The Modulatory Role of Hypothermia in Post-Stroke Brain Inflammation: Mechanisms and Clinical Implications.

BACKGROUND: Acute ischemic stroke remains a major contributor to mortality and disability worldwide. The use of hypothermia has emerged as a promising neuroprotective strategy, with proven effectiveness in cardiac arrest and neonatal hypoxic-ischemic injury. SUMMARY: This review explores the therapeutic potential of hypothermia in ischemic stroke by examining its impact on post-stroke inflammatory responses. We synthesized evidence from basic and clinical studies to illustrate the inhibitory effects of hypothermia on post-stroke brain inflammation. The underlying mechanisms include modulation of microglial activation and polarization, downregulation of key inflammatory pathways such as MAPKs, NF-KB, and JAK/STAT, protection of the blood-brain barrier integrity, and reduction of immune cell infiltration into the brain. We also discuss the current limitations of hypothermia treatment in clinical practice and highlight future research directions for optimizing protocols and evaluating its clinical efficacy in stroke patients. KEY MESSAGES: Therapeutic hypothermia (TH) has evolved significantly with advancements in medical technologies, especially with the introduction of automated cooling devices, both intravascular and surface based. However, a refined, highly individualized and effective hypothermia protocol may stand robust against the devastating consequences of ischemic stroke, and we think it should become the future development goal.

Balloon Angioplasty vs Medical Management for Intracranial Artery Stenosis: The BASIS Randomized Clinical Trial.

Importance: Previous randomized clinical trials did not demonstrate the superiority of endovascular stenting over aggressive medical management for patients with symptomatic intracranial atherosclerotic stenosis (sICAS). However, balloon angioplasty has not been investigated in a randomized clinical trial. Objective: To determine whether balloon angioplasty plus aggressive medical management is superior to aggressive medical management alone for patients with sICAS. Design, Setting, and Participants: A randomized, open-label, blinded end point clinical trial at 31 centers across China. Eligible patients aged 35 to 80 years with sICAS defined as recent transient ischemic attack (<90 days) or ischemic stroke (14-90 days) before enrollment attributed to a 70% to 99% atherosclerotic stenosis of a major intracranial artery receiving treatment with at least 1 antithrombotic drug and/or standard risk factor management were recruited between November 8, 2018, and April 2, 2022 (final follow-up: April 3, 2023). Interventions: Submaximal balloon angioplasty plus aggressive medical management (n = 249) or aggressive medical management alone (n = 252). Aggressive medical management included dual antiplatelet therapy for the first 90 days and risk factor control. Main Outcomes and Measures: The primary outcome was a composite of any stroke or death within 30 days after enrollment or after balloon angioplasty of the qualifying lesion or any ischemic stroke in the qualifying artery territory or revascularization of the qualifying artery after 30 days through 12 months after enrollment. Results: Among 512 randomized patients, 501 were confirmed eligible (mean age, 58.0 years; 158 [31.5%] women) and completed the trial. The incidence of the primary outcome was lower in the balloon angioplasty group than the medical management group (4.4% vs 13.5%; hazard ratio, 0.32 [95% CI, 0.16-0.63]; P < .001). The respective rates of any stroke or all-cause death within 30 days were 3.2% and 1.6%. Beyond 30 days through 1 year after enrollment, the rates of any ischemic stroke in the qualifying artery territory were 0.4% and 7.5%, respectively, and revascularization of the qualifying artery occurred in 1.2% and 8.3%, respectively. The rate of symptomatic intracranial hemorrhage in the balloon angioplasty and medical management groups was 1.2% and 0.4%, respectively. In the balloon angioplasty group, procedural complications occurred in 17.4% of patients and arterial dissection occurred in 14.5% of patients. Conclusions and Relevance: In patients with sICAS, balloon angioplasty plus aggressive medical management, compared with aggressive medical management alone, statistically significantly lowered the risk of a composite outcome of any stroke or death within 30 days or an ischemic stroke or revascularization of the qualifying artery after 30 days through 12 months. The findings suggest that balloon angioplasty plus aggressive medical management may be an effective treatment for sICAS, although the risk of stroke or death within 30 days of balloon angioplasty should be considered in clinical practice. Trial Registration: ClinicalTrials.gov Identifier: NCT03703635.

Induced Inflammatory and Oxidative Markers in Cerebral Microvasculature by Mentally Depressive Stress.

Background: Cerebrovascular disease (CVD) is recognized as the leading cause of permanent disability worldwide. Depressive disorders are associated with increased incidence of CVD. The goal of this study was to establish a chronic restraint stress (CRS) model for mice and examine the effect of stress on cerebrovascular inflammation and oxidative stress responses. Methods: A total of forty 6-week-old male C57BL/6J mice were randomly divided into the CRS and control groups. In the CRS group (n = 20), mice were placed in a well-ventilated Plexiglas tube for 6 hours per day for 28 consecutive days. On day 29, open field tests (OFT) and sucrose preference tests (SPT) were performed to assess depressive-like behaviors for the two groups (n = 10/group). Macrophage infiltration into the brain tissue upon stress was analyzed by measuring expression of macrophage marker (CD68) with immunofluorescence in both the CRS and control groups (n = 10/group). Cerebral microvasculature was isolated from the CRS and controls (n = 10/group). mRNA and protein expressions of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), and macrophage chemoattractant protein-1 (MCP-1) in the brain vessels were measured by real-time PCR and Western blot (n = 10/group). Reactive oxygen species (ROS), hydrogen peroxide (H2O2), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activities were quantified by ELISA to study the oxidative profile of the brain vessels (n = 10/group). Additionally, mRNA and protein expressions of NOX subunits (gp91phox, p47phox, p67phox, and p22phox) in the cerebrovascular endothelium were analyzed by real-time PCR and Western blot (n = 10/group). Results: CRS decreased the total distances (p < 0.05) and the time spent in the center zone in OFT (p < 0.001) and sucrose preference test ratio in SPT (p < 0.01). Positive ratio of CD68+ was increased with CRS in the entire region of the brain (p < 0.001), reflecting increased macrophage infiltration. CRS increased the expression of inflammatory factors and oxidative stress in the cerebral microvasculature, including TNF-α (p < 0.001), IL-1ß (p < 0.05), IL-6 (p < 0.05), VCAM-1 (p < 0.01), MCP-1 (p < 0.01), ROS (p < 0.001), and H2O2 (p < 0.001). NADPH oxidase (NOX) was activated by CRS (p < 0.01), and mRNA and protein expressions of NOX subunits (gp91phox, p47phox, p67phox, and p22phox) in brain microvasculature were found to be increased. Conclusions: To our knowledge, this is the first study to demonstrate that CRS induces depressive stress and causes inflammatory and oxidative stress responses in the brain microvasculature.

Combined Approach to Eptifibatide and Thrombectomy in Acute Ischemic Stroke Because of Large Vessel Occlusion: A Matched-Control Analysis.

BACKGROUND: In patients undergoing mechanical thrombectomy (MT), adjunctive antithrombotic might improve angiographic reperfusion, reduce the risk of distal emboli and reocclusion but possibly expose patients to a higher intracranial hemorrhage risk. This study evaluated the safety and efficacy of combined MT plus eptifibatide for acute ischemic stroke. METHODS: This was a propensity-matched analysis of data from 2 prospective trials in Chinese populations: the ANGEL-ACT trial (Endovascular Treatment Key Technique and Emergency Workflow Improvement of Acute Ischemic Stroke) in 111 hospitals between November 2017 and March 2019, and the EPOCH trial (Eptifibatide in Endovascular Treatment of Acute Ischemic Stroke) in 15 hospitals between April 2019 and March 2020. The primary efficacy outcome was good outcome (modified Rankin Scale score 0-2) at 3 months. Secondary efficacy outcomes included the distribution of 3-month modified Rankin Scale scores and poor outcome (modified Rankin Scale score 5-6) and successful recanalization. The safety outcomes included any intracranial hemorrhage, symptomatic intracranial hemorrhage, and 3-month mortality. Mixed-effects logistic regression models were used to account for within-hospital clustering in adjusted analyses. RESULTS: Eighty-one combination arm EPOCH subjects were matched with 81 ANGEL-ACT noneptifibatide patients. Compared with the no eptifibatide group, the eptifibatide group had significantly higher rates of successful recanalization (91.3% versus 81.5%; P=0.043) and 3-month good outcomes (53.1% versus 33.3%; P=0.016). No significant difference was found in the remaining outcome measures between the 2 groups. All outcome measures of propensity score matching were consistent with mixed-effects logistic regression models in the total population. CONCLUSIONS: This matched-control study demonstrated that MT combined with eptifibatide did not raise major safety concerns and showed a trend of better efficacy outcomes compared with MT alone. Overall, eptifibatide shows potential as a periprocedural adjunctive antithrombotic therapy when combined with MT. Further randomized controlled trials of MT plus eptifibatide should be prioritized. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03844594 (EPOCH), NCT03370939 (ANGEL-ACT).

Passing Extracranial Artery Occlusion by Intermediate Catheter With Expanding Microballoon (PEACE): A Novel Endovascular Therapy in Acute Tandem Occlusion Stroke.

PURPOSE: Endovascular treatment of atherosclerotic tandem occlusions in acute ischemic stroke (AIS) is a matter of debate. This article reports a single-center experience using an intermediate catheter with microballoon for treatment of tandem occlusions. METHODS: A total of 151 AIS patients with large vessel occlusion received endovascular therapy and a consecutive series of patients (n = 26) who suffered from tandem cervical intracranial occlusions were treated using the Passing Extracranial Artery Occlusion by Intermediate Catheter with Expanding Microballoon (PEACE) technique. Intracranial recanalization was achieved by aspiration or stent retriever and then emergency stenting was performed for extracranial internal carotid artery (ICA) lesion. Demographic, clinical characteristics, procedural details of endovascular therapy, and prognosis outcome were assessed. The outcomes of tandem occlusion group were compared with isolated intracranial occlusion group (n = 122) and previous studies. RESULTS: As compared to isolated intracranial occlusion groups, only a few patients suffered from atrial fibrillation (7.7% vs 38.5%, p<0.01) in tandem occlusions group. A larger proportion of patients (61.5% vs 29.5%) had tandem occlusions in which extracranial ICA occlusion was combined with intracranial terminus occlusion in ICA (p<0.01). 46.2% of tandem occlusions patients achieved intracranial recanalization by aspiration alone versus 15.6% in patients with isolated intracranial occlusion (p<0.01). In tandem occlusion patients treated with PEACE, 92.3% achieved successful reperfusion (thrombolysis in cerebral infarct [TICI] ≥2b). The median time from puncture to recanalization was 51 minutes (interquartile range [IQR], 41-66). 67.6% favorable functional prognosis (modified Rankin score [mRS], 0-2) was seen, with 11.5% mortality and 3.8% of symptomatic intracerebral hemorrhage (sICH) at 90 days. These outcomes are all consistent or better than previously reported studies performed for tandem occlusion. CONCLUSIONS: Endovascular therapy using the PEACE technique with intermediate catheter and lined expanding microballoon is safe, efficient, and fast in the treatment of atherosclerotic tandem occlusion patients.

Extracranial carotid plaque hemorrhage predicts ipsilateral stroke recurrence in patients with carotid atherosclerosis - a study based on high-resolution vessel wall imaging MRI.

BACKGROUND: Intraplaque hemorrhage (IPH) is a hallmark of carotid plaque vulnerability. We aim to investigate the association between IPH and recurrent ipsilateral ischemic stroke. METHODS: Patients with a recent stroke or transient ischemic attack (TIA) were prospectively recruited and underwent an ultrasonographic examination and carotid HR VWMRI on the side consistent with symptoms. Carotid plaque was defined as carotid intima-media-thickness (IMT) by ultrasound≥1.5 mm. IPH was determined that the ratio of the plaque signal intensity relative to that of adjacent muscle was > 1.5. All enrolled patients were clinically followed until an ipsilateral ischemic stroke, TIA, carotid endarterectomy (CEA)/carotid artery stenting (CAS), or death within 12 months. Univariate analysis was used to analyze the correlation between clinical characteristics and IPH. Kaplan-Meier survival analysis and a log-rank test were used to compare recurrence-free survival time between the IPH and non-IPH groups. Cox regression models evaluated IPH as the predictor of ipsilateral stroke recurrence. RESULTS: A total of 171 patients (mean age, 60.13 ± 10.04 years; 118 males) were included in the final analysis. Thirty-two patients (18.7%) showed carotid IPH. During the follow-up, patients with carotid IPH suffered 60.9% (14 of 23) of recurrent ipsilateral strokes and 60.0% (3 of 5) TIA. Multivariate Cox regression analysis proved IPH as a strong predictor of ipsilateral stroke; the adjusted hazard ratio (HR) was 6.64 (95% confidence interval [CI], 2.84-15.54, P < 0.001). Meanwhile, Cox regression analysis also proved that IPH could predict recurrent ischemic events; the adjusted HR was 8.08 (95% CI, 3.65-17.91, P < 0.001). CONCLUSIONS: Carotid intraplaque hemorrhage is strongly associated with recurrent ischemic events and could predict recurrent ipsilateral stroke.

Early neurological deterioration in acute ischemic stroke patients after intravenous thrombolysis with alteplase predicts poor 3-month functional prognosis - data from the Thrombolysis Implementation and Monitor of Acute Ischemic Stroke in China (TIMS-China).

BACKGROUND: We aimed to investigate the risk factors of early neurological deterioration (END) after intravenous thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) and the relationship between END and poor 3-month functional outcomes. METHODS: Patients who accepted intravenous recombinant rt-PA were enrolled continuously. END was defined as an increase in National Institute of Health Stroke (NIHSS) score ≥ 4 points or death within 24 hours after intravenous thrombolysis. The modified Rankin Scale (mRS) score was recorded to evaluate the functional outcome of stroke, and the poor 3-month prognosis was defined as an mRS score ≥ of 3. Univariate and multivariate analyses were used to analyze the risk factors of END. The relation between END and 3-month functional outcome was analyzed by multivariate logistic regression analysis. RESULTS: A total of 1107 patients (mean age, 63.42 ± 11.33 years; 673 males) were included in the final analysis, and 81(7.32%) patients had END. In multivariate analysis, the serum glucose level was significantly associated with END; the odds ratio was 1.10 (95% CI 1.03 to 1.18, p = 0.004). The multivariate logistic analysis showed END has a notable association with the poor 3-month functional recovery even after adjusting for confounding factors; the adjusted OR was 8.25 (95% CI 3.77 to 18.03, p < 0.0001). CONCLUSIONS: The initial serum glucose level might be an independent risk factor of END, and END might predict a poor 3-month prognosis.

Arterial Glyceryl Trinitrate in Acute Ischemic Stroke after Thrombectomy for Neuroprotection (AGAIN): Rationale, design and protocol for a prospective randomized controlled trial.

BACKGROUND: Although endovascular recanalization therapy demonstrates robust clinical efficacy in acute ischemic stroke (AIS), not all victims of these cerebrovascular accidents can benefit from it and achieve a favorable prognosis after successful reperfusion. Therefore, alternative neuroprotective strategies are urgently needed for AIS patients after vessel recanalization. Nitric oxide (NO) levels are low after AIS and NO donor drugs may be neuroprotective against cerebral ischemia-reperfusion injury. Glyceryl trinitrate (GTN), often used in the clinic as a NO donor, may provide a novel neuroprotective strategy. This rationale, design, and protocol for a prospective pilot study plans to explore the preliminary safety, feasibility, and neuroprotective benefits of Arterial Glyceryl Trinitrate in Acute Ischemic Stroke after Thrombectomy for Neuroprotection (AGAIN). METHODS: AGAIN, a prospective RCT, is proposed for AIS patients after mechanical thrombectomy. Subjects will be randomly assigned in a 1:1 fashion (n = 40) to either the control group or the intervention group. Participants assigned to the intervention group will be administered 800 µg GTN in the catheter immediately after recanalization, whereas those in the control group will be administered the same volume of normal saline. All participants from either group will be given concurrent treatment with standard of care therapies in accordance with the current guidelines for stroke management. The primary outcome is safety [symptomatic intracranial hemorrhage (ICH), hypotension, neurological deterioration, ICH, fatal ICH, as well as headache, tachycardia, emesis, and seizures], whereas secondary outcomes included changes in poststroke functional outcomes, infarction volumes, and blood nitrate index detection. DISCUSSIONS: This study is a prospective randomized controlled trial to test the safety and efficacy of intra-arterial GTN in AIS patients after endovascular therapy. The results from this study will give insight for future GTN studies and new neuroprotective strategies for future AIS treatment strategies. TRIAL REGISTRATION NUMBER: ChiCTR2100045254. Registered on March 21, 2021.

Chlorpromazine and Promethazine (C+P) Reduce Brain Injury after Ischemic Stroke through the PKC-δ/NOX/MnSOD Pathway.

Cerebral ischemia-reperfusion (I/R) incites neurologic damage through a myriad of complex pathophysiological mechanisms, most notably, inflammation and oxidative stress. In I/R injury, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) produces reactive oxygen species (ROS), which promote inflammatory and apoptotic pathways, augmenting ROS production and promoting cell death. Inhibiting ischemia-induced oxidative stress would be beneficial for reducing neuroinflammation and promoting neuronal cell survival. Studies have demonstrated that chlorpromazine and promethazine (C+P) induce neuroprotection. This study investigated how C+P minimizes oxidative stress triggered by ischemic injury. Adult male Sprague-Dawley rats were subject to middle cerebral artery occlusion (MCAO) and subsequent reperfusion. 8 mg/kg of C+P was injected into the rats when reperfusion was initiated. Neurologic damage was evaluated using infarct volumes, neurological deficit scoring, and TUNEL assays. NOX enzymatic activity, ROS production, protein expression of NOX subunits, manganese superoxide dismutase (MnSOD), and phosphorylation of PKC-δ were assessed. Neural SHSY5Y cells underwent oxygen-glucose deprivation (OGD) and subsequent reoxygenation and C+P treatment. We also evaluated ROS levels and NOX protein subunit expression, MnSOD, and p-PKC-δ/PKC-δ. Additionally, we measured PKC-δ membrane translocation and the level of interaction between NOX subunit (p47phox) and PKC-δ via coimmunoprecipitation. As hypothesized, treatment with C+P therapy decreased levels of neurologic damage. ROS production, NOX subunit expression, NOX activity, and p-PKC-δ/PKC-δ were all significantly decreased in subjects treated with C+P. C+P decreased membrane translocation of PKC-δ and lowered the level of interaction between p47phox and PKC-δ. This study suggests that C+P induces neuroprotective effects in ischemic stroke through inhibiting oxidative stress. Our findings also indicate that PKC-δ, NOX, and MnSOD are vital regulators of oxidative processes, suggesting that C+P may serve as an antioxidant.

PM2.5 induces liver fibrosis via triggering ROS-mediated mitophagy.

BACKGROUND: The increasing epidemic of fine particulate matter (PM2.5) is a serious threat to human health. It induces the occurrence of liver fibrosis, but its molecular mechanism is not yet clear. The molecular mechanisms of PM2.5 inducing liver fibrosis were investigated in this study. METHODS: The cell viability of LX-2 cells and primary hepatic stellate cells (HSCs) was detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In vitro enzyme-linked immune sorbent assay (ELISA) kits were used to detect the concentrations of antioxidant enzymes and reactive oxygen species (ROS). The mitochondrial transmembrane potential (MTP) was determined by JC-1 dye. Knockdown of Parkin was carried out by Parkin-specific siRNA transfection. Relative mRNA and protein expressions were evaluated by qRT-PCR, Western blotting, and immunofluorescence analysis. RESULTS: PM2.5 activated LX-2 cells and primary HSCs, inducing the liver fibrosis along with down-regulation of the gelatinases MMP-2, and up-regulation of myofibroblast markers collagen type I and α-SMA. The levels of ROS and reactive nitrogen species (RNS), as well as the lipid peroxidation marker malondialdehyde (MDA) were significantly up-regulated in LX-2 cells and primary HSCs treated with PM2.5. Also, the enzymatic antioxidants levels were disturbed by PM2.5. Furthermore, PM2.5 decreased the MTP, releasing cytochrome c from the mitochondria to the cytosol. The dynamics of mitochondria were regulated by PM2.5 via facilitating mitochondrial fission. The excess ROS induced by PM2.5 triggered the mitophagy by activating PINK1/Parkin pathway, and inhibition of mitophagy induced by PM2.5 diminished the liver fibrosis. CONCLUSION: PM2.5 may induce mitophagy via activating PINK1/Parking signal pathway by increasing ROS, thereby activating HSCs and causing liver fibrosis.

PM2.5 exposure induces systemic inflammation and oxidative stress in an intracranial atherosclerosis rat model.

OBJECTIVES: Exposure to airborne particle (PM2.5 ) is a risk factor for intracranial atherosclerosis (ICA). Because of the established role of systemic inflammation and oxidative stress by PM2.5 , we determined whether these processes account for PM2.5 -mediated ICA, and also whether omega-3 fatty acid (O3FA) dietary supplementation could attenuate them. METHODS: Adult Sprague-Dawley rats were exposed to filtered air (FA) or PM2.5 and fed either a normal chow diet (NCD) or a high-cholesterol diet (HCD), administered with or without O3FA (5 mg/kg/day by gavage) for 12 weeks. The lumen and thickness of the middle cerebral artery (MCA) were assessed. Serum tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin-1ß (IL-1ß), and interferon gamma (IFN-γ) were detected by ELISA. Reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) activity, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) activity, mRNA levels of Nrf2, HO-1, NQO-1, and protein level of NOX subunit gp91 were quantified to determine the oxidative profile of brain vessels. RESULTS: PM2.5 increased (P < .05) ICA, especially in the HCD group; elevated serum TNF-α, IL-6, IL-1ß, and IFN-γ; increased cerebrovascular ROS, MDA, NOX activity, and gp91 protein levels; and decreased cerebrovascular SOD activity. Nrf2, HO-1, and NQO-1 mRNA levels were upregulated (P < .05) by PM2.5 exposure, especially in the HCD group. O3FA attenuated (P < .05) PM2.5 -induced systemic inflammation, vascular oxidative injury, and ICA. CONCLUSIONS: PM2.5 exposure induced systemic inflammation, cerebrovascular oxidative injury, and ICA in rats with HCD. O3FA prevented ICA development, and may therefore exert a protective effect against the atherogenic potential of PM2.5 .

Splenic responses play an important role in remote ischemic preconditioning-mediated neuroprotection against stroke.

BACKGROUND: Remote ischemic preconditioning (RIPC) of a limb has been reported to protect against ischemic stroke. Our previous results demonstrated that the RIPC-mediated neuroprotection is associated with alterations in circulating immune cell populations. Here, we evaluated the effect of the spleen, the largest reservoir of immune cells, on RIPC-mediated neuroprotection against stroke. METHODS: Noninvasive RIPC was achieved by four repeated cycles of 5-min blood flow constriction in the hindlimbs using a tourniquet. The blood and spleens were collected before and 1 h and 3 days after preconditioning to analyze the effect of RIPC on the spleen and the correlation between splenic and peripheral lymphocytes. Moreover, spleen weight and splenic lymphocytes were compared in stroke rats with or without RIPC. Finally, splenectomy was made 1 day or 2 weeks before RIPC and 90-min middle cerebral artery occlusion (MCAO). The infarct areas and deficits were assessed. Blood was collected 1 h after RIPC and 3 days after MCAO to explore the impact of splenectomy on RIPC-induced neuroprotection and immune changes. The contralateral and ipsilateral hemispheres were collected 3 days after MCAO to detect the infiltration of immune cells after RIPC and splenectomy. RESULTS: Flow cytometry analysis demonstrated that the RIPC promptly increased the percentages of CD3+CD8+ cytotoxic T (Tc) cells in the spleen with a relatively delayed elevation in CD3+CD161+ natural killer T (NKT) and CD3-CD45RA+ B lymphocytes. The percentages of circulating lymphocytes are positively correlated with the percentages of splenic lymphocytes in normal rats. Interestingly, RIPC resulted in negative correlations between the percentages of splenic and circulating T lymphocytes, while the correlation between splenic and circulating B lymphocytes remained positive. For animals subjected to RIPC followed by MCAO, RIPC increased splenic volume with an expansion of splenic lymphocytes 3 days after MCAO. Furthermore, the removal of the spleen 1 day or 2 weeks before RIPC and MCAO reduced the protective effect of RIPC on ischemic brain injury and reversed the effects of RIPC on circulating immune cell composition. RIPC significantly reduced brain infiltration of Tc and NKT cells. Prior splenectomy showed no effect on immune cell infiltration after RIPC and stroke. CONCLUSION: These results reveal an immunomodulatory effect of the spleen, effecting mainly the spleen-derived lymphocytes, during RIPC-afforded neuroprotection against cerebral ischemia.

Enhanced apoptosis from early physical exercise rehabilitation following ischemic stroke.

The effectiveness of the rehabilitative benefits of physical exercise appears to be contingent upon when the exercise is initiated after stroke. The present study assessed the hypothesis that very early exercise increases the extent of apoptotic cell death via increased expression of proapoptotic proteins in a rat stroke model. Adult male Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 2 hr using an intraluminal filament and assigned to four nonexercise and three exercise groups. Exercise on a Rota-Rod was initiated for 30 min at 6 hr (considered very early), at 24 hr (early), and at 3 days (relatively late) after reperfusion. At 24 hr after exercise, apoptotic cell death was determined. At 3 and 24 hr after exercise, the expression of pro- and antiapoptotic proteins was evaluated through Western blotting. As expected, ischemic stroke significantly increased the levels of apoptotic cell death. Compared with the stroke group without exercise, apoptotic cell death was further increased (P < 0.05) at 6 hr but not at 24 hr or 3 days with exercise. This exacerbated cell injury was associated with increased expression of proapoptotic proteins (BAX and caspase-3). The expression of Bcl-2, an antiapoptotic protein, was not affected by exercise. In ischemic stroke, apoptotic cell death was enhanced by very early exercise in association with increased expression of proapoptotic proteins. These results shed light on the time-sensitive effect of exercise in poststroke rehabilitation. © 2016 Wiley Periodicals, Inc.

Endovascular Hypothermia in Acute Ischemic Stroke: Pilot Study of Selective Intra-Arterial Cold Saline Infusion.

BACKGROUND AND PURPOSE: We conducted a pilot feasibility and safety study of selective brain cooling with intra-arterial infusion of cold saline combined with endovascular reperfusion for acute ischemic stroke. METHODS: Patients with large-vessel occlusion within 8 hours after symptom onset were enrolled. All patients received intra-arterial recanalization combined with infusion of cold isotonic saline (4°C) in the ischemic territory through the angiographic catheter. RESULTS: Twenty-six patients underwent the procedure, which was technically successful in all. The temperature of ischemic cerebral tissue was decreased by at least 2°C during infusion of the cold solution, and systemic temperature was mildly reduced (maximum 0.3°C). No obvious complications related to intra-arterial hypothermia were observed. CONCLUSIONS: Selective brain cooling by intra-arterial infusion of cold saline combined with endovascular recanalization therapy in acute ischemic stroke seems feasible and safe.

Combination therapy of normobaric oxygen with hypothermia or ethanol modulates pyruvate dehydrogenase complex in thromboembolic cerebral ischemia.

Pyruvate dehydrogenase complex (PDH) is a brain mitochondrial matrix enzyme. PDH impairment after stroke is particularly devastating given PDH's critical role in the link between anaerobic and aerobic metabolism. This study evaluates the restoration of oxidative metabolism and energy regulation with a therapeutic combination of normobaric oxygen (NBO) plus either therapeutic hypothermia (TH) or ethanol. Sprague-Dawley rats were subjected to middle cerebral artery occlusion with an autologous embolus. One hour after occlusion, tissue-type plasminogen activator (t-PA) was administered alone or with NBO (60%), EtOH (1.0 g/kg), or TH (33°C), either singly or in combination. Neurological deficit score and infarct volume were assessed 24 hr after t-PA-induced reperfusion. PDH activity and reactive oxygen species (ROS) levels were measured 3 and 24 hr after t-PA. Western blotting was used to detect PDH and pyruvate dehydrogenase kinase (PDK) protein expression. After t-PA in ischemic rats, NBO combined with TH or EtOH most effectively decreased infarct volume and neurological deficit. The combined therapies produced greater increases in PDH activity and protein expression as well as greater decreases in PDK expression. Compared with the monotherapeutic approaches, the combined therapies provided the most significant declines in ROS generation. Reperfusion with t-PA followed by 60% NBO improves the efficacy of EtOH or TH in neuroprotection by ameliorating oxidative injury and improving PDH regulation. Comparable neuroprotective effects were found when treating with either EtOH or TH, suggesting a similar mechanism of neuroprotection and the possibility of substituting EtOH for TH in clinical settings. © 2016 Wiley Periodicals, Inc.

Progress in AQP Research and New Developments in Therapeutic Approaches to Ischemic and Hemorrhagic Stroke.

Cerebral edema often manifests after the development of cerebrovascular disease, particularly in the case of stroke, both ischemic and hemorrhagic. Without clinical intervention, the influx of water into brain tissues leads to increased intracranial pressure, cerebral herniation, and ultimately death. Strategies to manage the development of edema constitute a major unmet therapeutic need. However, despite its major clinical significance, the mechanisms underlying cerebral water transport and edema formation remain elusive. Aquaporins (AQPs) are a class of water channel proteins which have been implicated in the regulation of water homeostasis and cerebral edema formation, and thus represent a promising target for alleviating stroke-induced cerebral edema. This review examines the significance of relevant AQPs in stroke injury and subsequently explores neuroprotective strategies aimed at modulating AQP expression, with a particular focus on AQP4, the most abundant AQP in the central nervous system.

Ethanol and normobaric oxygen: novel approach in modulating pyruvate dehydrogenase complex after severe transient and permanent ischemic stroke.

BACKGROUND AND PURPOSE: Ischemic stroke induces metabolic disarray. A central regulatory site, pyruvate dehydrogeanse complex (PDHC) sits at the cross-roads of 2 fundamental metabolic pathways: aerobic and anaerobic. In this study, we combined ethanol (EtOH) and normobaric oxygen (NBO) to develop a novel treatment to modulate PDHC and its regulatory proteins, namely pyruvate dehydrogenase phosphatase and pyruvate dehydrogenase kinase, leading to improved metabolism and reduced oxidative damage. METHODS: Sprague-Dawley rats were subjected to transient (2, 3, or 4 hours) middle cerebral artery occlusion followed by 3- or 24-hour reperfusion, or permanent (28 hours) middle cerebral artery occlusion without reperfusion. At 2 hours after the onset of ischemia, rats received either an intraperitoneal injection of saline, 1 dose of EtOH (1.5 g/kg) for 2- and 3-hour middle cerebral artery occlusion, 2 doses of EtOH (1.5 g/kg followed by 1.0 g/kg in 2 hours) in 4 hours or permanent middle cerebral artery occlusion, and EtOH+95% NBO (at 2 hours after the onset of ischemia for 6 hours) in permanent stroke. Infarct volumes and neurological deficits were examined. Oxidative metabolism and stress were determined by measuring ADP/ATP ratio and reactive oxygen species levels. Protein levels of PDHC, pyruvate dehydrogenase kinase, and pyruvate dehydrogenase phosphatase were assessed. RESULTS: EtOH induced dose-dependent neuroprotection in transient ischemia. Compared to EtOH or NBO alone, NBO+EtOH produced the best outcomes in permanent ischemia. These therapies improved brain oxidative metabolism by decreasing ADP/ATP ratios and reactive oxygen species levels, in association with significantly raised levels of PDHC and pyruvate dehydrogenase phosphatase, as well as decreased pyruvate dehydrogenase kinase. CONCLUSIONS: Both EtOH and EtOH+NBO treatments conferred neuroprotection in severe stroke by affecting brain metabolism. The treatment may modulate the damaging cascade of metabolic events by bringing the PDHC activity back to normal metabolic levels.

Comparison of self-expanding stents with distal embolic protection to balloon-expandable stents without a protection device in the treatment of symptomatic vertebral artery origin stenosis: a prospective randomized trial.

PURPOSE: To compare the angiographic and clinical outcomes of self-expanding stents (SES) with distal embolic protection devices (EPD) vs balloon-expandable stents (BES) without EPD in the treatment of symptomatic atherosclerotic vertebral artery ostial stenosis (VAOS). METHODS: Between July 2011 and March 2013, a prospective randomized trial was conducted involving 127 patients (mean age 67.3±10.2 years; 94 men) with symptomatic VAOS randomly assigned to treatment with SES + EPD (Precise RX or RX Acculink stent + Spider FX EPD; n=61) or BES (Palmaz Blue or Resolute RX; n=66) without EPD. In-stent restenosis (ISR) >50% detected by duplex ultrasound was the primary endpoint. Technical success, clinical success, complications within 30 days, and signal intensity abnormalities on diffusion weighted imaging (DWI) after stenting were compared. RESULTS: The 30-day technical success rate was 95.5% (63/66) for SES+EPD vs 100% (70/70) for BES without EPD (p=0.072). DWI at 24 hours poststenting showed 2 hyperintense lesions in 2 (3.3%) SES + EPD cases and 15 hyperintense lesions in 13 (18.6%) BES patients (p<0.01). At a mean 18-month follow-up, the clinical success rate was 93.9% (62/66) for the SES + EPD group vs 85.7% (60/70) for the BES group (p=0.115). The ISR was seen in 16/70 (22.9%) arteries in the BES group and 2/66 (3.1%) arteries in SES + EPD group (p<0.01). Target vessel revascularization was performed in 7 (10.0%) BES arteries vs none in the SES + EPD group (p<0.01). CONCLUSION: SES with EPD in the treatment of symptomatic VAOS is technically feasible and safe, with low rates of ISR and significantly reduced thromboembolic events on imaging when compared to BES without EPD.

Exploring the Therapeutic Potential of Peritoneal Dialysis (PD) in the Treatment of Neurological Disorders.

Peritoneal dialysis (PD) is a well-established renal replacement therapy commonly employed in clinical practice. While its primary application is in the treatment of kidney disease, its potential in addressing other systemic disorders, including neurological diseases, has garnered increasing interest. This study provides a comprehensive overview of the related technologies, unique advantages, and clinical applications of PD in the context of neurological disorders. By exploring the mechanism underlying PD, its application in neurological diseases, and associated complications, we addressed the feasibility and benefits of PD as an adjunct therapy for various neurological conditions. Our study aims to highlight its role in detoxification and symptom management, as well as its advantages over other universally accepted methods of renal replacement therapy. Our goal is to bring to the spotlight the therapeutic potential of PD in neurological diseases, such as stroke, stimulate further research, and broaden the scope of its application in the clinical setting.