Targeting phospholamban by gene transfer in human heart failure.
BACKGROUND
Myocardial cells from failing human hearts are characterized by abnormal calcium handling, a negative force-frequency relationship, and decreased sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) activity. In this study, we tested whether contractile function can be improved by decreasing the inhibitory effects of phospholamban on SERCA2a with adenoviral gene transfer of antisense phospholamban (asPL).


RESULTS
Myocardial cells isolated from 9 patients with end-stage heart failure and 18 donor nonfailing hearts were infected with adenoviruses encoding for either the antisense of phospholamban (Ad.asPL), the SERCA2a gene (Ad.SERCA2a), or the reporter genes beta-galactosidase and green fluorescent protein (Ad.betagal-GFP). Adenoviral gene transfer with Ad.asPL decreased phospholamban expression over 48 hours, increasing the velocity of both contraction and relaxation. Compared with cardiomyocytes infected with Ad.asPL (n=13), human myocytes infected with Ad.betagal-GFP (n=8) had enhanced contraction velocity (20.3 +/- 3.9% versus 8.7 +/- 2.6% shortening/second; P<0.01) and relaxation velocity (26.0 +/- 6.2% versus 8.6 +/- 4.3% shortening/second; P<0.01). The improvement in contraction and relaxation velocities was comparable to cardiomyocytes infected with Ad.SERCA2a. Failing human cardiomyocytes had decreased contraction and Ca2+ release with increasing frequency (0.1 to 2 Hz). Phospholamban ablation restored the frequency response in the failing cardiomyocytes to normal; increasing frequency resulted in enhanced sarcoplasmic reticulum Ca2+ release and contraction.


CONCLUSIONS
These results show that gene transfer of asPL can improve the contractile function in failing human myocardium. Targeting phospholamban may provide therapeutic benefits in human heart failure.
del Monte
Federica
F
Cardiovascular Research Center, Massachusetts General Hospital, Heart Failure and Cardiac Transplantation Center, Boston, Mass 02129, USA.
Harding
Sian E
SE
Dec
G William
GW
Gwathmey
Judith K
JK
Hajjar
Roger J
RJ
D000256:Adenoviridae / Q000235:genetics; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D016373:DNA, Antisense / Q000235:genetics / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D022761:Gene Transfer, Horizontal; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D006333:Heart Failure / Q000235:genetics / Q000503:physiopathology*; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000099211:Phospholamban
D002118:Calcium; D002135:Calcium-Binding Proteins; D000252:Calcium-Transporting ATPases; D016373:DNA, Antisense; D007527:Isoenzymes; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000099211:Phospholamban