Hereditary sensory neuropathy type 1-associated deoxysphingolipids cause neurotoxicity, acute calcium handling abnormalities and mitochondrial dysfunction in vitro.
Neurobiol Dis
; 117: 1-14, 2018 09.
Article
en En
| MEDLINE
| ID: mdl-29778900
ABSTRACT
Hereditary sensory neuropathy type 1 (HSN-1) is a peripheral neuropathy most frequently caused by mutations in the SPTLC1 or SPTLC2 genes, which code for two subunits of the enzyme serine palmitoyltransferase (SPT). SPT catalyzes the first step of de novo sphingolipid synthesis. Mutations in SPT result in a change in enzyme substrate specificity, which causes the production of atypical deoxysphinganine and deoxymethylsphinganine, rather than the normal enzyme product, sphinganine. Levels of these abnormal compounds are elevated in blood of HSN-1 patients and this is thought to cause the peripheral motor and sensory nerve damage that is characteristic of the disease, by a largely unresolved mechanism. In this study, we show that exogenous application of these deoxysphingoid bases causes dose- and time-dependent neurotoxicity in primary mammalian neurons, as determined by analysis of cell survival and neurite length. Acutely, deoxysphingoid base neurotoxicity manifests in abnormal Ca2+ handling by the endoplasmic reticulum (ER) and mitochondria as well as dysregulation of cell membrane store-operated Ca2+ channels. The changes in intracellular Ca2+ handling are accompanied by an early loss of mitochondrial membrane potential in deoxysphingoid base-treated motor and sensory neurons. Thus, these results suggest that exogenous deoxysphingoid base application causes neuronal mitochondrial dysfunction and Ca2+ handling deficits, which may play a critical role in the pathogenesis of HSN-1.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Esfingolípidos
/
Neuropatías Hereditarias Sensoriales y Autónomas
/
Calcio
/
Mitocondrias
/
Neuronas Motoras
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Neurobiol Dis
Asunto de la revista:
NEUROLOGIA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Reino Unido