Interaction of caveolin-1, nitric oxide, and nitric oxide synthases in hypoxic human SK-N-MC neuroblastoma cells

J Neurochem. 2008 Oct;107(2):478-87. doi: 10.1111/j.1471-4159.2008.05630.x. Epub 2008 Aug 20.

Abstract

Neuroblastoma cells are capable of hypoxic adaptation, but the mechanisms involved are not fully understood. We hypothesized that caveolin-1 (cav-1), a plasma membrane signal molecule, might play a role in protecting neuroblastoma cells from oxidative injury by modulating nitric oxide (NO) production. We investigated the alterations of cav-1, cav-2, nitric oxide synthases (NOS), and NO levels in human SK-N-MC neuroblastoma cells exposed to hypoxia with 2% [O2]. The major discoveries include: (i) cav-1 but not cav-2 was up-regulated in the cells exposed to 15 h of hypoxia; (ii) NO donor 1-[N, N-di-(2-aminoethyl) amino] diazen-1-ium-1, 2-diolate up-regulated the expression of cav-1, whereas the non-selective NOS inhibitor N(G)-nitro-L-arginine methyl ester and inducible NOS (iNOS) inhibitor 1400W each abolished the increase in cav-1 expression in the hypoxic SK-N-MC cells. These results suggest that iNOS-induced NO production contributes to the up-regulation of cav-1 in the hypoxic SK-N-MC cells. Furthermore, we studied the roles played by cav-1 in regulating NO, NOS, and apoptotic cell death in the SK-N-MC cells subjected to 15 h of hypoxic treatment. Both cav-1 transfection and cav-1 scaffolding domain peptide abolished the induction of iNOS, reduced the production of NO, and reduced the rates of apoptotic cell death in the hypoxic SK-N-MC cells. These results suggest that increased expression of cav-1 in response to hypoxic stimulation could prevent oxidative injury induced by reactive oxygen species. The interactions of cav-1, NO, and NOS could be an important signal pathway in protecting the neuroblastoma cells from oxidative injury, contributing to the hypoxic tolerance of neuroblastoma cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Annexin A5 / metabolism
  • Caveolin 1 / genetics
  • Caveolin 1 / metabolism*
  • Caveolin 2 / genetics
  • Caveolin 2 / metabolism
  • Cell Hypoxia / drug effects
  • Cell Hypoxia / physiology*
  • Cell Line, Tumor
  • DEET / pharmacology
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / physiology
  • Humans
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Neuroblastoma
  • Nitric Oxide / genetics
  • Nitric Oxide / metabolism*
  • Nitric Oxide / pharmacology
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type II / metabolism*
  • RNA, Messenger / metabolism
  • Time Factors
  • Transfection / methods

Substances

  • Annexin A5
  • Caveolin 1
  • Caveolin 2
  • Enzyme Inhibitors
  • RNA, Messenger
  • DEET
  • Nitric Oxide
  • Nitric Oxide Synthase Type II
  • NG-Nitroarginine Methyl Ester