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Uzelac I, Crowley CJ, Iravanian S, Kim TY, Cho HC, Fenton FH. Methodology for Cross-Talk Elimination in Simultaneous Voltage and Calcium Optical Mapping Measurements With Semasbestic Wavelengths. Front Physiol 2022; 13:812968. [PMID: 35222080 PMCID: PMC8874316 DOI: 10.3389/fphys.2022.812968] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/03/2022] [Indexed: 02/04/2023] Open
Abstract
Most cardiac arrhythmias at the whole heart level result from alteration of cell membrane ionic channels and intracellular calcium concentration ([Ca2+] i ) cycling with emerging spatiotemporal behavior through tissue-level coupling. For example, dynamically induced spatial dispersion of action potential duration, QT prolongation, and alternans are clinical markers for arrhythmia susceptibility in regular and heart-failure patients that originate due to changes of the transmembrane voltage (V m) and [Ca2+] i . We present an optical-mapping methodology that permits simultaneous measurements of the V m - [Ca2+] i signals using a single-camera without cross-talk, allowing quantitative characterization of favorable/adverse cell and tissue dynamical effects occurring from remodeling and/or drugs in heart failure. We demonstrate theoretically and experimentally in six different species the existence of a family of excitation wavelengths, we termed semasbestic, that give no change in signal for one dye, and thus can be used to record signals from another dye, guaranteeing zero cross-talk.
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Affiliation(s)
- Ilija Uzelac
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
| | | | - Shahriar Iravanian
- Division of Cardiology, Section of Electrophysiology, Emory University Hospital, Atlanta, GA, United States
| | - Tae Yun Kim
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Hee Cheol Cho
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
- Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, United States
- The Sibley Heart Center, Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Flavio H. Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, GA, United States
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Role of ranolazine in heart failure: From cellular to clinic perspective. Eur J Pharmacol 2022; 919:174787. [PMID: 35114190 DOI: 10.1016/j.ejphar.2022.174787] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/25/2021] [Accepted: 01/25/2022] [Indexed: 12/17/2022]
Abstract
Ranolazine was approved by the US Food and Drug Administration as an antianginal drug in 2006, and has been used since in certain groups of patients with stable angina. The therapeutic action of ranolazine was initially attributed to inhibitory effects on fatty acids metabolism. As investigations went on, however, it developed that the main beneficial effects of ranolazine arise from its action on the late sodium current in the heart. Since late sodium currents were discovered to be involved in various heart pathologies such as ischemia, arrhythmias, systolic and diastolic dysfunctions, and all these conditions are associated with heart failure, ranolazine has in some way been tested either directly or indirectly on heart failure in numerous experimental and clinical studies. As the heart continuously remodels following any sort of severe injury, the inhibition by ranolazine of the underlying mechanisms of cardiac remodeling including ion disturbances, oxidative stress, inflammation, apoptosis, fibrosis, metabolic dysregulation, and neurohormonal impairment are discussed, along with unresolved issues. A projection of pathologies targeted by ranolazine from cellular level to clinical is provided in this review.
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Yamakawa S, Wu D, Dasgupta M, Pedamallu H, Gupta B, Modi R, Mufti M, O'Callaghan C, Frisk M, Louch WE, Arora R, Shiferaw Y, Burrell A, Ryan J, Nelson L, Chow M, Shah SJ, Aistrup G, Zhou J, Marszalec W, Wasserstrom JA. Role of t-tubule remodeling on mechanisms of abnormal calcium release during heart failure development in canine ventricle. Am J Physiol Heart Circ Physiol 2021; 320:H1658-H1669. [PMID: 33635163 PMCID: PMC8260383 DOI: 10.1152/ajpheart.00946.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/16/2021] [Accepted: 02/22/2021] [Indexed: 11/22/2022]
Abstract
The goal of this work was to investigate the role of t-tubule (TT) remodeling in abnormal Ca2+ cycling in ventricular myocytes of failing dog hearts. Heart failure (HF) was induced using rapid right ventricular pacing. Extensive changes in echocardiographic parameters, including left and right ventricular dilation and systolic dysfunction, diastolic dysfunction, elevated left ventricular filling pressures, and abnormal cardiac mechanics, indicated that severe HF developed. TT loss was extensive when measured as the density of total cell volume, derived from three-dimensional confocal image analysis, and significantly increased the distances in the cell interior to closest cell membrane. Changes in Ca2+ transients indicated increases in heterogeneity of Ca2+ release along the cell length. When critical properties of Ca2+ release variability were plotted as a function of TT organization, there was a complex, nonlinear relationship between impaired calcium release and decreasing TT organization below a certain threshold of TT organization leading to increased sensitivity in Ca2+ release below a TT density threshold of 1.5%. The loss of TTs was also associated with a greater incidence of triggered Ca2+ waves during rapid pacing. Finally, virtually all of these observations were replicated by acute detubulation by formamide treatment, indicating an important role of TT remodeling in impaired Ca2+ cycling. We conclude that TT remodeling itself is a major contributor to abnormal Ca2+ cycling in HF, reducing myocardial performance. The loss of TTs is also responsible for a greater incidence of triggered Ca2+ waves that may play a role in ventricular arrhythmias arising in HF.NEW & NOTEWORTHY Three-dimensional analysis of t-tubule density showed t-tubule disruption throughout the whole myocyte in failing dog ventricle. A double-linear relationship between Ca2+ release and t-tubule density displays a steeper slope at t-tubule densities below a threshold value (∼1.5%) above which there is little effect on Ca2+ release (T-tubule reserve). T-tubule loss increases incidence of triggered Ca2+ waves. Chemically induced t-tubule disruption suggests that t-tubule loss alone is a critical component of abnormal Ca2+ cycling in heart failure.
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Affiliation(s)
- Sean Yamakawa
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Daniel Wu
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Mona Dasgupta
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Havisha Pedamallu
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Binita Gupta
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rishi Modi
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Maryam Mufti
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Caitlin O'Callaghan
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K. G. Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K. G. Jebsen Cardiac Research Center, University of Oslo, Oslo, Norway
| | - William E Louch
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rishi Arora
- California State University Northridge, Los Angeles, California
| | - Yohannes Shiferaw
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Amy Burrell
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Juliet Ryan
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Lauren Nelson
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Madeleine Chow
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Sanjiv J Shah
- The Masonic Medical Research Institute, Utica, New York
| | - Gary Aistrup
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Junlan Zhou
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - William Marszalec
- Feinberg Cardiovascular and Renal Research Institute and Department of Medicine (Cardiology), Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Ischemia/Reperfusion Injury following Acute Myocardial Infarction: A Critical Issue for Clinicians and Forensic Pathologists. Mediators Inflamm 2017; 2017:7018393. [PMID: 28286377 PMCID: PMC5327760 DOI: 10.1155/2017/7018393] [Citation(s) in RCA: 257] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/26/2016] [Accepted: 11/30/2016] [Indexed: 12/27/2022] Open
Abstract
Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality. Reperfusion strategies are the current standard therapy for AMI. However, they may result in paradoxical cardiomyocyte dysfunction, known as ischemic reperfusion injury (IRI). Different forms of IRI are recognized, of which only the first two are reversible: reperfusion-induced arrhythmias, myocardial stunning, microvascular obstruction, and lethal myocardial reperfusion injury. Sudden death is the most common pattern for ischemia-induced lethal ventricular arrhythmias during AMI. The exact mechanisms of IRI are not fully known. Molecular, cellular, and tissue alterations such as cell death, inflammation, neurohumoral activation, and oxidative stress are considered to be of paramount importance in IRI. However, comprehension of the exact pathophysiological mechanisms remains a challenge for clinicians. Furthermore, myocardial IRI is a critical issue also for forensic pathologists since sudden death may occur despite timely reperfusion following AMI, that is one of the most frequently litigated areas of cardiology practice. In this paper we explore the literature regarding the pathophysiology of myocardial IRI, focusing on the possible role of the calpain system, oxidative-nitrosative stress, and matrix metalloproteinases and aiming to foster knowledge of IRI pathophysiology also in terms of medicolegal understanding of sudden deaths following AMI.
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Wu CYC, Chen B, Jiang YP, Jia Z, Martin DW, Liu S, Entcheva E, Song LS, Lin RZ. Calpain-dependent cleavage of junctophilin-2 and T-tubule remodeling in a mouse model of reversible heart failure. J Am Heart Assoc 2014; 3:e000527. [PMID: 24958777 PMCID: PMC4309042 DOI: 10.1161/jaha.113.000527] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background A highly organized transverse tubule (T‐tubule) network is necessary for efficient Ca2+‐induced Ca2+ release and synchronized contraction of ventricular myocytes. Increasing evidence suggests that T‐tubule remodeling due to junctophilin‐2 (JP‐2) downregulation plays a critical role in the progression of heart failure. However, the mechanisms underlying JP‐2 dysregulation remain incompletely understood. Methods and Results A mouse model of reversible heart failure that is driven by conditional activation of the heterotrimeric G protein Gαq in cardiac myocytes was used in this study. Mice with activated Gαq exhibited disruption of the T‐tubule network and defects in Ca2+ handling that culminated in heart failure compared with wild‐type mice. Activation of Gαq/phospholipase Cβ signaling increased the activity of the Ca2+‐dependent protease calpain, leading to the proteolytic cleavage of JP‐2. A novel calpain cleavage fragment of JP‐2 is detected only in hearts with constitutive Gαq signaling to phospholipase Cβ. Termination of the Gαq signal was followed by normalization of the JP‐2 protein level, repair of the T‐tubule network, improvements in Ca2+ handling, and reversal of heart failure. Treatment of mice with a calpain inhibitor prevented Gαq‐dependent JP‐2 cleavage, T‐tubule disruption, and the development of heart failure. Conclusions Disruption of the T‐tubule network in heart failure is a reversible process. Gαq‐dependent activation of calpain and subsequent proteolysis of JP‐2 appear to be the molecular mechanism that leads to T‐tubule remodeling, Ca2+ handling dysfunction, and progression to heart failure in this mouse model.
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Affiliation(s)
- Chia-Yen C Wu
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.)
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (B.C., L.S.S.)
| | - Ya-Ping Jiang
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.)
| | - Zhiheng Jia
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY (Z.J., E.E.)
| | - Dwight W Martin
- Department of Medicine and Proteomics Center, Stony Brook University, Stony Brook, NY (D.W.M.)
| | - Shengnan Liu
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.)
| | - Emilia Entcheva
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.) Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY (Z.J., E.E.)
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA (B.C., L.S.S.)
| | - Richard Z Lin
- Department of Physiology and Biophysics and Institute of Molecular Cardiology, Stony Brook University, Stony Brook, NY (C.Y.C.W., Y.P.J., S.L., E.E., R.Z.L.) Department of Veterans Affairs Medical Center, Northport, NY (R.Z.L.)
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Aistrup GL, Gupta DK, Kelly JE, O'Toole MJ, Nahhas A, Chirayil N, Misener S, Beussink L, Singh N, Ng J, Reddy M, Mongkolrattanothai T, El-Bizri N, Rajamani S, Shryock JC, Belardinelli L, Shah SJ, Wasserstrom JA. Inhibition of the late sodium current slows t-tubule disruption during the progression of hypertensive heart disease in the rat. Am J Physiol Heart Circ Physiol 2013; 305:H1068-79. [PMID: 23873796 DOI: 10.1152/ajpheart.00401.2013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The treatment of heart failure (HF) is challenging and morbidity and mortality are high. The goal of this study was to determine if inhibition of the late Na(+) current with ranolazine during early hypertensive heart disease might slow or stop disease progression. Spontaneously hypertensive rats (aged 7 mo) were subjected to echocardiographic study and then fed either control chow (CON) or chow containing 0.5% ranolazine (RAN) for 3 mo. Animals were then restudied, and each heart was removed for measurements of t-tubule organization and Ca(2+) transients using confocal microscopy of the intact heart. RAN halted left ventricular hypertrophy as determined from both echocardiographic and cell dimension (length but not width) measurements. RAN reduced the number of myocytes with t-tubule disruption and the proportion of myocytes with defects in intracellular Ca(2+) cycling. RAN also prevented the slowing of the rate of restitution of Ca(2+) release and the increased vulnerability to rate-induced Ca(2+) alternans. Differences between CON- and RAN-treated animals were not a result of different expression levels of voltage-dependent Ca(2+) channel 1.2, sarco(endo)plasmic reticulum Ca(2+)-ATPase 2a, ryanodine receptor type 2, Na(+)/Ca(2+) exchanger-1, or voltage-gated Na(+) channel 1.5. Furthermore, myocytes with defective Ca(2+) transients in CON rats showed improved Ca(2+) cycling immediately upon acute exposure to RAN. Increased late Na(+) current likely plays a role in the progression of cardiac hypertrophy, a key pathological step in the development of HF. Early, chronic inhibition of this current slows both hypertrophy and development of ultrastructural and physiological defects associated with the progression to HF.
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Affiliation(s)
- Gary L Aistrup
- Department of Medicine (Cardiologyand the Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, Illinois; and
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Shaw RM, Colecraft HM. L-type calcium channel targeting and local signalling in cardiac myocytes. Cardiovasc Res 2013; 98:177-86. [PMID: 23417040 DOI: 10.1093/cvr/cvt021] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In the heart, Ca(2+) influx via Ca(V)1.2 L-type calcium channels (LTCCs) is a multi-functional signal that triggers muscle contraction, controls action potential duration, and regulates gene expression. The use of LTCC Ca(2+) as a multi-dimensional signalling molecule in the heart is complicated by several aspects of cardiac physiology. Cytosolic Ca(2+) continuously cycles between ~100 nM and ~1 μM with each heartbeat due to Ca(2+) linked signalling from LTCCs to ryanodine receptors. This rapid cycling raises the question as to how cardiac myocytes distinguish the Ca(2+) fluxes originating through L-type channels that are dedicated to contraction from Ca(2+) fluxes originating from other L-type channels that are used for non-contraction-related signalling. In general, disparate Ca(2+) sources in cardiac myocytes such as current through differently localized LTCCs as well as from IP3 receptors can signal selectively to Ca(2+)-dependent effectors in local microdomains that can be impervious to the cytoplasmic Ca(2+) transients that drive contraction. A particular challenge for diversified signalling via cardiac LTCCs is that they are voltage-gated and, therefore, open and presumably flood their microdomains with Ca(2+) with each action potential. Thus spatial localization of Cav1.2 channels to different types of microdomains of the ventricular cardiomyocyte membrane as well as the existence of particular macromolecular complexes in each Cav1.2 microdomain are important to effect different types of Cav1.2 signalling. In this review we examine aspects of Cav1.2 structure, targeting and signalling in two specialized membrane microdomains--transverse tubules and caveolae.
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Affiliation(s)
- Robin M Shaw
- Cardiovascular Research Institute and Department of Medicine, University of California, San Francisco, CA 94143, USA
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