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Wang Q, Yuan J, Shen H, Zhu Q, Chen B, Wang J, Zhu W, Yorek MA, Hall DD, Wang Z, Song LS. Calpain inhibition protects against atrial fibrillation by mitigating diabetes-associated atrial fibrosis and calcium handling dysfunction in type 2 diabetes mice. Heart Rhythm 2024; 21:1143-1151. [PMID: 38395244 DOI: 10.1016/j.hrthm.2024.02.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024]
Abstract
BACKGROUND Diabetes mellitus (DM) is a major risk factor for atrial structural remodeling and atrial fibrillation (AF). Calpain activity is hypothesized to promote atrial remodeling and AF. OBJECTIVE The purpose of this study was to investigate the role of calpain in diabetes-associated AF, fibrosis, and calcium handling dysfunction. METHODS DM-associated AF was induced in wild-type (WT) mice and in mice overexpressing the calpain inhibitor calpastatin (CAST-OE) using high-fat diet feeding followed by low-dose streptozotocin injection (75 mg/kg). DM and AF outcomes were assessed by measuring blood glucose levels, fibrosis, and AF susceptibility during transesophageal atrial pacing. Intracellular Ca2+ transients, spontaneous Ca2+ release events, and intracellular T-tubule membranes were measured by in situ confocal microscopy. RESULTS WT mice with DM had significant hyperglycemia, atrial fibrosis, and AF susceptibility with increased atrial myocyte calpain activity and Ca2+ handling dysfunction relative to control treated animals. CAST-OE mice with DM had a similar level of hyperglycemia as diabetic WT littermates but lacked significant atrial fibrosis and AF susceptibility. DM-induced atrial calpain activity and downregulation of the calpain substrate junctophilin-2 were prevented by CAST-OE. Atrial myocytes of diabetic CAST-OE mice exhibited improved T-tubule membrane organization, Ca2+ handling, and reduced spontaneous Ca2+ release events compared to littermate controls. CONCLUSION This study confirmed that DM promotes calpain activation, atrial fibrosis, and AF in mice. CAST-OE effectively inhibits DM-induced calpain activation and reduces atrial remodeling and AF incidence through improved intracellular Ca2+ homeostasis. Our results support calpain inhibition as a potential therapy for preventing and treating AF in DM patients.
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Affiliation(s)
- Qing Wang
- Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; The Collaborative Innovation Center, Jining Medical University, Jining, Shandong, China; Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Jinxiang Yuan
- The Collaborative Innovation Center, Jining Medical University, Jining, Shandong, China; Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Hua Shen
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa; Department of Cardiovascular Surgery, Chinese PLA General Hospital, Beijing, China
| | - Qi Zhu
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa; Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu, China
| | - Biyi Chen
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Jinxi Wang
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Weizhong Zhu
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu, China
| | - Mark A Yorek
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa; Department of Veterans Affairs Iowa City Health Care System, Iowa City, Iowa; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa
| | - Duane D Hall
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Zhinong Wang
- Department of Cardiothoracic Surgery, Changzheng Hospital, Naval Medical University, Shanghai, China.
| | - Long-Sheng Song
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa; Department of Veterans Affairs Iowa City Health Care System, Iowa City, Iowa; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa.
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Ninni S, Algalarrondo V, Brette F, Lemesle G, Fauconnier J. Left atrial cardiomyopathy: Pathophysiological insights, assessment methods and clinical implications. Arch Cardiovasc Dis 2024; 117:283-296. [PMID: 38490844 DOI: 10.1016/j.acvd.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 03/17/2024]
Abstract
Atrial cardiomyopathy is defined as any complex of structural, architectural, contractile or electrophysiological changes affecting atria, with the potential to produce clinically relevant manifestations. Most of our knowledge about the mechanistic aspects of atrial cardiomyopathy is derived from studies investigating animal models of atrial fibrillation and atrial tissue samples obtained from individuals who have a history of atrial fibrillation. Several noninvasive tools have been reported to characterize atrial cardiomyopathy in patients, which may be relevant for predicting the risk of incident atrial fibrillation and its related outcomes, such as stroke. Here, we provide an overview of the pathophysiological mechanisms involved in atrial cardiomyopathy, and discuss the complex interplay of these mechanisms, including aging, left atrial pressure overload, metabolic disorders and genetic factors. We discuss clinical tools currently available to characterize atrial cardiomyopathy, including electrocardiograms, cardiac imaging and serum biomarkers. Finally, we discuss the clinical impact of atrial cardiomyopathy, and its potential role for predicting atrial fibrillation, stroke, heart failure and dementia. Overall, this review aims to highlight the critical need for a clinically relevant definition of atrial cardiomyopathy to improve treatment strategies.
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Affiliation(s)
- Sandro Ninni
- CHU de Lille, Université de Lille, 59000 Lille, France.
| | - Vincent Algalarrondo
- Department of Cardiology, Bichat University Hospital, AP-HP, 75018 Paris, France
| | - Fabien Brette
- PhyMedExp, University of Montpellier, INSERM, CNRS, 34093 Montpellier, France
| | | | - Jérémy Fauconnier
- PhyMedExp, University of Montpellier, INSERM, CNRS, 34093 Montpellier, France
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