Decreased expression of cardiac sarcoplasmic reticulum Ca2+-pump ATPase in congestive heart failure due to myocardial infarction
Myocardial infarction in rats induced by occluding the left coronary artery for 4, 8 and 16 weeks has been shown to result in congestive heart failure (CHF) characterized by hypertrophy of the viable ventricular myocardial tissue. We have previously demonstrated a decreased calcium transport activity in the sarcoplasmic reticulum (SR) of post-myocardial infarction failing rat hearts. In this study we have measured the steady state levels of the cardiac SR Ca2+-pump ATPase (SERCA2) mRNA using Northern blot and slot blot analyses. The relative amounts of SERCA2 mRNA were decreased with respect to GAPDH mRNA and 28 S rRNA in experimental failing hearts at 4 and 8 weeks post myocardial infarction by about 20% whereas those at 16 weeks declined by about 35% of control values. The results obtained by Western blot analysis, revealed that the immunodetectable levels of SERCA2 protein in 8 and 16 weeks postinfarcted animals were decreased by about 20% and 30%, respectively. The left ventricular SR Ca2+-pump ATPase specific activity was depressed in the SR preparations of failing hearts as early as 4 weeks post myocardial infarction and declined by about 65% at 16 weeks compared to control. These results indicate that the depressed SR Ca2+-pump ATPase activity in CHF may partly be due to decreased steady state amounts of SERCA2 mRNA and SERCA2 protein in the failing myocardium.
Key wordsCa2+-pump ATPase cardiac SERCA2 myocardial infarction congestive heart failure cardiac SR
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- 4.Ganguly PK, Pierce GN, Dhalla KS, Dhalla NS: Defective sarcoplasmic reticular calcium transport in diabetic cardiomyopathy. Am J Physiol 244: E528–E535, 1985Google Scholar
- 5.Movsesian MA, Bristow MR, Krall J: Ca2+ uptake by cardiac sarcoplasmic reticulum from patients with idiopathic dilated cardiomyopathy. CircRes 65: 1141–1144, 1989Google Scholar
- 7.Lytton J, MacLennan DH: In: HA Fozzard, E Haber, RB Jennings, AM Katz and HE Morgan (eds). The Heart and the Cardiovascular System. Raven Press, New York, 1991, pp 1203–1222Google Scholar
- 8.Inesi G, Lewis D, Nikic D, Hussain A, Kirtley ME: Long-range intramolecular linked functions in the calcium transport ATPase. Adv Enzymol Relat Areas Mol Biol 65: 185–215, 1994Google Scholar
- 11.Chomozynski P, Sacchi N: Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem 162: 156–159, 1987Google Scholar
- 12.Sambrook J, Fritsch EF, Maniatis T: Molecular Cloning: A Laboratory Manual, 2nd Ed. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 1989Google Scholar
- 18.Towbin H, Staehelin T, Gordon J: Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Biotechnology 24: 145–149, 1979Google Scholar
- 20.Morenhouse CA, Stull, GAL: Statistical principles and procedures with applications for physical education. Lea and Febiger, Philadelphia, 1975Google Scholar
- 24.de la Bastie D, Levitsky D, Rappaport L, Mercadier JJ, Marotte F, Wisnewsky C, Brovkovich V, Schwartz K, Lompre A-M: Function of the sarcoplasmic reticulum and expression of its Ca2+- ATPase gene in pressure overload-induced cardiac hypertrophy in the rat. Circ Res 66: 554–564, 1990PubMedGoogle Scholar