1
|
Liu R, Zhao H, Lu Z, Zeng L, Shi H, Wu L, Wang J, Zhong F, Liu C, Zhang Y, Qiu Z. Toxicity profiles of immune checkpoint inhibitors in nervous system cancer: a comprehensive disproportionality analysis using FDA adverse event reporting system. Clin Exp Med 2024; 24:216. [PMID: 39249163 PMCID: PMC11383843 DOI: 10.1007/s10238-024-01403-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Accepted: 06/12/2024] [Indexed: 09/10/2024]
Abstract
BACKGROUND Immune-related adverse events (irAEs) always occur during treatment with immune checkpoint inhibitors (ICIs). Patients with nervous system cancer (NSC) may gain clinical benefit from ICIs, but irAEs in NSC patients are rarely examined. Therefore, our study systematically summarized reports of irAEs in NSC. METHODS We obtained information from the FDA adverse event reporting system from the first quarter (Q1) of 2013 to the fourth quarter (Q4) of 2022. We examined use of a combination of ICIs and chemotherapy (ICI_Chemo) or chemotherapy only (ICI_Chemo) for patients with NSC. Multiple disproportionality analyses were applied to assess irAEs. Multiomics data from the gene expression omnibus (GEO) database were analyzed to explore potential molecular mechanisms associated with irAEs in NSC patients. RESULTS Fourteen irAEs were identified in 8,357 NSC patients after removing duplicates; the top five events were seizure, confused state, encephalopathy, muscular weakness and gait disturbance. Older patients were more likely to develop irAEs than were younger patients. From the start of ICIs_Chemo to irAE occurrence, there was a significant difference in the time to onset of irAEs between age groups. irAEs may occur via mechanisms involving the inflammatory response, secretion of inflammatory mediators, and aberrant activation of pathologic pathways. CONCLUSIONS This study helps to characterize irAEs in NSC patients treated with ICIs. We combined GEO database analysis to explore the potential molecular mechanisms of irAEs. The results of this study provide a basis for improving the toxic effects of ICIs in NSC patients.
Collapse
Affiliation(s)
- Rongrong Liu
- Department of Neurology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Hui Zhao
- Department of Sleep Medicine, Ganzhou People's Hospital, Ganzhou, Jiangxi, China
| | - Zenghong Lu
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Lingshuai Zeng
- Major of Rehabilitation, Faculty of Medicine, Jinggangshan University, Ji'an, Jiangxi, China
| | - Huaqiu Shi
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Longqiu Wu
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Jing Wang
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Fangjun Zhong
- Department of Neurology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Chuanjian Liu
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China
| | - Yu Zhang
- Department of Neurology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China.
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China.
| | - Zhengang Qiu
- Department of Neurology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China.
- Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi, China.
| |
Collapse
|
2
|
Mascarenhas L, Downey M, Schwartz G, Adabag S. Antiarrhythmic effects of metformin. Heart Rhythm O2 2024; 5:310-320. [PMID: 38840768 PMCID: PMC11148504 DOI: 10.1016/j.hroo.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024] Open
Abstract
Atrial fibrillation/flutter (AF) is a major public health problem and is associated with stroke, heart failure, dementia, and death. It is estimated that 20%-30% of Americans will develop AF at some point in their life. Current medications to prevent AF have limited efficacy and significant adverse effects. Newer and safer therapies to prevent AF are needed. Ventricular arrhythmias are less prevalent than AF but may have significant consequences including sudden cardiac death. Metformin is the most prescribed, first-line medication for treatment of diabetes mellitus (DM). It decreases hepatic glucose production but also reduces inflammation and oxidative stress. Experimental studies have shown that metformin improves metabolic, electrical, and histologic risk factors associated with AF and ventricular arrhythmias. Furthermore, in large clinical observational studies, metformin has been associated with a reduced risk of AF in people with DM. These data suggest that metformin may have antiarrhythmic properties and may be a candidate to be repurposed as a medication to prevent cardiac arrhythmias. In this article, we review the clinical observational and experimental evidence for the association between metformin and cardiac arrhythmias. We also discuss the potential antiarrhythmic mechanisms underlying this association. Repurposing a well-tolerated, safe, and inexpensive medication to prevent cardiac arrhythmias has significant positive public health implications.
Collapse
Affiliation(s)
- Lorraine Mascarenhas
- Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota
| | - Michael Downey
- Department of Cardiology, Hennepin County Medical Center, Minneapolis, Minnesota
| | - Gregory Schwartz
- Cardiology Section, Rocky Mountain Regional VA Medical Center and University of Colorado School of Medicine, Aurora, Colorado
| | - Selcuk Adabag
- Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota
- Department of Cardiology, Minneapolis Veterans Affairs Medical Center and University of Minnesota, Minneapolis, Minnesota
| |
Collapse
|
3
|
Thongsuk Y, Hwang NC. Perioperative Glycemic Management in Cardiac Surgery: A Narrative Review. J Cardiothorac Vasc Anesth 2024; 38:248-267. [PMID: 37743132 DOI: 10.1053/j.jvca.2023.08.149] [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: 03/03/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/26/2023]
Abstract
Diabetes and hyperglycemic events in cardiac surgical patients are associated with postoperative morbidity and mortality. The causes of dysglycemia, the abnormal fluctuations in blood glucose concentrations, in the perioperative period include surgical stress, surgical techniques, medications administered perioperatively, and patient factors. Both hyperglycemia and hypoglycemia lead to poor outcomes after cardiac surgery. While trying to control blood glucose concentration tightly for better postoperative outcomes, hypoglycemia is the main adverse event. Currently, there is no definite consensus on the optimum perioperative blood glucose concentration to be maintained in cardiac surgical patients. This review provides an overview of perioperative glucose homeostasis, the pathophysiology of dysglycemia, factors that affect glycemic control in cardiac surgery, and current practices for glycemic control in cardiac surgery.
Collapse
Affiliation(s)
- Yada Thongsuk
- Department of Anesthesiology, King Chulalongkorn Memorial Hospital, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Department of Cardiothoracic Anaesthesia, National Heart Centre, Singapore
| | - Nian Chih Hwang
- Department of Cardiothoracic Anaesthesia, National Heart Centre, Singapore; Department of Anaesthesiology, Singapore General Hospital, Singapore.
| |
Collapse
|
4
|
Guichard JB, Guasch E, Roche F, Da Costa A, Mont L. Premature atrial contractions: A predictor of atrial fibrillation and a relevant marker of atrial cardiomyopathy. Front Physiol 2022; 13:971691. [PMID: 36353376 PMCID: PMC9638131 DOI: 10.3389/fphys.2022.971691] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/14/2022] [Indexed: 09/08/2023] Open
Abstract
An increased burden of premature atrial contractions (PACs) has long been considered a benign phenomenon. However, strong evidence of their involvement in the occurrence of atrial fibrillation (AF), ischemic stroke, and excess mortality suggests the need for management. The central question to be resolved is whether increased ectopic atrial rhythm is only a predictor of AF or whether it is a marker of atrial cardiomyopathy and therefore of ischemic stroke. After reviewing the pathophysiology of PACs and its impact on patient prognosis, this mini-review proposes to 1) detail the physiological and clinical elements linking PACs and AF, 2) present the evidence in favor of supraventricular ectopic activity as a marker of cardiomyopathy, and 3) outline the current limitations of this concept and the potential future clinical implications.
Collapse
Affiliation(s)
- Jean-Baptiste Guichard
- Arrhythmia Unit, Hospital Clínic de Barcelona, Institut d’Investigacions Biomèdiques August Pi iSunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Department of Cardiology, University Hospital of Saint-Étienne, Saint-Étienne, France
- Sainbiose, DVH, Inserm U1059, University Hospital of Saint-Étienne, Saint-Étienne, France
| | - Eduard Guasch
- Arrhythmia Unit, Hospital Clínic de Barcelona, Institut d’Investigacions Biomèdiques August Pi iSunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Frederic Roche
- Sainbiose, DVH, Inserm U1059, University Hospital of Saint-Étienne, Saint-Étienne, France
| | - Antoine Da Costa
- Department of Cardiology, University Hospital of Saint-Étienne, Saint-Étienne, France
- Sainbiose, DVH, Inserm U1059, University Hospital of Saint-Étienne, Saint-Étienne, France
| | - Lluís Mont
- Arrhythmia Unit, Hospital Clínic de Barcelona, Institut d’Investigacions Biomèdiques August Pi iSunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| |
Collapse
|
5
|
Kani K, Fujiu K. Electrical Storm. Int Heart J 2021; 62:1195-1198. [PMID: 34853216 DOI: 10.1536/ihj.21-662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Kunihiro Kani
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo
| | - Katsuhito Fujiu
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo
| |
Collapse
|
6
|
Hong L, Zhang M, Ly OT, Chen H, Sridhar A, Lambers E, Chalazan B, Youn SW, Maienschein-Cline M, Feferman L, Ong SG, Wu JC, Rehman J, Darbar D. Human induced pluripotent stem cell-derived atrial cardiomyocytes carrying an SCN5A mutation identify nitric oxide signaling as a mediator of atrial fibrillation. Stem Cell Reports 2021; 16:1542-1554. [PMID: 34019817 PMCID: PMC8190590 DOI: 10.1016/j.stemcr.2021.04.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 12/13/2022] Open
Abstract
Mutations in SCN5A, encoding the cardiac sodium channel, are linked with familial atrial fibrillation (AF) but the underlying pathophysiologic mechanisms and implications for therapy remain unclear. To characterize the pathogenesis of AF-linked SCN5A mutations, we generated patient-specific induced pluripotent stem cell-derived atrial cardiomyocytes (iPSC-aCMs) from two kindreds carrying SCN5A mutations (E428K and N470K) and isogenic controls using CRISPR-Cas9 gene editing. We showed that mutant AF iPSC-aCMs exhibited spontaneous arrhythmogenic activity with beat-to-beat irregularity, prolonged action potential duration, and triggered-like beats. Single-cell recording revealed enhanced late sodium currents (INa,L) in AF iPSC-aCMs that were absent in a heterologous expression model. Gene expression profiling of AF iPSC-aCMs showed differential expression of the nitric oxide (NO)-mediated signaling pathway underlying enhanced INa,L. We showed that patient-specific AF iPSC-aCMs exhibited striking in vitro electrophysiological phenotype of AF-linked SCN5A mutations, and transcriptomic analyses supported that the NO signaling pathway modulated the INa,L and triggered AF.
Collapse
Affiliation(s)
- Liang Hong
- Division of Cardiology, Department of Medicine, Chicago, IL, USA.
| | - Meihong Zhang
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | - Olivia Thao Ly
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | - Hanna Chen
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | - Arvind Sridhar
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | - Erin Lambers
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | - Brandon Chalazan
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | - Seock-Won Youn
- Division of Cardiology, Department of Medicine, Chicago, IL, USA
| | | | - Leonid Feferman
- Research Informatics Core, Research Resources Center, Chicago, IL, USA
| | - Sang-Ging Ong
- Division of Cardiology, Department of Medicine, Chicago, IL, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, USA
| | - Joseph C Wu
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Jalees Rehman
- Division of Cardiology, Department of Medicine, Chicago, IL, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, USA
| | - Dawood Darbar
- Division of Cardiology, Department of Medicine, Chicago, IL, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, USA; Jesse Brown Veterans Administration Medical Center, Chicago, IL, USA.
| |
Collapse
|
7
|
Liu X, Pan Z. Store-Operated Calcium Entry in the Cardiovascular System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:303-333. [DOI: 10.1007/978-981-16-4254-8_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
Shiferaw Y, Aistrup GL, Louch WE, Wasserstrom JA. Remodeling Promotes Proarrhythmic Disruption of Calcium Homeostasis in Failing Atrial Myocytes. Biophys J 2019; 118:476-491. [PMID: 31889516 DOI: 10.1016/j.bpj.2019.12.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/19/2019] [Accepted: 12/09/2019] [Indexed: 01/31/2023] Open
Abstract
It is well known that heart failure (HF) typically coexists with atrial fibrillation (AF). However, until now, no clear mechanism has been established that relates HF to AF. In this study, we apply a multiscale computational framework to establish a mechanistic link between atrial myocyte structural remodeling in HF and AF. Using a spatially distributed model of calcium (Ca) signaling, we show that disruption of the spatial relationship between L-type Ca channels (LCCs) and ryanodine receptors results in markedly increased Ca content of the sarcoplasmic reticulum (SR). This increase in SR load is due to changes in the balance between Ca entry via LCCs and Ca extrusion due to the sodium-calcium exchanger after an altered spatial relationship between these signaling proteins. Next, we show that the increased SR load in atrial myocytes predisposes these cells to subcellular Ca waves that occur during the action potential (AP) and are triggered by LCC openings. These waves are common in atrial cells because of the absence of a well-developed t-tubule system in most of these cells. This distinct spatial architecture allows for the presence of a large pool of orphaned ryanodine receptors, which can fire and sustain Ca waves during the AP. Finally, we incorporate our atrial cell model in two-dimensional tissue simulations and demonstrate that triggered wave generation in cells leads to electrical waves in tissue that tend to fractionate to form wavelets of excitation. This fractionation is driven by the underlying stochasticity of subcellular Ca waves, which perturbs AP repolarization and consequently induces localized conduction block in tissue. We outline the mechanism for this effect and argue that it may explain the propensity for atrial arrhythmias in HF.
Collapse
Affiliation(s)
- Yohannes Shiferaw
- Department of Physics, California State University, Northridge, California.
| | - Gary L Aistrup
- Department of Experimental Cardiology, Masonic Medical Research Institute, Utica, New York
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway; KG Jebsen Center for Cardiac Research, University of Oslo, Oslo, Norway
| | - J A Wasserstrom
- Department of Medicine (Cardiology) and The Feinberg Cardiovascular and Renal Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
10
|
Dan GA, Dobrev D. Antiarrhythmic drugs for atrial fibrillation: Imminent impulses are emerging. IJC HEART & VASCULATURE 2018; 21:11-15. [PMID: 30225340 PMCID: PMC6138883 DOI: 10.1016/j.ijcha.2018.08.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/15/2018] [Accepted: 08/30/2018] [Indexed: 12/19/2022]
Abstract
Rhythm and rate strategies are considered equivalent for the management of atrial fibrillation (AF). Moreover, both strategies are intended for improving symptoms and quality of life. Despite the clinical availability of several antiarrhythmic drugs (AAD) the alternatives for the patient with comorbidities are significantly fewer because of the concern regarding many adverse effects, including proarrhythmias. The impetuous development of AF ablation gave rise to a false impression that AAD are a second line therapy. All these statements reflect, in fact, the weakness of the classical paradigm and classification regarding AAD and the gap between the current knowledge of AF mechanism and determinants and the "classical" AAD non-discriminatory action. A new paradigm in development of effective and safe AAD is based on modern knowledge of vulnerable parameters involved in the genesis and perpetuation of AF. New AAD will target specific triggers of AF and ion currents which are expressed preferentially in fibrillatory atrium. Such targets will include repolarizing currents and channels, as ultrarapid potassium current, two pore potassium current, the acetylcholine-gated potassium current, small-conductance calcium-dependent potassium channels, but, also, molecular targets involved in intracellular calcium kinetics, as Ca2+-calmodulin-dependent protein kinase, ryanodine receptors and non-coding miRNA. New mechanistic discoveries link AF to inflammation and modern anti-cytokine drugs. There is still a long way to win between basic research and clinical practice, but, without any doubt, antiarrhythmic drug therapy will remain and develop as a cornerstone therapy for AF not in conflict, but complementary and alternative to interventional therapy.
Collapse
Affiliation(s)
- Gheorghe-Andrei Dan
- Carol Davila Medicine University, Bucharest, Romania
- Colentina University Hospital, Bucharest, Romania
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany
| |
Collapse
|
11
|
Calcium and Ca 2+/Calmodulin-dependent kinase II as targets for helminth parasite control. Biochem Soc Trans 2018; 46:1743-1751. [PMID: 30420417 DOI: 10.1042/bst20180480] [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: 05/17/2018] [Revised: 09/07/2018] [Accepted: 10/01/2018] [Indexed: 11/17/2022]
Abstract
In eukaryotes, effective calcium homeostasis is critical for many key biological processes. There is an added level of complexity in parasites, particularly multicellular helminth worms, which modulate calcium levels while inhabiting the host microenvironment. Parasites ensure efficient calcium homeostasis through gene products, such as the calmodulin-dependent kinases (CaMK), the main focus of this review. The importance of CaMK is becoming increasingly apparent from recent functional studies of helminth and protozoan parasites. Investigations on the molecular regulation of calcium and the role of CaMK are important for both supplementing current drug regimens and finding new antiparasitic compounds. Whereas calcium regulators, including CaMK, are well characterised in mammalian systems, knowledge of their functional properties in parasites is increasing but is still in its infancy.
Collapse
|
12
|
Shiferaw Y, Aistrup GL, Wasserstrom JA. Synchronization of Triggered Waves in Atrial Tissue. Biophys J 2018; 115:1130-1141. [PMID: 30195941 DOI: 10.1016/j.bpj.2018.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/31/2018] [Accepted: 08/10/2018] [Indexed: 10/28/2022] Open
Abstract
When an atrial cell is paced rapidly, calcium (Ca) waves can form on the cell boundary and propagate to the cell interior. These waves are referred to as "triggered waves" because they are initiated by Ca influx from the L-type Ca channel and occur during the action potential. However, the consequences of triggered waves in atrial tissue are not known. Here, we develop a phenomenological model of Ca cycling in atrial myocytes that accounts for the formation of triggered waves. Using this model, we show that a fundamental requirement for triggered waves to induce abnormal electrical activity in tissue is that these waves must be synchronized over large populations of cells. This is partly because triggered waves induce a long action potential duration (APD) followed by a short APD. Thus, if these events are not synchronized between cells, then they will on average cancel and have minimal effects on the APD in tissue. Using our computational model, we identify two distinct mechanisms for triggered wave synchronization. The first relies on cycle length (CL) variability, which can prolong the CL at a given beat. In cardiac tissue, we show that CL prolongation leads to a substantial amplification of APD because of the synchronization of triggered waves. A second synchronization mechanism applies in a parameter regime in which the cell exhibits stochastic alternans in which a triggered wave fires, on average, only every other beat. In this scenario, we identify a slow synchronization mechanism that relies on the bidirectional feedback between the APD in tissue and triggered wave initiation. On large cables, this synchronization mechanism leads to spatially discordant APD alternans with spatial variations on a scale of hundreds of cells. We argue that these spatial patterns can potentially serve as an arrhythmogenic substrate for the initiation of atrial fibrillation.
Collapse
Affiliation(s)
- Yohannes Shiferaw
- Department of Physics, California State University, Northridge, California.
| | - Gary L Aistrup
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, New York
| | - John A Wasserstrom
- Department of Medicine (Cardiology) and The Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
13
|
Liu B, Walton SD, Ho HT, Belevych AE, Tikunova SB, Bonilla I, Shettigar V, Knollmann BC, Priori SG, Volpe P, Radwański PB, Davis JP, Györke S. Gene Transfer of Engineered Calmodulin Alleviates Ventricular Arrhythmias in a Calsequestrin-Associated Mouse Model of Catecholaminergic Polymorphic Ventricular Tachycardia. J Am Heart Assoc 2018; 7:JAHA.117.008155. [PMID: 29720499 PMCID: PMC6015318 DOI: 10.1161/jaha.117.008155] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial arrhythmogenic syndrome characterized by sudden death. There are several genetic forms of CPVT associated with mutations in genes encoding the cardiac ryanodine receptor (RyR2) and its auxiliary proteins including calsequestrin (CASQ2) and calmodulin (CaM). It has been suggested that impairment of the ability of RyR2 to stay closed (ie, refractory) during diastole may be a common mechanism for these diseases. Here, we explore the possibility of engineering CaM variants that normalize abbreviated RyR2 refractoriness for subsequent viral‐mediated delivery to alleviate arrhythmias in non–CaM‐related CPVT. Methods and Results To that end, we have designed a CaM protein (GSH‐M37Q; dubbed as therapeutic CaM or T‐CaM) that exhibited a slowed N‐terminal Ca dissociation rate and prolonged RyR2 refractoriness in permeabilized myocytes derived from CPVT mice carrying the CASQ2 mutation R33Q. This T‐CaM was introduced to the heart of R33Q mice through recombinant adeno‐associated viral vector serotype 9. Eight weeks postinfection, we performed confocal microscopy to assess Ca handling and recorded surface ECGs to assess susceptibility to arrhythmias in vivo. During catecholamine stimulation with isoproterenol, T‐CaM reduced isoproterenol‐promoted diastolic Ca waves in isolated CPVT cardiomyocytes. Importantly, T‐CaM exposure abolished ventricular tachycardia in CPVT mice challenged with catecholamines. Conclusions Our results suggest that gene transfer of T‐CaM by adeno‐associated viral vector serotype 9 improves myocyte Ca handling and alleviates arrhythmias in a calsequestrin‐associated CPVT model, thus supporting the potential of a CaM‐based antiarrhythmic approach as a therapeutic avenue for genetically distinct forms of CPVT.
Collapse
Affiliation(s)
- Bin Liu
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH.,Department of Biological Sciences, Mississippi State University, Starkville, MI
| | - Shane D Walton
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Hsiang-Ting Ho
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Andriy E Belevych
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Svetlana B Tikunova
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Ingrid Bonilla
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Vikram Shettigar
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Bjorn C Knollmann
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Vanderbilt, TN
| | - Silvia G Priori
- Division of Cardiology and Molecular Cardiology, Maugeri Foundation-University of Pavia, Italy
| | - Pompeo Volpe
- Department of Biomedical Sciences, University of Padova, Italy
| | - Przemysław B Radwański
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Jonathan P Davis
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| | - Sándor Györke
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, Ohio State University, Columbus, OH
| |
Collapse
|
14
|
Rietdorf K, MacQueen H. Investigating interactions between epicardial adipose tissue and cardiac myocytes: what can we learn from different approaches? Br J Pharmacol 2017; 174:3542-3560. [PMID: 27882550 PMCID: PMC5610165 DOI: 10.1111/bph.13678] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/14/2016] [Accepted: 11/18/2016] [Indexed: 01/08/2023] Open
Abstract
Heart disease is a major cause of morbidity and mortality throughout the world. Some cardiovascular conditions can be modulated by lifestyle factors such as increased exercise or a healthier diet, but many require surgical or pharmacological interventions for their management. More targeted and less invasive therapies would be beneficial. Recently, it has become apparent that epicardial adipose tissue plays an important role in normal and pathological cardiac function, and it is now the focus of considerable research. Epicardial adipose tissue can be studied by imaging of various kinds, and these approaches have yielded much useful information. However, at a molecular level, it is more difficult to study as it is relatively scarce in animal models and, for practical and ethical reasons, not always available in sufficient quantities from patients. What is needed is a robust model system in which the interactions between epicardial adipocytes and cardiac myocytes can be studied, and physiologically relevant manipulations performed. There are drawbacks to conventional culture methods, not least the difficulty of culturing both cardiac myocytes and adipocytes, each of which has special requirements. We discuss the benefits of a three-dimensional co-culture model in which in vivo interactions can be replicated. LINKED ARTICLES This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.
Collapse
Affiliation(s)
- Katja Rietdorf
- School of Life, Health and Chemical SciencesThe Open UniversityMilton KeynesUK
| | - Hilary MacQueen
- School of Life, Health and Chemical SciencesThe Open UniversityMilton KeynesUK
| |
Collapse
|
15
|
Kane C, Terracciano CMN. Concise Review: Criteria for Chamber-Specific Categorization of Human Cardiac Myocytes Derived from Pluripotent Stem Cells. Stem Cells 2017; 35:1881-1897. [PMID: 28577296 PMCID: PMC5575566 DOI: 10.1002/stem.2649] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/25/2017] [Accepted: 05/12/2017] [Indexed: 11/30/2022]
Abstract
Human pluripotent stem cell‐derived cardiomyocytes (PSC‐CMs) have great potential application in almost all areas of cardiovascular research. A current major goal of the field is to build on the past success of differentiation strategies to produce CMs with the properties of those originating from the different chambers of the adult human heart. With no anatomical origin or developmental pathway to draw on, the question of how to judge the success of such approaches and assess the chamber specificity of PSC‐CMs has become increasingly important; commonly used methods have substantial limitations and are based on limited evidence to form such an assessment. In this article, we discuss the need for chamber‐specific PSC‐CMs in a number of areas as well as current approaches used to assess these cells on their likeness to those from different chambers of the heart. Furthermore, describing in detail the structural and functional features that distinguish the different chamber‐specific human adult cardiac myocytes, we propose an evidence‐based tool to aid investigators in the phenotypic characterization of differentiated PSC‐CMs. Stem Cells2017;35:1881–1897
Collapse
Affiliation(s)
- Christopher Kane
- Imperial College London, National Heart and Lung Institute, Hammersmith Campus, BHF Centre for Regenerative Medicine, London, United Kingdom
| | - Cesare M N Terracciano
- Imperial College London, National Heart and Lung Institute, Hammersmith Campus, BHF Centre for Regenerative Medicine, London, United Kingdom
| |
Collapse
|
16
|
Dobrev D, Wehrens XHT. Calcium-mediated cellular triggered activity in atrial fibrillation. J Physiol 2017; 595:4001-4008. [PMID: 28181690 DOI: 10.1113/jp273048] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/25/2017] [Indexed: 12/29/2022] Open
Abstract
Although atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia, the basic mechanisms underlying this disorder remain incompletely understood. During the past decade or so, it has become clear that alterations in intracellular Ca2+ handling may play a role in the pathogenesis of AF. Studies in small and large animal models, as well as atrial samples from patients with different forms of AF, have implicated ryanodine receptor type 2 (RyR2) dysfunction and enhanced spontaneous Ca2+ release events from the sarcoplasmic reticulum (SR) as a potential cause of proarrhythmic cellular ectopic (triggered) activity in AF. The molecular mechanisms leading to RyR2 dysfunction and SR Ca2+ leak depend on the clinical stage of AF or specific animal model studied. This review focuses on the mechanisms and role of calcium-mediated cellular triggered activity in AF, and addresses some of the current controversies in the field.
Collapse
Affiliation(s)
- Dobromir Dobrev
- Institute for Pharmacology, West German Heart and Vascular Centre, University Duisburg-Essen, Essen, Germany.,Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA.,Departments of Molecular Physiology & Biophysics, Pediatrics (Cardiology), Medicine (Cardiology), Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
17
|
Tissue Specificity: Store-Operated Ca 2+ Entry in Cardiac Myocytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:363-387. [PMID: 28900924 DOI: 10.1007/978-3-319-57732-6_19] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Calcium (Ca2+) is a key regulator of cardiomyocyte contraction. The Ca2+ channels, pumps, and exchangers responsible for the cyclical cytosolic Ca2+ signals that underlie contraction are well known. In addition to those Ca2+ signaling components responsible for contraction, it has been proposed that cardiomyocytes express channels that promote the influx of Ca2+ from the extracellular milieu to the cytosol in response to depletion of intracellular Ca2+ stores. With non-excitable cells, this store-operated Ca2+ entry (SOCE) is usually easily demonstrated and is essential for prolonging cellular Ca2+ signaling and for refilling depleted Ca2+ stores. The role of SOCE in cardiomyocytes, however, is rather more elusive. While there is published evidence for increased Ca2+ influx into cardiomyocytes following Ca2+ store depletion, it has not been universally observed. Moreover, SOCE appears to be prominent in embryonic cardiomyocytes but declines with postnatal development. In contrast, there is overwhelming evidence that the molecular components of SOCE (e.g., STIM, Orai, and TRPC proteins) are expressed in cardiomyocytes from embryo to adult. Moreover, these proteins have been shown to contribute to disease conditions such as pathological hypertrophy, and reducing their expression can attenuate hypertrophic growth. It is plausible that SOCE might underlie Ca2+ influx into cardiomyocytes and may have important signaling functions perhaps by activating local Ca2+-sensitive processes. However, the STIM, Orai, and TRPC proteins appear to cooperate with multiple protein partners in signaling complexes. It is therefore possible that some of their signaling activities are not mediated by Ca2+ influx signals, but by protein-protein interactions.
Collapse
|
18
|
Jang SP, Oh JG, Kang DH, Kang JY, Kang SW, Hajjar RJ, Park WJ. A Decoy Peptide Targeted to Protein Phosphatase 1 Attenuates Degradation of SERCA2a in Vascular Smooth Muscle Cells. PLoS One 2016; 11:e0165569. [PMID: 27792751 PMCID: PMC5085086 DOI: 10.1371/journal.pone.0165569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/13/2016] [Indexed: 01/14/2023] Open
Abstract
Neointimal growth in the injured vasculature is largely facilitated by the proliferation of vascular smooth muscle cells (VSMC), which associates with reduced sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) activity. The gene transfer-mediated restoration of the SERCA2a level thus attenuates neointimal growth and VSMC proliferation. We previously reported that a peptide targeted to protein phosphatase 1, ψPLB-SE, normalizes SERCA2a activity in cardiomyocytes. In this study, we found that ψPLB-SE attenuated neointimal growth in balloon-injured rat carotid arteries, and the proliferation and migration of VSMC cultured in high-serum media (synthetic conditions). In parallel, ψPLB-SE inhibited the degradation of SERCA2a in the injured carotid arteries and VSMC under synthetic conditions. The calpain inhibitor MDL28170 also attenuated SERCA2a degradation and VSMC proliferation under synthetic conditions, indicating that calpain degrades SERCA2a. The Ca2+ ionophore A23187 induced SERCA2a degradation in VSMC, which was blocked by either ψPLB-SE or MDL28170. Additionally, ψPLB-SE normalized the cytosolic Ca2+ level in VSMC that was increased by either A23187 or synthetic stimulation. Collectively, these data indicate that ψPLB-SE corrects the abnormal Ca2+ handling by activating SERCA2a, which further protects SERCA2a from calpain-dependent degradation in VSMC. We conclude that ψPLB-SE may form the basis of a therapeutic strategy for vascular proliferative disorders.
Collapse
Affiliation(s)
- Seung Pil Jang
- College of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Jae Gyun Oh
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States of America
| | - Dong Hoon Kang
- Department of Life Science, Ewha Womans University, Seoul, Korea
| | - Ju Young Kang
- College of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
| | - Sang Won Kang
- Department of Life Science, Ewha Womans University, Seoul, Korea
| | - Roger J. Hajjar
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States of America
| | - Woo Jin Park
- College of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea
- * E-mail:
| |
Collapse
|
19
|
Pulmonary vein sleeve cell excitation-contraction-coupling becomes dysynchronized by spontaneous calcium transients. Biochem Soc Trans 2016; 43:410-6. [PMID: 26009184 DOI: 10.1042/bst20140299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia. Substantial evidence indicates that cardiomyocytes located in the pulmonary veins [pulmonary vein sleeve cells (PVCs)] cause AF by generating ectopic electrical activity. Electrical ablation, isolating PVCs from their left atrial junctions, is a major treatment for AF. In small rodents, the sleeve of PVCs extends deep inside the lungs and is present in lung slices. Here we present data, using the lung slice preparation, characterizing how spontaneous Ca2+ transients in PVCs affect their capability to respond to electrical pacing. Immediately after a spontaneous Ca2+ transient the cell is in a refractory period and it cannot respond to electrical stimulation. Consequently, we observe that the higher the level of spontaneous activity in an individual PVC, the less likely it is that this PVC responds to electrical field stimulation. The spontaneous activity of neighbouring PVCs can be different from each other. Heterogeneity in the Ca2+ signalling of cells and in their responsiveness to electrical stimuli are known pro-arrhythmic events. The tendency of PVCs to show spontaneous Ca2+ transients and spontaneous action potentials (APs) underlies their potential to cause AF.
Collapse
|
20
|
Chang KC, Bayer JD, Trayanova NA. Disrupted calcium release as a mechanism for atrial alternans associated with human atrial fibrillation. PLoS Comput Biol 2014; 10:e1004011. [PMID: 25501557 PMCID: PMC4263367 DOI: 10.1371/journal.pcbi.1004011] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 10/29/2014] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, but our knowledge of the arrhythmogenic substrate is incomplete. Alternans, the beat-to-beat alternation in the shape of cardiac electrical signals, typically occurs at fast heart rates and leads to arrhythmia. However, atrial alternans have been observed at slower pacing rates in AF patients than in controls, suggesting that increased vulnerability to arrhythmia in AF patients may be due to the proarrythmic influence of alternans at these slower rates. As such, alternans may present a useful therapeutic target for the treatment and prevention of AF, but the mechanism underlying alternans occurrence in AF patients at heart rates near rest is unknown. The goal of this study was to determine how cellular changes that occur in human AF affect the appearance of alternans at heart rates near rest. To achieve this, we developed a computational model of human atrial tissue incorporating electrophysiological remodeling associated with chronic AF (cAF) and performed parameter sensitivity analysis of ionic model parameters to determine which cellular changes led to alternans. Of the 20 parameters tested, only decreasing the ryanodine receptor (RyR) inactivation rate constant (kiCa) produced action potential duration (APD) alternans seen clinically at slower pacing rates. Using single-cell clamps of voltage, fluxes, and state variables, we determined that alternans onset was Ca2+-driven rather than voltage-driven and occurred as a result of decreased RyR inactivation which led to increased steepness of the sarcoplasmic reticulum (SR) Ca2+ release slope. Iterated map analysis revealed that because SR Ca2+ uptake efficiency was much higher in control atrial cells than in cAF cells, drastic reductions in kiCa were required to produce alternans at comparable pacing rates in control atrial cells. These findings suggest that RyR kinetics may play a critical role in altered Ca2+ homeostasis which drives proarrhythmic APD alternans in patients with AF. Atrial fibrillation is an irregular heart rhythm affecting millions of people worldwide. Effective treatment of this cardiac disorder relies upon our detailed knowledge and understanding of the mechanisms that lead to arrhythmia. Recent clinical observations have suggested that alternans, a phenomenon where the shape of the electrical signal in the heart alternates from beat to beat, may play an important role in this process, but the underlying mechanisms remain unknown. In this study, we use computational models to conduct a detailed examination of the causes and contributors to alternans associated with human atrial fibrillation. We find that in atria remodeled by atrial fibrillation, alternans appears near resting heart rates because several aspects of calcium cycling are disrupted in the atrial cells. In particular, the release and uptake of calcium from the cellular storage compartment, the sarcoplasmic reticulum, becomes imbalanced, leading to alternation in calcium signals from beat to beat. These findings provide important insights into the mechanisms of proarrhythmic alternans in human atrial fibrillation which may be used to develop novel therapeutic targets and treatment strategies in the future.
Collapse
Affiliation(s)
- Kelly C. Chang
- Institute for Computational Medicine, Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jason D. Bayer
- IHU-LIRYC - L'Institut de RYthmologie et Modélisation Cardiaque, University of Bordeaux, Bordeaux, France
| | - Natalia A. Trayanova
- Institute for Computational Medicine, Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
21
|
Tatsuishi W, Adachi H, Murata M, Tomono J, Okonogi S, Okada S, Hasegawa Y, Ezure M, Kaneko T, Ohshima S. Postoperative hyperglycemia and atrial fibrillation after coronary artery bypass graft surgery. Circ J 2014; 79:112-8. [PMID: 25392072 DOI: 10.1253/circj.cj-14-0989] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Postoperative atrial fibrillation (AF) is a common complication following coronary artery bypass grafting (CABG). We investigated the risk factors for postoperative AF and analyzed the relationship between blood sugar concentration (BS) and AF after CABG. METHODS AND RESULTS A total of 199 consecutive patients who underwent isolated CABG were retrospectively examined and classified according to the presence (n=95) or absence (n=104) of postoperative AF. On univariate analysis mean postoperative BS (P<0.001), postoperative drainage volume (P<0.001), age (P=0.034), presence of diabetes mellitus (DM; P=0.004), and postoperative estimated glomerular filtration rate (P=0.032) were significant risk factors for postoperative AF. On multivariate analysis mean postoperative BS (OR, 1.041; 95% CI: 1.008-1.079; P<0.001), postoperative drainage volume (OR, 1.003; 95% CI: 1.001-1.006; P=0.001), and age (OR, 1.040; 95% CI: 1.002-1.083; P=0.041) were significant risk factors for postoperative AF. Postoperative AF often occurred in patients with high postoperative BS, irrespective of DM. The BS cut-off that predicted postoperative AF occurrence was 180 mg/dl. A strong positive correlation existed between the time of the maximum postoperative BS and AF onset time (ρ=0.746). CONCLUSIONS Mean postoperative BS and postoperative drainage volume are risk factors for AF after CABG. AF was strongly associated with maximum postoperative BS. Intensive glycemic control could reduce AF occurrence after CABG.
Collapse
Affiliation(s)
- Wataru Tatsuishi
- Department of Cardiovascular Surgery, Tokyo Women's Medical University, Medical Center East, Tokyo; Department of Cardiovascular Surgery, Gunma Prefectural Cardiovascular Center, Maebashi, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Heijman J, Voigt N, Wehrens XHT, Dobrev D. Calcium dysregulation in atrial fibrillation: the role of CaMKII. Front Pharmacol 2014; 5:30. [PMID: 24624086 PMCID: PMC3940963 DOI: 10.3389/fphar.2014.00030] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 02/15/2014] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most frequently encountered clinical arrhythmia and is associated with increased morbidity and mortality. Ectopic activity and reentry are considered major arrhythmogenic mechanisms contributing to the initiation and maintenance of AF. In addition, AF is self-reinforcing through progressive electrical and structural remodeling which stabilize the arrhythmia and make it more difficult to treat. Recent research has suggested an important role for Ca(2+)-dysregulation in AF. Ca(2+)-handling abnormalities may promote ectopic activity, conduction abnormalities facilitating reentry, and AF-related remodeling. In this review article, we summarize the Ca(2+)-handling derangements occurring in AF and discuss their impact on fundamental arrhythmogenic mechanisms. We focus in particular on the role of the multifunctional Ca(2+)/calmodulin-dependent protein kinase type-II (CaMKII), which acts as a major link between Ca(2+)-dysregulation and arrhythmogenesis. CaMKII expression and activity are increased in AF and promote arrhythmogenesis through phosphorylation of various targets involved in cardiac electrophysiology and excitation-contraction coupling. We discuss the implications for potential novel therapeutic strategies for AF based on CaMKII and Ca(2+)-handling abnormalities.
Collapse
Affiliation(s)
- Jordi Heijman
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen Essen, Germany
| | - Niels Voigt
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen Essen, Germany
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Departments of Molecular Physiology and Biophysics, and Medicine-Cardiology, Baylor College of Medicine Houston, TX, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen Essen, Germany
| |
Collapse
|
23
|
Rietdorf K, Bootman MD, Sanderson MJ. Spontaneous, pro-arrhythmic calcium signals disrupt electrical pacing in mouse pulmonary vein sleeve cells. PLoS One 2014; 9:e88649. [PMID: 24586364 PMCID: PMC3930634 DOI: 10.1371/journal.pone.0088649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/08/2014] [Indexed: 11/18/2022] Open
Abstract
The pulmonary vein, which returns oxygenated blood to the left atrium, is ensheathed by a population of unique, myocyte-like cells called pulmonary vein sleeve cells (PVCs). These cells autonomously generate action potentials that propagate into the left atrial chamber and cause arrhythmias resulting in atrial fibrillation; the most common, often sustained, form of cardiac arrhythmia. In mice, PVCs extend along the pulmonary vein into the lungs, and are accessible in a lung slice preparation. We exploited this model to study how aberrant Ca(2+) signaling alters the ability of PVC networks to follow electrical pacing. Cellular responses were investigated using real-time 2-photon imaging of lung slices loaded with a Ca(2+)-sensitive fluorescent indicator (Ca(2+) measurements) and phase contrast microscopy (contraction measurements). PVCs displayed global Ca(2+) signals and coordinated contraction in response to electrical field stimulation (EFS). The effects of EFS relied on both Ca(2+) influx and Ca(2+) release, and could be inhibited by nifedipine, ryanodine or caffeine. Moreover, PVCs had a high propensity to show spontaneous Ca(2+) signals that arose via stochastic activation of ryanodine receptors (RyRs). The ability of electrical pacing to entrain Ca(2+) signals and contractile responses was dramatically influenced by inherent spontaneous Ca(2+) activity. In PVCs with relatively low spontaneous Ca(2+) activity (<1 Hz), entrainment with electrical pacing was good. However, in PVCs with higher frequencies of spontaneous Ca(2+) activity (>1.5 Hz), electrical pacing was less effective; PVCs became unpaced, only partially-paced or displayed alternans. Because spontaneous Ca(2+) activity varied between cells, neighboring PVCs often had different responses to electrical pacing. Our data indicate that the ability of PVCs to respond to electrical stimulation depends on their intrinsic Ca(2+) cycling properties. Heterogeneous spontaneous Ca(2+) activity arising from stochastic RyR opening can disengage them from sinus rhythm and lead to autonomous, pro-arrhythmic activity.
Collapse
Affiliation(s)
- Katja Rietdorf
- Department of Microbiology and Physiological Systems, University of Massachusetts, Medical School, Worcester, Massachusetts, United States of America
- Department of Life, Health and Chemical Science, The Open University, Milton Keynes, United Kingdom
- * E-mail:
| | - Martin D. Bootman
- Department of Life, Health and Chemical Science, The Open University, Milton Keynes, United Kingdom
- Signalling Programme, The Babraham Institute, Cambridge, United Kingdom
| | - Michael J. Sanderson
- Department of Microbiology and Physiological Systems, University of Massachusetts, Medical School, Worcester, Massachusetts, United States of America
| |
Collapse
|
24
|
Deftereos S, Giannopoulos G, Papoutsidakis N, Panagopoulou V, Kossyvakis C, Raisakis K, Cleman MW, Stefanadis C. Colchicine and the Heart. J Am Coll Cardiol 2013; 62:1817-25. [DOI: 10.1016/j.jacc.2013.08.726] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/12/2013] [Accepted: 08/13/2013] [Indexed: 12/31/2022]
|
25
|
Heijman J, Heusch G, Dobrev D. Pleiotropic effects of antiarrhythmic agents: dronedarone in the treatment of atrial fibrillation. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2013; 7:127-40. [PMID: 23997577 PMCID: PMC3747997 DOI: 10.4137/cmc.s8445] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Atrial fibrillation remains the most common arrhythmia in clinical practice. Dronedarone is an antiarrhythmic drug for the maintenance of sinus rhythm in patients with atrial fibrillation. Dronedarone is an amiodarone derivative developed to reduce the number of extracardiovascular side effects. Dronedarone has undergone extensive experimental and clinical testing during the last decade. On the aggregate, these studies have highlighted a complex set of pleiotropic actions that may contribute to dronedarone's antiarrhythmic effects. In this review, we summarize the clinical studies that have evaluated dronedarone and provide an overview of dronedarone's electrophysiological and nonelectrophysiological pleiotropic actions.
Collapse
Affiliation(s)
- Jordi Heijman
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | - Gerd Heusch
- Institute for Pathophysiology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| |
Collapse
|
26
|
Heijman J, Voigt N, Dobrev D. New directions in antiarrhythmic drug therapy for atrial fibrillation. Future Cardiol 2013; 9:71-88. [DOI: 10.2217/fca.12.78] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and has a significant impact on morbidity and mortality. Current antiarrhythmic drugs for AF suffer from limited safety and efficacy, probably because they were not designed based on specific pathological mechanisms. Recent research has provided important insights into the mechanisms contributing to AF and highlighted several potential novel antiarrhythmic strategies. In this review, we highlight the main pathological mechanisms of AF, discuss traditional and novel aspects of atrial antiarrhythmic drugs in relation to these pathological mechanisms, and present potential novel therapeutic approaches including structure-based modulation of atrial-specific cardiac ion channels, restoring abnormal Ca2+ handling in AF and targeting atrial remodeling.
Collapse
Affiliation(s)
- Jordi Heijman
- Institute of Pharmacology, Medical Faculty Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany
| | - Niels Voigt
- Institute of Pharmacology, Medical Faculty Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany
- Division of Experimental Cardiology, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Dobromir Dobrev
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| |
Collapse
|
27
|
Backx PH. Could Plugging the Oxidation-Mediated Ca
2+
Leak Stem the Tide of the Atrial Fibrillation Epidemic? Circ Res 2012; 111:662-5. [DOI: 10.1161/circresaha.112.275453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|