Selenium Drives a Transcriptional Adaptive Program to Block Ferroptosis and Treat Stroke.

Ferroptosis, a non-apoptotic form of programmed cell death, is triggered by oxidative stress in cancer, heat stress in plants, and hemorrhagic stroke. A homeostatic transcriptional response to ferroptotic stimuli is unknown. We show that neurons respond to ferroptotic stimuli by induction of selenoproteins, including antioxidant glutathione peroxidase 4 (GPX4). Pharmacological selenium (Se) augments GPX4 and other genes in this transcriptional program, the selenome, via coordinated activation of the transcription factors TFAP2c and Sp1 to protect neurons. Remarkably, a single dose of Se delivered into the brain drives antioxidant GPX4 expression, protects neurons, and improves behavior in a hemorrhagic stroke model. Altogether, we show that pharmacological Se supplementation effectively inhibits GPX4-dependent ferroptotic death as well as cell death induced by excitotoxicity or ER stress, which are GPX4 independent. Systemic administration of a brain-penetrant selenopeptide activates homeostatic transcription to inhibit cell death and improves function when delivered after hemorrhagic or ischemic stroke.

Glutamate acts on acid-sensing ion channels to worsen ischaemic brain injury.

Glutamate is traditionally viewed as the first messenger to activate NMDAR (N-methyl-D-aspartate receptor)-dependent cell death pathways in stroke1,2, but unsuccessful clinical trials with NMDAR antagonists implicate the engagement of other mechanisms3-7. Here we show that glutamate and its structural analogues, including NMDAR antagonist L-AP5 (also known as APV), robustly potentiate currents mediated by acid-sensing ion channels (ASICs) associated with acidosis-induced neurotoxicity in stroke4. Glutamate increases the affinity of ASICs for protons and their open probability, aggravating ischaemic neurotoxicity in both in vitro and in vivo models. Site-directed mutagenesis, structure-based modelling and functional assays reveal a bona fide glutamate-binding cavity in the extracellular domain of ASIC1a. Computational drug screening identified a small molecule, LK-2, that binds to this cavity and abolishes glutamate-dependent potentiation of ASIC currents but spares NMDARs. LK-2 reduces the infarct volume and improves sensorimotor recovery in a mouse model of ischaemic stroke, reminiscent of that seen in mice with Asic1a knockout or knockout of other cation channels4-7. We conclude that glutamate functions as a positive allosteric modulator for ASICs to exacerbate neurotoxicity, and preferential targeting of the glutamate-binding site on ASICs over that on NMDARs may be strategized for developing stroke therapeutics lacking the psychotic side effects of NMDAR antagonists.

Tenecteplase for Stroke at 4.5 to 24 Hours with Perfusion-Imaging Selection.

BACKGROUND: Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS: The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS: Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).

Tirofiban for Stroke without Large or Medium-Sized Vessel Occlusion.

BACKGROUND: The effects of the glycoprotein IIb/IIIa receptor inhibitor tirofiban in patients with acute ischemic stroke but who have no evidence of complete occlusion of large or medium-sized vessels have not been extensively studied. METHODS: In a multicenter trial in China, we enrolled patients with ischemic stroke without occlusion of large or medium-sized vessels and with a National Institutes of Health Stroke Scale score of 5 or more and at least one moderately to severely weak limb. Eligible patients had any of four clinical presentations: ineligible for thrombolysis or thrombectomy and within 24 hours after the patient was last known to be well; progression of stroke symptoms 24 to 96 hours after onset; early neurologic deterioration after thrombolysis; or thrombolysis with no improvement at 4 to 24 hours. Patients were assigned to receive intravenous tirofiban (plus oral placebo) or oral aspirin (100 mg per day, plus intravenous placebo) for 2 days; all patients then received oral aspirin until day 90. The primary efficacy end point was an excellent outcome, defined as a score of 0 or 1 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. Secondary end points included functional independence at 90 days and a quality-of-life score. The primary safety end points were death and symptomatic intracranial hemorrhage. RESULTS: A total of 606 patients were assigned to the tirofiban group and 571 to the aspirin group. Most patients had small infarctions that were presumed to be atherosclerotic. The percentage of patients with a score of 0 or 1 on the modified Rankin scale at 90 days was 29.1% with tirofiban and 22.2% with aspirin (adjusted risk ratio, 1.26; 95% confidence interval, 1.04 to 1.53, P = 0.02). Results for secondary end points were generally not consistent with the results of the primary analysis. Mortality was similar in the two groups. The incidence of symptomatic intracranial hemorrhage was 1.0% in the tirofiban group and 0% in the aspirin group. CONCLUSIONS: In this trial involving heterogeneous groups of patients with stroke of recent onset or progression of stroke symptoms and nonoccluded large and medium-sized cerebral vessels, intravenous tirofiban was associated with a greater likelihood of an excellent outcome than low-dose aspirin. Incidences of intracranial hemorrhages were low but slightly higher with tirofiban. (Funded by the National Natural Science Foundation of China; RESCUE BT2 Chinese Clinical Trial Registry number, ChiCTR2000029502.).

Trial of Endovascular Therapy for Acute Ischemic Stroke with Large Infarct.

BACKGROUND: The role of endovascular therapy for acute stroke with a large infarction has not been extensively studied in differing populations. METHODS: We conducted a multicenter, prospective, open-label, randomized trial in China involving patients with acute large-vessel occlusion in the anterior circulation and an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower values indicating larger infarction) or an infarct-core volume of 70 to 100 ml. Patients were randomly assigned in a 1:1 ratio within 24 hours from the time they were last known to be well to undergo endovascular therapy and receive medical management or to receive medical management alone. The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability), and the primary objective was to determine whether a shift in the distribution of the scores on the modified Rankin scale at 90 days had occurred between the two groups. Secondary outcomes included scores of 0 to 2 and 0 to 3 on the modified Rankin scale. The primary safety outcome was symptomatic intracranial hemorrhage within 48 hours after randomization. RESULTS: A total of 456 patients were enrolled; 231 were assigned to the endovascular-therapy group and 225 to the medical-management group. Approximately 28% of the patients in both groups received intravenous thrombolysis. The trial was stopped early owing to the efficacy of endovascular therapy after the second interim analysis. At 90 days, a shift in the distribution of scores on the modified Rankin scale toward better outcomes was observed in favor of endovascular therapy over medical management alone (generalized odds ratio, 1.37; 95% confidence interval, 1.11 to 1.69; P = 0.004). Symptomatic intracranial hemorrhage occurred in 14 of 230 patients (6.1%) in the endovascular-therapy group and in 6 of 225 patients (2.7%) in the medical-management group; any intracranial hemorrhage occurred in 113 (49.1%) and 39 (17.3%), respectively. Results for the secondary outcomes generally supported those of the primary analysis. CONCLUSIONS: In a trial conducted in China, patients with large cerebral infarctions had better outcomes with endovascular therapy administered within 24 hours than with medical management alone but had more intracranial hemorrhages. (Funded by Covidien Healthcare International Trading [Shanghai] and others; ANGEL-ASPECT ClinicalTrials.gov number, NCT04551664.).

Trial of Endovascular Thrombectomy for Large Ischemic Strokes.

BACKGROUND: Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations. METHODS: We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome. RESULTS: The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group. CONCLUSIONS: Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial.

BACKGROUND: Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients. METHODS: SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed. FINDINGS: The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]). INTERPRETATION: In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up. FUNDING: Stryker Neurovascular.

Endovascular Therapy for Acute Stroke with a Large Ischemic Region.

BACKGROUND: Endovascular therapy for acute ischemic stroke is generally avoided when the infarction is large, but the effect of endovascular therapy with medical care as compared with medical care alone for large strokes has not been well studied. METHODS: We conducted a multicenter, open-label, randomized clinical trial in Japan involving patients with occlusion of large cerebral vessels and sizable strokes on imaging, as indicated by an Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) value of 3 to 5 (on a scale from 0 to 10, with lower values indicating larger infarction). Patients were randomly assigned in a 1:1 ratio to receive endovascular therapy with medical care or medical care alone within 6 hours after they were last known to be well or within 24 hours if there was no early change on fluid-attenuated inversion recovery images. Alteplase (0.6 mg per kilogram of body weight) was used when appropriate in both groups. The primary outcome was a modified Rankin scale score of 0 to 3 (on a scale from 0 to 6, with higher scores indicating greater disability) at 90 days. Secondary outcomes included a shift across the range of modified Rankin scale scores toward a better outcome at 90 days and an improvement of at least 8 points in the National Institutes of Health Stroke Scale (NIHSS) score (range, 0 to 42, with higher scores indicating greater deficit) at 48 hours. RESULTS: A total of 203 patients underwent randomization; 101 patients were assigned to the endovascular-therapy group and 102 to the medical-care group. Approximately 27% of patients in each group received alteplase. The percentage of patients with a modified Rankin scale score of 0 to 3 at 90 days was 31.0% in the endovascular-therapy group and 12.7% in the medical-care group (relative risk, 2.43; 95% confidence interval [CI], 1.35 to 4.37; P = 0.002). The ordinal shift across the range of modified Rankin scale scores generally favored endovascular therapy. An improvement of at least 8 points on the NIHSS score at 48 hours was observed in 31.0% of the patients in the endovascular-therapy group and 8.8% of those in the medical-care group (relative risk, 3.51; 95% CI, 1.76 to 7.00), and any intracranial hemorrhage occurred in 58.0% and 31.4%, respectively (P<0.001). CONCLUSIONS: In a trial conducted in Japan, patients with large cerebral infarctions had better functional outcomes with endovascular therapy than with medical care alone but had more intracranial hemorrhages. (Funded by Mihara Cerebrovascular Disorder Research Promotion Fund and the Japanese Society for Neuroendovascular Therapy; RESCUE-Japan LIMIT ClinicalTrials.gov number, NCT03702413.).

Trial of Endovascular Treatment of Acute Basilar-Artery Occlusion.

BACKGROUND: Data from trials investigating the effects and risks of endovascular thrombectomy for the treatment of stroke due to basilar-artery occlusion are limited. METHODS: We conducted a multicenter, prospective, randomized, controlled trial of endovascular thrombectomy for basilar-artery occlusion at 36 centers in China. Patients were assigned, in a 2:1 ratio, within 12 hours after the estimated time of basilar-artery occlusion to receive endovascular thrombectomy or best medical care (control). The primary outcome was good functional status, defined as a score of 0 to 3 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]), at 90 days. Secondary outcomes included a modified Rankin scale score of 0 to 2, distribution across the modified Rankin scale score categories, and quality of life. Safety outcomes included symptomatic intracranial hemorrhage at 24 to 72 hours, 90-day mortality, and procedural complications. RESULTS: Of the 507 patients who underwent screening, 340 were in the intention-to-treat population, with 226 assigned to the thrombectomy group and 114 to the control group. Intravenous thrombolysis was used in 31% of the patients in the thrombectomy group and in 34% of those in the control group. Good functional status at 90 days occurred in 104 patients (46%) in the thrombectomy group and in 26 (23%) in the control group (adjusted rate ratio, 2.06; 95% confidence interval [CI], 1.46 to 2.91, P<0.001). Symptomatic intracranial hemorrhage occurred in 12 patients (5%) in the thrombectomy group and in none in the control group. Results for the secondary clinical and imaging outcomes were generally in the same direction as those for the primary outcome. Mortality at 90 days was 37% in the thrombectomy group and 55% in the control group (adjusted risk ratio, 0.66; 95% CI, 0.52 to 0.82). Procedural complications occurred in 14% of the patients in the thrombectomy group, including one death due to arterial perforation. CONCLUSIONS: In a trial involving Chinese patients with basilar-artery occlusion, approximately one third of whom received intravenous thrombolysis, endovascular thrombectomy within 12 hours after stroke onset led to better functional outcomes at 90 days than best medical care but was associated with procedural complications and intracerebral hemorrhage. (Funded by the Program for Innovative Research Team of the First Affiliated Hospital of USTC and others; ATTENTION ClinicalTrials.gov number, NCT04751708.).

Trial of Thrombectomy 6 to 24 Hours after Stroke Due to Basilar-Artery Occlusion.

BACKGROUND: The effects and risks of endovascular thrombectomy 6 to 24 hours after stroke onset due to basilar-artery occlusion have not been extensively studied. METHODS: In a trial conducted over a 5-year period in China, we randomly assigned, in a 1:1 ratio, patients with basilar-artery stroke who presented between 6 to 24 hours after symptom onset to receive either medical therapy plus thrombectomy or medical therapy only (control). The original primary outcome, a score of 0 to 4 on the modified Rankin scale (range, 0 to 6, with a score of 0 indicating no disability, 4 moderately severe disability, and 6 death) at 90 days, was changed to a good functional status (a modified Rankin scale score of 0 to 3, with a score of 3 indicating moderate disability). Primary safety outcomes were symptomatic intracranial hemorrhage at 24 hours and 90-day mortality. RESULTS: A total of 217 patients (110 in the thrombectomy group and 107 in the control group) were included in the analysis; randomization occurred at a median of 663 minutes after symptom onset. Enrollment was halted at a prespecified interim analysis because of the superiority of thrombectomy. Thrombolysis was used in 14% of the patients in the thrombectomy group and in 21% of those in the control group. A modified Rankin scale score of 0 to 3 (primary outcome) occurred in 51 patients (46%) in the thrombectomy group and in 26 (24%) in the control group (adjusted rate ratio, 1.81; 95% confidence interval [CI], 1.26 to 2.60; P<0.001). The results for the original primary outcome of a modified Rankin scale score of 0 to 4 were 55% and 43%, respectively (adjusted rate ratio, 1.21; 95% CI, 0.95 to 1.54). Symptomatic intracranial hemorrhage occurred in 6 of 102 patients (6%) in the thrombectomy group and in 1 of 88 (1%) in the control group (risk ratio, 5.18; 95% CI, 0.64 to 42.18). Mortality at 90 days was 31% in the thrombectomy group and 42% in the control group (adjusted risk ratio, 0.75; 95% CI, 0.54 to 1.04). Procedural complications occurred in 11% of the patients who underwent thrombectomy. CONCLUSIONS: Among patients with stroke due to basilar-artery occlusion who presented 6 to 24 hours after symptom onset, thrombectomy led to a higher percentage with good functional status at 90 days than medical therapy but was associated with procedural complications and more cerebral hemorrhages. (Funded by the Chinese National Ministry of Science and Technology; BAOCHE ClinicalTrials.gov number, NCT02737189.).

Strokes Averted by Intravenous Thrombolysis: A Secondary Analysis of a Prospective, Multicenter, Controlled Trial of Mobile Stroke Units.

OBJECTIVE: This study was undertaken to examine averted stroke in optimized stroke systems. METHODS: This secondary analysis of a multicenter trial from 2014 to 2020 compared patients treated by mobile stroke unit (MSU) versus standard management. The analytical cohort consisted of participants with suspected stroke treated with intravenous thrombolysis. The main outcome was a tissue-defined averted stroke, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis and no acute infarction/hemorrhage on imaging. An additional outcome was stroke with early symptom resolution, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis. RESULTS: Among 1,009 patients with a median last known well to thrombolysis time of 87 minutes, 159 (16%) had tissue-defined averted stroke and 276 (27%) had stroke with early symptom resolution. Compared with standard management, MSU care was associated with more tissue-defined averted stroke (18% vs 11%, adjusted odds ratio [aOR] = 1.82, 95% confidence interval [CI] = 1.13-2.98) and stroke with early symptom resolution (31% vs 21%, aOR = 1.74, 95% CI = 1.12-2.61). The relationships between thrombolysis treatment time and averted/early recovered stroke appeared nonlinear. Most models indicated increased odds for stroke with early symptom resolution but not tissue-defined averted stroke with earlier treatment. Additionally, younger age, female gender, hyperlipidemia, lower National Institutes of Health Stroke Scale, lower blood pressure, and no large vessel occlusion were associated with both tissue-defined averted stroke and stroke with early symptom resolution. INTERPRETATION: In optimized stroke systems, 1 in 4 patients treated with thrombolysis recovered within 24 hours and 1 in 6 had no demonstrable brain injury on imaging. ANN NEUROL 2024;95:347-361.

Inhibiting metabotropic glutamate receptor 5 after stroke restores brain function and connectivity.

Stroke results in local neural disconnection and brain-wide neuronal network dysfunction leading to neurological deficits. Beyond the hyper-acute phase of ischaemic stroke, there is no clinically-approved pharmacological treatment that alleviates sensorimotor impairments. Functional recovery after stroke involves the formation of new or alternative neuronal circuits including existing neural connections. The type-5 metabotropic glutamate receptor (mGluR5) has been shown to modulate brain plasticity and function and is a therapeutic target in neurological diseases outside of stroke. We investigated whether mGluR5 influences functional recovery and network reorganization rodent models of focal ischaemia. Using multiple behavioural tests, we observed that treatment with negative allosteric modulators (NAMs) of mGluR5 (MTEP, fenobam and AFQ056) for 12 days, starting 2 or 10 days after stroke, restored lost sensorimotor functions, without diminishing infarct size. Recovery was evident within hours after initiation of treatment and progressed over the subsequent 12 days. Recovery was prevented by activation of mGluR5 with the positive allosteric modulator VU0360172 and accelerated in mGluR5 knock-out mice compared with wild-type mice. After stroke, multisensory stimulation by enriched environments enhanced recovery, a result prevented by VU0360172, implying a role of mGluR5 in enriched environment-mediated recovery. Additionally, MTEP treatment in conjunction with enriched environment housing provided an additive recovery enhancement compared to either MTEP or enriched environment alone. Using optical intrinsic signal imaging, we observed brain-wide disruptions in resting-state functional connectivity after stroke that were prevented by mGluR5 inhibition in distinct areas of contralesional sensorimotor and bilateral visual cortices. The levels of mGluR5 protein in mice and in tissue samples of stroke patients were unchanged after stroke. We conclude that neuronal circuitry subserving sensorimotor function after stroke is depressed by a mGluR5-dependent maladaptive plasticity mechanism that can be restored by mGluR5 inhibition. Post-acute stroke treatment with mGluR5 NAMs combined with rehabilitative training may represent a novel post-acute stroke therapy.

DAPK1 interaction with NMDA receptor NR2B subunits mediates brain damage in stroke.

N-methyl-D-aspartate (NMDA) receptors constitute a major subtype of glutamate receptors at extrasynaptic sites that link multiple intracellular catabolic processes responsible for irreversible neuronal death. Here, we report that cerebral ischemia recruits death-associated protein kinase 1 (DAPK1) into the NMDA receptor NR2B protein complex in the cortex of adult mice. DAPK1 directly binds with the NMDA receptor NR2B C-terminal tail consisting of amino acid 1292-1304 (NR2B(CT)). A constitutively active DAPK1 phosphorylates NR2B subunit at Ser-1303 and in turn enhances the NR1/NR2B receptor channel conductance. Genetic deletion of DAPK1 or administration of NR2B(CT) that uncouples an activated DAPK1 from an NMDA receptor NR2B subunit in vivo in mice blocks injurious Ca(2+) influx through NMDA receptor channels at extrasynaptic sites and protects neurons against cerebral ischemic insults. Thus, DAPK1 physically and functionally interacts with the NMDA receptor NR2B subunit at extrasynaptic sites and this interaction acts as a central mediator for stroke damage.

ß-Caryophyllene mitigates ischemic stroke-induced white matter lesions by inhibiting pyroptosis.

ß-Caryophyllene (BCP), a selective agonist for cannabinoid receptor 2 (CB2R), has demonstrated promising protective effects in various pathological conditions. However, the neuroprotective effects of BCP on white matter damage induced by ischemic stroke have not been elucidated previously. In this study, we find that BCP not only improves sensorimotor and cognitive function via CB2R but also mitigates white matter lesions in mice following ischemic stroke. Furthermore, BCP enhances the viability of MO3.13 oligodendrocytes after oxygen-glucose deprivation and reoxygenation (OGD/R), attenuating OGD/R-induced cellular damage and pyroptosis. Notably, these protective effects of BCP are partially enhanced by the NLRP3 inhibitor MCC950 and counteracted by the NLRP3 activator nigericin. In addition, nigericin significantly exacerbates neurological outcomes and increases white matter lesions following BCP treatment in middle cerebral artery occlusion (MCAO) mice. These results suggest that BCP may ameliorate neurological deficits and white matter damage induced by cerebral ischemia through inhibiting NLRP3-mediated pyroptosis.

After EVT for ischemic stroke, intensive vs. conventional BP management reduced functional independence at 3 mo.

SOURCE CITATION: Nam HS, Kim YD, Heo J, et al; OPTIMAL-BP Trial Investigators. Intensive vs conventional blood pressure lowering after endovascular thrombectomy in acute ischemic stroke: the OPTIMAL-BP randomized clinical trial. JAMA. 2023;330:832-842. 37668619.

The NEDD8-activating enzyme inhibitor MLN4924 reduces ischemic brain injury in mice.

Blood-brain barrier (BBB) breakdown and inflammation occurring at the BBB have a key, mainly a deleterious role in the pathophysiology of ischemic stroke. Neddylation is a ubiquitylation-like pathway that is critical in various cellular functions by conjugating neuronal precursor cell-expressed developmentally down-regulated protein 8 (NEDD8) to target proteins. However, the roles of neddylation pathway in ischemic stroke remain elusive. Here, we report that NEDD8 conjugation increased during acute phase after ischemic stroke and was present in intravascular and intraparenchymal neutrophils. Inhibition of neddylation by MLN4924, also known as pevonedistat, inactivated cullin-RING E3 ligase (CRL), and reduced brain infarction and improved functional outcomes. MLN4924 treatment induced the accumulation of the CRL substrate neurofibromatosis 1 (NF1). By using virus-mediated NF1 silencing, we show that NF1 knockdown abolished MLN4924-dependent inhibition of neutrophil trafficking. These effects were mediated through activation of endothelial P-selectin and intercellular adhesion molecule-1 (ICAM-1), and blocking antibodies against P-selectin or anti-ICAM-1 antibodies reversed NF1 silencing-induced increase in neutrophil infiltration in MLN4924-treated mice. Furthermore, we found that NF1 silencing blocked MLN4924-afforded BBB protection and neuroprotection through activation of protein kinase C δ (PKCδ), myristoylated alanine-rich C-kinase substrate (MARCKS), and myosin light chain (MLC) in cerebral microvessels after ischemic stroke, and treatment of mice with the PKCδ inhibitor rottlerin reduced this increased BBB permeability. Our study demonstrated that increased neddylation promoted neutrophil trafficking and thus exacerbated injury of the BBB and stroke outcomes. We suggest that the neddylation inhibition may be beneficial in ischemic stroke.

Sulfated Polysaccharide-Based Nanocarrier Drives Microenvironment-Mediated Cerebral Neurovascular Remodeling for Ischemic Stroke Treatment.

Stroke is a leading cause of global mortality and severe disability. However, current strategies used for treating ischemic stroke lack specific targeting capabilities, exhibit poor immune escape ability, and have limited drug release control. Herein, we developed an ROS-responsive nanocarrier for targeted delivery of the neuroprotective agent rapamycin (RAPA) to mitigate ischemic brain damage. The nanocarrier consisted of a sulfated chitosan (SCS) polymer core modified with a ROS-responsive boronic ester enveloped by a red blood cell membrane shell incorporating a stroke homing peptide. When encountering high levels of intracellular ROS in ischemic brain tissues, the release of SCS combined with RAPA from nanoparticle disintegration facilitates effective microglia polarization and, in turn, maintains blood-brain barrier integrity, reduces cerebral infarction, and promotes cerebral neurovascular remodeling in a mouse stroke model involving transient middle cerebral artery occlusion (tMCAO). This work offers a promising strategy to treat ischemic stroke therapy.

Drugs/agents for the treatment of ischemic stroke: Advances and perspectives.

Ischemic stroke (IS) poses a significant threat to global human health and life. In recent decades, we have witnessed unprecedented progresses against IS, including thrombolysis, thrombectomy, and a few medicines that can assist in reopening the blocked brain vessels or serve as standalone treatments for patients who are not eligible for thrombolysis/thrombectomy therapies. However, the narrow time windows of thrombolysis/thrombectomy, coupled with the risk of hemorrhagic transformation, as well as the lack of highly effective and safe medications, continue to present big challenges in the acute treatment and long-term recovery of IS. In the past 3 years, several excellent articles have reviewed pathophysiology of IS and therapeutic medicines for the treatment of IS based on the pathophysiology. Regretfully, there is no comprehensive overview to summarize all categories of anti-IS drugs/agents designed and synthesized based on molecular mechanisms of IS pathophysiology. From medicinal chemistry view of point, this article reviews a multitude of anti-IS drugs/agents, including small molecule compounds, natural products, peptides, and others, which have been developed based on the molecular mechanism of IS pathophysiology, such as excitotoxicity, oxidative/nitrosative stresses, cell death pathways, and neuroinflammation, and so forth. In addition, several emerging medicines and strategies, including nanomedicines, stem cell therapy and noncoding RNAs, which recently appeared for the treatment of IS, are shortly introduced. Finally, the perspectives on the associated challenges and future directions of anti-IS drugs/agents are briefly provided to move the field forward.

Huanglian Jiedu decoction alleviates ischemia-induced cerebral injury in rats by mitigating NET formation and activiting GABAergic synapses.

Huanglian Jiedu decoction (HLJD) has been used to treat ischemic stroke in clinic. However, the detailed protective mechanisms of HLJD on ischemic stroke have yet to be elucidated. The aim of this study is to elucidate the underlying pharmacological mechanisms of HLJD based on the inhibition of neuroinflammation and the amelioration of nerve cell damage. A middle cerebral artery occlusion reperfusion (MCAO/R) model was established in rats and received HLJD treatment. Effects of HLJD on neurological function was assessed based on Bederson's score, postural reflex test and asymmetry score. 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining, Hematein and eosin (HE) and Nissl staining were used to observe the pathological changes in brain. Then, transcriptomics was used to screen the differential genes in brain tissue in MCAO/R model rats following HLJD intervention. Subsequently, the effects of HLJD on neutrophil extracellular trap (NET) formation-related neuroinflammation, gamma-aminobutyric acid (GABA)ergic synapse activation, nerve cell damage and proliferation were validated using immunofluorescence, western blot and enzyme-linked immunosorbent assay (ELISA). Our results showed that HLJD intervention reduced the Bederson's score, postural reflex test score and asymmetry score in MCAO/R model rats. Pathological staining indicated that HLJD treatment decreased the cerebral infarction area, mitigated neuronal damage and increased the numbers of Nissl bodies. Transcriptomics suggested that HLJD affected 435 genes in MCAO/R rats. Among them, several genes involving in NET formation and GABAergic synapses pathways were dysregulated. Subsequent experimental validation showed that HLJD reduced the MPO+CitH3+ positive expression area, reduced the protein expression of PAD4, p-P38/P38, p-ERK/ERK and decreased the levels of IL-1ß, IL-6 and TNF-α, reversed the increase of Iba1+TLR4+, Iba1+p65+ and Iba1+NLRP3+ positive expression area in brain. Moreover, HLJD increased GABA levels, elevated the protein expression of GABRG1 and GAT3, decreased the TUNEL positive expression area and increased the Ki67 positive expression area in brain. HLJD intervention exerts a multifaceted positive impact on ischemia-induced cerebral injury in MCAO/R rats. This intervention effectively inhibits neuroinflammation by mitigating NET formation, and concurrently improves nerve cell damage and fosters nerve cell proliferation through activating GABAergic synapses.

Shorter Door-to-Needle Times Are Associated With Better Outcomes After Intravenous Thrombolytic Therapy and Endovascular Thrombectomy for Acute Ischemic Stroke.

BACKGROUND: Existing data and clinical trials could not determine whether faster intravenous thrombolytic therapy (IVT) translates into better long-term functional outcomes after acute ischemic stroke among those treated with endovascular thrombectomy (EVT). Patient-level national data can provide the required large population to study the associations between earlier IVT, versus later, with longitudinal functional outcomes and mortality in patients receiving IVT+EVT combined treatment. METHODS: This cohort study included older US patients (age ≥65 years) who received IVT within 4.5 hours or EVT within 7 hours after acute ischemic stroke using the linked 2015 to 2018 Get With The Guidelines-Stroke and Medicare database (38 913 treated with IVT only and 3946 with IVT+EVT). Primary outcome was home time, a patient-prioritized functional outcome. Secondary outcomes included all-cause mortality in 1 year. Multivariate logistic regression and Cox proportional hazards models were used to evaluate the associations between door-to-needle (DTN) times and outcomes. RESULTS: Among patients treated with IVT+EVT, after adjusting for patient and hospital factors, including onset-to-EVT times, each 15-minute increase in DTN times for IVT was associated with significantly higher odds of zero home time in a year (never discharged to home) (adjusted odds ratio, 1.12 [95% CI, 1.06-1.19]), less home time among those discharged to home (adjusted odds ratio, 0.93 per 1% of 365 days [95% CI, 0.89-0.98]), and higher all-cause mortality (adjusted hazard ratio, 1.07 [95% CI, 1.02-1.11]). These associations were also statistically significant among patients treated with IVT but at a modest degree (adjusted odds ratio, 1.04 for zero home time, 0.96 per 1% home time for those discharged to home, and adjusted hazard ratio 1.03 for mortality). In the secondary analysis where the IVT+EVT group was compared with 3704 patients treated with EVT only, shorter DTN times (≤60, 45, and 30 minutes) achieved incrementally more home time in a year, and more modified Rankin Scale 0 to 2 at discharge (22.3%, 23.4%, and 25.0%, respectively) versus EVT only (16.4%, P<0.001 for each). The benefit dissipated with DTN>60 minutes. CONCLUSIONS: Among older patients with stroke treated with either IVT only or IVT+EVT, shorter DTN times are associated with better long-term functional outcomes and lower mortality. These findings support further efforts to accelerate thrombolytic administration in all eligible patients, including EVT candidates.