Diagnostic value of transcranial doppler to predict delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage : To predict delayed cerebral ischemia.

BACKGROUND: Transcranial Doppler (TCD) is a technique to assess blood flow velocity in the cerebral arteries. TCD is frequently used to monitor aneurysmal subarachnoid hemorrhage (aSAH) patients. This study compares TCD-criteria for vasospasm and its association with Delayed Cerebral Ischemia (DCI). An overall score based on flow velocities of various intracranial arteries was developed and evaluated. METHODS: A retrospective diagnostic accuracy study was conducted between 1998 and 2017 with 621 patients included. Mean flow velocity (MFV) of the cerebral artery was measured between 2-5 days and between 6-9 days after ictus. Cutoff values from the literature, new cutoff values, and a new composite score (Combined Severity Score) were used to predict DCI. Sensitivity, specificity, and area under the curve (AUC) were determined, and logistic regression analysis was performed. RESULTS: The Combined Severity Score showed an AUC 0.64 (95%CI 0.56-.71) at days 2-5, with sensitivity 0.53 and specificity 0.74. The Combined Severity Score had an adjusted Odds Ratio of 3.41 (95CI 1.86-6.32) for DCI. MCA-measurements yielded the highest AUC to detect DCI at day 2-5: AUC 0.65 (95%CI 0.58-0.73). Optimal cutoff MFV of 83 cm/s for MCA resulted in sensitivity 0.73 and specificity 0.50 at days 2-5. CONCLUSION: TCD-monitoring of aSAH patients may be a valuable strategy for DCI risk stratification. Lower cutoff values can be used in the early phase after the ictus (day 2-5) than are commonly used now. The Combined Severity Score incorporating all major cerebral arteries may provide a meaningful contribution to interpreting TCD measurements.

Disulfiram downregulates ferredoxin 1 to maintain copper homeostasis and inhibit inflammation in cerebral ischemia/reperfusion injury.

In the current study, we aimed to investigate whether disulfiram (DSF) exerts a neuroprotective role in cerebral ischemiareperfusion (CI-RI) injury by modulating ferredoxin 1 (FDX1) to regulate copper ion (Cu) levels and inhibiting inflammatory responses. To simulate CI-RI, a transient middle cerebral artery occlusion (tMCAO) model in C57/BL6 mice was employed. Mice were administered with or without DSF before and after tMCAO. Changes in infarct volume after tMCAO were observed using TTC staining. Nissl staining and hematoxylin-eosin (he) staining were used to observe the morphological changes of nerve cells at the microscopic level. The inhibitory effect of DSF on initial inflammation was verified by TUNEL assay, apoptosis-related protein detection and iron concentration detection. FDX1 is the main regulatory protein of copper death, and the occurrence of copper death will lead to the increase of HSP70 stress and inflammatory response. Cuproptosis-related proteins and downstream inflammatory factors were detected by western blotting, immunofluorescence staining, and immunohistochemistry. The content of copper ions was detected using a specific kit, while electron microscopy was employed to examine mitochondrial changes. We found that DSF reduced the cerebral infarction volume, regulated the expression of cuproptosis-related proteins, and modulated copper content through down regulation of FDX1 expression. Moreover, DSF inhibited the HSP70/TLR-4/NLRP3 signaling pathway. Collectively, DSF could regulate Cu homeostasis by inhibiting FDX1, acting on the HSP70/TLR4/NLRP3 pathway to alleviate CI/RI. Accordingly, DSF could mitigate inflammatory responses and safeguard mitochondrial integrity, yielding novel therapeutic targets and mechanisms for the clinical management of ischemia-reperfusion injury.

RNA sequencing reveals the potential mechanism of exercise preconditioning for cerebral ischemia reperfusion injury in rats.

INTRODUCTION: Cerebral ischemia reperfusion injury (CIRI) often leads to deleterious complications after stroke patients receive reperfusion therapy. Exercise preconditioning (EP) has been reported to facilitate brain function recovery. We aim to explore the specific mechanism of EP in CIRI. METHODS: Sprague-Dawley rats were randomized into Sham, middle cerebral artery occlusion (MCAO), and EP groups (n = 11). The rats in the EP group received adaptive training for 3 days (10 m/min, 20 min/day, with a 0° incline) and formal training for 3 weeks (6 days/week, 25 m/min, 30 min/day, with a 0° incline). Then, rats underwent MCAO surgery to establish CIRI models. After 48 h, neurological deficits and cerebral infarction of the rats were measured. Neuronal death and apoptosis in the cerebral cortices were detected. Furthermore, RNA sequencing was conducted to investigate the specific mechanism of EP on CIRI, and qPCR and Western blotting were further applied to confirm RNA sequencing results. RESULTS: EP improved neurological deficit scores and reduced cerebral infarction in MCAO rats. Additionally, pre-ischemic exercise also alleviated neuronal death and apoptosis of the cerebral cortices in MCAO rats. Importantly, 17 differentially expressed genes (DEGs) were identified through RNA sequencing, and these DEGs were mainly enriched in the HIF-1 pathway, cellular senescence, proteoglycans in cancer, and so on. qPCR and Western blotting further confirmed that EP could suppress TIMP1, SOCS3, ANGPTL4, CDO1, and SERPINE1 expressions in MCAO rats. CONCLUSION: EP can improve CIRI in vivo, the mechanism may relate to TIMP1 expression and HIF-1 pathway, which provided novel targets for CIRI treatment.

Combining metabolomics and network pharmacology to investigate the protective effect of Jiawei Xinglou Chengqi Granules in ischemic stroke.

Jiawei Xinglou Chengqi Granule (JXCG) is an effective herbal medicine for the treatment of ischemic stroke (IS). JXCG has been shown to effectively ameliorate cerebral ischemic symptoms in clinical practice, but the underlying mechanisms are unclear. In this study, we investigated the mechanisms of action of JXCG in the treatment of IS by combining metabolomics with network pharmacology. The chemical composition of JXCG was analyzed using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Ultra-high performance liquid chromatography-tandem time-of-flight mass spectrometry (UHPLC-Q-TOF MS) untargeted metabolomics were used to identify differential metabolites within metabolic pathways. Network pharmacology was applied to mine potential targets of JXCG in the treatment of IS. The identified key targets were validated by constructing an integrated network of metabolomics and network pharmacology and by molecular docking using Cytoscape. The effect of JXCG on IS was evaluated in vivo, and the predicted targets and pathways of JXCG in IS therapy were assessed using immunoblotting. Combining metabolomics and network pharmacology, we identified the therapeutic targets of JXCG for IS. Notably, JXCG lessened neuronal damage and reduced cerebral infarct size in rats with IS. Western blot analysis showed that JXCG upregulated PRKCH and downregulated PRKCE and PRKCQ proteins. Our combined network pharmacology and metabolomics findings showed that JXCG may have therapeutic potential in the treatment of IS by targeting multiple factors and pathways.

Chikusetsu Saponin IVa liposomes modified with a retro-enantio peptide penetrating the blood-brain barrier to suppress pyroptosis in acute ischemic stroke rats.

BACKGROUND: The therapeutic strategies for acute ischemic stroke were faced with substantial constraints, emphasizing the necessity to safeguard neuronal cells during cerebral ischemia to reduce neurological impairments and enhance recovery outcomes. Despite its potential as a neuroprotective agent in stroke treatment, Chikusetsu saponin IVa encounters numerous challenges in clinical application. RESULT: Brain-targeted liposomes modified with THRre peptides showed substantial uptake by bEnd. 3 and PC-12 cells and demonstrated the ability to cross an in vitro blood-brain barrier model, subsequently accumulating in PC-12 cells. In vivo, they could significantly accumulate in rat brain. Treatment with C-IVa-LPs-THRre notably reduced the expression of proteins in the P2RX7/NLRP3/Caspase-1 pathway and inflammatory factors. This was evidenced by decreased cerebral infarct size and improved neurological function in MCAO rats. CONCLUSION: The findings indicate that C-IVa-LPs-THRre could serve as a promising strategy for targeting cerebral ischemia. This approach enhances drug concentration in the brain, mitigates pyroptosis, and improves the neuroinflammatory response associated with stroke.

Beyond nimodipine: advanced neuroprotection strategies for aneurysmal subarachnoid hemorrhage vasospasm and delayed cerebral ischemia.

The clinical management of aneurysmal subarachnoid hemorrhage (SAH)-associated vasospasm remains a challenge in neurosurgical practice, with its prevention and treatment having a major impact on neurological outcome. While considered a mainstay, nimodipine is burdened by some non-negligible limitations that make it still a suboptimal candidate of pharmacotherapy for SAH. This narrative review aims to provide an update on the pharmacodynamics, pharmacokinetics, overall evidence, and strength of recommendation of nimodipine alternative drugs for aneurysmal SAH-associated vasospasm and delayed cerebral ischemia. A PRISMA literature search was performed in the PubMed/Medline, Web of Science, ClinicalTrials.gov, and PubChem databases using a combination of the MeSH terms "medical therapy," "management," "cerebral vasospasm," "subarachnoid hemorrhage," and "delayed cerebral ischemia." Collected articles were reviewed for typology and relevance prior to final inclusion. A total of 346 articles were initially collected. The identification, screening, eligibility, and inclusion process resulted in the selection of 59 studies. Nicardipine and cilostazol, which have longer half-lives than nimodipine, had robust evidence of efficacy and safety. Eicosapentaenoic acid, dapsone and clazosentan showed a good balance between effectiveness and favorable pharmacokinetics. Combinations between different drug classes have been studied to a very limited extent. Nicardipine, cilostazol, Rho-kinase inhibitors, and clazosentan proved their better pharmacokinetic profiles compared with nimodipine without prejudice with effective and safe neuroprotective role. However, the number of trials conducted is significantly lower than for nimodipine. Aneurysmal SAH-associated vasospasm remains an area of ongoing preclinical and clinical research where the search for new drugs or associations is critical.

[Mechanism study of 6-shogaol alleviating cerebral ischemia/reperfusion injury by regulating microRNA-26a-5p/death-associated protein kinase 1].

OBJECTIVE: To investigate whether 6-shogaol (6-SH) alleviates oxygen-glucose deprivation/reoxygenation (OGD/R)-induced neuronal autophagy and calcium overload by promoting the expression of microRNA-26a-5p (miR-26a-5p) and inhibiting death-associated protein kinase 1 (DAPK1), and to explore its potential mechanisms. METHODS: Primary cultured logarithmic growth phase mouse hippocampal neurons HT22 cells were taken and cell counting kit-8 (CCK-8) was used to detect cell viability, searching for the optimal concentration of Na2S2O4. HT22 cells were divided into blank control group (NC group), OGD/R group (sugar-free culture medium + 10 mmol/L Na2S2O4 treatment for 1.5 hours followed by normal culture medium for 4 hours), 6-SH intervention group (cultured with 10 µmol/L 6-SH for 4 hours after OGD), negative control inhibitor pretreatment group (transfected with negative control inhibitor for 48 hours followed by OGD, then cultured with 6-SH for 4 hours), and miR-26a-5p inhibitor pretreatment group (transfected with miR-26a-5p inhibitor for 48 hours followed by OGD, then cultured with 6-SH for 4 hours). Cell viability of each group was detected by CCK-8 method; cell ultrastructure was observed under transmission electron microscopy; real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the gene expressions of DAPK1 and miR-26a-5p; molecular docking were used to verify the interaction between 6-SH and miR-26a-5p; dual-luciferase assay was used to verify the targeting relationship between DAPK1 and miR-26a-5p; flow cytometry was used to determine the levels of intracellular Ca2+; Western blotting was used to detect the protein expressions of phosphorylated-glutamate receptor 2B (p-NMDAR2B) Ser1303, DAPK1, autophagy related protein Beclin1, light chain 3 (LC3), and p-DAPK1 Ser308; immunofluorescence was used to detect the expression of LC3 and Beclin1. RESULTS: The results of the CCK-8 assay showed that the cell viability of the 6-SH intervention group was significantly increased compared to the OGD/R group, while the cell viability of the miR-26a-5p inhibitor pretreatment group was significantly decreased compared to the 6-SH intervention group. Transmission electron microscopy revealed that the number of autophagosomes in the 6-SH intervention group was significantly reduced compared to the OGD/R group, while the number of autophagosomes in the miR-26a-5p inhibitor pretreatment group was significantly increased compared to the 6-SH intervention group. RT-qPCR results showed that compared with the OGD/R group, the expression of miR-26a-5p was significantly upregulated and the expression of DAPK1 mRNA was significantly downregulated in the 6-SH intervention group; compared with the 6-SH intervention group, the expression of miR-26a-5p was significantly downregulated and the expression of DAPK1 mRNA was significantly upregulated in the miR-26a-5p inhibitor pretreatment group. Molecular docking verified the interaction between 6-SH and miR-26a-5p. Dual-luciferase reporter gene assay showed that compared with the negative control group, mmu-miR-26a-5p significantly downregulated the luciferase expression of m-DAPK1-3UTR-WT, indicating a binding interaction between them. Flow cytometry results showed that compared with the OGD/R group, the level of intracellular Ca2+; was significantly decreased in the 6-SH intervention group; compared with the 6-SH intervention group, the level of Ca2+ was significantly increased in the miR-26a-5p inhibitor pretreatment group. Western blotting results showed that compared with the OGD/R group, the protein expressions of p-NMDAR2B Ser1303, DAPK1, Beclin1, and LC3 were significantly decreased in the 6-SH intervention group (p-NMDAR2B Ser1303/ß-actin: 2.34±0.27 vs. 4.78±0.39, DAPK1/ß-actin: 1.40±0.13 vs. 2.37±0.21, Beclin1/ß-actin: 2.61±0.32 vs. 4.32±0.29, LC3/ß-actin: 2.52±0.45 vs. 5.09±0.18, all P < 0.05), while the protein expression of p-DAPK1 Ser308 was significantly increased (p-DAPK1 Ser308/ß-actin: 0.66±0.09 vs. 0.40±0.02, P < 0.05); compared with the 6-SH intervention group, the protein expressions of p-NMDAR2B Ser1303, DAPK1, Beclin1, and LC3 were significantly increased in the miR-26a-5p inhibitor pretreatment group (p-NMDAR2B Ser1303/ß-actin: 4.08±0.14 vs. 2.34±0.27, DAPK1/ß-actin: 1.96±0.15 vs. 1.40±0.13, Beclin1/ß-actin: 3.92±0.31 vs. 2.61±0.32, LC3/ß-actin: 4.33±0.33 vs. 2.52±0.45, all P < 0.05), while the expression of p-DAPK1 Ser308 protein was significantly decreased (p-DAPK1 Ser308/ß-actin: 0.33±0.12 vs. 0.66±0.09, P < 0.05); immunofluorescence staining showed that compared with the OGD/R group, the fluorescence intensity of LC3 and Beclin1 was significantly decreased in the 6-SH intervention group; compared with the 6-SH intervention group, the fluorescence intensity of LC3 and Beclin1 was significantly increased in the miR-26a-5p inhibitor pretreatment group. CONCLUSIONS: 6-SH can alleviate neuronal damage by regulating miR-26a-5p/DAPK1 to reduce autophagy and calcium overload in cells.

Microsurgical clipping versus endovascular therapy for treating patients with middle cerebral artery aneurysms presenting with neurological ischemic symptoms.

Studies comparing different treatment methods in patients with middle cerebral artery (MCA) aneurysms in different subgroups of onset symptoms are lacking. It is necessary to explore the safety and efficacy of open surgical treatment and endovascular therapy in patients with MCA aneurysms in a specific population. This study aimed to compare microsurgical clipping versus endovascular therapy regarding complication rates and outcomes in patients with MCA aneurysms presenting with neurological ischemic symptoms. This was a retrospective cohort study in which 9656 patients with intracranial aneurysms were screened between January 2014 and July 2022. Further, 130 eligible patients were enrolled. The primary outcome was the incidence of serious adverse events (SAEs) within 30 days of treatment, whereas secondary outcomes included postprocedural target vessel-related stroke, disabling stroke or death, mortality, and aneurysm occlusion rate. Among the 130 included patients, 45 were treated with endovascular therapy and 85 with microsurgical clipping. The primary outcome of the incidence of SAEs within 30 days of treatment was significantly higher in the clipping group [clipping: 23.5%(20/85) vs endovascular: 8.9%(4/45), adjusted OR:4.05, 95% CI:1.20-13.70; P = 0.024]. The incidence of any neurological complications related to the treatment was significantly higher in the clipping group [clipping:32.9%(28/85) vs endovascular:15.6%(7/45); adjusted OR:3.49, 95%CI:1.18-10.26; P = 0.023]. Postprocedural target vessel-related stroke, disabling stroke or death, mortality rate, and complete occlusion rate did not differ significantly between the two groups. Endovascular therapy seemed to be safer in treating patients with MCA aneurysms presenting with neurological ischemic symptoms compared with microsurgical clipping, with a significantly lower incidence of SAEs within 30 days of treatment and any neurological complications related to the treatment during follow-up.

MSE-VGG: A Novel Deep Learning Approach Based on EEG for Rapid Ischemic Stroke Detection.

Ischemic stroke is a type of brain dysfunction caused by pathological changes in the blood vessels of the brain which leads to brain tissue ischemia and hypoxia and ultimately results in cell necrosis. Without timely and effective treatment in the early time window, ischemic stroke can lead to long-term disability and even death. Therefore, rapid detection is crucial in patients with ischemic stroke. In this study, we developed a deep learning model based on fusion features extracted from electroencephalography (EEG) signals for the fast detection of ischemic stroke. Specifically, we recruited 20 ischemic stroke patients who underwent EEG examination during the acute phase of stroke and collected EEG signals from 19 adults with no history of stroke as a control group. Afterwards, we constructed correlation-weighted Phase Lag Index (cwPLI), a novel feature, to explore the synchronization information and functional connectivity between EEG channels. Moreover, the spatio-temporal information from functional connectivity and the nonlinear information from complexity were fused by combining the cwPLI matrix and Sample Entropy (SaEn) together to further improve the discriminative ability of the model. Finally, the novel MSE-VGG network was employed as a classifier to distinguish ischemic stroke from non-ischemic stroke data. Five-fold cross-validation experiments demonstrated that the proposed model possesses excellent performance, with accuracy, sensitivity, and specificity reaching 90.17%, 89.86%, and 90.44%, respectively. Experiments on time consumption verified that the proposed method is superior to other state-of-the-art examinations. This study contributes to the advancement of the rapid detection of ischemic stroke, shedding light on the untapped potential of EEG and demonstrating the efficacy of deep learning in ischemic stroke identification.

Reversal of cerebral ischaemia and hypoxia and of sickness behaviour by megadose sodium ascorbate in ovine Gram-negative sepsis.

BACKGROUND: The mechanisms by which megadose sodium ascorbate improves clinical status in experimental sepsis is unclear. We determined its effects on cerebral perfusion, oxygenation, and temperature, and plasma levels of inflammatory biomarkers, nitrates, nitrites, and ascorbate in ovine Gram-negative sepsis. METHODS: Sepsis was induced by i.v. infusion of live Escherichia coli for 31 h in unanaesthetised Merino ewes instrumented with a combination sensor in the frontal cerebral cortex to measure tissue perfusion, oxygenation, and temperature. Fluid resuscitation at 23 h was followed by i.v. megadose sodium ascorbate (0.5 g kg-1 over 30 min+0.5 g kg-1 h-1 for 6.5 h) or vehicle (n=6 per group). Norepinephrine was titrated to restore mean arterial pressure (MAP) to 70-80 mm Hg. RESULTS: At 23 h of sepsis, MAP (mean [sem]: 85 [2] to 64 [2] mm Hg) and plasma ascorbate (27 [2] to 15 [1] µM) decreased (both P<0.001). Cerebral ischaemia (901 [58] to 396 [40] units), hypoxia (34 [1] to 19 [3] mm Hg), and hyperthermia (39.5 [0.1]°C to 40.8 [0.1]°C) (all P<0.001) developed, accompanied by malaise and lethargy. Sodium ascorbate restored cerebral perfusion (703 [121] units], oxygenation (30 [2] mm Hg), temperature (39.2 [0.1]°C) (all PTreatment<0.05), and the behavioural state to normal. Sodium ascorbate slightly reduced the sepsis-induced increase in interleukin-6, returned VEGF-A to normal (both PGroupxTime<0.01), and increased plasma ascorbate (20 000 [300] µM; PGroup<0.001). The effects of sodium ascorbate were not reproduced by equimolar sodium bicarbonate. CONCLUSIONS: Megadose sodium ascorbate rapidly reversed sepsis-induced cerebral ischaemia, hypoxia, hyperthermia, and sickness behaviour. These effects were not reproduced by an equimolar sodium load.

Biochanin A restored the blood-brain barrier in cerebral ischemia-reperfusion in rats.

OBJECTIVE: Blood-brain barrier is a protective layer that regulates the influx and efflux of biological materials for cerebral tissue. The aim of this study was to investigate the effects of Biochanin A on cerebral histopathology and blood-brain barrier immunohistochemically. METHODS: A total of 24 rats were assigned to three groups: sham, ischemia-reperfusion, and ischemia-reperfusion+Biochanin A. Ischemia-reperfusion was performed by occluding the left carotid artery for 2/24 h. Notably, 20 mg/kg Biochanin A was administered to rats for 7 days after ischemia-reperfusion. Blood was collected for malondialdehyde and total oxidant/antioxidant status analysis. Cerebral tissues were processed for histopathology and further for immunohistochemical analysis. RESULTS: Malondialdehyde content with total oxidant status value was significantly increased and total antioxidant status values were significantly decreased in the ischemia-reperfusion group compared with the sham group. Biochanin A treatment significantly improved scores in the ischemia-reperfusion+Biochanin A group. The normal histological appearance was recorded in the cerebral sections of the sham group. Degenerated neurons and vascular structures with disrupted integrity of the cerebral cortex were observed after ischemia-reperfusion. Biochanin A alleviated the histopathology in the cerebrum in the ischemia-reperfusion+Biochanin A group. Ischemia-reperfusion injury decreased the expression of blood-brain barrier in the ischemia-reperfusion group compared to the sham group. Administration of Biochanin A upregulated the blood-brain barrier immunoreactivity in the cerebrum by restoring blood-brain barrier. CONCLUSION: Cerebral ischemia-reperfusion caused an increase in oxidative stress and pathological lesions in the cerebrum. Biochanin A treatment restored the adverse effects of ischemia-reperfusion injury by restoring blood-brain barrier.

Modulating the RPS27A/PSMD12/NF-κB pathway to control immune response in mouse brain ischemia-reperfusion injury.

BACKGROUND: Investigating immune cell infiltration in the brain post-ischemia-reperfusion (I/R) injury is crucial for understanding and managing the resultant inflammatory responses. This study aims to unravel the role of the RPS27A-mediated PSMD12/NF-κB axis in controlling immune cell infiltration in the context of cerebral I/R injury. METHODS: To identify genes associated with cerebral I/R injury, high-throughput sequencing was employed. The potential downstream genes were further analyzed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-Protein Interaction (PPI) analyses. For experimental models, primary microglia and neurons were extracted from the cortical tissues of mouse brains. An in vitro cerebral I/R injury model was established in microglia using the oxygen-glucose deprivation/reoxygenation (OGD/R) technique. In vivo models involved inducing cerebral I/R injury in mice through the middle cerebral artery occlusion (MCAO) method. These models were used to assess neurological function, immune cell infiltration, and inflammatory factor release. RESULTS: The study identified RPS27A as a key player in cerebral I/R injury, with PSMD12 likely acting as its downstream regulator. Silencing RPS27A in OGD/R-induced microglia decreased the release of inflammatory factors and reduced neuron apoptosis. Additionally, RPS27A silencing in cerebral cortex tissues mediated the PSMD12/NF-κB axis, resulting in decreased inflammatory factor release, reduced neutrophil infiltration, and improved cerebral injury outcomes in I/R-injured mice. CONCLUSION: RPS27A regulates the expression of the PSMD12/NF-κB signaling axis, leading to the induction of inflammatory factors in microglial cells, promoting immune cell infiltration in brain tissue, and exacerbating brain damage in I/R mice. This study introduces novel insights and theoretical foundations for the treatment of nerve damage caused by I/R, suggesting that targeting the RPS27A and downstream PSMD12/NF-κB signaling axis for drug development could represent a new direction in I/R therapy.

Single-nucleus RNA sequencing reveals glial cell type-specific responses to ischemic stroke in male rodents.

Neuroglia critically shape the brain´s response to ischemic stroke. However, their phenotypic heterogeneity impedes a holistic understanding of the cellular composition of the early ischemic lesion. Here we present a single cell resolution transcriptomics dataset of the brain´s acute response to infarction. Oligodendrocyte lineage cells and astrocytes range among the most transcriptionally perturbed populations and exhibit infarction- and subtype-specific molecular signatures. Specifically, we find infarction restricted proliferating oligodendrocyte precursor cells (OPCs), mature oligodendrocytes and reactive astrocytes, exhibiting transcriptional commonalities in response to ischemic injury. OPCs and reactive astrocytes are involved in a shared immuno-glial cross talk with stroke-specific myeloid cells. Within the perilesional zone, osteopontin positive myeloid cells accumulate in close proximity to CD44+ proliferating OPCs and reactive astrocytes. In vitro, osteopontin increases the migratory capacity of OPCs. Collectively, our study highlights molecular cross talk events which might govern the cellular composition of acutely infarcted brain tissue.

[Exogenous leptin improves cerebral ischemia-reperfusion-induced glutamate excitotoxic injury in mice by up-regulating GLT-1 and GLAST expression in astrocytes].

OBJECTIVE: To investigate the protective effect of exogenous leptin against focal cerebral ischemia-reperfusion (I/R) injury in mice and explore the underlying mechanism. METHODS: A total of 100 C57BL/6 mice were randomly divided into 5 groups, including a sham-operated group, cerebral I/R model group, and 3 leptin treatment groups with intraperitoneal injections of 0.5, 1.0 or 2.0 leptin immediately after occlusion of the internal carotid artery. At 24 h after reperfusion, neurological function scores of the mice were assessed, and TTC staining was used to determine the area of cerebral infarction. The pathological changes in the cortical brain tissue of the mice were observed using HE staining, and degenerative damage of the cortical neurons were assessed with Fluoro-Jade C staining. The expression of glial fibrillary acidic protein in cortical brain tissues was detected using immunohistochemistry and Western blotting. In another 45 C57BL/6 mice with sham operation, I/R modeling, or leptin (1 mg/kg) treatment, glutamic acid in the cortical brain tissue was detected using glutamate assay, and cortical glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) protein expressions were detected using immunohistochemistry. RESULTS: Compared with the I/R model mice, the leptin-treated mice had significantly lower neurological deficit scores, smaller cerebral infarct area, milder pathologies in the cortical brain tissue, and lessened cortical neuronal damage with normal morphology and less excessive proliferation of the astrocytes. Leptin treatment significantly up-regulated the expressions of GLT-1 and GLAST and lowered the content of glutamic acid in the brain tissue of the I/R mice. CONCLUSION: Exogenous leptin has obvious neuroprotective effect against cerebral I/R injury in mice, mediated probably by controlling excessive astrocyte proliferation and up-regulating cortical GLT-1 and GLAST expressions to reduce glutamate-mediated excitotoxic injury of the astrocytes.

[Soy isoflavones alleviates calcium overload in rats with cerebral ischemia-reperfusion by inhibiting the Wnt/Ca2+ signaling pathway].

OBJECTIVE: To explore the mechanism by which soybean isoflavone (SI) reduces calcium overload induced by cerebral ischemia-reperfusion (I/R). METHODS: Forty-eight SD rats were randomized into 4 groups to receive sham operation, cerebral middle artery occlusion for 2 h followed by 24 h of reperfusion (I/R model group), or injection of adeno-associated virus carrying Frizzled-2 siRNA or empty viral vector into the lateral cerebral ventricle after modeling.Western blotting was used to examine Frizzled-2 knockdown efficiency and changes in protein expressions in the Wnt/Ca2+ signaling pathway.Calcium levels and pathological changes in the ischemic penumbra (IP) were measured using calcium chromogenic assay and HE staining, respectively.Another 72 SD randomly allocated for sham operation, I/R modeling, or soy isoflavones pretreatment before modeling were examined for regional cerebral blood flow using a Doppler flowmeter, and the cerebral infarct volume was assessed using TTC staining.Pathologies in the IP area were evaluated using HE and Nissl staining, and ROS level, Ca2+ level, cell apoptosis, and intracellular calcium concentration were analyzed using immunofluorescence assay or flow cytometry; the protein expressions of Wnt5a, Frizzled-2, and P-CaMK Ⅱ in the IP were detected with Western blotting and immunohistochemistry. RESULTS: In rats with cerebral I/R, Frizzled-2 knockdown significantly lowered calcium concentration (P < 0.001) and the expression levels of Wnt5a, Frizzled-2, and P-CaMK Ⅱ in the IP area.In soy isoflavones-pretreated rats, calcium concentration, ROS and MDA levels, cell apoptosis rate, cerebral infarct volume, and expression levels of Wnt/Ca2+ signaling pathway-related proteins were all significantly lower while SOD level was higher than those in rats in I/R model group. CONCLUSION: Soy isoflavones can mitigate calcium overload in rats with cerebral I/R by inhibiting the Wnt/Ca2+ signaling pathway.

Advances in development of biomarkers for brain damage and ischemia.

Acquired brain injury is an urgent situation that requires rapid diagnosis and treatment. Magnetic resonance imaging (MRI) and computed tomography (CT) are required for accurate diagnosis. However, these methods are costly and require substantial infrastructure and specialized staff. Circulatory biomarkers of acute brain injury may help in the management of patients with acute cerebrovascular events and prevent poor outcome and mortality. The purpose of this review is to provide an overview of the development of potential biomarkers of brain damage to increase diagnostic possibilities. For this purpose, we searched the PubMed database of studies on the diagnostic potential of brain injury biomarkers. We also accessed information from Clinicaltrials.gov to identify any clinical trials of biomarker measurements for the diagnosis of brain damage. In total, we present 41 proteins, enzymes and hormones that have been considered as biomarkers for brain injury, of which 20 have been studied in clinical trials. Several microRNAs have also emerged as potential clinical biomarkers for early diagnosis. Combining multiple biomarkers in a panel, along with other parameters, is yielding promising outcomes.

Neutrophil migration participates in the side effect of recombinant human tissue plasminogen activator.

AIMS: Ischemic stroke remains a challenge in medical research because of the limited treatment options. Recombinant human tissue plasminogen activator (rtPA) is the primary treatment for recanalization. However, nearly 50% of the patients experience complications that result in ineffective reperfusion. The precise factors contributing to ineffective reperfusion remain unclear; however, recent studies have suggested that immune cells, notably neutrophils, may influence the outcome of rtPA thrombolysis via mechanisms such as the formation of neutrophil extracellular traps. This study aimed to explore the nonthrombolytic effects of rtPA on neutrophils and highlight their contribution to ineffective reperfusion. METHODS: We evaluated the effects of rtPA treatment on middle cerebral artery occlusion in rats. We also assessed neutrophil infiltration and activation after rtPA treatment in vitro and in vivo in a small cohort of patients with massive cerebral ischemia (MCI). RESULTS: rtPA increased neutrophil infiltration into the brain microvessels and worsened blood-brain barrier damage during ischemia. It also increased the neutrophil counts of the patients with MCI. CONCLUSION: Neutrophils play a crucial role in promoting ischemic injury and blood-brain barrier disruption, making them potential therapeutic targets.

In vivo mapping of cellular resolution neuropathology in brain ischemia with diffusion MRI.

Noninvasive mapping of cellular pathology can provide critical diagnostic and prognostic information. Recent advances in diffusion magnetic resonance imaging enabled in vivo examination of tissue microstructures well beyond the imaging resolution. Here, we proposed to use diffusion time-dependent diffusion kurtosis imaging (tDKI) to simultaneously assess cellular morphology and transmembrane permeability in hypoxic-ischemic (HI) brain injury. Through numerical simulations and organoid imaging, we demonstrated the feasibility of capturing effective size and permeability changes using tDKI. In vivo MRI of HI-injured mouse brains detected a shift of the tDKI peak to longer diffusion times, suggesting swelling of the cellular processes. Furthermore, we observed a faster decrease of the tDKI tail, reflecting increased transmembrane permeability associated with up-regulated water exchange or necrosis. Such information, unavailable from a single diffusion time, can predict salvageable tissues. Preliminary applications of tDKI in patients with ischemic stroke suggested increased transmembrane permeability in stroke regions, illustrating tDKI's potential for detecting pathological changes in the clinics.