Stroke Model Research Articles

Dual-tDCS Ameliorates Cerebral Injury and Promotes Motor Function Recovery via cGAS-STING Signaling Pathway in a Rat Model of Ischemic Stroke.

Ischemic stroke is one of the leading causes of death and disability. Dual transcranial direct current stimulation (dual-tDCS) is a promising intervention to treat ischemic stroke, but its efficacy and underlying mechanism remain to be verified. Cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has recently emerged as a key mediator in cerebral injury. However, little is known about the effect of cGAS-STING on neuronal damage in ischemic stroke, and it remains to be studied whether the cGAS-STING pathway is involved in tDCS intervention for ischemic stroke. Therefore, we aimed to investigate whether dual-tDCS can alleviate ischemic brain injury in a rat model of ischemic stroke and if so, whether via cGAS-STING pathway. Middle cerebral artery occlusion (MCAO) was employed to induce a rat model of ischemic stroke. Male SD rats weighing 250-280g were randomly assigned to the Sham, MCAO, Dual-tDCS, Dual-tDCS + RU.521, and Dual-tDCS + 2'3'-cGAMP groups, with 10 rats in each group completing the experiment. Behavioral, morphological, MRI, and molecular biological methods were performed. We found that the cGAS-STING pathway was activated and expressed in neurons after MCAO. Dual-tDCS improved motor function and infarct volume, inhibited neuronal apoptosis, promoted the expression of neurotrophins (BDNF and NGF), CD31, and VEGF, and suppressed inflammation reaction after MCAO via the cGAS-STING pathway. Taken together, dual-tDCS may improve MCAO-induced brain injury and promote the recovery of motor function, resulting from the inhibition of neuronal apoptosis and inflammation reaction, as well as promotion of the expression of nerve plasticity- and angiogenesis-related proteins, via cGAS-STING pathway.

Automated, Reproducible, and Reconfigurable Human Head Phantom for Experimental Testing of Microwave Systems for Stroke Classification

ABSTRACTMicrowave systems for prehospital stroke classification are currently being developed. In the future, these systems should enable rapid recognition of the type of stroke, shorten the time to start treatment, and thus significantly improve the prognosis of patients. In this study, we realized a realistic and reconfigurable 3D human head phantom for the development, testing, and validation of these newly developed diagnostic methods. The phantom enables automated and reproducible measurements for different positions of the stroke model. The stroke model itself is also interchangeable, so measurements can be made for different types, sizes, and shapes of strokes. Furthermore, an extensive series of measurements was performed at a frequency of 1 GHz, and an SVM classification algorithm was deployed, which successfully identified ischemic stroke in 80% of the corresponding measured data. If similar classification accuracy could be achieved in patients, it would lead to a dramatic reduction in the consequences of strokes.

First-in-Human Phase I Clinical Trial of the Adenosine A1R/A3R Agonist AST-004 in Healthy Subjects.

AST-004 is a small-molecule adenosine A1/A3 receptor agonist that has exhibited significant cerebroprotective efficacy in preclinical models of acute ischemic stroke and traumatic brain injury. The primary objectives of this clinical phase I first-in-human study were to evaluate the safety and tolerability profile of single ascending intravenous doses in healthy subjects. The secondary objectives were to characterize the single-dose pharmacokinetic profiles in plasma, cerebrospinal fluid (CSF), and urine. In part 1 of the study, AST-004 was administered in ascending dose cohorts of 5, 25, 50, 75, and 100 mg, with 6 subjects in each cohort receiving the study drug and 2 receiving placebo. In part 2, all 12 subjects received a 100 mg IV infusion of the study drug followed by a single CSF collection per subject via lumbar puncture at 20, 40, or 60 minutes after infusion. A total of 42 subjects received AST-004, with no severe or serious adverse events observed. Twelve of these subjects experienced a treatment-emergent adverse event, the most frequent across groups being headache. In part 2, pharmacokinetic analyses confirmed that AST-004 was distributed in the CSF, with the CSF-to-plasma ratio increasing over the 3 timepoints sampled. The mean half-life was 1.1 to 1.4 hours for doses of 25 to 100 mg, and the geometric mean maximum plasma concentration obtained in the highest dosing cohort (100 mg) was 2232±428 ng/mL. AST-004 was safe and well-tolerated at plasma concentrations 3 to 8× higher than those associated with significant efficacy in astrocyte's preclinical primate stroke efficacy studies, with CSF concentrations highest at the 60-minute collection timepoint, the last timepoint tested. This study supports additional clinical investigations, including evaluation of an extended infusion to support the phase 2 program in stroke and traumatic brain injury.

Rifaximin alleviates intestinal barrier disruption and systemic inflammation via the PXR/NFκB/MLCK pathway and modulates intestinal Lachnospiraceae abundance in heat-stroke mice

Heatstroke is a critical condition with a high mortality rate and intestinal barrier dysfunction is a key factor in its progression to sepsis in some patients. This study aimed to explore the protective effects of rifaximin on the intestinal barrier in heat-stroke mice and the underlying mechanisms. A mouse model of heat stroke was established, followed by rifaximin intervention. Rifaximin significantly improved survival rates, reduced core body temperature, and alleviated intestinal tissue damage. Further mechanistic studies revealed that rifaximin restored heat stroke-induced damage to intestinal barrier function by upregulating the expression of the tight junction proteins, ZO-1 and occludin. Additionally, 16S rRNA sequencing showed that rifaximin significantly increased the abundance of Lachnospiraceae in the gut and enhanced short-chain fatty acid butyrate levels. In vitro experiment results revealed that butyrate promotes the expression of the intestinal epithelial cell protein MUC2, thereby strengthening the intestinal barrier. Rifaximin also activated the pregnane X receptor (PXR) signaling pathway and inhibited the NF-κB/MLCK signaling pathway, reducing the permeability of intestinal epithelial cells. This study demonstrated that rifaximin protects the intestinal barrier in mice with heat stroke through multiple pathways by modulating the gut microbiota, increasing butyrate production, and activating the PXR signaling pathway. These findings provide a new theoretical basis for the clinical application of rifaximin in heat stroke treatment.

Interaction between subventricular zone microglia and neural stem cells impacts the neurogenic response in a mouse model of cortical ischemic stroke

After a stroke, the neurogenic response from the subventricular zone (SVZ) to repair the brain is limited. Microglia, as an integral part of the distinctive SVZ microenvironment, control neural stem / precursor cell (NSPC) behavior. Here, we show that discrete stroke-associated SVZ microglial clusters negatively impact the innate neurogenic response, and we propose a repository of relevant microglia–NSPC ligand–receptor pairs. After photothrombosis, a mouse model of ischemic stroke, the altered SVZ niche environment leads to immediate activation of microglia in the niche and an abnormal neurogenic response, with cell-cycle arrest of neural stem cells and neuroblast cell death. Pharmacological restoration of the niche environment increases the SVZ-derived neurogenic repair and microglial depletion increases the formation and survival of newborn neuroblasts in the SVZ. Therefore, we propose that altered cross-communication between microglial subclusters and NSPCs regulates the extent of the innate neurogenic repair response in the SVZ after stroke.

Mechanism of acid-sensing ion channel modulation by Hi1a.

Acid-sensing ion channels (ASICs) are trimeric cation-selective channels activated by extracellular acidification. Amongst many pathological roles, ASICs are an important mediator of ischemic cell death and hence an attractive drug target for stroke treatment as well as other conditions. A peptide called Hi1a, isolated from Australian funnel web spider venom, inhibits ASIC1a and attenuates cell death in a stroke model up to 8 h after stroke induction. Here, we set out to understand the molecular basis for Hi1a's action. Hi1a is a bivalent toxin with two inhibitory cystine knot domains joined by a short linker. We found that both Hi1a domains modulate human ASIC1a gating with the N-terminal domain impairing channel activation while the C-terminal domain produces a "pro-open" phenotype even at submicromolar concentrations. Interestingly, both domains bind at the same site since a single point mutation, F352A, abolishes functional effects and reduces toxin affinity in surface plasmon resonance measurements. Therefore, the action of Hi1a at ASIC1a appears to arise through a mutually exclusive binding model where either the N or C domain of a single Hi1a binds one ASIC1a subunit. An ASIC1a trimer may bind several inhibitory N domains and one or more pro-open C domains at any one time, accounting for the incomplete inhibition of wild type Hi1a. We also found that the functional differences between these two domains are partially transferred by mutagenesis, affording new insight into the channel function and possible novel avenues of drug design.

Recovery after human bone marrow mesenchymal stem cells (hBM-MSCs)-derived extracellular vesicles (EVs) treatment in post-MCAO rats requires repeated handling.

Rehabilitation is the only current intervention that improves sensorimotor function in ischemic stroke patients, similar to task-specific intensive training in animal models of stroke. Bone marrow mesenchymal stem cells (BM-MSCs)-derived extracellular vesicles (EVs) are promising in restoring brain damage and function in stroke models. Additionally, the non-invasive intranasal route allows EVs to reach the brain and target specific ischemic regions. Yet unclear is how handling might enhance recovery or influence other therapies such as EVs after stroke. We used the transient middle cerebral artery occlusion (MCAO) model of stroke in rats to assess how intensive handling alone, in the form of sensorimotor behavioral tests, or in combination with an intranasal treatment of EVs restored neurological function and ischemic damage. Handled rats were exposed to a battery of sensorimotor tests, including the modified Neurological Severity Score (mNSS), beam balance, corner, grid walking, forelimb placement, and cylinder tests, together with Magnetic Resonance Imaging (MRI) at 2, 7, 14, 21, and 28 days post-stroke (dps). Handled MCAO rats were also exposed to an intranasal multidose or single dose of EVs. Non-handled rats were evaluated only by mNSS and MRI at 2, 28, and 56 dps and were treated with a single intranasal dose of EVs. Our results showed that handling animals after MCAO is necessary for EVs to work at the tested dose and frequency, and that a single cumulative dose of EVs further improves the neurological function recovered during handling. These results show the importance of rehabilitation in combination with other treatments such as EVs, and highlight how extensive behavioral testing might influence functional recovery after stroke.

Tetramethylpyrazine Analogue T-006 Protects Neuronal and Endothelial Cells Against Oxidative Stress via PI3K/AKT/mTOR and Nrf2 Signaling.

T-006, a novel neuroprotective derivative of tetramethylpyrazine (TMP), exhibits multifunctional neuroprotective properties. T-006 has been shown to improve neurological and behavioral functions in animal models of ischemic stroke and neurodegenerative diseases. The present study aims to further elucidate the mechanisms underlying the protective effects of T-006 against oxidative injuries induced by glutamate or hypoxia. Mouse hippocampal HT22 cells were used to evaluate the neuroprotective effects of T-006 against glutamate-induced injuries, while mouse brain endothelial bEnd.3 cells were used to evaluate the cerebrovascular protective effects of T-006 against oxygen-glucose deprivation followed by reperfusion (OGD/R)-induced injuries. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were used to measure cell viability and oxidative stress. Western blot and immunofluorescence analyses of protein expression were used to study cell signaling pathways. T-006 exhibited significant protective effects in both oxidative injury models. In HT22 cells, T-006 reduced cell death and enhanced antioxidant capacity by upregulating mTOR and nuclear factor erythroid 2-related factor 2/Heme oxygenase-1 (Nrf2/HO-1) signaling. Similarly, in bEnd.3 cells, T-006 reduced oxidative injuries and preserved tight junction integrity through Nrf2/HO-1 upregulation. These effects were inhibited by LY294002, a Phosphoinositide 3-kinase (PI3K) inhibitor. T-006 may exert its neuroprotective and cerebrovascular protective effects via the regulation of PI3K/AKT-mediated pathways, which facilitate downstream mTOR and Nrf2 signaling, leading to improved cell survival and antioxidant defenses.

Enhancing amide proton transfer imaging in ischemic stroke using a machine learning approach with partially synthetic data.

Amide proton transfer (APT) imaging, a technique sensitive to tissue pH, holds promise in the diagnosis of ischemic stroke. Achieving accurate and rapid APT imaging is crucial for this application. However, conventional APT quantification methods either lack accuracy or are time-consuming. Machine learning (ML) has recently been recognized as a potential solution to improve APT quantification. In this paper, we applied an ML model trained on a new type of partially synthetic data, along with an optimization approach utilizing recursive feature elimination, to predict APT imaging in an animal stroke model. This partially synthetic datum is not a simple blend of measured and simulated chemical exchange saturation transfer (CEST) signals. Rather, it integrates the underlying components including all CEST, direct water saturation, and magnetization transfer effects partly derived from measurements and simulations to reconstruct the CEST signals using an inverse summation relationship. Training with partially synthetic data requires less in vivo data compared to training entirely with fully synthetic or in vivo data, making it a more practical approach. Since this type of data closely resembles real tissue, it leads to more accurate predictions than ML models trained on fully synthetic data. Results indicate that an ML model trained on this partially synthetic data can successfully predict the APT effect with enhanced accuracy, providing significant contrast between stroke lesions and normal tissues, thus clearly delineating lesions. In contrast, conventional quantification methods such as the asymmetric analysis method, three-point method, and multiple-pool model Lorentzian fit showed inadequate accuracy in quantifying the APT effect. Moreover, ML methods trained using in vivo data and fully synthetic data exhibited poor predictive performance due to insufficient training data and inaccurate simulation pool settings or parameter ranges, respectively. Following optimization, only 13 frequency offsets were selected from the initial 69, resulting in significantly reduced scan time.

L-PGDS-PGD2-DP1 Axis Regulates Phagocytosis by CD36+ MGs/MΦs That Are Exclusively Present Within Ischemic Areas After Stroke.

Brain injuries, such as ischemic stroke, cause cell death. Although phagocytosis of cellular debris is mainly performed by microglia/macrophages (MGs/MΦs), excessive accumulation beyond their phagocytic capacities results in waste product buildup, delaying brain cell regeneration. Therefore, it is essential to increase the potential for waste product removal from damaged brains. Lipocalin-type prostaglandin D synthase (L-PGDS) is the primary synthase for prostaglandin D2 (PGD2) and has been reported as a scavenger of waste products. However, the mechanism by which the L-PGDS-PGD2 axis exerts such an effect remains unelucidated. In this study, using a mouse model of ischemic stroke, we found that L-PGDS and its downstream signaling pathway components, including PGD2 and PGD2 receptor DP1 (but not DP2), were significantly upregulated in ischemic areas. Immunohistochemistry revealed the predominant expression of L-PGDS in the leptomeninges of ischemic areas and high expression levels of DP1 in CD36+ MGs/MΦs that were specifically present within ischemic areas. Furthermore, PGD2 treatment promoted the conversion of MGs/MΦs into CD36+ scavenger types and increased phagocytic activities of CD36+ MGs/MΦs. Because CD36+ MGs/MΦs specifically appeared within ischemic areas after stroke, our findings suggest that the L-PGDS-PGD2-DP1 axis plays an important role in brain tissue repair by regulating phagocytic activities of CD36+ MGs/MΦs.

Prediction Models for Post-Stroke Hospital Readmission: A Systematic Review.

This study aims to evaluate the predictive performance and methodological quality of post-stroke readmission prediction models, identify key predictors associated with readmission, and provide guidance for selecting appropriate risk assessment tools. A comprehensive literature search was conducted from inception to February 1, 2024. Two independent researchers screened the literature and extracted relevant data using the CHARMS checklist. Eleven studies and 16 prediction models were included, with sample sizes ranging from 108 to 803,124 cases and outcome event incidences between 5.2% and 50.0%. The four most frequently included predictors in the models were length of stay, hypertension, age, and functional disability. Twelve models reported an area under the curve (AUC) ranging from 0.520 to 0.940, and five models provided calibration metrics. Only one model included both internal and external validation, while six models had internal validation. Eleven studies were found to have a high risk of bias (ROB), predominantly in the area of data analysis. This systematic review included 16 readmission prediction models for stroke, which generally exhibited good predictive performance and can effectively identify high-risk patients likely to be readmitted. However, the generalizability of these models remains uncertain due to methodological limitations. Rather than developing new readmission prediction models for stroke, the focus should shift toward external validation and the iterative adaptation of existing models. These models should be tailored to local settings, extended with new predictors if necessary, and presented in an interactive graphical user interface.

Plasma metabolites, systolic blood pressure, lifestyle and stroke risk: a UK Biobank based cohort study.

Background To estimate the associations of stroke risk with plasma metabolites, metabolic risk score (MRS), the combinations of MRS with hypertension or lifestyle, and lifestyle-related metabolic signature. To assess the improvement of the stroke risk prediction model through the incorporation of MRS. Methods A total of 77,315 participants from the UK Biobank were included in this study. Xgboost and LASSO-COX regression were used to select metabolites and construct MRS. Elastic net regression was utilized to construct the lifestyle-related metabolic signature. Multivariate Cox regression was used to estimate the associations between metabolites, MRS, the combinations of MRS with hypertension or lifestyle, lifestyle-related metabolic signature and stroke risk. Results We identified 48, 63, 39, and 4 metabolites associated with the risk of stroke, ischemic stroke (IS), subarachnoid hemorrhage (SAH), and intracerebral hemorrhage (ICH), respectively. High MRS significantly increased the risk of stroke (HR= 2.65 [95%CI 2.09-3.35]), IS (HR= 2.45 [95%CI 1.89-3.17]), ICH (HR= 2.74 [95%CI 1.55-4.85]), and SAH (HR= 4.64 [95%CI 2.25-9.56]). In the combination analyses, compared with normal SBP and low MRS, normal/high SBP and high MRS significantly increased stroke risk (HR= 5.80 [95% CI: 2.75-12.27]/6.37 [95% CI 3.22-12.62]). A favorable/unfavorable lifestyle and high MRS also significantly increased stroke risk (HR= 2.38 [95% CI: 1.73-3.28]/3.86 [95% CI 2.63-5.67]) compared with a favorable lifestyle and low MRS. Incorporating MRS into the 15-year stroke and IS risk prediction model increased the AUCs from 0.746 to 0.766 and from 0.771 to 0.811, respectively. The metabolic signature was correlated with adherence to a healthy lifestyle (r = 0.414; P = 2.22e-16) and inversely associated with stroke risk (HR= 0.80 [95% CI 0.73-0.86]). Conclusions Various metabolites and MRS were significantly associated with the risk of stroke, IS, ICH and SAH. Individuals with a high MRS may face an elevated stroke risk among populations with high SBP or unhealthy lifestyle, even those with normal SBP or healthy lifestyle. MRS provided modest improvement to the stroke risk prediction model. The lifestyle-related metabolic signature could reduce 20% stroke risk.

A stroke organoids-multiomics platform to study injury mechanism and drug response

Stroke is one of the top causes of death and disability worldwide, and its pathogenesis and mechanism have not been fully elucidated. Several agents have shown protective effects against stroke in animal models; however, few studies have shown obvious effects in clinical practice. This might be due to differences in brain structure and physiological function between humans and rodents. In this study, we established a hypoxic stroke model in human-induced pluripotent stem cell (hiPSC)-derived brain organoids to simulate the hypoxic stroke caused by ischemia. Then, by combining proteomics, single-cell transcriptome analysis, and histopathological analysis, a significant increase of three types of astrocytes was identified and they showed different responses to hypoxic environments; also the main type of astrocyte that cause brain tissue hyperplasia in ischemia brains was identified. In addition, the cortical excitatory neurons had signs of apoptosis and aging after hypoxia both in vivo and in vitro. Most importantly, we identified a possible role of a traditional Chinese medicine formula called DengZhanShengMai capsule in ischemic and hypoxic stroke treatment through regulation of lipid metabolism related biological functions. These results indicate that the combination of brain organoids and multiomics method is helpful for developing a new strategy to direct study stroke, and could provide a promising platform for drug screening of stroke in the future.

Von Willebrand factor targeted thrombolysis in canine basilar artery occlusion.

Posterior circulation strokes, accounting for 20% of acute ischemic strokes, significantly contribute to morbidity and mortality. Fibrinolysis by rtPA improves outcomes in stroke but the risk of intracranial hemorrhage limits benefit. Arterial recanalization of basilar artery occlusion by thrombolysis or endovascular thrombectomy improves outcomes in posterior circulation strokes. This study investigates a VWF-targeting RNA aptamer as a safer and more effective alternative to rtPA in a canine model. Autologous clots were placed into the basilar artery to induce stroke in 24 beagles. To compare reperfusion, 0.9 mg/kg rtPA, 0.5 mg/kg BB-031, or vehicle were administered 60 min after the initiation of occlusion. Digital subtraction angiography, laser speckle imaging and magnetic resonance imaging were used to assess recanalization, reperfusion and infarct volume, respectively. Treatment with BB-031 resulted in recanalization of the posterior circulation on digital subtraction angiography with no evidence of microembolism assessed at sacrifice. 66.5% of animals treated with BB-031 resulted in reperfusion with a TICI score of ≥1 whereas vehicle remained at TICI score 0 as did all but one rtPA animal at sacrifice. Improved perfusion was seen in the basilar artery and surrounding blood vessels visualized through the cranial window with laser speckle imaging to ~47% of its original baseline in BB-031 group compared to rtPA at 37% and vehicle at 22%. Finally, BB-031-treatment resulted in an approximate 32% mean infarct volume, significantly smaller on magnetic resonance imaging compared to 56% in vehicle treated and 48% with rtPA treatment. Targeted inhibition of VWF by BB-031 increased recanalization and reperfusion, and reduced infarct volume in a canine model of BAO stroke. It represents a promising target based on preliminary results for treating acute ischemic stroke.

Neuroprotective effects of psilocybin in a rat model of stroke

BackgroundPsilocybin is a psychedelic 5HT2A receptor agonist found in “magic mushrooms”. Recent studies have indicated that 5HT2A agonists, such as dimethyltryptamine, given before middle cerebral artery occlusion (MCAo), improve staircase behavior, increased BDNF expression, and reduce brain infarction in stroke rats. The objective of this study is to determine the protective effect of psilocybin in cellular and animal models of stroke.MethodsAdult male and timed-pregnant Sprague-Dawley rats were used for this study. The neural protective effects of psilocybin were determined in primary rat cortical neurons and adult rats. Rats were subjected to a 60-min middle cerebral artery occlusion. Brain tissues were collected for histological and qRTPCR analysis.ResultsPsilocybin reduced glutamate-mediated neuronal loss in rat primary cortical neuronal cultures. Psilocybin-mediated protection in culture was antagonized by the BDNF inhibitor ANA12. Pretreatment with psilocybin reduced brain infarction and neurological deficits in stroke rats. Early post-treatment with psilocybin improved locomotor behavior, upregulated the expression of MAP2 and synaptophysin, and down-regulated the expression of IBA1 in the stroke brain. ANA12 significantly attenuated psilocybin-mediated reduction in brain infarction and improvements in locomotor behavior.ConclusionsPsilocybin reduced brain infarction and improved locomotor behavior in stroke rats; the protective mechanisms involve regulating BDNF expression. Our data support a novel therapeutic approach of psilocybin in stroke.

Ozone therapy mitigates parthanatos after ischemic stroke

BackgroundStroke is a leading cause of death worldwide, with oxidative stress and calcium overload playing significant roles in the pathophysiology of the disease. Ozone, renowned for its potent antioxidant properties, is commonly employed as an adjuvant therapy in clinical settings. Nevertheless, it remains unclear whether ozone therapy on parthanatos in cerebral ischemia–reperfusion injury (CIRI). This study aims to investigate the impact of ozone therapy on reducing parthanatos during CIRI and to elucidate the underlying mechanism.MethodsHydrogen peroxide (H2O2) was utilized to mimic the generation of reactive oxygen species (ROS) in SH-SY5Y cell reperfusion injury in vitro, and an in vivo ischemic stroke model was established. Ozone saline was introduced for co-culture or intravenously administered to mice. Apoptosis and oxidative stress were assessed using flow cytometry and immunofluorescence. Western blotting was utilized to examine the expression of parthanatos signature proteins. The mechanism by which ozone inhibits parthanatos was elucidated through inhibiting PPARg or Nrf2 activity. ResultsThe findings demonstrated that ozone mitigated H2O2-induced parthanatos by either upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) or activating peroxisome proliferator-activated receptorg (PPARg). Furthermore, through the use of calcium chelators and ROS inhibitors, it was discovered that ROS directly induced parthanatos and facilitated intracellular calcium elevation. Notably, a malignant feedback loop between ROS and calcium was identified, further amplifying the induction of parthanatos. Ozone therapy exhibited its efficacy by increasing PPARg activity or enhancing the Nrf2 translation, thereby inhibiting ROS production induced by H2O2. Concurrently, our study demonstrated that ozone treatment markedly inhibited parthanatos in stroke-afflicted mice. Additionally, ozone therapy demonstrated significant neuroprotective effects on cortical neurons, effectively suppressing parthanatos.ConclusionsThese findings contribute valuable insights into the potential of ozone therapy as a therapeutic strategy for reducing parthanatos during CIRI, highlighting its impact on key molecular pathways associated with oxidative stress and calcium regulation.

Exploring Lysophosphatidylcholine as a Biomarker in Ischemic Stroke: The Plasma-Brain Disjunction.

Lipids and their bioactive metabolites, notably lysophosphatidylcholine (LPC), are increasingly important in ischemic stroke research. Reduced plasma LPC levels have been linked to stroke occurrence and poor outcomes, positioning LPC as a potential prognostic or diagnostic marker. Nonetheless, the connection between plasma LPC levels and stroke severity remains unclear. This study aimed to elucidate this relationship by examining plasma LPC levels in conjunction with brain LPC levels to provide a deeper understanding of the underlying mechanisms. Adult male Sprague-Dawley rats underwent transient middle cerebral artery occlusion and were randomly assigned to different groups (sham-operated, vehicle, LPC supplementation, or LPC inhibition). We measured multiple LPC species in the plasma and brain, alongside assessing sensorimotor dysfunction, cerebral perfusion, lesion volume, and markers of BBB damage, inflammation, apoptosis, and oxidative stress. Among five LPC species, plasma LPC(16:0) and LPC(18:1) showed strong correlations with sensorimotor dysfunction, lesion severity, and mechanistic biomarkers in the rat stroke model. Despite notable discrepancies between plasma and brain LPC levels, both were strongly linked to functional outcomes and mechanistic biomarkers, suggesting that LPC's prognostic value is retained extracranially. This study advances the understanding of LPC as a blood marker in ischemic stroke and highlights directions for future research to further elucidate its association with stroke severity, particularly through investigations in more clinically representative models.

Cognitive-Enhancing Effect of Marine Brown Algae-Derived Phenolics through S100B Inhibition and Antioxidant Activity in the Rat Model of Ischemic Stroke.

Cognitive impairments are frequently reported after ischemic strokes. Novel and effective treatments are required. This study aimed to develop a functional ingredient obtained from marine algae and to determine the effect of the extract on antioxidative stress, as well as neuroprotective effects, in a rat model of MCAO-induced ischemic stroke. Among the selected marine algal extracts, Sargassum polycystum displayed the highest total phenolic content and antioxidative potential, and was subsequently used to evaluate cognitive function in rat models of ischemic stroke. The S. polycystum extract, administered at doses of 100, 300, and 500 mg/kg BW, significantly improved cognitive function by enhancing cognitive performance in the Morris water maze and novel object recognition tests. Biochemical changes revealed that providing S. polycystum increased the activities of SOD, CAT, and GSH-Px by 52.48%, 50.77%, and 66.20%, respectively, and decreased the concentrations of MDA by 51.58% and S100B by 36.64% compared to the vehicle group. These findings suggest that S. polycystum extract may mitigate cognitive impairment in ischemic stroke by reducing oxidative stress and inhibiting S100B expression, thus highlighting its potential as a functional ingredient for drugs and nutraceuticals aimed at neuroprotection.

Two-phase therapy for improving neuroprotection and neurogenesis: Preventive use of omega fatty acids plus Copolymer-1 immunization after stroke

Stroke is a major global health issue, ranking as the second leading cause of death and the primary cause of disability worldwide. However, current therapeutic options remain limited. Nutritional supplementation as a form of primary prevention stands as a potential stroke therapeutic. In particular, the intake of omega-3 fatty acids (omega-3FA) exerts anti-inflammatory and neuroprotective effects that help reduce the risk of stroke. In parallel, treatment with Copolymer-1 (COP-1), a peptide with immunomodulatory properties through Th1/Th2/Th3 phenotype switching, similarly affords neuroprotective and neurorestorative effects in stroke models. To investigate the combined effects of these treatments, we designed a two-phase therapy: the first phase involved preventive supplementation with omega-3FA, while the second phase included COP-1 immunization following stroke injury. Sprague-Dawley rats were randomly assigned to one of the four groups: 1) control, 2) omega-3FA, 3) COP-1, and 4) omega-3FA + COP-1. Omega-3FAs were administered for 28 days before inducing stroke. Thirty minutes after reperfusion, the respective groups were immunized with COP-1. Seven days post-stroke, neurological deficits were assessed using the Zea-Longa scale, infarct volumes with 2,3,5-triphenyltetrazolium chloride (TTC) staining, and levels of neurogenesis via immunofluorescence imaging. The results showed that the two-phase therapy produced significant synergistic effects, markedly reducing neurological deficits, and infarct volumes, while enhancing neurogenic activities in neurogenic niches. This combined approach underscores the potential of integrating nutritional and pharmacological strategies to enhance stroke recovery.

The AGEs/RAGE Signaling Pathway Regulates NLRP3-Mediated Neuronal Pyroptosis After MCAO Injury in Lepr-/- Obese Rats.

Obesity is recognized as a primary risk factor for cerebral ischemia, which has shown a significant increase in its incidence among obese patients. The exact mechanism by which obesity exacerbates cerebral ischemic injury is not fully understood though. The present study validated the hypothesis that obesity mediates pyroptosis by the AGEs/RAGE signaling pathway to exacerbate cerebral ischemic injury. Leptin receptor knockout (Lepr-/- ) rats were used in this study to construct an obesity model, and the middle cerebral artery occlusion (MCAO) models of ischemic stroke were established in Lepr-/- obese rats and their wild-type (WT) littermates respectively. Zea-Longa score, TTC and H&E staining were utilized to evaluate the neurological impairment. Western Blot, immunohistochemistry, and immunofluorescence were used to detect protein expressions. Transmission electron microscopy was used to observe the pores in the neuronal cell membrane in the ischemic penumbra cortex. Compared with WT littermates, Lepr-/- obese rats exhibited exacerbated neuronal injury after MCAO, with higher expressions of NLRP3 inflammasome and pyroptosis-related proteins in the cortical tissue of the penumbra. Moreover, more GSDMD pores were observed on the neuronal cell membranes of Lepr-/- obese rats according to the electron microscopy. Inhibition of NLRP3 inflammasome expression with MCC950 inhibited neuronal pyroptosis after cerebral ischemia in Lepr-/- obese rats, thus reducing neuronal injury. We also found that compared with WT littermates, the levels of AGEs and RAGE in the cortex of Lepr-/- obese rats are significantly higher, with further increase after cerebral ischemia. Inhibition of AGEs/RAGE signaling pathway with FPS-ZM1 reduced the NLRP3 inflammasome-mediated neuronal pyroptosis in Lepr-/- obese rats, thereby mitigating the neuronal damage after cerebral ischemia. The AGEs/RAGE signaling pathway is involved in the exacerbation of cerebral ischemic injury in Lepr-/- obese rats via regulating NLRP3-mediated neuronal pyroptosis.