CRS induces depression-like behavior after MCAO in rats possibly by activating p38 MAPK.

Post-stroke depression (PSD) is a common neuropsychiatric complication of stroke, which seriously affects the quality of life and prognosis of patients. Nevertheless, the pathogenesis of PSD remains unclear. In our study, a PSD rat model was established by chronic restraint stress (CRS) combined with middle cerebral artery occlusion (MCAO). Depressive and anxiety-like behaviors were tested, as well as Neuronal loss and Apoptosis. The expression of synapse and p38 MAPK signaling pathway -relevant proteins was detected. Our data indicated that CRS combined with MCAO could induce depression-like and anxiety-like behaviors, which led to neuronal damage, apoptosis, and cellular loss in the left parietal cortex and left hippocampus. Furthermore, CRS combined with MCAO decreased synaptic plasticity in the parietal cortex and left hippocampus. We found that CRS combined with MCAO had activated the p38 MAPK signaling pathway, and decreased the expression of pathway-related proteins MKK6 and MKK3. These results suggested that CRS combined with MCAO could lead to depression-like behavior via neuronal damage, apoptosis and reduced synaptic plasticity, which might be related to the activation of the p38 MAPK pathway. Therefore, it provides novel ideas for the research on the intervention and prevention mechanisms of PSD.

Behavioral and histopathological consequences of transient ischemic stroke in the Flinders Sensitive Line rat, a genetic animal model of depression.

Patients with depression have an increased risk for stroke, higher mortality rates following stroke and worse functional outcomes among survivors. Preclinical studies may help to better understand the underlying mechanisms linking these two diseases, but only a few animal studies have investigated the effects of prestroke depression. The present study investigates whether Flinders Sensitive Line (FSL) rats, a genetic depression model, respond differently to focal ischemic stroke compared to control strains (Flinders Resistant Line [FRL] and Sprague-Dawley [SD]). Male adult FSL, FRL and SD rats received a unilateral injection of either vehicle or Endothelin-1 (ET-1) adjacent to the middle cerebral artery (MCA). Motor function was assessed at 48 h followed by euthanasia and infarct volume measurement using 2,3,5-triphenyltetrazolium chloride (TTC) staining and image analysis. In a separate cohort behavior was assessed using standard tests for motor function, locomotor activity, cognition, anxiety- and depression-like behavior beginning at 10 days post-injection followed by infarct quantification. We found that ET-1-induced MCA occlusion produced significant infarcts in all three strains. Stroke animals had slightly impaired motor function, but there was no clear interaction effects between strain and stroke surgery on behavioral outcomes. We conclude that FSL rats show no increased susceptibility to brain damage or behavioral deficits following ET-1-induced focal ischemic stroke compared to controls.

Different combinations of high-frequency rTMS and cognitive training improve the cognitive function of cerebral ischemic rats.

Poststroke cognitive impairment (PSCI) occurs frequently after stroke, but lacks effective treatments. Previous studies have revealed that high-frequency repetitive transcranial magnetic stimulation (rTMS) has a beneficial effect on PSCI and is often used with other cognitive training methods to improve its effect. This study aimed to evaluate the effect of different combinations of rTMS and cognitive training (rTMS-COG) on PSCI and identify the optimal combination protocol. A cerebral infarction rat model was established by transient middle cerebral artery occlusion (tMCAO). The Morris water maze test was conducted to assess the cognitive function of rats. RNA sequencing and bioinformatics analysis were employed to study the underlying mechanisms. rTMS, COG and rTMS-COG all had beneficial effects on PSCI, while cognitive training immediately after rTMS (rTMS-COG0h) achieved a better effect than cognitive training 1 h and 4 h after rTMS, rTMS and COG. We identified 179 differentially expressed genes (DEGs), including 24 upregulated and 155 downregulated genes, between the rTMS-COG0h and rTMS groups. GO analysis revealed that the major categories associated with the DEGs were antigen procession and presentation, regulation of protein phosphorylation and axoneme assembly. KEGG analysis showed that the DEGs were enriched in processes related to phagosome, circadian entrainment, dopaminergic synapse, apelin signaling pathway, long-term depression, neuroactive ligand-receptor interaction, axon guidance and glucagon signaling pathway. PPI analysis identified Calb2, Rsph1, Ccdc114, Acta2, Ttll9, Dnah1, Dlx2, Dlx1, Ccdc40 and Ccdc113 as related genes. These findings prompt exploration of the potential mechanisms and key genes involved in the effect of rTMS-COG0h on PSCI.

Dexmedetomidine exerts a protective effect on ischemic brain injury by inhibiting the P2X7R/NLRP3/Caspase-1 signaling pathway.

Dexmedetomidine (Dex) has been suggested to exert a protective function in ischemic brain injury. In this study, we aimed to elucidate the intrinsic mechanisms of Dex in regulating microglia pyroptosis in ischemic brain injury via the purinergic 2X7 receptor (P2X7R)/NLRP3/Caspase-1 signaling pathway. First, permanent middle cerebral artery occlusion (p-MCAO) rat model was established, followed by the measurement of behavioral deficit, neuronal injury, the volume of brain edema and the infarct size. Dex treatment was suggested to alleviate the neurological deficits in p-MCAO rats and reduce the brain water content and infarct size. Additionally, rat microglia were cultured in vitro and a model of oxygen and glucose (OGD) was established. Microglia cell activity and ultrastructure were detected. Dex could increase cell activity and reduce LDH activity, partially reversing the changes in cell morphology. Furthermore, the activation of P2X7R/NLRP3/Caspase-1 pathway was tested. The obtained findings indicated Dex suppressed microglial pyroptosis by inhibiting the P2X7R/NLRP3/Caspase-1 pathway. Inhibition of P2X7R or NLRP3 could inhibit Caspase-1 p10 expression, improve cell activity, and reduce LDH activity. The same result was verified in vivo experiments. This study indicated that Dex inhibited microglia pyroptosis by blocking the P2X7R/NLRP3/Caspase-1 pathway, thus playing a protective role against ischemic brain injury.

Exosomes containing miR-451a is involved in the protective effect of cerebral ischemic preconditioning against cerebral ischemia and reperfusion injury.

AIM: To study the role of exosomes in the protective effect of cerebral ischemic preconditioning (cerebral-IPC) against cerebral I/R injury. METHOD: Mouse models of cerebral-IPC and MCAO/R were established as described previously, and their behavioral, pathological, and proteomic changes were analyzed. Neuro-2a subjected to OGD/R were treated with exosomes isolated from the plasma of sham-operated and cerebral-IPC mice. The differentially expressed miRNAs between exosomes derived from sham-operated (S-exosomes) and preconditioned (IPC-exosomes) mice were identified through miRNA array, and their targets were identified through database search. The control and OGD/R cells were treated with the IPC-exosomes, miRNA mimic or target protein inhibitor, and their viability, oxidative, stress and apoptosis rates were measured. The activated pathways were identified by analyzing the levels of relevant proteins. RESULTS: Cerebral-IPC mitigated the cerebral injury following ischemia and reperfusion, and increased the number of plasma exosomes. IPC-exosomes increased the survival of Neuro-2a cells after OGD/R. The miR-451a targeting Rac1 was upregulated in the IPC-exosomes relative to S-exosomes. The miR-451a mimic and the Rac1 inhibitor NSC23766 reversed OGD/R-mediated activation of Rac1 and its downstream pathways. CONCLUSION: Cerebral-IPC ameliorated cerebral I/R injury by inducing the release of exosomes containing miR-451a.

Expression of fibroblast growth factor 9 and its receptors in the dentate gyrus of hippocampus in poststroke depression rats.

Studies have found that fibroblast growth factor 9 (FGF9) might have a negative effect in the psychiatric diseases, such as depression or anxiety, but its potential role in the pathophysiology of poststroke depression (PSD) remains uncertain. Here, we set out to investigate the expression changes of FGF9 and its receptors in PSD rats. Middle cerebral artery occlusion (MCAO) combined with chronic unpredictable mild stress was used to establish the PSD rat model. Then, the rats were randomly divided into four groups: control (sham-operation), MCAO, PSD and treated (fluoxetine injection by intraperitoneal). Weight measurement, sucrose preference test, open-field test and forced swim test were performed to evaluate the behavioral changes, and then Western blot and real-time quantitative PCR were used to detect the expression level of FGF9, fibroblast growth factor receptor 1 (FGFR1) and receptor 3 (FGFR3) in the dentate gyrus of rat hippocampus. We found that FGF9 protein and mRNA expression increased significantly in the MCAO and PSD groups; FGFR3 protein and mRNA expression decreased significantly in the MCAO and PSD groups; FGFR1 protein and mRNA expression decreased significantly in the PSD group, but increased in the treated group. Furthermore, the changes mentioned above were reversed obviously by fluoxetine. These results indicated that upregulated FGF9 expression and downregulated FGFR1 and FGFR3 expression may be involved in the pathogenesis of PSD, and the FGF9/FGFR signaling pathway may be considered as an attractive target for further study.

Microarray Profiling Reveals Distinct Circulating miRNAs in Aged Male and Female Mice Subjected to Post-stroke Social Isolation.

Social isolation (SI) increases ischemic injury and significantly delays recovery after experimental stroke. Changes in circulating microRNAs (miRNAs) have been implicated in several neurological disorders, including stroke. However, potential biomarkers to elucidate the mechanisms that underlie the detrimental effects of post-stroke isolation are unknown. Aged C57BL/6 male and female mice (18-20 months) were subjected to a 60-min middle cerebral artery occlusion followed by reperfusion and were assigned to either isolation (SI) or continued pair housing (PH) immediately after stroke. On day 15, mice were sacrificed, and plasma samples were collected for miRNAome analysis. Top candidate miRNAs and their biological functions were identified using integrated bioinformatics. The miRNAome analysis revealed a total of 21 differentially expressed miRNAs across both sexes with fold change of 3 or higher. Within the female cohort, miR-206-3p, -376a-3p, -34b-5p, -133a-5p, -466f, and -671-3p were highly altered relative to the PH housing condition. Similarly in males, miR-376c-3p, -181d-5p, -712-5p, -186-5p, -21a-3p, -30d-3p, -495-3p, -669c-5p, -335-5p, -429-3p, -31-3p, and -217-5p were identified. Following Kyoto Encyclopedia of Genes and Genomes analysis, the identified miRNAs effected distinct subset of pathways within sexes. Interactional network analysis revealed miR-495-3p (male) and miR-34b-5p (female) as pivotal nodes that targeted the largest subset of genes. We identified several sex-specific miRNAs as candidate biomarkers for post-stroke SI in aged male and female mice. Additionally, these results suggest that there is potential to use plasma-based circulating miRNAs as a source of novel biomarkers to identify biological pathways involved in post-stroke SI.

Protective effect of DLX6-AS1 silencing against cerebral ischemia/reperfusion induced impairments.

In the present study, we investigated the role of lncRNA mus distal-less homeobox 6 antisense 1 (DLX6-AS1) during cerebral impairment induced by stroke. DLX6-AS1 levels were upregulated during ischemia/reperfusion (I/R) and downregulation of DLX6-AS1 reduced acute injury and ameliorated long-term neurological impairments induced by cerebral I/R in mice. Additionally, silencing of DLX6-AS1 significantly decreased the neuronal apoptosis in vivo and in vitro. Furthermore, inhibition of miRNA-149-3p led to enhance the apoptosis, which confirmed that DLX6-AS1 could sponge miR-149-3p. Finally, BOK was predicted to be the target of miR-149-3p using TargetScanVert software. And the silencing of DLX6-AS1 inhibited BOK expression both in vivo and in vitro, which was reversed by a miR-149-3p inhibitor. At meantime, BOK promoted OGD/R induced apoptosis in N2a cells. Therefore, this suggests that miR-149-3p sponging by DLX6-AS1 may lead to cerebral neuron I/R-induced impairments through upregulation of apoptotic BOK activity, which offers a new approach to the treatment of stroke impairment.

Combination of Scalp Acupuncture with Exercise Therapy Effectively Counteracts Ischemic Brain Injury in Rats.

BACKGROUND: Stroke is one of the leading causes of death and disability worldwide. Scalp acupuncture and exercise therapy have been proven as two effective methods for the treatment of stroke. However, their combined action and mechanisms have not been fully elucidated. The present study aimed to investigate the protective effect of scalp acupuncture combined with exercise therapy on neurons in rats with ischemic brain injury. METHODS: 100 rats were randomly divided into 5 groups including sham group, model group, acupuncture group, rehabilitation group, and experimental group (scalp acupuncture combined with exercise therapy). Middle cerebral artery occlusion (MCAO) model in rats was established according to Longa modified suture method to mimic ischemic stroke. The modified Bedexer's neurological function score was used to evaluate the neurological deficits of rats and the brain infarct volume was measured using 2, 3, 5-triphenyl tetrazolium chloride monohydrate (TTC) staining. Moreover, the apoptosis in the hippocampus was detected by western blotting and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The pro-inflammatory cytokines such as interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α), reactive oxygen species (ROS) and superoxide dismutase (SOD) were determined by corresponding kits. Immunohistochemistry or immunofluorescence was performed to detect the expression of brain-derived neurotrophic factor (BDNF), S100ß and glial fibrillary acidic protein (GFAP) in the hippocampi of rats. RESULTS: The neurological deficit score, the expression levels of apoptotic factors such as cleaved caspase-3 and Bax, and the TUNEL-positive cell rate of the experimental group were significantly lower than those of the acupuncture group and the rehabilitation group. However, apoptosis inhibitor Bcl-2 showed downregulated expression in the MCAO model rats but this trend was reverted by single and combinatorial treatments. In addition, the contents of TNF-α, IL-1ß and ROS in the acupuncture group and the rehabilitation group were significantly lower than those in the model group, but higher than the experimental group. While the opposite results were obtained in SOD activity. Furthermore, compared with the model group, the ratios of BDNF, S100ß, and GFAP-positive cells in the acupuncture, rehabilitation and experimental groups were significantly increased, and the highest ratios were recorded in the experimental group. CONCLUSIONS: This study demonstrated that scalp acupuncture combined with exercise therapy effectively counteracts ischemic brain injury via the downregulation of pro-inflammatory mediators and ROS, the increased production of the antioxidant enzyme SOD, neurotrophic factor BDNF and astrocyte activities.

Response to Speech and Language Therapy According to Artery Involvement and Lesion Location in Post-stroke Aphasia.

PURPOSE: Aphasia is one of the most common complications after stroke and occurs in 21-38% of the patients during acute period. The present study aimed to investigate the response to speech and language therapy according to artery involvement and lesion location in patients with post-stroke aphasia. METHOD: The medical records of 107 patients with post-stroke aphasia (mean age, 58.8 ± 14.8 years) who were admitted to a single rehabilitation center for usual care after stroke were reviewed. Location of the ischemic lesion and involved artery was determined assessing the brain MRI of the patients. All the patients received 24 sessions speech and language therapy (3 days a week) as a part of 8-week rehabilitation program. Evaluation of the aphasia was performed with Gülhane Aphasia Test-2 (GAT-2) at baseline and at the end of the rehabilitation program. RESULTS: Baseline GAT-2 scores was significantly worse in patients with middle cerebral artery (MCA) involvement compared to patients with other artery involvements (p = 0.007). While the GAT-2 scores of patients with MCA involvement were improved significantly after speech and language therapy (p < 0.001), the changes in those with anterior cerebral artery (ACA) and posterior cerebral artery (PCA) involvements were not significant (p > 0.05). CONCLUSIONS: The present findings suggested that speech functions might be more affected in ischemic lesion of MCA and response to SLT might be better in patients with MCA involvement.

Long-term follow-up of patients undergoing decompressive hemicraniectomy for malignant stroke: Quality of life and caregiver's burden in a real-world setting.

BACKGROUND AND PURPOSE: Decompressive hemicraniectomy is a life-saving procedure for the treatment of space-occupying middle cerebral artery infarctions (malignant stroke); however, patients may survive severely disabled. Comprehensive data on long-term sequelae outside randomized controlled trials are scarce. METHODS: We retrospectively evaluated the survival rates, quality of life, ability to perform activities of daily living, and caregiver burden of 61 patients (aged from 37 to 83) who had previously undergone decompressive hemicraniectomy for malignant stroke between 2012 and 2017. RESULTS: The mortality rate was higher among patients older than 60 years than among younger patients (71.0 % vs 36.7 %, p = 0.007; odds ratio 4.222, 95 % confidence interval 1.443-12.355). The mean survival time was 37.9 ± 6.0 months for 19 survivors of the younger group and 22.6 ± 5.7 months for 9 survivors of the older group. Among the 28 surviving patients, 22 (78.6 %) were interviewed, and we found that age was a determining factor for functional outcome (Barthel indices of 65.7 ± 10.6 for younger patients vs 48.0 ± 9.3 for older patients, p < 0.001), but not for quality of life. The caregiver burden was significantly correlated (R = -0.53, p < 0.01) with the severity of disability and age (R = 0.544, p = 0.011) of the patients. CONCLUSION: Our findings show that the degree of impairment, as well as caregiver burden, is higher in patients older than 60 years than in younger patients.

Eating and Grooming Abilities Predict Outcomes in Patients with Early Middle Cerebral Infarction: A Retrospective Cohort Study.

Patients with cerebrovascular disorders are often forced to rest, with early prognosis made by bedside examination. However, overloading, for example, talking for a long time, may worsen the condition. We hypothesized that activities of daily living (ADL) from the Functional Independence Measure (FIM) that were actually performed regularly are useful to predict prognosis. The present study was aimed at determining the predictive items related to predicting prognosis from the status of early motor paralysis and ADL in patients with acute middle cerebral artery (MCA) infarction. We examined 367 patients with MCA infarction for Brunnstrom recovery stage (BRS) and FIM within 4 days of admission and modified the Rankin Scale before onset and just before discharge. Logistic regression analysis was used to compare two groups of patients based on their postdischarge destination (Home/another hospital or facility). The logistic regression analysis showed the following: BRS Hand: odds ratio (OR) 1.641 (95% CI 1.642 (1.336-2.017), p < 0.001); FIM Grooming: OR 1.279 (95% CI 1.220-1.807, p < 0.001); and FIM Eating: OR 1.280 (95% CI 1.102-1.488, p < 0.001). On the other hand, the ROC analysis showed the ROC area for Eating to be 0.830 (95% CI 0.787-0.874), for Grooming to be 0.81 (95% CI 0.765-0.865), and for BRS Hand to be 0.805 (95% CI 0.760-0.851). The BRS Hand and FIM Eating and Grooming domains were identified as predictive factors using the following cutoff points: BRS Hand stage V and FIM scores of 5 for Eating and 4 for Grooming. The cutoff points for the BRS Hand and FIM Eating revealed that, at a minimum, such patients can use the nonaffected hand. The presence of cognitive dysfunction or dysphagia affects these domains. Therefore, these results suggested that Eating and Grooming are appropriate as evaluation items.

Empathy in stroke rats is modulated by social settings.

Rodents display "empathy" defined as perceived physical pain or psychological stress by cagemates when co-experiencing socially distinct traumatic events. The present study tested the hypothesis that empathy occurs in adult rats subjected to an experimental neurological disorder, by allowing co-experience of stroke with cagemates. Psychological stress was measured by general locomotor activity, Rat Grimace Scale (RGS), and plasma corticosterone. Physiological correlates were measured by Western blot analysis of advanced glycation endproducts (AGE)-related proteins in the thymus. General locomotor activity was impaired in stroke animals and in non-stroke rats housed with stroke rats suggesting transfer of behavioral manifestation of psychological stress from an injured animal to a non-injured animal leading to social inhibition. RGS was higher in stroke rats regardless of social settings. Plasma corticosterone levels at day 3 after stroke were significantly higher in stroke animals housed with stroke rats, but not with non-stroke rats, indicating that empathy upregulated physiological stress level. The expression of five proteins related to AGE in the thymus reflected the observed pattern of general locomotor activity, RGS, and plasma corticosterone levels. These results indicate that stroke-induced psychological stress manifested on both the behavioral and physiological levels and appeared to be affected by empathy-associated social settings.

Neuropsychological impairment in adults with moyamoya angiopathy: preoperative assessment and correlation to MRI and H215O PET.

Patients with moyamoya angiopathy (MMA) are known to have an increased risk of impaired executive function (dysexecutive cognitive syndrome (DCS)). Numbers of moyamoya patients with DCS vary strongly in the literature; evidence of a correlation to affected vascular territories is low. This study aims to identify cognitive impairment in adult moyamoya patients and to correlate findings with imaging results. In addition, the predictive value of individual tests for the identification of DCS was analyzed. Neuropsychological test data of 41 adult moyamoya patients was analyzed for a possible correlation with territorial hypoperfusion on H215O PET with acetazolamide (ACZ) challenge (cerebrovascular reserve-CVR) and infarction patterns observed in MRI. Each vascular territory was analyzed separately and correlated to neuropsychological test results and to the presence of DCS. In total, 41.5% of patients presented with DCS. Significant association of DCS and affection of the right middle cerebral artery (MCA) territory was seen for insufficient CVR in PET (p = 0.030) and for patients with infarctions seen in MRI (p = 0.014). Analysis of individual neuropsychological test results confirmed the main association with the right MCA territory, as well as some association with the right anterior cerebral artery (ACA) territory. Analysis of a subgroup of patients with chronic disease on MRI (presence of large post-infarction gliosis and brain atrophy in affected territories) revealed a significantly higher risk for DCS (85% affected) than non-chronic patients (21% affected) (p < 0.001). Analysis of neuropsychological test data in this moyamoya cohort reveals DCS in 41.5% of all patients. Correlation between DCS and an impairment of CVR seen in PET and/or infarctions seen in MRI was significant for the right MCA territory. Patients with chronic disease had a significantly higher risk for DCS than non-chronic patients (p < 0.001).

Clematichinenoside Facilitates Recovery of Neurological and Motor Function in Rats after Cerebral Ischemic Injury through Inhibiting Notch/NF-κB Pathway.

PURPOSE: The present study was to observe the therapeutic efficiency of Clematichinenoside (AR) on cerebral ischemic injury in rats, especially on neurological and motor function recovery and to explore the underlying mechanism. METHODS: Following middle cerebral artery occlusion/reperfusion (MCAO/R) surgery, rats were treated orally with 32, 16, and 8 mg/kg AR respectively for 14 days during which cerebral injury was evaluated and proinflammatory factors tumor necrosis factor-α and interleukin-6 as well as neurotrophic factors brain-derived neurotrophic factor and Neurotrophin-3 levels were determined with ELISA kits. Immunohistochemical analysis on number of neurons and reactive astrocytes in the hippocampus was to demonstrate the effect of AR on neuronal survival. Motor, learning, and memory recovery were assessed by Morris water maze, passive avoidance experiment, and rotatory rod test. Neuroprotection and anti-inflammation-related Notch and nuclear factor-κB (NF-κB) signaling pathways were analyzed by PCR and Western blot techniques on mammalian achaete-scute homologs1, Notch-1, intracellular Notch receptor domain, Jagged-1, transcription factor hairy, enhancer of split1 (Hes1), as well as the nuclear import of NF-κB in hippocampus. RESULTS: AR administration reduced cerebral injury in rats exposed to MCAO/R and after treatment of AR for 14 days, proinflammatory reaction was inhibited, with neuronal survival rate raised and motor function recovery facilitated. PCR and WB analysis of Notch/NF-κB signaling pathway revealed the inhibitory effect of AR on pathway related components. CONCLUSIONS: AR is beneficial to recovery of neurological and motor function in rats after cerebral ischemic injury via inhibiting Notch/NF-κB pathway.

The effect of pyruvate on the development and progression of post-stroke depression: A new therapeutic approach.

Post-stroke depression (PSD) is a common and serious complication following stroke. Both stroke and depression have independently been associated with pathologically elevated glutamate levels in the brain's extra-cerebral fluid (ECF). Here we evaluate an alternative therapeutic approach to PSD with pyruvate. Rats were randomly assigned into one of 3 groups: Middle Cerebral Artery Occlusion (MCAO) plus pyruvate treatment, MCAO plus placebo treatment, and sham operated rats. Post-MCAO depressive and anxiety-like behavior was assessed, along with neurological status, brain infarct zone, brain edema, blood brain barrier (BBB) breakdown, cerebrospinal fluid and blood glutamate levels. Anxiety-like behavior and levels of blood alanine and α-ketoglutarate were measured in naïve rats treated with pyruvate, as a control. Post-stroke neurological deficit with concurrent elevation in glutamate levels were demonstrated, with peak glutamate levels 24 h after MCAO. Treatment with pyruvate led to reduced glutamate levels 24 h after MCAO and improved neurologic recovery. Pyruvate treatment reduced lesion volume, brain edema and the extent of BBB permeability 24 h post-MCAO. Naïve rats treated with pyruvate showed increased levels of α-ketoglutarate. Rats demonstrated post-stroke depressive behavior that was improved by the administration of pyruvate. There was less anxiety-like behavior in post-stroke rats treated with placebo in comparison to the post-stroke rats treated with pyruvate or sham operated rats. Glutamate scavenging with pyruvate appears to be an effective as a method in providing neuroprotection following stroke and as a therapeutic option for the treatment of PSD by reducing the consequent elevations in CNS glutamate levels.

Effects of Integrin ß1 on behavior and neurovascular regeneration in rats with cerebral ischemia-reperfusion injury.

OBJECTIVE: The aim of this study is to investigate the effect of Integrin ß1 on neurological behavior and neurovascular regeneration in rats with a cerebral ischemia-reperfusion injury. MATERIALS AND METHODS: Rat middle cerebral artery occlusion (MCAO) was performed with a modified suture embolization method. Neurological function score of each rat was recorded. Cerebral infarct volume was calculated by Image J after TTC stain. Subsequently, behavioral tests were performed to evaluate neuronal damage, including griping strength test, corner test, cylinder test and sucrose preference test. The expression levels of VEGF, HIF-1α, Claudin5, and ZO-1 in rat brain tissues were detected by Western blot and quantitative Reverse Transcriptase-Polymerase Chain Reaction (qRT-PCR), respectively. RESULTS: Neurological function score of the rat was remarkably decreased after cerebral ischemia-reperfusion. Anti-Integrin ß1 administration aggravated neurological deficit and increased cerebral infarct volume of I/R rats. Symptoms of hemidysesthesia, dyskinesia, and affective disorder of rats were worse after anti-Integrin ß1 administration in I/R rats. Anti-Integrin ß1 administration downregulated VEGF and HIF-1α in rat brain tissues (p<0.05). However, no significant differences in Claudin5 and ZO-1 expressions were found before and after Integrin ß1 treatment. CONCLUSIONS: The inhibition of Integrin ß1 pathway during cerebral ischemia-reperfusion aggravates the behavior and neurovascular regeneration of I/R rats. In the process of cerebral ischemia-reperfusion, Integrin ß1 plays a key role in the repair and protection of neurovascular units by promoting angiogenesis.

MicroRNA-132 attenuates cerebral injury by protecting blood-brain-barrier in MCAO mice.

MicroRNAs (miRNAs) have been widely reported to induce posttranscriptional gene silencing and led to an explosion of new strategies for the treatment of human disease. It has been reported that the expression of MicroRNA-132 (miR-132) are altered both in the blood and brain after stroke. However, the effect of miR-132 on blood-brain barrier (BBB) disruption in ischemia stroke has not been studied. Here we will investigate the effects of miR-132 on the permeability of BBB after ischemic stroke and explore the potential mechanism underlying observed protection. Eight week-old mice were injected intracerebroventricularly with miR-132, antagomir-132 or agomir negative control (agomir-NC) 2 h before middle cerebral artery occlusion (MCAO), followed by animal behavior tests and infraction volume measurement at 24 h after MCAO. BBB permeability and integrity were measured by Evan's blue extravasation and brain water content. The expression of tight junction proteins was detected by immnostaining and Western blots. The level of MiR-132 and its targeted gene Mmp9 were assayed. Treatment with exogenous MiR-132 (agomir-132) decreased the infraction volume, reduced brain edema, and improved neurological functions compared to control mice. Agomir-132 increased the level of MiR-132 in brain tissue, suppressed the expression of MMP-9 mRNA and decreased the degradation of tight junction proteins VE-cadherin and ß-Catenin in ischemic stroke mice. Inhibition of MMP-9 has a similar protective effect to agomir-132 on infraction volume, brain edema, and tight-junction protein expression after MCAO. Our results indicated that miR-132/MMP-9 axis might be a novel therapeutic target for BBB protection in ischemic stroke.

Role of Perivascular Oligodendrocyte Precursor Cells in Angiogenesis After Brain Ischemia.

Background Oligodendrocyte precursor cells ( OPC s) regulate neuronal, glial, and vascular systems in diverse ways and display phenotypic heterogeneity beyond their established role as a reservoir for mature oligodendrocytes. However, the detailed phenotypic changes of OPC s after cerebral ischemia remain largely unknown. Here, we aimed to investigate the roles of reactive OPC s in the ischemic brain. Methods and Results The behavior of OPC s was evaluated in a mouse model of ischemic stroke produced by transient middle cerebral artery occlusion in vivo. For in vitro experiments, the phenotypic change of OPC s after oxygen glucose derivation was examined using a primary rat OPC culture. Furthermore, the therapeutic potential of hypoxic OPC s was evaluated in a mouse model of middle cerebral artery occlusion in vivo. Perivascular OPC s in the cerebral cortex were increased alongside poststroke angiogenesis in a mouse model of middle cerebral artery occlusion. In vitro RNA -seq analysis revealed that primary cultured OPC s increased the gene expression of numerous pro-angiogenic factors after oxygen glucose derivation. Hypoxic OPC s secreted a greater amount of pro-angiogenic factors, such as vascular endothelial growth factor and angiopoietin-1, compared with normoxic OPC s. Hypoxic OPC -derived conditioned media increased the viability and tube formation of endothelial cells. In vivo studies also demonstrated that 5 consecutive daily treatments with hypoxic OPC -conditioned media, beginning 2 days after middle cerebral artery occlusion, facilitated poststroke angiogenesis, alleviated infarct volume, and improved functional disabilities. Conclusions Following cerebral ischemia, the phenotype of OPC s in the cerebral cortex shifts from the parenchymal subtype to the perivascular subtype, which can promote angiogenesis. The optimal use of hypoxic OPC s secretome would provide a novel therapeutic option for stroke.

Angiotensin II type 2 receptor stimulation with compound 21 improves neurological function after stroke in female rats: a pilot study.

The angiotensin II type 2 receptor (AT2R) agonist, compound 21 (C21), has been shown to be neurovascularly protective after ischemic stroke in male rats. In the current study, we aim to study the impact of C21 treatment on female rats. Young female Wistar rats were subjected to different durations of middle cerebral artery occlusion (MCAO) (3 h, 2 h, and 1 h) using a silicone-coated monofilament, treated at reperfusion with 0.03 mg/kg ip of C21 and followed up for different times (1, 3, and 14 days) after stroke. Behavioral tests were performed (Bederson, paw grasp, beam walk, and rotarod), and animals were euthanized for infarct size analysis and Western blot analysis. In vitro, primary male and female brain microvascular endothelial cells (ECs) were grown in culture, and the expression of the AT2R was compared between males and females. At 1 day, C21 treatment resulted in an improvement in Bederson scores. However, at 3 days and 14 days, the impact of C21 on stroke outcomes was less robust. In vitro, the expression of the AT2R was significantly higher in female ECs compared with male ECs. In conclusion, C21 improves Bederson scores after stroke in female rats when administered early at reperfusion. The ability of C21 to exert its neuroprotective effects might be affected by fluctuating levels of female hormones. NEW & NOTEWORTHY The present study shows the neuroprotective impact of C21 on ischemic stroke in female rats and how the protective effects of C21 can be influenced by the hormonal status of female rodents.