Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 133
Filtrar
Mais filtros










Filtros aplicados
Base de dados
Intervalo de ano de publicação
1.
Int J Neurosci ; 129(10): 955-962, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30889362

RESUMO

Objectives: Despite the etiology of trigeminal neuralgia has been verified by microvascular decompression as vascular compression of the trigeminal root, very few researches concerning its underlying pathogenesis has been reported in the literature. The present study focused on those voltage-gated sodium channels, which are the structural basis for generation of ectopic action potentials. Methods: The trigeminal neuralgia modeling was obtained with infraorbital nerve chronic constriction injury (ION-CCI) in rats. Two weeks postoperatively, the infraorbital nerve (TN), the trigeminal ganglion (TG), and the brain stem (BS) were removed and analyzed with a series of molecular biological techniques. Results: Western blot depicted a significant up-regulation of Nav1.3 in TN and TG but not in BS, while none of the other isoforms (Nav1.6, Nav1.7, Nav1.8, or Nav1.9) presented a statistical change. The Nav1.3 from ION-CCI group was quantified as 2.5-fold and 1.7-fold than that from sham group in TN and TG, respectively (p < .05). Immunocytochemistry showed the Nav1.3-IR from ION-CCI group accounted for 21.2 ± 2.3% versus 6.1 ± 1.2% from sham group in TN, while the Nav1.3-positive neurons from ION-CCI group accounted for 34.1 ± 3.5% versus 11.2 ± 1.8% from sham group in TG. Immunohistochemical labeling showed the Nav1.3 was co-localized with CGRP and IB4 but not with GFAP or NF-200 in TG. Conclusion: ION-CCI may give rise to an up-regulation of Nav1.3 in trigeminal nerve as well as in C-type neurons at the trigeminal ganglion. It implied that the ectopic action potential may generate from both the compressed site of the trigeminal nerve and the ganglion rather than from the trigeminal nuclei.


Assuntos
Canal de Sódio Disparado por Voltagem NAV1.3/biossíntese , Nervo Trigêmeo/metabolismo , Neuralgia do Trigêmeo/metabolismo , Animais , Constrição , Expressão Gênica , Masculino , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Fibras Nervosas Amielínicas/metabolismo , Ratos , Ratos Sprague-Dawley , Gânglio Trigeminal/metabolismo , Neuralgia do Trigêmeo/genética , Canais de Sódio Disparados por Voltagem/biossíntese , Canais de Sódio Disparados por Voltagem/genética
2.
Sci Rep ; 9(1): 206, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30659253

RESUMO

We have previously reported the deregulatory impact of ethanol on global DNA methylation of brain-derived neural stem cells (NSC). Here, we conducted a genome-wide RNA-seq analysis in differentiating NSC exposed to different modes of ethanol exposure. RNA-seq results showed distinct gene expression patterns and canonical pathways induced by ethanol exposure and withdrawal. Short-term ethanol exposure caused abnormal up-regulation of synaptic pathways, while continuous ethanol treatment profoundly affected brain cells' morphology. Ethanol withdrawal restored the gene expression profile of differentiating NSC without rescuing impaired expression of epigenetics factors. Ingenuity Pathway Analysis (IPA) analysis predicated that ethanol may impact synaptic functions via GABA receptor signalling pathway and affects neural system and brain morphology. We identified Sptbn2, Dcc, and Scn3a as candidate genes which may link alcohol-induced neuronal morphology to brain structural abnormalities, predicted by IPA analysis. Cross-examination of Scn3a and As3mt in differentiated NSC from two different mouse strains (BL6 and CD1) showed a consistent pattern of induction and reduction, respectively. Collectively, our study identifies genetic networks, which may contribute to alcohol-mediated cellular and brain structural dysmorphology, contributing to our knowledge of alcohol-mediated damage to central nervous system, paving the path for better understanding of FASD pathobiology.


Assuntos
Alcoolismo/genética , Etanol/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/genética , Alcoolismo/metabolismo , Animais , Encéfalo/metabolismo , Diferenciação Celular/efeitos dos fármacos , Depressores do Sistema Nervoso Central/farmacologia , Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Etanol/metabolismo , Etanol/farmacologia , Feminino , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/efeitos dos fármacos , Estudo de Associação Genômica Ampla , Masculino , Camundongos , Camundongos Endogâmicos C57BL/embriologia , Camundongos Endogâmicos/embriologia , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Gravidez , Análise de Sequência de RNA/métodos , Síndrome de Abstinência a Substâncias/metabolismo , Transcriptoma/efeitos dos fármacos
3.
Biochim Biophys Acta Biomembr ; 1861(1): 142-150, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30463697

RESUMO

To1, previously named Tc49b, is a peptide neurotoxin isolated from venom of the scorpion Tityus obscurus that is responsible for lethal human poisoning cases in the Brazilian Amazonian region. Previously, To1 was shown to be lethal to mice and to change Na+ permeation in cerebellum granular neurons from rat brain. In addition, To1 did not affect Shaker B K+ channels. Based on sequence similarities, To1 was described as a ß-toxin. In the present work, To1 was purified from T. obscurus venom and submitted to an electrophysiological characterization in human and invertebrate NaV channels. The analysis of the electrophysiological experiments reveal that To1 enhances the open probability at more negative potentials of human NaV 1.3 and 1.6, of the insect channel BgNaV1 and of arachnid VdNaV1 channel. In addition, To1 reduces the peak of Na+ currents in some of the NaVs tested. These results support the classification of the To1 as a ß-toxin. A structure and functional comparison to other ß-toxins that share sequence similarity to To1 is also presented.


Assuntos
Canal de Sódio Disparado por Voltagem NAV1.3/química , Canal de Sódio Disparado por Voltagem NAV1.6/química , Venenos de Escorpião/química , Escorpiões/química , Canais de Sódio/química , Animais , Fenômenos Eletrofisiológicos , Células HEK293 , Humanos , Proteínas de Insetos/química , Cinética , Peptídeos , Probabilidade , Ligação Proteica , Sódio/química
4.
Sci Rep ; 8(1): 15913, 2018 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-30374194

RESUMO

Alcohol abuse can induce brain injury and neurodegeneration, and recent evidence shows the participation of immune receptors toll-like in the neuroinflammation and brain damage. We evaluated the role of miRNAs as potential modulators of the neuroinflammation associated with alcohol abuse and the influence of the TLR4 response. Using mice cerebral cortex and next-generation sequencing (NGS), we identified miRNAs that were differentially expressed in the chronic alcohol-treated versus untreated WT or TLR4-KO mice. We observed a differentially expression of miR-183 Cluster (C) (miR-96/-182/-183), miR-200a and miR-200b, which were down-regulated, while mirR-125b was up-regulated in alcohol-treated WT versus (vs.) untreated mice. These miRNAs modulate targets genes related to the voltage-gated sodium channel, neuron hyperexcitability (Nav1.3, Trpv1, Smad3 and PP1-γ), as well as genes associated with innate immune TLR4 signaling response (Il1r1, Mapk14, Sirt1, Lrp6 and Bdnf). Functional enrichment of the miR-183C and miR-200a/b family target genes, revealed neuroinflammatory pathways networks involved in TLR4 signaling and alcohol abuse. The changes in the neuroinflammatory targets genes associated with alcohol abuse were mostly abolished in the TLR4-KO mice. Our results show the relationship between alcohol intake and miRNAs expression and open up new therapeutically targets to prevent deleterious effects of alcohol on the brain.


Assuntos
Córtex Cerebral/metabolismo , Inflamação/patologia , MicroRNAs/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Etanol/toxicidade , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Inflamação/induzido quimicamente , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Mapas de Interação de Proteínas/genética , Análise de Sequência de RNA , Transdução de Sinais/genética , Proteína Smad3/genética , Proteína Smad3/metabolismo , Receptor 4 Toll-Like/deficiência , Receptor 4 Toll-Like/genética
5.
Neuron ; 99(5): 867-868, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30189204

RESUMO

Channelopathies are disorders that affect the function of ion channels, typically resulting in epilepsy. Smith et al. (2018) discover an unusual association between SCN3A, neuronal migration, and cortical folding, outlining sodium channels as important regulators of brain development.


Assuntos
Epilepsia , Canais de Sódio , Córtex Cerebral , Humanos , Canais Iônicos , Canal de Sódio Disparado por Voltagem NAV1.3 , Sódio
6.
Neurosci Lett ; 687: 146-152, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30267849

RESUMO

Abnormal synchronized oscillatory bursts occurring in the basal ganglia (BG) are suggested to be correlated with motor symptoms in Parkinson's disease (PD) patients and animal models of PD. Voltage-gated sodium channels (VGSCs) have been demonstrated to play an important role in the abnormal electrical activity of neurons in the BG. Nav1.3, a VGSCs subtype, is predominantly expressed in embryonic and neonatal nervous system but barely detected in the normal adult nervous system in rodents. Here we investigated the expression patterns of Nav1.3 in the BG of 6-OHDA lesioned Sprague Dawley rats. The results showed that Nav1.3 at mRNA and protein levels was abundantly re-expressed in the ipsilateral and contralateral SN at 49 days postlesion, but was rarely detected in the other nuclei of the BG in the 6-OHDA lesioned rats. Furthermore, Nav1.3 was not only expressed in TH-positive dopaminergic neurons of the ipsilateral and contralateral SN, but also in nestin-positive neural progenitor cells surrounding the ipsilateral SN and the midline region adjacent to the ipsilateral SN in the midbrain at 49 days postlesion. These results suggested that the re-expression of Nav1.3 may influence the electrical activity of dopaminergic neurons in the SN in 6-OHDA lesioned rats.


Assuntos
Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Substância Negra/metabolismo , Animais , Modelos Animais de Doenças , Masculino , Oxidopamina/metabolismo , Doença de Parkinson/metabolismo , Ratos Sprague-Dawley
7.
Neuron ; 99(5): 905-913.e7, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30146301

RESUMO

Channelopathies are disorders caused by abnormal ion channel function in differentiated excitable tissues. We discovered a unique neurodevelopmental channelopathy resulting from pathogenic variants in SCN3A, a gene encoding the voltage-gated sodium channel NaV1.3. Pathogenic NaV1.3 channels showed altered biophysical properties including increased persistent current. Remarkably, affected individuals showed disrupted folding (polymicrogyria) of the perisylvian cortex of the brain but did not typically exhibit epilepsy; they presented with prominent speech and oral motor dysfunction, implicating SCN3A in prenatal development of human cortical language areas. The development of this disorder parallels SCN3A expression, which we observed to be highest early in fetal cortical development in progenitor cells of the outer subventricular zone and cortical plate neurons and decreased postnatally, when SCN1A (NaV1.1) expression increased. Disrupted cerebral cortical folding and neuronal migration were recapitulated in ferrets expressing the mutant channel, underscoring the unexpected role of SCN3A in progenitor cells and migrating neurons.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/crescimento & desenvolvimento , Desenvolvimento da Linguagem , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Canais de Sódio/genética , Adolescente , Adulto , Animais , Movimento Celular/fisiologia , Células Cultivadas , Córtex Cerebral/patologia , Criança , Pré-Escolar , Feminino , Furões , Células HEK293 , Humanos , Lactente , Masculino , Megalencefalia/diagnóstico por imagem , Megalencefalia/genética , Megalencefalia/patologia , Pessoa de Meia-Idade , Linhagem , Polimicrogiria/diagnóstico por imagem , Polimicrogiria/genética , Polimicrogiria/patologia
8.
BMC Psychiatry ; 18(1): 248, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-30071822

RESUMO

BACKGROUND: Mutations in voltage-gated sodium channel (SCN) genes are supposed to be of importance in the etiology of psychiatric and neurological diseases, in particular in the etiology of seizures. Previous studies report a potential susceptibility region at the chromosomal locus 2q including SCN1A, SCN2A and SCN3A genes for autism spectrum disorder (ASD). To date, there is no previous description of a patient with comorbid ASD and Tourette syndrome showing a deletion containing SCN2A and SCN3A. CASE PRESENTATION: We present the unique complex case of a 28-year-old male patient suffering from developmental retardation and exhibiting a range of behavioral traits since birth. He received the diagnoses of ASD (in early childhood) and of Tourette syndrome (in adulthood) according to ICD-10 and DSM-5 criteria. Investigations of underlying genetic factors yielded a heterozygous microdeletion of approximately 719 kb at 2q24.3 leading to a deletion encompassing the five genes SCN2A (exon 1 to intron 14-15), SCN3A, GRB14 (exon 1 to intron 2-3), COBLL1 and SCL38A11. CONCLUSIONS: We discuss the association of SCN2A, SCN3A, GRB14, COBLL1 and SCL38A11 deletions with ASD and Tourette syndrome and possible implications for treatment.


Assuntos
Transtorno do Espectro Autista/genética , Deficiências do Desenvolvimento/genética , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Canais de Sódio/genética , Síndrome de Tourette/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Deleção Cromossômica , Humanos , Masculino , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Fenótipo , Fatores de Transcrição/genética
9.
Seizure ; 60: 91-93, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29929112

RESUMO

SCN2A encodes the alpha-subunit of voltage-gated sodium channel, Nav1.2, which is highly expressed at an early stage of the postnatal brain. Genetic studies revealed that de novo heterozygous mutations of SCN2A caused severe developmental disorders in childhood, such as autism and epileptic encephalopathy. However, few reports have demonstrated the cases carrying segmental deletions at the SCN2A locus for those with epileptic disorders. In this study, we report a 1.8-year-old boy, who presented with West syndrome in infancy and developed the sequelae of psychomotor delay and autism. Since whole-exome sequencing did not detect pathogenic mutations, we extensively searched for microdeletions and duplications by applying the eXome Hidden Markov Model (XHMM) for read depths of sequenced intervals. Using this approach, we identified a de novo deletion spanning the 1.1-Mb region of chromosome 2q24.3. We found that the deleted interval included the SCN2A and SCN3A loci. These data validate the utility of XHMM and support that SCN2A is involved in the pathogenic processes underlying epileptic encephalopathy in childhood.


Assuntos
Transtorno do Espectro Autista/genética , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Deleção de Sequência , Canais de Sódio/genética , Espasmos Infantis/genética , Transtorno do Espectro Autista/complicações , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Diagnóstico Diferencial , Humanos , Lactente , Masculino , Espasmos Infantis/complicações , Espasmos Infantis/diagnóstico por imagem , Espasmos Infantis/fisiopatologia
10.
Mol Pain ; 14: 1744806918778491, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29783906

RESUMO

Background Oral administration of Bulleyaconitine A, an extracted diterpenoid alkaloid from Aconitum bulleyanum plants, is effective for treating chronic pain in rats and in human patients, but the underlying mechanisms are poorly understood. Results As the hyperexcitability of dorsal root ganglion neurons resulting from the upregulation of voltage-gated sodium (Nav) channels has been proved critical for development of chronic pain, we tested the effects of Bulleyaconitine A on Nav channels in rat spared nerve injury model of neuropathic pain. We found that Bulleyaconitine A at 5 nM increased the threshold of action potentials and reduced the firing rate of dorsal root ganglion neurons in spared nerve injury rats but not in sham rats. Bulleyaconitine A preferably blocked tetrodotoxin-sensitive Nav channels over tetrodotoxin-resistant ones in dorsal root ganglion neurons of spared nerve injury rats. Bulleyaconitine A was more potent for blocking Nav1.3 and Nav1.7 than Nav1.8 in cell lines. The half maximal inhibitory concentration (IC50) values for resting Nav1.3, Nav1.7, and Nav1.8 were 995.6 ± 139.1 nM, 125.7 ± 18.6 nM, and 151.2 ± 15.4 µM, respectively, which were much higher than those for inactivated Nav1.3 (20.3 ± 3.4 pM), Nav1.7 (132.9 ± 25.5 pM), and Nav1.8 (18.0 ± 2.5 µM). The most profound use-dependent blocking effect of Bulleyaconitine A was observed on Nav1.7, less on Nav1.3, and least on Nav1.8 at IC50 concentrations. Bulleyaconitine A facilitated the inactivation of Nav channels in each subtype. Conclusions Preferably blocking tetrodotoxin-sensitive Nav1.7 and Nav1.3 in dorsal root ganglion neurons may contribute to Bulleyaconitine A's antineuropathic pain effect.


Assuntos
Aconitina/análogos & derivados , Gânglios Espinais/patologia , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.7/metabolismo , Tecido Nervoso/lesões , Neurônios/metabolismo , Aconitina/farmacologia , Animais , Linhagem Celular , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Humanos , Ativação do Canal Iônico/efeitos dos fármacos , Masculino , Tecido Nervoso/efeitos dos fármacos , Tecido Nervoso/metabolismo , Tecido Nervoso/patologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Ratos Sprague-Dawley
13.
J Pharmacol Sci ; 137(1): 93-97, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29773519

RESUMO

The neurosteroid allopregnanolone has potent analgesic effects, and its potential use for neuropathic pain is supported by recent reports. However, the analgesic mechanisms are obscure. The voltage-gated sodium channels (Nav) α subunit Nav1.3 is thought to play an essential role in neuropathic pain. Here, we report the effects of allopregnanolone sulfate (APAS) on sodium currents (INa) in Xenopus oocytes expressing Nav1.3 with ß1 or ß3 subunits. APAS suppressed INa of Nav1.3 with ß1 and ß3 in a concentration-dependent manner (IC50 values; 75 and 26 µmol/L). These results suggest the possible importance of Nav1.3 inhibition for the analgesic mechanisms of allopregnanolone.


Assuntos
Analgésicos , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Neurotransmissores/farmacologia , Oócitos/metabolismo , Pregnanolona/farmacologia , Bloqueadores do Canal de Sódio Disparado por Voltagem , Animais , Relação Dose-Resposta a Droga , Feminino , Neuralgia/tratamento farmacológico , Neurotransmissores/uso terapêutico , Pregnanolona/uso terapêutico , Xenopus
14.
Neurobiol Aging ; 67: 202.e7-202.e8, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29691093

RESUMO

Recently, 17 new Parkinson's disease (PD) risk loci were identified in a genome-wide association studies meta-analysis in Caucasians; however, their association with PD in Chinese patients is largely unknown. Therefore, we performed a replication study of 5 of the most commonly identified candidate variants, including SORBS3 rs2280104, SCN3A rs353116, TOX3 rs4784227, GLAC rs8005172, and ZNF184 rs9468199, in a large sample of patients with PD (1506) and multiple system atrophy (MSA, 496) in a Chinese population. These 5 variants were found to not be associated with PD and MSA in the Chinese population. Our results suggest that these variants are not risk factors for PD or MSA in the Chinese population.


Assuntos
Loci Gênicos/genética , Estudo de Associação Genômica Ampla , Atrofia de Múltiplos Sistemas/genética , Doença de Parkinson/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Grupo com Ancestrais do Continente Asiático/genética , Variação Genética , Proteínas de Grupo de Alta Mobilidade , Humanos , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Receptores de Progesterona/genética , Fatores de Risco , Canais de Sódio/genética
15.
Chin J Physiol ; 61(2): 124-129, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29689688

RESUMO

Diabetes is a common metabolic disease which leads to diabetic peripheral neuropathy. Recently, the role of microRNA-96 (miR-96) in alleviating neuropathic pain by inhibiting the expression of NaV1.3, an isoform of voltage-gated sodium channels, has been shown. Peripheral nerve injuries result in NaV1.3 elevation. Exercise has beneficial role in diabetes management and peripheral neuropathy. However, the effects of exercise on miR-96 and its target gene NaV1.3 in diabetic rats are unknown. Therefore, the present study investigated the effects of exercise training on the expression of miR-96 and NaV1.3 in diabetic rats. For this purpose, rats were randomly divided into four groups: control, exercise, diabetic and diabetic-exercise groups. Type 2 diabetes was induced by a high-fat diet and the administration of streptozotocin (STZ) (35 mg/kg, i.p.). The exercise groups were subjected to swimming exercise 5 days/week for 10 weeks. At the end of the treatment period, thermal pain threshold, determined through the tail-flick test, and the expression levels of miR-96 and its target gene NaV1.3 were determined by reverse transcription (RT)-PCR in the sciatic nerve tissues of the rats. Data of the present study indicated that diabetes diminished miR-96 expression levels, but significantly upregulated NaV1.3 expression in the sciatic nerve. On exercise training, miR-96 expression was reversed with concurrent down-regulation of the NaV1.3 expression. This study introduced a new and potential miRNA-dependent mechanism for exerciseinduced protective effects against diabetic thermal hyperalgesia.


Assuntos
Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 2/terapia , Neuropatias Diabéticas/terapia , Terapia por Exercício/métodos , MicroRNAs/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Nervo Isquiático/metabolismo , Natação , Animais , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Neuropatias Diabéticas/genética , Neuropatias Diabéticas/metabolismo , Neuropatias Diabéticas/fisiopatologia , Dieta Hiperlipídica , Regulação da Expressão Gênica , Hiperalgesia/genética , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatologia , Hiperalgesia/terapia , Masculino , MicroRNAs/genética , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Limiar da Dor , Ratos Wistar , Nervo Isquiático/fisiopatologia , Estreptozocina , Fatores de Tempo
16.
Neurosci Lett ; 674: 148-155, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29578003

RESUMO

Epileptic seizures are the main clinical manifestation of low-grade astrocytoma. Voltage-gated sodium channels (VGSCs) play a crucial role in epilepsy. Until now, the role of VGSCs and the relationships between calmodulin (CaM)/CaM-dependent protein kinase II (CaMKII) and VGSCs in low-grade astrocytoma have not been demonstrated. In our study, the protein expression of NaV1.3, NaV1.6 and CaM was significantly increased in the tumor compared to control tissue, while the level of p-CaMKII/CaMKII was significantly decreased in the tumor group as determined by Western Blotting and immunohistochemistry. Furthermore, double-labeling immunofluorescence results showed that NaV1.3/NaV1.6 and CaM co-localization was significantly increased in the tumor group compared to control tissue. This study represents the first evidence of the abnormal changes in VGSCs subtypes and CaM/CaMKII pathway in human brain low-grade astrocytoma, providing new potential targets for molecular therapies of this disease.


Assuntos
Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Calmodulina/metabolismo , Canais de Sódio Disparados por Voltagem/metabolismo , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Canal de Sódio Disparado por Voltagem NAV1.1/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.6/metabolismo , Fosforilação , Transdução de Sinais , Canais de Sódio/metabolismo , Adulto Jovem
17.
Anesthesiology ; 128(6): 1151-1166, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29509584

RESUMO

BACKGROUND: Voltage-gated sodium channels generate action potentials in excitable cells, but they have also been attributed noncanonical roles in nonexcitable cells. We hypothesize that voltage-gated sodium channels play a functional role during extravasation of neutrophils. METHODS: Expression of voltage-gated sodium channels was analyzed by polymerase chain reaction. Distribution of Nav1.3 was determined by immunofluorescence and flow cytometry in mouse models of ischemic heart and kidney injury. Adhesion, transmigration, and chemotaxis of neutrophils to endothelial cells and collagen were investigated with voltage-gated sodium channel inhibitors and lidocaine in vitro. Sodium currents were examined with a whole cell patch clamp. RESULTS: Mouse and human neutrophils express multiple voltage-gated sodium channels. Only Nav1.3 was detected in neutrophils recruited to ischemic mouse heart (25 ± 7%, n = 14) and kidney (19 ± 2%, n = 6) in vivo. Endothelial adhesion of mouse neutrophils was reduced by tetrodotoxin (56 ± 9%, unselective Nav-inhibitor), ICA121431 (53 ± 10%), and Pterinotoxin-2 (55 ± 9%; preferential inhibitors of Nav1.3, n = 10). Tetrodotoxin (56 ± 19%), ICA121431 (62 ± 22%), and Pterinotoxin-2 (59 ± 22%) reduced transmigration of human neutrophils through endothelial cells, and also prevented chemotactic migration (n = 60, 3 × 20 cells). Lidocaine reduced neutrophil adhesion to 60 ± 9% (n = 10) and transmigration to 54 ± 8% (n = 9). The effect of lidocaine was not increased by ICA121431 or Pterinotoxin-2. CONCLUSIONS: Nav1.3 is expressed in neutrophils in vivo; regulates attachment, transmigration, and chemotaxis in vitro; and may serve as a relevant target for antiinflammatory effects of lidocaine.


Assuntos
Adesão Celular/fisiologia , Quimiotaxia/fisiologia , Rim/metabolismo , Isquemia Miocárdica/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/biossíntese , Neutrófilos/metabolismo , Canais de Sódio/biossíntese , Migração Transendotelial e Transepitelial/fisiologia , Animais , Adesão Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Expressão Gênica , Humanos , Rim/irrigação sanguínea , Rim/efeitos dos fármacos , Lidocaína/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Isquemia Miocárdica/tratamento farmacológico , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Neutrófilos/efeitos dos fármacos , Canais de Sódio/genética , Migração Transendotelial e Transepitelial/efeitos dos fármacos
18.
Sci Rep ; 8(1): 3845, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29497094

RESUMO

Voltage-gated sodium channels NaV1.7, NaV1.8 and NaV1.9 have been the focus for pain studies because their mutations are associated with human pain disorders, but the role of NaV1.6 in pain is less understood. In this study, we selectively knocked out NaV1.6 in dorsal root ganglion (DRG) neurons, using NaV1.8-Cre directed or adeno-associated virus (AAV)-Cre mediated approaches, and examined the specific contribution of NaV1.6 to the tetrodotoxin-sensitive (TTX-S) current in these neurons and its role in neuropathic pain. We report here that NaV1.6 contributes up to 60% of the TTX-S current in large, and 34% in small DRG neurons. We also show NaV1.6 accumulates at nodes of Ranvier within the neuroma following spared nerve injury (SNI). Although NaV1.8-Cre driven NaV1.6 knockout does not alter acute, inflammatory or neuropathic pain behaviors, AAV-Cre mediated NaV1.6 knockout in adult mice partially attenuates SNI-induced mechanical allodynia. Additionally, AAV-Cre mediated NaV1.6 knockout, mostly in large DRG neurons, significantly attenuates excitability of these neurons after SNI and reduces NaV1.6 accumulation at nodes of Ranvier at the neuroma. Together, NaV1.6 in NaV1.8-positive neurons does not influence pain thresholds under normal or pathological conditions, but NaV1.6 in large NaV1.8-negative DRG neurons plays an important role in neuropathic pain.


Assuntos
Canal de Sódio Disparado por Voltagem NAV1.6/metabolismo , Neuralgia/genética , Animais , Feminino , Gânglios Espinais/metabolismo , Hiperalgesia/genética , Hiperalgesia/metabolismo , Masculino , Camundongos , Camundongos Knockout , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.6/genética , Canal de Sódio Disparado por Voltagem NAV1.6/fisiologia , Canal de Sódio Disparado por Voltagem NAV1.8/metabolismo , Tecido Nervoso/metabolismo , Neuralgia/metabolismo , Neurônios/metabolismo , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Sódio/farmacologia , Tetrodotoxina/farmacologia , Canais de Sódio Disparados por Voltagem/genética , Canais de Sódio Disparados por Voltagem/metabolismo
19.
J Physiol ; 596(9): 1601-1626, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29441586

RESUMO

KEY POINTS: Na+ current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na+ (NaV ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary ß-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-ß-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary ß-cells, but not in HEK cells, inactivation of a single NaV subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that NaV channels adopt different inactivation behaviours depending on the local membrane environment. ABSTRACT: Pancreatic ß-cells are equipped with voltage-gated Na+ channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na+ current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na+ channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the ß-cell. It has been proposed that the biphasic inactivation reflects the contribution of different NaV α-subunits. We tested this possibility by expression of TTX-resistant variants of the NaV subunits found in ß-cells (NaV 1.3, NaV 1.6 and NaV 1.7) in insulin-secreting Ins1 cells and in non-ß-cells (including HEK and CHO cells). We found that all NaV subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. NaV 1.7 inactivated at 15--20 mV more negative membrane potentials than NaV 1.3 and NaV 1.6 in Ins1 cells but this small difference is insufficient to solely explain the biphasic inactivation in Ins1 cells. In Ins1 cells, but never in the other cell types, widely different components of NaV inactivation (separated by 30 mV) were also observed following expression of a single type of NaV α-subunit. The more positive component exhibited a voltage dependence of inactivation similar to that found in HEK and CHO cells. We propose that biphasic NaV inactivation in insulin-secreting cells reflects insertion of channels in membrane domains that differ with regard to lipid and/or membrane protein composition.


Assuntos
Regulação da Expressão Gênica , Células Secretoras de Insulina/metabolismo , Insulinoma/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.3/química , Canal de Sódio Disparado por Voltagem NAV1.6/química , Canal de Sódio Disparado por Voltagem NAV1.7/química , Bloqueadores dos Canais de Sódio/farmacologia , Potenciais de Ação , Sequência de Aminoácidos , Animais , Cricetinae , Cricetulus , Fenômenos Eletrofisiológicos , Células HEK293 , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Insulinoma/tratamento farmacológico , Insulinoma/patologia , Potenciais da Membrana , Camundongos , Camundongos Knockout , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.6/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.7/metabolismo , Ratos , Homologia de Sequência , Sódio/metabolismo
20.
Ann Neurol ; 83(4): 703-717, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29466837

RESUMO

OBJECTIVE: Voltage-gated sodium (Na+ ) channels underlie action potential generation and propagation and hence are central to the regulation of excitability in the nervous system. Mutations in the genes SCN1A, SCN2A, and SCN8A, encoding the Na+ channel pore-forming (α) subunits Nav1.1, 1.2, and 1.6, respectively, and SCN1B, encoding the accessory subunit ß1 , are established causes of genetic epilepsies. SCN3A, encoding Nav1.3, is known to be highly expressed in brain, but has not previously been linked to early infantile epileptic encephalopathy. Here, we describe a cohort of 4 patients with epileptic encephalopathy and heterozygous de novo missense variants in SCN3A (p.Ile875Thr in 2 cases, p.Pro1333Leu, and p.Val1769Ala). METHODS: All patients presented with treatment-resistant epilepsy in the first year of life, severe to profound intellectual disability, and in 2 cases (both with the variant p.Ile875Thr), diffuse polymicrogyria. RESULTS: Electrophysiological recordings of mutant channels revealed prominent gain of channel function, with a markedly increased amplitude of the slowly inactivating current component, and for 2 of 3 mutants (p.Ile875Thr and p.Pro1333Leu), a leftward shift in the voltage dependence of activation to more hyperpolarized potentials. Gain of function was not observed for Nav1.3 variants known or presumed to be inherited (p.Arg1642Cys and p.Lys1799Gln). The antiseizure medications phenytoin and lacosamide selectively blocked slowly inactivating over transient current in wild-type and mutant Nav1.3 channels. INTERPRETATION: These findings establish SCN3A as a new gene for infantile epileptic encephalopathy and suggest a potential pharmacologic intervention. These findings also reinforce the role of Nav1.3 as an important regulator of neuronal excitability in the developing brain, while providing additional insight into mechanisms of slow inactivation of Nav1.3. Ann Neurol 2018;83:703-717.


Assuntos
Mutação/genética , Canal de Sódio Disparado por Voltagem NAV1.3/genética , Canais de Sódio/genética , Espasmos Infantis/genética , Adolescente , Adulto , Análise de Variância , Linhagem Celular Transformada , Pré-Escolar , Estudos de Coortes , Estimulação Elétrica , Feminino , Humanos , Lacosamida/farmacologia , Imagem por Ressonância Magnética , Masculino , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/genética , Modelos Moleculares , Técnicas de Patch-Clamp , Fenitoína/farmacologia , Espasmos Infantis/diagnóstico por imagem , Espasmos Infantis/fisiopatologia , Transfecção , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA