RESUMEN

Regular exercise improves several functions, including cognition, in patients with stroke. However, the effect of regular exercise on neurogenesis related to cognition remains doubtful. We investigated the most effective exercise intensity for functional recovery after stroke using RNA sequencing following regular treadmill exercise. Photothrombotic cerebral infarction was conducted for 10-week-old male Sprague-Dawley rats (n = 36). A Morris water maze (MWM) test was performed before a regular treadmill exercise program (5 days/week, 4 weeks). Rats were randomly divided into four groups: group A (no exercise); group B (low intensity, maximal velocity 18 m/min); group C (moderate intensity, maximal velocity 24 m/min) and group D (high intensity, maximal velocity 30 m/min). After 4 weeks, another MWM test was performed, and all rats were sacrificed. RNA sequencing was performed with ipsilesional hippocampal tissue. On the day after cerebral infarction, no differences in escape latency and velocity were observed among the groups. At 4 weeks after cerebral infarction, the escape latencies in groups B, C, and D were shorter than in group A. The escape latencies in groups B and C were shorter than in group D. The velocity in groups A, B, and C was faster than in group D. Thirty gene symbols related to neurogenesis were detected (p < 0.05, fold change > 1.0, average normalized read count > four times). In the neurotrophin-signaling pathway, the CHK gene was upregulated, and the NF-κB gene was downregulated in the low-intensity group. The CHK and NF-κB genes were both downregulated in the moderate-intensity group. The Raf and IRAK genes were downregulated in the high-intensity group. Western blot analysis showed that NF-κB expression was lowest in the moderate-intensity group, whereas CHK and Raf were elevated, and IRAK was decreased in the high-intensity group. Moderate-intensity exercise may contribute to neuroplasticity. Variation in the expression of neurotrophins in neurogenesis according to exercise intensity may reveal the mechanism of neuroplasticity. Thus, NF-κB is the key neurotrophin for neurogenesis related to exercise intensity.

Asunto(s)

Infarto Cerebral , Modelos Animales de Enfermedad , Neurogénesis , Condicionamiento Físico Animal , Ratas Sprague-Dawley , Animales , Neurogénesis/genética , Infarto Cerebral/genética , Infarto Cerebral/metabolismo , Infarto Cerebral/fisiopatología , Infarto Cerebral/patología , Ratas , Masculino , Hipocampo/metabolismo , Regulación de la Expresión Génica

RESUMEN

Neuronal loss is a hallmark of stroke and other neurodegenerative diseases, and as such, neuronal loss caused by microglia has been thought to be a contributing factor to disease progression. Here, we show that microglia indeed contribute significantly to neuronal loss in a mouse model of stroke, but this microglial-dependent process of neuronal clearance specifically targets stressed and degenerating neurons in the ischemic cortical region and not healthy non-ischemic neurons. Nonspecific stimulation of microglia decreased the density of neurons in the ischemic cortical region, whereas specific inhibition of MFG-E8 signaling, which is required for microglial phagocytosis of neurons, had the opposite effect. In both scenarios, the effects were microglia specific, as the same treatments had no effect in mice whose microglia were depleted prior to stroke. Finally, even though the inhibition of MFG-E8 signaling increased neuronal density in the ischemic brain region, it substantially exacerbated the development of cortical infarction. In conclusion, microglia through MFG-E8 signaling contribute to the loss of ischemic neurons and, in doing so, minimize the development of cortical infarction after stroke.

Asunto(s)

Antígenos de Superficie , Microglía , Proteínas de la Leche , Neuronas , Transducción de Señal , Accidente Cerebrovascular , Animales , Microglía/metabolismo , Microglía/patología , Neuronas/metabolismo , Neuronas/patología , Ratones , Proteínas de la Leche/metabolismo , Antígenos de Superficie/metabolismo , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/complicaciones , Masculino , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Infarto Cerebral/patología , Infarto Cerebral/metabolismo , Infarto Cerebral/etiología , Encéfalo/metabolismo , Encéfalo/patología , Fagocitosis , Corteza Cerebral/metabolismo , Corteza Cerebral/patología

Asunto(s)

Infarto Cerebral , Trombosis Intracraneal , Imagen por Resonancia Magnética , Trombosis de la Vena , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adulto , Estudios Retrospectivos , Trombosis de la Vena/patología , Trombosis Intracraneal/patología , Trombosis Intracraneal/diagnóstico por imagen , Trombosis Intracraneal/metabolismo , Adulto Joven , Infarto Cerebral/patología , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/metabolismo , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Cefalea/etiología , Corteza Cerebral/patología , Corteza Cerebral/irrigación sanguínea , Corteza Cerebral/diagnóstico por imagen , Diagnóstico Diferencial , Lóbulo Temporal/patología , Lóbulo Temporal/diagnóstico por imagen , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/patología , Convulsiones/etiología , Edema Encefálico/patología , Lóbulo Frontal/patología , Lóbulo Frontal/diagnóstico por imagen , Lóbulo Frontal/irrigación sanguínea

RESUMEN

Ischemic stroke followed by reperfusion (IR) leads to extensive cerebrovascular injury characterized by neuroinflammation and brain cell death. Inhibition of matrix metalloproteinase-3 (MMP-3) emerges as a promising therapeutic approach to mitigate IR-induced stroke injury. We employed middle cerebral artery occlusion with subsequent reperfusion (MCAO/R) to model ischemic stroke in adult mice. Specifically, we investigated the impact of MMP-3 knockout (KO) on stroke pathophysiology using RNA sequencing (RNA-seq) of stroke brains harvested 48 h post-MCAO. MMP-3 KO significantly reduced brain infarct size following stroke. Notably, RNA-seq analysis showed that MMP-3 KO altered expression of 333 genes (252 downregulated) in male stroke brains and 3768 genes (889 downregulated) in female stroke brains. Functional pathway analysis revealed that inflammation, integrin cell surface signaling, endothelial- and epithelial-mesenchymal transition (EndMT/EMT), and apoptosis gene signatures were decreased in MMP-3 KO stroke brains. Intriguingly, MMP-3 KO downregulated gene signatures more profoundly in females than in males, as indicated by greater negative enrichment scores. Our study underscores MMP-3 inhibition as a promising therapeutic strategy, impacting multiple cellular pathways following stroke.

Asunto(s)

Infarto Cerebral , Modelos Animales de Enfermedad , Accidente Cerebrovascular Isquémico , Metaloproteinasa 3 de la Matriz , Ratones Noqueados , Animales , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/metabolismo , Masculino , Femenino , Ratones , Accidente Cerebrovascular Isquémico/genética , Accidente Cerebrovascular Isquémico/metabolismo , Accidente Cerebrovascular Isquémico/patología , Infarto Cerebral/genética , Infarto Cerebral/patología , Infarto Cerebral/metabolismo , Infarto de la Arteria Cerebral Media/genética , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Ratones Endogámicos C57BL , Transcriptoma , Regulación de la Expresión Génica , Encéfalo/metabolismo , Encéfalo/patología

RESUMEN

This paper aims to explore the effect of Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern on cerebral ischemic injury and angiogenesis in the rat model of acute cerebral infarction. SD rats were randomized into 6 groups: sham group, model group, low-, medium-, and high-dose(5.13, 10.26, and 20.52 g·kg~(-1), respectively) Xuming Decoction groups, and butylphthalide(0.06 g·kg~(-1)) group. After the successful establishment of the rat model by middle cerebral artery occlusion(MCAO), rats in the sham and model groups were administrated with distilled water and those in other groups with corresponding drugs for 7 consecutive days. After the neurological function was scored, all the rats were sacrificed, and the brain tissue samples were collected. The degree of cerebral ischemic injury was assessed by the neurological deficit score and staining with 2,3,5-triphenyltetrazolium chloride. Hematoxylin-eosin staining was performed to observe the pathological changes in the brain. Transmission electron microscopy was employed to observe the ultrastructures of neurons and microvascular endothelial cells(ECs) on the ischemic side of the brain tissue. Immunofluorescence assay was employed to detect the expression of von Willebrand factor(vWF) and hematopoietic progenitor cell antigen CD34(CD34) in the ischemic brain tissue. Real-time PCR and Western blot were employed to determine the mRNA and protein levels, respectively, of Runt-related transcription factor 1(RUNX1), vascular endothelial growth factor(VEGF), angiopoietin-1(Ang-1), angiopoietin-2(Ang-2), and VEGF receptor 2(VEGFR2) in the ischemic brain tissue. The results showed that compared with the sham group, the model group showed increased neurological deficit score and cerebral infarction area(P<0.01), pathological changes, and damaged ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Furthermore, the modeling up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.05 or P<0.01). Compared with the model group, high-dose Xuming Decoction and butylphthalide decreased the neurological deficit score and cerebral infarction area(P<0.01) and alleviated the pathological changes and damage of the ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Moreover, they up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P<0.01). The results suggest that Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern can promote the angiogenesis and collateral circulation establishment to alleviate neurological dysfunction of the ischemic brain tissue in MCAO rats by regulating the RUNX1/VEGF pathway.

Asunto(s)

Isquemia Encefálica , Infarto Cerebral , Modelos Animales de Enfermedad , Medicamentos Herbarios Chinos , Ratas Sprague-Dawley , Animales , Ratas , Masculino , Medicamentos Herbarios Chinos/farmacología , Infarto Cerebral/tratamiento farmacológico , Infarto Cerebral/metabolismo , Infarto Cerebral/genética , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/metabolismo , Isquemia Encefálica/genética , Humanos , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Angiopoyetina 2/genética , Angiopoyetina 2/metabolismo , Angiogénesis

RESUMEN

BACKGROUND: Exogenous neural cell transplantation may be therapeutic for stroke, cerebral ischemic injury. Among other mechanisms, increasing findings indicated circular RNAs (circRNAs) regulate the pathogenesis progression of cerebral ischemia. Mmu_circ_0015034 (circEfnb2) was upregulated in focal cortical infarction established by middle cerebral artery occlusion (MCAO) in mice. Our study was designed to probe the molecular mechanism of circEfnb2 in the oxygen-glucose deprivation/reperfusion (OGD/R)-induced neuronal damage in cerebral ischemia. METHODS: We established an in vitro OGD/R cell model. CircEfnb2 and microRNA-202-5p (miR-202-5p) levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Lactate dehydrogenase (LDH), malondialdehyde (MDA), and reactive oxygen species (ROS) levels were assessed using specific kits. Tumor necrosis factor-α (TNF-α) and Interleukin-1ß (IL-1ß) levels were examined using an Enzyme-linked immunosorbent assay (ELISA). Flow cytometry analysis evaluated cell apoptosis. Protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), cleaved caspase 3, and Tumor necrosis factor receptor-associated factor 3 (TRAF3) were determined using Western blot assay. RESULTS: Overall, circEfnb2 was highly expressed whereas miR-202-5p was decreased in OGD/R-treated mouse hippocampal neuronal HT22 cells compared to normal controls (both p > 0.05). From an in vitro functional perspective, circEfnb2 knockdown attenuated an OGD/R-triggered neuronal injury compared to controls (p > 0.05). Mechanically, circEfnb2 acted as a sponge of miR-202-5p; downregulation of miR-202-5p annulled the inhibitory roles of circEfnb2 silencing in an OGD/R-caused neuronal injury model. Our analysis showed that miR-202-5p directly targeted TRAF3 as enhanced TRAF3 abolished the effects of miR-202-5p in the OGD/R-induced neuronal injury. In vivo, lentivirus with a short hairpin (sh)-circEfnb2 inhibited cerebral injury, when injected into cerebral cortex in MCAO mice (p > 0.05). CONCLUSION: Our results suggest that circEfnb2 deficiency may decrease OGD/R-induced HT22 cell damage by modulating the miR-202-5p/TRAF3 axis. This explanation may provide a new direction for cerebral infarction potential therapeutic targets.

Asunto(s)

Apoptosis , Infarto Cerebral , MicroARNs , ARN Circular , Factor 3 Asociado a Receptor de TNF , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Animales , Factor 3 Asociado a Receptor de TNF/genética , Factor 3 Asociado a Receptor de TNF/metabolismo , Ratones , Infarto Cerebral/metabolismo , Infarto Cerebral/genética , Infarto Cerebral/patología , Masculino , Regulación de la Expresión Génica , Humanos , Daño por Reperfusión/metabolismo , Daño por Reperfusión/genética , Neuronas/metabolismo , Neuronas/patología , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/genética , Infarto de la Arteria Cerebral Media/patología , Glucosa/metabolismo

RESUMEN

Ischemia Stroke (IS) is an acute neurological condition with high morbidity, disability, and mortality due to a severe reduction in local cerebral blood flow to the brain and blockage of oxygen and glucose supply. Oxidative stress induced by IS predisposes neurons to ferroptosis. TP53-induced glycolysis and apoptosis regulator (TIGAR) inhibits the intracellular glycolytic pathway to increase pentose phosphate pathway (PPP) flux, promotes NADPH production and thus generates reduced glutathione (GSH) to scavenge reactive oxygen species (ROS), and thus shows strong antioxidant effects to ameliorate cerebral ischemia/reperfusion injury. However, in the current study, prolonged ischemia impaired the PPP, and TIGAR was unable to produce NADPH but was still able to reduce neuronal ferroptosis and attenuate ischemic brain injury. Ferroptosis is a form of cell death caused by free radical-driven lipid peroxidation, and the vast majority of ROS leading to oxidative stress are generated by mitochondrial succinate dehydrogenase (SDH) driving reverse electron transfer (RET) via the mitochondrial electron transport chain. Overexpression of TIGAR significantly inhibited hypoxia-induced enhancement of SDH activity, and TIGAR deficiency further enhanced SDH activity. We also found that the inhibitory effect of TIGAR on SDH activity was related to its mitochondrial translocation under hypoxic conditions. TIGAR may inhibit SDH activity by mediating post-translational modifications (acetylation and succinylation) of SDH A through interaction with SDH A. SDH activity inhibition reduces neuronal ferroptosis by decreasing ROS production, eliminating MitoROS levels and attenuating lipid peroxide accumulation. Notably, TIGAR-mediated inhibition of SDH activity and ferroptosis was not dependent on the PPP-NADPH-GPX4 pathways. In conclusion, mitochondrial translocation of TIGAR in prolonged ischemia is an important pathway to reduce neuronal ferroptosis and provide sustainable antioxidant defense for the brain under prolonged ischemia, further complementing the mechanism of TIGAR resistance to oxidative stress induced by IS.

Asunto(s)

Isquemia Encefálica , Ferroptosis , Daño por Reperfusión , Humanos , Especies Reactivas de Oxígeno/metabolismo , Succinato Deshidrogenasa/metabolismo , NADP/metabolismo , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Infarto Cerebral/metabolismo , Glucólisis , Daño por Reperfusión/metabolismo , Hipoxia/metabolismo , Neuronas/metabolismo

RESUMEN

Global cerebral ischemia (GCI) caused by clinical conditions such as cardiac arrest leads to delayed neuronal death in the hippocampus, resulting in physical and mental disability. However, the mechanism of delayed neuronal death following GCI remains unclear. To elucidate the mechanism, we performed a metabolome analysis using a mouse model in which hypothermia (HT) during GCI, which was induced by the transient occlusion of the bilateral common carotid arteries, markedly suppressed the development of delayed neuronal death in the hippocampus after reperfusion. Fifteen metabolites whose levels were significantly changed by GCI and 12 metabolites whose levels were significantly changed by HT were identified. Furthermore, the metabolites common for both changes were narrowed down to two, adenosine monophosphate (AMP) and xanthosine monophosphate (XMP). The levels of both AMP and XMP were found to be decreased by GCI, but increased by HT, thereby preventing their decrease. In contrast, the levels of adenosine, inosine, hypoxanthine, xanthine, and guanosine, the downstream metabolites of AMP and XMP, were increased by GCI, but were not affected by HT. Our results may provide a clue to understanding the mechanism by which HT during GCI suppresses the development of delayed neuronal death in the hippocampus.

Asunto(s)

Isquemia Encefálica , Hipotermia , Ribonucleótidos , Humanos , Hipotermia/metabolismo , Isquemia Encefálica/metabolismo , Xantina/metabolismo , Infarto Cerebral/metabolismo , Hipocampo/metabolismo , Adenosina Monofosfato/metabolismo

RESUMEN

Mesencephalic astrocyte-derived neurotrophic factor (MANF) has cytoprotective effects on various injuries, including cerebral ischemia, and it can promote recovery even when delivered intracranially several days after ischemic stroke. In the uninjured rodent brain, MANF protein is expressed almost exclusively in neurons, but post-ischemic MANF expression has not been characterized. We aimed to investigate how endogenous cerebral MANF protein expression evolves in infarcted human brains and rodent ischemic stroke models. During infarct progression, the cerebral MANF expression pattern both in human and rat brains shifted drastically from neurons to expression in inflammatory cells. Intense MANF immunoreactivity took place in phagocytic microglia/macrophages in the ischemic territory, peaking at two weeks post-stroke in human and one-week post-stroke in rat ischemic cortex. Using double immunofluorescence and mice lacking MANF gene and protein from neuronal stem cells, neurons, astrocytes, and oligodendrocytes, we verified that MANF expression was induced in microglia/macrophage cells in the ischemic hemisphere. Embarking on the drastic expression transition towards inflammatory cells and the impact of blood-borne inflammation in stroke, we hypothesized that exogenously delivered MANF protein can modulate tissue recovery processes. In an attempt to enhance recovery, we designed a set of proof-of-concept studies using systemic delivery of recombinant MANF in a rat model of cortical ischemic stroke. Intranasal recombinant MANF treatment decreased infarct volume and reduced the severity of neurological deficits. Intravenous recombinant MANF treatment decreased the levels of pro-inflammatory cytokines and increased the levels of anti-inflammatory cytokine IL-10 in the infarcted cortex one-day post-stroke. In conclusion, MANF protein expression is induced in activated microglia/macrophage cells in infarcted human and rodent brains, and this could implicate MANF's involvement in the regulation of post-stroke inflammation in patients and experimental animals. Moreover, systemic delivery of recombinant MANF shows promising immunomodulatory effects and therapeutic potential in experimental ischemic stroke.

Asunto(s)

Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Ratas , Ratones , Animales , Accidente Cerebrovascular Isquémico/metabolismo , Ratas Sprague-Dawley , Encéfalo/metabolismo , Factores de Crecimiento Nervioso/genética , Factores de Crecimiento Nervioso/metabolismo , Factores de Crecimiento Nervioso/uso terapéutico , Accidente Cerebrovascular/metabolismo , Infarto Cerebral/metabolismo , Inflamación/metabolismo

RESUMEN

Ischemic stroke causes secondary neurodegeneration in the thalamus ipsilateral to the infarction site and impedes neurological recovery. Axonal degeneration of thalamocortical fibers and autophagy overactivation are involved in thalamic neurodegeneration after ischemic stroke. However, the molecular mechanisms underlying thalamic neurodegeneration remain unclear. Sterile /Armadillo/Toll-Interleukin receptor homology domain protein (SARM1) can induce Wallerian degeneration. Herein, we aimed to investigate the role of SARM1 in thalamic neurodegeneration and autophagy activation after photothrombotic infarction. Neurological deficits measured using modified neurological severity scores and adhesive-removal test were ameliorated in Sarm1-/- mice after photothrombotic infarction. Compared with wild-type mice, Sarm1-/- mice exhibited unaltered infarct volume; however, there were markedly reduced neuronal death and gliosis in the ipsilateral thalamus. In parallel, autophagy activation was attenuated in the thalamus of Sarm1-/- mice after cerebral infarction. Thalamic Sarm1 re-expression in Sarm1-/- mice increased thalamic neurodegeneration and promoted autophagy activation. Auotophagic inhibitor 3-methyladenine partially alleviated thalamic damage induced by SARM1. Moreover, autophagic initiation through rapamycin treatment aggravated post-stroke neuronal death and gliosis in Sarm1-/- mice. Taken together, SARM1 contributes to secondary thalamic neurodegeneration after cerebral infarction, at least partly through autophagy inhibition. SARM1 deficiency is a potential therapeutic strategy for secondary thalamic neurodegeneration and functional deficits after stroke.

Asunto(s)

Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Ratones , Animales , Gliosis , Infarto Cerebral/metabolismo , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular Isquémico/metabolismo , Tálamo/metabolismo , Axones/metabolismo , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Proteínas del Dominio Armadillo/genética , Proteínas del Dominio Armadillo/metabolismo

RESUMEN

The SUR1-TRPM4-AQP4 complex is overexpressed in the initial phase of edema induced after cerebral ischemia, allowing the massive internalization of Na+ and water within the brain micro endothelial cells (BMEC) of the blood-brain barrier. The expression of the Abcc8 gene encoding SUR1 depends on transcriptional factors that are responsive to oxidative stress. Because reactive oxygen species (ROS) are generated during cerebral ischemia, we hypothesized that antioxidant compounds might be able to regulate the expression of SUR1. Therefore, the effect of resveratrol (RSV) on SUR1 expression was evaluated in the BMEC cell line HBEC-5i subjected to oxygen and glucose deprivation (OGD) for 2 h followed by different recovery times. Different concentrations of RSV were administered. ROS production was detected with etidine, and protein levels were evaluated by Western blotting and immunofluorescence. Intracellular Na+ levels and cellular swelling were detected by imaging; cellular metabolic activity and rupture of the cell membrane were detected by MTT and LDH release, respectively; and EMSA assays measured the activity of transcriptional factors. OGD/recovery increased ROS production induced the AKT kinase activity and the activation of SP1 and NFκB. SUR1 protein expression and intracellular Na+ concentration in the HBEC-5i cells increased after a few hours of OGD. These effects correlated with cellular swelling and necrotic cell death, responses that the administration of RSV prevented. Our results indicate that the ROS/AKT/SP1-NFκB pathway is involved in SUR1 expression during OGD/recovery in BMEC of the blood-brain barrier. Thus, RSV prevented cellular edema formation through modulation of SUR1 expression.

Asunto(s)

Isquemia Encefálica , Oxígeno , Humanos , Resveratrol/farmacología , Oxígeno/metabolismo , Células Endoteliales/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Glucosa/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/metabolismo , Infarto Cerebral/metabolismo , Edema

RESUMEN

This study aimed to treat diabetic cerebral ischemia-reperfusion injury (CI/RI) by affecting blood brain barrier (BBB) permeability and integrity. The CI/RI model in DM mice and a high glucose (HG) treated oxygen and glucose deprivation/reoxygenation (OGD/R) brain endothelial cell model were established for the study. Evans blue (EB) staining was used to evaluate the permeability of BBB in vivo. TTC staining was used to analyze cerebral infarction. The location and expression of tribbles homolog 3 (TRIB3) in endothelial cells were detected by immunofluorescence. Western blotting was used to detect the protein expressions of TRIB3, tight junction molecules, adhesion molecules, phosphorylated protein kinase B (p-AKT) and AKT. The levels of pro-inflammatory cytokines were detected by qRT-PCR. Trans-epithelial electrical resistance (TEER) and fluorescein isothiocyanate (FITC)-dextran were used to measure vascular permeability in vitro. TRIB3 ubiquitination and acetylation levels were detected. Acetyltransferase bound to TRIB3 were identified by immunoprecipitation. TRIB3 was localized in cerebral endothelial cells and was highly expressed in diabetic CI/R mice. The BBB permeability in diabetic CI/R mice and HG-treated OGD/R cells was increased, while the junction integrity was decreased. Interference with TRIB3 in vitro reduces BBB permeability and increases junction integrity. In vivo interfering with TRIB3 reduced cerebral infarction volume, BBB permeability and inflammation levels, and upregulated p-AKT levels. The phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin reversed the effects of TRIB3-interfering plasmid. In vitro HG treatment induced TRIB3 acetylation through acetyltransferase p300, which in turn reduced ubiquitination and stabilized TRIB3. Interfering TRIB3 protects BBB by activating PI3K/AKT pathway and alleviates brain injury, which provides a new target for diabetic CI/RI.

Asunto(s)

Isquemia Encefálica , Diabetes Mellitus , Daño por Reperfusión , Ratones , Animales , Barrera Hematoencefálica , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Células Endoteliales , Fosfatidilinositol 3-Quinasa/metabolismo , Fosfatidilinositol 3-Quinasa/farmacología , Daño por Reperfusión/prevención & control , Daño por Reperfusión/metabolismo , Infarto Cerebral/metabolismo , Oxígeno/metabolismo , Glucosa/metabolismo , Acetiltransferasas/metabolismo , Acetiltransferasas/farmacología , Diabetes Mellitus/metabolismo

RESUMEN

Persistent post-ischemic alterations to the hypothalamic-pituitary-adrenal (HPA) axis occur following global cerebral ischemia (GCI) in rodents. However, similar effects on hypothalamic-pituitary-gonadal (HPG) axis activation remain to be determined. Therefore, this study evaluated the effects of GCI in adult female rats (via four-vessel occlusion) on the regularity of the estrous cycle for 24-days post ischemia. A second objective aimed to assess persistent alterations of HPG axis activation through determination of the expression of estrogen receptor alpha (ERα), kisspeptin (Kiss1), and gonadotropin-inhibitory hormone (GnIH/RFamide-related peptide; RFRP3) in the medial preoptic area (POA), arcuate nucleus (ARC), dorsomedial nucleus (DMH) of the hypothalamus, and CA1 of the hippocampus 25 days post ischemia. Expression of glucocorticoid receptors (GR) in the paraventricular nucleus of the hypothalamus (PVN) and CA1 served as a proxy of altered HPA axis activation. Our findings demonstrated interruption of the estrous cycle in 87.5 % of ischemic rats, marked by persistent diestrus, lasting on average 11.86 days. Moreover, compared to sham-operated controls, ischemic female rats showed reduced Kiss1 expression in the hypothalamic ARC and POA, concomitant with elevated ERα in the ARC and increased GnIH in the DMH and CA1. Reduced GR expression in the CA1 was associated with increased GR-immunoreactivity in the PVN, indicative of lasting dysregulation of HPA axis activation. Together, these findings demonstrate GCI disruption of female rats' estrous cycle over multiple days, with a lasting impact on HPG axis regulators within the reproductive axis.

Asunto(s)

Isquemia Encefálica , Sistema Hipotálamo-Hipofisario , Ratas , Femenino , Animales , Sistema Hipotálamo-Hipofisario/metabolismo , Kisspeptinas/metabolismo , Eje Hipotálamico-Pituitario-Gonadal , Receptor alfa de Estrógeno/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , Hipotálamo/metabolismo , Ciclo Estral/metabolismo , Isquemia Encefálica/metabolismo , Infarto Cerebral/metabolismo , Periodicidad

RESUMEN

This study investigated the effects of isosakuranetin (5,7-dihydroxy-4'-methoxyflavanone) on cerebral infarction and blood brain barrier (BBB) damage in cerebral ischemia and reperfusion (I/R) in a rat model. The right middle cerebral artery was occluded for 2 h followed by reperfusion. The experimental rats were divided into five groups: a sham, or control group; vehicle group; and 5 mg/kg, 10 mg/kg, and 20 mg/kg bodyweight isosakuranetin-treated I/R groups. After 24 h of reperfusion, the rats were tested using a six-point neurological function score. The percentage of cerebral infarction was evaluated using 2,3,5-triphenyltetrazolium chloride (TTC) staining. BBB leakage was determined by Evan Blue injection assay and brain morphology changes were observed under light microscopy following staining with hematoxylin and eosin (H&E). The results of neurological function score revealed that isosakuranetin reduced the severity of neurological damage. A dose of 10 and 20 mg/kg bodyweight of isosakuranetin significantly decreased the infarct volume. All three doses of isosakuranetin significantly decreased Evan Blue leakage. The penumbra area of the I/R brains revealed the characteristics of apoptotic cell death. Therefore, isosakuranetin-treated I/R attenuated the brain damage from cerebral I/R injury and further investigation of the mechanisms warrant further investigation to assist in the development of protective strategies against cerebral I/R injury in clinical trials.Communicated by Ramaswamy H. Sarma.

Asunto(s)

Isquemia Encefálica , Flavonoides , Daño por Reperfusión , Ratas , Animales , Barrera Hematoencefálica , Ratas Sprague-Dawley , Azul de Evans/metabolismo , Azul de Evans/farmacología , Azul de Evans/uso terapéutico , Infarto Cerebral/tratamiento farmacológico , Infarto Cerebral/metabolismo , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/metabolismo , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/metabolismo

RESUMEN

Disruption of the blood-brain barrier (BBB) following cerebral ischemia-reperfusion injury (CIRI) is a major factor in the pathophysiology of stroke. Endothelial cell-cell communication is essential for maintaining BBB integrity. By analyzing GSE227651 data, we found that a decrease in endothelial cell-cell communication mediated by Sema3/Nrp1 may be due to the downregulation of Nrp1 transcription, which could contribute to BBB breakdown after CIRI. We confirmed this hypothesis by using western blot analysis to show a reduction in Nrp1 protein levels in penumbra endothelial cells after CIRI in mice. We then overexpressed Nrp1 specifically in brain endothelial cells using adeno-associated virus in mice. Furthermore, Nrp1 overexpression had a protective effect on BBB integrity, as evidenced by a decrease in IgG and albumin leakage caused by CIRI in mice. Finally, we found that Nrp1 overexpression also reduced brain cell death and neurological deficits induced by cerebral ischemia-reperfusion in mice. Our findings suggest that Nrp1 downregulation may be a key factor in the breakdown of endothelial cell-cell communication and subsequent BBB disruption following CIRI. Targeting Nrp1-mediated pathways may be a promising approach for mitigating BBB damage and alleviating neurological consequences in stroke patients.

Asunto(s)

Barrera Hematoencefálica , Isquemia Encefálica , Daño por Reperfusión , Accidente Cerebrovascular , Animales , Humanos , Ratones , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Isquemia Encefálica/metabolismo , Infarto Cerebral/metabolismo , Regulación hacia Abajo , Células Endoteliales/metabolismo , Infarto de la Arteria Cerebral Media/metabolismo , Neuropilina-1/metabolismo , Reperfusión/efectos adversos , Daño por Reperfusión/metabolismo

RESUMEN

To investigate the effect of micro ribonucleic acid (miR)-211 on the apoptosis of nerve cells in rats with cerebral infarction through phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. A total of 36 Sprague-Dawley (SD) rats were randomly divided into sham operation group (n=12), model group (n=12) and miR-211 mimics group (n=12). Only the common carotid artery, external carotid artery, and internal carotid artery were exposed in sham operation group, and the models of cerebral infarction were constructed via suture method in the other two groups. After modeling, the rats in sham operation group and model group were intraperitoneally injected with normal saline, while those in miR-211 mimics group were given miR-211 mimics via intraperitoneal injection. At 2 weeks after intervention, samples were collected. Neurological deficit in rats was assessed using the Zea-longa score, and Nissl staining assay was performed to observe neuronal morphology. Western blotting (WB), quantitative polymerase chain reaction (qPCR) assay and enzyme-linked immunosorbent assay (ELISA) were employed to measure the relative protein expressions of PI3K and phosphorylated AKT (p-AKT), mRNA expression of miR-211 and content of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax), respectively. Additionally, the apoptosis was detected via terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay. The neuronal morphology was normal in sham operation group, while it was disordered in model group, with damaged neurons. In miR-211 mimics group, the morphology of neurons was improved. The Zea-longa score was obviously higher in model group and miR-211 mimics group than that in sham operation group (P<0.05), while it was notably lower in miR-211 mimics group than that in model group (P<0.05). Compared with those in sham operation group, the relative protein expression levels of PI3K and p-AKT remarkably declined in model group and miR-211 mimics group (P<0.05), whereas they were clearly higher in miR-211 mimics group than those in model group (P<0.05). The relative expression level of miR-211 was lower in model group and miR-211 mimics group than that in sham operation group (P<0.05), while it was markedly higher in miR-211 mimics group than that in model group (P<0.05). In comparison with sham operation group, model group and miR-211 mimics group had remarkably increased content of Bax and evidently lowered content of Bcl-2 (P<0.05), whereas compared with model group, miR-211 mimics group displayed clearly reduced Bax content and notably raised Bcl-2 content (P<0.05). The apoptosis rate was distinctly higher in model group and miR-211 mimics group than that in sham operation group (P<0.05), while it was visibly lower in miR-211 mimics group than that in model group (P<0.05). MiR-211 represses the apoptosis of nerve cells in rats with cerebral infarction by up-regulating the PI3K/AKT signaling pathway, thereby protecting nerves.

Asunto(s)

Infarto Cerebral , MicroARNs , Animales , Ratas , Apoptosis/genética , Proteína X Asociada a bcl-2/metabolismo , Infarto Cerebral/genética , Infarto Cerebral/metabolismo , Modelos Animales de Enfermedad , MicroARNs/metabolismo , Neuronas/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Transducción de Señal

RESUMEN

Stroke is reported to be the second leading cause of death worldwide, among which ischemic stroke has fourfold greater incidence than intracerebral hemorrhage. Excitotoxicity induced by NMDAR plays a central role in ischemic stroke-induced neuronal death. However, intervention targeted NMDARs against ischemic stroke has failed, which may result from the complex composition of NMDARs and the dynamic changes of their subunits. In this current study, the levels of NR1, NR2A and NR2B subunits of NMDARs were observed upon different time points during the reperfusion after 1 h ischemia with the western blot assay. It was found that the changes of NR1 subunit were only detected after ischemia 1 h/reperfusion 1 day (1 d). While, the changes of NR2A and NR2B subunits may last to ischemia 1 h/reperfusion 7 day(7 d), indicating that NR2subunits may be a potential target for ischemia-reperfusion injuries at the sub-acute stage of ischemic stroke. Simultaneously, mitochondrial injuries in neurons were investigated with transmission electron microscopy (TEM), and mitochondrial dysfunction was evaluated with mitochondrial membrane proteins oxidative respiratory chain complex and OCR. When the antagonist of NMDARs was used before ischemic exposure, the neuronal mitochondrial dysfunction was alleviated, suggesting that these aberrant deviations of NMDARs from basal levels led to mitochondrial dysfunction. Furthermore, when the antagonist of NR2B was administrated intracerebroventricularly at the sub-acute cerebral ischemia, the volume of cerebral infarct region was decreased and the neural functions were improved. To sum up, the ratio of NR2B-containing NMDARs is vital for mitochondrial homeostasis and then neuronal survival. NR2B-targeted intervention should be chosen at the sub-acute stage of cerebral ischemia.

Asunto(s)

Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Humanos , Isquemia Encefálica/complicaciones , Isquemia Encefálica/tratamiento farmacológico , Receptores de N-Metil-D-Aspartato/metabolismo , Infarto Cerebral/metabolismo , Accidente Cerebrovascular Isquémico/metabolismo , Neuronas/metabolismo

RESUMEN

To study the influence of long non-coding ribonucleic acid maternally expressed gene 3 (lncRNA MEG3) on the neuronal apoptosis in rats with ischemic cerebral infarction, and to analyze its regulatory effect on the transforming growth factor-beta 1 (TGF-ß1) pathway. A total of 36 Sprague-Dawley rats were randomly assigned into sham group, model group and low expression group. Ischemic cerebral infarction modeling was constructed in rats of the model group and low expression group. Corresponding adenoviruses were intracranially injected in rats of low expression group to knock down lncRNA MEG3 expression. At 24 h after the operation, the neurological function of rats was evaluated in each group, and the expression level of lncRNA MEG3 in cerebral tissues was determined using quantitative polymerase chain reaction (qPCR). The infarct size was measured via 2,3,5-triphenyltetrazolium chloride (TTC) staining. The apoptosis level of neurons in cerebral tissues was determined using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Besides, enzyme-linked immunosorbent assay (ELISA) was performed to determine the contents of inflammatory factors in cerebral tissues. Expression levels of apoptosis-associated proteins and vital genes in the TGF-ß1 signaling pathway in rat cerebral tissues were measured using Western blotting. Compared with the sham group, rats in the model group exhibited substantial increases in the neurological score and apoptosis level of neurons (p<0.01). Relative levels of lncRNA MEG3, interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), Caspase-3, TGF-ß1, small mothers against decapentaplegic homolog 2 (Smad2) and Smad3 (p<0.01) were higher in a model group than those in sham group. Notable declines in the content of IL-10 (p<0.01) and the ratio of B-cell lymphoma 2 (Bcl-2)/Bcl associated X protein (Bax) (p<0.01) were seen in the model group compared with the sham group. The abovementioned changes in the model group were partially abolished in the low expression group. LncRNA MEG3 is upregulated in the cerebral tissues of rats with ischemic cerebral infarction. It induces an inflammatory response, expands cerebral infarct size, and promotes neuronal apoptosis and impairment by activating the TGF-ß1 pathway.

Asunto(s)

Apoptosis , Infarto Cerebral , ARN Largo no Codificante , Animales , Ratas , Apoptosis/genética , Infarto Cerebral/genética , Infarto Cerebral/metabolismo , Modelos Animales de Enfermedad , Ratas Sprague-Dawley , ARN Largo no Codificante/genética , Transducción de Señal , Factor de Crecimiento Transformador beta1/metabolismo

RESUMEN

Involving in the immune response after cerebral infarction, astrocytes could secrete large amounts of pro- and anti-inflammatory factors. The aim of this study is to investigate the effect of Wnt3a intervention on the inflammatory response of oxygen-glucose deprivation (OGD) followed by reoxygenation (OGD/R) astrocyte model, and to provide a new target for immunoprotective treatment of cerebral infarction. We constructed the OGD/R rat astrocyte model, the astrocytes were treated by different concentrations of glucose (25, 50, 100 mM) intervened with/without Wnt3a (25 µg/ml). Microscope was used to observe the cell survival in rat astrocytes. The relative expression of inflammatory factors (TNF-a, IL-6, HIF-a) in rat astrocytes was detected by qRT-PCR. The expression of inflammatory factors such as TNF-a, IL-6 and HIF-a in rat astrocytes was increased after OGD/R treatment. The Wnt3a intervention promoted cell survival and decreased the expression of inflammatory factors in rat astrocytes induced by OGD/R. There is a neuroprotective effect that Wnt3a intervention could reduce inflammatory response in the OGD/R rat astrocyte model.

Asunto(s)

Glucosa , Oxígeno , Ratas , Animales , Glucosa/metabolismo , Oxígeno/farmacología , Oxígeno/metabolismo , Astrocitos/metabolismo , Interleucina-6/metabolismo , Interleucina-6/farmacología , Infarto Cerebral/metabolismo

RESUMEN

PURPOSE: To investigate the role of KLF4 in CI/R injury and whether Nrf2/Trx1 axis acted as a downstream pathway of KLF4 to exert the protective role in blood-brain barrier destruction after CI/R. METHODS: The tMCAO rat model in vivo was constructed and received the intracerebroventricular injection of 5 µg/kg and 10 µg/kg rhKLF4 before operation. TTC, brain water content, neurological function, ELISA, behavioral tests, HE, TUNEL, and qRT-PCR were performed to detect the protective role of KLF4 on CIR. Double-fluorescence staining and western blot were performed to determine the localization and spatiotemporal expression in brain tissues. Furthermore, we also analyzed the effect of KLF4 on the blood-brain barrier (BBB) and related mechanisms in vivo and in vitro. Nrf2 inhibitor tretinoin was applied, which was intraperitoneally injected into CIR rat. Evans blue staining was conducted. In vitro OGD/R models of bEnd.3 cells were also established, and received KLF4 overexpressed transfection and 12.5 µM tretinoin incubation. The permeability of bEnd.3 cells was evaluated by TEER and FITC-dextran leakage. BBB-related factors and oxidative stress were also analyzed, respectively. The tubular ability of KLF4 on OGD/R bEnd3 cells was also evaluated. RESULTS: In vivo study confirmed that KLF4 was expressed in astrocyte, and its content increased with time. KLF4 protected against brain injury caused by cerebral ischemia-reperfusion, reduced cerebral infarction area and oxidative stress levels, and promoted the recovery of behavioral ability in rats. Simultaneously, mechanism experiments confirmed that the repair effect of KLF4 on cerebral ischemia-reperfusion injury was closely related to the Nrf2/Trx1 pathway. KLF4 exerted the neuroprotective effect through upregulating Nrf2/Trx1 pathway. Consistent with in vivo animal study, in vitro study also confirmed the effect of KLF4 on the permeability of bEnd.3 cells after OGD/R injury through Nrf2/Trx1 pathway. CONCLUSION: Collectively, KLF4 played neuroprotective role in CIR induced MCAO and OGD/R, and the beneficial effects of KLF4 was partly linked to Nrf2/Trx1 pathway.

Asunto(s)

Isquemia Encefálica , Fármacos Neuroprotectores , Daño por Reperfusión , Animales , Ratones , Ratas , Barrera Hematoencefálica , Infarto Cerebral/metabolismo , Células Endoteliales/metabolismo , Fármacos Neuroprotectores/farmacología , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Ratas Sprague-Dawley , Reperfusión , Daño por Reperfusión/metabolismo