Oxidation of CaMKII determines the cardiotoxic effects of aldosterone

BJ He, MLA Joiner, MV Singh, ED Luczak… - Nature medicine, 2011 - nature.com
BJ He, MLA Joiner, MV Singh, ED Luczak, PD Swaminathan, OM Koval, W Kutschke…
Nature medicine, 2011nature.com
Excessive activation of the β-adrenergic, angiotensin II (Ang II) and aldosterone signaling
pathways promotes mortality after myocardial infarction, and antagonists targeting these
pathways are core therapies for treating this condition. Catecholamines and Ang II activate
the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII), the inhibition of
which prevents isoproterenol-mediated and Ang II–mediated cardiomyopathy. Here we
show that aldosterone exerts direct toxic actions on myocardium by oxidative activation of …
Abstract
Excessive activation of the β-adrenergic, angiotensin II (Ang II) and aldosterone signaling pathways promotes mortality after myocardial infarction, and antagonists targeting these pathways are core therapies for treating this condition. Catecholamines and Ang II activate the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII), the inhibition of which prevents isoproterenol-mediated and Ang II–mediated cardiomyopathy. Here we show that aldosterone exerts direct toxic actions on myocardium by oxidative activation of CaMKII, causing cardiac rupture and increased mortality in mice after myocardial infarction. Aldosterone induces CaMKII oxidation by recruiting NADPH oxidase, and this oxidized and activated CaMKII promotes matrix metalloproteinase 9 (MMP9) expression in cardiomyocytes. Myocardial CaMKII inhibition, overexpression of methionine sulfoxide reductase A (an enzyme that reduces oxidized CaMKII) or NADPH oxidase deficiency prevented aldosterone-enhanced cardiac rupture after myocardial infarction. These findings show that oxidized myocardial CaMKII mediates the cardiotoxic effects of aldosterone on the cardiac matrix and establish CaMKII as a nodal signal for the neurohumoral pathways associated with poor outcomes after myocardial infarction.
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