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1-Deoxysphingolipid-induced neurotoxicity involves N-methyl-d-aspartate receptor signaling

Citation

Guntert, T and Hanggi, P and Othman, A and Suriyanarayanan, S and Sonda, S and Zuelling, RA and Hornemann, T and Ogunshola, OO, 1-Deoxysphingolipid-induced neurotoxicity involves N-methyl-d-aspartate receptor signaling, Neuropharmacology, 110 pp. 211-222. ISSN 0028-3908 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 Elsevier Ltd.

DOI: doi:10.1016/j.neuropharm.2016.03.033

Abstract

1-Deoxysphingolipids (1-deoxySL) are atypical and neurotoxic sphingolipids formed by alternate substrate usage of the enzyme serine-palmitoyltransferase. Pathologically increased 1-deoxySL formation causes hereditary sensory and autosomal neuropathy type 1 (HSAN1) - a progressive peripheral axonopathy. However, the underlying molecular mechanisms by which 1-deoxySL acts are unknown. Herein we studied the effect of 1-deoxysphinganine (1-deoxySA) and its canonical counterpart sphinganine (SA) in aged cultured neurons comparing their outcome on cell survival and cytoskeleton integrity. 1-deoxySA caused rapid neuronal cytoskeleton disruption and modulated important cytoskeletal regulatory and associated components including Rac1, Ezrin and insulin receptor substrate 53. We show that 1-deoxySA is internalized and metabolized downstream to 1-deoxydihydroceramide since inhibition of ceramide synthase protected neurons from 1-deoxySA-mediated cell death. In addition, 1-deoxySA reduced protein levels of N-methyl-d-aspartate receptor (NMDAR) subunit GluN2B, the postsynaptic density protein 95 and induced cleavage of p35 to p25. Notably, blocking NMDAR activation by MK-801 or memantine significantly prevented 1-deoxySA neurotoxicity. Functional studies of differentiating primary neurons via the patch-clamp technique demonstrated that 1-deoxySA irreversibly depolarizes the neuronal membrane potential in an age-dependent manner. Notably, only neuronal cells that displayed functional NMDAR- and NMDA-induced whole-cell currents responded to 1-deoxySA treatment. Furthermore, pre-exposure to the non-competitive antagonist MK-801 blocked the current response of NMDA and glycine, as well as 1-deoxySA. We conclude that 1-deoxySA-induced neurotoxicity compromises cytoskeletal stability and targets NMDAR signaling in an age-dependent manner. Thus stabilization of cytoskeletal structures and/or inhibition of glutamate receptors could be a potential therapeutic approach to prevent 1-deoxySA-induced neurodegeneration.

Item Details

Item Type:Refereed Article
Keywords:Deoxysphingolipids, neurons, cytotoxicity
Research Division:Biological Sciences
Research Group:Biochemistry and cell biology
Research Field:Signal transduction
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Sonda, S (Dr Sabrina Sonda)
ID Code:127549
Year Published:2016
Web of Science® Times Cited:20
Deposited By:Health Sciences
Deposited On:2018-08-02
Last Modified:2018-09-12
Downloads:0

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