Research Paper
Subject Category: Cardiovascular and pulmonary pharmacology
British Journal of Pharmacology (2008) 153, 508–516; doi:10.1038/sj.bjp.0707585; published online 3 December 2007
Paraoxonase 1 gene transfer lowers vascular oxidative stress and improves vasomotor function in apolipoprotein E-deficient mice with pre-existing atherosclerosis
P-J Guns1,4, T Van Assche1,4, W Verreth2, P Fransen1, B Mackness3, M Mackness3, P Holvoet2 and H Bult1
- 1Division of Pharmacology, University of Antwerp, Wilrijk, Belgium
- 2Atherosclerosis and Metabolism Unit, Department of Cardiovascular Diseases, Katholieke Universiteit Leuven, Leuven, Belgium
- 3Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
Correspondence: Dr H Bult, Division of Pharmacology, University of Antwerp, CDE, Universiteitsplein 1, B2610 Wilrijk, Belgium. E-mail: pieter-jan.guns@ua.ac.be
4These authors contributed equally to the work.
Received 15 May 2007; Revised 20 July 2007; Accepted 19 October 2007; Published online 3 December 2007.
Abstract
Background and purpose:
Transgenesis of human paraoxonase 1 (PON1), a HDL-associated enzyme that destroys lipid peroxides, has been reported to reduce early atherogenesis in mice. The present study explored the therapeutic potential of human PON1 gene transfer in old apolipoprotein E-deficient (apoE-/-) mice with advanced atherosclerosis.
Experimental approach:
ApoE-/- mice (18 months, regular chow) were transfected with PON1 adenovirus (AdPON1, n=10) or control adenovirus (AdRR5, n=10). Non-transfected apoE-/- (n=9) and C57Bl/6J (WT, n=6) mice served as controls. Three weeks later, plaque size and composition, and endothelial cell (EC) and smooth muscle cell (SMC) function were assessed in the aorta.
Key results:
PON1 gene transfer raised total PON1 serum activity 13-15 fold during the 3-week study period, without affecting hypercholesterolaemia or lesion size. However, PON1 decreased the oxLDL content of the plaque. Plaque-free thoracic aorta rings from apoE-/- mice displayed, like rings from WT mice, complete relaxation to acetylcholine (ACh, 86
2%), ATP (902%) or UTP (833%). In contrast, in plaque-bearing segments amplitude (557%, 688%, 528% respectively) and sensitivity were decreased. EC function was completely (ATP, UTP) or largely (ACh) restored by AdPON1. Furthermore, apoE-/- SMCs released less intracellular calcium than WT upon sarco-endoplasmic reticulum calcium ATPase (SERCA) inhibition by cyclopiazonic acid. This defect was also restored by AdPON1 transfection.
Conclusions and implications:
These data indicate that AdPON1 gene transfer improved vascular wall oxidative stress, EC function, and SMC Ca2+ homeostasis in segments with pre-existing atherosclerosis, independently of an effect on plaque size.
Keywords:
atherosclerosis, paraoxonase 1, oxidative stress, endothelial dysfunction, vascular smooth muscle cells, apoE
Abbreviations:
AdPON1, paraoxonase 1 recombinant adenovirus; AdRR5, control recombinant adenovirus; apoE-/-, apolipoprotein E-deficient (mice); CPA, cyclopiazonic acid; EC, endothelial cell; eNOS, endothelial nitric oxide synthase; HDL, high-density lipoprotein; LDL, low-density lipoprotein; MDA, malondialdehyde; OCT, optimal compound temperature; oxLDL, oxidized low-density lipoprotein; PON1, paraoxonase 1; SERCA, sarco-endoplasmic reticulum Ca2+-ATPase; SMC, smooth muscle cell; SOD, superoxide dismutase; WT, wild type
