Ischaemic stroke

The Reactive Species Interactome in the Brain

Significance: Redox pioneer Helmut Sies attempted to explain reactive species' challenges faced by organelles, cells, tissues, and organs via three complementary definitions: (i) oxidative stress, that is, the disturbance in the prooxidant-antioxidant defense balance in favor of the prooxidants; (ii) oxidative eustress, the low physiological exposure to prooxidants; and (iii) oxidative distress, the supraphysiological exposure to prooxidants. Recent Advances: Identification, concentration, and interactions are the most important elements to improve our understanding of reactive species in physiology and pathology. In this context, the reactive species interactome (RSI) is a new multilevel redox regulatory system that identifies reactive species families, reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species, and it integrates their interactions with their downstream biological targets. Critical Issues: We propose a united view to fully combine reactive species identification, oxidative eustress and distress, and the RSI system. In this view, we also propose including the forgotten reactive carbonyl species, an increasingly rediscovered reactive species family related to the other reactive families, and key enzymes within the RSI. We focus on brain physiology and pathology to demonstrate why this united view should be considered. Future Directions: More studies are needed for an improved understanding of the contributions of reactive species through their identification, concentration, and interactions, including in the brain. Appreciating the RSI in its entirety should unveil new molecular players and mechanisms in physiology and pathology in the brain and elsewhere.

Total Synthesis of the Spider-Venom Peptide Hi1a

Hi1a is a venom peptide from the Australian funnel-web spider Hadronyche infensa with a complex tertiary structure. Hi1a has neuroprotective and cardioprotective properties due to its potent inhibition of acid-sensing ion channel 1a (ASIC1a) and is currently being pursued as a novel therapy for acute ischemic events. Herein, we describe the total synthesis of Hi1a using native chemical ligation. The synthetic peptide was successfully folded and exhibited similar inhibitory activity on ASIC1a to recombinant Hi1a.

Vagus nerve stimulation mediates microglia M1/2 polarization via inhibition of TLR4 pathway after ischemic stroke

Ischemic stroke is the leading cause of death and disability. Microglia are polarized toward the proinflammatory M1 phenotype and neuroprotective M2 phenotype after stroke and play an important role in the pathological process of ischemic stroke. Emerging research suggests that vagus nerve stimulation (VNS) can mediate microglia polarization after ischemic stroke and may serve as a potential treatment for ischemic stroke. However, the mechanism by which VNS mediates microglia polarization remains unclear. In this study, we aimed to investigate the underlying mechanism. Sprague-Dawley rats were randomly divided into the sham, ischemic stroke, ischemic stroke + VNS, ischemic stroke + VNS + lentivirus (LV)-TLR4 and ischemic stroke + VNS + LV-CON groups. LV was injected into the lateral ventricles of the rats 14 days before ischemic stroke surgery, and VNS was administered after 30 min of occlusion. We assessed the infarct volume, neurological scores, the TLR4/MyD88/NF-κB protein level and microglia polarization after 3 days of reperfusion. Our results revealed that VNS can promote M2 microglia polarization and inhibit M1 microglia polarization to alleviate brain injury via inhibition of the TLR4/MyD88/NF-κB pathway in microglia in the acute stage of stroke.

Metabolic MRI with hyperpolarized [1-13C]pyruvate separates benign oligemia from infarcting penumbra in porcine stroke

Acute ischemic stroke patients benefit from reperfusion in a short time-window after debut. Later treatment may be indicated if viable brain tissue is demonstrated and this outweighs the inherent risks of late reperfusion. Magnetic resonance imaging (MRI) with hyperpolarized [1-13C]pyruvate is an emerging technology that directly images metabolism. Here, we investigated its potential to detect viable tissue in ischemic stroke. Stroke was induced in pigs by intracerebral injection of endothelin 1. During ischemia, the rate constant of pyruvate-to-lactate conversion, kPL, was 52% larger in penumbra and 85% larger in the infarct compared to the contralateral hemisphere (P = 0.0001). Within the penumbra, the kPL was 50% higher in the regions that later infarcted compared to non-progressing regions (P = 0.026). After reperfusion, measures of pyruvate-to-lactate conversion were slightly decreased in the infarct compared to contralateral. In addition to metabolic imaging, we used hyperpolarized pyruvate for perfusion-weighted imaging. This was consistent with conventional imaging for assessment of infarct size and blood flow. Lastly, we confirmed the translatability of simultaneous assessment of metabolism and perfusion with hyperpolarized MRI in healthy volunteers. In conclusion, hyperpolarized [1-13C]pyruvate may aid penumbral characterization and increase access to reperfusion therapy for late presenting patients.

Machine learning enables discovery of Gentianine targeting TLR4/NF-κB pathway to repair ischemic stroke injury

Inflammatory response is believed to accelerate the development of stroke injury. Gentianine, an alkaloid isolated from Gentiana Scabra Bunge, shows effectiveness in anti-inflammation. In this study, the effect of Gentianine on transient middle cerebral artery occlusion (tMCAO) induced mouse model in vivo and further related mechanism in LPS-injuried microglia BV-2 cells in vitro were explored. Effect of Gentianine on tMCAO mouse demonstrated that Gentianine significantly ameliorated tMCAO induced ischemic injury by decreasing brain infarct volume and increasing the neurological score and upper limb muscle strength. Meanwhile, Gentianine significantly decreased the release of serum inflammatory cytokines. Machine learning enables that Gentianine might had anti-ischemic stroke effect through the TLR4/NF-κB signaling pathway. This was verified in vivo and in vitro. Gentianine significantly decrease the TLR4 and Iba-1 expression in vivo. These results also verified in BV-2 cells. Gentianine significantly decreased TLR4, MyD88 and NF-κB expression, as well as NO production and inflammatory cytokines release. Gentianine co-treatment with TLR4 inhibitor, further decreased TLR4, MyD88 and NF-κB expression, NO production, as well as the inflammatory cytokines. Taken together, Gentianine could be used as a potential anti-ischemic stroke agent by suppressing inflammatory responses via TLR4/NF-κB signaling pathway. This study is expected to provide an integrated traditional Chinese and western medicine solution to find potential anti-ischemic stroke compounds based on machine learning.

Single-Target Versus Multi-Target Drugs Versus Combinations of Drugs With Multiple Targets: Preclinical and Clinical Evidence for the Treatment or Prevention of Epilepsy

Rationally designed multi-target drugs (also termed multimodal drugs, network therapeutics, or designed multiple ligands) have emerged as an attractive drug discovery paradigm in the last 10-20 years, as potential therapeutic solutions for diseases of complex etiology and diseases with significant drug-resistance problems. Such agents that modulate multiple targets simultaneously are developed with the aim of enhancing efficacy or improving safety relative to drugs that address only a single target or to combinations of single-target drugs. Although this strategy has been proposed for epilepsy therapy >25 years ago, to my knowledge, only one antiseizure medication (ASM), padsevonil, has been intentionally developed as a single molecular entity that could target two different mechanisms. This novel drug exhibited promising effects in numerous preclinical models of difficult-to-treat seizures. However, in a recent randomized placebo-controlled phase IIb add-on trial in treatment-resistant focal epilepsy patients, padsevonil did not separate from placebo in its primary endpoints. At about the same time, a novel ASM, cenobamate, exhibited efficacy in several randomized controlled trials in such patients that far surpassed the efficacy of any other of the newer ASMs. Yet, cenobamate was discovered purely by phenotype-based screening and its presumed dual mechanism of action was only described recently. In this review, I will survey the efficacy of single-target vs. multi-target drugs vs. combinations of drugs with multiple targets in the treatment and prevention of epilepsy. Most clinically approved ASMs already act at multiple targets, but it will be important to identify and validate new target combinations that are more effective in drug-resistant epilepsy and eventually may prevent the development or progression of epilepsy.

Prediction of large vessel occlusion for ischaemic stroke by using the machine learning model random forests

BACKGROUNDS

The timely identification of large vessel occlusion (LVO) in the prehospital stage is extremely important given the disease morbidity and narrow time window for intervention. The current evaluation strategies still remain challenging. The goal of this study was to develop a machine learning (ML) model to predict LVO using prehospital accessible data.

METHODS

Consecutive acute ischaemic stroke patients who underwent CT or MR angiography and received reperfusion therapy within 8 hours from symptom onset in the Computer-based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation-II dataset from January 2016 to August 2021 were included. We developed eight ML models to integrate National Institutes of Health Stroke Scale (NIHSS) items with demographics, medical history and vascular risk factors to identify LVO and validate its efficiency.

RESULTS

Finally, 15 365 patients were included in the training set and 4215 patients were included in the test set. On the test set, random forests (RF), gradient boosting machine and extreme gradient boosting presented area under the curve (AUC) of 0.831 (95% CI 0.819 to 0.843), which were higher than other models, and RF presented the highest specificity (0.827). In addition, the AUC of RF was higher than other scales, and the accuracy of the model was improved by 6.4% compared with NIHSS. We also found the top five items of identifying LVO were total NIHSS score, gaze deviation, level of consciousness (LOC), LOC commands and motor left leg.

CONCLUSIONS

Our proposed model could be a useful screening tool to predict LVO based on the prehospital accessible medical data.

TRIAL REGISTRATION NUMBER

NCT04487340.

Functionalized nanoparticles with monocyte membranes and rapamycin achieve synergistic chemoimmunotherapy for reperfusion-induced injury in ischemic stroke

BACKGROUND

Ischemic stroke is an acute and severe neurological disease, and reperfusion is an effective way to reverse brain damage after stroke. However, reperfusion causes secondary tissue damage induced by inflammatory responses, called ischemia/reperfusion (I/R) injury. Current therapeutic strategies that control inflammation to treat I/R are less than satisfactory.

RESULTS

We report a kind of shield and sword nano-soldier functionalized nanoparticles (monocyte membranes-coated rapamycin nanoparticles, McM/RNPs) that can reduce inflammation and relieve I/R injury by blocking monocyte infiltration and inhibiting microglia proliferation. The fabricated McM/RNPs can actively target and bind to inflammatory endothelial cells, which inhibit the adhesion of monocytes to the endothelium, thus acting as a shield. Subsequently, McM/RNPs can penetrate the endothelium to reach the injury site, similar to a sword, and release the RAP drug to inhibit the proliferation of inflammatory cells. In a rat I/R injury model, McM/RNPs exhibited improved active homing to I/R injury areas and greatly ameliorated neuroscores and infarct volume. Importantly, in vivo animal studies revealed good safety for McM/RNPs treatment.

CONCLUSION

The results demonstrated that the developed McM/RNPs may serve as an effective and safe nanovehicles for I/R injury therapy.

Synthesis and evaluation of peptidic thrombin inhibitors bearing acid-stable sulfotyrosine analogues

Tyrosine sulfation is an important post-translational modification of peptides and proteins which underpins and modulates many protein-protein interactions. In order to overcome the inherent instability of the native modification, we report the synthesis of two sulfonate analogues and their incorporation into two thrombin-inhibiting sulfopeptides. The effective mimicry of these sulfonate analogues for native sulfotyrosine was validated in the context of their thrombin inhibitory activity and binding mode, as determined by X-ray crystallography.

Stroke Etiology and Outcomes after Endovascular Thrombectomy: Results from the SITS Registry and a Meta-Analysis

BACKGROUND AND PURPOSE

The influence of stroke etiology on outcomes after endovascular thrombectomy (EVT) is not well understood. We aimed to investigate whether stroke etiology subgrouped as large artery atherosclerosis (LAA) and cardiac embolism (CE) influences outcomes in large artery occlusion (LAO) treated by EVT.

METHODS

We included EVT treated LAO stroke patients registered in the Safe Implementation of Treatment in Stroke (SITS) thrombectomy register between January 1, 2014 and September 3, 2019. Primary outcome was successful reperfusion (modified Treatment in Cerebral Infarction 2b-3). Secondary outcomes were symptomatic intracranial hemorrhage (SICH), 3-month functional independence (modified Ranking Scale 0-2) and death. Multivariable logistic regression models were used for comparisons. In addition, a meta-analysis of aggregate data from the current literature was conducted (PROSPERO, ID 167447).

RESULTS

Of 7,543 patients, 1,903 (25.2%) had LAA, 3,214 (42.6%) CE, and 2,426 (32.2%) unknown, other, or multiple etiologies. LAA patients were younger (66 vs. 74, P<0.001) and had lower National Institutes of Health Stroke Scale score at baseline (15 vs. 16, P<0.001) than CE patients. Multivariable analyses showed that LAA patients had lower odds of successful reperfusion (odds ratio [OR], 0.70; 95% confidence interval [CI], 0.57 to 0.86) and functional independence (OR, 0.74; 95% CI, 0.63 to 0.85), higher risk of death (OR, 1.44; 95% CI, 1.21 to 1.71), but no difference in SICH (OR, 1.09; 95% CI, 0.71 to 1.66) compared to CE patients. The systematic review found 25 studies matching the criteria. The meta-analysis did not find any difference between etiologies.

CONCLUSIONS

From the SITS thrombectomy register, we observed a lower chance of reperfusion and worse outcomes after thrombectomy in patients with LAA compared to CE etiology, despite more favorable baseline characteristics. In contrast, the meta-analysis did not find any difference between etiologies with aggregate data.

Enriched Environment Attenuates Pyroptosis to Improve Functional Recovery After Cerebral Ischemia/Reperfusion Injury

Enriched environment (EE) is a complex containing social, cognitive, and motor stimuli. Exposure to EE can promote functional recovery after ischemia/reperfusion (I/R) injury. However, the underlying mechanisms remained unclear. Pyroptosis has recently been identified and demonstrated a significant role in ischemic stroke. The purpose of this study was to explore the effect of EE on neuronal pyroptosis after cerebral I/R injury. In the current study, middle cerebral artery occlusion/reperfusion (MCAO/R) was applied to establish the cerebral I/R injury model. Behavior tests including the modified Neurological Severity Scores (mNSS) and the Morris Water Maze (MWM) were performed. The infarct volume was evaluated by Nissl staining. To evaluate the levels of pyroptosis-related proteins, the levels of GSDMD-N and nod-like receptor protein 1/3 (NLRP1/3) inflammasome-related proteins were examined. The mRNA levels of IL-1β and IL-18 were detected by Quantitative Real-Time PCR (qPCR). The secretion levels of IL-1β and IL-18 were analyzed by ELISA. Also, the expression of p65 and p-p65 were detected. The results showed that EE treatment improved functional recovery, reduced infarct volume, attenuated neuronal pyroptosis after cerebral I/R injury. EE treatment also suppressed the activities of NLRP1/NLRP3 inflammasomes. These may be affected by inhabiting the NF-κB p65 signaling pathway. Our findings suggested that neuronal pyroptosis was probably the neuroprotective mechanism that EE treatment rescued neurological deficits after I/R injury.

Hypoxia Tolerant Species: The Wisdom of Nature Translated into Targets for Stroke Therapy

Human neurons rapidly die after ischemia and current therapies for stroke management are limited to restoration of blood flow to prevent further brain damage. Thrombolytics and mechanical thrombectomy are the available reperfusion treatments, but most of the patients remain untreated. Neuroprotective therapies focused on treating the pathogenic cascade of the disease have widely failed. However, many animal species demonstrate that neurons can survive the lack of oxygen for extended periods of time. Here, we reviewed the physiological and molecular pathways inherent to tolerant species that have been described to contribute to hypoxia tolerance. Among them, Foxo3 and Eif5A were reported to mediate anoxic survival in Drosophila and Caenorhabditis elegans, respectively, and those results were confirmed in experimental models of stroke. In humans however, the multiple mechanisms involved in brain cell death after a stroke causes translation difficulties to arise making necessary a timely and coordinated control of the pathological changes. We propose here that, if we were able to plagiarize such natural hypoxia tolerance through drugs combined in a pharmacological cocktail it would open new therapeutic opportunities for stroke and likely, for other hypoxic conditions.

LncRNA CASC15 Promotes Cerebral Ischemia/Reperfusion Injury via miR-338-3p/ETS1 Axis in Acute Ischemic Stroke

Purpose

Acute ischemic stroke (AIS) is a leading health problem caused by cerebral ischemia/reperfusion (CI/R). This study aimed to unveil the potential clinical value and mechanism of lncRNA CASC15.

Patients and Methods

The expression of CASC15, miR-338-3p was detected by quantitative real-time PCR (qRT-PCR). The correlations between CASC15 and national institutes of health stroke scale (NIHSS) scores or miR-338-3p were evaluated by Pearson correlation. A receiver operating characteristic (ROC) curve was performed to provide the diagnostic value of CASC15. Cell Counting Kit-8 (CCK-8) and flow cytometer were used to detect the condition of cell viability and apoptosis. The levels of interleukin-1beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) was detected by enzyme-linked immunosorbent assay (ELISA) assay.

Results

The expression of CASC15 was increased and the levels of miR-338-3p were decreased in AIS patients. A positive association between CASC15 and NIHSS score and an inverse association between CASC15 and miR-338-3p were revealed by Pearson correlation. CASC15 might discriminate AIS patients from healthy people. Silenced CASC15 exerted neuroprotective roles on cell viability, apoptosis, and inflammation via the miR-338-3p/ETS1 axis.

Conclusion

CASC15 might act as a potential diagnostic biomarker for AIS patients. CASC15/miR-338-3p/ETS1 axis played an essential role in cell viability, apoptosis, and neuroinflammation.

Association of Rosacea With Cardiovascular Disease: A Retrospective Cohort Study

Background There is emerging evidence that rosacea, a chronic cutaneous inflammatory disease, is associated with various systemic diseases. However, its association with cardiovascular disease (CVD) remains controversial. We aimed to investigate whether patients with rosacea are at increased risk of developing CVD. Methods and Results This retrospective cohort study from the Korean National Health Insurance Service-Health Screening Cohort included patients with newly diagnosed rosacea (n=2681) and age-, sex-, and index year-matched reference populations without rosacea (n=26 810) between 2003 and 2014. The primary outcome was subsequent CVD including coronary heart disease and stroke. Multivariable Cox regression analyses were used to evaluate adjusted hazard ratios for subsequent CVD adjusted for major risk factors of CVD. Compared with the reference population (13 410 women; mean [SD] age, 57.7 [9.2] years), patients with rosacea (1341 women; mean [SD] age, 57.7 [9.2] years) displayed an increased risk for CVD (adjusted hazard ratios, 1.20; 95% CI, 1.03-1.40) and coronary heart disease (adjusted hazard ratios, 1.29; 95% CI, 1.05-1.60). The risk for stroke was not significantly elevated (adjusted hazard ratios, 1.12; 95% CI, 0.91-1.37). Conclusions This study suggests that patients with rosacea are more likely to develop subsequent CVD. Proper education for patients with rosacea to manage other modifiable risk factors of CVD along with rosacea is needed.

Refined Ischemic Penumbra Imaging with Tissue pH and Diffusion Kurtosis Magnetic Resonance Imaging

Imaging has played a vital role in our mechanistic understanding of acute ischemia and the management of acute stroke patients. The most recent DAWN and DEFUSE-3 trials showed that endovascular therapy could be extended to a selected group of late-presenting stroke patients with the aid of imaging. Although perfusion and diffusion MRI have been commonly used in stroke imaging, the approximation of their mismatch as the penumbra is oversimplified, particularly in the era of endovascular therapy. Briefly, the hypoperfusion lesion includes the benign oligemia that does not proceed to infarction. Also, with prompt and effective reperfusion therapy, a portion of the diffusion lesion is potentially reversible. Therefore, advanced imaging that provides improved ischemic tissue characterization may enable new experimental stroke therapeutics and eventually further individualize stroke treatment upon translation to the clinical setting. Specifically, pH imaging captures tissue of altered metabolic state that demarcates the hypoperfused lesion into ischemic penumbra and benign oligemia, which remains promising to define the ischemic penumbra's outer boundary. On the other hand, diffusion kurtosis imaging (DKI) differentiates the most severely damaged and irreversibly injured diffusion lesion from the portion of diffusion lesion that is potentially reversible, refining the inner boundary of the penumbra. Altogether, the development of advanced imaging has the potential to not only transform the experimental stroke research but also aid clinical translation and patient management.

Long non-coding RNA Gm11974 aggravates oxygen-glucose deprivation-induced injury via miR-122-5p/SEMA3A axis in ischaemic stroke

Long non-coding RNAs (lncRNAs) play important roles in ischaemic stroke. This study aimed to investigate the role and potential mechanism of lncRNA Gm11974 in ischaemic stroke. Mouse neuroblastoma N2a cells were treated with oxygen-glucose deprivation (OGD). The levels of Gm11974, microRNA-122-5p (miR-122-5p) and semaphorin 3A (SEMA3A) were detected by quantitative real-time PCR (qRT-PCR) or western blot. Cell viability and apoptosis were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, Caspase-3 Assay Kit and flow Cytometry. The levels of oxidative stress indicators were measured by using commercial kits. The relationship between miR-122-5p and Gm11974 or SEMA3A was verified by dual-luciferase reporter, RNA immunoprecipitation and RNA pull-down assays. Middle cerebral artery occlusion (MCAO) in mice was used to mimic ischaemic stroke. Gm11974 and SEMA3A were up-regulated, while miR-122-5p was down-regulated in OGD-treated N2a cells and MCAO mice. Down-regulation of Gm11974 ameliorated OGD-mediated N2a cell damage by increasing cell viability and reducing cell apoptosis and oxidative stress. Gm11974 promoted OGD-induced injury in N2a cells via negatively regulating miR-122-5p. Also, miR-122-5p alleviated OGD-resulted N2a cell injury by targeting SEMA3A. Moreover, silencing of Gm11974 decreased infarct volume and neurological score in MCAO mice. Knockdown of Gm11974 attenuated neuronal injury in ischaemic stroke by regulating miR-122-5p/SEMA3A signaling pathway.

Oxygen-glucose deprivation in neurons: implications for cell transplantation therapies

Cell replacement therapies hold the potential to restore neuronal networks compromised by neurodegenerative diseases (such as Parkinson's disease or Huntington's disease), or focal tissue damage (via a stroke or spinal cord injury). Despite some promising results achieved to date, transplanted cells typically exhibit poor survival in the central nervous system, thus limiting therapeutic efficacy of the graft. Although cell death post-transplantation is likely to be multifactorial in causality, growing evidence suggests that the lack of vascularisation at the graft site, and the resulting ischemic host environment, may play a fundamental role in the fate of grafted cells. Herein, we summarise data showing how the deprivation of either oxygen, glucose, or both in combination, impacts the survival of neurons and review strategies which may improve graft survival in the central nervous system.

Reporting quality evaluation of the stroke clinical practice guidelines: a systematic review

OBJECTIVES

To analyze the effectiveness and quality of stroke clinical practice guidelines (CPGs) published in recent years in order to guide future guideline developers to develop better guidelines.

PARTICIPANTS

No patient involved METHOD: PubMed, China Biology Medicine (CBM), Wanfang, CNKI, and CPG-relevant websites were searched from January 2015 to December 2019 by two researchers independently. The RIGHT (Reporting Items for Practice Guidelines in Healthcare) checklist was used to assess the reporting quality in terms of domains and items. Then, a subgroup analysis of the results was performed.

PRIMARY AND SECONDARY OUTCOME MEASURES

RIGHT checklist reporting rate RESULTS: A total of 66 CPGs were included. Twice as many CPGs were published internationally as were published in China. More than half were updated. Most CPGs are published in journals, developed by societies or associations, and were evidence-based grading. The average reporting rate for all included CPGs was 47.6%. Basic information got the highest (71.7% ± 19.7%) reporting rate, while review and quality assurance got the lowest (22.0% ± 24.6%). Then, a cluster analysis between countries, publishing channels, and institutions was performed. There were no statistically significant differences in the reporting quality on the CPGs between publishing countries (China vs. international), publishing channels (journals vs. websites), and institutions (associations vs. non-associations).

CONCLUSIONS

Current stroke CPGs reports are of low quality. We recommend that guideline developers improve the quality of reporting of key information and improve the management of conflicts of interest. We recommend that guideline developers consider the RIGHT checklist as an important tool for guideline development.

TRIAL REGISTRATION

https://doi.org/10.17605/OSF.IO/PBWUX .

Restoration of HDAC1 Enzymatic Activity after Stroke Protects Neurons from Ischemia/Reperfusion Damage and Attenuates Behavioral Deficits in Rats

A therapeutic approach for promoting neuroprotection and brain functional regeneration after strokes is still lacking. Histone deacetylase 1 (HDAC1), which belongs to the histone deacetylase family, is involved in the transcriptional repression of cell-cycle-modulated genes and DNA damage repair during neurodegeneration. Our previous data showed that the protein level and enzymatic activity of HDAC1 are deregulated in stroke pathogenesis. A novel compound named 5104434 exhibits efficacy to selectively activate HDAC1 enzymatic function in neurodegeneration, but its potential in stroke therapy is still unknown. In this study, we adopted an induced rat model with cerebral ischemia using the vessel dilator endothelin-1 to evaluate the potential of compound 5104434. Our results indicated compound 5104434 selectively restored HDAC1 enzymatic activity after oxygen and glucose deprivation, preserved neurite morphology, and protected neurons from ischemic damage in vitro. In addition, compound 5104434 attenuated the infarct volume, neuronal loss, apoptosis, DNA damage, and DNA breaks in cerebral ischemia rats. It further ameliorated the behavioral outcomes of neuromuscular response, balance, forepaw strength, and functional recovery. Collectively, our data support the efficacy of compound 5104434 in stroke therapy and contend that it can be considered for clinical trial evaluation.

Mitochondrial Dynamics: A Potential Therapeutic Target for Ischemic Stroke

Stroke is one of the leading causes of death and disability worldwide. Brain injury after ischemic stroke involves multiple pathophysiological mechanisms, such as oxidative stress, mitochondrial dysfunction, excitotoxicity, calcium overload, neuroinflammation, neuronal apoptosis, and blood-brain barrier (BBB) disruption. All of these factors are associated with dysfunctional energy metabolism after stroke. Mitochondria are organelles that provide adenosine triphosphate (ATP) to the cell through oxidative phosphorylation. Mitochondrial dynamics means that the mitochondria are constantly changing and that they maintain the normal physiological functions of the cell through continuous division and fusion. Mitochondrial dynamics are closely associated with various pathophysiological mechanisms of post-stroke brain injury. In this review, we will discuss the role of the molecular mechanisms of mitochondrial dynamics in energy metabolism after ischemic stroke, as well as new strategies to restore energy homeostasis and neural function. Through this, we hope to uncover new therapeutic targets for the treatment of ischemic stroke.

Acute Ischaemic Stroke in Infective Endocarditis: Pathophysiology and Clinical Outcomes in Patients Treated with Reperfusion Therapy

Infective endocarditis in the setting of acute stroke poses a clinical challenge given the high mortality and morbidity associated with the condition. The pathophysiological mechanisms including clinical and imaging biomarkers that can provide insights into clinical trajectories of such patients are of immense interest. The current paper aims to provide a comprehensive overview of acute stroke with infective endocarditis and provide insights into various clinical factors mediating outcomes and therapeutic strategies, specifically in the setting of reperfusion therapy. Prognostic and therapeutic pathways to potentially improve functional outcomes in these patients are also discussed.

Second near-infrared (NIR-II) imaging: a novel diagnostic technique for brain diseases

Imaging in the second near-infrared II (NIR-II) window, a kind of biomedical imaging technology with characteristics of high sensitivity, high resolution, and real-time imaging, is commonly used in the diagnosis of brain diseases. Compared with the conventional visible light (400-750 nm) and NIR-I (750-900 nm) imaging, the NIR-II has a longer wavelength of 1000-1700 nm. Notably, the superiorities of NIR-II can minimize the light scattering and autofluorescence of biological tissue with the depth of brain tissue penetration up to 7.4 mm. Herein, we summarized the main principles of NIR-II in animal models of traumatic brain injury, cerebrovascular visualization, brain tumor, inflammation, and stroke. Simultaneously, we encapsulated the in vivo process of NIR-II probes and their in vivo and in vitro toxic effects. We further dissected its limitations and following optimization measures.

Neutrophils Obstructing Brain Capillaries Are a Major Cause of No-Reflow in Ischemic Stroke

Despite successful clot retrieval in large vessel occlusion stroke, ∼50% of patients have an unfavorable clinical outcome. The mechanisms underlying this functional reperfusion failure remain unknown, and therapeutic options are lacking. In the thrombin-model of middle cerebral artery (MCA) stroke in mice, we show that, despite successful thrombolytic recanalization of the proximal MCA, cortical blood flow does not fully recover. Using in vivo two-photon imaging, we demonstrate that this is due to microvascular obstruction of ∼20%-30% of capillaries in the infarct core and penumbra by neutrophils adhering to distal capillary segments. Depletion of circulating neutrophils using an anti-Ly6G antibody restores microvascular perfusion without increasing the rate of hemorrhagic complications. Strikingly, infarct size and functional deficits are smaller in mice treated with anti-Ly6G. Thus, we propose neutrophil stalling of brain capillaries to contribute to reperfusion failure, which offers promising therapeutic avenues for ischemic stroke.

SWATH-MS for prospective identification of protein blood biomarkers of rtPA-associated intracranial hemorrhage in acute ischemic stroke: a pilot study

Intravenous recombinant tissue plasminogen activator (rtPA) is, besides mechanical thrombectomy, the highest class evidence based reperfusion treatment of acute ischemic stroke (AIS). The biggest concern of the therapy is symptomatic intracranial hemorrhage (sICH), which occurs in 3-7% of all treated patients, and is associated with worse functional outcome. Finding a method of the powerful identification of patients at highest risk of sICH, in order to increase the percentage of stroke patients safely treated with rtPA, is one of the most important challenges in stroke research. To address this problem, we designed a complex project to identify blood, neuroimaging, and clinical biomarkers combined for prospective assessment of the risk of rtPA-associated ICH. In this paper we present results of blood proteomic and peptide analysis of pilot 41 AIS patients before rtPA administration (the test ICH group, n = 9 or the controls, without ICH, n = 32). We demonstrated that pre-treatment blood profiles of 15 proteins differ depending on whether the patients develop rtPA-associated ICH or not. SWATH-MS quantification of serum or plasma proteins might allow for robust selection of blood biomarkers to increase the prospective assessment of rtPA-associated ICH over that based solely on clinical and neuroimaging characteristics.

Combined Preconditioning Reduces the Negative Influence of Cerebral Ischemia on the Morphofunctional Condition of CNS

We studied the influence of combined preconditioning (compound pQ-4 and moderate hypoxia) on morphometrical parameters of neuronal populations in hippocampal fields CA1 and CA3 in rats after bilateral ligation of the common carotid artery. Preconditioning produced a neuroprotective effect, improved survival of pyramidal neurons in the early and delayed periods of modeled ischemia, prevented the formation of necrotic and apoptotic neurons and hyperactivation of microglia, and protected endotheliocytes. The positive influence of preconditioning factors on the morphometric parameters of the brain under ischemic conditions agrees with the results of behavioral tests (open field and elevated plus maze) that demonstrated increased locomotor activity and exploratory behavior of animals.

Pharmacological preconditioning by TERT inhibitor BIBR1532 confers neuronal ischemic tolerance through TERT-mediated transcriptional reprogramming

After a sublethal ischemic preconditioning (IPC) stimulus, the brain has a remarkable capability of acquiring tolerance to subsequent ischemic insult by establishing precautionary self-protective mechanism. Understanding this endogenous mechanism would reveal novel and effective neuroprotective targets for ischemic brain injury. Our previous study has implied that telomerase reverse transcriptase (TERT) is associated with IPC-induced tolerance. Here, we investigated the mechanism of TERT-mediated ischemic tolerance. Preconditioning was modeled by oxygen-glucose deprivation (OGD) and by TERT inhibitor BIBR1532 in primary neurons. We found that ischemic tolerance was conferred by BIBR1532 preconditioning. We used the Cleavage-Under-Targets-And-Tagmentation approach, a recently developed method with superior signal-to-noise ratio, to comprehensively map the genomic binding sites of TERT in primary neurons, and showed that more than 50% of TERT-binding sites were located at the promoter regions. Mechanistically, we demonstrated that under normal conditions TERT physically bound to many previously unknown genomic loci in neurons, whereas BIBR1532 preconditioning significantly altered TERT-chromatin-binding profile. Intriguingly, we found that BIBR1532-preconditioned neurons showed significant up-regulation of promoter binding of TERT to the mitochondrial anti-oxidant genes, which were correlated with their elevated expression. Functional analysis further indicated that BIBR1532-preconditioning significantly reduced ROS levels and enhanced tolerance to severe ischemia-induced mitochondrial oxidative stress in neurons in a TERT-dependent manner. Together, these results demonstrate that BIBR1532 confers neuronal ischemic tolerance through TERT-mediated transcriptional reprogramming for up-regulation of mitochondrial anti-oxidation gene expression, suggesting the translational potential of BIBR1532 as a therapeutic agent for the treatment of cerebral ischemic injury and oxidative stress-induced neurological disorders.

TGFβ-Neurotrophin Interactions in Heart, Retina, and Brain

Ischemic insults to the heart and brain, i.e., myocardial and cerebral infarction, respectively, are amongst the leading causes of death worldwide. While there are therapeutic options to allow reperfusion of ischemic myocardial and brain tissue by reopening obstructed vessels, mitigating primary tissue damage, post-infarction inflammation and tissue remodeling can lead to secondary tissue damage. Similarly, ischemia in retinal tissue is the driving force in the progression of neovascular eye diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD), which eventually lead to functional blindness, if left untreated. Intriguingly, the easily observable retinal blood vessels can be used as a window to the heart and brain to allow judgement of microvascular damages in diseases such as diabetes or hypertension. The complex neuronal and endocrine interactions between heart, retina and brain have also been appreciated in myocardial infarction, ischemic stroke, and retinal diseases. To describe the intimate relationship between the individual tissues, we use the terms heart-brain and brain-retina axis in this review and focus on the role of transforming growth factor β (TGFβ) and neurotrophins in regulation of these axes under physiologic and pathologic conditions. Moreover, we particularly discuss their roles in inflammation and repair following ischemic/neovascular insults. As there is evidence that TGFβ signaling has the potential to regulate expression of neurotrophins, it is tempting to speculate, and is discussed here, that cross-talk between TGFβ and neurotrophin signaling protects cells from harmful and/or damaging events in the heart, retina, and brain.

Neuroprotective Effect of a Novel ATP-Synthase Inhibitor Bedaquiline in Cerebral Ischemia-Reperfusion Injury

Mitochondrial dysfunction during ischemic stroke ultimately manifests as ATP depletion. Mitochondrial ATP synthase upon loss of mitochondrial membrane potential during ischemia rapidly hydrolyses ATP and thus contributes to ATP depletion. Increasing evidence suggests that inhibition of ATP synthase limits ATP depletion and is protective against ischemic tissue damage. Bedaquiline (BDQ) is an anti-microbial agent, approved for clinical use, that inhibits ATP synthase of Mycobacteria; however recently it has been shown to act on mitochondrial ATP synthase, inhibiting both ATP synthesis and hydrolysis in low micromolar concentrations. In this study, we investigated whether preconditioning with BDQ can alleviate ischemia/reperfusion-induced brain injury in Wistar rats after middle cerebral artery occlusion-reperfusion and whether it affects mitochondrial functions. We found that BDQ was effective in limiting necrosis and neurological dysfunction during ischemia-reperfusion. BDQ also caused inhibition of ATPase activity, mild uncoupling of respiration, and stimulated mitochondrial respiration both in healthy and ischemic mitochondria. Mitochondrial calcium retention capacity was unaffected by BDQ preconditioning. We concluded that BDQ has neuroprotective properties associated with its action on mitochondrial respiration and ATPase activity.

Neurovascular protection of salvianolic acid B and ginsenoside Rg1 combination against acute ischemic stroke in rats

Ischemic stroke continues to be a major global health problem associated with considerable mortality and morbidity. Thus, it is still targeted by researchers for developing new strategies or drugs to alleviate the lesion of stroke. In the present study, both the permanent occlusion of the middle cerebral artery (MCAO) model and the restoration of cerebral blood flow after middle cerebral artery occlusion (CI/R) model were set up for evaluating the efficiency of salvianolic acid B and ginsenoside Rg1 combination (SalB-Rg1). SalB-Rg1 decreased infarct area through 3,5-triphenyltetrazolium chloride stain and improved neurological behavior through Longa Score or Left-Biased Swings on both MCAO rats and CI/R rats. Neural protection of SalB-Rg1 against ischemia or ischemic reperfusion injury was evidenced by the inhibition of nucleus pyknosis, liquefaction necrosis through H&E stain and Nissl stain. Furthermore, protection of SalB-Rg1 on blood-brain barrier (BBB) was more significant on CI/R rats, accompanying with the downregulation of matrix metalloproteinase-2 and matrix metalloproteinase-9, and recovery of zonula occludens-1 expression. These results provide compelling evidence that SalB-Rg1 holds the potential to be developed as an optimal therapeutic strategy to alleviate the injury of ischemia or ischemic reperfusion.

Nanoparticles-mediated emerging approaches for effective treatment of ischemic stroke

Ischemic stroke leads to high disability and mortality. The limited delivery efficiency of most therapeutic substances is a major challenge for effective treatment of ischemic stroke. Inspired by the prominent merit of nanoscale particles in brain targeting and blood-brain barrier (BBB) penetration, various functional nanoparticles have been designed as promising drug delivery platforms that are expected to improve the therapeutic effect of ischemic stroke. Based on the complex pathological mechanisms of ischemic stroke, this review outline and summarize the rationally designed nanoparticles-mediated emerging approaches for effective treatment of ischemic stroke, including recanalization therapy, neuroprotection therapy, and combination therapy. On this bases, the potentials and challenges of nanoparticles in the treatment of ischemic stroke are revealed, and new thoughts and perspectives are proposed for the design of feasible nanoparticles for effective treatment of ischemic stroke.

Serum Occludin Level Combined With NIHSS Score Predicts Hemorrhage Transformation in Ischemic Stroke Patients With Reperfusion

Hemorrhagic transformation (HT) is a severe complication following acute ischemic stroke, particularly with reperfusion interventions, leading to poor prognosis. Serum occludin level is related with blood brain barrier disruption, and the National Institute of Health stroke scale (NIHSS) score reflects stroke severity. We investigated whether the two covariates are independently associated with HT and their combination can improve the accuracy of HT prediction in ischemic stroke patients with reperfusion therapy. Seventy-six patients were screened from the established database of acute ischemic stroke in our previous study, which contains all clinical information, including serum occludin levels, baseline NIHSS score, and hemorrhagic events. Multivariate logistic regression analysis showed that serum occludin level (OR = 4.969, 95% CI: 2.069-11.935, p < 0.001) and baseline NIHSS score (OR = 1.293, 95% CI 1.079-1.550, p = 0.005) were independent risk factors of HT after adjusting for potential confounders. Compared with non-HT patients, HT patients had higher baseline NIHSS score [12 (10.5-18.0) versus 6 (4-12), p = 0.003] and serum occludin level (5.47 ± 1.25 versus 3.81 ± 1.19, p < 0.001). Moreover, receiver operating characteristic curve based on leave-one-out cross-validation showed that the combination of serum occludin level and NIHSS score significantly improved the accuracy of predicting HT (0.919, 95% CI 0.857-0.982, p < 0.001). These findings suggest that the combination of two methods may provide a better tool for HT prediction in acute ischemic stroke patients with reperfusion therapy.

Assessment of patients with a suspected cardioembolic ischemic stroke. A national consensus statement

OBJECTIVES

Several cardiovascular, structural, and functional abnormalities have been considered as potential causes of cardioembolic ischemic strokes. Beyond atrial fibrillation, other sources of embolism clearly exist and may warrant urgent action, but they are only a minor part of the many stroke mechanisms and strokes that seem to be of embolic origin remain without a determined source. The associations between stroke and findings like atrial fibrillation, valve calcification, or heart failure are confounded by co-existing risk factors for atherosclerosis and vascular disease. In addition, a patent foramen ovale which is a common abnormality in the general population is mostly an innocent bystander in patients with ischemic stroke. For these reasons, experts from the national Danish societies of cardiology, neurology, stroke, and neuroradiology sought to develop a consensus document to provide national recommendations on how to manage patients with a suspected cardioembolic stroke. Design: Comprehensive literature search and analyses were done by a panel of experts and presented at a consensus meeting. Evidence supporting each subject was vetted by open discussion and statements were adjusted thereafter. Results: The most common sources of embolic stroke were identified, and the statement provides advise on how neurologist can identify cases that need referral, and what is expected by the cardiologist. Conclusions: A primary neurological and neuroradiological assessment is mandatory and neurovascular specialists should manage the initiation of secondary prophylactic treatment. If a cardioembolic stroke is suspected, a dedicated cardiologist experienced in the management of cardioembolism should provide a tailored clinical and echocardiographic assessment.

MiR-499a prevents astrocytes mediated inflammation in ischemic stroke by targeting PTEN

INTRODUCTION

Ischemic stroke (IS) is a common and severe neurological disorder and is associated with high rates of mortality and morbidity. Inflammatory reaction in astrocytes is one of the important pathological factors of stroke. Improved understanding of the underlying molecular mechanisms should aid better treatment of the disease. This study aimed to test our hypothesis that a miR-499a played an important role in the inflammatory response in astrocytes induced by IS targeting phosphatase and tensin homologue deleted on chromosome 10 (PTEN).

METHODS

This study was comprised of two models: oxygen-glucose deprivation (OGD) and reoxygenation model. Quantitative real-time PCR (qRT-PCR) and Western blot were used to examine gene expression levels, and MTT assay analysis were used to examine cell states. The relationships between miR-499a and PTEN were confirmed by luciferase reporter assay.

RESULTS

MiR-499a was robustly downregulated with OGD induced injury in astrocytes. Forced transient expression of miR-499a in OGD astrocytes nearly completely reversed the inflammatory response. Knockdown of miR-499a by its specific inhibitor in healthy astrocytes induced the inflammatory response resembling those produced by OGD. On the other hand, PTEN was markedly upregulated in OGD astrocytes, which was reciprocal to the expression of miR-499a. PTEN was experimentally validated as a direct target gene for miR-499a. Overexpression of PTEN was able to induce an inflammatory response of astrocytes. Moreover, PTEN siRNA counteracted the inflammatory response induced by OGD.

CONCLUSIONS

Taken together, our findings indicate miR-499a as an important factor to prevent inflammatory response and suggest miR-499a as a new molecule for the treatment of IS. The present study also demonstrated the relationship between miR-499a and PTEN, with PTEN as a downstream signaling mediator of miR-499a in the inflammatory response of astrocytes induced by IS.

Notoginsenoside R1 intervenes degradation and redistribution of tight junctions to ameliorate blood-brain barrier permeability by Caveolin-1/MMP2/9 pathway after acute ischemic stroke

BACKGROUND

The leakage of blood-brain barrier (BBB) is main pathophysiological change in acute stage of ischemic stroke, which not only deteriorates neurological function, but also increases the risk of hemorrhagic transformation after thrombolysis.

PURPOSE/STUDY DESIGN

This article investigates the efficacy of Notoginsenoside R1, an active ingredient of Panax notoginseng, on BBB permeability and explores related mechanisms after acute ischemic stroke.

METHODS

In vivo, male Sprague-Dawley rats (260-280 g) were selected and randomly divided into 6 groups: sham group, model group, low, middle and high doses of Notoginsenoside R1 groups and positive drug Dl-3-n-Butylphthalide group. Except for sham group, rats were performed with permanent middle cerebral artery occlusion model in each group. Twelve hours later, rats were evaluated for Bederson neurological function, and BBB integrity by Evans blue leak imaging; Triphenyltetrazolium chloride staining was used to detect the volume of cerebral infarction. Frozen sections of rats' brain tissue were prepared for detection of MMPs activity in situ zymography. Peripheral tissue of cerebral infarction was collected and tested the expression of MMP2, 9 and tight junction proteins (zo1, claudin5, occludin) by western blot. In vitro, transwell endothelial barrier model was established by bEnd.3 cells. Oxygen glucose deprivation (OGD) was chosen to simulate the hypoxic environment. Suitable OGD stimulation time as well as Notoginsenoside R1 and Dl-3-n-Butylphthalide optimal dose concentrations were determined through transwell leakage and CCK8 assay. Furthermore, endothelial subcellular component proteins were extracted. The change of zo1, claudin5, occludin and caveolin1 was detected by western blot.

RESULTS

Notoginsenoside R1 treatment significantly reduced BBB leakage and cerebral infarction volume, weakened neurological deficits in post-stroke rats. Moreover, it inhibited the activity of MMPs in infarcted cortex and striatum, down-regulated MMP2, 9 and up-regulated zo1 and claudin5 expressions in penumbra. In vitro, Notoginsenoside R1 treatment decreased OGD-induced endothelial barrier permeability, restored expressions of zo1, claudin5 on cellular membrane and cytoplasm, as well as mediated membrane redistribution of occludin and caveolin1 from actin cytoskeletal fraction.

CONCLUSIONS

Notoginsenoside R1 treatment attenuates BBB permeability, cerebral infarction volume and neurological impairments in rats with acute cerebral ischemia. The mechanisms might be related to intervening degradation and redistribution of zo1, caludin5 and occludin by caveolin1/ MMP2/9 pathway. More effects and mechanisms of Notoginsenoside R1 on rehabilitation of stroke are worthy to be explored in the future.

LncRNA NKILA relieves astrocyte inflammation and neuronal oxidative stress after cerebral ischemia/reperfusion by inhibiting the NF-κB pathway

BACKGROUND

Ischemic stroke is one of the major diseases of the cerebral vasculature. Currently, Ischemic stroke is the leading cause of neurological disability worldwide and has a high morbidity and mortality rate. The NF-κB interacting lncRNA (NKILA), the recently identified, is a key booster of NF-κB pathway. Accumulating studies have shown that NKILA plays a cancer suppressor in a variety of malignancies by regulating the NF-κB pathway. Nevertheless, the role of NKILA in ischemic stroke remains to be elucidated.

METHODS

We constructed a mouse model of middle cerebral artery occlusion-reperfusion (MCAO/R). TTC staining and dry and wet weight method were used to evaluate infarction and water content of brain tissue. RT-qPCR was performed to detect NKILA expression in cerebral infarction tissues. After labeling astrocytes and neurons with GFAP and NeuN, respectively, EDU and TUNEL staining were performed. Inflammatory factor levels were detected by ELISA. Commercial kits were used to detect the levels of oxidative stress-related factors. In in vitro, the HT22/U251 cell co-culture model was used for oxygen-glucose deprivation and re-introduction (OGD/R) to verify the effect of NKILA on neuronal cell inflammation and oxidative stress through astrocytes.

RESULTS

In in vivo experiments, NKILA significantly reduced cerebral infarction volume, brain water content and neurological score caused by MCAO/R. Moreover, NKILA blocked the activation of the NF-κB pathway, and inhibited astrocyte proliferation and neuron apoptosis as well as inflammation and oxidative stress. In in vitro experiments, NKILA significantly inhibited NF-κB pathway in HT22 cells. In addition, NKILA alleviated the inflammatory response and oxidative stress of U251 cells mediated by HT22 cells after OGD/R, and promoted U251 cell proliferation and inhibit their apoptosis.

CONCLUSIONS

In summary, we found for the first time that NKILA alleviates inflammatory response and oxidative stress after cerebral ischemia/reperfusion by blocking the activation of NF-κB pathway.

Modulating poststroke inflammatory mechanisms: Novel aspects of mesenchymal stem cells, extracellular vesicles and microglia

Inflammation plays an important role in the pathological process of ischemic stroke, and systemic inflammation affects patient prognosis. As resident immune cells in the brain, microglia are significantly involved in immune defense and tissue repair under various pathological conditions, including cerebral ischemia. Although the differentiation of M1 and M2 microglia is certainly oversimplified, changing the activation state of microglia appears to be an intriguing therapeutic strategy for cerebral ischemia. Recent evidence indicates that both mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (EVs) regulate inflammation and modify tissue repair under preclinical stroke conditions. However, the precise mechanisms of these signaling pathways, especially in the context of the mutual interaction between MSCs or MSC-derived EVs and resident microglia, have not been sufficiently unveiled. Hence, this review summarizes the state-of-the-art knowledge on MSC- and MSC-EV-mediated regulation of microglial activity under ischemic stroke conditions with respect to various signaling pathways, including cytokines, neurotrophic factors, transcription factors, and microRNAs.

Non-immunogenic recombinant staphylokinase versus alteplase for patients with acute ischaemic stroke 4·5 h after symptom onset in Russia (FRIDA): a randomised, open label, multicentre, parallel-group, non-inferiority trial

BACKGROUND

Non-immunogenic staphylokinase is modified recombinant staphylokinase with low immunogenicity, high thrombolytic activity, and selectivity to fibrin. We aimed to assess the safety and efficacy of a single intravenous bolus of non-immunogenic staphylokinase compared with alteplase in patients with acute ischaemic stroke within 4·5 h after symptom onset.

METHODS

We did a randomised, open-label, multicentre, parallel-group, non-inferiority trial in 18 clinical sites in Russia. We included patients aged 18 years and older with a diagnosis of acute ischaemic stroke (up to 25 points on the National Institutes of Health Stroke Scale). The study drug had to be administered within 4·5 h after the onset of symptoms. Patients were randomly assigned to receive either non-immunogenic staphylokinase (10 mg) or alteplase (0·9 mg/kg, maximum 90 mg), both administered intravenously. The randomisation sequence was created by an independent biostatistician using computer-generated random numbers. 84 blocks (block size of four) of opaque sealed envelopes were numbered sequentially from 1 to 336 and were opened in numerical order. Patients were unaware of their assigned treatment and were assessed by the study investigators who were also unaware of the treatment assignment on all trial days. Emergency department staff, who administered the assigned drug and opened the envelopes, were not masked to treatment. The primary efficacy endpoint was a favourable outcome, defined as a modified Rankin scale (mRS) score of 0-1 on day 90. The margin of non-inferiority was established as 16% for the difference in mRS score of 0-1 on day 90. Non-inferiority was tested using Welch's t-test for the primary outcome only. Endpoints were analysed in the per-protocol population, which comprised all randomly assigned patients who completed treatment without any protocol violations; this population was identical to the intention-to-treat population. This trial is completed and registered at ClinicalTrials.gov, NCT03151993.

FINDINGS

Of 385 patients recruited from March 18, 2017, to March 23, 2019, 336 (87%) were included in the trial. 168 (50%) patients were randomly assigned to receive non-immunogenic staphylokinase and 168 (50%) to receive alteplase. The median duration of follow-up was 89 days (IQR 89-89). 84 (50%) of 168 patients in the non-immunogenic staphylokinase group had a favourable outcome at day 90 compared with 68 (40%) of 168 patients in the alteplase group (odds ratio [OR] 1·47, 95% CI 0·93 to 2·32; p=0·10). The difference in the rate of favourable outcome at day 90 was 9·5% (95% CI -1·7 to 20·7) and the lower limit did not cross the margin of non-inferiority (p_{non-inferiority} <0·0001). Symptomatic intracranial haemorrhage occurred in five (3%) patients in the non-immunogenic staphylokinase group and in 13 (8%) patients in the alteplase group (p=0·087). On day 90, 17 (10%) patients in the non-immunogenic staphylokinase group and 24 (14%) patients in the alteplase group had died (p=0·32). 22 (13%) patients in the non-immunogenic staphylokinase group had serious adverse events, compared with 37 (22%) patients in the alteplase group (p=0·044).

INTERPRETATION

Non-immunogenic staphylokinase was non-inferior to alteplase for patients with acute ischaemic stroke. Mortality, symptomatic intracranial haemorrhage, and serious adverse events did not differ significantly between groups. Future studies are needed to continue to assess the safety and efficacy of non-immunogenic staphylokinase in patients with acute ischaemic stroke within the 4·5 h time window, and to assess the drug in patients with acute ischaemic stroke outside this time window with reperfusion CT or magnetic resonance angiography followed by thrombectomy if necessary.

FUNDING

The Russian Academy of Sciences.

Mechanism of Endoplasmic Reticulum Stress in Cerebral Ischemia

Endoplasmic reticulum (ER) is the main organelle for protein synthesis, trafficking and maintaining intracellular Ca²⁺ homeostasis. The stress response of ER results from the disruption of ER homeostasis in neurological disorders. Among these disorders, cerebral ischemia is a prevalent reason of death and disability in the world. ER stress stemed from ischemic injury initiates unfolded protein response (UPR) regarded as a protection mechanism. Important, disruption of Ca²⁺ homeostasis resulted from cytosolic Ca²⁺ overload and depletion of Ca²⁺ in the lumen of the ER could be a trigger of ER stress and the misfolded protein synthesis. Brain cells including neurons, glial cells and endothelial cells are involved in the complex pathophysiology of ischemic stroke. This is generally important for protein underfolding, but even more for cytosolic Ca²⁺ overload. Mild ER stress promotes cells to break away from danger signals and enter the adaptive procedure with the activation of pro-survival mechanism to rescue ischemic injury, while chronic ER stress generally serves as a detrimental role on nerve cells via triggering diverse pro-apoptotic mechanism. What’s more, the determination of some proteins in UPR during cerebral ischemia to cell fate may have two diametrically opposed results which involves in a specialized set of inflammatory and apoptotic signaling pathways. A reasonable understanding and exploration of the underlying molecular mechanism related to ER stress and cerebral ischemia is a prerequisite for a major breakthrough in stroke treatment in the future. This review focuses on recent findings of the ER stress as well as the progress research of mechanism in ischemic stroke prognosis provide a new treatment idea for recovery of cerebral ischemia.

Promoter polymorphism of TNF-α (rs1800629) is associated with ischemic stroke susceptibility in a southern Thai population

Stroke represents the leading cause of disability and mortality amongst the elderly worldwide. Multiple risk factors, including both genetic and non-genetic components, as well as their interactions, are proposed as etiological factors involved in the development of ischemic stroke (IS). Promoter polymorphisms of the IL-6-174G/C (rs1800795) and TNF-α-308G/A (rs1800629) genes have been considered as predictive risk factors of IS; however, these have not yet been evaluated in a Thai population. The aims of this study were to investigate the association of IL-6-174G/C and TNF-α-308G/A polymorphisms with IS. Genomic DNA from 200 patients with IS and 200 controls were genotyped for IL-6-174G/C and TNF-α-308G/A polymorphisms using TaqMan™ SNP genotyping and quantitative PCR-high resolution melting analysis, respectively. It was found that the TNF-α-308 A allele was significantly associated with an increased risk of IS development compared with the G allele [odds ratio (OR)=2.044; 95% CI=1.154-3.620; P=0.014]. Moreover, the IS risk was significantly higher in the presence of TNF-α-308 GA or AA genotypes compared with that in the presence of GG genotypes with a dominant inheritance (OR=1.971; 95% CI=1.080-3.599; P=0.027). However, there was no association between IL-6-174G/C and the risk of IS development. The interaction study demonstrated that IL-6-174 GG and TNF-α-308 GG genotypes enhanced IS susceptibility when combined with hypertension, hyperlipidemia and alcohol consumption. Hypertensive and hyperlipidemic subjects with the TNF-α-308 GA and AA genotypes were more likely to develop IS compared with those who did not have these two conditions and had the GG genotype. In a matched study design (1:1), the IL-6-174 GC genotype was associated with higher IL-6 levels in the control group. Collectively, the present results highlight the utility of the TNF-α-308G/A polymorphism as a predictive genetic risk factor for development of IS.

Protective effects of dexmedetomidine on cerebral ischemia/reperfusion injury via the microRNA-214/ROCK1/NF-κB axis

BACKGROUND

Cerebral ischemia/reperfusion injury (CIRI) is a complication of surgical procedure associated with high mortality. The protective effect of dexmedetomidine (DEX) on CIRI has been explored in previous works, yet the underlying molecular mechanism remains unclear. Our study explored the protective effect of DEX and its regulatory mechanism on CIRI.

METHODS

A CIRI rat model was established using middle cerebral artery occlusion (MCAO). Neurological deficit scores for rats received MCAO modeling or DEX treatment were measured. Cerebral infarction area of rats was detected by TTC staining, while damage of neurons in hippocampal regions of rats was determined by hematoxylin-eosin (HE) staining. Apoptosis rate of neurons in hippocampal regions was examined by TUNEL staining. The dual-luciferase assay was performed to detect the binding of microRNA-214 (miR-214) to Rho-associated kinase 1 (ROCK1).

RESULTS

DEX treatment significantly reduced infarction area of MCAO rats and elevated miR-214 expression. Injection of miR-214 inhibitor attenuated the effect of DEX in MCAO rats by increasing the area of cerebral infarction in rats and apoptosis rate of hippocampal neurons. ROCK1 was targeted and negatively regulated by miR-214. The overexpression of ROCK1 led to activation of NF-κB to aggravate CIRI.

CONCLUSION

Therapeutic effects of DEX on CIRI was elicited by overexpressing miR-214 and impairing ROCK1 expression and NF-κB activation. Our finding might provide novel insights into the molecular mechanism of DEX in rats with CIRI.

The therapeutic effect and mechanism of Qishen Yiqi dripping pills on cardiovascular and cerebrovascular diseases and diabetic complications

The alterations in vascular homeostasis is deeply involved in the development of numerous diseases, such as coronary heart disease, stroke, and diabetic complications. Changes in blood flow and endothelial permeability caused by vascular dysfunction are the common mechanisms for these three types of diseases. The disorders of glucose and lipid metabolism can result in changes of the energy production patterns in endothelium and surrounding cells which may consequently cause local energy metabolic disorders, oxidative stress and inflammatory responses. Traditional Chinese medicine (TCM) follows the principle of the "treatment by the syndrome differentiation". TCM considers of that coronary heart disease, stroke and diabetes complications all as the type of "Qi deficiency and Blood stasis" syndrome, which mainly happens to the vascular system. Therefore, the common pathogenesis of these three types of diseases suggests the treatment strategy by TCM should be in a close manner and named as "treating different diseases by the same treatment". Qishen Yiqi dripping pills is a modern Chinese herbal medicine which has been widely used for treatment of patients with coronary heart disease characterized as "Qi deficiency and blood stasis" in China. Recently, many clinical reports have demonstrated the potent therapeutic effects of Qishen Yiqi dripping pills on ischemic stroke and diabetic nephropathy. Based on these reports, we will summarize the clinical applications of Qishen Yiqi dripping pills on coronary heart disease, ischemic stroke and diabetic nephropathy, including the involved mechanisms with basic researches.

Decrease in intravenous thrombolysis and poor short-term functional prognosis for acute ischemic stroke during the COVID-19 pandemic

Background and purpose

Since the outbreak of the coronavirus pandemic in 2019 (COVID-19), healthcare systems around the world have been hit to varying degrees. As a neurologist team, for patients with acute ischemic stroke (AIS), we compared the situations of intravenous thrombolysis (IVT) treatment from 2019 to 2020 to investigate the influence of COVID-19 pandemic on the attendance and prognosis of the IVT patients.

Methods

We collected the messages of objects who had received IVT (Bridging surgery was ruled out) during 2019–2020. We analyzed differences in age, gender, time from onset to start IVT, door to needle time (DNT), pretreatment NIHSS score, postoperative NIHSS score, and so on. Statistical tests were also performed to respectively compare the discharged modified Rankin score (mRS) and discharged NIHSS score between two years.

Results

Since the onset of COVID-19 restrictions in Wenzhou, we observed a significant reduction of 24.7% (p = 0.023) from 267(2019) to 201(2020) of received IVT on hospital admission. We compared the DNT between two years and it reflected that the DNT (min) in 2020 was obviously longer than in 2019 (51.60 ± 23.80 vs 46.80 ± 21.90, p = 0.026). We also compared the discharged mRS, which reflected much more IVT patients in 2020 during the COVID-19 pandemic had a poor short-term functional prognosis (38.2% vs 29.2%, p = 0.043).

Conclusions

The COVID-19 pandemic caused the decrease of admissions and prolonged the time of the green channel for stroke, which led to the worse short-term prognosis of AIS patients during the pandemic. It’s necessary to ensure an effective green channel and provide adequate medical resources during the pandemic period to reduce the damage caused by COVID-19.

Prediction of Myoelectric Biomarkers in Post-Stroke Gait

Electromyography (EMG) is sensitive to neuromuscular changes resulting from ischemic stroke and is considered a potential predictive tool of post-stroke gait and rehabilitation management. This study aimed to evaluate the potential myoelectric biomarkers for the classification of stroke-impaired muscular activity of the stroke patient group and the muscular activity of the control healthy adult group. We also proposed an EMG-based gait monitoring system consisting of a portable EMG device, cloud-based data processing, data analytics, and a health advisor service. This system was investigated with 48 stroke patients (mean age 70.6 years, 65% male) admitted into the emergency unit of a hospital and 75 healthy elderly volunteers (mean age 76.3 years, 32% male). EMG was recorded during walking using the portable device at two muscle positions: the bicep femoris muscle and the lateral gastrocnemius muscle of both lower limbs. The statistical result showed that the mean power frequency (MNF), median power frequency (MDF), peak power frequency (PKF), and mean power (MNP) of the stroke group differed significantly from those of the healthy control group. In the machine learning analysis, the neural network model showed the highest classification performance (precision: 88%, specificity: 89%, accuracy: 80%) using the training dataset and highest classification performance (precision: 72%, specificity: 74%, accuracy: 65%) using the testing dataset. This study will be helpful to understand stroke-impaired gait changes and decide post-stroke rehabilitation.

Betulinic Acid Ameliorates Cerebral Injury in Middle Cerebral Artery Occlusion Rats through Regulating Autophagy

Cerebral ischemic stroke (CIS) is an acute cerebrovascular disease that is caused by the sudden rupture of blood vessels inside the brain and the intervention of reperfusion to the brain, resulting in severe cerebral injury. Autophagy has been reported to be involved in the occurrence and progression of CIS. Betulinic acid (BA) is a pentacyclic triterpene acid mainly extracted from birch bark. Studies have shown the neuroprotective effects of BA. Here, the effect and mechanism of BA on ischemia-reperfusion induced cerebral injury was explored using a CIS model in vivo via 1 h middle cerebral artery occlusion (MCAO) and 24 h reperfusion in rats and in vitro via oxygen-glucose deprivation/reperfusion (OGD/R) of PC12 cells, respectively. We found that BA not only reduced cerebral injury by reducing oxidative stress but also activated the SIRT1/FoxO1 pathway to suppress autophagy and improve cerebral injury in MCAO rats. These results provide a basis for the potential clinical application of BA.

Acute ischemic stroke triggers a cellular senescence-associated secretory phenotype

Senescent cells are capable of expressing a myriad of inflammatory cytokines and this pro-inflammatory phenomenon is known as senescence-associated secretory phenotype (SASP). The contribution of this phenomenon in brain ischemia was scarce. A mouse model of transient focal cerebral ischemia by compressing the distal middle cerebral artery (tMCAo) for 60 min was used. SASP, pro-inflammatory cytokines and cell cycle mRNAs levels were quantified at 30-min and 72 h post-surgery. Immunohistochemistry in paraffin embedded human brain slides and mouse brain tissue was performed. Our results showed an increase of both p16 and p21 mRNA restricted to the infarct area in the tMCAo brain. Moreover, there was an induction of Il6, Tnfa, Cxc11, and its receptor Cxcr2 mRNA pro-inflammatory cytokines with a high positive correlation with p16/p21 mRNA levels. The p16 was mainly shown in cytoplasm of neurons and cytoplasm/membrane of microglial cells. The p21 was observed in membrane of neurons and also it showed a mixed cytoplasmic and membranous pattern in the microglial cells. In a human stroke patient, an increase of P16 in the perimeter of the MCA infarct area was observed. These suggest a role of SASP in tMCAo mouse model and in human brain tissue. SASP potentially has a physiological role in acute ischemic stroke and neurological function loss.

The Cytoskeletal Elements MAP2 and NF-L Show Substantial Alterations in Different Stroke Models While Elevated Serum Levels Highlight Especially MAP2 as a Sensitive Biomarker in Stroke Patients

In the setting of ischemic stroke, the neurofilament subunit NF-L and the microtubule-associated protein MAP2 have proven to be exceptionally ischemia-sensitive elements of the neuronal cytoskeleton. Since alterations of the cytoskeleton have been linked to the transition from reversible to irreversible tissue damage, the present study investigates underlying time- and region-specific alterations of NF-L and MAP2 in different animal models of focal cerebral ischemia. Although NF-L is increasingly established as a clinical stroke biomarker, MAP2 serum measurements after stroke are still lacking. Therefore, the present study further compares serum levels of MAP2 with NF-L in stroke patients. In the applied animal models, MAP2-related immunofluorescence intensities were decreased in ischemic areas, whereas the abundance of NF-L degradation products accounted for an increase of NF-L-related immunofluorescence intensity. Accordingly, Western blot analyses of ischemic areas revealed decreased protein levels of both MAP2 and NF-L. The cytoskeletal alterations are further reflected at an ultrastructural level as indicated by a significant reduction of detectable neurofilaments in cortical axons of ischemia-affected areas. Moreover, atomic force microscopy measurements confirmed altered mechanical properties as indicated by a decreased elastic strength in ischemia-affected tissue. In addition to the results from the animal models, stroke patients exhibited significantly elevated serum levels of MAP2, which increased with infarct size, whereas serum levels of NF-L did not differ significantly. Thus, MAP2 appears to be a more sensitive stroke biomarker than NF-L, especially for early neuronal damage. This perspective is strengthened by the results from the animal models, showing MAP2-related alterations at earlier time points compared to NF-L. The profound ischemia-induced alterations further qualify both cytoskeletal elements as promising targets for neuroprotective therapies.

Clinical translation of amide proton transfer (APT) MRI for ischemic stroke: a systematic review (2003-2020)

Amide proton transfer (APT) magnetic resonance imaging (MRI) is a pH-sensitive imaging technique that can potentially complement existing clinical imaging protocol for the assessment of ischemic stroke. This review aims to summarize the developments in the clinical research of APT imaging of ischemic stroke after 17 years of progress since its first preclinical study in 2003. Three electronic databases: PubMed, Scopus, and Cochrane Library were systematically searched for articles reporting clinical studies on APT imaging of ischemic stroke. Only articles in English published between 2003 to 2020 that involved patients presenting ischemic stroke-like symptoms that underwent APT MRI were included. Of 1,093 articles screened, 14 articles met the inclusion criteria with a total of 282 patients that had been scanned using APT imaging. Generally, the clinical studies agreed APT effect to be hypointense in ischemic tissue compared to healthy tissue, allowing for the detection of ischemic stroke. Other uses of APT imaging have also been investigated in the studies, including penumbra identification, predicting long term clinical outcome, and serving as a biomarker for supportive treatment monitoring. The published results demonstrated the potential of APT imaging in these applications, but further investigations and larger trials are needed for conclusive evidence. Future studies are recommended to report the result of asymmetry analysis at 3.5 ppm along with the findings of the study to reduce this contribution to the heterogeneity of experimental methods observed and to facilitate effective comparison of results between studies and centers. In addition, it is important to focus on the development of fast 3D imaging for full volumetric ischemic tissue assessment for clinical translation.

Danhong injection alleviates cerebral ischemia/reperfusion injury by improving intracellular energy metabolism coupling in the ischemic penumbra

Danhong injection (DHI) is a compound Chinese medicine widely used in China for treatment of ischemic cardio-cerebrovascular diseases. However, limited data are available regarding the protective effect of DHI on the ischemic penumbra in ischemic stroke. This study aimed to investigate the effect of intravenous DHI on neuronal injure in the ischemic penumbra after cerebral ischemia/reperfusion (CI/R), focusing especially on the involvement of intracellular energy metabolism coupling. Male Sprague-Dawley rats were subjected to right middle cerebral artery occlusion for 60 min followed by reperfusion with or without intravenous DHI (0.5, 1.0, or 2.0 mL/kg) once daily for 7 days. Post-treatment with DHI ameliorated neurological defects, diminished cerebral infarction, alleviated cerebral edema, improved microcirculatory perfusion after 7days of reperfusion, and inhibited apoptosis and enhanced neuronal survival in the ischemic penumbra. In addition, DHI significantly ameliorated oxidative stress, reduced DNA damage, and inhibited the activation of PARP1/AIF pathway, thereby restoring cytoplasmic glycolytic activity. Furthermore, this drug increased PDH activity by inhibiting the HIF1α/PDK1 signaling pathway, thus eliminating the inhibitory effect of CI/R on mitochondrial metabolism. The results of this study suggest that DHI can alleviate cerebral edema after CI/R and rescue the ischemic penumbra, and these protective effects are due to the regulation of intracellular energy metabolic coupling.