Neuronal injuries in cerebral infarction and ischemic stroke: From mechanisms to treatment (Review)

Repressing iron overload ameliorates central post-stroke pain via the Hdac2-Kv1.2 axis in a rat model of hemorrhagic stroke

JOURNAL/nrgr/04.03/01300535-202412000-00027/figure1/v/2024-04-08T165401Z/r/image-tiff Thalamic hemorrhage can lead to the development of central post-stroke pain. Changes in histone acetylation levels, which are regulated by histone deacetylases, affect the excitability of neurons surrounding the hemorrhagic area. However, the regulatory mechanism of histone deacetylases in central post-stroke pain remains unclear. Here, we show that iron overload leads to an increase in histone deacetylase 2 expression in damaged ventral posterolateral nucleus neurons. Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium (Kv) channel subunit gene in a rat model of central post-stroke pain, thereby increasing Kcna2 expression and relieving central pain. However, in the absence of nerve injury, increasing histone deacetylase 2 expression decreased Kcna2 expression, decreased Kv current, increased the excitability of neurons in the ventral posterolateral nucleus area, and led to neuropathic pain symptoms. Moreover, treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage, reversed histone deacetylase 2 upregulation and Kv1.2 downregulation, and alleviated mechanical hypersensitivity in central post-stroke pain rats. These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation, mediated by iron overload, are important factors in central post-stroke pain pathogenesis and could serve as new targets for central post-stroke pain treatment.

Application of artificial hibernation technology in acute brain injury

Controlling intracranial pressure, nerve cell regeneration, and microenvironment regulation are the key issues in reducing mortality and disability in acute brain injury. There is currently a lack of effective treatment methods. Hibernation has the characteristics of low temperature, low metabolism, and hibernation rhythm, as well as protective effects on the nervous, cardiovascular, and motor systems. Artificial hibernation technology is a new technology that can effectively treat acute brain injury by altering the body's metabolism, lowering the body's core temperature, and allowing the body to enter a state similar to hibernation. This review introduces artificial hibernation technology, including mild hypothermia treatment technology, central nervous system regulation technology, and artificial hibernation-inducer technology. Upon summarizing the relevant research on artificial hibernation technology in acute brain injury, the research results show that artificial hibernation technology has neuroprotective, anti-inflammatory, and oxidative stress-resistance effects, indicating that it has therapeutic significance in acute brain injury. Furthermore, artificial hibernation technology can alleviate the damage of ischemic stroke, traumatic brain injury, cerebral hemorrhage, cerebral infarction, and other diseases, providing new strategies for treating acute brain injury. However, artificial hibernation technology is currently in its infancy and has some complications, such as electrolyte imbalance and coagulation disorders, which limit its use. Further research is needed for its clinical application.

Albiflorin alleviates neuroinflammation of rats after MCAO via PGK1/Nrf2/HO-1 signaling pathway

Ischemic stroke is acknowledged as one of the most frequent causes of death and disability, in which neuroinflammation plays a critical role. Emerging evidence supports that the PGK1/Nrf2/HO-1 signaling can modulate inflammation and oxidative injury. Albiflorin (ALB), a main component of Radix paeoniae Alba, possesses anti-inflammatory and antioxidative properties. However, how it exerts a protective role still needs further exploration. In our study, the middle cerebral artery occlusion (MCAO) model was established, and the Longa score was applied to investigate the degree of neurological impairment. Dihydroethidium (DHE) staining and Malondialdehyde (MDA) assay were used to detect the level of lipid peroxidation. 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining was used to measure the infarct area. Evans blue staining was employed to observe the integrality of the blood-brain barrier (BBB). The injury of brain tissue in each group was observed via HE staining. Immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA) and western blot assay were used for the measurement of inflammatory factors and protein levels. We finally observed that ALB relieved cerebral infarction symptoms, attenuated oxidative damage in brain tissues, and reduced neuroinflammation and cell injury in MCAO rats. The overexpression of PGK1 abrogated the protective effect of ALB after experimental cerebral infarction. ALB promoted PGK1 degradation and induced Nrf2 signaling cascade activation for subsequent anti-inflammatory and antioxidant damage. Generally speaking, ALB exerted a protective role in treating cerebral ischemia, and it might target at PGK1/Nrf2/HO-1 signaling. Thus, ALB might be a potential therapeutic agent to alleviate neuroinflammation and protect brain cells after cerebral infarction.

Voacangine protects hippocampal neuronal cells against oxygen-glucose deprivation/reoxygenation-caused oxidative stress and ferroptosis by activating the PI3K-Akt-FoxO signaling

Voacangine, a naturally occurring alkaloid, has been testified to display beneficial effects on a variety of human diseases, but its role in ischemic stroke is unclear. The impacts of voacangine on oxygen-glucose deprivation/reoxygenation (OGD/R)-tempted hippocampal neuronal cells are investigated. The bioinformatics analysis found that voacangine is a bioactive ingredient that may have good effects on ischemic stroke. KEGG pathways analysis found that voacangine may regulate ischemic stroke through modulating the PI3K-Akt-FoxO signaling pathway. Voacangine could mitigate OGD/R-tempted cytotoxicity in HT22 cells. Voacangine mitigated OGD/R-tempted oxidative stress in HT22 cells by diminishing reactive oxygen species level and enhancing superoxide dismutase level. Voacangine mitigated OGD/R-tempted ferroptosis in HT22 cells. Voacangine promoted activation of the PI3K-Akt-FoxO signaling in OGD/R-induced HT22 cells. Inactivation of the PI3K-Akt-FoxO signaling pathway reversed the protective effects of voacangine against OGD/R-tempted oxidative stress, cytotoxicity, and ferroptosis in HT22 cells. In conclusion, voacangine protects hippocampal neuronal cells against OGD/R-caused oxidative stress and ferroptosis by activating the PI3K-Akt-FoxO signaling.

Systems-level computational modeling in ischemic stroke: from cells to patients

Ischemic stroke, a significant threat to human life and health, refers to a class of conditions where brain tissue damage is induced following decreased cerebral blood flow. The incidence of ischemic stroke has been steadily increasing globally, and its disease mechanisms are highly complex and involve a multitude of biological mechanisms at various scales from genes all the way to the human body system that can affect the stroke onset, progression, treatment, and prognosis. To complement conventional experimental research methods, computational systems biology modeling can integrate and describe the pathogenic mechanisms of ischemic stroke across multiple biological scales and help identify emergent modulatory principles that drive disease progression and recovery. In addition, by running virtual experiments and trials in computers, these models can efficiently predict and evaluate outcomes of different treatment methods and thereby assist clinical decision-making. In this review, we summarize the current research and application of systems-level computational modeling in the field of ischemic stroke from the multiscale mechanism-based, physics-based and omics-based perspectives and discuss how modeling-driven research frameworks can deliver insights for future stroke research and drug development.

Nanozymes: Potential Therapies for Reactive Oxygen Species Overproduction and Inflammation in Ischemic Stroke and Traumatic Brain Injury

Nanozymes, which can selectively scavenge reactive oxygen species (ROS), have recently emerged as promising candidates for treating ischemic stroke and traumatic brain injury (TBI) in preclinical models. ROS overproduction during the early phase of these diseases leads to oxidative brain damage, which has been a major cause of mortality worldwide. However, the clinical application of ROS-scavenging enzymes is limited by their short in vivo half-life and inability to cross the blood-brain barrier. Nanozymes, which mimic the catalytic function of natural enzymes, have several advantages, including cost-effectiveness, high stability, and easy storage. These advantages render them superior to natural enzymes for disease diagnosis and therapeutic interventions. This review highlights recent advancements in nanozyme applications for ischemic stroke and TBI, emphasizing their potential to mitigate the detrimental effect of ROS overproduction, oxidative brain damage, inflammation, and blood-brain barrier compromise. Therefore, nanozymes represent a promising treatment modality for ROS overproduction conditions in future medical practices.

CEBPD aggravates apoptosis and oxidative stress of neuron after ischemic stroke by Nrf2/HO-1 pathway

CCAAT enhancer binding protein delta (CEBPD) is a transcription factor and plays an important role in apoptosis and oxidative stress, which are the main pathogenesis of ischemic stroke. However, whether CEBPD regulates ischemic stroke through targeting apoptosis and oxidative stress is unclear. Therefore, to answer this question, rat middle cerebral artery occlusion (MCAO) reperfusion model and oxygen-glucose deprivation/reoxygenation (OGD/R) primary cortical neuron were established to mimic ischemic reperfusion injury. We found that CEBPD was upregulated and accompanied with increased neurological deficit scores and infarct size, and decreased neuron in MCAO rats. The siRNA targeted CEBPD inhibited CEBPD expression in rats, and meanwhile lentivirus system was used to blocked CEBPD expression in primary neuron. CEBPD degeneration decreased neurological deficit scores, infarct size and brain water content of MCAO rats. Knockdown of CEBPD enhanced cell viability and reduced apoptosis as well as oxidative stress in vivo and in vitro. CEBPD silencing promoted the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) to the nucleus and the expression of heme oxygenase 1 (HO-1). Newly, CEBPD facilitated the transcription of cullin 3 (CUL3), which intensified ischemic stroke through Nrf2/HO-1 pathway that was proposed by our team in the past. In conclusion, targeting CEBPD-CUL3-Nrf2/HO-1 axis may be contributed to cerebral ischemia therapy.

Antioxidant effects of Paeoniflorin and relevant molecular mechanisms as related to a variety of diseases: A review

Paeoniflorin (PF), which is the main component of the Paeonia lactiflora Pall extract, is one of the traditional Chinese medicines. The pharmacological effects associated with PF include antioxidant, immunomodulatory, anti-inflammatory, anticancer, antidepressant-like and neuroprotective effects. Our previous studies had revealed that PF protected melanocytes and inhibited photodamage through the suppression of oxidative stress (OS). As OS plays a vital role in the progression of a variety of diseases, the capacity for PF to suppress OS may exert important effects upon them. However, no review exists on these antioxidant effects of PF as related to various diseases. Therefore, in this review we summarized studies involved with examining the antioxidant effects and molecular mechanisms of PF. Through its capacity to inhibit OS, PF has been shown to exert beneficial effects upon several systems including nervous, cardiac/vascular, digestive, and respiratory as well as specific diseases such as diabetes, autoimmune, pregnancy related, ocular, kidney, dermatology, along with suppression of distal flap necrosis, postoperative adhesions, and hearing loss. Such findings provide new insights and directions for future research directed at the development of PF as a natural antioxidant for the treatment of clinical diseases.

The evaluation value of intracranial magnetic resonance angiography combined with carotid ultrasound in cerebral infarction

Objective

To explore the evaluation value of intracranial magnetic resonance angiography (MRA) combined with carotid ultrasound (CU) in patients with cerebral infarction (CI).

Methods

A retrospective analysis was conducted on 122 patients with CI who underwent intracranial MRA combined with CU examination in Shengzhou People's Hospital from January 2021 to October 2022. Vascular stenosis rate and CU parameters of patients with different degrees of nerve damage (ND) and size of CI lesion were analyzed.

Results

The rate of vascular stenosis and ultrasound parameters significantly varied between patients with different degrees of ND and different sizes of CI lesion. Spearman test showed a significant positive correlation between vascular stenosis, pulsatile index (PI), and resistance index (RI) with the degree of ND and the size of CI lesions in patients. There was a significant negative correlation between peak systolic velocity (PSV) and end-diastolic velocity (EDV) and the degree of ND and the size of CI lesions (P<0.05).

Conclusions

Intracranial MRA combined with CU can clarify the vascular stenosis and hemodynamic characteristics of patients with CI, and the combined approach closely correlates with the characteristics of CI, which can be used for disease assessment.

A novel phthalein component ameliorates neuroinflammation and cognitive dysfunction by suppressing the CXCL12/CXCR4 axis in rats with vascular dementia

ETHNOPHARMACOLOGICAL RELEVANCE

Chuanxiong, a plant of the Umbelliferae family, is a genuine medicinal herb from Sichuan Province. Phthalides are one of its main active components and exhibit good protective effect against cerebrovascular diseases. However, the mechanism by which phthalides exert neuroprotective effects is still largely unclear.

AIM OF THE STUDY

In this study, we extracted a phthalein component (named as QBT) from Ligusticum Chuanxiong, and investigated its neuroprotective effects against vascular dementia (VaD) rats and the underlying mechanism, focusing on the chemokine 12 (CXCL12)/chemokine (C-X-C motif) receptor 4 (CXCR4) axis.

METHODS

A rat model of VaD was established, and treated with QBT. Cognitive dysfunction in VaD rats was assessed using the Y-maze, new object recognition, and Morris water maze tests. Neuronal damage and inflammatory response in VaD rats were examined through Nissl staining, immunofluorescence, enzyme-linked immunospecific assay, and western blotting analysis. Furthermore, the effects of QBT on CXCL12/CXCR4 axis and its downstream signaling pathways, Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/nuclear factor-κB (NF-κB), were investigated in VaD rats and BV2 microglial cells exposed to oxygen glucose deprivation.

RESULTS

QBT significantly alleviated cognitive dysfunction and neuronal damage in VaD rats, along with inhibition of VaD-induced over-activation of microglia and astrocytes and inflammatory response. Moreover, QBT exhibited anti-inflammatory effects by inhibiting the CXCL12/CXCR4 axis and its downstream JAK2/STAT3 and PI3K/AKT/NF-κB pathways, thereby attenuating the neuroinflammatory response both in vivo and in vitro.

CONCLUSION

QBT effectively mitigated neuronal damage and cognitive dysfunction in VaD rats, exerting neuroprotective effects by suppressing neuroinflammatory response through inhibition of the CXCL12/CXCR4 axis.

Gelatin methacryloyl microneedle loaded with 3D-MSC-Exosomes for the protection of ischemia-reperfusion

Exosomes (Exo) generated from mesenchymal stem cells (MSCs) have great therapeutic potential in ischemia-reperfusion treatment. For best therapeutic effect, high quality Exo product and effective delivery system are indispensable. In this study, we developed a new strategy for ischemia-reperfusion recovery by combining MSCs 3D (3D-MSC) culturing technology to generate Exo (3D-MSC-Exo) and microneedle for topical delivery. Firstly, primary MSCs from neonatal mice were isolated and 3D cultured with gelatin methacryloyl (GelMA) hydrogel to prepare 3D-MSC-Exo. The 3D-MSC showed better viability and 3D-MSC-Exo exhibited more effective effects of reducing neuroinflammation, inhibiting glial scarring, and promoting angiogenesis. Subsequently, the biocompatible GelMA was used to construct microneedles for 3D-Exo delivery (GelMA-MN@3D-Exo). The results demonstrated GelMA microneedles had excellent 3D-Exo loading capacity and enabled continuous 3D-Exo release to maintain effective therapeutic concentrations. Furthermore, the rat middle cerebral artery occlusion (MCAO) model was established to evaluate the therapeutic effect of GelMA-MN@3D-Exo in ischemia-reperfusion in vivo. Animal experiments showed that the GelMA-MN@3D-Exo system could effectively reduce the local neuroinflammatory reaction, promote angiogenesis and minimize glial scar proliferation in ischemia-reperfusion. The underlying reasons for the stronger neuroprotective effect of 3D-Exo was further studied using mass spectrometry and transcriptome assays, verifying their effects on immune regulation and cell proliferation. Taken together, our findings demonstrated that GelMA-MN@3D-Exo microneedle can effectively attenuate ischemia-reperfusion cell damage in the MCAO model, which provides a promising therapeutic strategy for ischemia-reperfusion recovery.

Isoquercitrin alleviates OGD/R-induced oxidative stress and impaired mitochondrial biogenesis in SH-SY5Y cells via the NRF1/TFAM pathway

Isoquercitrin (ISO) is a traditional Chinese medicine extract, that has been found to possess potent neuroprotective properties. However, its precise role in the context of ischemic stroke (IS) remains to be fully elucidated. We constructed an in vitro model of IS induced by OGD/R in SH-SY5Y cells. Cell viability, the levels of oxidative stress-related indicators (8-OHDG, MDA, SOD, GSH, and GSH-Px), ROS, and mitochondrial membrane potential were measured by using detection kits. The protein levels of GPX1, SOD, Cytc were measured. The mRNA levels of mitochondrial biogenesis-related indicators (Cytb, CO1, ND2, ND5, and ND6), and mtDNA copy number were measured by RT-qPCR. ATP levels were measured. Molecular docking between ISO and NRF1, and Co-IP assay for NRF1 and TFAM interaction were performed. Expression of NRF1 and TFAM was evaluated. ISO treatment reversed the detrimental effects of OGD/R on cell viability, attenuated the elevation of oxidative stress markers, restored antioxidant levels, and alleviated the impairment of mitochondrial biogenesis in SH-SY5Y cells. ISO interacted with NRF1 and increased its expression along with TFAM. Silencing NRF1 reversed the protective effects of ISO, suggesting its involvement in mediating the neuroprotective effects of ISO. ISO alleviates oxidative stress and mitochondrial biogenesis damage induced by OGD/R in SH-SY5Y cells by upregulating the NRF1/TFAM pathway.

Applications of Functional Near-Infrared Spectroscopy (fNIRS) Neuroimaging During Rehabilitation Following Stroke: A Review

Stroke is a cerebrovascular disease that impairs blood supply to localized brain tissue regions due to various causes. This leads to ischemic and hypoxic lesions, necrosis of the brain tissue, and a variety of functional disorders. Abnormal cortical activation and functional connectivity occur in the brain after a stroke, but the activation patterns and functional reorganization are not well understood. Rehabilitation interventions can enhance functional recovery in stroke patients. However, clinicians require objective measures to support their practice, as outcome measures for functional recovery are based on scale scores. Furthermore, the most effective rehabilitation measures for treating patients are yet to be investigated. Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging method that detects changes in cerebral hemodynamics during task performance. It is widely used in neurological research and clinical practice due to its safety, portability, high motion tolerance, and low cost. This paper briefly introduces the imaging principle and the advantages and disadvantages of fNIRS to summarize the application of fNIRS in post-stroke rehabilitation.

Risk factors of acute ischemic stroke and the role of angiotensin I in predicting prognosis of patients undergoing endovascular thrombectomy

Purpose

The interaction between the renin-angiotensin system (RAS) and the acute ischemic stroke (AIS) is definite but not fully understood. This study aimed to analyze the risk factors of AIS and explore the role of serum indicators such as angiotensin I (Ang I) in the prognosis of patients undergoing endovascular thrombectomy (EVT).

Patients and methods

Patients with AIS who underwent EVT and healthy controls were retrospectively enrolled in this study, and the patients were divided into a good or a poor prognosis group. We compared Ang I, blood routine indexes, biochemical indexes, electrolyte indexes, and coagulation indexes between patients and controls. We used univariate and multivariate logistic regression analyses to evaluate possible risk factors for AIS and the prognosis of patients undergoing EVT. Independent risk factors for the prognosis of patients undergoing EVT were identified through multifactorial logistic regression analyses to construct diagnostic nomograms, further assessed by receiver operating characteristic curves (ROC).

Results

Consistent with previous studies, advanced age, high blood glucose, high D-dimer, and high prothrombin activity are risk factors for AIS. In addition, Ang I levels are lower in AIS compared to the controls. The level of Ang I was higher in the good prognosis group. Furthermore, we developed a nomogram to evaluate its ability to predict the prognosis of AIS after EVT. The AUC value of the combined ROC model (Ang I and albumin-globulin ratio (AGR)) was 0.859.

Conclusions

In conclusion, advanced age, high blood glucose, high D-dimer, and high prothrombin activity are risk factors for AIS. The combined Ang I and AGR model has a good predictive ability for the prognosis of AIS patients undergoing arterial thrombectomy.

Investigating the Pharmacological Mechanisms of Total Flavonoids from Eucommia ulmoides Oliver Leaves for Ischemic Stroke Protection

The aim of this study was to explore how the total flavonoids from Eucommia ulmoides leaves (EULs) regulate ischemia-induced nerve damage, as well as the protective effects mediated by oxidative stress. The cell survival rate was significantly improved compared to the ischemic group (p < 0.05) after treatment with the total flavonoids of EULs. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) decreased, while catalase (CAT) and glutathione (GSH) increased, indicating that the total flavonoids of EULs can significantly alleviate neurological damage caused by ischemic stroke by inhibiting oxidative stress (p < 0.01). The mRNA expression level of VEGF increased (p < 0.01), which was consistent with the protein expression results. Meanwhile, the protein expression of ERK and CCND1 increased (p < 0.01), suggesting that the total flavonoids of EULs could protect PC12 cells from ischemic injury via VEGF-related pathways. MCAO rat models indicated that the total flavonoids of EULs could reduce brain ischemia-reperfusion injury. In conclusion, this study demonstrates the potential mechanisms of the total flavonoids of EULs in treating ischemic stroke and their potential therapeutic effects in reducing ischemic injury, which provides useful information for ischemic stroke drug discovery.

Neuromuscular Electrical Stimulation for Post-Stroke Dysphagia Treatment: A Systemic Evaluation and Meta-Analysis of Randomized Controlled Trials

Neuromuscular electrical stimulation (NMES) is a novel treatment method that stimulates patients' swallowing functions. This systemic review was designed to evaluate the impact of NMES on dysphagia in stroke patients. Databases including PubMed, Embase, Web of Science, and Cochrane Library were searched from the date of establishment to January 28th, 2022. Two investigators identified all included studies and compared the swallowing function after NMES treatment with traditional therapy (TT). The Cochrane risk bias assessment tool was utilized to analyze the quality of included studies. Research outcomes included Swallowing Quality of Life (SWAL-QoL), Penetration-Aspiration Scale (PAS), Functional Oral Intake Scale (FOIS), Dysphagia Outcomes and Severity Scale (DOSS), the Repeat Salivary Swallowing Test (RSST), and Water Swallowing Test (WST). We extracted the mean and standard deviation of specific outcomes at the baseline level and after the treatment in both NMES and TT groups for subsequent meta-analysis. 9 randomized controlled trials (RCTs) and quasi-RCTs were included, and remarkable differences were found between patients treated with or without NMES in respect of FOIS scores (SMD = 0.48; 95% CI 0.26-0.70, P < 0.0001), PAS scores (SMD = - 0.56; 95% CI 1.01-0.10, P = 0.02), and SWAL-QoL scores (SMD = 0.57; 95% CI 0.00-1.14, P = 0.05). No significant difference was manifested in WST, RSST, and DOSS (SMD: - 0.02; 95% CI  0.38-0.35, P = 0.93). Evidence suggests that NMES is more effective for post-stroke dysphagia patients than treatment without NMES.

Factors associated with clopidogrel resistance and clinical outcomes in ischemic cerebrovascular disease: A retrospective study

OBJECTIVE

Clopidogrel resistance may lead to the recurrence of cerebrovascular diseases. We aimed to identify potential factors associated with clopidogrel resistance and evaluate the clinical outcomes of the patients.

MATERIALS AND METHODS

In this retrospective study, patients with ischemic cerebrovascular disease treated with clopidogrel were included and classified into 2 groups according to the adenosine diphosphate (ADP)-induced platelet aggregation. Patients with the ADP inhibition rate of <30 % were included in clopidogrel resistance group, otherwise were included in clopidogrel sensitive group. CYP2C19 genotype and other clinical data were analyzed to identify factors and clinical features in the multivariate analysis. The outcomes were vascular events in 6 months.

RESULTS

In total, 139 patients were enrolled with 81 (58.27 %) in clopidogrel sensitive group and 58 (41.73 %) in clopidogrel resistance group. Female and CYP2C19 *2*3 carrying were risk factors for clopidogrel resistance, and female was an independent risk factor (OR 2.481, 95 % CI 1.066-5.771, P=0.035). The clopidogrel resistance group showed a higher use rate of argatroban (P=0.030) and a lower arachidonic acid-induced inhibition of platelet aggregation (P=0.036). Clopidogrel resistance was related to the progressing stroke (HR 3.521, 95 % CI 1.352-9.170, P=0.010), but had no influence on the bleeding events (P>0.05).

CONCLUSIONS

The risk of clopidogrel resistance increased significantly in female patients. Patients with clopidogrel resistance may have an increased incidence of stroke progression in the acute phase.

Catalpol attenuates ischemic stroke by promoting neurogenesis and angiogenesis via the SDF-1α/CXCR4 pathway

BACKGROUND

Stroke is a leading cause of disability and death worldwide. Currently, there is a lack of clinically effective treatments for the brain damage following ischemic stroke. Catalpol is a bioactive compound derived from the traditional Chinese medicine Rehmannia glutinosa and shown to be protective in various neurological diseases. However, the potential roles of catalpol against ischemic stroke are still not completely clear.

PURPOSE

This study aimed to further elucidate the protective effects of catalpol against ischemic stroke.

METHODS

A rat permanent middle cerebral artery occlusion (pMCAO) and oxygen-glucose deprivation (OGD) model was established to assess the effect of catalpol in vivo and in vitro, respectively. Behavioral tests were used to examine the effects of catalpol on neurological function of ischemic rats. Immunostaining was performed to evaluate the proliferation, migration and differentiation of neural stem cells (NSCs) as well as the angiogenesis in each group. The protein level of related molecules was detected by western-blot. The effects of catalpol on cultured NSCs as well as brain microvascular endothelial cells (BMECs) subjected to OGD in vitro were also examined by similar methods.

RESULTS

Catalpol attenuated the neurological deficits and improved neurological function of ischemic rats. It stimulated the proliferation of NSCs in the subventricular zone (SVZ), promoted their migration to the ischemic cortex and differentiation into neurons or glial cells. At the same time, catalpol increased the cerebral vessels density and the number of proliferating cerebrovascular endothelial cells in the infracted cortex of ischemic rats. The level of SDF-1α and CXCR4 in the ischemic cortex was found to be enhanced by catalpol treatment. Catalpol was also shown to promote the proliferation and migration of cultured NSCs as well as the proliferation of BMECs subjected to OGD insult in vitro. Interestingly, the impact of catalpol on cultured cells was inhibited by CXCR4 inhibitor AMD3100. Moreover, the culture medium of BMECs containing catalpol promoted the proliferation of NSCs, which was also suppressed by AMD3100.

CONCLUSION

Our data demonstrate that catalpol exerts neuroprotective effects by promoting neurogenesis and angiogenesis via the SDF-1α/CXCR4 pathway, suggesting the therapeutic potential of catalpol in treating cerebral ischemia.

Effect of remote ischemic preconditioning intervention on serum levels of microRNA-582-5p/HMGB1 in patients with acute cerebral infarction

OBJECTIVE

Acute cerebral infarction (ACI) contributes to disability and death accross the globe. Remote ischemic preconditioning (RIPC) reduces cerebral infarct size and improves neurological function in ACI. We conducted this research to reveal the effects of RIPC intervention on serum levels of microRNA-582-5p (miR-582-5p)/high mobility group box-1 protein (HMGB1), inflammation, oxidative stress and neurological function in patients with ACI.

METHODS

In this study, 158 patients with ACI were prospectively selected and randomized into the control (administered symptomatic medication alone) and the RIPC (underwent RIPC of the limbs based on medication) groups, with their clinical baseline data documented. Serum levels of miR-582-5p, and HMGB1 and inflammatory factors [tumor necrosis factor alpha (TNF-α)/interleukin-1beta (IL-1β)/IL-10] were assessed by RT-qPCR/ELISA, followed by comparisons of oxidative stress indices [glutathione-peroxidase (GSH-Px)/catalase (CAT)/superoxide dismutase (SOD)] using a fully automatic biochemical analyzer. Correlations between serum miR-582-5p with serum HMGB1, and between their levels with TNF-α/IL-1β/IL-10 were analyzed by Pearson analysis. The NIHSS score/Barthel Index scale were used to assess neurological function/daily living ability. Intervention safety for ACI patients was evaluated.

RESULTS

RIPC intervention increased serum miR-582-5p levels and decreased serum HMGB1 levels in ACI patients. RIPC intervention significantly reduced inflammation (diminished TNF-α/IL-1β levels, increased IL-10 level) and oxidative stress (elevated GSH-Px/CAT/SOD levels) in ACI patients. Serum miR-582-5p was negatively correlated with TNF-α and IL-1β levels, while positively correlated with IL-10 level, while HMGB1 was positively correlated with TNF-α and IL-1β levels, while negatively correlated with IL-10 level. miR-582-5p was negatively correlated with HMGB1. RIPC intervention improved neurological function (reduced NIHSS, increased Barthel scores) in ACI patients to some extent. RIPC had certain effectiveness and safety in the treatment of ACI.

CONCLUSION

After RIPC intervention, serum miR-582-5p levels were increased, HMGB1 levels were decreased, and inflammation and oxidative stress were reduced in ACI patients, which mitigated neurological deficits, improved patients' ability to perform life activities, and exerted neuroprotective effects to some extent.

Neuroprotective effects of anti-TRAIL-ICG nanoagent and its multimodal imaging evaluation in cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion injury (CIRI) is a major challenge to neuronal survival in acute ischemic stroke (AIS). However, effective neuroprotective agents remain to be developed for the treatment of CIRI. In this work, we have developed an Anti-TRAIL protein-modified and indocyanine green (ICG)-responsive nanoagent (Anti-TRAIL-ICG) to target ischemic areas and then reduce CIRI and rescue the ischemic penumbra. In vitro and in vivo experiments have demonstrated that the carrier-free nanoagent can enhance drug transport across the blood-brain barrier (BBB) in stroke mice, exhibiting high targeting ability and good biocompatibility. Anti-TRAIL-ICG nanoagent played a better neuroprotective role by reducing apoptosis and ferroptosis, and significantly improved ischemia-reperfusion injury. Moreover, the multimodal imaging platform enables the dynamic in vivo examination of multiple morphofunctional information, so that the dynamic molecular events of nanoagent can be detected continuously and in real time for early treatment in transient middle cerebral artery occlusion (tMCAO) models. Furthermore, it has been found that Anti-TRAIL-ICG has great potential in the functional reconstruction of neurovascular networks through optical coherence tomography angiography (OCTA). Taken together, our work effectively alleviates CIRI after stoke by blocking multiple cell death pathways, which offers an innovative strategy for harnessing the apoptosis and ferroptosis against CIRI.

Effects of immune cells on ischemic stroke and the mediating roles of metabolites

Objective

Previous studies have not shown an association between IgD-CD24-B-cell absolute count (IgD-CD24-AC) and ischemic stroke (IS). Our study aimed to assess the causal effect of IgD-CD24-AC on IS and to explore the role of ascorbic acid 2-sulfate (AA2S) as a potential mediator.

Methods

Our study was based on the largest available genome-wide association study (GWAS). Inverse variance weighting (IVW), MR-Egger, weighted median (WMN), simple mode, and weighted mode methods were used to assess causal effects, with IVW as the primary outcome. Subsequently, we further performed a two-step MR analysis to evaluate whether AA2S mediated this causal effect. In addition, several sensitivity analyses were conducted to evaluate heterogeneity, including Cochran's Q test, the MR-Egger intercept test, the MR-PRESSO global test, and the leave-one-out analysis.

Results

Using the IVW approach, the risk ratio of IgD-CD24-AC to IS was estimated to be 1.216 (95% CI = 1.079-1.371, p = 0.001). This result was supported by the WMN method (OR = 1.204, 95% CI = 1.020-1.421, p = 0.028) and the MR-Egger method (OR = 1.177, 95% CI = 0.962-1.442, p = 0.133). We also observed the same trend with the simple model and weighted model. Furthermore, the proportion of genetically predicted IgD-CD24-AC mediated through AA2S levels was 3.73%.

Conclusion

Our study revealed a causal relationship between IgD-CD24-AC and IS, a small part of which was mediated by AA2S. These findings offer critical insights for developing immune-targeted therapies in the future and lay a strong foundation for advancements in precision medicine.

From Immunity to Neurogenesis: Toll-like Receptors as Versatile Regulators in the Nervous System

Toll-like receptors (TLRs) are among the main components of the innate immune system. They can detect conserved structures in microorganisms and molecules associated with stress and cellular damage. TLRs are expressed in resident immune cells and both neurons and glial cells of the nervous system. Increasing evidence is emerging on the participation of TLRs not only in the immune response but also in processes of the nervous system, such as neurogenesis and cognition. Below, we present a review of the literature that evaluates the expression and role of TLRs in processes such as neurodevelopment, behavior, cognition, infection, neuroinflammation, and neurodegeneration.

Gypenoside XVII Reduces Synaptic Glutamate Release and Protects against Excitotoxic Injury in Rats

Excitotoxicity is a common pathological process in neurological diseases caused by excess glutamate. The purpose of this study was to evaluate the effect of gypenoside XVII (GP-17), a gypenoside monomer, on the glutamatergic system. In vitro, in rat cortical nerve terminals (synaptosomes), GP-17 dose-dependently decreased glutamate release with an IC50 value of 16 μM. The removal of extracellular Ca2+ or blockade of N-and P/Q-type Ca2+ channels and protein kinase A (PKA) abolished the inhibitory effect of GP-17 on glutamate release from cortical synaptosomes. GP-17 also significantly reduced the phosphorylation of PKA, SNAP-25, and synapsin I in cortical synaptosomes. In an in vivo rat model of glutamate excitotoxicity induced by kainic acid (KA), GP-17 pretreatment significantly prevented seizures and rescued neuronal cell injury and glutamate elevation in the cortex. GP-17 pretreatment decreased the expression levels of sodium-coupled neutral amino acid transporter 1, glutamate synthesis enzyme glutaminase and vesicular glutamate transporter 1 but increased the expression level of glutamate metabolism enzyme glutamate dehydrogenase in the cortex of KA-treated rats. In addition, the KA-induced alterations in the N-methyl-D-aspartate receptor subunits GluN2A and GluN2B in the cortex were prevented by GP-17 pretreatment. GP-17 also prevented the KA-induced decrease in cerebral blood flow and arginase II expression. These results suggest that (i) GP-17, through the suppression of N- and P/Q-type Ca2+ channels and consequent PKA-mediated SNAP-25 and synapsin I phosphorylation, reduces glutamate exocytosis from cortical synaptosomes; and (ii) GP-17 has a neuroprotective effect on KA-induced glutamate excitotoxicity in rats through regulating synaptic glutamate release and cerebral blood flow.

Effect of Cyclosporin H on ischemic injury and neutrophil infiltration in cerebral infarct model of rats via PET imaging

BACKGROUND

Brain ischemia-reperfusion injury is a complex process, and neuroinflammation is an important secondary contributing pathological event. Neutrophils play major roles in ischemic neuroinflammation. Once activated, neutrophils express formyl peptide receptors (FPRs), which are special receptors of a class of chemoattractants and may be potential targets to regulate the activity of neutrophils and control cerebral ischemic injury. This study was aimed to explore the ameliorating effect of Cyclosporin H (CsH), a potent FPR antagonist, on brain ischemic injury by inhibiting the activation and migration of neutrophils, and improving cerebral blood flow.

METHODS

We employed a middle cerebral artery occlusion (MCAO) Model on rats and performed behavioral, morphological, and microPET imaging assays to investigate the potential restoring efficacy of CsH on cerebral ischemic damages. Peptide N-cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF), an antagonist to the neutrophil FPR with a high binding affinity, was used for imaging neutrophil distribution.

RESULTS

We found that CsH had similar effect with edaravone on improving the neurobehavioral deficient symptoms after cerebral ischemia-reperfusion, and treatment with CsH also alleviated ischemic cerebral infarction. Compared with the MCAO Model group, [18F]FDG uptake ratios of the CsH and edaravone treatment groups were significantly higher. The CsH-treated groups also showed significant increases in [18F]FDG uptake at 144 h when compared with that of 24 h. This result indicates that like edaravone, treatment with both doses of CsH promoted the recovery of blood supply after cerebral ischemic event. Moreover, MCAO-induced cerebral ischemia significantly increased the radiouptake of [68Ga]Ga-cFLFLF at 72 h after ischemia-reperfusion operation. Compared with MCAO Model group, radiouptake values of [68Ga]-cFLFLF in both doses of CsH and edaravone groups were all decreased significantly. These results showed that both doses of CsH resulted in a similar therapeutic effect with edaravone on inhibiting neutrophil infiltration in cerebral infarction.

CONCLUSION

Potent FPR antagonist CsH is promisingly beneficial in attenuating neuroinflammation and improving neurobehavioral function against cerebral infarction. Therefore, FPR may become a novel target for regulating neuroinflammation and improving prognosis for ischemic cerebrovascular disorders.

The lactate-to-albumin ratio relationship with all-cause mortality in cerebral infarction patients: analysis from the MIMIC-IV database

Objective

To examine the association of lactate-to-albumin ratio (LAR) with 30-day and 90-day mortality in patients with cerebral infarction admitted to the intensive care unit (ICU).

Methods

In this retrospective observational study, 1,089 patients with cerebral infarction were recruited. The concentration of blood lactate and serum albumin on the first day of ICU admission were recorded. The relationship between LAR levels and mortality was evaluated through univariate and multivariate Cox regression analyses, four-knot multivariate restricted cubic spline regression, and Kaplan-Meier (KM) curves.

Results

The overall 30-day and 90-day mortality rates in the entire cohort were 27.3 and 35.8%, respectively. KM analysis revealed a significant relationship between high LAR index and the risk of all-cause mortality (log-rank p < 0.001). Furthermore, multivariate Cox proportional risk analysis showed that the LAR index independently predicted the risk of 30-day mortality (HR: 1.38, 95% CI 1.15-1.64, p = 0.004) and 90-day mortality (HR: 1.53, 95% CI 1.32-1.77, p < 0.001) in the study population. Furthermore, a higher LAR exceeding 0.53 was positively correlated with the risk of 30-day and 90-day mortalities. Subsequent subgroup analyses demonstrated that LAR could predict the primary outcome.

Conclusion

In summary, the LAR index is a reliable and independent predictor of increased mortality among critically ill patients suffering from cerebral infarction. Nonetheless, there is a need for additional comprehensive prospective studies to validate these findings.

Analysis and prevention strategies of risk factors for postoperative stroke complications in cardiac surgery

OBJECTIVE

To analyze the risk factors associated with postoperative stroke complications in cardiac surgery.

METHODS

A retrospective analysis was conducted on the clinical data of 549 patients who underwent cardiac surgery. Among these patients, 501 did not experience a stroke postoperatively (non-stroke group), while 48 developed a postoperative stroke (stroke group). Patients who experienced a stroke postoperatively were divided into two groups based on the type of surgery: those who underwent surgery with cardiopulmonary bypass (18 patients) and those without cardiopulmonary bypass (30 patients). The clinical characteristics of the two groups of patients with postoperative strokes were compared, and the risk factors influencing the occurrence of postoperative stroke complications in cardiac surgery were analyzed.

RESULTS

① Clinical findings: Cardiopulmonary bypass group had lower cortical infarction rates but higher large-area and bilateral infarction rates compared to the non-cardiopulmonary bypass group (p < 0.05). No significant gender, age, or infarction type differences were observed (p > 0.05). ② Univariate analysis: No significant differences were found in gender, smoking, alcohol, lipids, or glucose levels (p > 0.05). However, age, education, hypertension, diabetes, hypotension, and atrial fibrillation showed significant differences (p < 0.05). ③ Multivariate Logistic regression: Age, education, hypertension, diabetes, hypotension, and atrial fibrillation were independent risk factors for postoperative stroke complications (p < 0.05).

CONCLUSION

Cardiopulmonary bypass increases risk of large-area and bilateral strokes; non-bypass surgery associates with cortical strokes. Age, educational level, hypertension, diabetes, postoperative hypotension, and atrial fibrillation are all factors independently associated with the occurrence of postoperative cerebral infarctions in cardiac surgery. Early interventions may reduce postoperative strokes.

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.

Current and further outlook on the protective potential of Antrodia camphorata against neurological disorders

Prevalent neurological disorders such as Alzheimer's disease, Parkinson's disease, and stroke are increasingly becoming a global burden as society ages. It is well-known that degeneration and loss of neurons are the fundamental underlying processes, but there are still no effective therapies for these neurological diseases. In recent years, plenty of studies have focused on the pharmacology and feasibility of natural products as new strategies for the development of drugs that target neurological disorders. Antrodia camphorata has become one of the most promising candidates, and the crude extracts and some active metabolites of it have been reported to play various pharmacological activities to alleviate neurological symptoms at cellular and molecular levels. This review highlights the current evidence of Antrodia camphorata against neurological disorders, including safety evaluation, metabolism, blood-brain barrier penetration, neuroprotective activities, and the potential on regulating the gut-microbiome-brain axis. Furthermore, potential strategies to resolve problematic issues identified in previous studies are also discussed. We aim to provide an overview for the ongoing development and utilization of Antrodia camphorata in cerebral neuropathology.

Modulation of the Circadian Rhythm and Oxidative Stress as Molecular Targets to Improve Vascular Dementia: A Pharmacological Perspective

The circadian rhythms generated by the master biological clock located in the brain's hypothalamus influence central physiological processes. At the molecular level, a core set of clock genes interact to form transcription-translation feedback loops that provide the molecular basis of the circadian rhythm. In animal models of disease, a desynchronization of clock genes in peripheral tissues with the central master clock has been detected. Interestingly, patients with vascular dementia have sleep disorders and irregular sleep patterns. These alterations in circadian rhythms impact hormonal levels, cardiovascular health (including blood pressure regulation and blood vessel function), and the pattern of expression and activity of antioxidant enzymes. Additionally, oxidative stress in vascular dementia can arise from ischemia-reperfusion injury, amyloid-beta production, the abnormal phosphorylation of tau protein, and alterations in neurotransmitters, among others. Several signaling pathways are involved in the pathogenesis of vascular dementia. While the precise mechanisms linking circadian rhythms and vascular dementia are still being studied, there is evidence to suggest that maintaining healthy sleep patterns and supporting proper circadian rhythm function may be important for reducing the risk of vascular dementia. Here, we reviewed the main mechanisms of action of molecular targets related to the circadian cycle and oxidative stress in vascular dementia.

Association between serum calcium and prognosis in patients with acute ischemic stroke in ICU: analysis of the MIMIC-IV database

BACKGROUND

While serum Ca has proven to be a reliable predictor of mortality across various diseases, its connection with the clinical outcomes of ischemic stroke (IS) remains inconclusive. Our research aimed to explore the relationships between serum total Ca (tCa) and serum ionized Ca (iCa) and mortality among acute IS (AIS) patients.

METHODS

We gathered data from 1773 AIS patients in the Medical Information Mart for Intensive Care Database IV, including baseline demographic data, comorbidities, vital signs, laboratory-based data, and scoring systems. Endpoints for the study encompassed 30-d, 90-d, and 365-d all-cause mortalities. Employing restricted cubic spline Cox regression, we explored potential nonlinear relationships between admission serum iCa and tCa levels and mortality. Participants were categorized into four groups based on serum iCa and tCa quartiles. Multivariable Cox regression analysis was then conducted to evaluate the independent association of iCa and tCa quartiles with all-cause mortality.

RESULTS

The restricted cubic spline revealed a U-shaped association between iCa and 30-d and 90-d mortality (P<0.05), while the relationship between iCa and 365-d mortality was linear (P<0.05). After adjusting for confounders, multivariable Cox analysis demonstrated that the lowest serum iCa level quartile was independently associated with increased risks of 30-d, 90-d, and 365-d mortality. Similarly, the highest serum iCa level quartile was independently associated with increased risks of 30-d and 90-d mortality, but not 365-d mortality. Notably, serum tCa level showed no association with increased risks of 30-d, 90-d, and 365-d mortality.

CONCLUSIONS

Our findings suggest that serum iCa, rather than tCa, is linked to ischemic stroke prognosis. Both high and low serum iCa levels are associated with poor short-term prognosis, while only low serum iCa is associated with poor long-term prognosis in AIS patients.

Causal effects of gut microbiota on the prognosis of ischemic stroke: evidence from a bidirectional two-sample Mendelian randomization study

Background

Increasing research has implicated the possible effect of gut microbiota (GM) on the prognosis of ischemic stroke (IS). However, the precise causal relationship between GM and functional outcomes after IS remains unestablished.

Methods

Data on 211 GM taxa from the MiBioGen consortium and data on prognosis of IS from the Genetics of Ischemic Stroke Functional Outcome (GISCOME) network were utilized as summary-level data of exposure and outcome. Four kinds of Mendelian randomization (MR) methods were carried out to ascertain the causal effect of GM on functional outcomes following IS. A reverse MR analysis was performed on the positive taxa identified in the forward MR analysis to determine the direction of causation. In addition, we conducted a comparative MR analysis without adjusting the baseline National Institute of Health Stroke Scale (NIHSS) of post-stroke functional outcomes to enhance confidence of the results obtained in the main analysis.

Results

Four taxa were identified to be related to stroke prognosis in both main and comparative analyses. Specifically, genus Ruminococcaceae UCG005 and the Eubacterium oxidoreducens group showed significantly negative effects on stroke prognosis, while the genus Lachnospiraceae NK4A136 group and Lachnospiraceae UCG004 showed protective effects against stroke prognosis. The reverse MR analysis did not support a causal role of stroke prognosis in GM. No evidence of heterogeneity, horizontal pleiotropy, and outliers was found.

Conclusion

This MR study provided evidence that genetically predicted GM had a causal link with post-stroke outcomes. Specific gut microbiota taxa associated with IS prognosis were identified, which may be helpful to clarify the pathogenesis of ischemic stroke and making treatment strategies.

Luteolin-7-O-β-d-glucuronide Ameliorates Cerebral Ischemic Injury: Involvement of RIP3/MLKL Signaling Pathway

Luteolin-7-O-β-d-glucuronide (LGU) is a major active flavonoid glycoside compound that is extracted from Ixeris sonchifolia (Bge.) Hance, and it is a Chinese medicinal herb mainly used for the treatment of coronary heart disease, angina pectoris, cerebral infarction, etc. In the present study, the neuroprotective effect of LGU was investigated in an oxygen glucose deprivation (OGD) model and a middle cerebral artery occlusion (MCAO) rat model. In vitro, LGU was found to effectively improve the OGD-induced decrease in neuronal viability and increase in neuronal death by a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) leakage rate assay, respectively. LGU was also found to inhibit OGD-induced intracellular Ca2+ overload, adenosine triphosphate (ATP) depletion, and mitochondrial membrane potential (MMP) decrease. By Western blotting analysis, LGU significantly inhibited the OGD-induced increase in expressions of receptor-interacting serine/threonine-protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL). Moreover, molecular docking analysis showed that LGU might bind to RIP3 more stably and firmly than the RIP3 inhibitor GSK872. Immunofluorescence combined with confocal laser analyses disclosed that LGU inhibited the aggregation of MLKL to the nucleus. Our results suggest that LGU ameliorates OGD-induced rat primary cortical neuronal injury via the regulation of the RIP3/MLKL signaling pathway in vitro. In vivo, LGU was proven, for the first time, to protect the cerebral ischemia in a rat middle cerebral artery occlusion (MCAO) model, as shown by improved neurological deficit scores, infarction volume rate, and brain water content rate. The present study provides new insights into the therapeutic potential of LGU in cerebral ischemia.

Clinical application of repetitive transcranial magnetic stimulation in improving functional impairments post-stroke: review of the current evidence and potential challenges

In recent years, the stroke incidence has been increasing year by year, and the related sequelae after stroke, such as cognitive impairment, motor dysfunction, and post-stroke depression, seriously affect the patient's rehabilitation and daily activities. Repetitive transcranial magnetic stimulation (rTMS), as a safe, non-invasive, and effective new rehabilitation method, has been widely recognized in clinical practice. This article reviews the application and research progress of rTMS in treating different functional impairments (cognitive impairment, motor dysfunction, unilateral spatial neglect, depression) after stroke in recent years, and preliminary summarized the possible mechanisms. It has been found that the key parameters that determine the effectiveness of rTMS in improving post-stroke functional impairments include pulse number, stimulated brain areas, stimulation intensity and frequency, as well as duration. Generally, high-frequency stimulation is used to excite the ipsilateral cerebral cortex, while low-frequency stimulation is used to inhibit the contralateral cerebral cortex, thus achieving a balance of excitability between the two hemispheres. However, the specific mechanisms and the optimal stimulation mode for different functional impairments have not yet reached a consistent conclusion, and more research is needed to explore and clarify the best way to use rTMS. Furthermore, we will identify the issues and challenges in the current research, explore possible mechanisms to deepen understanding of rTMS, propose future research directions, and offer insightful insights for better clinical applications.

Radiation-Induced Cerebral Contrast Enhancements Strongly Share Ischemic Stroke Risk Factors

PURPOSE

Radiation-induced cerebral contrast enhancements (RICE) are frequent after photon and particularly proton radiation therapy and are associated with a significant risk for neurologic morbidity. Nevertheless, risk factors are poorly understood. A more robust understanding of RICE risk factors is crucial to improve management and offer adaptive therapy at the outset and during follow-up.

METHODS AND MATERIALS

We analyzed the comorbidities in detail of 190 consecutive adult patients treated at a single European national comprehensive cancer center with proton radiation therapy (54 Gy relative biological effectiveness) for LGG from 2010 to 2020 who were followed with serial clinical examinations and magnetic resonance imaging for a median 5.6 years.

RESULTS

Classical vascular risk factors including age (≥50 vs <50 years: 1.6-fold; P = .0024), hypertension (2.7-fold; P = .00012), and diabetes (11.7-fold; P = .0066) were observed more frequently in the cohort that developed RICE. Dyslipidemia (2.1-fold), being overweight (2.0-fold), and smoking (2.6-fold), as well as history of previous stroke (1.7-fold), were also more frequently observed in the RICE cohort, although these factors did not reach the threshold for significance. Multivariable regression modeling supported the influence of age (P = .05), arterial hypertension (P = .01), and potentially male sex (P = .02), diabetes (P = .0008), and smoking (P = .001) on RICE occurrence over time, independent of each other and further vascular risk factors. If RICE occurred, bevacizumab treatment was 2-fold more frequently needed in the cohort with vascular risk factors, but RICE long-term prognosis did not differ between the RICE subcohorts with and without vascular risk factors.

CONCLUSIONS

This is the first report in the literature demonstrating that RICE strongly shares vascular risk factors with ischemic stroke, which further enhances the nebulous understanding of the multifactorial pathophysiology of RICE. Classical vascular risk factors, especially age, hypertension, and diabetes, clearly correlated independently with RICE risk. Risk-adapted screening and management for RICE can be directly derived from these data to assist in clinical management.

The immune system in neurological diseases: What innate-like T cells have to say

The immune system classically consists of 2 lines of defense, innate and adaptive, both of which interact with one another effectively to protect us against any pathogenic threats. Importantly, there is a diverse subset of cells known as innate-like T cells that act as a bridge between the innate and adaptive immune systems and are pivotal players in eliciting inflammatory immune responses. A growing body of evidence has demonstrated the regulatory impact of these innate-like T cells in central nervous system (CNS) diseases and that such immune cells can traffic into the brain in multiple pathological conditions, which can be typically attributed to the breakdown of the blood-brain barrier. However, until now, it has been poorly understood whether innate-like T cells have direct protective or causative properties, particularly in CNS diseases. Therefore, in this review, our attention is focused on discussing the critical roles of 3 unique subsets of unconventional T cells, namely, natural killer T cells, γδ T cells, and mucosal-associated invariant T cells, in the context of CNS diseases, disorders, and injuries and how the interplay of these immune cells modulates CNS pathology, in an attempt to gain a better understanding of their complex functions.

Kaempferol regulates apoptosis and migration of neural stem cells to attenuate cerebral infarction by O-GlcNAcylation of β-catenin

Ischemic stroke remains a major cause of disability and death. Kaempferol (Kae) is a neuroprotective flavonoid compound. Thus, this study aimed to explore the impact of Kae on cerebral infarction. We generated the middle cerebral artery occlusion (MCAO) mouse model to study the effects of Kae on infarction volume and neurological function. The oxygen and glucose deprivation (OGD)/reoxygenation (R) model of neural stem cells (NSCs) was established to study the effects of Kae on cell viability, migration, and apoptosis. Cell processes were assessed by cell counting kit-8, Transwell assay, flow cytometry, and TUNEL analysis. The molecular mechanism was assessed using the Western blot. The results indicated that Kae attenuated MCAO-induced cerebral infarction and neurological injury. Besides, Kae promoted cell viability and migration and inhibited apoptosis of OGD/R-treated NSCs. Moreover, OGD/R suppressed total O-GlcNAcylation level and O-GlcNAcylation of β-catenin, thereby suppressing the Wnt/β-catenin pathway, whereas Kae reversed the suppression. Inactivation of the Wnt/β-catenin pathway abrogated the biological functions of NSCs mediated by Kae. In conclusion, Kae suppressed cerebral infarction by facilitating NSC viability, migration, and inhibiting apoptosis. Mechanically, Kae promoted O-GlcNAcylation of β-catenin to activate the Wnt/β-catenin pathway. Kae may have a lessening effect on ischemic stroke.

A vivid outline demonstrating the benefits of exosome-mediated drug delivery in CNS-associated disease environments

The efficacy of drug delivery mechanisms has been improvised with time for different therapeutic purposes. In most cases, nano-sized delivery systems have been modeled over decades for the on-target applicability of the drugs. The use of synthetic drug delivery materials has been a common practice, although research has now focussed more on using natural vehicles, to avoid the side effects of synthetic delivery systems and easy acceptance by the body. Exosome is such a natural nano-sized vehicle that exceeds the efficiency of many natural vehicles, for being immune-friendly, due to its origin. Unlike, other natural drug delivery systems, exosomes are originated within the body's cells, and from there, they happen to travel through the extracellular matrices into neighboring cells. This capacity of exosomes has made them an efficient drug delivery system over recent years and now a large number of researches have been carried out to develop exosomes as natural drug delivery vehicles. Several experimental strategies have been practiced in this regard which have shown that exosomes are exclusively capable of carrying drugs and they can also be used in targeted delivery, for which they efficiently can reach and release the drug at their target cells for consecutive effects. One of the most interesting features of exosomes is they can cross the blood-brain barrier (BBB) in the body and hence, for the disease where other delivery vehicles are incapable of reaching the destination of the drug, exosomes can overcome the hurdle. This review particularly, focuses on the different aspects of using exosomes as a potential nano-sized drug delivery system for some of the severe diseases associated with the central nervous system of the human body.

Therapeutic gene delivery by mesenchymal stem cell for brain ischemia damage: Focus on molecular mechanisms in ischemic stroke

Cerebral ischemic damage is prevalent and the second highest cause of death globally across patient populations; it is as a substantial reason of morbidity and mortality. Mesenchymal stromal cells (MSCs) have garnered significant interest as a potential treatment for cerebral ischemic damage, as shown in ischemic stroke, because of their potent intrinsic features, which include self-regeneration, immunomodulation, and multi-potency. Additionally, MSCs are easily obtained, isolated, and cultured. Despite this, there are a number of obstacles that hinder the effectiveness of MSC-based treatment, such as adverse microenvironmental conditions both in vivo and in vitro. To overcome these obstacles, the naïve MSC has undergone a number of modification processes to enhance its innate therapeutic qualities. Genetic modification and preconditioning modification (with medications, growth factors, and other substances) are the two main categories into which these modification techniques can be separated. This field has advanced significantly and is still attracting attention and innovation. We examine these cutting-edge methods for preserving and even improving the natural biological functions and therapeutic potential of MSCs in relation to adhesion, migration, homing to the target site, survival, and delayed premature senescence. We address the use of genetically altered MSC in stroke-induced damage. Future strategies for improving the therapeutic result and addressing the difficulties associated with MSC modification are also discussed.

Tetrahydropiperine, a natural alkaloid with neuroprotective effects in ischemic stroke

BACKGROUND

Ischemic stroke (IS) is a life-threatening neurological disease with various pathological mechanisms. Tetrahydropiperine (THP) is a natural alkaloid with protective effects against multiple diseases, such as seizure, and pain. This study was to examine the impact of THP on IS and investigate its potential mechanism.

MATERIAL AND METHODS

We employed network pharmacology and molecular docking techniques to identify the target proteins of THP for intervention in IS. Adult male Sprague-Dawley rats were used to create a permanent middle cerebral artery occlusion model. PC-12 cells were chosen to establish an oxygen-glucose deprivation (OGD) cell model. Disease modeling followed by nimodipine (NIMO); 3-methyladenine (3-MA) and rapamycin (RAP) interventions. Open field test, Longa score, balance beam test, and forelimb grip test were used to measure motor and neurological functions. The degree of neurological damage recovery was assessed through behavioral analysis, and cerebral infarction volume was determined using TTC staining. Morphological changes were examined through HE and Nissl staining, and ultrastructural changes in neurons were observed using transmission electron microscopy. The protein expression of autophagy and related pathways was analyzed through Western blot (WB). The appropriate hypoxia time and drug concentration were determined using CCK-8 assay, which also measured cell survival rate.

RESULTS

The network pharmacology findings indicated that the impact of THP on IS was enhanced in the PI3K/Akt signaling pathway. THP demonstrated robust docking capability with proteins associated with the autophagy and PI3K/Akt/mTOR, as indicated by the molecular docking outcomes. THP significantly improved behavioral damage, reduced the area of cerebral infarction, ameliorated histopathological damage from ischemia, increase neuronal survival, and alleviated ultrastructural damage in neurons (P < 0.05). THP enhanced the survival of PC-12 cells induced by OGD and ameliorated the morphological harm to the cells (P < 0.05). THP was found to elevate the quantities of P62, LC3-Ⅰ, PI3K, P-AKt/Akt, and P-mTOR/mTOR proteins while reducing the levels of Atg7 and Beclin1 proteins. The results of transmission electron microscopy showed no autophagosomes in the THP, 3-MA, and 3-MA + THP groups.

CONCLUSION

The activation of the PI3K/Akt/mTOR signaling pathway by THP inhibits autophagy and provides relief from neurological damage in IS.

Transplantation of Neural Stem Cells-Overexpressed Ku70 Improves Neurological Deficits in a Mice Model of Cerebral Ischemia Stroke

Cerebral ischemic stroke is a cerebrovascular disease, which is related to DNA damage. Many researches have shown that Ku70 is a key regulator for DNA damage. Here, we aimed to explore Ku70 roles in cerebral ischemic stroke and its potential molecular mechanism. In our study, neural stem cells (NSCs) were induced by oxygen-glucose deprivation/reoxygenation (OGD/R) for constructing cerebral ischemic stroke cell model. CCK8 assay, Brdu/GFP staining, flow cytometry and TUNEL staining were performed to examine cell proliferation, cell cycle and apoptosis, respectively. Relative mRNA and protein levels were detected by quantitative real-time PCR and western blot analysis, respectively. Ku70 positive cells were examined by immunofluorescence staining. Comet assay was employed to determine DNA damage. Animal experiments were performed to assess the effect of transplanting NSCs and Ku70-overexpressed NSCs on neurological deficits, infarct volume, brain edema and blood‒brain barrier (BBB) integrity in middle cerebral artery occlusion (MCAO) model. Our data found that Ku70 expression was decreased in NSCs after OGD/R. Overexpression of Ku70 reduced DNA damage and apoptosis of OGD/R-induced NSCs. Knockdown of Ku70 promoted the activity of ATM/p53. Moreover, KU60019 (ATM-specific inhibitor) reversed the promoting effects of Ku70 silencing on DNA damage and apoptosis in OGD/R-induced NSCs. In animal experiments, transplantation of NSCs-overexpressed Ku70 enhanced cell survival, improved motor function, reduced infarct volume, relieved brain edema and alleviated BBB dysfunction in MCAO mice models. In conclusion, Ku70 overexpression repressed the DNA damage and apoptosis in OGD/R-induced NSCs by regulating ATM/p53 pathway, and transplantation of NSCs-overexpressed Ku70 played neuroprotective effects in MCAO mice models.

MRPS9-Mediated Regulation of the PI3K/Akt/mTOR Pathway Inhibits Neuron Apoptosis and Protects Ischemic Stroke

Neuronal apoptosis is crucial in the pathophysiology of ischemic stroke (IS), albeit its underly24ing mechanism remaining elusive. Investigating the mechanism of neuronal apoptosis in the context of IS holds substantial clinical value for enhancing the prognosis of IS patients. Notably, the MRPS9 gene plays a pivotal role in regulating mitochondrial function and maintaining structural integrity. Utilizing bioinformatic tactics and the extant gene expression data related to IS, we conducted differential analysis and weighted correlation network analysis (WGCNA) to select important modules. Subsequent gene interaction analysis via the STRING website facilitated the identification of the key gene-mitochondrial ribosomal protein S9 (MRPS9)-that affects the progression of IS. Moreover, possible downstream signaling pathways, namely PI3K/Akt/mTOR, were elucidated via Kyoto Encyclopedia of Gene and Genomes (KEGG) and Gene Ontology (GO) pathway analysis. Experimental models were established utilizing oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro and middle cerebral artery occlusion/reperfusion (MCAO/R) in mice. Changes in gene and protein expression, as well as cell proliferation and apoptosis, were monitored through qPCR, WB, CCK8, and flow cytometry. An OGD/R cell model was further employed to investigate the role of MRPS9 in IS post transfusion of MRPS9 overexpression plasmids into cells. Further studies were conducted by transfecting overexpressed cells with PI3K/Akt/mTOR signaling pathway inhibitor LY294002 to unveil the mechanism of MRPS9 in IS. Bioinformatic analysis revealed a significant underexpression of MRPS9 in ischemic stroke patients. Correspondingly, in vitro experiments with HN cells subjected to OGD/R treatment demonstrated a marked reduction in MRPS9 expression, accompanied by a decline in cell viability, and an increase cell apoptosis. Notably, the overexpression of MRPS9 mitigated the OGD/R-induced decrease in cell viability and augmentation of apoptosis. In animal models, MRPS9 expression was significantly lower in the MCAO/R group compared to the sham surgery group. Further, the KEGG pathway analysis associated MRPS9 expression with the PI3K/Akt/mTOR signaling pathway. In cells treated with the specific PI3K/Akt/mTOR inhibitor LY294002, phosphorylation levels of Akt and mTOR were decreased, cell viability decreased, and apoptosis increased compared to the MRPS9 overexpression group. These findings collectively indicate that MRPS9 overexpression inhibits PI3K/Akt/mTOR pathway activation, thereby protecting neurons from apoptosis and impeding IS progression. However, the PI3K/Akt/mTOR inhibitor LY294002 is capable of counteracting the protective effect of MRPS9 overexpression on neuronal apoptosis and IS. Our observations underscore the potential protective role of MRPS9 in modulating neuronal apoptosis and in attenuating the pathophysiological developments associated with IS. This is achieved through the regulation of the PI3K/Akt/mTOR pathway. These insights forge new perspectives and propose novel targets for the strategic diagnosis and treatment of IS.

Mesenchymal Stem Cell (MSC)-Based Drug Delivery into the Brain across the Blood-Brain Barrier

At present, stem cell-based therapies using induced pluripotent stem cells (iPSCs) or mesenchymal stem cells (MSCs) are being used to explore the potential for regenerative medicine in the treatment of various diseases, owing to their ability for multilineage differentiation. Interestingly, MSCs are employed not only in regenerative medicine, but also as carriers for drug delivery, homing to target sites in injured or damaged tissues including the brain by crossing the blood-brain barrier (BBB). In drug research and development, membrane impermeability is a serious problem. The development of central nervous system drugs for the treatment of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, remains difficult due to impermeability in capillary endothelial cells at the BBB, in addition to their complicated pathogenesis and pathology. Thus, intravenously or intraarterially administered MSC-mediated drug delivery in a non-invasive way is a solution to this transendothelial problem at the BBB. Substances delivered by MSCs are divided into artificially included materials in advance, such as low molecular weight compounds including doxorubicin, and expected protein expression products of genetic modification, such as interleukins. After internalizing into the brain through the fenestration between the capillary endothelial cells, MSCs release their cargos to the injured brain cells. In this review, I introduce the potential and advantages of drug delivery into the brain across the BBB using MSCs as a carrier that moves into the brain as if they acted of their own will.

Enhanced the treatment of ischemic stroke through intranasal temperature-sensitive hydrogels of edaravone and borneol inclusion complex

Since ischemic stroke occurs by a combination of multiple mechanisms, therapies that modulate multiple mechanisms are required for its treatment. The combination of edaravone (EDA) and borneol can significantly ameliorate the symptoms of neurological deficits in cerebral ischemia-reperfusion model in rats. In this study, the solubility of borneol and edaravone was improved by hydroxypropyl-β-cyclodextrin and PEG400. Furthermore, a nasal temperature-sensitive hydrogel containing both edaravone and borneol inclusion complex (EDA-BP TSGS) was developed to overcome the obstacles of ischemic stroke treatment including the obstruction of the blood-brain barrier (BBB) and the unavailability and untimely of intravenous injection. The effectiveness of the thermosensitive hydrogel was investigated in transient middle cerebral artery occlusion/reperfusion model rats (MCAO/R). The results showed that EDA-BP TSGS could significantly alleviate the symptoms of neurological deficits and decrease the cerebral infarct area and the degree of brain damage. In summary, nasal EDA-BP TSGS is a secure and effective brain-targeting formulation that may provide a viable option for the clinical prophylaxis and treatment of ischemic stroke.

METTL3 Mediates Microglial Activation and Blood-Brain Barrier Permeability in Cerebral Ischemic Stroke by Regulating NLRP3 Inflammasomes Through m6A Methylation Modification

Cerebral ischemic stroke (CIS) is the main cause of disability. METTL3 is implicated in CIS, and we explored its specific mechanism. Middle cerebral artery occlusion (MCAO) rat model and oxygen-glucose deprivation/reperfusion (OGD/R) HAPI cell model were established and treated with LV-METTL3 or DAA, oe-METTL3, miR-335-3p mimics, or DAA, to assess their effects on MCAO rat neurological and motor function, cerebral infarction area, brain water content, microglial activation, blood-brain barrier (BBB) permeability, and NLRP3 inflammasome activation. METTL3, pri-miR-335-3p, mature miR-335-3p, and miR-335-3p mRNA levels were assessed by RT-qPCR; M1/M2 microglial phenotype proportion and M1/M2 microglia ratio, inflammatory factor levels, and m6A modification were assessed. MCAO rats manifested cerebral ischemia injury. METTL3 was under-expressed in CIS. METTL3 overexpression inhibited microglial activation and M1 polarization and BBB permeability in MCAO rats and inhibited OGD/R-induced microglial activation and reduced M1 polarization. METTL3 regulated miR-335-3p expression and inhibited NLRP3 inflammasome activation. m6A methylation inhibition averted METTL3's effects on NLRP3 activation, thus promoting microglial activation in OGD/R-induced cells and METTL3's effects on BBB permeability in MCAO rats. Briefly, METTL3 regulated miR-335-3p expression through RNA m6A methylation and inhibited NLRP3 inflammasome activation, thus repressing microglial activation, BBB permeability, and protecting against CIS.

Peripheral blood mononuclear cell low molecular mass protein 7 in acute ischemic stroke: vertical change from admission to discharge and correlation with disability, stroke recurrence, and death

Objective

Low molecular mass protein 7 (LMP7) aggravates abnormal T cell differentiation and atherosclerosis, but its clinical role in acute ischemic stroke (AIS) is still unclear. This study aimed to investigate the correlation of peripheral blood mononuclear cell (PBMC) LMP7 with T cell subsets, disease severity, and prognosis in AIS patients.

Methods

A total of 162 AIS patients were enrolled for detecting PBMC LMP7 and T helper (Th) 1, Th2, and Th17 cells via reverse transcriptase-polymerase chain reaction and flow cytometry, respectively. In addition, PBMC LMP7 at discharge was also quantified.

Results

Increased LMP7 at admission was associated with decreased Th2 cells (P=0.014), elevated Th17 cells (P<0.001), C-reactive protein (P=0.005), National Institutes of Health Stroke Scale (NIHSS) score (P=0.007), and disease severity (defined by NIHSS score) (P=0.010). LMP7 at admission reflected a high risk of stroke recurrence (area under curve (AUC): 0.748, 95% confidence interval (CI): 0.564-0.932), but not mRS score at month 3 (M3) >2 (AUC: 0.585, 95%CI: 0.479-0.691), or death (AUC: 0.723, 95%CI: 0.338-1.000). LMP7 at discharge was reduced compared to that at admission (P<0.001). LMP7 at discharge was positively correlated with the risk of stroke recurrence (AUC: 0.849, 95%CI: 0.735-0.963) and death (AUC: 0.919, 95%CI: 0.836-1.000), but had a weak capacity to reflect mRS score at M3 >2 (AUC: 0.671, 95%CI: 0.578-0.765).

Conclusion

PBMC LMP7 positively correlates with Th17 cells, inflammation, and disease severity in AIS patients, meanwhile, its level at discharge shows a good ability to reflect the risks of stroke recurrence and death.

Application and mechanisms of Sanhua Decoction in the treatment of cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion is a process in which the blood supply to the brain is temporarily interrupted and subsequently restored. However, it is highly likely to lead to further aggravation of pathological damage to ischemic tissues or the nervous system., and has accordingly been a focus of extensive clinical research. As a traditional Chinese medicinal formulation, Sanhua Decoction has gradually gained importance in the treatment of cerebrovascular diseases. Its main constituents include Citrus aurantium, Magnolia officinalis, rhubarb, and Qiangwu, which are primarily used to regulate qi. In the treatment of neurological diseases, the therapeutic effects of the Sanhua Decoction are mediated via different pathways, including antioxidant, anti-inflammatory, and neurotransmitter regulatory pathways, as well as through the protection of nerve cells and a reduction in cerebral edema. Among the studies conducted to date, many have found that the application of Sanhua Decoction in the treatment of neurological diseases has clear therapeutic effects. In addition, as a natural treatment, the Sanhua Decoction has received widespread attention, given that it is safer and more effective than traditional Western medicines. Consequently, research on the mechanisms of action and efficacy of the Sanhua Decoctions in the treatment of cerebral ischemia-reperfusion injury is of considerable significance. In this paper, we describe the pathogenesis of cerebral ischemia-reperfusion injury and review the current status of its treatment to examine the therapeutic mechanisms of action of the Sanhua Decoction. We hope that the findings of the research presented herein will contribute to a better understanding of the efficacy of this formulation in the treatment of cerebral ischemia-reperfusion, and provide a scientific basis for its application in clinical practice.

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.

Vialinin A alleviates oxidative stress and neuronal injuries after ischaemic stroke by accelerating Keap1 degradation through inhibiting USP4-mediated deubiquitination

BACKGROUND

Oxidative stress is known as a hallmark of cerebral ischaemia‒reperfusion injury and it exacerbates the pathologic progression of ischaemic brain damage. Vialinin A, derived from a Chinese edible mushroom, possesses multiple pharmacological activities in cancer, Kawasaki disease, asthma and pathological scarring. Notably, vialinin A is an inhibitor of ubiquitin-specific peptidase 4 (USP4) that shows anti-inflammatory and antioxidative properties. However, the precise effect of vialinin A in ischaemic stroke, as well as its underlying mechanisms, remains largely unexplored.

PURPOSE

The present research focuses on the impacts of vialinin A on oxidative stress and explores the underlying mechanisms involved while also examining its potentiality as a therapeutic candidate for ischaemic stroke.

METHODS

Mouse ischaemic stroke was conducted by MCAO surgery. Vialinin A was administered via lateral ventricular injection at a dose of 2 mg/kg after reperfusion. Subsequent experiments were meticulously conducted at the appropriate time points. Stroke outcomes were evaluated by TTC staining, neurological score, Nissl staining and behavioural analysis. Co-IP assays were operated to examine the protein-protein interactions. Immunoblot analysis, qRT-PCR, and luciferase reporter assays were conducted to further investigate its underlying mechanisms.

RESULTS

In this study, we initially showed that administration of vialinin A alleviated cerebral ischaemia‒reperfusion injury-induced neurological deficits and neuronal apoptosis. Furthermore, vialinin A, which is an antioxidant, reduced oxidative stress injury, promoted the activation of the Keap1-Nrf2-ARE signaling pathway and increased the protein degradation of Keap1. The substantial neuroprotective effects of vialinin A against ischaemic stroke were compromised by the overexpression of USP4. Mechanistically, vialinin A inhibited the deubiquitinating enzymatic activity of USP4, leading to enhanced ubiquitination of Keap1 and subsequently promoting its degradation. This cascade caused the activation of Nrf2-dependent antioxidant response, culminating in a reduction of neuronal apoptosis and the amelioration of neurological dysfunction following ischaemic stroke.

CONCLUSIONS

This study demonstrates that inhibition of USP4 to activate Keap1-Nrf2-ARE signaling pathway may represent a mechanism by which vialinin A conferred protection against cerebral ischaemia‒reperfusion injury and sheds light on its promising prospects as a therapeutic intervention for ischaemic stroke.