Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice

Background Orai3 is a mammalian‐specific member of the Orai family (Orai1‒3) and a component of the store‐operated Ca2+ entry channels. There is little understanding of the role of Orai channels in cardiomyocytes, and its role in cardiac function remains unexplored. Thus, we developed mice lacking O...

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Main Authors: Jesse Gammons, Mohamed Trebak, Salvatore Mancarella
Format: Article
Language:English
Published: Wiley 2021-04-01
Series:Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease
Subjects:
Online Access:https://www.ahajournals.org/doi/10.1161/JAHA.120.019486
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author Jesse Gammons
Mohamed Trebak
Salvatore Mancarella
author_facet Jesse Gammons
Mohamed Trebak
Salvatore Mancarella
author_sort Jesse Gammons
collection DOAJ
description Background Orai3 is a mammalian‐specific member of the Orai family (Orai1‒3) and a component of the store‐operated Ca2+ entry channels. There is little understanding of the role of Orai channels in cardiomyocytes, and its role in cardiac function remains unexplored. Thus, we developed mice lacking Orai1 and Orai3 to address their role in cardiac homeostasis. Methods and Results We generated constitutive and inducible cardiomyocyte‐specific Orai3 knockout (Orai3cKO) mice. Constitutive Orai3‐loss led to ventricular dysfunction progressing to dilated cardiomyopathy and heart failure. Orai3cKO mice subjected to pressure overload developed a fulminant dilated cardiomyopathy with rapid heart failure onset, characterized by interstitial fibrosis and apoptosis. Ultrastructural analysis of Orai3‐deficient cardiomyocytes showed abnormal M‐ and Z‐line morphology. The greater density of condensed mitochondria in Orai3‐deficient cardiomyocytes was associated with the upregulation of DRP1 (dynamin‐related protein 1). Cardiomyocytes isolated from Orai3cKO mice exhibited profoundly altered myocardial Ca2+ cycling and changes in the expression of critical proteins involved in the Ca2+ clearance mechanisms. Upregulation of TRPC6 (transient receptor potential canonical type 6) channels was associated with upregulation of the RCAN1 (regulator of calcineurin 1), indicating the activation of the calcineurin signaling pathway in Orai3cKO mice. A more dramatic cardiac phenotype emerged when Orai3 was removed in adult mice using a tamoxifen‐inducible Orai3cKO mouse. The removal of Orai1 from adult cardiomyocytes did not change the phenotype of tamoxifen‐inducible Orai3cKO mice. Conclusions Our results identify a critical role for Orai3 in the heart. We provide evidence that Orai3‐mediated Ca2+ signaling is required for maintaining sarcomere integrity and proper mitochondrial function in adult mammalian cardiomyocytes.
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spelling doaj.art-11c6da05831a47faa74d700ab2a2f6152022-12-21T17:59:24ZengWileyJournal of the American Heart Association: Cardiovascular and Cerebrovascular Disease2047-99802021-04-0110810.1161/JAHA.120.019486Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in MiceJesse Gammons0Mohamed Trebak1Salvatore Mancarella2Department of Physiology University of Tennessee Health Science Center Memphis TNDepartment of Cellular and Molecular Physiology The Pennsylvania State University College of Medicine Hershey PADepartment of Physiology University of Tennessee Health Science Center Memphis TNBackground Orai3 is a mammalian‐specific member of the Orai family (Orai1‒3) and a component of the store‐operated Ca2+ entry channels. There is little understanding of the role of Orai channels in cardiomyocytes, and its role in cardiac function remains unexplored. Thus, we developed mice lacking Orai1 and Orai3 to address their role in cardiac homeostasis. Methods and Results We generated constitutive and inducible cardiomyocyte‐specific Orai3 knockout (Orai3cKO) mice. Constitutive Orai3‐loss led to ventricular dysfunction progressing to dilated cardiomyopathy and heart failure. Orai3cKO mice subjected to pressure overload developed a fulminant dilated cardiomyopathy with rapid heart failure onset, characterized by interstitial fibrosis and apoptosis. Ultrastructural analysis of Orai3‐deficient cardiomyocytes showed abnormal M‐ and Z‐line morphology. The greater density of condensed mitochondria in Orai3‐deficient cardiomyocytes was associated with the upregulation of DRP1 (dynamin‐related protein 1). Cardiomyocytes isolated from Orai3cKO mice exhibited profoundly altered myocardial Ca2+ cycling and changes in the expression of critical proteins involved in the Ca2+ clearance mechanisms. Upregulation of TRPC6 (transient receptor potential canonical type 6) channels was associated with upregulation of the RCAN1 (regulator of calcineurin 1), indicating the activation of the calcineurin signaling pathway in Orai3cKO mice. A more dramatic cardiac phenotype emerged when Orai3 was removed in adult mice using a tamoxifen‐inducible Orai3cKO mouse. The removal of Orai1 from adult cardiomyocytes did not change the phenotype of tamoxifen‐inducible Orai3cKO mice. Conclusions Our results identify a critical role for Orai3 in the heart. We provide evidence that Orai3‐mediated Ca2+ signaling is required for maintaining sarcomere integrity and proper mitochondrial function in adult mammalian cardiomyocytes.https://www.ahajournals.org/doi/10.1161/JAHA.120.019486calcium signalingdilated cardiomyopathyion channelsOrai3
spellingShingle Jesse Gammons
Mohamed Trebak
Salvatore Mancarella
Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice
Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease
calcium signaling
dilated cardiomyopathy
ion channels
Orai3
title Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice
title_full Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice
title_fullStr Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice
title_full_unstemmed Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice
title_short Cardiac‐Specific Deletion of Orai3 Leads to Severe Dilated Cardiomyopathy and Heart Failure in Mice
title_sort cardiac specific deletion of orai3 leads to severe dilated cardiomyopathy and heart failure in mice
topic calcium signaling
dilated cardiomyopathy
ion channels
Orai3
url https://www.ahajournals.org/doi/10.1161/JAHA.120.019486
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AT salvatoremancarella cardiacspecificdeletionoforai3leadstoseveredilatedcardiomyopathyandheartfailureinmice