Worse Stroke Outcome Research Articles

Maternal dietary deficiencies in folic acid or choline reduce primary neuron viability after exposure to hypoxia through increased levels of apoptosis.

Objective: Ischemic stroke is the leading cause of death and disability globally. By addressing modifiable risk factors, particularly nutrition, the prevalence of stroke and its dire consequences can be mitigated. One-carbon (1C) metabolism is a critical biosynthetic process that is involved in neural tube closure, DNA synthesis, plasticity, and cellular proliferation. Folates and choline are two active components of 1C metabolism. We have previously demonstrated that maternal dietary deficiencies during pregnancy and lactation in folic acid or choline result in worse stroke outcomes in offspring. However, there is insufficient data to understand the neuronal mechanisms involved.Methods: Using C57Bl/6J female mice maintained on control, folic acid (0.3 mg/kg) or choline (choline bitrate 300 mg/kg) deficient diets we collected embryonic primary neurons from offspring and exposed them to hypoxic conditions for 6 hours. To determine whether increased levels of either folic acid or choline can rescue reduced neuronal viability, we supplemented cell media with folic acid and choline prior to and after exposure to hypoxia.Results: Our results suggest that maternal dietary deficiencies in either folic acid or choline during pregnancy negatively impacts offspring neuronal viability after hypoxia. Furthermore, increasing levels of folic acid (250 mg/ml) or choline chloride (250 mg/ml) prior to and after hypoxia have a beneficial impact on neuronal viability.Conclusion: The findings contribute to our understanding of the intricate interplay between maternal dietary factors, 1C metabolism, and the outcome of offspring to hypoxic events, emphasizing the potential for nutritional interventions in mitigating adverse outcomes.

Safety and efficacy of tight versus loose glycemic control in acute stroke patients: A meta-analysis of randomized controlled trials.

Hyperglycemia is associated with worse stroke outcomes, but it is uncertain whether tight glycemic control during the acute stroke period is associated with a better outcome. We conducted a meta-analysis to compare the effect of tight glycemic control versus loose glycemic control in the acute phase of stroke patients. A literature search was performed to identify randomized controlled trials comparing the safety and efficacy of tight glycemic control with a relatively loose control of blood glucose of acute stroke (ischemic or hemorrhagic) patients within 24 h after stroke onset. We required that the blood glucose level of the patients should not be lower than 6.11 mmol/L at the time of enrollment, and for the intensive blood glucose control range, we defined the blood glucose level as lower than that of the control group. The primary efficacy outcome measure was deaths from any cause at 90 days. Secondary efficacy outcomes comprised the number of participants with modified Rankin score (mRS). We define mRS scores 0-2 as favorable scores, recurrent stroke, and the National Institute of Health Stroke Scale or the European Stroke Scale scores. We defined the number of participants with hypoglycemia as our primary safety outcome. Subgroup analysis was performed according to age, the variety of interventions, maintained glucose level, and status of hypoglycemia on National Institute of Health Stroke Scale (NIHSS) scores or European Stroke Scale (ESS) scores. Fifteen randomized controlled trials (RCTs) with 2957 participants meeting the including criteria were identified and included in this meta-analysis, although not all included data on every outcome measure. Data on the primary efficacy endpoint, mortality at 90 days, was available in 11 RCTs, a total of 2575 participants. There was no significant difference between the intervention and control groups (odds ratio (OR): 1.00; 95% confidence interval (CI): 0.81-1.23; P = 0.99). For secondary endpoints, there was no difference between intervention and control groups for a mRS from 0 to 2 (OR: 0.96; 95% CI: 0.80-1.15; P = 0.69; data from 9 RCTs available), or recurrent stroke (OR: 1.34; 95% CI: 0.92-1.96; P = 0.13; data from 3 RCTs available). For NIHSS scores or ESS scores, there was a small difference in favor of intensive controls (standardized mean difference: -0.29; 95% CI: -0.54 to -0.04; P = 0.02). There was a marked increase in hypoglycemia with tight control: (OR of 9.46 (95% CI: 4.59-19.50; P < 0.00001; data from 9 RCTs available). There was no difference between tight and loose glycemic control on mortality, independence, or recurrent stroke outcome in acute stroke, but an increase in hypoglycemia. There was a small effect improvement on neurological scales, but the relevance of this needs to be confirmed in future adequately powered studies.

The LPS-inactivating enzyme acyloxyacyl hydrolase protects the brain from experimental stroke

Blood-brain-barrier (BBB) disruption is a pathological hallmark of ischemic stroke, and inflammation occurring at the BBB contributes to the pathogenesis of ischemic brain injury. Lipopolysaccharide (LPS), a cell wall component of Gram-negative bacteria, is elevated in patients with acute stroke. The activity of LPS is controlled by acyloxyacyl hydrolase (AOAH), a host enzyme that deacylates LPS to inactivated forms. However, whether AOAH influences the pathogenesis of ischemic stroke remain elusive. We performed in vivo experiments to explore the role and mechanism of AOAH on neutrophil extravasation, BBB disruption, and brain infarction. We found that AOAH was upregulated in neutrophils in peri-infarct areas from mice with transient focal cerebral ischemia. AOAH deficiency increased neutrophil extravasation into the brain parenchyma and proinflammatory cytokine production, broke down the BBB and worsened stroke outcomes in mice. These effects require Toll-like receptor 4 (TLR4) because absence of TLR4 or pharmacologic inhibition of TLR4 signaling prevented the exacerbated inflammation and BBB damage in Aoah−/− mice after ischemic stroke. Importantly, neutrophil depletion or inhibition of neutrophil trafficking by blocking LFA-1 integrin dramatically reduced stroke-induced BBB breakdown in Aoah−/− mice. Furthermore, virus-mediated overexpression of AOAH induced a substantial decrease in neutrophil recruitment that was accompanied by reducing BBB damage and stroke volumes. Our findings show the importance of AOAH in regulating neutrophil-dependent BBB breakdown and cerebral infarction. Consequently, strategies that modulate AOAH may be a new therapeutic approach for treatment of ischemic stroke.

LOX-1 and MMP-9 Inhibition Attenuates the Detrimental Effects of Delayed rt-PA Therapy and Improves Outcomes After Acute Ischemic Stroke.

Acute ischemic stroke triggers endothelial activation that disrupts vascular integrity and increases hemorrhagic transformation leading to worsened stroke outcomes. rt-PA (recombinant tissue-type plasminogen activator) is an effective treatment; however, its use is limited due to a restricted time window and hemorrhagic transformation risk, which in part may involve activation of MMPs (matrix metalloproteinases) mediated through LOX-1 (lectin-like oxLDL [oxidized low-density lipoprotein] receptor 1). This study's overall aim was to evaluate the therapeutic potential of novel MMP-9 (matrix metalloproteinase 9) ± LOX-1 inhibitors in combination with rt-PA to improve stroke outcomes. A rat thromboembolic stroke model was utilized to investigate the impact of rt-PA delivered 4 hours poststroke onset as well as selective MMP-9 (JNJ0966) ±LOX-1 (BI-0115) inhibitors given before rt-PA administration. Infarct size, perfusion, and hemorrhagic transformation were evaluated by 9.4-T magnetic resonance imaging, vascular and parenchymal MMP-9 activity via zymography, and neurological function was assessed using sensorimotor function testing. Human brain microvascular endothelial cells were exposed to hypoxia plus glucose deprivation/reperfusion (hypoxia plus glucose deprivation 3 hours/R 24 hours) and treated with ±tPA and ±MMP-9 ±LOX-1 inhibitors. Barrier function was assessed via transendothelial electrical resistance, MMP-9 activity was determined with zymography, and LOX-1 and barrier gene expression/levels were measured using qRT-PCR (quantitative reverse transcription PCR) and Western blot. Stroke and subsequent rt-PA treatment increased edema, hemorrhage, MMP-9 activity, LOX-1 expression, and worsened neurological outcomes. LOX-1 inhibition improved neurological function, reduced edema, and improved endothelial barrier integrity. Elevated MMP-9 activity correlated with increased edema, infarct volume, and decreased neurological function. MMP-9 inhibition reduced MMP-9 activity and LOX-1 expression. In human brain microvascular endothelial cells, LOX-1/MMP-9 inhibition differentially attenuated MMP-9 levels, inflammation, and activation following hypoxia plus glucose deprivation/R. Our findings indicate that LOX-1 inhibition and ± MMP-9 inhibition attenuate negative aspects of ischemic stroke with rt-PA therapy, thus resulting in improved neurological function. While no synergistic effect was observed with simultaneous LOX-1 and MMP-9 inhibition, a distinct interaction is evident.

Abstract TMP118: Aged Maternal Gut Microbiome Impairs Offspring Behavior and Exacerbates Stroke Outcome

The microbiome plays a significant role in influencing general health. A disruption of the gut biome homeostasis, dysbiosis, can be both the effect of disease or a precondition. The maternal biome has been shown to play a vital role in offspring brain and immune development by shaping the metabolic environment for the embryo. Therefore, an aged dysbiotic maternal biome may increase stroke risk factors among offspring and additionally, worsen stroke outcome. Young female C57B6 mice 3-month (M) of age had their host gut bacteria cleared via antibiotic treatment prior to recolonization via fecal microbiome transplants from 3M control, and 14M middle aged female mice. After breeding, the subsequent offspring was aged to 14 months, followed by behavioral tests, glucose tolerance, prior to a transient 60-minute middle cerebral artery occlusion (MCAO or sham surgery). The maternal biome had a significant effect on offspring biome at 2M, 6M and 9M of age, shifting the beta-diversity of females significantly (p=&lt;0.01), and males to a lesser extent (p=0.241), extending into adulthood. Additional sex specific changes were observed in adult mouse behavior with decreased motor function and increased anxiety being prevalent in male offspring at 2 months of age (p=0.0338 and 0.0261 respectively) but not in females. At 6 months of age female offspring from dysbiotic mothers exhibited significantly impaired object recognition abilities compared to control (p=&gt;0.01). Once the offspring had been subjected to a 60 min MCAO, a spontaneous recovery was observed in NDS scores in all females and in the control males, but not in males from dysbiotic mothers, suggesting that male stroke outcome is negatively affected by dysbiotic mothers. The maternal microbiome has a significant impact on offspring biome composition and health. Mice from mothers with aged microbiome exhibited sex specific early life motor function and cognitive impairment. Additionally, male offspring from dysbiotic mothers have a worsened stroke outcome.

Abstract TP307: oxLDL Preconditioning Intensifies Ischemic-Like Injury Mediated Alterations in Human Male Brain Endothelial Cell Tight Junction Protein Levels and Proinflammatory Mediators

Introduction: Acute ischemic stroke (AIS) triggers endothelial activation and induces cerebrovascular inflammation which can result in vascular function and integrity loss leading to worsened stroke outcome. A clinically correlated risk factor for stroke shown to mediate vascular dysfunction and injury is elevated levels of oxidized low density lipoprotein (oxLDL). We hypothesized that oxLDL would exacerbate acute ischemic injury mediated alteration of endothelial proinflammatory mediator and integral barrier protein levels. Methods: Primary adult male human brain microvascular endothelial cells (HBMEC) were preconditioned with human oxLDL (50 or 100ug/dL; 6, 12, 24, or 36h) or vehicle, using a serum dose reported in AIS patients. HBMECs were then exposed to normoxia (21% O 2 ) or ischemic-like injury, hypoxia plus glucose deprivation (HGD; 1% O 2 ), for 3 or 6h. HBMEC levels or expression of barrier markers, adhesion molecules, and inflammatory mediators were examined using qRT-PCR, in cell western, and FIJI mediated immunocytochemical analysis. Secondary analysis was performed on RNA sequencing of adult male aortic endothelial cells (HAoECs) exposed to oxLDL (50ug/mL; 3, 6, 12, 24h) obtained from GEO dataset GSE13139. Results: HGD injury concomitantly decreased HBMEC claudin-5, occludin, and ZO-1 as well as increased IL-1b, ICAM-1, VCAM-1, iNOS, and TNF-a. OxLDL exacerbated an HGD mediated decrease in HBMEC barrier levels and increase in proinflammatory levels in a dose and time dependent manner. HAoEC barrier, adhesion, and proinflammatory levels were not altered by oxLDL. Conclusion: OxLDL may preferentially alter brain endothelial barrier and proinflammatory levels, as opposed to aortic endothelial cells in dose and time dependent manner. Mitigating the effect of oxLDL on brain endothelial permeability and inflammation, possibly via receptor inhibition may be a novel, viable therapeutic target in the treatment of AIS.

Abstract WP303: Hypertension Disrupts the Relationship Between Pial Collateral Flow and Tissue Oxygenation During Ischemic Stroke

Introduction: Chronic hypertension decreases collateral blood flow through leptomeningeal anastomoses (LMAs) during ischemic stroke, which has been linked to worsened stroke outcome. Given the important relationship between LMA flow, tissue oxygenation and cortical cerebral blood flow (CBF), we characterized the interplay between CBF and tissue oxygenation during the sub-acute progression of ischemia in normotensive Wistar (n=6) and spontaneously hypertensive rats (SHR, n=5). Methods: Transient middle cerebral artery occlusion was used to induce ischemia for 2 hours. Relative change in LMA flow, normalized to initial drop after occlusion, was measured via surface laser Doppler; tissue oxygenation and change in parenchymal CBF were measured using a combined laser Doppler-oxygen sensor placed in the expected cortical peri-infarct region. Recording was done at 400Hz, and data analyzed in 20 second blocks over the first hour of ischemia. Data reported as mean ± SEM, statistical comparisons done via Mann-Whitney tests. Results: CBF through LMAs was significantly higher in Wistars compared to SHR at 60 min of occlusion (156±18% vs 80±4% p&lt;0.05). Pial LMA flow strongly correlated with tissue CBF (Wistar: r=0.91, SHR: r=0.75), which was also greater in Wistars at 60 min compared to SHR (80±14% vs.19±3%, p&lt;0.05). Tissue oxygenation initially dropped below 10mmHg in all animals, increasing in Wistars over the course of ischemia to 22.8±0.34 mmHg at 60 min. However, oxygenation did not recover in SHR (5.9±0.23 mmHg). The relationship between CBF and oxygenation was strongly correlated in Wistar rats with both LMA (r=0.88) and tissue CBF (r=0.88). However, in SHR, oxygenation had an inverse relationship with CBF (LMA: r= - 0.56, tissue CBF r= - 0.37). Conclusion: Under normotensive conditions the relationship between CBF and oxygenation had a strong, linear relationship. However, this relationship was disrupted by chronic hypertension, with LMA and tissue CBF increasing without an increase in tissue oxygenation. This uncoupling was potentially due to cerebrovascular dysfunction and metabolic dysregulation due to chronic hypertension. These findings could be an important consideration for the development of stroke therapeutics in hypertensive patients.

Abstract TP304: Ischemic Stroke Increases Levels of One-Carbon Enzymes and the Folate Receptor in Male and Female Brain Tissue

Stroke is the second most common cause of death worldwide and predominantly affects individuals over 65 years old. Its prevalence is projected to increase in parallel with the aging global population. Nutrition is a modifiable risk factor for ischemic stroke. Folates, B-vitamins and choline play a central role in one-carbon (1C) metabolism, which is a key metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, epigenetics, regulation of cell proliferation, and stress resistance. Our research group has previously shown that deficiencies in 1C lead to worsened stroke outcomes using preclinical models. However, the impact of ischemic stroke on 1C enzymes remains unknown. The objective of this study is to investigate whether ischemic stroke contributes to a change in the levels of 1C enzymes after ischemic stroke in male and female patients. Brain tissue sections from ischemic stroke patients and controls were stained, all tissue was co-stained with neuronal nuclei (NeuN) and DAPI (4′,6-diamidino-2-phenylindole). The colocalization of all three markers was evaluated by two individuals who were blinded to the experimental groups. Ischemic stroke increased neuronal levels of the folate receptor and 1C enzymes, methylenetetrahydrofolate reductase (MTHFR), thymidylate synthase (TS) and serine hydroxymethyltransferase (SHMT). In male stroke brain tissue was observed to have increased levels of MTHFR, TS, and SHMT. Female brain tissue had increases in the folate receptor and TS. The results suggest that ischemic stroke leads to increased demand on 1C and that there are some small differences between males and females.

Abstract TP316: Treatment With Tamoxifen, a Selective Estrogen Receptor Modulator, Has a Cell Type-Specific Effect on Mitochondrial Stress From Oxygen Glucose Deprivation in Astrocytes and Microglia

Introduction: Tamoxifen (TAM), a selective estrogen receptor modulator, is a first-line treatment to prevent recurrence of hormone receptor positive breast cancer. Stroke risk is increased in women with low estrogen and doubles in women after the age of 55 (average age of menopause). Critically, women taking TAM as breast cancer therapy had increased risk of ischemic stroke (82%). We hypothesize treatment with TAM will increase stroke severity, which is associated with increased blood brain barrier (BBB) damage and worsened neuroinflammation. We investigated effects of TAM on mitochondrial stress and cellular function in astrocytes and microglia, key cells of the BBB and neuroimmune response, respectively. Methods: Cultured female human astrocytes and HMC3 microglia were treated with TAM (1uM), 17ß-estradiol (10nM, E2), or vehicle (DMSO) for 24 hours. Cells were separated into two groups: normoxic (21% O 2 , 25mM glucose) or oxygen and glucose deprivation (OGD) conditions 6 hours before analysis. Mitochondrial function was assessed using a Seahorse XFe96 Analyzer. Microglial expression of mitochondrial proteins (Complex I &amp; III and DRP1) was analyzed with western blot, and function was assessed with flow cytometry after in vitro phagocytosis of pHrodo red zymosan. Results: TAM reduced maximal (p =0.0174) and basal respiration (p =0.0149) under OGD conditions in microglia compared with DMSO or E2 treatment. However, in astrocytes, maximal and basal respiration were increased in OGD (p =0.0003, p =0.0002). There was no significant difference in expression of mitochondrial proteins or phagocytic function in HMC3 microglia under either normoxic or OGD conditions after TAM treatment. Conclusions: TAM treatment resulted in a cell type-specific alteration in mitochondrial stress response. Since mitochondrial stress is a hallmark of stroke pathophysiology, and microglia and astrocytes are among the earliest cells to respond to ischemia, treatment with tamoxifen might alter the cellular environment, by its divergent actions on these two cell types, leading to worsened stroke outcomes. These data support the need for in vivo investigation to elucidate the mechanism by which TAM is altering cellular response. Support: RFAG042189 to FS, 1F30NS131053 to MEZ

Cerebral small vessel disease and stroke: Linked by stroke aetiology, but not stroke lesion location or size

BackgroundCerebral small vessel disease (SVD) has previously been associated with worse stroke outcome, vascular dementia, and specific post-stroke cognitive deficits. The underlying causal mechanisms of these associations are not yet fully understood. We investigated whether a relationship between SVD and certain stroke aetiologies or a specific stroke lesion anatomy provides a potential explanation. MethodsIn a retrospective observational study, we examined 859 patients with first-ever, non-SVD anterior circulation ischemic stroke (age = 69.0±15.2). We evaluated MRI imaging markers to assess an SVD burden score and mapped stroke lesions on diffusion-weighted MRI. We investigated the association of SVD burden with i) stroke aetiology, and ii) lesion anatomy using topographical statistical mapping. ResultsWith increasing SVD burden, stroke of cardioembolic aetiology was more frequent (ρ = 0.175; 95 %-CI = 0.103;0.244), whereas cervical artery dissection (ρ = -0.143; 95 %-CI = -0.198;-0.087) and a patent foramen ovale (ρ = -0.165; 95 %-CI = -0.220;-0.104) were less frequent stroke etiologies. However, no significant associations between SVD burden and stroke aetiology remained after additionally controlling for age (all p>0.125). Lesion-symptom-mapping and Bayesian statistics showed that SVD burden was not associated with a specific stroke lesion anatomy or size. ConclusionsIn patients with a high burden of SVD, non-SVD stroke is more likely to be caused by cardioembolic aetiology. The common risk factor of advanced age may link both pathologies and explain some of the existing associations between SVD and stroke. The SVD burden is not related to a specific stroke lesion location.

Sleep disorders as both risk factors for, and a consequence of, stroke: A narrative review.

Sleep disorders are increasingly implicated as risk factors for stroke, as well as a determinant of stroke outcome. They can also occur secondary to the stroke itself. In this review, we describe the variety of different sleep disorders associated with stroke and analyze their effect on stroke risk and outcome. A search term-based literature review ("sleep," "insomnia," "narcolepsy," "restless legs syndrome," "periodic limb movements during sleep," "excessive daytime sleepiness" AND "stroke" OR "cerebrovascular" in PubMed; "stroke" and "sleep" in ClinicalTrials.gov) was performed. English articles from 1990 to March 2023 were considered. Increasing evidence suggests that sleep disorders are risk factors for stroke. In addition, sleep disturbance has been reported in half of all stroke sufferers; specifically, an increase is not only sleep-related breathing disorders but also periodic limb movements during sleep, narcolepsy, rapid eye movement (REM) sleep behavior disorder, insomnia, sleep duration, and circadian rhythm sleep-wake disorders. Poststroke sleep disturbance has been associated with worse outcome. Sleep disorders are risk factors for stroke and associated with worse stroke outcome. They are also a common consequence of stroke. Recent guidelines suggest screening for sleep disorders after stroke. It is possible that treatment of sleep disorders could both reduce stroke risk and improve stroke outcome, although further data from clinical trials are required.

Mild traumatic brain injury induces pericyte detachment independent of stroke vulnerability

Mild traumatic brain injury (mTBI) is an independent risk factor for ischemic stroke and can result in poorer outcomes- an effect presumed to involve the cerebral vasculature. Here we tested the hypothesis that mTBI-induced pericyte detachment from the cerebrovascular endothelium is responsible for worsened stroke outcomes. We performed a mild closed-head injury and/or treated C57/bl6 mice with imatinib mesylate, a tyrosine kinase inhibitor that induces pericyte detachment. The time course of pericyte detachment was assessed 7, 14, and 28 days post injury (DPI). To test the role of pericytes in TBI-induced exacerbation of ischemic stroke outcomes, we induced mTBI and/or treated mice with imatinib for one week prior to transient middle cerebral artery occlusion. We found that injury promoted pericyte detachment from the vasculature commensurate with the levels of detachment seen in imatinib-only treated animals, and that the detachment persisted for at least 14DPI, but recovered to sham levels by 28DPI. Further, mTBI, but not imatinib-induced pericyte detachment, increased infarct volume. Thus, we conclude that the transient detachment of pericytes caused by mTBI may not be sufficient to exacerbate subsequent ischemic stroke damage. These data have important implications for understanding cerebrovascular dysfunction following mTBI and potential mechanisms of increased risk for future ischemic strokes.

Ozanimod Differentially Preserves Human Cerebrovascular Endothelial Barrier Proteins and Attenuates MMP-9 Activity Following In Vitro Acute Ischemic Injury.

Endothelial integrity is critical in mitigating a vicious cascade of secondary injuries following acute ischemic stroke (AIS). Matrix metalloproteinase-9 (MMP-9), a contributor to endothelial integrity loss, is elevated during stroke and is associated with worsened stroke outcome. We investigated the FDA approved selective sphingosine-1-phosphate receptor 1 (S1PR1) ligand, ozanimod, on the regulation/activity of MMP-9 as well as endothelial barrier components (PECAM-1, claudin-5, and ZO-1) in human brain microvascular endothelial cells (HBMECs) following hypoxia plus glucose deprivation (HGD). We previously reported that S1PR1 activation improves HBMEC integrity; however, mechanisms underlying S1PR1 involvement in endothelial cell barrier integrity have not been clearly elucidated. We hypothesized that ozanimod would attenuate an HGD-induced increase in MMP-9 activity which would concomitantly attenuate the loss of integral barrier components. Male HBMECs were treated with ozanimod or vehicle and exposed to 3h of normoxia (21% O2) or HGD (1% O2). Immunoblotting, zymography, qRT-PCR, and immunocytochemical labeling techniques assessed processes related to MMP-9 and barrier markers. We observed that HGD acutely increased MMP-9 activity and reduced claudin-5 and PECAM-1 levels, and ozanimod attenuated these responses. In situ analysis via PROSPER, suggested that attenuation of MMP-9 activity may be a primary factor in maintaining these integral barrier proteins. We also observed that HGD increased intracellular mechanisms associated with augmented MMP-9 activation, however ozanimod had no effect on these select factors. Thus, we conclude that ozanimod has the potential to attenuate HGD mediated decreases in HBMEC integrity in part by decreasing MMP-9 activity as well as preserving barrier properties.

Lauric acid provides neuroprotection against oxidative stress in mouse model of hyperglycaemic stroke

During ischemic stroke, higher glucose level linked worse outcomes were reported even in patients without pre-existing diabetes. Evidence suggest that such worse stroke outcomes were mainly due to production of reactive, toxic glucose metabolites that expands oxidative damage inside the brain. As a consequence of high oxidative stress, microvasculature structures and tight junctions compromised their functionally, infarct volume expands and brain edema exacerbates. In a mouse model of ischemic stroke with induced acute hyperglycaemia, Lauric acid (LA) as a natural saturated fatty acid demonstrated neuroprotection by attenuating infarct volume and brain edema. In addition, in the ipsilateral hyperglycaemic brain, the LA significantly increased the expression of tight junction representative protein (occludin) as well as anti-oxidative markers; Manganese superoxide dismutase (Mn) SOD, Extracellular superoxide dismutase (Ec-SOD) and nuclear factor-erythroid factor 2-related factor 2 (Nrf2) in the ipsilateral region against hyperglycemic ischemic stroke. LA treated animals showed a significant reduction in the production of lipid peroxidation products (4-HNE) in the microvascular structures, maintained the blood brain barrier (BBB) integrity. LA linked neuroprotective outcomes were further confirmed by behavioral tests, where functional outcomes and motor coordination were improved significantly. Furthermore, LA treatment enhanced food intake, decreased mortality rate, and net body weight loss. Conclusively, LA modulated ischemic insult exacerbated by hyperglycemia and provided neuroprotection.

Early Epileptic Seizures after Ischemic Stroke: Their Association with Stroke Risk Factors and Stroke Characteristics.

Background and Objectives: A growing number of stroke survivors face various stroke complications, including new-onset epileptic seizures (ESs). Post-stroke ESs are divided into early and late ESs based on the time of onset after stroke. Early ESs are associated with worse stroke outcomes, longer hospitalization and an increased risk of late ESs. A variety of risk factors for early ESs are being studied in order to prevent their occurrence. Therefore, we aim to determine the association of early ESs with ischemic stroke risk factors and characteristics. Materials and Methods: A total of 166 patients, treated for ischemic stroke in the Hospital of Lithuanian University of Health Sciences Kaunas Clinics, were enrolled in a prospective cohort study. Initially, data about stroke risk factors, localization, severity and treatment were collected, followed by an observation period of 14 days for early ESs. Results: Early ESs occurred in 11 (6.6%) participants. The probability of early ESs after ischemic stroke among males and females (LogRank = 1.281; p > 0.05), younger (≤65 y) and older (>65 y) participants (LogRank = 0.129; p > 0.05) was the same. The presence of ischemic stroke risk factors, such as atrial fibrillation (LogRank = 0.004; p > 0.05), diabetes mellitus (LogRank = 1.168; p > 0.05) and dyslipidemia (LogRank = 0.092; p > 0.05), did not increase the probability of early ESs. However, participants without a prior history of arterial hypertension (LogRank = 4.453; p < 0.05) were more likely to develop early ESs. Stroke localization (anterior versus posterior) (LogRank = 0.011; p > 0.05), stroke severity (LogRank = 0.395; p > 0.05) and type of treatment (specific versus non-specific) (LogRank = 1.783; p > 0.05) did not affect the probability of early ESs.

The aging ovary impairs acute stroke outcomes

In experimental stroke, ovariectomized (OVX) adult rats have larger infarct volumes and greater sensory-motor impairment as compared to ovary-intact females and is usually interpreted to indicate that ovarian hormones are neuroprotective for stroke. Previous work from our lab shows that middle-aged, acyclic reproductively senescent (RS) females have worse stroke outcomes as compared to adult (normally cycling) females. We hypothesized that if loss of ovarian estrogen is the critical determinant of stroke outcomes, then ovary-intact middle-aged acyclic females, who have reduced levels of estradiol, should have similar stroke outcomes as age-matched OVX. Instead, the data demonstrated that OVX RS animals showed better sensory-motor function after stroke and reduced infarct volume as compared to ovary-intact females. Inflammatory cytokines were decreased in the aging ovary after stroke as compared to non-stroke shams, which led to the hypothesis that immune cells may be extravasated from the ovaries post-stroke. Flow cytometry indicated reduced overall T cell populations in the aging ovary after middle cerebral artery occlusion (MCAo), with a paradoxical increase in regulatory T cells (Tregs) and M2-like macrophages. Moreover, in the brain, OVX RS animals showed increased Tregs, increased M2-like macrophages, and increased MHC II + cells as compared to intact RS animals, which have all been shown to be correlated with better prognosis after stroke. Depletion of ovary-resident immune cells after stroke suggests that there may be an exaggerated response to ischemia and possible increased burden of the inflammatory response via extravasation of these cells into circulation. Increased anti-inflammatory cells in the brain of OVX RS animals further supports this hypothesis. These data suggest that stroke severity in aging females may be exacerbated by the aging ovary and underscore the need to assess immunological changes in this organ after stroke.

Race and sex disparities in acute outcomes of patients with acute ischemic stroke and diabetes mellitus. A national inpatient sample study

BackgroundDiabetes Mellitus (DM) disproportionately affects racial minority groups and is a well-established risk factor for ischemic stroke and worse stroke outcomes. Whether racial disparities exist in acute outcomes of patients presenting with Acute Ischemic Stroke (AIS) and comorbid DM, including potential differences in the administration of evidence-based reperfusion therapy, remains unclear. We aimed to assess whether racial and sex differences exist in the acute outcomes and treatment of patients with DM presenting with AIS. MethodsJanuary 2016-December 2018 AIS admissions with diabetes were extracted from the US National Inpatient Sample (NIS). Multivariable logistic regressions assessed the association between race, sex, and differences in in-hospital outcomes (mortality, hospitalisation >4 days, routine discharge, and stroke severity). Further models assessed the relationship between race, sex, and receipt of thrombolysis and thrombectomy. All models were adjusted for relevant confounders, including comorbidities and stroke severity. Results92,404 records representative of 462,020 admissions were extracted. Median (IQR) age was 72 (61−79), with 49 % women, 64 % White, 23 % African American, and 10 % Hispanic patients. African Americans had lower odds of in-hospital mortality compared to Whites (adjusted odds ratio; 99 % confidence interval=0.72;0.61–0.86), but were more likely to have prolonged hospitalisation (1.46;1.39–1.54), be discharged to locations other than home (0.78;0.74–0.82) and have moderate/severe stroke (1.17;1.08–1.27). Additionally, African American (0.76;0.62–0.93) and Hispanic patients (0.66;0.50–0.89) had lower odds of receiving thrombectomy. Compared to men, women had increased odds of in-hospital mortality (1.15;1.01–1.32). ConclusionsRacial and sex disparities exist in both evidence-based reperfusion therapy and in-hospital outcomes amongst patients with AIS and diabetes. Further measures are needed to address these disparities and reduce the excess risk of adverse outcomes among women and African American patients.

Maternal dietary deficiencies in folic acid or choline worsen stroke outcomes in adult male and female mouse offspring.

Maternal one-carbon metabolism plays an important role in early life programming. There is a well-established connection between the fetal environment and the health status of the offspring. However, there is a knowledge gap on how maternal nutrition impacts stroke outcomes in offspring. The aim of our study was to investigate the role of maternal dietary deficiencies in folic acid or choline on stroke outcomes in 3-month-old offspring. Adult female mice were fed a folic acid-deficient diet, choline-deficient diet, or control diet 4 weeks before pregnancy. They were continued on diets during pregnancy and lactation. Male and female offspring were weaned onto a control diet and at 2 months of age were subjected to ischemic stroke within the sensorimotor cortex via photothrombotic damage. Mothers maintained on either a folic acid-deficient diet or choline-deficient diet had reduced levels of S-adenosylmethionine in the liver and S-adenosylhomocysteine in the plasma. After ischemic stroke, motor function was impaired in 3-month-old offspring from mothers receiving either a folic acid-deficient diet or choline-deficient diet compared to the animals receiving a control diet. In brain tissue, there was no difference in ischemic damage volume. When protein levels were assessed in ischemic brain tissue, there were lower levels of active caspase-3 and hypoxia-inducible factor 1α in males compared to females and betaine levels were reduced in offspring from the mothers receiving a choline-deficient diet. Our results demonstrate that a deficient maternal diet at critical time points in neurodevelopment results in worse stroke outcomes. This study emphasizes the importance of maternal diet and the impact it can have on offspring health.

Dietary vitamin B12 deficiency impairs motor function and changes neuronal survival and choline metabolism after ischemic stroke in middle-aged male and female mice

ABSTRACT Nutrition is a modifiable risk factor for ischemic stroke. As people age their ability to absorb some nutrients decreases, a primary example is vitamin B12. Older individuals with a vitamin B12 deficiency are at a higher risk for ischemic stroke and have worse stroke outcome. However, the mechanisms through which these occur remain unknown. The aim of the study was to investigate the role of vitamin B12 deficiency in ischemic stroke outcome and mechanistic changes in a mouse model. Ten-month-old male and female mice were put on control or vitamin B12 deficient diets for 4 weeks prior to and after ischemic stroke to the sensorimotor cortex. Motor function was measured, and tissues were collected to assess potential mechanisms. All deficient mice had increased levels of total homocysteine in plasma and liver tissues. After ischemic stroke, deficient mice had impaired motor function compared to control mice. There was no difference between groups in ischemic damage volume. However, within the ischemic damage region, there was an increase in total apoptosis of male deficient mice compared to controls. Furthermore, there was an increase in neuronal survival in ischemic brain tissue of the vitamin B12 deficient mice compared to controls. Additionally, there were changes in choline metabolites in ischemic brain tissue because of a vitamin B12 deficiency. The data presented in this study confirms that a vitamin B12 deficiency worsens stroke outcome in male and female mice. The mechanisms driving this change may be a result of neuronal survival and compensation in choline metabolism within the damaged brain tissue.

Worsened Stroke Outcome in a Model of Preeclampsia is Associated With Poor Collateral Flow and Oxidative Stress.

Preeclampsia increases the incidence of maternal stroke, a devastating condition that is on the rise. We investigated stroke outcome in a model of experimental preeclampsia with and without treatment with clinically relevant doses of magnesium sulfate (experimental preeclampsia+MgSO4) compared to normal late-pregnant and nonpregnant rats. Transient middle cerebral artery occlusion was used to induce focal stroke for either 1.5 or 3 hours. Infarct volume and hemorrhagic transformation were determined as measures of stroke outcome. Changes in core middle cerebral artery and collateral flow were measured by dual laser Doppler. The relationship between middle cerebral artery perfusion deficit and infarction was used as a measure of ischemic tolerance. Oxidative stress and endothelial dysfunction were measured by 3-nitrotyrosine and 8-isoprostane, in brain and serum, respectively. Late-pregnant animals had robust collateral flow and greater ischemic tolerance of brain tissue, whereas experimental preeclampsia had greater infarction that was related to poor collateral flow, endothelial dysfunction, and oxidative stress. Importantly, pregnancy appeared preventative of hemorrhagic transformation as it occurred only in nonpregnant animals. MgSO4 did not provide benefit to experimental preeclampsia animals for infarction. Stroke outcome was worse in a model of preeclampsia. As preeclampsia increases the risk of future stroke and cardiovascular disease, it is worth understanding the influence of preeclampsia on the material brain and factors that might potentiate injury both during the index pregnancy and years postpartum.