Loss-of-function of Nav1.8/D1639N linked to human pain can be rescued by lidocaine.
Pflugers Arch
; 470(12): 1787-1801, 2018 12.
Article
em En
| MEDLINE
| ID: mdl-30099632
ABSTRACT
Mutations in voltage-gated sodium channels are associated with altered pain perception in humans. Most of these mutations studied to date present with a direct and intuitive link between the altered electrophysiological function of the channel and the phenotype of the patient. In this study, we characterize a variant of Nav1.8, D1639N, which has been previously identified in a patient suffering from the chronic pain syndrome "small fiber neuropathy". Using a heterologous expression system and patch-clamp analysis, we show that Nav1.8/D1639N reduces current density without altering biophysical gating properties of Nav1.8. Therefore, the D1639N variant causes a loss-of-function of the Nav1.8 sodium channel in a patient suffering from chronic pain. Using immunocytochemistry and biochemical approaches, we show that Nav1.8/D1639N impairs trafficking of the channel to the cell membrane. Neither co-expression of ß1 or ß3 subunit, nor overnight incubation at 27 °C rescued current density of the D1639N variant. On the other hand, overnight incubation with lidocaine fully restored current density of Nav1.8/D1639N most likely by overcoming the trafficking defect, whereas phenytoin failed to do so. Since lidocaine rescues the loss-of-function of Nav1.8/D1639N, it may offer a future therapeutic option for the patient carrying this variant. These results demonstrate that the D1639N variant, identified in a patient suffering from chronic pain, causes loss-of-function of the channel due to impaired cell surface trafficking and that this trafficking defect can be rescued by lidocaine.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Dor Crônica
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Canal de Sódio Disparado por Voltagem NAV1.8
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Mutação com Perda de Função
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Anestésicos Locais
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Lidocaína
Limite:
Animals
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Humans
Idioma:
En
Revista:
Pflugers Arch
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Alemanha