Docosahexanoic acid signals through the Nrf2-Nqo1 pathway to maintain redox balance and promote neurite outgrowth

Mol Biol Cell. 2021 Apr 1;32(7):511-520. doi: 10.1091/mbc.E20-09-0599. Epub 2021 Jan 27.

Abstract

Evidence suggests that n-3 polyunsaturated fatty acids may act as activators of the Nrf2 antioxidant pathway. The antioxidant response, in turn, promotes neuronal differentiation and neurite outgrowth. Nrf2 has recently been suggested to be a cell intrinsic mediator of docosohexanoic acid (DHA) signaling. In the current study, we assessed whether DHA-mediated axodendritic development was dependent on activation of the Nrf2 pathway and whether Nrf2 protected from agrochemical-induced neuritic retraction. Expression profiling of the DHA-enriched Fat-1 mouse brain relative to wild type showed a significant enrichment of genes associated with neuronal development and neuronal projection and genes associated with the Nrf2-transcriptional pathway. Moreover, we found that primary cortical neurons treated with DHA showed a dose-dependent increase in Nrf2 transcriptional activity and Nrf2-target gene expression. DHA-mediated activation of Nrf2 promoted neurite outgrowth and inhibited oxidative stress-induced neuritic retraction evoked by exposure to agrochemicals. Finally, we provide evidence that this effect is largely dependent on induction of the Nrf2-target gene NAD(P)H: (quinone acceptor) oxidoreductase 1 (NQO1), and that silencing of either Nrf2 or Nqo1 blocks the effects of DHA on the axodendritic compartment. Collectively, these data support a role for the Nrf2-NQO1 pathway in DHA-mediated axodendritic development and protection from agrochemical exposure.

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Cell Line, Tumor
  • Dendrites / metabolism
  • Docosahexaenoic Acids / pharmacology
  • Humans
  • Mice
  • NAD(P)H Dehydrogenase (Quinone) / metabolism*
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism*
  • Neuronal Outgrowth / genetics
  • Neuronal Outgrowth / physiology*
  • Neurons / metabolism
  • Oxidation-Reduction
  • Oxidative Stress / drug effects
  • Signal Transduction / drug effects
  • Transcription, Genetic / drug effects

Substances

  • Antioxidants
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • Nfe2l2 protein, mouse
  • Docosahexaenoic Acids
  • NAD(P)H Dehydrogenase (Quinone)
  • NQO1 protein, human
  • Nqo1 protein, mouse