Circulating circular RNAs as novel biomarkers and functional prediction for the early diagnosis in post-stroke cognitive impairment: A single-center prospective study in China.

BACKGROUND: Early evaluation and intervention for post-stroke cognitive impairment are crucial for improving the prognosis of acute ischemic stroke. The search for specific diagnostic markers and feasible therapeutic targets is extremely urgent.The characteristics of circular RNAs make them promising candidates. AIMS: To screen circular RNAs as novel biomarkers and therapeutic targets for post-stroke cognitive impairment in large-artery atherosclerosis anterior circulation cerebral infarction patients. METHODS: In this prospective observational study, patients with first-ever large-artery atherosclerosis anterior circulation cerebral infarction were recruited. The Montreal Cognitive Assessment was used to assess the cognitive statuses of patients. Venous blood samples were collected on the seventh day after stroke onset. A circRNA microarray was used to identify differentially expressed circular RNAs in the discovery cohort (four patients with post-stroke cognitive impairment and four patients with post-stroke cognitive normal characteristics), and validation was performed in the validation cohorts (45 patients with post-stroke cognitive impairment and 30 patients with post-stroke cognitive normal characteristics) using quantitative real-time polymerase chain reaction. Receiver operating characteristic curves of the validated circular RNAs and the NIHSS score were constructed, and the area under the curve, sensitivity, and specificity were calculated. Correlation analysis was performed to explore the relationship between the copy number of circular RNAs and the cognitive status. The functions of the differentially expressed circular RNAs were predicted using bioinformatics analysis. RESULTS: CircRNA microarray analysis revealed 189 human circular RNAs (152 upregulated and 37 downregulated) that were differentially expressed in the plasma samples of patients with post-stroke cognitive impairment and PSCN characteristics. The expression of hsa_circ_0089763, hsa_circ_0064644, and hsa_circ_0089762 was validated using quantitative real-time polymerase chain reaction. The area under the curve, sensitivity, and specificity of hsa_circ_0089762 in post-stroke cognitive impairment diagnosis were 0.993, 97.8%, and 96.7%, respectively, and the correlation coefficient between hsa_circ_0089762 expression and the Montreal Cognitive Assessment score was -0.693 (p < 0.001), which made it an ideal biomarker. Bioinformatic analysis revealed that the targeted mRNAs of the three circular RNAs were enriched in pathologically related signaling pathways of post-stroke cognitive impairment, such as the MAPK and PI3K-Akt signaling pathways. Based on the circRNA-miRNA-mRNA network, the three circular RNAs play a crucial role in numerous pathological processes of acute ischemic stroke and post-stroke cognitive impairment by sponging miRNAs such as MiR-335, MiR-424, and MiR-670. By building the protein-protein interaction network, we identified cluster 1 according to the MCODE score; cluster 1 was composed of ERBB4, FGFR1, CACNA2D1, NRG1, PPP2R5E, CACNB4, CACNB2, CCND1, NTRK2, and PTCH. CONCLUSION: Hsa_circ_0089762, hsa_circ_0064644, and hsa_circ_0089763 are potential novel biomarkers and focal points for exploring intervention targets in post-stroke cognitive impairment of large-artery atherosclerosis anterior circulation cerebral infarction patients. REGISTRATION NUMBER: ChiCTR2000035074.

RIPK3 activation promotes DAXX-dependent neuronal necroptosis after intracerebral hemorrhage in mice.

BACKGROUND: Necroptosis induced by receptor-interacting protein kinase 3 (RIPK3) is engaged in intracerebral hemorrhage (ICH) pathology. In this study, we explored the impact of RIPK3 activation on neuronal necroptosis and the mechanism of the death domain-associated protein (DAXX)-mediated nuclear necroptosis pathway after ICH. METHODS: Potential molecules linked to the progression of ICH were discovered using RNA sequencing. The level of DAXX was assessed by quantitative real-time PCR, ELISA, and western blotting. DAXX localization was determined by immunofluorescence and immunoprecipitation assays. The RIPK3 inhibitor GSK872 and DAXX knockdown with shRNA-DAXX were used to examine the nuclear necroptosis pathway associated with ICH. Neurobehavioral deficit assessments were performed. RESULTS: DAXX was increased in patients and mice after ICH. In an ICH mouse model, shRNA-DAXX reduced brain water content and alleviated neurologic impairments. GSK872 administration reduced the expression of DAXX. shRNA-DAXX inhibited the expression of p-MLKL. Immunofluorescence and immunoprecipitation assays showed that RIPK3 and AIF translocated into the nucleus and then bound with nuclear DAXX. CONCLUSIONS: RIPK3 revitalization promoted neuronal necroptosis in ICH mice, partially through the DAXX signaling pathway. RIPK3 and AIF interacted with nuclear DAXX to aggravate ICH injury.

Meningitis due to Streptococcus parasanguinis after percutaneous radiofrequency treatment for trigeminal neuralgia: A case report.

Bacterial meningitis after percutaneous radiofrequency trigeminal ganglion is a rare but severe complication. In this article, we report a case of meningitis due to Streptococcus parasanguinis and review the related literature. A 62-year-old male patient with uremia and severe trigeminal neuralgia presented to another hospital and was offered to undergo radiofrequency treatment for a trigeminal ganglion lesion (2022.08.05). The next day (2022.08.06), he presented with a headache and right shoulder and back pain. The pain continued to worsen, so he came to our hospital (The First Affiliated Hospital of Wannan Medical College) and received a diagnosis of bacterial meningitis, which was confirmed by a lumbar puncture. The patient was treated with appropriate antibiotics, and subsequently recovered before being discharged. Although this complication is relatively rare, its progression is rapid. Meningitis must be suspected when a patient presents with headache, fever, and other symptoms associated with meningitis within days after undergoing radiofrequency treatment for a trigeminal ganglion lesion, especially if the patient has an underlying disease that causes a decline in immunity. We discuss this case in terms of clinical presentation, time of onset, treatment, prognosis, past history, and sex. Although early detection of this complication is beneficial, it is better to effectively prevent its occurrence.

CRP as a potential predictor of outcome in acute ischemic stroke.

Ischemic stroke is one of the major causes of death and long-term disability worldwide. C-reactive protein (CRP) as a potential biomarker for functional outcome after acute ischemic stroke remains controversial. The aim of the present study was to examine the association between the level of CRP and functional outcome of stroke. A total of 218 consecutive patients with acute ischemic stroke within 24 h after onset were recruited for the study. Poor functional outcome was defined as a modified Rankin scale score of >2 at 3 months after stroke. The retrospective analysis was performed to investigate whether CRP within 24 h after stroke is associated with poor functional outcome at 3 months. Multivariate logistic regression analysis indicated that the CRP level (odds ratio=1.146, 95%CI: 1.012-1.297, P=0.031) was an independent risk factor for poor outcome. The receiver operating characteristics curve analysis revealed that the optimal cut-off value of CRP to distinguish favorable from poor outcome was 6.34 (area under the curve=0.829, 95%CI: 0.772-0.887, P<0.001), with 68.2% sensitivity and 85.7% specificity. Spearman correlation analysis indicated that the CRP level was positively related to the baseline National Institutes of Health Stroke Scale (NIHSS) score (r=0.551, P<0.001), fasting glucose (r=0.301, P<0.001) and age (r=0.252, P<0.001). In conclusion, a high level of CRP within 24 h after onset was associated with a poor functional outcome after the acute ischemic event. The elevation of CRP may be correlated with the baseline NIHSS score, fasting glucose and age.

miR-590-3p protects against ischaemia/reperfusion injury in an oxygen-glucose deprivation and reoxygenation cellular model by regulating HMGB1/TLR4/MyD88/NF-κB signalling.

miR-590-3p has been reported to be reduced in myocardial ischaemia-reperfusion (I/R) injury, but its specific role in cerebral I/R injury is still uncertain. Thus, we explored the function and mechanism of miR-590-3p in cerebral I/R injury using a cellular model. miR-590-3p, high mobility group Box 1 (HMGB1), and signalling-related factor levels were assessed using qPCR or a western blot analysis. Cell apoptosis was measured by flow cytometry. Inflammatory factors were detected by ELISA. The target of miR-590-3p was confirmed by dual-luciferase reporter assay and western blot analysis. We found that miR-590-3p was decreased and HMGB1 was increased in the OGD/R model. Upregulation of miR-590-3p reduced cell apoptosis and inflammation in the OGD/R model, and the TLR4/MyD88/NF-κB signalling pathway was suppressed. However, inhibition of miR-590-3p showed the opposite effects. Moreover, HMGB1 was verified as a target gene of miR-590-3p. HMGB1 reversed the decrease in apoptosis and inflammation caused by overexpression of miR590-3p, and the TLR4/MyD88/NF-κB signalling pathway was activated. Our results suggest that miR-590-3p regulates the TLR4/MyD88/NF-κB pathway by interacting with HMGB1 to protect against OGD/R-induced I/R injury. Thus, miR-590-3p may serve as a potential therapeutic target in cerebral I/R repair.

Neutrophil to High-Density Lipoprotein Ratio is Associated with Hemorrhagic Transformation in Patients with Acute Ischemic Stroke.

Background: Hemorrhagic transformation (HT) is one of the most common and severe complications in patients with acute ischemic stroke (AIS). It indicates a poor prognosis in AIS patients. However, the association of neutrophil to high-density lipoprotein ratio (NHR) with HT remains unclear. Purpose: This study examined whether the NHR has a predictive effect on HT in AIS patients and explored the predictive cutoff value of the NHR. Methods: This is a retrospective study and consecutively included AIS patients admitted to the Department of Neurology of the First Affiliated Hospital of Wannan Medical College between December 2019 and January 2022. All subjects had blood samples collected within 24 h of admission, and neutrophil counts and high-density lipoprotein counts were detected. HT was diagnosed with hemorrhage on subsequent magnetic resonance imaging (MRI) or computed tomography (CT) of the brain. Univariate logistic regression analysis was performed to identify confounding factors, and multivariate logistic regression analysis determined the correlation between NHR and HT. Receiver operating characteristic (ROC) curves were used to evaluate the clinical predictive value of NHR. Results: A total of 725 patients were finally included in this study, of which 87 (12%) developed HT. The median NHR value in the HT group was 4.31, which was significantly higher than that in the non-HT group, and the difference was statistically significant [4.31 (3.54-6.24) vs 3.63 (2.68-4.64), p < 0.001]. The binary logistic regression analysis showed that NHR was independently associated with HT in AIS patients (OR: 1.180, 95% CI: 1.036-1.344, p = 0.013). The area under ROC curve (AUC) of NHR for predicting HT in AIS patients was 0.633 (95% CI: 0.567-0.699, p < 0.001), and its optimal cutoff were 3.52. Conclusion: The NHR was a reliable and simple independent predictor of HT in AIS patients.

Efficacy and safety of calcitonin gene-related peptide antagonists in migraine treatment: A meta-analysis.

INTRODUCTION: We systematically reviewed the efficacy and safety of Calcitonin Gene-Related Peptide (CGRP) antagonists for migraine treatment. METHODS: Various databases including PubMed, Embase, The Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), WanFang Data were electronically searched for randomized controlled trials (RCTs) on CGRP antagonists for migraine treatment since inception to March 2021. The trials were screened for inclusion, after which the methodological quality of the included trials was assessed. Then meta-analysis was performed using the Revman 5.3 software. RESULTS: A total of 26 RCTs involving 21,736 patients were included. The CGRP antagonists group included 13,635 patients while the control group included 8101 patients. Meta-analysis showed that compared to the control group, CGRP antagonists were associated with various significant effects, including the following outcome indicators: (1) number of patients with ≥50% reduction from baseline in mean monthly migraine days (RR = 1.50, 95% CI [1.39,1.62], p < .00001); (2) number of patients with pain free at 2 h postdose (RR = 1.98, 95% CI [1.77, 2.20], p < .00001), and (3) number of patients with 2-24 h sustained pain free postdose (RR = 2.18, 95% CI [1.93, 2.46], p < .00001). However, the number of patients with any adverse events was significantly high in the antagonists group, relative to the control group (RR = 1.08, 95% CI [1.04, 1.12], p < .0001). CONCLUSIONS: CGRP antagonists are significantly effective for migraine treatment; however, they are associated with various adverse events. Due to limitations with regards to quantity and quality of the included studies, the above conclusions should be verified by more high quality studies.

Pre-Existing Non-Disabling Encephalomalacia Confers Risk to Stroke Outcomes After Endovascular Treatment.

BACKGROUND: Patients with previous stroke episodes tend to have poor outcomes after an endovascular treatment (EVT). Encephalomalacia (EM) is an objective indicator of previous strokes but has not been systematically investigated. The fundamental aim of this exploration is to investigate the effects of a pre-existing non-disabling EM on clinical outcomes after EVT. METHODS: Consecutive patients undergoing an EVT due to the anterior circulation large vessel occlusion (LVO) strokes were enrolled in the study. The pre-existing EM was defined as the focal hypodense lesions (≥ 3 mm in maximum diameter) on a non-contrast cranial CT using axial images before EVT. The primary outcome was the 90-day functional assessment using the modified Rankin Scale (mRS) score. The safety outcome was the incidence of symptomatic intracranial hemorrhage (sICH) defined as any hemorrhage within 24 h after an EVT, which is responsible for an increase of ≥ 4 points in the score of National Institutes of Health Stroke Scale (NIHSS). RESULTS: Of the 433 patients analyzed in this investigation, a pre-existing non-disabling EM was observed in 106 (24.5%) patients. After adjusting for potential confounding factors, patients with contralateral EM (OR = 2.68, 95% CI = 1.13-6.31; P = 0.025) and with an EM+ > 20 mm in maximum diameter (OR = 2.21, 95% CI = 1.01-4.85; P =0.048) were substantially associated with unfavorable outcomes (mRS > 2). For the sICH, we did not observe any association with the pre-existing EM (P > 0.05). CONCLUSIONS: A pre-existing non-disabling EM is common and safe in patients undergoing EVT. However, a contralateral EM and the large size of EM may predict an unfavorable outcome at 90 days, which should receive more attention before EVT.

RIPK3-Dependent Necroptosis Activates MCP-1-Mediated Inflammation in Mice after Intracerebral Hemorrhage.

BACKGROUND: Recent studies have reported that receptor-interacting protein kinase 3 (RIPK3)-dependent necroptosis is related to the pathological process of intracerebral hemorrhage (ICH). Some studies support the view that inhibiting necroptosis is a key mechanism preventing inflammation. Inflammation is a crucial factor contributing to neurological injuries and unfavorable outcomes after ICH. The aim of this study was to clarify the association between necroptosis and monocyte chemoattractant protein-1 (MCP-1)-mediated inflammation and identify a new target for the treatment of ICH. METHODS: An ICH model was established in C57BL/6 mice by injecting collagenase IV into the right basal ganglia. The RIPK3 inhibitor GSK872 was administered through intraventricular injection. Then, we assessed brain edema and neurobehavioral function. Western blotting was employed to detect changes in RIPK3, phospho-mixed lineage kinase domain-like protein (p-MLKL), MCP-1, phospho-c-Jun N-terminal kinase (p-JNK) and interleukin 6 (IL-6) levels in the brain tissue. The localization of RIPK3 and MCP-1 was observed using immunofluorescence staining. Co-immunoprecipitation was performed to determine the interaction between RIPK3 and MCP-1. RESULTS: Compared with the sham group, the levels of RIPK3, p-MLKL, MCP-1, p-JNK and IL-6 were increased post-ICH. GSK872 pretreatment significantly reduced RIPK3, p-MLKL, MCP-1, p-JNK and IL-6 expression, accompanied by mitigated cerebral edema and neurobehavioral defects. RIPK3 and MCP-1 colocalized in the perinuclear region after ICH. We detected the formation of the RIPK3-MCP-1 complex in ICH brain tissue. CONCLUSIONS: There exerted an association between RIPK3 and MCP-1. The inhibition of RIPK3 alleviated MCP-1-mediated inflammation following ICH.

Time Course and Clinical Relevance of Neurological Deterioration After Endovascular Recanalization Therapy for Anterior Circulation Large Vessel Occlusion Stroke.

Neurological deterioration (ND) is a devastating complication for patients with ischemic stroke after endovascular recanalization therapy (EVT). We aimed to investigate the time course and clinical relevance of ND after EVT. Consecutive patients with acute ischemic stroke who underwent EVT for large arterial occlusions of the anterior cerebral circulation were enrolled. The National Institutes of Health Stroke Scale (NIHSS) scores were assessed before EVT, at the end of EVT, at 24 h (d1), on day 3 (d3), on day 15 (d15), at discharge and anytime when ND was indicated. ND was defined as an increase of ≥ 4 points in the NIHSS score and was divided into acute ND (AD, within 24 h), subacute ND (SD, d1-d3), and delayed ND (DD, d3-d15 or discharge). Using multivariable logistic regression analysis, we explored predictors and outcomes of ND at different time periods. As a result, of 343 patients, 129 (37.6%) experienced ND, including 90 (26.2%) with AD, 27 (7.9%) with SD and 12 (3.5%) with DD. Multivariable logistic regression analysis revealed that history of hypertension, cardioembolic stroke, lower Alberta Stroke Program Early Computed Tomography Score (ASPECTS), and poor collaterals were significantly associated with an increased risk of AD; history of hypertension, lower ASPECTS, poor collaterals, and unsuccessful recanalization, with SD; and high admission NIHSS score, with DD. In addition, patients who experienced AD (OR = 10.22, P < 0.001), SD (OR = 15.89, P = 0.004), or DD (OR = 8.31, P = 0.015) were more likely to have poor outcomes. ND was a strong predictor of poor stroke outcomes. Management of related risk factors at different ND time periods might improve the prognosis of EVT.

RIP3 facilitates necroptosis through CaMKII and AIF after intracerebral hemorrhage in mice.

BACKGROUND: Necroptosis-induced neuronal damage after intracerebral hemorrhage (ICH) has been documented recently. Previous studies have reported that RIP3 and its complex are recognized as central mediators of necroptosis. In this study, the role of RIP3 in the activation of CaMKII and AIF was investigated. METHODS: We induced ICH in C57BL/6 mice by injecting collagenase IV into the basal ganglia. ICH mice were pretreated with the mPTP inhibitor CsA and the CAMKII inhibitor Kn-93, RIP3 siRNA or RIP3 rAAV. Brain edema and neurobehavior were evaluated. The expression of RIP3, p-MLKL, AIF, and CaMKII proteins was evaluated by western blotting, immunofluorescence (IF) and immunoprecipitation (IP). RESULTS: Significant increases in RIP3, p-MLKL, CaMKII and AIF expression were observed in ICH mice, and RIP3-AIF colocalized in the nucleus. Overexpression of RIP3 by rAAV upregulated AIF expression in both the cytoplasm and nucleus, while CaMKII expression was increased in the cytoplasm. The interaction of RIP3-AIF and RIP3-CaMKII was detected after ICH injury. These complexes were inhibited by CsA with Kn-93 or RIP3 siRNA pretreatment, which reduced brain edema and neurological deficits. CONCLUSIONS: Our findings revealed that ICH induced necroptotic neuronal death through the RIP3-CaMKII complex and the RIP3-AIF signaling pathway. Moreover, blockade of mPTP opening could suppress the pathogenesis of necroptosis.

Euxanthone improves cognitive impairment by attenuating mitochondrial fragmentation and suppressing oxidative stress.

Mitophagy and apoptosis significantly contribute to the dynamics of mitochondria and their associated disorders. Euxanthone (EUX) is a xanthone derivative that exhibits several therapeutic effects at a preclinical level. However, its impact in a cerebral ischemia and reperfusion model has not been investigated. The investigation aimed to determine the protective effect of EUX in cerebral ischemia and cognitive impairment and explore its underlying mechanism. A bilateral common carotid artery occlusion (BCCAO) model was employed in the present work. Forty male ICR mice were divided into four groups - Sham, BCCAO, EUX30 (BCCAO + EUX 30 mg/kg) and EUX60 (BCCAO + EUX 60 mg/kg). The mice were then subjected to a Morris water maze study for investigation of learning and memorizing capabilities. The hippocampal specimens of mice were quantified for the presence of oxidative markers. Homogenized hippocampal fractions were determined for the levels of Beclin-1, LC3, p53, Bax, caspase-3, Bnip3, DRP1 and Nrf2. The present investigation revealed that BCCAO caused oxidative stress in mitochondria and led to mitochondrial breakdown. EUX administration markedly attenuated BCCAO triggered mitochondrial stress and related breakdown. EUX treatment normalized Bnip3, Beclin1, Pink1, Parkin, p53, Bax, caspase-3, and LC3 II/I. Altogether, EUX treatment modulated mitophagy and apoptosis induced by mitochondrial stress mediated by mitochondrial fragmentation, due to cerebral ischemia and reperfusion injury.

CD200-CD200R1 signaling pathway regulates neuroinflammation after stroke.

OBJECTIVE: To study how the CD200-CD200R1 signaling pathway modulates poststroke inflammation and advances our knowledge of immune responses to ischemia insults in stroke. METHODS: Focal middle cerebral artery occlusion (MCAO) was induced in mice for 90 min, and mice were sacrificed at 1, 3, and 7 days of reperfusion. CD200, CD200R1, iNOS, and Arg-1 expression in ischemic brains was assessed by Western blotting (WB), and immunohistochemical (IHC) staining was performed to examine the expression of CD200 on neurons and CD200R1 on infiltrating lymphocytes. The severity of neurobehavioral deficits was evaluated by neurological deficit scores (NDS) and infarction volume estimated by TTC staining. To study the relationship between CD200/CD200R1 expression and the diversity of the neuroinflammatory response in stroke, CD200Fc (CD200R1 agonist) was subcutaneously injected at onset, at 1 day and 2 days after MCAO operation, and the brains were collected for detection at 3 days after MCAO/R (reperfusion). RESULTS: CD200 expression on neurons increased at 1 day and then decreased at 3 days after MCAO/R, and the expression of CD200R1 on lymphocytes showed an opposite temporal pattern as tested by IHC. The WB results showed that CD200/CD200R1 variance exhibited a similar pattern of IHC results, and the level of iNOS peaked at 1 day and then decreased gradually, but Arg-1 increased with time after MCAO/R in ischemic brains. After CD200Fc injection, CD200R1 expression significantly increased, and CD200Fc promoted Arg-1 but inhibited iNOS expression. The infarct volume and NDS of the group treated with CD200Fc were significantly smaller than those of the IgG2a-treated group. CONCLUSIONS: The CD200-CD200R1 signaling pathway regulates neuroinflammation after stroke. Stimulation of CD200R1 by CD200Fc promotes the anti-inflammatory response and alleviates ischemic injury.

Association of tau accumulation and atrophy in mild cognitive impairment: a longitudinal study.

OBJECTIVE: To examine the patterns of longitudinal tau accumulation and cortical atrophy and their association in subjects with mild cognitive impairment (MCI). METHODS: We collected 23 participants (60-89 years old, 11 males/12 females) with MCI from the Alzheimer's Disease Neuroimaging Initiative database. All participants underwent 18F flortaucipir (FTP) positron emission tomography (PET) and structural magnetic resonance imaging (MRI) scans at the baseline and follow-up visits (12-36 months). General linear models with covariates (baseline age, sex) were used to detect brain areas of significant tau accumulation and atrophy over time. Mediation analysis was employed to explore the potential reason for sequential biomarker changes in MCI progression, adjusting for baseline age, sex, and education level. RESULTS: Voxel-wise tau accumulation in MCI subjects was predominantly located in the inferior temporal cortex, middle temporal cortex, parietal cortex, posterior cingulate, precuneus, and temporoparietal regions (P < 0.001), and MRI atrophy included the inferior-middle temporal lobe, parietal lobe, and precuneus (P < 0.001). Longitudinal FTP accumulation was moderately associated with annualized MRI cortical atrophy (r = 0.409, 95% CI: 0.405-0.414, P < 0.01). Regional analyses indicated significant bivariate associations between annualized MRI cortical atrophy and FTP accumulation (baseline FTP cortical uptake and longitudinal FTP change). The results of the mediation analysis showed that the relationship between baseline FTP uptake and longitudinal cortical atrophy was partly mediated by the longitudinal FTP cortical change (indirect effect: 0.0107, P = 0.04). CONCLUSIONS: Our findings provide a preliminary description of the patterns of longitudinal FTP accumulation and annualized cortical atrophy in MCI progression, and MCI subjects with high tau binding levels show an increase risk of longitudinal tau accumulation, atrophy, and cognitive decline. Trial registration NCT00106899. Registered 1 April 2005, https://clinicaltrials.gov/ct2/show/study/NCT00106899.

Regulation of JNK signaling pathway and RIPK3/AIF in necroptosis-mediated global cerebral ischemia/reperfusion injury in rats.

Receptor-interacting protein kinase 3 (RIPK3) regulates a newly discovered cell death form called necroptosis. RIPK3 nuclear translocation and inflammatory factor release are involved in necroptosis after rat global cerebral ischemia/reperfusion (I/R) injury. The purpose of this study was to investigate the effects of interactions between the RIPK3 and apoptosis-inducing factor (AIF) necroptosis pathway and the JNK-mediated inflammatory pathway. Rats were subjected to 4-vessel occlusion and reperfusion injury. RIPK3 inhibitor GSK872, RIPk3 recombinant adeno-associated virus (rAAV) and JNK-specific inhibitor SP600125 were intracerebroventricular injected before I/R. Hippocampus CA1 tissue were obtained and RIPK3, AIF, p-JNK, IL-6 were determined by western blot analysis. The RIPK3 and AIF interaction were also analyzed by immunofluorescence and immunoprecipitation. The expression of endogenous RIPK3, AIF, p-JNK and IL-6 was increased in hippocampus CA1 in I/R group. In addition, RIPK3 was increased in both the total protein and nuclear protein. GSK872 administration reduced the number of neuron deaths and the expression of RIPK3, p-JNK and IL-6. GSK872 also improve the rat neurobehavior. While use RIPk3 rAAV treatment to overexpress RIPK3, it appeared lower neuron survival. Immunofluorescence staining demonstrated that RIPK3 and AIF formed as a novel complex in the cytoplasm first, and then nuclear translocation. GSK872 pretreatment decreased the number of RIPK3-positive cells and related to the generation of RIPK3-AIF complex in nuclear. Moreover, the production of inflammatory factors levels was found to be significantly elevated after I/R. We further use SP600125 to attenuate inflammation cascade. It not only inhibits the expression of inflammatory factors p-JNK and IL-6, but also inhibits RIPK3 and AIF in the cytoplasm. Collectively, the results of our study indicate that RIPK3-mediated necroptosis interacts with the JNK-mediated inflammatory signaling pathway to participate in global cerebral I/R injury. JNK-regulated inflammatory mediators may promote the necroptosis initiation.

MST4 Kinase Inhibitor Hesperadin Attenuates Autophagy and Behavioral Disorder via the MST4/AKT Pathway in Intracerebral Hemorrhage Mice.

BACKGROUND: The aim of this study was to explore the role of hesperadin in intracerebral hemorrhage (ICH) mice, with the involvement of the mammalian ste20-like kinase 4 (MST4)/AKT signaling pathway. METHODS: All mice were divided into four groups: sham group, sham+hesperidin group, ICH group, and ICH+hesperadin group. The effects of hesperadin were assessed on the basis of brain edema and neurobehavioral function. Furthermore, we observed MST4, AKT, phosphorylation of AKT (pAKT), and microtubule-associated protein light chain 3 (LC3) by western blotting. Protein localization of MST4 and LC3 was determined by immunofluorescence. RESULTS: The expression of MST4 was upregulated at 12 h and 24 h after ICH. Brain edema was significantly decreased and neurological function was improved in the hesperadin treatment group compared to the ICH group (P < 0.05). Hesperadin decreases the expressions of MST and increases pAKT after ICH. Autophagy significantly increased in the ICH group, while hesperadin reduced this increase. CONCLUSION: Hesperadin provides neuroprotection against ICH by inhibiting the MST4/AKT signaling pathway.

MST4 modulates the neuro-inflammatory response by regulating IκBα signaling pathway and affects the early outcome of experimental ischemic stroke in mice.

MST4 limits peripheral, macrophage-dependent inflammatory responses through direct phosphorylation of the adaptor TRAF6; though its role in neuro-inflammation is unclear. We investigated microglia expression of MST4 and whether is attenuates neuro-inflammatory response after cerebral ischemia-reperfusion injury in mice. Adult male C57BL6 mice were subjected to a 90-minute middle cerebral artery occlusion (MCAO) followed by a 72 -h reperfusing. The results showed that MST4 was involved in the pathological process after cerebral ischemia-reperfusion and was expressed in microglia. MST4-Adeno Associated Virus attenuated brain damage after MCAO and reduced expression of p-IκBα, p-ERK and p-JNK, while MST4 shRNA aggravated brain damage after MCAO and increased expression of p-IκBα, p-ERK and p-JNK. Our results show that MST4 inhibits neuro-inflammatory response in cerebral ischemia-reperfusion injury, improves neurological deficits, and reduces cerebral infarction volume in mice. Strategies to enhance MST4 in response to ischemic stroke may be a potential therapeutic strategy.

Neutrophil-to-lymphocyte ratio predicts hemorrhagic transformation in ischemic stroke: A meta-analysis.

INTRODUCTION: The neutrophil-to-lymphocyte ratio (NLR) has been shown to be a marker associated with inflammation and is independently associated with the adverse clinical outcomes of symptomatic intracranial hemorrhage, cancer, and cardiovascular disease. Hemorrhagic transformation (HT) is a serious complication of ischemic cerebral infarction and can be intensified by therapeutic interventions for acute ischemic stroke (AIS). The purpose of our research was to explore the predictive effect of NLR for HT in patients with AIS and to determine the best predictive value. METHODS: PubMed, Web of Science, EMBASE, MEDLINE, Cochrane, and Google Scholar were searched. The primary endpoint was HT, and subgroup analysis was performed. Review Manager software version 5.3 was used to statistically analyze the outcomes. RESULTS: A total of seven studies including 3,726 patients met the inclusion criteria. The pooled odds ratio (OR) value of the high NLR that predicted HT in AIS patients was 1.53 (95% CI, 1.21-1.92; p = .0003). In addition, 1.10 (95% CI, 1.05-1.15; p < .0001) was the pooled OR of the high NLR associated with increased 3-month mortality in patients with AIS. In the subgroup analysis with an NLR cutoff value of 7.5-11, the correlation between NLR above the cutoff value and the rate of HT in patients with AIS was statistically significant (OR, 7.93; 95% CI, 2.25-27.95; p = .001). CONCLUSION: A high NLR can predict HT and 3-month mortality in patients with AIS. Regardless of the country of origin and the sampling time, an NLR with a cutoff value of 7.5-11 was independently associated with HT in AIS patients.

Severe Stroke Patients With Left-Sided Occlusion of the Proximal Anterior Circulation Benefit More From Thrombectomy.

Background and Purpose: Endovascular thrombectomy improves the functional independence of patients with proximal anterior circulation occlusion. However, a subset of patients fail to benefit from thrombectomy procedures, the reasons for which remain poorly defined. In this study, we investigated whether the effectiveness of thrombectomy was affected by left- or right-sided occlusion among patients with similar stroke severities. Methods: Patients with proximal anterior circulation occlusion (internal carotid or M1 of middle cerebral artery) treated with the Solitaire stent retriever within 8 h of the onset of acute ischemic stroke were enrolled from the Yijishan Hospital of Wannan Medical College. Stroke severity was measured using the National Institutes of Health Stroke Scale (NIHSS) on admission. The functional outcomes were assessed using the modified Rankin scale (mRS) at 90 days. Results: We enrolled 174 patients including 90 left-sided occlusion and 84 right-sided occlusion. The NIHSS scores on admission were higher in the left-sided (median, 19; interquartile range, 16 to 20) compared to the right-sided occlusion group (median, 15, interquartile range, 13 to 18) (P < 0.001). Following adjustment for potential risk factors, patients with left-sided occlusion had higher rates of functional independence (mRS ≤ 2) and lower rates of mortality (mRS = 6) compared to the right-sided occlusion patients (39.5 vs. 19.6% and 28.9 vs. 47.8%, respectively) in the severe stroke group (NIHSS ≥ 15). Conclusions: In severe stroke patients with proximal anterior circulation occlusion, stent retriever thrombectomy within 8 h of the onset of symptoms provides more benefits to left-sided occlusion.

The Pathogenesis of Necroptosis-Dependent Signaling Pathway in Cerebral Ischemic Disease.

Necroptosis is the best-described form of regulated necrosis at present, which is widely recognized as a component of caspase-independent cell death mediated by the concerted action of receptor-interacting protein kinase 1 (RIPK1) and receptor-interacting protein kinase 3 (RIPK3). Mixed-lineage kinase domain-like (MLKL) was phosphorylated by RIPK3 at the threonine 357 and serine 358 residues and then formed tetramers and translocated onto the plasma membrane, which destabilizes plasma membrane integrity leading to cell swelling and membrane rupture. Necroptosis is downstream of the tumor necrosis factor (TNF) receptor family, and also interaction with NOD-like receptor pyrin 3 (NLRP3) induced inflammasome activation. Multiple inhibitors of RIPK1 and MLKL have been developed to block the cascade of signal pathways for procedural necrosis and represent potential leads for drug development. In this review, we highlight recent progress in the study of roles for necroptosis in cerebral ischemic disease and discuss how these modifications delicately control necroptosis.