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Bak T, Sato D. Spatially discordant alternans due to periodic pacing site alternation. Heart Rhythm 2024:S1547-5271(24)02900-X. [PMID: 39025387 DOI: 10.1016/j.hrthm.2024.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 07/07/2024] [Accepted: 07/08/2024] [Indexed: 07/20/2024]
Abstract
BACKGROUND Bidirectional ventricular tachycardia (BVT) is a rare type of ventricular tachycardia that is characterized by a beat-to-beat alternation in the QRS axis. Previous studies have shown that it is caused by alternating focal activities from two locations. OBJECTIVE This study proposes a novel mechanism for the formation of spatially discordant alternans (SDA) due to the periodic pacing site alternation that occurs in BVT. METHODS We used mathematical models of cardiac tissue to understand the dynamical and physiological mechanisms underlying SDA formation. RESULTS We found that SDA was formed due to periodic pacing site alternation. When tissue was paced from two locations alternately, the timing of pacing at distant locations varied, creating a long-short-long-short sequence of pacing periods and thus action potential durations. Importantly, the nodal lines were perpendicular to the wavefront, which is more arrhythmogenic than when nodal lines are parallel to the wavefront. A positive correlation was observed between the separation distance of the two sites and the alternans amplitude. SDA patterns can be predicted from the tissue geometry and pacing site locations. CONCLUSION Periodic pacing site alternation, which occurs in BVT, leads to arrhythmogenic SDA. The nodal lines associated with this phenomenon can be predicted based on tissue geometry and focal locations.
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Affiliation(s)
- Tymoteusz Bak
- Department of Pharmacology, University of California, Davis, California, 95616
| | - Daisuke Sato
- Department of Pharmacology, University of California, Davis, California, 95616.
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2
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Yu C, Qiu Y, Yao F, Wang C, Li J. Chemically Programmed Hydrogels for Spatiotemporal Modulation of the Cardiac Pathological Microenvironment. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2404264. [PMID: 38830198 DOI: 10.1002/adma.202404264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 05/20/2024] [Indexed: 06/05/2024]
Abstract
After myocardial infarction (MI), sustained ischemic events induce pathological microenvironments characterized by ischemia-hypoxia, oxidative stress, inflammatory responses, matrix remodeling, and fibrous scarring. Conventional clinical therapies lack spatially targeted and temporally responsive modulation of the infarct microenvironment, leading to limited myocardial repair. Engineered hydrogels have a chemically programmed toolbox for minimally invasive localization of the pathological microenvironment and personalized responsive modulation over different pathological periods. Chemically programmed strategies for crosslinking interactions, interfacial binding, and topological microstructures in hydrogels enable minimally invasive implantation and in situ integration tailored to the myocardium. This enhances substance exchange and signal interactions within the infarcted microenvironment. Programmed responsive polymer networks, intelligent micro/nanoplatforms, and biological therapeutic cues contribute to the formation of microenvironment-modulated hydrogels with precise targeting, spatiotemporal control, and on-demand feedback. Therefore, this review summarizes the features of the MI microenvironment and chemically programmed schemes for hydrogels to conform, integrate, and modulate the cardiac pathological microenvironment. Chemically programmed strategies for oxygen-generating, antioxidant, anti-inflammatory, provascular, and electrointegrated hydrogels to stimulate iterative and translational cardiac tissue engineering are discussed.
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Affiliation(s)
- Chaojie Yu
- School of Chemical Engineering and Technology, Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, 300350, China
| | - Yuwei Qiu
- School of Chemical Engineering and Technology, Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, 300350, China
| | - Fanglian Yao
- School of Chemical Engineering and Technology, Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, 300350, China
| | - Changyong Wang
- Tissue Engineering Research Center, Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Junjie Li
- School of Chemical Engineering and Technology, Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Tianjin University, Tianjin, 300350, China
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3
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Ruud M, Frisk M, Melleby AO, Norseng PA, Mohamed BA, Li J, Aronsen JM, Setterberg IE, Jakubiczka J, van Hout I, Coffey S, Shen X, Nygård S, Lunde IG, Tønnessen T, Jones PP, Sjaastad I, Gullestad L, Toischer K, Dahl CP, Christensen G, Louch WE. Regulation of cardiomyocyte t-tubule structure by preload and afterload: Roles in cardiac compensation and decompensation. J Physiol 2024. [PMID: 38686538 DOI: 10.1113/jp284566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/02/2024] [Indexed: 05/02/2024] Open
Abstract
Mechanical load is a potent regulator of cardiac structure and function. Although high workload during heart failure is associated with disruption of cardiomyocyte t-tubules and Ca2+ homeostasis, it remains unclear whether changes in preload and afterload may promote adaptive t-tubule remodelling. We examined this issue by first investigating isolated effects of stepwise increases in load in cultured rat papillary muscles. Both preload and afterload increases produced a biphasic response, with the highest t-tubule densities observed at moderate loads, whereas excessively low and high loads resulted in low t-tubule levels. To determine the baseline position of the heart on this bell-shaped curve, mice were subjected to mildly elevated preload or afterload (1 week of aortic shunt or banding). Both interventions resulted in compensated cardiac function linked to increased t-tubule density, consistent with ascension up the rising limb of the curve. Similar t-tubule proliferation was observed in human patients with moderately increased preload or afterload (mitral valve regurgitation, aortic stenosis). T-tubule growth was associated with larger Ca2+ transients, linked to upregulation of L-type Ca2+ channels, Na+-Ca2+ exchanger, mechanosensors and regulators of t-tubule structure. By contrast, marked elevation of cardiac load in rodents and patients advanced the heart down the declining limb of the t-tubule-load relationship. This bell-shaped relationship was lost in the absence of electrical stimulation, indicating a key role of systolic stress in controlling t-tubule plasticity. In conclusion, modest augmentation of workload promotes compensatory increases in t-tubule density and Ca2+ cycling, whereas this adaptation is reversed in overloaded hearts during heart failure progression. KEY POINTS: Excised papillary muscle experiments demonstrated a bell-shaped relationship between cardiomyocyte t-tubule density and workload (preload or afterload), which was only present when muscles were electrically stimulated. The in vivo heart at baseline is positioned on the rising phase of this curve because moderate increases in preload (mice with brief aortic shunt surgery, patients with mitral valve regurgitation) resulted in t-tubule growth. Moderate increases in afterload (mice and patients with mild aortic banding/stenosis) similarly increased t-tubule density. T-tubule proliferation was associated with larger Ca2+ transients, with upregulation of the L-type Ca2+ channel, Na+-Ca2+ exchanger, mechanosensors and regulators of t-tubule structure. By contrast, marked elevation of cardiac load in rodents and patients placed the heart on the declining phase of the t-tubule-load relationship, promoting heart failure progression. The dependence of t-tubule structure on preload and afterload thus enables both compensatory and maladaptive remodelling, in rodents and humans.
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Affiliation(s)
- Marianne Ruud
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Arne Olav Melleby
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Per Andreas Norseng
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Belal A Mohamed
- Department of Cardiology and Pneumology, Georg-August-University, Göttingen, Germany
| | - Jia Li
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Ingunn E Setterberg
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Joanna Jakubiczka
- Department of Cardiology and Pneumology, Georg-August-University, Göttingen, Germany
| | - Isabelle van Hout
- Department of Physiology, School of Biomedical Sciences and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Sean Coffey
- Department of Medicine and HeartOtago, Dunedin School of Medicine, Dunedin Hospital, Dunedin, New Zealand
| | - Xin Shen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Ståle Nygård
- Department of Informatics, University of Oslo, Oslo, Norway
| | - Ida G Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Theis Tønnessen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
- Department of Cardiothoracic Surgery, Oslo University Hospital, Oslo, Norway
| | - Peter P Jones
- Department of Physiology, School of Biomedical Sciences and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Lars Gullestad
- Department of Cardiology, Oslo University Hospital, Oslo, Norway
| | - Karl Toischer
- Department of Cardiology and Pneumology, Georg-August-University, Göttingen, Germany
| | - Cristen P Dahl
- Department of Cardiology, Oslo University Hospital, Oslo, Norway
| | - Geir Christensen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
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4
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Mira Hernandez J, Shen EY, Ko CY, Hourani Z, Spencer ER, Smoliarchuk D, Bossuyt J, Granzier H, Bers DM, Hegyi B. Differential sex-dependent susceptibility to diastolic dysfunction and arrhythmia in cardiomyocytes from obese diabetic HFpEF model. Cardiovasc Res 2024:cvae070. [PMID: 38666446 DOI: 10.1093/cvr/cvae070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 02/29/2024] [Accepted: 03/17/2024] [Indexed: 06/06/2024] Open
Abstract
AIM Sex-differences in heart failure with preserved ejection fraction (HFpEF) are important, but key mechanisms involved are incompletely understood. While animal models can inform about sex-dependent cellular and molecular changes, many previous preclinical HFpEF models have failed to recapitulate sex-dependent characteristics of human HFpEF. We tested for sex-differences in HFpEF using a two-hit mouse model (leptin receptor-deficient db/db mice plus aldosterone infusion for 4 weeks; db/db+Aldo). METHODS AND RESULTS We performed echocardiography, electrophysiology, intracellular Ca2+ imaging, and protein analysis. Female HFpEF mice exhibited more severe diastolic dysfunction in line with increased titin N2B isoform expression and PEVK element phosphorylation, and reduced troponin-I phosphorylation. Female HFpEF mice had lower BNP levels than males despite similar comorbidity burden (obesity, diabetes) and cardiac hypertrophy in both sexes. Male HFpEF mice were more susceptible to cardiac alternans. Male HFpEF cardiomyocytes (versus female) exhibited higher diastolic [Ca2+], slower Ca2+ transient decay, reduced L-type Ca2+ current, more pronounced enhancement of the late Na+ current, and increased short-term variability of action potential duration (APD). However, male and female HFpEF myocytes showed similar downregulation of inward rectifier and transient outward K+ currents, APD prolongation, and frequency of delayed afterdepolarizations. Inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) reversed all pathological APD changes in HFpEF in both sexes, and empagliflozin pretreatment mimicked these effects of CaMKII inhibition. Vericiguat had only slight benefits, and these effects were larger in HFpEF females. CONCLUSION We conclude that the db/db+Aldo preclinical HFpEF murine model recapitulates key sex-specific mechanisms in HFpEF and provides mechanistic insights into impaired excitation-contraction coupling and sex-dependent differential arrhythmia susceptibility in HFpEF with potential therapeutic implications. In male HFpEF myocytes, altered Ca2+ handling and electrophysiology aligned with diastolic dysfunction and arrhythmias, while worse diastolic dysfunction in females may depend more on altered myofilaments properties.
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Affiliation(s)
- Juliana Mira Hernandez
- Department of Pharmacology, University of California, Davis, CA, USA
- Research Group Biogenesis, Faculty of Agricultural Sciences, Veterinary Medicine, University of Antioquia, Medellin-Colombia
| | - Erin Y Shen
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Christopher Y Ko
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Zaynab Hourani
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Emily R Spencer
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Daria Smoliarchuk
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Bence Hegyi
- Department of Pharmacology, University of California, Davis, CA, USA
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5
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Yu C, Shi M, He S, Yao M, Sun H, Yue Z, Qiu Y, Liu B, Liang L, Zhao Z, Yao F, Zhang H, Li J. Chronological adhesive cardiac patch for synchronous mechanophysiological monitoring and electrocoupling therapy. Nat Commun 2023; 14:6226. [PMID: 37803005 PMCID: PMC10558550 DOI: 10.1038/s41467-023-42008-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023] Open
Abstract
With advances in tissue engineering and bioelectronics, flexible electronic hydrogels that allow conformal tissue integration, online precision diagnosis, and simultaneous tissue regeneration are expected to be the next-generation platform for the treatment of myocardial infarction. Here, we report a functionalized polyaniline-based chronological adhesive hydrogel patch (CAHP) that achieves spatiotemporally selective and conformal embedded integration with a moist and dynamic epicardium surface. Significantly, CAHP has high adhesion toughness, rapid self-healing ability, and enhanced electrochemical performance, facilitating sensitive sensing of cardiac mechanophysiology-mediated microdeformations and simultaneous improvement of myocardial fibrosis-induced electrophysiology. As a result, the flexible CAHP platform monitors diastolic-systolic amplitude and rhythm in the infarcted myocardium online while effectively inhibiting ventricular remodeling, promoting vascular regeneration, and improving electrophysiological function through electrocoupling therapy. Therefore, this diagnostic and therapeutic integration provides a promising monitorable treatment protocol for cardiac disease.
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Affiliation(s)
- Chaojie Yu
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, 300350, Tianjin, China
| | - Mingyue Shi
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
- School of Chemical Science and Engineering, Tongji University, 200092, Shanghai, China
| | - Shaoshuai He
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
- Thrust of Sustainable Energy and Environment, The Hong Kong University of Science and Technology (Guangzhou), 511400, Guangzhou, China
| | - Mengmeng Yao
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
| | - Hong Sun
- School of Basic Medical Sciences, North China University of Science and Technology, 063210, Tangshan, China.
| | - Zhiwei Yue
- School of Basic Medical Sciences, North China University of Science and Technology, 063210, Tangshan, China
| | - Yuwei Qiu
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
| | - Baijun Liu
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
| | - Lei Liang
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
| | - Zhongming Zhao
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China
| | - Fanglian Yao
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China.
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, 300350, Tianjin, China.
| | - Hong Zhang
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China.
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, 300350, Tianjin, China.
| | - Junjie Li
- School of Chemical Engineering and Technology, Tianjin University, 300350, Tianjin, China.
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education, Tianjin University, 300350, Tianjin, China.
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6
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Fowler ED, Azarov JE, Brette F. Editorial: Stretch and the heart: mechanoelectrical coupling and arrhythmias. Front Physiol 2023; 14:1278561. [PMID: 37692999 PMCID: PMC10486263 DOI: 10.3389/fphys.2023.1278561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 09/12/2023] Open
Affiliation(s)
- Ewan Douglas Fowler
- School of Biosciences, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jan E. Azarov
- Department of Cardiac Physiology, Institute of Physiology, Komi Science Center, Ural Branch, Russian Academy of Sciences, Syktyvkar, Russia
- Institute of Medicine, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
| | - Fabien Brette
- INSERM U1045 -Université de Bordeaux, Bordeaux, France
- IHU LIRYC-CRCTB U1045, Pessac, France
- Phymedexp INSERM U1046, CNRS, Université de Montpellier, Montpellier University Hospital (CHRU), Montpellier, France
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7
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Chen-Izu Y, Hegyi B, Jian Z, Horvath B, Shaw JA, Banyasz T, Izu LT. INNOVATIVE TECHNIQUES AND NEW INSIGHTS: Studying cardiac ionic currents and action potentials in physiologically relevant conditions. PHYSIOLOGICAL MINI-REVIEWS 2023; 16:22-34. [PMID: 38107545 PMCID: PMC10722976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Cardiac arrhythmias are associated with various forms of heart diseases. Ventricular arrhythmias present a significant risk for sudden cardiac death. Atrial fibrillations predispose to blood clots leading to stroke and heart attack. Scientists have been developing patch-clamp technology to study ion channels and action potentials (APs) underlying cardiac excitation and arrhythmias. Beyond the traditional patch-clamp techniques, innovative new techniques were developed for studying complex arrhythmia mechanisms. Here we review the recent development of methods including AP-Clamp, Dynamic Clamp, AP-Clamp Sequential Dissection, and Patch-Clamp-in-Gel. These methods provide powerful tools for researchers to decipher how the dynamic systems in excitation-Ca2+ signaling-contraction feedforward and feedback to control cardiac function and how their dysregulations lead to heart diseases.
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Affiliation(s)
- Ye Chen-Izu
- Department of Pharmacology, University of California, Davis, USA
- Department of Biomedical Engineering, University of California, Davis, USA
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of California, Davis, USA
| | - Bence Hegyi
- Department of Pharmacology, University of California, Davis, USA
| | - Zhong Jian
- Department of Pharmacology, University of California, Davis, USA
| | - Balazs Horvath
- Department of Pharmacology, University of California, Davis, USA
- Department of Physiology, University of Debrecen, Hungary
| | - John A. Shaw
- Department of Pharmacology, University of California, Davis, USA
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, USA
| | - Tamas Banyasz
- Department of Pharmacology, University of California, Davis, USA
- Department of Physiology, University of Debrecen, Hungary
| | - Leighton T. Izu
- Department of Pharmacology, University of California, Davis, USA
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8
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Doran MH, Rynkiewicz MJ, Rassici D, Bodt SM, Barry ME, Bullitt E, Yengo CM, Moore JR, Lehman W. Conformational changes linked to ADP release from human cardiac myosin bound to actin-tropomyosin. J Gen Physiol 2023; 155:213802. [PMID: 36633586 PMCID: PMC9859928 DOI: 10.1085/jgp.202213267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/11/2022] [Accepted: 12/14/2022] [Indexed: 01/13/2023] Open
Abstract
Following binding to the thin filament, β-cardiac myosin couples ATP-hydrolysis to conformational rearrangements in the myosin motor that drive myofilament sliding and cardiac ventricular contraction. However, key features of the cardiac-specific actin-myosin interaction remain uncertain, including the structural effect of ADP release from myosin, which is rate-limiting during force generation. In fact, ADP release slows under experimental load or in the intact heart due to the afterload, thereby adjusting cardiac muscle power output to meet physiological demands. To further elucidate the structural basis of this fundamental process, we used a combination of cryo-EM reconstruction methodologies to determine structures of the human cardiac actin-myosin-tropomyosin filament complex at better than 3.4 Å-resolution in the presence and in the absence of Mg2+·ADP. Focused refinements of the myosin motor head and its essential light chains in these reconstructions reveal that small changes in the nucleotide-binding site are coupled to significant rigid body movements of the myosin converter domain and a 16-degree lever arm swing. Our structures provide a mechanistic framework to understand the effect of ADP binding and release on human cardiac β-myosin, and offer insights into the force-sensing mechanism displayed by the cardiac myosin motor.
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Affiliation(s)
- Matthew H. Doran
- School of Medicine, Department of Physiology and Biophysics, Boston University, Boston, MA, USA,Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Michael J. Rynkiewicz
- School of Medicine, Department of Physiology and Biophysics, Boston University, Boston, MA, USA
| | - David Rassici
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Skylar M.L. Bodt
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Meaghan E. Barry
- Department of Biological Science, University of Massachusetts Lowell, Lowell, MA, USA
| | - Esther Bullitt
- School of Medicine, Department of Physiology and Biophysics, Boston University, Boston, MA, USA
| | - Christopher M. Yengo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA, USA
| | - Jeffrey R. Moore
- Department of Biological Science, University of Massachusetts Lowell, Lowell, MA, USA
| | - William Lehman
- School of Medicine, Department of Physiology and Biophysics, Boston University, Boston, MA, USA
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9
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Chen X, Zhu L, Wang X, Xiao J. Insight into Heart-Tailored Architectures of Hydrogel to Restore Cardiac Functions after Myocardial Infarction. Mol Pharm 2023; 20:57-81. [PMID: 36413809 DOI: 10.1021/acs.molpharmaceut.2c00650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
With permanent heart muscle injury or death, myocardial infarction (MI) is complicated by inflammatory, proliferation and remodeling phases from both the early ischemic period and subsequent infarct expansion. Though in situ re-establishment of blood flow to the infarct zone and delays of the ventricular remodeling process are current treatment options of MI, they fail to address massive loss of viable cardiomyocytes while transplanting stem cells to regenerate heart is hindered by their poor retention in the infarct bed. Equipped with heart-specific mimicry and extracellular matrix (ECM)-like functionality on the network structure, hydrogels leveraging tissue-matching biomechanics and biocompatibility can mechanically constrain the infarct and act as localized transport of bioactive ingredients to refresh the dysfunctional heart under the constant cyclic stress. Given diverse characteristics of hydrogel including conductivity, anisotropy, adhesiveness, biodegradability, self-healing and mechanical properties driving local cardiac repair, we aim to investigate and conclude the dynamic balance between ordered architectures of hydrogels and the post-MI pathological milieu. Additionally, our review summarizes advantages of heart-tailored architectures of hydrogels in cardiac repair following MI. Finally, we propose challenges and prospects in clinical translation of hydrogels to draw theoretical guidance on cardiac repair and regeneration after MI.
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Affiliation(s)
- Xuerui Chen
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China.,Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai 200444, China
| | - Liyun Zhu
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China.,Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai 200444, China
| | - Xu Wang
- Hangzhou Medical College, Binjiang Higher Education Park, Binwen Road 481, Hangzhou 310053, China
| | - Junjie Xiao
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People's Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China.,Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, Shanghai Engineering Research Center of Organ Repair, School of Life Science, Shanghai University, Shanghai 200444, China
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10
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Hegyi B, Mira Hernandez J, Ko CY, Hong J, Shen EY, Spencer ER, Smoliarchuk D, Navedo MF, Bers DM, Bossuyt J. Diabetes and Excess Aldosterone Promote Heart Failure With Preserved Ejection Fraction. J Am Heart Assoc 2022; 11:e027164. [PMID: 36416174 PMCID: PMC9851441 DOI: 10.1161/jaha.122.027164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Background The pathobiology of heart failure with preserved ejection fraction (HFpEF) is still poorly understood, and effective therapies remain limited. Diabetes and mineralocorticoid excess are common and important pathophysiological factors that may synergistically promote HFpEF. The authors aimed to develop a novel animal model of HFpEF that recapitulates key aspects of the complex human phenotype with multiorgan impairments. Methods and Results The authors created a novel HFpEF model combining leptin receptor-deficient db/db mice with a 4-week period of aldosterone infusion. The HFpEF phenotype was assessed using morphometry, echocardiography, Ca2+ handling, and electrophysiology. The sodium-glucose cotransporter-2 inhibitor empagliflozin was then tested for reversing the arrhythmogenic cardiomyocyte phenotype. Continuous aldosterone infusion for 4 weeks in db/db mice induced marked diastolic dysfunction with preserved ejection fraction, cardiac hypertrophy, high levels of B-type natriuretic peptide, and significant extracardiac comorbidities (including severe obesity, diabetes with marked hyperglycemia, pulmonary edema, and vascular dysfunction). Aldosterone or db/db alone induced only a mild diastolic dysfunction without congestion. At the cellular level, cardiomyocyte hypertrophy, prolonged Ca2+ transient decay, and arrhythmogenic action potential remodeling (prolongation, increased short-term variability, delayed afterdepolarizations), and enhanced late Na+ current were observed in aldosterone-treated db/db mice. All of these arrhythmogenic changes were reversed by empagliflozin pretreatment of HFpEF cardiomyocytes. Conclusions The authors conclude that the db/db+aldosterone model may represent a distinct clinical subgroup of HFpEF that has marked hyperglycemia, obesity, and increased arrhythmia risk. This novel HFpEF model can be useful in future therapeutic testing and should provide unique opportunities to better understand disease pathobiology.
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Affiliation(s)
- Bence Hegyi
- Department of PharmacologyUniversity of CaliforniaDavisCA
| | - Juliana Mira Hernandez
- Department of PharmacologyUniversity of CaliforniaDavisCA
- Research Group in Veterinary Medicine (GIVET), School of Veterinary MedicineUniversity Corporation Lasallista (Unilasallista)CaldasAntioquiaColombia
| | | | - Junyoung Hong
- Department of PharmacologyUniversity of CaliforniaDavisCA
| | - Erin Y. Shen
- Department of PharmacologyUniversity of CaliforniaDavisCA
| | | | | | | | - Donald M. Bers
- Department of PharmacologyUniversity of CaliforniaDavisCA
| | - Julie Bossuyt
- Department of PharmacologyUniversity of CaliforniaDavisCA
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Alim CC, Ko CY, Mira Hernandez J, Shen EY, Baidar S, Chen‐Izu Y, Bers DM, Bossuyt J. Nitrosylation of cardiac CaMKII at Cys290 mediates mechanical afterload-induced increases in Ca 2+ transient and Ca 2+ sparks. J Physiol 2022; 600:4865-4879. [PMID: 36227145 PMCID: PMC9827875 DOI: 10.1113/jp283427] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/30/2022] [Indexed: 01/12/2023] Open
Abstract
Cardiac mechanical afterload induces an intrinsic autoregulatory increase in myocyte Ca2+ dynamics and contractility to enhance contraction (known as the Anrep effect or slow force response). Our prior work has implicated both nitric oxide (NO) produced by NO synthase 1 (NOS1) and calcium/calmodulin-dependent protein kinase II (CaMKII) activity as required mediators of this form of mechano-chemo-transduction. To test whether a single S-nitrosylation site on CaMKIIδ (Cys290) mediates enhanced sarcoplasmic reticulum Ca2+ leak and afterload-induced increases in sarcoplasmic reticulum (SR) Ca2+ uptake and release, we created a novel CRISPR-based CaMKIIδ knock-in (KI) mouse with a Cys to Ala mutation at C290. These CaMKIIδ-C290A-KI mice exhibited normal cardiac morphometry and function, as well as basal myocyte Ca2+ transients (CaTs) and β-adrenergic responses. However, the NO donor S-nitrosoglutathione caused an acute increased Ca2+ spark frequency in wild-type (WT) myocytes that was absent in the CaMKIIδ-C290A-KI myocytes. Using our cell-in-gel system to exert multiaxial three-dimensional mechanical afterload on myocytes during contraction, we found that WT myocytes exhibited an afterload-induced increase in Ca2+ sparks and Ca2+ transient amplitude and rate of decline. These afterload-induced effects were prevented in both cardiac-specific CaMKIIδ knockout and point mutant CaMKIIδ-C290A-KI myocytes. We conclude that CaMKIIδ activation by S-nitrosylation at the C290 site is essential in mediating the intrinsic afterload-induced enhancement of myocyte SR Ca2+ uptake, release and Ca2+ transient amplitude (the Anrep effect). The data also indicate that NOS1 activation is upstream of S-nitrosylation at C290 of CaMKII, and that this molecular mechano-chemo-transduction pathway is beneficial in allowing the heart to increase contractility to limit the reduction in stroke volume when aortic pressure (afterload) is elevated. KEY POINTS: A novel CRISPR-based CaMKIIδ knock-in mouse was created in which kinase activation by S-nitrosylation at Cys290 (C290A) is prevented. How afterload affects Ca2+ signalling was measured in cardiac myocytes that were embedded in a hydrogel that imposes a three-dimensional afterload. This mechanical afterload induced an increase in Ca2+ transient amplitude and decay in wild-type myocytes, but not in cardiac-specific CaMKIIδ knockout or C290A knock-in myocytes. The CaMKIIδ-C290 S-nitrosylation site is essential for the afterload-induced enhancement of Ca2+ transient amplitude and Ca2+ sparks.
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Affiliation(s)
- Chidera C. Alim
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | | | - Juliana Mira Hernandez
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA,Research Group in Veterinary MedicineSchool of Veterinary MedicineUniversity Corporation LasallistaCaldasAntioquiaColombia
| | - Erin Y. Shen
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | - Sonya Baidar
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | - Ye Chen‐Izu
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA,Department of Biomedical EngineeringUniversity of CaliforniaDavisCAUSA,Department of Internal Medicine/CardiologyUniversity of CaliforniaDavisCAUSA
| | - Donald M. Bers
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
| | - Julie Bossuyt
- Department of PharmacologyUniversity of CaliforniaDavisCAUSA
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Kazemi-Lari MA, Shimkunas R, Jian Z, Hegyi B, Izu L, Shaw JA, Wineman AS, Chen-Izu Y. Modeling Cardiomyocyte Mechanics and Autoregulation of Contractility by Mechano-Chemo-Transduction Feedback. iScience 2022; 25:104667. [PMID: 35860762 PMCID: PMC9289640 DOI: 10.1016/j.isci.2022.104667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 05/22/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022] Open
Abstract
The heart pumps blood into circulation against vascular resistance and actively regulates the contractile force to compensate for mechanical load changes. Our experimental data show that cardiomyocytes have a mechano-chemo-transduction (MCT) mechanism that increases intracellular Ca2+ transient to enhance contractility in response to increased mechanical load. This study advances the cardiac excitation- Ca2+ signaling-contraction (E-C) coupling model on conceptual and technical fronts. First, we developed analytical and computational models to perform 3-dimensional mechanical analysis of cardiomyocytes contracting in a viscoelastic medium under mechanical load. Next, we proposed an MCT feedback loop in the E-C coupling dynamic system to shift the feedforward paradigm of cardiac E-C coupling to an autoregulation model. Our combined modeling and experimental studies reveal that MCT enables autoregulation of E-C coupling and contractility in single cardiomyocytes, which underlies the heart’s intrinsic autoregulation in compensatory response to load changes in order to maintain the stroke volume and cardiac output. Excitation-contraction (E-C) coupling has mechano-chemo-transduction (MCT) feedback MCT feedback enables autoregulation of E-C coupling when contracting under load Models for 3D mechanical analyses of cardiomyocytes contraction Shifts the paradigm of cardiac E-C coupling from feedforward to autoregulation model
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13
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Art Decoration Design of Electrochemical Silicon Oxide Ceramic Sculpture Based on 3D Printing Technology. J CHEM-NY 2022. [DOI: 10.1155/2022/9728402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In order to solve the art decoration design of silicon oxide ceramic sculpture, a method for silicon oxide ceramic sculpture based on 3D printing technology is proposed. Firstly, the density of photosensitive resin premix before curing was measured by pycnometer method; the photosensitive resin was coated on tinplate and then put into a self-made UV curing box for curing. Secondly, the critical exposure and critical transmission depth of photosensitive resin without formula are calculated. Finally, the viscosity of ceramic slurry was measured by mixing S2 photosensitive resin formula with ceramic powder with different nano silica content. It is proved that the addition of nano silica powder can promote the decomposition of quartz glass and increase the sintering degree of the ceramic core. The primary sintering shrinkage of ceramic core gradually increases with the increase of nano silica content. In the length direction, the shrinkage increases from 3.33% to 5.61%; in the width direction, the shrinkage increases from 2.98% to 4.74%; and in the height direction, the shrinkage increases from 3.18% to 5.00%.
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Single cardiomyocytes from papillary muscles show lower preload-dependent activation of force compared to cardiomyocytes from the left ventricular free wall. J Mol Cell Cardiol 2022; 166:127-136. [DOI: 10.1016/j.yjmcc.2022.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 02/05/2022] [Accepted: 02/22/2022] [Indexed: 01/21/2023]
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Khokhlova A, Myachina T, Volzhaninov D, Butova X, Kochurova A, Berg V, Gette I, Moroz G, Klinova S, Minigalieva I, Solovyova O, Danilova I, Sokolova K, Kopylova G, Shchepkin D. Type 1 Diabetes Impairs Cardiomyocyte Contractility in the Left and Right Ventricular Free Walls but Preserves It in the Interventricular Septum. Int J Mol Sci 2022; 23:ijms23031719. [PMID: 35163643 PMCID: PMC8836009 DOI: 10.3390/ijms23031719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 12/14/2022] Open
Abstract
Type 1 diabetes (T1D) leads to ischemic heart disease and diabetic cardiomyopathy. We tested the hypothesis that T1D differently affects the contractile function of the left and right ventricular free walls (LV, RV) and the interventricular septum (IS) using a rat model of alloxan-induced T1D. Single-myocyte mechanics and cytosolic Ca2+ concentration transients were studied on cardiomyocytes (CM) from LV, RV, and IS in the absence and presence of mechanical load. In addition, we analyzed the phosphorylation level of sarcomeric proteins and the characteristics of the actin-myosin interaction. T1D similarly affected the characteristics of actin-myosin interaction in all studied regions, decreasing the sliding velocity of native thin filaments over myosin in an in vitro motility assay and its Ca2+ sensitivity. A decrease in the thin-filament velocity was associated with increased expression of β-myosin heavy-chain isoform. However, changes in the mechanical function of single ventricular CM induced by T1D were different. T1D depressed the contractility of CM from LV and RV; it decreased the auxotonic tension amplitude and the slope of the active tension–length relationship. Nevertheless, the contractile function of CM from IS was principally preserved.
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Affiliation(s)
- Anastasia Khokhlova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
- Institute of Physics and Technology, Ural Federal University, Mira 19, 620002 Yekaterinburg, Russia
- Correspondence:
| | - Tatiana Myachina
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Denis Volzhaninov
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Xenia Butova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Anastasia Kochurova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Valentina Berg
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Irina Gette
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Gleb Moroz
- Institute of Natural Sciences and Mathematics, Ural Federal University, Mira 19, 620002 Yekaterinburg, Russia;
| | - Svetlana Klinova
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Popova 30, 620014 Yekaterinburg, Russia; (S.K.); (I.M.)
| | - Ilzira Minigalieva
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Popova 30, 620014 Yekaterinburg, Russia; (S.K.); (I.M.)
| | - Olga Solovyova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
- Institute of Physics and Technology, Ural Federal University, Mira 19, 620002 Yekaterinburg, Russia
- Institute of Natural Sciences and Mathematics, Ural Federal University, Mira 19, 620002 Yekaterinburg, Russia;
| | - Irina Danilova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Ksenia Sokolova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Galina Kopylova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
| | - Daniil Shchepkin
- Institute of Immunology and Physiology, Russian Academy of Sciences, Pervomajskaya 106, 620049 Yekaterinburg, Russia; (T.M.); (D.V.); (X.B.); (A.K.); (V.B.); (I.G.); (O.S.); (I.D.); (K.S.); (G.K.); (D.S.)
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Wright PT, Gorelik J, Harding SE. Electrophysiological Remodeling: Cardiac T-Tubules and ß-Adrenoceptors. Cells 2021; 10:cells10092456. [PMID: 34572106 PMCID: PMC8468945 DOI: 10.3390/cells10092456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 01/09/2023] Open
Abstract
Beta-adrenoceptors (βAR) are often viewed as archetypal G-protein coupled receptors. Over the past fifteen years, investigations in cardiovascular biology have provided remarkable insights into this receptor family. These studies have shifted pharmacological dogma, from one which centralized the receptor to a new focus on structural micro-domains such as caveolae and t-tubules. Important studies have examined, separately, the structural compartmentation of ion channels and βAR. Despite links being assumed, relatively few studies have specifically examined the direct link between structural remodeling and electrical remodeling with a focus on βAR. In this review, we will examine the nature of receptor and ion channel dysfunction on a substrate of cardiomyocyte microdomain remodeling, as well as the likely ramifications for cardiac electrophysiology. We will then discuss the advances in methodologies in this area with a specific focus on super-resolution microscopy, fluorescent imaging, and new approaches involving microdomain specific, polymer-based agonists. The advent of powerful computational modelling approaches has allowed the science to shift from purely empirical work, and may allow future investigations based on prediction. Issues such as the cross-reactivity of receptors and cellular heterogeneity will also be discussed. Finally, we will speculate as to the potential developments within this field over the next ten years.
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Affiliation(s)
- Peter T. Wright
- School of Life & Health Sciences, University of Roehampton, Holybourne Avenue, London SW15 4JD, UK;
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
| | - Julia Gorelik
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
| | - Sian E. Harding
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
- Correspondence:
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