Systemic infection, inflammation and acute ischemic stroke

Application of neutrophil to lymphocyte ratio to identify CT-negative cerebral infarction with nonfocal symptoms

Background

The neutrophil to lymphocyte ratio (NLR) has emerged as a strong predictor of mortality in stroke patients. Our study aimed to investigate the correlation between NLR and cerebral infarction with nonfocal symptoms confirmed by diffusion-weighted imaging (DWI) (+).

Methods

A total of 439 patients with nonfocal stroke symptoms with CT-negative findings were included from January 1 to December 31, 2018. All patients underwent a head MRI examination within seven days following a head CT examination. The patients’ demographics, medical history, presenting symptoms, and stroke location were recorded. Logistic regression and receiver operating characteristic (ROC) curve analysis were used to identify variables with a significant association with cerebral infarction.

Results

Cerebral infarction was detected in 79 (18%) patients confirmed by DWI(+), located mostly in the cerebellum (40.51%). Dizziness (85.19%) was the most common symptom. The cerebral infarction group showed a higher prevalence of hypertension (P<0.0001), diabetes mellitus (P<0.0001), and smoking status (P=0.001) than non-cerebral infarction group. The NLR (P<0.0001) was higher in the cerebral infarction group. There was no significant difference in NIHSS (P=0.09). Logistic analysis revealed that male gender (P=0.046), a history of hypertension (P=0.001), diabetes mellitus (P=0.001), smoking (P=0.023), and NLR (P<0.0001) were the best predictors of cerebral infarction. When integrating sex, hypertension, diabetes mellitus, smoking and NLR, the area under ROC value of the combined method was 0.785, higher than any separate parameters (P<0.05).

Conclusions

NLR combined with male gender, a history of hypertension, diabetes mellitus, and smoking, could predict DWI-confirmed cerebral infarction with nonfocal neurologic symptoms with high diagnostic accuracy.

Dynamic increase in neutrophil levels predicts parenchymal hemorrhage and function outcome of ischemic stroke with r-tPA thrombolysis

BACKGROUND

The higher level of neutrophil on admission has been reported to predict worse 3-month outcomes in ischemic stroke patients. Our study was to explore the dynamic changes of neutrophil and lymphocyte after r-tPA thrombolysis of ischemic stroke and the relationship with parenchymal hemorrhage (PH) and 3-month function outcome.

METHODS

A total of 208 acute ischemic stroke (AIS) patients with intravenous thrombolysis were included and then received 3-month follow-up in the present study. Blood samples for neutrophil and lymphocyte counts were obtained on admission, at 24 h and at 7 days after r-tPA infusion. The associations of increase in neutrophil, lymphocyte, and neutrophil to lymphocyte ratio (NLR) with PH or 3-month poor outcome were examined by logistic regression.

RESULTS

Increasing trends in the neutrophil and NLR were observed in AIS patients after r-tPA treatment. Increased level of neutrophil at 24 h after r-tPA infusion but not that on admission was associated with PH (OR = 2.86, P = 0.029) and 3-month poorer functional outcomes (OR = 2.67, P = 0.009). Moreover, patients were divided into four groups according to the percent change in neutrophil within 24 h following r-tPA treatment, and we found that there was a trend of incremental OR when compared higher increase group with lower ones.

CONCLUSIONS

Dynamic increase in neutrophil and NLR after stroke may predict PH and 3-month poor outcome in AIS patients receiving r-tPA treatment. Therefore, neutrophil and NLR may serve as activity markers for PH and 3-month poor prognosis in AIS patients with intravenous thrombolysis.

The Protective Effects and Mechanisms of Apelin/APJ System on Ischemic Stroke: A Promising Therapeutic Target

The orphan receptor APJ and its endogenous ligand apelin, which are expressed in the brain, are the major components of the apelin/APJ system. Growing evidence shows that the apelin/APJ system plays a vital role in the pathophysiology of cerebral ischemic injury. Targeting the apelin/APJ system may have protective effects on cerebral ischemic injury. In this review, we sum up the latest research progress relating to the actions and therapeutic potential of the apelin/APJ system in ischemic stroke. An in-depth knowledge of the pathophysiological effects of the apelin/APJ system and the underlying mechanisms will help to develop novel therapeutic interventions for ischemic stroke.

Inflammation in Post-Traumatic Stress Disorder (PTSD): A Review of Potential Correlates of PTSD with a Neurological Perspective

Post-traumatic stress disorder (PTSD) is a chronic condition characterized by symptoms of physiological and psychosocial burden. While growing research demonstrated signs of inflammation in PTSD, specific biomarkers that may be representative of PTSD such as the detailed neural correlates underlying the inflammatory responses in relation to trauma exposure are seldom discussed. Here, we review recent studies that explored alterations in key inflammatory markers in PTSD, as well as neuroimaging-based studies that further investigated signs of inflammation within the brain in PTSD, as to provide a comprehensive summary of recent literature with a neurological perspective. A search was conducted on studies published from 2009 through 2019 in PubMed and Web of Science. Fifty original articles were selected. Major findings included elevated levels of serum proinflammatory cytokines in individuals with PTSD across various trauma types, as compared with those without PTSD. Furthermore, neuroimaging-based studies demonstrated that altered inflammatory markers are associated with structural and functional alterations in brain regions that are responsible for the regulation of stress and emotion, including the amygdala, hippocampus, and frontal cortex. Future studies that utilize both central and peripheral inflammatory markers are warranted to elucidate the underlying neurological pathway of the pathophysiology of PTSD.

Characteristics of Cerebral Stroke in the Tibet Autonomous Region of China

It is well known that cerebrovascular disease has become an important cause of adult death and disability. Strikingly, the Tibet Autonomous Region (TAR) ranks on the top in China for the incidence of stroke. To help explain this phenomenon, we have searched for and analyzed stroke-related literature for the TAR in the past 2 decades and have referenced reports from other regions at similar altitudes. This article focuses on epidemiology features, risk factors, and pathogenesis of stroke in the TAR in an effort to generate a better understanding of the characteristics of stroke in this region. The special plateau-related factors such as its high elevation, limited oxygen, the high incidence of hypertension, smoking, and the unique dietary habits of the region are correlated with the high incidence of stroke. In addition to these factors, the pathogenesis of stroke in this high-altitude area is also unique. However, there is no established explanation for the unique occurrence and high incidence of stroke in the TAR. Our study provides an important rationale not only for the clinic to prevent and treat this disease, but also for the government to develop appropriate health policies for the prevention of stroke in the TAR.

Association of postoperative covert stroke and cognitive dysfunction among elderly patients undergoing non-cardiac surgery: protocol for a prospective cohort study (PRECISION study)

INTRODUCTION

The incidence of covert stroke and cognitive dysfunction has gradually increased due to an ageing population. Recently, a prospective cohort study reported perioperative covert stroke was associated with an increased risk of postoperative cognitive dysfunction (POCD) 1 year after non-cardiac surgery. However, the mechanism remains unclear.

METHODS AND ANALYSIS

This is a prospective observational trial aiming to investigate the cumulative incidence of perioperative covert stroke and test the hypothesis that perioperative covert stroke associates with POCD in elderly patients undergoing non-cardiac and non-neurological surgery. Data on risk factors, brain MRI, cognitive function evaluation and serum immune-inflammatory cytokines will be collected and analysed.

ETHICS AND DISSEMINATION

Ethical approval has been granted by the Medical Ethics Committee of Beijing Tiantan Hospital, Capital Medical University (reference number: KY2017-027-02). The results of this study will be disseminated through presentations at scientific conferences and publication in scientific journals.

TRIAL REGISTRATION NUMBER

NCT03081429.

Association Between IL-6 and Seizure Recurrence in Patients with the First Post-Ischemic Stroke Seizure

PURPOSE

To study the association between IL-6 level and seizure recurrence in patients with the first post-ischemic stroke seizure and assess its predictive value for seizure recurrence.

PATIENTS AND METHODS

A total of 2976 consecutive ischemic stroke patients were retrospectively enrolled. Among them, 209 (7.02%) patients with the first post-ischemic stroke seizure were included in this analysis. The IL-6 mRNA expression level was evaluated through quantitative real-time PCR (qRT-PCR) and the 2^-ΔΔCt method. Demographic data and clinical characteristics were collected. Univariate analysis was performed with independent-samples t-test, Mann-Whitney U-test, or chi-square test. Multivariate analysis was conducted using a backward stepwise logistic regression model for variables with P<0.10 in univariate analysis. The predictive value was assessed using a receiver operating characteristic (ROC) curve.

RESULTS

Among the patients included, 105 (50.24%) had recurrence of seizures, and 104 (49.76%) had no recurrence. Multivariate analysis demonstrated that the IL-6 mRNA expression level was independently correlated with seizure recurrence in patients with the first post-ischemic stroke seizure after adjusting for age, NIHSS scores, time of seizure, seizure type, lesion size, location of the offending lesion to different hemispheric lobes, cortical involvement, gender, electroencephalography (EEG) findings, and hemorrhagic transformation. When the IL-6 mRNA expression level was used to predict seizure recurrence, the area under the ROC curve (AUC) was 0.763 (SE=0.033, 95% CI=0.698-0.829). The diagnostic power was moderate.

CONCLUSION

IL-6 was independently correlated with seizure recurrence in patients with the first post-ischemic stroke seizure and might be a potential biomarker for prediction of seizure recurrence.

Lipopolysaccharide worsens the prognosis of experimental cerebral ischemia via interferon gamma-induced protein 10 recruit in the acute stage

BACKGROUND

Infection is an important clinical complication facing stroke-patients and triples the risk of death within 30 days post-stroke via mechanisms which are poorly understood.

AIMS

We tried to explore the mechanisms that inflammation caused by infections aggravated the ischemic brain injury after middle cerebral artery occlusion (MCAO).

METHODS

We used lipopolysaccharide (LPS) as systemic inflammatory stimuli to explore the mechanisms of aggravated ischemic brain injury after Sprague-Dawley male rats subjected to MCAO. Brain damage was evaluated by cerebral blood perfusion, Longa-5 scores, infarct volume and edema degree. Systemic cytokine responses and inflammatory changes in the plasma and brain were analyzed by ELISA kit, RT² Profiler™ PCR array, and quantitative real-time PCR. The differential genes were subjected to Gene Ontology enrichment analysis and protein-protein interaction (PPI) network construction.

RESULTS

Lipopolysaccharide profoundly aggravated the brain damage after 24 h post-MCAO. At the acute stage (ischemia/reperfusion 90 min/3 h), the brain homogenate gene expression of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and Interferon gamma-induced protein 10 (IP-10) was significantly up-regulated and the contents in plasma and brain homogenate were significantly increased in MCAO and MCAO + LPS group. IP-10 was the only gene with significant difference between MCAO and MCAO + LPS group, which was also in an important position with degrees of ≥ 14 in PPI network.

CONCLUSIONS

It was possible that trace LPS aggravated the ischemic brain injury by induction of excessive IP-10 secretion in the acute stage, leading to excessive inflammatory response, which consequently increased the infarct volume and edema degree 24 h post-MCAO.

Evaluation of Patients with High National Institutes of Health Stroke Scale as Thrombectomy Candidates Using the Kentucky Appalachian Stroke Registry

INTRODUCTION

Mechanical thrombectomy has become standard of care for emergent large vessel occlusive stroke. Estimates of incidence for thrombectomy eligibility vary significantly. National Institutes of Health Stroke Scale (NIHSS) of 10 or greater is highly predictive of large vessel occlusion. Using our Kentucky Appalachian Stroke Registry (KApSR), we evaluated temporal trends in stroke admissions with NIHSS ≥10 to determine patient characteristics among that group along with effects and needs in thrombectomy utilization.

METHODS

Using the KApSR database that captures patients throughout the Appalachian region in our stroke network, we evaluated patients admitted with ischemic stroke with NIHSS ≥10. We recorded demographics, comorbidities, treatment (thrombectomy, decompressive craniectomy), and county of origin. Change in NIHSS from admission to discharge was used as an indicator of inpatient outcome.

RESULTS

Between 2010 and 2016, 1,510 patients were admitted with NIHSS ≥10. 87.2% had high blood pressure, 69.6% had dyslipidemia, and 41.7% used tobacco. There were significant sex differences in the types of patients presenting with NIHSS ≥10 with females being older on average and having more atrial fibrillation and obesity. There was an increase in thrombectomy utilization from 2010 to 2016, but only 7.5% of the potentially eligible patients underwent the procedure. In comparison to the period 2010-2014, the 2015-2016 period had higher rates of obesity and tobacco abuse.

CONCLUSION

Among patients with significant burden of ischemic stroke, the most common coexisting medical condition was high blood pressure. Patients who underwent thrombectomy had significantly better inpatient clinical improvement. These data support the need to maximize utilization of thrombectomy along with need to devote increased resources on modifiable stroke risk factors.

Molecular imaging of carotid artery atherosclerosis with PET: a systematic review

PURPOSE

To conduct a systematic review of articles on PET imaging of carotid atherosclerosis with emphasis on clinical usefulness and comparison with other imaging modalities.

METHODS

Research articles reporting carotid artery PET imaging with different radiotracers until 30 November 2018 were systematically searched for in Medline/PubMed, Scopus, Embase, Google Scholar, and Cochrane Library. Duplicates were removed, and editorials, case studies, and investigations on feasibility or reproducibility of PET imaging and of patients with end-stage diseases or immunosuppressive medications were omitted. After quality assessment of included articles using Joanna Briggs Institute checklists, all eligible articles were reviewed.

RESULTS

Of 1718 primary hits, 53 studies comprising 4472 patients, aged 47-91 years (78.8% males), were included and grouped under the following headlines: diagnostic performance, risk factors, laboratory findings, imaging modalities, and treatment. ¹⁸F-fluorodeoxyglucose (FDG) (49/53) and ¹⁸F-sodium fluoride (NaF) (5/53) were the most utilized tracers to visualize carotid wall inflammation and microcalcification, respectively. Higher carotid FDG uptake was demonstrated in patients with than without symptomatic carotid atherosclerosis. Normal carotid arteries presented with the lowest FDG uptake. In symptomatic atherosclerosis, carotid arteries ipsilateral to a cerebrovascular event had higher FDG uptake than the contralateral carotid artery. FDG uptake was significantly associated with age, male gender, and body mass index in healthy individuals, and in addition with arterial hypertension, hypercholesterolemia, and diabetes mellitus in patients. Histological assessment indicated a strong correlation between microcalcification and NaF uptake in symptomatic patients. Histological evidence of calcification correlated inversely with FDG uptake, which was associated with increased macrophage and CD68 count, both accounting for increased local inflammatory response.

CONCLUSION

FDG-PET visualizes the inflammatory part of carotid atherosclerosis enabling risk stratification to a certain degree, whereas NaF-PET seems to indicate long-term consequences of ongoing inflammation by demonstrating microcalcification allowing discrimination of atherosclerotic from normal arteries and suggesting clinically significant carotid atherosclerosis.

Serum Amyloid A-Mediated Inflammasome Activation of Microglial Cells in Cerebral Ischemia

Serum amyloid A (SAA) proteins are acute-phase reactant associated with high-density lipoprotein (HDL) particles and increase in the plasma 1000-fold during inflammation. Recent studies have implicated SAAs in innate immunity and various disorders; however, the precise mechanism eludes us. Previous studies have shown SAAs are elevated following stroke and cerebral ischemia, and our studies demonstrated that SAA-deficient mice reduce inflammation and infarct volumes in a mouse stroke model. Our studies demonstrate that SAA increases the cytokine interleukin-1β (IL-1β), which is mediated by Nod-like receptor protein 3 (NLRP3) inflammasome, cathepsin B, and caspase-1 and may play a role in the pathogenesis of neurological disorders. SAA induced the expression of NLRP3, which mediated IL-1β induction in murine BV-2 cells and both sex primary mouse microglial cells, in a dose- and time-dependent fashion. Inhibition or KO of the NLRP3 in microglia prevented the increase in IL-1β. N-acetyl-l-cysteine and mito-TEMPO blocked the induction of IL-1β by inhibiting ROS with SAA treatment. In addition, inhibition of cathepsin B with different drugs or microglia from CatB-deficient mice attenuated inflammasome activation. Our studies suggest that the impact of SAA on inflammasome stimulation is mediated in part by the receptor for advanced glycation endproducts and Toll-like receptor proteins 2 and 4. SAA induced inflammatory cytokines and an M1 phenotype in the microglial cells while downregulating anti-inflammation M2 phenotype. These studies suggest that brain injury to can elicit a systemic inflammatory response mediated through SAA that contributes to the pathological outcomes.SIGNIFICANCE STATEMENT In the present study, serum amyloid A can induce that activation of the inflammasome in microglial cells and give rise to IL-1β release, which can further inflammation in the brain following neurological diseases. The also presents a novel target for therapeutic approaches in stroke.

Brain involvement in non-alcoholic fatty liver disease (NAFLD): A systematic review

Non-alcoholic fatty liver disease (NAFLD) is associated with high cardiovascular morbidity and mortality which usually is considered to be related to cardiac involvement, while scarce attention is addressed to brain damage. Viceversa NAFLD is associated with asymptomatic brain lesions, alterations in cerebral perfusion and activity, cognitive impairment and brain aging and with increased risk and severity of both ischemic and haemorrhagic stroke. Besides known metabolic risk factors, NAFLD is characterized by a pro inflammatory state, which contributes to atherosclerosis and microglia activation, endothelial dysfunction, pro-coagulant state and platelets activation, which in turn promote both micro and macrovascular damage eventually responsible for clinical and subclinical cerebrovascular alterations. A better knowledge of the association between NAFLD and brain alterations could lead to an improved management of risk factors underpinning both liver and cerebral disease, possibly preventing the progression of asymptomatic brain lesions to clinical cerebrovascular accidents.

The Prognostic Value of Serum Cytokines in Patients with Acute Ischemic Stroke

The inflammatory response is an unavoidable process and contributes to the destruction of cerebral tissue during the acute ischemic stroke (AIS) phase and has not been addressed fully to date. Insightful understanding of correlation of inflammatory mediators and stroke outcome may provide new biomarkers or therapeutic approaches for ischemic stroke. Here, we prospectively recruited 180 first-ever AIS patients within 72 hrs after stroke onset. We used the National Institutes of Health Stroke Scale (NIHSS) to quantify stroke severity and modified Rankin scale (mRS) to assess the 3-month outcome for AIS patients. Initially, we screened 35 cytokines, chemokines, and growth factors in sera from 75 AIS patients and control subjects. Cytokines that were of interest were further investigated in the 180 AIS patients and 14 heathy controls. We found that IL-1RA, IL-1β, IL-4, IL-5, IL-6, IL-7, IL-9, IL-10, IL-13, IL-15, EGF, G-CSF, Flt-3L, GM-CSF and Fractalkine levels were significantly decreased in severe stroke patients. In particular, IL-1β, IL-4, IL-5, IL-7, IL-9, IL-10, IL-15, G-CSF and GM-CSF were significantly reduced in AIS patients with poor outcome, compared to those with good prognosis. IL-6 was notably higher in the poor outcome group. Only IL-9 level decreased in the large infarct volume group. After adjusting for confounders, we found that IL-5 was an independent protective factor for prognosis in AIS patients with an adjusted OR of 0.042 (P = 0.007), whereas IL-6 was an independent risk predictor for AIS patients with an adjusted OR of 1.293 (P = 0.003). Our study suggests the levels of serum cytokines are related to stroke severity, short-term prognosis and cerebral infarct volume in AIS patients.

The effect of acupuncture on the expression of inflammatory factors TNF-α, IL-6,IL-1 and CRP in cerebral infarction: A protocol of systematic review and meta-analysis

BACKGROUND

The mechanisms of acupuncture on the treatment of cerebral infarction remain unclear, the aim of the present study was to provides a protocol of systematic review and meta-analysis, with which we will collect clinical evidence to verify whether acupuncture will have an effect on reducing the levels of tumor necrosis factor α (TNF-α), C-reactive protein (CRP), interleukin-1 (IL-1), and interleukin (IL-6) after cerebral infarction based on evidence-based studies.

METHODS

Included studies will be retrieved according to inclusion and exclusion criteria from 5 English databases (the MEDLINE via PubMed, the Cochrane Library, Embase, the Web of Science, and Ovid database), and 4 Chinese databases (China Science and Technology Journal Database (VIP), Chinese Biomedical Literature Database (CBM), Wan-fang Database, China National Knowledge Infrastructure (CNKI)) from October 1990 to October 2017. The inflammatory factor levels of TNF-α and IL-1,IL-6,CRP will be marked as major outcomes. We will use RevMan V.5.3 software to calculate the data synthesis and will conduct meta-analysis based on the collected data.

RESULTS

The inflammatory factor levels of TNF-α and IL-1,IL-6,CRP, mortality and adverse effects will be measured and comprehensively assessed to evaluate the adjunctive effect of XBP on CHF from this systematic review and meta-analysis with current clinical evidence.

CONCLUSION

The systematic review and meta-analysis will assess the effect of acupuncture on the expression of inflammatory factors TNF-α, IL-6, IL-1 and CRP in cerebral infarction with up-to-date clinical evidence.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42017078583.

Assessing the performance of monocyte to high-density lipoprotein ratio for predicting ischemic stroke: insights from a population-based Chinese cohort

Background

Monocyte to high-density lipoprotein cholesterol ratio (MHR) is a recently emerged measure of inflammation and oxidative stress and has been used to predict multiple cardiovascular abnormalities, but data relative to ischemic stroke are lacking. The goal of this study was to estimate the associations of MHR and prevalent ischemic stroke among a large cohort of general Chinese population.

Method

The study analyzed 8148 individuals (mean age: 54.1 years; 45.7% males) enrolled in a cross-sectional population-based Northeast China Rural Cardiovascular Health Study (NCRCHS). We identified 194 patients admitted from January and August 2013 with ischemic stroke.

Results

After adjustment for age, sex, and potential confounders, each standard deviation (SD) increment of MHR was predictive to a greater odd of ischemic stroke (odds ratio, 1.276; 95% confidence interval [CI], 1.082–1.504), with subjects in the highest quartile of MHR levels having a 1.6-fold higher risk of prevalent ischemic stroke (95% CI, 1.045–2.524) as compared with those in the lowest quartile. Moreover, smoothing curve showed a linear positive pattern of this association. The area under the curve (AUC) significantly increased (P = 0.042) to 0.808 (95% CI, 0.779–0.837) when the combined MHR was added to the baseline logistic regression model with ischemic stroke risk factors. Also, MHR (0.004) significantly improved integrated discrimination improvement when added to the baseline model.

Conclusions

The present study demonstrated for the first time a linear relation between MHR levels and the odds of ischemic stroke in a large community-based population. The MHR, a marker of high atherosclerotic burden, demonstrated incremental predictive value over traditional clinical risk factors, thus providing clinical utility in risk stratification in subjects presenting with ischemic stroke. These findings had implications for strategies aimed at lowering MHR to prevent adverse cardiovascular and cerebrovascular outcomes.

Natural Dietary Supplementation of Curcumin Protects Mice Brains against Ethanol-Induced Oxidative Stress-Mediated Neurodegeneration and Memory Impairment via Nrf2/TLR4/RAGE Signaling

The aim of the current study was to explore the underlying neuroprotective mechanisms of curcumin (50 mg/kg, for six weeks) against ethanol (5 mg/kg i.p., for six weeks) induced oxidative stress and inflammation-mediated cognitive dysfunction in mice. According to our findings, ethanol triggered reactive oxygen species (ROS), apoptosis, neuroinflammation, and memory impairment, which were significantly inhibited with the administration of curcumin, as assessed by ROS, lipid peroxidation (LPO), and Nrf2/HO-1 (nuclear factor erythroid 2-related factor 2/Heme-oxygenase-1) expression in the experimental mice brains. Moreover, curcumin regulated the expression of the glial cell markers in ethanol-treated mice brains, as analyzed by the relative expression TLR4 (Toll like Receptor 4), RAGE (Receptor for Advanced Glycations End products), GFAP (Glial fibrillary acidic protein), and Iba-1 (Ionized calcium binding adaptor molecule 1), through Western blot and confocal microscopic analysis. Moreover, our results showed that curcumin downregulated the expression of p-JNK (Phospo c-Jun N-Terminal Kinase), p-NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells), and its downstream targets, as assessed by Western blot and confocal microscopic analysis. Finally, the expression of synaptic proteins and the behavioral results also supported the hypothesis that curcumin may inhibit memory dysfunction and behavioral alterations associated with ethanol intoxication. Altogether, to the best of our knowledge, we believe that curcumin may serve as a potential, promising, and cheaply available neuroprotective compound against ethanol-associated neurodegenerative diseases.

Effect of single-nucleotide polymorphism in pri-microRNA-124 on poststroke motor function recovery

BACKGROUND

Stroke is a leading cause of long-term disability and further one of the main causes of motor impairment. The current study aimed to investigate whether miR-124 polymorphism (rs531564) influences the motor function of patients after stroke.

METHODS

In total, 56 patients with stroke-induced motor dysfunction were enrolled. Box and block test (BBT) and Fugl-Meyer assessment (FMA) were performed to evaluate the motor functions in all participants. Computation analysis, luciferase activity, PCR assays, and Western blot analysis were performed to reveal the molecular mechanism underlying the effect of miR-124 polymorphism on motor functions.

RESULTS

The 56 participants were genotyped as CC, CG, and GG, respectively. The serum miR-124 was significantly upregulated in the CC group than that in the GC and GG groups. According to the result of FMA or BBT, there was no obvious difference in upper and lower limb motor functions between CC and CG/GG groups 1 week after the treatment. In addition, scores of BBT and FMA exhibited apparent improvement in both groups at 1 month and 3 months after the treatment. Furthermore, improvements in the CG/GG groups were more significant as compared with those in the CC group. CDK4 was a target of miR-124, and the effect of miR-124 on the motor function recovery might be mediated by CDK4.

CONCLUSION

The presence of a minor allele, G, of miR-124 polymorphism (rs531564) reduced the expression of miRNA and upregulated the expression of CDK4, which may contribute to the effect of rs531564 on the motor function recovery in poststroke patients.

Intraperitoneal delivery of acetate-encapsulated liposomal nanoparticles for neuroprotection of the penumbra in a rat model of ischemic stroke

Background

Ischemic stroke is a devastating condition, with metabolic derangement and persistent inflammation enhancing the initial insult of ischaemia. Recombinant tissue plasminogen remains the only effective treatment but limited as therapy must commence soon after the onset of symptoms.

Purpose

We investigated whether acetate, which modulates many pathways including inflammation, may attenuate brain injury in stroke. As acetate has a short blood half-life and high amounts irritate the gastrointestinal tract, acetate was administered encapsulated in a liposomal nanoparticle (liposomal-encapsulated acetate, LITA).

Methods

Transient ischemia was induced by 90 mins middle-cerebral artery occlusion (MCAO) in Sprague-Dawley rats, and LITA or control liposomes given intraperitoneally at occlusion and daily for up to two weeks post-MCAO. Magnetic resonance imaging (MRI) was used to estimate lesion volume at 24 h, 1 and 2 weeks post-MCAO and anterior lateral ventricular volume (ALVv) at 2 weeks post-MCAO. Locomotive behaviour was tested prior to the final MRI scan. After the final scan, brains were collected, and immunohistochemistry was performed.

Results

Lesion volumes were decreased by ~80% from 24 h to one-week post-MCAO, in both control and LITA groups (P⩽0.05). However, the lesion was increased by ~50% over the subsequent 1 to 2 weeks after MCAO in the control group (from 24.1±10.0 to 58.7±28.6 mm³; P⩽0.05) but remained unchanged in the LITA group. ALVv were also attenuated by LITA treatment at 2 weeks post-MCAO (177.2±11.9% and 135.3±10.9% of contralateral ALVv for control and LITA groups, respectively; P⩽0.05). LITA-treated animals also appeared to have improved motor activity, moving with greater average velocity than control animals. Microglial immunoreactivity was ~40% lower in the LITA group compared to the control group (P⩽0.05), but LITA did not modulate neurogenesis, apoptosis, histone acetylation and lipid peroxidation.

Conclusion

LITA appears to attenuate the harmful chronic neuroinflammation observed during brain remodeling after a focal ischemic insult.

Lipoxin A4 Regulates Lipopolysaccharide-Induced BV2 Microglial Activation and Differentiation via the Notch Signaling Pathway

Inflammatory responses contribute to the pathogenesis of various neurological diseases, and microglia plays an important role in the process. Activated microglia can differentiate into the pro-inflammatory, tissue-damaging M1 phenotype or the anti-inflammatory, tissue-repairing M2 phenotype. Regulating microglia differentiation, hence limiting a harmful response, might help improve the prognosis of inflammation-related nervous system diseases. The present study aimed 1. to observe the anti-inflammatory effect of lipoxin A4 (LXA4) on the inflammatory response associated to lipopolysaccharide (LPS)-induced microglia activation, 2. to clarify that LXA4 modulates the activation and differentiation of microglia induced by LPS stimulation, 3. to determine whether LXA4 regulates the activation and differentiation of microglia through the Notch signaling pathway, 4. to provide a foundation for the use of LXA4 for the treatment of inflammatory related neurological diseases. To construct a model of cellular inflammation, immortalized murine BV2 microglia cells were provided 200 ng/ml LPS. To measure the mRNA and protein levels of inflammatory factors (interleukin [IL]-1β, IL-10, and tumor necrosis factor [TNF]-α) and M1 and M2 microglia markers (inducible nitric oxide synthase [iNOS], cluster of differentiation [CD]32, arginase [Arg]1, and CD206), we performed quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), immunofluorescence, or flow cytometry. To determine the mRNA and protein levels of Notch signaling components (Notch1, Hes1, and Hes5), we performed qRT-PCR and western blot. LXA4 inhibits the expression of Notch1 and Hes1 associated with M1 type microglial differentiation and decreases the M1 type microglia marker iNOS and related inflammatory factors IL-1β and TNF-α. Moreover, LXA4 upregulates the expression of the M2-associated Hes5, as well as the expression of the M2 microglia marker Arg1 and the associated inflammatory factor IL-10. These effects are blocked by the administration of the γ-secretase inhibitor DAPT, a specific blocker of the Notch signaling pathway. LXA4 inhibits the microglia activation induced by LPS and the differentiation into M1 type with pro-inflammatory effect, while promoting the differentiation to M2 type with anti-inflammatory effect. LXA4 downregulates the inflammatory mediators IL-1β, TNF-α, and iNOS, while upregulating the anti-inflammatory mediator IL-10, which acts through the Notch signaling pathway.

Helicobacter pylori infection and prevalence of stroke

BACKGROUND

Helicobacter pylori causes peptic ulcer disease; however, conflicting evidence exists regarding its role in extragastric conditions. We aimed to examine associations of H pylori infection and peptic ulcer disease with stroke.

METHODS

A cross-sectional study was undertaken using data of 147 936 individuals aged 25-95 years who underwent the urea breath test during 2002-2012, based on the computerized database of the second largest health maintenance organization in Israel. Logistic regression models were fitted to control for potential confounders.

RESULTS

Overall, 1397 (0.9%) patients had stroke and 76 965 (52.0%) had a H pylori positive test. The likelihood of prevalent stroke increased in relation to H pylori infection: adjusted odds ratio (aOR) 1.16 (95% confidence intervals [CI]: 1.04-1.29), gastric ulcer: aOR 1.50 (95% CI: 1.18-1.91), and duodenal ulcer: aOR 1.25 (95% CI: 1.07-1.46).

CONCLUSIONS

The results support the premise that stroke may be associated with a history of H pylori infection.

Subacute stroke physical rehabilitation evidence in activities of daily living outcomes: A systematic review of meta-analyses of randomized controlled trials

BACKGROUND

Stroke is a leading cause of disabilities worldwide. One of the key disciplines in stroke rehabilitation is physical therapy which is primarily aimed at restoring and maintaining activities of daily living (ADL). Several meta-analyses have found different interventions improving functional capacity and reducing disability.

OBJECTIVES

To systematically evaluate existing evidence, from published systematic reviews of meta-analyses, of subacute physical rehabilitation interventions in (ADLs) for stroke patients.

METHODS

Umbrella review on meta-analyses of RCTs ADLs in MEDLINE, Web of Science, Scopus, Cochrane, and Google Scholar up to April 2018. Two reviewers independently applied inclusion criteria to select potential systematic reviews of meta-analyses of randomized controlled trials (RCTs) of physical rehabilitation interventions (during subacute phase) reporting results in ADLs. Two reviewers independently extracted name of the 1st author, year of publication, physical intervention, outcome(s), total number of participants, and number of studies from each eligible meta-analysis. The number of subjects (intervention and control), ADL outcome, and effect sizes were extracted from each study.

RESULTS

Fifty-five meta-analyses on 21 subacute rehabilitation interventions presented in 30 different publications involving a total of 314 RCTs for 13,787 subjects were identified. Standardized mean differences (SMDs), 95% confidence intervals (fixed and random effects models), 95% prediction intervals, and statistical heterogeneity (I and Q test) were calculated. Virtual reality, constraint-induced movement, augmented exercises therapy, and transcranial direct current stimulation interventions resulted statistically significant (P < .05) with moderate improvements (0.5 ≤ SMD ≤ 0.8) and no heterogeneity (I = 0%). Moxibustion, Tai Chi, and acupuncture presented best improvements (SMD > 0.8) but with considerable heterogeneity (I2 > 75%). Only acupuncture reached "suggestive" level of evidence.

CONCLUSION

Despite the range of interventions available for stroke rehabilitation in subacute phase, there is lack of high-quality evidence in meta-analyses, highlighting the need of further research reporting ADL outcomes.

Association between PPARs Gene Functional Polymorphisms and Ischemic Stroke in Chinese Uyghur Population

PPARγ and PPARα belong to a receptor family of ligand-activated transcription factors involved in the regulation of inflammation, cellular glucose uptake, protection against atherosclerosis and endothelial cell function. Through these effects, they might be involved with the ischemic stroke (IS). We recruited 100 IS patients diagnosed by CTs or/and magnetic resonance imaging (MRI) and 100 normal healthy controls from Chinese Uyghur Population to assess the nature of the functional polymorphisms of PPARs and any links with IS in this unique population which has 60% European ancestry and 40% East Asian ancestry. We found that the Ala allele of the PPARγ Pro12Ala polymorphism was more common in controls than IS subjects (P = 0.008, corrected for multiple testing) in the Uyghur Population. Pro/Ala carriage may be associated with a decreased risk of IS in Uyghurs (OR 0.542, 95% CI 0.346-0.850). Additionally, the 162Val allele frequency at the DNA-binding region of PPARα was extremely rare in Chinese Uguhur IS patients and controls. Our population and ethnic-based study demonstrates that the 162Val allele frequency was extremely low in the Chinese Uyghur Population different from Some European and African populations and the PPARγ 12 Pro/Ala resulting in an amino acid exchange in N-terminal sequence may be an independent protective factor for IS in the Chinese Uyghur Population.

The promoter polymorphism of NFKB1 gene contributes to susceptibility of ischemic stroke in Korean population

The progression of ischemic stroke is associated with inflammatory response, in which the nuclear factor kappa B subunit 1 (NFKB1) plays an important role. The aim of present study was to determine whether promoter single nucleotide polymorphism (SNP) in the NFKB1 gene was contributed to susceptibility of ischemic stroke. One hundred twenty-one Korean adult patients with ischemic stroke (65.7±12.1 years in age) and 291 Korean healthy controls (63.0±9.3 years in age) were recruited. We genotyped a promoter SNP (rs11940017, −1727, C/T) of NFKB1 gene using direct sequencing in 121 Korean ischemic stroke patients and 291 control subjects. The T/C genotype of rs11940017 SNP in the codominant model (vs. the T/T genotype) (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.15–0.92; P=0.032) and the genotype containing C allele (T/C and C/C) in the dominant model (vs. the T/T genotype) (OR, 0.33; 95% CI, 0.14–0.81; P=0.0068) were associated with a decreased risk of ischemic stroke. The frequency of C allele was decreased in ischemic stroke patients, compared with control subjects (OR, 0.31; 95% CI, 0.13–0.74; P=0.008). These results suggest that the promoter SNP (rs11940017, −1727, C/T) of NFKB1 gene may affect ischemic stroke susceptibility in Korean population.

The Traditional Chinese Medicine MLC901 inhibits inflammation processes after focal cerebral ischemia

Inflammation is considered as a major contributor to brain injury following cerebral ischemia. The therapeutic potential of both MLC601/MLC901, which are herbal extract preparations derived from Chinese Medicine, has been reported both in advanced stroke clinical trials and also in animal and cellular models. The aim of this study was to investigate the effects of MLC901 on the different steps of post-ischemic inflammation in focal ischemia in mice. In vivo injury was induced by 60 minutes of middle cerebral artery occlusion (MCAO) followed by reperfusion. MLC901 was administered in post-treatment 90 min after the onset of ischemia and once a day during reperfusion. MLC901 treatment resulted in a reduction in infarct volume, a decrease of Blood Brain Barrier leakage and brain swelling, an improvement in neurological scores and a reduction of mortality rate at 24 hours after MCAO. These beneficial effects of MLC901 were accompanied by an inhibition of astrocytes and microglia/macrophage activation, a drastically decreased neutrophil invasion into the ischemic brain as well as by a negative regulation of pro-inflammatory mediator expression (cytokines, chemokines, matrix metalloproteinases). MLC901 significantly inhibited the expression of Prx6 as well as the transcriptional activity of NFκB and the activation of Toll-like receptor 4 (TLR4) signaling, an important pathway in the immune response in the ischemic brain. MLC901 effects on the neuroinflammation cascade induced by cerebral ischemia probably contribute, in a very significant way, in its potential therapeutic value.

Oxidative Stress and the Microbiota-Gut-Brain Axis

The gut-brain axis is increasingly recognized as an important pathway of communication and of physiological regulation, and gut microbiota seems to play a significant role in this mutual relationship. Oxidative stress is one of the most important pathogenic mechanisms for both neurodegenerative diseases, such as Alzheimer's or Parkinson's, and acute conditions, such as stroke or traumatic brain injury. A peculiar microbiota type might increase brain inflammation and reactive oxygen species levels and might favor abnormal aggregation of proteins. Reversely, brain lesions of various etiologies result in alteration of gut properties and microbiota. These recent hypotheses could open a door for new therapeutic approaches in various neurological diseases.

Iron Dysregulation and Dormant Microbes as Causative Agents for Impaired Blood Rheology and Pathological Clotting in Alzheimer's Type Dementia

Alzheimer’s disease and other similar dementias are debilitating neurodegenerative disorders whose etiology and pathogenesis remain largely unknown, even after decades of research. With the anticipated increase in prevalence of Alzheimer’s type dementias among the more susceptible aging population, the need for disease-modifying treatments is urgent. While various hypotheses have been put forward over the last few decades, we suggest that Alzheimer’s type dementias are triggered by external environmental factors, co-expressing in individuals with specific genetic susceptibilities. These external stressors are defined in the Iron Dysregulation and Dormant Microbes (IDDM) hypothesis, previously put forward. This hypothesis is consistent with current literature in which serum ferritin levels of individuals diagnosed with Alzheimer’s disease are significantly higher compared those of age- and gender-matched controls. While iron dysregulation contributes to oxidative stress, it also causes microbial reactivation and virulence of the so-called dormant blood (and tissue) microbiome. Dysbiosis (changes in the microbiome) or previous infections can contribute to the dormant blood microbiome (atopobiosis¹), and also directly promotes systemic inflammation via the amyloidogenic formation and shedding of potent inflammagens such as lipopolysaccharides. The simultaneous iron dysregulation and microbial aberrations affect the hematological system, promoting fibrin amylodiogenesis, and pathological clotting. Systemic inflammation and oxidative stress can contribute to blood brain barrier permeability and the ensuing neuro-inflammation, characteristic of Alzheimer’s type dementias. While large inter-individual variability exists, especially concerning disease pathogenesis, the IDDM hypothesis acknowledges primary causative factors which can be targeted for early diagnosis and/or for prevention of disease progression.

The role of neutrophil granulocytes in immune-to-brain communication

Immune-to-brain communication has been studied in a variety of experimental models. Crucial insights into signalling and mechanisms were previously revealed in studies investigating fever induction pathways. The scientific community has primarily focused on neuronal and humoral pathways in the manifestation of this response. Emerging evidence has now shown that immune-to-brain signalling via immune cells is pivotal for normal brain function and brain pathology. The present manuscript aims to provide a brief overview on the current understanding of how immune cells signal to the brain. Insights are summarized on the potential physiological significance of some immune cells signalling from the periphery to the brain. A particular focus is laid on the role of neutrophil granulocytes. As such, IL-1β expressing neutrophil granulocytes have been shown to transfer inflammatory information to the brain and contribute to prolonged behavioural changes due to septic encephalopathy in rats during severe systemic inflammation induced by the bacterial component and TLR4 agonist lipopolysaccharide. Modulation of immune cell recruitment to the brain is discussed by various confounding factors including sleep, exercise, the nutritional status e.g. obesity, leptin and omega 3 fatty acids, and psychological or inflammatory stressors. The physiological significance of immune cell mediated communication between the immune system and the brain is highlighted by the fact that systemic inflammatory insults can exacerbate ongoing brain pathologies via immune cell trafficking. New insights into mechanisms and mediators of immune cell mediated immune-to-brain communication are important for the development of new therapeutic strategies and the better understanding of existing ones. Abbreviations: ACTH: adrenocorticotropic hormone; BBB: blood-brain barrier; BBI: blood-brain interface; CD: cluster of differentiation; CINC: cytokine-induced neutrophil chemoattractant; CRH: corticotropin releasing hormone; CVOs: circumventricular organs; CXCR: chemokine receptor; DAPI: 40:6-diamidino-2-phenylindole dilactate; DHA: docosahexaenoid acid; ICAM: intracellular adhesion molecule; IL: interleukin; i.p.: intraperitoneal; i.v.: intravenous; KC: keratinocytes-derived chemokine; LPS: lipopolysaccharide; MIP: macrophage inflammatory protein; MS: multiple sclerosis; NFκB: nuclear factor kappa B; NF-IL6: nuclear factor IL-6; PCTR: protectin conjugates in tissue regeneration; PG: prostaglandin; p.i.: post injection; PVN: paraventricular nucleus; ra: receptor antagonist; STAT3: signal transducer and activator of transcription 3; TIMP: tissue inhibitors of metalloproteinases; TLR: toll-like receptor; TNFα: tumor necrosis factor alpha.

The prognostic value of interleukin 6 in multiple chronic diseases and all-cause death: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

We aimed to evaluate the associations and prognostic value of interleukin-6 (IL6) for the prediction of atherosclerotic cardiovascular disease (ASCVD) events, heart failure (HF), and other chronic diseases in a large, multi-ethnic, contemporary population.

METHODS

We included 6617 participants from the Multi-Ethnic Study of Atherosclerosis (5640 non-users, 977 users of statins at baseline). Main outcomes were hard ASCVD events and HF; secondary outcomes included all-cause death, atrial fibrillation, venous thromboembolism and cancer.

RESULTS

Median follow-up was 13.2 years. Strong associations were observed in Cox regression analyses between higher IL6 levels and ASCVD events, HF, and mortality, particularly among statins users. In the latter, associations remained strong after adjusting for traditional risk factors and other inflammation biomarkers (e.g., risk factor, hsCRP-adjusted hazard ratio for incident HF comparing 3rd vs. 1st IL6 tertiles: 3.55, 95% CI 1.23-10.27). Although IL6 did not improve CHD prediction beyond traditional risk factors, among statin users it improved the prediction of stroke (improvement in the C statistic +0.018), incident HF (+0.028, the largest C statistic increase across all study outcomes), and all-cause death (+0.017).

CONCLUSIONS

IL6 is strongly and independently associated with ASCVD events, HF, and all-cause mortality, particularly among statin users. Although the prognostic value of IL6 is limited for the prediction of CHD events, it may have a role for the prediction of stroke, HF and all-cause death in asymptomatic statin users. Larger studies are needed to replicate these findings.

Regenerative Medicine Therapies for Targeting Neuroinflammation After Stroke

Inflammation is a major pathological event following ischemic stroke that contributes to secondary brain tissue damage leading to poor functional recovery. Following the initial ischemic insult, post-stroke inflammatory damage is driven by initiation of a central and peripheral innate immune response and disruption of the blood-brain barrier (BBB), both of which are triggered by the release of pro-inflammatory cytokines and infiltration of circulating immune cells. Stroke therapies are limited to early cerebral blood flow reperfusion, and whilst current strategies aim at targeting neurodegeneration and/or neuroinflammation, innovative research in the field of regenerative medicine aims at developing effective treatments that target both the acute and chronic phase of inflammation. Anti-inflammatory regenerative strategies include the use of nanoparticles and hydrogels, proposed as therapeutic agents and as a delivery vehicle for encapsulated therapeutic biological factors, anti-inflammatory drugs, stem cells, and gene therapies. Biomaterial strategies-through nanoparticles and hydrogels-enable the administration of treatments that can more effectively cross the BBB when injected systemically, can be injected directly into the brain, and can be 3D-bioprinted to create bespoke implants within the site of ischemic injury. In this review, these emerging regenerative and anti-inflammatory approaches will be discussed in relation to ischemic stroke, with a perspective on the future of stroke therapies.

Tetramethylpyrazine‑2'O‑sodium ferulate provides neuroprotection against neuroinflammation and brain injury in MCAO/R rats by suppressing TLR-4/NF-κB signaling pathway

BACKGROUND

Neuroinflammation following cerebral ischemia is a serious risk factor in stroke patients. The purpose of this study was to investigate the neuroprotective effects of tetramethylpyrazine‑2'O‑sodium ferulate (TSF), a structurally modified compound from tetramethylpyrazine and ferulate, on cerebral ischemic injury and the underlying mechanisms.

METHODS

Focal transient cerebral ischemia was induced in rat for 2 h by middle cerebral artery occlusion (MCAO) and the protective effect of TSF was studied using different doses of the drug (10.8, 18, 30 mg/kg, intravenously); Ozagrel (18 mg/kg) was used as the positive control. The drugs were given immediately after MCAO and the efficacy and mechanisms were evaluated at 72 h of reperfusion. The level of pro-inflammatory cytokines such as TNF-α, IL-1β and anti-inflammatory molecules such as IL-10 was measured; other factors such as neurological deficit, brain water content and infarct size and the level of MCP-1, ICAM-1, iNOS, CD11b, TLR-4/NF-κBp65 were also measured.

RESULTS

TSF at the doses of 18, 30 mg/kg significantly improved neurological deficit, reduced brain water content and infarct size, accompanied by a decrease in the concentration of TNF-α, IL-1β, MCP-1, ICAM-1, iNOS and an increase in the concentration of IL-10. The amount of CD11b and ICAM-1 was found largely decreased and the expression of TLR-4 and the nuclear NF-κBp65 was weakened in TSF-treatment group.

CONCLUSIONS

Our study suggests that TSF possesses a neuroprotective effect against ischemic stroke which might be mediated through suppression of the inflammatory pathways in the brain following ischemic stroke.

Neuroprotective Effects of DTIO, A Novel Analog of Nec-1, in Acute and Chronic Stages After Ischemic Stroke

Receptor-interacting protein 1 kinase (RIP1K) plays a key role in necroptosis. Necrostatin-1 (Nec-1), a specific inhibitor of RIP1K, provides neuroprotection against ischemic brain injury, associating with inhibition of inflammation. Recently, our group synthesized a novel analog of Nec-1, 5-(3',5'-dimethoxybenzal)-2-thio-imidazole-4-ketone (DTIO). The present study investigated the effect of DTIO on ischemic stroke-induced brain injury in both acute and chronic phase and its underlying mechanism. In vivo, DTIO treatment reduced infarct volume and improved neurological deficits in the acute phase after permanent middle cerebral artery occlusion (pMCAO) and it also attenuated brain atrophy and promoted brain functional recovery in the chronic phase post-cerebral ischemia/reperfusion (I/R). In vitro, DTIO treatment decreased lactate dehydrogenase (LDH) leakage and necrotic cell death in the oxygen and glucose deprivation (OGD) or oxygen and glucose deprivation and reoxygenation (OGD/R)-induced neuronal or astrocytic cell injury. Simultaneously, DTIO suppressed the production and release of inflammatory cytokines, and reduced the formation of glial scar. Homology modeling analysis illustrated that DTIO had an ability of binding to RIP1K. Furthermore, immunoprecipitation analysis showed that DTIO inhibited the phosphorylation of RIP1K and decreased the interaction between the RIP1K and RIP3K. In addition, knockdown of RIP1K had neuroprotective effects and inhibited the release of proinflammatory cytokines, but didn't have a significant effect on DTIO-mediated neuroprotection. In conclusion, DTIO has protective effects on acute ischemic stroke and promotes functional recovery during chronic phase, associating with protecting ischemic neurons and astrocytes, inhibiting inflammation, and lessening the glial scar formation via inhibiting of the RIP1K.

Inflammation and dementia: Using rheumatoid arthritis as a model to develop treatments?

Dementia is a major international public health problem which looks set to grow as the ageing population increases. Despite large amounts of investment there has been relatively little progress in developing new therapies to combat this. There is a growing body of evidence that both local and systemic inflammation are important in dementia; with cerebral inflammation occurring secondarily to beta-amyloid plaques, raised levels of serum inflammatory molecules and cytokines being present in Alzheimer's disease patients and systemic inflammation being associated with cerebral microvasculature disease in vascular dementia. Observational studies had suggested that non-steroidal anti-inflammatory drugs may reduce the risk of dementia, but subsequent interventional studies have been disappointing. More recently some observational studies have suggested a protective effect from conventional synthetic disease modifying anti-rheumatic drugs (csDMARDS) and tumour necrosis factor inhibiting (TNFi) biological therapies. Treatments for inflammatory rheumatic diseases have previously been repurposed and used successfully in other diseases, such as TNFi for inflammatory bowel disease. There are also studies looking at the use of csDMARDs such as methotrexate to improve outcomes after cardiovascular events. Ongoing interventional trials are currently looking at whether therapies designed to treat inflammatory and autoimmune diseases have the potential to be used to treat dementia.

Identification and functional analysis of differentially expressed genes associated with cerebral ischemia/reperfusion injury through bioinformatics methods

Cerebral ischemia/reperfusion (I/R) injury results in detrimental complications. However, little is known about the underlying molecular mechanisms involved in the reperfusion stage. The aim of the present study was to identify a gene expression profile associated with cerebral ischemia/reperfusion injury. The GSE23160 dataset, which comprised data from sham control samples and post-I/R injury brain tissues that were obtained using a middle cerebral artery occlusion (MCAO) model at 2, 8 and 24 h post-reperfusion, was downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) in the MCAO samples compared with controls were screened using the GEO2R web tool. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for DEGs was performed using the online tool DAVID. Furthermore, a protein-protein interaction (PPI) network was constructed using the STRING database and Cytoscape software. In total, 32 DEGs at 2 h post-reperfusion, 39 DEGs at 8 h post-reperfusion and 91 DEGs at 24 h post-reperfusion were identified, while 15 DEGs were common among all three groups. GO analysis revealed that the DEGs at all three time-points were enriched in ‘chemotaxis’ and ‘inflammatory response’ terms, while KEGG pathway analysis demonstrated that DEGs were significantly enriched in the ‘chemokine signaling pathway’. Furthermore, following PPI network construction, Cxcl1 was identified as the only hub gene that was common among all three time-points. In conclusion, the present study has demonstrated a global view of the potential molecular differences following cerebral I/R injury and may contribute to an improved understanding of the reperfusion stage, which may ultimately aid in the development of future clinical strategies.

Inflammatory cytokines and cells are potential markers for patients with cerebral apoplexy in intensive care unit

Cerebral apoplexy is a disease caused by obstruction of the blood circulation in the brain. Evidence has indicated that inflammatory cytokines are implicated in ischaemic cerebral apoplexy and are regarded as a general cardiovascular risk factor, which may be a possible immediate trigger, a component of the response to tissue injury and a therapeutic target. The present study investigated changes of inflammatory cytokines and cells in patients with cerebral apoplexy at the intensive care unit (ICU). The plasma concentrations of inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-8, IL-10, IL-1β and IL-17A were evaluated using ELISA. Changes in the plasma concentrations of inflammatory cells were detected by using flow cytometry. The results indicated that serum levels of TNF-α, IL-4, IL-8, IL-1β and IL-17A were upregulated in patients with cerebral apoplexy compared with those in healthy individuals, while those of IL-6 and IL-10 were downregulated. Furthermore, it was demonstrated that the plasma concentration of lymphocytes, granulocytes and mononuclear cells was decreased in patients with cerebral apoplexy in the ICU compared with that in healthy individuals. Of note, humoral as well as cellular inflammatory cytokines were evidently increased in patients with cerebral apoplexy in ICU. In conclusion, the present study provided evidence that inflammatory cytokines and inflammatory cells are upregulated, while anti-inflammatory cytokines are downregulated in patients with cerebral apoplexy in an ICU setting. These results suggest that anti-inflammatory interventions may be beneficial either in the prevention or acute treatment of patients with cerebral apoplexy.

[18F]DPA-714 PET imaging shows immunomodulatory effect of intravenous administration of bone marrow stromal cells after transient focal ischemia

Background

The potential application of bone marrow stromal cell (BMSC) therapy in stroke has been anticipated due to its immunomodulatory effects. Recently, positron emission tomography (PET) with [¹⁸F]DPA-714, a translocator protein (TSPO) ligand, has become available for use as a neural inflammatory indicator. We aimed to evaluate the effects of BMSC administration after transient middle cerebral artery occlusion (MCAO) using [¹⁸F]DPA-714 PET.

The BMSCs or vehicle were administered intravenously to rat MCAO models at 3 h after the insult. Neurological deficits, body weight, infarct volume, and histology were analyzed. [¹⁸F]DPA-714 PET was performed 3 and 10 days after MCAO.

Results

Rats had severe neurological deficits and body weight loss after MCAO. Cell administration ameliorated these effects as well as the infarct volume. Although weight loss occurred in the spleen and thymus, cell administration suppressed it. In both vehicle and BMSC groups, [¹⁸F]DPA-714 PET showed a high standardized uptake value (SUV) around the ischemic area 3 days after MCAO. Although SUV was increased further 10 days after MCAO in both groups, the increase was inhibited in the BMSC group, significantly. Histological analysis showed that an inflammatory reaction occurred in the lymphoid organs and brain after MCAO, which was suppressed in the BMSC group.

Conclusions

The present results suggest that BMSC therapy could be effective in ischemic stroke due to modulation of systemic inflammatory responses. The [¹⁸F]DPA-714 PET/CT system can accurately demonstrate brain inflammation and evaluate the BMSC therapeutic effect in an imaging context. It has great potential for clinical application.

Short-term nighttime wind turbine noise and cardiovascular events: A nationwide case-crossover study from Denmark

AIMS

The number of people exposed to wind turbine noise (WTN) is increasing. WTN is reported as more annoying than traffic noise at similar levels. Long-term exposure to traffic noise has consistently been associated with cardiovascular disease, whereas effects of short-term exposure are much less investigated due to little day-to-day variation of e.g. road traffic noise. WTN varies considerably due to changing weather conditions allowing investigation of short-term effects of WTN on cardiovascular events.

METHODS AND RESULTS

We identified all hospitalisations and deaths from stroke (16,913 cases) and myocardial infarction (MI) (17,559 cases) among Danes exposed to WTN between 1982 and 2013. We applied a time-stratified, case-crossover design. Using detailed data on wind turbine type and hourly wind data at each wind turbine, we simulated mean nighttime outdoor (10-10,000 Hz) and nighttime low frequency (LF) indoor WTN (10-160 Hz) over the 4 days preceding diagnosis and reference days. For indoor LF WTN between 10 and 15 dB(A) and above 15 dB(A), odds ratios (ORs) for MI were 1.27 (95% confidence interval (CI): 0.97-1.67; cases = 198) and 1.62 (95% CI: 0.76-3.45; cases = 21), respectively, when compared to indoor LF WTN below 5 dB(A). For stroke, corresponding ORs were 1.17 (95% CI: 0.95-1.69; cases = 166) and 2.30 (95% CI: 0.96-5.50; cases = 15). The elevated ORs above 15 dB(A) persisted across sensitivity analyses. When looking at specific lag times, noise exposure one day before MI events and three days before stroke events were associated with the highest ORs. For outdoor WTN at night, we observed both increased and decreased risk estimates.

CONCLUSION

This study did not provide conclusive evidence of an association between WTN and MI or stroke. It does however suggest that indoor LF WTN at night may trigger cardiovascular events, whereas these events seemed largely unaffected by nighttime outdoor WTN. These findings need reproduction, as they were based on few cases and may be due to chance.

Neutrophil counts, neutrophil ratio, and new stroke in minor ischemic stroke or TIA

Objective

Evidence about whether neutrophil counts or neutrophil ratio is associated with new stroke is scant. The aim of this study is to assess the association of neutrophil counts or neutrophil ratio with a new stroke in patients with minor stroke or TIA.

Methods

We derived data from the Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events trial. Patients with a minor stroke or TIA were categorized into 4 groups according to the quartile of neutrophil counts or neutrophil ratio. The primary outcome was a new stroke (ischemic or hemorrhagic), and secondary outcomes included a new composite vascular event (stroke, myocardial infarction, or death resulting from cardiovascular causes) and ischemic stroke during the 90-day follow-up. We assessed the association between neutrophil counts, neutrophil ratio, and risk of new stroke.

Results

A total of 4,854 participants were enrolled, among whom 495 had new strokes at 90 days. Compared with the first quartile, the second, third, and fourth quartiles of neutrophil counts were associated with increased risk of new stroke (adjusted hazard ratio 1.40 [95% confidence interval (CI) 1.05–1.87], 1.55 [95% CI 1.17–2.05], and 1.69 [95% CI 1.28–2.23], respectively, p for trend <0.001). Similar results were observed for the endpoint of composite events and ischemic stroke. Parallel results were found for neutrophil ratio.

Conclusion

High levels of both neutrophil counts and neutrophil ratio were associated with an increased risk of new stroke, composite events, and ischemic stroke in patients with a minor ischemic stroke or TIA.

Risk of stroke associated with use of nonsteroidal anti-inflammatory drugs during acute respiratory infection episode

BACKGROUND

Previous studies suggested that acute respiratory infection (ARI) could trigger stroke and that use of nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with increased risk of stroke. In many countries, NSAIDs have been widely used among patients with ARI or common cold for pain and fever relief. However, studies evaluating whether NSAIDs use during ARI episodes may further increase the risk of stroke were very limited.

METHODS AND RESULTS

During 2007 to 2011, 29 518 patients with an incident hospitalization of stroke were identified. The date of admission was defined as the index date. Using case-crossover design, we compared the following exposure status between the case period (1- to 7-d period before the index date) and matched control period (366- to 372-d period before the index date): NSAIDs use during ARI episodes, ARI episodes without NSAIDs use, NSAIDs use only, or no exposure. Multivariable conditional regression models were used to estimate odds ratios adjusting potential confounders. The results suggested that NSAIDs use during ARI episodes was associated with a 2.3-fold increased risk of stroke (ischemic: adjusted odds ratio, aOR 2.27, 95% confidence interval, 95% CI, 2.00-2.58; hemorrhagic: aOR 2.28, 95% CI, 1.71-3.02). We also determined that parenteral NSAIDs were associated with much higher risk of stroke in patients with ARI.

CONCLUSIONS

Nonsteroidal anti-inflammatory drugs use during ARI episodes, especially parenteral NSAIDs use, was associated with a further increased risk of stroke.

Alarmin HMGB1 induces systemic and brain inflammatory exacerbation in post-stroke infection rat model

Post-stroke infection (PSI) is known to worsen functional outcomes of stroke patients and accounts to one-third of stroke-related deaths in hospital. In our previous reports, we demonstrated that massive release of high-mobility group box protein 1 (HMGB1), an endogenous danger signal molecule, is promoted by N-methyl-D-aspartic acid-induced acute damage in the postischemic brain, exacerbating neuronal damage by triggering delayed inflammatory processes. Moreover, augmentation of proinflammatory function of lipopolysaccharides (LPS) by HMGB1 via direct interaction has been reported. The aim of this study was to investigate the role of HMGB1 in aggravating inflammation in the PSI by exacerbating the function of LPS. PSI animal model was produced by administrating a low-dose LPS at 24 h post-middle cerebral artery occlusion (MCAO). Profound aggravations of inflammation, deterioration of behavioral outcomes, and infarct expansion were observed in LPS-injected MCAO animals, in which serum HMGB1 surge, especially disulfide type, occurred immediately after LPS administration and aggravated brain and systemic inflammations probably by acting in synergy with LPS. Importantly, blockage of HMGB1 function by delayed administrations of therapeutic peptides known to inhibit HMGB1 (HMGB1 A box, HPep1) or by treatment with LPS after preincubation with HMGB1 A box significantly ameliorated damages observed in the rat PSI model, demonstrating that HMGB1 plays a crucial role. Furthermore, administration of Rhodobacter sphaeroides LPS, a selective toll-like receptor 4 antagonist not only failed to exert these effects but blocked the effects of LPS, indicating its TLR4 dependence. Together, these results indicated that alarmin HMGB1 mediates potentiation of LPS function, exacerbating TLR4-dependent systemic and brain inflammation in a rat PSI model and there is a positive-feedback loop between augmentation of LPS function by HMGB1 and subsequent HMGB1 release/serum. Therefore, HMGB1 might be a valuable therapeutic target for preventing post-stroke infection.

Autonomic Nervous System and Stress to Predict Secondary Ischemic Events after Transient Ischemic Attack or Minor Stroke: Possible Implications of Heart Rate Variability

Transient ischemic attack (TIA) and minor stroke have high risks of recurrence and deterioration into severe ischemic strokes. Risk stratification of TIA and minor stroke is essential for early effective treatment. Traditional tools have only moderate predictive value, likely due to their inclusion of the limited number of stroke risk factors. Our review follows Hans Selye’s fundamental work on stress theory and the progressive shift of the autonomic nervous system (ANS) from adaptation to disease when stress becomes chronic. We will first show that traditional risk factors and acute triggers of ischemic stroke are chronic and acute stress factors or “stressors,” respectively. Our first review shows solid evidence of the relationship between chronic stress and stroke occurrence. The stress response is tightly regulated by the ANS whose function can be assessed with heart rate variability (HRV). Our second review demonstrates that stress-related risk factors of ischemic stroke are correlated with ANS dysfunction and impaired HRV. Our conclusions support the idea that HRV parameters may represent the combined effects of all body stressors that are risk factors for ischemic stroke and, thus, may be of important predictive value for the risk of subsequent ischemic events after TIA or minor stroke.

Mechanisms of poststroke fatigue

Poststroke fatigue is a debilitating symptom and is poorly understood. Here we summarise molecular, behavioural and neurophysiological changes related to poststroke fatigue and put forward potential theories for mechanistic understanding of poststroke fatigue.

Hypoxia Inducible Factor 1α Plays a Key Role in Remote Ischemic Preconditioning Against Stroke by Modulating Inflammatory Responses in Rats

Background

Limb remote ischemic preconditioning (RIPC) protects against brain injury induced by stroke, but the underlying protective mechanisms remain unknown. As hypoxia inducible factor 1α (HIF‐1α) is neuroprotective in stroke and mediates neuroinflammation, we tested the hypothesis that HIF‐1α is a key factor of RIPC against stroke by mediating inflammation.

Methods and Results

Stroke was induced by transient middle cerebral artery occlusion in rats, and RIPC was conducted in both hind limbs. The HIF‐1α mRNA was examined by quantitative reverse transcription polymerase chain reaction after RIPC. In addition, inflammatory cytokines in the peripheral blood and brain were measured using the AimPlex multiplex immunoassays. Data showed that RIPC reduced the infarct size, improved neurological functions, and increased HIF‐1α mRNA levels, interleukin (IL)‐4, and IL‐10 protein levels in the peripheral blood. Intraperitoneal injection of the HIF activator, dimethyloxaloylglycine, reduced the infarct size and inhibited interferon‐γ protein levels, while promoting IL‐4 and IL‐10 protein levels, while decreasing interferon‐γ protein levels in both the peripheral blood and ischemic brain. In addition, injection of dimethyloxaloylglycine had a synergistic effect with RIPC on reducing infarction and improving neurological functions, as well as decreasing interferon‐γ in the peripheral blood and ischemic brain. In contrast, injection of the HIF inhibitor, acriflavine hydrochloride, abolished the protective effects of RIPC on infarction, and reduced IL‐4 and IL‐10 protein levels in both the peripheral blood and ischemic brain.

Conclusions

We conclude that HIF‐1α plays a key role in RIPC, likely mediated by a systemic modulation of the inflammatory response.