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1.
J Neuroinflammation ; 20(1): 247, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880726

RESUMO

BACKGROUND: The astrocytes in the central nervous system (CNS) exhibit morphological and functional diversity in brain region-specific pattern. Functional alterations of reactive astrocytes are commonly present in human temporal lobe epilepsy (TLE) cases, meanwhile the neuroinflammation mediated by reactive astrocytes may advance the development of hippocampal epilepsy in animal models. Nuclear factor I-A (NFIA) may regulate astrocyte diversity in the adult brain. However, whether NFIA endows the astrocytes with regional specificity to be involved in epileptogenesis remains elusive. METHODS: Here, we utilize an interference RNA targeting NFIA to explore the characteristics of NFIA expression and its role in astrocyte reactivity in a 4-aminopyridine (4-AP)-induced seizure model in vivo and in vitro. Combined with the employment of a HA-tagged plasmid overexpressing NFIA, we further investigate the precise mechanisms how NIFA facilitates epileptogenesis. RESULTS: 4-AP-induced NFIA upregulation in hippocampal region is astrocyte-specific, and primarily promotes detrimental actions of reactive astrocyte. In line with this phenomenon, both NFIA and vanilloid transient receptor potential 4 (TRPV4) are upregulated in hippocampal astrocytes in human samples from the TLE surgical patients and mouse samples with intraperitoneal 4-AP. NFIA directly regulates mouse astrocytic TRPV4 expression while the quantity and the functional activity of TRPV4 are required for 4-AP-induced astrocyte reactivity and release of proinflammatory cytokines in the charge of NFIA upregulation. NFIA deficiency efficiently inhibits 4-AP-induced TRPV4 upregulation, weakens astrocytic calcium activity and specific astrocyte reactivity, thereby mitigating aberrant neuronal discharges and neuronal damage, and suppressing epileptic seizure. CONCLUSIONS: Our results uncover the critical role of NFIA in astrocyte reactivity and illustrate how epileptogenic brain injury initiates cell-specific signaling pathway to dictate the astrocyte responses.


Assuntos
Epilepsia do Lobo Temporal , Epilepsia , Fatores de Transcrição NFI , Canais de Cátion TRPV , Animais , Humanos , Camundongos , 4-Aminopiridina/efeitos adversos , Astrócitos/metabolismo , Encéfalo/metabolismo , Sistema Nervoso Central/metabolismo , Epilepsia/metabolismo , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Fatores de Transcrição NFI/genética , Fatores de Transcrição NFI/metabolismo , Canais de Cátion TRPV/metabolismo , Regulação para Cima
2.
FASEB J ; 35(2): e21330, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33417289

RESUMO

Epilepsy is a common brain disorder, repeated seizures of epilepsy may lead to a series of brain pathological changes such as neuronal or glial damage. However, whether circular RNAs are involved in neuronal injury during epilepsy is not fully understood. Here, we screened circIgf1r in the status epilepticus model through circRNA sequencing, and found that it was upregulated after the status epilepticus model through QPCR analysis. Astrocytes polarizing toward neurotoxic A1 phenotype and neurons loss were observed after status epilepticus. Through injecting circIgf1r siRNA into the lateral ventricle, it was found that knocking down circIgf1r in vivo would induce the polarization of astrocytes to phenotype A2 and reduce neuronal loss. The results in vitro further confirmed that inhibiting the expression of circIgf1r in astrocytes could protect neurons by converting reactive astrocytes from A1 to the protective A2. In addition, knocking down circIgf1r in astrocytes could functionally promote astrocyte autophagy and relieve the destruction of 4-AP-induced autophagy flux. In terms of mechanism, circIgf1r promoted the polarization of astrocytes to phenotype A1 by inhibiting autophagy. Taken together, our results reveal circIgf1r may serve as a potential target for the prevention and treatment of neuron damage after epilepsy.


Assuntos
Astrócitos/metabolismo , Epilepsia/genética , Inativação Gênica , RNA Circular/metabolismo , Animais , Astrócitos/citologia , Células Cultivadas , Epilepsia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurogênese , Neurônios/metabolismo , RNA Circular/genética , Receptor IGF Tipo 1/genética
3.
J Neuroinflammation ; 16(1): 114, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142341

RESUMO

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is a serious birth complication with high incidence in both advanced and developing countries. Children surviving from HIE often have severe long-term sequela including cerebral palsy, epilepsy, and cognitive disabilities. The severity of HIE in infants is tightly associated with increased IL-1ß expression and astrocyte activation which was regulated by transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel in the TRP family. METHODS: Neonatal hypoxic ischemia (HI) and oxygen-glucose deprivation (OGD) were used to simulate HIE in vivo and in vitro. Primarily cultured astrocytes were used for investigating the expression of glial fibrillary acidic protein (GFAP), IL-1ß, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), and activation of the nucleotide-binding, oligomerization domain (NOD)-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome by using Western blot, q-PCR, and immunofluorescence. Brain atrophy, infarct size, and neurobehavioral disorders were evaluated by Nissl staining, 2,3,5-triphenyltetrazolium chloride monohydrate (TTC) staining and neurobehavioral tests (geotaxis reflex, cliff aversion reaction, and grip test) individually. RESULTS: Astrocytes were overactivated after neonatal HI and OGD challenge. The number of activated astrocytes, the expression level of IL-1ß, brain atrophy, and shrinking infarct size were all downregulated in TRPV1 KO mice. TRPV1 deficiency in astrocytes attenuated the expression of GFAP and IL-1ß by reducing phosphorylation of JAK2 and STAT3. Meanwhile, IL-1ß release was significantly reduced in TRPV1 deficiency astrocytes by inhibiting activation of NLRP3 inflammasome. Additionally, neonatal HI-induced neurobehavioral disorders were significantly improved in the TRPV1 KO mice. CONCLUSIONS: TRPV1 promotes activation of astrocytes and release of astrocyte-derived IL-1ß mainly via JAK2-STAT3 signaling and activation of the NLRP3 inflammasome. Our findings provide mechanistic insights into TRPV1-mediated brain damage and neurobehavioral disorders caused by neonatal HI and potentially identify astrocytic TRPV1 as a novel therapeutic target for treating HIE in the subacute stages (24 h).


Assuntos
Astrócitos/metabolismo , Encéfalo/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Interleucina-1beta/metabolismo , Canais de Cátion TRPV/deficiência , Animais , Astrócitos/patologia , Encéfalo/patologia , Células Cultivadas , Feminino , Hipóxia-Isquemia Encefálica/genética , Hipóxia-Isquemia Encefálica/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Canais de Cátion TRPV/genética
4.
J Neuroinflammation ; 16(1): 214, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722723

RESUMO

BACKGROUND: Neonatal hypoxic-ischemic brain damage (HIBD), a leading cause of neonatal mortality, has intractable sequela such as epilepsy that seriously affected the life quality of HIBD survivors. We have previously shown that ion channel dysfunction in the central nervous system played an important role in the process of HIBD-induced epilepsy. Therefore, we continued to validate the underlying mechanisms of TRPV1 as a potential target for epilepsy. METHODS: Neonatal hypoxic ischemia and oxygen-glucose deprivation (OGD) were used to simulate HIBD in vivo and in vitro. Primarily cultured astrocytes were used to assess the expression of TRPV1, glial fibrillary acidic protein (GFAP), cytoskeletal rearrangement, and inflammatory cytokines by using Western blot, q-PCR, and immunofluorescence. Furthermore, brain electrical activity in freely moving mice was recorded by electroencephalography (EEG). TRPV1 current and neuronal excitability were detected by whole-cell patch clamp. RESULTS: Astrocytic TRPV1 translocated to the membrane after OGD. Mechanistically, astrocytic TRPV1 activation increased the inflow of Ca2+, which promoted G-actin polymerized to F-actin, thus promoted astrocyte migration after OGD. Moreover, astrocytic TRPV1 deficiency decreased the production and release of pro-inflammatory cytokines (TNF, IL-6, IL-1ß, and iNOS) after OGD. It could also dramatically attenuate neuronal excitability after OGD and brain electrical activity in HIBD mice. Behavioral testing for seizures after HIBD revealed that TRPV1 knockout mice demonstrated prolonged onset latency, shortened duration, and decreased seizure severity when compared with wild-type mice. CONCLUSIONS: Collectively, TRPV1 promoted astrocyte migration thus helped the infiltration of pro-inflammatory cytokines (TNF, IL-1ß, IL-6, and iNOS) from astrocytes into the vicinity of neurons to promote epilepsy. Our study provides a strong rationale for astrocytic TRPV1 to be a therapeutic target for anti-epileptogenesis after HIBD.


Assuntos
Astrócitos/metabolismo , Epilepsia/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Inflamação/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Encéfalo/metabolismo , Movimento Celular/fisiologia , Citocinas/metabolismo , Epilepsia/etiologia , Hipóxia-Isquemia Encefálica/complicações , Camundongos , Camundongos Knockout , Neurônios/metabolismo
5.
Dev Neurosci ; 40(4): 289-300, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30391952

RESUMO

Nuclear factor of activated T cells 5 (NFAT5) has recently been classified as a new member of the Rel family. In addition, there are 5 more well-defined members (NF-κB and NFAT1-4) in the Rel family, which participate in regulating the expression of immune and inflammatory response-related genes. NFAT5 was initially identified in renal medullary cells where it regulated the expression of osmoprotective-related genes during the osmotic response. Many studies have demonstrated that NFAT5 is highly expressed in the nuclei of neurons in fetal and adult brains. Additionally, its expression is approximately 10-fold higher in fetal brains. With the development of detection technologies (laser scanning confocal microscopy, transgene technology, etc.), recent studies suggest that NFAT5 is also expressed in glial cells and plays a more diverse functional role. This article aims to summarize the current knowledge regarding the expression of NFAT5, its regulation of activation, and varied biological functions in the brain.


Assuntos
Encéfalo/metabolismo , NF-kappa B/metabolismo , Neuroglia/metabolismo , Fatores de Transcrição/metabolismo , Animais , Regulação da Expressão Gênica/genética , Humanos , Neurônios/metabolismo
6.
J Neuroinflammation ; 15(1): 186, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29925377

RESUMO

BACKGROUND: Neonatal hypoxic-ischemic brain damage, characterized by tissue loss and neurologic dysfunction, is a leading cause of mortality and a devastating disease of the central nervous system. We have previously shown that vitexin has been attributed various medicinal properties and has been demonstrated to have neuroprotective roles in neonatal brain injury models. In the present study, we continued to reinforce and validate the basic understanding of vitexin (45 mg/kg) as a potential treatment for epilepsy and explored its possible underlying mechanisms. METHODS: P7 Sprague-Dawley (SD) rats that underwent right common carotid artery ligation and rat brain microvascular endothelial cells (RBMECs) were used for the assessment of Na+-K+-Cl- co-transporter1 (NKCC1) expression, BBB permeability, cytokine expression, and neutrophil infiltration by western blot, q-PCR, flow cytometry (FCM), and immunofluorescence respectively. Furthermore, brain electrical activity in freely moving rats was recorded by electroencephalography (EEG). RESULTS: Our data showed that NKCC1 expression was attenuated in vitexin-treated rats compared to the expression in the HI group in vivo. Oxygen glucose deprivation/reoxygenation (OGD) was performed on RBMECs to explore the role of NKCC1 and F-actin in cytoskeleton formation with confocal microscopy, N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide, and FCM. Concomitantly, treatment with vitexin effectively alleviated OGD-induced NKCC1 expression, which downregulated F-actin expression in RBMECs. In addition, vitexin significantly ameliorated BBB leakage and rescued the expression of tight junction-related protein ZO-1. Furthermore, inflammatory cytokine and neutrophil infiltration were concurrently and progressively downregulated with decreasing BBB permeability in rats. Vitexin also significantly suppressed brain electrical activity in neonatal rats. CONCLUSIONS: Taken together, these results confirmed that vitexin effectively alleviates epilepsy susceptibility through inhibition of inflammation along with improved BBB integrity. Our study provides a strong rationale for the further development of vitexin as a promising therapeutic candidate treatment for epilepsy in the immature brain.


Assuntos
Anticonvulsivantes/uso terapêutico , Apigenina/uso terapêutico , Epilepsia/tratamento farmacológico , Epilepsia/etiologia , Hipóxia-Isquemia Encefálica/complicações , Membro 2 da Família 12 de Carreador de Soluto/metabolismo , Animais , Animais Recém-Nascidos , Hipóxia Celular/efeitos dos fármacos , Células Cultivadas , Cloretos/metabolismo , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/deficiência , Fator Estimulador de Colônias de Granulócitos/genética , Fator Estimulador de Colônias de Granulócitos/metabolismo , Interleucina-3/genética , Interleucina-3/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Membro 2 da Família 12 de Carreador de Soluto/genética , Proteína da Zônula de Oclusão-1/metabolismo
7.
Brain Behav Immun ; 64: 354-366, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28342781

RESUMO

Transient receptor potential vanilloid type 1 channel (TRPV1), as a ligand-gated non-selective cation channel, has recently been demonstrated to have wide expression in the neuro-immune axis, where its multiple functions occur through regulation of both neuronal and non-neuronal activities. Growing evidence has suggested that TRPV1 is functionally expressed in glial cells, especially in the microglia and astrocytes. Glial cells perform immunological functions in response to pathophysiological challenges through pro-inflammatory or anti-inflammatory cytokines and chemokines in which TRPV1 is involved. Sustaining inflammation might mediate a positive feedback loop of neuroinflammation and exacerbate neurological disorders. Accumulating evidence has suggested that TRPV1 is closely related to immune responses and might be recognized as a molecular switch in the neuroinflammation of a majority of seizures and neurodegenerative diseases. In this review, we evidenced that inflammation modulates the expression and activity of TRPV1 in the central nervous system (CNS) and TRPV1 exerts reciprocal actions over neuroinflammatory processes. Together, the literature supports the hypothesis that TRPV1 may represent potential therapeutic targets in the neuro-immune axis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Encefalite/tratamento farmacológico , Encefalite/imunologia , Encefalite/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Humanos , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Camundongos , Neuroglia/imunologia , Neuroglia/metabolismo , Neurônios/imunologia , Neurônios/metabolismo , Transdução de Sinais , Canais de Cátion TRPV/imunologia
8.
Brain Behav Immun ; 48: 68-77, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25801060

RESUMO

Febrile seizure (FS) is the most common seizure disorder in children, and children with FS are regarded as a high risk for the eventual development of epilepsy. Brain inflammation may be implicated in the mechanism of FS. Transient receptor potential vanilloid 1 (TRPV1) is believed to act as a monitor and regulator of body temperature. The role of inflammation in synaptic plasticity mediation indicates that TRPV1 is relevant to several nervous system diseases, such as epilepsy. Here, we report a critical role for TRPV1 in a febrile seizure mouse model and reveal increased levels of pro-inflammatory factors in the immature brain. Animals were subjected to hyperthermia for 30 min, which generates seizures lasting approximately 20 min, and then were used for experiments. To invoke frequently repetitive febrile seizures, mice are exposed to hyperthermia for three times daily at an interval of 4h between every time induced seizure, and a total of 4 days to induce. Behavioral testing for febrile seizures revealed that a TRPV1 knock-out mouse model demonstrated a prolonged onset latency and a shortened duration and seizure grade of febrile seizure when compared with wild type (WT) mice. The expression levels of both TRPV1 mRNA and protein increased after a hyperthermia-induced febrile seizure in WT mice. Notably, TRPV1 activation resulted in a significant elevation in the expression of pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α and HMGB1) in the hippocampus and cortex. These data indicate that the reduction of TRPV1 expression parallels a decreased susceptibility to febrile seizures. Thus, preventative strategies might be developed for use during febrile seizures.


Assuntos
Encéfalo/metabolismo , Citocinas/metabolismo , Hipertermia Induzida , Convulsões Febris/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Encéfalo/imunologia , Linhagem Celular , Modelos Animais de Doenças , Hipocampo/imunologia , Hipocampo/metabolismo , Camundongos , Camundongos Knockout , Convulsões Febris/imunologia , Canais de Cátion TRPV/genética
9.
Med Sci Monit ; 21: 94-9, 2015 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-25582342

RESUMO

BACKGROUND: The aim of this study was to determine if shRNA constructs targeting insulin-like growth factor binding protein-3 can rehabilitate decreased serum testosterone concentrations in streptozotocin-induced diabetic rats. MATERIAL/METHODS: After 12 weeks of intracavernous administration of IGFBP-3 shRNA, intracavernous pressure responses to electrical stimulation of cavernous nerves were evaluated. The expression of IGFBP-3 at mRNA and protein levels was detected by quantitative real-time PCR analysis and Western blot, respectively. The concentrations of serum testosterone and cavernous cyclic guanosine monophosphate were detected by enzyme-linked immunosorbent assay. RESULTS: After 12 weeks of intracavernous administration of IGFBP-3 shRNA, the cavernosal pressure was significantly increased in response to the cavernous nerves stimulation compared to the diabetic control group (p<0.01). Cavernous IGFBP-3 expression at both mRNA and protein levels was significantly inhibited. Both serum testosterone and cavernous cyclic guanosine monophosphate concentrations were significantly increased in the IGFBP-3 shRNA treatment group compared to the diabetic control group (p<0.01). CONCLUSIONS: These results suggest that IGFBP-3 shRNA may rehabilitate erectile function via increases of concentrations of serum testosterone and cavernous cyclic guanosine monophosphate in streptozotocin-induced diabetic rats.


Assuntos
Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , RNA Interferente Pequeno/metabolismo , Testosterona/sangue , Animais , GMP Cíclico/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 1/sangue , Estimulação Elétrica , Ensaio de Imunoadsorção Enzimática , Disfunção Erétil/metabolismo , Disfunção Erétil/terapia , Masculino , Metiltestosterona/sangue , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real/métodos , Transdução de Sinais
10.
Epilepsy Behav ; 31: 276-80, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24269027

RESUMO

This study was designed to investigate the role of experimental febrile seizures in the induction of generalized clonic seizures and the involvement of heat-sensitive channel TRPV1. Pentylenetetrazol-induced clonic seizure was used as the seizure model, and Trpv1 gene knock-out and wild-type C57/BL6 mice were used as experimental subjects. Electroencephalograph and seizure behavior were recorded for the evaluation of the severity of seizures. Increased frequency of the experimental febrile seizures facilitated PTZ-induced generalized clonic seizures. Trpv1 gene deficiency decreased the properties of generalized clonic seizure. The intensity of experimental febrile seizures reduced the threshold to generalized clonic seizure, and Trpv1 gene deficiency decreased the susceptibility to PTZ-induced seizures following early-life hyperthermia challenges in mice.


Assuntos
Convulsivantes/toxicidade , Hipertermia Induzida , Pentilenotetrazol/toxicidade , Convulsões Febris/induzido quimicamente , Convulsões Febris/genética , Canais de Cátion TRPV/metabolismo , Análise de Variância , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Eletroencefalografia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Canais de Cátion TRPV/deficiência , Fatores de Tempo
11.
J Biol Chem ; 287(35): 29479-94, 2012 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-22761436

RESUMO

The voltage-gated Kv1.3 K(+) channel in effector memory T cells serves as a new therapeutic target for multiple sclerosis. In our previous studies, the novel peptide ADWX-1 was designed and synthesized as a specific Kv1.3 blocker. However, it is unclear if and how ADWX-1 alleviates experimental autoimmune encephalomyelitis, a model for multiple sclerosis. In this study, the administration of ADWX-1 significantly ameliorated the rat experimental autoimmune encephalomyelitis model by selectively inhibiting CD4(+)CCR7(-) phenotype effector memory T cell activation. In contrast, the Kv1.3-specific peptide had little effect on CD4(+)CCR7(+) cells, thereby limiting side effects. Furthermore, we determined that ADWX-1 is involved in the regulation of NF-κB signaling through upstream protein kinase C-θ (PKCθ) in the IL-2 pathway of CD4(+)CCR7(-) cells. The elevated expression of Kv1.3 mRNA and protein in activated CD4(+)CCR7(-) cells was reduced by ADWX-1 engagement; however, an apparent alteration in CD4(+)CCR7(+) cells was not observed. Moreover, the selective regulation of the Kv1.3 channel gene expression pattern by ADWX-1 provided a further and sustained inhibition of the CD4(+)CCR7(-) phenotype, which depends on the activity of Kv1.3 to modulate its activation signal. In addition, ADWX-1 mediated the activation of differentiated Th17 cells through the CCR7(-) phenotype. The efficacy of ADWX-1 is supported by multiple functions, which are based on a Kv1.3(high) CD4(+)CCR7(-) T cell selectivity through two different pathways, including the classic channel activity-associated IL-2 pathway and the new Kv1.3 channel gene expression pathway.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Encefalomielite Autoimune Experimental/tratamento farmacológico , Memória Imunológica/efeitos dos fármacos , Canal de Potássio Kv1.3/antagonistas & inibidores , Esclerose Múltipla/tratamento farmacológico , Peptídeos/farmacologia , Receptores CCR7 , Animais , Encefalomielite Autoimune Experimental/imunologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Humanos , Interleucina-2/imunologia , Células Jurkat , Canal de Potássio Kv1.3/imunologia , Esclerose Múltipla/imunologia , RNA Mensageiro/imunologia , Ratos , Ratos Sprague-Dawley
12.
Epilepsia ; 54(7): 1223-31, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23815572

RESUMO

PURPOSE: Cerebral hypoxia is a major cause of neonatal seizures, and can lead to epilepsy. Pathologic anatomic and physiologic changes in the dentate gyrus have been associated with epileptogenesis in many experimental models, as this region is widely believed to gate the propagation of limbic seizures. However, the consequences of hypoxia-induced seizures for the immature dentate gyrus have not been extensively examined. METHODS: Seizures were induced by global hypoxia (5-7% O2 for 15 min) in rat pups on postnatal day 10. Whole-cell voltage-clamp recordings were used to examine A-type potassium currents (IA ) in dentate granule cells in hippocampal slices obtained 1-17 days after hypoxia treatment. KEY FINDINGS: Seizure-inducing hypoxia resulted in decreased maximum IA amplitude in dentate granule cells recorded within the first week but not at later times after hypoxia treatment. The decreased IA amplitude was not associated with changes in the voltage-dependence of activation or inactivation removal, or in sensitivity to inhibition by 4-aminopyridine (4-AP). However, consistent with the role of IA in shaping firing patterns, we observed in the hypoxia group a significantly decreased latency to first spike with depolarizing current injection from hyperpolarized potentials. These differences were not associated with changes in resting membrane potential or input resistance, and were eliminated by application of 10 m 4-AP. SIGNIFICANCE: Given the role of IA to slow action potential firing, decreased IA could contribute to long-term hippocampal pathology after neonatal seizure-inducing hypoxia by increasing dentate granule cell excitability during a critical window of activity-dependent hippocampal maturation.


Assuntos
Hipocampo/patologia , Hipóxia/complicações , Neurônios/fisiologia , Canais de Potássio/fisiologia , Convulsões/etiologia , Convulsões/patologia , 4-Aminopiridina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Animais Recém-Nascidos , Biofísica , Modelos Animais de Doenças , Estimulação Elétrica/efeitos adversos , Técnicas In Vitro , Masculino , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio/efeitos dos fármacos , Ratos , Ratos Long-Evans
13.
Mol Neurobiol ; 60(3): 1232-1249, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36434370

RESUMO

Transient receptor potential vanilloid 4 (TRPV4) is a nonselective cation channel that can be activated by diverse stimuli, such as heat, mechanical force, hypo-osmolarity, and arachidonic acid metabolites. TRPV4 is widely expressed in the central nervous system (CNS) and participates in many significant physiological processes. However, accumulative evidence has suggested that deficiency, abnormal expression or distribution, and overactivation of TRPV4 are involved in pathological processes of multiple neurological diseases. Here, we review the latest studies concerning the known features of this channel, including its expression, structure, and its physiological and pathological roles in the CNS, proposing an emerging therapeutic strategy for CNS diseases.


Assuntos
Sistema Nervoso Central , Canais de Cátion TRPV , Canais de Cátion TRPV/metabolismo , Sistema Nervoso Central/metabolismo , Ácido Araquidônico/metabolismo , Temperatura Alta
14.
Mol Neurobiol ; 60(9): 5482-5492, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37316759

RESUMO

Mitochondria are the structures in cells that are responsible for producing energy. They contain a specific translation unit for synthesizing mitochondria-encoded respiratory chain components: the mitochondrial DNA (mt DNA). Recently, a growing number of syndromes associated with the dysfunction of mt DNA translation have been reported. However, the functions of these diseases still need to be precise and thus attract much attention. Mitochondrial tRNAs (mt tRNAs) are encoded by mt DNA; they are the primary cause of mitochondrial dysfunction and are associated with a wide range of pathologies. Previous research has shown the role of mt tRNAs in the epileptic mechanism. This review will focus on the function of mt tRNA and the role of mitochondrial aminoacyl-tRNA synthetase (mt aaRS) in order to summarize some common relevant mutant genes of mt aaRS that cause epilepsy and the specific symptoms of the disease they cause.


Assuntos
Aminoacil-tRNA Sintetases , Epilepsia , Humanos , Aminoacil-tRNA Sintetases/genética , Aminoacil-tRNA Sintetases/metabolismo , Mutação/genética , Mitocôndrias/metabolismo , Biossíntese de Proteínas , Epilepsia/patologia , RNA de Transferência/genética , RNA de Transferência/metabolismo
15.
Pharmacol Ther ; 238: 108180, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35367516

RESUMO

Cluster of differentiation 20 (CD20) is an integral membrane protein expressed mainly on different developmental stages of B lymphocytes and rarely on T lymphocytes, and it functions as a link to B cell antigen receptor (BCR) and immune microenvironment via regulating calcium ion influx, cell cycle progression and interaction between isotypic BCRs and their co-receptors. Diverse therapeutic monoclonal antibodies (mAbs) targeting CD20 are generated and grouped into two types based on the ability to redistribute CD20 into lipid rafts, which results in huge differences in response. Currently, multiple anti-CD20 mAbs have been approved as drugs for neurological and neuromuscular diseases with promising clinical efficacy. This review aims to summarize the potential mechanisms, development and current evidence for anti-CD20 therapy in neurological and neuromuscular diseases.


Assuntos
Antígenos CD20 , Doenças Neuromusculares , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Antígenos CD20/metabolismo , Cálcio/metabolismo , Humanos , Doenças Neuromusculares/tratamento farmacológico , Receptores de Antígenos de Linfócitos B
16.
Neurotherapeutics ; 19(2): 660-681, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35182379

RESUMO

Astrocytes are critical regulators of the immune/inflammatory response in several human central nervous system (CNS) diseases. Emerging evidence suggests that dysfunctional astrocytes are crucial players in seizures. The objective of this study was to investigate the role of transient receptor potential vanilloid 4 (TRPV4) in 4-aminopyridine (4-AP)-induced seizures and the underlying mechanism. We also provide evidence for the role of Yes-associated protein (YAP) in seizures. 4-AP was administered to mice or primary cultured astrocytes. YAP-specific small interfering RNA (siRNA) was administered to primary cultured astrocytes. Mouse brain tissue and surgical specimens from epileptic patient brains were examined, and the results showed that TRPV4 was upregulated, while astrocytes were activated and polarized to the A1 phenotype. The levels of glial fibrillary acidic protein (GFAP), cytokine production, YAP, signal transducer activator of transcription 3 (STAT3), intracellular Ca2+([Ca2+]i) and the third component of complement (C3) were increased in 4-AP-induced mice and astrocytes. Perturbations in the immune microenvironment in the brain were balanced by TRPV4 inhibition or the manipulation of [Ca2+]i in astrocytes. Knocking down YAP with siRNA significantly inhibited 4-AP-induced pathological changes in astrocytes. Our study demonstrated that astrocytic TRPV4 activation promoted neuroinflammation through the TRPV4/Ca2+/YAP/STAT3 signaling pathway in mice with seizures. Astrocyte TRPV4 inhibition attenuated neuroinflammation, reduced neuronal injury, and improved neurobehavioral function. Targeting astrocytic TRPV4 activation may provide a promising therapeutic approach for managing epilepsy.


Assuntos
Astrócitos , Convulsões , Canais de Cátion TRPV , Animais , Astrócitos/metabolismo , Humanos , Camundongos , Neurônios/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Convulsões/induzido quimicamente , Convulsões/genética , Convulsões/metabolismo , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo
17.
Neurosci Bull ; 37(10): 1427-1440, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34309810

RESUMO

Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Recent studies have shown that complement component 3 (C3) aggravate the neuronal injury in epilepsy. And our previous studies revealed that TRPV1 (transient receptor potential vanilloid type 1) is involved in epilepsy. Whether complement C3 regulation of neuronal injury is related to the activation of TRPV1 during epilepsy is not fully understood. We found that in a mouse model of status epilepticus (SE), complement C3 derived from astrocytes was increased and aggravated neuronal injury, and that TRPV1-knockout rescued neurons from the injury induced by complement C3. Circular RNAs are abundant in the brain, and the reduction of circRad52 caused by complement C3 promoted the expression of TRPV1 and exacerbated neuronal injury. Mechanistically, disorders of neuron-glia interaction mediated by the C3-TRPV1 signaling pathway may be important for the induction of neuronal injury. This study provides support for the hypothesis that the C3-TRPV1 pathway is involved in the prevention and treatment of neuronal injury and cognitive disorders.


Assuntos
Complemento C3 , Epilepsia , Neurônios/patologia , Estado Epiléptico , Canais de Cátion TRPV , Animais , Astrócitos/metabolismo , Complemento C3/metabolismo , Camundongos , Canais de Cátion TRPV/metabolismo
18.
Exp Parasitol ; 125(2): 165-71, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20122928

RESUMO

In this study, effects of GRA1 organelle-targeted expression on macrophage functions were investigated. The recombinant plasmid pCMV/myc/ER-GRA1 was constructed and then was transfected into murine macrophage RAW264.7 by Lipofectamine, selected by resistance of G418. The selected mono-clone cell line was named ER-GRA1-RAW264.7. The expression of GRA1 was localized in ER of ER-GRA1-RAW264.7 cells by indirect immunofluorescence detection. GRA1 mRNA expression level in ER-GRA1-RAW264.7 cell was significantly enhanced with a concomitant increase in its growth and adherence activity. Fluorescence intensity of intracellular calcium in ER-GRA1-RAW264.7, ER-ctrl-RAW264.7 and RAW264.7 cells in the presence of 1 mmol/l arachidonic acid (AA) were assayed by confocal microscopy using calcium-sensitive dye, Fluo-3 AM. Cytoplasm [Ca2+]i peaked at about 18 s after AA treatment, and cytoplasm [Ca2+]i of RAW264.7 cell almost instantly stepped up after AA was added, and peaked in 3 s, with a minor cytoplasm [Ca2+]i vibration subsequently. These results demonstrated that the expression of GRA1 in ER of macrophages promotes both growth and adherence of macrophages and modulates the intracellular calcium release stimulated by AA.


Assuntos
Antígenos de Protozoários/genética , Cálcio/metabolismo , Retículo Endoplasmático/imunologia , Macrófagos/parasitologia , Toxoplasma/genética , Animais , Antígenos de Protozoários/análise , Ácido Araquidônico/farmacologia , Adesão Celular/genética , Linhagem Celular , DNA Recombinante/análise , Eletroforese em Gel de Ágar , Expressão Gênica , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Plasmídeos , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Fluorescência , Toxoplasma/fisiologia , Transfecção
19.
Sci Rep ; 10(1): 18926, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33144676

RESUMO

To explore the possibility of predicting the clinical types of Corona-Virus-Disease-2019 (COVID-19) pneumonia by analyzing the non-focus area of the lung in the first chest CT image of patients with COVID-19 by using automatic machine learning (Auto-ML). 136 moderate and 83 severe patients were selected from the patients with COVID-19 pneumonia. The clinical and laboratory data were collected for statistical analysis. The texture features of the Non-focus area of the first chest CT of patients with COVID-19 pneumonia were extracted, and then the classification model of the first chest CT of COVID-19 pneumonia was constructed by using these texture features based on the Auto-ML method of radiomics, The area under curve(AUC), true positive rate(TPR), true negative rate (TNR), positive predictive value(PPV) and negative predictive value (NPV) of the operating characteristic curve (ROC) were used to evaluate the accuracy of the first chest CT image classification model in patients with COVID-19 pneumonia. The TPR, TNR, PPV, NPV and AUC of the training cohort and test cohort of the moderate group and the control group, the severe group and the control group, the moderate group and the severe group were all greater than 95% and 0.95 respectively. The non-focus area of the first CT image of COVID-19 pneumonia has obvious difference in different clinical types. The AUTO-ML classification model of Radiomics based on this difference can be used to predict the clinical types of COVID-19 pneumonia.


Assuntos
Infecções por Coronavirus/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Aprendizado de Máquina , Pneumonia Viral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , COVID-19 , Infecções por Coronavirus/patologia , Feminino , Humanos , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/patologia
20.
Front Cell Dev Biol ; 7: 339, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31921851

RESUMO

Hypoxic-ischemic encephalopathy (HIE) is a serious birth complication with severe long-term sequelae such as cerebral palsy, epilepsy and cognitive disabilities. Na+-K+-2Cl- cotransporters 1 (NKCC1) is dramatically upregulated after hypoxia-ischemia (HI), which aggravates brain edema and brain damage. Clinically, an NKCC1-specific inhibitor, bumetanide, is used to treat diseases related to aberrant NKCC1 expression, but the underlying mechanism of aberrant NKCC1 expression has rarely been studied in HIE. In this study, the cooperative effect of hypoxia-inducible factor-1α (HIF-1α) and nuclear factor of activated T cells 5 (NFAT5) on NKCC1 expression was explored in hippocampal neurons under hypoxic conditions. HI increased HIF-1α nuclear localization and transcriptional activity, and pharmacological inhibition of the HIF-1α transcription activity or mutation of hypoxia responsive element (HRE) motifs recovered the hypoxia-induced aberrant expression and promoter activity of NKCC1. In contrast, oxygen-glucose deprivation (OGD)-induced downregulation of NFAT5 expression was reversed by treating with hypertonic saline, which ameliorated aberrant NKCC1 expression. More importantly, knocking down NFAT5 or mutation of the tonicity enhancer element (TonE) stimulated NKCC1 expression and promoter activity under normal physiological conditions. The positive regulation of NKCC1 by HIF-1α and the negative regulation of NKCC1 by NFAT5 may serve to maintain NKCC1 expression levels, which may shed light on the transcription regulation of NKCC1 in hippocampal neurons after hypoxia.

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