Reversible redox modifications of ryanodine receptor ameliorate ventricular arrhythmias in the ischemic-reperfused heart

作者：Romina Valeria Becerra, Bárbara Román, Mariano Nahuel Di Carlo, Juan Ignacio Elio Mariángelo, Margarita Salas, Gina Sánchez, P Donoso, Guillermo Schinella, Leticia Vittone, Xander H.T. Wehrens, Cecilia Mundiña‐Weilenmann, Matilde Said · 发表于：American Journal of Physiology-Heart and Circulatory Physiology · 年份：2016 · DOI：10.1152/ajpheart.00142.2016 · 被引用次数：32 · 研究领域：Cardiac electrophysiology and arrhythmias、Ion channel regulation and function、Electron Spin Resonance Studies

Previous results from our laboratory showed that phosphorylation of ryanodine receptor 2 (RyR2) by Ca(2+) calmodulin-dependent kinase II (CaMKII) was a critical but not the unique event responsible for the production of reperfusion-induced arrhythmogenesis, suggesting the existence of other mechanisms cooperating in an additive way to produce these rhythm alterations. Oxidative stress is a prominent feature of ischemia/reperfusion injury. Both CaMKII and RyR2 are proteins susceptible to alteration by redox modifications. This study was designed to elucidate whether CaMKII and RyR2 redox changes occur during reperfusion and whether these changes are involved in the genesis of arrhythmias. Langendorff-perfused hearts from rats or transgenic mice with genetic ablation of CaMKII phosphorylation site on RyR2 (S2814A) were subjected to ischemia-reperfusion in the presence or absence of a free radical scavenger (mercaptopropionylglycine, MPG) or inhibitors of NADPH oxidase and nitric oxide synthase. Left ventricular contractile parameters and monophasic action potentials were recorded. Oxidation and phosphorylation of CaMKII and RyR2 were assessed. Increased oxidation of CaMKII during reperfusion had no consequences on the level of RyR2 phosphorylation. Avoiding the reperfusion-induced thiol oxidation of RyR2 with MPG produced a reduction in the number of arrhythmias and did not modify the contractile recovery. Conversely, selective prevention of S-nitrosylation and S-glutathionylat...