Increased functional connectivity between default mode network and visual network potentially correlates with duration of residual dizziness in patients with benign paroxysmal positional vertigo.

Objective: To assess changes in static and dynamic functional network connectivity (sFNC and dFNC) and explore their correlations with clinical features in benign paroxysmal positional vertigo (BPPV) patients with residual dizziness (RD) after successful canalith repositioning maneuvers (CRM) using resting-state fMRI. Methods: We studied resting-state fMRI data from 39 BPPV patients with RD compared to 38 BPPV patients without RD after successful CRM. Independent component analysis and methods of sliding window and k-means clustering were adopted to investigate the changes in dFNC and sFNC between the two groups. Additionally, temporal features and meta-states were compared between the two groups. Furthermore, the associations between fMRI results and clinical characteristics were analyzed using Pearson's partial correlation analysis. Results: Compared with BPPV patients without RD, patients with RD had longer duration of BPPV and higher scores of dizziness handicap inventory (DHI) before successful CRM. BPPV patients with RD displayed no obvious abnormal sFNC compared to patients without RD. In the dFNC analysis, patients with RD showed increased FNC between default mode network (DMN) and visual network (VN) in state 4, the FNC between DMN and VN was positively correlated with the duration of RD. Furthermore, we found increased mean dwell time (MDT) and fractional windows (FW) in state 1 but decreased MDT and FW in state 3 in BPPV patients with RD. The FW of state 1 was positively correlated with DHI score before CRM, the MDT and FW of state 3 were negatively correlated with the duration of BPPV before CRM in patients with RD. Additionally, compared with patients without RD, patients with RD showed decreased number of states and state span. Conclusion: The occurrence of RD might be associated with increased FNC between DMN and VN, and the increased FNC between DMN and VN might potentially correlate with the duration of RD symptoms. In addition, we found BPPV patients with RD showed altered global meta-states and temporal features. These findings are helpful for us to better understand the underlying neural mechanisms of RD and potentially contribute to intervention development for BPPV patients with RD.

MiR129-5p-loaded exosomes suppress seizure-associated neurodegeneration in status epilepticus model mice by inhibiting HMGB1/TLR4-mediated neuroinflammation.

BACKGROUND: Neuroinflammation contributes to both epileptogenesis and the associated neurodegeneration, so regulation of inflammatory signaling is a potential strategy for suppressing epilepsy development and pathological progression. Exosomes are enriched in microRNAs (miRNAs), considered as vital communication tools between cells, which have been proven as potential therapeutic method for neurological disease. Here, we investigated the role of miR129-5p-loaded mesenchymal stem cell (MSC)-derived exosomes in status epilepticus (SE) mice model. METHODS: Mice were divided into four groups: untreated control (CON group), kainic acid (KA)-induced SE groups (KA group), control exosome injection (KA + Exo-con group), miR129-5p-loaded exosome injection (KA + Exo-miR129-5p group). Hippocampal expression levels of miR129-5p, HMGB1, and TLR4 were compared among groups. Nissl and Fluoro-jade B staining were conducted to evaluate neuronal damage. In addition, immunofluorescence staining for IBA-1 and GFAP was performed to assess glial cell activation, and inflammatory factor content was determined by ELISA. Hippocampal neurogenesis was assessed by BrdU staining. RESULTS: The expression of HMGB1 was increased after KA-induced SE and peaking at 48 h, while hippocampal miR129-5p expression decreased in SE mice. Exo-miR129-5p injection reversed KA-induced upregulation of hippocampal HMGB1 and TLR4, alleviated neuronal damage in the hippocampal CA3, reduced IBA-1 + and GFAP + staining intensity, suppressed SE-associated increases in inflammatory factors, and decreased BrdU + cell number in dentate gyrus. CONCLUSIONS: Exosomes loaded with miR129-5p can protect neurons against SE-mediated degeneration by inhibiting the pro-inflammatory HMGB1/TLR4 signaling axis.

Altered parietal operculum cortex 2 functional connectivity in benign paroxysmal positional vertigo patients with residual dizziness: A resting-state fMRI study.

AIMS: To investigate changes in functional connectivity (FC) focusing on parietal operculum cortex 2 (OP2) in benign paroxysmal positional vertigo (BPPV) patients with residual dizziness (RD) after successful canalith repositioning procedure (CRP). METHODS: High-resolution three-dimensional T1 and resting-state functional magnetic resonance imaging (fMRI) were performed on 55 healthy controls (HCs), 55 BPPV patients with RD, and 55 patients without RD after successful CRP. Seed-based (bilateral OP2) FC was calculated to investigate the changes in FC among the three groups. Additionally, we further explored the associations between abnormal FC and clinical symptoms. RESULTS: One-way analysis of covariance showed significant FC differences among the three groups. Post-hoc analysis showed that patients with RD exhibited decreased FC between left OP2 and regions of left angular gyrus (AG), thalamus, precuneus, middle frontal gyrus (MFG), and right cerebellum posterior lobe (CPL) in comparison with HCs. In addition, compared with patients without RD, patients with RD showed decreased FC between left OP2 and regions of left MFG, AG, middle temporal gyrus, and right CPL. Moreover, in patients with RD, the FC between left thalamus and OP2 was negatively correlated with duration of RD, and the FC between left AG and OP2 was negatively correlated with duration of BPPV. CONCLUSION: BPPV patients with RD showed reduced FC between brain regions involved in vestibular processing and spatial cognition; These results suggested that BPPV patients with RD might have diminished central processing of vestibular information and impaired spatial cognition.

A clinical prediction model based on interpretable machine learning algorithms for prolonged hospital stay in acute ischemic stroke patients: a real-world study.

Objective: Acute ischemic stroke (AIS) brings an increasingly heavier economic burden nowadays. Prolonged length of stay (LOS) is a vital factor in healthcare expenditures. The aim of this study was to predict prolonged LOS in AIS patients based on an interpretable machine learning algorithm. Methods: We enrolled AIS patients in our hospital from August 2017 to July 2019, and divided them into the "prolonged LOS" group and the "no prolonged LOS" group. Prolonged LOS was defined as hospitalization for more than 7 days. The least absolute shrinkage and selection operator (LASSO) regression was applied to reduce the dimensionality of the data. We compared the predictive capacity of extended LOS in eight different machine learning algorithms. SHapley Additive exPlanations (SHAP) values were used to interpret the outcome, and the most optimal model was assessed by discrimination, calibration, and clinical utility. Results: Prolonged LOS developed in 149 (22.0%) of the 677 eligible patients. In eight machine learning algorithms, prolonged LOS was best predicted by the Gaussian naive Bayes (GNB) model, which had a striking area under the curve (AUC) of 0.878 ± 0.007 in the training set and 0.857 ± 0.039 in the validation set. The variables sorted by the gap values showed that the strongest predictors were pneumonia, dysphagia, thrombectomy, and stroke severity. High net benefits were observed at 0%-76% threshold probabilities, while good agreement was found between the observed and predicted probabilities. Conclusions: The model using the GNB algorithm proved excellent for predicting prolonged LOS in AIS patients. This simple model of prolonged hospitalization could help adjust policies and better utilize resources.

Development and validation of a machine learning-based prognostic risk stratification model for acute ischemic stroke.

Acute ischemic stroke (AIS) is a most prevalent cause of serious long-term disability worldwide. Accurate prediction of stroke prognosis is highly valuable for effective intervention and treatment. As such, the present retrospective study aims to provide a reliable machine learning-based model for prognosis prediction in AIS patients. Data from AIS patients were collected retrospectively from the Second Affiliated Hospital of Xuzhou Medical University between August 2017 and July 2019. Independent prognostic factors were identified by univariate and multivariate logistic analysis and used to develop machine learning (ML) models. The ML model performance was assessed by area under the receiver operating characteristic curve (AUC) and radar plot. Shapley Additive explanations (SHAP) values were used to interpret the importance of all features included in the predictive model. A total of 677 AIS patients were included in the present study. Poor prognosis was observed in 209 patients (30.9%). Six variables, including neuron specific enolase (NSE), homocysteine (HCY), S-100ß, dysphagia, C-reactive protein (CRP), and anticoagulation were included to establish ML models. Six different ML algorithms were tested, and Random Forest model was selected as the final predictive model with the greatest AUC of 0.908. Moreover, according to SHAP results, NSE impacted the predictive model the most, followed by HCY, S-100ß, dysphagia, CRP and anticoagulation. Based on the RF model, an online tool was constructed to predict the prognosis of AIS patients and assist clinicians in optimizing patient treatment. The present study revealed that NSE, HCY, CRP, S-100ß, anticoagulation, and dysphagia were important factors for poor prognosis in AIS patients. ML algorithms were used to develop predictive models for predicting the prognosis of AIS patients, with the RF model presenting the optimal performance.

Corrigendum: A machine learning model for visualization and dynamic clinical prediction of stroke recurrence in acute ischemic stroke patients: a real-world retrospective study.

[This corrects the article DOI: 10.3389/fnins.2023.1130831.].

A machine learning model for visualization and dynamic clinical prediction of stroke recurrence in acute ischemic stroke patients: A real-world retrospective study.

Background and purpose: Recurrent stroke accounts for 25-30% of all preventable strokes, and this study was conducted to establish a machine learning-based clinical predictive rice idol for predicting stroke recurrence within 1 year in patients with acute ischemic stroke (AIS). Methods: A total of 645 AIS patients at The Second Affiliated Hospital of Xuzhou Medical University were screened, included and followed up for 1 year for comprehensive clinical data. Univariate and multivariate logistic regression (LR) were used to screen the risk factors of stroke recurrence. The data set was randomly divided into training set and test set according to the ratio of 7:3, and the following six prediction models were established by machine algorithm: random forest (RF), Naive Bayes model (NBC), decision tree (DT), extreme gradient boosting (XGB), gradient boosting machine (GBM) and LR. The model with the strongest prediction performance was selected by 10-fold cross-validation and receiver operating characteristic (ROC) curves, and the models were investigated for interpretability by SHAP. Finally, the models were constructed to be visualized using a web calculator. Results: Logistic regression analysis showed that right hemisphere, homocysteine (HCY), C-reactive protein (CRP), and stroke severity (SS) were independent risk factors for the development of stroke recurrence in AIS patients. In 10-fold cross-validation, area under curve (AUC) ranked from 0.777 to 0.959. In ROC curve analysis, AUC ranged from 0.887 to 0.946. RF model has the best ability to predict stroke recurrence, and HCY has the largest contribution to the model. A web-based calculator https://mlmedicine-re-stroke2-re-stroke2-baylee.streamlitapp.com/ has been developed accordingly. Conclusion: This study identified four independent risk factors affecting recurrence within 1 year in stroke patients, and the constructed RF-based prediction model had good performance.

The predictors of death within 1 year in acute ischemic stroke patients based on machine learning.

Objective: To explore the predictors of death in acute ischemic stroke (AIS) patients within 1 year based on machine learning (ML) algorithms. Methods: This study retrospectively analyzed the clinical data of patients hospitalized and diagnosed with AIS in the Second Affiliated Hospital of Xuzhou Medical University between August 2017 and July 2019. The patients were randomly divided into training and validation sets at a ratio of 7:3, and the clinical characteristic variables of the patients were screened using univariate and multivariate logistics regression. Six ML algorithms, including logistic regression (LR), gradient boosting machine (GBM), extreme gradient boosting (XGB), random forest (RF), decision tree (DT), and naive Bayes classifier (NBC), were applied to develop models to predict death in AIS patients within 1 year. During training, a 10-fold cross-validation approach was used to validate the training set internally, and the models were interpreted using important ranking and the SHapley Additive exPlanations (SHAP) principle. The validation set was used to externally validate the models. Ultimately, the highest-performing model was selected to build a web-based calculator. Results: Multivariate logistic regression analysis revealed that C-reactive protein (CRP), homocysteine (HCY) levels, stroke severity (SS), and the number of stroke lesions (NOS) were independent risk factors for death within 1 year in patients with AIS. The area under the curve value of the XGB model was 0.846, which was the highest among the six ML algorithms. Therefore, we built an ML network calculator (https://mlmedicine-de-stroke-de-stroke-m5pijk.streamlitapp.com/) based on XGB to predict death in AIS patients within 1 year. Conclusions: The network calculator based on the XGB model developed in this study can help clinicians make more personalized and rational clinical decisions.

Aberrant dynamic functional network connectivity in vestibular migraine patients without peripheral vestibular lesion.

PURPOSE: This study aimed to investigate changes in dynamic functional network connectivity (FNC) in patients with vestibular migraine (VM) and explore their relationship with clinical manifestations. METHODS: Resting-state functional magnetic resonance imaging (rs-fMRI) data were scanned from 35 VM patients without peripheral vestibular lesion and 40 age-, sex- and education-matched healthy controls (HC). Independent component analysis (ICA), sliding window (SW) and k-means clustering analysis were performed to explore the difference in FNC and temporal characteristics between two groups. Additionally, Pearson's partial correlation analysis was adopted to investigate the relationship between clinical manifestations and rs-fMRI results in patients with VM. RESULTS: Compared with HC, patients with VM showed increased FNC in pairs of extrastriate visual network (eVN)-ventral attention network (VAN), eVN-default mode network (DMN) and eVN-left frontoparietal network (lFPN), and exhibited decreased FNC in pairs of VAN-auditory network (AuN). The altered FNC was correlated with clinical manifestations of patients with VM. Additionally, we found increased mean dwell time and fractional windows in state 2 in VM patients compared with HC. Mean dwell time was positively correlated with headache impact test-6 (HIT-6) scores, fractional windows was positively associated with dizziness handicap inventory (DHI) scores. CONCLUSION: Our results indicated that patients with VM showed altered FNC primarily between sensory networks and networks related to cognitive, emotional and attention implementation, with more time spent in a state characterized by positive FNC between sensor cortex system and dorsal attention network (DAN). These findings could help reinforce the understanding on the neural mechanisms of VM.

Altered brain function in patients with vestibular migraine: a study on resting state functional connectivity.

PURPOSE: To characterize the altered brain function in patients with vestibular migraine (VM) using resting-state functional magnetic resonance imaging (fMRI). METHODS: In this prospective study, fMRI images as well as clinical characteristics and behavioral scales were collected from 40 VM patients and 40 healthy controls (HC). All patients received neurological, neuro-otological, and conventional MRI examinations to exclude peripheral vestibular lesions, focal lesions, and other neurological diseases. Seed-based (bilateral parietal operculum cortex 2, OP2) functional connectivity (FC) and independent component analysis (ICA)-based functional network connectivity (FNC) were performed to investigate the brain functional changes in patients with VM. Additionally, the correlations between the altered FC/FNC and behavioral results were analyzed. RESULTS: Compared with HC, patients with VM showed increased FC between the left OP2 and right precuneus and exhibited decreased FC between the left OP2 and left anterior cingulate cortex. We also observed increased FC between the right OP2 and regions of the right middle frontal gyrus and bilateral precuneus, as well as decreased FC between the bilateral OP2. Furthermore, patients with VM showed decreased FNC between visual network (VN) and networks of auditory and default mode, and exhibited increased FNC between VN and executive control network. A correlation analysis found that FC between the left OP2 and right precuneus was positively correlated with scores of dizziness handicap inventory (DHI) in patients with VM. CONCLUSION: The present study demonstrated altered brain function in patients with VM.

Early blood pressure changes during systemic thrombolysis and its association with unexplained early neurological deterioration in small subcortical infarct.

Early neurological deterioration (END), observed in the acute phase of small subcortical infarct treated with intravenous thrombolysis (IVT), is not uncommon in these patients. However, in over half of the END cases, the exact cause is yet incompletely understood, which is so-called unexplained END (unEND). Our aim was to investigate the association of early blood pressure (BP) changes with unEND in patients with small subcortical infarct in the perforator territory of middle cerebral artery treated with IVT. Consecutive patients with acute small subcortical infarct treated with IVT were enrolled in this study. unEND was defined as≧2-point increase of NIHSS from baseline to 24 hours, without straightforward causes. BP excursions and BP variability were calculated and compared between patients with unNED and those without. A total of 168 patients with acute small subcortical infarct were included. Of them, there were 29 patients with unEND and 139 without END. During the first 24 hours following IVT, 66 (39.29%) patients had at least one BP excursion. Logistic regression analyses indicated that BP excursion presence (OR = 3.185, 95% CI: 1.238-8.198), SBP excursion presence (OR = 3.535, 95% CI: 1.366-9.143), and number of SBP excursion (OR = 1.466, 95% CI: 1.090-1.973) were independently associated with unEND. Although SBPSD (P < .001) and SBPCV (P < .001) were higher in patients with unEND than those without END, none of the parameters of BP variability predicted unEND in multivariate analyses. BP excursions above guideline thresholds during the first 24 hours following IVT for small subcortical infarct are common and are independently associated with unEND.

Impact of Stress Hyperglycemia on Early Neurological Deterioration in Acute Ischemic Stroke Patients Treated With Intravenous Thrombolysis.

Background and Purpose: It has been widely reported that stress hyperglycemia contributes to poor prognosis in patients experiencing acute ischemic stroke (AIS). However, its predictive value for early neurological deterioration (END) after intravenous administration of recombinant tissue-type plasminogen activator (IV-rtPA) in AIS patients is still unclear. The aim of this study was to evaluate the impact of stress hyperglycemia on the risk of END after IV-rtPA. Methods: A total of 798 consecutive patients treated with IV-rtPA were included in this study. The stress hyperglycemia ratio (SHR) was calculated as fasting plasma glucose level at admission (mg/dl)/glycosylated hemoglobin (HbAlc) (%). END was defined as a National Institutes of Health Stroke Scale Score (NIHSS) ≥ 4 points 24 h after IV-rtPA, and poor functional outcome at discharge was defined as a modified Rankin Scale (mRS) score of 3-6 at discharge. Patients with a prior history of diabetes or HbAlc ≥ 6.5% were considered to have diabetes mellitus. Patients were grouped according to SHR values. Multivariate logistical regression was used to evaluate the risk of END for patients within specific SHR categories. Results: In total, 139 (17.4%) patients had END. After adjusting for confounders, the highest tertile group had higher risks of END and poor functional outcome at discharge than those of patients in the lowest tertile group (OR, 1.95; 95% CI, 1.21-3.15; p = 0.006) (OR, 1.85; 95% CI, 1.163-2.941; p = 0.009), and the predictive value of high SHR for END was also significant in patients with diabetes mellitus (OR, 3.05; 95% CI, 1.29-7.21; p = 0.011). However, a significant association of high SHR and poor functional outcome was only found in patients without diabetes (OR, 1.85; 95% CI, 1.002-3.399; p = 0.045). Conclusion: A higher SHR predicted that patients with severe stress hyperglycemia had higher risks of END and poor functional outcome at discharge after IV-rtPA.

The effect of metabolic syndrome and/or hyperglycemia on outcomes of acute ischemic stroke patients treated with intravenous thrombolysis.

BACKGROUNDS AND OBJECTIVES: The impact of metabolic syndrome (MetS)/hyperglycemia on the clinical outcomes of ischemic stroke treated with intravenous thrombolysis (IVT) remains controversial. This study aimed to determine the risks conferred by MetS and hyperglycemia to clinical outcomes in acute ischemic stroke patients treated with IVT. METHOD: Three hundred forty-three ischemic stroke patients treated with IVT were prospective recruited and stratified into four groups: neither, MetS only, hyperglycemia only, or both. The primary outcome was the 3-month poor functional outcome (PFO) which was defined as a 3-month modified Rankin Score (mRS) score ≧3. The secondary outcome included the hemorrhagic transformation (HT) and symptomatic intracranial hemorrhage (sICH) after IVT. RESULTS: MetS was recognized in 197 (57.43%) patients. During the first 24 h after IVT, 44 (12.83%) patients had HT, of which 17 had sICH. Three-month PFO was found in 98 (28.57%) patients. After adjustment for potential confounders, MetS (odds ratio (OR) = 3.140, 95% confidence interval (CI) = 1.724-5.718) was independently associated with PFO. However, neither MetS nor its components were associated with 24-h HT or sICH. In the further subgroup analysis, we used the "neither" group as reference and found that the presence of both MetS and hyperglycemia (OR = 3.192, 95% CI = 1.338-7.615) and the presence of hyperglycemia only (OR = 2.097, 95% CI = 1.052-4.179) were significantly related to the 3-month PFO. CONCLUSION: MetS is an independent risk factor on 3-month PFO in acute ischemic stroke patients treated with IVT. Compared with "neither," hyperglycemia only or concurrent with MetS was associated with an elevated risk of PFO after receiving IVT.

PSD-93 mediates the crosstalk between neuron and microglia and facilitates acute ischemic stroke injury by binding to CX3CL1.

Post-synaptic density 93 (PSD-93) mediates glutamate excitotoxicity induced by ischemic brain injury, which then induces microglial inflammatory response. However, the underlying mechanisms of how PSD-93 mediates the crosstalk between neurons and microglia in the post-synaptic dense region remain elusive. CX3 chemokine ligand 1 (CX3CL1) is a chemokine specifically expressed in neurons while its receptor CX3CR1 is highly expressed in microglia. In this study, we examined the interaction of PSD-93 and CX3CL1 in the crosstalk between neurons and microglia in acute ischemic stroke. We utilized male C57BL/6 mice to establish the middle cerebral artery occlusion model (MCAO) and designed a fusion small peptide Tat-CX3CL1 (357-395aa) to inhibit PSD-93 and CX3CL1 interaction. The combination peaks of PSD-93 and CX3CL1 at 6 hr after I/R were observed. The binding sites were located at the 420-535 amino acid sequence of PSD-93 and 357-395 amino acid sequence of CX3CL1. Tat-CX3CL1 (357-395aa) could inhibit the interaction of PSD-93 and CX3CL1 and inhibited the pro-inflammatory cytokine IL-1ß and TNF-α expression and provided neuroprotection following reperfusion. Together, these data suggest that PSD-93 binds CX3CL1 to activate microglia and initiate neuroinflammation. Specific blockade of PSD-93-CX3CL1 interaction reduces I/R induced neuronal cell death, and provides a new therapeutic target for ischemic stroke.

Butylphthalide soft capsules combined with modified tonic exercise therapy on neurological function and ability of daily living of patients with stroke hemiplegia.

OBJECTIVE: To explore the effect of butylphthalide soft capsules combined with modified tonic exercise therapy on neurologic function and the abilities of daily living in patients with stroke hemiplegia. METHODS: In this retrospective trial, a total of 90 patients with stroke hemiplegia admitted to our hospital from January 2019 to January 2020 were enrolled and divided into a control group and an experimental group according to different treatment methods. The two groups were both treated with butylphthalide soft capsules, and the experimental group was additionally treated by modified tonic exercise therapy. The clinical efficacy, endothelial injury indicators, molecular indicators of oxidative stress, and adverse reactions of the two groups were compared. Generic Quality of Life Inventory-74 (GQOLI-74) was used to assess the quality of life of patients after treatment. The Fugl-Meyer Upper Extremity Assessment (FMA) was used to evaluate their limb function before and after treatment, the National Institute of Health Stroke Scale (NIHSS) was used to evaluate their brain nerve function before and after the treatment, and the activities of daily living (ADL) were employed to assess their activities of daily living before and after treatment. RESULTS: After treatment, the experimental group outperformed the control group in terms of total clinical efficacy (P<0.05). The experimental group had significantly lower endothelial injury indicators and higher molecular indicators of oxidative stress than the control group (all P<0.001). The incidence of adverse reactions in the experimental group was lower than that in the control group (P<0.05). Higher GQOLI-74, FMA, and ADL scores and a significantly lower NIHSS score were obtained in the experimental group than the control group after treatment (P<0.001). CONCLUSION: For patients with stroke hemiplegia, butylphthalide soft capsule combined with modified tonic exercise therapy effectively improves their neurologic function, abilities of daily living, and quality of life.

Analysis of Antiapoptosis Effect of Netrin-1 on Ischemic Stroke and Its Molecular Mechanism under Deleted in Colon Cancer/Extracellular Signal-Regulated Kinase Signaling Pathway.

To analyze the regulatory effect of Netrin-1 in ischemic stroke and its influence on Deleted in Colon Cancer (DCC)/Extracellular Signal-regulated Kinase (ERK) signaling pathway, 20 male rats were selected to construct the rat model of middle cerebral artery occlusion (MCAO), 10 normal rats were selected as healthy controls (Normal Saline (NS)), and they were divided into the MCAO+Netrin-1 group, MCAO group, and NS group according to different treatment schemes. The positive expression of Netrin-1 was detected by immunostaining, magnetic resonance imaging (MRI) was adopted to detect the percentage of rat cerebral infarct volume in the cerebral hemispheres, and Modified Neurological Severity Score (mNSS) was adopted to evaluate postoperative neurological function in rats. Besides, a tunnel staining experiment was applied to detect the apoptosis rate of rat neurons, the sticker removal test was applied to evaluate the postoperative sensory function of rats, and fluorescence staining was adopted to detect the expression of DCC and ERK in rats. The results showed that the percentage of cerebral infarction volume in the cerebral hemispheres of the MCAO+Netrin-1 group was higher than that of the MCAO and NS groups (P < 0.05); in the MCAO+Netrin-1 group, the MCAO mNSS scoring and the time spent in the sticker removal test were lower than the MCAO group (P < 0.05); the apoptosis rate of rats in the MCAO+Netrin-1 group was lower than that in the MCAO group (P < 0.05); the average fluorescence intensity of DCC and p-ERK in the MCAO+Netrin-1 group was higher than that in the MCAO group (P < 0.05); the average fluorescence intensity of p-ERK in the MCAO+Netrin-1 group was higher than that in the MCAO group (P < 0.05). In short, Netrin-1 can effectively reduce the brain tissue damage in rats with ischemic stroke, improve the nerve function and sensory function of rats, and inhibit neuronal cell apoptosis. Netrin-1 can promote DCC expression and ERK phosphorylation, and the EPK signaling pathway may be involved in the antiapoptotic effect of Netrin-1.

PSD-93 Interacts with SynGAP and Promotes SynGAP Ubiquitination and Ischemic Brain Injury in Mice.

Postsynaptic density protein-93 (PSD-93) plays an important role in ischemic brain injury through N-methyl-D-aspartate receptor (NMDAR)-triggered neurotoxicity. GTPase-activating protein for Ras (SynGAP) is a GAP specifically expressed in the central nervous system to regulate nerve development and synaptic plasticity. However, the link between PSD-93 and SynGAP and their role in ischemic brain injury remain elusive. Here, we showed that PSD-93 interacted with SynGAP and mediated SynGAP ubiquitination and degradation following ischemic brain injury. Proteasome inhibitor MG-132 could reverse the decrease of SynGAP protein level in wild-type mice following cerebral ischemia reperfusion through inhibiting SynGAP ubiquitination. Furthermore, NMDA receptor inhibitor MK801 could increase SynGAP protein level in wild-type mice following cerebral ischemia reperfusion. However, in PSD-93 knockout mice, MG-132 or NMDAR inhibitor had no significant effect on SynGAP expression. Both MG-132 and PSD-93 knockout reduced infarct volume and improved neurological deficit in mice at different time points after cerebral ischemia reperfusion. Furthermore, we identified that 670-685 amino acid sequence of SynGAP was essential to the binding of SynGAP to PSD-93, and designed a fusion peptide Tat-SynGAP (670-685aa) that could attenuate ischemic brain damage in wild-type mice. In conclusion, we provide the first evidence that PSD-93 directly interacts with SynGAP and mediates its ubiquitination and degradation to aggravate ischemic brain damage. Tat-SynGAP (670-685aa) may be considered as a candidate for treatment of acute ischemic stroke.

Efficacy of cattle encephalon glycoside and ignotin in patients with acute cerebral infarction: a randomized, double-blind, parallel-group, placebo-controlled study.

Cattle encephalon glycoside and ignotin (CEGI) injection is a compound preparation formed by a combination of muscle extract from healthy rabbits and brain gangliosides from cattle, and it is generally used as a neuroprotectant in the treatment of central and peripheral nerve injuries. However, there is still a need for high-level clinical evidence from large samples to support the use of CEGI. We therefore carried out a prospective, multicenter, randomized, double-blind, parallel-group, placebo-controlled study in which we recruited 319 patients with acute cerebral infarction from 16 centers in China from October 2013 to May 2016. The patients were randomized at a 3:1 ratio into CEGI (n = 239; 155 male, 84 female; 61.2 ± 9.2 years old) and placebo (n = 80; 46 male, 34 female; 63.2 ± 8.28 years old) groups. All patients were given standard care once daily for 14 days, including a 200 mg aspirin enteric-coated tablet and 20 mg atorvastatin calcium, both taken orally, and intravenous infusion of 250-500 mL 0.9% sodium chloride containing 40 mg sodium tanshinone IIA sulfonate. Based on conventional treatment, patients in the CEGI and placebo groups were given 12 mL CEGI or 12 mL sterile water, respectively, in an intravenous drip of 250 mL 0.9% sodium chloride (2 mL/min) once daily for 14 days. According to baseline National Institutes of Health Stroke Scale scores, patients in the two groups were divided into mild and moderate subgroups. Based on the modified Rankin Scale results, the rate of patients with good outcomes in the CEGI group was higher than that in the placebo group, and the rate of disability in the CEGI group was lower than that in the placebo group on day 90 after treatment. In the CEGI group, neurological deficits were decreased on days 14 and 90 after treatment, as measured by the National Institutes of Health Stroke Scale and the Barthel Index. Subgroup analysis revealed that CEGI led to more significant improvements in moderate stroke patients. No drug-related adverse events occurred in the CEGI or placebo groups. In conclusion, CEGI may be a safe and effective treatment for acute cerebral infarction patients, especially for moderate stroke patients. This study was approved by the Ethical Committee of Peking University Third Hospital, China (approval No. 2013-068-2) on May 20, 2013, and registered in the Chinese Clinical Trial Registry (registration No. ChiCTR1800017937).

Fasudil hydrochloride protects neurons in rat hippocampal CA1 region through inhibiting GluR6-MLK3-JNKs signal pathway.

Fasudil hydrochloride (FH), a Rho kinase (ROCK) inhibitor, has been reported to prevent cerebral ischemia in vivo from increasing cerebral blood flow and inhibiting inflammatory responses. However, it is uncertain by what mechanism a ROCK inhibitor can directly protect neurons against ischemic damage. The present study was designed to evaluate whether FH decreased the increased phosphorylation of glutamate receptor 6 (GluR6) and its downstream in GluR6-MLK3-JNKs signal transduction pathway following global transient cerebral ischemia, as a result of protecting against neuronal apoptosis and death. Transient cerebral ischemia was induced by the Pulsinelli-Brierley four-vessel occlusion method. FH (15 mg/kg) was administered to rats by intraperitoneal injection 30 min before ischemia. The phosphorylation and protein expression of GluR6 at 6 h during reperfusion were detected using immunoprecipitation and immunoblotting analysis. The phosphorylation and protein expression of Mixed lineage kinase 3 (MLK3) at ischemia/reperfusion (I/R) 6 h and c-Jun N-terminal kinase (JNK) at I/R 3 d were detected using immunoblotting analysis, respectively. The same method was used to detect the expression of caspase-3 at I/R 6 h. Furthermore, we also use TUNEL staining and Cresyl violet staining to examine the survival neurons in rat hippocampal CA1 regions after 3 and 5 d reperfusion, respectively. Our study indicated that FH could inhibit the increased phosphorylation of GluR6 and MLK3 and the expression of caspase-3 at peaked 6 h of reperfusion and the phosphorylation of JNK (3 d) (p < 0.5). The results of TUNEL staining and Cresyl violet showed that the number of surviving pyramidal neurons in rats hippocampal CA1 subfield increased markedly in FH-treated rats compared with ischemic groups after 3 or 5 d of reperfusion following ischemia (p < 0.5). These results suggested that FH, as a ROCK inhibitor, may be partly responsible for its protective effects against such damage by taking part in GluR6-MLK3-JNKs signaling pathway which modulates ischemic damage. Taken together, this is the first study investigating Rho and ROCK as the upstream of GluR6 taking part in GluR6-MLK3-JNKs signal transduction pathway following cerebral ischemia.

Assembly of the FKBP51-PHLPP2-AKT signaling complex in cerebral ischemia/reperfusion injury in rats.

The imbalance of cell pro-death and pro-survival signaling pathways determines the neuronal fate during cerebral ischemia/reperfusion (I/R) injury. However, the biological mechanisms regulating the balance between activation of the pro-death or the pro-survival signaling pathways remain unclear. In this study, a rat model of I/R injury was established using four-vessel occlusion followed by different times of reperfusion. I/R injury did not affect the level of FK506 binding protein 51 (FKBP51), PH domain and leucine rich repeat protein phosphatases (PHLPP)-2, and AKT, but induced assembly of the FKBP51-PHLPP2-AKT signaling complex, as indicated by the enhancement of interactions among these compounds following reperfusion. Using an antisense oligonucleotide, PHLPP2 expression was effectively inhibited. Critically, the inhibition of PHLPP2 prohibited the interactions of FKBP51, PHLPP2 and AKT, reversed the decrease of p-AKT expression and increased the expression of p-JNKs and p-c-Jun elicited by I/R injury. In addition, PHLPP2 inhibition reversed I/R-injury-induced Caspase-3 cleavage and loss of pyramid neurons in the CA1 region of hippocampus. The results of the current study indicate that the assembly of the FKBP51-PHLPP2-AKT signaling complex plays a critical role in mediating cell death in I/R injury. The inhibition of PHLPP2 via antisense oligonucleotide treatment may be an effective method to prohibit the assembly of the FKBP51-PHLPP-AKT signaling complex, thus balancing the cell pro-survival and pro-death signaling pathways ultimately mitigating cell death in I/R injury.