Quinolinic acid induces neuritogenesis in SH-SY5Y neuroblastoma cells independently of NMDA receptor activation

Eur J Neurosci. 2017 Mar;45(5):700-711. doi: 10.1111/ejn.13499. Epub 2017 Jan 26.


Glutamate and nicotinamide adenine dinucleotide (NAD+ ) have been implicated in neuronal development and several types of cancer. The kynurenine pathway of tryptophan metabolism includes quinolinic acid (QA) which is both a selective agonist at N-methyl-D-aspartate (NMDA) receptors and also a precursor for the formation of NAD+ . The effect of QA on cell survival and differentiation has therefore been examined on SH-SY5Y human neuroblastoma cells. Retinoic acid (RA, 10 μm) induced differentiation of SH-SY5Y cells into a neuronal phenotype showing neurite growth. QA (50-150 nm) also caused a concentration-dependent increase in the neurite/soma ratio, indicating differentiation. Both RA and QA increased expression of the neuronal marker β3-tubulin in whole-cell homogenates and in the neuritic fraction assessed using a neurite outgrowth assay. Expression of the neuronal proliferation marker doublecortin revealed that, unlike RA, QA did not decrease the number of mitotic cells. QA-induced neuritogenesis coincided with an increase in the generation of reactive oxygen species. Neuritogenesis was prevented by diphenylene-iodonium (an inhibitor of NADPH oxidase) and superoxide dismutase, supporting the involvement of reactive oxygen species. NMDA itself did not promote neuritogenesis and the NMDA antagonist dizocilpine (MK-801) did not prevent quinolinate-induced neuritogenesis, indicating that the effects of QA were independent of NMDA receptors. Nicotinamide caused a significant increase in the neurite/soma ratio and the expression of β3-tubulin in the neuritic fraction. Taken together, these results suggest that QA induces neuritogenesis by promoting oxidizing conditions and affecting the availability of NAD+ , independently of NMDA receptors.

Keywords: NAD +; differentiation; glutamate; kynurenines; nicotinamide.

MeSH terms

  • Cell Line, Tumor
  • Dizocilpine Maleate / pharmacology
  • Doublecortin Domain Proteins
  • Enzyme Inhibitors / pharmacology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Humans
  • Microtubule-Associated Proteins / metabolism
  • NADPH Oxidases / antagonists & inhibitors
  • Neurites / drug effects*
  • Neurites / metabolism
  • Neuronal Outgrowth*
  • Neuropeptides / metabolism
  • Onium Compounds / pharmacology
  • Quinolinic Acid / pharmacology*
  • Receptors, N-Methyl-D-Aspartate / agonists*
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors
  • Tretinoin / pharmacology
  • Tubulin / metabolism


  • Doublecortin Domain Proteins
  • Enzyme Inhibitors
  • Excitatory Amino Acid Antagonists
  • Microtubule-Associated Proteins
  • Neuropeptides
  • Onium Compounds
  • Receptors, N-Methyl-D-Aspartate
  • Tubulin
  • Tretinoin
  • diphenyleneiodonium
  • Dizocilpine Maleate
  • NADPH Oxidases
  • Quinolinic Acid