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The cardiac ryanodine receptor, but not sarcoplasmic reticulum Ca2-ATPase, is a major determinant of Ca2 alternans in intact mouse hearts

dc.contributor.authorSun, Bo
dc.contributor.authorWei, Jinhong
dc.contributor.authorZhong, Xiaowei
dc.contributor.authorVallmitjana Lees, Alexander
dc.contributor.authorBenítez Iglesias, Raúl
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament d'Enginyeria de Sistemes, Automàtica i Informàtica Industrial
dc.date.accessioned2018-11-30T09:29:21Z
dc.date.available2019-07-09T00:25:33Z
dc.date.issued2018-07-09
dc.identifier.citationSun, B., Wei, J., Zhong, X., Vallmitjana, A., Benitez, R. The cardiac ryanodine receptor, but not sarcoplasmic reticulum Ca2-ATPase, is a major determinant of Ca2 alternans in intact mouse hearts. "The journal of biological chemistry (Versió web)", 9 Juliol 2018, vol. 293, p. 13650-13677.
dc.identifier.issn1083-351X
dc.identifier.urihttp://hdl.handle.net/2117/125271
dc.description.abstractSarcoplasmic reticulum (SR) Ca2+ cycling is governed by the cardiac ryanodine receptor (RyR2) and SR Ca2+-ATPase (SERCA2a). Abnormal SR Ca2+ cycling is thought to be the primary cause of Ca2+ alternans that can elicit ventricular arrhythmias and sudden cardiac arrest. Although alterations in either RyR2 or SERCA2a function are expected to affect SR Ca2+ cycling, whether and to what extent altered RyR2 or SERCA2a function affects Ca2+ alternans is unclear. Here we employed a gain-of-function RyR2 variant (R4496C) and the phospholamban-knockout (PLB-KO) mouse model to assess the effect of genetically enhanced RyR2 or SERCA2a function on Ca2+ alternans. Confocal Ca2+ imaging revealed that RyR2-R4496C shortened SR Ca2+ release refractoriness and markedly suppressed rapid pacing-induced Ca2+ alternans. Interestingly, despite enhancing RyR2 function, intact RyR2-R4496C hearts exhibited no detectable spontaneous SR Ca2+ release events during pacing. Unlike for RyR2, enhancing SERCA2a function by ablating PLB exerted a relatively minor effect on Ca2+ alternans in intact hearts expressing RyR2 wildtype or a loss-of-function RyR2 variant, E4872Q, that promotes Ca2+ alternans. Furthermore, partial SERCA2a inhibition with 3 µM 2,5-di-tert-butylhydroquinone (tBHQ) also had little impact on Ca2+ alternans, while strong SERCA2a inhibition with 10 µM tBHQ markedly reduced the amplitude of Ca2+ transients and suppressed Ca2+ alternans in intact hearts. Our results demonstrate that enhanced RyR2 function suppresses Ca2+ alternans in the absence of spontaneous Ca2+ release and that RyR2, but not SERCA2a, is a key determinant of Ca2+ alternans in intact working hearts, making RyR2 an important therapeutic target for cardiac alternans.
dc.format.extent28 p.
dc.language.isoeng
dc.rightsAttribution-NonCommercial-NoDerivs 3.0 Spain
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
dc.subjectÀrees temàtiques de la UPC::Enginyeria biomèdica
dc.subject.lcshVentricular tachycardia
dc.subject.lcshCalcium
dc.subject.lcshRyanodine--Receptors
dc.subject.lcshEndoplasmic reticulum
dc.subject.otherVentricular tachyarrhythmia
dc.subject.otherCa2+ alternans
dc.subject.otherCa2+ release refractoriness
dc.subject.otherphospholamban
dc.subject.otherintact heart imaging
dc.subject.othercalcium intracellular release
dc.subject.othercalcium
dc.subject.othercalcium ATPase
dc.subject.otherryanodine receptor
dc.subject.othersarcoplasmic reticulum (SR)
dc.subject.othercalcium imaging
dc.subject.otherendoplasmic reticulum (ER)
dc.titleThe cardiac ryanodine receptor, but not sarcoplasmic reticulum Ca2-ATPase, is a major determinant of Ca2 alternans in intact mouse hearts
dc.typeArticle
dc.subject.lemacCalci
dc.subject.lemacTaquicàrdia ventricular
dc.contributor.groupUniversitat Politècnica de Catalunya. B2SLab - Bioinformatics and Biomedical Signals Laboratory
dc.contributor.groupUniversitat Politècnica de Catalunya. ANCORA - Anàlisi i control del ritme cardíac
dc.identifier.doi10.1074/jbc.RA118.003760
dc.description.peerreviewedPeer Reviewed
dc.relation.publisherversionhttp://www.jbc.org/content/early/2018/07/09/jbc.RA118.003760.abstract
dc.rights.accessOpen Access
drac.iddocument23340926
dc.description.versionPostprint (published version)
upcommons.citation.authorSun, B.; Wei, J.; Zhong, X.; Vallmitjana, A.; Benitez, R.
upcommons.citation.publishedtrue
upcommons.citation.publicationNameThe journal of biological chemistry (Versió web)
upcommons.citation.volume293
upcommons.citation.startingPage13650
upcommons.citation.endingPage13677


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