NAD+ attenuates bilirubin-induced augmentation of voltage-gated calcium currents in neurons of the ventral cochlear nucleus

Neurosci Lett. 2022 Jul 27:784:136747. doi: 10.1016/j.neulet.2022.136747. Epub 2022 Jun 18.

Abstract

Nicotinamide adenine dinucleotide (NAD+) is a ubiquitous molecule with wide-ranging roles in several cell processes, such as regulation of calcium homeostasis and protection against cell injuries. However, the roles of NAD+ in neuroprotection is poorly understood. The main neurons in ventral cochlear nucleus (VCN) are highly susceptible to bilirubin-associated excitotoxicity. We investigated the effects of NAD+ on VCN neurons by whole cell patch-clamp recordings. We found that NAD+ effectively reverses and inhibits bilirubin-mediated enhancement of voltage-gated calcium (VGCC) currents in VCN neurons. Moreover, NAD+ itself did not affect VGCC currents. These results collectively suggest that NAD+ may be neuroprotective by attenuating Ca2+ influx to suppress bilirubin-induced intracellular Ca2+ overloads. Our research provides a basis for evaluation of NAD+ as a promising therapeutic target for bilirubin encephalopathy and excitotoxicity associated with other neurological disorders.

Keywords: Bilirubin encephalopathy; Ca(2+) overload; Nicotinamide adenine dinucleotide; Ventral cochlear nucleus; Voltage-gated calcium channels; Whole-cell patch-clamp recording.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bilirubin / pharmacology
  • Calcium
  • Cochlear Nucleus*
  • NAD / pharmacology
  • Neurons

Substances

  • NAD
  • Bilirubin
  • Calcium