Regulation of heme oxygenase-1 gene expression in vascular smooth muscle cells by nitric oxide. Academic Article uri icon

Overview

MeSH

  • Animals
  • Aorta
  • Carbon Monoxide
  • Cell Nucleus
  • Cells, Cultured
  • Cyclic GMP
  • Dactinomycin
  • Enzyme Inhibitors
  • Guanylate Cyclase
  • Heme Oxygenase-1
  • Kinetics
  • Nitrogen Oxides
  • Oligonucleotide Probes
  • Oxadiazoles
  • Quinoxalines
  • RNA Processing, Post-Transcriptional
  • RNA, Messenger
  • Rats

MeSH Major

  • Gene Expression Regulation, Enzymologic
  • Heme Oxygenase (Decyclizing)
  • Muscle, Smooth, Vascular
  • Nitric Oxide
  • Spermine
  • Transcription, Genetic

abstract

  • Heme oxygenase (HO)-mediated heme degradation is the primary mechanism for production of cellular carbon monoxide (CO). Analogous to nitric oxide (NO), CO mediates physiological and cellular functions such as vasodilation, stimulation of guanylate cyclase, and neuronal transmission. In view of accumulating data demonstrating a correlation between the activity of these two gaseous molecules and that the predominant source of CO is via HO catalysis, we hypothesized that NO regulates HO expression. We demonstrate that the NO donor spermine NONOate (SNN) increases steady-state levels of HO-1 mRNA in aortic vascular smooth muscle cells (aSMC) in both a time- and dose-dependent manner. The accumulation of HO-1 mRNA that correlated with increased HO-1 protein synthesis resulted from both an increased rate of gene transcription and a decreased rate of mRNA turnover. Inhibition of the NO-induced HO-1 mRNA expression by cycloheximide suggests that new protein synthesis is required for increased HO-1 gene expression. Induction of HO-1 expression by SNN occurs in a guanosine 3',5'-cyclic monophosphate (cGMP)-independent manner because exposure of cells to 8-bromoguanosine 3',5'-cyclic monophosphate, a cGMP analog, did not increase HO-1 mRNA levels, and pretreatment of cells with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a selective guanylate cyclase inhibitor, did not prevent SNN-induced HO-1 mRNA accumulation. The antioxidant N-acetyl-L-cysteine markedly inhibited SNN-induced HO-1 mRNA expression, whereas peroxynitrite did not induce HO-1 expression in aSMC. Interestingly, CO did not attenuate NO-induced HO-1 expression through an autocrine negative feedback mechanism as had been observed for hypoxia-induced HO-1 expression. These data provide evidence for an important regulatory network between NO and CO via HO-1.

publication date

  • November 1997

has subject area

  • Animals
  • Aorta
  • Carbon Monoxide
  • Cell Nucleus
  • Cells, Cultured
  • Cyclic GMP
  • Dactinomycin
  • Enzyme Inhibitors
  • Gene Expression Regulation, Enzymologic
  • Guanylate Cyclase
  • Heme Oxygenase (Decyclizing)
  • Heme Oxygenase-1
  • Kinetics
  • Muscle, Smooth, Vascular
  • Nitric Oxide
  • Nitrogen Oxides
  • Oligonucleotide Probes
  • Oxadiazoles
  • Quinoxalines
  • RNA Processing, Post-Transcriptional
  • RNA, Messenger
  • Rats
  • Spermine
  • Transcription, Genetic

Research

keywords

  • Journal Article

Identity

Language

  • eng

PubMed ID

  • 9374724

Additional Document Info

start page

  • L980

end page

  • L988

volume

  • 273

number

  • 5 Pt 1