Inflammatory mechanisms in ischemic stroke: therapeutic approaches

Investigating the therapeutic effects of nimodipine on vasogenic cerebral edema and blood-brain barrier impairment in an ischemic stroke rat model

Vasogenic brain edema, a potentially life-threatening consequence following an acute ischemic stroke, is a major clinical problem. This research aims to explore the therapeutic benefits of nimodipine, a calcium channel blocker, in mitigating vasogenic cerebral edema and preserving blood-brain barrier (BBB) function in an ischemic stroke rat model. In this research, animals underwent the induction of ischemic stroke via a 60-min blockage of the middle cerebral artery and treated with a nonhypotensive dose of nimodipine (1 mg/kg/day) for a duration of five days. The wet/dry method was employed to identify cerebral edema, and the Evans blue dye extravasation technique was used to assess the permeability of the BBB. Furthermore, immunofluorescence staining was utilized to assess the protein expression levels of matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1). The study also examined mitochondrial function by evaluating mitochondrial swelling, succinate dehydrogenase (SDH) activity, the collapse of mitochondrial membrane potential (MMP), and the generation of reactive oxygen species (ROS). Post-stroke administration of nimodipine led to a significant decrease in cerebral edema and maintained the integrity of the BBB. The protective effects observed were associated with a reduction in cell apoptosis as well as decreased expression of MMP-9 and ICAM-1. Furthermore, nimodipine was observed to reduce mitochondrial swelling and ROS levels while simultaneously restoring MMP and SDH activity. These results suggest that nimodipine may reduce cerebral edema and BBB breakdown caused by ischemia/reperfusion. This effect is potentially mediated through the reduction of MMP-9 and ICAM-1 levels and the enhancement of mitochondrial function.

The gut-immune axis during hypertension and cardiovascular diseases

The gut-immune axis is a relatively novel phenomenon that provides mechanistic links between the gut microbiome and the immune system. A growing body of evidence supports it is key in how the gut microbiome contributes to several diseases, including hypertension and cardiovascular diseases (CVDs). Evidence over the past decade supports a causal link of the gut microbiome in hypertension and its complications, including myocardial infarction, atherosclerosis, heart failure, and stroke. Perturbations in gut homeostasis such as dysbiosis (i.e., alterations in gut microbial composition) may trigger immune responses that lead to chronic low-grade inflammation and, ultimately, the development and progression of these conditions. This is unsurprising, as the gut harbors one of the largest numbers of immune cells in the body, yet is a phenomenon not entirely understood in the context of cardiometabolic disorders. In this review, we discuss the role of the gut microbiome, the immune system, and inflammation in the context of hypertension and CVD, and consolidate current evidence of this complex interplay, whilst highlighting gaps in the literature. We focus on diet as one of the major modulators of the gut microbiota, and explain key microbial-derived metabolites (e.g., short-chain fatty acids, trimethylamine N-oxide) as potential mediators of the communication between the gut and peripheral organs such as the heart, arteries, kidneys, and the brain via the immune system. Finally, we explore the dual role of both the gut microbiome and the immune system, and how they work together to not only contribute, but also mitigate hypertension and CVD.

Exploring the therapeutic efficacy and pharmacological mechanism of Guizhi Fuling Pill on ischemic stroke: a meta-analysis and network pharmacology analysis

The role of Guizhi Fuling Pill (GZFL) in the treatment of ischemic stroke (IS) is still controversial, and its pharmacological mechanism remains unclear. To evaluate the efficacy and potential pharmacological mechanisms of GZFL on IS, a comprehensive method integrating meta-analysis, network pharmacology, and molecular docking was employed. Eight electronic databases were searched from inception to November 2023. Review Manager 5.4.1 software was used for meta-analysis. Active compounds and targets of GZFL were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database, Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine, and Encyclopaedia of Traditional Chinese Medicine. Relevant targets of IS were obtained from the DisGeNet, Genecards, and DrugBank databases. GO biological function analysis and KEGG enrichment analysis were performed in the Metascape database. AutoDock Tools and PyMOL software were employed for Molecular docking. The intervention group significantly increased the total effective rate and decreased the NIHSS score. Administration of GZFL also improved the whole blood viscosity (low and high shear rates) and levels of fibrinogen, TNF-α, and IL-6. The key active compounds included quercetin, kaempferol, catechin, and beta-sitosterol, and the core target proteins included SRC, MAPK1, TP53, JUN, RELA, AKT1, and TNF. GO analysis mainly involved inflammation response, cellular response to lipids, and regulation of ion transport. The core pathways were lipid and atherosclerosis, cAMP, calcium, IL-17, and MAPK signaling pathways. Key active compounds showed good affinity with the core targets. The underlying mechanisms of GZFL in IS treatment are primarily related to its anti-inflammatory, anti-atherosclerosis, and neuroprotective effects.

Recent advances in anti-inflammation via AMPK activation

Inflammation is a complex physiological phenomenon, which is the body's defensive response, but abnormal inflammation can have adverse effects, and many diseases are related to the inflammatory response. AMPK, as a key sensor of cellular energy status, plays a crucial role in regulating cellular energy homeostasis and glycolipid metabolism. In recent years, the anti-inflammation effect of AMPK and related signalling cascade has begun to enter everyone's field of vision - not least the impact on metabolic diseases. A great number of studies have shown that anti-inflammatory drugs work through AMPK and related pathways. Herein, this article summarises recent advances in compounds that show anti-inflammatory effects by activating AMPK and attempts to comment on them.

Beam narrowing test: a motor index of post-stroke motor evaluation in an aged rat model of cerebral ischemia

Each year, 15 million people worldwide suffer from strokes. Consequently, researchers face increasing pressure to develop reliable behavioural tests for assessing functional recovery after a stroke. Our aim was to establish a new motor performance index that can be used to evaluate post-stroke recovery in both young and aged animals. Furthermore, we validate the proposed procedure and recommend the necessary number of animals for experimental stroke studies. Young (n = 20) and aged (n = 27) Sprague-Dawley rats were randomly assigned to receive either sham or stroke surgery. The newly proposed performance index was calculated for the post-stroke acute, subacute and chronic phases. The advantage of using our test over current tests lies in the fact that the newly proposed motor index test evaluates not only the performance of the unaffected side in comparison to the affected one but also assesses overall performance by taking into account speed and coordination. Moreover, it reduces the number of animals needed to achieve a statistical power of 80%. This aspect is particularly crucial when studying aged rodents. Our approach can be used to monitor and assess the effectiveness of stroke therapies in experimental models using aged animals.

Hemorrhagic Shock and Resuscitation Causes Excessive Dopaminergic Signaling in the mPFC and Cognitive Dysfunction

Peri-operative hemorrhagic shock and resuscitation (HSR), a severe traumatic stress, is closely associated with post-operative anxiety, depression, and cognitive dysfunction, subsequently causing a serious burden on families and society. Following the co-release of corticotropin-releasing factor and catecholamine, traumatic stress activates dopaminergic neurons, increasing the addictive behavior and neurocognitive impairment risks. This study investigates the association between cognitive dysfunction and dopaminergic neurons in the mPFC under HSR conditions. This study established an HSR model by bleeding and re-transfusion in the mice. After HSR exposure, a dopamine D1 receptor antagonist, SKF-83566, was administered intraperitoneally for three consecutive days. Novel object recognition (NOR), conditioned fearing (FC), and conditioned place preference (CPP) were used to assess cognitive changes 16 days after HSR exposure. Local field potential (LFP) in the mPFC was also investigated during the novel object exploration. Compared with the mice exposed to sham, there was a significant decrease in the object recognition index, a reduction in context- and tone-related freezing time, an increase in CPP values, a downregulation of β-power but upregulation of γ-power in the mPFC in the mice exposed to HSR. Moreover, the mice exposed to HSR showed significantly upregulated TH-positive cell number, cleaved caspase-1- and TH-positive cells, and interleukin (IL)-1β/18 expression in the mPFC compared with sham; SKF-83566 could partially reverse these alternations. The HSR caused excessive dopaminergic signaling and cognitive dysfunction in the mPFC, a condition that might be ameliorated using a dopamine D1 receptor inhibitor.

Potential of CBD Acting on Cannabinoid Receptors CB1 and CB2 in Ischemic Stroke

Stroke is one of the leading causes of death. It not only affects adult people but also many children. It is estimated that, every year, 15 million people suffer a stroke worldwide. Among them, 5 million people die, while 5 million people are left permanently disabled. In this sense, the research to find new treatments should be accompanied with new therapies to combat neuronal death and to avoid developing cognitive impairment and dementia. Phytocannabinoids are among the compounds that have been used by mankind for the longest period of history. Their beneficial effects such as pain regulation or neuroprotection are widely known and make them possible therapeutic agents with high potential. These compounds bind cannabinoid receptors CB1 and CB2. Unfortunately, the psychoactive side effect has displaced them in the vast majority of areas. Thus, progress in the research and development of new compounds that show efficiency as neuroprotectors without this psychoactive effect is essential. On the one hand, these compounds could selectively bind the CB2 receptor that does not show psychoactive effects and, in glia, has opened new avenues in this field of research, shedding new light on the use of cannabinoid receptors as therapeutic targets to combat neurodegenerative diseases such as Alzheimer's, Parkinson's disease, or stroke. On the other hand, a new possibility lies in the formation of heteromers containing cannabinoid receptors. Heteromers are new functional units that show new properties compared to the individual protomers. Thus, they represent a new possibility that may offer the beneficial effects of cannabinoids devoid of the unwanted psychoactive effect. Nowadays, the approval of a mixture of CBD (cannabidiol) and Δ9-THC (tetrahydrocannabinol) to treat the neuropathic pain and spasticity in multiple sclerosis or purified cannabidiol to combat pediatric epilepsy have opened new therapeutic possibilities in the field of cannabinoids and returned these compounds to the front line of research to treat pathologies as relevant as stroke.

Role of Brain Derived Neurotrophic Factor and Related Therapeutic Strategies in Central Post-Stroke Pain

Brain-derived neurotrophic factor (BDNF) is vital for synaptic plasticity, cell persistence, and neuronal development in peripheral and central nervous systems (CNS). Numerous intracellular signalling pathways involving BDNF are well recognized to affect neurogenesis, synaptic function, cell viability, and cognitive function, which in turn affects pathological and physiological aspects of neurons. Stroke has a significant psycho-socioeconomic impact globally. Central post-stroke pain (CPSP), also known as a type of chronic neuropathic pain, is caused by injury to the CNS following a stroke, specifically damage to the somatosensory system. BDNF regulates a broad range of functions directly or via its biologically active isoforms, regulating multiple signalling pathways through interactions with different types of receptors. BDNF has been shown to play a major role in facilitating neuroplasticity during post-stroke recovery and a pro-nociceptive role in pain development in the nervous system. BDNF-tyrosine kinase receptors B (TrkB) pathway promotes neurite outgrowth, neurogenesis, and the prevention of apoptosis, which helps in stroke recovery. Meanwhile, BDNF overexpression plays a role in CPSP via the activation of purinergic receptors P2X4R and P2X7R. The neuronal hyperexcitability that causes CPSP is linked with BDNF-TrkB interactions, changes in ion channels and inflammatory reactions. This review provides an overview of BDNF synthesis, interactions with certain receptors, and potential functions in regulating signalling pathways associated with stroke and CPSP. The pathophysiological mechanisms underlying CPSP, the role of BDNF in CPSP, and the challenges and current treatment strategies targeting BDNF are also discussed.

Ischemic stroke and diabetes: a TLR4-mediated neuroinflammatory perspective

Ischemic stroke is the major contributor to morbidity and mortality in people with diabetes mellitus. In ischemic stroke patients, neuroinflammation is now understood to be one of the main underlying mechanisms for cerebral damage and recovery delay. It has been well-established that toll-like receptor 4 (TLR4) signaling pathway plays a key role in neuroinflammation. Emerging research over the last decade has revealed that, compared to ischemic stroke without diabetes mellitus, ischemic stroke with diabetes mellitus significantly upregulates TLR4-mediated neuroinflammation, increasing the risk of cerebral and neuronal damage as well as neurofunctional recovery delay. This review aims to discuss how ischemic stroke with diabetes mellitus amplifies TLR4-mediated neuroinflammation and its consequences. Additionally covered in this review is the potential application of TLR4 antagonists in the management of diabetic ischemic stroke.

Neuroinflammation: A Critical Factor in Neurodegenerative Disorders

This review offers a comprehensive review of the signals and the paramount role neuroinflammation plays in neurodegenerative diseases such as Alzheimer's, Parkinson's, Huntington's, and amyotrophic lateral sclerosis. The study explores the sophisticated interactions between microglial, astrocytic, and dendritic cells and how neuroinflammation affects long-term neuronal damage and dysfunction. There are specific pathways related to the mentioned inflammatory processes, including Janus kinases/signal transducer and activator of transcriptions, nuclear factor-κB, and mitogen-activated protein kinases pathways. Neuroinflammation is argued to be a double-edged sword, being not only a protective agent that prevents further neuron damage but also the causative factor in more cell injury development. This concept of contrasting inflammation with neuroprotection advocates for the use of therapeutic techniques that seek to modulate neuroinflammatory responses as part of the neurodegeneration treatment. The recent research findings are integrated with the established knowledge to help present a comprehensive image of neuroinflammation's impact on neurodegenerative diseases and its implications for future therapy.

Bioactivities of morroniside: A comprehensive review of pharmacological properties and molecular mechanisms

Morroniside (MOR) is an iridoid glycoside and the main active principle of the medicinal plant, Cornus officinalis Sieb. This phytochemical is associated with numerous health benefits due to its antioxidant properties. The primary objective of the present study was to assess the pharmacological effects and underlying mechanisms of MOR, utilizing published data obtained from literature databases. Data collection involved accessing various sources, including PubMed/Medline, Scopus, Science Direct, Google Scholar, Web of Science, and SpringerLink. Our findings demonstrate that MOR can be utilized for the treatment of several diseases and disorders, as numerous studies have revealed its significant therapeutic activities. These activities encompass anti-inflammatory, antidiabetic, lipid-lowering capability, anticancer, trichogenic, hepatoprotective, gastroprotective, osteoprotective, renoprotective, and cardioprotective effects. MOR has also shown promising benefits against various neurological ailments, including Alzheimer's disease, Parkinson's disease, spinal cord injury, cerebral ischemia, and neuropathic pain. Considering these therapeutic features, MOR holds promise as a lead compound for the treatment of various ailments and disorders. However, further comprehensive preclinical and clinical trials are required to establish MOR as an effective and reliable therapeutic agent.

Dynamically changed HSP70 after reperfusion following cerebral infarction in human and rats: correlation with p38 MAPK

We aimed to clarify the correlation between dynamic change of blood HSP70 and the prognosis of thrombolysis in human and rats, so as to explain the neuroprotection and early warning role of HSP70 in cerebral ischemia-reperfusion. Forty-two patients with acute ischemic stroke were divided into two groups according to the time from onset to thrombolytic therapy: 0 h-3 h (27 patients) and 3-4.5 h group (15 patients). The level of HSP70 in serum before and after thrombolysis was detected by ELISA. Furthermore, a rat model was also used to mimic the ischemic stroke and reperfusion. Peripheral blood of rat samples was collected to detect the level of HSP70 using Elisa. Several signal proteins from MAPK signaling pathway including JNK, p38, ERK (p42/44) were detected at different time points by Western blot of brain tissue. Patients who underwent thrombolytic therapy within 0-3 h had the highest HSP70 level at 1 h after thrombolysis. The higher HSP70 after thrombolysis, the better the patient prognosis. NIHSS scores showed HSP70 was positively correlated with cerebral ischemia. The levels of ERK family (p42/44 MAPK) and p-JNK were decreased gradually along with the time suffering cerebral ischemia. P-ERK, JNK, p-p38 had dynamic changes with increased ischemic time in the middle cerebral artery occlusion model. Dynamic change of HSP70 level in blood may be a biological index that reflects the functional condition of cell survival for cerebral ischemia and estimating the prognostic conditions. Importantly, HSP70 levels in blood were positively correlated with the p38 MAPK pathway in brain tissue.

Transcriptome Analysis Reveals Dynamic Microglial-Induced A1 Astrocyte Reactivity via C3/C3aR/NF-κB Signaling After Ischemic Stroke

Microglia and astrocytes are key players in neuroinflammation and ischemic stroke. A1 astrocytes are a subtype of astrocytes that are extremely neurotoxic and quickly kill neurons. Although the detrimental A1 astrocytes are present in many neurodegenerative diseases and are considered to accelerate neurodegeneration, their role in the pathophysiology of ischemic stroke is poorly understood. Here, we combined RNA-seq, molecular and immunological techniques, and behavioral tests to investigate the role of A1 astrocytes in the pathophysiology of ischemic stroke. We found that astrocyte phenotypes change from a beneficial A2 type in the acute phase to a detrimental A1 type in the chronic phase following ischemic stroke. The activated microglial IL1α, TNF, and C1q prompt commitment of A1 astrocytes. Inhibition of A1 astrocytes induction attenuates reactive gliosis and ameliorates morphological and functional defects following ischemic stroke. The crosstalk between astrocytic C3 and microglial C3aR contributes to the formation of A1 astrocytes and morphological and functional defects. In addition, NF-κB is activated following ischemic stroke and governs the formation of A1 astrocytes via direct targeting of inflammatory cytokines and chemokines. Taken together, we discovered that A2 astrocytes and A1 astrocytes are enriched in the acute and chronic phases of ischemic stroke respectively, and that the C3/C3aR/NF-κB signaling leads to A1 astrocytes induction. Therefore, the C3/C3aR/NF-κB signaling is a novel therapeutic target for ischemic stroke treatment.

Targeting lipid nanoparticles to the blood-brain barrier to ameliorate acute ischemic stroke

Effective delivery of mRNA or small molecule drugs to the brain is a significant challenge in developing treatment for acute ischemic stroke (AIS). To address the problem, we have developed targeted nanomedicine to increase drug concentrations in endothelial cells of the blood-brain barrier (BBB) of the injured brain. Inflammation during ischemic stroke causes continuous neuronal death and an increase in the infarct volume. To enable targeted delivery to the inflamed BBB, we conjugated lipid nanocarriers (NCs) with antibodies that bind cell adhesion molecules expressed at the BBB. In the transient middle cerebral artery occlusion mouse model, NCs targeted to vascular cellular adhesion molecule-1 (VCAM) achieved the highest level of brain delivery, nearly two orders of magnitude higher than untargeted ones. VCAM-targeted lipid nanoparticles with luciferase-encoding mRNA and Cre-recombinase showed selective expression in the ischemic brain. Anti-inflammatory drugs administered intravenously after ischemic stroke reduced cerebral infarct volume by 62% (interleukin-10 mRNA) or 35% (dexamethasone) only when they were encapsulated in VCAM-targeted NCs. Thus, VCAM-targeted lipid NCs represent a new platform for strongly concentrating drugs within the compromised BBB of penumbra, thereby ameliorating AIS.

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).

Rhoa/ROCK, mTOR and Secretome-Based Treatments for Ischemic Stroke: New Perspectives

Ischemic stroke triggers a complex cascade of cellular and molecular events leading to neuronal damage and tissue injury. This review explores the potential therapeutic avenues targeting cellular signaling pathways implicated in stroke pathophysiology. Specifically, it focuses on the articles that highlight the roles of RhoA/ROCK and mTOR signaling pathways in ischemic brain injury and their therapeutic implications. The RhoA/ROCK pathway modulates various cellular processes, including cytoskeletal dynamics and inflammation, while mTOR signaling regulates cell growth, proliferation, and autophagy. Preclinical studies have demonstrated the neuroprotective effects of targeting these pathways in stroke models, offering insights into potential treatment strategies. However, challenges such as off-target effects and the need for tissue-specific targeting remain. Furthermore, emerging evidence suggests the therapeutic potential of MSC secretome in stroke treatment, highlighting the importance of exploring alternative approaches. Future research directions include elucidating the precise mechanisms of action, optimizing treatment protocols, and translating preclinical findings into clinical practice for improved stroke outcomes.

Angiography-based hemodynamic features predict recurrent ischemic events after angioplasty and stenting of intracranial vertebrobasilar atherosclerotic stenosis

OBJECTIVES

To assess the predictive value of hemodynamic features for stroke relapse in patients with intracranial vertebrobasilar atherosclerotic stenosis treated with percutaneous transluminal angioplasty and stenting (PTAS) using quantitative digital subtraction angiography (q-DSA).

METHODS

In this retrospective longitudinal study, patients with intracranial vertebrobasilar atherosclerotic stenosis and who underwent PTAS treatment between January 2012 and May 2020 were enrolled. The q-DSA assessment was performed before and after PTAS. ROIs 1-4 were placed along the vertebral artery, proximal and distal basilar artery, and posterior cerebral artery; ROIs 5-8 were in 5 mm and 10 mm proximal and distal to the lesion, respectively. Relative time to peak (rTTP) was defined as the difference in TTP between ROIs. Cox regression analyses were performed to determine risk factors for recurrent stroke.

RESULTS

A total of 137 patients (mean age, 62 years ± 10 [standard deviation], 83.2% males) were included, and 26 (19.0%) patients had stroke relapse during follow-up (median time of 42.6 months [interquartile range, 19.7-60.7]). Preprocedural rTTP4-1 (adjusted hazard ratio (HR) = 2.270; 95% CI 1.371-3.758; p = 0.001) and preprocedural rTTP8-5 (adjusted HR = 0.240; 95% CI 0.088-0.658; p = 0.006) were independently associated with the recurrent stroke. These hemodynamic parameters provided an incremental prognostic value for stroke relapse (AUC, 0.817 [0.704-0.931]; the net reclassification index, 0.431 [0.057-0.625]; and the integrated discrimination index, 0.140 [0.035-0.292]).

CONCLUSIONS

In patients with intracranial vertebrobasilar atherosclerosis treated with PTAS, preprocedural prolonged TTP of the target vessel and shortened trans-stenotic TTP difference were associated with stroke relapse. Q-DSA-defined hemodynamic parameters provided incremental predictive value over conventional parameters for stroke recurrence.

CLINICAL RELEVANCE STATEMENT

Quantitative DSA analysis enables intuitive observation and semi-quantitative evaluation of peri-therapeutic cerebral blood flow. More importantly, quantitative DSA-defined hemodynamic parameters have the potential for risk stratification of patients with intracranial atherosclerotic stenosis.

KEY POINTS

Semi-quantitative angiography-based parameters can reflect pre- and postprocedural subtle changes in blood flow in patients with intracranial atherosclerotic stenosis. Although angioplasty procedures can significantly improve blood flow status, patients with more restricted baseline blood flow still show a higher risk of stroke recurrence. Angiography-based hemodynamic features possess prognostic value and can serve as clinical markers to assess stroke risk of patients with intracranial atherosclerotic stenosis.

Edaravone-loaded poly(amino acid) nanogel inhibits ferroptosis for neuroprotection in cerebral ischemia injury

Neurological injury caused by ischemic stroke is a major cause of permanent disability and death. The currently available neuroprotective drugs fail to achieve desired therapeutic efficacy mainly due to short circulation half-life and poor blood-brain barrier (BBB) permeability. For that, an edaravone-loaded pH/glutathione (pH/GSH) dual-responsive poly(amino acid) nanogel (NG/EDA) was developed to improve the neuroprotection of EDA. The nanogel was triggered by acidic and EDA-induced high-level GSH microenvironments, which enabled the selective and sustained release of EDA at the site of ischemic injury. NG/EDA exhibited a uniform sub-spherical morphology with a mean hydrodynamic diameter of 112.3 ± 8.2 nm. NG/EDA efficiently accumulated at the cerebral ischemic injury site of permanent middle cerebral artery occlusion (pMCAO) mice, showing an efficient BBB crossing feature. Notably, NG/EDA with 50 µM EDA significantly increased neuron survival (29.3%) following oxygen and glucose deprivation by inhibiting ferroptosis. In addition, administering NG/EDA for 7 d significantly reduced infarct volume to 22.2% ± 7.2% and decreased neurobehavioral scores from 9.0 ± 0.6 to 2.0 ± 0.8. Such a pH/GSH dual-responsive nanoplatform might provide a unique and promising modality for neuroprotection in ischemic stroke and other central nervous system diseases.

Neuroprotective Effects of Melittin Against Cerebral Ischemia and Inflammatory Injury via Upregulation of MCPIP1 to Suppress NF-κB Activation In Vivo and In Vitro

Melittin, a principal constituent of honeybee venom, exhibits diverse biological effects, encompassing anti-inflammatory capabilities and neuroprotective actions against an array of neurological diseases. In this study, we probed the prospective protective influence of melittin on cerebral ischemia, focusing on its anti-inflammatory activity. Mechanistically, we explored whether monocyte chemotactic protein-induced protein 1 (MCPIP1, also known as ZC3H12A), a recently identified zinc-finger protein, played a role in melittin-mediated anti-inflammation and neuroprotection. Male C57/BL6 mice were subjected to distal middle cerebral artery occlusion to create a focal cerebral cortical ischemia model, with melittin administered intraperitoneally. We evaluated motor functions, brain infarct volume, cerebral blood flow, and inflammatory marker levels within brain tissue, employing quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assays, and western blotting. In vitro, an immortalized BV-2 microglia culture was stimulated with lipopolysaccharide (LPS) to establish an inflammatory cell model. Post-melittin exposure, cell viability, and cytokine expression were examined. MCPIP1 was silenced using siRNA in LPS-induced BV-2 cells, with the ensuing nuclear translocation of nuclear factor-κB assessed through cellular immunofluorescence. In vivo, melittin enhanced motor functions, diminished infarction, fostered blood flow restoration in ischemic brain regions, and markedly inhibited the expression of inflammatory cytokines (interleukin-1β, interleukin-6, tumor necrosis factor-α, and nuclear factor-κB). In vitro, melittin augmented MCPIP1 expression in LPS-induced BV-2 cells and ameliorated inflammation-induced cell death. The neuroprotective effect conferred by melittin was attenuated upon MCPIP1 knockdown. Our findings establish that melittin-induced tolerance to ischemic injury is intrinsically linked with its anti-inflammatory capacity. Moreover, MCPIP1 is, at the very least, partially implicated in this process.

The efficacy and safety of interleukin-1 receptor antagonist in stroke patients: A systematic review

Stroke is the leading cause of disability worldwide, yet there is currently no effective treatment available to mitigate its negative consequences. Pro-inflammatory cytokines, such as interleukin-1 (IL-1), are known to play a crucial role in exacerbating the aftermath of stroke. Thus, it is hypothesized that blocking inflammation and administering anti-inflammatory drugs at an optimal time and dosage may improve the long-term quality of life for stroke patients. This systematic review examines the effectiveness and safety of IL-1 receptor antagonist (IL-1Ra), commercially known as "anakinra," in clinical studies involving the treatment of stroke patients. A comprehensive literature search was conducted until October 2023 to identify relevant studies. The search yielded 1403 articles, out of which 598 were removed due to duplication. After a thorough review of 805 titles and abstracts, 797 articles were further excluded, resulting in 8 studies being included in this systematic review. The findings from all the included studies demonstrate that IL-1Ra is safe for use in acute ischemic and hemorrhagic stroke patients, with no significant adverse events reported. Additionally, biomarkers, clinical assessments, serious adverse events (AEs), and non-serious AEs consistently showed more favorable outcomes in IL-1Ra receiving patients. Stroke elevates the levels of several inflammatory cytokines, however, administration of IL-1RA directly or indirectly modulates these markers and improves some clinical outcomes, suggesting a potential therapeutic benefit of this intervention.

Desflurane improves electrical activity of neurons and alleviates oxygen-glucose deprivation-induced neuronal injury by activating the Kcna1-dependent Kv1.1 channel

Several volatile anesthetics have presented neuroprotective functions in ischemic injury. This study investigates the effect of desflurane (Des) on neurons following oxygen-glucose deprivation (OGD) challenge and explores the underpinning mechanism. Mouse neurons HT22 were subjected to OGD, which significantly reduced cell viability, increased lactate dehydrogenase release, and promoted cell apoptosis. In addition, the OGD condition increased oxidative stress in HT22 cells, as manifested by increased ROS and MDA contents, decreased SOD activity and GSH/GSSG ratio, and reduced nuclear protein level of Nrf2. Notably, the oxidative stress and neuronal apoptosis were substantially blocked by Des treatment. Bioinformatics suggested potassium voltage-gated channel subfamily A member 1 (Kcna1) as a target of Des. Indeed, the Kcna1 expression in HT22 cells was decreased by OGD but restored by Des treatment. Artificial knockdown of Kcna1 negated the neuroprotective effects of Des. By upregulating Kcna1, Des activated the Kv1.1 channel, therefore enhancing K+ currents and inducing neuronal repolarization. Pharmacological inhibition of the Kv1.1 channel reversed the protective effects of Des against OGD-induced injury. Collectively, this study demonstrates that Des improves electrical activity of neurons and alleviates OGD-induced neuronal injury by activating the Kcna1-dependent Kv1.1 channel.

Edaravone dexborneol alleviates cerebral ischemia-reperfusion injury through NF-κB/NLRP3 signal pathway

Inflammatory injury following ischemia-reperfusion (I/R) severely limits the efficacy of stroke treatment. Edaravone dexborneol (C.EDA) has been shown to reduce inflammation following a cerebral hemorrhage. However, the precise anti-inflammatory mechanism of C.EDA is unknown. In this study, we investigated whether C.EDA provides neuroprotection after I/R in rats, as well as the potential mechanisms involved. A middle cerebral artery occlusion/reperfusion (I/R) model was created using Sprague-Dawley rats. The blood flow of the central cerebral artery was monitored by a laser speckle imaging system. The neurological score was used to assess behavioral improvement. Cerebral infarction volume was measured by TTC staining. And the integrity of the blood-brain barrier was detected by Evan's blue staining. The expression of the nuclear factor kappa-B (NF-κB)/ the NOD-like receptor protein (NLRP3) inflammasome signal pathway and microglia polarization were detected by immunofluorescence and Western blotting. The cerebral blood flow ratio indicates that the cerebral I/R model was successfully established. After reperfusion for 72 h, the improvement of neurological scores, infarct volume reduction, and integrity of the blood-brain barrier was observed in I/R rats with C.EDA treatment. Meanwhile, the immunofluorescence result showed that the expression of iNOS, NLRP3, and NF-κB protein was decreased and the level of Arg1 was increased. Western blot analysis showed that the expression of NF-κB/NLRP3 signal pathway-related protein was decreased. In conclusion, this study indicates that C.EDA alleviates I/R injury by blocking the activation of the NLRP3 inflammasome and regulating the polarization of M1/M2 microglia via the NF-κB signal pathway.

ULK1 confers neuroprotection by regulating microglial/macrophages activation after ischemic stroke

Microglial activation and autophagy play a critical role in the progression of ischemic stroke and contribute to the regulation of neuroinflammation. Unc-51-like kinase 1 (ULK1) is the primary autophagy kinase involved in autophagosome formation. However, the impact of ULK1 on neuroprotection and microglial activation after ischemic stroke remains unclear. In this study, we established a photothrombotic stroke model, and administered SBI-0206965 (SBI), an ULK1 inhibitor, and LYN-1604 hydrochloride (LYN), an ULK1 agonist, to modulate ULK1 activity in vivo. We assessed sensorimotor deficits, neuronal apoptosis, and microglial/macrophage activation to evaluate the neurofunctional outcome. Immunofluorescence results revealed ULK1 was primarily localized in the microglia of the infarct area following ischemia. Upregulating ULK1 through LYN treatment significantly reduced infarct volume, improved motor function, promoted the increase of anti-inflammatory microglia. In conclusion, ULK1 facilitated neuronal repair and promoted the formation of anti-inflammatory microglia pathway after ischemic injury.

Expression, Functional Polymorphism, and Diagnostic Values of MIAT rs2331291 and H19 rs217727 Long Non-Coding RNAs in Cerebral Ischemic Stroke Egyptian Patients

Cerebral ischemic stroke (CIS) is a severe cerebral vascular event. This research aimed to evaluate the role of single-nucleotide polymorphisms (SNPs) of the lncRNAs MIAT rs2331291 and H19 rs217727 and epigenetic methylation in the expression patterns of serum lncRNA H19 in CIS Egyptian patients. It included 80 CIS cases and 40 healthy subjects. Serum MIAT expression levels decreased, whereas serum H19 expression levels increased among CIS compared to controls. For MIAT rs2331291, there were significant differences in the genotypic and allelic frequencies between the CIS and healthy subjects at p = 0.02 and p = 0.0001, respectively. Our findings illustrated a significantly increased MIAT T/T genotype frequency in hypertensive CIS compared to non-hypertensive CIS at p = 0.004. However, H19 rs217727 gene frequency C/C was not significantly higher in non-hypertensive CIS than in hypertensive CIS. The methylation of the H19 gene promoter was significantly higher in CIS patients compared to healthy subjects. The level of MIAT was positively correlated with serum H19 in CIS. Receiver operating characteristics (ROC) analysis revealed that serum MIAT and H19 have a high diagnostic potential for distinguishing CIS subjects from healthy ones. In conclusion, the MIAT-rs2331291 polymorphism might serve as a novel potential indicator of CIS.

Interfering TRIB3 protects the blood brain barrier through PI3K/Akt pathway to alleviate cerebral ischemia-reperfusion injury in diabetes mellitus mice

This study aimed to treat diabetic cerebral ischemia-reperfusion injury (CI/RI) by affecting blood brain barrier (BBB) permeability and integrity. The CI/RI model in DM mice and a high glucose (HG) treated oxygen and glucose deprivation/reoxygenation (OGD/R) brain endothelial cell model were established for the study. Evans blue (EB) staining was used to evaluate the permeability of BBB in vivo. TTC staining was used to analyze cerebral infarction. The location and expression of tribbles homolog 3 (TRIB3) in endothelial cells were detected by immunofluorescence. Western blotting was used to detect the protein expressions of TRIB3, tight junction molecules, adhesion molecules, phosphorylated protein kinase B (p-AKT) and AKT. The levels of pro-inflammatory cytokines were detected by qRT-PCR. Trans-epithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran were used to measure vascular permeability in vitro. TRIB3 ubiquitination and acetylation levels were detected. Acetyltransferase bound to TRIB3 were identified by immunoprecipitation. TRIB3 was localized in cerebral endothelial cells and was highly expressed in diabetic CI/R mice. The BBB permeability in diabetic CI/R mice and HG-treated OGD/R cells was increased, while the junction integrity was decreased. Interference with TRIB3 in vitro reduces BBB permeability and increases junction integrity. In vivo interfering with TRIB3 reduced cerebral infarction volume, BBB permeability and inflammation levels, and upregulated p-AKT levels. The phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin reversed the effects of TRIB3-interfering plasmid. In vitro HG treatment induced TRIB3 acetylation through acetyltransferase p300, which in turn reduced ubiquitination and stabilized TRIB3. Interfering TRIB3 protects BBB by activating PI3K/AKT pathway and alleviates brain injury, which provides a new target for diabetic CI/RI.

Blocking of microglia-astrocyte proinflammatory signaling is beneficial following stroke

Microglia and astrocytes play an important role in the neuroinflammatory response and contribute to both the destruction of neighboring tissue as well as the resolution of inflammation following stroke. These reactive glial cells are highly heterogeneous at both the transcriptomic and functional level. Depending upon the stimulus, microglia and astrocytes mount a complex, and specific response composed of distinct microglial and astrocyte substates. These substates ultimately drive the landscape of the initiation and recovery from the adverse stimulus. In one state, inflammation- and damage-induced microglia release tumor necrosis factor (TNF), interleukin 1α (IL1α), and complement component 1q (C1q), together "TIC." This cocktail of cytokines drives astrocytes into a neurotoxic reactive astrocyte (nRA) substate. This nRA substate is associated with loss of many physiological astrocyte functions (e.g., synapse formation and maturation, phagocytosis, among others), as well as a gain-of-function release of neurotoxic long-chain fatty acids which kill neighboring cells. Here we report that transgenic removal of TIC led to reduction of gliosis, infarct expansion, and worsened functional deficits in the acute and delayed stages following stroke. Our results suggest that TIC cytokines, and likely nRAs play an important role that may maintain neuroinflammation and inhibit functional motor recovery after ischemic stroke. This is the first report that this paradigm is relevant in stroke and that therapies against nRAs may be a novel means to treat patients. Since nRAs are evolutionarily conserved from rodents to humans and present in multiple neurodegenerative diseases and injuries, further identification of mechanistic role of nRAs will lead to a better understanding of the neuroinflammatory response and the development of new therapies.

Impact of NQO1 dysregulation in CNS disorders

NAD(P)H Quinone Dehydrogenase 1 (NQO1) plays a pivotal role in the regulation of neuronal function and synaptic plasticity, cellular adaptation to oxidative stress, neuroinflammatory and degenerative processes, and tumorigenesis in the central nervous system (CNS). Impairment of the NQO1 activity in the CNS can result in abnormal neurotransmitter release and clearance, increased oxidative stress, and aggravated cellular injury/death. Furthermore, it can cause disturbances in neural circuit function and synaptic neurotransmission. The abnormalities of NQO1 enzyme activity have been linked to the pathophysiological mechanisms of multiple neurological disorders, including Parkinson's disease, Alzheimer's disease, epilepsy, multiple sclerosis, cerebrovascular disease, traumatic brain injury, and brain malignancy. NQO1 contributes to various dimensions of tumorigenesis and treatment response in various brain tumors. The precise mechanisms through which abnormalities in NQO1 function contribute to these neurological disorders continue to be a subject of ongoing research. Building upon the existing knowledge, the present study reviews current investigations describing the role of NQO1 dysregulations in various neurological disorders. This study emphasizes the potential of NQO1 as a biomarker in diagnostic and prognostic approaches, as well as its suitability as a target for drug development strategies in neurological disorders.

Endogenous defense mechanism-based neuroprotection in large-vessel acute ischemic stroke: A hope for future

BACKGROUND

Stroke is a leading cause of morbidity and mortality worldwide and a leading cause of disability. None of the neuroprotective agents have been approved internationally except edaravone in Japanese guidelines in acute ischemic stroke. We here discuss that there are two types of endogenous defense mechanisms (EDMs) after acute stroke for neuromodulation and neuroregeneration, and if both can be activated simultaneously, then we can have better recovery in stroke.

AIMS AND OBJECTIVES

We aimed to study the effect of combination of neuroprotection therapies acting on the two wings of EDM in acute large-vessel middle cerebral artery (LMCA) ischemic stroke.

METHODS

Sixty patients of LMCA stroke were enrolled and randomized within 72 h into two groups of 30 patients each. The control group received standard medical care without any neuroprotective agents while the intervention group received standard medical care combined with oral citicoline with vinpocetine for 3 months with initial 1 week intravenous and edaravone and cerebrolysin injection, started within 72 h of onset of stroke. Patients were assessed on the basis of the National Institutes of Health Stroke Scale, Fugl-Meyer Assessment Score, Glasgow Coma Scale, and Mini-Mental Status Examination at admission, discharge, and after 90 days.

RESULTS

The intervention group showed significant and early improvements in motor as well as cognitive recovery.

CONCLUSION

Combination therapy for neuroprotection which is acting on two pathways of EDM can be useful in functional recovery after acute ischemic stroke.

NR3C2 activates LCN2 transcription to promote endoplasmic reticulum stress and cell apoptosis in ischemic cerebral infarction

Endoplasmic reticulum (ER) stress can lead to cell death and worsen tissue damage during ischemic events. Nuclear receptor subfamily 3 group C member 2 (NR3C2) and lipocalin 2 (LCN2) are known to be associated with ER stress. In this study, we obtained a potential interaction between NR3C2 and LCN2 through bioinformatics. The primary objective was to investigate their roles and interactions in the context of ER stress in ischemic cerebral infarction (ICI). A mouse model of ICI was generated by middle cerebral artery occlusion, resulting in elevated levels of NR3C2 and LCN2 in brain tissues. NR3C2 bound to the LCN2 promoter, thereby activating its transcription. Either knockdown of LCN2 or NR3C2 led to an improvement in neurologic deficits in mice, along with a reduction in infract size, tissue damage, ER stress, inflammation, and cell apoptosis in their brain tissues. Similar results were reproduced in HT22 cells, where LCN2 or NR3C2 knockdown alleviated oxygen-glucose deprivation-induced ER stress, inflammation, and cell apoptosis while improving cell viability. However, the protective effects of NR3C2 knockdown were counteracted when LCN2 was overexpressed, both in vitro and in vivo. Overall, this study demonstrates that NR3C2 activates LCN2 transcription, ultimately promoting ER stress and cell apoptosis in the context of ICI.

Exploring Mechanisms of Houshiheisan in Treating Ischemic Stroke with Network Pharmacology and Independent Cascade Model

BACKGROUND

Houshiheisan (HSHS) has been effective in the treatment of ischemic stroke (IS) for centuries. However, its mechanisms are still underexplored.

OBJECTIVE

The objective of this study is to identify the active ingredients and mechanisms of HSHS in treating IS.

METHODS

We searched the main active compounds in HSHS and their potential targets, and key targets related to IS. Based on the common targets of HSHS and IS, we further expanded genes by KEGG database to obtain target genes and related genes, as well as gene interactions in the form of A→B, and then constructed a directed network including traditional Chinese medicines (TCMs), active compounds and genes. Finally, based on enrichment analysis, independent cascade (IC) model, and molecular docking, we explored the mechanisms of HSHS in treating IS.

RESULTS

A directed network with 6,348 nodes and 64,996 edges was constructed. The enrichment analysis suggested that the AGE pathway, glucose metabolic pathway, lipid metabolic pathway, and inflammation pathway played critical roles in the treatment of IS by HSHS. Furthermore, the gene ontologies (GOs) of three monarch drugs in HSHS mainly involved cellular response to chemical stress, blood coagulation, hemostasis, positive regulation of MAPK cascade, and regulation of inflammatory response. Several candidate drug molecules were identified by molecular docking.

CONCLUSION

This study advocated potential drug development with targets in the AGE signaling pathway, with emphasis on neuroprotective, anti-inflammatory, and anti-apoptotic functions. The molecular docking simulation indicated that the ligand-target combination selection method based on the IC model was effective and reliable.

The effects of curcumin-piperine supplementation on inflammatory, oxidative stress and metabolic indices in patients with ischemic stroke in the rehabilitation phase: a randomized controlled trial

BACKGROUND

Stroke is a leading cause of death worldwide, which is associated with a heavy economic and social burden. The purpose of this study was to investigate the effects of supplementation with curcumin-piperine combination in patients with ischemic stroke in the rehabilitation stage.

METHODS

In this randomized controlled trial, 66 patients with stroke were randomized into two groups receiving curcumin-piperine tablets (500 mg curcumin + 5 mg piperine) and matched placebo tablets for 12 weeks. High-sensitivity C-reactive protein (hs-CRP), carotid intima-media thickness (CIMT), thrombosis, total antioxidant capacity (TAC), lipid profile, anthropometric indices, blood pressure, and quality of life were assessed before and after the intervention. Statistical data analysis was done using SPSS22 software.

RESULTS

A total of 56 patients with a mean age of 59.80 ± 4.25 years completed the trial. Based on ANCOVA test, adjusted for baseline values, curcumin-piperine supplementation for 12 weeks resulted in significant reductions in serum levels of hs-CRP (p = 0.026), total cholesterol (TC) (p = 0.009), triglycerides (TG) (p = 0.001), CIMT (p = 0.002), weight (P = 0.001), waist circumference (p = 0.024), and systolic and diastolic blood pressure (p < 0.001), and a significant increase in TAC (p < 0.001) in comparison to the placebo. Pain score significantly increased in both groups; however, its increase was significantly higher in the placebo group compared with the intervention group (p = 0.007). No significant changes were observed between the two groups in terms of serum fibrinogen, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and quality of life indices.

CONCLUSION

Curcumin-piperine supplementation had beneficial effects on CIMT, serum hs-CRP, TC, TG, TAC, and systolic and diastolic blood pressure in patients with ischemic stroke in the rehabilitation stage.

Lost in Translation: Neurotrophins Biology and Function in the Neurovascular Unit

The neurovascular unit (NVU) refers to the functional building unit of the brain and the retina, where neurons, glia, and microvasculature orchestrate to meet the demand of the retina's and brain's function. Neurotrophins (NTs) are structural families of secreted proteins and are known for exerting neurotrophic effects on neuronal differentiation, survival, neurite outgrowth, synaptic formation, and plasticity. NTs include several molecules, such as nerve growth factor, brain-derived neurotrophic factor, NT-3, NT-4, and their precursors. Furthermore, NTs are involved in signaling pathways such as inflammation, apoptosis, and angiogenesis in a nonneuronal cell type. Interestingly, NTs and the precursors can bind and activate the p75 neurotrophin receptor (p75NTR) at low and high affinity. Mature NTs bind their cognate tropomyosin/tyrosine-regulated kinase receptors, crucial for maintenance and neuronal development in the brain and retina axis. Activation of p75NTR results in neuronal apoptosis and cell death, while tropomysin receptor kinase upregulation contributes to differentiation and cell growth. Recent findings indicate that modulation of NTs and their receptors contribute to neurovascular dysfunction in the NVU. Several chronic metabolic and acute ischemic diseases affect the NVU, including diabetic and ischemic retinopathy for the retina, as well as stroke, acute encephalitis, and traumatic brain injury for the brain. This work aims to review the current evidence through published literature studying the impact of NTs and their receptors, including the p75NTR receptor, on the injured and healthy brain-retina axis.

microRNA-184 in the landscape of human malignancies: a review to roles and clinical significance

MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) with a short length of 19-22 nucleotides. miRNAs are posttranscriptional regulators of gene expression involved in various biological processes like cell growth, apoptosis, and angiogenesis. miR-184 is a well-studied miRNA, for which most studies report its downregulation in cancer cells and tissues and experiments support its role as a tumor suppressor inhibiting malignant biological behaviors of cancer cells in vitro and in vivo. To exert its functions, miR-184 affects some signaling pathways involved in tumorigenesis like Wnt and β-catenin, and AKT/mTORC1 pathway, oncogenic factors (e.g., c-Myc) or apoptotic proteins, such as Bcl-2. Interestingly, clinical investigations have shown miR-184 with good performance as a prognostic/diagnostic biomarker for various cancers. Additionally, exogenous miR-184 in cell and xenograft animal studies suggest it as a therapeutic anticancer target. In this review, we outline the studies that evaluated the roles of miR-184 in tumorigenesis as well as its clinical significance.

Amentoflavone attenuates oxidative stress and neuroinflammation induced by cerebral ischemia/reperfusion in rats by targeting HMGB1-mediated TLR4/NF-κB signaling pathway

Surveys indicated that stroke classified among the leading cause of death as well as combined death and disability worldwide resulting in a great loss for the global economy. The present study aims to evaluate the neuroprotective potential of the biflavonoid amentoflavone (AMNT) in alleviating cerebral ischemia/reperfusion (IR) injury in rats, and to elucidate the possible underlying mechanism of an experimental condition with similar circumstances to stroke. Cerebral ischemia was achieved through left common carotid artery occlusion for 60 min, followed by blood flow restoration. Sham-operated control rats subjected to the same surgical process except for brain IR. Rats were orally administered AMNT/ or vehicle for three days' prior surgical operation, and for another three days after left brain IR. Rats of all groups were assessed for neurological deficits 24 h following brain IR. Each group was divided into two subgroups one for the rotarod testing and biochemical assessment while the other subgroup to perform the activity cage testing, histopathological study, immunohistochemistry, and gene expression analysis. AMNT enhanced brain levels of GSH and CAT activities, suppressed neuroinflammation via reducing the inflammatory cytokines in the serum, and enhanced brain contents of TBK1 and IFNβ. AMNT downregulated TLR4-/NF-κB signaling pathway as a result of the HMGB1 suppression. Moreover, AMNT blocked apoptotic cell death by suppressing the NF-κB signaling pathway and reducing the activation of caspase-3. These findings revealed that AMNT attenuates I/R-induced cerebral injury possibly by regulating the HMGB1-mediated TLR4/NF-kB pathway. Thus, AMNT could provide potential preventive and therapeutic option for cerebral stroke.

Ellagic acid alleviates motor, cognitive and hippocampal electrical activity deficits in the male rats with 2-vessel occlusion cerebral ischemia/reperfusion

Objective

Cerebral ischemia/reperfusion (I/R) has been known as a major cause of inability and mortality worldwide. Ellagic acid (EA) has many pharmacological effects including antioxidant, antithrombotic and neurorestoration activities. The aim of this study was evaluation of the effects of EA on motor and cognitive behaviors, hippocampal local field potential (LFP), brain oxidative stress in male rats with cerebral 2-vessel occlusion ischemia/reperfusion (2VO I/R).

Materials and Methods

Forty-eight male Wistar rats (250-300 g) were assigned into six groups. 1) The Sham: rats were treated with DMSO10%/normal saline as solvent of EA 3 times daily for 1 week; 2) I/R+Veh; I/R rats received vehicle; 3-5) EA-treated groups: I/R rats received 50, 75, or 100 mg/kg EA; and 6) Cont+EA100: intact rats received EA. The cerebral 2VO I/R was made by the bilateral common carotid arteries closing for 20 min followed by reperfusion. The behavioral tests and hippocampal LFP recording were performed after treatment with EA. The oxidative stress parameters were assayed by special ELISA kits.

Results

Cerebral 2VO I/R significantly decreased motor coordination, memory and hippocampal LFP and significantly increased oxidative stress. Treatment with EA improved all I/R complications.

Conclusion

The current findings showed that treatment of I/R rats with EA could reverse cognitive and motor functions, and improve the LFP and oxidative stress markers. So, effects of EA on cognitive and motor function may at least in part, be due to its antioxidative actions.

Refined Qingkailing protects the in vitro neurovascular unit against oxygen-glucose deprivation and re-oxygenation-induced injury

Since the proposal of the neurovascular unit (NVU) theory, it has become almost mandatory for neuroprotective medicines against ischaemic stroke (IS) to focus on this unit. Refined Qingkailing (RQKL) is a compound composed of hyodeoxycholic acid, geniposide, baicalin and cholic acid, which has shown great potential in the treatment of IS, but its effect on NVU has not been fully studied. The purpose of this study was to investigate the potential biological pathways that underlie the protective effects of RQKL against NVU damage induced by oxygen-glucose deprivation and re-oxygenation (OGD/R). Using in vitro OGD/R models, we looked into whether RQKL protects the NVU. In order to create an in vitro NVU that resembles IS, we created an OGD/R injury model using primary cultures of brain microvascular endothelial cells, neurons, and astrocytes. Based on our results, we present evidence, for the first time, that RQKL treatment of the injury caused by OGD/R significantly (1) kept the blood brain barrier (BBB) functioning and maintained the architecture of the neurons, (2) mitigated the oxidative stress damage, inflammatory cytokine release, and neuronal death, and (3) upregulated the expression of neurotrophic factors generated from glial cells and the brain in the in vitro model. Therefore, RQKL has a variety of preventive effects against NVU damage caused by OGD/R. RQKL may be a suitable medication for treating IS in a clinical setting.

Blocking Formation of Neurotoxic Reactive Astrocytes is Beneficial Following Stroke

Microglia and astrocytes play an important role in the neuroinflammatory response and contribute to both the destruction of neighboring tissue as well as the resolution of inflammation following stroke. These reactive glial cells are highly heterogeneous at both the transcriptomic and functional level. Depending upon the stimulus, microglia and astrocytes mount a complex, and specific response composed of distinct microglial and astrocyte substates. These substates ultimately drive the landscape of the initiation and recovery from the adverse stimulus. In one state, inflammation- and damage-induced microglia release tumor necrosis factor (TNF), interleukin 1α (IL1α), and complement component 1q (C1q), together 'TIC'. This cocktail of cytokines drives astrocytes into a neurotoxic reactive astrocyte (nRA) substate. This nRA substate is associated with loss of many physiological astrocyte functions (e.g., synapse formation and maturation, phagocytosis, among others), as well as a gain-of-function release of neurotoxic long-chain fatty acids which kill neighboring cells. Here we report that transgenic removal of TIC led to reduction of gliosis, infarct expansion, and worsened functional deficits in the acute and delayed stages following stroke. Our results suggest that TIC cytokines, and likely nRAs play an important role that may maintain neuroinflammation and inhibit functional motor recovery after ischemic stroke. This is the first report that this paradigm is relevant in stroke and that therapies against nRAs may be a novel means to treat patients. Since nRAs are evolutionarily conserved from rodents to humans and present in multiple neurodegenerative diseases and injuries, further identification of mechanistic role of nRAs will lead to a better understanding of the neuroinflammatory response and the development of new therapies.

Bibliometric analysis of global research trends on regulatory T cells in neurological diseases

This bibliometric study aimed to summarize and visualize the current research status, emerging trends, and research hotspots of regulatory T (Treg) cells in neurological diseases. Relevant documents were retrieved from the Web of Science Core Collection. Tableau Public, VOSviewer, and CiteSpace software were used to perform bibliometric analysis and network visualization. A total of 2,739 documents were included, and research on Treg cells in neurological diseases is still in a prolific period. The documents included in the research were sourced from 85 countries/regions, with the majority of them originating from the United States, and 2,811 organizations, with a significant proportion of them coming from Harvard Medical School. Howard E Gendelman was the most prolific author in this research area. Considering the number of documents and citations, impact factors, and JCR partitions, Frontiers in Immunology was the most popular journal in this research area. Keywords "multiple sclerosis," "inflammation," "regulatory T cells," "neuroinflammation," "autoimmunity," "cytokines," and "immunomodulation" were identified as high-frequency keywords. Additionally, "gut microbiota" has recently emerged as a new topic of interest. The study of Treg cells in neurological diseases continues to be a hot topic. Immunomodulation, gut microbiota, and cytokines represent the current research hotspots and frontiers in this field. Treg cell-based immunomodulatory approaches have shown immense potential in the treatment of neurological diseases. Modifying gut microbiota or regulating cytokines to boost the numbers and functions of Treg cells represents a promising therapeutic strategy for neurological diseases.

Intracerebral hirudin injection alleviates cognitive impairment and oxidative stress and promotes hippocampal neurogenesis in rats subjected to cerebral ischemia

Cerebral ischemia starts with cerebral blood flow interruption that causes severely limited oxygen and glucose supply, eliciting a cascade of pathological events, such as excitotoxicity, oxidative stress, calcium dysregulation, and inflammatory response, which could ultimately result in neuronal death. Hirudin has beneficial effects in ischemic stroke and possesses antioxidant and anti-inflammatory properties. Therefore, we investigated the biological functions of hirudin and its related mechanisms in cerebral ischemia. The ischemia-like conditions were induced by transient middle cerebral artery occlusion (MCAO). To investigate hirudin roles, intracerebroventricular injection of 10 U hirudin was given to the rats. Cognitive and motor functions were examined by beam walking and Morris water maze tests. 2,3,5-triphenyl tetrazolium chloride-stained brain sections were used to measure infarct volume. Oxidative stress was determined by assessment of oxidative stress markers. The proliferated cells were labeled by BrdU and Nestin double staining. Western blotting was performed to measure protein levels. Hirudin administration improved cognitive and motor deficits post-ischemia. Hirudin reduced brain infarction and neurological damage in MCAO-subjected rats. Hirudin alleviated oxidative stress and enhanced neurogenesis in ischemic rats. Hirudin facilitated the promotion of phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and serine-threonine kinase. In sum, hirudin alleviates cognitive deficits by attenuating oxidative stress and promoting hippocampal neurogenesis through the regulation of ERK1/2 and serine-threonine kinase in MCAO-subjected rats.

Time-dependent dual effect of microglia in ischemic stroke

Stroke, the third leading cause of death and disability worldwide, is classified into ischemic or hemorrhagic, in which approximately 85% of strokes are ischemic. Ischemic stroke occurs as a result of arterial occlusion due to embolus or thrombus, with ischemia in the perfusion territory supplied by the occluded artery. The traditional concept that ischemic stroke is solely a vascular occlusion disorder has been expanded to include the dynamic interaction between microglia, astrocytes, neurons, vascular cells, and matrix components forming the "neurovascular unit." Acute ischemic stroke triggers a wide spectrum of neurovascular disturbances, glial activation, and secondary neuroinflammation that promotes further injury, ultimately resulting in neuronal death. Microglia, as the resident macrophages in the central nervous system, is one of the first responders to ischemic injury and plays a significant role in post-ischemic neuroinflammation. In this review, we reviewed the mechanisms of microglia in multiple stages of post-ischemic neuroinflammation development, including acute, sub-acute and chronic phases of stroke. A comprehensive understanding of the dynamic variation and the time-dependent role of microglia in post-stroke neuroinflammation could aid in the search for more effective therapeutics and diagnostic strategies for ischemic stroke.

Research progress on the mechanism of curcumin in cerebral ischemia/reperfusion injury: a narrative review

Cerebral ischemia/reperfusion (I/R) injury can result in different levels of cerebral impairment, and in severe cases, death. Curcumin, an essential bioactive component of turmeric, has a rich history as a traditional medicine for various ailments in numerous countries. Experimental and clinical research has established that curcumin offers a protective effect against cerebral I/R injury. Curcumin exerts its protective effects by acting on specific mechanisms such as antioxidant, anti-inflammatory, inhibition of ferroptosis and pyroptosis, protection of mitochondrial function and structure, reduction of excessive autophagy, and improvement of endoplasmic reticulum (ER) stress, which ultimately help to preserve the blood-brain barrier (BBB) and reducing apoptosis. There is currently a shortage of drugs undergoing clinical trials for the treatment of cerebral I/R injury, highlighting the pressing need for research and development of novel treatments to address this injury. The primary objective of this study is to establish a theoretical basis for future clinical applications of curcumin by delineating the mechanisms and protective effects of curcumin against cerebral I/R injury. Adapted with permission from [1].

Cynaropicrin Averts the Oxidative Stress and Neuroinflammation in Ischemic/Reperfusion Injury Through the Modulation of NF-kB

Cerebral ischemia and successive reperfusion are the prevailing cause of cerebral stroke. Currently cerebral stroke is considered to be one of the prior causes for high mortality, disability, and morbidity. Cynaropicrin, a sesquiterpene lactone, exhibits various pharmacologic properties and also has an anti-inflammatory property associated with the suppression of the key pro-inflammatory NF-κB pathway. The protective effect of cynaropicrin against oxidative stress and neuroinflammation during CIR injury through the modulation of NF-κB pathway was studied in the current investigation. The experimental rats split into 5 groups as sham-operated control group (group 1), middle cerebral artery occlusion (MCAO)-induced rats (group 2), MCAO rats treated with cynaropicrin (diluted in saline) immediately 2 h after MCAO with 5, 10, and 25 mg/kg administration orally were designated as groups 3, 4, and 5, respectively. In MCAO-induced animals, the severity of ischemic was evident by the elevated level nitrate, MDA, MMPs, inflammatory mediators, Bax, caspase-3, and NF-κB. The level of Nrf-2, antioxidant enzymes, Bcl-2, and IL-10 was reduced in the MCAO-induced animals. Treatment with cynaropicrin in dosage-based manner increased the level of antioxidant enzymes, IL-10, Nrf-2, and Bcl-2 in the animals which indicates the antioxidative effect of cynaropicrin. The level of nitrate, MDA, MMPs, proinflammatory cytokines, inflammatory mediators, Bax, caspase-3, and NF-κB was reduced in the rats treated with cynaropicrin in a dosage-based manner. Experimental animals treated with cynaropicrin in a dosage-dependent way showed a defensive mechanism against oxidative stress and neuroinflammation by inhibiting the NF-κB pathway.

Inhibition of the NLRP3 Inflammasome Activation/Assembly through the Activation of the PI3K Pathway by Naloxone Protects Neural Stem Cells from Ischemic Condition

Naloxone is a well-known opioid antagonist and has been suggested to have neuroprotective effects in cerebral ischemia. We investigated whether naloxone exhibits anti-inflammatory and neuroprotective effects in neural stem cells (NSCs) injured by oxygen-glucose deprivation (OGD), whether it affects the NOD-like receptor protein 3 (NLRP3) inflammasome activation/assembly, and whether the role of the phosphatidylinositol 3-kinase (PI3K) pathway is important in the control of NLRP3 inflammasome activation/assembly by naloxone. Primary cultured NSCs were subjected to OGD and treated with different concentrations of naloxone. Cell viability, proliferation, and the intracellular signaling proteins associated with the PI3K pathway and NLRP3 inflammasome activation/assembly were evaluated in OGD-injured NSCs. OGD significantly reduced survival, proliferation, and migration and increased apoptosis of NSCs. However, treatment with naloxone significantly restored survival, proliferation, and migration and decreased apoptosis of NSCs. Moreover, OGD markedly increased NLRP3 inflammasome activation/assembly and cleaved caspase-1 and interleukin-1β levels in NSCs, but naloxone significantly attenuated these effects. These neuroprotective and anti-inflammatory effects of naloxone were eliminated when cells were treated with PI3K inhibitors. Our results suggest that NLRP3 inflammasome is a potential therapeutic target and that naloxone reduces ischemic injury in NSCs by inhibiting NLRP3 inflammasome activation/assembly mediated by the activation of the PI3K signaling pathway.

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.

Enhanced Cerebroprotection of Xenon-Loaded Liposomes in Combination with rtPA Thrombolysis for Embolic Ischemic Stroke

Xenon (Xe) has shown great potential as a stroke treatment due to its exceptional ability to protect brain tissue without inducing side effects. We have previously developed Xe-loaded liposomes for the ultrasound-activated delivery of Xe into the cerebral region and demonstrated their therapeutic efficacy. At present, the sole FDA-approved thrombolytic agent for stroke treatment is recombinant tissue plasminogen activator (rtPA). In this study, we aimed to investigate the potential of combining Xe-liposomes with an intravenous rtPA treatment in a clinically relevant embolic rat stroke model. We evaluated the combinational effect using an in vitro clot lysis model and an in vivo embolic middle cerebral artery occlusion (eMCAO) rat model. The treatment groups received intravenous administration of Xe-liposomes (20 mg/kg) at 2 h post-stroke onset, followed by the administration of rtPA (10 mg/kg) at either 2 or 4 h after the onset. Three days after the stroke, behavioral tests were conducted, and brain sections were collected for triphenyltetrazolium chloride (TTC) and TUNEL staining. Infarct size was determined as normalized infarct volume (%). Both in vitro and in vivo clot lysis experiments demonstrated that Xe-liposomes in combination with rtPA resulted in effective clot lysis comparable to the treatment with free rtPA alone. Animals treated with Xe-liposomes in combination with rtPA showed reduced TUNEL-positive cells and demonstrated improved neurological recovery. Importantly, Xe-liposomes in combination with late rtPA treatment reduced rtPA-induced hemorrhage, attributing to the reduction of MMP9 immunoreactivity. This study demonstrates that the combined therapy of Xe-liposomes and rtPA provides enhanced therapeutic efficacy, leading to decreased neuronal cell death and a potential to mitigate hemorrhagic side effects associated with late rtPA treatment.

Antioxidant Effects of Argan Oil and Olive Oil against Iron-Induced Oxidative Stress: In Vivo and In Vitro Approaches

Recently, the study of the protective powers of medicinal plants has become the focus of several studies. Attention has been focused on the identification of new molecules with antioxidant and chelating properties to counter reactive oxygen species (ROS) involved as key elements in several pathologies. Considerable attention is given to argan oil (AO) and olive oil (OO) due to their particular composition and preventive properties. Our study aimed to determine the content of AO and OO on phenolic compounds, chlorophylls, and carotenoid pigments and their antioxidant potential by FRAP and DPPH tests. Thus, several metallic elements can induce oxidative stress, as a consequence of the formation of ROS. Iron is one of these metal ions, which participates in the generation of free radicals, especially OH from H2O2 via the Fenton reaction, initiating oxidative stress. To study the antioxidant potential of AO and OO, we evaluated their preventives effects against oxidative stress induced by ferrous sulfate (FeSO4) in the protozoan Tetrahymena pyriformis and mice. Then, we evaluated the activities of the enzymatic (superoxide dismutase (SOD), glutathione peroxidase (GPx)) and metabolite markers (lipid peroxidation (MDA) and glutathione (GSH)) of the antioxidant balance. The results of the antioxidant compounds show that both oils contain phenolic compounds and pigments. Moreover, AO and OO exhibit antioxidant potential across FRAP and DPPH assays. On the other hand, the results in Tetrahymena pyriformis and mice show a variation in the level of iron-changed SOD and GPx activities and MDA and GSH levels. By contrast, treating Tetrahymena pyriformis and mice with argan and olive oils shows significant prevention in the SOD and GPx activities. These results reveal that the iron-changed ROS imbalance can be counteracted by AO and OO, which is probably related to their composition, especially their high content of polyphenols, sterols, and tocopherols, which is underlined by their antioxidant activities.

Comparative transcriptome findings reveal the neuroinflammatory network and potential biomarkers to early detection of ischemic stroke

INTRODUCTION

Ischemic stroke accounts for 70-80% of all stroke cases, leading to over two million people dying every year. Poor diagnosis and late detection are the major causes of the high death and disability rate.

METHODS

In the present study, we used the middle cerebral artery occlusion (MCAO) rat model and applied comparative transcriptomic analysis, followed by a systematic advanced bioinformatic analysis, including gene ontology enrichment analysis and Ingenuity Pathway Analysis (IPA). We aimed to identify novel biomarkers for the early detection of ischemic stroke. In addition, we aimed to delineate the molecular mechanisms underlying the development of ischemic stroke, in which we hoped to identify novel therapeutic targets for treating ischemic stroke.

RESULTS

In the comparative transcriptomic analysis, we identified 2657 differentially expressed genes (DEGs) in the brain tissue of the MCAO model. The gene enrichment analysis highlighted the importance of these DEGs in oxygen regulation, neural functions, and inflammatory and immune responses. We identified the elevation of angiopoietin-2 and leptin receptor as potential novel biomarkers for early detection of ischemic stroke. Furthermore, the result of IPA suggested targeting the inflammasome pathway, integrin-linked kinase signaling pathway, and Th1 signaling pathway for treating ischemic stroke.

CONCLUSION

The results of the present study provide novel insight into the biomarkers and therapeutic targets as potential treatments of ischemic stroke.

Anti-Neuroinflammatory Effects of the Human Milk Oligosaccharide, 2'-Fucosyllactose, Exerted via Modulation of M2 Microglial Activation in a Mouse Model of Ischemia-Reperfusion Injury

Cerebral ischemic stroke is one of the leading causes of death and disability worldwide. 2'-fucosyllactose (2'-FL), a human milk oligosaccharide, exerts anti-inflammatory effects and plays a protective role in arterial thrombosis; however, its role in ischemic stroke remains unclear. This study aimed to investigate the neuroprotective effects of 2'-FL and its potential mechanisms in a mouse model of ischemic stroke. Neurological score and behavior tests revealed that 2'-FL promoted the recovery of neurological deficits and motor function in middle cerebral artery occlusion (MCAO) mice, and that 2'FL led to a reduction in the size of cerebral infarct. Biochemical studies showed that administration of 2'-FL led to a reduction of reactive oxygen species (ROS)-related products in the brain of MCAO mice. 2'-FL upregulated IL-10 and downregulated TNF-α level. In addition, 2'-FL enhanced M2-type microglial polarization and upregulated CD206 expression at 7 days after MCAO. At 3 days after MCAO, 2'-FL increased IL-4 levels and activated STAT6. Our data show that 2'-FL reduced the neurological symptoms of ischemic stroke and ROS accumulation in the brain through IL-4/STAT6-dependent M2-type microglial polarization in MCAO mice. These results demonstrate that 2'-FL is a potentially effective therapeutic agent for ischemic stroke.

Targeting lipid nanoparticles to the blood brain barrier to ameliorate acute ischemic stroke

After more than 100 failed drug trials for acute ischemic stroke (AIS), one of the most commonly cited reasons for the failure has been that drugs achieve very low concentrations in the at-risk penumbra. To address this problem, here we employ nanotechnology to significantly enhance drug concentration in the penumbra's blood-brain barrier (BBB), whose increased permeability in AIS has long been hypothesized to kill neurons by exposing them to toxic plasma proteins. To devise drug-loaded nanocarriers targeted to the BBB, we conjugated them with antibodies that bind to various cell adhesion molecules on the BBB endothelium. In the transient middle cerebral artery occlusion (tMCAO) mouse model, nanocarriers targeted with VCAM antibodies achieved the highest level of brain delivery, nearly 2 orders of magnitude higher than untargeted ones. VCAM-targeted lipid nanoparticles loaded with either a small molecule drug (dexamethasone) or mRNA (encoding IL-10) reduced cerebral infarct volume by 35% or 73%, respectively, and both significantly lowered mortality rates. In contrast, the drugs delivered without the nanocarriers had no effect on AIS outcomes. Thus, VCAM-targeted lipid nanoparticles represent a new platform for strongly concentrating drugs within the compromised BBB of penumbra, thereby ameliorating AIS.

Graphical abstract

Acute ischemic stroke induces upregulation of VCAM. We specifically targeted upregulated VCAM in the injured region of the brain with drug- or mRNA-loaded targeted nanocarriers. Nanocarriers targeted with VCAM antibodies achieved the highest brain delivery, nearly orders of magnitude higher than untargeted ones. VCAM-targeted nanocarriers loaded with dexamethasone and mRNA encoding IL-10 reduced infarct volume by 35% and 73%, respectively, and improved survival rates.