Copyright © 2005, European Society of Cardiology
Mechanism of cGMP-mediated protection in a cellular model of myocardial reperfusion injury
Institute of Physiology, Justus-Liebig-University, Aulweg 129, D-35392 Giessen, Germany
* Corresponding author. Tel.: +49 641 99 47241; fax: +49 641 99 47239. Email address: Yaser.Abdallah{at}physiologie.med.uni-giessen.de
Objective: Reperfusion injury of the myocardium is characterised by development of cardiomyocyte hypercontracture. Previous studies have shown that cGMP-mediated stimuli protect against reperfusion injury, but the cellular mechanism is still unknown.
Methods: To simulate ischemia/reperfusion, adult rat cardiomyocytes were incubated anoxically (pHo 6.4) and then reoxygenated (pHo 7.4). Cytosolic calcium [Ca2+]i (fura-2 ratio), pHi (BCECF ratio), cell length, and phospholamban phosphorylation were analysed. Under simulated ischemia cardiomyocytes develop [Ca2+]i overload. When reoxygenated they rapidly undergo hypercontracture, triggered by oscillations of [Ca2+]i. We investigated whether cGMP-mediated stimuli can modulate [Ca2+]i or pHi recovery and whether this contributes to their protective effect. Membrane-permeable cGMP analogues, 8-bromo-cGMP (1 mmol/L) or 8-pCPT-cGMP (10 µmmol/L), or a receptor-mediated activator of particulate guanylyl cyclase, urodilatin (1 µmol/L), were applied.
Results: The investigated stimuli protect against reoxygenation-induced hypercontracture (cell length as percent of end-ischemic length; control: 68 ± 1.6; 8-bromo-cGMP: 88 ± 1.5*; 8-pCPT-cGMP: 84 ± 2.9*; urodilatin: 87 ± 1.1*; n=24; *p<0.05). Recovery from [Ca2+]i overload after 2 min reoxygenation [fura-2 ratio (a.u.); control: 1.43 ± 0.15; 8-bromo-cGMP: 1.86 ± 0.15*; 8-pCPT-cGMP: 1.92 ± 0.19*; urodilatin: 1.93 ± 0.24*; n=25; *p<0.05] was accelerated, and the frequency of [Ca2+]i oscillations (min–1) was significantly reduced (control: 49 ± 5.0 min–1; 8-bromo-cGMP: 18 ± 3.5* min–1; 8-pCPT-cGMP: 18 ± 4.5* min–1; urodilatin: 16 ± 4.1* min–1; n=24; *p<0.05). cGMP-mediated stimuli increased sarcoplasmic Ca2+ sequestration (caffeine-releasable Ca2+ pool: 2–3 fold increase vs. control). Inhibition of sarcoplasmic Ca2+-ATPase (SERCA) by thapsigargin (150 nmol/L) or of protein kinase G with KT-5823 (1 µmol/L) abolished the effect of these stimuli on [Ca2+]i recovery. The investigated stimuli significantly enhanced phospholamban phosphorylation.
Conclusions: We conclude that cGMP-dependent signals activate SERCA via a protein kinase G-dependent phosphorylation of phospholamban. The increase in SERCA activity seems to reduce peak [Ca2+]i and [Ca2+]i oscillation during reoxygenation and to attenuate the excessive activation of the contractile machinery that otherwise leads to the development of hypercontracture.
KEYWORDS Reperfusion injury; Cardiomyocytes; Calcium; cGMP; Sarcoplasmic reticulum
* Guy Vassort, Montpellier, served as guest editor for this article.
Time for primary review 21 days
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  G. Szabo, T. Radovits, G. Veres, N. Krieger, S. Loganathan, P. Sandner, and M. Karck Vardenafil protects against myocardial and endothelial injuries after cardiopulmonary bypass Eur. J. Cardiothorac. Surg., October 1, 2009; 36(4): 657 - 664. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Kasseckert, C. Schafer, A. Kluger, D. Gligorievski, J. Tillmann, K.-D. Schluter, T. Noll, H. Sauer, H. M. Piper, and Y. Abdallah Stimulation of cGMP signalling protects coronary endothelium against reperfusion-induced intercellular gap formation Cardiovasc Res, July 15, 2009; 83(2): 381 - 387. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Inserte, J. A. Barrabes, V. Hernando, and D. Garcia-Dorado Orphan targets for reperfusion injury Cardiovasc Res, July 15, 2009; 83(2): 169 - 178. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kuno, N. V. Solenkova, V. Solodushko, T. Dost, Y. Liu, X.-M. Yang, M. V. Cohen, and J. M. Downey Infarct limitation by a protein kinase G activator at reperfusion in rabbit hearts is dependent on sensitizing the heart to A2b agonists by protein kinase C Am J Physiol Heart Circ Physiol, September 1, 2008; 295(3): H1288 - H1295. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. D.T. Costa, S. V. Pierre, M. V. Cohen, J. M. Downey, and K. D. Garlid cGMP signalling in pre- and post-conditioning: the role of mitochondria Cardiovasc Res, January 15, 2008; 77(2): 344 - 352. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. M. Piper, Y. Abdallah, S. Kasseckert, and K.-D. Schluter Sarcoplasmic reticulum-mitochondrial interaction in the mechanism of acute reperfusion injury Cardiovasc Res, January 15, 2008; 77(2): 234 - 236. [Full Text] [PDF]
|
|
|
|
 |
|
 T.-T. Pan, K. L. Neo, L.-F. Hu, Q. C. Yong, and J.-S. Bian H2S preconditioning-induced PKC activation regulates intracellular calcium handling in rat cardiomyocytes Am J Physiol Cell Physiol, January 1, 2008; 294(1): C169 - C177. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. H. Talukder, A. Kalyanasundaram, X. Zhao, L. Zuo, P. Bhupathy, G. J. Babu, A. J. Cardounel, M. Periasamy, and J. L. Zweier Expression of SERCA isoform with faster Ca2+ transport properties improves postischemic cardiac function and Ca2+ handling and decreases myocardial infarction Am J Physiol Heart Circ Physiol, October 1, 2007; 293(4): H2418 - H2428. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Vila-Petroff, M. A. Salas, M. Said, C. A. Valverde, L. Sapia, E. Portiansky, R. J. Hajjar, E. G. Kranias, C. Mundina-Weilenmann, and A. Mattiazzi CaMKII inhibition protects against necrosis and apoptosis in irreversible ischemia-reperfusion injury Cardiovasc Res, March 1, 2007; 73(4): 689 - 698. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Elrod, J. J. M. Greer, and D. J. Lefer Sildenafil-mediated acute cardioprotection is independent of the NO/cGMP pathway Am J Physiol Heart Circ Physiol, January 1, 2007; 292(1): H342 - H347. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. M. Piper, S. Kasseckert, and Y. Abdallah The sarcoplasmic reticulum as the primary target of reperfusion protection Cardiovasc Res, May 1, 2006; 70(2): 170 - 173. [Full Text] [PDF]
|
|
|
|
|
|
D. Garcia-Dorado, A. Rodriguez-Sinovas, M. Ruiz-Meana, J. Inserte, L. Agullo, and A. Cabestrero The end-effectors of preconditioning protection against myocardial cell death secondary to ischemia-reperfusion Cardiovasc Res, May 1, 2006; 70(2): 274 - 285. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Valverde, C. Mundina-Weilenmann, M. Reyes, E. G. Kranias, A. L. Escobar, and A. Mattiazzi Phospholamban phosphorylation sites enhance the recovery of intracellular Ca2+ after perfusion arrest in isolated, perfused mouse heart Cardiovasc Res, May 1, 2006; 70(2): 335 - 345. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Abdallah, A. Gkatzoflia, D. Gligorievski, S. Kasseckert, G. Euler, K.-D. Schluter, M. Schafer, H.-M. Piper, and C. Schafer Insulin protects cardiomyocytes against reoxygenation-induced hypercontracture by a survival pathway targeting SR Ca2+ storage Cardiovasc Res, May 1, 2006; 70(2): 346 - 353. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Abdallah and C. Schafer Insulin: An overall cardiovascular protector? Cardiovasc Res, January 1, 2006; 69(1): 4 - 6. [Full Text] [PDF]
|
|
|
|
|
|
A. Mattiazzi, C. Mundina-Weilenmann, C. Guoxiang, L. Vittone, and E. Kranias Role of phospholamban phosphorylation on Thr17 in cardiac physiological and pathological conditions Cardiovasc Res, December 1, 2005; 68(3): 366 - 375. [Abstract] [Full Text] [PDF]
|
|