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1.
Int J Mol Sci ; 22(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33804063

RESUMO

Besides its insulinotropic actions on pancreatic ß cells, neuroprotective activities of glucagon-like peptide-1 (GLP-1) have attracted attention. The efficacy of a GLP-1 receptor (GLP-1R) agonist exendin-4 (Ex-4) for functional repair after sciatic nerve injury and amelioration of diabetic peripheral neuropathy (DPN) has been reported; however, the underlying mechanisms remain unclear. In this study, the bioactivities of Ex-4 on immortalized adult rat Schwann cells IFRS1 and adult rat dorsal root ganglion (DRG) neuron-IFRS1 co-culture system were investigated. Localization of GLP-1R in both DRG neurons and IFRS1 cells were confirmed using knockout-validated monoclonal Mab7F38 antibody. Treatment with 100 nM Ex-4 significantly enhanced survival/proliferation and migration of IFRS1 cells, as well as stimulated the movement of IFRS1 cells toward neurites emerging from DRG neuron cell bodies in the co-culture with the upregulation of myelin protein 22 and myelin protein zero. Because Ex-4 induced phosphorylation of serine/threonine-specific protein kinase AKT in these cells and its effects on DRG neurons and IFRS1 cells were attenuated by phosphatidyl inositol-3'-phosphate-kinase (PI3K) inhibitor LY294002, Ex-4 might act on both cells to activate PI3K/AKT signaling pathway, thereby promoting myelination in the co-culture. These findings imply the potential efficacy of Ex-4 toward DPN and other peripheral nerve lesions.


Assuntos
Neuropatias Diabéticas/tratamento farmacológico , Exenatida/farmacologia , Peptídeo 1 Semelhante ao Glucagon/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Animais , Movimento Celular/genética , Sobrevivência Celular/genética , Cromonas/farmacologia , Técnicas de Cocultura , Neuropatias Diabéticas/genética , Neuropatias Diabéticas/patologia , Exenatida/genética , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/patologia , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Morfolinas/farmacologia , Bainha de Mielina/genética , Bainha de Mielina/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Células de Schwann/citologia , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Nervo Isquiático/lesões
2.
Int J Mol Sci ; 22(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806699

RESUMO

Nociceptors sense hazards via plasmalemmal cation channels, including transient receptor potential vanilloid 1 (TRPV1). Nerve growth factor (NGF) sensitises TRPV1 to capsaicin (CAPS), modulates nociceptor excitability and induces thermal hyperalgesia, but cellular mechanisms remain unclear. Confocal microscopy was used to image changes in intracellular Ca2+ concentration ([Ca2+]i) across neuronal populations in dorsal root ganglia (DRG) explants from pirt-GCaMP3 adult mice, which express a fluorescent reporter in their sensory neurons. Raised [Ca2+]i was detected in 84 neurons of three DRG explants exposed to NGF (100 ng/mL) and most (96%) of these were also excited by 1 µM CAPS. NGF elevated [Ca2+]i in about one-third of the neurons stimulated by 1 µM CAPS, whether applied before or after the latter. In neurons excitable by NGF, CAPS-evoked [Ca2+]i signals appeared significantly sooner (e.g., respective lags of 1.0 ± 0.1 and 1.9 ± 0.1 min), were much (>30%) brighter and lasted longer (6.6 ± 0.4 vs. 3.9 ± 0.2 min) relative to those non-responsive to the neurotrophin. CAPS tachyphylaxis lowered signal intensity by ~60% but was largely prevented by NGF. Increasing CAPS from 1 to 10 µM nearly doubled the number of cells activated but only modestly increased the amount co-activated by NGF. In conclusion, a sub-population of the CAPS-sensitive neurons in adult mouse DRG that can be excited by NGF is more sensitive to CAPS, responds with stronger signals and is further sensitised by transient exposure to the neurotrophin.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Capsaicina/farmacologia , Gânglios Espinais/efeitos dos fármacos , Fator de Crescimento Neural/farmacologia , Neurônios/efeitos dos fármacos , Nociceptividade/efeitos dos fármacos , Animais , Feminino , Gânglios Espinais/metabolismo , Hiperalgesia/metabolismo , Masculino , Camundongos , Fatores de Crescimento Neural/metabolismo , Neurônios/metabolismo , Nociceptores/metabolismo , Transdução de Sinais/efeitos dos fármacos , Canais de Cátion TRPV/metabolismo
3.
Toxicol Appl Pharmacol ; 416: 115468, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33639149

RESUMO

High glucose (HG)-induced nucleotide-binding and oligomerization (NACHT) domain, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome activation leads to diabetic neuropathic pain. We recently showed that salidroside could suppress NLRP3 inflammasome activation in hepatocytes exposed to HG. The aim of this study was to evaluate the analgesic effect of salidroside on diabetic rats and to explore its underlying mechanisms. Rat models with diabetic neuropathic pain were induced by high-fat diet feeding combined with low dose streptozotocin injections. Doses of salidroside at 50 and 100 mg.kg-1.day-1 were administered by gavage to diabetic rats for 6 weeks. Mechanical allodynia test, thermal hyperalgesia test and biochemical analysis were performed to evaluate therapeutic effects. Primary dorsal root ganglion (DRG) cells exposed to HG at 45 mM were used to further study the effects of salidroside on the AMP-activated protein kinase (AMPK)-NLRP3 inflammasome axis and insulin sensitivity in vitro. Salidroside administration improved hyperglycemia, ameliorated insulin resistance, and alleviated neuropathic pain in diabetic rats. Moreover, salidroside induced AMPK activation and suppressed NLRP3 inflammasome activation in the DRGs of diabetic rats. In addition, salidroside treatment relieved oxidative stress, improved insulin sensitivity and regulated the AMPK-NLRP3 inflammasome axis in HG-treated DRGs in vitro. Furthermore, AMPK inhibition in vivo or AMPK silencing in vitro abolished the beneficial effects of salidroside on diabetic neuropathic pain. Together, these results indicate that salidroside alleviates diabetic neuropathic pain through its regulation of the AMPK-NLRP3 inflammasome axis in DRGs.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Analgésicos/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Neuropatias Diabéticas/prevenção & controle , Gânglios Espinais/efeitos dos fármacos , Glucosídeos/farmacologia , Hipoglicemiantes/farmacologia , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Neuralgia/prevenção & controle , Fenóis/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Células Cultivadas , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/enzimologia , Neuropatias Diabéticas/etiologia , Neuropatias Diabéticas/fisiopatologia , Gânglios Espinais/enzimologia , Gânglios Espinais/fisiopatologia , Resistência à Insulina , Masculino , Neuralgia/enzimologia , Neuralgia/etiologia , Neuralgia/fisiopatologia , Estresse Oxidativo/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Ratos Sprague-Dawley , Transdução de Sinais
4.
Int J Mol Sci ; 22(1)2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33401689

RESUMO

The sodium-activated potassium channel Slack (KNa1.1, Slo2.2, or Kcnt1) is highly expressed in populations of sensory neurons, where it mediates the sodium-activated potassium current (IKNa) and modulates neuronal activity. Previous studies suggest that Slack is involved in the processing of neuropathic pain. However, mechanisms underlying the regulation of Slack activity in this context are poorly understood. Using whole-cell patch-clamp recordings we found that Slack-mediated IKNa in sensory neurons of mice is reduced after peripheral nerve injury, thereby contributing to neuropathic pain hypersensitivity. Interestingly, Slack is closely associated with ATP-sensitive P2X3 receptors in a population of sensory neurons. In vitro experiments revealed that Slack-mediated IKNa may be bidirectionally modulated in response to P2X3 activation. Moreover, mice lacking Slack show altered nocifensive responses to P2X3 stimulation. Our study identifies P2X3/Slack signaling as a mechanism contributing to hypersensitivity after peripheral nerve injury and proposes a potential novel strategy for treatment of neuropathic pain.


Assuntos
Trifosfato de Adenosina/análogos & derivados , Cálcio/farmacologia , Proteínas do Tecido Nervoso/metabolismo , Neuralgia/metabolismo , Canais de Potássio Ativados por Sódio/metabolismo , Receptores Purinérgicos P2X3/metabolismo , Células Receptoras Sensoriais/fisiologia , Trifosfato de Adenosina/farmacologia , Animais , Escala de Avaliação Comportamental , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Técnicas de Patch-Clamp , Nervos Periféricos/patologia , Canais de Potássio/metabolismo , Canais de Potássio/fisiologia , Canais de Potássio Ativados por Sódio/genética , Receptores Purinérgicos P2X3/fisiologia , Células Receptoras Sensoriais/efeitos dos fármacos , Células Receptoras Sensoriais/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
5.
Biomed Pharmacother ; 133: 111059, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33378963

RESUMO

Paclitaxel (PTX), a drug widely used in lung cancer, has serious limitations including the development of peripheral neurotoxicity, which may lead to treatment discontinuation and therapy failure. The transport of PTX in large cationic liposomes could avoid this undesirable effect, improving the patient's prognosis. PTX was encapsulated in cationic liposomes with two different sizes, MLV (180-200 nm) and SUV (80-100 nm). In both cases, excellent biocompatibility and improved internalization and antitumor effect of PTX were observed in human and mice lung cancer cells in culture, multicellular spheroids and cancer stem cells (CSCs). In addition, both MLV and SUV with a polyethylene glycol (PEG) shell, induced a greater tumor volume reduction than PTX (56.4 % and 57.1 % vs. 36.7 %, respectively) in mice. Interestingly, MLV-PEG-PTX did not induce either mechanical or heat hypersensitivity whereas SUV-PEG-PTX produced a similar response to free PTX. Analysis of PTX distribution showed a very low concentration of the drug in the dorsal root ganglia (DRG) with MLV-PEG-PTX, but not with SUV-PEG-PTX or free PTX. These results support the hypothesis that PTX induces peripheral neuropathy by penetrating the endothelial fenestrations of the DRG (80-100 nm, measured in mice). In conclusion, our larger liposomes (MLV-PEG-PTX) not only showed biocompatibility, antitumor activity against CSCs, and in vitro and in vivo antitumor effect that improved PTX free activity, but also protected from PTX-induced painful peripheral neuropathy. These advantages could be used as a new strategy of lung cancer chemotherapy to increase the PTX activity and reduce its side effects.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Lipídeos/química , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/administração & dosagem , Polietilenoglicóis/química , Células A549 , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Antineoplásicos Fitogênicos/toxicidade , Cátions , Proliferação de Células/efeitos dos fármacos , Composição de Medicamentos , Feminino , Gânglios Espinais/efeitos dos fármacos , Humanos , Lipossomos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos C57BL , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Paclitaxel/química , Paclitaxel/farmacocinética , Paclitaxel/toxicidade , Tamanho da Partícula , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/prevenção & controle , Carga Tumoral
6.
Mol Pharmacol ; 99(1): 49-59, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33298520

RESUMO

Voltage-gated sodium channels (Navs) are promising targets for analgesic and antiepileptic therapies. Although specificity between Nav subtypes may be desirable to target specific neural types, such as nociceptors in pain, many broadly acting Nav inhibitors are clinically beneficial in neuropathic pain and epilepsy. Here, we present the first systematic characterization of vixotrigine, a Nav blocker. Using recombinant systems, we find that vixotrigine potency is enhanced in a voltage- and use-dependent manner, consistent with a state-dependent block of Navs. Furthermore, we find that vixotrigine potently inhibits sodium currents produced by both peripheral and central nervous system Nav subtypes, with use-dependent IC50 values between 1.76 and 5.12 µM. Compared with carbamazepine, vixotrigine shows higher potency and more profound state-dependent inhibition but a similar broad spectrum of action distinct from Nav1.7- and Nav1.8-specific blockers. We find that vixotrigine rapidly inhibits Navs and prolongs recovery from the fast-inactivated state. In native rodent dorsal root ganglion sodium channels, we find that vixotrigine shifts steady-state inactivation curves. Based on these results, we conclude that vixotrigine is a broad-spectrum, state-dependent Nav blocker. SIGNIFICANCE STATEMENT: Vixotrigine blocks both peripheral and central voltage-gated sodium channel subtypes. Neurophysiological approaches in recombinant systems and sensory neurons suggest this block is state-dependent.


Assuntos
Éteres Fenílicos/metabolismo , Éteres Fenílicos/farmacologia , Prolina/análogos & derivados , Bloqueadores do Canal de Sódio Disparado por Voltagem/metabolismo , Bloqueadores do Canal de Sódio Disparado por Voltagem/farmacologia , Canais de Sódio Disparados por Voltagem/fisiologia , Animais , Células CHO , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/fisiologia , Células HEK293 , Humanos , Masculino , Éteres Fenílicos/química , Prolina/química , Prolina/metabolismo , Prolina/farmacologia , Ratos , Ratos Sprague-Dawley , Bloqueadores do Canal de Sódio Disparado por Voltagem/química , Canais de Sódio Disparados por Voltagem/química
7.
Nat Commun ; 11(1): 4178, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826895

RESUMO

Friedreich's ataxia (FRDA) is an autosomal-recessive neurodegenerative and cardiac disorder which occurs when transcription of the FXN gene is silenced due to an excessive expansion of GAA repeats into its first intron. Herein, we generate dorsal root ganglia organoids (DRG organoids) by in vitro differentiation of human iPSCs. Bulk and single-cell RNA sequencing show that DRG organoids present a transcriptional signature similar to native DRGs and display the main peripheral sensory neuronal and glial cell subtypes. Furthermore, when co-cultured with human intrafusal muscle fibers, DRG organoid sensory neurons contact their peripheral targets and reconstitute the muscle spindle proprioceptive receptors. FRDA DRG organoids model some molecular and cellular deficits of the disease that are rescued when the entire FXN intron 1 is removed, and not with the excision of the expanded GAA tract. These results strongly suggest that removal of the repressed chromatin flanking the GAA tract might contribute to rescue FXN total expression and fully revert the pathological hallmarks of FRDA DRG neurons.


Assuntos
Ataxia de Friedreich/genética , Ataxia de Friedreich/patologia , Gânglios Espinais/metabolismo , Edição de Genes/métodos , Proteínas de Ligação ao Ferro/genética , Organoides/metabolismo , Células Receptoras Sensoriais/metabolismo , Antioxidantes/farmacologia , Sistemas CRISPR-Cas , Diferenciação Celular , Cromatina/metabolismo , Ataxia de Friedreich/tratamento farmacológico , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/patologia , Predisposição Genética para Doença/genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Íntrons , Mitocôndrias/metabolismo , Organoides/efeitos dos fármacos , Organoides/patologia , Células Receptoras Sensoriais/patologia , Análise de Sequência de RNA , Transcriptoma
8.
Life Sci ; 257: 118112, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32682914

RESUMO

AIMS: STW 5 is an herbal drug combination used for the treatment of functional gastrointestinal disorders (FGIDs) with visceral hypersensitivity as the therapy-resistant hallmark. STW 5 has been clinically proven to alleviate visceral hypersensitivity-related symptoms, including abdominal pain, bloating, nausea, and early satiety. However, the molecular and cellular mechanisms underlying the antinociceptive action of STW 5 remain unknown. Here, we investigate the role of STW 5 in the calcium mobilisation of dorsal root ganglion (DRG) sensory neurons. MAIN METHODS: Calcium imaging experiments were performed with freshly dissociated cultured murine DRG neurons isolated from mice by microfluorometry. TRPA1-deficient DRGs, TRPV1-deficient DRGs, TRPA1/V1 double-deficient DRGs, and wild-type DRGs have been used to investigate the role of TRPs ion channels in mediating STW 5 action. KEY FINDINGS: STW 5 (1.74 and 5.8 mg/ml) induced calcium ion influx into DRG neurons in a concentration-dependent manner. Calcium transients were desensitised during repeated exposure to STW 5, an effect that was facilitated in TRPA1-deficient DRGs and less pronounced in TRPV1-deficient DRGs compared to wild-type (WT) DRGs. SIGNIFICANCE: Repeated exposure to STW 5 induced desensitisation of sensory neurons and may ultimately contribute to its proven clinical efficacy against sensory-related symptoms in patients with FGID, including abdominal pain, bloating, nausea, and early satiety. This effect is modulated by the two prominent irritant sensors in nociceptors, TRPA1 and TRPV1.


Assuntos
Gânglios Espinais/efeitos dos fármacos , Extratos Vegetais/farmacologia , Canais de Receptores Transientes de Potencial/efeitos dos fármacos , Animais , Cálcio/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Canal de Cátion TRPA1/metabolismo , Canais de Cátion TRPV/metabolismo
9.
PLoS One ; 15(6): e0234176, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497151

RESUMO

Chronic neuropathic pain (NP) is a growing clinical problem for which effective treatments, aside from non-steroidal anti-inflammatory drugs and opioids, are lacking. Cannabinoids are emerging as potentially promising agents to manage neuroimmune effects associated with nociception. In particular, Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and their combination are being considered as therapeutic alternatives for treatment of NP. This study aimed to examine whether sex affects long-term outcomes on persistent mechanical hypersensitivity 7 weeks after ceasing cannabinoid administration. Clinically relevant low doses of THC, CBD, and a 1:1 combination of THC:CBD extracts, in medium chain triglyceride (MCT) oil, were orally gavaged for 14 consecutive days to age-matched groups of male and female sexually mature Sprague Dawley rats. Treatments commenced one day after surgically inducing a pro-nociceptive state using a peripheral sciatic nerve cuff. The analgesic efficacy of each phytocannabinoid was assessed relative to MCT oil using hind paw mechanical behavioural testing once a week for 9 weeks. In vivo intracellular electrophysiology was recorded at endpoint to characterize soma threshold changes in primary afferent sensory neurons within dorsal root ganglia (DRG) innervated by the affected sciatic nerve. The thymus, spleen, and DRG were collected post-sacrifice and analyzed for long-term effects on markers associated with T lymphocytes at the RNA level using qPCR. Administration of cannabinoids, particularly the 1:1 combination of THC, elicited a sustained mechanical anti-hypersensitive effect in males with persistent peripheral NP, which corresponded to beneficial changes in myelinated Aß mechanoreceptive fibers. Specific immune cell markers associated with T cell differentiation and pro-inflammatory cytokines, previously implicated in repair processes, were differentially up-regulated by cannabinoids in males treated with cannabinoids, but not in females, warranting further investigation into sexual dimorphisms that may underlie treatment outcomes.


Assuntos
Analgésicos/administração & dosagem , Analgésicos/farmacologia , Canabidiol/efeitos adversos , Canabidiol/farmacologia , Dronabinol/administração & dosagem , Dronabinol/farmacologia , Óleos/química , Administração Oral , Analgésicos/química , Animais , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Canabidiol/química , Dronabinol/química , Composição de Medicamentos , Interações Medicamentosas , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley
10.
J Neurosci ; 40(18): 3517-3532, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32245829

RESUMO

One of the first signs of viral infection is body-wide aches and pain. Although this type of pain usually subsides, at the extreme, viral infections can induce painful neuropathies that can last for decades. Neither of these types of pain sensitization is well understood. A key part of the response to viral infection is production of interferons (IFNs), which then activate their specific receptors (IFNRs) resulting in downstream activation of cellular signaling and a variety of physiological responses. We sought to understand how type I IFNs (IFN-α and IFN-ß) might act directly on nociceptors in the dorsal root ganglion (DRG) to cause pain sensitization. We demonstrate that type I IFNRs are expressed in small/medium DRG neurons and that their activation produces neuronal hyper-excitability and mechanical pain in mice. Type I IFNs stimulate JAK/STAT signaling in DRG neurons but this does not apparently result in PKR-eIF2α activation that normally induces an anti-viral response by limiting mRNA translation. Rather, type I IFNs stimulate MNK-mediated eIF4E phosphorylation in DRG neurons to promote pain hypersensitivity. Endogenous release of type I IFNs with the double-stranded RNA mimetic poly(I:C) likewise produces pain hypersensitivity that is blunted in mice lacking MNK-eIF4E signaling. Our findings reveal mechanisms through which type I IFNs cause nociceptor sensitization with implications for understanding how viral infections promote pain and can lead to neuropathies.SIGNIFICANCE STATEMENT It is increasingly understood that pathogens interact with nociceptors to alert organisms to infection as well as to mount early host defenses. Although specific mechanisms have been discovered for diverse bacterial and fungal pathogens, mechanisms engaged by viruses have remained elusive. Here we show that type I interferons, one of the first mediators produced by viral infection, act directly on nociceptors to produce pain sensitization. Type I interferons act via a specific signaling pathway (MNK-eIF4E signaling), which is known to produce nociceptor sensitization in inflammatory and neuropathic pain conditions. Our work reveals a mechanism through which viral infections cause heightened pain sensitivity.


Assuntos
Viroses do Sistema Nervoso Central/metabolismo , Interferon Tipo I/toxicidade , Nociceptores/metabolismo , Limiar da Dor/fisiologia , Dor/metabolismo , Doenças do Sistema Nervoso Periférico/metabolismo , Animais , Células Cultivadas , Viroses do Sistema Nervoso Central/induzido quimicamente , Viroses do Sistema Nervoso Central/patologia , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Gânglios Espinais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Nociceptores/efeitos dos fármacos , Nociceptores/patologia , Dor/induzido quimicamente , Dor/patologia , Limiar da Dor/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/patologia
11.
Am J Pathol ; 190(7): 1530-1544, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32246920

RESUMO

HIV-associated sensory neuropathy is a common neurologic comorbidity of HIV infection and prevails in the post-antiretroviral therapy (ART) era. HIV infection drives pathologic changes in the dorsal root ganglia (DRG) through inflammation, altered metabolism, and neuronal dysfunction. Herein, we characterized specific neuronal populations in an SIV-infected macaque model with or without ART. DRG neuronal populations were identified by neurofilament H-chain 200, I-B4 isolectin (IB4), or tropomyosin receptor kinase A expression and assessed for cell body diameter, population size, apoptotic markers, and regeneration signaling. IB4+ and tropomyosin receptor kinase A-positive neurons showed a reduced cell body size (atrophy) and decreased population size (cell death) in the DRG of SIV-infected animals compared with uninfected animals. IB4+ nonpeptidergic neurons were less affected in the presence of ART. DRG neurons showed accumulation of cleaved caspase 3 (apoptosis) and nuclear-localized activating transcription factor 3 (regeneration) in SIV infection, which was significantly lower in uninfected animals and SIV-infected animals receiving ART. Nonpeptidergic neurons predominantly colocalized with cleaved caspase 3 staining. Nonpeptidergic and peptidergic neurons colocalized with nuclear-accumulated activating transcription factor 3, showing active regeneration in sensory neurons. These data suggest that nonpeptidergic and peptidergic neurons are susceptible to pathologic changes from SIV infection, and intervention with ART did not fully ameliorate damage to the DRG, specifically to peptidergic neurons.


Assuntos
Atrofia/patologia , Nociceptores/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Animais , Antirretrovirais/farmacologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/patologia , Lectinas/metabolismo , Macaca mulatta , Masculino , Nociceptores/efeitos dos fármacos , Nociceptores/metabolismo , Polineuropatias/patologia , Polineuropatias/virologia , Receptor trkA/metabolismo , Vírus da Imunodeficiência Símia
12.
Chin J Integr Med ; 26(3): 197-204, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32180149

RESUMO

OBJECTIVE: To investigate protective effects of hirudin on oxidative stress and apoptosis of spinal dorsal root ganglion cells in high-glucose rats at the cellular and molecular level. METHODS: Dorsal root ganglion neurons (DRGn) were harvested from embryonic day in 15 SD rats, purified and identificated after primary culture. They were divided into the normal control group, high-glucose (HG) group, positive control (alpha-lipoic acid, ALA) group, low-dose hirudin group (H1), medium-dose hirudin group (H2) and high-dose hirudin group (H3). The control group was cultured by neuron specific culture medium, while the HG group was cultured by neuron specific culture medium and 20 mmol/L glucose (HG medium). The hirudin groups were cultured by HG medium+0.25 IU/mL hirudin (H1), HG medium+0.5 IU/mL hirudin (H2) and HG medium+1 IU/mL hirudin (H3). The ALA group was cultured by HG medium+100 µ mol/L ALA. 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenylt etrazolium bromide (MTT) assay was used to explore the optimum concentration and intervention time. Flow cytometry assay was used to detect the level of reactive oxygen series (ROS). Western blot and quantificational realtime polymerase chain reaction (qRT-PCR) were used to detect the expression of protein and mRNA of nuclear factor erythroid 2-related factor 2 (Nrf-2), hemeoxygence-1 (HO-1), nuclear factor-κ B (NF-κ B) and Caspase-3. TUNEL assay was used to test the apoptosis rate of different groups. RESULTS: After 24 h of culture, the cell activity of hirudin and ALA groups were higher than that of HG group, and there was a statistical difference between the H1 group and HG group (P<0.05). In hirudin groups, the apoptosis rate of cells, the expression of activated Caspase-3 protein and Caspase-3 mRNA were lower than those of HG group (P<0.01), higher than those of ALA group (P<0.01 or P<0.05). The ROS level of hirudin groups was higher than that of ALA group (P<0.01), lower than that of HG group (P<0.01 or P<0.05). The expression of NF-κ B (P65) protein in H3 group were lower than those of HG group (P<0.05). The expression of Nrf-2 protein in hirudin groups was higher than that of HG group (P<0.01), lower than that of ALA group (P<0.01 or P<0.05). The expression of HO-1 protein in hirudin groups was lower than that of ALA group (P<0.01 or P<0.05), higher than that of HG group (P<0.01 or P<0.05). CONCLUSIONS: The activity of DRGn cells can be promoted by hirudin under HG conditions. The effects of hirudin on the inhibition of HG on DRGn cells damage mainly include scavenging ROS, up-regulating Nrf-2/HO-1 pathway, inhibiting activation of NF-κ B pathway, down-regulating the expression of and Caspase-3 and reducing DRGn cell apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Gânglios Espinais/efeitos dos fármacos , Hirudinas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Caspase 3/metabolismo , China , Modelos Animais de Doenças , Heme Oxigenase (Desciclizante)/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Transcrição RelA/metabolismo
13.
Am J Physiol Lung Cell Mol Physiol ; 318(5): L953-L964, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32159971

RESUMO

The lungs and the immune and nervous systems functionally interact to respond to respiratory environmental exposures and infections. The lungs are innervated by vagal sensory neurons of the jugular and nodose ganglia, fused together in smaller mammals as the jugular-nodose complex (JNC). Whereas the JNC shares properties with the other sensory ganglia, the trigeminal (TG) and dorsal root ganglia (DRG), these sensory structures express differential sets of genes that reflect their unique functionalities. Here, we used RNA sequencing (RNA-seq) in mice to identify the differential transcriptomes of the three sensory ganglia types. Using a fluorescent retrograde tracer and fluorescence-activated cell sorting, we isolated a defined population of airway-innervating JNC neurons and determined their differential transcriptional map after pulmonary exposure to lipopolysaccharide (LPS), a major mediator of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after infection with gram-negative bacteria or inhalation of organic dust. JNC neurons activated an injury response program, leading to increased expression of gene products such as the G protein-coupled receptor Cckbr, inducing functional changes in neuronal sensitivity to peptides, and Gpr151, also rapidly induced upon neuropathic nerve injury in pain models. Unique JNC-specific transcripts, present at only minimal levels in TG, DRG, and other organs, were identified. These included TMC3, encoding for a putative mechanosensor, and urotensin 2B, a hypertensive peptide. These findings highlight the unique properties of the JNC and reveal that ALI/ARDS rapidly induces a nerve injury-related state, changing vagal excitability.


Assuntos
Gânglio Nodoso/efeitos dos fármacos , Pneumonia/genética , Receptor de Colecistocinina B/genética , Células Receptoras Sensoriais/efeitos dos fármacos , Transcriptoma , Traumatismos do Nervo Vago/genética , Animais , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/imunologia , Gânglios Espinais/patologia , Perfilação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Gânglio Nodoso/imunologia , Gânglio Nodoso/patologia , Hormônios Peptídicos/genética , Hormônios Peptídicos/imunologia , Pneumonia/induzido quimicamente , Pneumonia/imunologia , Pneumonia/patologia , Receptor de Colecistocinina B/imunologia , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/imunologia , Células Receptoras Sensoriais/imunologia , Células Receptoras Sensoriais/patologia , Análise de Sequência de RNA , Gânglio Trigeminal/efeitos dos fármacos , Gânglio Trigeminal/imunologia , Gânglio Trigeminal/patologia , Traumatismos do Nervo Vago/induzido quimicamente , Traumatismos do Nervo Vago/imunologia , Traumatismos do Nervo Vago/patologia
14.
J Med Chem ; 63(7): 3577-3595, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32141297

RESUMO

Free fatty acid receptor 3 (FFA3, previously GPR41) is activated by short-chain fatty acids, mediates health effects of the gut microbiota, and is a therapeutic target for metabolic and inflammatory diseases. The shortage of well-characterized tool compounds has however impeded progress. Herein, we report structure-activity relationship of an allosteric modulator series and characterization of physicochemical and pharmacokinetic properties of selected compounds, including previous and new tools. Two representatives, 57 (TUG-1907) and 63 (TUG-2015), showed improved solubility and preserved potency. Of these, 57, with EC50 = 145 nM and a solubility of 33 µM, showed high clearance in vivo but is a preferred tool in vitro. In contrast, 63, with EC50 = 162 nM and a solubility of 9 µM, showed lower clearance and seems better suited for in vivo studies. Using 57, we demonstrate for the first time that FFA3 activation leads to calcium mobilization in murine dorsal root ganglia.


Assuntos
Quinolonas/farmacologia , Receptores Acoplados a Proteínas-G/metabolismo , Regulação Alostérica , Animais , Estabilidade de Medicamentos , Gânglios Espinais/efeitos dos fármacos , Humanos , Camundongos Knockout , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Quinolonas/síntese química , Quinolonas/metabolismo , Quinolonas/farmacocinética , Receptores Acoplados a Proteínas-G/genética , Relação Estrutura-Atividade
15.
J Med Chem ; 63(7): 3665-3677, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32162512

RESUMO

TWIK-related K+ (TREK) channels are potential analgesic targets. However, selective activators for TREK with both defined action mechanism and analgesic ability for chronic pain have been lacking. Here, we report (1S,3R)-3-((4-(6-methylbenzo[d]thiazol-2-yl)phenyl)carbamoyl)cyclopentane-1-carboxylic acid (C3001a), a selective activator for TREK, against other two-pore domain K+ (K2P) channels. C3001a binds to the cryptic binding site formed by P1 and TM4 in TREK-1, as suggested by computational modeling and experimental analysis. Furthermore, we identify the carboxyl group of C3001a as a structural determinant for binding to TREK-1/2 and the key residue that defines the subtype selectivity of C3001a. C3001a targets TREK channels in the peripheral nervous system to reduce the excitability of nociceptive neurons. In neuropathic pain, C3001a alleviated spontaneous pain and cold hyperalgesia. In a mouse model of acute pancreatitis, C3001a alleviated mechanical allodynia and inflammation. Together, C3001a represents a lead compound which could advance the rational design of peripherally acting analgesics targeting K2P channels without opioid-like adverse effects.


Assuntos
Analgésicos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Benzotiazóis/uso terapêutico , Inflamação Neurogênica/tratamento farmacológico , Dor/tratamento farmacológico , Canais de Potássio de Domínios Poros em Tandem/agonistas , Analgésicos/metabolismo , Analgésicos/farmacocinética , Animais , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/farmacocinética , Benzotiazóis/metabolismo , Benzotiazóis/farmacocinética , Sítios de Ligação , Gânglios Espinais/efeitos dos fármacos , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Estrutura Molecular , Pancreatite/tratamento farmacológico , Canais de Potássio de Domínios Poros em Tandem/química , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Ligação Proteica , Ratos Sprague-Dawley , Relação Estrutura-Atividade
16.
Proc Natl Acad Sci U S A ; 117(10): 5494-5501, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32079727

RESUMO

Somatosensory neurons have historically been classified by a variety of approaches, including structural, anatomical, and genetic markers; electrophysiological properties; pharmacological sensitivities; and more recently, transcriptional profile differentiation. These methodologies, used separately, have yielded inconsistent classification schemes. Here, we describe phenotypic differences in response to pharmacological agents as measured by changes in cytosolic calcium concentration for the rapid classification of neurons in vitro; further analysis with genetic markers, whole-cell recordings, and single-cell transcriptomics validated these findings in a functional context. Using this general approach, which we refer to as tripartite constellation analysis (TCA), we focused on large-diameter dorsal-root ganglion (L-DRG) neurons with myelinated axons. Divergent responses to the K-channel antagonist, κM-conopeptide RIIIJ (RIIIJ), reliably identified six discrete functional cell classes. In two neuronal subclasses (L1 and L2), block with RIIIJ led to an increase in [Ca] i Simultaneous electrophysiology and calcium imaging showed that the RIIIJ-elicited increase in [Ca] i corresponded to different patterns of action potentials (APs), a train of APs in L1 neurons, and sporadic firing in L2 neurons. Genetically labeled mice established that L1 neurons are proprioceptors. The single-cell transcriptomes of L1 and L2 neurons showed that L2 neurons are Aδ-low-threshold mechanoreceptors. RIIIJ effects were replicated by application of the Kv1.1 selective antagonist, Dendrotoxin-K, in several L-DRG subclasses (L1, L2, L3, and L5), suggesting the presence of functional Kv1.1/Kv1.2 heteromeric channels. Using this approach on other neuronal subclasses should ultimately accelerate the comprehensive classification and characterization of individual somatosensory neuronal subclasses within a mixed population.


Assuntos
Gânglios Espinais/citologia , Células Receptoras Sensoriais/classificação , Células Receptoras Sensoriais/fisiologia , Animais , Cálcio/metabolismo , Conotoxinas/farmacologia , Citosol/metabolismo , Gânglios Espinais/efeitos dos fármacos , Canal de Potássio Kv1.1/antagonistas & inibidores , Camundongos , Camundongos Transgênicos , Peptídeos/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Células Receptoras Sensoriais/efeitos dos fármacos , Análise de Célula Única , Transcriptoma
17.
Anesthesiology ; 132(4): 867-880, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32011337

RESUMO

BACKGROUND: Recent emerging evidence suggests that extra-adrenal synthesis of aldosterone occurs (e.g., within the failing heart and in certain brain areas). In this study, the authors investigated evidence for a local endogenous aldosterone production through its key processing enzyme aldosterone synthase within peripheral nociceptive neurons. METHODS: In male Wistar rats (n = 5 to 8 per group) with Freund's complete adjuvant hind paw inflammation, the authors examined aldosterone, aldosterone synthase, and mineralocorticoid receptor expression in peripheral sensory neurons using quantitative reverse transcriptase-polymerase chain reaction, Western blot, immunohistochemistry, and immunoprecipitation. Moreover, the authors explored the nociceptive behavioral changes after selective mineralocorticoid receptor antagonist, canrenoate-K, or specific aldosterone synthase inhibitor application. RESULTS: In rats with Freund's complete adjuvant-induced hind paw inflammation subcutaneous and intrathecal application of mineralocorticoid receptor antagonist, canrenoate-K, rapidly and dose-dependently attenuated nociceptive behavior (94 and 48% reduction in mean paw pressure thresholds, respectively), suggesting a tonic activation of neuronal mineralocorticoid receptors by an endogenous ligand. Indeed, aldosterone immunoreactivity was abundant in peptidergic nociceptive neurons of dorsal root ganglia and colocalized predominantly with its processing enzyme aldosterone synthase and mineralocorticoid receptors. Moreover, aldosterone and its synthesizing enzyme were significantly upregulated in peripheral sensory neurons under inflammatory conditions. The membrane mineralocorticoid receptor consistently coimmunoprecipitated with endogenous aldosterone, confirming a functional link between mineralocorticoid receptors and its endogenous ligand. Importantly, inhibition of endogenous aldosterone production in peripheral sensory neurons by a specific aldosterone synthase inhibitor attenuated nociceptive behavior after hind paw inflammation (a 32% reduction in paw pressure thresholds; inflammation, 47 ± 2 [mean ± SD] vs. inflammation + aldosterone synthase inhibitor, 62 ± 2). CONCLUSIONS: Local production of aldosterone by its processing enzyme aldosterone synthase within peripheral sensory neurons contributes to ongoing mechanical hypersensitivity during local inflammation via intrinsic activation of neuronal mineralocorticoid receptors.


Assuntos
Citocromo P-450 CYP11B2/biossíntese , Hiperalgesia/metabolismo , Medição da Dor/métodos , Células Receptoras Sensoriais/metabolismo , Adjuvantes Imunológicos/toxicidade , Aldosterona/biossíntese , Animais , Adjuvante de Freund/toxicidade , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Masculino , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Medição da Dor/efeitos dos fármacos , Estimulação Física/efeitos adversos , Ratos , Ratos Wistar , Células Receptoras Sensoriais/efeitos dos fármacos
18.
Pain Res Manag ; 2020: 3740162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32104520

RESUMO

Background: Treatment of diabetic neuropathic pain (DNP) continues to be a major challenge, and underlying mechanisms of DNP remain elusive. We investigated treatment effects of B vitamins on DPN- and DNP-associated alterations of neurochemical signaling in the nociceptive dorsal root ganglion (DRG) neurons and the spinal cord in rats. Methods: DNP was produced in male, adult, Sprague Dawley rats by single i.p. streptozotocin (STZ). Western blot analysis and immunohistochemistry were used to analyze protein expressions in DRG and ELISA to measure the proinflammatory cytokines in the spinal cord. Behaviorally expressed DNP was determined by measuring the sensitivity of hindpaw skin to mechanical and thermal stimulation. Results: There were 87.5% (77/88) rats which developed high blood glucose within 1-2 weeks following STZ injection. Of which, 70.13% (n = 54/77) animals exhibited DNP manifested as mechanical allodynia and/or thermal hyperalgesia. Intraperitoneal administration of vitamins B1/B6/B12 (100/100/2 mg/kg, one or multiple doses) significantly attenuated DNP without affecting the blood glucose. Expressions of P2X3 and TRPV1 in CGRP-positive and IB4-positive DRG neurons as well as the interleukin-1ß, tumor necrosis factor-α, and nerve growth factor in the lumbar spinal cord were greatly increased in DNP rats. Such DNP-associated neurochemical alterations were also greatly suppressed by the B-vitamin treatment. Conclusions: B-vitamin treatment can greatly suppress chronic DNP and DNP-associated increased activities of P2X3 and TRPV1 in DRG and the spinal proinflammatory cytokines, which may contribute to the pathogenesis of DNP. Systematic administration of B vitamins can be a strategy for DNP management in clinic.


Assuntos
Neuropatias Diabéticas , Gânglios Espinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Complexo Vitamínico B/farmacologia , Animais , Citocinas/efeitos dos fármacos , Citocinas/metabolismo , Diabetes Mellitus Experimental/complicações , Gânglios Espinais/metabolismo , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Purinérgicos P2X3/metabolismo , Medula Espinal/metabolismo , Canais de Cátion TRPV/efeitos dos fármacos , Canais de Cátion TRPV/metabolismo
19.
Invest Ophthalmol Vis Sci ; 61(1): 4, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31999819

RESUMO

Purpose: Neurotrophic keratopathy is a degenerative disease that may be improved by nerve growth factor (NGF). Our aim was to investigate the use of pergolide, a dopamine (D1 and D2) receptor agonist known to increase the synthesis and release of NGF for regeneration of damaged corneal nerve fibers. Methods: Pergolide function was evaluated by measuring axon length and NGF levels by enzyme-linked immunosorbent assay in cultured chicken dorsal root ganglion (DRG) cells with serial doses of pergolide (10, 25, 50, 150, and 300 µg/ml) and with different concentrations of a D1 antagonist. Pergolide function was further evaluated by cornea nerve fiber density and wound healing in a cornea scratch mouse model. Results: Pergolide increased DRG axon length significantly at a dose between 50 and 300 µg/ml. Different concentrations of D1 antagonist (12, 24, 48, and 96 µg/ml) inhibited DRG axon length growth with pergolide (300 µg/ml). Pergolide (50 µg/ml) upregulated NGF expression in DRG cells at both 24 hours and 48 hours. Pergolide improved cornea nerve fiber density at both 1 week and 2 weeks. Pergolide also improved cornea wound healing. Conclusions: We demonstrated that pergolide can act to promote an increase in NGF which promotes corneal nerve regeneration and would therefore improve corneal sensation and visual acuity in eyes with peripheral neurotrophic keratopathy.


Assuntos
Lesões da Córnea/tratamento farmacológico , Agonistas de Dopamina/uso terapêutico , Fibras Nervosas/efeitos dos fármacos , Pergolida/uso terapêutico , Animais , Axônios/efeitos dos fármacos , Galinhas , Agonistas de Dopamina/farmacologia , Gânglios Espinais/efeitos dos fármacos , Camundongos , Regeneração Nervosa , Pergolida/farmacologia , Cicatrização/fisiologia
20.
Biochem Pharmacol ; 174: 113826, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31987857

RESUMO

BACKGROUND: Volatile anaesthetics (VAs) are the most widely used compounds to induce reversible loss of consciousness and maintain general anaesthesia during surgical interventions. Although the mechanism of their action is not yet fully understood, it is generally believed, that VAs depress central nervous system functions mainly through modulation of ion channels in the neuronal membrane, including 2-pore-domain K+ channels, GABA and NMDA receptors. Recent research also reported their action on nociceptive and thermosensitive TRP channels expressed in the peripheral nervous system, including TRPV1, TRPA1, and TRPM8. Here, we investigated the effect of VAs on TRPM3, a less characterized member of the thermosensitive TRP channels playing a central role in noxious heat sensation. METHODS: We investigated the effect of VAs on the activity of recombinant and native TRPM3, by monitoring changes in the intracellular Ca2+ concentration and measuring TRPM3-mediated transmembrane currents. RESULTS: All the investigated VAs (chloroform, halothane, isoflurane, sevoflurane) inhibited both the agonist-induced (pregnenolone sulfate, CIM0216) and heat-activated Ca2+ signals and transmembrane currents in a concentration dependent way in HEK293T cells overexpressing recombinant TRPM3. Among the tested VAs, halothane was the most potent blocker (IC50 = 0.52 ± 0.05 mM). We also investigated the effect of VAs on native TRPM3 channels expressed in sensory neurons of the dorsal root ganglia. While VAs activated certain sensory neurons independently of TRPM3, they strongly and reversibly inhibited the agonist-induced TRPM3 activity. CONCLUSIONS: These data provide a better insight into the molecular mechanism beyond the analgesic effect of VAs and propose novel strategies to attenuate TRPM3 dependent nociception.


Assuntos
Anestésicos Inalatórios/farmacologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Canais de Cátion TRPM/antagonistas & inibidores , Canais de Cátion TRPM/metabolismo , Animais , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL
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