Ketamine-induced prevention of SD-associated late infarct progression in experimental ischemia.

Spreading depolarizations (SDs) occur frequently in patients with malignant hemispheric stroke. In animal-based experiments, SDs have been shown to cause secondary neuronal damage and infarct expansion during the initial period of infarct progression. In contrast, the influence of SDs during the delayed period is not well characterized yet. Here, we analyzed the impact of SDs in the delayed phase after cerebral ischemia and the potential protective effect of ketamine. Focal ischemia was induced by distal occlusion of the left middle cerebral artery in C57BL6/J mice. 24 h after occlusion, SDs were measured using electrocorticography and laser-speckle imaging in three different study groups: control group without SD induction, SD induction with potassium chloride, and SD induction with potassium chloride and ketamine administration. Infarct progression was evaluated by sequential MRI scans. 24 h after occlusion, we observed spontaneous SDs with a rate of 0.33 SDs/hour which increased during potassium chloride application (3.37 SDs/hour). The analysis of the neurovascular coupling revealed prolonged hypoemic and hyperemic responses in this group. Stroke volume increased even 24 h after stroke onset in the SD-group. Ketamine treatment caused a lesser pronounced hypoemic response and prevented infarct growth in the delayed phase after experimental ischemia. Induction of SDs with potassium chloride was significantly associated with stroke progression even 24 h after stroke onset. Therefore, SD might be a significant contributor to delayed stroke progression. Ketamine might be a possible drug to prevent SD-induced delayed stroke progression.

Dihydroergotamine protects against ischemic stroke by modulating microglial/macrophage polarization and inhibiting inflammation in mice.

OBJECTIVES: The search for drugs that can protect the brain tissue and reduce nerve damage in acute ischemic stroke has emerged as a research hotspot. We investigated the potential protective effects and mechanisms of action of dihydroergotamine against ischemic stroke. METHODS: C57BL/6 mice were subjected to middle cerebral artery occlusion (MCAO), and dihydroergotamine at a dose of 10 mg/kg/day was intraperitoneally injected for 14 days. Adhesive removal and beam walking tests were conducted 1, 3, 5, 7, 10, and 14 days after MCAO surgery. Thereafter, the mechanism by which dihydroergotamine regulates microglia/macrophage polarization and inflammation and imparts ischemic stroke protection was studied using enzyme-linked immunosorbent assay, immunofluorescence staining, and western blotting. RESULTS: From the perspective of a drug repurposing strategy, dihydroergotamine was found to inhibit oxygen-glucose deprivation damage to neurons, significantly improve cell survival rate, and likely exert a protective effect on ischemic brain injury. Dihydroergotamine significantly improved neural function scores and survival rates and reduced brain injury severity in mice. Furthermore, dihydroergotamine manifests its protective effect on ischemic brain injury by reducing the expression of TNF-α and IL-1ß in mouse ischemic brain tissue, inhibiting the polarization of microglia/macrophage toward the M1 phenotype and promoting polarization toward the M2 phenotype. CONCLUSION: This study is the first to demonstrate the protective effect of dihydroergotamine, a first-line treatment for migraine, against ischemic nerve injury in vitro and in vivo.

Echinatin protects from ischemic brain injury by attenuating NLRP3-related neuroinflammation.

BACKGROUND: Microglia-mediated neuroinflammation is the major contributor to the secondary brain injury of ischemic stroke. NLRP3 is one of the major components of ischemia-induced microglial activation. Echinatin, a chalcone found in licorice, was reported to have the activity of anti-inflammation and antioxidant. However, the relative study of echinatin in microglia or ischemic stroke is still unclear. METHODS: We intravenously injected echinatin or vehicle into adult ischemic male C57/BL6J mice induced by 60-min transient middle cerebral artery occlusion (tMCAO). The intraperitoneal injection was performed 4.5 h after reperfusion and then daily for 2 more days. Infarct size, blood brain barrier (BBB) leakage, neurobehavioral tests, and microglial-mediated inflammatory reaction were examined to assess the outcomes of echinatin treatment. LPS and LPS/ATP stimulation on primary microglia were used to explore the underlying anti-inflammatory mechanism of echinatin. RESULTS: Echinatin treatment efficiently decreased the infarct size, alleviated blood brain barrier (BBB) damage, suppressed microglial activation, reduced the production of inflammatory factors (e.g., IL-1ß, IL-6, IL-18, TNF-α, iNOS, COX2), and relieved post-stroke neurological defects in tMCAO mice. Mechanistically, we found that echinatin could suppress the NLRP3 assembly and reduce the production of inflammatory mediators independently of NF-κB and monoamine oxidase (MAO). CONCLUSION: Based on our study, we have identified echinatin as a promising therapeutic strategy for the treatment of ischemic stroke.

Inhibition of piezo1 prevents chronic cerebral hypoperfusion-induced cognitive impairment and blood brain barrier disruption.

Chronic cerebral hypoperfusion (CCH) plays a critical role in the onset and progression of vascular dementia (VD), which is now recognized as the second most common form of dementia after Alzheimer's disease (AD). The mechanosensitive piezo1 channel has been identified to play important roles in several neurological disorders. However, the roles and possible mechanisms of piezo1 in CCH-induced cognitive decline and blood brain barrier (BBB) disruption, as well as the underlying mechanisms remain elusive. In this study, the CCH model was established by bilateral common carotid artery occlusion in rats and by oxygen and glucose deprivation/reoxygenation (OGD/R) in bEnd.3 cells. The results demonstrated that the antagonist of piezo1 GsMTx4 ameliorated CCH-induced cognitive dysfunction and mitigated cerebral edema. Furthermore, this study indicated that GsMTx4 improved the permeability and integrity of BBB and protected cerebral microvasculature after CCH. In vitro, GsMTx4 improved cell viability, promoted the ability of cell motility and migration, and inhibited the degradation of BBB integrity-related proteins by inhibiting NLRP3 inflammasome activation. In addition, NLRP3 agonist abolished the beneficial effects of GsMTx4. Collectively, our results demonstrate that piezo1 might be involved in CCH-induced cognitive impairment and BBB damage, which may be at least partially mediated through regulation of NLRP3 inflammasome.

Neutrophils and Neutrophil Extracellular Traps Cause Vascular Occlusion and Delayed Cerebral Ischemia After Subarachnoid Hemorrhage in Mice.

BACKGROUND: After subarachnoid hemorrhage (SAH), neutrophils are deleterious and contribute to poor outcomes. Neutrophils can produce neutrophil extracellular traps (NETs) after ischemic stroke. Our hypothesis was that, after SAH, neutrophils contribute to delayed cerebral ischemia (DCI) and worse outcomes via cerebrovascular occlusion by NETs. METHODS: SAH was induced via endovascular perforation, and SAH mice were given either a neutrophil-depleting antibody, a PAD4 (peptidylarginine deiminase 4) inhibitor (to prevent NETosis), DNAse-I (to degrade NETs), or a vehicle control. Mice underwent daily neurological assessment until day 7 and then euthanized for quantification of intravascular brain NETs (iNETs). Subsets of mice were used to quantify neutrophil infiltration, NETosis potential, iNETs, cerebral perfusion, and infarction. In addition, NET markers were assessed in the blood of aneurysmal SAH patients. RESULTS: In mice, SAH led to brain neutrophil infiltration within 24 hours, induced a pro-NETosis phenotype selectively in skull neutrophils, and caused a significant increase in iNETs by day 1, which persisted until at least day 7. Neutrophil depletion significantly reduced iNETs, improving cerebral perfusion, leading to less neurological deficits and less incidence of DCI (16% versus 51.9%). Similarly, PAD4 inhibition reduced iNETs, improved neurological outcome, and reduced incidence of DCI (5% versus 30%), whereas degrading NETs marginally improved outcomes. Patients with aneurysmal SAH who developed DCI had elevated markers of NETs compared with non-DCI patients. CONCLUSIONS: After SAH, skull-derived neutrophils are primed for NETosis, and there are persistent brain iNETs, which correlated with delayed deficits. The findings from this study suggest that, after SAH, neutrophils and NETosis are therapeutic targets, which can prevent vascular occlusion by NETs in the brain, thereby lessening the risk of DCI. Finally, NET markers may be biomarkers, which can predict which patients with aneurysmal SAH are at risk for developing DCI.

Ischaemic stroke in a patient with non-valvular atrial fibrillation (NVAF) despite non-vitamin K oral anticoagulant (NOAC) therapy.

Primary stroke prevention in non-valvular atrial fibrillation (NVAF) is primarily with non-vitamin K oral anticoagulant (NOAC) therapy. However, 20-36% of ischaemic strokes seem to occur in patients with atrial fibrillation while already on anticoagulation. We present a case of an ischaemic stroke in an elderly female in her 70s with medical history significant for hypertension and NVAF. She had a CHA2DS2-VASc score of 3 and was on apixaban for thromboprophylaxis. She presented with neurological deficits consistent with a left middle cerebral artery stroke, confirmed via head imaging; the most likely stroke aetiology was determined to be cardioembolic in the setting of NVAF. She was treated with continuation of her apixaban at the same dosage She displayed improved function, although with residual expressive aphasia at her 2-month neurology follow-up. Cardioembolic ischaemic stroke in NVAF despite current NOAC therapy does not have current management guidelines.

Resveratrol Preconditioning Downregulates PARP1 Protein to Alleviate PARP1-Mediated Cell Death Following Cerebral Ischemia.

Stroke remains a leading cause of mortality; however, available therapeutics are limited. The study of ischemic tolerance, in paradigms such as resveratrol preconditioning (RPC), provides promise for the development of novel prophylactic therapies. The heavily oxidative environment following stroke promotes poly-ADP-ribose polymerase 1 (PARP1)-overactivation and parthanatos, both of which are major contributors to neuronal injury. In this study, we tested the hypothesis that RPC instills ischemic tolerance through decreasing PARP1 overexpression and parthanatos following in vitro and in vivo cerebral ischemia. To test this hypothesis, we utilized rat primary neuronal cultures (PNCs) and middle cerebral artery occlusion (MCAO) in the rat as in vitro and in vivo models, respectively. RPC was administered 2 days preceding ischemic insults. RPC protected PNCs against oxygen and glucose deprivation (OGD)-induced neuronal loss, as well as increases in total PARP1 protein, implying protection against PARP1-overactivation. Twelve hours following OGD, we observed reductions in NAD+/NADH as well as an increase in AIF nuclear translocation, but RPC ameliorated NAD+/NADH loss and blocked AIF nuclear translocation. MCAO in the rat induced AIF nuclear translocation in the ischemic penumbra after 24 h, which was ameliorated with RPC. We tested the hypothesis that RPC's neuroprotection was instilled through long-term downregulation of nuclear PARP1 protein. RPC downregulated nuclear PARP1 protein for at least 6 days in PNCs, likely contributing to RPC's ischemic tolerance. This study describes a novel mechanism by which RPC instills prophylaxis against ischemia-induced PARP1 overexpression and parthanatos, through a long-term reduction of nuclear PARP1 protein.

Stroke and bleeding risk in atrial fibrillation with CHA2DS2-VASC risk score of one: the Norwegian AFNOR study.

BACKGROUND AND AIMS: The benefit of oral anticoagulant (OAC) therapy in atrial fibrillation (AF) and intermediate stroke risk is debated. In a nationwide Norwegian cohort with a non-sex CHA2DS2-VASc risk score of one, this study aimed to investigate (i) stroke and bleeding risk in AF patients with and without OAC treatment, and (ii) the risk of stroke in non-anticoagulated individuals with and without AF. METHODS: A total of 1 118 762 individuals including 34 460 AF patients were followed during 2011-18 until ischaemic stroke, intracranial haemorrhage, increased CHA2DS2-VASc score, or study end. One-year incidence rates (IRs) were calculated as events per 100 person-years (%/py). Cox regression models provided adjusted hazard ratios (aHRs [95% confidence intervals]). RESULTS: Among AF patients, the ischaemic stroke IR was 0.51%/py in OAC users and 1.05%/py in non-users (aHR 0.47 [0.37-0.59]). Intracranial haemorrhage IR was 0.28%/py in OAC users and 0.19%/py in non-users (aHR 1.23 [0.88-1.72]). Oral anticoagulant use was associated with an increased risk of major bleeding (aHR 1.37 [1.16-1.63]) but lower risk of the combined outcome of ischaemic stroke, major bleeding, and mortality (aHR 0.57 [0.51-0.63]). Non-anticoagulated individuals with AF had higher risk of ischaemic stroke compared to non-AF individuals with the same risk profile (aHR 2.47 [2.17-2.81]). CONCLUSIONS: In AF patients at intermediate risk of stroke, OAC use was associated with overall favourable clinical outcomes. Non-anticoagulated AF patients had higher risk of ischaemic stroke compared to the general population without AF with the same risk profile.

Pharmacological Prevention of Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH) include early brain injury and delayed neurologic deterioration, which may result from delayed cerebral ischemia (DCI). Complex pathophysiological mechanisms underlie DCI, which often includes angiographic vasospasm (aVSP) of cerebral arteries. METHODS: Despite the study of many pharmacological therapies for the prevention of DCI in aSAH, nimodipine-a dihydropyridine calcium channel blocker-remains the only drug recommended universally in this patient population. A common theme in the research of preventative therapies is the use of promising drugs that have been shown to reduce the occurrence of aVSP but ultimately did not improve functional outcomes in large, randomized studies. An example of this is the endothelin antagonist clazosentan, although this agent was recently approved in Japan. RESULTS: The use of the only approved drug, nimodipine, is limited in practice by hypotension. The administration of nimodipine and its counterpart nicardipine by alternative routes, such as intrathecally or formulated as prolonged release implants, continues to be a rational area of study. Additional agents approved in other parts of the world include fasudil and tirilazad. CONCLUSIONS: We provide a brief overview of agents currently being studied for prevention of aVSP and DCI after aSAH. Future studies may need to identify subpopulations of patients who can benefit from these drugs and perhaps redefine acceptable outcomes to demonstrate impact.

Narirutin Attenuates Cerebral Ischemia-Reperfusion Injury by Suppressing the TXNIP/NLRP3 Pathway.

Narirutin (Nar) is a flavonoid that is abundantly present in citrus fruits and has attracted considerable attention because of its diverse pharmacological activities and low toxicity. Here, we evaluated the preventive effects of Nar in middle cerebral artery occlusion/reperfusion (MCAO/R)-injured mice and oxygen-glucose deprivation/reperfusion (OGD/R)-injured bEnd.3 cells. Pretreatment with Nar (150 mg/kg) for 7 days effectively reduced infarct volume, improved neurological deficits, and significantly inhibited neuronal death in the hippocampus and cortex in MCAO/R-injured mice. Moreover, anti-apoptotic effects of Nar (50 µM) were observed in OGD/R-injured bEnd.3 cells. In addition, Nar pre-administration regulated blood-brain barrier function by increasing tight junction-related protein expression after MCAO/R and OGD/R injury. Nar also inhibited NOD-like receptor protein 3 (NLRP3) inflammasome activation by reducing the expression of thioredoxin-interacting protein (TXNIP) in vivo and in vitro. Taken together, these results provide new evidence for the use of Nar in the prevention and treatment of ischemic stroke.

Intake reminders are effective in enhancing adherence to direct oral anticoagulants in stroke patients: a randomised cross-over trial (MAAESTRO study).

BACKGROUND: Direct oral anticoagulants (DOAC) effectively prevent recurrent ischaemic events in atrial fibrillation (AF) patients with recent stroke. However, excellent adherence to DOAC is mandatory to guarantee sufficient anticoagulation as the effect quickly subsides. AIM: To investigate the effect of intake reminders on adherence to DOAC. METHODS: MAAESTRO was a randomised, cross-over study in DOAC-treated AF patients hospitalised for ischaemic stroke. Adherence was measured by electronic monitoring for 12 months. After an observational phase, patients were randomised to obtain an intake reminder either in the first or the second half of the subsequent 6-month interventional phase. The primary outcome was 100%-timing adherence. Secondary outcomes were 100%-taking adherence, and overall timing and taking adherence. We analysed adherence outcomes using McNemar's test or mixed-effects logistic models. RESULTS: Between January 2018 and March 2022, 130 stroke patients were included, of whom 42 dropped out before randomisation. Analysis was performed with 84 patients (mean age: 76.5 years, 39.3% women). A 100%-timing adherence was observed in 10 patients who were using the reminder, and in zero patients without reminder (p = 0.002). The reminder significantly improved adherence to DOAC, with study participants having 2.7-fold increased odds to achieve an alternative threshold of 90%-timing adherence (OR 2.65; 95% CI 1.05-6.69; p = 0.039). A similar effect was observed for 90%-taking adherence (OR 3.06; 95% CI 1.20-7.80; p = 0.019). Overall timing and taking adherence increased significantly when using the reminder (OR 1.70; 95% CI 1.55-1.86, p < 0.01; and OR 1.67; 95% CI 1.52-1.84; p < 0.01). CONCLUSION: Intake reminders increased adherence to DOAC in patients with stroke attributable to atrial fibrillation. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03344146.

Remote ischemic conditioning after stroke: Research progress in clinical study.

BACKGROUND AND PURPOSE: Stroke is a leading cause of global morbidity and mortality, indicating the necessity and urgency of effective prevention and treatment. Remote ischemic conditioning (RIC) is a convenient, simple, non-intrusive, and effective method that can be easily added to the treatment regime of stroke patients. Animal experiments and clinical trials have proved the neuroprotective effects of RIC on brain injury including (examples of neuroprotective effects). This neuroprotection is achieved by raising brain tolerance to ischemia, increasing local cerebral blood perfusion, promoting collateral circulations, neural regeneration, and reducing the incidence of hematomas in brain tissue. This current paper will summarize the studies within the last 2 years for the comprehensive understanding of the use of RIC in the treatment of stroke. METHODS: This paper summarizes the clinical research progress of RIC on stroke (ischemic stroke and hemorrhagic stroke (HS)). This paper is a systematic review of research published on registered clinical trials using RIC in stroke from inception through November 2022. Four major databases (PUBMED, WEB OF SCIENCE, EMBASE, and ClinicalTrials.gov) were searched. RESULTS: Forty-eight studies were identified meeting our criteria. Of these studies, 14 were in patients with acute ischemic stroke with onset times ranging from 6 h to 14 days, seven were in patients with intravenous thrombolysis or endovascular thrombectomy, 10 were in patients with intracranial atherosclerotic stenosis, six on patients with vascular cognitive impairment, three on patients with moyamoya disease, and eight on patients with HS. Of the 48 studies, 42 were completed and six are ongoing. CONCLUSIONS: RIC is safe, feasible, and effective in the treatment of stroke. Large-scale research is still required to explore the optimal treatment options and mechanisms of RIC in the future to develop a breakthrough in stroke prevention and treatment.

Safety and efficacy of factor XIa inhibition with milvexian for secondary stroke prevention (AXIOMATIC-SSP): a phase 2, international, randomised, double-blind, placebo-controlled, dose-finding trial.

BACKGROUND: People with factor XI deficiency have lower rates of ischaemic stroke than the general population and infrequent spontaneous bleeding, suggesting that factor XI has a more important role in thrombosis than in haemostasis. Milvexian, an oral small-molecule inhibitor of activated factor XI, added to standard antiplatelet therapy, might reduce the risk of non-cardioembolic ischaemic stroke without increasing the risk of bleeding. We aimed to estimate the dose-response of milvexian for recurrent ischaemic cerebral events and major bleeding in patients with recent ischaemic stroke or transient ischaemic attack (TIA). METHODS: AXIOMATIC-SSP was a phase 2, randomised, double-blind, placebo-controlled, dose-finding trial done at 367 hospitals in 27 countries. Eligible participants aged 40 years or older, with acute (<48 h) ischaemic stroke or high-risk TIA, were randomly assigned by a web-based interactive response system in a 1:1:1:1:1:2 ratio to receive one of five doses of milvexian (25 mg once daily, 25 mg twice daily, 50 mg twice daily, 100 mg twice daily, or 200 mg twice daily) or matching placebo twice daily for 90 days. All participants received clopidogrel 75 mg daily for the first 21 days and aspirin 100 mg daily for the first 90 days. Investigators, site staff, and participants were masked to treatment assignment. The primary efficacy endpoint was the composite of ischaemic stroke or incident covert brain infarct on MRI at 90 days, assessed in all participants allocated to treatment who completed a follow-up MRI brain scan, and the primary analysis assessed the dose-response relationship with Multiple Comparison Procedure-Modelling (MCP-MOD). The main safety outcome was major bleeding at 90 days, assessed in all participants who received at least one dose of the study drug. This trial is registered with ClinicalTrials.gov (NCT03766581) and the EU Clinical Trials Register (2017-005029-19). FINDINGS: Between Jan 27, 2019, and Dec 24, 2021, 2366 participants were randomly allocated to placebo (n=691); milvexian 25 mg once daily (n=328); or twice-daily doses of milvexian 25 mg (n=318), 50 mg (n=328), 100 mg (n=310), or 200 mg (n=351). The median age of participants was 71 (IQR 62-77) years and 859 (36%) were female. At 90 days, the estimates of the percentage of participants with either symptomatic ischaemic stroke or covert brain infarcts were 16·8 (90·2% CI 14·5-19·1) for placebo, 16·7 (14·8-18·6) for 25 mg milvexian once daily, 16·6 (14·8-18·3) for 25 mg twice daily, 15·6 (13·9-17·5) for 50 mg twice daily, 15·4 (13·4-17·6) for 100 mg twice daily, and 15·3 (12·8-19·7) for 200 mg twice daily. No significant dose-response was observed among the five milvexian doses for the primary composite efficacy outcome. Model-based estimates of the relative risk with milvexian compared with placebo were 0·99 (90·2% CI 0·91-1·05) for 25 mg once daily, 0·99 (0·87-1·11) for 25 mg twice daily, 0·93 (0·78-1·11) for 50 mg twice daily, 0·92 (0·75-1·13) for 100 mg twice daily, and 0·91 (0·72-1·26) for 200 mg twice daily. No apparent dose-response was observed for major bleeding (four [1%] of 682 participants with placebo, two [1%] of 325 with milvexian 25 mg once daily, two [1%] of 313 with 25 mg twice daily, five [2%] of 325 with 50 mg twice daily, five [2%] of 306 with 100 mg twice daily, and five [1%] of 344 with 200 mg twice daily). Five treatment-emergent deaths occurred, four of which were considered unrelated to the study drug by the investigator. INTERPRETATION: Factor XIa inhibition with milvexian, added to dual antiplatelet therapy, did not substantially reduce the composite outcome of symptomatic ischaemic stroke or covert brain infarction and did not meaningfully increase the risk of major bleeding. Findings from our study have informed the design of a phase 3 trial of milvexian for the prevention of ischaemic stroke in patients with acute ischaemic stroke or TIA. FUNDING: Bristol Myers Squibb and Janssen Research & Development.

Effects of preceding antiplatelet agents on severity of ischemic stroke in patients with a history of stroke.

INTRODUCTION: Antiplatelet agents are effective for secondary prevention of ischemic stroke and can reduce the severity of first-ever ischemic stroke. However, it is uncertain if prophylactic antiplatelet therapy reduces the severity of recurrent ischemic stroke. The aim of this study was to determine the effect of preceding antiplatelet treatment on the severity of thrombotic stroke (TS) in patients with a prior history of stroke. METHODS: From a prospective hospital registry of 1338 consecutive patients with acute ischemic stroke, we identified patients with a prior history of stroke who were admitted for cardioembolic stroke (CE); TS including large-artery atherosclerosis, small vessel occlusion, and branch atheromatous disease; or other cause or cryptogenic stroke (OCS). Cases in each subtype were categorized based on preceding medication: antiplatelet agents (AP) and none (N). Severity of stroke (National Institutes of Health Stroke Scale: NIHSS) on admission was compared between AP and N cases. RESULTS: The total cohort of 252 patients included 83 with CE, 102 with TS, and 67 with OCS. After excluding those with prior anticoagulants, the median NIHSS on admission was lower in AP cases than in N cases (3 vs. 5, p = 0.002). In multivariate analysis, preceding AP treatment was independently associated with minor stroke (NIHSS ≤4) on admission in CE group (OR 8.48, 95% CI 1.71-62.9, p = 0.008) and TS group (OR 4.24, 95% CI 1.44-13.4, p = 0.009). CONCLUSION: Preceding antiplatelet treatment in patients with a prior history of stroke may reduce the severity of subsequent thrombotic and cardiogenic stroke.

Fasudil mediates neuroprotection in ischemia/reperfusion by modulating the ROCK-PPARα-NOX axis.

PURPOSE: Cerebral ischemia-reperfusion (I/R) is a neurovascular disorder that leads to brain injury. In mice, Fasudil improves nerve injury induced by I/R. However, it is unclear if this is mediated by increased peroxisome proliferator-activated receptor-α (PPARα) expression and reduced oxidative damage. This study aimed to investigate the neuroprotective mechanism of action of Fasudil. METHODS: MCAO (Middle cerebral artery occlusion) was performed in male C57BL/6J wild-type and PPARα KO mice between September 2021 to April 2023. Mice were treated with Fasudil and saline; 2,3,5-Triphenyltetrazolium chloride (TTC) staining was performed to analyze cerebral infarction. PPARα and Rho-associated protein kinase (ROCK) expression were detected using Western blot, and the expression of NADPH subunit Nox2 mRNA was detected using real-time polymerase chain reaction. The NADPH oxidase activity level and reactive oxygen species (ROS) content were also investigated. RESULTS: After cerebral ischemia, the volume of cerebral necrosis was reduced in wild-type mice treated with Fasudil. The expression of PPARα was increased, while ROCK was decreased. Nox2 mRNA expression, NADPH oxidase activity, and ROS content decreased. There were no significant changes in cerebral necrosis volumes, NADPH oxidase activity, and ROS content in the PPARα KO mice treated with Fasudil. CONCLUSIONS: In mice, the neuroprotective effect of Fasudil depends on the expression of PPARα induced by ROCK-PPARα-NOX axis-mediated reduction in ROS and associated oxidative damage.

[Severe Carotid Artery Disease:Monitoring and Precautions for Prevention of Cerebral Ischemia].

Cerebrovascular complications in cardiovascular surgery have long been documented. It is very important to diagnose and evaluate the stenosis of carotid artery before cardiovascular surgery. When indicated, carotid endarterectomy( CEA) or carotid artery stenting( CAS) for severe carotid artery stenosis may be considered before cardiovascular surgery. However, it has not been necessary performed in the real-world. It seems to be appropriate to maintain a mean arterial pressure of 50-70 mmHg during cardiovascular surgery with extracorporeal circulation. In addition, perioperative cerebral metabolism and circulation monitoring using a near-infrared cerebral oxygen monitor such as rSO2 is very useful from the viewpoint of preventing exacerbation of cerebral ischemia.

Effect of an herbal medicine, Chunghyul-dan, on prevention of recurrence in patients with ischemic stroke: A retrospective cohort study.

Research indicates that Chunghyul-dan (CHD), a herbal medicine, has an inhibitory effect on stroke recurrence in small vessel disease. Recent studies have suggested that CHD might also act on large arteries. This study aimed to verify the preventive effect of CHD on strokes of all the Trial of Org 10172 in Acute Stroke Treatment (TOAST) causative classifications. We retrospectively analyzed 2 years of medical records of patients with ischemic stroke treated with CHD, 600 mg once daily, in combination with antiplatelet or anticoagulant agents. The prevalence of stroke recurrence in 2 years was analyzed. Stroke recurrence was defined as new neurological symptoms with corresponding brain imaging results. Nine of the 202 patients (4.46%) had recurrent ischemic stroke. Four occurred within 180 days, 3 between 180 and 365 days, and 2 between 365 and 730 days. All had only 1 recurrence. The recurrence rates were 1.12%, 5%, and 5.48% for small vessel occlusion, cardioembolism, and large vessel atherosclerosis, respectively. There were no adverse effects. These results suggest that CHD could inhibit ischemic stroke recurrence of all TOAST causative categories. A randomized controlled trial is needed to confirm this hypothesis.

Decreased long-chain acylcarnitine content increases mitochondrial coupling efficiency and prevents ischemia-induced brain damage in rats.

Long-chain acylcarnitines (LCACs) are intermediates of fatty acid oxidation and are known to exert detrimental effects on mitochondria. This study aimed to test whether lowering LCAC levels with the anti-ischemia compound 4-[ethyl(dimethyl)ammonio]butanoate (methyl-GBB) protects brain mitochondrial function and improves neurological outcomes after transient middle cerebral artery occlusion (MCAO). The effects of 14 days of pretreatment with methyl-GBB (5 mg/kg, p.o.) on brain acylcarnitine (short-, long- and medium-chain) concentrations and brain mitochondrial function were evaluated in Wistar rats. Additionally, the mitochondrial respiration and reactive oxygen species (ROS) production rates were determined using ex vivo high-resolution fluorespirometry under normal conditions, in models of ischemia-reperfusion injury (reverse electron transfer and anoxia-reoxygenation) and 24 h after MCAO. MCAO model rats underwent vibrissae-evoked forelimb-placing and limb-placing tests to assess neurological function. The infarct volume was measured on day 7 after MCAO using 2,3,5-triphenyltetrazolium chloride (TTC) staining. Treatment with methyl-GBB significantly reduced the LCAC content in brain tissue, which decreased the ROS production rate without affecting the respiration rate, indicating an increase in mitochondrial coupling. Furthermore, methyl-GBB treatment protected brain mitochondria against anoxia-reoxygenation injury. In addition, treatment with methyl-GBB significantly reduced the infarct size and improved neurological outcomes after MCAO. Increased mitochondrial coupling efficiency may be the basis for the neuroprotective effects of methyl-GBB. This study provides evidence that maintaining brain energy metabolism by lowering the levels of LCACs protects against ischemia-induced brain damage in experimental stroke models.