1
|
Hussaini S, Mamyraiym Kyzy A, Schröder-Schetelig J, Lädke SL, Venkatesan V, Diaz-Maue L, Quiñonez Uribe RA, Richter C, Biktashev VN, Majumder R, Krinski V, Luther S. Efficient termination of cardiac arrhythmias using optogenetic resonant feedback pacing. CHAOS (WOODBURY, N.Y.) 2024; 34:031103. [PMID: 38526981 DOI: 10.1063/5.0191519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/03/2024] [Indexed: 03/27/2024]
Abstract
Malignant cardiac tachyarrhythmias are associated with complex spatiotemporal excitation of the heart. The termination of these life-threatening arrhythmias requires high-energy electrical shocks that have significant side effects, including tissue damage, excruciating pain, and worsening prognosis. This significant medical need has motivated the search for alternative approaches that mitigate the side effects, based on a comprehensive understanding of the nonlinear dynamics of the heart. Cardiac optogenetics enables the manipulation of cellular function using light, enhancing our understanding of nonlinear cardiac function and control. Here, we investigate the efficacy of optically resonant feedback pacing (ORFP) to terminate ventricular tachyarrhythmias using numerical simulations and experiments in transgenic Langendorff-perfused mouse hearts. We show that ORFP outperforms the termination efficacy of the optical single-pulse (OSP) approach. When using ORFP, the total energy required for arrhythmia termination, i.e., the energy summed over all pulses in the sequence, is 1 mJ. With a success rate of 50%, the energy per pulse is 40 times lower than with OSP with a pulse duration of 10 ms. We demonstrate that even at light intensities below the excitation threshold, ORFP enables the termination of arrhythmias by spatiotemporal modulation of excitability inducing spiral wave drift.
Collapse
Affiliation(s)
- S Hussaini
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - A Mamyraiym Kyzy
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - J Schröder-Schetelig
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - S L Lädke
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - V Venkatesan
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - L Diaz-Maue
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
- Research Electronics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - R A Quiñonez Uribe
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - C Richter
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
- WG Cardiovascular Optogenetics, Lab Animal Science Unit, Leibniz Institute for Primate Research, Göttingen 37077, Germany
| | - V N Biktashev
- Department of Mathematics and Statistics, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - R Majumder
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - V Krinski
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - S Luther
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| |
Collapse
|
2
|
Huang J, Pang X, Zhang X, Qiu W, Zhang X, Wang R, Xie W, Bai Y, Zhou S, Liao J, Xiong Z, Tang Z, Su R. N-acetylcysteine combined with insulin attenuates myocardial injury in canines with type 1 diabetes mellitus by modulating TNF-α-mediated apoptotic pathways and affecting linear ubiquitination. Transl Res 2023; 262:1-11. [PMID: 37422055 DOI: 10.1016/j.trsl.2023.07.003] [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: 04/20/2023] [Revised: 06/24/2023] [Accepted: 07/03/2023] [Indexed: 07/10/2023]
Abstract
The exact pathogenesis of type 1 diabetes mellitus (DM) is still unclear. Numerous organs, including the heart, will suffer damage and malfunction as a result of long-term hyperglycemia. Currently, insulin therapy alone is still not the best treatment for type 1 DM. In order to properly treat and manage patients with type 1 DM, it is vital to seek a combination that includes both insulin and additional medications. This study aims to explore the therapeutic effect and mechanism of N-acetylcysteine (NAC) combined with insulin on type 1 DM. By giving beagle canines injections of streptozotocin (STZ) and alloxan (ALX) (20 mg/kg each), a model of type 1 DM was created. The results showed that this combination could effectively control blood sugar level, improve heart function, avoid the damage of mitochondria and myocardial cells, and prevent the excessive apoptosis of myocardial cells. Importantly, the combination can activate nuclear factor kappa-B (NF-κB) by promoting linear ubiquitination of receptor-interacting protein kinase 1 (RIPK1) and NF-κB-essential modulator (NEMO) and inhibitor of NF-κB (IκB) phosphorylation. The combination can increase the transcription and linear ubiquitination of Cellular FLICE (FADD-like IL-1β-converting enzyme) -inhibitory protein (c-FLIP), diminish the production of cleaved-caspase-8 p18 and cleaved-caspase-3 to reduce apoptosis. This study confirmed that NAC combined with insulin can promote the linear ubiquitination of RIPK1, NEMO and c-FLIP and regulate the apoptosis pathway mediated by TNF-α to attenuate the myocardial injury caused by type 1 DM. Meanwhile, the research served as a resource when choosing a clinical strategy for DM cardiac complications.
Collapse
Affiliation(s)
- Jianjia Huang
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xiaoyue Pang
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xinting Zhang
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Wenyue Qiu
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xuluan Zhang
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Rongmei Wang
- Department of Animal Science, Henry Fok School of Biology and Agriculture, Shaoguan University, Shaoguan, Guangdong, China
| | - Wenting Xie
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Yuman Bai
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Shuilian Zhou
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jianzhao Liao
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Zhaojun Xiong
- Department of Cardiovascular Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhaoxin Tang
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China
| | - Rongsheng Su
- Department of Veterinary Internal Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China.
| |
Collapse
|
3
|
Hussaini S, Lädke SL, Schröder-Schetelig J, Venkatesan V, Quiñonez Uribe RA, Richter C, Majumder R, Luther S. Dissolution of spiral wave's core using cardiac optogenetics. PLoS Comput Biol 2023; 19:e1011660. [PMID: 38060618 PMCID: PMC10729946 DOI: 10.1371/journal.pcbi.1011660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 12/19/2023] [Accepted: 11/04/2023] [Indexed: 12/20/2023] Open
Abstract
Rotating spiral waves in the heart are associated with life-threatening cardiac arrhythmias such as ventricular tachycardia and fibrillation. These arrhythmias are treated by a process called defibrillation, which forces electrical resynchronization of the heart tissue by delivering a single global high-voltage shock directly to the heart. This method leads to immediate termination of spiral waves. However, this may not be the only mechanism underlying successful defibrillation, as certain scenarios have also been reported, where the arrhythmia terminated slowly, over a finite period of time. Here, we investigate the slow termination dynamics of an arrhythmia in optogenetically modified murine cardiac tissue both in silico and ex vivo during global illumination at low light intensities. Optical imaging of an intact mouse heart during a ventricular arrhythmia shows slow termination of the arrhythmia, which is due to action potential prolongation observed during the last rotation of the wave. Our numerical studies show that when the core of a spiral is illuminated, it begins to expand, pushing the spiral arm towards the inexcitable boundary of the domain, leading to termination of the spiral wave. We believe that these fundamental findings lead to a better understanding of arrhythmia dynamics during slow termination, which in turn has implications for the improvement and development of new cardiac defibrillation techniques.
Collapse
Affiliation(s)
- Sayedeh Hussaini
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Sarah L. Lädke
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Johannes Schröder-Schetelig
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Vishalini Venkatesan
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Raúl A. Quiñonez Uribe
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Claudia Richter
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
- WG Cardiovascular Optogenetics, Lab Animal Science Unit, Leibniz Institute for Primate research, Göttingen, Germany
| | - Rupamanjari Majumder
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Stefan Luther
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
- Institute for the Dynamics of Complex Systems, Göttingen University, Germany
| |
Collapse
|
4
|
Hussaini S, Majumder R, Krinski V, Luther S. In silico optical modulation of spiral wave trajectories in cardiac tissue. Pflugers Arch 2023; 475:1453-1461. [PMID: 38095694 PMCID: PMC10730633 DOI: 10.1007/s00424-023-02889-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/21/2023]
Abstract
Life-threatening cardiac arrhythmias such as ventricular tachycardia and fibrillation are common precursors to sudden cardiac death. They are associated with the occurrence of abnormal electrical spiral waves in the heart that rotate at a high frequency. In severe cases, arrhythmias are combated with a clinical method called defibrillation, which involves administering a single global high-voltage shock to the heart to reset all its activity and restore sinus rhythm. Despite its high efficiency in controlling arrhythmias, defibrillation is associated with several negative side effects that render the method suboptimal. The best approach to optimize this therapeutic technique is to deepen our understanding of the dynamics of spiral waves. Here, we use computational cardiac optogenetics to study and control the dynamics of a single spiral wave in a two-dimensional, electrophysiologically detailed, light-sensitive model of a mouse ventricle. First, we illuminate the domain globally by applying a sequence of periodic optical pulses with different frequencies in the sub-threshold regime where no excitation wave is induced. In doing so, we obtain epicycloidal, hypocycloidal, and resonant drift trajectories of the spiral wave core. Then, to effectively control the wave dynamics, we use a method called resonant feedback pacing. In this approach, each global optical pulse is applied when the measuring electrode positioned on the domain registers a predefined value of the membrane voltage. This enables us to steer the spiral wave in a desired direction determined by the position of the electrode. Our study thus provides valuable mechanistic insights into the success or failure of global optical stimulation in executing efficient arrhythmia control.
Collapse
Affiliation(s)
- Sayedeh Hussaini
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Niedersachsen, Germany.
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Am Fassberg, 37077, Göttingen, Niedersachsen, Germany.
| | - Rupamanjari Majumder
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Niedersachsen, Germany
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Am Fassberg, 37077, Göttingen, Niedersachsen, Germany
| | - Valentin Krinski
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Am Fassberg, 37077, Göttingen, Niedersachsen, Germany
| | - Stefan Luther
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Niedersachsen, Germany.
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Am Fassberg, 37077, Göttingen, Niedersachsen, Germany.
| |
Collapse
|
5
|
Asfaw TN, Bondarenko VE. A compartmentalized mathematical model of the β 1- and β 2-adrenergic signaling systems in ventricular myocytes from mouse in heart failure. Am J Physiol Cell Physiol 2023; 324:C263-C291. [PMID: 36468844 DOI: 10.1152/ajpcell.00366.2022] [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: 12/12/2022]
Abstract
Mouse models of heart failure are extensively used to research human cardiovascular diseases. In particular, one of the most common is the mouse model of heart failure resulting from transverse aortic constriction (TAC). Despite this, there are no comprehensive compartmentalized mathematical models that describe the complex behavior of the action potential, [Ca2+]i transients, and their regulation by β1- and β2-adrenergic signaling systems in failing mouse myocytes. In this paper, we develop a novel compartmentalized mathematical model of failing mouse ventricular myocytes after TAC procedure. The model describes well the cell geometry, action potentials, [Ca2+]i transients, and β1- and β2-adrenergic signaling in the failing cells. Simulation results obtained with the failing cell model are compared with those from the normal ventricular myocytes. Exploration of the model reveals the sarcoplasmic reticulum Ca2+ load mechanisms in failing ventricular myocytes. We also show a larger susceptibility of the failing myocytes to early and delayed afterdepolarizations and to a proarrhythmic behavior of Ca2+ dynamics upon stimulation with isoproterenol. The mechanisms of the proarrhythmic behavior suppression are investigated and sensitivity analysis is performed. The developed model can explain the existing experimental data on failing mouse ventricular myocytes and make experimentally testable predictions of a failing myocyte's behavior.
Collapse
Affiliation(s)
- Tesfaye Negash Asfaw
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
| |
Collapse
|
6
|
Yang F, Liu P, Zhang X, Zhang Z, Lu H, Geng N. Mechanism of Datura metel on sinus bradycardia based on network pharmacology and molecular docking. Medicine (Baltimore) 2022; 101:e32190. [PMID: 36626429 PMCID: PMC9750526 DOI: 10.1097/md.0000000000032190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE To investigate the mechanism of action of Datura metel in the treatment of sinus bradycardia based on network pharmacology and molecular docking. METHODS The active ingredients and targets of Datura metel were collected by TCMSP database, and the Cytoscape software was used to map to show the interrelationship. Use 5 databases: GeneCards, PharmGKB, OMIM, DisGeNET, and Drugbank to obtain targets related to sinus bradycardia; establish a protein-to-protein interaction network with the help of the STRING platform; GO and Kyoto Encyclopedia of Genes and Genomes analysis of the selected core targets using the Metascape platform; Finally, the AutoDock platform was used for molecular docking and the results were displayed through Pymol. RESULTS 27 kinds of active ingredients of the drug were screened, including 10 kinds of main ingredients; 198 drug targets and 1059 disease targets. There are 54 targets of action in the treatment of sinus bradycardia, of which 19 targets such as AKT1, IL6, TNF, and VEGFA are the core targets of Datura metel in the treatment of sinus bradycardia. Kyoto Encyclopedia of Genes and Genomes obtained 18 results suggesting that AGE-RAGE, hepatitis C, relaxin, and JAK-STAT may be key signaling pathways. Molecular docking shows that most components of the drug have good docking ability with the core target, indicating that the prediction results have certain reliability. CONCLUSION This study preliminarily explores the potential active ingredients and possible mechanisms of action of Datura metel in the treatment of sinus bradycardia and provides a basis for in-depth investigation of its medicinal material basis and mechanism of action.
Collapse
Affiliation(s)
- Feifei Yang
- Heilongjiang University of Chinese Medicine, Harbin, China
| | - Pihong Liu
- First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, China
| | - Xiaosi Zhang
- Beijing University of Chinese Medicine, Bingjing, China
| | - Zhe Zhang
- Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Hao Lu
- Tianshui City Hospital of Traditional Chinese Medicine, Tianshui, China
| | - Naizhi Geng
- First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, China
- *Correspondence: Naizhi Geng, First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin 150040, China (e-mail: )
| |
Collapse
|
7
|
Optogenetic manipulation of cardiac electrical dynamics using sub-threshold illumination: dissecting the role of cardiac alternans in terminating rapid rhythms. Basic Res Cardiol 2022; 117:25. [PMID: 35488105 PMCID: PMC9054908 DOI: 10.1007/s00395-022-00933-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/01/2022] [Accepted: 04/18/2022] [Indexed: 02/01/2023]
Abstract
Cardiac action potential (AP) shape and propagation are regulated by several key dynamic factors such as ion channel recovery and intracellular Ca2+ cycling. Experimental methods for manipulating AP electrical dynamics commonly use ion channel inhibitors that lack spatial and temporal specificity. In this work, we propose an approach based on optogenetics to manipulate cardiac electrical activity employing a light-modulated depolarizing current with intensities that are too low to elicit APs (sub-threshold illumination), but are sufficient to fine-tune AP electrical dynamics. We investigated the effects of sub-threshold illumination in isolated cardiomyocytes and whole hearts by using transgenic mice constitutively expressing a light-gated ion channel (channelrhodopsin-2, ChR2). We find that ChR2-mediated depolarizing current prolongs APs and reduces conduction velocity (CV) in a space-selective and reversible manner. Sub-threshold manipulation also affects the dynamics of cardiac electrical activity, increasing the magnitude of cardiac alternans. We used an optical system that uses real-time feedback control to generate re-entrant circuits with user-defined cycle lengths to explore the role of cardiac alternans in spontaneous termination of ventricular tachycardias (VTs). We demonstrate that VT stability significantly decreases during sub-threshold illumination primarily due to an increase in the amplitude of electrical oscillations, which implies that cardiac alternans may be beneficial in the context of self-termination of VT.
Collapse
|
8
|
Lyu J, Huang J, Wu J, Yu T, Wei X, Lei Q. Lack of Macrophage Migration Inhibitory Factor Reduces Susceptibility to Ventricular Arrhythmias During the Acute Phase of Myocardial Infarction. J Inflamm Res 2021; 14:1297-1311. [PMID: 33854357 PMCID: PMC8039209 DOI: 10.2147/jir.s304553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/16/2021] [Indexed: 12/29/2022] Open
Abstract
Background Macrophages are involved in inflammatory responses and play a crucial role in aggravating ventricular arrhythmias (VAs) after myocardial infarction (MI). Macrophage migration inhibitory factor (MIF) participates in inflammatory responses during acute MI. In the present study, we hypothesized that knockout (KO) of MIF may prevent VAs during the acute phase of MI by inhibiting macrophage-derived pro-inflammatory mediators. Methods and Results We demonstrated that MIF-KO mice in a mouse model of MI exhibited a significant decrease in susceptibility to VAs both in vivo (84.6% vs 40.7%, P < 0.05) and ex vivo (86.7% vs 40.0%, P < 0.05) at day 3 after MI compared with that in wild-type (WT) mice. Both WT and MIF-KO mice presented similar left ventricular contractility, peri-infarct myocardial fibrosis and sympathetic reinnervation, and circulating and local norepinephrine levels during the acute phase of MI. Meanwhile, MIF-KO mice had inhibited macrophage aggregation, alleviated connexin 43 (Cx43) redistribution, and reduced level of pro-inflammatory mediators, including tumor necrosis factor-α and interleukin-1β (P < 0.05) at day 3 after MI. The differences in susceptibility to VAs, expression of pro-inflammatory mediators, and Cx43 redistribution after MI between WT and MIF-KO mice disappeared by macrophage depletion with clodronate liposomes in both groups. Furthermore, the pro-inflammatory activity of cultured peritoneal macrophages was inhibited by MIF deficiency and recovered with replenishment of exogenous MIF in vitro. Conclusion In conclusion, we found that lack of MIF reduced the susceptibility to VAs in mouse heart during the acute phase of MI by inhibiting pro-inflammatory activity of macrophages and improving gap-junction and electrical remodeling.
Collapse
Affiliation(s)
- Juanjuan Lyu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Jia Huang
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China
| | - Jin Wu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, People's Republic of China
| | - Tao Yu
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China.,Department of Cardiac Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China
| | - Xinchuan Wei
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China
| | - Qian Lei
- Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, People's Republic of China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, People's Republic of China
| |
Collapse
|
9
|
Dariolli R, Campana C, Gutierrez A, Sobie EA. In vitro and In silico Models to Study SARS-CoV-2 Infection: Integrating Experimental and Computational Tools to Mimic "COVID-19 Cardiomyocyte". Front Physiol 2021; 12:624185. [PMID: 33679437 PMCID: PMC7925402 DOI: 10.3389/fphys.2021.624185] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/25/2021] [Indexed: 01/08/2023] Open
Abstract
The rapid dissemination of SARS-CoV-2 has made COVID-19 a tremendous social, economic, and health burden. Despite the efforts to understand the virus and treat the disease, many questions remain unanswered about COVID-19 mechanisms of infection and progression. Severe Acute Respiratory Syndrome (SARS) infection can affect several organs in the body including the heart, which can result in thromboembolism, myocardial injury, acute coronary syndromes, and arrhythmias. Numerous cardiac adverse events, from cardiomyocyte death to secondary effects caused by exaggerated immunological response against the virus, have been clinically reported. In addition to the disease itself, repurposing of treatments by using "off label" drugs can also contribute to cardiotoxicity. Over the past several decades, animal models and more recently, stem cell-derived cardiomyocytes have been proposed for studying diseases and testing treatments in vitro. In addition, mechanistic in silico models have been widely used for disease and drug studies. In these models, several characteristics such as gender, electrolyte imbalance, and comorbidities can be implemented to study pathophysiology of cardiac diseases and to predict cardiotoxicity of drug treatments. In this Mini Review, we (1) present the state of the art of in vitro and in silico cardiomyocyte modeling currently in use to study COVID-19, (2) review in vitro and in silico models that can be adopted to mimic the effects of SARS-CoV-2 infection on cardiac function, and (3) provide a perspective on how to combine some of these models to mimic "COVID-19 cardiomyocytes environment.".
Collapse
Affiliation(s)
- Rafael Dariolli
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | | | | | | |
Collapse
|
10
|
Hussaini S, Venkatesan V, Biasci V, Romero Sepúlveda JM, Quiñonez Uribe RA, Sacconi L, Bub G, Richter C, Krinski V, Parlitz U, Majumder R, Luther S. Drift and termination of spiral waves in optogenetically modified cardiac tissue at sub-threshold illumination. eLife 2021; 10:59954. [PMID: 33502313 PMCID: PMC7840178 DOI: 10.7554/elife.59954] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 11/28/2020] [Indexed: 01/01/2023] Open
Abstract
The development of new approaches to control cardiac arrhythmias requires a deep understanding of spiral wave dynamics. Optogenetics offers new possibilities for this. Preliminary experiments show that sub-threshold illumination affects electrical wave propagation in the mouse heart. However, a systematic exploration of these effects is technically challenging. Here, we use state-of-the-art computer models to study the dynamic control of spiral waves in a two-dimensional model of the adult mouse ventricle, using stationary and non-stationary patterns of sub-threshold illumination. Our results indicate a light-intensity-dependent increase in cellular resting membrane potentials, which together with diffusive cell-cell coupling leads to the development of spatial voltage gradients over differently illuminated areas. A spiral wave drifts along the positive gradient. These gradients can be strategically applied to ensure drift-induced termination of a spiral wave, both in optogenetics and in conventional methods of electrical defibrillation.
Collapse
Affiliation(s)
- Sayedeh Hussaini
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,Institute for the Dynamics of Complex Systems, Goettingen University, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Vishalini Venkatesan
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,University Medical Center Goettingen, Clinic of Cardiology and Pneumology, Goettingen, Germany
| | - Valentina Biasci
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino (FI), Italy.,Division of Physiology, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | | | - Raul A Quiñonez Uribe
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, Sesto Fiorentino (FI), Italy.,Institute for Experimental Cardiovascular Medicine, University of Freiburg, Freiburg, Germany.,National Institute of Optics, National Research Council, Florence, Italy
| | - Gil Bub
- Department of Physiology, MGill University, Montreal, Canada
| | - Claudia Richter
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany.,University Medical Center Goettingen, Clinic of Cardiology and Pneumology, Goettingen, Germany
| | - Valentin Krinski
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany.,INPHYNI, CNRS, Sophia Antipolis, Paris, France
| | - Ulrich Parlitz
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,Institute for the Dynamics of Complex Systems, Goettingen University, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Rupamanjari Majumder
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany
| | - Stefan Luther
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany.,Institute for the Dynamics of Complex Systems, Goettingen University, Goettingen, Germany.,German Center for Cardiovascular Research, Partner Site Goettingen, Goettingen, Germany.,University Medical Center Goettingen, Institute of Pharmacology and Toxicology, Goettingen, Germany
| |
Collapse
|
11
|
Abstract
Computer simulations show how low-intensity illumination can be used to terminate cardiac arrhythmias.
Collapse
Affiliation(s)
- Eike M Wülfers
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg – Bad KrozingenBad KrozingenGermany
- Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Franziska Schneider-Warme
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg – Bad KrozingenBad KrozingenGermany
- Faculty of Medicine, University of FreiburgFreiburgGermany
| |
Collapse
|
12
|
Interplay of pro-inflammatory cytokines, pro-inflammatory microparticles and oxidative stress and recurrent ventricular arrhythmias in elderly patients after coronary stent implantations. Cytokine 2020; 137:155345. [PMID: 33137563 DOI: 10.1016/j.cyto.2020.155345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 09/09/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND The roles of pro-inflammatory microparticles, pro-inflammatory cytokines and oxidative stress were unknown in elderly patients with recurrent ventricular arrhythmias (VA). We evaluated whether cross talk between oxidative stress, pro-inflammatory microparticles, and pro-inflammatory cytokines play the roles in elderly patients with recurrent VA after coronary stenting. This research sought to investigate the effects of oxidative stress, pro-inflammatory microparticles, and pro-inflammatory cytokines on recurrent VA in elderly patients after coronary stenting. METHODS In this study, we included 613 consecutive elderly patients with recurrent ventricular arrhythmias induced by coronary reocclusions after coronary stenting. We measured CD31+ endothelial microparticle (CD31+EMP), CD62E+ endothelial microparticle (CD62E+EMP), high-sensitivity C-reactive protein (hs-CRP), aldosterone (ALD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), soluble tumor necrosis factor receptor-1 (sTNFR-1) and soluble tumor necrosis factor receptor-2 (sTNFR-2) in elderly patients with recurrent VA and assessed impacts of pro-inflammatory microparticles, pro-inflammatory cytokines and oxidative stress on recurrent VA in elderly patients after coronary stenting. RESULTS The levels of CD31+EMP, CD62E+EMP, hs-CRP, ALD, MDA, TNF-α, sTNFR-1 and sTNFR-2 were increased in recurrent malignant ventricular arrhythmia, sustained ventricular tachycardia, multiple ventricular premature beat and left and right ventricular bundle branch block groups (P < 0.001) in elderly patients with coronary reocclusions after coronary stent implantation. Upregulation of pro-inflammatory microparticles, pro-inflammatory cytokines and oxidative stress markers induced recurrent VA in elderly patients after coronary stenting. CONCLUSIONS High levels of pro-inflammatory microparticles, pro-inflammatory cytokines and oxidative stress markers were associated with recurrent VA in elderly patients after coronary stenting. Our results suggested that the pro-inflammatory microparticles, pro-inflammatory cytokines and oxidative stress may simultaneously induce and aggravate recurrent VA in elderly patients after coronary stenting.
Collapse
|
13
|
Rolski F, Błyszczuk P. Complexity of TNF-α Signaling in Heart Disease. J Clin Med 2020; 9:E3267. [PMID: 33053859 PMCID: PMC7601316 DOI: 10.3390/jcm9103267] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 02/07/2023] Open
Abstract
Heart disease is a leading cause of death with unmet clinical needs for targeted treatment options. Tumor necrosis factor alpha (TNF-α) represents a master pro-inflammatory cytokine that plays an important role in many immunopathogenic processes. Anti-TNF-α therapy is widely used in treating autoimmune inflammatory disorders, but in case of patients with heart disease, this treatment was unsuccessful or even harmful. The underlying reasons remain elusive until today. This review summarizes the effects of anti-TNF-α treatment in patients with and without heart disease and describes the involvement of TNF-α signaling in a number of animal models of cardiovascular diseases. We specifically focused on the role of TNF-α in specific cardiovascular conditions and in defined cardiac cell types. Although some mechanisms, mainly in disease development, are quite well known, a comprehensive understanding of TNF-α signaling in the failing heart is still incomplete. Published data identify pathogenic and cardioprotective mechanisms of TNF-α in the affected heart and highlight the differential role of two TNF-α receptors pointing to the complexity of the TNF-α signaling. In the light of these findings, it seems that targeting the TNF-α pathway in heart disease may show therapeutic benefits, but this approach must be more specific and selectively block pathogenic mechanisms. To this aim, more research is needed to better understand the molecular mechanisms of TNF-α signaling in the failing heart.
Collapse
Affiliation(s)
- Filip Rolski
- Department of Clinical Immunology, Jagiellonian University Medical College, 30-663 Cracow, Poland;
| | - Przemysław Błyszczuk
- Department of Clinical Immunology, Jagiellonian University Medical College, 30-663 Cracow, Poland;
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, 8952 Schlieren, Switzerland
| |
Collapse
|
14
|
Lyu J, Wang M, Kang X, Xu H, Cao Z, Yu T, Huang K, Wu J, Wei X, Lei Q. Macrophage-mediated regulation of catecholamines in sympathetic neural remodeling after myocardial infarction. Basic Res Cardiol 2020; 115:56. [DOI: 10.1007/s00395-020-0813-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 07/20/2020] [Indexed: 12/17/2022]
|
15
|
Asfaw TN, Tyan L, Glukhov AV, Bondarenko VE. A compartmentalized mathematical model of mouse atrial myocytes. Am J Physiol Heart Circ Physiol 2020; 318:H485-H507. [PMID: 31951471 DOI: 10.1152/ajpheart.00460.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Various experimental mouse models are extensively used to research human diseases, including atrial fibrillation, the most common cardiac rhythm disorder. Despite this, there are no comprehensive mathematical models that describe the complex behavior of the action potential and [Ca2+]i transients in mouse atrial myocytes. Here, we develop a novel compartmentalized mathematical model of mouse atrial myocytes that combines the action potential, [Ca2+]i dynamics, and β-adrenergic signaling cascade for a subpopulation of right atrial myocytes with developed transverse-axial tubule system. The model consists of three compartments related to β-adrenergic signaling (caveolae, extracaveolae, and cytosol) and employs local control of Ca2+ release. It also simulates ionic mechanisms of action potential generation and describes atrial-specific Ca2+ handling as well as frequency dependences of the action potential and [Ca2+]i transients. The model showed that the T-type Ca2+ current significantly affects the later stage of the action potential, with little effect on [Ca2+]i transients. The block of the small-conductance Ca2+-activated K+ current leads to a prolongation of the action potential at high intracellular Ca2+. Simulation results obtained from the atrial model cells were compared with those from ventricular myocytes. The developed model represents a useful tool to study complex electrical properties in the mouse atria and could be applied to enhance the understanding of atrial physiology and arrhythmogenesis.NEW & NOTEWORTHY A new compartmentalized mathematical model of mouse right atrial myocytes was developed. The model simulated action potential and Ca2+ dynamics at baseline and after stimulation of the β-adrenergic signaling system. Simulations showed that the T-type Ca2+ current markedly prolonged the later stage of atrial action potential repolarization, with a minor effect on [Ca2+]i transients. The small-conductance Ca2+-activated K+ current block resulted in prolongation of the action potential only at the relatively high intracellular Ca2+.
Collapse
Affiliation(s)
- Tesfaye Negash Asfaw
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia
| | - Leonid Tyan
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Alexey V Glukhov
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
| |
Collapse
|
16
|
A Mathematical Model of the Human Cardiac Na + Channel. J Membr Biol 2019; 252:77-103. [PMID: 30637460 DOI: 10.1007/s00232-018-00058-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 12/31/2018] [Indexed: 01/07/2023]
Abstract
Sodium ion channel is a membrane protein that plays an important role in excitable cells, as it is responsible for the initiation of action potentials. Understanding the electrical characteristics of sodium channels is essential in predicting their behavior under different physiological conditions. We investigated several Markov models for the human cardiac sodium channel NaV1.5 to derive a minimal mathematical model that describes the reported experimental data obtained using major voltage clamp protocols. We obtained simulation results for peak current-voltage relationships, the voltage dependence of normalized ion channel conductance, steady-state inactivation, activation and deactivation kinetics, fast and slow inactivation kinetics, and recovery from inactivation kinetics. Good agreement with the experimental data provides us with the mechanisms of the fast and slow inactivation of the human sodium channel and the coupling of its inactivation states to the closed and open states in the activation pathway.
Collapse
|
17
|
Najjari M, Vaezi G, Hojati V, Mousavi Z, Bakhtiarian A, Nikoui V. Involvement of IL-1β and IL-6 in antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in rats. Immunopharmacol Immunotoxicol 2018; 40:256-261. [PMID: 29486618 DOI: 10.1080/08923973.2018.1440592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE Evidence show that statins possess wide beneficial cardioprotective and anti-inflammatory effects; therefore, in the present experiment, we investigated the antiarrhythmic properties of atorvastatin in ouabain-induced arrhythmia in isolated rat atria and the role of several inflammatory cytokines in this effect. MATERIALS AND METHODS Male rats were pretreated with either of atorvastatin (10 mg/kg) or vehicle, orally once daily for 6 weeks. After induction of anesthesia, we isolated the atria and after incubation with ouabain, time of onset of arrhythmia and asystole as well as atrial beating rate and contractile force were recorded. We also measured the atrial levels of IL-1β, IL-6, and TNF-α after the injection of ouabain to animals. RESULTS Pretreatment with atorvastatin significantly delayed the onset of arrhythmia and asystole compared with vehicle-treated group (p < .01, p < .001, respectively). Incubation of ouabain boosted both atrial beating rate and contractile force in vehicle-treated group (p < .05), while these responses in atorvastatin-treated group were not significant (p > .05). Injection of ouabain elevated the atrial levels of IL-1β, IL-6, and TNF-α, while pretreatment of animals with atorvastatin could reverse the ouabain-induced increase in atrial IL-1β and IL-6 (p < .01 and p < .05, respectively). CONCLUSIONS It is concluded that observed antiarrhythmic effects of atorvastatin might be attributed to modulation of some inflammatory cytokines, at least IL-1β and IL-6.
Collapse
Affiliation(s)
- Mahya Najjari
- a Department of Biology, Damghan Branch , Islamic Azad University , Damghan , Iran
| | - Gholamhassan Vaezi
- a Department of Biology, Damghan Branch , Islamic Azad University , Damghan , Iran
| | - Vida Hojati
- a Department of Biology, Damghan Branch , Islamic Azad University , Damghan , Iran
| | - Zahra Mousavi
- b Department of Pharmacology-Toxicology, Faculty of Pharmacy , Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS) , Tehran , Iran
| | - Azam Bakhtiarian
- c Department of Pharmacology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.,d Experimental Medicine Research Center , Tehran University of Medical Sciences , Tehran , Iran
| | - Vahid Nikoui
- e Razi Drug Research Center , Iran University of Medical Sciences , Tehran , Iran
| |
Collapse
|
18
|
Bondarenko VE, Shilnikov AL. Bursting dynamics in the normal and failing hearts. Sci Rep 2017; 7:5927. [PMID: 28725037 PMCID: PMC5517618 DOI: 10.1038/s41598-017-05198-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/15/2017] [Indexed: 01/03/2023] Open
Abstract
A failing heart differs from healthy hearts by an array of symptomatic characteristics, including impaired Ca2+ transients, upregulation of Na+/Ca2+ exchanger function, reduction of Ca2+ uptake to sarcoplasmic reticulum, reduced K+ currents, and increased propensity to arrhythmias. While significant efforts have been made in both experimental studies and model development to display the causes of heart failure, the full process of deterioration from a healthy to a failing heart yet remains deficiently understood. In this paper, we analyze a highly detailed mathematical model of mouse ventricular myocytes to disclose the key mechanisms underlying the continual transition towards a state of heart failure. We argue that such a transition can be described in mathematical terms as a sequence of bifurcations that the healthy cells undergo while transforming into failing cells. They include normal action potentials and [Ca2+]i transients, action potential and [Ca2+]i alternans, and bursting behaviors. These behaviors where supported by experimental studies of heart failure. The analysis of this model allowed us to identify that the slow component of the fast Na+ current is a key determining factor for the onset of bursting activity in mouse ventricular myocytes.
Collapse
Affiliation(s)
- Vladimir E Bondarenko
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, 30 Pryor Street, Atlanta, GA 30303, United States.
| | - Andrey L Shilnikov
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, 30 Pryor Street, Atlanta, GA 30303, United States.,Institute for Information Technologies, Mathematics and Mechanics, Nizhni Novgorod State University, Gagarin Av. 23, 606950, Nizhni Novgorod, Russia
| |
Collapse
|
19
|
Involvement of Inflammatory Cytokines in Antiarrhythmic Effects of Clofibrate in Ouabain-Induced Arrhythmia in Isolated Rat Atria. Adv Pharmacol Sci 2016; 2016:9128018. [PMID: 26977143 PMCID: PMC4764719 DOI: 10.1155/2016/9128018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/06/2016] [Accepted: 01/13/2016] [Indexed: 11/18/2022] Open
Abstract
Considering the cardioprotective and anti-inflammatory properties of clofibrate, the aim of the present experiment was to investigate the involvement of local and systemic inflammatory cytokines in possible antiarrhythmic effects of clofibrate in ouabain-induced arrhythmia in rats. Rats were orally treated with clofibrate (300 mg/kg), and ouabain (0.56 mg/kg) was administered to animals intraperitoneally. After induction of anesthesia, the atria were isolated and the onset of arrhythmia and asystole was recorded. The levels of inflammatory cytokines in atria were also measured. Clofibrate significantly postponed the onset of arrhythmia and asystole when compared to control group (P ≤ 0.05 and P ≤ 0.01, resp.). While ouabain significantly increased the atrial beating rate in control group (P ≤ 0.05), same treatment did not show similar effect in clofibrate-treated group (P > 0.05). Injection of ouabain significantly increased the atrial and systemic levels of all studied inflammatory cytokines (P ≤ 0.05). Pretreatment with clofibrate could attenuate the ouabain-induced elevation of IL-6 and TNF-α in atria (P ≤ 0.01 and P ≤ 0.05, resp.), as well as ouabain-induced increase in IL-6 in plasma (P ≤ 0.05). Based on our findings, clofibrate may possess antiarrhythmic properties through mitigating the local and systemic inflammatory factors including IL-6 and TNF-α.
Collapse
|
20
|
Zhang D, Zhang Y, Zhao C, Zhang W, Shao G, Zhang H. Effect of lysophosphatidic acid on the immune inflammatory response and the connexin 43 protein in myocardial infarction. Exp Ther Med 2016; 11:1617-1624. [PMID: 27168781 DOI: 10.3892/etm.2016.3132] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/09/2016] [Indexed: 12/16/2022] Open
Abstract
Lysophosphatidic acid (LPA) is an intermediate product of membrane phospholipid metabolism. Recently, LPA has gained attention for its involvement in the pathological processes of certain cardiovascular diseases. The aim of the present study was to clarify the association between the effect of LPA and the immune inflammatory response, and to investigate the effects of LPA on the protein expression levels of connexin 43 during myocardial infarction. Surface electrocardiograms of myocardial infarction rats and isolated rat heart tissue samples were obtained in order to determine the effect of LPA on the incidence of arrhythmia in rats that exhibited changes in immune status. The results demonstrated that the incidence of arrhythmia decreased when the rat immune systems were suppressed, and the incidence of arrhythmia increased when the rat immune systems were enhanced. The concentration levels of tumor necrosis factor (TNF)-α were determined by ELISA, and the results demonstrated that LPA induced T lymphocyte synthesis and TNF-α release. Using a patch-clamp technique, LPA was shown to increase the current amplitude of the voltage-dependent potassium channels (Kv) and calcium-activated potassium channels (KCa) in Jurkat T cells. The protein expression of connexin 43 (Cx43) was determined by immunohistochemical staining. The results indicated that LPA caused the degradation of Cx43 and decreased the expression of Cx43. This effect was associated with the immune status of the rats. There was a further decrease in Cx43 expression in the rats of the immune-enhanced group. To the best of our knowledge, these results provide the first evidence that LPA causes arrhythmia through the regulation of immune inflammatory cells and the decrease of Cx43 protein expression. The present study provided an experimental basis for the treatment of arrhythmia and may guide clinical care.
Collapse
Affiliation(s)
- Duoduo Zhang
- Department of Thoracic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China; Department of Surgery, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China
| | - Yan Zhang
- Department of Anesthesiology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China
| | - Chunyan Zhao
- Department of Physiology, Norman Bethune College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Wenjie Zhang
- Department of Physiology, Norman Bethune College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| | - Guoguang Shao
- Department of Thoracic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Hong Zhang
- Department of Physiology, Norman Bethune College of Medicine, Jilin University, Changchun, Jilin 130021, P.R. China
| |
Collapse
|
21
|
Wescott AP, Jafri MS, Lederer WJ, Williams GSB. Ryanodine receptor sensitivity governs the stability and synchrony of local calcium release during cardiac excitation-contraction coupling. J Mol Cell Cardiol 2016; 92:82-92. [PMID: 26827896 PMCID: PMC4807626 DOI: 10.1016/j.yjmcc.2016.01.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/13/2016] [Accepted: 01/27/2016] [Indexed: 11/27/2022]
Abstract
Calcium-induced calcium release is the principal mechanism that triggers the cell-wide [Ca(2+)]i transient that activates muscle contraction during cardiac excitation-contraction coupling (ECC). Here, we characterize this process in mouse cardiac myocytes with a novel mathematical action potential (AP) model that incorporates realistic stochastic gating of voltage-dependent L-type calcium (Ca(2+)) channels (LCCs) and sarcoplasmic reticulum (SR) Ca(2+) release channels (the ryanodine receptors, RyR2s). Depolarization of the sarcolemma during an AP stochastically activates the LCCs elevating subspace [Ca(2+)] within each of the cell's 20,000 independent calcium release units (CRUs) to trigger local RyR2 opening and initiate Ca(2+) sparks, the fundamental unit of triggered Ca(2+) release. Synchronization of Ca(2+) sparks during systole depends on the nearly uniform cellular activation of LCCs and the likelihood of local LCC openings triggering local Ca(2+) sparks (ECC fidelity). The detailed design and true SR Ca(2+) pump/leak balance displayed by our model permits investigation of ECC fidelity and Ca(2+) spark fidelity, the balance between visible (Ca(2+) spark) and invisible (Ca(2+) quark/sub-spark) SR Ca(2+) release events. Excess SR Ca(2+) leak is examined as a disease mechanism in the context of "catecholaminergic polymorphic ventricular tachycardia (CPVT)", a Ca(2+)-dependent arrhythmia. We find that that RyR2s (and therefore Ca(2+) sparks) are relatively insensitive to LCC openings across a wide range of membrane potentials; and that key differences exist between Ca(2+) sparks evoked during quiescence, diastole, and systole. The enhanced RyR2 [Ca(2+)]i sensitivity during CPVT leads to increased Ca(2+) spark fidelity resulting in asynchronous systolic Ca(2+) spark activity. It also produces increased diastolic SR Ca(2+) leak with some prolonged Ca(2+) sparks that at times become "metastable" and fail to efficiently terminate. There is a huge margin of safety for stable Ca(2+) handling within the cell and this novel mechanistic model provides insight into the molecular signaling characteristics that help maintain overall Ca(2+) stability even under the conditions of high SR Ca(2+) leak during CPVT. Finally, this model should provide tools for investigators to examine normal and pathological Ca(2+) signaling characteristics in the heart.
Collapse
Affiliation(s)
- Andrew P Wescott
- Center for Biomedical Engineering and Technology & Department of Physiology, University of Maryland, Baltimore, Baltimore, MD, United States
| | - M Saleet Jafri
- Center for Biomedical Engineering and Technology & Department of Physiology, University of Maryland, Baltimore, Baltimore, MD, United States; Molecular Neuroscience Department, George Mason University, Fairfax, VA, United States
| | - W J Lederer
- Center for Biomedical Engineering and Technology & Department of Physiology, University of Maryland, Baltimore, Baltimore, MD, United States
| | - George S B Williams
- Center for Biomedical Engineering and Technology & Department of Physiology, University of Maryland, Baltimore, Baltimore, MD, United States.
| |
Collapse
|
22
|
Bondarenko VE. A compartmentalized mathematical model of the β1-adrenergic signaling system in mouse ventricular myocytes. PLoS One 2014; 9:e89113. [PMID: 24586529 PMCID: PMC3931689 DOI: 10.1371/journal.pone.0089113] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 01/14/2014] [Indexed: 01/08/2023] Open
Abstract
The β1-adrenergic signaling system plays an important role in the functioning of cardiac cells. Experimental data shows that the activation of this system produces inotropy, lusitropy, and chronotropy in the heart, such as increased magnitude and relaxation rates of [Ca2+]i transients and contraction force, and increased heart rhythm. However, excessive stimulation of β1-adrenergic receptors leads to heart dysfunction and heart failure. In this paper, a comprehensive, experimentally based mathematical model of the β1-adrenergic signaling system for mouse ventricular myocytes is developed, which includes major subcellular functional compartments (caveolae, extracaveolae, and cytosol). The model describes biochemical reactions that occur during stimulation of β1-adrenoceptors, changes in ionic currents, and modifications of Ca2+ handling system. Simulations describe the dynamics of major signaling molecules, such as cyclic AMP and protein kinase A, in different subcellular compartments; the effects of inhibition of phosphodiesterases on cAMP production; kinetics and magnitudes of phosphorylation of ion channels, transporters, and Ca2+ handling proteins; modifications of action potential shape and duration; magnitudes and relaxation rates of [Ca2+]i transients; changes in intracellular and transmembrane Ca2+ fluxes; and [Na+]i fluxes and dynamics. The model elucidates complex interactions of ionic currents upon activation of β1-adrenoceptors at different stimulation frequencies, which ultimately lead to a relatively modest increase in action potential duration and significant increase in [Ca2+]i transients. In particular, the model includes two subpopulations of the L-type Ca2+ channels, in caveolae and extracaveolae compartments, and their effects on the action potential and [Ca2+]i transients are investigated. The presented model can be used by researchers for the interpretation of experimental data and for the developments of mathematical models for other species or for pathological conditions.
Collapse
Affiliation(s)
- Vladimir E. Bondarenko
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
23
|
Mullins PD, Bondarenko VE. A mathematical model of the mouse ventricular myocyte contraction. PLoS One 2013; 8:e63141. [PMID: 23671664 PMCID: PMC3650013 DOI: 10.1371/journal.pone.0063141] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/29/2013] [Indexed: 12/05/2022] Open
Abstract
Mathematical models of cardiac function at the cellular level include three major components, such as electrical activity, Ca2+ dynamics, and cellular shortening. We developed a model for mouse ventricular myocyte contraction which is based on our previously published comprehensive models of action potential and Ca2+ handling mechanisms. The model was verified with extensive experimental data on mouse myocyte contraction at room temperature. In the model, we implemented variable sarcomere length and indirect modulation of the tropomyosin transition rates by Ca2+ and troponin. The resulting model described well steady-state force-calcium relationships, dependence of the contraction force on the sarcomere length, time course of the contraction force and myocyte shortening, frequency dependence of the contraction force and cellular contraction, and experimentally measured derivatives of the myocyte length variation. We emphasized the importance of the inclusion of variable sarcomere length into a model for ventricular myocyte contraction. Differences in contraction force and cell shortening for epicardial and endocardial ventricular myocytes were investigated. Model applicability for the experimental studies and model limitations were discussed.
Collapse
Affiliation(s)
- Paula D. Mullins
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia, United States of America
| | - Vladimir E. Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia, United States of America
- Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
24
|
Niederer SA, Land S, Omholt SW, Smith NP. Interpreting genetic effects through models of cardiac electromechanics. Am J Physiol Heart Circ Physiol 2012; 303:H1294-303. [PMID: 23042948 DOI: 10.1152/ajpheart.00121.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Multiscale models of cardiac electromechanics are being increasingly focused on understanding how genetic variation and environment underpin multiple disease states. In this paper we review the current state of the art in both the development of specific models and the physiological insights they have produced. This growing research body includes the development of models for capturing the effects of changes in function in both single and multiple proteins in both specific expression systems and in vivo contexts. Finally, the potential for using this approach for ultimately predicting phenotypes from genetic sequence information is discussed.
Collapse
Affiliation(s)
- S A Niederer
- Department of Biomedical Engineering, King's College London, King's Health Partners, Saint Thomas' Hospital, London, UK
| | | | | | | |
Collapse
|