Recombinant adenovirus-mediated cardiac gene transfer of superoxide dismutase and catalase attenuates postischemic contractile dysfunction.
BACKGROUND
Coronary revascularization entails obligatory myocardial ischemia followed by reperfusion with occasional resultant postischemic contractile dysfunction, a state associated with significant morbidity and mortality. This injury is attributed in part to oxygen free radicals and has been partially ameliorated with exogenous antioxidants, a strategy limited by agent instability, low titer, and inadequate cardiomyocyte uptake. Cardiac gene transfer with antioxidant encoding vectors may significantly enhance intracellular free radical scavenger activity.


RESULTS
C57/BL6 neonatal mice (age, 2 days; n = 131) underwent intrapericardial delivery of recombinant adenoviruses encoding superoxide dismutase (SOD) and catalase (Cat) (n = 76) or beta-galactosidase (LacZ) as a control (n = 55). After 3 days, hearts were explanted, and SOD and Cat transgene expression was detected by Western blot analysis. Spectrophotometric enzyme assays demonstrated enhanced SOD activity 1.6-fold (P < 0.0001) and Cat 3.6-fold (P < 0.00001) in experimental versus LacZ hearts. Isolated perfused hearts were subjected to 5 minutes of warm ischemia, and at 5, 10, and 15 minutes after initiation of reperfusion, LacZ controls lost 24%, 33%, and 41% of peak systolic apicobasal force, respectively, whereas experimental hearts lost 5%, 12%, and 20% (P < 0.001, each time point). In controls, rate of force generation diminished 8%, 17%, and 35%; in experimental hearts, it increased 1% at 5 minutes and decreased 5% and 15% and 10 and 15 minutes (P < 0.01, P < 0.05, P < 0.05). LacZ hearts exhibited dysfunction similar to hearts from uninjected animals (P = NS, each time point).


CONCLUSIONS
Adenovirus-mediated cardiac gene transfer and expression of SOD and Cat augment antioxidant enzyme activity and minimize contractile dysfunction after ischemic reperfusion in the isolated perfused neonatal mouse heart.
Woo
Y J
YJ
Department of Surgery, School of Medicine, University of Pennsylvania, Philadelphia, USA.
Zhang
J C
JC
Vijayasarathy
C
C
Zwacka
R M
RM
Englehardt
J F
JF
Gardner
T J
TJ
Sweeney
H L
HL
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000502:physiology; D018014:Gene Transfer Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D009200:Myocardial Contraction / Q000502:physiology*; D017202:Myocardial Ischemia / Q000201:enzymology / Q000503:physiopathology*; D009206:Myocardium / Q000201:enzymology*; D011995:Recombination, Genetic; D013053:Spectrophotometry; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*
D002374:Catalase; D013482:Superoxide Dismutase