Exosomes: the next-generation therapeutic platform for ischemic stroke.

Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery. Therefore, there is an urgent need to develop new methods for the treatment of this condition. Exosomes are natural cell-derived vesicles that mediate signal transduction between cells under physiological and pathological conditions. They have low immunogenicity, good stability, high delivery efficiency, and the ability to cross the blood-brain barrier. These physiological properties of exosomes have the potential to lead to new breakthroughs in the treatment of ischemic stroke. The rapid development of nanotechnology has advanced the application of engineered exosomes, which can effectively improve targeting ability, enhance therapeutic efficacy, and minimize the dosages needed. Advances in technology have also driven clinical translational research on exosomes. In this review, we describe the therapeutic effects of exosomes and their positive roles in current treatment strategies for ischemic stroke, including their anti-inflammation, anti-apoptosis, autophagy-regulation, angiogenesis, neurogenesis, and glial scar formation reduction effects. However, it is worth noting that, despite their significant therapeutic potential, there remains a dearth of standardized characterization methods and efficient isolation techniques capable of producing highly purified exosomes. Future optimization strategies should prioritize the exploration of suitable isolation techniques and the establishment of unified workflows to effectively harness exosomes for diagnostic or therapeutic applications in ischemic stroke. Ultimately, our review aims to summarize our understanding of exosome-based treatment prospects in ischemic stroke and foster innovative ideas for the development of exosome-based therapies.

Prognostic Value of Fibrosis-4 in Acute Ischemic Stroke Patients Undergoing Intravenous Thrombolysis.

Purpose: Although recombinant tissue plasminogen activator (rt-PA) treatment is efficient in patients with acute ischemic stroke (AIS), a significant percentage of patients who received rt-PA intravenous thrombolysis (IVT) do not achieve a good prognosis. Therefore, the factors that affect the poor prognosis of patients with IVT are needed. The Fibrosis-4 (FIB-4) index has been used as a liver fibrosis biomarker. We aimed to investigate the relationship between the FIB-4 index and functional outcomes in patients with AIS receiving IVT. Patients and Methods: This study prospectively included consecutive patients with AIS receiving IVT between April 2015 and May 2022. We collected clinical and laboratory data and calculated the FIB-4 index. Clinical outcome was poor functional outcome (mRS ≥3) at 3 months after IVT. Multivariate logistic regression analysis was used to analyze the association between FIB-4 and outcome. We explored the interactive effect of FIB-4 and dyslipidemia on poor outcomes, and subgroup analysis was performed. Furthermore, an individualized prediction model based on the FIB-4 for functional outcome was established in the dyslipidemia group. Results: A total of 1135 patients were included, and 41.50% had poor 3-month outcomes. After adjusted by other variants that P value <0.05 in univariable analysis, FIB-4 was independently associated with poor outcomes (OR=1.420; 95% CI: 1.113-1.812; P=0.004). There was a significant interaction between FIB-4 and dyslipidemia on poor outcome (P=0.036), and the independent association between FIB-4 and poor outcome was maintained in the dyslipidemia subgroup (OR=1.646; 95% CI: 1.228-2.206; P=0.001). Furthermore, in the dyslipidemia group, the FIB-4-based prediction model had good predictive value (the AUC of the training and validation sets were 0.767 and 0.708, respectively), good calibration (P-values for the Hosmer-Lemeshow test >0.05), and clinical usefulness. Conclusion: FIB-4 is an independent risk factor for poor outcomes in IVT patients with dyslipidemia, which can be used as a simple predictor of their prognosis.

The association between serum S100ß levels and prognosis in acute stroke patients after intravenous thrombolysis: a multicenter prospective cohort study.

BACKGROUND: S100ß is a biomarker of astroglial damage, the level of which is significantly increased following brain injury. However, the characteristics of S100ß and its association with prognosis in patients with acute ischemic stroke following intravenous thrombolysis (IVT) remain unclear. METHODS: Patients in this multicenter prospective cohort study were prospectively and consecutively recruited from 16 centers. Serum S100ß levels were measured 24 h after IVT. National Institutes of Health Stroke Scale (NIHSS) and hemorrhagic transformation (HT) were measured simultaneously. NIHSS at 7 days after stroke, final infarct volume, and modified Rankin Scale (mRS) scores at 90 days were also collected. An mRS score ≥ 2 at 90 days was defined as an unfavorable outcome. RESULTS: A total of 1072 patients were included in the analysis. The highest S100ß levels (> 0.20 ng/mL) correlated independently with HT and higher NIHSS at 24 h, higher NIHSS at 7 days, larger final infarct volume, and unfavorable outcome at 3 months. The patients were divided into two groups based on dominant and non-dominant stroke hemispheres. The highest S100ß level was similarly associated with the infarct volume in patients with stroke in either hemisphere (dominant: ß 36.853, 95% confidence interval (CI) 22.659-51.048, P < 0.001; non-dominant: ß 23.645, 95% CI 10.774-36.516, P = 0.007). However, serum S100ß levels at 24 h were more strongly associated with NIHSS scores at 24 h and 3-month unfavorable outcome in patients with dominant hemisphere stroke (NIHSS: ß 3.470, 95% CI 2.392-4.548, P < 0.001; 3-month outcome: odds ratio (OR) 5.436, 95% CI 2.936-10.064, P < 0.001) than in those with non-dominant hemisphere stroke (NIHSS: ß 0.326, 95% CI  - 0.735-1.387, P = 0.547; 3-month outcome: OR 0.882, 95% CI 0.538-1.445, P = 0.619). The association of S100ß levels and HT was not significant in either stroke lateralization group. CONCLUSIONS: Serum S100ß levels 24 h after IVT were independently associated with HT, infarct volume, and prognosis in patients with IVT, which suggests the application value of serum S100ß in judging the degree of disease and predicting prognosis.

Lipocalin-2 aggravates blood-brain barrier dysfunction after intravenous thrombolysis by promoting endothelial cell ferroptosis via regulating the HMGB1/Nrf2/HO-1 pathway.

BACKGROUND: Disruption of the blood-brain barrier (BBB) is a major contributor to hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) following intravenous thrombolysis (IVT). However, the clinical therapies aimed at BBB protection after IVT remain limited. METHODS: One hundred patients with AIS who underwent IVT were enrolled (42 with HT and 58 without HT 24 h after IVT). Based on the cytokine chip, the serum levels of several AIS-related proteins, including LCN2, ferritin, matrix metalloproteinase-3, vascular endothelial-derived growth factor, and X-linked inhibitor of apoptosis, were detected upon admission, and their associations with HT were analyzed. After finding that LCN2 was related to HT in patients with IVT, we clarified whether the modulation of LCN2 influenced BBB dysfunction and HT after thrombolysis and investigated the potential mechanism. RESULTS: In patients with AIS following IVT, logistic regression analysis showed that baseline serum LCN2 (p = 0.023) and ferritin (p = 0.046) levels were independently associated with HT. A positive correlation between serum LCN2 and ferritin levels was identified in patients with HT. In experimental studies, recombinant LCN2 (rLCN2) significantly aggravated BBB dysfunction and HT in the thromboembolic stroke rats after thrombolysis, whereas LCN2 inhibition by ZINC006440089 exerted opposite effects. Further mechanistic studies showed that, LCN2 promoted endothelial cell ferroptosis, accompanied by the induction of high mobility group box 1 (HMGB1) and the inhibition of nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins. Ferroptosis inhibitor ferrostatin-1 (fer-1) significantly restricted the LCN2-mediated BBB disruption. Transfection of LCN2 and HMGB1 siRNA inhibited the endothelial cell ferroptosis, and this effects was reversed by Nrf2 siRNA. CONCLUSION: LCN2 aggravated BBB disruption after thrombolysis by promoting endothelial cell ferroptosis via regulating the HMGB1/Nrf2/HO-1 pathway, this may provide a promising therapeutic target for the prevention of HT after IVT.

Increased peripheral leukocyte aggravates brain injury and leads to poor outcome in stroke patients receiving intravenous thrombolysis: A study based on clinical evidence.

Whether the dynamic development of peripheral inflammation aggravates brain injury and leads to poor outcome in stroke patients receiving intravenous thrombolysis (IVT), remains unclear and warrants further study. In this study, total of 1034 patients with acute ischemic stroke who underwent IVT were enrolled. Serum leukocyte variation (whether increase from baseline to 24 h after IVT), National Institutes of Health Stroke Scale (NIHSS), infarct volume, early neurologic deterioration (END), the unfavorable outcome at 3-month (modified Rankin Scale [mRS] score ≥3) and mortality were recorded. Serum brain injury biomarkers, including Glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase L1 (UCH-L1), S100ß, neuron-specific enolase (NSE), were measured to reflect the extent of brain injury. We found that patients with increased serum leukocytes had elevated brain injury biomarkers (GFAP, UCH-L1, and S100ß), larger infarct volume, higher 24 h NIHSS, higher proportion of END, unfavorable outcome and mortality. Furthermore, an increase in serum leukocytes was independently associated with infarct volume, 24 h NIHSS, END, and unfavorable outcome at 3 months, and serum UCH-L1, S100ß, and NSE levels. These results suggest that an increase in serum leukocytes indicates severe brain injury and may be used to predict the outcome of patients with ischemic stroke who undergo IVT.

Cellular senescence: A novel therapeutic target for central nervous system diseases.

The underlying mechanisms of diseases affecting the central nervous system (CNS) remain unclear, limiting the development of effective therapeutic strategies. Remarkably, cellular senescence, a biological phenomenon observed in cultured fibroblasts in vitro, is a crucial intrinsic mechanism that influences homeostasis of the brain microenvironment and contributes to the onset and progression of CNS diseases. Cellular senescence has been observed in disease models established in vitro and in vivo and in bodily fluids or tissue components from patients with CNS diseases. These findings highlight cellular senescence as a promising target for preventing and treating CNS diseases. Consequently, emerging novel therapies targeting senescent cells have exhibited promising therapeutic effects in preclinical and clinical studies on aging-related diseases. These innovative therapies can potentially delay brain cell loss and functional changes, improve the prognosis of CNS diseases, and provide alternative treatments for patients. In this study, we examined the relevant advancements in this field, particularly focusing on the targeting of senescent cells in the brain for the treatment of chronic neurodegenerative diseases (e.g., Alzheimer's disease, Parkinson's disease, and multiple sclerosis) and acute neurotraumatic insults (e.g., ischemic stroke, spinal cord injury, and traumatic brain injury).

Impact of peripheral lymphocyte subsets on prognosis for patients after acute ischemic stroke: A potential disease prediction model approach.

AIMS: To investigate the relationship between peripheral blood lymphocyte subsets and prognosis in patients with acute ischemic stroke (AIS). METHODS: We enrolled 294 patients with AIS and collected peripheral blood samples for analysis of lymphocyte subsets. Prognosis was assessed at 3 months using the modified Rankin Scale (mRS). Association between lymphocyte count and poor outcomes (mRS score >2) was assessed using logistic regression. Individualized prediction models were developed to predict poor outcomes. RESULTS: Patients in the mRS score ≤2 group had higher T-cell percentage (odds ratio [OR] = 0.947; 95% confidence interval [CI]: 0.899-0.998; p = 0.040), CD3+ T-cell count (OR = 0.999; 95% CI: 0.998-1.000; p = 0.018), and CD4+ T-cell count (OR = 0.998; 95% CI: 0.997-1.000; p = 0.030) than those in the mRS score >2 group 1-3 days after stroke. The prediction model for poor prognosis based on the CD4+ T-cell count showed good discrimination (area under the curve of 0.844), calibration (p > 0.05), and clinical utility. CONCLUSION: Lower T cell percentage, CD3+, and CD4+ T-cell counts 1-3 days after stroke were independently associated with increased risk of poor prognosis. Individualized predictive model of poor prognosis based on CD4+ T-cell count have good accuracy and may predict disease prognosis.

Beat-to-Beat Blood Pressure Variability Within 24 Hours of Ischemic Stroke Onset: A Potential Predictor of Functional Prognosis.

BACKGROUND: Beat-to-beat blood pressure variability (BPV) is based on each heartbeat and represents a dynamic equilibrium process modulated by artery and cardiac involvement of pressure-receptive reflexes. To date, there remains a lack of prospective studies illustrating the clinical value of beat-to-beat BPV within 24 hours of acute ischemic stroke onset. METHODS AND RESULTS: This study prospectively monitored beat-to-beat blood pressure and heart rate in patients with acute ischemic stroke within 24 hours of onset using a noninvasive plethysmograph and calculated beat-to-beat BPV, heart rate variability, and the cross-correlation baroreflex sensitivity. A modified Rankin Scale score of ≥2 at 90 days was defined as an unfavorable prognosis. Multivariate logistic regression was performed, and the nomogram model was developed by adding the beat-to-beat BPV to the traditional model for predicting prognosis. Beat-to-beat BPV increased significantly in the unfavorable outcome group (P<0.05) compared with that in the favorable outcome group, whereas no difference was observed in beat-to-beat heart rate variability and cross-correlation baroreflex sensitivity between both groups (P>0.05). Furthermore, beat-to-beat BPV within 24 hours of acute ischemic stroke onset was independently associated with unfavorable outcome at 90 days (P<0.005). The addition of beat-to-beat BPV to the traditional model for predicting prognosis enhanced the area under the receiver operating characteristic curve from 0.816 to 0.830. CONCLUSIONS: Increased beat-to-beat BPV within 24 hours of acute ischemic stroke onset was independently associated with a poor prognosis at 90 days and may be a potential predictor for discriminating unfavorable prognosis.

Brain Injury Biomarkers and Applications in Neurological Diseases.

ABSTRACT: Neurological diseases are a major health concern, and brain injury is a typical pathological process in various neurological disorders. Different biomarkers in the blood or the cerebrospinal fluid are associated with specific physiological and pathological processes. They are vital in identifying, diagnosing, and treating brain injuries. In this review, we described biomarkers for neuronal cell body injury (neuron-specific enolase, ubiquitin C-terminal hydrolase-L1, αII-spectrin), axonal injury (neurofilament proteins, tau), astrocyte injury (S100ß, glial fibrillary acidic protein), demyelination (myelin basic protein), autoantibodies, and other emerging biomarkers (extracellular vesicles, microRNAs). We aimed to summarize the applications of these biomarkers and their related interests and limits in the diagnosis and prognosis for neurological diseases, including traumatic brain injury, status epilepticus, stroke, Alzheimer's disease, and infection. In addition, a reasonable outlook for brain injury biomarkers as ideal detection tools for neurological diseases is presented.

Intravenous tenecteplase for acute ischemic stroke between 4.5 and 6 h of onset (EXIT-BT2): Rationale and Design.

RATIONALE: To date, the benefit of intravenous thrombolysis for acute ischemic stroke (AIS) patients without advanced neuroimaging selection is confined to within 4.5 h of onset. Our phase II EXIT-BT (Extending the tIme window of Thrombolysis by ButylphThalide up to 6 h after onset) trial suggested the safety, feasibility, and potential benefit of intravenous tenecteplase (TNK) in AIS between 4.5 and 6 h of onset. The EXIT-BT2 trial is a pivotal study undertaken to confirm or refute this signal. AIM: To investigate the efficacy and safety of TNK for AIS between 4.5 and 6 h of onset with or without endovascular treatment. SAMPLE SIZE ESTIMATES: A maximum of 1440 patients are required to test the superiority hypothesis with 80% power according to a two-sided 0.05 level of significance, stratified by age, sex, history of diabetes, location of vessel occlusion, baseline National Institute of Health stroke scale score, stroke etiology, and plan for endovascular treatment. DESIGN: EXIT-BT2 is a prospective, randomized, open-label, blinded assessment of endpoint (PROBE), and multi-center study. Eligible AIS patients between 4.5 and 6 h of onset are randomly assigned 1:1 into a TNK group or control group. The TNK group will receive TNK (0.25 mg/kg, a single bolus over 5-10 s, maximum 25 mg). The control group will receive standard medical care in compliance with national guidelines for acute ischemic stroke. Both groups will receive standard stroke care from randomization to 90 days after stroke onset according to national guidelines. OUTCOME: The primary efficacy endpoint is excellent functional outcome, defined as a modified Rankin Scale score 0-1 at 90 days after randomization, while the primary safety endpoint is symptomatic intracerebral hemorrhage, defined as National Institutes of Health Stroke Scale score increase ⩾4 caused by intracranial hemorrhage within 24 (-6/+12) h after randomization. CONCLUSIONS: The results of EXIT-BT2 may determine whether intravenous TNK has a favorable risk/benefit profile in AIS between 4.5 and 6 h of onset.

A novel NIR-II albumin-escaping probe for cerebral arteries and perfusion imaging in stroke mice model.

In order to guide the formulation of post-stroke treatment strategy in time, it is necessary to have real-time feedback on collateral circulation and revascularization. Currently used near-infrared II (NIR-II) probes have inherent binding with endogenous albumin, resulting in significant background signals and uncontrollable pharmacokinetics. Therefore, the albumin-escaping properties of the new probe, IR-808AC, was designed, which achieved timely excretion and low background signal, enabling the short-term repeatable injection for visualization of cerebral vessels and perfusion. We further achieved continuous observation of changes in collateral vessels and perfusion during the 7-d period in middle cerebral artery occlusion mice using IR-808AC in vivo. Furthermore, using IR-808AC, we confirmed that remote ischemic conditioning could promote collateral vessels and perfusion. Finally, we evaluated the revascularization after thrombolysis on time in embolic stroke mice using IR-808AC. Overall, our study introduces a novel methodology for safe, non-invasive, and repeatable assessment of collateral circulation and revascularization in real-time that is crucial for the optimization of treatment strategies.

Blood-brain barrier disruption and hemorrhagic transformation in acute stroke before endovascular reperfusion therapy.

Background and purpose: Early blood-brain barrier (BBB) disruption in patients with acute ischemic stroke (AIS) can be detected on perfusion computed tomography (PCT) images before undergoing reperfusion therapy. In this study, we aimed to determine whether early disruption of the BBB predicts intracranial hemorrhage transformation (HT) in patients with AIS undergoing endovascular therapy and further identify factors influencing BBB disruption. Methods: We retrospectively analyzed general clinical and imaging data derived from 159 consecutive patients with acute anterior circulation stroke who were admitted to the Department of Neurology of the First Hospital of Jilin University, and who underwent endovascular treatment between January 1, 2021, and March 31, 2023. We evaluated the relationship between BBB destruction and intracranial HT before endovascular reperfusion therapy and examined the risk factors for early BBB destruction. Results: A total of 159 patients with assessable BBB leakage were included. The median (interquartile range, IQR) age was 63 (54-70) years, 108 (67.9%) patients were male, and the median baseline National Institutes of Health Stroke Scale (NHISS) score was 12 (10-15). Follow-up non-contrast computed tomography (NCCT) detected HT in 63 patients. After logistic regression modeling adjustment, we found that BBB leakage in the true leakage area was slightly more than 2-fold risk of HT (odds ratio [OR], 2.01; 95% confidence interval [CI] 1.02-3.92). Heart rate was also associated with HT (OR, 1.03, 95% CI, 1.00-1.05). High Blood-brain barrier permeability (BBBP) in the true leakage area was positively correlated with infarct core volume (OR, 1.03; 95% CI, 1.01-1.05). Conclusion: Early BBB destruction before endovascular reperfusion therapy was associated with HT, whereas high BBBP correlated positively with infarct core volume.

Cerebral autoregulation: A reliable predictor of prognosis in patients receiving intravenous thrombolysis.

AIMS: To investigate the characteristics of dynamic cerebral autoregulation (dCA) after intravenous thrombolysis (IVT) and assess the relationship between dCA and prognosis. METHODS: Patients with unilateral acute ischemic stroke receiving IVT were prospectively enrolled; those who did not were selected as controls. All patients underwent dCA measurements, by quantifying the phase difference (PD) and gain, at 1-3 and 7-10 days after stroke onset. Simultaneously, two dCA-based nomogram models were established to verify the predictive value of dCA for patients with mild-to-moderate stroke. RESULTS: Finally, 202 patients who received IVT and 238 who did not were included. IVT was positively correlated with higher PD on days 1-3 and 7-10 after stroke onset. PD values in both sides at 1-3 days after stroke onset and in the affected side at 7-10 days after onset were independent predictors of unfavorable outcomes in patients who received IVT. Additionally, in patients with mild-to-moderate stroke who received IVT, the dCA-based nomogram models significantly improved the risk predictive ability for 3-month unfavorable outcomes. CONCLUSION: IVT has a positive effect on dCA in patients with acute stroke; furthermore, dCA may be useful to predict the prognosis of patients with IVT.

Compromised Dynamic Cerebral Autoregulation in Patients with Restless Legs Syndrome.

Background: Restless legs syndrome (RLS) is a prevalent sensorimotor nervous system disorder in patients accompanied with insomnia, blood pressure fluctuation, and sympathetic dysfunction. These symptoms may disrupt cerebral hemodynamics. Dynamic cerebral autoregulation (dCA) describes the temporary response of cerebrovascular system to abrupt fluctuations in blood pressure, which keep cerebral blood flow stable and serve as a marker of cerebrovascular system ability. Objective: This research aimed to assess dCA in RLS patients. Methods: In this study, RLS patients were recruited and subsequently classified into four groups (mild, moderate, severe, and very severe) based on the International RLS Rating Scale (IRLS). Healthy controls matched for age and sex were enrolled. All participants were evaluated dCA by assessing phase difference (PD). A portion of patients with RLS was reassessed for dCA after one month of medication therapy (pramipexole [0.125 mg/day] and gabapentin [300 mg/day]). Results: There were altogether 120 patients with RLS and 30 controls completed the polysomnography and dCA assessment. PD was lower in the moderate, severe, and very severe RLS groups than that in the controls and mild RLS groups. Periodic limb movement index (PLMI), arousal index, and IRLS all showed a linear correlation with PD in RLS patients. Additionally, PD increased in RLS patients after therapy. Conclusion: The dCA was compromised in moderate, severe, and very severe RLS patients and was negatively correlated with the IRLS, arousal index, and PLMI. After 1 month of therapy, dCA improved in RLS patients.

Effects of a Planned Web-Based Educational Intervention Based on the Health Belief Model for Patients With Ischemic Stroke in Promoting Secondary Prevention During the COVID-19 Lockdown in China: Quasi-Experimental Study.

Background: Some common modified vascular risk factors remain poorly controlled among stroke survivors, and educational programs may help improve these conditions. Objective: This study aimed to evaluate the effect of a planned web-based educational intervention based on the health belief model (HBM) in promoting secondary prevention among patients with ischemic stroke. Methods: An evaluation-blinded quasi-experimental trial with a historical control group was conducted. Patients admitted from March to June 2020 were assigned to the historical control group, and patients admitted from July to October 2020 were assigned to the intervention group. The control group received routine health management. The intervention group received 6 additional sessions based on the HBM via Tencent Meeting, an audio and video conferencing application, within 3 months after discharge. Sessions were held every 2 weeks, with each session lasting approximately 40 minutes. These sessions were conducted in small groups, with about 8 to 10 people in each group. The primary outcomes were changes in blood pressure (BP), low-density lipoprotein cholesterol (LDL-C), hemoglobin A1c (HbA1c), and the proportion of patients achieving the treatment target. The secondary outcomes were medication adherence, assessed with the Morisky Medicine Adherence Scale (MMAS), and disability, assessed with the modified Rankin scale. Results: In total, 315 patients experiencing their first-ever stroke were analyzed. More patients in the intervention group had controlled BP (41.9% vs 28.4%; adjusted odds ratio [aOR] 1.93; P=.01), LDL-C (83.1% vs 67.7%; aOR 2.66; P=.001), and HbA1c (91.9% vs 83.9%; aOR: 3.37; P=.04) levels as well as a significant postintervention decrease in the systolic BP (adjusted ß -3.94; P=.02), LDL-C (adjusted ß -0.21; P=.008), and HbA1c (adjusted ß -0.27; P<.001), compared with control groups. Significant between-group differences were observed in medication adherence (79.4% vs 63.2%; aOR 2.31; P=.002) but not in favorable functional outcomes. Conclusions: A web-based education program based on the HBM may be more effective than current methods used to educate patients having strokes on optimal vascular risk factors and medication adherence.

Emerging strategies for nerve repair and regeneration in ischemic stroke: neural stem cell therapy.

Ischemic stroke is a major cause of mortality and disability worldwide, with limited treatment options available in clinical practice. The emergence of stem cell therapy has provided new hope to the field of stroke treatment via the restoration of brain neuron function. Exogenous neural stem cells are beneficial not only in cell replacement but also through the bystander effect. Neural stem cells regulate multiple physiological responses, including nerve repair, endogenous regeneration, immune function, and blood-brain barrier permeability, through the secretion of bioactive substances, including extracellular vesicles/exosomes. However, due to the complex microenvironment of ischemic cerebrovascular events and the low survival rate of neural stem cells following transplantation, limitations in the treatment effect remain unresolved. In this paper, we provide a detailed summary of the potential mechanisms of neural stem cell therapy for the treatment of ischemic stroke, review current neural stem cell therapeutic strategies and clinical trial results, and summarize the latest advancements in neural stem cell engineering to improve the survival rate of neural stem cells. We hope that this review could help provide insight into the therapeutic potential of neural stem cells and guide future scientific endeavors on neural stem cells.

Baseline Uric Acid Levels and Intravenous Thrombolysis Outcomes in Patients With Acute Ischemic Stroke: A Prospective Cohort Study.

BACKGROUND: The study aimed to investigate the relationship between uric acid (UA) levels and functional outcomes at 3 months in patients with acute ischemic stroke (AIS) who underwent intravenous thrombolysis (IVT). METHODS AND RESULTS: This prospective cohort study included 1001 consecutive patients with AIS who underwent IVT. The correlation between UA levels and post-IVT AIS outcomes was examined. Any nonlinear relationship was assessed using a restricted cubic spline function. The nonlinear P value for the association of UA levels with favorable (modified Rankin Scale [mRS] score ≤2) and excellent (mRS score ≤1) outcomes at 3 months post-IVT were <0.001 and 0.001, respectively. However, for patients with and without hyperuricemia, no evident nonlinear relationship was observed between UA levels and favorable 3-month post-IVT outcomes, with nonlinear P values of 0.299 and 0.207, respectively. The corresponding interaction analysis yielded a P value of 0.001, indicating significant heterogeneity. Similar results were obtained for excellent outcomes at 3 months post-IVT. In the hyperuricemia group, increased UA levels by 50 µmol/L reduced the odds of a favorable 3-month post-AIS outcome (odds ratio [OR], 0.75 [95% CI, 0.57-0.97]). Conversely, in the nonhyperuricemia group, a similar UA increase was linked to higher favorable outcome odds (OR, 1.31 [95% CI, 1.15-1.50]). CONCLUSIONS: An inverted U-shaped nonlinear relationship was observed between UA levels and favorable and excellent outcomes at 3 months in patients with AIS who underwent IVT. Higher UA levels predict favorable outcomes in patients without hyperuricemia but unfavorable outcomes in those with hyperuricemia.

Nanodrug delivery systems for regulating microglial polarization in ischemic stroke treatment: A review.

The incidence of ischemic stroke (IS) is rising in tandem with the global aging population. There is an urgent need to delve deeper into the pathological mechanisms and develop new neuroprotective strategies. In the present review, we discuss the latest advancements and research on various nanodrug delivery systems (NDDSs) for targeting microglial polarization in IS treatment. Furthermore, we critically discuss the different strategies. NDDSs have demonstrated exceptional qualities to effectively permeate the blood-brain barrier, aggregate at the site of ischemic injury, and target specific cell types within the brain when appropriately modified. Consequently, NDDSs have considerable potential for reshaping the polarization phenotype of microglia and could be a prospective therapeutic strategy for IS. The treatment of IS remains a challenge. However, this review provides a new perspective on neuro-nanomedicine for IS therapies centered on microglial polarization, thereby inspiring new research ideas and directions.

Targeted exosome-based nanoplatform for new-generation therapeutic strategies.

Exosomes, typically 30-150 nm in size, are lipid-bilayered small-membrane vesicles originating in endosomes. Exosome biogenesis is regulated by the coordination of various mechanisms whereby different cargoes (e.g. proteins, nucleic acids, and lipids) are sorted into exosomes. These components endow exosomes with bioregulatory functions related to signal transmission and intercellular communication. Exosomes exhibit substantial potential as drug-delivery nanoplatforms owing to their excellent biocompatibility and low immunogenicity. Proteins, miRNA, siRNA, mRNA, and drugs have been successfully loaded into exosomes, and these exosome-based delivery systems show satisfactory therapeutic effects in different disease models. To enable targeted drug delivery, genetic engineering and chemical modification of the lipid bilayer of exosomes are performed. Stimuli-responsive delivery nanoplatforms designed with appropriate modifications based on various stimuli allow precise control of on-demand drug delivery and can be utilized in clinical treatment. In this review, we summarize the general properties, isolation methods, characterization, biological functions, and the potential role of exosomes in therapeutic delivery systems. Moreover, the effective combination of the intrinsic advantages of exosomes and advanced bioengineering, materials science, and clinical translational technologies are required to accelerate the development of exosome-based delivery nanoplatforms.