Thromb Haemost 2015; 113(03): 441-451
DOI: 10.1160/TH14-10-0901
Theme Issue Article
Schattauer GmbH

Altered FoF1 ATP synthase and susceptibility to mitochondrial permeability transition pore during ischaemia and reperfusion in aging cardiomyocytes

Celia Fernandez-Sanz
1   Vall d’Hebron Institut de Recerca, Universitat Autònoma, Barcelona, Spain
,
Marisol Ruiz-Meana
1   Vall d’Hebron Institut de Recerca, Universitat Autònoma, Barcelona, Spain
,
José Castellano
1   Vall d’Hebron Institut de Recerca, Universitat Autònoma, Barcelona, Spain
,
Elisabet Miro-Casas
1   Vall d’Hebron Institut de Recerca, Universitat Autònoma, Barcelona, Spain
,
Estefanía Nuñez
2   Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
,
Javier Inserte
1   Vall d’Hebron Institut de Recerca, Universitat Autònoma, Barcelona, Spain
,
Jesús Vázquez
2   Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
,
David Garcia-Dorado
1   Vall d’Hebron Institut de Recerca, Universitat Autònoma, Barcelona, Spain
› Author Affiliations

Financial support:Supported by the Spanish Ministry of Science (SAF2008–03067, BIO2012–37926 and ProteoRed-PT13/0001/0017) and the Instituto de Salud Carlos III (RETICS-RECAVA RD12/0042/0021, RD12/0042/0056 and FIS-PI12/00788). The CNIC is supported by the Spanish Ministry of Economy and Competitiveness and the Pro-CNIC Foundation. Celia Fernandez-Sanz is a predoctoral student at International Research Training Group PROMISE (”Protecting the Heart from Ischemia“) Giessen – Barcelona (DFG IRTG – 1566).
Further Information

Publication History

Received: 30 October 2014

Accepted after minor revision: 15 January 2015

Publication Date:
29 November 2017 (online)

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Summary

Aging is a major determinant of the incidence and severity of ischaemic heart disease. Preclinical information suggests the existence of intrinsic cellular alterations that contribute to ischaemic susceptibility in senescent myocardium, by mechanisms not well established. We investigated the role of altered mitochondrial function in the adverse effect of aging. Isolated perfused hearts from old mice (> 20 months) displayed increased ischaemia-reperfusion injury as compared to hearts from adult mice (6 months) despite delayed onset of ischaemic rigor contracture. In cardiomyocytes from aging hearts there was a more rapid decline of mitochondrial membrane potential (ΔΨm) as compared to young ones, but ischaemic rigor shortening was also delayed. Transient recovery of ΔΨm observed during ischaemia, secondary to the reversal of mitochondrial FoF1 ATP synthase to ATPase mode, was markedly reduced in aging cardiomyocytes. Proteomic analysis demonstrated increased oxidation of different subunits of ATP synthase. Altered bionergetics in aging cells was associated with reduced mitochondrial calcium uptake and more severe cytosolic calcium overload during ischaemia-reperfusion. Despite attenuated ROS burst and mitochondrial calcium overload, mitochondrial permeability transition pore (mPTP) opening and cell death was increased in reperfused aged cells. In vitro studies demonstrated a significantly reduced calcium retention capacity in interfibrillar mitochondria from aging hearts. Our results identify altered FoF1 ATP synthase and increased sensitivity of mitochondria to undergo mPTP opening as important determinants of the reduced tolerance to ischaemia-reperfusion in aging hearts. Because ATP synthase has been proposed to conform mPTP, it is tempting to hypothesise that oxidation of ATP synthase underlie both phenomena.