Systemic infection, inflammation and acute ischemic stroke

Risk of Uveitis in Dengue Fever Patients: A Population-Based Cohort Study in Taiwan

Dengue-related ocular complications were considered rare, but recent evidence points to a broader spectrum of manifestations, including uveitis. This study utilized the Taiwan National Health Insurance Research Database (NHIRD) to investigate the incidence of uveitis in dengue patients, aiming to fill this research gap. This population-based, retrospective cohort study utilized the Taiwan National Health Insurance Research Database (NHIRD) and included patients with and without Dengue fever. The non-Dengue fever cohort comprised randomly selected control patients who were matched. Hazard ratios and Kaplan-Meier analysis were conducted to compare the incidence of uveitis in the Dengue and non-Dengue cohorts. Subgroup analyses were carried out based on age groups, genders, and comorbidities. A total of 26 950 patients diagnosed with Dengue fever were included in the study (49.6% female, mean age at index 41.63 years). Based on a 1:4 matching ratio, 107 800 control subjects without uveitis (50.03% female, mean age at index 41.41 years) were also included. The adjusted hazard ratio (aHR) of uveitis was higher in the Dengue fever group than in the non-Dengue fever group (aHR = 1.38, p < 0.001). A history of stroke or transient ischemic attack (TIA) was not associated with uveitis. Stratified analyses revealed that patients with Dengue fever had an increased risk regardless of their sex and age. The Kaplan-Meier method with the log-rank test showed a significantly higher cumulative incidence of uveitis in the Dengue fever cohort than in the non-Dengue fever cohort (p < 0.001). In the subgroup analysis for most major comorbidities, the significantly higher risk for uveitis in those patients with Dengue fever, was only demonstrated in the subgroups of those without these major comorbidities. Our findings showed Dengue infection to be associated with increased risk for uveitis. Clinicians should be attentive to a history of stroke or TIA in patients with Dengue fever.

Catecholamine-Induced Inflammasome Activation in the Heart Following Photothrombotic Stroke

Cerebrovascular stroke patients exhibit an increased incidence of cardiac arrhythmias. The pathomechanisms underlying post-traumatic cardiac dysfunction include a surge of catecholamines and an increased systemic inflammatory response, but whether inflammasome activation contributes to cardiac dysfunction remains unexplored. Here, we used a mouse model of photothrombotic stroke (PTS) to investigate the role of inflammasome activation in post-stroke cardiac dysfunction by catecholamines and to evaluate the effectiveness of the inflammasome inhibitor IC100 on inflammasome activation. To evaluate functional electrophysiological changes in the heart by catecholamine treatment, we recorded action potential duration in excised zebrafish hearts with and without IC100 treatment. We show that PTS induced AIM2 inflammasome activation in atria and ventricles that was significantly reduced by administration of IC100. Injection of epinephrine into naïve mice induced a significant increase in AIM2, IL-1b and caspase-8 in atria. Treatment of excised zebrafish hearts with epinephrine shortened the action potential duration and this shortening that was reduced by IC100. These findings indicate that stroke initiates a catecholamine surge that induces inflammasome activation and pyroptosis in the heart that is blocked by IC100, thus providing a framework for the development of therapeutics for stroke-related cardiovascular injury.

High Systemic Inflammatory Protein Index Is Associated with Clinically Ineffective Reperfusion in Acute Anterior Circulation Ischemic Stroke Patients Undergoing Endovascular Treatment

Nearly half of the patients undergoing endovascular treatment (EVT) do not have favorable outcomes despite successful recanalization of the occluded artery, which is also known as clinically ineffective reperfusion. We proposed a novel index-the systemic inflammatory protein index (SIPI), based on albumin, globulin, and C-reaction protein (CRP). We aimed to evaluate the relationship between inflammatory biomarkers at varying time points and the 90-day functional outcomes and investigate inflammatory biomarkers' dynamic changes during hospitalization in acute ischemic stroke (AIS) patients of anterior circulation undergoing EVT. We retrospectively recruited consecutive patients diagnosed with AIS of anterior circulation and treated with EVT from January 2018 to June 2022 in Nanfang Hospital. Albumin, globulin, and CRP were recorded on admission, 1 day, 3 days, and 7 days after EVT. An unfavorable functional outcome was defined as 90-day modified Rankin Scale (mRS) of 3-6. Albumin-to-globulin ratio (AGR), C-reactive protein-to-albumin ratio (CAR), and SIPI were calculated as follows: AGR = albumin/globulin; CAR = CRP/albumin; SIPI = CRP × globulin/albumin. A total of 238 consecutive anterior circulation AIS patients with EVT were included, among which 145 (60.9%) patients had unfavorable outcomes. After adjusting for confounding factors, admission globulin, admission AGR, 1-day AGR, 3-day albumin, 3-day CRP, 3-day CAR, 3-day SIPI, 7-day albumin, 7-day CRP, 7-day CAR, and 7-day SIPI showed an independent association with 90-day functional outcome. Of them, 3-day SIPI had the most robust discriminative ability with an area under the curve of 0.719 (CI 0.630-0.808, p < 0.001). There were differences in the dynamic change of inflammatory biomarkers between the subjects with favorable and unfavorable functional outcomes. Inflammatory biomarkers, including albumin, globulin, CRP, AGR, CAR, and SIPI, are independent predictors of 90-day unfavorable outcomes in anterior circulation AIS patients with EVT. SIPI of day 3 has the highest predictive value.

Oligodendrocytes in central nervous system diseases: the effect of cytokine regulation

Cytokines including tumor necrosis factor, interleukins, interferons, and chemokines are abundantly produced in various diseases. As pleiotropic factors, cytokines are involved in nearly every aspect of cellular functions such as migration, survival, proliferation, and differentiation. Oligodendrocytes are the myelin-forming cells in the central nervous system and play critical roles in the conduction of action potentials, supply of metabolic components for axons, and other functions. Emerging evidence suggests that both oligodendrocytes and oligodendrocyte precursor cells are vulnerable to cytokines released under pathological conditions. This review mainly summarizes the effects of cytokines on oligodendrocyte lineage cells in central nervous system diseases. A comprehensive understanding of the effects of cytokines on oligodendrocyte lineage cells contributes to our understanding of central nervous system diseases and offers insights into treatment strategies.

The Multifaceted Nature of Macrophages in Cardiovascular Disease

As the leading cause of mortality worldwide, cardiovascular disease (CVD) represents a variety of heart diseases and vascular disorders, including atherosclerosis, aneurysm, ischemic injury in the heart and brain, arrythmias, and heart failure. Macrophages, a diverse population of immune cells that can promote or suppress inflammation, have been increasingly recognized as a key regulator in various processes in both healthy and disease states. In healthy conditions, these cells promote the proper clearance of cellular debris, dead and dying cells, and provide a strong innate immune barrier to foreign pathogens. However, macrophages can play a detrimental role in the progression of disease as well, particularly those inflammatory in nature. This review will focus on the current knowledge regarding the role of macrophages in cardiovascular diseases.

Protein inhibitor of activated STAT1 (PIAS1) alleviates cerebral infarction and inflammation after cerebral ischemia in rats

Background

Ischemic stroke is a severe disorder with high incidence, disability rate and mortality. Multiple pathogenesis mechanisms are involved in ischemic stroke, such as inflammation and neuronal cell apoptosis. Protein inhibitor of activated signal transducer and activators of transcription 1 (PIAS1) plays a crucial role in various biological processes, including inflammation. PIAS1 is also downregulated in ischemia-reperfusion injury and involved in the disease processes. However, the role of PIAS1 in cerebral ischemia is unclear.

Methods

Sprague-Dawley (SD) rats were induced with middle cerebral artery occlusion (MCAO). The role and mechanisms of PIAS1 in ischemic cerebral infarction were explored by Longa test, 2,3,5-triphenyltetrazolium chloride (TTC) staining, Morris water maze (MWM) test, hematoxylin-eosin (HE) staining, quantification of brain water content, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), Western blot and immunofluorescence assays.

Results

The expression of PIAS1 in MCAO-induced rat was declined compared to sham rats. Overexpression of PIAS1 reduced the Longa neurological scores, the percent of infarction area, the pathological abnormality, the escape latency of swimming and the percent of brain water content, and increased the number of platform crossings and time in the target quadrant in the MCAO-induced rats. Besides, overexpression of PIAS1 decreased the MCAO-induced the contents of IL-1β, IL-6 and TNF-α, but further elevated the concentrations of IL-10 in both sera and brain tissues. Moreover, overexpression of PIAS1 reversed the MCAO-induced apoptosis rate and the relative protein level of Bax, cleaved caspase3 and Bcl-2. Overexpression of PIAS1 also reversed the level of proteins involved in NF-κB pathway.

Conclusion

PIAS1 reduced inflammation and apoptosis, thereby alleviating ischemic cerebral infarction in MCAO-induced rats through regulation NF-κB pathway.

Role of Qufeng Tongqiao Prescription in the protection of cerebral ischemia and associated molecular network mechanism

To explore the of Qufeng Tongqiao Prescription in the treatment of cerebral ischemia-reperfusion (CIR) and associated molecular network mechanism. Venny diagram, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analysis, protein-protein interaction (PPI), hub genes mining, molecular docking, combined with animal experiments and Nissl stain were performed to determine the molecular network mechanism of Qufeng Tongqiao Prescription for CIR treatment. Fifty three intersecting genes between Qufeng Tongqiao Prescription and cerebral ischemia reperfusion were acquired from Venny analysis. GO analysis showed that the main biological process (BP) was response to lipopolysaccharide, and the main cell localization (CC) process was membrane raft, while the most important molecular function (MF) process is Cytokine receptor binding. Moreover, AGE-RAGE signaling pathway in diabetic complications is the most important signaling pathway in KEGG pathway. Through molecular docking, it was found that Astragalus membranaceus was docked with MAPK14, IL4, FOS, IL6, and JUN; pueraria membranaceus was directly docked with JUN and IL4; Acorus acorus was linked to JUN and MAPK14; Ganoderma ganoderma and human were involved in JUN docking, and Ligusticum chuanqi and pueraria could not be docked with MAPK14, respectively. The results of animal experiments showed that Qufeng Tongqiao Prescription significantly improved behavioral performance and reduced the number of neuronal deaths in rats subjected to CIR, and molecular mechanisms are associated with FOS, IL-6, IL4, JUN, and MAPK14, of there, IL-6, as a vital candidator, which has been confirmed by immunostaining detection. Together, Qufeng Tongqiao Prescription has positive therapeutic effect on CIR, and the underlying mechanism is involved MAPK14, FOS, IL4, and JUN network, while IL-6 may be as a vital target.

Risk of dementia in survivors of active tuberculosis in Korea: A nationwide cohort study

BACKGROUND

Concern has been growing regarding post-tuberculosis (TB) morbidities, including neurologic and vascular comorbidities. However, the association between post-TB status and the risk of dementia has been evaluated in only few studies. Therefore, in the present study, the risk of dementia was investigated in a nationwide population-based cohort.

METHODS

Using the Korean National Health Insurance Service (KNHIS) database, this study included TB survivors (n = 50,182) and matched controls (n = 50,182) for age, sex, and year of index date. The risk of dementia was estimated using Cox proportional hazards regression, and stratified analyses for related factors were performed.

RESULTS

During a mean 3.5 years of follow-up, the incidence of dementia was 9.32 for Alzheimer disease and 1.17 for vascular dementia per 1000 person-years for TB survivors and 7.21 and 0.67, respectively, for matched controls. The overall risk of Alzheimer disease was 1.11 (95% confidence interval (CI) 1.03-1.20)-fold higher in TB survivors than in matched controls. For vascular dementia, 1.48 (95% CI 1.16-1.89)-fold higher risk was found in TB survivors than in matched controls. The strength of the association between TB and dementia was higher in CNS TB (aHR 1.76, 95% CI 1.18 -2.64) than non-CNS TB (aHR 1.11, 95% CI 1.05-1.19) compared to controls, especially for patients with vascular dementia (3.33, 95% CI 1.06-10.49).

CONCLUSION

TB survivors had a significantly higher risk of dementia than the general population.

Infection, Inflammation, and Poststroke Cognitive Impairment

BACKGROUND

Infection and inflammation are dementia risk factors in population-based cohorts; however, studies in stroke are scarce. We determined the prevalence of infection after stroke and routinely measured inflammatory biomarkers during hospitalization and their associations with acute and 6-month cognitive impairment.

METHODS AND RESULTS

A prospective stroke cohort completed the Oxford Cognitive Screen at ≤2 weeks and 6 months after stroke. Infection, inflammatory markers (C-reactive protein, white cell count, and neutrophil/lymphocyte ratio), and systemic inflammatory response syndrome were ascertained throughout admission with electronic patient records supplemented by hand searches. Associations with acute and 6-month global and domain-specific cognitive impairment were analyzed using multivariable regression, adjusting for demographic/vascular factors and stroke severity. Among 255 patients (mean age, 73.9 [SD, 12.6] years; 46.3% women; mean education, 12.6 [SD, 3.7] years; median National Institutes of Health Stroke Scale score 5 [range, minimum-maximum, 0-30]), infection was present in 90 patients (35.3%) at mean 4.4 (SD, 6.9) days after stroke, consisting predominantly of pneumonia (47/90; 52%) and urinary tract infection (39/90; 43%). Admission white cell count was elevated in 25.1% (n=64; mean, 9.5×109/L [SD, 3.2×109/L]), C-reactive protein in 41.2% (n=105; mean, 27.5 [SD, 50.9 mg/L]), neutrophil/lymphocyte ratio in 55.7% (n=97; mean, 5.5 [SD, 4.5]), and systemic inflammatory response syndrome in 26.6% (n=53 [45.2%] positive during hospitalization). Infection was associated with acute and 6-month poststroke cognitive impairment (P<0.05adj) with stronger associations acutely for severe infection (infection+systemic inflammatory response syndrome; P=0.03adj). Acute language, executive function and attention domain impairments, and 6-month number processing impairment were associated with infection (P<0.05adj). No significant relationships were found for any biomarker and cognitive impairment.

CONCLUSIONS

Infection and elevations in routinely measured inflammatory biomarkers are common following stroke; however, only infection is associated with poststroke cognitive impairment, suggesting that increases in these biomarkers may be nonspecific. Infection may present a tractable target for reducing poststroke cognitive impairment.

Oral health and functional outcomes following mechanical thrombectomy for ischemic stroke

BACKGROUND

An association between poor dentition and the risk of ischemic stroke has previously been reported in the literature. In this study we assessed oral hygiene (OH), including tooth loss and the presence of dental disease, to determine if an association exists with functional outcomes following mechanical thrombectomy (MT) for large-vessel ischemic stroke.

METHODS

A retrospective review was conducted of consecutive adult patients at a single comprehensive stroke center who underwent MT from 2012 to 2018. Inclusion criteria included availability of CT imaging to radiographically assess OH. A multivariate analysis was performed, with the primary outcome being 90-day post-thrombectomy modified Rankin Scale (mRS) score >2.

RESULTS

A total of 276 patients met the inclusion criteria. The average number of missing teeth was significantly higher in patients with a poor functional outcome (mean (SD) 10 (11) vs 4 (6), p<0.001). The presence of dental disease was associated with poor functional outcome, including cavities (21 (27%) vs 13 (8%), p<0.001), periapical infection (18 (23%) vs 11 (6.7%), p<0.001), and bone loss (27 (35%) vs 11 (6.7%), p<0.001). Unadjusted, missing teeth was a univariate predictor of poor outcome (OR 1.09 (95% CI 1.06 to 1.13), p<0.001). After adjustment for recanalization scores and use of tissue plasminogen activator (tPA), missing teeth remained a predictor of poor outcome (OR 1.07 (95% CI 1.03 to 1.11), p<0.001).

CONCLUSION

Missing teeth and the presence of dental disease are inversely correlated with functional independence following MT, independent of thrombectomy success or tPA status.

Small extracellular vesicles administered directly in the brain promote neuroprotection and decreased microglia reactivity in a stroke mouse model

Herein, we investigate the bioactivity of small extracellular vesicles (sEVs), focusing on their local effect in the brain. sEVs from mononuclear cells (MNCs) showed superior effects in vitro to sEVs from mesenchymal stem cells (MSCs) and were able to promote neuroprotection and decrease microglia reactivity in a stroke mouse model.

Neuroprotective strategies for neonatal hypoxic-ischemic brain damage: Current status and challenges

Neonatal hypoxic-ischemic brain damage (HIBD) is a prominent contributor to both immediate mortality and long-term impairment in newborns. The elusive nature of the underlying mechanisms responsible for neonatal HIBD presents a significant obstacle in the effective clinical application of numerous pharmaceutical interventions. This comprehensive review aims to concentrate on the potential neuroprotective agents that have demonstrated efficacy in addressing various pathogenic factors associated with neonatal HIBD, encompassing oxidative stress, calcium overload, mitochondrial dysfunction, endoplasmic reticulum stress, inflammatory response, and apoptosis. In this review, we conducted an analysis of the precise molecular pathways by which these drugs elicit neuroprotective effects in animal models of neonatal hypoxic-ischemic brain injury (HIBD). Our objective was to provide a comprehensive overview of potential neuroprotective agents for the treatment of neonatal HIBD in animal experiments, with the ultimate goal of enhancing the feasibility of clinical translation and establishing a solid theoretical foundation for the clinical management of neonatal HIBD.

Association between recently raised anticholinergic burden and risk of acute cardiovascular events: nationwide case-case-time-control study

OBJECTIVE

To evaluate the association between recently raised anticholinergic burden and risk of acute cardiovascular events in older adults.

DESIGN

Case-case-time-control study (ie, incorporating a case crossover design and a control crossover design consisting of future cases).

SETTING

Taiwan's National Health Insurance Research Database.

PARTICIPANTS

317 446 adults aged ≥65 who were admitted to hospital because of an incident acute cardiovascular event between 2011 and 2018. Acute cardiovascular events included myocardial infarction, strokes, arrhythmias, conduction disorders, and cardiovascular death.

MAIN OUTCOME MEASURES

The anticholinergic burden was measured for each participant by adding up the anticholinergic scores for individual drugs using the Anticholinergic Cognitive Burden Scale. Scores were classified into three levels (0 points, 1-2 points, and ≥3 points). For each participant, anticholinergic burden levels during hazard periods (day -1 to -30 before the cardiovascular event) were compared with randomly selected 30 day reference periods (ie, periods between days -61 and -180). Conditional logistic regression determined odds ratios with 95% confidence intervals to evaluate the association between acute cardiovascular events and recently raised anticholinergic burden.

RESULTS

The crossover analyses included 248 579 current cases. Participants' average age on the index date was 78.4 years (standard deviation 0.01), and 53.4% were men. The most frequently prescribed drugs with anticholinergic activity were antihistamines (68.9%), gastrointestinal antispasmodics (40.9%), and diuretics (33.8%). Among patients with varying levels of anticholinergic burden in different periods, more patients carried higher levels of anticholinergic burden during hazard periods than during reference periods. For example, 17 603 current cases had 1-2 points of anticholinergic burden in the hazard period with 0 points in the reference period, while 8507 current cases had 0 points in the hazard period and 1-2 points in the reference period. In the comparison of 1-2 points versus 0 points of anticholinergic burden, the odds ratio was 1.86 (95% confidence interval 1.83 to 1.90) in the case crossover analysis and 1.35 (1.33 to 1.38) in the control crossover analysis, which yielded a case-case-time-control odds ratio of 1.38 (1.34 to 1.42). Similar results were found in the comparison of ≥3 versus 0 points (2.03, 1.98 to 2.09) and ≥3 versus 1-2 points (1.48, 1.44 to 1.52). The findings remained consistent throughout a series of sensitivity analyses (eg, cut-off points for anticholinergic burden categories were redefined and different scales were used to measure anticholinergic burden).

CONCLUSIONS

An association was found between recently raised anticholinergic burden and increased risk of acute cardiovascular events. Furthermore, a greater increase in anticholinergic burden was associated with a higher risk of acute cardiovascular events.

APP96-110 Elicits Neuroprotective Effects Following Ischemic Insult in Animal Models

Competitive amyloidogenic pathways play an important role in many neurological diseases such as the onset of various degenerative diseases and ischemic stroke. Overexpression of amyloid precursor protein (APP) and amyloid-beta is modulated via the amyloidogenic pathway, which plays a crucial role in neuroinflammation. During ischemic conditions, the activity of the anti-inflammatory non-amyloidogenic pathway decreases, thus increasing the activity of amyloidogenic pathway. The soluble alpha form of APP (sAPPα), formed via the non-amyloidogenic pathway, exhibits neuroprotective effects against neurological diseases. sAPPα is thought to have a modulatory effect on several cell survival pathways, including its ability to inhibit the phosphoinositide 3-kinases (PI3K) pathway, thereby inhibiting the inflammatory response. The APP derivative, APP96-110, could act as a functional substitute for native sAPPα. Herein, we investigated whether APP96-110 has neuroprotective effects against neuroinflammation and damage following cerebral ischemic stroke. Treatment with diluted APP96-110 (0.005 mg/kg) in mice after 30 min of transient middle cerebral artery occlusion (tMCAO) showed improved motor function and reduced expression of the inflammatory marker CD86. APP96-110 decreased the infarct size and induced an anti-inflammatory response by inhibiting the PI3K pathway. These results suggest that the treatment of APP96-110 is efficacious in reducing neuroinflammation and infarct size in ischemic stroke.

Long-term exposure to particulate matter and risk of Alzheimer's disease and vascular dementia in Korea: a national population-based Cohort Study

BACKGROUND

The prevalence of age-related neurodegenerative diseases has risen in conjunction with an increase in life expectancy. Although there is emerging evidence that air pollution might accelerate or worsen dementia progression, studies on Asian regions remains limited. This study aimed to investigate the relationship between long-term exposure to PM₁₀ and the risk of developing Alzheimer's disease and vascular dementia in the elderly population in South Korea.

METHODS

The baseline population was 1.4 million people aged 65 years and above who participated in at least one national health checkup program from the National Health Insurance Service between 2008 and 2009. A nationwide retrospective cohort study was designed, and patients were followed from the date of cohort entry (January 1, 2008) to the date of dementia occurrence, death, moving residence, or the end of the study period (December 31, 2019), whichever came first. Long-term average PM₁₀ exposure variable was constructed from national monitoring data considering time-dependent exposure. Extended Cox proportional hazard models with time-varying exposure were used to estimate hazard ratios (HR) for Alzheimer's disease and vascular dementia.

RESULTS

A total of 1,436,361 participants were selected, of whom 167,988 were newly diagnosed with dementia (134,811 with Alzheimer's disease and 12,215 with vascular dementia). The results show that for every 10 µg/m³ increase in PM₁₀, the HR was 0.99 (95% CI 0.98-1.00) for Alzheimer's disease and 1.05 (95% CI 1.02-1.08) for vascular dementia. Stratified analysis according to sex and age group showed that the risk of vascular dementia was higher in men and in those under 75 years of age.

CONCLUSION

The results found that long-term PM₁₀ exposure was significantly associated with the risk of developing vascular dementia but not with Alzheimer's disease. These findings suggest that the mechanism behind the PM₁₀-dementia relationship could be linked to vascular damage.

Vascular Effects on Cerebrovascular Permeability and Neurodegeneration

Neurons and glial cells in the brain are protected by the blood brain barrier (BBB). The local regulation of blood flow is determined by neurons and signal conducting cells called astrocytes. Although alterations in neurons and glial cells affect the function of neurons, the majority of effects are coming from other cells and organs of the body. Although it seems obvious that effects beginning in brain vasculature would play an important role in the development of various neuroinflammatory and neurodegenerative pathologies, significant interest has only been directed to the possible mechanisms involved in the development of vascular cognitive impairment and dementia (VCID) for the last decade. Presently, the National Institute of Neurological Disorders and Stroke applies considerable attention toward research related to VCID and vascular impairments during Alzheimer's disease. Thus, any changes in cerebral vessels, such as in blood flow, thrombogenesis, permeability, or others, which affect the proper vasculo-neuronal connection and interaction and result in neuronal degeneration that leads to memory decline should be considered as a subject of investigation under the VCID category. Out of several vascular effects that can trigger neurodegeneration, changes in cerebrovascular permeability seem to result in the most devastating effects. The present review emphasizes the importance of changes in the BBB and possible mechanisms primarily involving fibrinogen in the development and/or progression of neuroinflammatory and neurodegenerative diseases resulting in memory decline.

MicroRNA-124-3p alleviates cerebral ischaemia-induced neuroaxonal damage by enhancing Nrep expression

OBJECTIVE

Ischaemic stroke has a high death rate and frequently results in long-term and severe brain damage in survivors. miRNA-124-3p (miR-124-3p) treatment has been suggested to reduce ischaemia and play a vital function in avoiding neuron death. An investigation of the role of miR-124-3p, in the ischaemia damage repair or protection in the middle cerebral artery occlusion (MCAO) model and oxygen-glucose deprivation/reperfusion (OGD/R) model, was the purpose of this research.

METHODS

The expression of miRNA and mRNA in the MCAO model was predicted using bioinformatics analysis. The OGD/R neuronal model was developed. We examined the influence of a number of compounds on the OGD/R model in vitro using gain- and loss-of-function approaches.

RESULTS

For starters, miR-124-3p and Nrep level in the MCAO model were found to be lower in the model predicted by bioinformatics than in the sham-operated group. And then in the OGD/R model, miR-124-3p treatment reduced OGD/R neuronal damage, increased neuronal survival, and reduced apoptosis in cell lines. Moreover, we further looked at the impact of miR-124-3p on downstream Rnf38 and Nrep using the OGD/R model. Western blot analysis and dual-luciferase reporter assays indicated that miR-124-3p binds and inhibits Rnf38. Finally, although Nrep expression was reduced in the OGD/R model neuronal model, it was shown that miR-124-3p administration reduced apoptosis and increased neuronal activity, particularly with regard to axon regeneration-related proteins.

CONCLUSION

Our studies have shown that miR-124-3p may reduce neuronal injury by preventing Rnf38-mediated effects on the Nrep axis.

Efficacy of curculigoside in protecting against ischemic brain injury through regulation of oxidative stress and NF-κB and PI3K/Akt expression

ETHNOPHARMACOLOGICAL RELEVANCE

The ancient Chinese medicine book "Huangdi Neijing" reports that "the brain is the sea of marrow" and that the kidney "mainly induces bones to produce marrow". Therefore, Chinese medicine has a "kidney-brain axis" theory, but supporting evidence is lacking. In this study, curculigoside, the main component of the kidney-tonifying drug Rhizoma Curculiginis, was used to explore whether a kidney-tonifying drug could regulate the pathological state of the brain.

AIM OF THE STUDY

To explore the efficacy of curculigoside in protecting against ischemic brain injury (IBI) through the regulation of oxidative stress and NF-κB and PI3K/Akt expression.

MATERIALS AND METHODS

Middle cerebral artery occlusion (MCAO) was used to induce IBI in rats, and curculigoside was administered. The degree of IBI, morphological changes and severity of nerve injury (using neurological severity scores; NSSs) in the rats were assessed. Enzyme-linked immunosorbent assays (ELISAs), Western blotting, and immunohistochemistry were used to evaluate changes in hydrogen peroxide (H₂O₂), nitric oxide (NO), malondialdehyde (MDA), TNF-α, IL-1β, catalase (CAT), superoxide dismutase (SOD), nitric oxide synthase (NOS), NF-κB, PI3K and Akt levels.

RESULTS

Curculigoside significantly alleviated behavioral deficits and reduced the degree of cerebral ischemia in the rats. After curculigoside treatment, the levels of H₂O₂, NO, MDA, NOS, iNOS, TNF-α, IL-1β, intercellular adhesion molecule-1 (ICAM-1) and NF-κB in the ischemic area of the brain were significantly reduced. The activities of CAT, SOD, PI3K and Akt were significantly increased.

CONCLUSION

Curculigoside is a potentially effective drug for the treatment of IBI.

Neutrophil-to-Lymphocyte Ratio as a Predictor of Short-Term Functional Outcomes in Acute Ischemic Stroke Patients

Background: Neutrophil-to-lymphocyte ratio (NLR), a systemic inflammatory biomarker, has been associated with poorer outcomes in acute ischemic stroke patients. The present study was designed to expand these findings by investigating the association between NLR and short-term functional outcomes in acute ischemic stroke patients. Methods: This retrospective study evaluated patients within 7 days after the onset of acute ischemic stroke. Stroke severity on admission was measured using the National Institutes of Health Stroke Scale (NIHSS). The functional outcomes were assessed using the Berg Balance Scale (BBS), Manual Function Test (MFT), the Korean version of the modified Barthel Index (K-MBI), and the Korean Mini-Mental State Examination (K-MMSE) within 2 weeks of stroke onset. The modified Rankin Scale (mRS) was evaluated at discharge. Results: This study included 201 patients, who were grouped into three NLR tertiles (<1.84, 1.84−2.71, and >2.71) on admission. A multivariate analysis showed that the top tertile group (NLR > 2.71) had significantly higher risks of unfavorable outcomes on the K-MBI (p = 0.010) and K-MMSE (p = 0.029) than the bottom tertile group (NLR < 1.84). Based on the optimal cut-off values from a receiver operating characteristic curve analysis, a higher NLR was significantly associated with higher NIHSS scores (p = 0.011) and unfavorable outcomes on the K-MBI (p = 0.002) and K-MMSE (p = 0.001). Conclusions: A higher NLR is associated with poorer short-term functional outcomes in acute ischemic stroke patients.

Investigating sphingolipids as biomarkers for the outcomes of acute ischemic stroke patients receiving endovascular treatment

BACKGROUND

Long-chain ceramides are associated with the mechanisms and clinical outcomes of acute ischemic stroke (AIS). This study aimed to investigate the plasma ceramides and sphingosine-1-phosphate in AIS patients undergoing endovascular thrombectomy (EVT) and their associations with outcomes.

METHODS

Plasma samples were collected from 75 AIS patients who underwent EVT before (T1), immediately after (T2), and 24 h after (T3) the procedures and 19 controls that were matched with age, sex, and co-morbidities. The levels of ceramides with different fatty acyl chain lengths and sphingosine-1-phosphate were measured by UHPLC-ESI-MS/MS. A poor outcome was defined as a modified Rankin Scale score of 3-6 at 3 months after stroke.

RESULTS

The plasma levels of long-chain ceramides Cer (d18:1/16:0) at all three time points, Cer (d18:1/18:0) at T1 and T3, and Cer (d18:1/20:0) at T1 and very-long-chain ceramide Cer (d18:1/24:1) at T1 were significantly higher in AIS patients than those in the controls. In contrast, the plasma levels of sphingosine-1-phosphate in AIS patients were significantly lower than those in the controls at all three time points. Among the AIS patients, 34 (45.3%) had poor functional outcomes at 3 months poststroke. Multivariable analysis showed that higher levels of Cer (d18:1/16:0) and Cer (d18:1/18:0) at all three time points, Cer (d18:1/20:0) at T1 and T2, and Cer (d18:1/24:0) at T2 remained significantly associated with poor functional outcomes after adjustment for potential confounding factors.

CONCLUSION

Plasma ceramides were elevated early in AIS patients with acute large artery occlusion. Furthermore, Cer (d18:1/16:0) and Cer (d18:1/18:0) could be early prognostic indicators for AIS patients undergoing EVT.

Links between inflammation and immune functioning with cognitive status among older Americans in the Health and Retirement Study

Elevated inflammation and poor immune functioning are tied to worse cognitive health. Both processes are fundamental to aging and are strongly implicated in the development of age-related health outcomes, including cognitive status. However, results from prior studies evaluating links between indicators of inflammation and immune function and cognitive impairment have been inconsistent due to biomarker selection, sample selection, and cognitive outcome. Using the Health and Retirement Study (HRS), a nationally representative study of older adults in the United States, we assessed how indicators of inflammation (neutrophil-lymphocyte ratio (NLR), albumin, CRP, IL6, IL10, IL-1Ra, sTNFR1, and TGFβ1) and immune functioning (CMV, CD4+ TN/TM, and CD8+ TN/TM) are associated with cognitive status. First, to examine the association between each biomarker and cognitive status, we tested whether markers of inflammation and immune functioning varied across cognitive status categories. We found that dementia and cognitive impairment without dementia (CIND) were associated with elevated inflammation and poorer immune functioning across biomarkers except for CD4+ TN/TM. Next, we estimated multinomial logistic regression models to assess which biomarkers would continue to be associated with dementia and CIND, net of each other. In these models, albumin, cytokines, CMV, CD4+ TN/TM, and CD8+ TN/TM are associated with cognitive status. Because poor immune functioning and increased inflammation are associated with cognitive impairment, improving immune functioning and reducing inflammation may provide a mechanism for reducing ADRD risk in the population.

The value of circulating lymphocytic subpopulations in the diagnosis and repair of ischemic stroke patients with dizziness

Background

To determine whether dizziness can contribute to stroke as a main cause still remains challenging. This study aims to explore clinical biomarkers in the identification of ischemic stroke patients from people with dizziness and the prediction of their long-term recovery.

Methods

From January 2018 to June 2019, 21 ischemic stroke patients with a main complaint of dizziness, 84 non-stroke dizziness patients and 87 healthy volunteers were recruited in this study. Then, their peripheral blood samples were collected, and the percentages of circulating lymphocytes T cells, CD4⁺ T cells, CD8⁺ T cells, T^−/− cells (DNTs), CD4⁺ regulatory T cells (Tregs), CD8⁺ Tregs, B cells and regulatory B cells (Bregs) were examined to identify biomarkers with clinical value.

Results

According to our data, a significant difference in the DNTs proportion was detected between non-stroke dizziness and ischemic stroke patients with dizziness (p = 0.0009). The Bregs proportion in ischemic stroke patients with dizziness was lower than that in non-stroke dizziness patients (p = 0.035). In addition, the percentage of Bregs and DNTs within lymphocytes in patients’ peripheral blood exhibited a significant negative correlation with stroke occurrence (Bregs, p = 0.039; DNTs, p = 0.046). Moreover, the Bregs and DNTs within lymphocytes were negatively related to participants’ age, while presented a weak relationship with clinical risks like smoking, hypertension, and diabetes. Then, area under the receiver operating characteristic curve (AUC) of Bregs and DNTs together was 0.768, the risk factors and Bregs or DNTs ranged from 0.795 and 0.792, respectively, and the AUC value of risk factors, Bregs and DNTs combination was further increased to 0.815. Furthermore, the Bregs percentage within lymphocytes at admission was also a potential predictor of repair at discharge and the following 3 months.

Conclusion

Bregs and DNTs could be the clinical biomarkers together in the identification of ischemic stroke patients from people with dizziness.

Uveitis increases the risk of stroke among patients with ankylosing spondylitis: A nationwide population-based longitudinal study

Ankylosing spondylitis (AS) is known to increase the risk of stroke. Among patients with AS, uveitis is the most common extra-articular manifestation. However, no previous investigations have discussed the association between uveitis and the risk for developing stroke in patients with AS. This retrospective cohort study aimed to explore the relationship between uveitis and the incidence of stroke in patients with AS by obtaining medical records from January 1, 2000, to December 31, 2015, from the National Health Insurance Research Database, according to the International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes. The primary outcome was the incidence of stroke. Pearson’s chi-square test and Fisher’s exact test were used to analyze variables. Kaplan–Meier survival curves and univariate and multivariate Cox proportional hazard regression models with and without Fine and Gray’s competing risk model were used to analyze data. Total 828 AS patients with uveitis and 3,312 AS patients without uveitis were identified. During the follow-up period, 137 patients in the uveitis group and 344 in the non-uveitis group developed stroke. Uveitis is a significant risk factor for stroke development in patients with AS (adjusted hazard ratio = 1.846, p < 0.001). Age, diabetes mellitus, hyperlipidemia, hypertension, congestive heart failure, chronic obstructive pulmonary disease, asthma, coronary artery disease, and atrial fibrillation were associated with a higher risk of stroke. After subgroup analysis, both anterior uveitis and posterior segment involvement were found to increase the risk of stroke in patients with AS. Uveitis is associated with an increased risk in both ischemic and hemorrhagic strokes in patients with AS. Therefore, when uveitis is identified, clinicians should pay more attention to the cerebrovascular risk in patients with AS, especially in those with underlying comorbidities.

The action of curcumin against damage resulting from cerebral stroke: a systematic review

Stroke is the second leading cause of morbidity and mortality globally. Treatments for stroke are limited, and preventive treatments are scarce. Curcumin (CUR) has several biological effects, as described in the literature, which highlight its antioxidant and neuroprotective effects. Therefore, this qualitative systematic review aimed to investigate the effects of CUR on damage caused by stroke in rodent models. A systematic search was performed on three databases PubMed, Scopus, and Web of Science. In addition, the risk-of-bias and quality of the studies were assessed using SYRCLE and Collaborative Approach for Meta-Analysis and Review of Animal Data from Experimental Studies, respectively. The selection, inclusion, and exclusion criteria were established by the authors. At the end of our systematic search of the three databases, we found a total of 728 articles. After excluding duplicates and triplicates and reading the abstracts, keywords, and full texts, 53 articles were finally included in this systematic review. CUR exerts several beneficial effects against the damage caused by both ischemic and hemorrhagic stroke, via different pathways. However, because of its low bioavailability, Free-form CUR only exerted significant effects when it was administered at high concentrations. In contrast, when CUR was administered using nanostructured systems, positive responses were observed even at low concentrations. The mechanisms of action of CUR, free or in nanostructure, are extremely important for the recovery of injured brain tissue after a stroke; CUR has neuroprotective, antioxidant, anti-inflammatory, and anti-apoptotic effects and helps to maintain the integrity of the blood-brain barrier. Finally, we concluded that CUR presents an extremely important and significant response profile against the damage caused by stroke, making it a possible therapeutic candidate for individuals affected by this disease.

Association of White Blood Cell Count With Clinical Outcome Independent of Treatment With Alteplase in Acute Ischemic Stroke

Introduction

Higher white blood cell (WBC) count is associated with poor functional outcome in acute ischemic stroke (AIS). However, little is known about whether the association is modified by treatment with intravenous alteplase.

Methods

WAKE-UP was a randomized controlled trial of the efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in unknown onset stroke. WBC count was measured on admission and again at 22–36 h after randomization to treatment (follow-up). Favorable outcome was defined by a score of 0 or 1 on the modified Rankin scale (mRS) 90 days after stroke. Further outcome were stroke volume and any hemorrhagic transformation (HT) that were assessed on follow-up CT or MRI. Multiple logistic regression analysis was used to assess the association between outcome and WBC count and treatment group.

Results

Of 503 randomized patients, WBC count and baseline parameters were available in 437 patients (μ = 64.7 years, 35.2% women) on admission and 355 patients (μ = 65.1 years, 34.1% women) on follow-up. Median WBC count on admission was 7.6 × 10⁹/L (interquartile range, IQR, 6.1–9.4 × 10⁹/L) and 8.2 × 10⁹/L (IQR, 6.7–9.7 × 10⁹/L) on follow-up. Higher WBC count both on admission and follow-up was associated with lower odds of favorable outcome, adjusted for age, National Institutes of Health (NIH) Stroke Scale Score, temperature, and treatment (alteplase vs. placebo, adjusted odds ratio, aOR 0.85, 95% confidence interval [CI] 0.78–0.94 and aOR 0.88, 95% CI 0.79–0.97). No interaction between WBC count and treatment group was observed (p = 0.11). Furthermore, WBC count on admission and follow-up was significantly associated with HT (aOR 1.14, 95% CI 1.05–1.24 and aOR 1.13, 95% CI 1.00–1.26). Finally, WBC count on follow-up was associated with larger stroke volume (aOR 2.57, 95% CI 1.08–6.07).

Conclusion

Higher WBC count is associated with unfavorable outcome, an increased risk of HT, and larger stroke volume, independent of treatment with alteplase. Whether immunomodulatory manipulation of WBC count improves stroke outcome needs to be tested.

Trial Registration

ClinicalTrials.gov Identifier: NCT01525290.

Elevated Albumin to Globulin Ratio on Day 7 is Associated with Improved Function Outcomes in Acute Ischemic Stroke Patients with Intravenous Thrombolysis

Background and Purpose

Albumin to globulin ratio (A/G) has been established as a representative biomarker for assessing inflammation and nutritional status. However, the prognostic value of A/G has rarely been reported in acute ischemic stroke (AIS) patients with intravenous thrombolysis (IVT).

Methods

A total of 311 AIS patients who had undergone IVT and completed 3-month follow-up were retrospectively recruited in this study. Albumin (Alb), globulin (Glb) and A/G on admission, within 24 hours after IVT and on day 7 were recorded. Poor outcome was defined as death or major disability (modified Rankin Scale, 3–6) at 3 months.

Results

Among the 311 cases, 260 patients had admission blood samples, 296 cases had blood samples within 24 hours after IVT and 126 cases had blood samples on day 7. The patients with and without available blood samples were well-balanced. During the first 24 h, we observed A/G to increase significantly compared with baseline whereas at day 7 it was almost back to baseline in patients with a poor outcome. Receiver operating characteristic (ROC) curves analysis showed that A/G had a better performance in discriminating patients at high risk and low risk of a poor outcome than either Alb or Glb alone and carried the highest predictive ability on day 7 (AUC = 0.807). Lower 7-day A/G was independently associated with a poor outcome (per-SD increase, OR = 0.182, 95% CI: 0.074–0.446).

Conclusion

A/G is an important prognostic indicator for AIS outcomes and merits dynamic monitoring.

Perioperative stroke: A perspective on challenges and opportunities for experimental treatment and diagnostic strategies

Perioperative stroke is an ischemic or hemorrhagic cerebral event during or up to 30 days after surgery. It is a feared condition due to a relatively high incidence, difficulties in timely detection, and unfavorable outcome compared to spontaneously occurring stroke. Recent preclinical data suggest that specific pathophysiological mechanisms such as aggravated neuroinflammation contribute to the detrimental impact of perioperative stroke. Conventional treatment options are limited in the perioperative setting due to difficult diagnosis and medications affecting coagulation in may cases. On the contrary, the chance to anticipate cerebrovascular events at the time of surgery may pave the way for prevention strategies. This review provides an overview on perioperative stroke incidence, related problems, and underlying pathophysiological mechanisms. Based on this analysis, we assess experimental stroke treatments including neuroprotective approaches, cell therapies, and conditioning medicine strategies regarding their potential use in perioperative stroke. Interestingly, the specific aspects of perioperative stroke might enable a more effective application of experimental treatment strategies such as classical neuroprotection whereas others including cell therapies may be of limited use. We also discuss experimental diagnostic options for perioperative stroke augmenting classical clinical and imaging stroke diagnosis. While some experimental stroke treatments may have specific advantages in perioperative stroke, the paucity of established guidelines or multicenter clinical research initiatives currently limits their thorough investigation.

The roles of Eph receptors, neuropilin-1, P2X7, and CD147 in COVID-19-associated neurodegenerative diseases: inflammasome and JaK inhibitors as potential promising therapies

The novel coronavirus disease 2019 (COVID-19) pandemic has spread worldwide, and finding a safe therapeutic strategy and effective vaccine is critical to overcoming severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, elucidation of pathogenesis mechanisms, especially entry routes of SARS-CoV-2 may help propose antiviral drugs and novel vaccines. Several receptors have been demonstrated for the interaction of spike (S) protein of SARS-CoV-2 with host cells, including angiotensin-converting enzyme (ACE2), ephrin ligands and Eph receptors, neuropilin 1 (NRP-1), P2X7, and CD147. The expression of these entry receptors in the central nervous system (CNS) may make the CNS prone to SARS-CoV-2 invasion, leading to neurodegenerative diseases. The present review provides potential pathological mechanisms of SARS-CoV-2 infection in the CNS, including entry receptors and cytokines involved in neuroinflammatory conditions. Moreover, it explains several neurodegenerative disorders associated with COVID-19. Finally, we suggest inflammasome and JaK inhibitors as potential therapeutic strategies for neurodegenerative diseases.

Relationships Among Gut Microbiota, Ischemic Stroke and Its Risk Factors: Based on Research Evidence

Stroke is a highly lethal disease and disabling illness while ischemic stroke accounts for the majority of stroke. It has been found that inflammation plays a key role in the initiation and progression of stroke, and atherosclerotic plaque rupture is considered to be the leading cause of ischemic stroke. Furthermore, chronic inflammatory diseases, such as obesity, type 2 diabetes mellitus (T2DM) and hypertension, are also considered as the high-risk factors for stroke. Recently, the topic on how gut microbiota affects human health has aroused great concern. The initiation and progression of ischemic stroke has been found to have close relation with gut microbiota dysbiosis. Hence, this manuscript briefly summarizes the roles of gut microbiota in ischemic stroke and its related risk factors, and the practicability of preventing and alleviating ischemic stroke by reconstructing gut microbiota.

Bihemispheric ischemic strokes in patients with COVID-19

BACKGROUND:

There is emerging evidence that COVID-19 can trigger thrombosis because of a hypercoagulable state, including large-vessel occlusion ischemic strokes. Bihemispheric ischemic stroke is uncommon and is thought to indicate an embolic source. Here, we examine the findings and outcomes of patients with bihemispheric stroke in the setting of COVID-19.

METHODS:

We performed a retrospective cohort study at a quaternary academic medical center between March 1, 2020, and April 30, 2020. We identified all patients with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who presented with simultaneous bihemispheric ischemic strokes.

RESULTS:

Of 637 COVID-19 admissions during the 2-month period, 13 had a diagnosis of acute ischemic stroke, including 5 who developed bihemispheric cerebral infarction. Three of those 5 (60%) were female, median age was 54 (range 41–67), and all five were being managed for severe COVID-19-related pneumonia complicated by acute kidney injury and liver failure before the diagnosis of cerebral infarction was established. Five presented with elevated ferritin, lactate dehydrogenase, and interleukin-6 (IL-6) levels, and four had lymphopenia and elevated D-dimer levels. All patients underwent neuroimaging with computed tomography for persistent depressed mentation, with or without a focal neurologic deficit, demonstrating multifocal ischemic strokes with bihemispheric involvement. Outcome was poor in all patients: two were discharged to a rehabilitation facility with moderate-to-severe disability and three (60%) patients died.

CONCLUSIONS:

Stroke is implicated in SARS-CoV-2 infection. Although causality cannot be established, we present the imaging and clinical findings of patients with COVID-19 and simultaneous bihemispheric ischemic strokes. Multifocal ischemic strokes with bihemispheric involvement should be considered in COVID-19 patients with severe infection and poor neurologic status and may be associated with poor outcomes.

Neuroinflammatory Triangle Presenting Novel Pharmacological Targets for Ischemic Brain Injury

Ischemic stroke is one of the leading causes of morbidity and mortality globally. Hundreds of clinical trials have proven ineffective in bringing forth a definitive and effective treatment for ischemic stroke, except a myopic class of thrombolytic drugs. That, too, has little to do with treating long-term post-stroke disabilities. These studies proposed diverse options to treat stroke, ranging from neurotropic interpolation to venting antioxidant activity, from blocking specific receptors to obstructing functional capacity of ion channels, and more recently the utilization of neuroprotective substances. However, state of the art knowledge suggests that more pragmatic focus in finding effective therapeutic remedy for stroke might be targeting intricate intracellular signaling pathways of the 'neuroinflammatory triangle': ROS burst, inflammatory cytokines, and BBB disruption. Experimental evidence reviewed here supports the notion that allowing neuroprotective mechanisms to advance, while limiting neuroinflammatory cascades, will help confine post-stroke damage and disabilities.

How cytosolic compartments play safeguard functions against neuroinflammation and cell death in cerebral ischemia

Ischemic stroke is the second leading cause of mortality and disability globally. Neuronal damage following ischemic stroke is rapid and irreversible, and eventually results in neuronal death. In addition to activation of cell death signaling, neuroinflammation is also considered as another pathogenesis that can occur within hours after cerebral ischemia. Under physiological conditions, subcellular organelles play a substantial role in neuronal functionality and viability. However, their functions can be remarkably perturbed under neurological disorders, particularly cerebral ischemia. Therefore, their biochemical and structural response has a determining role in the sequel of neuronal cells and the progression of disease. However, their effects on cell death and neuroinflammation, as major underlying mechanisms of ischemic stroke, are still not understood. This review aims to provide a comprehensive overview of the contribution of each organelle on these pathological processes after ischemic stroke.

Emerging Role of LncRNAs in Ischemic Stroke-Novel Insights into the Regulation of Inflammation

As a crucial kind of pervasive gene, long noncoding RNAs (lncRNAs) are abundant and key players in brain function as well as numerous neurological disorders, especially ischemic stroke. The mechanisms underlying ischemic stroke include angiogenesis, autophagy, apoptosis, cell death, and neuroinflammation. Inflammation plays a vital role in the pathological process of ischemic stroke, and systemic inflammation affects the patient’s prognosis. Although a great deal of research has illustrated that various lncRNAs are closely relevant to regulate neuroinflammation and microglial activation in ischemic stroke, the specific interactional relationships and mechanisms between lncRNAs and neuroinflammation have not been described clearly. This review aimed to summarize the therapeutic effects and action mechanisms of lncRNAs on ischemia by regulating inflammation and microglial activation. In addition, we emphasize that lncRNAs have the potential to modulate inflammation by inhibiting and activating various signaling pathways, such as microRNAs, NF‐κB and ERK.

Modulating poststroke inflammatory mechanisms: Novel aspects of mesenchymal stem cells, extracellular vesicles and microglia

Inflammation plays an important role in the pathological process of ischemic stroke, and systemic inflammation affects patient prognosis. As resident immune cells in the brain, microglia are significantly involved in immune defense and tissue repair under various pathological conditions, including cerebral ischemia. Although the differentiation of M1 and M2 microglia is certainly oversimplified, changing the activation state of microglia appears to be an intriguing therapeutic strategy for cerebral ischemia. Recent evidence indicates that both mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (EVs) regulate inflammation and modify tissue repair under preclinical stroke conditions. However, the precise mechanisms of these signaling pathways, especially in the context of the mutual interaction between MSCs or MSC-derived EVs and resident microglia, have not been sufficiently unveiled. Hence, this review summarizes the state-of-the-art knowledge on MSC- and MSC-EV-mediated regulation of microglial activity under ischemic stroke conditions with respect to various signaling pathways, including cytokines, neurotrophic factors, transcription factors, and microRNAs.

Eosinophil-to-Neutrophil Ratio Predicts Poor Prognosis of Acute Ischemic Stroke Patients Treated With Intravenous Thrombolysis

Background and Purpose: The eosinophil-to-neutrophil ratio (ENR) was recently reported as a novel inflammatory marker in acute ischemic stroke (AIS). However, few studies reported the predictive value of ENR in AIS patients, especially for those with intravenous thrombolysis.

Methods: Two hundred sixty-six AIS patients receiving intravenous thrombolysis were retrospectively recruited in this study and followed up for 3 months and 1 year. The Modified Rankin Scale (mRS) and the time of death were recorded. Poor outcome was defined as mRS 3–6. After excluding patients who were lost to follow-up, the remaining 250 patients were included in the 3-month prognosis analysis and the remaining 223 patients were included in the 1-year prognosis analysis.

Results: ENR levels in the patients were lower than those in the healthy controls. The optimal cutoff values for the ability of ENR × 10² to predict 3-month poor outcome were 0.74 with 67.8% sensitivity and 77.3% specificity. Patients with ENR × 10² ≥ 0.74 have a lower baseline National Institutes of Health Stroke Scale (NIHSS) score (median: 7 vs. 11, p < 0.001). After multivariate adjustment, patients with ENR × 10² ≥ 0.74 were more likely to come to a better 3-month outcome (OR = 0.163; 95% CI, 0.076–0.348, p < 0.001). At the 1-year follow-up, the patients with ENR × 10² ≥ 0.74 showed a lower risk of mortality (HR = 0.314; 95% CI, 0.135–0.731; p = 0.007).

Conclusions: A lower ENR is independently associated with a 3-month poor outcome and a 3-month and 1-year mortality in AIS patients treated with intravenous thrombolysis.

Increased serum interleukin-34 levels as a novel diagnostic and prognostic biomarker in patients with acute ischemic stroke

BACKGROUND

Recent data reveal that interleukin-34 (IL-34) can drive inflammatory response, thereby participating in the pathogenesis of inflammatory diseases. However, the potential effect of IL-34 in acute ischemic stroke (AIS) remains unknown. The purpose of this study was to explore whether the levels of serum IL-34 were correlated with clinical severity or prognosis in AIS patients.

METHODS

In this prospective cohort study, serum IL-34 levels were detected in 150 healthy controls and 155 AIS patients. Univariate and multivariate logistic regression analysis were conducted to investigate the effect of IL-34 on the diagnosis and prognosis of AIS. ROC curve was utilized to evaluate predictive values for IL-34.

RESULTS

Serum IL-34 levels at admission were significantly higher in AIS patients than those in the healthy controls. Univariate and multivariate logistics regression analysis showed that IL-34 was an independent predictor of occurrence and functional outcome of AIS. The ROC curve demonstrated that IL-34 had a good predictive effect on the diagnosis and prognosis of AIS.

CONCLUSIONS

IL-34 can be used as a novel and independent diagnostic and predicting prognostic biomarker in AIS.

Dynamics of T Lymphocyte between the Periphery and the Brain from the Acute to the Chronic Phase Following Ischemic Stroke in Mice

Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4^-CD8^-CD3⁺ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10⁺Foxp3⁺ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10⁺Foxp3⁺ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.

Embryonic Stem Cell Derived Small Extracellular Vesicles Modulate Regulatory T Cells to Protect against Ischemic Stroke

Stem cell derived small extracellular vesicles (sEVs) have been proved to promote neurological recovery after stroke. Recent studies demonstrate a phenomenal tissue repair ability in embryonic stem cell derived sEVs (ESC-sEVs). However, whether ESC-sEVs could protect against ischemic stroke remains unknown. Immune responses play an essential role in the pathogenesis of ischemic stroke, and modulating post-stroke immune responses ameliorates ischemia-induced brain damage. In this study, we aim to determine the therapeutic function of ESC-sEVs, specifically focusing on their role in immunomodulation after ischemic stroke. ESC-sEVs are intravenously administered after transient middle cerebral artery occlusion. ESC-sEVs significantly decrease leukocyte infiltration, inflammatory cytokine expression, neuronal death, and infarct volume and alleviate long-term neurological deficits and tissue loss after ischemic stroke. Interestingly, ESC-sEVs induce a marked increase in regulatory T cells (Tregs) after stroke. Further, ESC-sEV-afforded immunomodulatory function and neuroprotection against stroke are dependent on Tregs, as the depletion of Tregs almost completely abrogates the protective effects. Mechanistically, proteomic analysis reveals the enrichment of TGF-β, Smad2, and Smad4 proteins in ESC-sEVs, which could be delivered to activate the TGF-β/Smad pathway in CD4⁺ T cells and therefore induce Treg expansion. ESC-sEVs modulate neuroinflammation and protect against ischemic stroke through the expansion of Tregs, a process that is partially dependent on the activation of the TGF-β/Smad signaling pathway by the transfer of TGF-β, Smad2, and Smad4. The results suggest ESC-sEVs might be a candidate for immune modulation.

Monocyte-based inflammatory indices predict outcomes following aneurysmal subarachnoid hemorrhage

The contribution of specific immune cell populations to the post-hemorrhagic inflammatory response in aneurysmal subarachnoid hemorrhage (aSAH) and correlations with clinical outcomes, such as vasospasm and functional status, remains unclear. We aimed to compare the predictive value of leukocyte ratios that include monocytes as compared to the neutrophil-to-lymphocyte ratio (NLR) in aSAH. A prospectively accrued database of consecutive patients presenting to our institution with aSAH between January 2013 and December 2018 was used. Patients with signs and symptoms of infection (day 1-3) were excluded. Admission values of the NLR, monocyte-neutrophil-to-lymphocyte ratio (M-NLR), and lymphocyte-to-monocyte ratio (LMR) were calculated. Associations with functional status, the primary outcome, and vasospasm were evaluated using univariable and multivariable logistic regression analyses. In the cohort of 234 patients with aSAH, the M-NLR and LMR, but not the NLR, were significantly associated with poor functional status (modified Rankin scale > 2) at 12-18 months following discharge (p = 0.001, p = 0.023, p = 0.161, respectively). The area under the curve for predicting poor functional status was significantly lower for the NLR (0.543) compared with the M-NLR (0.603, p = 0.024) and LMR (0.608, p = 0.040). The M-NLR (OR = 1.01 [1.01-1.02]) and LMR (OR = 0.88 [0.78-0.99]) were independently associated with poor functional status while controlling for age, hypertension, Fisher grade, and baseline clinical status. The LMR was significantly associated with vasospasm (OR = 0.84 [0.70-0.99]) while adjusting for age, hypertension, Fisher grade, aneurysm size, and current smoking. Inflammatory indices that incorporate monocytes (e.g., M-NLR and LMR), but not those that include only neutrophils, predict outcomes after aSAH.

Serum ICAM-1 as a Predictor of Prognosis in Patients with Acute Ischemic Stroke

Objective

Inflammation is one of the key mechanisms involved in functional impairment after stroke. Intercellular adhesion molecule-1 (ICAM-1) is an important inflammatory molecule in the body. The purpose of our study was to determine the correlation between ICAM-1 and the prognosis of acute ischemic stroke (AIS).

Methods

286 AIS patients treated at Beijing Tiantan Hospital were continuously included in the study. The demographic data of the patients were collected, and the fasting blood within 24 hours of admission was collected to detect the clinical indicators. The functional prognosis was measured using the modified Rankin Scale (mRS) 3 months after stroke. The poor prognosis is defined as mRS ≥ 3. The enzyme-linked immunosorbent assay (ELISA) was used to determine the serum ICAM-1 levels.

Results

The serum ICAM-1 levels of patients with poor prognosis were significantly higher than that of patients with good prognosis (144.2 ± 14.8 vs 117.5 ± 12.1 pg/ml). Receiver operating characteristic curve (ROC) analysis showed that the sensitivity and specificity of serum ICAM-1 for predicting the prognosis of AIS were 74% and 76%, respectively. In logistic regression analysis, the serum ICAM-1 level is still an independent predictor of poor prognosis (odds ratio [OR]: 0.52; 95% confidence interval [CI]: 0.318-0.839).

Conclusions

Higher serum ICAM-1 levels on admission in AIS patients might increase the risk of poor prognosis.

Triggering of cardiovascular disease by infection type: The Atherosclerosis Risk in Communities study (ARIC)

INTRODUCTION

Acute infections are known triggers of cardiovascular disease (CVD) but how this association varies across infection types is unknown. We hypothesized while acute infections increase CVD risk, the strength of this association varies across infection types.

METHOD

Acute coronary heart disease (CHD) and ischemic stroke cases were identified in the Atherosclerosis Risk in Communities Study (ARIC). ICD-9 codes from Medicare claims were used to identify cellulitis, pneumonia, urinary tract infections (UTI), and bloodstream infections. A case-crossover design and conditional logistic regression were used to compare infection types among acute CHD and stroke cases 14, 30, 42, and 90 days before the event with two corresponding control periods (1 and 2 years prior).

RESULTS

Of the 1312 acute CHD cases, 116 had a UTI, 102 had pneumonia, 43 had cellulitis, and 28 had a bloodstream infection 90 days before the CHD event. Pneumonia (OR = 25.53 (9.21,70.78)), UTI (OR = 3.32 (1.93, 5.71)), bloodstream infections (OR = 5.93 (2.07, 17.00)), and cellulitis (OR = 2.58 (1.09, 6.13)) were associated with higher acute CHD risk within 14 days of infection. Of the 727 ischemic stroke cases, 12 had cellulitis, 27 had pneumonia, 56 had a UTI, and 5 had a bloodstream infection within 90 days of the stroke. Pneumonia (OR = 5.59 (1.77, 17.67)) and UTI (OR = 3.16 (1.68, 5.94)) were associated with higher stroke risk within 14 days of infection.

CONCLUSIONS

Patients with pneumonia, UTI, or bloodstream infection appear to be at a 2.5 to 25.5 fold elevated CVD risk following infection. Preventive therapies during this high-risk period should be considered.

Associations of the neutrophil to lymphocyte ratio with intracranial artery stenosis and ischemic stroke

Background

The neutrophil-to-lymphocyte ratio (NLR) has emerged as an inflammatory marker. However, the associations of NLR with intracranial artery stenosis (ICAS) and ischemic stroke remain unclear. This study aimed to examine the associations of NLR with ICAS and ischemic stroke among a large and high-risk population.

Methods

Participants with records of clinical characteristics were prospectively recruited from the Neurology Department and Health & Physical Examination Center of Qingdao Municipal Hospital. Logistic regression analysis was used to examine the associations of NLR with ICAS and ischemic stroke. Moreover, we also conducted parametric mediation analysis to estimate the effect of NLR on the risk of ischemic stroke mediated through ICAS.

Results

A total of 2989 participants were enrolled in this study. After adjusting for covariates, NLR (OR = 1.125, 95%CI 1.070–1.183) and ICAS (OR = 1.638, 95%CI 1.364–1.967) were significantly associated with ischemic stroke. Compared with the first quartile NLR, the second, third and fourth quartiles NLR were independent risk predictors for ischemic stroke (P for trend < 0.001); the third and fourth quartiles were independent predictors for ICAS (P for trend < 0.001). The mediation analysis showed that ICAS partially mediated the association between NLR and ischemic stroke, accounting for 14.4% of the total effect (P < 0.001).

Conclusions

NLR was significantly associated with ICAS and ischemic stroke. Besides, ICAS partially mediated the association between NLR and ischemic stroke.

S100A8 Promotes Inflammation via Toll-Like Receptor 4 After Experimental Traumatic Brain Injury

INTRODUCTION

S100 calcium-binding protein A8 (S100A8) is also known as macrophage-related protein 8, which is involved in various pathological processes in the central nervous system post-traumatic brain injury (TBI), and plays a critical role in inducing inflammatory cytokines. Accumulating evidences have indicated that toll-like receptor 4 (TLR4) is considered to be involved in inflammatory responses post TBI. The present study was designed to analyze the hypothesis that S100A8 is the key molecule that induces inflammation via TLR4 in TBI.

METHODS

The weight-drop TBI model was used and randomly implemented on mice that were categorized into six groups: Sham, NS, S100A8, S100A8+TAK-242, TBI, and TBI+TAK-242 groups. In the S100A8+TAK-242 and TBI+TAK-242 groups, at half an hour prior to the intracerebroventricular administration of S100A8 or TBI, mice were intraperitoneally treated with TAK-242 that acts as a selective antagonist and inhibitor of TLR4. Furthermore, the protein recombinant of S100A8 was injected into the lateral ventricle of the brain of mice in the S100A8 and S100A8+TAK-242 groups. Sterile normal saline was injected into the lateral ventricle in the NS group. To evaluate the association between S100A8 and TLR4, Western blot, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and Nissl staining were employed. Simultaneously, the neurological score and brain water content were assessed. In the in vitro analysis, BV-2 microglial cells were stimulated with lipopolysaccharide LPS or S100A8 recombinant protein, with or without TAK-242. The expression of the related proteins was subsequently detected by Western blot or enzyme-linked immunosorbent assay.

RESULTS

The levels of S100A8 protein and pro-inflammatory cytokines were significantly elevated after TBI. There was a reduction in the neurological scores of non-TBI animals with remarkable severe brain edema after the intracerebroventricular administration of S100A8. Furthermore, the TLR4, p-p65, and myeloid differentiation factor 88 (MyD88) levels were elevated after the administration of S100A8 or TBI, which could be restored by TAK-242. Meanwhile, in the in vitro analysis, due to the stimulation of S100A8 or LPS, there was an upregulation of p-p65 and MyD88, which could also be suppressed by TAK-242.

CONCLUSION

The present study demonstrated that the TLR4-MyD88 pathway was activated by S100A8, which is essential for the development of inflammation in the brain after TBI.

COVID-19 Pathophysiology Predicts That Ischemic Stroke Occurrence Is an Expectation, Not an Exception-A Systematic Review

Clinical reports of neurological manifestations associated with severe coronavirus disease 2019 (COVID-19), such as acute ischemic stroke (AIS), encephalopathy, seizures, headaches, acute necrotizing encephalitis, cerebral microbleeds, posterior reversible leukoencephalopathy syndrome, hemophagocytic lymphohistiocytosis, peripheral neuropathy, cranial nerve palsies, transverse myelitis, and demyelinating disorders, are increasing rapidly. However, there are comparatively few studies investigating the potential impact of immunological responses secondary to hypoxia, oxidative stress, and excessive platelet-induced aggregation on the brain. This scoping review has focused on the pathophysiological mechanisms associated with peripheral and consequential neural (central) inflammation leading to COVID-19-related ischemic strokes. It also highlights the common biological processes shared between AIS and COVID-19 infection and the importance of the recognition that severe respiratory dysfunction and neurological impairments associated with COVID and chronic inflammation [post-COVID-19 neurological syndrome (PCNS)] may significantly impact recovery and ability to benefit from neurorehabilitation. This study provides a comprehensive review of the pathobiology of COVID-19 and ischemic stroke. It also affirms that the immunological contribution to the pathophysiology of COVID-19 is predictive of the neurological sequelae particularly ischemic stroke, which makes it the expectation rather than the exception. This work is of fundamental significance to the neurorehabilitation community given the increasing number of COVID-related ischemic strokes, the current limited knowledge regarding the risk of reinfection, and recent reports of a PCNS. It further highlights the need for global collaboration and research into new pathobiology-based neurorehabilitation treatment strategies and more integrated evidence-based care.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Potential Predictors of Prognosis in Acute Ischemic Stroke

Objective: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been emerging as the novel inflammatory biomarkers for determining the prognosis of various diseases. This study aimed to investigate the individual and joint effects of NLR and PLR on functional outcomes of acute ischemic stroke (AIS). Methods: Our study involved 448 eligible patients with first-ever AIS. Clinical and laboratory data were collected on admission within 72 h from stroke onset. Unfavorable functional outcome was defined as a modified Rankin Scale score of 3-6 at 3 months after AIS. Cox proportional hazard model and spline regression models was used to estimate the effect of NLR and PLR on risk of adverse outcomes after the last patient who completed a 3-months follow-up was enrolled. Results: After adjusting confounders, NLR were significantly associated with the unfavorable functional outcomes (P-trend < 0.001). So were PLR (P-trend < 0.001). NLR was discovered to have higher predictive value than PLR (AUC = 0.776, 95%CI = 0.727-0.825, P < 0.001; AUC = 0.697, 95%CI = 0.641-0.753, P < 0.001). The optimal cutoff values for NLR and PLR was 3.51 and 141.52, respectively. Stratified analysis performed by cox proportional hazard model showed that high level of NLR and PLR (NLR ≥ 3.51, PLR ≥ 141.52) presented the highest risk of unfavorable functional outcomes (adjusted HR, 3.77; 95% CI: 2.38-5.95; P < 0.001). Followed by single high level of NLR (adjusted HR, 2.32; 95% CI: 1.10-4.87; P = 0.027). Single high level of PLR (NLR < 3.51, PLR ≥ 141.52) also showed higher risk than low level of the combination, but it did not reach statistical significance (adjusted HR, 1.42; 95% CI: 0.75-2.70; P = 0.285). No obvious additive [relative excess risk due to interaction (RERI) not significant] or multiplicative (adjusted HR, 0.71; 95%CI: 0.46-1.09; P = 0.114) interaction was found between the effects of NLR and PLR on the risk of unfavorable functional outcomes. Conclusion: This study demonstrated that both NLR and PLR were independent predictors of 3-months functional outcomes of AIS. They may help to identify high-risk patients more forcefully when combined together.

Immunological mechanisms in poststroke dementia

PURPOSE OF REVIEW

To review new evidence on links between poststroke dementia and inflammation.

RECENT FINDINGS

Although there are still no treatments for poststroke dementia, recent evidence has improved our understanding that stroke increases the risk of incident dementia and worsens cognitive trajectory for at least a decade afterwards. Within approximately the first year dementia onset is associated with stroke severity and location, whereas later absolute risk is associated with more traditional dementia risk factors, such as age and imaging findings. The molecular mechanisms that underlie increased risk of incident dementia in stroke survivors remain unproven; however new data in both human and animal studies suggests links between cognitive decline and inflammation. These point to a model where chronic brain inflammation, provoked by inefficient clearance of myelin debris and a prolonged innate and adaptive immune response, causes poststroke dementia. These localized immune events in the brain may themselves be influenced by the peripheral immune state at key times after stroke.

SUMMARY

This review recaps clinical evidence on poststroke dementia, new mechanistic links between the chronic inflammatory response to stroke and poststroke dementia, and proposes a model of immune-mediated neurodegeneration after stroke.

Predictive Values of the SeLECT Score and IL-1β for Post-Stroke Epilepsy

PURPOSE

To establish a new prognostic tool for the prediction of post-stroke epilepsy (PSE) through combining the SeLECT score with IL-1β.

PATIENTS AND METHODS

This prospective observational study included 915 patients with acute ischemic stroke. The SeLECT score was calculated, and serum IL-1β levels were measured within 24 h of their admission. One unprovoked late seizure following the acute phase of stroke was diagnosed as PSE. All patients were divided into PSE group and non-PSE group according to the occurrence of PSE. Multivariate analysis was performed to determine the independent associations between the SeLECT score, IL-1β and PSE. Receiver operating characteristic (ROC) curve was employed to assess the predictive values of the SeLECT score, IL-1β and their combination for PSE.

RESULTS

Fifty-three patients occurred PSE within 1 year after stroke onset (5.8%). Multivariate analysis demonstrated that the SeLECT score [odds ratio (OR): 1.416, 95% confidence interval (CI): 1.191-1.863, P=0.013] and IL-1β (OR: 1.457, 95% CI: 1.215-1.894, P<0.001) were independent risk factors for PSE after adjusting for more than one comorbidity, stroke laterality, large-artery atherosclerosis, thrombolysis, age and use of statins. The AUC of the SeLECT score and IL-1β for predicting PSE was 0.756 (SE: 0.033, 95% CI: 0.692-0.819) and 0.811 (SE: 0.032, 95% CI: 0.748-0.875), respectively. The AUC of their combination was 0.933 (SE: 0.027, 95% CI: 0.880-0.985). Z test showed that the AUC of their combination was significantly higher than that of the SeLECT score or IL-1β alone (0.933 vs 0.756, Z=4.151, P<0.01; 0.933 vs 0.811, Z=2.914, P<0.01). Combination prediction of the SeLECT score and IL-1β for PSE had a high predictive value with a sensitivity of 88.06% and specificity of 82.37%.

CONCLUSION

The combination of the SeLECT score and IL-1β had a potential to act as a new prognostic tool for the prediction of PSE.

Protective Effects of Polydatin Against Dementia-Related Disorders

Dementia is a collection of symptoms affecting a person's cognition. Dementia is debilitating, and therefore, finding an effective treatment is of utmost importance. Resveratrol, which exhibits neuroprotective effects, has low bioavailability. However, its glucoside polydatin is more bioavailable. Here, the evidence that supports the protective role of polydatin against dementia- related diseases such as Alzheimer's disease, vascular dementia, alcohol-related dementia, and Lewy body dementias is presented. The beneficial effects of polydatin from a mechanistic perspective are specifically emphasized in this review. Future directions in this area of research are also discussed.