Neuroinflammatory Mechanisms in Ischemic Stroke: Focus on Cardioembolic Stroke, Background, and Therapeutic Approaches

Damage mechanism and therapy progress of the blood-brain barrier after ischemic stroke

The blood-brain barrier (BBB) serves as a defensive line protecting the central nervous system, while also maintaining micro-environment homeostasis and inhibiting harmful materials from the peripheral blood. However, the BBB's unique physiological functions and properties make drug delivery challenging for patients with central nervous system diseases. In this article, we briefly describe the cell structure basis and mechanism of action of the BBB, as well as related functional proteins involved. Additionally, we discuss the various mechanisms of BBB damage following the onset of an ischemic stroke, and lastly, we mention several therapeutic strategies accounting for impairment mechanisms. We hope to provide innovative ideas for drug delivery research via the BBB.

Phenylethanoid glycosides derived from Cistanche deserticola promote neurological functions and the proliferation of neural stem cells for improving ischemic stroke

Phenylethanoid glycosides derived from Cistanche deserticola (PhGs) are plant-derived natural medicinal compounds that occur in many medicinal plants. This study aims to investigate whether PhGs treatment improves the stroke and its potential mechanisms. Adult male C57BL/6 J mice were administrated PhGs once daily for 7 days after MCAO surgery. The neurological score, and catwalk were evaluated on Day 1, 3 and 7 after ischemic stroke. Furthermore, triphenyl-2,3,5-tetrazoliumchloride (TTC) and hematoxylin-eosin (H&E) staining were used for evaluating the infarct volume and neuronal restoration. The effects of PhGs on NSCs proliferation were investigated in vitro and in vivo. Western blot was used to detect the proteins of Wnt/β-catenin signaling pathway. This study found that PhGs effectively improved the neurological functions in ischemic stroke mice. TTC and H&E staining demonstrated that PhGs not only reduced infarct volume, but also improved neuronal restoration. The immunohistochemistry and 5-Ethynyl-2-deoxyuridine (EdU) incorporation assays revealed that PhGs promoted the proliferation of neural stem cells (NSCs) in subventricular zone (SVZ). In addition, transcriptome analysis of NSCs showed that the Wnt/β-catenin signaling pathway was involved in the PhGs induced NSCs proliferation. Importantly, the related proteins in the Wnt/β-catenin signaling pathway were changed after PhGs treatment, including β-catenin, Wnt3a, GSK-3β, c-Myc. PhGs treatment improved the stroke through enhancing endogenous NSCs proliferation via activating Wnt/β-catenin signaling pathway. Due to its effect on the proliferation of NSCs, PhGs are a potential adjuvant therapeutic drug for post-stroke treatment.

Aucubin promotes activation of AMPK and alleviates cerebral ischemia/reperfusion injury in rats

In the current investigation, we explored the benefits of aucubin against rodent ischemia/reperfusion (I/R) damages in brains and elucidated the role of 5'-AMP-activated protein kinase (AMPK) in its neuroprotective action. I/R model of brain was established in male three-month-old rats through 2 h of middle cerebral artery occlusion followed by two days of reperfusion. Aucubin boosted phosphorylation of AMPKα in ipsilateral cortex of injured rats. Then, rats were exposed to cerebral I/R damage and received treatment of aucubin and compound C (a well-known AMPK inhibitor). It was found that aucubin administration improved neurological symptom score, decreased infarct volume, and mitigated cerebral edema in injured rats. Aucubin administration upregulated Nrf2 expression and abated oxidative stress in ipsilateral cortex of injured rats. Aucubin administration reduced levels of multiple pro-inflammatory cytokines, suppressed microglial activation and neutrophil infiltration, and promoted M2 polarization in injured rats. More importantly, compound C abolished the neuroprotective, anti-oxidant and inflammation-modulating effects of aucubin in injured rats, at least in part. Therefore, we concluded that activation of AMPK by aucubin alleviated I/R injury in brain through abating oxidative stress and suppressing inflammation, identifying a potential candidate for those patients of ischemic stroke.

The relationship between trimethylamine-N-oxide and the risk of acute ischemic stroke: A dose‒response meta-analysis

BACKGROUND

Although trimethylamine-N-oxide (TMAO) shows a notable correlation with cardiovascular disease, its association with acute ischemic stroke (AIS) remains uncertain and necessitates further investigation.

OBJECTIVE

A meta-analysis was conducted to assess the relationship between trimethylamine-N-oxide and acute ischemic stroke.

METHODS

We conducted a comprehensive search in PubMed, Embase, Cochrane, CNKI, VIP, Wanfang, and CBM, spanning from their inception to 23 September 2023. The search was consistently updated and supplemented by bibliographies of retrieved articles and previous reviews. A total of 20 eligible studies, including 17 case‒controls and 3 cohort studies, were selected, involving 9141 participants (5283 case group, 3858 control group). For the dose‒response analysis, three case-control studies were eligible. We extracted and pooled TMAO mean and standard deviation from observational studies for control and ischemic stroke groups. The effect sizes were combined using the random-effects model. Where possible, dose‒response analysis was performed.

RESULT

Overall, the pooled standardized mean difference (SMD) demonstrated significantly higher concentrations of serum/plasma TMAO in AIS compared to the control group (SMD = 1.27; 95% CI: 0.9, 1.61, P<0.001). Additionally, the dose‒response meta-analysis revealed a 12.1% relative increase in the risk of acute ischemic stroke per 1 μmol/L rise in TMAO concentration (RR = 1.12; 95% CI 1.07-1.17; P<0.05; I2 = 1.6%, P = 0.4484).

CONCLUSION

These findings indicate a potential increased risk of AIS associated with elevated TMAO levels.

Montelukast sodium protects against focal cerebral ischemic injury by regulating inflammatory reaction via promoting microglia polarization

BACKGROUND

Neuroinflammation plays an important role in brain injury and repair. Regulation of post-stroke inflammation may be a reasonable strategy to treat ischemic stroke. The present study demonstrates that montelukast sodium protected brain tissue by regulating the post-stroke inflammatory reaction.

METHODS

Adult male mice underwent distal occlusion of the middle cerebral artery (d-MCAO) surgery, followed by intraperitoneal injection of montelukast sodium or equivalent saline, from day 0-7 after the operation. On the 7th day, Rotarod and adhesive-removal test were performed. M AP2 staining, and Iba1, CD206, and CD16/32 co staining were performed. BV2 microglial cell lines were co-cultured with different concentrations of montelukast sodium with or without lipopolysaccharide (LPS). Real-time polymerase chain reaction (rt-PCR) and enzyme linked immunosorbent assay (ELISA) were used to detect the mRNA expression of M1 and M2 phenotypic microglia markers and the release of cytokines representing from different phenotypes of microglia cells.

RESULTS

Montelukast sodium prolonged the time that d-MCAO mice remained on the rotating bar, shortened the time to remove the sticker on the opposite claw, and reduced the infarct volume, promoting the transformation of microglial cells/macrophages around the infarct to the M2 phenotype. Montelukast sodium increased the mRNA expression of Arg-1, CD206, TGF-β, and IL-10 in BV2 microglial cell lines stimulated by LPS, while decreased the expression of iNOS, TNF-α, and CD16/32.

CONCLUSION

Montelukast sodium can protect against focal cerebral ischemic injury by regulating inflammatory reaction via promoting microglia polarization.

Proteomic profiling identifies novel inflammation-related plasma proteins associated with ischemic stroke outcome

BACKGROUND

The inflammatory response to cerebral ischemia is complex; however, most clinical studies of stroke outcome focus on a few selected proteins. We, therefore, aimed to profile a broad range of inflammation-related proteins to: identify proteins associated with ischemic stroke outcome that are independent of established clinical predictors; identify proteins subsets for outcome prediction; and perform sex and etiological subtype stratified analyses.

METHODS

Acute-phase plasma levels of 65 inflammation-related proteins were measured in 534 ischemic stroke cases. Logistic regression was used to estimate associations to unfavorable 3-month functional outcome (modified Rankin Scale score > 2) and LASSO regressions to identify proteins with independent effects.

RESULTS

Twenty proteins were associated with outcome in univariable models after correction for multiple testing (FDR < 0.05), and for 5 the association was independent of clinical variables, including stroke severity (TNFSF14 [LIGHT], OSM, SIRT2, STAMBP, and 4E-BP1). LASSO identified 9 proteins that could best separate favorable and unfavorable outcome with a predicted diagnostic accuracy (AUC) of 0.81; three associated with favorable (CCL25, TRAIL [TNFSF10], and Flt3L) and 6 with unfavorable outcome (CSF-1, EN-RAGE [S100A12], HGF, IL-6, OSM, and TNFSF14). Finally, we identified sex- and etiologic subtype-specific associations with the best discriminative ability achieved for cardioembolic, followed by cryptogenic stroke.

CONCLUSIONS

We identified candidate blood-based protein biomarkers for post-stroke functional outcome involved in, e.g., NLRP3 inflammasome regulation and signaling pathways, such as TNF, JAK/STAT, MAPK, and NF-κB. These proteins warrant further study for stroke outcome prediction as well as investigations into the putative causal role for stroke outcome.

Simultaneous Pericytes and M2 Microglia Transplantation Improve Cognitive Function in Mice Model of mPFC Ischemia

Cerebral ischemia is one of the major problems threatening global health. Many of the cerebral ischemia survivors would suffer from the physical and cognitive disabilities for their whole lifetime. Cell based-therapies have been introduced as a therapeutic approach for alleviating ischemia-enforced limitations. Photothrombotic stroke model was applied on the left medial prefrontal cortex (mPFC) of adult male BALB/c mice. Then, pericytes isolated from brain microvessels of adult male BALB/c mice, microglia isolated from brain cortices of the neonatal male BALB/c mice, and M2 phenotype shifted microglia by IL-4 treatment were used for transplantation into the injured area after 24 h of ischemia induction. The behavioural outcomes evaluated by social interaction and Barnes tests and the levels of growth associated protein (GAP)-43 and inflammatory cytokine interleukin (IL)-1 protein were assessed by western blotting 7 days after cell transplantation. Animals in both of the microglia + pericytes and microglia M2 + pericytes transplanted groups showed better performance in social memory as well as enhanced spatial learning and memory compared to ischemic controls. Also, improved escape latency was only observed in microglia M2 + pericytes (p < 0.01) group compared to ischemic controls. GAP-43 showed significant protein expression in microglia + pericytes and microglia M2 + pericytes groups compared to the control group. Conversely, IL-1 levels diminished in all of the pericytes microglia + pericytes, and microglia M2 + pericytes groups compared to the ischemic controls. Current study highlights efficiency of M2 microglia and pericytes combinatory transplantation therapeutic role on relieving ischemic stroke outcomes.

Mesenchymal stem cells (MSCs) and MSC-derived exosomes in animal models of central nervous system diseases: Targeting the NLRP3 inflammasome

The NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome is a multimeric protein complex that is engaged in the innate immune system and plays a vital role in inflammatory reactions. Activation of the NLRP3 inflammasome and subsequent release of proinflammatory cytokines can be triggered by microbial infection or cellular injury. The NLRP3 inflammasome has been implicated in the pathogenesis of many disorders affecting the central nervous system (CNS), ranging from stroke, traumatic brain injury, and spinal cord injury to Alzheimer's disease, Parkinson's disease, epilepsy, multiple sclerosis, and depression. Furthermore, emerging evidence has suggested that mesenchymal stem cells (MSCs) and their exosomes may modulate NLRP3 inflammasome activation in a way that might be promising for the therapeutic management of CNS diseases. In the present review, particular focus is placed on highlighting and discussing recent scientific evidence regarding the regulatory effects of MSC-based therapies on the NLRP3 inflammasome activation and their potential to counteract proinflammatory responses and pyroptotic cell death in the CNS, thereby achieving neuroprotective impacts and improvement in behavioral impairments.

12/15-lipoxygenase inhibition attenuates neuroinflammation by suppressing inflammasomes

Introduction

Lipoxygenases (LOXs) have essential roles in stroke, atherosclerosis, diabetes, and hypertension. 12/15-LOX inhibition was shown to reduce infarct size and brain edema in the acute phase of experimental stroke. However, the significance of 12/15-LOX on neuroinflammation, which has an essential role in the pathophysiology of stroke, has not been clarified yet.

Methods

In this study, ischemia/recanalization (I/R) was performed by occluding the proximal middle cerebral artery (pMCAo) in mice. Either the 12/15-LOX inhibitor (ML351, 50 mg/kg) or its solvent (DMSO) was injected i.p. at recanalization after 1 h of occlusion. Mice were sacrificed at 6, 24, and 72-h after ischemia induction. Infarct volumes were calculated on Nissl-stained sections. Neurological deficit scoring was used for functional analysis. Lipid peroxidation was determined by the MDA assay, and the inflammatory cytokines IL-6, TNF-alpha, IL-1beta, IL-10, and TGF-beta were quantified by ELISA. The inflammasome proteins NLRP1 and NLRP3, 12/15-LOX, and caspase-1 were detected with immunofluorescence staining.

Results

Infarct volumes, neurological deficit scores, and lipid peroxidation were significantly attenuated in ML351-treated groups at 6, 24, and 72-h. ELISA results revealed that the pro-inflammatory cytokines IL-1beta, IL-6, and TNF-alpha were significantly decreased at 6-h and/or 24-h of I/R, while the anti-inflammatory cytokines IL-10 and TNF-alpha were increased at 24-h or 72-h of ML351 treatment. NLRP1 and NLRP3 immunosignaling were enhanced at three time points after I/R, which were significantly diminished by the ML351 application. Interestingly, NLRP3 immunoreactivity was more pronounced than NLRP1. Hence, we proceeded to study the co-localization of NLRP3 immunoreactivity with 12/15-LOX and caspase-1, which indicated that NLRP3 was co-localized with 12/15-LOX and caspase-1 signaling. Additionally, NLRP3 was found in neurons at all time points but in non-neuronal cells 72 h after I/R.

Discussion

These results suggest that 12/15-LOX inhibition suppresses ischemia-induced inflammation in the acute and subacute phases of stroke via suppressing inflammasome activation. Understanding the mechanisms underlying lipid peroxidation and its associated pathways, like inflammasome activation, may have broader implications for the treatment of stroke and other neurological diseases characterized by neuroinflammation.

Ketogenic diet and β-Hydroxybutyrate alleviate ischemic brain injury in mice via an IRAKM-dependent pathway

Ketogenic diet (KD) is a classical nonpharmacological therapy that has recently been shown to benefit cerebral ischemia, but the mechanism remains unclear. This study investigated the neuroprotective effects of KD pretreatment and β-hydroxybutyrate (BHB, bioactive product of KD) post-treatment in a mouse model of temporary middle cerebral artery occlusion (tMCAO). Neurological function, infarct volume, as well as inflammatory reactions are evaluated 24 h after ischemia. Results showed that both KD pretreatment or BHB post-treatment improved the Bederson score and Grip test score, reduced infarct volume and the extravasation of IgG, suppressed the over-activation of microglia, and modulated the expression of cytokines. Mechanically, we found that both KD pretreatment or BHB post-treatment significantly stimulated the expression of interleukin-1 receptor-associated kinase M (IRAKM) and then inhibited the nuclear translocation of NF-κB. IRAKM deletion (Irakm-/-) exacerbated tMCAO-induced neurovascular injuries, and aggravated neuroinflammatory response. Moreover, KD pretreatment or BHB post-treatment lost their neuroprotection in the tMCAO-treated Irakm-/- mice. Our results support that KD pretreatment and BHB post-treatment alleviate ischemic brain injury in mice, possibly via an IRAKM-dependent way.

Elevated white blood cell counts in ischemic stroke patients are associated with increased mortality and new vascular events

Background and purpose

High levels of white blood cells (WBC) in ischemic stroke have been shown to increase the risk of new vascular events and mortality in short and intermediate follow-up studies, but long-term effects remain unknown. We studied whether elevated levels of WBC in ischemic stroke patients are associated with new vascular events and mortality in a 10-year follow-up period.

Methods

We included ischemic stroke patients hospitalized between 2011 and 2012, categorizing their WBC counts within 48 h of stroke onset as high or normal (3.5-8.8 × 109 mmol/L; >8.8 × 109 mmol/L). Using Aahlen Johansen and Cox proportional hazard models with competing risk, we analyzed the association between WBC levels and new vascular events. Kaplan-Meier and standard Cox proportional hazard models were used to assess the risk of all-cause mortality.

Results

Among 395 patients (median age 69, [IQR: 63, 78], female patients 38,0%), 38.5% had elevated WBC at admission. During the 10-year follow-up, 113 vascular events occurred, with 46% in patients with elevated WBC and 54% in patients with normal WBC. After adjusting for relevant factors, elevated WBC levels were independently associated with increased risk of new vascular events (HR: 1.61, CI: 1.09-2.39 p < 0.05) and death (HR: 1.55, CI: 1.15-2.09, p < 0.05).

Conclusion

Elevated WBC levels in ischemic stroke patients are linked to a higher risk of new vascular events and mortality. Thus, ischemic stroke patients with elevated WBC without clinical infection need special attention to investigate possible underlying conditions to prevent future vascular events and reduce mortality. The interpretation of our results is limited by the absence of adjustment to premorbid functional status, stroke severity, and stroke treatment.

Applicability of the low-grade inflammation score in predicting 90-day functional outcomes after acute ischemic stroke

BACKGROUND AND PURPOSE

The low-grade inflammation (LGI) score, a novel indicator of chronic LGI, combines C-reactive protein (CRP), leukocyte counts, the neutrophil/lymphocyte ratio (NLR), and the platelet (PLT) count to predict outcomes of patients with various conditions, such as cardiovascular diseases, cancers, and neurodegenerative diseases. However, few studies have examined the role of the LGI score in predicting functional outcomes of patients with ischemic stroke. The present study aimed to evaluate the association between the LGI score and functional outcomes of patients with ischemic stroke.

METHODS

A total of 1,215 patients were screened in the present study, and 876 patients were finally included in this retrospective observational study based on the inclusion and exclusion criteria. Blood tests were conducted within 24 h of admission. Severity of ischemic stroke was assessed using the NIHSS score with severe stroke denoted by NIHSS > 5. Early neurological deterioration (END) was defined as an increment in the total NIHSS score of ≥ 2 points within 7 days after admission. Patient outcomes were assessed on day 90 after stroke onset using the modified Rankin Scale (mRS).

RESULTS

The LGI score was positively correlated with baseline and the day 7 NIHSS scores (R2 = 0.119, p < 0.001;R2 = 0.123, p < 0.001). Multivariate regression analysis showed that the LGI score was an independent predictor of stroke severity and END. In the crude model, the LGI score in the fourth quartile was associated with a higher risk of poor outcomes on day 90 compared with the LGI score in the first quartile (OR = 5.02, 95% CI: 3.09-8.14, p for trend < 0.001). After adjusting for potential confounders, the LGI score in the fourth quartile was independently associated with poor outcomes on day 90 (OR = 2.65, 95% CI: 1.47-4.76, p for trend = 0.001). Finally, the ROC curve analysis showed an AUC of 0.682 for poor outcomes on day 90 after stroke onset.

CONCLUSION

The LGI score is strongly correlated with the severity of acute ischemic stroke and that the LGI score might be a good predictor for poor outcomes on day 90 in patients with acute ischemic stroke.

Chemical composition, pharmacology and pharmacokinetic studies of GuHong injection in the treatment of ischemic stroke

GuHong injection is composed of safflower and N-acetyl-L-glutamine. It is widely used in clinical for cerebrovascular diseases, such as ischemic stroke and related diseases. The objective of this review is to comprehensively summarize the most recent information related to GuHong in the treatment of stroke, including chemical composition, clinical studies, potential pharmacological mechanisms and pharmacokinetics. Additionally, it examines possible scientific gaps in current study and aims to provide a reliable reference for future GuHong studies. The systematic review reveals that the chemical composition of safflower in GuHong is more than 300 chemical components in five categories. GuHong injection is primarily used in clinical applications for acute ischemic stroke and related diseases. Pharmacological investigations have indicated that GuHong acts in the early and recovery stages of ischemic stroke by anti-inflammatory, anti-oxidative stress, anti-coagulation, neuroprotective and anti-apoptotic mechanisms simultaneously. Pharmacokinetic studies found that the main exposed substances in rat plasma after GuHong administration are hydroxysafflor yellow A and N-acetyl-L-glutamine, and N-acetyl-L-glutamine could exert its pharmacological effect across the blood-brain barrier. As a combination of Chinese herb and chemical drug, GuHong injection has great value in drug research and clinical treatment, especially for ischemic stroke disease. This article represents a comprehensive and systematic review of existing studies on GuHong injection, including chemical composition, pharmacological mechanism, and pharmacokinetics, which provides reference significance for the clinical treatment of ischemic stroke with GuHong, as well as provides guidance for further study.

Neuroinflammatory Biomarkers in the Brain, Cerebrospinal Fluid, and Blood After Ischemic Stroke

The most frequent type of stroke, known as ischemic stroke (IS), is a significant global public health issue. The pathological process of IS and post-IS episodes has not yet been fully explored, but neuroinflammation has been identified as one of the key processes. Biomarkers are objective indicators used to assess normal or pathological processes, evaluate responses to treatment, and predict outcomes, and some biomarkers can also be used as therapeutic targets. After IS, various molecules are produced by different cell types, such as microglia, astrocytes, infiltrating leukocytes, endothelial cells, and damaged neurons, that participate in the neuroinflammatory response within the ischemic brain region. These molecules may either promote or inhibit neuroinflammation and may be released into extracellular spaces, including cerebrospinal fluid (CSF) and blood, due to reasons such as BBB damage. These neuroinflammatory molecules should be valued as biomarkers to monitor whether their expression levels in the blood, CSF, and brain correlate with the diagnosis and prognosis of IS patients or whether they have potential as therapeutic targets. In addition, although some molecules do not directly participate in the process of neuroinflammation, they have been reported to have potential diagnostic or therapeutic value against post-IS neuroinflammation, and these molecules will also be listed. In this review, we summarize the neuroinflammatory biomarkers in the brain, CSF, and blood after an IS episode and the potential value of these biomarkers for the diagnosis, treatment, and prognosis of IS patients.

l-borneol promotes neurovascular unit protection in the subacute phase of transient middle cerebral artery occlusion rats: p38-MAPK pathway activation, anti-inflammatory, and anti-apoptotic effect

Our previous study showed l-borneol reduced cerebral infarction in the acute stage after cerebral ischemia, but there is little about the study of subacute phase. We herein investigated the cerebral protective effects of l-borneol on neurovascular units (NVU) in the subacute phase after transient middle cerebral artery occlusion (t-MCAO). The t-MCAO model was prepared by the line embolus method. Zea Longa, mNss, HE, and TTC staining were used to evaluate the effect of l-borneol. We evaluated the mechanisms of l-borneol on inflammation, p38 MAPK pathway, and apoptosis, etc. through various technologies. l-borneol 0.2, 0.1, 0.05 g·kg-1 could significantly reduce cerebral infarction rate, alleviate the pathological injury, and inhibit inflammation reaction. l-borneol could also significantly increase brain blood supply, Nissl bodies, and the expression of GFAP. Additionally, l-borneol activated the p38 MAPK signaling pathway, inhibited cell apoptosis, and maintained BBB integrity. l-borneol had a neuroprotective effect, which was related to activating the p38 MAPK signaling pathway, inhibiting inflammatory response and apoptosis, and improving cerebral blood supply to protect BBB and stabilize and remodel NVU. The study will provide a reference for the use of l-borneol in the treatment of ischemic stroke in the subacute phase.

NLRP3 inflammasome activation after ischemic stroke

Cerebral ischemia is a pathological condition resulting from the cessation or reduction of blood supply to the cerebral arteries. Neurological deficits that are clinically relevant can arise as a result of brain damage. The etiology of stroke is multifaceted and intricate, with the inflammatory response being a crucial component that warrants significant attention. Following a cerebrovascular accident, the levels of interleukin-1 beta and interleukin-18 within the central nervous system escalate due to the activation of the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 inflammasome. The inflammation is aggravated by the subsequent occurrence of pyroptosis. The mechanisms that activate the NLRP3 inflammasome pyroptosis signaling pathway axis are described in this article. In addition, we go over how pyroptosis interacts with other processes for regulated cell death. In addition, specific NLRP3 inflammasome pathway inhibitors are identified, which offer new approaches to preventing ischemic brain injury.

The value of RPS15 and MRPS27 in ischemic stroke

Ischemic stroke is caused by insufficient blood supply to the brain. It has acute onset, often disturbance of consciousness, and high mortality and disability rate. However, relationship between ribosomal proteins (RP)-S15 and mitochondrial ribosomal proteins (MRP)-S27 and ischemic stroke remains unclear. The ischemic stroke datasets GSE22255, GSE16561, and GSE199435 were downloaded from gene expression omnibus generated by GPL6883, GPL11154, and GPL570. Differentially expressed genes (DEGs) were screened, and the construction and analysis of protein-protein interaction network, functional enrichment analysis and gene set enrichment analysis were performed. The gene expression heat map was drawn. Comparative toxicogenomics database analysis were performed to find the disease most related to core gene. TargetScan screened miRNAs that regulated central DEGs. Five hundred DEGs were identified. According to gene ontology analysis, they were mainly enriched in leukocyte activation, myoid cell activation involved in immune response, cell membrane, mitochondria, secretory vesicles, catalytic activity, enzyme binding, ribonucleic acid binding, splicing. Gene set enrichment analysis showed that the enrichment items are similar to the enrichment items of differentially expressed genes. And 20 core genes were obtained. Comparative toxicogenomics database analysis showed that 6 genes (RPS15, RPS2, RPS3, MRPS27, POLR2A, MRPS26) were found to be associated with chemical and drug-induced liver injury, necrosis, delayed prenatal exposure, nephropathy, hepatomegaly and tumor. RPS15 and MRPS27 are the core genes of ischemic stroke and play an important role in ischemic stroke.

TREM2, microglial and ischemic stroke

Ischemic stroke (IS) is a leading cause of morbidity and mortality worldwide. Immunity and inflammation are key factors in the pathophysiology of IS. The inflammatory response is involved in all stages of stroke, and microglia are the predominant cells involved in the post-stroke inflammatory response. Resident microglia are the main immune cells of the brain and the first line of defense of the nervous system. After IS, activated microglia can be both advantageous and detrimental to surrounding tissue; they can be divided into the harmful M1 types or the neuro-protective M2 type. Currently, with the latest progress of transcriptomics analysis, different and more complex phenotypes of microglia activation have been described, such as disease-related microglia (DAM) associated with Alzheimer's disease (AD), white matter associated microglia (WAMs) in aging, and stroke-related microglia (SAM) etc. The triggering receptor expressed on myeloid cell 2 (TREM2) is an immune-related receptor on the surface of microglia. Its expression increases after IS, which is related to microglial inflammation and phagocytosis, however, its relationship with the microglia phenotype is not clear. This paper reviews the following: 1) the phenotypic changes of microglia in various pathological stages after IS and its relationship with inflammatory factors; 2) the relationship between the expression of the TREM2 receptor and inflammatory factors; 3) the relationship between phenotypic changes of microglia and its surface receptor TREM2; 4) the TREM2-related signalling pathway of microglia after IS and treatment for TREM2 receptor; and finally 5) To clarify the relationship among TREM2, inflammation, and microglia phenotype after IS, as well as the mechanism among them and the some possible treatment of IS targeting TREM2. Moreover, the relationship between the new phenotype of microglia such as SAM and TREM2 has also been systematically summarized, but there are no relevant research reports on the relationship between TREM2 and SAM after IS.

Assessment of corticospinal tract remodeling based on diffusion tensor imaging in the treatment of motor dysfunction after ischemic stroke by acupuncture: A meta-analysis

BACKGROUND

To investigate the efficacy of acupuncture in improving motor dysfunction after ischemic stroke (IS) and to investigate the effect of acupuncture on corticospinal tract (CST) remodeling using diffusion tensor imaging.

METHODS

Published literature on the effect of acupuncture on CST remodeling after IS using diffusion tensor imaging in the form of randomized controlled trials (RCTs) were systematically retrieved and screened from Cochrane Library, Web of Science, PubMed, Embase, CNKI, CBM, VIP, and Wanfang databases from inception to December 2022. The methodological quality of the included studies was critically and independently evaluated by 2 reviewers using the Cochrane Risk of Bias Assessment Tool for RCTs. The correlated data were extracted using the pre-designed form, and all analyses were performed using Reviewer Manager version 5.4.

RESULTS

Eleven eligible RCTs involving 459 patients were eventually included. The combined evidence results showed that the acupuncture group significantly improved patients' National Institute of Health stroke scale, Fugl-Meyer Assessment Scale, and Barthel index compared with conventional medical treatment. The acupuncture group significantly promoted remodeling of the CST, as reflected by an increase in fractional anisotropy (FA) throughout the CST [MD = 0.04, 95% CI (0.02, 0.07), P = .001], and in addition, subgroup analysis showed that the acupuncture group significantly improved FA in the infarct area compared with conventional medical treatment at around 4 weeks [MD = 0.04, 95% CI (0.02, 0.06), P = .0002] and FA of the affected cerebral peduncle [MD = 0.03, 95% CI (0.00, 0.07), P = .02]. Also, compared with conventional medical treatment, the acupuncture group significantly increased average diffusion coefficient of the affected cerebral peduncle [MD = -0.21, 95% CI (-0.28, -0.13), P < .00001].

CONCLUSION

The results of the meta-analysis suggest that acupuncture therapy can improve the clinical manifestations of motor dysfunction in patients after IS and advance a possibly beneficial effect on CST remodeling. However, due to the number and quality of eligible studies, these findings need to be further validated in more standardized, rigorous, high-quality clinical trials.

Microglia Negatively Regulate the Proliferation and Neuronal Differentiation of Neural Stem/Progenitor Cells Isolated from Poststroke Mouse Brains

We previously demonstrated that neural stem/progenitor cells (NSPCs) were induced within and around the ischemic areas in a mouse model of ischemic stroke. These injury/ischemia-induced NSPCs (iNSPCs) differentiated to electrophysiologically functional neurons in vitro, indicating the presence of a self-repair system following injury. However, during the healing process after stroke, ischemic areas were gradually occupied by inflammatory cells, mainly microglial cells/macrophages (MGs/MΦs), and neurogenesis rarely occurred within and around the ischemic areas. Therefore, to achieve neural regeneration by utilizing endogenous iNSPCs, regulation of MGs/MΦs after an ischemic stroke might be necessary. To test this hypothesis, we used iNSPCs isolated from the ischemic areas after a stroke in our mouse model to investigate the role of MGs/MΦs in iNSPC regulation. In coculture experiments, we show that the presence of MGs/MΦs significantly reduces not only the proliferation but also the differentiation of iNSPCs toward neuronal cells, thereby preventing neurogenesis. These effects, however, are mitigated by MG/MΦ depletion using clodronate encapsulated in liposomes. Additionally, gene ontology analysis reveals that proliferation and neuronal differentiation are negatively regulated in iNSPCs cocultured with MGs/MΦs. These results indicate that MGs/MΦs negatively impact neurogenesis via iNSPCs, suggesting that the regulation of MGs/MΦs is essential to achieve iNSPC-based neural regeneration following an ischemic stroke.

The Effects of Andrographis paniculata (Burm.F.) Wall. Ex Nees and Andrographolide on Neuroinflammation in the Treatment of Neurodegenerative Diseases

Neurodegenerative diseases (NDs) affect millions of people worldwide, and to date, Alzheimer's and Parkinson's diseases are the most common NDs. Of the many risk factors for neurodegeneration, the aging process has the most significant impact, to the extent that it is tempting to consider neurodegenerative disease as a manifestation of accelerated aging. However, genetic and environmental factors determine the course of neurodegenerative disease progression. It has been proposed that environmental stimuli influence neuroplasticity. Some clinical studies have shown that healthy lifestyles and the administration of nutraceuticals containing bioactive molecules possessing antioxidant and anti-inflammatory properties have a preventive impact or mitigate symptoms in previously diagnosed patients. Despite ongoing research efforts, the therapies currently used for the treatment of NDs provide only marginal therapeutic benefits; therefore, the focus is now directly on the search for natural products that could be valuable tools in combating these diseases, including the natural compound Andrographis paniculata (Ap) and its main constituent, andrographolide (Andro). Preclinical studies have shown that the aqueous extract of Ap can modulate neuroinflammatory and neurodegenerative responses, reducing inflammatory markers and oxidative stress in various NDs. Therefore, in this review, we will focus on the molecular mechanisms by which Ap and Andro can modulate the processes of neurodegeneration and neuroinflammation, which are significant causes of neuronal death and cognitive decline.

Neuroinflammation in Acute Ischemic and Hemorrhagic Stroke

PURPOSE OF REVIEW

This review aims to provide an overview of neuroinflammation in ischemic and hemorrhagic stroke, including recent findings on the mechanisms and cellular players involved in the inflammatory response to brain injury.

RECENT FINDINGS

Neuroinflammation is a crucial process following acute ischemic stroke (AIS) and hemorrhagic stroke (HS). In AIS, neuroinflammation is initiated within minutes of the ischemia onset and continues for several days. In HS, neuroinflammation is initiated by blood byproducts in the subarachnoid space and/or brain parenchyma. In both cases, neuroinflammation is characterized by the activation of resident immune cells, such as microglia and astrocytes, and infiltration of peripheral immune cells, leading to the release of pro-inflammatory cytokines, chemokines, and reactive oxygen species. These inflammatory mediators contribute to blood-brain barrier disruption, neuronal damage, and cerebral edema, promoting neuronal apoptosis and impairing neuroplasticity, ultimately exacerbating the neurologic deficit. However, neuroinflammation can also have beneficial effects by clearing cellular debris and promoting tissue repair. The role of neuroinflammation in AIS and ICH is complex and multifaceted, and further research is necessary to develop effective therapies that target this process. Intracerebral hemorrhage (ICH) will be the HS subtype addressed in this review. Neuroinflammation is a significant contributor to brain tissue damage following AIS and HS. Understanding the mechanisms and cellular players involved in neuroinflammation is essential for developing effective therapies to reduce secondary injury and improve stroke outcomes. Recent findings have provided new insights into the pathophysiology of neuroinflammation, highlighting the potential for targeting specific cytokines, chemokines, and glial cells as therapeutic strategies.

Plasma lncRNA LIPCAR Expression Levels Associated with Neurological Impairment and Stroke Subtypes in Patients with Acute Cerebral Infarction: A Prospective Observational Study with a Control Group

INTRODUCTION

This prospective observational study with a control group aimed to compare the plasma levels of long non-coding RNA (lncRNA) LIPCAR between patients with acute cerebral infarction (ACI) and healthy controls, and to assess the prognostic abilities of LIPCAR for adverse outcomes of patients with ACI at 1-year follow-up.

METHODS

Eighty patients with ACI, of whom 40 had large artery atherosclerosis (LAA) and 40 had cardioembolism (CE) and who were hospitalized at Xi'an No. 1 Hospital from July 2019 to June 2020, were selected as the case group. Age- and sex-matched non-stroke patients from the same hospital throughout the same time period were chosen as the control group. Real-time quantitative reverse transcription polymerase chain reaction was used to measure the levels of plasma lncRNA LIPCAR. The correlations of LIPCAR expression among the LAA, CE, and control groups were assessed using Spearman's correlation analysis. Curve fitting and multivariate logistic regression were used to analyze the LIPCAR levels and 1-year adverse outcomes of patients with ACI and its subtypes.

RESULTS

The expression of plasma LIPCAR in the case group was noticeably higher than that of the control group (2.42 ± 1.49 vs. 1.00 ± 0.47, p < 0.001). Patients with CE had considerably higher levels of LIPCAR expression than those with LAA. The National Institute of Health Stroke Scale score and modified Rankin scale score on admission were significantly positively correlated with LIPCAR expression in patients with CE and LAA. Furthermore, the correlation was stronger in patients with CE than in those with LAA, with correlation coefficients of 0.69 and 0.64, respectively. Curve fitting revealed a non-linear correlation between LIPCAR expression levels, 1-year recurrent stroke, all-cause mortalities, and poor prognoses, with a cut-off value of 2.2.

CONCLUSION

The expression level of lncRNA LIPCAR may play a potential role in the identification of neurological impairment and CE subtype in patients with ACI. Increased 1-year risk of adverse outcomes may be associated with high levels of LIPCAR expression.

Klotho gene might antagonize ischemic injury in stroke rats by reducing the expression of AQP4 via P38MAPK pathway

OBJECTIVES

This study was aimed at exploring whether klotho improved neurologic function in rats with cerebral infarction by inhibiting P38 mitogen-activated protein kinase (MAPK) activation and thus down-regulating aquaporin 4 (AQP4).

METHODS

In this study, we induced intracerebral Klotho overexpression in 6-week-old Sprague Dawley rats by injecting lentivirus carrying full-length rat Klotho cDNA into the lateral ventricle of the brain, followed by middle cerebral artery occlusion (MCAO) surgery after three days. Neurologic function was evaluated by neurological deficit scores. Infarct volume was assessed by 2,3,5-triphenyl tetrazolium chloride (TTC) staining. The expressions of Klotho, AQP4, and P38 MAPK were detected by Western blot and Immunofluorescence.

RESULTS

when rats were subjected to cerebral ischemia, their neurologic function was impaired, the protein expressions of klotho downregulated, the protein expressions of AQP4 and P38 MAPK increased, and the ratios of AQP4 and P-P38-positive area were significantly increased compared with the sham group rats. LV-KL-induced Klotho overexpression greatly improved neurobehavioral deficits and reduced infarct volume in MCAO rats. Klotho overexpression significantly reduced AQP4 and P38 MAPK pathway-related protein expression levels and the ratios of P-P38 and AQP4-positive area in MCAO rats. In addition, SB203580, a P38 MAPK signal pathway inhibitor, improved neurobehavioral deficits, reduced infarct volume, downregulated the expressions levels of AQP4 and P38 MAPK, and reduced the size of P-P38 and AQP4-positive area in MCAO rats.

CONCLUSION

Klotho could alleviate the infraction volume and neurological dysfunction in MCAO rats, and its mechanism may involve AQP4 expression downregulation by suppressing P38-MAPK activation.

Isoflurane Anesthesia's Impact on Gene Expression Patterns of Rat Brains in an Ischemic Stroke Model

BACKGROUND

Ischemic stroke (IS) is one of the most severe brain diseases. Animal models with anesthesia are actively used to study stroke genomics and pathogenesis. However, the anesthesia-related gene expression patterns of ischemic rat brains remain poorly understood. In this study, we sought to elucidate the impact of isoflurane (ISO) anesthesia on the extent of ischemic brain damage and gene expression changes associated with stroke.

METHODS

We used the transient middle cerebral artery occlusion (tMCAO) model under long-term and short-term ISO anesthesia, magnetic resonance imaging (MRI), RNA sequencing, and bioinformatics.

RESULTS

We revealed that the volume of cerebral damage at 24 h after tMCAO was inversely proportional to the duration of ISO anesthesia. Then, we revealed hundreds of overlapping ischemia-related differentially expressed genes (DEGs) with a cutoff of >1.5; Padj < 0.05, and 694 and 1557 DEGs only under long-term and short-term anesthesia, respectively, using sham-operated controls. Concomitantly, unique DEGs identified under short-term anesthesia were mainly associated with neurosignaling systems, whereas unique DEGs identified under long-term anesthesia were predominantly related to the inflammatory response.

CONCLUSIONS

We were able to determine the effects of the duration of anesthesia using isoflurane on the transcriptomes in the brains of rats at 24 h after tMCAO. Thus, specific genome responses may be useful in developing potential approaches to reduce damaged areas after cerebral ischemia and neuroprotection.

HS-CRP Modifies the Prognostic Value of Platelet Count for Clinical Outcomes After Ischemic Stroke

Background We examined whether the relationship between baseline platelet count and clinical outcomes is modulated by HS-CRP (high-sensitivity C-reactive protein) in patients with ischemic stroke. Methods and Results A total of 3267 patients with ischemic stroke were included in the analysis. The primary outcome was a combination of death and major disability at 1 year after ischemic stroke. Secondary outcomes included major disability, death, vascular events, composite outcome of vascular events or death, and an ordered 7-level categorical score of the modified Rankin Scale at 1 year. Multivariate logistic regression and Cox proportional hazards regression models were used to assess the association between the baseline platelet count and clinical outcomes stratified by HS-CRP levels when appropriate. There was an interaction effect of platelet count and HS-CRP on the adverse clinical outcomes after ischemic stroke (all P_interaction<0.05). The elevated platelet count was significantly associated with the primary outcome (odds ratio [OR], 3.14 [95% CI, 1.77-5.58]), major disability (OR, 2.07 [95% CI, 1.15-3.71]), death (hazard ratio [HR], 2.75 [95% CI, 1.31-5.79]), and composite outcome of vascular events or death (HR, 2.57 [95% CI, 1.38-4.87]) among patients with high HS-CRP levels (all P_trend<0.05). Conclusions The HS-CRP levels had a modifying effect on the association between platelet count and clinical outcomes in patients with ischemic stroke. Elevated platelet count was significantly associated with adverse clinical outcomes in patients with ischemic stroke with high HS-CRP levels, but not in those with low HS-CRP levels. These findings suggest that strategies for anti-inflammatory and antiplatelet therapy should be developed according to the results of both platelet and HS-CRP testing.

Histopathological lesions induced by stroke in the encephalon

Strokes are conditions with a high degree of morbidity and mortality worldwide. These conditions profoundly affect the quality of life of patients; in addition to physical disabilities, patients present various mental disorders, such as mood disorders, anxiety, depression, behavioral disorders, fatigue, etc. Microscopic lesions of the brain parenchyma explain the clinical symptoms and correlate with the severity of the stroke. Our study consisted of the histopathological (HP) and immunohistochemical analysis of brain fragments, collected from 23 patients, with a clinical and imagistic diagnosis of stroke, who died during hospital admission. The microscopic analysis showed that both neurons and glial cells are affected in the ischemic focus. Neuronal death in the ischemic focus was mostly caused by cell necrosis and only about 10% by apoptosis. Regarding vascular lesions, it was observed that the most frequent HP lesion of intracerebral arterioles was arteriosclerosis. The lumen of the arterioles was reduced, and the vascular endothelium had a discontinuous aspect, which indicates a change in the blood-brain barrier. Sometimes the arteriole lumen was completely obstructed, with fibrinoid necrosis in the internal and middle tunic, or with the proliferation of fibroblasts and the formation of young intraluminal connective tissue. Intraparenchymal blood capillaries in the ischemic area showed endothelium discontinuities, lumen collapse, and sometimes massive perivascular edema. As for neuroinflammation, the presence of numerous neutrophils, lymphocytes, plasma cells and macrophages was found in the ischemic focus, forming a complex and inhomogeneous cellular mixture. Of the inflammatory cells present in the ischemic focus and in the ischemic penumbra area, the most numerous were the macrophages. The HP analysis showed that neuroinflammation is very complex and different in intensity from one patient to another, most likely due to associated comorbidities, age, treatment administered until death, etc.

Association between depression and macrovascular disease: a mini review

Depression and macrovascular diseases are globally recognized as significant disorders that pose a substantial socioeconomic burden because of their associated disability and mortality. In addition, comorbidities between depression and macrovascular diseases have been widely reported in clinical settings. Patients afflicted with coronary artery disease, cerebrovascular disease or peripheral artery disease exhibit an elevated propensity for depressive symptoms. These symptoms, in turn, augment the risk of macrovascular diseases, thereby reflecting a bidirectional relationship. This review examines the physiological and pathological mechanisms behind comorbidity while also examining the intricate connection between depression and macrovascular diseases. The present mechanisms are significantly impacted by atypical activity in the hypothalamic-pituitary-adrenal axis. Elevated levels of cortisol and other hormones may disrupt normal endothelial cell function, resulting in vascular narrowing. At the same time, proinflammatory cytokines like interleukin-1 and C-reactive protein have been shown to disrupt the normal function of neurons and microglia by affecting blood-brain barrier permeability in the brain, exacerbating depressive symptoms. In addition, platelet hyperactivation or aggregation, endothelial dysfunction, and autonomic nervous system dysfunction are important comorbidity mechanisms. Collectively, these mechanisms provide a plausible physiological basis for the interplay between these two diseases. Interdisciplinary collaboration is crucial for future research aiming to reveal the pathogenesis of comorbidity and develop customised prevention and treatment strategies.

An In Silico Analysis Reveals Sustained Upregulation of Neuroprotective Genes in the Post-Stroke Human Brain

Ischemic stroke is a cerebrovascular disease caused by an interruption of blood flow to the brain, thus determining a lack of oxygen and nutrient supply. The ischemic event leads to the activation of several molecular signaling pathways involved in inflammation and the production of reactive oxygen species, causing irreversible neuronal damage. Several studies have focused on the acute phase of ischemic stroke. It is not clear if this traumatic event can influence some of the molecular processes in the affected area even years after the clinical event. In our study, we performed an in silico analysis using freely available raw data with the purpose of evaluating the transcriptomic state of post-mortem brain tissue. The samples were taken from non-fatal ischemic stroke patients, meaning that they suffered an ischemic stroke and lived for a period of about 2 years after the event. These samples were compared with healthy controls. The aim was to evaluate possible recovery processes useful to mitigating neuronal damage and the detrimental consequences of stroke. Our results highlighted differentially expressed genes codifying for proteins along with long non-coding genes with anti-inflammatory and anti-oxidant functions. This suggests that even after an amount of time from the ischemic insult, different neuroprotective mechanisms are activated to ameliorate brain conditions and repair post-stroke neuronal injury.

Predictive role of pre-thrombolytic hs-CRP on the safety and efficacy of intravenous thrombolysis in acute ischemic stroke

PURPOSE

To investigate the predictive role of pre-thrombolytic high sensitivity C-reactive protein (hs-CRP) on the safety and efficacy of intravenous thrombolysis in patients with acute ischemic stroke (AIS).

METHODS

Patients with AIS who underwent intravenous thrombolysis with recombinant plasminogen activator (rtPA) or urokinase without endovascular therapy from June 2019 to June 2022 were retrospectively analysed. All patients were grouped into two groups (high or low hs-CRP group) according to the median value of hs-CRP before intravenous thrombolysis. The baseline NIHSS, NIHSS changes before and after thrombolysis (ΔNIHSS), the rate of good thrombolysis response (NIHSS decreased ≥ 2 points from baseline), the rate of any intracranial hemorrhage, age, sex, hypertension, diabetes, uric acid and platelet count were compared between the two groups. Logistic regression analysis was performed to identify possible prognostic factors for a good thrombolysis response.

RESULTS

A total of 212 patients were included in the analysis, with a mean age of 66.3 ± 12.5 years. In total, 145 patients received rtPA, and 67 patients received urokinase. Patients were divided into a high hs-CRP group (> 1.60 mg/L) and a low hs-CRP group (≤ 1.60 mg/L) according to the median hs-CRP level (1.60 mg/L). The ΔNIHSS of the high hs-CRP group was significantly smaller than that of the low hs-CRP group (0 [-1 ~ 0] vs. -1 [-2 ~ 0], P < 0.05). The good rate of thrombolysis response in the high hs-CRP group was significantly lower than that in the low hs-CRP group (21.9% vs. 36.5%, P < 0.05). Similar results were shown in the rtPA subgroup between the high and low hs-CRP groups but not in the urokinase subgroup. Logistic regression analysis showed that hs-CRP > 1.60 mg/L was negatively correlated with a good thrombolysis response rate (OR = 0.496, 95% CI = 0.266-0.927, P = 0.028).

CONCLUSION

hs-CRP > 1.6 mg/L may serve as a poor prognosis predictive factor for patients with AIS receiving intravenous thrombolysis. However, due to the small sample size of this study, further studies are needed to verify our results.

Correlations between NLR, NHR, and clinicopathological characteristics, and prognosis of acute ischemic stroke

Neuroinflammation plays an essential role in the process of acute ischemic stroke (AIS) injury repair. The current study seeks to investigate the relationship between the neutrophil/lymphocyte ratio (NLR) and neutrophil/high-density lipoprotein cholesterol ratio (NHR) and AIS disease severity and short-term prognosis. As such, the primary aim of this study is to improve AIS diagnosis and treatment. A total of 136 patients with AIS at the Nantong Third People's Hospital were retrospectively analyzed. The inclusion criteria comprised patients with ischemic stroke admitted to the hospital <24 hours after symptom onset. Baseline, clinical, and laboratory data were collected from all patients within 24 hours of admission. Univariate, multivariate and receiver operating characteristic curve analysis were performed to determine the relationship between NLR, NHR, AIS severity, and short-term prognosis. NLR (odds ratio [OR] = 1.448, 95% confidence interval [CI] 1.116-1.878, P = .005) and NHR (OR = 1.480, 95% CI 1.158-1.892, P = .002) were identified as independent risk factors for stroke severity. Additionally, the correlation between combined NLR and NHR and AIS severity achieved a sensitivity of 81.4% and specificity of 60.4% with a best cutoff value of 6.989. This outcome was superior to that of the single composite inflammatory index. Moreover, NLR (OR = 1.252, 95% CI 1.008-1.554, P = .042) was an independent risk factor for poor short-term prognosis in patients with AIS. When the optimal cutoff value was 2.605, the sensitivity of NLR correlation with the short-term prognosis of AIS was 82.2%, and the specificity was 59.3%. NLR combined with NHR exhibits a strong correlation with disease severity in AIS. Meanwhile, an elevated NLR in patients with AIS can predict a poor short-term prognosis.

Uric acid and neurological disease: a narrative review

Hyperuricemia often accompanies hypertension, diabetes, dyslipidemia, metabolic syndrome, and chronic renal disease; it is also closely related to cardiovascular disease. Moreover, several epidemiological studies have linked hyperuricemia and ischemic stroke. However, uric acid may also have neuroprotective effects because of its antioxidant properties. An association between low uric acid levels and neurodegenerative diseases has been suggested, which may be attributed to diminished neuroprotective effects as a result of reduced uric acid. This review will focus on the relationship between uric acid and various neurological diseases including stroke, neuroimmune diseases, and neurodegenerative diseases. When considering both the risk and pathogenesis of neurological diseases, it is important to consider the conflicting dual nature of uric acid as both a vascular risk factor and a neuroprotective factor. This dual nature of uric acid is important because it may help to elucidate the biological role of uric acid in various neurological diseases and provide new insights into the etiology and treatment of these diseases.

Multidrug-loaded liposomes prevent ischemic stroke through intranasal administration

Baicalin (BA), a multi-target neuroprotective agent, has poor solubility resulting in low bioavailability. In this study, multidrug-loaded liposomes were prepared by encapsulating BA, borneol (BO) and cholic acid (CA) to prevent ischemic stroke. BBC-LP were administered intranasally (i.n.) to deliver into the brain for neuroprotection. Finally, potential mechanism of BBC treating ischemic stroke (IS) was explored by network pharmacology. In this study, BBC-LP was prepared by reverse evaporation method, and the encapsulation efficiency (EE) of the optimized liposomes was 42.69% and the drug loading (DL) was 6.17%. The liposomes had low mean particle size (156.62 ± 2.96 nm), polydispersity index (PDI) (0.195) and zeta potential (-0.99 mv). Compared to BBC, pharmacodynamic studies revealed that BBC-LP significantly improved neurological deficits, brain infarct volume, and cerebral pathology in MCAO rats. Toxicity studies showed that BBC-LP was not irritating to the nasal mucosa. These results suggest that BBC-LP can safely and effectively ameliorate IS injury by i.n. administration. Moreover, it's neuroprotective function may be related to the anti-apoptotic and anti-inflammatory effects exerted by phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway and mitogen-activated protein kinase (MAPK) signaling pathway.

BRG1 alleviates microglial activation by promoting the KEAP1-NRF2/HO-1 signaling pathway and minimizing oxidative damage in cerebral ischemia-reperfusion

BRG1 is a key factor in the process of apoptosis and oxidative damage; however, its role in the pathophysiology of ischemic stroke is unclear. Here, we discovered that during middle cerebral artery occlusion (MCAO) reperfusion in mice, microglia were significantly activated in the cerebral cortex of the infarct area, and BRG1 expression was increased in the mouse MCAO/R model, peaking at 4 days. In microglia subjected to OGD/R, BRG1 expression increased and peaked at 12 h after reoxygenation. After ischemic stroke, in vitro changing the expression of BRG1 expression levels greatly altered the activation of microglia and the production of antioxidant and pro-oxidant proteins. Knocking down BRG1 expression levels in vitro increased the inflammatory response, promoted microglial activation, and decreased the expression of the NRF2/HO-1 signaling pathway after ischemic stroke. In contrast, overexpression of BRG1 dramatically reduced the expression of NRF2/HO-1 signaling pathway and microglial activation. Our research reveals that BRG1 reduces postischemic oxidative damage via the KEAP1-NRF2/HO-1 signaling pathway, protecting against brain ischemia/reperfusion injury. Using BRG1 as a pharmaceutical target to inhibit inflammatory responses to reduce oxidative damage may be a unique way to explore techniques for the treatment of ischemic stroke and other cerebrovascular illnesses.

Puerarin: a potential natural neuroprotective agent for neurological disorders

Puerarin is an isoflavone compound derived from Pueraria lobata in traditional Chinese medicine. Accumulating evidence has indicated that puerarin demonstrates multiple pharmacological effects and exhibits treatment potential for various neurological disorders. Based on the latest research progress on puerarin as a neuroprotective agent, its pharmacological activity, molecular mechanism, and therapeutic application were systematically reviewed with emphasis on pre-clinical studies. The related information was extracted and compiled from major scientific databases, including PubMed, ScienceDirect, SpringerLink, and Chinese National Knowledge Infrastructure, using 'Puerarin', 'Neuroprotection', 'Apoptosis', 'Autophagy', 'Antioxidant', 'Mitochondria', 'Anti-inflammation' as keywords. This review complied with The Preferred Reporting Items for Systematic Reviews criteria. Forty-three articles met established inclusion and exclusion criteria. Puerarin has shown neuroprotective effects against a variety of neurological disorders, including ischemic cerebrovascular disease, subarachnoid hemorrhage, epilepsy, cognitive disorders, traumatic brain injury, Parkinson's disease, Alzheimer's disease, anxiety, depression, diabetic neuropathy, and neuroblastoma/glioblastoma. Puerarin demonstrates anti-apoptosis, proinflammatory mediator inhibitory, autophagy regulatory, anti-oxidative stress, mitochondria protection, Ca²⁺ influx inhibitory, and anti-neurodegenerative activities. Puerarin exerts noticeable neuroprotective effects on various models of neurological disorders in vivo (animal). This review will contribute to the development of puerarin as a novel clinical drug candidate for the treatment of neurological disorders. However, well-designed, high-quality, large-scale, multicenter randomized clinical studies are needed to determine the safety and clinical utility of puerarin in patients with neurological disorders.

TRIM67 alleviates cerebral ischemia‒reperfusion injury by protecting neurons and inhibiting neuroinflammation via targeting IκBα for K63-linked polyubiquitination

BACKGROUND

Excessive and unresolved neuroinflammation plays an important role in the pathophysiology of many neurological disorders, such as ischemic stroke, yet there are no effective treatments. Tripartite motif-containing 67 (TRIM67) plays a crucial role in the control of inflammatory disease and pathogen infection-induced inflammation; however, the role of TRIM67 in cerebral ischemia‒reperfusion injury remains poorly understood.

RESULTS

In the present study, we demonstrated that the expression level of TRIM67 was significantly reduced in middle cerebral artery occlusion and reperfusion (MCAO/R) mice and primary cultured microglia subjected to oxygen-glucose deprivation and reperfusion. Furthermore, a significant reduction in infarct size and neurological deficits was observed in mice after TRIM67 upregulation. Interestingly, TRIM67 upregulation alleviated neuroinflammation and cell death after cerebral ischemia‒reperfusion injury in MCAO/R mice. A mechanistic study showed that TRIM67 bound to IκBα, reduced K48-linked ubiquitination and increased K63-linked ubiquitination, thereby inhibiting its degradation and promoting the stability of IκBα, ultimately inhibiting NF-κB activity after cerebral ischemia.

CONCLUSION

Taken together, this study demonstrated a previously unidentified mechanism whereby TRIM67 regulates neuroinflammation and neuronal apoptosis and strongly indicates that upregulation of TRIM67 may provide therapeutic benefits for ischemic stroke.

After Ischemic Stroke, Minocycline Promotes a Protective Response in Neurons via the RNA-Binding Protein HuR, with a Positive Impact on Motor Performance

Ischemic stroke is the most common cause of adult disability and one of the leading causes of death worldwide, with a serious socio-economic impact. In the present work, we used a new thromboembolic model, recently developed in our lab, to induce focal cerebral ischemic (FCI) stroke in rats without reperfusion. We analyzed selected proteins implicated in the inflammatory response (such as the RNA-binding protein HuR, TNFα, and HSP70) via immunohistochemistry and western blotting techniques. The main goal of the study was to evaluate the beneficial effects of a single administration of minocycline at a low dose (1 mg/kg intravenously administered 10 min after FCI) on the neurons localized in the penumbra area after an ischemic stroke. Furthermore, given the importance of understanding the crosstalk between molecular parameters and motor functions following FCI, motor tests were also performed, such as the Horizontal Runway Elevated test, CatWalk™ XT, and Grip Strength test. Our results indicate that a single administration of a low dose of minocycline increased the viability of neurons and reduced the neurodegeneration caused by ischemia, resulting in a significant reduction in the infarct volume. At the molecular level, minocycline resulted in a reduction in TNFα content coupled with an increase in the levels of both HSP70 and HuR proteins in the penumbra area. Considering that both HSP70 and TNF-α transcripts are targeted by HuR, the obtained results suggest that, following FCI, this RNA-binding protein promotes a protective response by shifting its binding towards HSP70 instead of TNF-α. Most importantly, motor tests showed that reduced inflammation in the brain damaged area after minocycline treatment directly translated into a better motor performance, which is a fundamental outcome when searching for new therapeutic options for clinical practice.

A novel extract from Ginkgo biloba inhibits neuroinflammation and maintains white matter integrity in experimental stroke

Ginkgo biloba L. leaf extract (GBE) has been added in many commercial herbal formulations such as EGb 761 and Shuxuening Injection to treat cardiovascular diseases and stroke worldwide. However, the comprehensive effects of GBE on cerebral ischemia remained unclear. Using a novel GBE (nGBE), which consists of all the compounds of traditional (t)GBE and one new compound, pinitol, we investigated its effect on inflammation, white matter integrity, and long-term neurological function in an experimental stroke model. Both transient middle cerebral artery occlusion (MCAO) and distal MCAO were conducted in male C57/BL6 mice. We found that nGBE significantly reduced infarct volume at 1, 3, and 14 days after ischemia. Sensorimotor and cognitive functions were superior in nGBE treated mice after MCAO. nGBE inhibited the release of IL-1β in the brain, promoted microglial ramification, and regulated the microglial M1 to M2 phenotype shift at 7 days post injury. In vitro analyses showed that nGBE treatment reduced the production of IL-1β and TNFα in primary microglia. Administration of nGBE also decreased the SMI-32/MBP ratio and enhanced myelin integrity, thus exhibiting improved white matter integrity at 28 days post stroke. These findings demonstrate that nGBE protects against cerebral ischemia by inhibiting microglia-related inflammation and promoting white matter repair, suggesting that nGBE is a promising therapeutic strategy for long-term recovery after stroke.

A comparative study of the neuroprotective effects of dl-3-n-butylphthalide and edaravone dexborneol on cerebral ischemic stroke rats

INTRODUCTION

DL-3-n-butylphthalide (NBP) and edaravone dexborneol (Eda-Dex) are two promising reagents for stroke treatment. However, the impacts of NBP and Eda-Dex on poststroke mental deficits are still poorly understood. In this study, we aimed to investigate and compare the influences of NBP and Eda-Dex on neurological function and cognitive behavior in rats with ischemic stroke.

METHODS

An ischemic stroke model was established by middle cerebral artery occlusion (MCAO). After peritoneal administration of the drugs, the rats were subjected to neurological deficit evaluation, cerebral blood flow (CBF) assays, cerebral infarct area evaluations or behavioral tests. Brain tissues were collected and further analyzed by enzyme-linked immunosorbent assay (ELISA), western blotting or immunohistochemistry.

RESULTS

NBP and Eda-Dex significantly decreased the neurological score, reduced the cerebral infarct area and improved CBF. Behavioral changes as assessed in the sucrose preference test, novel object recognition test, and social interaction test were significantly alleviated by NBP and Eda-Dex in rats with ischemic stroke. Moreover, NBP and Eda-Dex significantly suppressed inflammation by targeting the nuclear factor kappa-B/inducible nitric oxide synthase (NF-κB/iNOS) pathway and significantly inhibited oxidative stress by targeting the kelch-1ike ECH-associated protein l/nuclear factor erythroid 2-related factor 2 (Keap1/Nrf2) pathway. In addition, NBP and Eda-Dex distinctly suppressed the activation of microglia and astrocytes and improved neuronal viability in the ischemic brain.

CONCLUSIONS

NBP and Eda-Dex improved neurological function and alleviated cognitive disorders in rats with ischemic stroke by synergistically inhibiting inflammation and oxidative stress.

Management of Cerebral 4-Vessel Disease With Anterior Circulation Symptoms by Stenting Both Vertebral Arteries at the Same Session

PURPOSE

Stroke is among the leading causes of mortality and morbidity worldwide. The coexistence of bilateral carotid and vertebral artery (VA) occlusion and/or stenosis is in the very rare entity group in the literature. Here, we present a case with bilateral carotid artery occlusion and bilateral VA stenosis, who presented with an atypical clinical presentation and underwent bilateral vertebral percutaneous transluminal angioplasty (PTA) and stenting in the same session.

CASE REPORT

A 67 year old male patient was brought to the emergency department with complaints of inability to speak and weakness in both legs for 1 day. There were bilateral infarct areas in the anterior cerebral artery region and an additional infarct area in the left middle cerebral artery region. First, the right VA stenosis level was crossed using a 0.14 guidewire. After PTA, balloon-expandable stenting was performed with a 3.0×12 mm NC (non-compliant) balloon, and nearly complete recanalization was observed. Therefore, it was decided to perform an intervention on the left VA in the same session.

CONCLUSION

As in this example case, in cases where cerebral perfusion is severely impaired, medical treatment after recanalization may be one of the best treatment options.

CLINICAL IMPACT

The carotid arteries are the main arteries supplying the anterior circulation, and the vertebral arteries supply blood to the posterior circulation. However, in cases where both carotid arteries are occluded/dysfunctional, all cerebral perfusion remains over the vertebrobasilar system. However, in cases such as this, where both carotid arteries are occluded/dysfunctional, all cerebral perfusion remains over the vertebrobasilar system and may be responsible for anterior circulation strokes. The situation becomes more severe if both vertebral artery critical stenosis is added. Synchronous carotid and vertebral artery revascularization is not recommended in the guidelines for patients with combined carotid and vertebral artery disease. In patients with four-vessel occlusion/stenosis, as in this particular case, the intervention method and priorities are unclear. We achieved a favorable clinical outcome with simultaneous bilateral vertebral artery angioplasty and stenting, a hazardous method that can be a guide as an approach option in similar cases.

Immunoinflammatory Background of Neuronal Damage in Stroke

Ischemic stroke is caused by a reduction in blood flow to the brain and is a major cause of mortality and disability worldwide [...].

Efficacy of puerarin in rats with focal cerebral ischemia through modulation of the SIRT1/HIF-1α/VEGF signaling pathway and its effect on synaptic plasticity

This study aimed to evaluate the efficacy of puerarin and its effect on synaptic plasticity in rats with focal cerebral ischemia (FCI) by modulating the silent mating type information regulation 2 homolog (SIRT1)/hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway. Fifty specific pathogen-free-grade healthy male rats were randomly divided into sham operation group (SOG), model group, low-dose group, medium-dose group, and high-dose group, with 10 rats in each group. The SOG group received sham operation and saline treatment, while the other four groups received the same amount of saline, 25 mg/kg, 50 mg/kg, and 100 mg/kg of puerarin injection, respectively. After modeling, the rats exhibited higher neurological deficit, inflammation, cerebral infarction rate, and lower forelimb motor function as well as lower protein expressions of SIRT1, HIF-1α, VEGF, synaptophysin (SYN), and postsynaptic density protein (PSD)-95. With the treatment of different doses of puerarin, the degree of neurological impairment, impaired motor function, cerebral infarction rate, and the levels of inflammatory factors (interleukin [IL]-1β, IL-6, and intercellular adhesion molecule 1) in brain tissues were reduced; the protein expressions of SIRT1, HIF-1α, VEGF, SYN, and PSD-95 in brain tissues were enhanced, and the synaptic volume density, numerical density, surface density, width of synaptic cleft, and curvature of the synaptic interface in the cerebral cortex were also improved. Notably, the effects of puerarin on the above-mentioned indicators were dose-dependent. Puerarin can improve neurological impairment and forelimb motor function, reduce inflammatory response, inhibit brain edema, regulate synaptic plasticity, and restore the curvature of synaptic interface in rats with FCI, and its mechanism of action may be related to the activation of SIRT1/HIF-1α/VEGF signaling pathway.

Cardioembolic stroke with hemorrhagic transformation in atrial fibrillation patients on anticoagulant therapy: A case report

Cardioembolic stroke is the second leading cause of mortality and the leading cause of long-term morbidity. Embolisms of cardiac origin, such as atrial fibrillation, represent about one-fifth of all ischemic strokes. Patients with acute atrial fibrillation frequently require anticoagulation, which increases the risk of hemorrhagic transformation. A 67-year-old woman was brought to the Emergency Department with decreased consciousness, weakness on the left side, facial expression, and slurred speech. The patient had a history of atrial fibrillation and was taking regular medications acarbose, warfarin, candesartan and bisoprolol. She has had an ischemic stroke about a year ago. Left hemiparesis, hyperreflexias, pathologic reflexes, and central type of facial nerve palsy were found. The CT-Scan results revealed hyperacute to acute thromboembolic cerebral infraction in the frontotemporoparietal lobe to the right basal ganglia accompanied by hemorrhagic transformation. Massive cerebral infarction, history of previous stroke, and use of anticoagulants are among the greatest risk factors for hemorrhagic transformation in these patients. The use of warfarin should be of particular concern to the clinician, because hemorrhagic transformation is associated with poorer functional outcome and morbidity and mortality.

Exploratory Transcriptomic Profiling Reveals the Role of Gut Microbiota in Vascular Dementia

Stroke is the second most common cause of cognitive impairment and dementia. Vascular dementia (VaD), a cognitive impairment following a stroke, is common and significantly impacts the quality of life. We recently demonstrated via gut microbe transplant studies that the gut microbe-dependent trimethylamine-N-oxide (TMAO) pathway impacts stroke severity, both infarct size and long-term cognitive outcomes. However, the molecular mechanisms that underly the role of the microbiome in VaD have not been explored in depth. To address this issue, we performed a comprehensive RNA-sequencing analysis to identify differentially expressed (DE) genes in the ischemic cerebral cortex of mouse brains at pre-stroke and post-stroke day 1 and day 3. A total of 4016, 3752 and 7861 DE genes were identified at pre-stroke and post-stroke day 1 and day 3, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated pathways of neurodegeneration in multiple diseases, chemokine signaling, calcium signaling, and IL-17 signaling as the key enriched pathways. Inflammatory response genes interleukin-1 beta (Il-1β), chemokines (C-X-C motif chemokine ligand 10 (Cxcl10), chemokine ligand 2 (Ccl2)), and immune system genes (S100 calcium binding protein 8 (S100a8), lipocalin-2 (Lcn2)) were among the most significantly upregulated genes. Hypocretin neuropeptide precursor (Hcrt), a neuropeptide, and transcription factors such as neuronal PAS domain protein 4 (Npas4), GATA binding protein 3 (Gata3), and paired box 7 (Pax7) were among the most significantly downregulated genes. In conclusion, our results indicate that higher plasma TMAO levels induce differential mRNA expression profiles in the ischemic brain tissue in our pre-clinical stroke model, and the predicted pathways provide the molecular basis for regulating the TMAO-enhanced neuroinflammatory response in the brain.

Immunomodulatory role of estrogen in ischemic stroke: neuroinflammation and effect of sex

Although estrogen is predominantly related to the maintenance of reproductive functioning in females, it mediates various physiological effects in nearly all tissues, especially the central nervous system. Clinical trials have revealed that estrogen, especially 17β-estradiol, can attenuate cerebral damage caused by an ischemic stroke. One mechanism underlying this effect of 17β-estradiol is by modulating the responses of immune cells, indicating its utility as a novel therapeutic strategy for ischemic stroke. The present review summarizes the effect of sex on ischemic stroke progression, the role of estrogen as an immunomodulator in immune reactions, and the potential clinical value of estrogen replacement therapy. The data presented here will help better understand the immunomodulatory function of estrogen and may provide a basis for its novel therapeutic use in ischemic stroke.

Qilong capsule alleviates ponatinib-induced ischemic stroke in a zebrafish model by regulating coagulation, inflammation and apoptosis

ETHOPHARMACOLOGICAL RELEVANCE

Qilong capsule (QLC) is a compound traditional Chinese medicine commonly used to treat ischemic stroke (IS). QLC is made of eight kinds of medicinal materials. It has two kinds of monarch medicine and six kinds of minister medicine. However, the pharmacodynamic mechanism of QLC is still unknown.

AIM OF THE STUDY

The aim of this paper was to evaluate the pharmacology mechanism of QLC against ischemic stroke through coagulation, inflammation and apoptosis.

MATERIALS AND METHODS

We used an existing zebrafish model to explore the protective mechanism of QLC on IS. We treated normally-developing zebrafish larvae with QLC and ponatinib 2 days post fertilization (dpf), and used the area of cerebral vascular thrombosis, red blood cell staining intensity, and brain cell apoptosis to quantitate QLC efficacy against IS. Evaluation of brain inflammation in zebrafish by observing macrophage aggregation and migration. In addition, we also explored the effect of QLC on zebrafish angiogenesis. Quantitative polymerase chain reaction (qPCR) was used to detect changes in the expression of genes involved in coagulation, inflammation, vascular endothelium, and apoptosis.

RESULTS

We found that QLC reduced the area affected by ponatinib-induced cerebral vascular embolism, erythrocyte staining intensity, and the number of apoptotic brain cells. For inflammation, QLC can improve the aggregation and migration of macrophages. QLC can significantly promote the formation of blood vessels in zebrafish. qPCR showed that QLC inhibited the expression of genes related to coagulation, inflammation, and apoptosis.

CONCLUSION

Qilong capsule had a significant protective efficacy in ponatinib-induced IS.

Elevated neutrophil-related immune-inflammatory biomarkers in acute anterior choroidal artery territory infarction with early progression

OBJECTIVE

The anterior choroidal artery territory (AChA) infarction has a high rate of progression and poor functional prognosis. The aim of the study is to search for fast and convenient biomarkers to forecast the early progression of acute AChA infarction.

METHODS

We respectively collected 51 acute AChA infarction patients, and compared the laboratorial index between early progressive and non-progressive acute AChA infarction patients. The receiver-operating characteristics curve (ROC) analysis was used to determine the discriminant efficacy of indicators that had statistical significance.

RESULTS

The white blood cell, neutrophil, monocyte, white blood cell to high-density lipoprotein cholesterol ratio, neutrophil to high-density lipoprotein cholesterol ratio (NHR), monocyte to high-density lipoprotein cholesterol ratio, monocyte to lymphocyte ratio, neutrophil to lymphocyte ratio (NLR), and hypersensitive C-reaction protein in acute AChA infarction are significantly higher than healthy controls (P < 0.05). The NHR (P = 0.020) and NLR (P = 0.006) are remarkably higher in acute AChA infarction patients with early progression than non-progression. The area under the ROC curve of NHR, NLR, the combine of NHR and NLR are 0.689 (P = 0.011), 0.723 (P = 0.003), 0.751 (P < 0.001), respectively. But there are no significant differences in efficiency between NHR and NLR and their combined marker in predicting progression (P > 0.05).

CONCLUSION

NHR and NLR may be significant predictors of early progressive patients with acute AChA infarction, and the combination of NHR and NLR could be a preferable prognostic marker for AChA infarction with early progressive course in acute stage.

Intercellular adhesion molecule 4 and ischemic stroke: a two-sample Mendelian randomization study

BACKGROUND

Experimental studies suggested that intercellular adhesion molecule 4 (ICAM-4) might be implicated in ischemic stroke, but the population-based evidence on the relationship between ICAM-4 and ischemic stroke were limited. Herein, we performed a two-sample Mendelian randomization (MR) analysis to investigate the associations of genetically determined plasma ICAM-4 with the risks of ischemic stroke and its subtypes.

METHODS

A total of 11 single-nucleotide polymorphisms associated with ICAM-4 were selected as instrumental variables based on the genome-wide association studies (GWAS) with 3,301 European individuals. Summary-level data about ischemic stroke and its subtypes were obtained from the Multi-ancestry GWAS launched by the International Stroke Genetics Consortium. We used the inverse-variance weighted method followed by a series of sensitivity analyses to evaluate the associations of genetically determined ICAM-4 with the risks of ischemic stroke and its subtypes.

RESULTS

Genetically determined higher ICAM-4 levels were significantly associated with increased risks of ischemic stroke (in the IVW method fitted to multiplicative random effects model: odds ratio [OR] per standard deviation [SD] increase, 1.04; 95% confidence interval [CI], 1.01-1.07; P = 0.006; in the IVW analysis with fixed effects model: OR per SD increase, 1.04; 95% CI, 1.01-1.07; P = 0.003) and cardioembolic stroke (in multiplicative random effects model: OR per SD increase, 1.08; 95% CI, 1.02-1.14; P = 0.004; in fixed effects model: OR per SD increase, 1.08; 95% CI, 1.03-1.13; P = 0.003). There was no association of ICAM-4 with the risks of large artery stroke and small vessel stroke. MR-Egger regression showed no directional pleiotropy for all associations, and the sensitivity analyses with different MR methods further confirmed these findings.

CONCLUSIONS

We found positive associations of genetically determined plasma ICAM-4 with the risks of ischemic stroke and cardioembolic stroke. Future studies are needed to explore the detailed mechanism and investigate the targeting effect of ICAM-4 on ischemic stroke.

Re-Evaluating the Relevance of the Oxygen-Glucose Deprivation Model in Ischemic Stroke: The Example of Cdk Inhibition

Previous research has shown that cyclin-dependent kinases (Cdks) that play physiological roles in cell cycle regulation become activated in post-mitotic neurons after ischemic stroke, resulting in apoptotic neuronal death. In this article, we report our results using the widely used oxygen-glucose deprivation (OGD) in vitro model of ischemic stroke on primary mouse cortical neurons to investigate whether Cdk7, as part of the Cdk-activating kinase (CAK) complex that activates cell cycle Cdks, might be a regulator of ischemic neuronal death and may potentially constitute a therapeutic target for neuroprotection. We found no evidence of neuroprotection with either pharmacological or genetic invalidation of Cdk7. Despite the well-established idea that apoptosis contributes to cell death in the ischemic penumbra, we also found no evidence of apoptosis in the OGD model. This could explain the absence of neuroprotection following Cdk7 invalidation in this model. Neurons exposed to OGD seem predisposed to die in an NMDA receptor-dependent manner that could not be prevented further downstream. Given the direct exposure of neurons to anoxia or severe hypoxia, it is questionable how relevant OGD is for modeling the ischemic penumbra. Due to remaining uncertainties about cell death after OGD, caution is warranted when using this in vitro model to identify new stroke therapies.

The Key Role of Initiation Timing on Stroke Rehabilitation by Remote Ischemic Conditioning with Exercise (RICE)

OBJECTIVE

Physical therapy is an integral part of post-stroke rehabilitation. Remote ischemic conditioning (RIC) induces neuroprotection within 24 hours after stroke, during which exercise is unsafe and ineffective. We combined RIC with exercise to establish a novel rehabilitation strategy, RICE (RIC+Exercise). The aim of this study was to optimize the RICE protocol in neurorehabilitation.

METHODS

Thirty-two adult male Sprague-Dawley rats were placed in one of four groups: stroke with no rehabilitation or stroke with various RICE protocols. To further understand the mechanisms underlying neurorehabilitation, sixteen adult male Sprague-Dawley were added, each placed in one of two groups: stroke with exerciseor RIC  . Long-term functional outcomes were determined by beam balance, rota-rod, grid walk, forelimb placing, and Morris water maze tests up to 28 days after stroke (p < 0.05). Changes in neuroplasticity including synaptogenesis (assessed by measuring synaptophysin, post-synaptic density protein-95, and brain-derived neutrophic factor), angiogenesis (via vascular endothelial growth factor, Angiopoietin-1, and Angiopoietin-2), and regulatory molecules (including hypoxia inducible factor-1α, phospholipase D2 and the mechanistic target of rapamycin pathway), were all measured at both mRNA and protein levels (p < 0.05).

RESULTS

All rehabilitation groups showed significant improvement in functional outcomes and levels of synaptogenesis and angiogenesis. 5 day RICE groups, in which RIC was started five days prior to exercise, demonstrated the greatest improvement among these parameters. The results also suggested that the HIF-1α/PLD2/mTOR signaling pathway may be implicated in post-stroke neuroplasticity.

CONCLUSIONS

RICE, particularly RIC initiation at hour 6 post-reperfusion followed by exercise on day 5, enhanced post-stroke rehabilitation in rats.