Oxidative stress increases glyceraldehyde-3-phosphate dehydrogenase
mrna levels in isolated rabbit aorta.
Ito, Yasushi, Patrick J. Pagano, Keith Tornheim, Peter Brecher,
Richard A. Cohen.
Vascular Biology Unit, Robert Dawson Evans Department of Clinical
Research, and Department of Biochemistry, Boston University Medical
Center, Boston, Massachusetts
APStracts 2:0299H, 1995.
We have recently shown that inhibition of endogenous Cu,Zn superoxide
dismutase (SOD) by diethyldithiocarbamate (DDC) increased superoxide
anion levels in isolated rabbit aortic rings, describing a useful
experimental model to examine the effects of oxidative stress on the
vessel wall. The present study examined the effects of oxidative
stress on the steady-state mRNA levels of glyceraldehyde-3-phosphate
dehydrogenase (GAPDH, EC 1.2.1.12). Aortic rings were incubated in
physiological salt solution at 37 C for up to 6 h. DDC (2 mM)
decreased total SOD activity to less than 5% of control levels and
increased superoxide anion level nine-fold. Steady-state mRNA levels
of GAPDH were increased under comparable conditions. Although
decreased biological activity of endothelium-derived nitric oxide
(NO) was indicated by lower basal guanosine 3',5'-cyclic
monophosphate levels in aortic rings treated with DDC compared to
those in control rings (1.2+/-0.1 vs 1.9+/-0.3 fmole/[mu]g protein,
p<0.05), neither endothelium denudation nor NG-nitro-L-arginine
methyl ester (L-NAME) had any effects on the steady-state mRNA levels
of GAPDH. The cell permeable iron chelator 1,10-phenanthroline
completely prevented the increases in GAPDH mRNA levels induced by
DDC. These results suggest that oxidative stress resulting from
inhibition of endogenous Cu,Zn SOD causes induction of GAPDH gene
expression and that the hydroxyl radical, produced through the iron
catalyzed Haber-Weiss reaction, is the intracellular reactive oxygen
species responsible for the DDC-stimulated increase in GAPDH mRNA.
Received 23 May 194; accepted in final form 28 June 1995.
APS Manuscript Number H446-4.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.