome, but not for 6-month mortality.

CONCLUSIONS

Elevated plasma Trx levels are correlated with the severity and poor prognosis, substantializing Trx as a potential prognostic predictive biomarker following aSAH.

Metabolic syndrome increases oxidative stress but does not influence disability and short-time outcome in acute ischemic stroke patients

Oxidative stress has been implicated in the pathophysiology of cardiovascular disease and MetS and it may be one of molecular mechanisms involved in stroke. The aims of the present study were to verify differences in oxidative stress markers in acute ischemic stroke patients with and without MetS and to verify whether MetS influences disability and short time outcome of the patients. 148 patients with acute ischemic stroke were divided in two groups: with MetS (n = 92) and without MetS (n = 56). The modified Rankin Scale (mRS) was used for measuring the functional disability after 3-month follow-up. The study assessed the metabolic profile and oxidative stress markers. Stroke patients with MetS had higher levels of lipid hydroperoxides (p < 0.0001) and advanced oxidation protein products (AOPP, p = 0.0302) than those without MetS. Hydroperoxides were directly and independently associated with MetS (OR: 1.000, 95 % IC = 1.000-1.000, p = 0.005). Linear regression demonstrated that AOPP levels (R(2) = 0.281, p < 0.0001) and oxidative stress index (OSI, R(2) = 0.223, p < 0.0001) were directly associated with triglycerides levels and hydroperoxides levels was also directly associated with glucose levels (R(2) = 0.080, p = 0.013. The mRS and short-come outcome did not differ after 3 months in both groups. In conclusion, an increase in oxidative stress markers was shown in acute ischemic stroke patients with MetS and this elevation seems to be involved mainly with changes in lipid profile, but the presence of MetS did not influence short-time disability and survival of the acute ischemic stroke patients.

Gene microarray analyses for potential biomarkers of single and recurrent venous thromboembolism

Venous thromboembolism is a major cause of morbidity and mortality with a high recurrence rate. The present study aimed to explore the molecular mechanisms and potential biomarkers of single venous thromboembolism (SVTE) and recurrent venous thromboembolism (RVTE). The microarray dataset GSE19151 was downloaded from Gene Expression Omnibus, which contained data from whole blood samples from 63 healthy controls, 32 SVTE and 38 RVTE patients. Differentially expressed genes (DEGs) in the SVTE and RVTE groups compared with those in the controls were identified using the t-test, followed by clustering analysis of DEGs and samples. Functional and pathway enrichment analyses were performed for DEGs in patients with RVTE and SVTE, as well as specific DEGs in patients with RVTE. The identified 42 DEGs in RVTE were mainly enriched in biological processes of cellular protein metabolism, gene expression and translational elongation as well as in pathways associated with ribosomes, Parkinson's disease and oxidative phosphorylation. In SVTE, 20 DEGs were identified, which were mainly involved in biological processes of biopolymer biosynthesis, translational elongation and cellular protein metabolism as well as pathways associated with ribosomes and cardiac muscle contraction. In RVTE, 22 specific DEGs were mainly involved in translational elongation, negative regulation of the force of heart contraction by chemical signals, cell proliferation, ribosomal pathways and protein export. The identified DEGs of SVTE, including COX7C and UQCRQ, may be potential biomarkers for SVTE, and the specific DEGs of RVTE, including ADRBK1, NDUFA5 and ATP5O, may be potential biomarkers for RVTE.

Meta-analysis reveals protective effects of vitamin B on stroke patients

Stroke is the loss of brain function due to a disturbance in the blood supply to the brain resulting from either ischemia or hemorrhage. Previous studies have evaluated the clinical importance of nutritional interventions such as vitamin B supplementation in the management of acute strokes. However, it is still inconclusive whether or not vitamin B supplementation will benefit patients with acute strokes. Therefore, a meta-analysis was performed to assess the efficacy of vitamin B supplementation in the treatment of stroke patients. Medline, Embase, Scopus, and Cochrane Library databases were searched (from 1960 to June 2015) and forest plots were generated to illustrate the treatment effects. A systemic review of the electronic databases yielded 12 eligible studies consisting of 7474 patients. Forest plots from the meta-analyses of the included studies illustrated that vitamin B supplementation significantly lowered the plasma concentration of total homocysteine (SMD = −0.82; 95% CI: −0.77; Z = −29.06, p < 0.0001) and resulted in significant reduction in stroke recurrence (OR = 0.86%; 95% CI: 0.76, 0.97; Z = −2.41; p = 0.016) as well as a combined incidence of vascular events, including recurrent strokes, myocardial infarctions and vascular deaths (OR = 0.87%; 95% CI: 0.79, 0.96; Z= −2.73; p = 0.0063).

Additionally, the nearly-symmetrical funnel plot (Egger’s test, t = −1.705, p = 0.1224) indicated the absence of publication bias regarding the meta-analysis that examined the effect of vitamin B supplementation on the plasma levels of homocysteine in acute stroke patients. These findings suggested that vitamin B supplementation presents a potential addition to the armamentarium for the management of acute stroke patients.

Serum antioxidant enzymes activities and oxidative stress levels in patients with acute ischemic stroke: influence on neurological status and outcome

BACKGROUND

Oxidative stress is well believed to play a role in the pathogenesis of acute ischemic stroke. Reports on antioxidant enzyme activities in patients with stroke are conflicting. Therefore, the aim of this study was to investigate serum antioxidant enzyme activities and oxidative stress levels in patients with acute ischemic stroke within 1st, 5th, and 21st day after stroke onset and also the relationship between these results and the clinical status of patients.

METHODS

The current study comprised 45 patients with acute ischemic stroke and 30 healthy controls. Serum malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase activities were measured spectrophotometrically.

RESULTS

Serum MDA levels were significantly higher in acute ischemic stroke patients within 24 h after stroke onset than controls (p < 0.05), whereas serum catalase activity was significantly lower (p < 0.05). There were no significant differences in GSH-Px and SOD activities. Serum catalase and SOD activities were significantly lower in fifth day than those of controls (both, p < 0.05) but GSH-Px activity and MDA levels did not change (p > 0.05). Serum SOD activity was significantly lower in 21st day compared to SOD activity of controls (p < 0.05) but MDA levels, GSH-Px, and CAT activities did not change significantly.

CONCLUSIONS

Our study demonstrated that acute ischemic stroke patients have increased oxidative stress and decreased antioxidant enzymes activities. These findings indicated that an imbalance of oxidant and antioxidant status might play a role in the pathogenesis of acute ischemic stroke.

Inhibition of adenylyl cyclase type 5 increases longevity and healthful aging through oxidative stress protection

Mice with disruption of adenylyl cyclase type 5 (AC5 knockout, KO) live a third longer than littermates. The mechanism, in part, involves the MEK/ERK pathway, which in turn is related to protection against oxidative stress. The AC5 KO model also protects against diabetes, obesity, and the cardiomyopathy induced by aging, diabetes, and cardiac stress and also demonstrates improved exercise capacity. All of these salutary features are also mediated, in part, by oxidative stress protection. For example, chronic beta adrenergic receptor stimulation induced cardiomyopathy was rescued by AC5 KO. Conversely, in AC5 transgenic (Tg) mice, where AC5 is overexpressed in the heart, the cardiomyopathy was exacerbated and was rescued by enhancing oxidative stress resistance. Thus, the AC5 KO model, which resists oxidative stress, is uniquely designed for clinical translation, since it not only increases longevity and exercise, but also protects against diabetes, obesity, and cardiomyopathy. Importantly, inhibition of AC5's action to prolong longevity and enhance healthful aging, as well as its mechanism through resistance to oxidative stress, is unique among all of the nine AC isoforms.

Thioredoxin is a novel diagnostic and prognostic marker in patients with ischemic stroke

Serum thioredoxin (TRX), a redox-regulating protein with antioxidant activity, was recognized as an oxidative-stress marker. The purpose of this study was to investigate the potential diagnostic and prognostic role of TRX in Chinese patients with acute ischemic stroke (AIS). From January 1, 2012, to December 31, 2013, all patients with first-ever acute ischemic stroke were recruited to participate in the study. Serum levels of TRX were assayed with solid-phase sandwich ELISA, and severity of stroke was evaluated with the National Institutes of Health Stroke Scale (NIHSS) score on admission. Short-term functional outcome was measured by a modified Rankin scale (mRS) 3 months after admission. Multivariate analyses were performed using logistic regression models. We found the serum TRX reflected the disease severity of AIS. There was a significant positive association between serum TRX levels and NIHSS scores (r= 0.476, P<0.0001). Based on the ROC curve, the optimal cutoff value of serum TRX levels as an indicator for auxiliary diagnosis of AIS was projected to be 11.0 ng/ml, which yielded a sensitivity of 80.3% and a specificity of 73.7%, with the area under the curve at 0.807 (95% CI, 0.766-0.847). Elevated TRX (≥ 20.0 ng/ml) was an independent prognostic marker of short-term functional outcome [odds ratio (OR) 9.482 (95% CI, 3.11-8.15) P<0.0001; adjusted for NIHSS, other predictors and vascular risk factors] in patients with AIS. TRX improved the area under the receiver operating characteristic curve of the NHISS score for functional outcome from 0.722 (95% CI, 0.662-0.782) to 0.905 (95% CI, 0.828-0.962; P<0.0001). Our study demonstrated that elevated serum TRX level at admission was a novel diagnostic and prognostic marker in patients with acute ischemic stroke.