Current Neurovascular Research - Volume 18, Issue 4, 2021

Background: The mossy fiber sprouting (MFS) in the dentate gyrus is a common pathological change of epilepsy. Previous studies suggested that it is associated with drug-resistant epilepsy, and mossy cells control spontaneous seizures and spatial memory. Methods: We investigated the correlations among cognitive impairment, MFS, seizure frequency and drug resistance in a rat model of epilepsy induced by lithium–pilocarpine. Phenytoin and phenobarbital were used to screen drug resistance. Cognitive function and MFS were detected through the novel object recognition (NOR) test, Morris water maze (MWM) test and Timm staining. Results: The results showed that object memory and spatial memory functions were both significantly impaired in rats with epilepsy, and only spatial memory impairment was more severe in rats with drug-resistant epilepsy. More frequent spontaneous seizures and more obvious MFS were observed in the drug-resistant rats. The seizure frequency was significantly associated with the MWM performance but not with the NOR performance in rats with epilepsy. The degree of MFS was significantly associated with seizure frequency and spatial memory function. Conclusion: Taken together, these correlations among drug resistance, seizure frequency, spatial memory impairment and MFS suggested the possibility of a common pathological mechanism. More studies are needed to clarify the underlying mechanism behind these correlations and the detailed role of MFS in epilepsy. The mechanism of mossy cell change may be an important target for the treatment of seizures, drug resistance and cognitive dysfunction in patients with epilepsy.

Aim and Purpose: Progressive Stroke (PS) lacks effective treatment measures and leads to serious disability or death. Retinol binding protein 4 (RBP4) could be closely associated with acute ischemic stroke (AIS). We aimed to explore plasma RBP4 as a biomarker for detecting the progression in patients with AIS. Methods: Participants of this retrospective study were 234 patients with AIS within the 48 h onset of disease. The primary endpoint was to ascertain if there was PS through the National Institute of Health stroke scale (NIHSS); the early prognosis was confirmed through the modified Rankin scale score (mRS) at discharge or 14 days after the onset of stroke, and the significance of demographic characteristics and clinical data was determined. Results: In this study, 43 of 234 patients demonstrated PS. The level of plasma RBP4 in patients with progressive stroke was significantly lower (29 mg/L, 22.60-40.38 mg/L) than that without progression (38.70 mg/L, 27.28-46.40 mg/L, P = 0.003). In patients with lower plasma RBP4, the proportion of patients with progression (χ2 = 9.63, P = 0.008) and with mRS scores ≥2 (χ2 = 6.73, P = 0.035) was significantly higher. Multivariate logistic regression analysis showed that a lower RBP4 level on admission was an independent risk factor for progressive stroke during hospitalization with an OR value of 2.70 (P = 0.03, 95% CI: 1.12-6.52). Conclusion: A low plasma RBP4 level on admission could be an independent risk factor of PS during hospitalization.

Introduction: This study aimed to investigate the clinical value of bispectral index (BIS) monitoring in assessing the consciousness and prognosis of Acute Cerebral Infarction (ACI) patients. Methods: In total, 64 patients who suffered from ACI with consciousness disturbance were enrolled in this study. Glasgow Coma Scale (GCS) was performed to evaluate the consciousness level of ACI patients, and BIS was used to monitor the depth of anesthesia and sedation. Then, patients were divided into good prognosis, poor prognosis and death groups according to Modified Rankin Score (mRS). Discrimination analysis of BIS values and GCS score for the prediction of prognosis was performed using the Receiver Operator Characteristic (ROC) curve. Results: GCS score and BIS values showed statistically significant differences among the three groups. Spearman rank correlation analysis revealed a significant positive correlation between BIS values and GCS score, while BIS values was negatively related with mRS. The ROC curve of prognosis prediction showed strong prognostic power, with Area Under the Curves (AUCs) between 0.830 and 0.917. Moreover, the AUC of BISmean score was higher than that of BISmax, BISmin and GCS, and BISmean of 74 was the best cut-off point for good prognosis. Conclusion: BIS directly reflects the degree of consciousness disturbance in ACI patients, and thus accurately predicts the prognosis, indicating potential application values of BIS in clinical practice.

Background: Extracellular Vesicle (EV)-based therapy has been identified as a leading alternative approach in several disease models. EV derived from the Olfactory Ensheathing Cell (OEC) has been documented for its strong neuro-regenerative capacity. However, no information on its cargo that may contribute to its therapeutic effect has been available. Objective: To report the first miRNA profile of human OEC (hOEC) -EV, and investigate the neuroprotective effects. Methods: hOEC-EV was isolated and sequenced. We established in vitro experiments to assess the therapeutic potential of hOEC-EVs with respect to insulted neural progenitor cells (NPCs), and the angiogenesis effect. Secondary post-injury insults were imitated using t-BHP-mediated oxidative stress. Results: We noted a strong abundance of hOEC-EV-miRNAs, including hsa-miR148a-3p, hasmiR151a- 3p and several members of let-7 family. The common targets of 15 miRNAs among the top 20 miRNAs were thrombospondin 1 and cyclin dependent kinase 6. We demonstrated that hOEC-EVs promote normal NPC proliferation and differentiation to neuron-like morphologies with prolonged axons. hOEC-EVs protect cells from t-BHP mediated apoptosis. We also found that the migration rate of either NPCs or endothelial cells significantly improved with hOEC-EVs. Furthermore, in vitro tube formation assays indicated that angiogenesis, an important process for tissue repair, was significantly enhanced in human umbilical vein endothelial cells exposed to hOEC-EVs. Conclusion: Our results revealed that hOEC-EVs exert neuroprotective effects by protecting cells from apoptosis and promoting in vitro biological processes that are important to neural tissue repair, including neural cell proliferation, axonal growth, and cell migration, in addition to enhancing angiogenesis.

Background: Stroke is one of the leading causes of death and disability in adulthood worldwide. A simple and convenient diagnostic method is needed for monitoring high-risk patients for stroke. Few POCTs are available for stroke diagnosis. Soluble blood P-selectin is known as a biomarker for platelet aggregation. Increased expression of P-selectin is observed in coronary artery disease, acute myocardial infarction, stroke and peripheral arterial disease. Objective: A simple method that can measure the increased expression of P-selectin in stroke patients is intended to be used for diagnosis or early detection and hospital monitoring of ischemic stroke. Methods: Plasma proteins in blood were separated using a three-layered filter system. Quantum dot and antibody were conjugated to detect biomarkers present in plasma and then measured with a fluorescence spectrophotometer. Results: The detection limit of soluble P-selectin confirmed by immunoassay was 1 ng/ul. In order to increase the sensitivity and simplify the reaction, the detection limit was measured to evaluate the sensitivity of the quantum dot labeled anti P-selectin antibody. As a result, P-selectin of 5 ng/ul or more showed saturation signal intensity, indicating the upper limit of detection, and 10 pg/ul was the lower limit of detection. Conclusion: In this study, we proposed a three-layer filter membrane system that can separate biomarker- rich fractions from whole blood, simplifying the analysis process and improving sensitivity by using quantum dot-labeled antibodies to detect biomarkers. We hope that our system complements the advantages of POCT and can be applied to real clinical applications.

Objective: Angiogenesis led by brain microvascular endothelial cells (BMECs) contributes to the remission of brain injury after brain ischemia reperfusion. In this study, we investigated the effects of hydroxysafflor yellow A(HSYA) on angiogenesis of BMECs injured by OGD/R via SIRT1-HIF-1α-VEGFA signaling pathway. Methods: The OGD/R model of BMECs was established in vitro by OGD for 2h and reoxygenation for 24h. At first, the concentrations of vascular endothelial growth factor (VEGF), Angiopoietin (ang) and platelet-derived growth factor (PDGF) in supernatant were detected by ELISA, and the proteins expression of VEGFA, Ang-2 and PDGFB in BMECs were tested by western blot; the proliferation, adhesion, migration (scratch healing and transwell) and tube formation experiment of BMECs; the expression of CD31 and CD34 were tested by immunofluorescence staining. The levels of sirtuin1(SIRT1), hypoxia-inducible factor-1α (HIF-1α), VEGFA mRNA and protein were tested. Results: HSYA up-regulated the levels of VEGF, Ang and PDGF in the supernatant of BMECs under OGD/R, and the protein expression of VEGFA, Ang-2 and PDGFB was increased; HSYA could significantly alleviate the decrease of cell proliferation, adhesion, migration and tube formation ability of BMECs during OGD/R; HSYA enhanced the fluorescence intensity of CD31 and CD34 of BMECs during OGD/R; HSYA remarkably up-regulated the expression of SIRT1, HIF-1α, VEGFA mRNA and protein after OGD/R, and these increase decreased after SIRT1 was inhibited. Conclusion: SIRT1-HIF-1α-VEGFA signaling pathway is involved in HSYA improves angiogenesis of BMECs injured by OGD/R.

Background: We investigated the combined effect of white blood cell (WBC) and platelet count on in-hospital mortality and pneumonia in acute ischemic stroke (AIS) patients. Methods: A total of 3,265 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included in the present study. We divided patients into four groups according to their level of WBC and platelet count: LWHP (low WBC and high platelet), LWLP (low WBC and low platelet), HWHP (high WBC and high platelet), and HWLP (high WBC and low platelet). A logistic regression model was used to estimate the combined effect of WBC and platelet counts on all-cause in-hospital mortality and pneumonia in AIS patients. Results: HWLP was associated with a 2.07-fold increase in the risk of in-hospital mortality in comparison to LWHP (adjusted odds ratio (OR) 2.07; 95% confidence interval (CI), 1.02-4.18; P-trend =0.020). The risk of pneumonia was significantly higher in patients with HWLP than those with LWHP (adjusted OR 2.29; 95% CI, 1.57-3.35; P-trend <0.001). The C-statistic for the combined WBC and platelet count was higher than WBC count or platelet count alone for the prediction of in- -hospital mortality and pneumonia (all P < 0.01). Conclusion: High WBC count combined with a low platelet count level at admission was independently associated with in-hospital mortality and pneumonia in AIS patients. Moreover, the combination of WBC count and platelet count level appeared to be a better predictor than WBC count or platelet count alone.

Objective: The objective of this study is to determine whether the administration of intravenous alteplase would be beneficial or futile to patients with acute ischemic stroke caused by large vessel occlusion (LVO) before endovascular treatment (EVT) and determine the relationship between Hounsfield units (HU) in non-contrast computed tomography (NCCT) and recanalization by alteplase. Methods: We performed a retrospective analysis of patients with acute ischemic stroke caused by LVO who received intravenous thrombolysis (IVT) or followed by EVT at our center during November 2016 and October 2020. The clinical characteristics and imaging features of patients who achieved recanalization after IVT, and those who did not, were compared. Results: Forty-three eligible patients were enrolled; 12 achieved recanalization by IVT. Baseline clinical characteristics did not differ between patients of the recanalization and non-recanalization groups. HU in the NCCT were estimated and statistically significant maximum and mean values of the ipsilateral middle cerebral artery (MCA) were found between the groups (P< 0.05). The results hint that patients in the non-recanalization group have a higher rHU and δHU value of the ipsilateral MCA compared with recanalization group (P< 0.05). With regards to the receiver operator characteristic (ROC) curve, we demonstrated that a high HU value of the ipsilateral MCA could be a predictor for non-recanalization by IVT. Conclusion: Patients suffering LVO stroke are less likely to obtain recanalization by IVT with a high HU value of the ipsilateral MCA. It is feasible to screen patients with LVO using HU for direct EVT.

Objective: Insulin resistance (IR) is a key pathological process during the development of cerebral small vessel disease (CSVD) and vascular cognitive impairment (VCI). The triglyceride- glucose index (TyG index) is considered a novel marker of insulin resistance and can represent peripheral tissue insulin sensitivity. Interleukin-34 (IL-34) is a cytokine of the short-chain helical hematopoietic cytokine family and recent studies have shown that its serum levels may represent an important biomarker for atherosclerosis. Here, we aimed to investigate whether the TyG index and serum IL-34 levels were related to VCI in patients with CSVD. Methods: This study included a total of 280 CSVD patients. TyG index, clinical baseline data, and fasted venous blood for quantification serum levels of IL-34 were acquired within 24 hours of admission. Multiple logistic regression analysis was applied to analyze the association between potential risk factors and VCI, and receiver operator characteristic (ROC) curve was used to evaluate the diagnostic value of IL-34, TyG index, and their combination for detecting VCI. Results: Among all included CSVD patients, 166 patients (59.3%) were diagnosed with VCI based on the cognitive function scale (MOCA). After adjusting for confounding factors, serum IL-34 levels and TyG index were independently associated with VCI (P<0.05). Using ROC curve analysis, the optimal thresholds for identification of VCI based on serum IL-34 levels and TyG index were 41.57pg/ml (area under the curve (AUC): 0.723; sensitivity 76.5%; specificity 64%) and 3.94 (AUC:0.727; sensitivity 72.3%; specificity 62.3%), respectively. Conclusion: This study demonstrated that IL-34 and TyG index are closely associated with VCI in CSVD patients and may represent clinical therapeutic targets for CSVD.

Aim: This study investigated the protective effect of dimethyl fumarate (DMF) in rats by mediating glycogen synthase kinase 3β (GSK-3β)/Nrf2 using the middle cerebral artery embolization reperfusion (MCAO/R) rat model. Background: After an acute ischemic stroke (AIS), oxidative stress occurs. Dimethyl fumarate (DMF), a nuclear factor-E2-related factor 2 (Nrf2) activator, approved by the US Food and Drug Administration (FDA), was observed to regulate the Nrf2 pathway by acting as an anti-oxidative stress agent; however, whether this agent is involved in inhibiting GSK-3β remains to be established. Methods: DMF model was used to explore the effects of GSK-3β on Nrf2 expression level, Nrf2- ARE binding activity and Nrf2/ARE downstream expression level of anti-oxidant stress protein in Cerebral ischemia-reperfusion injury (CIRI). 60 rats were randomly divided into Sham group, MCAO/R group, solvent control group (DMSO group) and DMF treatment group, with 15 rats in each group. The MCAO/R, DMSO and DMF groups were considered in the MCAO/R model using the modified thread embolization method. In contrast, the Sham group was only anaesthetized and disinfected, and tissue muscle was dissected without inserting suture emboli. DMF group was gavaged with 45mg/kg per day of DMF, DMSO control group was gavaged with DMSO of equal volume, while MCAO/R group was only modeled without any intragastric treatment. The rats were treated seven days after the operation, and a neurological function Longa score was estimated. The rats were sacrificed seven days later, and the infarct volume was assessed by TTC staining. Hematoxylin- eosin (HE) staining was used to observe the pathological changes in rat brain tissue. Nissl staining was used to observe the expression of neurons in the infarcted cortex. Western blotting (WB) was used to observe the protein expression levels of GSK-3β, Nrf2, downstream heme oxygenase 1 (HO1) and NADPH quinone oxidoreductase 1 (NQO1) in four groups. The expression levels of GSK-3β and Nrf2 in the four groups were observed by immunohistochemistry and immunofluorescence. Results: (1) The Longa score of the MCAO/R, DMSO and DMF groups was found to be higher compared to the Sham group, indicating successful operation. The Longa score of the DMF group was lower than that of the other three groups 4-7 days after surgery (P<0.05). (2) HE and Nissl staining showed that the DMF group had lower neuron necrosis and higher gliosis compared to the control groups. (3) TTC staining results showed that the infarct volume of the DMF group was significantly smaller than the MCAO/R and DMSO groups. (4) Protein results showed that the GSK-3β expression in the DMF group was lower than that in all groups, while the expression of Nrf2, HO1 and NQO1 was higher compared to other groups. Conclusion: DMF can reduce neurological deficits and infarct size in the MCAO/R model. The protective effect may be related to decreased GSK-3β expression and increased Nrf2 expression, which may play a role in anti-oxidative stress.

Objective: Previous studies revealed that 18F-FDOPA uptake was significantly decreased in the subregions of striatum contralateral to the side with predominant symptoms and was helpful for improving the early diagnostic accuracy of PD. However, in these studies, more than half of the PD patients already have bilateral motor symptoms (mH stage≥2). This study was aimed to extend previous findings to a milder disease stage. Methods: Sixteen PD patients with only mild and unilateral motor symptoms (mH stage=1 and disease duration≤2 years) and 22 healthy controls were involved. Striatal 18F-FDOPA uptake was analyzed using a ratio approach. Results: The SORs in the subregions of the contralateral striatum, including caudate, anterior putamen and posterior putamen were significantly decreased in the mild stage PD patients. The SOR for the contralateral posterior putamen had the largest area under the receiver operating characteristic curve (0.963) and separated mild stage PD patients from healthy controls with a sensitivity of 93.75% and a specificity of 95.45% when the cut-off value of <2.160 was selected. Conclusion: These data indicate that contralateral posterior putaminal 18F-FDOPA uptake may represent a potential marker for early diagnosis of PD, especially in patients with only mild and unilateral motor symptoms.