Immune-Inflammatory, Metabolic, Oxidative, and Nitrosative Stress Biomarkers Predict Acute Ischemic Stroke and Short-Term Outcome

Association of multiple sclerosis with stroke: A comprehensive review

Background

Multiple sclerosis (MS) is a chronic immune-mediated disorder characterized by the degradation of the myelin sheath in the central nervous system. Research indicates that individuals with MS exhibit a higher susceptibility to stroke compared to the general population. This association is rooted in shared underlying mechanisms, specifically involving neuroinflammatory processes.

Methodology

We performed an extensive search on PubMed, MEDLINE, Embase, Scopus, and Google Scholar using specific terms. The search terms included variations of "multiple sclerosis," "stroke," "cerebrovascular disease," "vascular risk factors," "disease-modifying therapies," and "neuroinflammation." The search was limited to articles published from January 1, 2000, up to 31 May, 2023.

Results and Discussion

Stroke, a global health burden characterized by significant mortality and adult disability, underscores the critical importance of understanding the link between MS and stroke. Despite a growing body of research establishing an elevated risk of stroke in MS patients, notable information gaps persist. Limited prospective multicenter studies on stroke incidence in MS patients contribute to an incomplete understanding of the precise relationship between these two conditions.

Conclusion

In conclusion, this review underscores the critical need for a thorough understanding of the complex relationship between MS and stroke. The identified risk factors and the influence of MS DMTs on stroke risk necessitate further investigation to inform evidence-based preventive and therapeutic strategies. Bridging the existing information gaps through prospective multicenter studies is imperative for a comprehensive understanding of this association. The development of targeted diagnostic and therapeutic approaches for acute stroke risk in MS patients is paramount to mitigate the impact of these debilitating conditions. Ultimately, this review serves as a foundation for future efforts to enhance preventative measures and therapeutic interventions, thereby improving the overall quality of life for individuals with MS susceptible to strokes.

Natural Fatty Acid Guards against Brain Endothelial Cell Death and Microvascular Pathology following Ischemic Insult in the Presence of Acute Hyperglycemia

Ischemic stroke is worsened by the presence of sudden high blood sugar levels, even in individuals without pre-existing diabetes. This elevated glucose concentration hampers the ability of energy-starved brain cells to efficiently use it as a source of energy. Consequently, this leads to the production of abundant amounts of toxic glucose metabolites, which trigger oxidative stress in the brain milieu, particularly in the microvasculature of the brain. A prominent feature of this oxidative stress is the demise of endothelial cells, causing detrimental changes in blood vessels, including a reduction in their vascular diameter, a decreased efficiency of vessel proliferation, and the impaired integrity of tight junctions. These vascular pathologies contributed to an increase in the volume of damaged tissues (infarct), an exacerbation of brain swelling (edema), and a decline in cognitive and motor functions. In a mouse model of ischemic stroke with induced acute hyperglycemia, a naturally occurring saturated fatty acid provides protective cover to the microvasculature by preventing damage related to oxidative stress. Our current research revealed that lauric acid (LA) attenuated infarct volume and reduced brain edema by reducing endothelial cell death, enhancing vessels' diameter, promoting vascular angiogenesis, and stabilizing barrier functions. Animals administered with this natural compound showed a significant reduction in 4-HNE-positive vessels. In conclusion, natural saturated fatty acids help to preserve brain microvascular functions following ischemic insults in the presence of acute hyperglycemia.

Stroke risk in multiple sclerosis: a critical appraisal of the literature

Observational studies suggest that the occurrence of stroke on multiple sclerosis (MS) patients is higher compared to the general population. MS is a heterogeneous disease that involves an interplay of genetic, environmental and immune factors. The occurrence of stroke is subject to a wide range of both modifiable and non-modifiable, short- and long-term risk factors. Both MS and stroke share common risk factors. The immune mechanisms that underlie stroke are similar to neurodegenerative diseases and are attributed to neuroinflammation. The inflammation in autoimmune diseases may, therefore, predispose to an increased risk for stroke or potentiate the effect of conventional stroke risk factors. There are, however, additional determinants that contribute to a higher risk and incidence of stroke in MS. Due to the challenges that are associated with their differential diagnosis, the objective is to present an overview of the factors that may contribute to increased susceptibility or occurrence of stroke in MSpatients by performing a review of the available to date literature. As both MS and stroke can individually detrimentally affect the quality of life of afflicted patients, the identification of factors that contribute to an increased risk for stroke in MS is crucial for the prompt implementation of preventative therapeutic measures to limit the additive burden that stroke imposes.

Paraoxonase 1 status is a major Janus-faced component of mild and moderate acute ischemic stroke and consequent disabilities

AIMS

This study aims to examine the associations between paraoxonase 1 (PON)1 status and acute ischemic stroke (AIS) and consequent disabilities.

METHODS

This study recruited 122 patients with AIS and 40 healthy controls and assessed the Q192R gene variants, arylesterase (AREase) and chloromethyl phenylacetate (CMPAase) activities, and high-density lipoprotein cholesterol (HDLc) in baseline conditions. AREase and CMPAase were measured 3 months later. The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin score (mRS) were assessed at baseline and 3 and 6 months later.

RESULTS

Reduced CMPAase and increased AREase activities are significantly associated with AIS and mRS and NIHSS scores (baseline and 3 and 6 months later). The best predictor of AIS/disabilities was a decrease in the z-unit-based composite zCMPAase-zAREase score. Serum high density lipoprotein cholsterol (HDLc) was significantly correlated with CMPAase, but not AREase, activity and a lowered zCMPAase + zHDLc score was the second best predictor of AIS/disabilities. Regression analysis showed that 34.7% of the variance in baseline NIHSS was explained by zCMPAase-zAREase and zCMPAase + zHDLc composites, HDLc, and hypertension. Neural network analysis showed that stroke was differentiated from controls with an area under the ROC curve of 0.975 using both new composite scores, PON1 status, hypertension, dyslipidemia, previous stroke as body mass index. The PON1 Q192R genotype has many significant direct and mediated effects on AIS/disabilities, however, its overall effect was not significant.

DISCUSSION

PON1 status and the CMPAase-HDLc complex play key roles in AIS and its disabilities at baseline and 3 and 6 months later.

The role of homocysteine levels as a risk factor of ischemic stroke events: a systematic review and meta-analysis

Introduction

Among numerous risk factors, homocysteine (Hcy) has been linked to cerebral infarction; however, results have been inconsistent. This review aimed to conduct a meta-analysis of published studies to investigate the relationship between plasma Hcy levels and the risk of ischemic stroke.

Methods

A systematic literature search was conducted until November 2022 to obtain articles reporting Hcy levels in ischemic stroke patients. Review Manager software was used to perform all statistical analyses (version 5.3).

Results

Initial investigation yielded 283 articles. The final evaluation included 21 articles, including two prospective studies, one retrospective cohort, and 18 case-control studies. These studies included 9888 participants, of which 5031 were admitted patients with ischemic stroke. An integrated analysis revealed that ischemic stroke patients had significantly higher levels of Hcy than controls (mean difference (MD) = +3.70, 95% confidence interval (CI) = 2.42-5.81, p < 0.001).

Conclusion

This meta-analysis and systematic review indicate that ischemic stroke patients have significantly higher homocysteine levels than controls. Detecting hyperhomocysteinemia and reducing homocysteine levels should be explored among individuals at increased risk for ischemic stroke.

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.

Stem Cells Attenuate the Inflammation Crosstalk Between Ischemic Stroke and Multiple Sclerosis: A Review

The immense neuroinflammation induced by multiple sclerosis (MS) promotes a favorable environment for ischemic stroke (IS) development, making IS a deadly complication of MS. The overlapping inflammation in MS and IS is a prelude to the vascular pathology, and an inherent cell death mechanism that exacerbates neurovascular unit (NVU) impairment in the disease progression. Despite this consequence, no therapies focus on reducing IS incidence in patients with MS. To this end, the preclinical and clinical evidence we review here argues for cell-based regenerative medicine that will augment the NVU dysfunction and inflammation to ameliorate IS risk.

Need for a Paradigm Shift in the Treatment of Ischemic Stroke: The Blood-Brain Barrier

Blood-brain barrier (BBB) integrity is essential to maintaining brain health. Aging-related alterations could lead to chronic progressive leakiness of the BBB, which is directly correlated with cerebrovascular diseases. Indeed, the BBB breakdown during acute ischemic stroke is critical. It remains unclear, however, whether BBB dysfunction is one of the first events that leads to brain disease or a down-stream consequence. This review will focus on the BBB dysfunction associated with cerebrovascular disease. An added difficulty is its association with the deleterious or reparative effect, which depends on the stroke phase. We will first outline the BBB structure and function. Then, we will focus on the spatiotemporal chronic, slow, and progressive BBB alteration related to ischemic stroke. Finally, we will propose a new perspective on preventive therapeutic strategies associated with brain aging based on targeting specific components of the BBB. Understanding BBB age-evolutions will be beneficial for new drug development and the identification of the best performance window times. This could have a direct impact on clinical translation and personalised medicine.

Protein Biomarkers in Blood Reflect the Interrelationships Between Stroke Outcome, Inflammation, Coagulation, Adhesion, Senescence and Cancer

The most important predictors for outcomes after ischemic stroke, that is, for health deterioration and death, are chronological age and stroke severity; gender, genetics and lifestyle/environmental factors also play a role. Of all these, only the latter can be influenced after the event. Recurrent stroke may be prevented by antiaggregant/anticoagulant therapy, angioplasty of high-grade stenoses, and treatment of cardiovascular risk factors. Blood cell composition and protein biomarkers such as C-reactive protein or interleukins in serum are frequently considered as biomarkers of outcome. Here we aim to provide an up-to-date protein biomarker signature that allows a maximum of mechanistic understanding, to predict health deterioration following stroke. We thus surveyed protein biomarkers that were reported to be predictive for outcome after ischemic stroke, specifically considering biomarkers that predict long-term outcome (≥ 3 months) and that are measured over the first days following the event. We classified the protein biomarkers as immune‑inflammatory, coagulation-related, and adhesion-related biomarkers. Some of these biomarkers are closely related to cellular senescence and, in particular, to the inflammatory processes that can be triggered by senescent cells. Moreover, the processes that underlie inflammation, hypercoagulation and cellular senescence connect stroke to cancer, and biomarkers of cancer-associated thromboembolism, as well as of sarcopenia, overlap strongly with the biomarkers discussed here. Finally, we demonstrate that most of the outcome-predicting protein biomarkers form a close-meshed functional interaction network, suggesting that the outcome after stroke is partially determined by an interplay of molecular processes relating to inflammation, coagulation, cell adhesion and cellular senescence.

Predictive value of hemoglobin level on early neurological outcomes in acute ischemic stroke

BACKGROUND

Few studies have examined the association between hemoglobin (Hb) levels and early neurological changes following acute ischemic stroke (AIS). The present research investigated whether higher or lower Hb level on admission was associated with early neurological deterioration (END) in AIS patients. Furthermore, we evaluated the predictive effect of Hb concentration on stable or improving outcome.

METHODS

In this prospective cohort study, a total of 1330 patients admitted within 24 hours after AIS onset were finally involved in the analysis. We classified participants into four groups according to baseline Hb levels: ≤120, 121-140, 141-160, and >160 g/L. The risk of END was accessed by means of logistic regression analysis, and tendency of improvement and stability by multinomial logit analysis. We further evaluated the pattern and magnitude of association of Hb as a continuous variable and END by multivariate logistic regression analysis of restricted cubic spline.

RESULTS

Compared with the reference group, hemoglobin >160 g/L was associated with END (OR, 95%CI; 2.149, 1.314-3.512) and severe END (OR, 95% CI as 2.317, 1.351-3.976 and 2.810,1.589-4.968, respectively). Comparatively, higher Hb level also independently predicted improving (OR, 95% CI; 0.322, 0.170-0.609) and stable (OR, 95% CI; 0.371, 0.205-0.673) outcome. Similar results were found when restricted to anterior circulation ischemic stroke after adjustment of variables including large vessel disease.

CONCLUSIONS

We concluded that patients with higher baseline Hb level are at significantly higher risk for END, and less likely to reach stable or improving status at the early stage of stroke.

Inflammatory Cytokines and Risk of Ischemic Stroke: A Mendelian Randomization Study

Background: Observational studies have revealed the association between some inflammatory cytokines and the occurrence of ischemic stroke, but the causal relationships remain unclear.

Methods: We conducted a two-sample Mendelian randomization (MR) analysis to assess the causal effects of thirty inflammatory cytokines and the risk of ischemic stroke. For exposure data, we collected genetic variants associated with inflammatory cytokines as instrumental variables (IVs) from a genome-wide association study (GWAS) meta-analysis from Finland (sample size up to 8,293). For the outcome data, we collected summary data of ischemic stroke from a large-scale GWAS meta-analysis involved 17 studies (34,217 cases and 406,111 controls). We further performed a series of sensitivity analyses as validation of primary MR results.

Results: According to the primary MR estimations and further sensitivity analyses, we established one robust association after Bonferroni correction: the odds ratio (95% CI) per unit change in genetically increased IL-4 was 0.84 (0.89–0.95) for ischemic stroke. The chemokine MCP3 showed a nominally significant association with ischemic stroke risk (OR: 0.93, 95% CI: 0.88–0.99, unadjusted p < 0.05). There was no evidence of a causal effect of other inflammatory cytokines and the risk of ischemic stroke.

Conclusions: Our study suggested that genetically increased IL-4 levels showed a protective effect on the risk of ischemic stroke, which provides important new insights into the potential therapeutic target for preventing ischemic stroke.

MicroRNA-210 regulates the metabolic and inflammatory status of primary human astrocytes

Background

Astrocytes are the most numerous glial cell type with important roles in maintaining homeostasis and responding to diseases in the brain. Astrocyte function is subject to modulation by microRNAs (miRs), which are short nucleotide strands that regulate protein expression in a post-transcriptional manner. Understanding the miR expression profile of astrocytes in disease settings provides insight into the cellular stresses present in the microenvironment and may uncover pathways of therapeutic interest.

Methods

Laser-capture microdissection was used to isolate human astrocytes surrounding stroke lesions and those from neurological control tissue. Astrocytic miR expression profiles were examined using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Primary human fetal astrocytes were cultured under in vitro stress conditions and transfection of a miR mimic was used to better understand how altered levels of miR-210 affect astrocyte function. The astrocytic response to stress was studied using qPCR, enzyme-linked immunosorbent assays (ELISAs), measurement of released lactate, and Seahorse.

Results

Here, we measured miR expression levels in astrocytes around human ischemic stroke lesions and observed differential expression of miR-210 in chronic stroke astrocytes compared to astrocytes from neurological control tissue. We also identified increased expression of miR-210 in mouse white matter tissue around middle cerebral artery occlusion (MCAO) brain lesions. We aimed to understand the role of miR-210 in primary human fetal astrocytes by developing an in vitro assay of hypoxic, metabolic, and inflammatory stresses. A combination of hypoxic and inflammatory stresses was observed to upregulate miR-210 expression. Transfection with miR-210-mimic (210M) increased glycolysis, enhanced lactate export, and promoted an anti-inflammatory transcriptional and translational signature in astrocytes. Additionally, 210M transfection resulted in decreased expression of complement 3 (C3) and semaphorin 5b (Sema5b).

Conclusions

We conclude that miR-210 expression in human astrocytes is modulated in response to ischemic stroke disease and under in vitro stress conditions, supporting a role for miR-210 in the astrocytic response to disease conditions. Further, the anti-inflammatory and pro-glycolytic impact of miR-210 on astrocytes makes it a potential candidate for further research as a neuroprotective agent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02373-y.

Risk Estimation of Infectious and Inflammatory Disorders in Hospitalized Patients With Acute Ischemic Stroke Using Clinical-Lab Nomogram

Background: Infections after acute ischemic stroke are common and likely to complicate the clinical course and negatively affect patient outcomes. Despite the development of various risk factors and predictive models for infectious and inflammatory disorders (IAID) after stroke, more objective and easily obtainable predictors remain necessary. This study involves the development and validation of an accessible, accurate nomogram for predicting in-hospital IAID in patients with acute ischemic stroke (AIS).

Methods: A retrospective cohort of 2,257 patients with AIS confirmed by neurological examination and radiography was assessed. The International Statistical Classification of Diseases and Health related Problem's definition was used for IAID. Data was obtained from two hospitals between January 2016 and March 2020.

Results: The incidence of IAID was 19.8 and 20.8% in the derivation and validation cohorts, respectively. Using an absolute shrinkage and selection operator (LASSO) algorithm, four biochemical blood predictors and four clinical indicators were optimized from fifty-five features. Using a multivariable analysis, four predictors, namely age (adjusted odds ratio, 1.05; 95% confidence interval [CI], 1.038–1.062; p < 0.001), comatose state (28.033[4.706–536.403], p = 0.002), diabetes (0.417[0.27–0.649], p < 0.001), and congestive heart failure (CHF) (5.488[2.451–12.912], p < 0.001) were found to be risk factors for IAID. Furthermore, neutrophil, monocyte, hemoglobin, and high-sensitivity C-reactive protein were also found to be independently associated with IAID. Consequently, a reliable clinical-lab nomogram was constructed to predict IAID in our study (C-index value = 0.83). The results of the ROC analysis were consistent with the calibration curve analysis. The decision curve demonstrated that the clinical-lab model added more net benefit than either the lab-score or clinical models in differentiating IAID from AIS patients.

Conclusions: The clinical-lab nomogram predicted IAID in patients with acute ischemic stroke. As a result, this nomogram can be used for identification of high-risk patients and to further guide clinical decisions.

Carotid intima media thickness measurements coupled with stroke severity strongly predict short-term outcome in patients with acute ischemic stroke: a machine learning study

Acute ischemic stroke (IS) is one of the leading causes of morbidity, functional disability and mortality worldwide. The objective was to evaluate IS risk factors and imaging variables as predictors of short-term disability and mortality in IS. Consecutive 106 IS patients were enrolled. We examined the accuracy of IS severity using the National Institutes of Health Stroke Scale (NIHSS), carotid intima-media thickness (cIMT) and carotid stenosis (both assessed using ultrasonography with doppler) predicting IS outcome assessed with the modified Rankin scale (mRS) three months after hospital admission. Poor prognosis (mRS ≥ 3) at three months was predicted by carotid stenosis (≥ 50%), type 2 diabetes mellitus and NIHSS with an accuracy of 85.2% (sensitivity: 90.2%; specificity: 81.8%). The mRS score at three months was strongly predicted by NIHSS (β = 0.709, p < 0.001). Short-term mortality was strongly predicted using a neural network model with cIMT (≥ 1.0 mm versus < 1.0 mm), NIHSS and age, yielding an area under the receiving operator characteristic curve of 0.977 and an accuracy of 94.7% (sensitivity: 100.0%; specificity: 90.9%). High NIHSS (≥ 15) and cIMT (≥ 1.0 mm) increased the probability of dying with hazard ratios of 7.62 and 3.23, respectively. Baseline NIHSS was significantly predicted by the combined effects of age, large artery atherosclerosis stroke, sex, cIMT, body mass index, and smoking. In conclusion, high values of cIMT and NIHSS at admission strongly predict short-term functional impairment as well as mortality three months after IS, underscoring the importance of those measurements to predict clinical IS outcome.

The Prognostic Value of Homocysteine in Acute Ischemic Stroke Patients: A Systematic Review and Meta-Analysis

Background: This comprehensive meta-analysis aimed to assess whether an increased homocysteine (Hcy) level is an independent predictor of unfavorable outcomes in acute ischemic stroke (AIS) patients.

Methods: A comprehensive literature search was conducted up to August 1, 2020 to collect studies reporting Hcy levels in AIS patients. We analyzed all the data using Review Manager 5.3 software.

Results: Seventeen studies with 15,636 AIS patients were selected for evaluation. A higher Hcy level was associated with a poorer survival outcome (OR 1.43, 95% CI: 1.25–1.63). Compared with the AIS group, Hcy levels were significantly lower in the healthy control patients, with an SMD of 5.11 and 95% CI (1.87–8.35). Analysis of the different subgroups of AIS demonstrated significant associations between high Hcy levels and survival outcomes only in Caucasian and Asian patients. Moreover, whereas high Hcy levels were closely associated with gender, B12 deficiency, smoking, and patients who received tissue plasminogen activator treatment, no significant difference was found between increased Hcy levels and age, drinking, hypertension, diabetes mellitus, and hyperlipidemia. In addition, the cut-off value (20.0 μmol/L) might be an optimum cut-off index for AIS patients in clinical practice.

Conclusion: This meta-analysis reveals that the Hcy level may serve as an independent predictor for unfavorable survival outcomes in AIS patients, particularly in Caucasian and Asian AIS patients. Further studies can be conducted to clarify this relationship.

Long-Term Outcomes in Patients with Stroke after in-Hospital Treatment-Study Protocol of the Prospective Stroke Cohort Augsburg (SCHANA Study)

INTRODUCTION

In Germany, stroke is the third leading cause of death, with more than 60,000 fatalities out of approximately 260,000 cases (first-ever and recurrent strokes) each year. So far, there are only a few long-term studies investigating determinants of the natural course of the disease, especially in the era of mechanical thrombectomy.

MATERIALS AND METHODS

The prospective single-center stroke cohort Augsburg (SCHANA) study will include about 1000 patients treated for stroke in the University Hospital of Augsburg. Patients aged 18 years or older with a confirmed diagnosis of ischemic or hemorrhagic stroke are included in the study. Information on demographic characteristics, onset of symptoms, etiologic factors, comorbidities, quality of life, invasive and non-invasive treatment, complications, and laboratory parameters are collected during a personal interview conducted during the patients' hospital stay and via a medical chart review. About 30 mL of blood is collected from each patient, and after processing and aliquoting, all blood specimens are frozen at -80° C. The study participants will be followed-up via postal questionnaires at three and 12 months after discharge from the hospital. Furthermore, mortality follow-ups will be conducted. Cox-regression analysis will be used to estimate relative risks.

CONCLUSION

The SCHANA study will generate comprehensive data on the long-term course of the disease. In addition to the main outcomes, recurrent events and survival, patient-oriented outcomes such as health-related quality of life and depression are the focus of the study.