RESUMO
Background: Accumulating evidence suggests that inflammation is a contributor to the cause and progression of neurodegenerative disease, such as Alzheimer's disease (AD) and Parkinson disease (PD). However, the exact mechanisms of neuroinflammation are still unclear. Here, we discussed the potential mechanisms of lipopolysaccharide (LPS)-induced brain injury via NR2B antagonists (Ro25-6981) treatment in mice. Methods: Neuroinflammation was induced in mice by virtue of LPS (1 mg/kg) by intraperitoneal injection. Immunoprecipitation was performed to measure the assembly of NR2B-calmodulin dependent protein kinase II (CaMKII)-Postsynaptic density protein 95 (PSD95) signal module in the hippocampus and frontal cortex. Nissl's staining was employed to access neuron injury in the brain. Results: Data demonstrated that LPS could induce neuron damage, and promote the assembly of NR2B-CaMKII-PSD95 signal module and increase the expression of phosphorylated CaMKII and c-Jun N-terminal kinase (JNK) in the frontal cortex and hippocampus. However, NR2B antagonists could protect neuron injury against LPS-induced inflammation, inhibit the assembly of NR2B-CaMKII-PSD95 signal module and decrease the level of phosphorylated CaMKII and JNKs in mice. Conclusions: These findings indicated that the assembly of NR2B-CaMKII-PSD95 signal module is related to LPS-induced neuroinflammation, NR2B plays a key role in the assembly of NR2B-CaMKII-PSD95 signal module and NR2B antagonists could alleviate LPS-related inflammation through the reduced assembly of NR2B-CaMKII-PSD95 signal module in frontal cortex and hippocampus.
Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína 4 Homóloga a Disks-Large/metabolismo , Lobo Frontal/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Fenóis/farmacologia , Piperidinas/farmacologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Lobo Frontal/imunologia , Lobo Frontal/metabolismo , Hipocampo/imunologia , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Transdução de SinaisRESUMO
Context: Researchers in a variety of fields have extensively focused on histone deacetylase 6 (HDAC6) due to its aggravation of inflammatory reaction. However, relevant studies examining whether HDAC6 could exacerbate lipopolysaccharide (LPS)-induced inflammation are still lacking. Objective: We assessed the role of HDAC6 in LPS-induced brain inflammation and used the HDAC6-selective inhibitor Tubastatin A (TBSA) to investigate the potential mechanisms further. Materials and methods: Brain inflammation was induced in Kunming (KM) mice via intraperitoneal (I.P.), injection of Lipopolysaccharide (LPS) (1 mg/kg), the TBSA (0.5 mg/kg) was delivered via intraperitoneal. The phosphorylated p38 (p-p38) Mitogen-activated protein kinases (MAPK) and expression of typical inflammatory mediators, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in both the hippocampus and cortex, were examined by immunoblotting. Nissl staining was used to detect the neuronal damage in the hippocampus and the cortex. Results: About 1 mg/kg LPS via daily intraperitoneal (I.P.) injections for 12 days significantly increased p38 MAPK phosphorylation, TNF-α and IL-6 expression, and neuronal loss. However, 0.5 mg/kg TBSA (three days before LPS treatment) by I.P. injections for 15 days could reverse the above results. Conclusions: This present study provided evidence that TBSA significantly suppressed LPS-induced neuroinflammation and the expression of p-p38. Results derived from our study might help reveal the effective targeting strategies of LPS-induced brain inflammation through inhibiting HDAC6.
Assuntos
Encefalite/prevenção & controle , Inibidores Enzimáticos/farmacologia , Desacetilase 6 de Histona/antagonistas & inibidores , Ácidos Hidroxâmicos/farmacologia , Indóis/farmacologia , Lipopolissacarídeos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Modelos Animais de Doenças , Encefalite/enzimologia , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos , FosforilaçãoRESUMO
Although Butylphthalide (BP) has protective effects that reduce ischemia-induced brain damage and neuronal cell death, little is known about the precise mechanisms occurring during cerebral ischemia/reperfusion (I/R). Therefore, the aim of this study was to investigate the neuroprotective mechanisms of BP against ischemic brain injury induced by cerebral I/R through inhibition of the c-Jun N-terminal kinase (JNK)-Caspase3 signaling pathway. BP in distilled non-genetically modified Soybean oil was administered intragastrically three times a day at a dosage of 15 mg/(kg day) beginning at 20 min after I/R in Sprague-Dawley rats. Immunohistochemical staining and Western blotting were performed to examine the expression of related proteins, and TUNEL-staining was used to detect the percentage of neuronal apoptosis in the hippocampal CA1 region. The results showed that BP could significantly protect neurons against cerebral I/R-induced damage. Furthermore, the expression of p-JNK, p-Bcl2, p-c-Jun, FasL, and cleaved-caspase3 was also decreased in the rats treated with BP. In summary, our results imply that BP could remarkably improve the survival of CA1 pyramidal neurons in I/R-induced brain injury and inhibit the JNK-Caspase3 signaling pathway.
Assuntos
Apoptose/efeitos dos fármacos , Benzofuranos/farmacologia , Isquemia Encefálica/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Animais , Benzofuranos/química , Isquemia Encefálica/metabolismo , Caspase 3/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Neurônios/metabolismo , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Chronic inflammation appears to play a critical role in sickness behavior caused by diabetes mellitus. Astaxanthin has been used in treating diabetes mellitus and diabetic complications because of its neuroprotective and anti-inflammatory actions. However, whether astaxanthin can improve sickness behavior induced by diabetes and its potential mechanisms are still unknown. The aim of this study was to investigate the effects of astaxanthin on diabetes-elicited abnormal behavior in mice and its corresponding mechanisms. An experimental diabetic model was induced by streptozotocin (150 mg/kg) and astaxanthin (25 mg/kg/day) was provided orally for 10 weeks. Body weight and water consumption were measured, and the sickness behavior was evaluated by the open field test (OFT) and closed field test (CFT). The expression of glial fibrillary acidic protein (GFAP) was measured, and the frontal cortical cleaved caspase-3 positive cells, interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) expression levels were also investigated. Furthermore, cystathionine ß-synthase (CBS) in the frontal cortex was detected to determine whether the protective effect of astaxanthin on sickness behavior in diabetic mice is closely related to CBS. As expected, we observed that astaxanthin improved general symptoms and significantly increase horizontal distance and the number of crossings in the OFT and CFT. Furthermore, data showed that astaxanthin could decrease GFAP-positive cells in the brain and down-regulate the cleaved caspase-3, IL-6, and IL-1ß, and up-regulate CBS in the frontal cortex. These results suggest that astaxanthin provides neuroprotection against diabetes-induced sickness behavior through inhibiting inflammation, and the protective effects may involve CBS expression in the brain.
Assuntos
Anti-Inflamatórios/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Comportamento de Doença/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Líquidos/fisiologia , Comportamento de Doença/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Resultado do Tratamento , Xantofilas/farmacologia , Xantofilas/uso terapêuticoRESUMO
Mangiferin has been extensively applied in different fields due to its anti-inflammatory properties. However, the precise mechanism used by mangiferin on lipopolysaccharide (LPS)-induced inflammation has not been elucidated. Here, we discuss the potential mechanism of mangiferin during a LPS-induced brain injury. Brain injury was induced in ICR mice via intraperitoneal LPS injection (5 mg/kg). Open- and closed-field tests were used to detect the behaviors of mice, while immunoblotting was performed to measure the expression of interleukin-6 (IL-6) and cystathionine-b-synthase (CBS) in the hippocampus after mangiferin was orally administered (p.o.). Mangiferin relieved LPS-induced sickness 6 and 24 h after LPS injection; in addition, this compound suppressed LPS-induced IL-6 production after 24 h of LPS induction as well as the downregulation of LPS-induced CBS expression after 6 and 24 h of LPS treatment in the hippocampus. Therefore, mangiferin attenuated sickness behavior by regulating the expression of IL-6 and CBS.
Assuntos
Lesões Encefálicas/tratamento farmacológico , Lesões Encefálicas/metabolismo , Cistationina beta-Sintase/fisiologia , Interleucina-6/fisiologia , Lipopolissacarídeos/toxicidade , Xantonas/uso terapêutico , Animais , Lesões Encefálicas/induzido quimicamente , Cistationina beta-Sintase/antagonistas & inibidores , Interleucina-6/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos ICR , Xantonas/farmacologiaRESUMO
The receptor for advanced glycation end products (RAGE) contributes to diabetes-associated cognitive dysfunction (DACD) through the interaction of its C-terminal AAs 2-5 with mitogen-activated protein kinase kinase 3 (MKK3). However, the associated MKK3 binding site is unknown. Here, db/db mice were used as a model for type 2 diabetes. GST pull-down assays and AutoDock Vina simulations were conducted to identify the key RAGE binding site in MKK3. This binding site was mutated to investigate its effects on DACD and to elucidate the underlying mechanisms. The interaction of MKK3 and RAGE, the levels of inflammatory factors, and the activation of microglia and astrocytes were tested. Synaptic morphology and plasticity in hippocampal neurons were assessed via electrophysiological recordings and Golgi staining. Behavioral tests were used to assess cognitive function. In this study, MKK3 bound directly to RAGE via its lysine 329 (K329), leading to the activation of the nuclear factor-κB (NF-κB) signaling pathway, which in turn triggered neuroinflammation and synaptic dysfunction, and ultimately contributed to DACD. MKK3 mutation at K329 reversed synaptic dysfunction and cognitive deficits by downregulating the NF-κB signaling pathway and inhibiting neuroinflammation. These results confirm that neuroinflammation and synaptic dysfunction in the hippocampus rely on the direct binding of MKK3 and RAGE. We conclude that MKK3 K329 binding to C-terminal RAGE (ct-RAGE) is a key mechanism by which neuroinflammation and synaptic dysfunction are induced in the hippocampus. This study presents a novel mechanism for DACD and proposes a novel therapeutic avenue for neuroprotection in DACD.
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Ischemic stroke is a devastative nervous system disease associated with high mortality and morbidity rates. Unfortunately, no clinically effective neuroprotective drugs are available now. In ischemic stroke, S100 calcium-binding protein b (S100b) binds to receptor for advanced glycation end products (Rage), leading to the neurological injury. Therefore, disruption of the interaction between S100B and Rage can rescue neuronal cells. Here, we designed a peptide, termed TAT-W61, derived from the V domain of Rage which can recognize S100b. Intriguingly, TAT-W61 can reduce the inflammatory caused by ischemic stroke through the direct binding to S100b. The further investigation demonstrated that TAT-W61 can improve pathological infarct volume and reduce the apoptotic rate. Particularly, TAT-W61 significantly improved the learning ability, memory, and motor dysfunction of the mouse in the ischemic stroke model. Our study provides a mechanistic insight into the abnormal expression of S100b and Rage in ischemic stroke and yields an invaluable candidate for the development of drugs in tackling ischemic stroke. KEY MESSAGES: S100b expression is higher in ischemic stroke, in association with a high expression of many genes, especially of Rage. S100b is directly bound to the V-domain of Rage. Blocking the binding of S100b to Rage improves the injury after ischemic stroke.
Assuntos
AVC Isquêmico , Camundongos , Animais , Receptor para Produtos Finais de Glicação Avançada , AVC Isquêmico/patologia , Neurônios , Peptídeos/farmacologia , Subunidade beta da Proteína Ligante de Cálcio S100/farmacologiaRESUMO
Ischemic stroke ranks among the leading causes of death and disability in humans and is accompanied by motor and cognitive impairment. However, the precise mechanisms underlying injury after stroke and effective treatment strategies require further investigation. Peroxiredoxin-1 (PRDX1) triggers an extensive inflammatory cascade that plays a pivotal role in the pathology of ischemic stroke, resulting in severe brain damage from activated microglia. In the present study, we used molecular dynamics simulation and nuclear magnetic resonance to detect the interaction between PRDX1 and a specific interfering peptide. We used behavioral, morphological, and molecular experimental methods to demonstrate the effect of PRDX1-peptide on cerebral ischemia-reperfusion (I/R) in mice and to investigate the related mechanism. We found that PRDX1-peptide bound specifically to PRDX1 and improved motor and cognitive functions in I/R mice. In addition, pretreatment with PRDX1-peptide reduced the infarct area and decreased the number of apoptotic cells in the penumbra. Furthermore, PRDX1-peptide inhibited microglial activation and downregulated proinflammatory cytokines including IL-1ß, IL-6, and TNF-α through inhibition of the TLR4/NF-κB signaling pathway, thereby attenuating ischemic brain injury. Our findings clarify the precise mechanism underlying PRDX1-induced inflammation after ischemic stroke and suggest that the PRDX1-peptide can significantly alleviate the postischemic inflammatory response by interfering with PRDX1 amino acids 70-90 and thereby inhibiting the TLR4/NF-κB signaling pathway. Our study provides a theoretical basis for a new therapeutic strategy to treat ischemic stroke.
RESUMO
Background: Neuroinflammation plays a pivotal role in the pathogenesis of Central Nervous System (CNS) diseases. The phenolic glucoside gastrodin (GAS), has been known to treat CNS disorders by exerting anti-inflammatory activities. Our aim was to investigate the potential neuroprotective mechanisms of GAS on lipopolysaccharide (LPS)-induced mice. Methods: Male C57BL/6J mice were treated by LPS, before which GAS was adminisrated. The behavior tests such as forced swim test, tail suspension test, and elevated plus maze were performed to evaluate depressive-anxiety-like behaviors. A high-throughput sequencing (HTS) analysis was performed to screen out distinctive miRNAs which were validated using quantitative real-time PCR. Then, miRNA agomir or NC was injected stereotaxically into hippocampus of mice to explore the role of miRNA on GAS in response to LPS. Furthermore, Immunofluorescence and the hematoxylin and eosin (H&E) staining were employed to observe the cellular morphology. The protein levels of pro-inflammatory factors were evaluated by western blot. Finally, the target mRNA of miRNA was predicted using bioinformatics analysis. GO and KEGG enrichment analyses were conducted to clarify the potential function of target protein, which were visualized by bubble charts. Results: The behavioral data showed that mice in the LPS group had obvious depressive-anxiety-like behaviors, and 100 mg/kg GAS could improve these behavioral changes and alleviate the levels of pro-inflammatory cytokines in the hippocampus when mice were exposed to LPS for 6 h. Meanwhile, LPS-induced microglia and astrocyte activation in the CA1, CA2, CA3, and DG regions of the hippocampus were also reversed by GAS. Furthermore, miR-107-3p were screened out and verified for GAS in response to LPS. Importantly, miR-107-3p overexpression negatively abrogated the neuroprotective effects of GAS. Moreover, KPNA1 might be the target molecular of miR-107-3p. KPNA1 might regulate 12 neuroinflammation-related genes, which were mainly involved in cytokine-mediated signaling pathway. Conclusion: These results suggested that GAS might alleviate the LPS-induced neuroinflammation and depressive-anxiety-like behaviors in mice by downregulating miR-107-3p and upregulating the downstream target KPNA1. The indicates miR-107-3p may provide a new strategy for the treatment of CNS diseases.
RESUMO
Rosmarinic acid, a common ester extracted from Rosemary, Perilla frutescens, and Salvia miltiorrhiza Bunge, has been shown to have protective effects against various diseases. This is an investigation into whether rosmarinic acid can also affect the changes of white matter fibers and cognitive deficits caused by hypoxic injury. The right common carotid artery of 3-day-old rats was ligated for 2 hours. The rats were then prewarmed in a plastic container with holes in the lid, which was placed in 37°C water bath for 30 minutes. Afterwards, the rats were exposed to an atmosphere with 8% O2 and 92% N2 for 30 minutes to establish the perinatal hypoxia/ischemia injury models. The rat models were intraperitoneally injected with rosmarinic acid 20 mg/kg for 5 consecutive days. At 22 days after birth, rosmarinic acid was found to improve motor, anxiety, learning and spatial memory impairments induced by hypoxia/ischemia injury. Furthermore, rosmarinic acid promoted the proliferation of oligodendrocyte progenitor cells in the subventricular zone. After hypoxia/ischemia injury, rosmarinic acid reversed to some extent the downregulation of myelin basic protein and the loss of myelin sheath in the corpus callosum of white matter structure. Rosmarinic acid partially slowed down the expression of oligodendrocyte marker Olig2 and myelin basic protein and the increase of oligodendrocyte apoptosis marker inhibitors of DNA binding 2. These data indicate that rosmarinic acid ameliorated the cognitive dysfunction after perinatal hypoxia/ischemia injury by improving remyelination in corpus callosum. This study was approved by the Animal Experimental Ethics Committee of Xuzhou Medical University, China (approval No. 20161636721) on September 16, 2017.
RESUMO
Cerebral ischemia/reperfusion (I/R) injury is a leading cause of learning and memory dysfunction. Hydrogen sulfide (H2S) has been shown to confer neuroprotection in various neurodegenerative diseases, including cerebral I/R-induced hippocampal CA1 injury. However, the underlying mechanisms have not been completely understood. In the present study, rats were pretreated with SAM/NaHS (SAM, an H2S agonist, and NaHS, an H2S donor) only or SAM/NaHS combined with CaM (an activator of CaMKII) prior to cerebral ischemia. The Morris water maze test demonstrated that SAM/NaHS could alleviate learning and memory impairment induced by cerebral I/R injury. Cresyl violet staining was used to show the survival of hippocampal CA1 pyramidal neurons. SAM/NaHS significantly increased the number of surviving cells, whereas CaM weakened the protection induced by SAM/NaHS. The immunohistochemistry results indicated that the number of Iba1-positive microglia significantly increased after cerebral I/R. Compared with the I/R group, the number of Iba1-positive microglia in the SAM/NaHS groups significantly decreased. Co-Immunoprecipitation and immunoblotting were conducted to demonstrate that SAM/NaHS suppressed the assembly of CaMKII with the ASK1-MKK3-p38 signal module after cerebral I/R, which decreased the phosphorylation of p38. In contrast, CaM significantly inhibited the effects of SAM/NaHS. Taken together, the results suggested that SAM/NaHS could suppress cerebral I/R injury by downregulating p38 phosphorylation via decreasing the assembly of CaMKII with the ASK1-MKK3-p38 signal module.
Assuntos
Região CA1 Hipocampal/efeitos dos fármacos , Calmodulina/farmacologia , Sulfeto de Hidrogênio/metabolismo , AVC Isquêmico/metabolismo , Transtornos da Memória/metabolismo , Traumatismo por Reperfusão/metabolismo , S-Adenosilmetionina/farmacologia , Sulfetos/farmacologia , Animais , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/patologia , Proteínas de Ligação ao Cálcio/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Regulação para Baixo , AVC Isquêmico/fisiopatologia , Aprendizagem/efeitos dos fármacos , MAP Quinase Quinase 3/efeitos dos fármacos , MAP Quinase Quinase 3/metabolismo , MAP Quinase Quinase Quinase 5/efeitos dos fármacos , MAP Quinase Quinase Quinase 5/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Transtornos da Memória/fisiopatologia , Proteínas dos Microfilamentos/efeitos dos fármacos , Proteínas dos Microfilamentos/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Teste do Labirinto Aquático de Morris , Fosforilação , Células Piramidais/efeitos dos fármacos , Células Piramidais/metabolismo , Ratos , Traumatismo por Reperfusão/fisiopatologia , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Our previous study showed that kainate (KA) receptor subunit GluR6 played an important role in ischemia-induced MLK3 and JNK activation and neuronal degeneration through the GluR6-PSD95-MLK3 signaling module. However, whether the KA receptors subunit GluR6 is involved in the activation of p38 MAP kinase during the transient brain ischemia/reperfusion (I/R) in the rat hippocampal CA1 subfield is still unknown. In this present study, we first evaluated the time-course of phospho-p38 MAP kinase at various time-points after 15 min of ischemia and then observed the effects of antagonist of KA receptor subunit GluR6, GluR6 antisence oligodeoxynucleotides on the phosphorylation of p38 MAP kinase induced by I/R. Results showed that inhibiting KA receptor GluR6 or suppressing the expression of KA receptor GluR6 could down-regulate the elevation of phospho-p38 MAP kinase induced by I/R. These drugs also reduced the phosphorylation of MLK3, MKK3/MKK6, MKK4, and MAPKAPK2. Additionally, our results indicated administration of three drugs, including p38 MAP kinase inhibitor before brain ischemia significantly decreased the number of TUNEL-positive cells detected at 3 days of reperfusion and increased the number of the surviving CA1 pyramidal cells at 5 days of reperfusion after 15 min of ischemia. Taken together, we suggest that GluR6-contained KA receptors can mediate p38 MAP kinase activation through a kinase cascade, including MLK3, MKK3/MKK6, and MKK4 and then induce increased phosphorylation of MAPKAPK-2 during ischemia injury and ultimately result in neuronal cell death in the rat hippocampal CA1 region.
Assuntos
Hipocampo/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Receptores de Ácido Caínico/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Infarto Encefálico/metabolismo , Infarto Encefálico/patologia , Infarto Encefálico/fisiopatologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Ativação Enzimática/fisiologia , Inibidores Enzimáticos/farmacologia , Ácido Glutâmico/metabolismo , Hipocampo/patologia , Hipocampo/fisiopatologia , Hipóxia-Isquemia Encefálica/patologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , MAP Quinase Quinase 3/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Oligodesoxirribonucleotídeos Antissenso/farmacologia , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Transmissão Sináptica/fisiologia , MAP Quinase Quinase Quinase 11 Ativada por Mitógeno , Receptor de GluK2 CainatoRESUMO
Previous studies have shown that KA receptor subunit GluR6 mediated c-Jun N-terminal protein kinase (JNK) signaling is involved in global ischemia injury. Our present study indicates that focal ischemic brain insult on rat middle cerebral artery occlusion (MACo) model enhances the assembly of the GluR6-PSD95-MLK3 module and facilitates the phosphorylation of JNK. Most importantly, a peptide containing the TAT protein transduction sequence, Tat-GluR6-9c, can perturb the assembly of the GluR6-PSD95-MLK3 signaling module and suppress the activation of MLK3, MKK7/4 and JNK. As result, the inhibition of JNK activation caused by Tat-GluR6-9c diminishes the phosphorylation of the transcription factor c-Jun, down-regulates FasL expression and attenuates bax translocation, release of cytochrome c and the activation of caspase-3. Furthermore, MCAo induced infract volume is reduced by intracerebroventricular injection of Tat-Glur6-9c. Oxygen-glucose-deprivation (OGD) cultured cortical neuronal cell also shows an improved cell viability by application of Tat-GluR6-9c. Taken together, our findings strongly suggest that GluR6-PSD95-MLK3 signaling module mediated activation of nuclear and non-nuclear pathways of JNK activation are involved in focal ischemia injury and OGD. Tat-GluR6-9c, the peptide we constructed, gives a new insight into the therapy for ischemic stroke.
Assuntos
Glucose/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Ataque Isquêmico Transitório/prevenção & controle , Proteínas de Membrana/metabolismo , Fármacos Neuroprotetores/farmacologia , Oxigênio/farmacologia , Receptores de Ácido Caínico/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética , Animais , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Proteína 4 Homóloga a Disks-Large , Técnicas In Vitro , Ataque Isquêmico Transitório/metabolismo , Masculino , Mutação , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Ratos , Ratos Sprague-Dawley , Receptores de Ácido Caínico/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/uso terapêutico , Receptor de GluK2 CainatoRESUMO
A convenient approach for (1E,3E)-1,4-diarylbuta-1,3-dienes via intermolecular Heck reaction of olefins and ß-bromostyrenes promoted by µ-OMs palladium-dimer complex has been successfully developed. The products 1,4-conjugated dienes could be obtained with good yield (up to 82%). The catalyst system has excellent chemical selectivity and group tolerance which could supply an alternative way to gain the valuable biaryl linkage building blocks. Furthermore, fluorescence studies of dienes showed that some of them may have potential applications as luminescent clusters.
RESUMO
Heme oxygenase (HO-1), which may be induced by Cobaltic protoporphyrin IX chloride (CoPPIX) or Rosiglitazone (Ros), is a neuroprotective agent that effectively reduces ischemic stroke. Previous studies have shown that the neuroprotective mechanisms of HO-1 are related to JNK signaling. The expression of HO-1 protects cells from death through the JNK signaling pathway. This study aimed to ascertain whether the neuroprotective effect of HO-1 depends on the assembly of the MLK3-MKK7-JNK3 signaling module scaffolded by JIP1 and further influences the JNK signal transmission through HO-1. Prior to the ischemia-reperfusion experiment, CoPPIX was injected through the lateral ventricle for 5 consecutive days or Ros was administered via intraperitoneal administration in the week prior to transient ischemia. Our results demonstrated that HO-1 could inhibit the assembly of the MLK3-MKK7-JNK3 signaling module scaffolded by JIP1 and could ultimately diminish the phosphorylation of JNK3. Furthermore, the inhibition of JNK3 phosphorylation downregulated the level of p-c-Jun and elevated neuronal cell death in the CA1 of the hippocampus. Taken together, these findings suggested that HO-1 could ameliorate brain injury by regulating the MLK3-MKK7-JNK3 signaling module, which was scaffolded by JIP1 and JNK signaling during cerebral ischemia/reperfusion.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Isquemia Encefálica/enzimologia , Heme Oxigenase (Desciclizante)/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Proteína Quinase 10 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Animais , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/patologia , Região CA1 Hipocampal/efeitos dos fármacos , Região CA1 Hipocampal/enzimologia , Região CA1 Hipocampal/patologia , Morte Celular/fisiologia , Modelos Animais de Doenças , Regulação para Baixo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/patologia , Neuroproteção/efeitos dos fármacos , Neuroproteção/fisiologia , Fármacos Neuroprotetores/farmacologia , Fosforilação , Proteínas Proto-Oncogênicas c-jun/metabolismo , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Rosiglitazona/farmacologia , MAP Quinase Quinase Quinase 11 Ativada por MitógenoRESUMO
In the title compound, [Na(H(2)O)(2)]ClO(4)·[Cu(2)(C(9)H(7)NO(3))(2)(C(6)H(7)N)(2)], the Cu(II) atom is coordinated by one N atom and two O atoms from a tridentate N-salicylideneglycinate Schiff base dianion and one N atom from a 3-methyl-pyridine ligand. Longer Cuâ¯O contacts [2.680â (2)â Å] complete an approximate square-based pyramidal coordination geometry around Cu(II), forming a dimeric complex across a centre of inversion. The dimeric complexes form stacks along the a axis, with Cuâ¯O contacts of 3.332â (2)â Å between them. The Na(+) cations and perchlorate anions lie on twofold rotation axes between the stacks. The former are coordinated by two disordered water mol-ecules (each with half-occupancy), and form Naâ¯O contacts of 3.698â (3)â Å to the perchlorate anions and Naâ¯π contacts to neighbouring salicylideneglycinate ligands [shortest Naâ¯C = 3.516â (3)â Å].
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In this study, we firstly reported the complete mitochondrial genome of Chilotilapia rhoadesii. The whole mitochondrial genome is 16,580 bp in length, including 2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-coding genes. Its GC content is 45.98%, similar to Alticorpus geoffreyi (45.82%). We also analyzed the complete mitochondrial genome of C. rhoadesii and its phylogenic relationship with other 14 related species, which would facilitate our understanding of the evolution of Cichlidae mitochondrial genome.
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In this study, we firstly reported the complete mitochondrial genome of Copadichromis trimaculatus. The whole mitochondrial genome is 16,581 bp in length, including 2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-coding genes. Its GC content is 46.00%, similar to Copadichromis virginalis (45.74%). We also analyzed its phylogenic relationship with other 14 related species, which would facilitate our understanding of the phylogenic relationship of Cichlidae mitochondrial genome.
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The Cyathochromis obliquidens, the only member of Cyathochromis genus, is widely spread in Africa. In this study, we firstly reported the complete mitochondrial genome of C. obliquidens. The whole mitochondrial genome is 16,581 bp in length, including 2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-coding genes. Its GC content is 45.94%, similar to the other species from the same family, like Alticorpus geoffreyi (45.82%). We also analyzed the complete mitochondrial genome of C. obliquidens and its phylogenic relationship with other 14 related species, which would help our better understanding of the evolution of Cichlidae mitochondrial genome.
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An efficient ratiometric electrochemical biosensor for Cu2+ determination was constructed using dual hydroxyl-functionalized poly (ionic liquid) (DHF-PIL) as the catalyst support. The DHF-PIL exhibited typical macroporous structure, which provided a high surface area of 39.31m2/g for the sufficient loading of biomolecules. The specific recognition of Cu2+ was accomplished by employing neurokinin B (NKB) for the first time, which could bind to Cu2+ to form a [CuII(NKB)2] complex with high specificity. Meanwhile, a common redox mediator, 2, 2'-Azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) was modified into DHF-PIL by electrostatic interactions to act as an inner reference molecule, which provided a built-in correction for environmental effects and improving the detection accuracy. With this strategy, the developed electrochemical biosensor was capable of determining Cu2+ with a linear range between 0.9 and 36.1µM and low detection limit (LOD) and quantification limit (LOQ) of 0.24 and 0.6µM, respectively. The sensor also displayed a satisfactory selectivity against a series of interferences in the brain, including metal ions, amino acids and other endogenous compounds. Accordingly, the present biosensor was successfully applied to evaluate Cu2+ levels in normal and AD rats.