Mitogen-activated protein kinases regulate expression of neuronal nitric oxide synthase and neurite outgrowth via non-classical retinoic acid receptor signaling in human neuroblastoma SH-SY5Y cells

J Pharmacol Sci. 2015 Oct;129(2):119-26. doi: 10.1016/j.jphs.2015.09.001. Epub 2015 Sep 11.

Abstract

We have previously shown that retinoic acid receptor (RAR) stimulation by an agonist Am80 recruits nitric oxide-dependent signaling via increased expression of neuronal nitric oxide synthase (nNOS) in rat midbrain slice cultures. Using neuroblastoma SH-SY5Y cells, here we investigated the mechanisms of RAR-induced nNOS expression, together with relationship between nNOS expression and neurite outgrowth. Am80 promoted neurite outgrowth, which was attenuated by inhibitors of phosphoinositide 3-kinase (PI3K; LY294002), c-Jun N-terminal kinase (JNK; SP600125) and p38 mitogen-activated protein kinase (p38 MAPK; SB203580). A selective nNOS inhibitor 3-bromo-nitroindazole also suppressed Am80-induced neurite outgrowth. Am80-induced increase in nNOS protein expression was attenuated by LY294002, SP600125 and SB203580, whereas increase in nNOS mRNA expression was attenuated only by LY294002. Am80-induced activation of JNK and p38 MAPK was blocked by LY294002, suggesting that these kinases acted downstream of PI3K. We also confirmed that DAX1, a nuclear receptor reported to regulate nNOS expression, was up-regulated in response to Am80. siRNA-mediated knockdown of DAX1 abrogated Am80-induced nNOS expression and neurite outgrowth. These results reveal for the first time that nNOS expression is crucial for RAR-mediated neurite outgrowth, and that non-genomic signaling such as JNK and p38 MAPK is involved in RAR-mediated nNOS expression.

Keywords: Mitogen-activated protein kinase; Neurite morphogenesis; Nitric oxide; PI3 kinase; Retinoid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzoates / pharmacology
  • Chromones / pharmacology
  • Gene Expression / drug effects
  • Gene Expression / genetics*
  • Gene Expression Regulation, Developmental / genetics*
  • Gene Expression Regulation, Enzymologic / genetics*
  • Humans
  • MAP Kinase Signaling System / genetics*
  • MAP Kinase Signaling System / physiology*
  • Mitogen-Activated Protein Kinases / physiology*
  • Morpholines / pharmacology
  • Neurites / physiology*
  • Neuroblastoma*
  • Nitric Oxide Synthase Type I / genetics*
  • Nitric Oxide Synthase Type I / metabolism*
  • Rats
  • Receptors, Retinoic Acid / physiology*
  • Tetrahydronaphthalenes / pharmacology
  • Tumor Cells, Cultured

Substances

  • Benzoates
  • Chromones
  • Morpholines
  • Receptors, Retinoic Acid
  • Tetrahydronaphthalenes
  • tamibarotene
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Nitric Oxide Synthase Type I
  • Mitogen-Activated Protein Kinases