RESUMO
Astrocytic glycogen serves as an important glucose reserve, and its degradation provides extra support for neighboring neurons during energy deficiency. Salvianolic acid B (SAB) exerts a neuroprotective effect on reperfusion insult after cerebrovascular occlusion, but the effect of SAB on astrocytic glycogen and its relationship with neuroprotection are not completely understood. Here, we knocked down astrocyte-specific glycogen phosphorylase (GP, the rate-limiting enzyme in glycogenolysis) in vitro and in vivo and investigated the changes in key enzymes in glycogen metabolism by performing immunoblotting in vitro and immunofluorescence in vivo. Neurobehavioral and morphological assessments were conducted to uncover the outcomes during brain reperfusion. SAB accelerated astrocytic glycogenolysis by upregulating GP activity but not GP expression after reperfusion. Suppression of astrocytic glycogenolysis weakened SAB-mediated neuroprotection against the reperfusion insult. In addition, activation of glycogenolysis by SAB contributed to the survival of astrocytes and surrounding neurons by increasing antioxidant levels in astrocytes. Our data reveal that astrocytic GP represents an important metabolic target in SAB-induced protection against brain damage after cerebrovascular recanalization.
Assuntos
Astrócitos/metabolismo , Benzofuranos/farmacologia , Glicogênio/metabolismo , AVC Isquêmico/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Antioxidantes/metabolismo , Comportamento Animal , Sobrevivência Celular , Feminino , Glicogênio Fosforilase/metabolismo , Glicogenólise , AVC Isquêmico/psicologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/patologia , Traumatismo por Reperfusão/psicologiaRESUMO
OBJECTIVE: To investigate the influence of melatonin on behavioral and neurological function of rats with focal cerebral ischemia-reperfusion injury via the JNK/FoxO3a/Bim pathway. METHODS: One hundred and twenty healthy male SD rats were randomized into the model group (Model: the middle cerebral artery occlusion (MCAO) model was constructed and received an equal volume of normal saline containing 5% DMSO), sham operation group (Sham: received no treatment except normal feeding), and low, medium, and high dose of melatonin group (L-MT, M-MT, and H-MT intraperitoneally injected 10, 20, and 40 mg/kg melatonin 30 min after IR, respectively), with 24 rats in each group. Following 24 h of reperfusion, the rats in each of the above groups were tested for neurological deficit symptoms and behavioral changes to screen the rats included in the study. HE and TUNEL stainings were performed to observe pathological changes. Levels of oxidative stress-related indexes, inflammatory factor-related indexes, nuclear factor-κB p65 (NF-κB p65), and interferon-γ (IFN-γ) in the rat brain were measured by ELISA. The JNK/FoxO3a/Bim pathway-related proteins as well as Bcl-2, Caspase-3, and Bax were examined using Western blot. RESULTS: Detection of behavioral indicators showed that the MACO model was successfully constructed in rats. L-MT, M-MT, and L-MT groups presented reduced malondialdehyde (MDA), reactive oxygen species (ROS), tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, IL-1ß, IFN-γ, NF-κB p65, and apoptosis compared with the Model group (P < 0.05), and the improvement degree was better in the M-MT group versus the L-HT group. Bcl-2 protein expression in the brain tissue of L-MT, M-MT, and H-MT groups increased significantly, while Bax, Caspase-3, p-JNK, p-FoxO3a, and Bim protein expression declined markedly, versus the Model group (P < 0.05). The changes of indexes were greater in the M-MT group compared with that in the L-MT group. No significant difference was observed in all the above indexes between the M-MT group and the H-MT group (P > 0.05). CONCLUSIONS: In the MACO rat model, melatonin can effectively reduce Bax and Caspase-3 levels by modulating the JNK/FoxO3a/Bim pathway, inhibit neuronal apoptosis, and alleviate neurological deficits by reducing the release of proinflammatory mediators, with anti-inflammatory and antioxidant effects. In addition, 20 mg/kg is the optimal melatonin concentration.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Melatonina/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Proteína 11 Semelhante a Bcl-2/metabolismo , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Encéfalo/fisiopatologia , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/psicologia , Biologia Computacional , Modelos Animais de Doenças , Proteína Forkhead Box O3 , Mediadores da Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Melatonina/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/fisiopatologia , Traumatismo por Reperfusão/psicologiaRESUMO
MicroRNAs (miRNAs) are known as important regulators of gene expression and play important roles in diverse biological activities. However, the involvement of miRNAs in cerebral ischemia remains elusive. In the present study, using the middle cerebral artery occlusion (MCAO) model and oxygen-glucose deprivation/reperfusion (OGD/RP)-induced cell injury model, we found that the expression levels of miR-34c-5p were significantly reduced in MCAO rats and OGD/RP cells. Overexpression of miR-34c-5p could improve the increased brain infarction, brain water content and neurological scores in MCAO rats, as well as the abnormal expression of inflammatory cytokines (TNF-α, IL-6, COX-2, iNOS, IL-10) in OGD/RP cells. Moreover, overexpression of miR-34c-5p was found to inhibit the activity of nuclear factor-kappa B (NF-κB) by regulating the expression of nuclear receptor coactivator 1 (NCOA1), and increase the apoptotic rate of cortical neurons by inhibiting the expression of Caspase-3 and Bax and upregulating the expression of Bcl-2. Taken together, our findings demonstrated that miR-34c-5p plays an important role in cerebral ischemia/reperfusion injury, which may be mediated through inflammatory and apoptotic signaling pathways.
Assuntos
Anti-Inflamatórios/uso terapêutico , Apoptose/efeitos dos fármacos , Isquemia Encefálica/prevenção & controle , MicroRNAs/genética , Traumatismo por Reperfusão/prevenção & controle , Animais , Comportamento Animal/efeitos dos fármacos , Água Corporal , Química Encefálica , Isquemia Encefálica/genética , Isquemia Encefálica/psicologia , Citocinas/genética , Hipóxia/complicações , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/prevenção & controle , Masculino , NF-kappa B/genética , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/psicologia , Transdução de Sinais/genéticaRESUMO
AIM: To study the role of exosomes in the protective effect of cerebral ischemic preconditioning (cerebral-IPC) against cerebral I/R injury. METHOD: Mouse models of cerebral-IPC and MCAO/R were established as described previously, and their behavioral, pathological, and proteomic changes were analyzed. Neuro-2a subjected to OGD/R were treated with exosomes isolated from the plasma of sham-operated and cerebral-IPC mice. The differentially expressed miRNAs between exosomes derived from sham-operated (S-exosomes) and preconditioned (IPC-exosomes) mice were identified through miRNA array, and their targets were identified through database search. The control and OGD/R cells were treated with the IPC-exosomes, miRNA mimic or target protein inhibitor, and their viability, oxidative, stress and apoptosis rates were measured. The activated pathways were identified by analyzing the levels of relevant proteins. RESULTS: Cerebral-IPC mitigated the cerebral injury following ischemia and reperfusion, and increased the number of plasma exosomes. IPC-exosomes increased the survival of Neuro-2a cells after OGD/R. The miR-451a targeting Rac1 was upregulated in the IPC-exosomes relative to S-exosomes. The miR-451a mimic and the Rac1 inhibitor NSC23766 reversed OGD/R-mediated activation of Rac1 and its downstream pathways. CONCLUSION: Cerebral-IPC ameliorated cerebral I/R injury by inducing the release of exosomes containing miR-451a.
Assuntos
Exossomos/metabolismo , Exossomos/fisiologia , Precondicionamento Isquêmico , MicroRNAs/metabolismo , Neuroproteção , Traumatismo por Reperfusão/prevenção & controle , Animais , Comportamento Animal , Lesões Encefálicas/prevenção & controle , Linhagem Celular Tumoral , Infarto Cerebral/prevenção & controle , Infarto Cerebral/psicologia , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/psicologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/psicologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Tetrapleura tetraptera Taub. (family Fabaceae), is generally found in the lowland forest of tropical Africa. Its leaves and fruits are traditionally used in West Africa for the management of brain disorders. AIM OF THE STUDY: This study evaluated the effect of Tetrapleura tetraptera methanol fruit extract (TT) on bilateral common carotid artery occlusion-induced cerebral ischemia/reperfusion (I/R) injury in male Wistar rats. MATERIALS AND METHODS: Rats pretreated with TT for 7 days before a 30 min bilateral common carotid artery occlusion and reperfusion for 24 h were assessed for neurobehavioural deficits. Cortical, striatal and hippocampal oxidative stress, pro-inflammatory events, electrolyte imbalance and neurochemical dysfunctions, as well as hippocampal histopathological alterations, were also evaluated. HPLC-DAD analysis was performed to identify likely compounds contributing to the bioactivity of the extract. RESULTS: TT reduced I/R-induced behavioral deficits and ameliorated I/R-induced oxidative stress by restoring reduced glutathione level, increasing catalase and superoxide dismutase activities, and also reducing both lipid peroxidation and xanthine oxidase activity in the brain. TT attenuated I/R-increased myeloperoxidase and lactate dehydrogenase activities as well as disturbances in Na+ and K+ levels. Alterations elicited by I/R in the activities of Na+/K+ ATPase, complex I, glutamine synthetase, acetylcholinesterase, and dopamine metabolism were abated by TT pretreatment. TT prevented I/R-induced histological changes in the hippocampus. HPLC-DAD analysis revealed the presence of aridanin, a marker compound for Tetrapleura tetraptera, and other phytochemicals. CONCLUSIONS: These findings indicate that Tetrapleura tetraptera fruit has a protective potential against stroke through modulation of redox and electrolyte imbalances, and attenuation of neurotransmitter dysregulation and other neurochemical dysfunctions. Tetrapleura tetraptera fruit could be a promising source for the discovery of bioactives for stroke therapy.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Frutas , Teste de Campo Aberto/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Tetrapleura , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/psicologia , Relação Dose-Resposta a Droga , Masculino , Teste de Campo Aberto/fisiologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/fisiologiaRESUMO
Memory impairments are frequently reported in patients suffering from brain ischemic diseases. Oxidative/nitrosative stress, synaptic plasticity, and brain-derived neurotrophic factor (BDNF) are involved in the physiopathology of brain ischemia-induced memory disorders. In the present study, the effect of paroxetine as an efficacious antidepressant medication with antioxidant properties was evaluated on passive avoidance memory deficit following cerebral ischemia in rats. Transient occlusion of common carotid arteries was applied to induce ischemia-reperfusion injury in male Wistar rats. Paroxetine (5, 10, 20 mg/kg) was administered intraperitoneally once daily before (for 3 days) or after (for 7 days) the induction of ischemia. A week after ischemia-reperfusion injury, passive avoidance memory, long-term potentiation (LTP), BDNF levels, total antioxidant capacity, the activity of antioxidant enzymes (including catalase, glutathione peroxidase, and superoxide dismutase), the concentration of malondialdehyde (MDA), and nitric oxide (NO) were investigated in the hippocampus. In the passive avoidance test, paroxetine significantly increased the step-through latency and decreased the time spent in the dark compartment. This affirmative function of paroxetine on the passive avoidance memory was accompanied by the improvement of hippocampal LTP and an obvious augmentation in the BDNF contents. Besides, paroxetine caused a significant rise in the total antioxidant capacity and antioxidant enzyme activity; while decreased the hippocampal levels of NO and MDA. It was ultimately attained that paroxetine attenuates cerebral ischemia-induced passive avoidance memory dysfunction in rats by the enhancement of hippocampal synaptic plasticity and BDNF content together with the suppression of oxidative/nitrosative stress.
Assuntos
Antioxidantes/farmacologia , Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Hipocampo/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Memória/efeitos dos fármacos , Paroxetina/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Modelos Animais de Doenças , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Masculino , Malondialdeído/metabolismo , Transtornos da Memória/metabolismo , Transtornos da Memória/fisiopatologia , Transtornos da Memória/psicologia , Plasticidade Neuronal/efeitos dos fármacos , Óxido Nítrico/metabolismo , Estresse Nitrosativo/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/fisiopatologia , Traumatismo por Reperfusão/psicologia , Transdução de SinaisRESUMO
In the present study, we investigated the role of lncRNA mus distal-less homeobox 6 antisense 1 (DLX6-AS1) during cerebral impairment induced by stroke. DLX6-AS1 levels were upregulated during ischemia/reperfusion (I/R) and downregulation of DLX6-AS1 reduced acute injury and ameliorated long-term neurological impairments induced by cerebral I/R in mice. Additionally, silencing of DLX6-AS1 significantly decreased the neuronal apoptosis in vivo and in vitro. Furthermore, inhibition of miRNA-149-3p led to enhance the apoptosis, which confirmed that DLX6-AS1 could sponge miR-149-3p. Finally, BOK was predicted to be the target of miR-149-3p using TargetScanVert software. And the silencing of DLX6-AS1 inhibited BOK expression both in vivo and in vitro, which was reversed by a miR-149-3p inhibitor. At meantime, BOK promoted OGD/R induced apoptosis in N2a cells. Therefore, this suggests that miR-149-3p sponging by DLX6-AS1 may lead to cerebral neuron I/R-induced impairments through upregulation of apoptotic BOK activity, which offers a new approach to the treatment of stroke impairment.
Assuntos
Comportamento Animal , Infarto da Artéria Cerebral Média/terapia , Neurônios/metabolismo , Interferência de RNA , RNA Longo não Codificante/genética , Terapêutica com RNAi , Traumatismo por Reperfusão/prevenção & controle , Animais , Apoptose , Linhagem Celular Tumoral , Humanos , Infarto da Artéria Cerebral Média/genética , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/psicologia , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Teste do Labirinto Aquático de Morris , Atividade Motora , Neurônios/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Longo não Codificante/metabolismo , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologiaRESUMO
The antioxidant-mediated neuroprotective effect of Allium cepa outer scale extract (ACE) in mice with cerebral ischemia-reperfusion (I-R) injury was demonstrated in our earlier work. The current investigation aimed at establishing the bioactive component(s) responsible for this activity. Thus ACE was fractionated into ethyl acetate (EF) and aqueous (AF) fractions. These fractions were evaluated against cerebral I-R injury in mice. I-R injury in mice was induced by bilateral common carotid artery occlusion followed by 24 hr reperfusion. Memory, sensorimotor functions, cerebral infarct size, and oxidative stress were measured to address the neuroprotective mechanism of test substances. EF showed marked improvement of memory and sensorimotor functions by reducing brain oxidative stress and infarct size in mice after I-R injury. The bioactive EF was subjected to chromatographic (HPLC-PDA, HPLC-MS, preparative HPLC) and spectroscopic studies to isolate and identify the neuroprotective compounds. This lead to separation of three components, namely quercetin, quercetin 4'-O-glucoside, and the remaining fraction, from EF. The separated components were biologically evaluated. These components showed improvement in mice with I-R injury. But, EF displayed more marked neuroprotective effects as compared to the isolated components. The distinct neuroprotective outcome of EF may be credited to the synergistic action of compounds present in EF. Further studies such as evaluation of neurotoxic effects and other possible neuroprotective mechanisms are required to develop EF as a neuroprotective drug.
Assuntos
Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/química , Cebolas/química , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Antioxidantes/administração & dosagem , Antioxidantes/química , Antioxidantes/isolamento & purificação , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Feminino , Humanos , Masculino , Memória/efeitos dos fármacos , Camundongos , Fármacos Neuroprotetores/isolamento & purificação , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologiaRESUMO
Metformin (MET),an antidiabetic drug, has shown antioxidative and neuroprotective effects. In the present investigation, we aimed to study the probable effects of MET on cerebral ischemia/reperfusion in rats. Rats underwent cerebral ischemia/reperfusion and MET was administered orally at doses of 100 and 200 mg/kg for 56 days. Anxiety- and depressive-like behaviors were evaluated by elevated plus-maze or forced swimming tests, respectively. was assessed by. Cognitive functions were assessed by Y-maze continuous alternation task and morris water maze. The activity of SOD and the level of BDNF were measured in brains samples. Our results showed that administration of 200 mg/kg MET reduced the percent of brain edema (84.00 ± 2.13) in comparison with the ischemic animals (91.25 ± 2.25) (p < 0.05). Administration of 200 mg/kg MET in ischemic animals improved anxiety-like behavior by increasing the percentage of the open arms entries (46.51 ± 3.13) and the percentage of the open arms time (32.70 ± 2.49) in comparison with the cerebral ischemia group (26.35 ± 7.02 and 15.32 ± 5.78, respectively) (all p < 0.001). MET treatment (200 mg/kg) increased the cognition index of correct alternations (90.20 ± 4.95) in comparison with the cerebral ischemia group (59.50 ± 8.01) (p < 0.05). MET at the both doses reduced escape latency compared to the cerebral ischemia animals (all p < 0.05). In addition, 200 mg/kg MET increased the time spent in the target quadrant (16.06 ± 0.58) in comparison with the ischemic animals (9.84 ± 0.92) (p < 0.001) and the both doses of the drug increased the number of crossing (5.42 ± 0.36 and 6.5 ± 0.42, respectively) compared to the cerebral ischemia group (3.75 ± 0.31) (p < 0.05 and p < 0.001, respectively). Moreover, 200 mg/kg MET reduced the immobility time (47.50 ± 9.00) in comparison with the cerebral ischemia group (93.43 ± 8.28) (p < 0.001). Furthermore, the both doses of MET increased the BDNF levels (4590 ± 197.6 and 4767 ± 44.10, respectively) in comparison with the ischemic animals (3807 ± 42.56) (p < 0.01 and p < 0.001, respectively). Also, the both doses of the drug increased the SOD activity of brain (52.67 ± 0.33 and 55.00 ± 0.57, respectively) compared to the ischemic animals (49.33 ± 0.33) (p < 0.01 and p < 0.001, respectively). Based on our data, long-term MET therapy may improve behavioral disorders following cerebral ischemia/reperfusion and can be considered as a novel therapeutic approach for the treatment of brain ischemic conditions.
Assuntos
Antioxidantes/administração & dosagem , Isquemia Encefálica/tratamento farmacológico , Aprendizagem em Labirinto/efeitos dos fármacos , Metformina/administração & dosagem , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/psicologia , Relação Dose-Resposta a Droga , Esquema de Medicação , Masculino , Aprendizagem em Labirinto/fisiologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologiaRESUMO
The γ-aminobutyric acid A (GABAA) receptor, which contains a chloride channel, is a typical inhibitory neurotransmitter receptor in the central nervous system. Although the GABAergic neurotransmitter system has been discovered to be involved in various psychological behaviors, such as anxiety, convulsions, and cognitive function, its functional changes under conditions of ischemic pathological situation are still uncovered. In the present study, we attempted to elucidate the functional changes in the GABAergic system after transient forebrain ischemia in mice. A bilateral common carotid artery occlusion for 20 min was used to establish a model of transient forebrain ischemia/reperfusion (tI/R). Delayed treatment with diazepam, a positive allosteric modulator of the GABAA receptor, increased locomotor activity in the open field test and spontaneous alternations in the Y-maze test in tI/R mice, but not in shams. Delayed treatment with diazepam did not alter neuronal death or the number of GABAergic neurons in tI/R mice. However, tI/R induced changes in the protein levels of GABAA receptor subunits in the hippocampus. In particular, the most marked increase in the tI/R group was found in the level of α5 subunit of the GABAA receptor. Similar to delayed treatment with diazepam, delayed treatment with imidazenil, an α5-sensitive benzodiazepine, increased spontaneous alternations in the Y-maze in tI/R mice, whereas zolpidem, an α5-insensitive benzodiazepine, failed to show such effects. These results suggest that tI/R-induced changes in the level of the α5 subunit of the GABAA receptor can alter the function of GABAergic drugs in a mouse model of forebrain ischemia.
Assuntos
Ataque Isquêmico Transitório/fisiopatologia , Ataque Isquêmico Transitório/psicologia , Memória de Curto Prazo , Atividade Motora , Receptores de GABA-A/efeitos dos fármacos , Animais , Ansiedade/psicologia , Benzodiazepinas/farmacologia , Estenose das Carótidas/fisiopatologia , Estenose das Carótidas/psicologia , Diazepam/farmacologia , Moduladores GABAérgicos , Imidazóis/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Traumatismo por Reperfusão/fisiopatologia , Traumatismo por Reperfusão/psicologia , Zolpidem/farmacologiaRESUMO
Hepatic ischemia reperfusion (HIR) has been found to induce hippocampus injury and cognitive dysfunction. The N-methyl-d-aspartate (NMDA) receptor subunit 2A (NR2A) is an important factor mediating excitotoxicity and neurons injury, and autophosphorylation of Src can up-regulate tyrosine phosphorylation of NR2A to improve its activity. However, the role of Src and NR2A in HIR-induced hippocampus injury in young mice remains unknown. In this study, we found that serum biomarkers of brain injury (S100ß and NSE) increased significantly and reached highest after reperfusion of 3â¯days which had the same trend with the levels of p-Src and p-NR2A. Interactions between Src and NR2A or PSD95 were increased after HIR. Hippocampal neuron apoptosis was increased, and long-term cognitive impairment was found after reperfusion of 1â¯month. Inhibition of Src and NR2A with PP2 and NVP-AAM077 respectively not only down-regulated the levels of p-Src and p-NR2A, but also ameliorated hippocampal neurons apoptosis and long-term cognitive impairment after HIR. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ) and interleukin (IL)-6 were increased after reperfusion of 3â¯days, while PP2 and NVP-AAM077 treatment didn't attenuate the changes. And no difference was found in serum TNF-α, IFN-γ, IL-6 concentrations as well as the levels of Src, p-Src, NR2A, p-NR2A, PSD95 among the four groups after reperfusion of 1â¯month. In summary, HIR can lead to hippocampus injury and long-term cognitive dysfunction, and Src-PSD95-NR2A pathway plays an important role in the process.
Assuntos
Disfunção Cognitiva/fisiopatologia , Hipocampo/metabolismo , Fígado/fisiopatologia , Receptores de N-Metil-D-Aspartato/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologia , Quinases da Família src/metabolismo , Animais , Apoptose , Disfunção Cognitiva/etiologia , Proteína 4 Homóloga a Disks-Large/metabolismo , Hipocampo/patologia , Fígado/irrigação sanguínea , Aprendizagem em Labirinto , Camundongos Endogâmicos C57BL , Fosforilação , Traumatismo por Reperfusão/complicações , Transdução de SinaisRESUMO
BACKGROUND: Cerebral ischemia/reperfusion (I/R) injury is a common pathological process after cardiac arrest, shock and acute cerebral infarction recanalization, which causes serious injury in brain function. Pinocembrin (Pino), a natural flavonoid at the highest concentration in propolis, exhibited a variety of biological effects, including antitumor, antimicrobial and anti-inflammatory activities. However, the effects of Pino on brain injured after I/R and the mechanisms of its neuroprotective effects remain elusive. METHODS: In the present study, we used I/R model rats underwent transient cerebral ischemia inducing by four-vessel occlusion and reperfusion. Pino alone or in combination with autophagy inducer rapamycin (RAPA) was administered to I/R rats. The behavior and cognitive function were evaluated by open field test and Morris water maze test. HE staining was used to determine the survival of hippocampus CA1 pyramidal cells. Three key proteins of autophagy, LC3, Beclin1 and p62, were detected by Western blot. RESULTS: Our results showed that Pino could significantly reduce the damage of hippocampus CA1 pyramidal neurons and alleviate the impairments of behavior and cognitive function in I/R rats. Pino also decreased the expression of LC3II and Beclin1 and increased the level of p62 in hippocampus CA1 of I/R rats. In addition, Pino also decreased RAPA-induced neuronal damage and excessive activation of autophagy in I/R rats. CONCLUSIONS: Taken together, these results suggested that Pino could protect the brain injury induced by I/R and the potential mechanisms might attribute to inhibition of autophagy activity.
Assuntos
Autofagia/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Região CA1 Hipocampal/efeitos dos fármacos , Flavanonas/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Proteína Beclina-1/metabolismo , Comportamento Animal/efeitos dos fármacos , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Isquemia Encefálica/psicologia , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/patologia , Região CA1 Hipocampal/fisiopatologia , Cognição/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Proteínas Associadas aos Microtúbulos/metabolismo , Atividade Motora/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/psicologia , Proteína Sequestossoma-1/metabolismo , Sirolimo/farmacologia , Fatores de TempoRESUMO
AIM: Previous studies indicated that cerebral ischemia/reperfusion injury (CI/RI) could induce behavioral deficits. Single treatment of vagus nerve stimulation (VNS) or curcumin is reported to restore CI/RI-induced behavioral deficits. However, the synergic effect remains unclear. MATERIALS AND METHODS: Rats were divided into 6 groups: sham, CI/RI, VNS, CI/RIâ¯+â¯VNS, VNSâ¯+â¯curcumin and CI/RIâ¯+â¯VNSâ¯+â¯curcumin groups. Each group was further divided into three or four subgroups for further assessments. In specific, Morris water maze task and shuttle box test were used to evaluate cognitive capacity. Rota-rod test, neurological deficits scores, 2,3,5-triphenyltetrazolium chloride staining, TUNEL staining were performed to estimate motor capacity, neurological deficits, the size of infarct volume and neural apoptosis, respectively. Finally, the expressions of apoptosis-associated proteins and key kinases in the AKT/extracellular signal-regulated kinase-2 (ERK2) pathway were measured by Western blot analysis. RESULTS: Combination of curcumin and VNS significantly restored the CI/RI-induced cognitive and motor impairments compared with the CI/RIâ¯+â¯VNS group (Pâ¯<â¯0.05 and Pâ¯<â¯0.01). Moreover, combination of curcumin and VNS significantly lowered CI/RI-induced neurological deficits, infract volume, neural apoptosis (all Pâ¯<â¯0.05) and inflammatory cytokines release (Pâ¯<â¯0.05 and Pâ¯<â¯0.01) when compared to the CI/RIâ¯+â¯VNS group. Additionally, the phosphorylation levels of AKT and ERK2 were both increased by combination of curcumin and VNS compared with the CI/RIâ¯+â¯VNS group. CONCLUSION: Combination of curcumin and VNS restored CI/RI-induced behavioral deficits by inhibiting apoptosis and inflammatory response. Besides, the AKT/ERK2 pathway might be implicated.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Isquemia Encefálica/terapia , Curcumina/administração & dosagem , Aprendizagem em Labirinto/efeitos dos fármacos , Traumatismo por Reperfusão/terapia , Estimulação do Nervo Vago/métodos , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/psicologia , Terapia Combinada/métodos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Aprendizagem em Labirinto/fisiologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologiaRESUMO
The aim of the present study was to study the effects of arachidonic acid (ARA) in a rat brain ischemia/reperfusion model induced by middle cerebral artery occlusion (MCAO). A total of 50 rats were randomly divided into five groups: control group, MCAO group, MCAO + ARA 0.3 g/kg group, MCAO + ARA 1 g/kg group, and MCAO + ARA 3 g/kg group. The MCAO + ARA groups received ARA by intraperitoneal injection daily for 14 consecutive days, while the rats in the control and MCAO groups were given equivalent volume of saline. We detected the Morris water maze test and pathological changes to investigate the ischemia/reperfusion injury. The protein levels of tumor necrosis factor-alpha and interleukin-6 in the hippocampus were detected by enzyme-linked immunosorbent assay kits. In addition, the activities of superoxide dismutase, glutathione peroxidase, and malondialdehyde were assayed in hippocampus homogenates to evaluate the oxidative stress after ischemia/reperfusion. The results indicated that ARA administration decreased biochemical parameters of inflammation and oxidative stress. Morris water maze test and histopathological examination further verified the protective effects of ARA on ischemia/reperfusion injury rats. These findings demonstrated that ARA could protect MCAO-induced brain injury rats by inhibition of inflammation and oxidative stress, suggesting that it may have potential as a therapy for cerebral ischemia/reperfusion injury.
Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Ácido Araquidônico/farmacologia , Hipocampo/efeitos dos fármacos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Mediadores da Inflamação/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Traumatismo por Reperfusão/prevenção & controle , Animais , Comportamento Animal/efeitos dos fármacos , Citoproteção , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Glutationa Peroxidase/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Hipocampo/fisiopatologia , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/psicologia , Interleucina-6/metabolismo , Masculino , Malondialdeído/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/psicologia , Superóxido Dismutase/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND To identify the effect of apigenin on cognitive deficits of rats after cerebral ischemia and reperfusion injury, and to investigate the potential molecular mechanisms. MATERIAL AND METHODS The rats were given sodium butyrate (NaB) or apigenin (20 or 40 mg/kg) for 28 days. Cognition was investigated by the Morris water maze (MWM) test. On day 28, the rats were euthanized and their hippocampal brain regions were used to identify biochemical and neurochemical alterations. The content of histone deacetylase (HDAC) was measured by enzyme-linked immunosorbent assay (ELISA). Western blot analysis was performed to determine the levels of BDNF, phosphorylated cAMP response element-binding protein (pCREB), acetylated H3, and acetylated H4. The mRNA expressions of brain-derived neurotrophic factor (BDNF) and synapsin-I (Syn-I) were examined by polymerase chain reaction (PCR). RESULTS The rats with chronic administration of apigenin (20 and 40 mg/kg) showed better performance in the MWM task than the model rats; there was no significant difference between the apigenin-treated and NaB-treated rats. At the higher apigenin dose of 40 mg/kg, the HDAC content was decreased, the BDNF level was markedly increased, and acetylated H3 and acetylated H4 expressions and Syn-I expressions in the hippocampus was upregulated compared with the model group. Apigenin at 20 mg/kg did not show reversal of the neurochemical alterations. CONCLUSIONS The improvement effect of apigenin on cognitive impairments after cerebral ischemia and reperfusion injury may involve multiple mechanisms, such as the inhibition of HDAC, induction of BDNF and Syn-I expression, and regulation of histone acetylation.
Assuntos
Apigenina/farmacologia , Disfunção Cognitiva/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/psicologia , Acetilação , Animais , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Ácido Butírico/farmacologia , Transtornos Cognitivos/tratamento farmacológico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Histona Desacetilases/metabolismo , Histonas/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologia , Acidente Vascular Cerebral/metabolismoRESUMO
Capsaicin, the ingredient responsible for the pungent taste of hot chili peppers, is widely used in the study and management of pain. Recently, its neuroprotective effect has been described in multiple studies. Herein, we investigated the underlying mechanisms for the neuroprotective effect of capsaicin. Direct injection of capsaicin (1 or 3nmol) into the peri-infarct area reduced the infarct volume and improved neurological behavioral scoring and motor coordination function in the middle cerebral artery occlusion (MCAO)/reperfusion model in rats. The time window of the protective effect of capsaicin was within 1h after reperfusion, when excitotoxicity is the main reason of cell death. In cultured cortical neurons, administration of capsaicin attenuated glutamate-induced excitotoxic injury. With respect to the mechanisms of the neuroprotective effect of capsaicin, reduced calcium influx after glutamate stimulation was observed following capsaicin pretreatment in cortical neurons. Trpv1 knock-out abolished the inhibitory effect of capsaicin on glutamate-induced calcium influx and subsequent neuronal death. Reduced expression of GluN1 and GluN2B, subunits of NMDA receptor, was examined after capsaicin treatment in cortical neurons. In summary, our studies reveal that the neuroprotective effect of capsaicin in cortical neurons is TRPV1-dependent and down-regulation of the expression and function of NMDA receptors contributes to the protection afforded by capsaicin.
Assuntos
Capsaicina/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Traumatismo por Reperfusão/prevenção & controle , Animais , Comportamento Animal , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Aminoácidos Excitatórios/antagonistas & inibidores , Aminoácidos Excitatórios/toxicidade , Ácido Glutâmico/toxicidade , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/biossíntese , Receptores de N-Metil-D-Aspartato/genética , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/psicologia , Canais de Cátion TRPV/efeitos dos fármacos , Canais de Cátion TRPV/metabolismoRESUMO
The aim of the present study was to investigate the effect of "nourishing liver and kidney" acupuncture therapy on motor and cognitive deficits, and the underlying mechanism following cerebral ischemia-reperfusion (I/R) via increasing the expression of brain derived neurotrophic factor (BDNF) and synaptophysin (SYN) in the hippocampus. Healthy adult male SD rats were randomly divided into sham operation group (n=51), model group (n=51), acupuncture group (n=51) and acupuncture control group (n=51). The middle cerebral I/R model was established. Acupunctures were performed in the acupuncture group and acupuncture control group at acupoints of Taixi (K103), Taichong (ST09) of both sides, for 30 min once daily every morning. The animals in the sham operation group and model group were conventionally fed in the cage, without any intervention therapy. The rats of each group were assessed with modified neurological severity scores (mNSS). The expression of BDNF and SYN in the hippocampus was detected by immunohistochemical SP method and the synaptic structure in hippocampus area was assessed morphologically and quantitatively at the 3rd, 7th and 14th day. The Morris water Maze (MWM) test was used to evaluate the rats' learning and memory abilities on the 15th day after acupuncture. The animals in the acupuncture control group and sham operation group presented no neurological deficit. In the acupuncture group, the nerve functional recovery was significantly better than that in the model group at the 7th and 14th day after modeling. The average MWM escape latency in the acupuncture group was shorter than that in the model group at the 3rd, 4th and 5th day. The number of crossings of the platform quadrant in the acupuncture group was significantly more than that in the model group. At the each time point, the expression levels of BDNF and SYN in the hippocampal regions increased significantly in the model group as compared with the sham operation group and the acupuncture control group. In the acupuncture group, the expression levels of BDNF at the 7th and 14th day increased more significantly than those in the model group. In the acupuncture group, the expression levels of SYN at the each time point increased more significantly than those in the model group. The post-synaptic density (PSD) was significantly increased and the synapse cleft width was narrowed in the acupuncture group as compared with other groups. The synaptic curvatures were improved obviously in the acupuncture group in contrast to the model group. It was concluded that the "nourishing liver and kidney" acupuncture therapy has positive effects on behavioral recovery, as well as learning and memory abilities, probably by promoting the expression of BDNF and SYN, and synaptic structure reconstruction in the ipsilateral hippocampus after I/R in rats. The "nourishing liver and kidney" acupuncture therapy can promote the functional recovery in rats after cerebral ischemia injury.
Assuntos
Isquemia Encefálica/terapia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Hipocampo/patologia , Traumatismo por Reperfusão/terapia , Sinaptofisina/metabolismo , Pontos de Acupuntura , Terapia por Acupuntura , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/psicologia , Modelos Animais de Doenças , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/psicologiaRESUMO
Sigma-1 receptor (σ1r) activation could attenuate the learning and memory deficits in the AD model, ischemia model and others. In our previous study, the activation of σ1r increased the expression of brain-derived neurotrophic factor (BDNF), possibly through the NR2A-induced pathway, and σ1r agonists might function as neuroprotectant agents in vascular dementia. Here, we used σ1r knockout mice to confirm the role of σ1r. Furthermore, an antagonist of NR2A was first used to investigate whether the NR2A-induced pathway is the necessary link between σ1r and BDNF. The operation of brain ischemia/reperfusion was induced by bilateral common carotid artery occlusion for 20min in C57BL/6 and σ1r knockout mice as the ischemic group. A σ1r agonist, PRE084 (1mg/kg, i.p.), and NR2A antagonist, PEAQX (10mg/kg, i.p.), were administered once daily throughout the experiment. Behavioral tests were performed starting on day 8. On day 22 after brain ischemia/reperfusion, mice were sacrificed and brains were immediately collected and the injured and the hippocampus was isolated and stored at -80°C for western blot analysis. After ischemic operation, contrast with the σ1r knockout mice, PRE084 significantly ameliorated learning and memory impairments in the behavioral evaluation, and prevented the protein decline of BDNF, NR2A, CaMKIV and TORC1 expression in wild-type mice. However, the effects of PRE084 on CaMKIV-TORC1-CREB and BDNF, even for learning and memory impairment, were antagonized by the co-administration of PEAQX, an antagonist of NR2A. The activation of σ1r improves the impairment of learning and memory in the ischemia/reperfusion model, and the expression of BDNF, which may have been achieved through the NR2A-CaMKIV-TORC1 pathway.
Assuntos
Isquemia Encefálica/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores sigma/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/patologia , Isquemia Encefálica/psicologia , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Modelos Animais de Doenças , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Memória/efeitos dos fármacos , Memória/fisiologia , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores sigma/agonistas , Receptores sigma/genética , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/psicologia , Receptor Sigma-1RESUMO
Treatment of enriched environment (EE) exerts neuroprotective effect in cerebral ischemia/reperfusion (I/R) injury. However, how the component of EE contributes to the functional recovery after brain ischemia remains unclear. Here we examined the effect of physical and social components of EE on poststroke astrocytes proliferation using an animal model of middle cerebral artery occlusion (MCAO) followed by reperfusion. Rats were divided into five groups: physical enrichment group (PE), social enrichment group (SE), physical and social enrichment group (PSE), ischemia + standard group (IS) and sham-operated + standard group (SS). In a set of behavioral tests, we demonstrated that animals in the enriched groups exhibited improved functional outcomes compared with those in standard group. Reduced infarct volume was only observed in PSE and PE groups. Double immunofluorescent labeling and western blot analysis revealed that rats in PSE and PE groups showed significantly more proliferated astrocytes and higher expression levels of brain-derived neurotrophic factor (BDNF) in the periinfarct cortex, compared with those in SE group. Astrocytes proliferation and BDNF expression were significantly correlated with functional outcomes. Collectively, this study suggests that physical activity is a more important component of EE regarding the effect on astrocytes proliferation and BDNF expression, which may contribute to the improved neurological function of stroke animals.
Assuntos
Astrócitos/metabolismo , Isquemia Encefálica/metabolismo , Meio Ambiente , Relações Interpessoais , Atividade Motora/fisiologia , Traumatismo por Reperfusão/metabolismo , Animais , Astrócitos/patologia , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/psicologia , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Proliferação de Células/fisiologia , Masculino , Condicionamento Físico Animal/fisiologia , Condicionamento Físico Animal/psicologia , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/diagnóstico por imagem , Traumatismo por Reperfusão/psicologiaRESUMO
Cerebral ischemia/reperfusion injury can result in neuronal death, which further results in brain damage and can even lead to death. Although recent studies showed that rosmarinic acid (RA) exerts neuroprotective effects and attenuates ischemia-induced brain injury and neuronal cell death, little is known about the precise mechanisms that occur during cerebral ischemia/reperfusion (I/R). Therefore, the aim of this study was to examine the underlying mechanism of the neuroprotective effects of RA against ischemic brain injury induced by cerebral I/R. Transient global brain ischemia was induced by 4-vessel occlusion in adult male Sprague-Dawley rats. We randomly divided rats into five groups: sham, I/R, I/R+RA, I/R+Vehicle and I/R+RA+LY. Open-field, closed-field and Morris water maze tests were carried our separately to examine the anxiety and cognitive behavior of each group. Cresyl violet staining was used to examine the survival of hippocampal CA1 pyramidal neurons. The levels of p-Akt, p-JNK3 and cleaved caspase-3 in the hippocampus were also examined by Western blotting. Our results showed that administration of RA protected locomotive ability, relieved anxiety behavior and protected cognitive ability in cerebral I/R-injured rats. Additionally, RA significantly protected neurons in the hippocampal CA1 region against cerebral I/R-induced damage. Furthermore, RA increased the phosphorylation of Akt1, downregulated the phosphorylation of JNK3 and reduced the expression of cleaved caspase-3. Finally, the Akt inhibitor LY294002 reversed all the protective effects of RA, indicating that RA protects neurons in the hippocampal CA1 region from ischemic damage through the Akt/JNK3/caspase-3 signaling pathway.