Improvement in survival and cardiac metabolism after gene transfer of sarcoplasmic reticulum Ca(2+)-ATPase in a rat model of heart failure.
BACKGROUND
In heart failure, sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a) activity is decreased, resulting in abnormal calcium handling and contractile dysfunction. We have previously shown that increasing SERCA2a expression by gene transfer improves ventricular function in a rat model of heart failure created by ascending aortic constriction.


RESULTS
In this study, we tested the effects of gene transfer of SERCA2a on survival, left ventricular (LV) volumes, and metabolism. By 26 to 27 weeks after aortic banding, all animals developed heart failure (as documented by >25% decrease in fractional shortening) and were randomized to receive either an adenovirus carrying the SERCA2a gene (Ad.SERCA2a) or control virus (Ad.betagal-GFP) by use of a catheter-based technique. Sham-operated rats, uninfected or infected with either Ad.betagal-GFP or Ad.SERCA2a, served as controls. Four weeks after gene transfer, survival in rats with heart failure treated with Ad.betagal-GFP was 9%, compared with 63% in rats receiving Ad.SERCA2a. LV volumes were significantly increased in heart failure (0.64+/-0.05 versus 0.35+/-0.03 mL, P<0.02). Overexpression of SERCA2a normalized LV volumes (0.46+/-0.07 mL) in the failing hearts. (31)P NMR analysis showed a reduced ratio of phosphocreatine to ATP content in failing+Ad.betagal-GFP compared with sham+Ad.betagal-GFP (0.82+/-0.13 versus 1.38+/-0.14, P<0.01). Overexpression of SERCA2a in failing hearts improved the phosphocreatine/ATP ratio (1.23+/-0.28).


CONCLUSIONS
In this study, we show that unlike inotropic agents that improve contractile function at the expense of increased mortality and worsening metabolism, gene transfer of SERCA2a improves survival and the energy potential in failing hearts.
del Monte
F
F
Cardiovascular Research Center and the Cardiology Division, Massachusetts General Hospital, Boston, MA 02129, USA.
Williams
E
E
Lebeche
D
D
Schmidt
U
U
Rosenzweig
A
A
Gwathmey
J K
JK
Lewandowski
E D
ED
Hajjar
R J
RJ
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D004195:Disease Models, Animal; D004452:Echocardiography; D015870:Gene Expression; D022761:Gene Transfer, Horizontal; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D006333:Heart Failure / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D013318:Stroke Volume / Q000187:drug effects; D015996:Survival Rate
D007527:Isoenzymes; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases