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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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2
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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:S1547-5271(24)00208-X. [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] [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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Marx N, Federici M, Schütt K, Müller-Wieland D, Ajjan RA, Antunes MJ, Christodorescu RM, Crawford C, Di Angelantonio E, Eliasson B, Espinola-Klein C, Fauchier L, Halle M, Herrington WG, Kautzky-Willer A, Lambrinou E, Lesiak M, Lettino M, McGuire DK, Mullens W, Rocca B, Sattar N. 2023 ESC Guidelines for the management of cardiovascular disease in patients with diabetes. Eur Heart J 2023; 44:4043-4140. [PMID: 37622663 DOI: 10.1093/eurheartj/ehad192] [Citation(s) in RCA: 115] [Impact Index Per Article: 115.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/26/2023] Open
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Sanganalmath SK, Dubey S, Veeranki S, Narisetty K, Krishnamurthy P. The interplay of inflammation, exosomes and Ca 2+ dynamics in diabetic cardiomyopathy. Cardiovasc Diabetol 2023; 22:37. [PMID: 36804872 PMCID: PMC9942322 DOI: 10.1186/s12933-023-01755-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 01/25/2023] [Indexed: 02/22/2023] Open
Abstract
Diabetes mellitus is one of the prime risk factors for cardiovascular complications and is linked with high morbidity and mortality. Diabetic cardiomyopathy (DCM) often manifests as reduced cardiac contractility, myocardial fibrosis, diastolic dysfunction, and chronic heart failure. Inflammation, changes in calcium (Ca2+) handling and cardiomyocyte loss are often implicated in the development and progression of DCM. Although the existence of DCM was established nearly four decades ago, the exact mechanisms underlying this disease pathophysiology is constantly evolving. Furthermore, the complex pathophysiology of DCM is linked with exosomes, which has recently shown to facilitate intercellular (cell-to-cell) communication through biomolecules such as micro RNA (miRNA), proteins, enzymes, cell surface receptors, growth factors, cytokines, and lipids. Inflammatory response and Ca2+ signaling are interrelated and DCM has been known to adversely affect many of these signaling molecules either qualitatively and/or quantitatively. In this literature review, we have demonstrated that Ca2+ regulators are tightly controlled at different molecular and cellular levels during various biological processes in the heart. Inflammatory mediators, miRNA and exosomes are shown to interact with these regulators, however how these mediators are linked to Ca2+ handling during DCM pathogenesis remains elusive. Thus, further investigations are needed to understand the mechanisms to restore cardiac Ca2+ homeostasis and function, and to serve as potential therapeutic targets in the treatment of DCM.
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Affiliation(s)
- Santosh K Sanganalmath
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Nevada Las Vegas School of Medicine, Las Vegas, NV, 89102, USA.
| | - Shubham Dubey
- Department of Biomedical Engineering, Schools of Medicine and Engineering, University of Alabama at Birmingham, University Blvd., Birmingham, AL, 35294, USA
| | - Sudhakar Veeranki
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40506, USA
| | | | - Prasanna Krishnamurthy
- Department of Biomedical Engineering, Schools of Medicine and Engineering, University of Alabama at Birmingham, University Blvd., Birmingham, AL, 35294, USA
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Jones TLM, Kaur S, Kang N, Ruygrok PN, Ward ML. Impaired calcium handling mechanisms in atrial trabeculae of diabetic patients. Physiol Rep 2023; 11:e15599. [PMID: 36750180 PMCID: PMC9904963 DOI: 10.14814/phy2.15599] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 01/15/2023] [Indexed: 06/18/2023] Open
Abstract
The aim of this study was to investigate cardiomyocyte Ca2+ handling and contractile function in freshly excised human atrial tissue from diabetic and non-diabetic patients undergoing routine surgery. Multicellular trabeculae (283 ± 20 μm in diameter) were dissected from the endocardial surface of freshly obtained right atrial appendage samples from consenting surgical patients. Trabeculae were mounted in a force transducer at optimal length, electrically stimulated to contract, and loaded with fura-2/AM for intracellular Ca2+ measurements. The response to stimulation frequencies encompassing the physiological range was recorded at 37°C. Myofilament Ca2+ sensitivity was assessed from phase plots and high potassium contractures of force against [Ca2+ ]i . Trabeculae from diabetic patients (n = 12) had increased diastolic (resting) [Ca2+ ]i (p = 0.03) and reduced Ca2+ transient amplitude (p = 0.04) when compared to non-diabetic patients (n = 11), with no difference in the Ca2+ transient time course. Diastolic stress was increased (p = 0.008) in trabeculae from diabetic patients, and peak developed stress decreased (p ≤ 0.001), which were not accounted for by reduction in the cardiomyocyte, or contractile protein, content of trabeculae. Trabeculae from diabetic patients also displayed diminished myofilament Ca2+ sensitivity (p = 0.018) compared to non-diabetic patients. Our data provides evidence of impaired calcium handling during excitation-contraction coupling with resulting contractile dysfunction in atrial tissue from patients with type 2 diabetes in comparison to the non-diabetic. This highlights the importance of targeting cardiomyocyte Ca2+ homeostasis in developing more effective treatment options for diabetic heart disease in the future.
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Affiliation(s)
- Timothy L M Jones
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Sarbjot Kaur
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Nicholas Kang
- Greenlane Cardiothoracic Surgical Unit, Auckland City Hospital, Auckland, New Zealand
| | - Peter N Ruygrok
- Department of Cardiology, Auckland City Hospital, Auckland, New Zealand
| | - Marie-Louise Ward
- Department of Physiology, University of Auckland, Auckland, New Zealand
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Sarco/endoplasmic reticulum calcium ATPase activity is unchanged despite increased myofilament calcium sensitivity in Zucker type 2 diabetic fatty rat heart. Sci Rep 2022; 12:16904. [PMID: 36207382 PMCID: PMC9546843 DOI: 10.1038/s41598-022-20520-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/14/2022] [Indexed: 11/11/2022] Open
Abstract
Systolic and diastolic dysfunction in diabetes have frequently been associated with abnormal calcium (Ca2+) regulation. However, there is emerging evidence that Ca2+ mishandling alone is insufficient to fully explain diabetic heart dysfunction, with focus shifting to the properties of the myofilament proteins. Our aim was to examine the effects of diabetes on myofilament Ca2+ sensitivity and Ca2+ handling in left ventricular tissues isolated from the same type 2 diabetic rat hearts. We measured the force-pCa relationship in skinned left ventricular cardiomyocytes isolated from 20-week-old type 2 diabetic and non-diabetic rats. Myofilament Ca2+ sensitivity was greater in the diabetic relative to non-diabetic cardiomyocytes, and this corresponded with lower phosphorylation of cardiac troponin I (cTnI) at ser23/24 in the diabetic left ventricular tissues. Protein expression of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), phosphorylation of phospholamban (PLB) at Ser16, and SERCA/PLB ratio were lower in the diabetic left ventricular tissues. However, the maximum SERCA Ca2+ uptake rate was not different between the diabetic and non-diabetic myocardium. Our data suggest that impaired contractility in the diabetic heart is not caused by SERCA Ca2+ mishandling. This study highlights the important role of the cardiac myofilament and provides new insight on the pathophysiology of diabetic heart dysfunction.
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Understanding the Role of SERCA2a Microdomain Remodeling in Heart Failure Induced by Obesity and Type 2 Diabetes. J Cardiovasc Dev Dis 2022; 9:jcdd9050163. [PMID: 35621874 PMCID: PMC9147026 DOI: 10.3390/jcdd9050163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/21/2022] [Accepted: 04/25/2022] [Indexed: 11/29/2022] Open
Abstract
Obesity and type 2 diabetes (T2D) are on trend to become a huge burden across all ages. They cause harm to almost every organ, especially the heart. For decades, the incidence of heart failure with impaired diastolic function (or called heart failure with preserved ejection fraction, HFpEF) has increased sharply. More and more studies have uncovered obesity and T2D to be closely associated with HFpEF. The sarcoplasmic/endoplasmic reticulum calcium ATPase2a (SERCA2a) microdomain is a key regulator of calcium reuptake into the sarcoplasmic reticulum (SR) during diastole. 3′,5′-cyclic adenosine monophosphate (cAMP) and its downstream effector cAMP dependent protein kinase (PKA) act locally within the SERCA2a microdomain to regulate the phosphorylation state of the small regulatory protein phospholamban (PLN), which forms a complex with SERCA2a. When phosphorylated, PLN promotes calcium reuptake into the SR and diastolic cardiac relaxation by disinhibiting SERCA2a pump function. In this review, we will discuss previous studies investigating the PLN/SERCA2a microdomain in obesity and T2D in order to gain a greater understanding of the underlying mechanisms behind obesity- and T2D-induced diastolic dysfunction, with the aim to identify the current state of knowledge and future work that is needed to guide further research in the field.
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Greenman AC, Diffee GM, Power AS, Wilkins GT, Gold OMS, Erickson JR, Baldi JC. Treadmill running increases the calcium sensitivity of myofilaments in diabetic rats. J Appl Physiol (1985) 2022; 132:1350-1360. [PMID: 35482324 DOI: 10.1152/japplphysiol.00785.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cardiovascular benefits of regular exercise are unequivocal, yet patients with type 2 diabetes respond poorly to exercise due to a reduced cardiac reserve. The contractile response of diabetic cardiomyocytes to beta-adrenergic stimulation is attenuated, which may result in altered myofilament calcium sensitivity and post-translational modifications of cardiac troponin I (cTnI). Treadmill running increases myofilament calcium sensitivity in non‑diabetic rats, and thus we hypothesized that endurance training would increase calcium sensitivity of diabetic cardiomyocytes and alter site-specific phosphorylation of cTnI. Calcium sensitivity, or pCa50, was measured in Zucker Diabetic Fatty (ZDF) non-diabetic (nDM) and diabetic (DM) rat hearts after 8 weeks of either a sedentary (SED) or progressive treadmill running (TR) intervention. Skinned cardiomyocytes were connected to a capacitance-gauge transducer and a torque motor to measure force as a function of pCa (‑log[Ca2+]). Specific phospho-sites on cTnI and O‑GlcNAcylation were quantified by immunoblot and total protein phosphorylation by fluorescent gel staining (ProQ Diamond). The novel finding in this study was that training increased pCa50 in both DM and nDM cardiomyocytes (p = 0.009). Phosphorylation of cTnI amino acid residues Ser23/24, a crucial protein kinase A site, and Threonine (Thr)144, was lower in DM hearts, but there was no effect of training on site-specific phosphorylation. Additionally, total phosphorylation and O-GlcNAcylation levels were not different between SED and TR groups. These findings suggest that regular exercise may benefit the diabetic heart by specifically targeting myofilament contractile function.
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Affiliation(s)
- Angela Claire Greenman
- Department of Medicine, Otago Medical School, University of Otago, Dunedin, New Zealand.,Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Gary M Diffee
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI
| | - Amelia S Power
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Gerard T Wilkins
- Department of Medicine, Otago Medical School, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Olivia M S Gold
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Jeffrey R Erickson
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - James C Baldi
- Department of Medicine, Otago Medical School, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
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Fauchier L, Boriani G, de Groot JR, Kreutz R, Rossing P, Camm AJ. Medical therapies for prevention of cardiovascular and renal events in patients with atrial fibrillation and diabetes mellitus. Europace 2021; 23:1873-1891. [PMID: 34411235 DOI: 10.1093/europace/euab184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/05/2021] [Indexed: 02/06/2023] Open
Abstract
Atrial fibrillation (AF), type 2 diabetes mellitus (DM), and chronic kidney disease (CKD) are three global epidemics with significant effects on morbidity and mortality. Diabetes is a risk factor for AF, and a risk factor for thromboembolism, comorbidity, and mortality when AF is present. The pathophysiology of diabetes-related AF and interrelationships with cardiovascular events and renal events is not fully understood but is in part related to structural, electrical, electromechanical, and autonomic remodelling. The current practice guidelines offer limited recommendations on the management of patients with AF (or risk of AF) and diabetes with its own heterogeneity for the prevention of cardiovascular and renal events. This document discusses possible clinical approaches for these patients. In the last decade, there have been major improvements for the prevention of stroke in AF patients with direct oral anticoagulants, which are preferable to vitamin K antagonists for stroke prevention in DM. Because of the increased risk rate for several cardiovascular adverse events in diabetic patients, a similar relative risk reduction generally translates into greater absolute risk reduction in the diabetic population. Recent trials with non-insulin diabetes drugs using glucagon-like peptide-1 agonists and sodium-glucose cotransporter-2 inhibitors showed a significant reduction for the risk of major adverse cardiovascular events in patients with type 2 DM. Sodium-glucose cotransporter-2 inhibitors also showed a large reduction in hospitalization for heart failure and renal events, which need to be more completely evaluated in patients with AF. Mechanisms, risks, and optimal management of AF patients with DM who have or are under risk of developing heart failure or CKD are also discussed in this document. The benefits of medical therapies for these patients still need to be put into perspective, and gaps in evidence on some of these issues are likely to be addressed in future years.
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Affiliation(s)
- Laurent Fauchier
- Department of Cardiology, Centre Hospitalier Universitaire Trousseau et Université de Tours, Tours 37044, France
| | - Giuseppe Boriani
- Cardiology Division, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Policlinico di Modena, Modena, Italy
| | - Joris R de Groot
- Department of Cardiology, Amsterdam University Medical Centres/University of Amsterdam, Amsterdam, The Netherlands
| | - Reinhold Kreutz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Department of Clinical Pharmacology and Toxicology, Charité University Medicine, Berlin, Germany
| | - Peter Rossing
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - A John Camm
- Cardiology Clinical Academic Group Molecular and Clinical Sciences Institute, St George's University of London, London, UK
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Sciacqua A, Succurro E, Armentaro G, Miceli S, Pastori D, Rengo G, Sesti G. Pharmacological treatment of type 2 diabetes in elderly patients with heart failure: randomized trials and beyond. Heart Fail Rev 2021; 28:667-681. [PMID: 34859336 DOI: 10.1007/s10741-021-10182-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/14/2021] [Indexed: 12/18/2022]
Abstract
Heart failure (HF) and type 2 diabetes mellitus (T2DM) represent two important public health problems, and despite improvements in the management of both diseases, they are responsible for high rates of hospitalizations and mortality. T2DM accelerates physiological cardiac aging through hyperglycemia and hyperinsulinemia. Thus, HF and T2DM are chronic diseases widely represented in elderly people who often are affected by numerous comorbidities with important functional limitations making it difficult to apply the current guidelines. Several antidiabetic drugs should be used with caution in elderly individuals with T2DM. For instance, sulfonylureas should be avoided due to the risk of hypoglycemia associated with its use. Insulin should be used with caution because it is associated with higher risk of hypoglycemia, and may determine fluid retention which can lead to worsening of HF. Thiazolindinediones should be avoided due to the increased risk of fluid retention and HF. Biguanides may lead to a slightly increased risk of lactic acidosis in particular in elderly individuals with impaired renal function. Dipeptidyl peptidase 4 (DPP-4) inhibitors are safe having few side effects, minimal risk of hypoglycemia, and a neutral effect on cardiovascular (CV) outcome, even if it has been reported that saxagliptin treatment is associated with increased risk of hospitalizations for HF (hHF). Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shown a CV protection without a significant reduction in hHF. On the other hand, sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown a significant improvement in CV outcome, with a strong reduction of hHF and a positive impact on renal damage progression. However, it is necessary to consider the possible some side effects related to their use in elderly individuals including hypotension, bone fractures, and ketoacidosis.It is important to remark that elderly patients, in particular the very elderly, are not sufficiently represented in the trials; thus, the management and treatment of elderly diabetic patients with HF should be mainly based on the integration of scientific evidence with clinical judgment and patients' condition, with respect to the dignity and quality of life.
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Affiliation(s)
- Angela Sciacqua
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Campus Universitario di Germaneto, V.le Europa, 88100, Catanzaro, Italy.
| | - Elena Succurro
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Campus Universitario di Germaneto, V.le Europa, 88100, Catanzaro, Italy
| | - Giuseppe Armentaro
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Campus Universitario di Germaneto, V.le Europa, 88100, Catanzaro, Italy
| | - Sofia Miceli
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Campus Universitario di Germaneto, V.le Europa, 88100, Catanzaro, Italy
| | - Daniele Pastori
- Department of Clinical, Internal, Anesthesiologic and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy
| | - Giuseppe Rengo
- Department of Translational Medical Sciences, University of Naples "Federico II", Naples, Italy
- Istituti Clinici Scientifici (ICS) Maugeri SPA, Società Benefit, IRCCS, Pavia, Italy
- Istituto Scientifico di Telese Terme, Telese, Terme, Italy
| | - Giorgio Sesti
- Department of Clinical and Molecular Medicine, University Rome-Sapienza, Rome, Italy
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Coffey S, Dixit P, Saw EL, Babakr AA, van Hout I, Galvin IF, Saxena P, Bunton RW, Davis PJ, Lamberts RR, Katare R, Williams MJA. Thiamine increases resident endoglin positive cardiac progenitor cells and atrial contractile force in humans: A randomised controlled trial. Int J Cardiol 2021; 341:70-73. [PMID: 34461161 DOI: 10.1016/j.ijcard.2021.08.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/13/2021] [Accepted: 08/24/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND The heart has an intrinsic ability to regenerate, orchestrated by progenitor or stem cells. However, the relative complexity of non-resident cardiac progenitor cell (CPC) therapy makes modulation of resident CPCs a more attractive treatment target. Thiamine analogues improve resident CPC function in pre-clinical models. In this double blinded randomised controlled trial (identifier: ACTRN12614000755639), we examined whether thiamine would improve CPC function in humans. METHODS AND RESULTS High dose oral thiamine (one gram twice daily) or matching placebo was administered 3-5 days prior to coronary artery bypass surgery (CABG). Right atrial appendages were collected at the time of CABG, and CPCs isolated. There was no difference in the primary outcome (proliferation ability of CPCs) between treatment groups. Older age was not associated with decreased proliferation ability. In exploratory analyses, isolated CPCs in the thiamine group showed an increase in the proportion of CD34-/CD105+ (endoglin) cells, but no difference in CD34-/CD90+ or CD34+ cells. Thiamine increased maximum force developed by isolated trabeculae, with no difference in relaxation time or beta-adrenergic responsiveness. CONCLUSION Thiamine does not improve proliferation ability of CPC in patients undergoing CABG, but increases the proportion of CD34-/CD105+ cells. Having not met its primary endpoint, this study provides the impetus to re-examine CPC biology prior to any clinical outcome-based trial examining potential beneficial cardiovascular effects of thiamine.
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Affiliation(s)
- Sean Coffey
- Department of Medicine - HeartOtago, Dunedin School of Medicine, University of Otago, New Zealand; Department of Cardiology, Southern District Health Board, New Zealand.
| | - Parul Dixit
- Department of Physiology - HeartOtago, School of Biomedical Sciences, University of Otago, New Zealand
| | - Eng Leng Saw
- Department of Physiology - HeartOtago, School of Biomedical Sciences, University of Otago, New Zealand
| | - Aram A Babakr
- Department of Physiology - HeartOtago, School of Biomedical Sciences, University of Otago, New Zealand
| | - Isabelle van Hout
- Department of Physiology - HeartOtago, School of Biomedical Sciences, University of Otago, New Zealand
| | - Ivor F Galvin
- Department of Cardiothoracic Surgery, Southern District Health Board, New Zealand
| | - Pankaj Saxena
- Department of Cardiothoracic Surgery, Southern District Health Board, New Zealand
| | - Richard W Bunton
- Department of Cardiothoracic Surgery, Southern District Health Board, New Zealand
| | - Philip J Davis
- Department of Cardiothoracic Surgery, Southern District Health Board, New Zealand
| | - Regis R Lamberts
- Department of Physiology - HeartOtago, School of Biomedical Sciences, University of Otago, New Zealand
| | - Rajesh Katare
- Department of Physiology - HeartOtago, School of Biomedical Sciences, University of Otago, New Zealand
| | - Michael J A Williams
- Department of Medicine - HeartOtago, Dunedin School of Medicine, University of Otago, New Zealand; Department of Cardiology, Southern District Health Board, New Zealand
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12
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Greenman AC, Diffee GM, Power AS, Wilkins GT, Gold OMS, Erickson JR, Baldi JC. Increased myofilament calcium sensitivity is associated with decreased cardiac troponin I phosphorylation in the diabetic rat heart. Exp Physiol 2021; 106:2235-2247. [PMID: 34605091 DOI: 10.1113/ep089730] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/23/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? In Zucker Diabetic Fatty rats, does cardiomyocyte myofilament function change through the time course of diabetes and what are the mechanisms behind alterations in calcium sensitivity? What is the main finding and its importance? Zucker Diabetic Fatty rats had increased myofilament calcium sensitivity and reduced phosphorylation at cardiac troponin I without differential O-GlcNAcylation. ABSTRACT The diabetic heart has impaired systolic and diastolic function independent of other comorbidities. The availability of calcium is altered, but does not fully explain the cardiac dysfunction seen in the diabetic heart. Thus, we explored if myofilament calcium regulation of contraction is altered while also categorizing the levels of phosphorylation and O-GlcNAcylation in the myofilaments. Calcium sensitivity (pCa50 ) was measured in Zucker Diabetic Fatty (ZDF) rat hearts at the initial stage of diabetes (12 weeks old) and after 8 weeks of uncontrolled hyperglycaemia (20 weeks old) and in non-diabetic (nDM) littermates. Skinned cardiomyocytes were connected to a capacitance-gauge transducer and a torque motor to measure force as a function of pCa (-log[Ca2+ ]). Fluorescent gel stain (ProQ Diamond) was used to measure total protein phosphorylation. Specific phospho-sites on cardiac troponin I (cTnI) and total cTnI O-GlcNAcylation were quantified using immunoblot. pCa50 was greater in both 12- and 20-week-old diabetic (DM) rats compared to nDM littermates (P = 0.0001). Total cTnI and cTnI serine 23/24 phosphorylation were lower in DM rats (P = 0.003 and P = 0.01, respectively), but cTnI O-GlcNAc protein expression was not different. pCa50 is greater in DM rats and corresponds with an overall reduction in cTnI phosphorylation. These findings indicate that myofilament calcium sensitivity is increased and cTnI phosphorylation is reduced in ZDF DM rats and suggests an important role for cTnI phosphorylation in the DM heart.
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Affiliation(s)
- Angela C Greenman
- Department of Medicine, Otago Medical School, University of Otago, Dunedin, New Zealand.,Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Gary M Diffee
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, USA
| | - Amelia S Power
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Gerard T Wilkins
- Department of Medicine, Otago Medical School, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Olivia M S Gold
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Jeffrey R Erickson
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - James C Baldi
- Department of Medicine, Otago Medical School, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
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13
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Veitch CR, Power AS, Erickson JR. CaMKII Inhibition is a Novel Therapeutic Strategy to Prevent Diabetic Cardiomyopathy. Front Pharmacol 2021; 12:695401. [PMID: 34381362 PMCID: PMC8350113 DOI: 10.3389/fphar.2021.695401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/14/2021] [Indexed: 11/24/2022] Open
Abstract
Increasing prevalence of diabetes mellitus worldwide has pushed the complex disease state to the foreground of biomedical research, especially concerning its multifaceted impacts on the cardiovascular system. Current therapies for diabetic cardiomyopathy have had a positive impact, but with diabetic patients still suffering from a significantly greater burden of cardiac pathology compared to the general population, the need for novel therapeutic approaches is great. A new therapeutic target, calcium/calmodulin-dependent kinase II (CaMKII), has emerged as a potential treatment option for preventing cardiac dysfunction in the setting of diabetes. Within the last 10 years, new evidence has emerged describing the pathophysiological consequences of CaMKII activation in the diabetic heart, the mechanisms that underlie persistent CaMKII activation, and the protective effects of CaMKII inhibition to prevent diabetic cardiomyopathy. This review will examine recent evidence tying cardiac dysfunction in diabetes to CaMKII activation. It will then discuss the current understanding of the mechanisms by which CaMKII activity is enhanced during diabetes. Finally, it will examine the benefits of CaMKII inhibition to treat diabetic cardiomyopathy, including contractile dysfunction, heart failure with preserved ejection fraction, and arrhythmogenesis. We intend this review to serve as a critical examination of CaMKII inhibition as a therapeutic strategy, including potential drawbacks of this approach.
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Affiliation(s)
- Christopher R Veitch
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Amelia S Power
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Jeffrey R Erickson
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
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14
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Bowman PRT, Smith GL, Gould GW. Run for your life: can exercise be used to effectively target GLUT4 in diabetic cardiac disease? PeerJ 2021; 9:e11485. [PMID: 34113491 PMCID: PMC8162245 DOI: 10.7717/peerj.11485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 04/27/2021] [Indexed: 12/25/2022] Open
Abstract
The global incidence, associated mortality rates and economic burden of diabetes are now such that it is considered one of the most pressing worldwide public health challenges. Considerable research is now devoted to better understanding the mechanisms underlying the onset and progression of this disease, with an ultimate aim of improving the array of available preventive and therapeutic interventions. One area of particular unmet clinical need is the significantly elevated rate of cardiomyopathy in diabetic patients, which in part contributes to cardiovascular disease being the primary cause of premature death in this population. This review will first consider the role of metabolism and more specifically the insulin sensitive glucose transporter GLUT4 in diabetic cardiac disease, before addressing how we may use exercise to intervene in order to beneficially impact key functional clinical outcomes.
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Affiliation(s)
- Peter R T Bowman
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Godfrey L Smith
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Gwyn W Gould
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
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15
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Aguilar M, Rose RA, Takawale A, Nattel S, Reilly S. New aspects of endocrine control of atrial fibrillation and possibilities for clinical translation. Cardiovasc Res 2021; 117:1645-1661. [PMID: 33723575 PMCID: PMC8208746 DOI: 10.1093/cvr/cvab080] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/25/2021] [Accepted: 03/11/2021] [Indexed: 12/20/2022] Open
Abstract
Hormones are potent endo-, para-, and autocrine endogenous regulators of the function of multiple organs, including the heart. Endocrine dysfunction promotes a number of cardiovascular diseases, including atrial fibrillation (AF). While the heart is a target for endocrine regulation, it is also an active endocrine organ itself, secreting a number of important bioactive hormones that convey significant endocrine effects, but also through para-/autocrine actions, actively participate in cardiac self-regulation. The hormones regulating heart-function work in concert to support myocardial performance. AF is a serious clinical problem associated with increased morbidity and mortality, mainly due to stroke and heart failure. Current therapies for AF remain inadequate. AF is characterized by altered atrial function and structure, including electrical and profibrotic remodelling in the atria and ventricles, which facilitates AF progression and hampers its treatment. Although features of this remodelling are well-established and its mechanisms are partly understood, important pathways pertinent to AF arrhythmogenesis are still unidentified. The discovery of these missing pathways has the potential to lead to therapeutic breakthroughs. Endocrine dysfunction is well-recognized to lead to AF. In this review, we discuss endocrine and cardiocrine signalling systems that directly, or as a consequence of an underlying cardiac pathology, contribute to AF pathogenesis. More specifically, we consider the roles of products from the hypothalamic-pituitary axis, the adrenal glands, adipose tissue, the renin–angiotensin system, atrial cardiomyocytes, and the thyroid gland in controlling atrial electrical and structural properties. The influence of endocrine/paracrine dysfunction on AF risk and mechanisms is evaluated and discussed. We focus on the most recent findings and reflect on the potential of translating them into clinical application.
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Affiliation(s)
- Martin Aguilar
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, QC, Canada.,Department of Pharmacology and Physiology/Institute of Biomedical Engineering, Université de Montréal, Montréal, QC, Canada
| | - Robert A Rose
- Department of Cardiac Sciences, Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, Health Research Innovation Center, University of Calgary, AB, Canada
| | - Abhijit Takawale
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, QC, Canada.,Department of Pharmacology and Physiology/Institute of Biomedical Engineering, Université de Montréal, Montréal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Stanley Nattel
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Faculty of Medicine, Department of Pharmacology and Physiology, and Research Centre, Montreal Heart Institute and University of Montreal, Montreal, QC, Canada.,Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Germany.,IHU LIRYC and Fondation Bordeaux Université, Bordeaux, France
| | - Svetlana Reilly
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford, John Radcliffe Hospital, Oxford, UK
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16
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Munro ML, van Hout I, Aitken-Buck HM, Sugunesegran R, Bhagwat K, Davis PJ, Lamberts RR, Coffey S, Soeller C, Jones PP. Human Atrial Fibrillation Is Not Associated With Remodeling of Ryanodine Receptor Clusters. Front Cell Dev Biol 2021; 9:633704. [PMID: 33718369 PMCID: PMC7947344 DOI: 10.3389/fcell.2021.633704] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/08/2021] [Indexed: 12/02/2022] Open
Abstract
The release of Ca2+ by ryanodine receptor (RyR2) channels is critical for cardiac function. However, abnormal RyR2 activity has been linked to the development of arrhythmias, including increased spontaneous Ca2+ release in human atrial fibrillation (AF). Clustering properties of RyR2 have been suggested to alter the activity of the channel, with remodeling of RyR2 clusters identified in pre-clinical models of AF and heart failure. Whether such remodeling occurs in human cardiac disease remains unclear. This study aimed to investigate the nanoscale organization of RyR2 clusters in AF patients – the first known study to examine this potential remodeling in diseased human cardiomyocytes. Right atrial appendage from cardiac surgery patients with paroxysmal or persistent AF, or without AF (non-AF) were examined using super-resolution (dSTORM) imaging. Significant atrial dilation and cardiomyocyte hypertrophy was observed in persistent AF patients compared to non-AF, with these two parameters significantly correlated. Interestingly, the clustering properties of RyR2 were remarkably unaltered in the AF patients. No significant differences were identified in cluster size (mean ∼18 RyR2 channels), density or channel packing within clusters between patient groups. The spatial organization of clusters throughout the cardiomyocyte was also unchanged across the groups. RyR2 clustering properties did not significantly correlate with patient characteristics. In this first study to examine nanoscale RyR2 organization in human cardiac disease, these findings indicate that RyR2 cluster remodeling is not an underlying mechanism contributing to altered channel function and subsequent arrhythmogenesis in human AF.
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Affiliation(s)
- Michelle L Munro
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Isabelle van Hout
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Hamish M Aitken-Buck
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | | | - Krishna Bhagwat
- Department of Cardiothoracic Surgery, Dunedin Hospital, Dunedin, New Zealand
| | - Philip J Davis
- Department of Cardiothoracic Surgery, Dunedin Hospital, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine and HeartOtago, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Christian Soeller
- Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Peter P Jones
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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17
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Daniels LJ, Annandale M, Koutsifeli P, Li X, Bussey CT, van Hout I, Bunton RW, Davis PJ, Coffey S, Katare R, Lamberts RR, Delbridge LMD, Mellor KM. Elevated myocardial fructose and sorbitol levels are associated with diastolic dysfunction in diabetic patients, and cardiomyocyte lipid inclusions in vitro. Nutr Diabetes 2021; 11:8. [PMID: 33558456 PMCID: PMC7870957 DOI: 10.1038/s41387-021-00150-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 01/05/2021] [Accepted: 01/13/2021] [Indexed: 12/22/2022] Open
Abstract
Diabetes is associated with cardiac metabolic disturbances and increased heart failure risk. Plasma fructose levels are elevated in diabetic patients. A direct role for fructose involvement in diabetic heart pathology has not been investigated. The goals of this study were to clinically evaluate links between myocardial fructose and sorbitol (a polyol pathway fructose precursor) levels with evidence of cardiac dysfunction, and to experimentally assess the cardiomyocyte mechanisms involved in mediating the metabolic effects of elevated fructose. Fructose and sorbitol levels were increased in right atrial appendage tissues of type 2 diabetic patients (2.8- and 1.5-fold increase respectively). Elevated cardiac fructose levels were confirmed in type 2 diabetic rats. Diastolic dysfunction (increased E/e’, echocardiography) was significantly correlated with cardiac sorbitol levels. Elevated myocardial mRNA expression of the fructose-specific transporter, Glut5 (43% increase), and the key fructose-metabolizing enzyme, Fructokinase-A (50% increase) was observed in type 2 diabetic rats (Zucker diabetic fatty rat). In neonatal rat ventricular myocytes, fructose increased glycolytic capacity and cytosolic lipid inclusions (28% increase in lipid droplets/cell). This study provides the first evidence that elevated myocardial fructose and sorbitol are associated with diastolic dysfunction in diabetic patients. Experimental evidence suggests that fructose promotes the formation of cardiomyocyte cytosolic lipid inclusions, and may contribute to lipotoxicity in the diabetic heart.
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Affiliation(s)
- Lorna J Daniels
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Marco Annandale
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Parisa Koutsifeli
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Xun Li
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Carol T Bussey
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Isabelle van Hout
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Richard W Bunton
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Philip J Davis
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine and HeartOtago, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Rajesh Katare
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Lea M D Delbridge
- Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Kimberley M Mellor
- Department of Physiology, University of Auckland, Auckland, New Zealand. .,Department of Physiology, University of Melbourne, Melbourne, Australia. .,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
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18
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Erdogan BR, Michel MC, Arioglu-Inan E. Expression and Signaling of β-Adrenoceptor Subtypes in the Diabetic Heart. Cells 2020; 9:cells9122548. [PMID: 33256212 PMCID: PMC7759850 DOI: 10.3390/cells9122548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/18/2022] Open
Abstract
Diabetes is a chronic, endocrine disorder that effects millions of people worldwide. Cardiovascular complications are the major cause of diabetes-related morbidity and mortality. Cardiac β1- and β2-adrenoceptor (AR) stimulation mediates positive inotropy and chronotropy, whereas β3-AR mediates negative inotropic effect. Changes in β-AR responsiveness are thought to be an important factor that contributes to the diabetic cardiac dysfunction. Diabetes related changes in β-AR expression, signaling, and β-AR mediated cardiac function have been studied by several investigators for many years. In the present review, we have screened PubMed database to obtain relevant articles on this topic. Our search has ended up with wide range of different findings about the effect of diabetes on β-AR mediated changes both in molecular and functional level. Considering these inconsistent findings, the effect of diabetes on cardiac β-AR still remains to be clarified.
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Affiliation(s)
- Betul R. Erdogan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey;
- Department of Pharmacology, Faculty of Pharmacy, Izmir Katip Celebi University, 35620 Izmir, Turkey
| | - Martin C. Michel
- Department of Pharmacology, Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey;
- Correspondence:
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19
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Bohne LJ, Jansen HJ, Daniel I, Dorey TW, Moghtadaei M, Belke DD, Ezeani M, Rose RA. Electrical and structural remodeling contribute to atrial fibrillation in type 2 diabetic db/db mice. Heart Rhythm 2020; 18:118-129. [PMID: 32911049 DOI: 10.1016/j.hrthm.2020.08.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/25/2020] [Accepted: 08/30/2020] [Indexed: 01/24/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) is highly prevalent in diabetes mellitus (DM), yet the basis for this finding is poorly understood. Type 2 DM may be associated with unique patterns of atrial electrical and structural remodeling; however, this has not been investigated in detail. OBJECTIVE The purpose of this study was to investigate AF susceptibility and atrial electrical and structural remodeling in type 2 diabetic db/db mice. METHODS AF susceptibility and atrial function were assessed in male and female db/db mice and age-matched wildtype littermates. Electrophysiological studies were conducted in vivo using intracardiac electrophysiology and programmed stimulation. Atrial electrophysiology was also investigated in isolated atrial preparations using high-resolution optical mapping and in isolated atrial myocytes using patch-clamping. Molecular biology studies were performed using quantitative polymerase chain reaction and western blotting. Atrial fibrosis was assessed using histology. RESULTS db/db mice were highly susceptible to AF in association with reduced atrial conduction velocity, action potential duration prolongation, and increased heterogeneity in repolarization in left and right atria. In db/db mice, atrial K+ currents, including the transient outward current (Ito) and the ultrarapid delayed rectifier current (IKur), were reduced. The reduction in Ito occurred in association with reductions in Kcnd2 mRNA expression and KV4.2 protein levels. The reduction in IKur was not related to gene or protein expression changes. Interstitial atrial fibrosis was increased in db/db mice. CONCLUSION Our study demonstrates that increased susceptibility to AF in db/db mice occurs in association with impaired electrical conduction as well as electrical and structural remodeling of the atria.
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Affiliation(s)
- Loryn J Bohne
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hailey J Jansen
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Irene Daniel
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tristan W Dorey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Motahareh Moghtadaei
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Darrell D Belke
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Martin Ezeani
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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20
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Aitken-Buck HM, Babakr AA, Fomison-Nurse IC, van Hout I, Davis PJ, Bunton RW, Williams MJA, Coffey S, Jones PP, Lamberts RR. Inotropic and lusitropic, but not arrhythmogenic, effects of adipocytokine resistin on human atrial myocardium. Am J Physiol Endocrinol Metab 2020; 319:E540-E547. [PMID: 32715745 DOI: 10.1152/ajpendo.00202.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The adipocytokine resistin is released from epicardial adipose tissue (EAT). Plasma resistin and EAT deposition are independently associated with atrial fibrillation. The EAT secretome enhances arrhythmia susceptibility and inotropy of human myocardium. Therefore, we aimed to determine the effect of resistin on the function of human myocardium and how resistin contributes to the proarrhythmic effect of EAT. EAT biopsies were obtained from 25 cardiac surgery patients. Resistin levels were measured by ELISA in 24-h EAT culture media (n = 8). The secretome resistin concentrations increased over the culture period to a maximal level of 5.9 ± 1.2 ng/mL. Coculture with β-adrenergic agonists isoproterenol (n = 4) and BRL37344 (n = 13) had no effect on EAT resistin release. Addition of resistin (7, 12, 20 ng/mL) did not significantly increase the spontaneous contraction propensity of human atrial trabeculae (n = 10) when given alone or in combination with isoproterenol. Resistin dose-dependently increased trabecula-developed force (maximal 2.9-fold increase, P < 0.0001), as well as the maximal rates of contraction (2.6-fold increase, P = 0.002) and relaxation (1.8-fold increase, P = 0.007). Additionally, the postrest potentiation capacity of human trabeculae was reduced at all resistin doses, suggesting that the inotropic effect induced by resistin might be due to altered sarcoplasmic reticulum Ca2+ handling. EAT resistin release is not modulated by common arrhythmia triggers. Furthermore, exogenous resistin does not promote arrhythmic behavior in human atrial trabeculae. Resistin does, however, induce an acute dose-dependent positive inotropic and lusitropic effect.
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Affiliation(s)
- Hamish M Aitken-Buck
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Aram A Babakr
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Ingrid C Fomison-Nurse
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Isabelle van Hout
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Philip J Davis
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Richard W Bunton
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Michael J A Williams
- Department of Medicine and HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine and HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Peter P Jones
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology and HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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21
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Jansen HJ, Bohne LJ, Gillis AM, Rose RA. Atrial remodeling and atrial fibrillation in acquired forms of cardiovascular disease. Heart Rhythm O2 2020; 1:147-159. [PMID: 34113869 PMCID: PMC8183954 DOI: 10.1016/j.hroo.2020.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Atrial fibrillation (AF) is prevalent in common conditions and acquired forms of heart disease, including diabetes mellitus (DM), hypertension, cardiac hypertrophy, and heart failure. AF is also prevalent in aging. Although acquired heart disease is common in aging individuals, age is also an independent risk factor for AF. Importantly, not all individuals age at the same rate. Rather, individuals of the same chronological age can vary in health status from fit to frail. Frailty can be quantified using a frailty index, which can be used to assess heterogeneity in individuals of the same chronological age. AF is thought to occur in association with electrical remodeling due to changes in ion channel expression or function as well as structural remodeling due to fibrosis, myocyte hypertrophy, or adiposity. These forms of remodeling can lead to triggered activity and electrical re-entry, which are fundamental mechanisms of AF initiation and maintenance. Nevertheless, the underlying determinants of electrical and structural remodeling are distinct in different conditions and disease states. In this focused review, we consider the factors leading to atrial electrical and structural remodeling in human patients and animal models of acquired cardiovascular disease or associated risk factors. Our goal is to identify similarities and differences in the cellular and molecular bases for atrial electrical and structural remodeling in conditions including DM, hypertension, hypertrophy, heart failure, aging, and frailty.
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Affiliation(s)
- Hailey J Jansen
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Loryn J Bohne
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Anne M Gillis
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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22
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Loss of insulin signaling may contribute to atrial fibrillation and atrial electrical remodeling in type 1 diabetes. Proc Natl Acad Sci U S A 2020; 117:7990-8000. [PMID: 32198206 DOI: 10.1073/pnas.1914853117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Atrial fibrillation (AF) is prevalent in diabetes mellitus (DM); however, the basis for this is unknown. This study investigated AF susceptibility and atrial electrophysiology in type 1 diabetic Akita mice using in vivo intracardiac electrophysiology, high-resolution optical mapping in atrial preparations, and patch clamping in isolated atrial myocytes. qPCR and western blotting were used to assess ion channel expression. Akita mice were highly susceptible to AF in association with increased P-wave duration and slowed atrial conduction velocity. In a second model of type 1 DM, mice treated with streptozotocin (STZ) showed a similar increase in susceptibility to AF. Chronic insulin treatment reduced susceptibility and duration of AF and shortened P-wave duration in Akita mice. Atrial action potential (AP) morphology was altered in Akita mice due to a reduction in upstroke velocity and increases in AP duration. In Akita mice, atrial Na+ current (INa) and repolarizing K+ current (IK) carried by voltage gated K+ (Kv1.5) channels were reduced. The reduction in INa occurred in association with reduced expression of SCN5a and voltage gated Na+ (NaV1.5) channels as well as a shift in INa activation kinetics. Insulin potently and selectively increased INa in Akita mice without affecting IK Chronic insulin treatment increased INa in association with increased expression of NaV1.5. Acute insulin also increased INa, although to a smaller extent, due to enhanced insulin signaling via phosphatidylinositol 3,4,5-triphosphate (PIP3). Our study reveals a critical, selective role for insulin in regulating atrial INa, which impacts susceptibility to AF in type 1 DM.
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Bussey CT, Babakr AA, Iremonger RR, van Hout I, Wilkins GT, Lamberts RR, Erickson JR. Carvedilol and metoprolol are both able to preserve myocardial function in type 2 diabetes. Physiol Rep 2020; 8:e14394. [PMID: 32170823 PMCID: PMC7070160 DOI: 10.14814/phy2.14394] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/13/2020] [Accepted: 02/16/2020] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Increasing cohorts of patients present with diabetic cardiomyopathy, and with no targeted options, treatment often rely on generic pharmaceuticals such as β-blockers. β-blocker efficacy is heterogenous, with second generation β-blocker metoprolol selectively inhibiting β1 -AR, while third generation β-blocker carvedilol has α1 -AR inhibition, antioxidant, and anti-apoptotic actions alongside nonselective β-AR inhibition. These additional properties have led to the hypothesis that carvedilol may improve cardiac contractility in the diabetic heart to a greater extent than metoprolol. The present study aimed to compare the efficacy of metoprolol and carvedilol on myocardial function in animal models and cardiac tissue from patients with type 2 diabetes and preserved ejection fraction. METHODS Echocardiographic examination of cardiac function and assessment of myocardial function in isolated trabeculae was carried out in patients with and without diabetes undergoing coronary artery bypass grafting (CABG) who were prescribed metoprolol or carvedilol. Equivalent measures were undertaken in Zucker Diabetic Fatty (ZDF) rats following 4 weeks treatment with metoprolol or carvedilol. RESULTS Patients receiving carvedilol compared to metoprolol had no difference in cardiac function, and no difference was apparent in myocardial function between β-blockers. Both β-blockers similarly improved myocardial function in diabetic ZDF rats treated for 4 weeks, without significantly affecting in vivo cardiac function. CONCLUSIONS Metoprolol and carvedilol were found to have no effect on cardiac function in type 2 diabetes with preserved ejection fraction, and were similarly effective in preventing myocardial dysfunction in ZDF rats.
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Affiliation(s)
- Carol T Bussey
- Department of Physiology-HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Aram A Babakr
- Department of Physiology-HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Rachael R Iremonger
- Department of Physiology-HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Isabelle van Hout
- Department of Physiology-HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Gerard T Wilkins
- Department of Medicine-HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology-HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Jeffrey R Erickson
- Department of Physiology-HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Babakr AA, Fomison-Nurse IC, van Hout I, Aitken-Buck HM, Sugunesegran R, Davis PJ, Bunton RW, Williams MJA, Coffey S, Stiles MK, Jones PP, Lamberts RR. Acute interaction between human epicardial adipose tissue and human atrial myocardium induces arrhythmic susceptibility. Am J Physiol Endocrinol Metab 2020; 318:E164-E172. [PMID: 31821041 DOI: 10.1152/ajpendo.00374.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epicardial adipose tissue (EAT) deposition has a strong clinical association with atrial arrhythmias; however, whether a direct functional interaction exists between EAT and the myocardium to induce atrial arrhythmias is unknown. Therefore, we aimed to determine whether human EAT can be an acute trigger for arrhythmias in human atrial myocardium. Human trabeculae were obtained from right atrial appendages of patients who have had cardiac surgery (n = 89). The propensity of spontaneous contractions (SCs) in the trabeculae (proxy for arrhythmias) was determined under physiological conditions and during known triggers of SCs (high Ca2+, β-adrenergic stimulation). To determine whether EAT could trigger SCs, trabeculae were exposed to superfusate of fresh human EAT, and medium of 24 h-cultured human EAT treated with β1/2 (isoproterenol) or β3 (BRL37344) adrenergic agonists. Without exposure to EAT, high Ca2+ and β1/2-adrenergic stimulation acutely triggered SCs in, respectively, 47% and 55% of the trabeculae that previously were not spontaneously active. Acute β3-adrenergic stimulation did not trigger SCs. Exposure of trabeculae to either superfusate of fresh human EAT or untreated medium of 24 h-cultured human EAT did not induce SCs; however, specific β3-adrenergic stimulation of EAT did trigger SCs in the trabeculae, either when applied to fresh (31%) or cultured (50%) EAT. Additionally, fresh EAT increased trabecular contraction and relaxation, whereas media of cultured EAT only increased function when treated with the β3-adrenergic agonist. An acute functional interaction between human EAT and human atrial myocardium exists that increases the propensity for atrial arrhythmias, which depends on β3-adrenergic rather than β1/2-adrenergic stimulation of EAT.
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Affiliation(s)
- Aram A Babakr
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Ingrid C Fomison-Nurse
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Isabelle van Hout
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Hamish M Aitken-Buck
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Ramanen Sugunesegran
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Philip J Davis
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Richard W Bunton
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Michael J A Williams
- Department of Medicine, HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine, HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Martin K Stiles
- Department of Cardiology, Waikato District Health Board, Hamilton, New Zealand
- Waikato Clinical School, University of Auckland, Hamilton, New Zealand
| | - Peter P Jones
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology, HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Yurista SR, Silljé HHW, Rienstra M, de Boer RA, Westenbrink BD. Sodium-glucose co-transporter 2 inhibition as a mitochondrial therapy for atrial fibrillation in patients with diabetes? Cardiovasc Diabetol 2020; 19:5. [PMID: 31910841 PMCID: PMC6945755 DOI: 10.1186/s12933-019-0984-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 12/26/2019] [Indexed: 02/07/2023] Open
Abstract
While patients with type 2 diabetes mellitus (T2DM) are at increased risk to develop atrial fibrillation (AF), the mechanistic link between T2DM and AF-susceptibility remains unclear. Common co-morbidities of T2DM, particularly hypertension, may drive AF in the setting of T2DM. But direct mechanisms may also explain this relation, at least in part. In this regard, recent evidence suggests that mitochondrial dysfunction drives structural, electrical and contractile remodelling of atrial tissue in patients T2DM. Mitochondrial dysfunction may therefore be the mechanistic link between T2DM and AF and could also serve as a therapeutic target. An elegant series of experiments published in Cardiovascular Diabetology provide compelling new evidence to support this hypothesis. Using a model of high fat diet (HFD) and low-dose streptozotocin (STZ) injection, Shao et al. provide data that demonstrate a direct association between mitochondrial dysfunction and the susceptibility to develop AF. But the authors also demonstrated that the sodium-glucose co-transporter 2 inhibitors (SGLT2i) empagliflozin has the capacity to restore mitochondrial function, ameliorate electrical and structural remodelling and prevent AF. These findings provide a new horizon in which mitochondrial targeted therapies could serve as a new class of antiarrhythmic drugs.
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Affiliation(s)
- Salva R Yurista
- Department of Cardiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Herman H W Silljé
- Department of Cardiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Michiel Rienstra
- Department of Cardiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - Rudolf A de Boer
- Department of Cardiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands
| | - B Daan Westenbrink
- Department of Cardiology, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands.
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Cook RF, Bussey CT, Fomison‐Nurse IC, Hughes G, Bahn A, Cragg PA, Lamberts RR. β
2
‐Adrenoceptors indirectly support impaired β
1
‐adrenoceptor responsiveness in the isolated type 2 diabetic rat heart. Exp Physiol 2019; 104:808-818. [DOI: 10.1113/ep087437] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/18/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Rosalind F. Cook
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Carol T. Bussey
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Ingrid C. Fomison‐Nurse
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Gillian Hughes
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Andrew Bahn
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Patricia A. Cragg
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
| | - Regis R. Lamberts
- Department of Physiology – HeartOtagoSchool of Biomedical SciencesUniversity of Otago Dunedin New Zealand
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Bohne LJ, Johnson D, Rose RA, Wilton SB, Gillis AM. The Association Between Diabetes Mellitus and Atrial Fibrillation: Clinical and Mechanistic Insights. Front Physiol 2019; 10:135. [PMID: 30863315 PMCID: PMC6399657 DOI: 10.3389/fphys.2019.00135] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 02/04/2019] [Indexed: 01/16/2023] Open
Abstract
A number of clinical studies have reported that diabetes mellitus (DM) is an independent risk factor for Atrial fibrillation (AF). After adjustment for other known risk factors including age, sex, and cardiovascular risk factors, DM remains a significant if modest risk factor for development of AF. The mechanisms underlying the increased susceptibility to AF in DM are incompletely understood, but are thought to involve electrical, structural, and autonomic remodeling in the atria. Electrical remodeling in DM may involve alterations in gap junction function that affect atrial conduction velocity due to changes in expression or localization of connexins. Electrical remodeling can also occur due to changes in atrial action potential morphology in association with changes in ionic currents, such as sodium or potassium currents, that can affect conduction velocity or susceptibility to triggered activity. Structural remodeling in DM results in atrial fibrosis, which can alter conduction patterns and susceptibility to re-entry in the atria. In addition, increases in atrial adipose tissue, especially in Type II DM, can lead to disruptions in atrial conduction velocity or conduction patterns that may affect arrhythmogenesis. Whether the insulin resistance in type II DM activates unique intracellular signaling pathways independent of obesity requires further investigation. In addition, the relationship between incident AF and glycemic control requires further study.
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Affiliation(s)
- Loryn J Bohne
- Department of Cardiac Sciences and Department of Physiology and Pharmacology, University of Calgary and Libin Cardiovascular Institute of Alberta, Calgary, AB, Canada
| | - Dustin Johnson
- Department of Cardiac Sciences and Department of Physiology and Pharmacology, University of Calgary and Libin Cardiovascular Institute of Alberta, Calgary, AB, Canada
| | - Robert A Rose
- Department of Cardiac Sciences and Department of Physiology and Pharmacology, University of Calgary and Libin Cardiovascular Institute of Alberta, Calgary, AB, Canada
| | - Stephen B Wilton
- Department of Cardiac Sciences and Department of Physiology and Pharmacology, University of Calgary and Libin Cardiovascular Institute of Alberta, Calgary, AB, Canada
| | - Anne M Gillis
- Department of Cardiac Sciences and Department of Physiology and Pharmacology, University of Calgary and Libin Cardiovascular Institute of Alberta, Calgary, AB, Canada
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Bussey CT, Thaung HPA, Hughes G, Bahn A, Lamberts RR. Cardiac β-adrenergic responsiveness of obese Zucker rats: The role of AMPK. Exp Physiol 2018; 103:1067-1075. [PMID: 29873129 DOI: 10.1113/ep087054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/30/2018] [Indexed: 01/30/2023]
Abstract
NEW FINDINGS What is the central question of the study? Is the reduced signalling of AMP-activated protein kinase (AMPK), a key regulator of energy homeostasis in the heart, responsible for the reduced β-adrenergic responsiveness of the heart in obesity? What is the main finding and its importance? Inhibition of AMPK in isolated hearts prevented the reduced cardiac β-adrenergic responsiveness of obese rats, which was accompanied by reduced phosphorylation of AMPK, a proxy of AMPK activity. This suggests a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart, and it suggests that AMPK might be an important target to restore the β-adrenergic responsiveness in the heart in obesity. ABSTRACT The obesity epidemic impacts heavily on cardiovascular health, in part owing to changes in cardiac metabolism. AMP-activated protein kinase (AMPK) is a key regulator of energy homeostasis in the heart and is regulated by β-adrenoceptors (β-ARs) in normal conditions. In obesity, chronic sympathetic overactivation leads to impaired cardiac β-AR responsiveness, although it is unclear whether AMPK signalling, downstream of β-ARs, contributes to this dysfunction. Therefore, we aimed to determine whether reduced AMPK signalling is responsible for the reduced β-AR responsiveness in obesity. In isolated hearts of lean and obese Zucker rats, we tested β-AR responsiveness to the β1 -AR agonist isoprenaline (ISO, 1 × 10-10 to 5 × 10-8 m) in the absence and presence of the AMPK inhibitor, compound C (CC, 10 μm). The β1 -AR expression and AMPK phosphorylation were assessed by Western blot. β-Adrenergic responsiveness was reduced in the hearts of obese rats (logEC50 of ISO-developed pressure dose-response curves: lean -8.53 ± 0.13 × 10x m versus obese -8.35 ± 0.10 × 10x m ; P < 0.05 lean versus obese, n = 6 per group). This difference was not apparent after AMPK inhibition (logEC50 of ISO-developed pressure curves: lean CC -8.19 ± 0.12 × 10x m versus obese CC 8.17 ± 0.13 × 10x m, P < 0.05, n = 6 per group). β1 -Adrenergic receptor expression and AMPK phosphorylation were reduced in hearts of obese rats (AMPK at Thr172 : lean 1.73 ± 0.17 a.u. versus lean CC 0.81 ± 0.13 a.u., and obese 1.18 ± 0.09 a.u. versus obese CC 0.81 ± 0.16 a.u., P < 0.05, n = 6 per group). Thus, a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart exists, and AMPK might be an important target to restore the reduced cardiac β-adrenergic responsiveness in obesity.
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Affiliation(s)
- Carol T Bussey
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - H P Aye Thaung
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Gillian Hughes
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Andrew Bahn
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Department of Physiology - HeartOtago, Otago School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Daniels LJ, Wallace RS, Nicholson OM, Wilson GA, McDonald FJ, Jones PP, Baldi JC, Lamberts RR, Erickson JR. Inhibition of calcium/calmodulin-dependent kinase II restores contraction and relaxation in isolated cardiac muscle from type 2 diabetic rats. Cardiovasc Diabetol 2018; 17:89. [PMID: 29903013 PMCID: PMC6001139 DOI: 10.1186/s12933-018-0732-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/06/2018] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Calcium/calmodulin-dependent kinase II-delta (CaMKIIδ) activity is enhanced during hyperglycemia and has been shown to alter intracellular calcium handling in cardiomyocytes, ultimately leading to reduced cardiac performance. However, the effects of CaMKIIδ on cardiac contractility during type 2 diabetes are undefined. METHODS We examined the expression and activation of CaMKIIδ in right atrial appendages from non-diabetic and type 2 diabetic patients (n = 7 patients per group) with preserved ejection fraction, and also in right ventricular tissue from Zucker Diabetic Fatty rats (ZDF) (n = 5-10 animals per group) during early diabetic cardiac dysfunction, using immunoblot. We also measured whole heart function of ZDF and control rats using echocardiography. Then we measured contraction and relaxation parameters of isolated trabeculae from ZDF to control rats in the presence and absence of CaMKII inhibitors. RESULTS CaMKIIδ phosphorylation (at Thr287) was increased in both the diabetic human and animal tissue, indicating increased CaMKIIδ activation in the type 2 diabetic heart. Basal cardiac contractility and relaxation were impaired in the cardiac muscles from the diabetic rats, and CaMKII inhibition with KN93 partially restored contractility and relaxation. Autocamtide-2-related-inhibitor peptide (AIP), another CaMKII inhibitor that acts via a different mechanism than KN93, fully restored cardiac contractility and relaxation. CONCLUSIONS Our results indicate that CaMKIIδ plays a key role in modulating performance of the diabetic heart, and moreover, suggest a potential therapeutic role for CaMKII inhibitors in improving myocardial function during type 2 diabetes.
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Affiliation(s)
- Lorna J Daniels
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand
| | - Rachel S Wallace
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand
| | - Olivia M Nicholson
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand
| | - Genevieve A Wilson
- Otago School of Medical Sciences, Department of Medicine and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Fiona J McDonald
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand
| | - Peter P Jones
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand
| | - J Chris Baldi
- Otago School of Medical Sciences, Department of Medicine and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand
| | - Jeffrey R Erickson
- Otago School of Medical Sciences, Department of Physiology and HeartOtago, University of Otago, 270 Great King Street, Dunedin, 9016, New Zealand.
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Sarapultsev P, Yushkov B, Sarapultsev A. Prevalence of arrhythmias in patients with type 2 diabetes and the role of structural changes in myocardium in their development. Diabetes Metab Syndr 2017; 11 Suppl 2:S567-S576. [PMID: 28412149 DOI: 10.1016/j.dsx.2017.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE The aim of the study was to evaluate the prevalence of arrhythmias in patients with type 2 diabetes and their relationships with the structural parameters of the heart. METHODS A retrospective case-control study was conducted using clinical and biochemical profiles of patients with diabetes at the Endocrinology Centre and City Clinical Hospital No. 40, Ekaterinburg, Russia. RESULTS The total study sample included 75 subjects. The average age (SD) was 48.2 (5.6) years, and the mean duration of diabetes (SD) was 6.2 (2.4) years. The most common type of extrasystoles were the single supraventricular extrasystoles, observed in 72.29% of cases (vs 38.89% in the control group) and paired supraventricular extrasystoles, which were identified in 30% of cases (vs 19.44% in the control group). Ventricular cardiac arrhythmias in the form of ventricular extrasystoles (VE) were identified in 25.71% of cases (13.89% in the control group). CONCLUSIONS This study revealed the signs of the morphological restructuring of the right chambers of the heart and a relatively high prevalence of supraventricular arrhythmias in the early stages of type 2 diabetes. Moreover, according to the results, the incidence of some types of supraventricular arrhythmias and the occurrence of tachycardia episodes in patients with type 2 diabetes mostly depends on the restructuring of the right chambers of the heart, which may be caused by the peculiarities of the cardiac innervation, with the higher density of choline and adrenergic plexuses in the right chambers.
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Affiliation(s)
- Petr Sarapultsev
- Ural Fed. Univ. named after the First Pres. of Russ. B.N. Yeltsin, 19 Mira street, Ekaterinburg, 620002, Russian Federation; Institute of Immunology and Physiology (IIP), Ural Division of Russian Academy of Sciences, 106 Pervomayskaya street, Ekaterinburg, 620049, Russian Federation
| | - Boris Yushkov
- Ural Fed. Univ. named after the First Pres. of Russ. B.N. Yeltsin, 19 Mira street, Ekaterinburg, 620002, Russian Federation; Institute of Immunology and Physiology (IIP), Ural Division of Russian Academy of Sciences, 106 Pervomayskaya street, Ekaterinburg, 620049, Russian Federation; Ural State Medical University, 3 Repina street, Ekaterinburg, 620014, Russian Federation
| | - Alexey Sarapultsev
- Ural Fed. Univ. named after the First Pres. of Russ. B.N. Yeltsin, 19 Mira street, Ekaterinburg, 620002, Russian Federation; Institute of Immunology and Physiology (IIP), Ural Division of Russian Academy of Sciences, 106 Pervomayskaya street, Ekaterinburg, 620049, Russian Federation.
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Markman TM, Habibi M, Venkatesh BA, Zareian M, Wu C, Heckbert SR, Bluemke DA, Lima JAC. Association of left atrial structure and function and incident cardiovascular disease in patients with diabetes mellitus: results from multi-ethnic study of atherosclerosis (MESA). Eur Heart J Cardiovasc Imaging 2017; 18:1138-1144. [PMID: 28329137 PMCID: PMC5837690 DOI: 10.1093/ehjci/jew332] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/19/2016] [Accepted: 01/17/2017] [Indexed: 12/20/2022] Open
Abstract
AIMS Diabetes mellitus (DM) is associated with the development of cardiovascular disease (CVD). Morphological changes in the left atrium (LA) may appear before symptoms. We aimed to investigate the association between cardiac magnetic resonance imaging (CMR) measured LA structure and function and incident CVD in asymptomatic individuals with DM. METHODS AND RESULTS Tissue tracking CMR was used to measure LA size and phasic function (emptying fractions and strain) on all 536 Multi-Ethnic Study of Atherosclerosis (MESA) participants with DM and available CMR at baseline in 2000-2002. At the time of enrolment, all participants were free of clinically recognized CVD, which was defined as MI, resuscitated cardiac arrest, angina, stroke, heart failure, and atrial fibrillation. Cox regression was used to assess the association of LA parameters with incident CVD adjusted for traditional cardiovascular risk factors, LV mass, NT Pro-BNP and maximum LA volume. Kaplan-Meier curves, adjusted for traditional risk factors, were generated for each LA measurement for the 25% of participants with the most abnormal values versus the remaining 75%. After a mean follow up of 11.4 ± 3.4 years, 141 individuals developed CVD. Individuals with incident CVD (mean age 66 years, 66% male vs. mean age 64 years, 50% male) had larger maximum and minimum LA volume index (LAVI) (32.1 vs. 26.8 mm3/m2; 19.4 vs. 14.2 mm3/m2 respectively, P < 0.001 for both), and lower total, passive, and active EF than those without CVD (P < 0.01 for all). In the fully adjusted model, there was a significant association of minimum LAVI, LA total EF, LA passive EF and LA active EF with incident CVD (HR 1.12 per mm3/m2, P < 0.001; HR 0.95 per %, P < 0.001; HR 0.97 per %, P = 0.021; HR 0.98 per %, P < 0.027, respectively). CONCLUSIONS CMR measured LA minimum volume and LA function as measured by emptying fraction are predictive of CVD in a diabetic multi-ethnic population free of any clinically recognized CVD at baseline.
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Affiliation(s)
- Timothy M Markman
- Department of Medicine, The Johns Hopkins University, 600 North Wolfe Street, MD 21287, Baltimore, USA
| | - Mohammadali Habibi
- Division of Cardiology, Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, New York, USA
| | - Bharath Ambale Venkatesh
- Department of Radiology, The Johns Hopkins University, 600 North Wolfe Street, MD 21287, Blalock 524, Baltimore, USA
| | - Mytra Zareian
- Department of Radiology, The Johns Hopkins University, 600 North Wolfe Street, MD 21287, Blalock 524, Baltimore, USA
| | - Colin Wu
- National Heart, Lung, and Blood Institute, 31 Center St, MD 20892, Bethesda, USA
| | - Susan R Heckbert
- Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Health Sciences Building, WA 98195, Seattle, USA
| | - David A Bluemke
- National Institutes of Health, Radiology and Imaging Sciences, 10 Center St, MD 20892, Bethesda, USA
| | - Joao A C Lima
- Department of Medicine, The Johns Hopkins University, 600 North Wolfe Street, MD 21287, Baltimore, USA
- Department of Radiology, The Johns Hopkins University, 600 North Wolfe Street, MD 21287, Blalock 524, Baltimore, USA
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Down-regulation of miR-15a/b accelerates fibrotic remodelling in the Type 2 diabetic human and mouse heart. Clin Sci (Lond) 2017; 131:847-863. [PMID: 28289072 DOI: 10.1042/cs20160916] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 03/03/2017] [Accepted: 03/13/2017] [Indexed: 12/13/2022]
Abstract
Aim: Myocardial fibrosis is a well-established cause of increased myocardial stiffness and subsequent diastolic dysfunction in the diabetic heart. The molecular regulators that drive the process of fibrotic events in the diabetic heart are still unknown. We determined the role of the microRNA (miR)-15 family in fibrotic remodelling of the diabetic heart.Methods and results: Right atrial appendage (RAA) and left ventricular (LV) biopsy tissues collected from diabetic and non-diabetic (ND) patients undergoing coronary artery bypass graft surgery showed significant down-regulation of miR-15a and -15b. This was associated with marked up-regulation of pro-fibrotic transforming growth factor-β receptor-1 (TGFβR1) and connective tissue growth factor (CTGF), direct targets for miR-15a/b and pro-senescence p53 protein. Interestingly, down-regulation of miR-15a/b preceded the development of diastolic dysfunction and fibrosis in Type 2 diabetic mouse heart. Therapeutic restoration of miR-15a and -15b in HL-1 cardiomyocytes reduced the activation of pro-fibrotic TGFβR1 and CTGF, and the pro-senescence p53 protein expression, confirming a causal regulation of these fibrotic and senescence mediators by miR-15a/b. Moreover, conditioned medium (CM) collected from cardiomyocytes treated with miR-15a/b markedly diminished the differentiation of diabetic human cardiac fibroblasts.Conclusion: Our results provide first evidence that early down-regulation of miR-15a/b activates fibrotic signalling in diabetic heart, and hence could be a potential target for the treatment/prevention of diabetes-induced fibrotic remodelling of the heart.
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Daniels L, Bell JR, Delbridge LMD, McDonald FJ, Lamberts RR, Erickson JR. The role of CaMKII in diabetic heart dysfunction. Heart Fail Rev 2016. [PMID: 26198034 DOI: 10.1007/s10741-015-9498-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Diabetes mellitus (DM) is an increasing epidemic that places a significant burden on health services worldwide. The incidence of heart failure (HF) is significantly higher in diabetic patients compared to non-diabetic patients. One underlying mechanism proposed for the link between DM and HF is activation of calmodulin-dependent protein kinase (CaMKIIδ). CaMKIIδ mediates ion channel function and Ca(2+) handling during excitation-contraction and excitation-transcription coupling in the myocardium. CaMKIIδ activity is up-regulated in the myocardium of diabetic patients and mouse models of diabetes, where it promotes pathological signaling that includes hypertrophy, fibrosis and apoptosis. Pharmacological inhibition and knockout models of CaMKIIδ have shown some promise of a potential therapeutic benefit of CaMKIIδ inhibition, with protection against cardiac hypertrophy and apoptosis reported. This review will highlight the pathological role of CaMKIIδ in diabetes and discuss CaMKIIδ as a therapeutic target in DM, and also the effects of exercise on CaMKIIδ.
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Affiliation(s)
- Lorna Daniels
- Department of Physiology, University of Otago, PO Box 56, Dunedin, New Zealand
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The Type 2 Diabetic Heart: Its Role in Exercise Intolerance and the Challenge to Find Effective Exercise Interventions. Sports Med 2016; 46:1605-1617. [DOI: 10.1007/s40279-016-0542-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Bening C, Sikand A, Conzelmann LO, Stumpf N, Vahl CF. Reduced right atrial contractile force in patients with left ventricular diastolic dysfunction: A study in human atrial fibers-contractile force and diastolic dysfunction. Asian J Surg 2015; 40:23-28. [PMID: 26409766 DOI: 10.1016/j.asjsur.2015.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/20/2015] [Accepted: 07/17/2015] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND/OBJECTIVE The aim of our study was to evaluate right heart contractile force in patients with diastolic dysfunction (DD) with preserved left heart ejection fraction undergoing cardiac surgery. We examined the contractile properties of skinned human fibers obtained from the right auricle in two groups (DD and controls). METHODS Right atrial tissue from 64 patients, who were undergoing cardiac surgery, were collected before extracorporal circulation. Tissue was conserved and prepared as "skinned fibers". We exposed the dissected fibers to increasing calcium concentrations and recorded the force values. RESULTS Patients with DD develop significantly less force at middle and higher calcium concentrations pCa 4.0: DD 2.58 ± 0.4 mN, controls 5.32 ± 0.4 mN, p = 0.02; pCa 5.5: DD 1.14 ± 0.3 mN, controls 1.45 ± 0.3 mN, p = 0.03. DD significantly correlates with left ventricular hypertrophy (LVH; p = 0.03). DD did not significantly occur more often in patients with mitral valve insufficiency, aortic insufficiency or stenosis, or coronary heart disease (all p > 0.10). LVH, which was associated with DD, correlated significantly with mitral valve prolapse (p = 0.05), aortic valve stenosis (p = 0.02), and mitral valve insufficiency (p = 0.03). CONCLUSION Contractile force is significantly reduced in right atrial skinned human fibers with DD. DD is significantly associated with LVH, but emerges independently from underlying pathologies like valve diseases or coronary heart disease. This underlines the hypothesis that impairment of contractile capacity directly results from DD-independent from volume or pressure overload due to valvular or ischemic heart disease.
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Affiliation(s)
- Constanze Bening
- Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany.
| | - Anjuli Sikand
- Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Lars Oliver Conzelmann
- Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Nicole Stumpf
- Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Christian-Friedrich Vahl
- Department of Cardiothoracic and Vascular Surgery, Medical Centre of the Johannes Gutenberg-University Mainz, Mainz, Germany
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Differential expression pattern of cardiovascular microRNAs in the human type-2 diabetic heart with normal ejection fraction. Int J Cardiol 2015; 202:40-3. [PMID: 26386917 DOI: 10.1016/j.ijcard.2015.08.161] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 08/21/2015] [Indexed: 12/21/2022]
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Thaung HPA, Baldi JC, Wang HY, Hughes G, Cook RF, Bussey CT, Sheard PW, Bahn A, Jones PP, Schwenke DO, Lamberts RR. Increased Efferent Cardiac Sympathetic Nerve Activity and Defective Intrinsic Heart Rate Regulation in Type 2 Diabetes. Diabetes 2015; 64:2944-56. [PMID: 25784543 DOI: 10.2337/db14-0955] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 03/09/2015] [Indexed: 11/13/2022]
Abstract
Elevated sympathetic nerve activity (SNA) coupled with dysregulated β-adrenoceptor (β-AR) signaling is postulated as a major driving force for cardiac dysfunction in patients with type 2 diabetes; however, cardiac SNA has never been assessed directly in diabetes. Our aim was to measure the sympathetic input to and the β-AR responsiveness of the heart in the type 2 diabetic heart. In vivo recording of SNA of the left efferent cardiac sympathetic branch of the stellate ganglion in Zucker diabetic fatty rats revealed an elevated resting cardiac SNA and doubled firing rate compared with nondiabetic rats. Ex vivo, in isolated denervated hearts, the intrinsic heart rate was markedly reduced. Contractile and relaxation responses to β-AR stimulation with dobutamine were compromised in externally paced diabetic hearts, but not in diabetic hearts allowed to regulate their own heart rate. Protein levels of left ventricular β1-AR and Gs (guanine nucleotide binding protein stimulatory) were reduced, whereas left ventricular and right atrial β2-AR and Gi (guanine nucleotide binding protein inhibitory regulatory) levels were increased. The elevated resting cardiac SNA in type 2 diabetes, combined with the reduced cardiac β-AR responsiveness, suggests that the maintenance of normal cardiovascular function requires elevated cardiac sympathetic input to compensate for changes in the intrinsic properties of the diabetic heart.
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Affiliation(s)
- H P Aye Thaung
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - J Chris Baldi
- Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Heng-Yu Wang
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Gillian Hughes
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Rosalind F Cook
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Carol T Bussey
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Phil W Sheard
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Andrew Bahn
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Peter P Jones
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Daryl O Schwenke
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Regis R Lamberts
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
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Bussey CT, Hughes G, Saxena P, Galvin IF, Bunton RW, Noye MK, Coffey S, Williams MJA, Baldi JC, Jones PP, Lamberts RR. Chamber-specific changes in calcium-handling proteins in the type 2 diabetic human heart with preserved ejection fraction. Int J Cardiol 2015; 193:53-5. [PMID: 26005176 DOI: 10.1016/j.ijcard.2015.05.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 05/09/2015] [Indexed: 10/23/2022]
Affiliation(s)
- Carol T Bussey
- Department of Physiology - HeartOtago, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Gillian Hughes
- Department of Physiology - HeartOtago, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Pankaj Saxena
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Ivor F Galvin
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Richard W Bunton
- Department of Cardiothoracic Surgery, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Marilyn K Noye
- Department of Medicine - HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine - HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand; NIHR Oxford Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom
| | - Michael J A Williams
- Department of Medicine - HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - J Chris Baldi
- Department of Medicine - HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Peter P Jones
- Department of Physiology - HeartOtago, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand.
| | - Regis R Lamberts
- Department of Physiology - HeartOtago, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand.
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Cassidy S, Hallsworth K, Thoma C, MacGowan GA, Hollingsworth KG, Day CP, Taylor R, Jakovljevic DG, Trenell MI. Cardiac structure and function are altered in type 2 diabetes and non-alcoholic fatty liver disease and associate with glycemic control. Cardiovasc Diabetol 2015; 14:23. [PMID: 25849783 PMCID: PMC4330943 DOI: 10.1186/s12933-015-0187-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/28/2015] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Both non-alcoholic fatty liver disease (NAFLD) and Type 2 diabetes increase the risk of developing cardiovascular disease. The metabolic processes underlying NAFLD and Type 2 diabetes are part of an integrated mechanism but little is known about how these conditions may differentially affect the heart. We compared the impact of NAFLD and Type 2 diabetes on cardiac structure, function and metabolism. METHODS 19 adults with Type 2 diabetes (62 ± 8 years), 19 adults with NAFLD (54 ± 15 years) and 19 healthy controls (56 ± 14 years) underwent assessment of cardiac structure, function and metabolism using high resolution magnetic resonance imaging, tagging and spectroscopy at 3.0 T. RESULTS Adults with NAFLD and Type 2 diabetes demonstrate concentric remodelling with an elevated eccentricity ratio compared to controls (1.05 ± 0.3 vs. 1.12 ± 0.2 vs. 0.89 ± 0.2 g/ml; p < 0.05). Despite this, only the Type 2 diabetes group demonstrate significant systolic and diastolic dysfunction evidenced by a reduced stroke index (31 ± 7vs. controls, 38 ± 10, p < 0.05 ml/m2) and reduced E/A (0.9 ± 0.4 vs. controls, 1.9 ± 1.4, p < 0.05) respectively. The torsion to shortening ratio was higher in Type 2 diabetes compared to NAFLD (0.58 ± 0.16 vs. 0.44 ± 0.13; p < 0.05). Significant associations were observed between fasting blood glucose/HbA1c and diastolic parameters as well as the torsion to shortening ratio (all p < 0.05). Phosphocreatine/adenosine triphosphate ratio was not altered in NAFLD or Type 2 diabetes compared to controls. CONCLUSIONS Changes in cardiac structure are evident in adults with Type 2 diabetes and NAFLD without overt cardiac disease and without changes in cardiac energy metabolism. Only the Type 2 diabetes group display diastolic and subendocardial dysfunction and glycemic control may be a key mediator of these cardiac changes. Therapies should be explored to target these preclinical cardiac changes to modify cardiovascular risk associated with Type 2 diabetes and NAFLD.
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Affiliation(s)
- Sophie Cassidy
- />Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Kate Hallsworth
- />Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Christian Thoma
- />Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Guy A MacGowan
- />Department of Cardiology, Freeman Hospital, Newcastle upon Tyne, UK
- />Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Kieren G Hollingsworth
- />Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Christopher P Day
- />Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Roy Taylor
- />Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | | | - Michael I Trenell
- />Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
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Bussey CT, de Leeuw AE, Lamberts RR. Increased haemodynamic adrenergic load with isoflurane anaesthesia in type 2 diabetic and obese rats in vivo. Cardiovasc Diabetol 2014; 13:161. [PMID: 25496763 PMCID: PMC4266208 DOI: 10.1186/s12933-014-0161-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/01/2014] [Indexed: 12/13/2022] Open
Abstract
Background Increasing numbers of type 2 diabetic and obese patients with enhanced rates of cardiovascular complications require surgical interventions, however they have a higher incidence of perioperative haemodynamic complications, which has been linked to adrenergic dysfunction. Therefore, we aimed to determine how α- and β-adrenoceptor (AR)-mediated haemodynamic responses are affected by isoflurane anaesthesia in experimental type 2 diabetes and obesity in vivo. Methods Sixteen-week old male Zucker type 2 Diabetic Fatty (ZDF) rats, Zucker Obese rats and their lean counterparts (n = 7-9 per group) were instrumented with radio telemeters to record blood pressure and heart rate and with vascular access ports for non-invasive intravenous drug delivery in vivo. Haemodynamic effects of α-AR (phenylephrine; 1-100 μg.kg−1) or β-AR (dobutamine; 2-120 μg.kg−1) stimulation were assessed under conscious and anaesthetised (isoflurane; 2%) conditions. Results Vascular α-AR sensitivity was increased in both diabetic (non-diabetic 80 ± 3 vs. diabetic 95 ± 4 ΔmmHg at 100 μg.kg−1; p < 0.05) and obese (lean 65 ± 6 vs. obese 84 ± 6 ΔmmHg at 20 μg.kg−1; p < 0.05) conscious rats. Interestingly, anaesthesia exacerbated and prolonged the increased α-AR function in both diabetic and obese animals (non-diabetic 51 ± 1 vs. diabetic 68 ± 4 ΔmmHg, lean 61 ± 5 vs. obese 84 ± 2 ΔmmHg at 20 μg.kg−1; p < 0.05). Meanwhile, β-AR chronotropic sensitivity was reduced in conscious diabetic and obese rats (non-diabetic 58 ± 7 vs. diabetic 27 ± 8 Δbpm, lean 103 ± 12 vs. obese 61 ± 9 Δbpm at 15 μg.kg−1; p < 0.05). Anaesthesia normalised chronotropic β-AR responses, via either a limited reduction in obese (lean 51 ± 3 vs. obese 66 ± 5 Δbpm; NS at 15 μg.kg−1) or increased responses in diabetic animals (non-diabetic 49 ± 8 vs. diabetic 63 ± 8 Δbpm, at 15 μg.kg−1; NS at 15 μg.kg−1). Conclusions Long term metabolic stress, such as during type 2 diabetes and obesity, alters α- and β-AR function, its dynamics and the interaction with isoflurane anaesthesia. During anaesthesia, enhanced α-AR sensitivity and normalised β-AR function may impair cardiovascular function in experimental type 2 diabetes and obesity.
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Affiliation(s)
- Carol T Bussey
- HeartOtago, Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin 9054, New Zealand.
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