Nicotinamide riboside, a form of vitamin B 3, protects against excitotoxicity-induced axonal degeneration

FASEB J. 2017 Dec;31(12):5440-5452. doi: 10.1096/fj.201700221RR. Epub 2017 Aug 21.

Abstract

NAD+ depletion is a common phenomenon in neurodegenerative pathologies. Excitotoxicity occurs in multiple neurologic disorders and NAD+ was shown to prevent neuronal degeneration in this process through mechanisms that remained to be determined. The activity of nicotinamide riboside (NR) in neuroprotective models and the recent description of extracellular conversion of NAD+ to NR prompted us to probe the effects of NAD+ and NR in protection against excitotoxicity. Here, we show that intracortical administration of NR but not NAD+ reduces brain damage induced by NMDA injection. Using cortical neurons, we found that provision of extracellular NR delays NMDA-induced axonal degeneration (AxD) much more strongly than extracellular NAD+ Moreover, the stronger effect of NR compared to NAD+ depends of axonal stress since in AxD induced by pharmacological inhibition of nicotinamide salvage, both NAD+ and NR prevent neuronal death and AxD in a manner that depends on internalization of NR. Taken together, our findings demonstrate that NR is a better neuroprotective agent than NAD+ in excitotoxicity-induced AxD and that axonal protection involves defending intracellular NAD+ homeostasis.-Vaur, P., Brugg, B., Mericskay, M., Li, Z., Schmidt, M. S., Vivien, D., Orset, C., Jacotot, E., Brenner, C., Duplus, E. Nicotinamide riboside, a form of vitamin B3, protects against excitotoxicity-induced axonal degeneration.

Keywords: FK866; NAD+; NMDA; NR; cortical neurons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / drug effects*
  • Axons / metabolism*
  • Cell Death / drug effects
  • Cells, Cultured
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • N-Methylaspartate / pharmacology
  • Neurons / drug effects
  • Neurons / metabolism
  • Neuroprotective Agents / pharmacology
  • Niacinamide / analogs & derivatives*
  • Niacinamide / pharmacology
  • Real-Time Polymerase Chain Reaction

Substances

  • Neuroprotective Agents
  • nicotinamide-beta-riboside
  • Niacinamide
  • N-Methylaspartate