TY - JOUR
T1 - The signaling pathway for aldosterone-induced mitochondrial production of superoxide anion in the myocardium
AU - Nolly, M. B.
AU - Caldiz, C. I.
AU - Yeves, A. M.
AU - Villa-Abrille, M. C.
AU - Morgan, P. E.
AU - Amado Mondaca, Nicolas
AU - Portiansky, Enrique L.
AU - Chiappe de Cingolani, G. E.
AU - Cingolani, H. E.
AU - Ennis, I. L.
N1 - Funding Information:
This work was supported in part by grants PICT 25475 and 078 from Agencia Nacional de Promoción Científica of Argentina to Dr. Horacio E. Cingolani and Dr. Gladys Chiappe de Cingolani, respectively. We specially thank Fabian Nishida for histological technical assistance as well as Gador SA, Buenos Aires, Argentina for kindly providing us eplerenone.
PY - 2014/2
Y1 - 2014/2
N2 - Mineralocorticoid receptor (MR) antagonists decrease morbidity and mortality in heart failure patients for whom oxidative stress is usual; however, the underlying mechanism for this protection is unclear. Since aldosterone stimulates reactive oxygen species (ROS) production in several tissues, we explored its effect and the intracellular pathway involved in the rat myocardium. Aldosterone dose-dependently increased O2- production in myocardial slices. At 10nmol/L, aldosterone increased O2- to 165±8.8% of control, an effect prevented not only by the MR antagonists eplerenone and spironolactone (107±7.8 and 103±5.3%, respectively) but also by AG1478 (105±8.0%), antagonist of the EGF receptor (EGFR). Similar results were obtained by silencing MR expression through the direct intramyocardial injection of a lentivirus coding for a siRNA against the MR. The aldosterone effect on O2- production was mimicked by the mKATP channel opener diazoxide and blocked by preventing its opening with 5-HD and glibenclamide, implicating the mitochondria as the source of O2-. Inhibiting the respiratory chain with rotenone or mitochondrial permeability transition (MPT) with cyclosporine A or bongkrekic acid also canceled aldosterone-induced O2- production. In addition, aldosterone effect depended on NADPH oxidase and phosphoinositide 3-kinase activation, as apocynin and wortmannin, respectively, inhibited it. EGF (0.1μg/mL) similarly increased O2-, although in this case MR antagonists had no effect, suggesting that EGFR transactivation occurred downstream from MR activation. Inhibition of mKATP channels, the respiratory chain, or MPT did not prevent Akt phosphorylation, supporting that it happened upstream of the mitochondria. Importantly, cardiomyocytes were confirmed as a source of aldosterone induced mitochondrial ROS production in experiments performed in isolated cardiac myocytes.These results allow us to speculate that the beneficial effects of MR antagonists in heart failure may be related to a decrease in oxidative stress.
AB - Mineralocorticoid receptor (MR) antagonists decrease morbidity and mortality in heart failure patients for whom oxidative stress is usual; however, the underlying mechanism for this protection is unclear. Since aldosterone stimulates reactive oxygen species (ROS) production in several tissues, we explored its effect and the intracellular pathway involved in the rat myocardium. Aldosterone dose-dependently increased O2- production in myocardial slices. At 10nmol/L, aldosterone increased O2- to 165±8.8% of control, an effect prevented not only by the MR antagonists eplerenone and spironolactone (107±7.8 and 103±5.3%, respectively) but also by AG1478 (105±8.0%), antagonist of the EGF receptor (EGFR). Similar results were obtained by silencing MR expression through the direct intramyocardial injection of a lentivirus coding for a siRNA against the MR. The aldosterone effect on O2- production was mimicked by the mKATP channel opener diazoxide and blocked by preventing its opening with 5-HD and glibenclamide, implicating the mitochondria as the source of O2-. Inhibiting the respiratory chain with rotenone or mitochondrial permeability transition (MPT) with cyclosporine A or bongkrekic acid also canceled aldosterone-induced O2- production. In addition, aldosterone effect depended on NADPH oxidase and phosphoinositide 3-kinase activation, as apocynin and wortmannin, respectively, inhibited it. EGF (0.1μg/mL) similarly increased O2-, although in this case MR antagonists had no effect, suggesting that EGFR transactivation occurred downstream from MR activation. Inhibition of mKATP channels, the respiratory chain, or MPT did not prevent Akt phosphorylation, supporting that it happened upstream of the mitochondria. Importantly, cardiomyocytes were confirmed as a source of aldosterone induced mitochondrial ROS production in experiments performed in isolated cardiac myocytes.These results allow us to speculate that the beneficial effects of MR antagonists in heart failure may be related to a decrease in oxidative stress.
KW - Mineralocorticoid receptor
KW - Oxidative stress
KW - SiRNA
KW - Transactivation
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U2 - 10.1016/j.yjmcc.2013.12.004
DO - 10.1016/j.yjmcc.2013.12.004
M3 - Article
C2 - 24355174
AN - SCOPUS:84892847812
SN - 0022-2828
VL - 67
SP - 60
EP - 68
JO - Journal of Molecular and Cellular Cardiology
JF - Journal of Molecular and Cellular Cardiology
ER -