Mechanisms of immune response and cell death in ischemic stroke and their regulation by natural compounds

Molecular mechanisms of programmed cell death and potential targeted pharmacotherapy in ischemic stroke (Review)

Stroke poses a threat to the elderly, being the second leading cause of death and the third leading cause of disability worldwide. Ischemic stroke (IS), resulting from arterial occlusion, accounts for ~85% of all strokes. The pathophysiological processes involved in IS are intricate and complex. Currently, tissue plasminogen activator (tPA) is the only Food and Drug Administration‑approved drug for the treatment of IS. However, due to its limited administration window and the risk of symptomatic hemorrhage, tPA is applicable to only ~10% of patients with stroke. Additionally, the reperfusion process associated with thrombolytic therapy can further exacerbate damage to brain tissue. Therefore, a thorough understanding of the molecular mechanisms underlying IS‑induced injury and the identification of potential protective agents is critical for effective IS treatment. Over the past few decades, advances have been made in exploring potential protective drugs for IS. The present review summarizes the specific mechanisms of various forms of programmed cell death (PCD) induced by IS and highlights potential protective drugs targeting different PCD pathways investigated over the last decade. The present review provides a theoretical foundation for basic research and insights for the development of pharmacotherapy for IS.

Exploring neuroprotective effects of PP2 in ischemic stroke via bioinformatics and experimental validation

BACKGROUND

Ischemic stroke is a leading cause of mortality and disability worldwide, yet effective therapeutic options remain limited. In this study, bioinformatics analyses were used to identify potential therapeutic targets and small-molecule compounds for ischemic stroke. A mouse model of cerebral ischemia was subsequently used to validate their neuroprotective efficacy.

METHODS

Bioinformatics methods were used to analyze and identify key signaling pathways and hub genes associated with ischemic stroke. Additionally, the Connectivity Map (CMap) database was queried to identify potential small-molecule compounds for ischemic stroke treatment. Finally, a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was employed to further evaluate the neuroprotective effects of the identified compounds.

RESULTS

GO and KEGG pathway enrichment analyses revealed that key signaling pathways such as TNF, NF-κB, and IL-17 play crucial roles in ischemic stroke. PPI network analysis identified five hub genes-IL-1β, IL-6, ICAM-1, Jun, and Fos-all closely associated with neuroinflammatory responses. The small-molecule compound PP2, a selective Src kinase inhibitor, was identified by CMap database. In the MCAO/R mouse model, PP2 exhibited significant neuroprotective effects. It reduced infarct volume and brain edema and improved neurological function. Mechanistically, PP2 inhibited Src phosphorylation, thereby suppressing the NF-κB signaling pathway and reducing levels of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6.

CONCLUSION

This study identifies Src kinase as a promising therapeutic target for ischemic stroke and highlights the value of bioinformatics in drug discovery and mechanistic research.

Identification immune-related hub genes in diagnosing atherosclerosis with ischemic stroke through comprehensive bioinformatics analysis and machine learning

Background

Atheroma plaques are major etiological factors in the pathogenesis of ischemic stroke (IS). Emerging evidence highlights the critical involvement of the immune microenvironment and dysregulated inflammatory responses throughout IS progression. Consequently, therapeutic strategies targeting specific immune-related markers or signaling pathways within this microenvironment hold significant promise for IS management.

Methods

We integrated Weighted Gene Co-expression Network Analysis (WGCNA), CIBERSORT, and machine learning (LASSO/Random Forest) to identify disease-associated modules and hub genes. Immune infiltration analysis evaluated hub gene-immune cell correlations, while protein-protein interaction (PPI) and ROC curve analyses assessed diagnostic performance.

Results

Comprehensive bioinformatics analysis identified three hub genes-OAS2, TMEM106A, and ABCB1-with high prognostic value for ischemic stroke. Immune infiltration profiling revealed significant correlations between these genes and distinct immune cell populations, underscoring their roles in modulating the immune microenvironment. The diagnostic performance of the gene panel was robust, achieving an area under the curve (AUC) was calculated as 0.9404 (p < 0.0001; 95% CI: 0.887-0.9939) for atherosclerotic plaques, demonstrating superior accuracy compared to conventional biomarkers.

Conclusion

By integrating machine learning with multi-omics bioinformatics, we established a novel three-gene signature (OAS2, TMEM106A, ABCB1) for precise diagnosis of atherosclerosis and ischemic stroke. These genes exhibit dual diagnostic utility and may influence disease progression through immune cell modulation. Our findings provide a foundation for developing targeted therapies and biomarker-driven clinical tools.

Calycosin Inhibit PANoptosis and Alleviate Brain Damage: A Bioinformatics and Experimental Verification Approach

PANoptosis is a newly identified form of cell death that encompasses pyroptosis, apoptosis, and necroptosis. Numerous studies have highlighted the significance of PANoptosis in brain ischemia-reperfusion (I/R) injury. Calycosin, a natural product with diverse biological activities, has demonstrated a significant reduction in neuronal death caused by ischemic brain injury by modulating multiple cell death pathways. In order to investigate the potential mechanisms underlying the neuroprotective role of calycosin in alleviating PANoptosis-induced damage in ischemic stroke therapy, we used mouse hippocampal neuronal cell line HT22 to stimulate ischemia in vitro through Oxygen and Glucose Deprivation/Reperfusion (OGD/R) and established molecular docking to assess the binding affinity of Calycosin with key targets and molecular dynamics simulations (MDS) to study the stability of the ligand-protein complex. The results demonstrate that Calycosin could improve the cell growth of HT22, leading to enhanced cell viability, reduced lactate dehydrogenase leakage, and decreased cell apoptosis after OGD/R. It also regulated the expression of PANoptosis-related genes such as NLRP3, GSDMD, MLKL, and RIPK1 and increased the Bcl-2/Bax ratio, effectively reducing cellular damage and providing protection. Molecular docking and MDS simulations demonstrated strong binding activity and stability between Calycosin and PANoptosis-related targets. Furthermore, Calycosin successfully passed the drug similarity (DS) evaluation and exhibited favorable absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties and biological activity. In conclusion, Calycosin could alleviate ischemic stroke by inhibiting PANoptosis, reducing neuronal inflammation and apoptosis, and improving damage caused by the OGD/R. Thus, it could serve as a potential therapy for ischemic stroke.

Neuroinflammation and energy metabolism: a dual perspective on ischemic stroke

Ischemic stroke is a prevalent form of cerebrovascular accident, with its pathogenesis involving the intricate interplay between neuroinflammation and energy metabolism. Cerebral ischemia disrupts oxygen and energy supply, triggering metabolic dysregulation and activating neuroinflammatory responses, ultimately resulting in cellular damage. This review provides an exhaustive analysis of the complex mechanisms of ischemic stroke, with a particular focus on the interaction between neuroinflammation and energy metabolism. The interruption of oxygen and energy supply due to cerebral ischemia initiates metabolic dysregulation and activates neuroinflammatory responses, including the release of inflammatory cytokines and the activation of immune cells, contributing to cellular damage and further metabolic disturbances. Studies indicate that dysregulation of energy metabolism significantly impairs neural cell function and interacts with neuroinflammation, exacerbating ischemic brain injury. Therapeutic strategies primarily concentrate on modulating energy metabolism and suppressing neuroinflammatory responses, emphasizing the importance of in-depth research into their interaction to provide a theoretical foundation for new treatment strategies for ischemic stroke. Future research should focus on how to balance anti-inflammatory treatment with energy regulation to minimize neural damage and promote recovery.

Association between C-reactive protein-albumin-lymphocyte index and stroke: an NHANES analysis (1999-2010)

Objective

This cross-sectional study is based on the NHANES (1999-2010) database and aims to explore the potential relationship between the CALLY index and stroke in the U.S. population.

Methods

This cross-sectional study utilized data from NHANES (1999-2010), including 17,511 American participants after data cleaning. Laboratory markers related to the CALLY index were obtained through standardized biological sample collection and analysis procedures performed by trained professionals. Stroke status was determined based on self-reported questionnaires. Various statistical methods were employed to examine the association between the CALLY index and stroke, as well as its predictive efficacy for stroke risk, including multivariable logistic regression, subgroup analysis, RCS analysis, and ROC analysis.

Results

Among the 17,511 participants analyzed, our findings revealed a nonlinear L-shaped negative association between the CALLY index and stroke risk. In Model 3, a higher CALLY index was significantly associated with a lower stroke risk (OR: 0.99, 95% CI: 0.98-0.99, p = 0.045). Additionally, participants in the highest quartile (Q4) of the CALLY index had a 25% lower likelihood of stroke compared to those in the lowest quartile (Q1) (OR: 0.75, 95% CI: 0.58-0.97, p = 0.030). Furthermore, ROC analysis demonstrated that the CALLY index had superior predictive performance for stroke risk compared to the SIRI and SII indices.

Conclusion

A reduced CALLY index may be linked to a higher risk of stroke. Furthermore, the CALLY index demonstrates superior predictive performance compared to the SIRI and SII indices. The association between the CALLY index and stroke risk provides valuable insights for future stroke prevention and management strategies.

Overexpressed CD73 attenuates GSDMD-mediated astrocyte pyroptosis induced by cerebral ischemia-reperfusion injury through the A2B/NF-κB pathway

Ischemic stroke, resulting from the blockage or narrowing of cerebral vessels, causes brain tissue damage due to ischemia and hypoxia. Although reperfusion therapy is essential to restore blood flow, it may also result in reperfusion injury, causing secondary damage through mechanisms like oxidative stress, inflammation, and excitotoxicity. These effects significantly impact astrocytes, neurons, and endothelial cells, aggravating brain injury and disrupting the blood-brain barrier. CD73, an ectoenzyme that regulates adenosine production through ATP hydrolysis, plays a critical role in purinergic signaling and neuroprotection. During ischemic stroke, CD73 expression is dynamically regulated in response to ischemia and inflammation. It catalyzes the conversion of AMP to adenosine, which activates adenosine receptors to exert neuroprotective effects. Targeting the CD73-adenosine pathway presents a potential therapeutic strategy for mitigating ischemic stroke damage. Pyroptosis, a highly inflammatory form of programmed cell death mediated by inflammasomes like NLRP3 and caspases, plays a significant role in cerebral ischemia-reperfusion injury. Astrocytes, the most abundant CNS cells, contribute to both neuroprotection and injury, with pyroptosis exacerbating inflammation and brain damage. Regulating astrocyte pyroptosis is a promising therapeutic target. Our study investigates CD73's role in regulating astrocyte pyroptosis during ischemia-reperfusion injury. Using CD73 knockout mice and overexpression models, along with in vitro oxygen-glucose deprivation/reperfusion experiments, we found that CD73 overexpression reduces GSDMD-mediated astrocyte pyroptosis via the A2B/NF-κB pathway. These findings offer a novel approach to reducing neuroinflammation, protecting astrocytes, and improving outcomes in ischemic stroke.

Neuroprotective potential of ApoE-mimetic peptide (ApoEFrag) in stroke models: Neurobehavioural and mechanistic study

Stroke is the second leading cause of death worldwide, and currently, there is no effective neuroprotective agent available for its treatment. Though apolipoprotein E (ApoE) showed potential as a neuroprotective agent for CNS disorders, however, its large size limits its clinical application. To overcome this issue, smaller ApoE-mimetic peptides that mimic the biological functions of ApoE have been developed. In this study, we designed and characterized a novel ApoE-mimetic peptide, ApoEFrag, and explored its neuroprotective potential in experimental stroke models. ApoEFrag was evaluated for its ability to interact with oxidized lipids and lack of self-aggregation potential. In the in vitro cerebral ischemia model, ApoEFrag demonstrated neuroprotection against glutamate-induced neuronal damage in SH-SY5Y cells by maintaining mitochondrial health and reducing reactive oxygen species (ROS) levels. To confirm ApoEFrag's neuroprotective potential, ApoEFrag was investigated in middle cerebral artery occlusion (MCAO) induced ischemic stroke in rats. ApoEFrag administration significantly reduced infarct size, improved neurological function, and lowered mortality. ApoEFrag exhibited anti-inflammatory effects, reduced astrocyte activation and apoptosis, and promoted neurogenesis. Overall, ApoEFrag shows promising neuroprotective effects and could be a potential therapeutic approach for the treatment of stroke.

Untargeted metabolomics unveils critical metabolic signatures in novel phenotypes of acute ischemic stroke

This study aimed to identify metabolic footprints associated with distinct phenotypes of acute ischemic stroke (AIS) using untargeted metabolomics. We included 20 samples each from AIS phenotype A (n = 251), B (n = 213), and C (n = 43) groups, along with 20 age- and gender-matched healthy controls (HCs). Plasma metabolic profiles were analyzed using liquid chromatography-mass spectrometry (LC-MS). Weighted gene correlation network analysis (WGCNA) evaluated associations between metabolite clusters and clinical traits, including the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS). We identified three, five, and six key differential metabolites for diagnosing phenotypes A, B, and C, respectively, demonstrating high diagnostic performance. These metabolites were focused on fatty acids, sex hormones, amino acids, and their derivatives. WGCNA identified 12 core metabolites involved in phenotype progression. Notably, phenylalanylphenylalanine and phenylalanylleucine were inversely correlated with disease severity and disability. Metabolites related to energy supply and inflammation were common across phenotypes, with additional changes in ionic homeostasis in phenotype A and decreased neurotransmitter release in phenotype C. Biosynthesis of unsaturated fatty acids and the pentose phosphate pathway (PPP) were relevant across all phenotypes, while the folate biosynthesis pathway was linked to phenotype C and clinical scales. Key metabolites, including phenylalanylphenylalanine and phenylalanylleucine, and pathways such as folate biosynthesis, significantly contribute to AIS severity and differentiation of phenotypes. These findings offer new insights into the pathogenesis and mechanisms underlying AIS phenotypes.

Immune genes involved in synaptic plasticity during early postnatal brain development contribute to post-stroke damage in the aging male rat brain

Stroke remains a leading cause of mortality and long-term disability worldwide, underscoring the urgent need to identify novel therapeutic targets to enhance brain circuitry repair and functional recovery. This study explores the concept of longevity assurance genes, which primarily function within genetic pathways responsible for repair and maintenance. These pathways encompass molecular and metabolic processes as well as organ- and system-level functions. To investigate this, we employed comparative transcriptomics to analyze gene expression patterns across three age groups with progressively decreasing brain plasticity: native postnatal day seven brains, and young and old naïve and lesioned rat male brains. Analysis revealed a highly symmetrical distribution of upregulated and downregulated genes in postnatal day 7 brains. In contrast, the gene expression profiles of post-stroke brains exhibited significant asymmetry, with a disproportionate increase in upregulated genes compared to downregulated ones in both young and old post-ischemic brains. Gene variance in juvenile brains predominantly reflected processes associated with brain plasticity (e.g., Dcx, Tubb2b, Dok4, Dpysl5) and cell proliferation (e.g., Bex4). Conversely, gene expression variance in young and aged post-stroke brains was largely linked to inflammatory pathways, driven by cytokine and chemokine signaling. Notably, several genes specifically upregulated in aged brains were identified, including Ehd4, Fut7, Lilrb4, Plek, Slfn13, Slc14a1, and Smpdl3a. Immune genes that facilitate synaptic plasticity during early postnatal brain development-through processes such as pruning and sprouting to establish new connections in response to external stimuli-also contribute to post-stroke damage, confirming the concept of antagonistic pleiotropy. Our results suggest that targeting age-related immune responses could be an effective therapeutic strategy for stroke recovery.

NDUFA11 may be the disulfidptosis-related biomarker of ischemic stroke based on integrated bioinformatics, clinical samples, and experimental analyses

Background

Programmed cell death plays an important role in neuronal injury and death after ischemic stroke (IS), leading to cellular glucose deficiency. Glucose deficiency can cause abnormal accumulation of cytotoxic disulfides, resulting in disulfidptosis. Ferroptosis, apoptosis, necroptosis, and autophagy inhibitors cannot inhibit this novel programmed cell death mechanism. Nevertheless, the potential mechanisms of disulfidptosis in IS remain unclear.

Methods

The GSE16561 dataset was used to screen for differentially expressed disulfidptosis-related biomarkers (DE-DRBs). A correlation between the DE-DRBs was detected. The optimal machine-learning (ML) model and predictor molecules were determined. The GSE58294 dataset was used to verify the accuracy of the optimal ML model. The DE-DRB expression was detected in the blood of patients with IS. Based on IS models, experimental analyses were performed to verify DE-DRB expression and the correlation between DE-DRBs.

Results

Leucine-rich pentatricopeptide repeat-containing (LRPPRC) and NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 11 (NDUFA11) were identified as DE-DRBs. The NADH: ubiquinone oxidoreductase core subunit S1 (NDUFS1) interacted with NDUFA11 and LRPPRC. The support vector machine (SVM) model was identified as the optimal ML model. The NDUFA11 expression level in the blood of patients with IS was 20.9% compared to that in normal controls. NDUFA11 expression was downregulated in the in vitro/in vivo models of IS. The number of formed complexes of NDUFS1 and NDUFA11 decreased in the in vitro/in vivo models of IS.

Conclusion

This research suggests that NDUFA11 is a specific DRB for IS and demonstrates alterations in the disulfidptosis-related protein complexes NDUFS1-NDUFA11.

Association between HALP (hemoglobin, albumin, lymphocyte, and platelet) score and poor outcomes in acute ischemic stroke patients with type 2 diabetes mellitus: a study from the Third China National Stroke Registry

Background

The combined index (HALP) of hemoglobin, albumin, lymphocytes, and platelets is considered a novel scoring system that reflects systemic inflammation and nutritional status. This study aimed to investigate the relationship between HALP scores and poor outcomes in acute ischemic stroke (AIS) patients with type 2 diabetes mellitus (DM).

Methods

Patients with AIS and type 2 DM were screened from the Third China National Stroke Registry (CNSR-III) and divided into quartiles based on their HALP scores at admission. Clinical outcomes were adverse functional outcomes (modified Rankin scale [mRS] score of 3-6 or 2-6) and all-cause mortality at 3 months and 1 year. The association of HALP with the risk of poor functional outcome and all-cause mortality were analyzed by multivariable logistic regression and Cox proportional hazards regression.

Results

A total of 3,603 patients were included in this study. After adjusting for confounders, it was found that patients in the highest HALP score quartile had lower mRS scores of 2-6 (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.51-0.80) and 3-6 (OR, 0.53; 95% CI, 0.51-0.82) at the 3-month follow-up. At the 1-year follow-up, a significant correlation was observed between HALP scores and mRS scores of 2-6 (OR, 0.65; 95%CI, 0.57-0.81) and 3-6 (OR, 0.64; 95%CI, 0.47-0.86). Additionally, the highest HALP score quartile was associated with a reduced risk of all-cause mortality at the 3-month follow-up (hazard ratio [HR], 0.35; 95%CI, 0.13-0.93). Similar results were observed at the 1-year follow-up (HR, 0.34; 95%CI, 0.18-0.63).

Conclusion

At 3 months of AIS patients with type 2 diabetes and 1-year follow-up, lower HALP scores were associated with poorer functional outcomes and all-cause mortality.

Therapeutic effects of mirodenafil, a phosphodiesterase 5 inhibitor, on stroke models in rats

Mirodenafil is a phosphodiesterase 5 (PDE5) inhibitor with high specificity for its target and good blood-brain barrier permeability. The drug, which is currently used for treatment of erectile dysfunction, reduces Aβ and pTau levels and improves cognitive function in mouse models of Alzheimer's disease. In the present study, we investigated the effect of mirodenafil in the transient and permanent middle cerebral artery occlusion (tMCAO and pMCAO) models of stroke in rats. Starting 24 ​h after cerebral artery occlusion, mirodenafil was administered subcutaneously at doses of 0.5, 1, and 2 ​mg/kg per day for 9 days in the tMCAO model and for 28 days in the pMCAO model. Mirodenafil significantly increased sensorimotor and cognitive recovery of tMCAO and pMCAO rats compared to saline control rats, and significantly decreased the amount of degenerative cells and cleaved caspase-3 and cleaved PARP immunoreactive cells. Effects were seen in a dose-dependent manner up to 1 ​mg/kg mirodenafil. The benefits of mirodenafil treatment increased with longer treatment duration, and the largest improvements over control were typically observed on the last assessment day. There was no effect of mirodenafil on infarct volume in both tMCAO and pMCAO rats. In an experiment to determine the treatment window for mirodenafil effects, a protective effect was observed when treatment was delayed 72 ​h after MCAO, although the most improvement was observed with shorter treatment windows. Using pMCAO and tMCAO rat models of stroke, we determined that mirodenafil improves the recovery of sensorimotor and cognitive functions after MCAO and protects cortical cells from apoptosis and degeneration. Greater benefit was observed with longer duration of treatment, and improvement was seen even when treatment was delayed.

Inhibition of Pyroptosis by Hydroxychloroquine as a Neuroprotective Strategy in Ischemic Stroke

Hydroxychloroquine (HCQ), a well-known antimalarial and anti-inflammatory drug, has demonstrated potential neuroprotective effects in ischemic stroke by inhibiting pyroptosis, a programmed cell death associated with inflammation. This study investigates the impact of HCQ on ischemic stroke pathology using both in vivo and in vitro models. In vivo, C57BL/6 mice subjected to middle cerebral artery occlusion (MCAO) were treated with HCQ. Neurological deficits, infarct volume, and the expression of pyroptosis markers were evaluated. The results demonstrated that HCQ significantly improved motor function and reduced infarct volume in the MCAO mouse model. In vitro, BV2 microglial cells exposed to lipopolysaccharide (LPS) and oxygen-glucose deprivation (OGD) were treated with HCQ. Western blot and immunofluorescence analyses revealed that HCQ effectively suppressed the expression of pyroptosis markers GSDMD and NLRP3 in both in vivo and in vitro models. These findings suggest that HCQ mitigates ischemic stroke damage by inhibiting pyroptosis, highlighting its potential as a therapeutic agent for ischemic stroke. This study provides novel insights into the molecular mechanisms by which HCQ exerts its neuroprotective effects, offering a promising new avenue for developing safe, cost-effective, and widely applicable stroke treatments. The potential of HCQ to modulate neuroinflammatory pathways presents a significant advancement in ischemic stroke therapy, emphasizing the importance of targeting pyroptosis in stroke management and the broader implications for treating neuroinflammatory conditions.Significance Statement Ischemic stroke remains a leading cause of disability and death globally, with limited effective treatments. This study reveals that HCQ significantly mitigates ischemic stroke damage by inhibiting pyroptosis, a form of programmed cell death. Using in vivo and in vitro models, HCQ was shown to improve motor function and reduce infarct volume, highlighting its potential as a neuroprotective agent. These findings offer a promising new therapeutic approach for ischemic stroke, emphasizing the importance of targeting pyroptosis in stroke treatment.

Interplay of cell death pathways and immune responses in ischemic stroke: insights into novel biomarkers

Stroke is a severe neurological disease and a major worldwide issue, mostly manifesting as ischemic stroke (IS). In order to create effective treatments for IS, it is imperative to fully understand the underlying pathologies, as the existing therapeutic choices are inadequate. Recent investigations have shown the complex relationships between several programmed cell death (PCD) pathways, including necroptosis, ferroptosis, and pyroptosis, and their correlation with immune responses during IS. However, this relationship is still unclear. To address this gap, this review study explored the cellular interactions in the immune microenvironment of IS. Then, to validate prior findings and uncover biomarkers, the study investigated bioinformatics studies. Several pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), Toll-like receptor 4 (TLR4), and receptor-interacting protein kinase (RIPK), were involved in PCD-immune interactions. The bioinformatics studies reported key biomarkers such as glutathione peroxidase 4 (GPX4), NOD-like receptor family pyrin domain containing 3 (NLRP3), gasdermin D (GSDMD), and TLR4, which have important implications in ferroptosis, cuproptosis, pyroptosis, and necroptosis respectively. These biomarkers were associated with PCD mechanisms such as oxidative stress and inflammatory reactions. The immune infiltration analysis consistently revealed a significant correlation between PCD pathways and detrimental immune cells, such as neutrophils and γδ T cells. Conversely, M2 macrophages and T helper cells showed protective effects. In conclusion, considering the intricate network of interactions between immune responses and PCD pathways, this study emphasized the necessity of a paradigm shift in therapeutic approaches to address the injuries that are related to this complex network.

A potential role of gut microbiota in stroke: mechanisms, therapeutic strategies and future prospective

RATIONALE

Neurological conditions like Stroke and Alzheimer's disease (AD) often include inflammatory responses in the nervous system. Stroke, linked to high disability and mortality rates, poses challenges related to organ-related complications. Recent focus on understanding the pathophysiology of ischemic stroke includes aspects like cellular excitotoxicity, oxidative stress, cell death mechanisms, and neuroinflammation.

OBJECTIVE

The objective of this paper is to summarize and explore the pathophysiology of ischemic stroke, elucidates the gut-brain axis mechanism, and discusses recent clinical trials, shedding light on novel treatments and future possibilities.

RESULTS

Changes in gut architecture and microbiota contribute to dementia by enhancing intestinal permeability, activating the immune system, elevating proinflammatory mediators, altering blood-brain barrier (BBB) permeability, and ultimately leading to neurodegenerative diseases (NDDs). The gut-brain axis's potential role in disease pathophysiology offers new avenues for cell-based regenerative medicine in treating neurological conditions.

CONCLUSION

In conclusion, the gut microbiome significantly impacts stroke prognosis by highlighting the role of the gut-brain axis in ischemic stroke mechanisms. This insight suggests potential therapeutic strategies for improving outcomes.

M1 Microglia-Derived Exosomes Promote A1 Astrocyte Activation and Aggravate Ischemic Injury via circSTRN3/miR-331-5p/MAVS/NF-κB Pathway

Background

After ischemic stroke (IS), microglia and astrocytes undergo polarization, transforming into a pro-inflammatory phenotype (M1 or A1). According to previous studies, exosomes might play an important role in the interplay between M1 microglia and A1 astrocytes after IS.

Methods

We used the microglial oxygen-glucose deprivation/reperfusion (OGD/R) model and ultracentrifugation to extract M1 microglial exosomes (M1-exos). Subsequently, we identified circSTRN3 enriched in exosomes through RNA sequencing and detected the role of circSTRN3 in astrocyte activation based on bioinformatics analysis, immunofluorescence, Western blotting, and polymerase chain reaction analysis. We validated these findings in the middle cerebral artery occlusion/reperfusion (MCAO/R) model of adult male C57BL/6J mice. Finally, we confirmed the correlation among circSTRN3, miR-331-5p, and stroke severity score in exosomes isolated from peripheral blood of IS patients.

Results

Our findings revealed that M1-exos promoted A1 astrocyte activation. CircSTRN3 was abundant in M1-exos, which could sponge miR-331-5p to affect mitochondrial antiviral signaling protein (MAVS), activate NF-κB pathway, and participate in A1 astrocyte activation. In addition, overexpressed circSTRN3 augmented the infarct size and neurological dysfunction in MCAO/R models, while miR-331-5p mimics reversed the effect. Furthermore, circSTRN3 in IS patients was positively correlated with stroke severity score (R 2 = 0.83, P < 0.001), while miR-331-5p demonstrated a negative correlation with the same score (R 2 = 0.81, P < 0.001).

Conclusion

Taken together, our research indicated that circSTRN3 from M1-exos could promote A1 astrocyte activation and exacerbate ischemic brain injury via miR331-5p/MAVS/NF-κB axis.

DL-3-n-Butylphthalide Ameliorates Post-stroke Emotional Disorders by Suppressing Neuroinflammation and PANoptosis

Post-stroke emotional disorders such as post-stroke anxiety and post-stroke depression are typical symptoms in patients with stroke. They are closely associated with poor prognosis and low quality of life. The State Food and Drug Administration of China has approved DL-3-n-butylphthalide (NBP) as a treatment for ischemic stroke (IS). Clinical research has shown that NBP alleviates anxiety and depressive symptoms in patients with IS. Therefore, this study explored the role and molecular mechanisms of NBP in cases of post-stroke emotional disorders using network pharmacology and experimental validation. The results showed that NBP treatment significantly increased the percentage of time spent in the center of the middle cerebral artery occlusion (MCAO) rats in the open field test and the percentage of sucrose consumption in the sucrose preference test. Network pharmacology results suggest that NBP may regulate neuroinflammation and cell death. Further experiments revealed that NBP inhibited the toll-like receptor 4/nuclear factor kappa B signaling pathway, decreased the level of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and interleukin-6, and M1-type microglia markers (CD68, inducible nitric oxide synthase), and reduced the expression of PANoptosis-related molecules including caspase-1, caspase-3, caspase-8, gasdermin D, and mixed lineage kinase domain-like protein in the hippocampus of the MACO rats. These findings demonstrate that the mechanisms through which NBP ameliorates post-stroke emotional disorders in rats are associated with inhibiting neuroinflammation and PANoptosis, providing a new strategy and experimental basis for treating post-stroke emotional disorders.

The interplay between cytokines and stroke: a bi-directional Mendelian randomization study

Stroke, the second leading cause of death and disability, causes massive cell death in the brain followed by secondary inflammatory injury initiated by disease associated molecular patterns released from dead cells. Nonetheless, the evidence regarding the causal relationship between inflammatory cytokines and stroke subtypes is obscure. To leverage large scale genetic association data to investigate the interplay between circulating cytokines and stroke, we adopted a two-sample bi-directional Mendelian randomization (MR) analysis. Firstly, we performed a forward MR analysis to examine the associations of genetically determined 31 cytokines with 6 stroke subtypes. Secondly, we conducted a reverse MR analysis to check the associations of 6 stroke subtypes with 31 cytokines. In the forward MR analysis, genetic evidence suggests that 21 cytokines were significantly associated with certain stroke subtype risk with |β| ranging from 1.90 × 10-4 to 0.74. In the reverse MR analysis, our results found that five stroke subtypes (intracerebral hemorrhage (ICH), large artery atherosclerosis ischemic stroke (LAAS), lacunar stroke (LS), cardioembolic ischemic stroke (CEI), small-vessel ischemic stroke (SV)) caused significantly changes in 16 cytokines with |β| ranging from 1.08 × 10-4 to 0.69. In particular, those five stroke subtypes were statistically significantly associated with C-reactive protein (CRP). In addition, ICH, LAAS, LS and SV were significantly correlated with vascular endothelial growth factor (VEGF), while LAAS, LS, CEI and SV were significantly related to fibroblast growth factor (FGF). Moreover, integrated bi-directional MR analysis, these factors (IL-3Rα, IL-6R, IL-6Rα, IL-1Ra, insulin-like growth factor-1(IGF-1), IL-12Rβ2) can be used as predictors of some specific stroke subtypes. As well as, IL-16 and C-C motif chemokine receptor 7 (CCR7) can be used as prognostic factors of stroke. Our findings prognostic identify potential pharmacological opportunities, including perturbation of circulating cytokines for both predicting stroke risk and post stroke treatment effects. As we conducted a comprehensive search and analysis of stroke subtype and cytokines in the existing publicly available GWAS database, the results have good population-generalizability.

Potential diagnostic biomarkers for immunogenic cell death in elderly female patients with ischemic stroke: identification and analysis

Ischemic stroke (IS) is of increasing concern given the aging population and prevalence of unhealthy lifestyles, with older females exhibiting higher susceptibility. This study aimed to identify practical diagnostic markers, develop a diagnostic model for immunogenic cell death (ICD)-associated IS, and investigate alterations in the immune environment caused by hub genes. Differentially expressed genes associated with ICD in IS were identified based on weighted gene co-expression network analysis and the identification of significant modules. Subsequently, machine learning algorithms were employed to screened hub genes, which were further assessed using Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis. A nomogram mode lwas then constructed for IS diagnosis, and its diagnostic value was assessed using a receiver operating characteristic curve. Finally, alterations in immune cell infiltration were assessed within patients with IS, and the pan-cancer expression patterns of hub genes were evaluated. Three hub genes associated with ICD (PDK4, CCL20, and FBL) were identified. The corresponding nomogram model for IS diagnosis could effectively identify older female patients with IS (area under the curve (AUC) = 0.9555). Overall, the three hub genes exhibit good diagnostic value (AUC > 0.8). CCL20 and FBL are significantly associated with the extent of immune cells infiltration. Moreover, a strong link exists between hub gene expression and pan-cancer prognosis. Cumulatively, these results indicate that ICD-related hub genes critically influence IS progression in older females, presenting novel diagnostic and therapeutic targets for personalized treatment.

MiR-122 overexpression alleviates oxygen-glucose deprivation-induced neuronal injury by targeting sPLA2-IIA

Background

Ischemic stroke (IS) is a neurological disease with significant disability and mortality. MicroRNAs were proven to be associated with cerebral ischemia. Previous studies have demonstrated miR-122 downregulation in both animal models of IS and the blood of IS patients. Nonetheless, the role and mechanism of miR-122-5p in IS remain unclear.

Methods

We established primary human and mouse astrocytes, along with HT22 mouse hippocampal neuronal cells, through oxygen-glucose deprivation/reoxygenation (OGD/R) treatment. To assess the impact of miR-122, we employed CCK8 assays, flow cytometry, RT-qPCR, western blotting, and ELISA to evaluate cell viability, apoptosis, reactive oxygen species (ROS) generation, and cytokine expression. A dual-luciferase reporter gene assay was employed to investigate the interaction between miR-122 and sPLA2-IIA.

Results

Overexpression of miR-122 resulted in decreased apoptosis, reduced cleaved caspase-3 expression, and increased cell viability in astrocytes and HT22 cells subjected to OGD/R. RT-qPCR and ELISA analyses demonstrated a decrease in mRNA and cytokine levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in both astrocytes and HT22 cells following miR-122 overexpression. Moreover, miR-122 overexpression reversed OGD/R-induced ROS levels and 8-OHdG formation in astrocytes. Additionally, miR-122 overexpression decreased the mRNA and protein expression of inducible nitric oxide synthase (iNOS). Furthermore, we found that miR-122 attaches to the 3'-UTR of sPLA2-IIA, thereby downregulate its expression.

Conclusion

Our study demonstrates that miR-122-mediated inhibition of sPLA2-IIA attenuates OGD/R-induced neuronal injury by suppressing apoptosis, alleviating post-ischemic inflammation, and reducing ROS production. Thus, the miR-122/sPLA2-IIA axis may represent a promising target for IS treatment.

Advanced Nano-Drug Delivery Systems in the Treatment of Ischemic Stroke

In recent years, the frequency of strokes has been on the rise year by year and has become the second leading cause of death around the world, which is characterized by a high mortality rate, high recurrence rate, and high disability rate. Ischemic strokes account for a large percentage of strokes. A reperfusion injury in ischemic strokes is a complex cascade of oxidative stress, neuroinflammation, immune infiltration, and mitochondrial damage. Conventional treatments are ineffective, and the presence of the blood-brain barrier (BBB) leads to inefficient drug delivery utilization, so researchers are turning their attention to nano-drug delivery systems. Functionalized nano-drug delivery systems have been widely studied and applied to the study of cerebral ischemic diseases due to their favorable biocompatibility, high efficiency, strong specificity, and specific targeting ability. In this paper, we briefly describe the pathological process of reperfusion injuries in strokes and focus on the therapeutic research progress of nano-drug delivery systems in ischemic strokes, aiming to provide certain references to understand the progress of research on nano-drug delivery systems (NDDSs).