(Circulation. 2002;105:904.)
© 2002 American Heart Association, Inc.
Brief Rapid Communications |
From the Cardiovascular Research Center, Massachusetts General Hospital, Heart Failure and Cardiac Transplantation Center (F.d.M., G.W.D., R.J.H.), Harvard Medical School (J.K.G.), Boston, Mass; and the National Heart and Lung Institute (S.E.H.), Imperial College, London, UK.
Correspondence to Roger J. Hajjar, MD, Massachusetts General Hospital, Cardiovascular Research Center, 149 13th St, CNY-4, 4215, Charlestown, MA 02129. E-mail rhajjar{at}partners.org
| Abstract |
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Methods and 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 ß-galactosidase and green fluorescent protein (Ad.ßgal-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.ßgal-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.
Conclusion 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.
Key Words: calcium heart failure gene therapy
| Introduction |
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In the present study, we have used such a strategy by generating adenoviral vectors expressing antisense of phospholamban and examining their effects on phospholamban expression, SERCA2a activity, and myocyte function in failing human cardiomyocytes.
| Methods |
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The antisense cDNA of phospholamban was first cloned into a shuttle vector, pAdTrack-CMV.9 The resultant plasmid was linearized with restriction endonuclease PmeI and subsequently was cotransformed into E coli BJ5183 cells with an adenoviral backbone plasmid, pAdEasy-1. Recombinants were selected for kanamycin resistance, and recombination was confirmed by multiple-restriction endonuclease analyses. The linearized recombinant plasmid was transfected into adenovirus-packaging cell lines (293 cells). Ad.ßgal-GFP, which contains both ß-galactosidase and green fluorescent protein (GFP) controlled by separate cytomegalovirus promoters, was used as control. Ad.SERCA2a, which carries both the SERCA2a and GFP genes, was also used.
Forty-eight hours after infection, myocytes were placed in a flow chamber on the stage of an inverted microscope, superfused with oxygenated Krebs-Henseleit solution, and electrically stimulated with biphasic pulse (0.2 Hz, 50% above threshold). Contraction amplitude and rates of contraction and relaxation were recorded online using a video-edge-detection system and data acquisition software (IonOptix). The fluorescent Ca2+ indicator Fura-2 (Molecular Probes) was used to measure intracellular Ca2+ through the use of a dual excitation spectrofluorometer (IonOptix), as described previously.8 Cumulative concentration-response experiments to isoproterenol, ranging from 0.01 nmol/L to 1 µmol/L, were performed. Cell shortening was measured at each dose and also at the maximum shortening response reached.
We isolated SR membranes from ventricular myocytes, and SERCA2a activity assays were carried out on the basis of Pyruvate/NADH-coupled reactions at [Ca2+] of 10 µmol/L, as previously described.8 Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed on the isolated membranes under reducing conditions on a 7.5% to 12.5% separation gel with a 4% stacking gel, and membranes were immunoblotted with 1:2500 diluted monoclonal anti-phospholamban and anti-SERCA2 antibody (Affinity BioReagents, Golden, Colo). The blot was then incubated in a chemiluminescence system and exposed to an X-OMAT AR x-ray film (Fuji Films) for 1 minute. Data are presented as mean±SEM and were analyzed using a 1-way ANOVA, with statistical differences identified at P<0.05.
| Results |
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To examine whether ablation of phospholamban improves calcium handling in human cardiomyocytes, we increased extracellular calcium and measured contractile parameters. As shown in Figure 2A, ablation of phospholamban improved contraction and relaxation velocities to the same degree as did overexpression of SERCA2a at calcium levels up to 4 mmol/L. However, cells overexpressing SERCA2a were more tolerant to the higher calcium concentrations than were the cells infected with Ad.asPL.
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Phospholamban plays an important role in modulating the response to ß-adrenergic stimulus because its phosphorylation leads to increased ATPase activity10 and acceleration of both contraction and relaxation. Addition of isoproterenol in nonfailing cardiomyocytes enhanced contraction but also was associated with aftercontractions (data not shown). Ablation of phospholamban increased contraction and significantly decreased the time of contraction, as depicted in Figure 2B. With the substantial decrease in the time course of contraction in failing human cardiomyocytes infected with Ad.asPL, the addition of isoproterenol still had additive effects on the time course of contractions, as shown in Figure 2B.
| Discussion |
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Studies by Kranias et al6,7 have shown clearly that murine models of phospholamban knockout have enhanced contractility. Furthermore, ablation of phospholamban prevented the development of heart failure and restored cardiac function in several murine models of heart failure, including muscle lim proteinknockout (MLP-/-) mice.11 Our results show that improving calcium cycling by decreasing phospholamban inhibition to SERCA2a restores contractility in failing human ventricular cardiomyocytes. These findings also extend previous results showing that overexpression of SERCA2a improves contractile function in human failing cardiac myocytes.
Even though the two strategiesphospholamban decrease and overexpression of SERCA2aimproved contractile function in the failing human cardiomyocytes to the same extent, there were certain differences. SERCA2a activity increased to a greater degree in cardiomyocytes overexpressing SERCA2a. In failing cardiomyocytes, relieving inhibition to SERCA2a pumps, which may be impaired because of oxidative stresses,12 may not restore ATPase activity to normal.
One concern about the strategy of increasing SERCA2a by diminishing phospholamban inhibition is the energy cost, which would be anticipated to increase ATP hydrolysis. Our group has recently shown that overexpression of SERCA2a in a rat model of heart failure enhances contractility without energetic compromise.13 In fact, in this model of heart failure, overexpression of SERCA2a restored the balance between ATP and creatine phosphate.
Another concern with the antisense approach is that it uncouples the ß-receptors from one of their downstream targets, phospholamban, rendering them "spare receptors." This would decrease the modulatory effects of isoproterenol. Interestingly, though, with phospholamban ablation, the contractile state of the cardiomyocyte at baseline is high. Furthermore, the human heart has only a small receptor reserve (if any) for ß-adrenoceptors.14,15 It is unclear from our study what the long-term effects of functionally increasing these spare receptors will be. Also, the ratio of the Na/Ca exchanger to SERCA2a has been shown to be increased in failing hearts and to be predictive of diastolic function in these hearts.16 Even though ablation of phospholamban would not affect the ratio of SERCA2a to Na/Ca, the resultant enhancement of SERCA2a activity would contribute to restoring diastolic function.
Our results demonstrate that targeting calcium regulation by ablation of phospholamban improves contractile function in failing human cardiomyocytes. This study validates the feasibility of cardiac gene transfer in failing hearts as a therapeutic modality.
| Acknowledgments |
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Received November 13, 2001; revision received January 7, 2002; accepted January 8, 2002.
| References |
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2.
Beuckelmann DJ, Nabauer M, Erdmann E. Intracellular calcium handling in isolated ventricular myocytes from patients with terminal heart failure. Circulation. 1992; 85: 10461055.
3. Schmidt U, Hajjar RJ, Kim CS, et al. Human heart failure: cAMP stimulation of SR Ca(2+)-ATPase activity and phosphorylation level of phospholamban. Am J Physiol. 1999; 277: H474H480.
4.
Schwinger RH, Bohm M, Schmidt U, et al. Unchanged protein levels of SERCAII and phospholamban but reduced Ca2+ uptake and Ca2+-ATPase activity of cardiac sarcoplasmic reticulum from dilated cardiomyopathy patients compared with patients with nonfailing hearts. Circulation. 1995; 92: 32203228.
5. Schwinger RH, Munch G, Bolck B, et al. Reduced Ca2+-sensitivity of SERCA 2a in failing human myocardium due to reduced serin-16 phospholamban phosphorylation. J Mol Cell Cardiol. 1999; 31: 479491.[CrossRef][Medline] [Order article via Infotrieve]
6.
Koss KL, Kranias EG. Phospholamban: a prominent regulator of myocardial contractility. Circ Res. 1996; 79: 10591063.
7.
Luo W, Grupp IL, Harrer J, et al. Targeted ablation of the phospholamban gene is associated with markedly enhanced myocardial contractility and loss of beta-agonist stimulation. Circ Res. 1994; 75: 401409.
8.
del Monte F, Harding SE, Schmidt U, et al. Restoration of contractile function in isolated cardiomyocytes from failing human hearts by gene transfer of SERCA2a. Circulation. 1999; 100: 23082311.
9.
He TC, Zhou S, da Costa LT, et al. A simplified system for generating recombinant adenoviruses. Proc Natl Acad Sci U S A. 1998; 95: 25092514.
10. Tada M, Kirchberger MA, Katz AM. Regulation of calcium transport in cardiac sarcoplasmic reticulum by cyclic AMP-dependent protein kinase. Recent Adv Stud Cardiac Struct Metab. 1976; 9: 225239.[Medline] [Order article via Infotrieve]
11. Minamisawa S, Hoshijima M, Chu G, et al. Chronic phospholamban-sarcoplasmic reticulum calcium ATPase interaction is the critical calcium cycling defect in dilated cardiomyopathy. Cell. 1999; 99: 313322.[CrossRef][Medline] [Order article via Infotrieve]
12.
Xu KY, Zweier JL, Becker LC. Hydroxyl radical inhibits sarcoplasmic reticulum Ca(2+)-ATPase function by direct attack on the ATP binding site. Circ Res. 1997; 80: 7681.
13.
del Monte F, Williams E, Lebeche D, et al. Improvement in survival and cardiac metabolism after gene transfer of sarcoplasmic reticulum Ca(2+)-ATPase in a rat model of heart failure. Circulation. 2001; 104: 14241429.
14. Schwinger RH, Bohm M, Erdmann E. Evidence against spare or uncoupled beta-adrenoceptors in the human heart. Am Heart J. 1990; 119: 899904.[CrossRef][Medline] [Order article via Infotrieve]
15. Brown L, Deighton NM, Bals S, et al. Spare receptors for beta-adrenoceptor-mediated positive inotropic effects of catecholamines in the human heart. J Cardiovasc Pharmacol. 1992; 19: 222232.[Medline] [Order article via Infotrieve]
16.
Hasenfuss G, Schillinger W, Lehnart SE, et al. Relationship between Na+-Ca2+-exchanger protein levels and diastolic function of failing human myocardium. Circulation. 1999; 99: 641648.
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