1
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Kanaporis G, Blatter LA. Increased Risk for Atrial Alternans in Rabbit Heart Failure: The Role of Ca 2+/Calmodulin-Dependent Kinase II and Inositol-1,4,5-trisphosphate Signaling. Biomolecules 2023; 14:53. [PMID: 38254653 PMCID: PMC10813785 DOI: 10.3390/biom14010053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/18/2023] [Accepted: 12/23/2023] [Indexed: 01/24/2024] Open
Abstract
Heart failure (HF) increases the probability of cardiac arrhythmias, including atrial fibrillation (AF), but the mechanisms linking HF to AF are poorly understood. We investigated disturbances in Ca2+ signaling and electrophysiology in rabbit atrial myocytes from normal and failing hearts and identified mechanisms that contribute to the higher risk of atrial arrhythmias in HF. Ca2+ transient (CaT) alternans-beat-to-beat alternations in CaT amplitude-served as indicator of increased arrhythmogenicity. We demonstrate that HF atrial myocytes were more prone to alternans despite no change in action potentials duration and only moderate decrease of L-type Ca2+ current. Ca2+/calmodulin-dependent kinase II (CaMKII) inhibition suppressed CaT alternans. Activation of IP3 signaling by endothelin-1 (ET-1) and angiotensin II (Ang II) resulted in acute, but transient reduction of CaT amplitude and sarcoplasmic reticulum (SR) Ca2+ load, and lowered the alternans risk. However, prolonged exposure to ET-1 and Ang II enhanced SR Ca2+ release and increased the degree of alternans. Inhibition of IP3 receptors prevented the transient ET-1 and Ang II effects and by itself increased the degree of CaT alternans. Our data suggest that activation of CaMKII and IP3 signaling contribute to atrial arrhythmogenesis in HF.
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Affiliation(s)
| | - Lothar A. Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL 60612, USA;
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2
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Mazhar F, Bartolucci C, Regazzoni F, Paci M, Dedè L, Quarteroni A, Corsi C, Severi S. A detailed mathematical model of the human atrial cardiomyocyte: integration of electrophysiology and cardiomechanics. J Physiol 2023. [PMID: 37641426 DOI: 10.1113/jp283974] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 08/02/2023] [Indexed: 08/31/2023] Open
Abstract
Mechano-electric regulations (MER) play an important role in the maintenance of cardiac performance. Mechano-calcium and mechano-electric feedback (MCF and MEF) pathways adjust the cardiomyocyte contractile force according to mechanical perturbations and affects electro-mechanical coupling. MER integrates all these regulations in one unit resulting in a complex phenomenon. Computational modelling is a useful tool to accelerate the mechanistic understanding of complex experimental phenomena. We have developed a novel model that integrates the MER loop for human atrial cardiomyocytes with proper consideration of feedforward and feedback pathways. The model couples a modified version of the action potential (AP) Koivumäki model with the contraction model by Quarteroni group. The model simulates iso-sarcometric and isometric twitches and the feedback effects on AP and Ca2+ -handling. The model showed a biphasic response of Ca2+ transient (CaT) peak to increasing pacing rates and highlights the possible mechanisms involved. The model has shown a shift of the threshold for AP and CaT alternans from 4.6 to 4 Hz under post-operative atrial fibrillation, induced by depressed SERCA activity. The alternans incidence was dependent on a chain of mechanisms including RyRs availability time, MCF coupling, CaMKII phosphorylation, and the stretch levels. As a result, the model predicted a 10% slowdown of conduction velocity for a 20% stretch, suggesting a role of stretch in creation of substrate formation for atrial fibrillation. Overall, we conclude that the developed model provides a physiological CaT followed by a physiological twitch. This model can open pathways for the future studies of human atrial electromechanics. KEY POINTS: With the availability of human atrial cellular data, interest in atrial-specific model integration has been enhanced. We have developed a detailed mathematical model of human atrial cardiomyocytes including the mechano-electric regulatory loop. The model has gone through calibration and evaluation phases against a wide collection of available human in-vitro data. The usefulness of the model for analysing clinical problems has been preliminaryly tested by simulating the increased incidence of Ca2+ transient and action potential alternans at high rates in post-operative atrial fibrillation condition. The model determines the possible role of mechano-electric feedback in alternans incidence, which can increase vulnerability to atrial arrhythmias by varying stretch levels. We found that our physiologically accurate description of Ca2+ handling can reproduce many experimental phenomena and can help to gain insights into the underlying pathophysiological mechanisms.
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Affiliation(s)
- Fazeelat Mazhar
- Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Cesena, Italy
| | - Chiara Bartolucci
- Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Cesena, Italy
| | | | - Michelangelo Paci
- Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Cesena, Italy
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Luca Dedè
- MOX - Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
| | - Alfio Quarteroni
- MOX - Dipartimento di Matematica, Politecnico di Milano, Milan, Italy
- Mathematics Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Cristiana Corsi
- Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Cesena, Italy
| | - Stefano Severi
- Department of Electrical, Electronic and Information Engineering 'Guglielmo Marconi', University of Bologna, Cesena, Italy
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3
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Su SA, Zhang Y, Li W, Xi Y, Lu Y, Shen J, Ma Y, Wang Y, Shen Y, Xie L, Ma H, Xie Y, Xiang M. Cardiac Piezo1 Exacerbates Lethal Ventricular Arrhythmogenesis by Linking Mechanical Stress with Ca 2+ Handling After Myocardial Infarction. RESEARCH (WASHINGTON, D.C.) 2023; 6:0165. [PMID: 37303604 PMCID: PMC10255393 DOI: 10.34133/research.0165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/17/2023] [Indexed: 06/13/2023]
Abstract
Ventricular arrhythmogenesis is a key cause of sudden cardiac death following myocardial infarction (MI). Accumulating data show that ischemia, sympathetic activation, and inflammation contribute to arrhythmogenesis. However, the role and mechanisms of abnormal mechanical stress in ventricular arrhythmia following MI remain undefined. We aimed to examine the impact of increased mechanical stress and identify the role of the key sensor Piezo1 in ventricular arrhythmogenesis in MI. Concomitant with increased ventricular pressure, Piezo1, as a newly recognized mechano-sensitive cation channel, was the most up-regulated mechanosensor in the myocardium of patients with advanced heart failure. Piezo1 was mainly located at the intercalated discs and T-tubules of cardiomyocytes, which are responsible for intracellular calcium homeostasis and intercellular communication. Cardiomyocyte-conditional Piezo1 knockout mice (Piezo1Cko) exhibited preserved cardiac function after MI. Piezo1Cko mice also displayed a dramatically decreased mortality in response to the programmed electrical stimulation after MI with a markedly reduced incidence of ventricular tachycardia. In contrast, activation of Piezo1 in mouse myocardium increased the electrical instability as indicated by prolonged QT interval and sagging ST segment. Mechanistically, Piezo1 impaired intracellular calcium cycling dynamics by mediating the intracellular Ca2+ overload and increasing the activation of Ca2+-modulated signaling, CaMKII, and calpain, which led to the enhancement of phosphorylation of RyR2 and further increment of Ca2+ leaking, finally provoking cardiac arrhythmias. Furthermore, in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), Piezo1 activation remarkably triggered cellular arrhythmogenic remodeling by significantly shortening the duration of the action potential, inducing early afterdepolarization, and enhancing triggered activity.This study uncovered a proarrhythmic role of Piezo1 during cardiac remodeling, which is achieved by regulating Ca2+ handling, implying a promising therapeutic target in sudden cardiac death and heart failure.
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Affiliation(s)
- Sheng-an Su
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Yuhao Zhang
- Department of Endocrinology, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Wudi Li
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Yutao Xi
- Texas Heart Institute, Houston, TX 77030, USA
| | - Yunrui Lu
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Jian Shen
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Yuankun Ma
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Yaping Wang
- Department of Endocrinology, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Yimin Shen
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Lan Xie
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Hong Ma
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Yao Xie
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Meixiang Xiang
- Department of Cardiology, Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital,
Zhejiang University School of Medicine, Hangzhou 310009, China
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4
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Haugsten Hansen M, Sadredini M, Hasic A, Anderson ME, Sjaastad I, Korseberg Stokke M. CaMKII and reactive oxygen species contribute to early reperfusion arrhythmias, but oxidation of CaMKIIδ at methionines 281/282 is not a determining factor. J Mol Cell Cardiol 2023; 175:49-61. [PMID: 36528076 DOI: 10.1016/j.yjmcc.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 12/16/2022]
Abstract
BACKGROUND Available evidence suggest that Ca2+/calmodulin-dependent protein kinase type IIδ (CaMKIIδ) and reactive oxygen species (ROS) are important in early ischemia-reperfusion arrhythmias (IRA). Since ROS can activate CaMKIIδ by oxidation of two methionines at positions 281/282, oxidized-CaMKIIδ (Ox-CaMKIIδ) has been proposed to be important for IRA. However, direct evidence for this is missing. METHODS We exposed Langendorff-perfused hearts and ventricular cardiomyocytes from C57BL/6 mice to global and simulated ischemia, respectively, and recorded arrhythmic events during early reperfusion. Hearts were collected for immunoblotting of key phosphoproteins. We evaluated the effects of beta-adrenoceptor stimulation, inhibition of CaMKII, and reduced ROS levels with isoprenaline, KN93/AIP and N-acetylcysteine (NAC), respectively. We further tested the importance of Ox-CaMKIIδ by using hearts and cardiomyocytes from mice with CaMKIIδ resistant to oxidation of methionines 281 and 282 (MMVV). RESULTS Hearts treated with KN93, AIP or NAC had lower incidence of early IRA, and NAC-treated cardiomyocytes had lower incidence of arrhythmogenic events. However, hearts from MMVV mice had a similar incidence of early IRA to wild type mice (WT), and MMVV and WT cardiomyocytes had a similar frequency of Ca2+ waves and Ca2+ sparks. Immunoblotting confirmed high levels of oxidation in early reperfusion, but revealed no significant differences in the phosphorylation levels of Ca2+-handling proteins in MMVV and WT hearts. CONCLUSIONS Although CaMKII and ROS both contribute to early IRA, hearts from mice with CaMKII resistant to oxidation at methionines 281/282 were not protected from such arrhythmias, suggesting that oxidation at these sites is not a determining factor.
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Affiliation(s)
- Marie Haugsten Hansen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Mani Sadredini
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Almira Hasic
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Mark E Anderson
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Mathis Korseberg Stokke
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway; Department of Cardiology, Oslo University Hospital Rikshospitalet, Oslo, Norway.
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5
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Wu J, Liu T, Shi S, Fan Z, Hiram R, Xiong F, Cui B, Su X, Chang R, Zhang W, Yan M, Tang Y, Huang H, Wu G, Huang C. Dapagliflozin reduces the vulnerability of rats with pulmonary arterial hypertension-induced right heart failure to ventricular arrhythmia by restoring calcium handling. Cardiovasc Diabetol 2022; 21:197. [PMID: 36171554 PMCID: PMC9516842 DOI: 10.1186/s12933-022-01614-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 09/01/2022] [Indexed: 12/20/2022] Open
Abstract
Background Malignant ventricular arrhythmia (VA) is a major contributor to sudden cardiac death (SCD) in patients with pulmonary arterial hypertension (PAH)-induced right heart failure (RHF). Recently, dapagliflozin (DAPA), a sodium/glucose cotransporter-2 inhibitor (SGLT2i), has been found to exhibit cardioprotective effects in patients with left ventricular systolic dysfunction. In this study, we examined the effects of DAPA on VA vulnerability in a rat model of PAH-induced RHF. Methods Rats randomly received monocrotaline (MCT, 60 mg/kg) or vehicle via a single intraperitoneal injection. A day later, MCT-injected rats were randomly treated with placebo, low-dose DAPA (1 mg/kg/day), or high-dose (3 mg/kg/day) DAPA orally for 35 days. Echocardiographic analysis, haemodynamic experiments, and histological assessments were subsequently performed to confirm the presence of PAH-induced RHF. Right ventricle (RV) expression of calcium (Ca2+) handling proteins were detected via Western blotting. RV expression of connexin 43 (Cx43) was determined via immunohistochemical staining. An optical mapping study was performed to assess the electrophysiological characteristics in isolated hearts. Cellular Ca2+ imaging from RV cardiomyocytes (RVCMs) was recorded using Fura-2 AM or Fluo-4 AM. Results High-dose DAPA treatment attenuated RV structural remodelling, improved RV function, alleviated Cx43 remodelling, increased the conduction velocity, restored the expression of key Ca2+ handling proteins, increased the threshold for Ca2+ and action potential duration (APD) alternans, decreased susceptibility to spatially discordant APD alternans and spontaneous Ca2+ events, promoted cellular Ca2+ handling, and reduced VA vulnerability in PAH-induced RHF rats. Low-dose DAPA treatment also showed antiarrhythmic effects in hearts with PAH-induced RHF, although with a lower level of efficacy. Conclusion DAPA administration reduced VA vulnerability in rats with PAH-induced RHF by improving RVCM Ca2+ handling. Supplementary Information The online version contains supplementary material available at 10.1186/s12933-022-01614-5.
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Affiliation(s)
- Jinchun Wu
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Department of Cardiology, Qinghai Provincial People's Hospital, No.2 Gong He Road, Xining, 810007, People's Republic of China
| | - Tao Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China. .,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China. .,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.
| | - Shaobo Shi
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - Zhixing Fan
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - Roddy Hiram
- Department of Medicine, Faculty of Medicine, Montreal Heart Institute (MHI), Université de Montréal, Montreal, QC, Canada
| | - Feng Xiong
- Department of Medicine, Faculty of Medicine, Montreal Heart Institute (MHI), Université de Montréal, Montreal, QC, Canada
| | - Bo Cui
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - Xiaoling Su
- Department of Cardiology, Qinghai Provincial People's Hospital, No.2 Gong He Road, Xining, 810007, People's Republic of China
| | - Rong Chang
- Department of Cardiology, Shenzhen Longhua District Central Hospital, The Affiliated Central Hospital of Shenzhen Longhua District, Guangdong Medical University, No. 187 Guanlan Road, Longhua District, Shenzhen, 518109, China
| | - Wei Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - Min Yan
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - Yanhong Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - He Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China
| | - Gang Wu
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China. .,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China. .,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, No. 238 Jiefang Road, Wuhan, 430060, People's Republic of China. .,Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuhan, 430060, People's Republic of China. .,Hubei Key Laboratory of Cardiology, 238 Jiefang Road, Wuhan, 430060, People's Republic of China.
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6
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Gonano LA, Vila Petroff M. AKAP18δ Puts CaMKII in the Right Place at the Right Time: Implications for Cardiac Ca 2+ Handling. Circ Res 2022; 130:45-47. [PMID: 34995136 DOI: 10.1161/circresaha.121.320537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Luis A Gonano
- Centro de Investigaciones Cardiovasculares, CONICET-CCT La Plata, Facultad de Ciencias Médicas, UNLP, Argentina
| | - Martin Vila Petroff
- Centro de Investigaciones Cardiovasculares, CONICET-CCT La Plata, Facultad de Ciencias Médicas, UNLP, Argentina
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7
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Wegener JW, Wagdi A, Wagner E, Katschinski DM, Hasenfuss G, Bruegmann T, Lehnart SE. The RyR2-R2474S Mutation Sensitizes Cardiomyocytes and Hearts to Catecholaminergic Stress-Induced Oxidation of the Mitochondrial Glutathione Pool. Front Physiol 2021; 12:777770. [PMID: 34955889 PMCID: PMC8696262 DOI: 10.3389/fphys.2021.777770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/19/2021] [Indexed: 11/24/2022] Open
Abstract
Missense mutations in the cardiac ryanodine receptor type 2 (RyR2) characteristically cause catecholaminergic arrhythmias. Reminiscent of the phenotype in patients, RyR2-R2474S knockin mice develop exercise-induced ventricular tachyarrhythmias. In cardiomyocytes, increased mitochondrial matrix Ca2+ uptake was recently linked to non-linearly enhanced ATP synthesis with important implications for cardiac redox metabolism. We hypothesize that catecholaminergic stimulation and contractile activity amplify mitochondrial oxidation pathologically in RyR2-R2474S cardiomyocytes. To investigate this question, we generated double transgenic RyR2-R2474S mice expressing a mitochondria-restricted fluorescent biosensor to monitor the glutathione redox potential (EGSH). Electrical field pacing-evoked RyR2-WT and RyR2-R2474S cardiomyocyte contractions resulted in a small but significant baseline EGSH increase. Importantly, β-adrenergic stimulation resulted in excessive EGSH oxidization of the mitochondrial matrix in RyR2-R2474S cardiomyocytes compared to baseline and RyR2-WT control. Physiologically β-adrenergic stimulation significantly increased mitochondrial EGSH further in intact beating RyR2-R2474S but not in RyR2-WT control Langendorff perfused hearts. Finally, this catecholaminergic EGSH increase was significantly attenuated following treatment with the RyR2 channel blocker dantrolene. Together, catecholaminergic stimulation and increased diastolic Ca2+ leak induce a strong, but dantrolene-inhibited mitochondrial EGSH oxidization in RyR2-R2474S cardiomyocytes.
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Affiliation(s)
- Jörg W Wegener
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), Georg-August University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Ahmed Wagdi
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany.,Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany
| | - Eva Wagner
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany
| | - Dörthe M Katschinski
- DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany.,Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany
| | - Gerd Hasenfuss
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Tobias Bruegmann
- Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), Georg-August University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany.,Institute of Cardiovascular Physiology, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany
| | - Stephan E Lehnart
- Department of Cardiology and Pulmonology, Heart Research Center Göttingen, University Medical Center Göttingen, Georg August University of Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), Georg-August University of Göttingen, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
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8
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Sadredini M, Manotheepan R, Lehnart SE, Anderson ME, Sjaastad I, Stokke MK. The oxidation-resistant CaMKII-MM281/282VV mutation does not prevent arrhythmias in CPVT1. Physiol Rep 2021; 9:e15030. [PMID: 34558218 PMCID: PMC8461029 DOI: 10.14814/phy2.15030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/11/2021] [Accepted: 08/16/2021] [Indexed: 11/24/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia type 1 (CPVT1) is an inherited arrhythmogenic disorder caused by missense mutations in the cardiac ryanodine receptors (RyR2), that result in increased β-adrenoceptor stimulation-induced diastolic Ca2+ leak. We have previously shown that exercise training prevents arrhythmias in CPVT1, potentially by reducing the oxidation of Ca2+ /calmodulin-dependent protein kinase type II (CaMKII). Therefore, we tested whether an oxidation-resistant form of CaMKII protects mice carrying the CPVT1-causative mutation RyR2-R2474S (RyR2-RS) against arrhythmias. Antioxidant treatment (N-acetyl-L-cysteine) reduced the frequency of β-adrenoceptor stimulation-induced arrhythmogenic Ca2+ waves in isolated cardiomyocytes from RyR2-RS mice. To test whether the prevention of CaMKII oxidation exerts an antiarrhythmic effect, mice expressing the oxidation-resistant CaMKII-MM281/282VV variant (MMVV) were crossed with RyR2-RS mice to create a double transgenic model (RyR2-RS/MMVV). Wild-type mice served as controls. Telemetric ECG surveillance revealed an increased incidence of ventricular tachycardia and an increased arrhythmia score in both RyR2-RS and RyR2-RS/MMVV compared to wild-type mice, both following a β-adrenoceptor challenge (isoprenaline i.p.), and following treadmill exercise combined with a β-adrenoceptor challenge. There were no differences in the incidence of arrhythmias between RyR2-RS and RyR2-RS/MMVV mice. Furthermore, no differences were observed in β-adrenoceptor stimulation-induced Ca2+ waves in RyR2-RS/MMVV compared to RyR2-RS. In conclusion, antioxidant treatment reduces β-adrenoceptor stimulation-induced Ca2+ waves in RyR2-RS cardiomyocytes. However, oxidation-resistant CaMKII-MM281/282VV does not protect RyR2-RS mice from β-adrenoceptor stimulation-induced Ca2+ waves or arrhythmias. Hence, alternative oxidation-sensitive targets need to be considered to explain the beneficial effect of antioxidant treatment on Ca2+ waves in cardiomyocytes from RyR2-RS mice.
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Affiliation(s)
- Mani Sadredini
- Institute for Experimental Medical Research and KG Jebsen Cardiac Research CentreOslo University Hospital and University of OsloOsloNorway
| | - Ravinea Manotheepan
- Institute for Experimental Medical Research and KG Jebsen Cardiac Research CentreOslo University Hospital and University of OsloOsloNorway
| | - Stephan E. Lehnart
- Heart Research Center GöttingenDepartment of Cardiology and PulmonologyUniversity Medical Center GöttingenGeorg August University GöttingenGöttingenGermany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC)University of GöttingenGöttingenGermany
- DZHK (German Centre for Cardiovascular Research)GöttingenGermany
| | - Mark E. Anderson
- Division of CardiologyDepartment of MedicineThe Johns Hopkins University School of MedicineBaltimoreUSA
| | - Ivar Sjaastad
- Institute for Experimental Medical Research and KG Jebsen Cardiac Research CentreOslo University Hospital and University of OsloOsloNorway
| | - Mathis K. Stokke
- Institute for Experimental Medical Research and KG Jebsen Cardiac Research CentreOslo University Hospital and University of OsloOsloNorway
- Department of CardiologyOslo University HospitalRikshospitaletOsloNorway
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