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Breviscapine (Bre), an extract from Erigeron breviscapus, has been widely used to treat cerebral ischemia but the mechanisms of its neuroprotective effects need to be clarified. The present study investigated whether Bre could alleviate excessive autophagy induced by cerebral ischemia in the rat middle cerebral artery occlusion (MCAO) ischemia model via activating the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 5 (STAT5)/B-cell lymphoma 2 (BCL2) pathway. Rats were randomly divided into 5 groups, i.e. Sham group, MCAO+saline group, MCAO+Bre group, MCAO+DMSO (Dimethyl sulfoxide) group, and MCAO+Bre+AG490 (Tyrphostin AG490, the inhibitor of STAT5) group. The model was established and neuroprotection was evaluated by determining infarct volumes and conducting neurological behavioral tests. Autophagy levels in the infarct penumbra were detected using transmission electron microscopy and Western blotting. The expression of proteins in the JAK2/STAT5/BCL2 pathway was tested by Western blotting. Compared to the MCAO+saline group, the infarct volumes in the MCAO+Bre group were significantly reduced and neurological behavior improved. Breviscapine administration also significantly increased p-JAK2, p-STAT5, and BCL2 expression but decreased autolysosome numbers; it also downregulated Beclin-1 expression and the LC3II/LCI ratio. The JAK2 inhibitor AG490 reversed these effects. These findings indicate that breviscapine can improve neural recovery following ischemia through alleviating excessive autophagy and activation of the JAK2/STAT5/BCL2 axis.
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Autofagia , Modelos Animales de Enfermedad , Flavonoides , Janus Quinasa 2 , Proteínas Proto-Oncogénicas c-bcl-2 , Ratas Sprague-Dawley , Factor de Transcripción STAT5 , Transducción de Señal , Animales , Janus Quinasa 2/metabolismo , Flavonoides/farmacología , Masculino , Ratas , Autofagia/efectos de los fármacos , Autofagia/fisiología , Factor de Transcripción STAT5/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Transducción de Señal/efectos de los fármacos , Ataque Isquémico Transitorio/tratamiento farmacológico , Ataque Isquémico Transitorio/patología , Ataque Isquémico Transitorio/metabolismo , Fármacos Neuroprotectores/farmacología , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/patología , TirfostinosRESUMEN
BACKGROUND: Ischemic stroke remains the predominant contributor to mortality and disability globally. Microglia undergo rapid activation and initiate inflammatory cascade reactions by phenotypic polarization, participating in the regulation of inflammatory injury and tissue repair post-ischemic stroke. Regulating microglia-mediated neuroinflammation is a promising therapeutic strategy for ischemic stroke. Previously, we designed and synthesized a novel p55PIK inhibitor, TAT-N15 polypeptide, which presents inhibitive activity on NF-κB signaling-mediated inflammation in acute conjunctivitis and allergic rhinitis. The present study aimed to explore the therapeutic effect and mechanism of TAT-N15 on ischemia stroke. METHODS: The mouse model of transient cerebral ischemia was made using the intraluminal filament method. After being treated with daily intraperitoneal injections of TAT-N15 (10 mg/kg) for 7 d, the neurological outcomes and the cerebral infarction volume were evaluated. Histopathology of the ischemia cerebral hemisphere was observed by H&E and Nissl staining. Neuronal survival, astrogliosis, and co-labeling of CD86/Iba1 and CD206/Iba1 were detected by immunofluorescence. The cell apoptosis was estimated by TUNEL staining. The expression levels of apoptosis-associated proteins, proinflammatory cytokines, protein markers of M1 and M2 microglia, and the phosphorylation of NF-κB and STAT3 proteins in the ischemic penumbra were detected by Western blot. RESULTS: TAT-N15 treatment significantly decreased the infarct volume and alleviated neurological functional impairment, neuronal injury, and neuron apoptosis. Meanwhile, TAT-N15 treatment restrained the activation of microglia and astrocytes as well as the protein expression of proinflammatory cytokine in ischemic penumbra. Additionally, the administration of TAT-N15 treatment resulted in a significant reduction in the density of M1 phenotype microglia while concurrently increasing the density of M2 phenotype microglia within the ischemic penumbra. Finally, mechanical analysis unveiled that TAT-N15 exerted a substantial inhibitory effect on the protein expression of phosphorylated STAT3 and NF-κB. CONCLUSION: TAT-N15 may inhibit neuroinflammation via regulating microglia activation and polarization through the STAT3/NF-κB pathway, which exhibits the neuroprotection effect in ischemic stroke.
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Antiinflamatorios , Apoptosis , Modelos Animales de Enfermedad , Mediadores de Inflamación , Ratones Endogámicos C57BL , Microglía , FN-kappa B , Enfermedades Neuroinflamatorias , Fármacos Neuroprotectores , Factor de Transcripción STAT3 , Transducción de Señal , Animales , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Microglía/efectos de los fármacos , Microglía/metabolismo , Microglía/patología , FN-kappa B/metabolismo , FN-kappa B/antagonistas & inhibidores , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Enfermedades Neuroinflamatorias/metabolismo , Fármacos Neuroprotectores/farmacología , Masculino , Antiinflamatorios/farmacología , Apoptosis/efectos de los fármacos , Mediadores de Inflamación/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Ataque Isquémico Transitorio/tratamiento farmacológico , Ataque Isquémico Transitorio/metabolismo , Ataque Isquémico Transitorio/patología , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Accidente Cerebrovascular Isquémico/metabolismo , Accidente Cerebrovascular Isquémico/patología , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patologíaRESUMEN
OBJECTIVES: Coptisine (Cop), an alkaloid isolated from Rhizoma Coptidis, has a protective effect against central nervous system diseases such as cerebral ischaemia-reperfusion (IR). Dysregulations in fatty acids metabolism are associated with neuroprotection and neuroinflammation. However, the effect of Cop on fatty acids metabolomics during anti-IR remains unclear. METHODS: Cerebral IR rats were established by middle cerebral artery occlusion, and the therapeutic effect of Cop was evaluated by 2, 3, 5-triphenytetrazolium chloride staining and neurological deficits scores. By liquid chromatography-tandem mass spectrometry (LC-MS/MS), fatty acids metabolomics analysis in ischaemic hemisphere and serum were investigated. RESULTS: We observed Cop (2 mg/kg/qd) was able to reduce cerebral infarct size and ameliorate the neurological function score. Meanwhile decrease in tumour necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) after Cop treatment. Compared with control, down-regulation of cyclopentenone PGs (e.g., PGA2, PGJ2, and 15-deoxy- delta-12,14-PGJ2) was observed in cerebral IR, but upregulation of them when followed by Cop treatment. Similarly, we found the ratios of 14,15-dihydroxyeicosatrienoic acid(14,15-DHET)/arachidonic acid and 11,12-DHET/arachidonic acid was lower in cerebral IR injury relative to control, while their ratios were increased after Cop treatment. CONCLUSION: Our results indicated that Cop protect against cerebral IR injury, and its mechanism might be closely associated with antiinflammation and the regulation of arachidonic acid metabolism.
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Ácido Araquidónico , Berberina , Infarto de la Arteria Cerebral Media , Ratas Sprague-Dawley , Daño por Reperfusión , Factor de Necrosis Tumoral alfa , Animales , Berberina/farmacología , Berberina/análogos & derivados , Ácido Araquidónico/metabolismo , Masculino , Ratas , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/metabolismo , Daño por Reperfusión/prevención & control , Factor de Necrosis Tumoral alfa/metabolismo , Fármacos Neuroprotectores/farmacología , Interleucina-1beta/metabolismo , Modelos Animales de Enfermedad , Espectrometría de Masas en Tándem , Ataque Isquémico Transitorio/tratamiento farmacológico , Ataque Isquémico Transitorio/metabolismo , Ataque Isquémico Transitorio/prevención & control , Metabolómica/métodos , Ácidos Grasos/metabolismoRESUMEN
AIMS: Studies showed that low-density lipoprotein cholesterol (LDL-C) to triglyceride (TG) ratio could be used as a predictive parameter of low-density lipoprotein oxidation in vivo and the level of small dense LDL-C. However, whether LDL-C/TG ratio is associated with stroke prognosis remains unclear. We investigated the associations of LDL-C/TG ratio with outcomes in patients with acute ischaemic stroke (AIS) or transient ischaemic attacks (TIA) and explored whether it produced more predictive value than LDL-C and TG. METHODS: Data were derived from the Third China National Stroke Registry (CNSR-III). Multivariable Cox regression for stroke recurrence, composite vascular events and all-cause death and logistic regression for the poor functional outcome (modified Rankin Scale score 3-6) were used. RESULTS: A total of 14123 patients were included. After adjusting for confounding factors, quartile 4 of LDL-C/TG ratio was associated with an increased risk of recurrent stroke (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.03-1.56), composite vascular events (HR,1.23; 95% CI, 1.00-1.52), death (HR,1.70; 95% CI, 1.13-2.54) and poor functional outcome (odds ratio, 1.34; 95% CI, 1.12-1.61) at 3 months follow-up compared with quartile 1. We also found that quartile 4 of LDL-C and TG was positively and negatively associated with poor functional outcome at 3 months, respectively. LDL-C/TG ratio performed better than LDL-C or TG in predicting clinical outcomes. CONCLUSIONS: LDL-C/TG ratio was associated with the risk of stroke recurrence, composite vascular events, death and poor functional outcome in patients with AIS or TIA.
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LDL-Colesterol , Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Triglicéridos , Humanos , Masculino , Femenino , Ataque Isquémico Transitorio/sangre , Ataque Isquémico Transitorio/metabolismo , Triglicéridos/sangre , Accidente Cerebrovascular Isquémico/sangre , Accidente Cerebrovascular Isquémico/diagnóstico , Persona de Mediana Edad , LDL-Colesterol/sangre , Pronóstico , Anciano , Biomarcadores/sangre , China/epidemiología , Estudios de Seguimiento , Sistema de Registros , Factores de Riesgo , RecurrenciaRESUMEN
AIM: In this study, we investigated the effects of Dendropanax morbifera extract (DME) on neuroprotection against ischemic damage in gerbils. METHODS: DME (100 or 300 mg/kg) was orally administered to gerbils for three weeks, and 2 h after the last DME treatment, transient forebrain ischemia in the common carotid arteries was induced for 5 min. The forebrain ischemia-related cognitive impairments were assessed by spontaneous motor activity and passive avoidance test one and four days after ischemia, respectively. In addition, surviving and degenerating neurons were morphologically confirmed by neuronal nuclei immunohistochemical staining and Fluoro-Jade C staining, respectively, four days after ischemia. Changes of glial morphology were visualized by immunohistochemical staining for each marker such as glial fibrillary acidic protein and ionized calcium-binding protein. Oxidative stress was determined by measurements of dihydroethidium, O2· (formation of formazan) and malondialdehyde two days after ischemia. In addition, glutathione redox system such as reduced glutathione, oxidized glutathione levels, glutathione peroxidase, and glutathione reductase activities were measured two days after ischemia. RESULTS: Spontaneous motor activity monitoring and passive avoidance tests showed that treatment with 300 mg/kg DME, but not 100 mg/kg, significantly alleviated ischemia-induced memory impairments. In addition, approximately 67 % of mature neurons survived and 29.3 % neurons were degenerated in hippocampal CA1 region four days after ischemia, and ischemia-induced morphological changes in astrocytes and microglia were decreased in the CA1 region after 300 mg/kg DME treatment. Furthermore, treatment with 300 mg/kg DME significantly ameliorated ischemia-induced oxidative stress, such as superoxide formation and lipid peroxidation, two days after ischemia. In addition, ischemia-induced reduction of the glutathione redox system in the hippocampus, assessed two days after the ischemia, was ameliorated by treatment with 300 mg/kg DME. These suggest that DME can potentially reduce ischemia-induced neuronal damage through its antioxidant properties.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Humanos , Animales , Gerbillinae/metabolismo , Ataque Isquémico Transitorio/metabolismo , Hipocampo/metabolismo , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/metabolismo , Estrés Oxidativo , Antioxidantes/farmacología , Glutatión/metabolismo , Infarto CerebralRESUMEN
BACKGROUND: Transient ischemic attack (TIA) induces ischemic tolerance that can reduce the subsequent ischemic damage and improve prognosis of patients with stroke. However, the underlying mechanisms remain elusive. Recent advances in plasma metabolomics analysis have made it a powerful tool to investigate human pathophysiological phenotypes and mechanisms of diseases. In this study, we aimed to identify the bioactive metabolites from the plasma of patients with TIA for determination of their prophylactic and therapeutic effects on protection against cerebral ischemic stroke, and the mechanism of TIA-induced ischemic tolerance against subsequent stroke. METHODS: Metabolomic profiling using liquid chromatography-mass spectrometry was performed to identify the TIA-induced differential bioactive metabolites in the plasma samples of 20 patients at day 1 (time for basal metabolites) and day 7 (time for established chronic ischemic tolerance-associated metabolites) after onset of TIA. Mouse middle cerebral artery occlusion (MCAO)-induced stroke model was used to verify their prophylactic and therapeutic potentials. Transcriptomics changes in circulating neutrophils of patients with TIA were determined by RNA-sequencing. Multivariate statistics and integrative analysis of metabolomics and transcriptomics were performed to elucidate the potential mechanism of TIA-induced ischemic tolerance. FINDINGS: Plasma metabolomics analysis identified five differentially upregulated metabolites associated with potentially TIA-induced ischemic tolerance, namely all-trans 13,14 dihydroretinol (atDR), 20-carboxyleukotriene B4, prostaglandin B2, cortisol and 9-KODE. They were associated with the metabolic pathways of retinol, arachidonic acid, and neuroactive ligand-receptor interaction. Prophylactic treatment of MCAO mice with these five metabolites significantly improved neurological functions. Additionally, post-stroke treatment with atDR or 9-KODE significantly reduced the cerebral infarct size and enhanced sensorimotor functions, demonstrating the therapeutic potential of these bioactive metabolites. Mechanistically, we found in patients with TIA that these metabolites were positively correlated with circulating neutrophil counts. Integrative analysis of plasma metabolomics and neutrophil transcriptomics further revealed that TIA-induced metabolites are significantly correlated with specific gene expression in circulating neutrophils which showed prominent enrichment in FoxO signaling pathway and upregulation of the anti-inflammatory cytokine IL-10. Finally, we demonstrated that the protective effect of atDR-pretreatment on MCAO mice was abolished when circulating neutrophils were depleted. INTERPRETATION: TIA-induced potential ischemic tolerance is associated with upregulation of plasma bioactive metabolites which can protect against cerebral ischemic damage and improve neurological functions through a positive role of circulating neutrophils. FUNDING: National Natural Science Foundation of China (81974210), Science and Technology Planning Project of Guangdong Province, China (2020A0505100045), Natural Science Foundation of Guangdong Province (2019A1515010671), Science and Technology Program of Guangzhou, China (2023A03J0577), and Natural Science Foundation of Jiangxi, Chinaï¼20224BAB216043).
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Ataque Isquémico Transitorio , Accidente Cerebrovascular , Humanos , Ratones , Animales , Ataque Isquémico Transitorio/complicaciones , Ataque Isquémico Transitorio/metabolismo , Neutrófilos/metabolismo , Accidente Cerebrovascular/complicaciones , Infarto de la Arteria Cerebral Media/metabolismo , MetabolómicaRESUMEN
Stroke is a leading cause of disability and death worldwide. Ivermectin is a broad-spectrum anti-parasitic agent with potential anti-bacterial, anti-viral, and anti-cancer effects. However, the effects of ivermectin on the brain are poorly described. This study examined the effects of ivermectin on cerebral ischemia-reperfusion (IR) in rats. A rat model of transient global IR was induced by bilateral carotid artery occlusion for 20 min. Rats received ivermectin (2 mg/kg/day, ip) one hour after inducing cerebral IR for three consecutive days at 24-h intervals. Next, we examined the effects of ivermectin on brain infarction, histopathology, malondialdehyde levels, myeloperoxidase activity, spatial learning and memory, and phospho-AMPK protein levels. The results showed that ivermectin reduced brain infarct size (P < 0.001) and histopathological changes such as cerebral leukocyte accumulation and edema (P < 0.05) compared to untreated rats with IR. Treatment with ivermectin also decreased myeloperoxidase activity (P < 0.01) and malondialdehyde levels (P < 0.05) while increasing AMPK activity (P < 0.001), memory, and learning compared to the untreated IR group. Overall, we show for the first time that ivermectin conferred neuroprotective effects in a rat model of cerebral IR. Our results indicate that three days of treatment with ivermectin reduced brain infarct size, lipid peroxidation, and myeloperoxidase activity and improved memory and learning in rats with cerebral IR. These effects likely occurred via AMPK-dependent mechanisms.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Fármacos Neuroprotectores , Daño por Reperfusión , Ratas , Animales , Ataque Isquémico Transitorio/tratamiento farmacológico , Ataque Isquémico Transitorio/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Peroxidasa/metabolismo , Ivermectina/farmacología , Ivermectina/uso terapéutico , Proteínas Quinasas Activadas por AMP/metabolismo , Ratas Wistar , Estrés Oxidativo , Daño por Reperfusión/metabolismo , Isquemia Encefálica/patología , Infarto Cerebral/patología , Antioxidantes/farmacología , Reperfusión/efectos adversos , Malondialdehído/farmacologíaRESUMEN
OBJECTIVE: We previously reported that mutations in inner mitochondrial membrane peptidase 2-like (Immp2l) increase infarct volume, enhance superoxide production, and suppress mitochondrial respiration after transient cerebral focal ischemia and reperfusion injury. The present study investigated the impact of heterozygous Immp2l mutation on mitochondria function after ischemia and reperfusion injury in mice. METHODS: Mice were subjected to middle cerebral artery occlusion for 1 h followed by 0, 1, 5, and 24 h of reperfusion. The effects of Immp2l+/- on mitochondrial membrane potential, mitochondrial respiratory complex III activity, caspase-3, and apoptosis-inducing factor (AIF) translocation were examined. RESULTS: Immp2l+/- increased ischemic brain damage and the number of TUNEL-positive cells compared with wild-type mice. Immp2l+/- led to mitochondrial damage, mitochondrial membrane potential depolarization, mitochondrial respiratory complex III activity suppression, caspase-3 activation, and AIF nuclear translocation. CONCLUSION: The adverse impact of Immp2l+/- on the brain after ischemia and reperfusion might be related to mitochondrial damage that involves depolarization of the mitochondrial membrane potential, inhibition of the mitochondrial respiratory complex III, and activation of mitochondria-mediated cell death pathways. These results suggest that patients with stroke carrying Immp2l+/- might have worse and more severe infarcts, followed by a worse prognosis than those without Immp2l mutations.
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Ataque Isquémico Transitorio , Daño por Reperfusión , Animales , Ratones , Caspasa 3/genética , Caspasa 3/metabolismo , Complejo III de Transporte de Electrones/metabolismo , Infarto de la Arteria Cerebral Media/genética , Infarto de la Arteria Cerebral Media/metabolismo , Ataque Isquémico Transitorio/metabolismo , Membranas Mitocondriales/metabolismo , Mutación , Daño por Reperfusión/metabolismoRESUMEN
Epigenetic modification contributes to the pathogenesis of cerebral ischemia. Piwil2 belongs to the PIWI proteins subfamily and has a key role in the regulation of gene transcription through epigenetics. However, the roles of Piwil2 in cerebral ischemia have not been investigated. In this study, we aim to elucidate the roles and the underlying molecular mechanisms of Piwil2 in ischemic tolerance induced by hypoxic postconditioning (HPC) against transient global cerebral ischemia (tGCI). We found that the expression of Piwil2 in CA1 was downregulated by HPC after tGCI. Silencing Piwil2 with antisense oligodeoxynucleotide (AS-ODN) in CA1 after tGCI decreased the expression of apoptosis-related proteins and exerted neuroprotective effects. Opposite results were observed after overexpression of Piwil2 induced by administration of Piwil2-carried lentivirus. Furthermore, we revealed differentially expressed Piwil2-interacting piRNAs in CA1 between HPC and tGCI groups by RNA binding protein immunoprecipitation (RIP) assay. Moreover, downregulating Piwil2 induced by HPC or AS-ODN after tGCI caused a marked reduction of DNA methyltransferase 3A (DNMT3A), which in turn abolished the tGCI-induced increase in the DNA methylation of cyclic AMP response element-binding 2 (CREB2), thus increasing mRNA and protein of CREB2. Finally, downregulating Piwil2 restored dendritic complexity and length, prevented the loss of dentritic spines, thereby improving cognitive function after tGCI. These data firstly reveal that Piwil2 plays an important part in HPC-mediated neuroprotection against cerebral ischemia through epigenetic regulation of CREB2.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Animales , Ratas , Isquemia Encefálica/patología , Región CA1 Hipocampal/patología , Infarto Cerebral/patología , Epigénesis Genética , Ataque Isquémico Transitorio/metabolismo , Ataque Isquémico Transitorio/patología , Ataque Isquémico Transitorio/prevención & control , Metilación , Ratas Wistar , Proteínas de Unión al ARN/metabolismoRESUMEN
Newborn neurons from the subventricular zone (SVZ) are essential to functional recovery following ischemic stroke. However, the number of newly generated neurons after stroke is far from enough to support a potent recovery. Adiponectin could increase neurogenesis in the dentate gyrus of hippocampus in neurodegenerative diseases. However, the effect of adiponectin on the neurogenesis from SVZ and the functional recovery after ischemic stroke was unknown, and the underlying mechanism was not specified either. The middle cerebral artery occlusion model of mice was adopted and adiponectin was administrated once a day from day 3 to 7 of reperfusion. The levels of BDNF and p-STAT3 were detected by western blotting on day 7 of reperfusion. The virus-encoded BDNF shRNA with GFAP promoter and a STAT3 inhibitor Stattic were used, respectively. Neurogenesis was evidenced by the expression of doublecortin and 5-bromo-2'-deoxyuridine (BrdU) labelling and brain atrophy was revealed by Nissl staining on day 28 of reperfusion. Neurological functional recovery was assessed by the adhesive removal test and the forepaw grip strength. We found that adiponectin increased both the doublecortin-positive cells and NeuN/BrdU double-positive cells around the injured area on day 28 of reperfusion, along with the improved long-term neurological recovery. Mechanistically, adiponectin increased the protein levels of p-STAT3 and BDNF in astrocytes on day 7 of reperfusion, while silencing BDNF diminished the adiponectin-induced neurogenesis and functional recovery. Moreover, inhibition of STAT3 not only prevented the increase of BDNF but also the improved neurogenesis and functional recovery after stroke. In conclusion, adiponectin enhances neurogenesis and functional recovery after ischemic stroke via STAT3/BDNF pathway in astrocytes.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Ratones , Animales , Ataque Isquémico Transitorio/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Adiponectina/farmacología , Regulación hacia Arriba , Astrocitos/metabolismo , Bromodesoxiuridina/metabolismo , Bromodesoxiuridina/farmacología , Accidente Cerebrovascular/metabolismo , Neurogénesis/fisiología , Infarto de la Arteria Cerebral Media/metabolismo , Accidente Cerebrovascular Isquémico/metabolismo , Proteínas de Dominio Doblecortina , Isquemia Encefálica/metabolismoRESUMEN
Transient ischemic attack (TIA) presents a high risk for subsequent stroke, Alzheimer's disease (AD), and related dementia (ADRD). However, the neuropathophysiology of TIA has been rarely studied. By evaluating recurrent TIA-induced neuropathological changes, our study aimed to explore the potential mechanisms underlying the contribution of TIA to ADRD. In the current study, we established a recurrent TIA model by three times 10-min middle cerebral artery occlusion within a week in rat. Neither permanent neurological deficit nor apoptosis was observed following recurrent TIA. No increase of AD-related biomarkers was indicated after TIA, including increase of tau hyperphosphorylation and ß-site APP cleaving enzyme 1 (BACE1). Neuronal cytoskeleton modification and neuroinflammation was found at 1, 3, and 7 days after recurrent TIA, evidenced by the reduction of microtubule-associated protein 2 (MAP2), elevation of neurofilament-light chain (NFL), and increase of glial fibrillary acidic protein (GFAP)-positive astrocytes and ionized calcium binding adaptor molecule 1 (Iba1)-positive microglia at the TIA-affected cerebral cortex and basal ganglion. Similar NFL, GFAP and Iba1 alteration was found in the white matter of corpus callosum. In summary, the current study demonstrated that recurrent TIA may trigger neuronal cytoskeleton change, astrogliosis, and microgliosis without induction of cell death at the acute and subacute stage. Our study indicates that TIA-induced neuronal cytoskeleton modification and neuroinflammation may be involved in the vascular contribution to cognitive impairment and dementia.
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Enfermedad de Alzheimer , Ataque Isquémico Transitorio , Ratas , Animales , Ataque Isquémico Transitorio/metabolismo , Gliosis/etiología , Secretasas de la Proteína Precursora del Amiloide , Enfermedades Neuroinflamatorias , Ácido Aspártico Endopeptidasas , Citoesqueleto/metabolismo , Modelos TeóricosRESUMEN
Transient ischemic attacks (TIA) result from a temporary blockage in blood circulation in the brain. As TIAs cause disabilities and often precede full-scale strokes, the effects of TIA are investigated to develop neuroprotective therapies. We analyzed changes in mitochondrial network dynamics, mitophagy and biogenesis in sections of gerbil hippocampus characterized by a different neuronal survival rate after 5-minute ischemia-reperfusion (I/R) insult. Our research revealed a significantly greater mtDNA/nDNA ratio in CA2-3, DG hippocampal regions (5.8 ± 1.4 vs 3.6 ± 0.8 in CA1) that corresponded to a neuronal resistance to I/R. During reperfusion, an increase of pro-fission (phospho-Ser616-Drp1/Drp1) and pro-fusion proteins (1.6 ± 0.5 and 1.4 ± 0.3 for Mfn2 and Opa1, respectively) was observed in CA2-3, DG. Selective autophagy markers, PINK1 and SQSTM1/p62, were elevated 24-96 h after I/R and accompanied by significant elevation of transcription factors proteins PGC-1α and Nrf1 (1.2 ± 0.4, 1.78 ± 0.6, respectively) and increased respiratory chain proteins (e.g., 1.5 ± 0.3 for complex IV at I/R 96 h). Contrastingly, decreased enzymatic activity of citrate synthase, reduced Hsp60 protein level and electron transport chain subunits (0.88 ± 0.03, 0.74 ± 0.1 and 0.71 ± 0.1 for complex IV at I/R 96 h, respectively) were observed in I/R-vulnerable CA1. The phospho-Ser616-Drp1/Drp1 was increased while Mfn2 and total Opa1 reduced to 0.88 ± 0.1 and 0.77 ± 0.17, respectively. General autophagy, measured as LC3-II/I ratio, was activated 3 h after reperfusion reaching 2.37 ± 0.9 of control. This study demonstrated that enhanced mitochondrial fusion, followed by late and selective mitophagy and mitochondrial biogenesis might together contribute to reduced susceptibility to TIA.
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Ataque Isquémico Transitorio , Dinámicas Mitocondriales , Animales , Gerbillinae , Ataque Isquémico Transitorio/genética , Ataque Isquémico Transitorio/metabolismo , Hipocampo/metabolismo , Isquemia/metabolismoRESUMEN
Tissue-type plasminogen activator (t-PA) expression is known to increase following transient focal cerebral ischemia and reperfusion. Previously, we reported downregulation of t-PA upon suppression of matrix metalloproteinase-12 (MMP-12), following transient focal cerebral ischemia and reperfusion. We now present data on the temporal expression of t-PA in the brain after transient ischemia, as well as the interaction between MMP-12 and t-PA, two proteases associated with the breakdown of the blood-brain barrier (BBB) and ischemic brain damage. We hypothesized that there might be reciprocal interactions between MMP-12 and t-PA in the brain after ischemic stroke. This hypothesis was tested using shRNA-mediated gene silencing and computational modeling. Suppression of t-PA following transient ischemia and reperfusion in rats attenuated MMP-12 expression in the brain. The overall effect of t-PA shRNA administration was to attenuate the degradation of BBB tight junction protein claudin-5, diminish BBB disruption, and reduce neuroinflammation by decreasing the expression of the microglia/macrophage pro-inflammatory M1 phenotype (CD68, iNOS, IL-1ß, and TNFα). Reduced BBB disruption and subsequent lack of infiltration of macrophages (the main source of MMP-12 in the ischemic brain) could account for the decrease in MMP-12 expression after t-PA suppression. Computational modeling of in silico protein-protein interactions indicated that MMP-12 and t-PA may interact physically. Overall, our findings demonstrate that MMP-12 and t-PA interact directly or indirectly at multiple levels in the brain following an ischemic stroke. The present findings could be useful in the development of new pharmacotherapies for the treatment of stroke.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Metaloproteinasa 12 de la Matriz , Activador de Tejido Plasminógeno , Animales , Ratas , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Ataque Isquémico Transitorio/metabolismo , Accidente Cerebrovascular Isquémico/metabolismo , Metaloproteinasa 12 de la Matriz/metabolismo , ARN Interferente Pequeño/genética , Activador de Tejido Plasminógeno/metabolismoRESUMEN
OBJECTIVES: Although Mesencephalic astrocyte-derived neurotrophic factor (MANF) shows protection in multiple cells, the role of circulating MANF in patients with acute ischemic stroke (AIS) and transient ischemic attack (TIA) remains unclear. Here, we aimed to explore the value of circulating MANF levels in cerebral ischemic events. MATERIALS AND METHODS: Using a rat cerebral ischemic model, MANF expression in ischemic brains and serum was detected. 50 AIS patients, 56 TIA patients and 48 controls were enrolled, and MANF mRNA, inflammatory cytokines and MANF concentrations in serum and different blood cell types were detected. The National Institutes of Health Stroke Scale (NIHSS) score and Alberta Stroke Program Early CT Score (ASPECTS) were used to evaluate stroke severity. Cerebrovascular recurrence within 90 d was documented during TIA follow-up. RESULTS: MANF expression increased at 2h, peaking at 24h and decreased to baseline at 7d in rat ischemic brains and serum. Serum MANF concentrations increased at 24h and 7d in AIS patients compared to controls and were correlated with NIHSS score, ASPECTS and inflammatory cytokines. MANF protein was present in blood cells, while MANF mRNA levels did not differ between AIS patients and controls. MANF levels revealed a good value to diagnose TIA with area under the curve (AUC) of 0.949 (95% CI: 0.9093-0.9892). MANF levels were lower in TIA patients with recurrence compared to non-recurrence patients. The AUC for MANF to predict a re-event was 0.80 (95% CI: 0.6746-0.9282). CONCLUSIONS: Serum MANF levels correlate with neuroprotection, stroke severity, inflammation, and TIA recurrence.
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Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Animales , Ratas , Accidente Cerebrovascular Isquémico/diagnóstico , Ataque Isquémico Transitorio/diagnóstico , Ataque Isquémico Transitorio/metabolismo , Astrocitos/metabolismo , Factores de Crecimiento Nervioso/genética , Accidente Cerebrovascular/genética , Citocinas/metabolismo , ARN Mensajero/metabolismoRESUMEN
INTRODUCTION AND AIMS: The limited therapeutic options for ischemic stroke treatment render necessary the identification of new strategies. In recent years, it has been shown that natural compounds may represent a valid therapeutic opportunity. Therefore, the present study aimed to evaluate the protective effect of Ruta graveolens water extract (RGWE) in an in vivo experimental model of brain ischemia. METHODS: RGWE effects on ischemic damage and neurological function were evaluated in adult rats subjected to transient occlusion of the Middle Cerebral Artery (tMCAO), receiving two intraperitoneal injections of RGWE, 100 and 300 min after the induction of ischemia. In addition, astroglial and microglial activation was measured as GFAP and IBA-1 expression by immunofluorescence and confocal microscopy analysis. RESULTS: Treatment with RGWE containing 10 mg/kg of Rutin, the major component, ameliorates the ischemic damage and improves neurological performances. Interestingly, the pro-inflammatory states of astrocytes and microglia, respectively detected by using C3 and iNOS markers, were significantly reduced in ipsilateral cortical and striatal areas in ischemic RGWE-treated rats. CONCLUSIONS: RGWE shows a neuroprotective effect on brain infarct volume extent in a transient focal cerebral ischemia model and this effect was paralleled by the prevention of pro-inflammatory astroglial and microglial activation. Collectively, our findings support the idea that natural compounds may represent potential therapeutic opportunities against ischemic stroke.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Fármacos Neuroprotectores , Ruta , Animales , Encéfalo , Isquemia Encefálica/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/complicaciones , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Isquemia , Ataque Isquémico Transitorio/complicaciones , Ataque Isquémico Transitorio/tratamiento farmacológico , Ataque Isquémico Transitorio/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Ratas , AguaRESUMEN
SMAD3 protein transduces signals from TGF-ß and activins. In vitro studies have shown that SMAD3 plays an important role in regulating of micoglia and astrocytic function. However, there is little information on the association between SMAD3 signaling and the pathophysiology of the glial cells in the post-ischemic hippocampus. In this study, we examined the time-course changes in the expression and phosphorylation of SMAD3 in the rat hippocampus using a rat model of global cerebral ischemia. Most pyramidal neuronal cells in the CA1 region died within 7 days after ischemia. The number of SMAD3- or phosphorylated SMAD3 (p-SMAD3)-immunopositive microglia or astrocytes increased in the CA1 region 7 days after ischemia. Real-time PCR analysis showed an increase in the level of TGF-ß1 mRNA in the hippocampus after ischemia. Intracerebroventricular injection of SB525334, a selective inhibitor of TGF-ß receptor I kinase (ALK5), reduced the ischemia-induced p-SMAD3 immunoreactivity in the microglia and astrocytes. By contrast, intracerebroventricular injection of SB525334 did not affect the ischemia-induced neuronal cell death. These results suggest that ischemia-induced SMAD3 phosphorylation in the microglia and astrocytes of post-ischemic hippocampi is associated with tissue repair and not neuroprotection.
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Isquemia Encefálica , Hipocampo , Ataque Isquémico Transitorio , Proteína smad3 , Animales , Ratas , Astrocitos/metabolismo , Isquemia Encefálica/metabolismo , Hipocampo/metabolismo , Isquemia/metabolismo , Ataque Isquémico Transitorio/metabolismo , Microglía/metabolismo , Fosforilación , Proteína smad3/metabolismoRESUMEN
Stem cell-based treatments have been recommended as a feasible therapy for stroke victims due to their potential for angiogenesis, neurogenesis, and synaptic plasticity. The intracellular mechanisms of stem cells against cerebral hypoperfusion are not well recognized. In this study, by releasing the clips, the reperfusion period was extended to 96 h, and two hours after cerebral ischemia, animals received adipose-derived MSCs. MSCs were isolated from the inguinal fat pads of rats and injected into two-vessel occlusion (2VO) rats 1 h after ischemia induction. Ninety-six hours after 2VO induction, behavioral and molecular tests were assessed. Adipose-derived MSCs treatment improves neurological scores, passive avoidance memory, and novel object recognition tests in the 2VO model compared to 2VO rats (P < 0.001). MSCs treatment decreased TNF-α (P < 0.01) and IL-6 (P < 0.01) and apoptotic factors (Bax/Bcl-2 ratio and caspase-3 level (P < 0.01)) compared with ischemic rats. MSCs treatment of ischemic rats could enhance Klotho-α and AMPK-α compared with ischemic rats (P < 0.001). The study disclosed that adipose-derived MSCs could improve neurological damage and memory deficits by reducing neuronal death in cerebral ischemia. Data proposed that adipose-derived MSCs inhibit pro-inflammatory factors such as IL-6 and TNF-α, consequently decreasing apoptosis in the hippocampus of CCAO rats. Besides, the Klotho-α and AMPK-α measurements found that MSCs might induce intracellular neuroprotective pathways via activation of Klotho-α/AMPK-α signaling.
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Isquemia Encefálica , Ataque Isquémico Transitorio , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Apoptosis , Isquemia Encefálica/metabolismo , Isquemia Encefálica/terapia , Modelos Animales de Enfermedad , Interleucina-6/metabolismo , Ataque Isquémico Transitorio/metabolismo , Ratas , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Neuronal loss (death) occurs selectively in vulnerable brain regions after ischemic insults. Astrogliosis is accompanied by neuronal death. It can change the molecular expression and morphology of astrocytes following ischemic insults. However, little is known about cerebral ischemia and reperfusion injury that can variously lead to damage of astrocytes according to the degree of ischemic injury, which is related to neuronal damage/death. Thus, the purpose of this study was to examine the relationship between damage to cortical neurons and astrocytes using gerbil models of mild and severe transient forebrain ischemia induced by blocking the blood supply to the forebrain for five or 15 min. Significant ischemia tFI-induced neuronal death occurred in the deep layers (layers V and VI) of the motor cortex: neuronal death occurred earlier and more severely in gerbils with severe ischemia than in gerbils with mild ischemia. Distinct astrogliosis was detected in layers V and VI. It gradually increased with time after both ischemiae. The astrogliosis was significantly higher in severe ischemia than in mild ischemia. The ischemia-induced increase of glial fibrillary acidic protein (GFAP; a maker of astrocyte) expression in severe ischemia was significantly higher than that in mild ischemia. However, GFAP-immunoreactive astrocytes were apparently damaged two days after both ischemiae. At five days after ischemiae, astrocyte endfeet around capillary endothelial cells were severely ruptured. They were more severely ruptured by severe ischemia than by mild ischemia. However, the number of astrocytes stained with S100 was significantly higher in severe ischemia than in mild ischemia. These results indicate that the degree of astrogliosis, including the disruption (loss) of astrocyte endfeet following ischemia and reperfusion in the forebrain, might depend on the severity of ischemia and that the degree of ischemia-induced neuronal damage may be associated with the degree of astrogliosis.
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Ataque Isquémico Transitorio , Corteza Motora , Daño por Reperfusión , Animales , Astrocitos/metabolismo , Células Endoteliales/metabolismo , Gerbillinae/metabolismo , Proteína Ácida Fibrilar de la Glía/metabolismo , Gliosis/metabolismo , Isquemia/metabolismo , Ataque Isquémico Transitorio/metabolismo , Corteza Motora/metabolismo , Prosencéfalo/metabolismo , Daño por Reperfusión/metabolismoRESUMEN
Purpurin has various effects, including anti-inflammatory effects, and can efficiently cross the blood-brain barrier. In the present study, we investigated the effects of purpurin on oxidative stress in HT22 cells and mild brain damage in the gerbil hippocampal CA1 region induced by transient forebrain ischemia. Oxidative stress induced by H2O2 was significantly ameliorated by treatment with purpurin, based on changes in cell death, DNA fragmentation, formation of reactive oxygen species, and pro-apoptotic (Bax)/anti-apoptotic (Bcl-2) protein levels. In addition, treatment with purpurin significantly reduced the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK), and p38 signaling in HT22 cells. Transient forebrain ischemia in gerbils led to a significant increase in locomotor activity 1 day after ischemia and significant decrease in number of surviving cells in the CA1 region 4 days after ischemia. Administration of purpurin reduced the travel distance 1 day after ischemia and abrogates the neuronal death in the hippocampal CA1 region 4 days after ischemia based on immunohistochemical and histochemical staining for NeuN and Fluoro-Jade C, respectively. Purpurin treatment significantly decreased the activation of microglia and astrocytes as well as the increases of nuclear factor kappa-light-chain-enhancer of activated B cells p65 in the hippocampal CA1 region 4 days after ischemia and ameliorated the ischemia-induced transient increases of interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α in the hippocampus 6 h after ischemia. In addition, purpurin significantly alleviated the ischemia-induced phosphorylation of JNK, ERK, and p38 in the hippocampus 1 day after ischemia. Furthermore, purpurin treatment significantly mitigated the increases of Bax in the hippocampus 1 day after ischemia and the lipid peroxidation based on malondialdehyde and hydroperoxides levels 2 days after ischemia. These results suggest that purpurin can be one of the potential candidates to reduce neuronal damage and inflammatory responses after oxidative stress in HT22 cells or ischemic damage in gerbils.
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Ataque Isquémico Transitorio , Fármacos Neuroprotectores , Animales , Antraquinonas , Gerbillinae/metabolismo , Hipocampo/metabolismo , Peróxido de Hidrógeno/metabolismo , Isquemia/metabolismo , Ataque Isquémico Transitorio/metabolismo , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Estrés Oxidativo , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Astrocytes experience significant metabolic shifts in the "sensitive period" of neurological function recovery following cerebral ischemia. However, the changes in astrocyte lipid metabolism and their implications for neurological recovery remain unknown. In the present study, we employed a mouse middle cerebral artery occlusion model to investigate the changes in de novo lipogenesis and interleukin-33 (IL-33) production in astrocytes and elucidate their role in blood-brain barrier (BBB) repair in the subacute phase of cerebral ischemia. Neurological behavior evaluation was used to assess functional changes in mice. Pharmacological inhibition and astrocyte-specific downregulation of fatty acid synthase (FASN) were used to evaluate the role of de novo lipogenesis in brain injury. Intracerebroventricular administration of recombinant IL-33 was performed to study the contribution of IL-33 to BBB disruption. Extravasation of Evans blue dye, dextran and IgG were used to assess BBB integrity. Western blotting of tight junction proteins ZO-1, Occludin, and Claudin-5 were performed at defined time points to evaluate changes in BBB. It was found that de novo lipogenesis was activated, and IL-33 production increased in astrocytes at the subacute stage of cerebral ischemia injury. Inhibition of lipogenesis in astrocytes decreased IL-33 production in the peri-infarct area, deteriorated BBB damage and interfered with neurological recovery. In addition, supplementation of IL-33 alleviated BBB destruction and improved neurological recovery worsened by lipogenesis inhibition. These findings indicate that astrocyte lipogenesis increases the production of IL-33 in the peri-infarct area, which promotes BBB repair in the subacute phase of cerebral ischemia injury and improves long-term functional recovery.