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Liu YB, Wang Q, Song YL, Song XM, Fan YC, Kong L, Zhang JS, Li S, Lv YJ, Li ZY, Dai JY, Qiu ZK. Abnormal phosphorylation / dephosphorylation and Ca 2+ dysfunction in heart failure. Heart Fail Rev 2024; 29:751-768. [PMID: 38498262 DOI: 10.1007/s10741-024-10395-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2024] [Indexed: 03/20/2024]
Abstract
Heart failure (HF) can be caused by a variety of causes characterized by abnormal myocardial systole and diastole. Ca2+ current through the L-type calcium channel (LTCC) on the membrane is the initial trigger signal for a cardiac cycle. Declined systole and diastole in HF are associated with dysfunction of myocardial Ca2+ function. This disorder can be correlated with unbalanced levels of phosphorylation / dephosphorylation of LTCC, endoplasmic reticulum (ER), and myofilament. Kinase and phosphatase activity changes along with HF progress, resulting in phased changes in the degree of phosphorylation / dephosphorylation. It is important to realize the phosphorylation / dephosphorylation differences between a normal and a failing heart. This review focuses on phosphorylation / dephosphorylation changes in the progression of HF and summarizes the effects of phosphorylation / dephosphorylation of LTCC, ER function, and myofilament function in normal conditions and HF based on previous experiments and clinical research. Also, we summarize current therapeutic methods based on abnormal phosphorylation / dephosphorylation and clarify potential therapeutic directions.
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Affiliation(s)
- Yan-Bing Liu
- Interventional Medical Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China
- Medical College, Qingdao University, Qingdao, China
| | - Qian Wang
- Medical College, Qingdao University, Qingdao, China
| | - Yu-Ling Song
- Department of Pediatrics, Huantai County Hospital of Traditional Chinese Medicine, Zibo, China
| | | | - Yu-Chen Fan
- Medical College, Qingdao University, Qingdao, China
| | - Lin Kong
- Medical College, Qingdao University, Qingdao, China
| | | | - Sheng Li
- Medical College, Qingdao University, Qingdao, China
| | - Yi-Ju Lv
- Medical College, Qingdao University, Qingdao, China
| | - Ze-Yang Li
- Medical College, Qingdao University, Qingdao, China
| | - Jing-Yu Dai
- Department of Oncology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China.
| | - Zhen-Kang Qiu
- Interventional Medical Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao, 266003, Shandong Province, China.
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Masjoan Juncos JX, Nadeem F, Shakil S, El-Husari M, Zafar I, Louch WE, Halade GV, Zaky A, Ahmad A, Ahmad S. Myocardial SERCA2 Protects Against Cardiac Damage and Dysfunction Caused by Inhaled Bromine. J Pharmacol Exp Ther 2024; 390:146-158. [PMID: 38772719 PMCID: PMC11192580 DOI: 10.1124/jpet.123.002084] [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: 12/22/2023] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 05/23/2024] Open
Abstract
Myocardial sarcoendoplasmic reticulum calcium ATPase 2 (SERCA2) activity is critical for heart function. We have demonstrated that inhaled halogen (chlorine or bromine) gases inactivate SERCA2, impair calcium homeostasis, increase proteolysis, and damage the myocardium ultimately leading to cardiac dysfunction. To further elucidate the mechanistic role of SERCA2 in halogen-induced myocardial damage, we used bromine-exposed cardiac-specific SERCA2 knockout (KO) mice [tamoxifen-administered SERCA2 (flox/flox) Tg (αMHC-MerCreMer) mice] and compared them to the oil-administered controls. We performed echocardiography and hemodynamic analysis to investigate cardiac function 24 hours after bromine (600 ppm for 30 minutes) exposure and measured cardiac injury markers in plasma and proteolytic activity in cardiac tissue and performed electron microscopy of the left ventricle (LV). Cardiac-specific SERCA2 knockout mice demonstrated enhanced toxicity to bromine. Bromine exposure increased ultrastructural damage, perturbed LV shape geometry, and demonstrated acutely increased phosphorylation of phospholamban in the KO mice. Bromine-exposed KO mice revealed significantly enhanced mean arterial pressure and sphericity index and decreased LV end diastolic diameter and LV end systolic pressure when compared with the bromine-exposed control FF mice. Strain analysis showed loss of synchronicity, evidenced by an irregular endocardial shape in systole and irregular vector orientation of contractile motion across different segments of the LV in KO mice, both at baseline and after bromine exposure. These studies underscore the critical role of myocardial SERCA2 in preserving cardiac ultrastructure and function during toxic halogen gas exposures. SIGNIFICANCE STATEMENT: Due to their increased industrial production and transportation, halogens such as chlorine and bromine pose an enhanced risk of exposure to the public. Our studies have demonstrated that inhalation of these halogens leads to the inactivation of cardiopulmonary SERCA2 and results in calcium overload. Using cardiac-specific SERCA2 KO mice, these studies further validated the role of SERCA2 in bromine-induced myocardial injury. These studies highlight the increased susceptibility of individuals with pathological loss of cardiac SERCA2 to the effects of bromine.
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Affiliation(s)
- Juan Xavier Masjoan Juncos
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Fahad Nadeem
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Shazia Shakil
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Malik El-Husari
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Iram Zafar
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - William E Louch
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Ganesh V Halade
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Ahmed Zaky
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Aftab Ahmad
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
| | - Shama Ahmad
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, Alabama (J.X.M.J., F.N., S.S., M.E.-H., I.Z, A.Z., A.A., S.A.); Institute for Experimental Medical Research, Oslo University Hospital and KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway (W.E.L.); and Division of Cardiovascular Sciences, University of South Florida, Tampa, Florida (G.V.H.)
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3
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Magtibay K, Massé S, Nanthakumar K, Umapathy K. Pro-arrhythmic role of adrenergic spatial densities in the human atria: An in-silico study. PLoS One 2023; 18:e0290676. [PMID: 37624832 PMCID: PMC10456151 DOI: 10.1371/journal.pone.0290676] [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: 06/06/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023] Open
Abstract
Chronic stress among young patients (≤ 45 years old) could result in autonomic dysfunction. Autonomic dysfunction could be exhibited via sympathetic hyperactivity, sympathetic nerve sprouting, and diffuse adrenergic stimulation in the atria. Adrenergic spatial densities could alter atrial electrophysiology and increase arrhythmic susceptibility. Therefore, we examined the role of adrenergic spatial densities in creating arrhythmogenic substrates in silico. We simulated three 25 cm2 atrial sheets with varying adrenergic spatial densities (ASD), activation rates, and external transmembrane currents. We measured their effects on spatial and temporal heterogeneity of action potential durations (APD) at 50% and 20%. Increasing ASD shortens overall APD, and maximum spatial heterogeneity (31%) is achieved at 15% ASD. The addition of a few (5% to 10%) adrenergic elements decreases the excitation threshold, below 18 μA/cm2, while ASDs greater than 10% increase their excitation threshold up to 22 μA/cm2. Increase in ASD during rapid activation increases APD50 and APD20 by 21% and 41%, respectively. Activation times of captured beats during rapid activation could change by as much as 120 ms from the baseline cycle length. Rapidly activated atrial sheets with high ASDs significantly increase temporal heterogeneity of APD50 and APD20. Rapidly activated atrial sheets with 10% ASD have a high likelihood (0.7 ± 0.06) of fragmenting otherwise uniform wavefronts due to the transient inexcitability of adrenergically stimulated elements, producing an effective functional block. The likelihood of wave fragmentation due to ASD highly correlates with the spatial variations of APD20 (ρ = 0.90, p = 0.04). Our simulations provide a novel insight into the contributions of ASD to spatial and temporal heterogeneities of APDs, changes in excitation thresholds, and a potential explanation for wave fragmentation in the human atria due to sympathetic hyperactivity. Our work may aid in elucidating an electrophysiological link to arrhythmia initiation due to chronic stress among young patients.
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Affiliation(s)
- Karl Magtibay
- Biomedical Signal and Image Processing Laboratory, Faculty of Engineering and Architectural Science, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Stéphane Massé
- Toby Hull Cardiac Fibrillation Management Laboratory, Department of Medicine/Cardiology, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Kumaraswamy Nanthakumar
- Toby Hull Cardiac Fibrillation Management Laboratory, Department of Medicine/Cardiology, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
| | - Karthikeyan Umapathy
- Biomedical Signal and Image Processing Laboratory, Department of Electrical, Computer, and Biomedical Engineering, Faculty of Engineering and Architectural Science, Toronto Metropolitan University, Toronto, Ontario, Canada
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4
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Roopnarine O, Yuen SL, Thompson AR, Roelike LN, Rebbeck RT, Bidwell PA, Aldrich CC, Cornea RL, Thomas DD. Fluorescence lifetime FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators. Sci Rep 2023; 13:10673. [PMID: 37393380 PMCID: PMC10314922 DOI: 10.1038/s41598-023-37704-x] [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: 02/16/2023] [Accepted: 06/26/2023] [Indexed: 07/03/2023] Open
Abstract
We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA's function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening two different small validation libraries using novel microplate readers that detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from FRET-HTS of 50,000 compounds using the same biosensor, with hit compounds functionally evaluated using assays for Ca2+-ATPase activity and Ca2+-transport. We focused on 18 hit compounds, from which we identified eight structurally unique scaffolds and four scaffold classes as SERCA modulators, approximately half of which are activators and half are inhibitors. Five of these compounds were identified as promising SERCA activators, one of which activates Ca2+-transport even more than Ca2+-ATPase activity thus improving SERCA efficiency. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.
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Affiliation(s)
- Osha Roopnarine
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Samantha L Yuen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Andrew R Thompson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Lauren N Roelike
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Philip A Bidwell
- Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
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5
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Rajanathan R, Riera CVI, Pedersen TM, Staehr C, Bouzinova EV, Nyengaard JR, Thomsen MB, Bøtker HE, Matchkov VV. Hypercontractile Cardiac Phenotype in Mice with Migraine-Associated Mutation in the Na +,K +-ATPase α 2-Isoform. Cells 2023; 12:cells12081108. [PMID: 37190017 DOI: 10.3390/cells12081108] [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: 03/13/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
Two α-isoforms of the Na+,K+-ATPase (α1 and α2) are expressed in the cardiovascular system, and it is unclear which isoform is the preferential regulator of contractility. Mice heterozygous for the familial hemiplegic migraine type 2 (FHM2) associated mutation in the α2-isoform (G301R; α2+/G301R mice) have decreased expression of cardiac α2-isoform but elevated expression of the α1-isoform. We aimed to investigate the contribution of the α2-isoform function to the cardiac phenotype of α2+/G301R hearts. We hypothesized that α2+/G301R hearts exhibit greater contractility due to reduced expression of cardiac α2-isoform. Variables for contractility and relaxation of isolated hearts were assessed in the Langendorff system without and in the presence of ouabain (1 µM). Atrial pacing was performed to investigate rate-dependent changes. The α2+/G301R hearts displayed greater contractility than WT hearts during sinus rhythm, which was rate-dependent. The inotropic effect of ouabain was more augmented in α2+/G301R hearts than in WT hearts during sinus rhythm and atrial pacing. In conclusion, cardiac contractility was greater in α2+/G301R hearts than in WT hearts under resting conditions. The inotropic effect of ouabain was rate-independent and enhanced in α2+/G301R hearts, which was associated with increased systolic work.
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Affiliation(s)
| | - Clàudia Vilaseca I Riera
- Department of Basic Science, School of Medicine and Health Sciences, International University of Catalonia, 08195 Barcelona, Spain
| | | | - Christian Staehr
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | | | - Jens Randel Nyengaard
- Department of Clinical Medicine, Core Center for Molecular Morphology, Section for Stereology and Microscopy, Aarhus University, 8000 Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Morten B Thomsen
- Biomedical Sciences, University of Copenhagen, 1168 Copenhagen, Denmark
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital, 8200 Aarhus, Denmark
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6
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Roopnarine O, Yuen SL, Thompson AR, Roelike LN, Rebbeck RT, Bidwell PA, Aldrich CC, Cornea RL, Thomas DD. FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators. RESEARCH SQUARE 2023:rs.3.rs-2596384. [PMID: 36909610 PMCID: PMC10002828 DOI: 10.21203/rs.3.rs-2596384/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA’s function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening a small validation library using novel microplate readers that can detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from a 50,000-compound screen using the same biosensor, with hit compounds functionally evaluated using Ca 2+ -ATPase and Ca 2+ -transport assays. We focused on 18 hit compounds, from which we identified eight structurally unique compounds and four compound classes as SERCA modulators, approximately half of which are activators and half are inhibitors. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.
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7
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Roopnarine O, Yuen SL, Thompson AR, Roelike LN, Rebbeck RT, Bidwell PA, Aldrich CC, Cornea RL, Thomas DD. FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.22.529557. [PMID: 36865289 PMCID: PMC9980093 DOI: 10.1101/2023.02.22.529557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA’s function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening a small validation library using novel microplate readers that can detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from a 50,000-compound screen using the same biosensor, with hit compounds functionally evaluated using Ca 2+ -ATPase and Ca 2+ -transport assays. We focused on 18 hit compounds, from which we identified eight structurally unique compounds and four compound classes as SERCA modulators, approximately half of which are activators and half are inhibitors. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.
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8
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Arici M, Ferrandi M, Barassi P, Hsu SC, Torre E, Luraghi A, Ronchi C, Chang GJ, Peri F, Ferrari P, Bianchi G, Rocchetti M, Zaza A. Istaroxime Metabolite PST3093 Selectively Stimulates SERCA2a and Reverses Disease-Induced Changes in Cardiac Function. J Pharmacol Exp Ther 2023; 384:231-244. [PMID: 36153005 DOI: 10.1124/jpet.122.001335] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/11/2022] [Accepted: 08/01/2022] [Indexed: 01/03/2023] Open
Abstract
Heart failure (HF) therapeutic toolkit would strongly benefit from the availability of ino-lusitropic agents with a favorable pharmacodynamics and safety profile. Istaroxime is a promising agent, which combines Na+/K+ pump inhibition with sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) stimulation; however, it has a very short half-life and extensive metabolism to a molecule named PST3093. The present work aims to investigate whether PST3093 still retains the pharmacodynamic and pharmacokinetic properties of its parent compound. We studied PST3093 for its effects on SERCA2a and Na+/K+ ATPase activities, Ca2+ dynamics in isolated myocytes, and hemodynamic effects in an in vivo rat model of diabetic [streptozotocin (STZ)-induced] cardiomyopathy. Istaroxime infusion in HF patients led to accumulation of PST3093 in the plasma; clearance was substantially slower for PST3093 than for istaroxime. In cardiac rat preparations, PST3093 did not inhibit the Na+/K+ ATPase activity but retained SERCA2a stimulatory activity. In in vivo echocardiographic assessment, PST3093 improved overall cardiac performance and reversed most STZ-induced abnormalities. PST3093 intravenous toxicity was considerably lower than that of istaroxime, and it failed to significantly interact with 50 off-targets. Overall, PST3093 is a "selective" SERCA2a activator, the prototype of a novel pharmacodynamic category with a potential in the ino-lusitropic approach to HF with prevailing diastolic dysfunction. Its pharmacodynamics are peculiar, and its pharmacokinetics are suitable to prolong the cardiac beneficial effect of istaroxime infusion. SIGNIFICANCE STATEMENT: Heart failure (HF) treatment would benefit from the availability of ino-lusitropic agents with favourable profiles. PST3093 is the main metabolite of istaroxime, a promising agent combining Na+/K+ pump inhibition and sarcoplasmic reticulum Ca2+ ATPase2a (SERCA2a) stimulation. PST3093 shows a longer half-life in human circulation compared to istaroxime, selectively activates SERCA2a, and improves cardiac performance in a model of diabetic cardiomyopathy. Overall, PST3093 as a selective SERCA2a activator can be considered the prototype of a novel pharmacodynamic category for HF treatment.
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Affiliation(s)
- Martina Arici
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Mara Ferrandi
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Paolo Barassi
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Shih-Che Hsu
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Eleonora Torre
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Andrea Luraghi
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Carlotta Ronchi
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Gwo-Jyh Chang
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Francesco Peri
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Patrizia Ferrari
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Giuseppe Bianchi
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Marcella Rocchetti
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
| | - Antonio Zaza
- Department of Biotechnology and Biosciences, Università degli Studi di Milano-Bicocca, Milan, Italy (M.A., E.T., A.L., C.R., F.P., M.R., A.Z.); Windtree Therapeutics Inc., Warrington, Pennsylvania (M.F., P.B., P.F., G.B.); CVie Therapeutics Limited, Taipei, Taiwan (S.-C.H.); Graduate Institute of Clinical Medicinal Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan (G.-J.C.); and Università Vita-Salute San Raffaele, Milan, Italy (G.B.)
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9
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Zaveri S, Srivastava U, Qu YS, Chahine M, Boutjdir M. Pathophysiology of Ca v1.3 L-type calcium channels in the heart. Front Physiol 2023; 14:1144069. [PMID: 37025382 PMCID: PMC10070707 DOI: 10.3389/fphys.2023.1144069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/07/2023] [Indexed: 04/08/2023] Open
Abstract
Ca2+ plays a crucial role in excitation-contraction coupling in cardiac myocytes. Dysfunctional Ca2+ regulation alters the force of contraction and causes cardiac arrhythmias. Ca2+ entry into cardiomyocytes is mediated mainly through L-type Ca2+ channels, leading to the subsequent Ca2+ release from the sarcoplasmic reticulum. L-type Ca2+ channels are composed of the conventional Cav1.2, ubiquitously expressed in all heart chambers, and the developmentally regulated Cav1.3, exclusively expressed in the atria, sinoatrial node, and atrioventricular node in the adult heart. As such, Cav1.3 is implicated in the pathogenesis of sinoatrial and atrioventricular node dysfunction as well as atrial fibrillation. More recently, Cav1.3 de novo expression was suggested in heart failure. Here, we review the functional role, expression levels, and regulation of Cav1.3 in the heart, including in the context of cardiac diseases. We believe that the elucidation of the functional and molecular pathways regulating Cav1.3 in the heart will assist in developing novel targeted therapeutic interventions for the aforementioned arrhythmias.
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Affiliation(s)
- Sahil Zaveri
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY, United States
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, Brooklyn, New York, NY, United States
| | - Ujala Srivastava
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY, United States
| | - Yongxia Sarah Qu
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY, United States
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, Brooklyn, New York, NY, United States
- Department of Cardiology, New York Presbyterian Brooklyn Methodist Hospital, New York, NY, United States
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut Universitaire en Santé Mentale de Québec, Québec, QC, Canada
- Department of Medicine, Faculté de Médecine, Université Laval, Quebec, QC, Canada
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY, United States
- Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, Brooklyn, New York, NY, United States
- Division of Cardiology, Department of Medicine, NYU Grossman School of Medicine, New York, NY, United States
- *Correspondence: Mohamed Boutjdir,
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10
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Averin AS, Konakov MV, Pimenov OY, Galimova MH, Berezhnov AV, Nenov MN, Dynnik VV. Regulation of Papillary Muscle Contractility by NAD and Ammonia Interplay: Contribution of Ion Channels and Exchangers. MEMBRANES 2022; 12:1239. [PMID: 36557146 PMCID: PMC9785361 DOI: 10.3390/membranes12121239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/04/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Various models, including stem cells derived and isolated cardiomyocytes with overexpressed channels, are utilized to analyze the functional interplay of diverse ion currents involved in cardiac automaticity and excitation-contraction coupling control. Here, we used β-NAD and ammonia, known hyperpolarizing and depolarizing agents, respectively, and applied inhibitory analysis to reveal the interplay of several ion channels implicated in rat papillary muscle contractility control. We demonstrated that: 4 mM β-NAD, having no strong impact on resting membrane potential (RMP) and action potential duration (APD90) of ventricular cardiomyocytes, evoked significant suppression of isometric force (F) of paced papillary muscle. Reactive blue 2 restored F to control values, suggesting the involvement of P2Y-receptor-dependent signaling in β-NAD effects. Meantime, 5 mM NH4Cl did not show any effect on F of papillary muscle but resulted in significant RMP depolarization, APD90 shortening, and a rightward shift of I-V relationship for total steady state currents in cardiomyocytes. Paradoxically, NH4Cl, being added after β-NAD and having no effect on RMP, APD, and I-V curve, recovered F to the control values, indicating β-NAD/ammonia antagonism. Blocking of HCN, Kir2.x, and L-type calcium channels, Ca2+-activated K+ channels (SK, IK, and BK), or NCX exchanger reverse mode prevented this effect, indicating consistent cooperation of all currents mediated by these channels and NCX. We suggest that the activation of Kir2.x and HCN channels by extracellular K+, that creates positive and negative feedback, and known ammonia and K+ resemblance, may provide conditions required for the activation of all the chain of channels involved in the interplay. Here, we present a mechanistic model describing an interplay of channels and second messengers, which may explain discovered antagonism of β-NAD and ammonia on rat papillary muscle contractile activity.
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Affiliation(s)
- Alexey S. Averin
- Institute of Theoretical and Experimental Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
| | - Maxim V. Konakov
- Institute of Theoretical and Experimental Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
| | - Oleg Y. Pimenov
- Institute of Theoretical and Experimental Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
| | - Miliausha H. Galimova
- Institute of Theoretical and Experimental Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
| | - Alexey V. Berezhnov
- Institute of Cell Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
| | - Miroslav N. Nenov
- Institute of Theoretical and Experimental Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
| | - Vladimir V. Dynnik
- Institute of Theoretical and Experimental Biophysics, the Russian Academy of Sciences, Pushchino 142290, Russia
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11
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A Large-Scale High-Throughput Screen for Modulators of SERCA Activity. Biomolecules 2022; 12:biom12121789. [PMID: 36551215 PMCID: PMC9776381 DOI: 10.3390/biom12121789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/21/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
The sarco/endoplasmic reticulum Ca-ATPase (SERCA) is a P-type ion pump that transports Ca2+ from the cytosol into the endoplasmic/sarcoplasmic reticulum (ER/SR) in most mammalian cells. It is critically important in muscle, facilitating relaxation and enabling subsequent contraction. Increasing SERCA expression or specific activity can alleviate muscle dysfunction, most notably in the heart, and we seek to develop small-molecule drug candidates that activate SERCA. Therefore, we adapted an NADH-coupled assay, measuring Ca-dependent ATPase activity of SERCA, to high-throughput screening (HTS) format, and screened a 46,000-compound library of diverse chemical scaffolds. This HTS platform yielded numerous hits that reproducibly alter SERCA Ca-ATPase activity, with few false positives. The top 19 activating hits were further tested for effects on both Ca-ATPase and Ca2+ transport, in both cardiac and skeletal SR. Nearly all hits increased Ca2+ uptake in both cardiac and skeletal SR, with some showing isoform specificity. Furthermore, dual analysis of both activities identified compounds with a range of effects on Ca2+-uptake and ATPase, which fit into distinct classifications. Further study will be needed to identify which classifications are best suited for therapeutic use. These results reinforce the need for robust secondary assays and criteria for selection of lead compounds, before undergoing HTS on a larger scale.
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12
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Adegoke TE, Sabinari IW, Usman TO, Abdulkareem TO, Michael OS, Adeyanju OA, Dibia C, Omotoye OO, Oyabambi AO, Olatunji LA. Allopurinol and valproic acid improve cardiac triglyceride and Na +-K +-ATPase activity independent of circulating aldosterone in female rats with glucose intolerance. Arch Physiol Biochem 2022; 128:1283-1289. [PMID: 32447998 DOI: 10.1080/13813455.2020.1767148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Context: Studies have shown that cardiac triglyceride accumulation and impaired Na+-K+-ATPase activity are linked to diabetes- related cardiovascular disease, particularly in women.Objectives: We hypothesised that allopurinol (ALL) and valproic acid (VPA) treatment would improve cardiac triglyceride and Na+-K+-ATPase activity independent of circulating aldosterone in Combined Oral Contraceptive (COC)-induced dysglycemiaMaterials and methods: Rats received COC (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel; po) with or without ALL (1 mg; po) and VPA (20 mg; po) for 6 weeks.Results: COC-treatment led to impaired glucose tolerance, accumulated abdominal fat, dyslipidemia, elevated plasma MDA, PAI-1 and aldosterone levels and also reduced plasma nitric oxide bioavailability and cardiac Na+-K+-ATPase activity. However, either ALL or VPA treatment ameliorated these alterations comparably independent of elevated aldosterone levelDiscussion and conclusion: Our results suggest that either ALL or VPA would improve cardiac TG and Na+-K+-ATPase activity comparably in COC-treated rats, regardless of circulating aldosterone level.
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Affiliation(s)
- Tolulope E Adegoke
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Isiah W Sabinari
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Taofeek O Usman
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
- Department of Physiology, Cardiometabolic Research Unit, College of Health Sciences, Osun State University, Osogbo, Nigeria
| | - Toyyib O Abdulkareem
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Olugbenga S Michael
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
- Department of Physiology, Cardiometabolic Research Unit, College of Health and Medical Sciences, Bowen University, Iwo, Nigeria
| | - Oluwaseun A Adeyanju
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
- Department of Physiology, Cardiometabolic Research Unit, College of Medicine and Health Sciences, Afe Babalola University, Ado-Ekiti, Nigeria
| | - Chinaza Dibia
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Omotola O Omotoye
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Adewumi O Oyabambi
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Lawrence A Olatunji
- Department of Physiology, HOPE Cardiometabolic Research Team, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
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13
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Lopez JR, Linares N, Adams JA, Mijares A. The Role of the Na+/Ca2+ Exchanger in Aberrant Intracellular Ca2+ in Cardiomyocytes of Chagas-Infected Rodents. Front Cell Infect Microbiol 2022; 12:890709. [PMID: 35903196 PMCID: PMC9318578 DOI: 10.3389/fcimb.2022.890709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 06/03/2022] [Indexed: 11/28/2022] Open
Abstract
Chagas disease is produced by the parasite Trypanosoma cruzi (T. cruzi), which is the leading cause of death and morbidity in Latin America. We have shown that in patients with Chagas cardiomyopathy, there is a chronic elevation of diastolic Ca2+ concentration ([Ca2+]d), associated with deterioration to further address this issue, we explored the role Na+/Ca2+ exchanger (NCX). Experiments were carried out in noninfected C57BL/6 mice and infected with blood-derived trypomastigotes of the T. cruzi Y strain. Anesthetized mice were sacrificed and the cardiomyocytes were enzymatically dissociated. Diastolic [Ca2+] ([Ca2+]d) was measured using Ca2+ selective microelectrodes in cardiomyocytes from control mice (CONT) and cardiomyocytes from T. cruzi infected mice in the early acute phase (EAP) at 20 dpi, in the acute phase (AP) at 40 dpi, and in the chronic phase (CP) at 120 dpi. [Ca2+]d was 1.5-times higher in EAP, 2.6-times in AP, and 3.4-times in CP compared to CONT. Exploring the reverse mode activity of NCX, we replaced extracellular Na+ in equivalent amounts with N-methyl-D-glucamine. Reduction of [Na+]e to 65 mM caused an increase in [Ca2+]d of 1.7 times in cardiomyocytes from CONT mice, 2 times in EAP infected mice, 2.4 times in AP infected mice and 2.8 in CP infected mice. The Na+ free solution caused a further elevation of [Ca2+]d of 2.5 times in cardiomyocytes from CONT, 2.8 times in EAP infected mice, 3.1 times in AP infected mice, and 3.3 times in CP infected mice. Extracellular Ca2+ withdrawal reduced [Ca2+]d in both CONT and cardiomyocytes from Chagas-infected mice and prevented the increase in [Ca2+]d induced by Na+ depletion. Preincubation with 10µM KB-R7943 or in 1µM YM-244769 reduced [Ca2+]d in cardiomyocytes from infected mice, but not control mice. Furthermore, both NCX blockers prevented the increase in [Ca2+]d associated with exposure to a solution without Na+. These results suggest that Ca2+ entry through the reverse NCX mode plays a significant role in the observed [Ca2+]d dyshomeostasis in Chagas infected cardiomyocytes. Additionally, NCX inhibitors may be a viable therapeutic approach for treating patients with Chagas cardiomyopathy.
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Affiliation(s)
- Jose R. Lopez
- Department of Research, Mount Sinai, Medical Center, Miami, FL, United States
| | - Nancy Linares
- Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
| | - Jose A. Adams
- Division of Neonatology, Mount Sinai, Medical Center, Miami, FL, United States
| | - Alfredo Mijares
- Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
- *Correspondence: Alfredo Mijares,
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14
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Groenendyk J, Wang WA, Robinson A, Michalak M. Calreticulin and the Heart. Cells 2022; 11:cells11111722. [PMID: 35681417 PMCID: PMC9179554 DOI: 10.3390/cells11111722] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022] Open
Abstract
Calreticulin is an endoplasmic Ca2+ binding protein and molecular chaperone. As a cardiac embryonic gene, calreticulin is essential for heart development. The protein supports Ca2+-dependent signaling events that are critical to cardiomyocyte differentiation and cardiogenesis. The increased expression of calreticulin and endoplasmic reticulum/sarcoplasmic reticulum Ca2+ capacity produces cardiomyocytes with enhanced efficiency, and detrimental mechanical stretching of cardiac fibroblasts, leading to cardiac pathology. Deletion of the calreticulin gene in adult cardiomyocytes results in left ventricle dilation, an impaired electrocardiogram, and heart failure. These observations indicate that a well-adjusted endoplasmic reticulum and calreticulin-dependent Ca2+ pool in cardiomyocytes are critical for the maintenance of proper cardiac function.
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Affiliation(s)
- Jody Groenendyk
- Correspondence: (J.G.); (M.M.); Tel.: +1-780-492-2256 (M.M.)
| | | | | | - Marek Michalak
- Correspondence: (J.G.); (M.M.); Tel.: +1-780-492-2256 (M.M.)
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15
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Bjertnæs LJ, Næsheim TO, Reierth E, Suborov EV, Kirov MY, Lebedinskii KM, Tveita T. Physiological Changes in Subjects Exposed to Accidental Hypothermia: An Update. Front Med (Lausanne) 2022; 9:824395. [PMID: 35280892 PMCID: PMC8904885 DOI: 10.3389/fmed.2022.824395] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/28/2022] [Indexed: 12/01/2022] Open
Abstract
Background Accidental hypothermia (AH) is an unintended decrease in body core temperature (BCT) to below 35°C. We present an update on physiological/pathophysiological changes associated with AH and rewarming from hypothermic cardiac arrest (HCA). Temperature Regulation and Metabolism Triggered by falling skin temperature, Thyrotropin-Releasing Hormone (TRH) from hypothalamus induces release of Thyroid-Stimulating Hormone (TSH) and Prolactin from pituitary gland anterior lobe that stimulate thyroid generation of triiodothyronine and thyroxine (T4). The latter act together with noradrenaline to induce heat production by binding to adrenergic β3-receptors in fat cells. Exposed to cold, noradrenaline prompts degradation of triglycerides from brown adipose tissue (BAT) into free fatty acids that uncouple metabolism to heat production, rather than generating adenosine triphosphate. If BAT is lacking, AH occurs more readily. Cardiac Output Assuming a 7% drop in metabolism per °C, a BCT decrease of 10°C can reduce metabolism by 70% paralleled by a corresponding decline in CO. Consequently, it is possible to maintain adequate oxygen delivery provided correctly performed cardiopulmonary resuscitation (CPR), which might result in approximately 30% of CO generated at normal BCT. Liver and Coagulation AH promotes coagulation disturbances following trauma and acidosis by reducing coagulation and platelet functions. Mean prothrombin and partial thromboplastin times might increase by 40–60% in moderate hypothermia. Rewarming might release tissue factor from damaged tissues, that triggers disseminated intravascular coagulation. Hypothermia might inhibit platelet aggregation and coagulation. Kidneys Renal blood flow decreases due to vasoconstriction of afferent arterioles, electrolyte and fluid disturbances and increasing blood viscosity. Severely deranged renal function occurs particularly in the presence of rhabdomyolysis induced by severe AH combined with trauma. Conclusion Metabolism drops 7% per °C fall in BCT, reducing CO correspondingly. Therefore, it is possible to maintain adequate oxygen delivery after 10°C drop in BCT provided correctly performed CPR. Hypothermia may facilitate rhabdomyolysis in traumatized patients. Victims suspected of HCA should be rewarmed before being pronounced dead. Rewarming avalanche victims of HCA with serum potassium > 12 mmol/L and a burial time >30 min with no air pocket, most probably be futile.
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Affiliation(s)
- Lars J Bjertnæs
- Department of Clinical Medicine, Faculty of Health Sciences, Anesthesia and Critical Care Research Group, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Torvind O Næsheim
- Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway.,Department of Clinical Medicine, Faculty of Health Sciences, Cardiovascular Research Group, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway
| | - Eirik Reierth
- Science and Health Library, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway
| | - Evgeny V Suborov
- The Nikiforov Russian Center of Emergency and Radiation Medicine, St. Petersburg, Russia
| | - Mikhail Y Kirov
- Department of Anesthesiology and Intensive Care, Northern State Medical University, Arkhangelsk, Russia
| | - Konstantin M Lebedinskii
- Department of Anesthesiology and Intensive Care, North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia.,Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia
| | - Torkjel Tveita
- Department of Clinical Medicine, Faculty of Health Sciences, Anesthesia and Critical Care Research Group, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
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16
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Korotkov SM, Sobol KV, Shemarova IV, Nesterov VP. Effect of Sodium Ions on Calcium-Loaded Rat Heart Mitochondria and Frog Myocardium. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021060041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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D'Imperio S, Monasky MM, Micaglio E, Ciconte G, Anastasia L, Pappone C. Brugada Syndrome: Warning of a Systemic Condition? Front Cardiovasc Med 2021; 8:771349. [PMID: 34722688 PMCID: PMC8553994 DOI: 10.3389/fcvm.2021.771349] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 09/23/2021] [Indexed: 12/19/2022] Open
Abstract
Brugada syndrome (BrS) is a hereditary disorder, characterized by a specific electrocardiogram pattern and highly related to an increased risk of sudden cardiac death. BrS has been associated with other cardiac and non-cardiac pathologies, probably because of protein expression shared by the heart and other tissue types. In fact, the most commonly found mutated gene in BrS, SCN5A, is expressed throughout nearly the entire body. Consistent with this, large meals and alcohol consumption can trigger arrhythmic events in patients with BrS, suggesting a role for organs involved in the digestive and metabolic pathways. Ajmaline, a drug used to diagnose BrS, can have side effects on non-cardiac tissues, such as the liver, further supporting the idea of a role for organs involved in the digestive and metabolic pathways in BrS. The BrS electrocardiogram (ECG) sign has been associated with neural, digestive, and metabolic pathways, and potential biomarkers for BrS have been found in the serum or plasma. Here, we review the known associations between BrS and various organ systems, and demonstrate support for the hypothesis that BrS is not only a cardiac disorder, but rather a systemic one that affects virtually the whole body. Any time that the BrS ECG sign is found, it should be considered not a single disease, but rather the final step in any number of pathways that ultimately threaten the patient's life. A multi-omics approach would be appropriate to study this syndrome, including genetics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics, and glycomics, resulting eventually in a biomarker for BrS and the ability to diagnose this syndrome using a minimally invasive blood test, avoiding the risk associated with ajmaline testing.
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Affiliation(s)
- Sara D'Imperio
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Michelle M Monasky
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Emanuele Micaglio
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Giuseppe Ciconte
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy
| | - Luigi Anastasia
- Faculty of Medicine and Surgery, University of Vita-Salute San Raffaele, Milan, Italy
| | - Carlo Pappone
- Arrhythmology Department, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Donato, Milan, Italy.,Faculty of Medicine and Surgery, University of Vita-Salute San Raffaele, Milan, Italy
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18
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Francica A, Tonelli F, Rossetti C, Tropea I, Luciani GB, Faggian G, Dobson GP, Onorati F. Cardioplegia between Evolution and Revolution: From Depolarized to Polarized Cardiac Arrest in Adult Cardiac Surgery. J Clin Med 2021; 10:jcm10194485. [PMID: 34640503 PMCID: PMC8509840 DOI: 10.3390/jcm10194485] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022] Open
Abstract
Despite current advances in perioperative care, intraoperative myocardial protection during cardiac surgery has not kept the same pace. High potassium cardioplegic solutions were introduced in the 1950s, and in the early 1960s they were soon recognized as harmful. Since that time, surgeons have minimized many of the adverse effects by lowering the temperature of the heart, lowering K+ concentration, reducing contact K+ time, changing the vehicle from a crystalloid solution to whole-blood, adding many pharmacological protectants and modifying reperfusion conditions. Despite these attempts, high potassium remains a suboptimalway to arrest the heart. We briefly review the historical advances and failures of finding alternatives to high potassium, the drawbacks of a prolonged depolarized membrane, altered Ca2+ intracellular circuits and heterogeneity in atrial-ventricular K+ repolarization during reanimation. Many of these untoward effects may be alleviated by a polarized membrane, and we will discuss the basic science and clinical experience from a number of institutions trialling different alternatives, and our institution with a non-depolarizing adenosine, lidocaine and magnesium (ALM) cardioplegia. The future of polarized arrest is an exciting one and may play an important role in treating the next generation of patients who are older, and sicker with multiple comorbidities and require more complex operations with prolonged cross-clamping times.
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Affiliation(s)
- Alessandra Francica
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
- Correspondence: ; Tel.: +39-3356213738
| | - Filippo Tonelli
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Cecilia Rossetti
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Ilaria Tropea
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Giovanni Battista Luciani
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Giuseppe Faggian
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Geoffrey Phillip Dobson
- Heart and Trauma Research Laboratory, College of Medicine and Dentistry, James Cook University, Townsville 4811, Australia;
| | - Francesco Onorati
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
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19
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Kaplan AD, Joca HC, Boyman L, Greiser M. Calcium Signaling Silencing in Atrial Fibrillation: Implications for Atrial Sodium Homeostasis. Int J Mol Sci 2021; 22:10513. [PMID: 34638854 PMCID: PMC8508839 DOI: 10.3390/ijms221910513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common type of cardiac arrhythmia, affecting more than 33 million people worldwide. Despite important advances in therapy, AF's incidence remains high, and treatment often results in recurrence of the arrhythmia. A better understanding of the cellular and molecular changes that (1) trigger AF and (2) occur after the onset of AF will help to identify novel therapeutic targets. Over the past 20 years, a large body of research has shown that intracellular Ca2+ handling is dramatically altered in AF. While some of these changes are arrhythmogenic, other changes counteract cellular arrhythmogenic mechanisms (Calcium Signaling Silencing). The intracellular Na+ concentration ([Na+])i is a key regulator of intracellular Ca2+ handling in cardiac myocytes. Despite its importance in the regulation of intracellular Ca2+ handling, little is known about [Na+]i, its regulation, and how it might be changed in AF. Previous work suggests that there might be increases in the late component of the atrial Na+ current (INa,L) in AF, suggesting that [Na+]i levels might be high in AF. Indeed, a pharmacological blockade of INa,L has been suggested as a treatment for AF. Here, we review calcium signaling silencing and changes in intracellular Na+ homeostasis during AF. We summarize the proposed arrhythmogenic mechanisms associated with increases in INa,L during AF and discuss the evidence from clinical trials that have tested the pharmacological INa,L blocker ranolazine in the treatment of AF.
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Affiliation(s)
- Aaron D. Kaplan
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Humberto C. Joca
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
| | - Liron Boyman
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
| | - Maura Greiser
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
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20
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Ellermann C, Wolfes J, Eckardt L, Frommeyer G. Role of the rabbit whole-heart model for electrophysiologic safety pharmacology of non-cardiovascular drugs. Europace 2021; 23:828-836. [PMID: 33200170 DOI: 10.1093/europace/euaa288] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/27/2020] [Indexed: 11/13/2022] Open
Abstract
Plenty of non-cardiovascular drugs alter cardiac electrophysiology and may ultimately lead to life-threatening arrhythmias. In clinical practice, measuring the QT interval as a marker for the repolarization period is the most common tool to assess the electrophysiologic safety of drugs. However, the sole measurement of the QT interval may be insufficient to determine the proarrhythmic risk of non-cardiovascular agents. Several other markers are considered in pre-clinical safety testing to determine potential harm on cardiac electrophysiology. Besides measuring typical electrophysiologic parameters such as repolarization duration, whole-heart models allow the determination of potential predictors for proarrhythmia. Spatial and temporal heterogeneity as well as changes of shape of the action potential can be easily assessed. In addition, provocation manoeuvers (either by electrolyte imbalances or programmed pacing protocols) may induce sustained arrhythmias and thereby determine ventricular vulnerability to arrhythmias. Compared with the human heart, the rabbit heart possesses a similar distribution of ion currents that govern cardiac repolarization, resulting in a rectangular action potential configuration in both species. In addition, similar biophysical properties of rabbit and human cardiac ion channels lead to a comparable pharmacologic response in human and rabbit hearts. Of note, arrhythmia patterns resemble in both species due to the similar effective size of human and rabbit hearts. Thus, the rabbit heart is particularly suitable for testing the electrophysiologic safety of drugs. Several experimental setups have been developed for studying cardiac electrophysiology in rabbits, ranging from single cell to tissue preparations, whole-heart setups, and in vivo models.
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Affiliation(s)
- Christian Ellermann
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Julian Wolfes
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Lars Eckardt
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
| | - Gerrit Frommeyer
- Department of Cardiology II (Electrophysiology), University Hospital Münster, Albert-Schweitzer-Campus 1, Münster D-48149, Germany
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21
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Liu J, Tian J, Sodhi K, Shapiro JI. The Na/K-ATPase Signaling and SGLT2 Inhibitor-Mediated Cardiorenal Protection: A Crossed Road? J Membr Biol 2021; 254:513-529. [PMID: 34297135 PMCID: PMC8595165 DOI: 10.1007/s00232-021-00192-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/06/2021] [Indexed: 12/17/2022]
Abstract
In different large-scale clinic outcome trials, sodium (Na+)/glucose co-transporter 2 (SGLT2) inhibitors showed profound cardiac- and renal-protective effects, making them revolutionary treatments for heart failure and kidney disease. Different theories are proposed according to the emerging protective effects other than the original purpose of glucose-lowering in diabetic patients. As the ATP-dependent primary ion transporter providing the Na+ gradient to drive other Na+-dependent transporters, the possible role of the sodium–potassium adenosine triphosphatase (Na/K-ATPase) as the primary ion transporter and its signaling function is not explored.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA.
| | - Jiang Tian
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Komal Sodhi
- Department of Surgery, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Joseph I Shapiro
- Departments of Medicine, JCE School of Medicine, Marshall University, Huntington, WV, USA
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22
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Gao L, Wang L, Wei Y, Krishnamurthy P, Walcott GP, Menasché P, Zhang J. Exosomes secreted by hiPSC-derived cardiac cells improve recovery from myocardial infarction in swine. Sci Transl Med 2021; 12:12/561/eaay1318. [PMID: 32938792 DOI: 10.1126/scitranslmed.aay1318] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 04/13/2020] [Accepted: 08/26/2020] [Indexed: 12/11/2022]
Abstract
Cell therapy treatment of myocardial infarction (MI) is mediated, in part, by exosomes secreted from transplanted cells. Thus, we compared the efficacy of treatment with a mixture of cardiomyocytes (CMs; 10 million), endothelial cells (ECs; 5 million), and smooth muscle cells (SMCs; 5 million) derived from human induced pluripotent stem cells (hiPSCs), or with exosomes extracted from the three cell types, in pigs after MI. Female pigs received sham surgery; infarction without treatment (MI group); or infarction and treatment with hiPSC-CMs, hiPSC-ECs, and hiPSC-SMCs (MI + Cell group); with homogenized fragments from the same dose of cells administered to the MI + Cell group (MI + Fra group); or with exosomes (7.5 mg) extracted from a 2:1:1 mixture of hiPSC-CMs:hiPSC-ECs:hiPSC-SMCs (MI + Exo group). Cells and exosomes were injected into the injured myocardium. In vitro, exosomes promoted EC tube formation and microvessel sprouting from mouse aortic rings and protected hiPSC-CMs by reducing apoptosis, maintaining intracellular calcium homeostasis, and increasing adenosine 5'-triphosphate. In vivo, measurements of left ventricular ejection fraction, wall stress, myocardial bioenergetics, cardiac hypertrophy, scar size, cell apoptosis, and angiogenesis in the infarcted region were better in the MI + Cell, MI + Fra, and MI + Exo groups than in the MI group 4 weeks after infarction. The frequencies of arrhythmic events in animals from the MI, MI + Cell, and MI + Exo groups were similar. Thus, exosomes secreted by hiPSC-derived cardiac cells improved myocardial recovery without increasing the frequency of arrhythmogenic complications and may provide an acellular therapeutic option for myocardial injury.
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Affiliation(s)
- Ling Gao
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA. .,Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, P.R. China
| | - Lu Wang
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Yuhua Wei
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Prasanna Krishnamurthy
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Gregory P Walcott
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Philippe Menasché
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA.,Department of Cardiovascular Surgery, Hôpital Européen Georges Pompidou, Université de Paris, PARCC, INSERM, F-75015 Paris, France
| | - Jianyi Zhang
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
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23
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Fill M, Gillespie D. Simulating cardiac Ca 2+ release units: effects of RyR cluster size and Ca 2+ buffers on diastolic Ca 2+ leak. Pflugers Arch 2021; 473:435-446. [PMID: 33608799 DOI: 10.1007/s00424-021-02539-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/27/2021] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
Abstract
Leak of Ca2+ out of the cardiac sarcoplasmic reticulum (SR) via ryanodine receptors (RyRs) during diastole is vital to regulate SR Ca2+ levels. This leak can become deleterious when large spontaneous RyR-mediated Ca2+ release events evoke proarrhythmic Ca2+ waves that can lead to delayed after-depolarizations. Here, we model diastolic SR Ca2+ leak at individual SR Ca2+ release sites using computer simulations of RyR arrays like those in the dyadic cleft. The results show that RyR arrays size has a significant effect on SR Ca2+ leak, with bigger arrays producing larger and more frequent Ca2+ release events. Moreover, big RyR arrays are more susceptible to small changes in the levels of dyadic Ca2+ buffers. Such changes in buffering shift Ca2+ leak from small Ca2+ release events (involving few open RyRs) to larger events (with many open RyRs). Moreover, by analyzing a large parameter space of possible buffering and SR Ca2+ loads, we find further evidence for the hypothesis that SR Ca2+ leak by RyR arrays can undergo a sudden phase transition.
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Affiliation(s)
- Michael Fill
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - Dirk Gillespie
- Department of Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA.
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24
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Ozturk N, Uslu S, Ozdemir S. Diabetes-induced changes in cardiac voltage-gated ion channels. World J Diabetes 2021; 12:1-18. [PMID: 33520105 PMCID: PMC7807254 DOI: 10.4239/wjd.v12.i1.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/05/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus affects the heart through various mechanisms such as microvascular defects, metabolic abnormalities, autonomic dysfunction and incompatible immune response. Furthermore, it can also cause functional and structural changes in the myocardium by a disease known as diabetic cardiomyopathy (DCM) in the absence of coronary artery disease. As DCM progresses it causes electrical remodeling of the heart, left ventricular dysfunction and heart failure. Electrophysiological changes in the diabetic heart contribute significantly to the incidence of arrhythmias and sudden cardiac death in diabetes mellitus patients. In recent studies, significant changes in repolarizing K+ currents, Na+ currents and L-type Ca2+ currents along with impaired Ca2+ homeostasis and defective contractile function have been identified in the diabetic heart. In addition, insulin levels and other trophic factors change significantly to maintain the ionic channel expression in diabetic patients. There are many diagnostic tools and management options for DCM, but it is difficult to detect its development and to effectively prevent its progress. In this review, diabetes-associated alterations in voltage-sensitive cardiac ion channels are comprehensively assessed to understand their potential role in the pathophysiology and pathogenesis of DCM.
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Affiliation(s)
- Nihal Ozturk
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey
| | - Serkan Uslu
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey
| | - Semir Ozdemir
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey
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25
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Namekata I, Odaka R, Hamaguchi S, Tanaka H. KB-R7943 Inhibits the Mitochondrial Ca 2+ Uniporter but Not Na +-Ca 2+ Exchanger in Cardiomyocyte-Derived H9c2 Cells. Biol Pharm Bull 2020; 43:1993-1996. [PMID: 33028749 DOI: 10.1248/bpb.b20-00747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of KB-R7943, an inhibitor of the plasmalemmal Na+-Ca2+ exchanger, on mitochondrial Ca2+ transporters was examined with membrane-permeabilized cardiomyocyte-derived H9c2 cells expressing the fluorescent Ca2+ indicator, yellow cameleon 3.1, in the mitochondria. KB-R7943, as well as ruthenium red, inhibited the rise in mitochondrial Ca2+ on increasing the extramitochondrial Ca2+ concentration from 0 nM to 300 nM. CGP-37157, but not KB-R7943, inhibited the decline in mitochondrial Ca2+on return to Ca2+ free extramitochondrial solution. These results indicated that KB-R7943 has inhibitory effects on the mitochondrial Ca2+ uniporter, but not on the mitochondrial Na+-Ca2+ exchanger.
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Affiliation(s)
- Iyuki Namekata
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Ryosuke Odaka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Shogo Hamaguchi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Hikaru Tanaka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
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26
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Zasadny FM, Dyavanapalli J, Dowling NM, Mendelowitz D, Kay MW. Cholinergic stimulation improves electrophysiological rate adaptation during pressure overload-induced heart failure in rats. Am J Physiol Heart Circ Physiol 2020; 319:H1358-H1368. [PMID: 33006920 PMCID: PMC7792708 DOI: 10.1152/ajpheart.00293.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Left ventricular (LV) electrical maladaptation to increased heart rate in failing myocardium contributes to morbidity and mortality. Recently, cardiac cholinergic neuron activation reduced loss of contractile function resulting from chronic trans-aortic constriction (TAC) in rats. We hypothesized that chronic activation of cardiac cholinergic neurons would also reduce TAC-induced derangement of cardiac electrical activity. METHODS We investigated electrophysiological rate adaptation in TAC rat hearts with and without daily chemogenetic activation of hypothalamic oxytocin neurons for downstream cardiac cholinergic neuron stimulation. Sprague Dawley rat hearts were excised, perfused, and optically mapped under dynamic pacing after 16 weeks of TAC with or without 12 weeks of daily chemogenetic treatment. Action potential duration (APD60) and conduction velocity (CV) maps were analyzed for regional rate adaptation to dynamic pacing. RESULTS At lower pacing rates, untreated TAC induced elevated LV epicardial APD60. Fitted APD60 steady state (APDss) was reduced in treated TAC hearts. At higher pacing rates, treatment heterogeneously reduced APD60 compared to untreated TAC hearts. Variance of conduction loss was reduced in treated hearts compared to untreated hearts during fast pacing. However, CV was markedly reduced in both treated and untreated TAC hearts throughout dynamic pacing. At 150msec pacing cycle length, APD60 v. diastolic interval (DI) dispersion was reduced in treated hearts compared to untreated hearts. CONCLUSIONS Chronic activation of cardiac cholinergic neurons improved electrophysiological adaptation to increases in pacing rate during development of TAC-induced heart failure. This provides insight into the electrophysiological benefits of cholinergic stimulation as a treatment for heart failure patients.
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Affiliation(s)
| | | | | | - David Mendelowitz
- Pharmacology and Physiology, George Washington University, United States
| | - Matthew W Kay
- Biomedical Engineering, George Washington University, United States
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27
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Otsomaa L, Levijoki J, Wohlfahrt G, Chapman H, Koivisto AP, Syrjänen K, Koskelainen T, Peltokorpi SE, Finckenberg P, Heikkilä A, Abi-Gerges N, Ghetti A, Miller PE, Page G, Mervaala E, Nagy N, Kohajda Z, Jost N, Virág L, Varró A, Papp JG. Discovery and characterization of ORM-11372, a novel inhibitor of the sodium-calcium exchanger with positive inotropic activity. Br J Pharmacol 2020; 177:5534-5554. [PMID: 32959887 PMCID: PMC7707092 DOI: 10.1111/bph.15257] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/14/2020] [Accepted: 09/03/2020] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose The lack of selective sodium–calcium exchanger (NCX) inhibitors has hampered the exploration of physiological and pathophysiological roles of cardiac NCX 1.1. We aimed to discover more potent and selective drug like NCX 1.1 inhibitor. Experimental Approach A flavan series‐based pharmacophore model was constructed. Virtual screening helped us identify a novel scaffold for NCX inhibition. A distinctively different NCX 1.1 inhibitor, ORM‐11372, was discovered after lead optimization. Its potency against human and rat NCX 1.1 and selectivity against other ion channels was assessed. The cardiovascular effects of ORM‐11372 were studied in normal and infarcted rats and rabbits. Human cardiac safety was studied ex vivo using human ventricular trabeculae. Key Results ORM‐11372 inhibited human NCX 1.1 reverse and forward currents; IC50 values were 5 and 6 nM respectively. ORM‐11372 inhibited human cardiac sodium 1.5 (INa) and hERG KV11.1 currents (IhERG) in a concentration‐dependent manner; IC50 values were 23.2 and 10.0 μM. ORM‐11372 caused no changes in action potential duration; short‐term variability and triangulation were observed for concentrations of up to 10 μM. ORM‐11372 induced positive inotropic effects of 18 ± 6% and 35 ± 8% in anaesthetized rats with myocardial infarctions and in healthy rabbits respectively; no other haemodynamic effects were observed, except improved relaxation at the lowest dose. Conclusion and Implications ORM‐11372, a unique, novel, and potent inhibitor of human and rat NCX 1.1, is a positive inotropic compound. NCX inhibition can induce clinically relevant improvements in left ventricular contractions without affecting relaxation, heart rate, or BP, without pro‐arrhythmic risk.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Piet Finckenberg
- Department of Pharmacology, Faculty of Medicine, Helsinki, Finland
| | | | | | | | | | - Guy Page
- R&D, AnaBios Corporation, San Diego, CA, USA
| | - Eero Mervaala
- Department of Pharmacology, Faculty of Medicine, Helsinki, Finland
| | - Norbert Nagy
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Zsófia Kohajda
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary
| | - Norbert Jost
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - András Varró
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Julius Gy Papp
- MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, Faculty of Medicine, University of Szeged, Szeged, Hungary
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28
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Njegic A, Wilson C, Cartwright EJ. Targeting Ca 2 + Handling Proteins for the Treatment of Heart Failure and Arrhythmias. Front Physiol 2020; 11:1068. [PMID: 33013458 PMCID: PMC7498719 DOI: 10.3389/fphys.2020.01068] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/04/2020] [Indexed: 12/18/2022] Open
Abstract
Diseases of the heart, such as heart failure and cardiac arrhythmias, are a growing socio-economic burden. Calcium (Ca2+) dysregulation is key hallmark of the failing myocardium and has long been touted as a potential therapeutic target in the treatment of a variety of cardiovascular diseases (CVD). In the heart, Ca2+ is essential for maintaining normal cardiac function through the generation of the cardiac action potential and its involvement in excitation contraction coupling. As such, the proteins which regulate Ca2+ cycling and signaling play a vital role in maintaining Ca2+ homeostasis. Changes to the expression levels and function of Ca2+-channels, pumps and associated intracellular handling proteins contribute to altered Ca2+ homeostasis in CVD. The remodeling of Ca2+-handling proteins therefore results in impaired Ca2+ cycling, Ca2+ leak from the sarcoplasmic reticulum and reduced Ca2+ clearance, all of which contributes to increased intracellular Ca2+. Currently, approved treatments for targeting Ca2+ handling dysfunction in CVD are focused on Ca2+ channel blockers. However, whilst Ca2+ channel blockers have been successful in the treatment of some arrhythmic disorders, they are not universally prescribed to heart failure patients owing to their ability to depress cardiac function. Despite the progress in CVD treatments, there remains a clear need for novel therapeutic approaches which are able to reverse pathophysiology associated with heart failure and arrhythmias. Given that heart failure and cardiac arrhythmias are closely associated with altered Ca2+ homeostasis, this review will address the molecular changes to proteins associated with both Ca2+-handling and -signaling; their potential as novel therapeutic targets will be discussed in the context of pre-clinical and, where available, clinical data.
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Affiliation(s)
- Alexandra Njegic
- Division of Cardiovascular Sciences, The University of Manchester, Manchester, United Kingdom.,Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Claire Wilson
- Division of Cardiovascular Sciences, The University of Manchester, Manchester, United Kingdom.,Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, The University of Manchester, Manchester, United Kingdom
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29
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Skogestad J, Aronsen JM, Tovsrud N, Wanichawan P, Hougen K, Stokke MK, Carlson CR, Sjaastad I, Sejersted OM, Swift F. Coupling of the Na+/K+-ATPase to Ankyrin B controls Na+/Ca2+ exchanger activity in cardiomyocytes. Cardiovasc Res 2020; 116:78-90. [PMID: 30949686 DOI: 10.1093/cvr/cvz087] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 02/22/2019] [Accepted: 04/03/2019] [Indexed: 01/28/2023] Open
Abstract
AIMS Ankyrin B (AnkB) is an adaptor protein that assembles Na+/K+-ATPase (NKA) and Na+/Ca2+ exchanger (NCX) in the AnkB macromolecular complex. Loss-of-function mutations in AnkB cause the AnkB syndrome in humans, characterized by ventricular arrhythmias and sudden cardiac death. It is unclear to what extent NKA binding to AnkB allows regulation of local Na+ and Ca2+ domains and hence NCX activity. METHODS AND RESULTS To investigate the role of NKA binding to AnkB in cardiomyocytes, we synthesized a disruptor peptide (MAB peptide) and its AnkB binding ability was verified by pulldown experiments. As opposed to control, the correlation between NKA and NCX currents was abolished in adult rat ventricular myocytes dialyzed with MAB peptide, as well as in cardiomyocytes from AnkB+/- mice. Disruption of NKA from AnkB (with MAB peptide) increased NCX-sensed cytosolic Na+ concentration, reduced Ca2+ extrusion through NCX, and increased frequency of Ca2+ sparks and Ca2+ waves without concomitant increase in Ca2+ transient amplitude or SR Ca2+ load, suggesting an effect in local Ca2+ domains. Selective inhibition of the NKAα2 isoform abolished both the correlation between NKA and NCX currents and the increased rate of Ca2+ sparks and waves following NKA/AnkB disruption, suggesting that an AnkB/NKAα2/NCX domain controls Ca2+ fluxes in cardiomyocytes. CONCLUSION NKA binding to AnkB allows ion regulation in a local domain, and acute disruption of the NKA/AnkB interaction using disruptor peptides lead to increased rate of Ca2+ sparks and waves. The functional effects were mediated through the NKAα2 isoform. Disruption of the AnkB/NKA/NCX domain could be an important pathophysiological mechanism in the AnkB syndrome.
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Affiliation(s)
- Jonas Skogestad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,Bjørknes College, Oslo, Norway
| | - Nils Tovsrud
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Pimthanya Wanichawan
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Karina Hougen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Mathis Korseberg Stokke
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway.,Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Cathrine Rein Carlson
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ole Mathias Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Fredrik Swift
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, N-0407 Oslo, Norway.,KG Jebsen Cardiac Research Centre and Center for Heart Failure Research, University of Oslo, Oslo, Norway.,Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
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30
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Kim S, Song J, Ernst P, Latimer MN, Ha CM, Goh KY, Ma W, Rajasekaran NS, Zhang J, Liu X, Prabhu SD, Qin G, Wende AR, Young ME, Zhou L. MitoQ regulates redox-related noncoding RNAs to preserve mitochondrial network integrity in pressure-overload heart failure. Am J Physiol Heart Circ Physiol 2020; 318:H682-H695. [PMID: 32004065 PMCID: PMC7099446 DOI: 10.1152/ajpheart.00617.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 01/04/2023]
Abstract
Evidence suggests that mitochondrial network integrity is impaired in cardiomyocytes from failing hearts. While oxidative stress has been implicated in heart failure (HF)-associated mitochondrial remodeling, the effect of mitochondrial-targeted antioxidants, such as mitoquinone (MitoQ), on the mitochondrial network in a model of HF (e.g., pressure overload) has not been demonstrated. Furthermore, the mechanism of this regulation is not completely understood with an emerging role for posttranscriptional regulation via long noncoding RNAs (lncRNAs). We hypothesized that MitoQ preserves mitochondrial fusion proteins (i.e., mitofusin), likely through redox-sensitive lncRNAs, leading to improved mitochondrial network integrity in failing hearts. To test this hypothesis, 8-wk-old C57BL/6J mice were subjected to ascending aortic constriction (AAC), which caused substantial left ventricular (LV) chamber remodeling and remarkable contractile dysfunction in 1 wk. Transmission electron microscopy and immunostaining revealed defective intermitochondrial and mitochondrial-sarcoplasmic reticulum ultrastructure in AAC mice compared with sham-operated animals, which was accompanied by elevated oxidative stress and suppressed mitofusin (i.e., Mfn1 and Mfn2) expression. MitoQ (1.36 mg·day-1·mouse-1, 7 consecutive days) significantly ameliorated LV dysfunction, attenuated Mfn2 downregulation, improved interorganellar contact, and increased metabolism-related gene expression. Moreover, our data revealed that MitoQ alleviated the dysregulation of an Mfn2-associated lncRNA (i.e., Plscr4). In summary, the present study supports a unique mechanism by which MitoQ improves myocardial intermitochondrial and mitochondrial-sarcoplasmic reticulum (SR) ultrastructural remodeling in HF by maintaining Mfn2 expression via regulation by an lncRNA. These findings underscore the important role of lncRNAs in the pathogenesis of HF and the potential of targeting them for effective HF treatment.NEW & NOTEWORTHY We have shown that MitoQ improves cardiac mitochondrial network integrity and mitochondrial-SR alignment in a pressure-overload mouse heart-failure model. This may be occurring partly through preventing the dysregulation of a redox-sensitive lncRNA-microRNA pair (i.e., Plscr4-miR-214) that results in an increase in mitofusin-2 expression.
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Affiliation(s)
- Seulhee Kim
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jiajia Song
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Patrick Ernst
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Mary N Latimer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Chae-Myeong Ha
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kah Yong Goh
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Wenxia Ma
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Xiaoguang Liu
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Sumanth D Prabhu
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Gangjian Qin
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Adam R Wende
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Martin E Young
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Lufang Zhou
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
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31
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Fu JL, Yu Q, Li MD, Hu CM, Shi G. Deleterious cardiovascular effect of exosome in digitalis-treated decompensated congestive heart failure. J Biochem Mol Toxicol 2020; 34:e22462. [PMID: 32045083 DOI: 10.1002/jbt.22462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 11/16/2019] [Accepted: 01/21/2020] [Indexed: 12/16/2022]
Abstract
Heart failure (HF) is a medical condition inability of the heart to pump sufficient blood to meet the metabolic demand of the body to take place. The number of hospitalized patients with cardiovascular diseases is estimated to be more than 1 million each year, of which 80% to 90% of patients ultimately progress to decompensated HF. Digitalis glycosides exert modest inotropic actions when administered to patients with decompensated HF. Although its efficacy in patients with HF and atrial fibrillation is clear, its value in patients with HF and sinus rhythm has often been questioned. A series of recent studies have cast serious doubt on the benefit of digoxin when added to contemporary HF treatment. We are hypothesizing the role and mechanism of exosome and its biological constituents responsible for worsening the disease state and mortality in decompensated HF patients on digitalis.
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Affiliation(s)
- Jin-Ling Fu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Qiong Yu
- Department of Hematology and Oncology, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Meng-Di Li
- Department of Hematology and Oncology, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Chun-Mei Hu
- Department of Hematology and Oncology, The Second Hospital of Jilin University, Changchun, Jilin, China
| | - Guang Shi
- Department of Hematology and Oncology, The Second Hospital of Jilin University, Changchun, Jilin, China
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32
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Gudbjartsson T, Helgadottir S, Sigurdsson MI, Taha A, Jeppsson A, Christensen TD, Riber LPS. New-onset postoperative atrial fibrillation after heart surgery. Acta Anaesthesiol Scand 2020; 64:145-155. [PMID: 31724159 DOI: 10.1111/aas.13507] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/02/2019] [Accepted: 11/10/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND New-onset postoperative atrial fibrillation (poAF) complicates approximately 20-60% of all cardiac surgical procedures and is associated with an increased periprocedural mortality and morbitity, prolonged hospital stay, increased costs, and worse long-term survival. Unfortunately multiple advances in surgery and perioperative care over the last two decades have not led to a reduction in the incidence of poAF or associated complications in the daily clinical practice. METHODS A narrative review of the available literature was performed. RESULTS An extensive review of the pathophysiology of poAF following cardiac surgery, clinical, and procedural risk-factors is provided, as well as prophylactic measures and treatment. CONCLUSION Multiple strategies to prevent and manage poAF following heart surgery already exist. Our hope is that this review will facilitate more rigorous testing of prevention strategies, implementation of prophylaxis regimens as well as optimal treatment of this common and serious complication.
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Affiliation(s)
- Tomas Gudbjartsson
- Department of Cardiothoracic Surgery Landspitali University Hospital Reykjavik Iceland
- Faculty of Medicine University of Iceland Reykjavik Iceland
| | - Solveig Helgadottir
- Department of Cardiothoracic Surgery and Anaesthesia Uppsala University Hospital Uppsala Sweden
| | - Martin Ingi Sigurdsson
- Faculty of Medicine University of Iceland Reykjavik Iceland
- Department of Anaesthesia and Critical Care Landspitali University Hospital Reykjavik Iceland
| | - Amar Taha
- Department of Cardiology Sahlgrenska University Hospital Gothenburg Sweden
- Department of Molecular and Clinical Medicine Institute of Medicine Sahlgrenska AcademyUniversity of Gothenburg Gothenburg Sweden
| | - Anders Jeppsson
- Department of Molecular and Clinical Medicine Institute of Medicine Sahlgrenska AcademyUniversity of Gothenburg Gothenburg Sweden
- Department of Cardiothoracic Surgery Sahlgrenska University Hospital Gothenburg Sweden
| | - Thomas Decker Christensen
- Department of Cardiothoracic and Vascular Surgery Department of Clinical Medicine Aarhus University Hospital Aarhus Denmark
| | - Lars Peter Schoedt Riber
- Department of Cardiothoracic and Vascular Surgery, Department of Clinical Medicine Odense University Hospital, University of Southern Denmark Odense Denmark
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33
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Pourrier M, Fedida D. The Emergence of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes (hiPSC-CMs) as a Platform to Model Arrhythmogenic Diseases. Int J Mol Sci 2020; 21:ijms21020657. [PMID: 31963859 PMCID: PMC7013748 DOI: 10.3390/ijms21020657] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 12/13/2022] Open
Abstract
There is a need for improved in vitro models of inherited cardiac diseases to better understand basic cellular and molecular mechanisms and advance drug development. Most of these diseases are associated with arrhythmias, as a result of mutations in ion channel or ion channel-modulatory proteins. Thus far, the electrophysiological phenotype of these mutations has been typically studied using transgenic animal models and heterologous expression systems. Although they have played a major role in advancing the understanding of the pathophysiology of arrhythmogenesis, more physiological and predictive preclinical models are necessary to optimize the treatment strategy for individual patients. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have generated much interest as an alternative tool to model arrhythmogenic diseases. They provide a unique opportunity to recapitulate the native-like environment required for mutated proteins to reproduce the human cellular disease phenotype. However, it is also important to recognize the limitations of this technology, specifically their fetal electrophysiological phenotype, which differentiates them from adult human myocytes. In this review, we provide an overview of the major inherited arrhythmogenic cardiac diseases modeled using hiPSC-CMs and for which the cellular disease phenotype has been somewhat characterized.
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Affiliation(s)
- Marc Pourrier
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada;
- IonsGate Preclinical Services Inc., Vancouver, BC V6T 1Z3, Canada
- Correspondence:
| | - David Fedida
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada;
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34
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Cardiomyocyte mitochondrial dysfunction in diabetes and its contribution in cardiac arrhythmogenesis. Mitochondrion 2019; 46:6-14. [DOI: 10.1016/j.mito.2019.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 02/16/2019] [Accepted: 03/20/2019] [Indexed: 01/09/2023]
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35
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Lookin O, Protsenko Y. The lack of slow force response in failing rat myocardium: role of stretch-induced modulation of Ca-TnC kinetics. J Physiol Sci 2019; 69:345-357. [PMID: 30560346 PMCID: PMC10717443 DOI: 10.1007/s12576-018-0651-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/08/2018] [Indexed: 10/27/2022]
Abstract
The slow force response (SFR) to stretch is an important adaptive mechanism of the heart. The SFR may result in ~ 20-30% extra force but it is substantially attenuated in heart failure. We investigated the relation of SFR magnitude with Ca2+ transient decay in healthy (CONT) and monocrotaline-treated rats with heart failure (MCT). Right ventricular trabeculae were stretched from 85 to 95% of optimal length and held stretched for 10 min at 30 °C and 1 Hz. Isometric twitches and Ca2+ transients were collected on 2, 4, 6, 8, 10 min after stretch. The changes in peak tension and Ca2+ transient decay characteristics during SFR were evaluated as a percentage of the value measured immediately after stretch. The amount of Ca2+ utilized by TnC was indirectly evaluated using the methods of Ca2+ transient "bump" and "difference curve." The muscles of CONT rats produced positive SFR and they showed prominent functional relation between SFR magnitude and the magnitude (amplitude, integral intensity) of Ca2+ transient "bump" and "difference curve." The myocardium of MCT rats showed negative SFR to stretch (force decreased in time) which was not correlated well with the characteristics of Ca2+ transient decay, evaluated by the methods of "bump" and "difference curve." We conclude that the intracellular mechanisms of Ca2+ balancing during stretch-induced slow adaptation of myocardial contractility are disrupted in failing rat myocardium. The potential significance of our findings is that the deficiency of slow force response in diseased myocardium may be diminished under augmented kinetics of Ca-TnC interaction.
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Affiliation(s)
- Oleg Lookin
- Laboratory of Biological Motility, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, 106 Pervomayskaya St., Yekaterinburg, 620049, Russian Federation.
- Ural Federal University, 19 Mira St., Yekaterinburg, 620002, Russian Federation.
| | - Yuri Protsenko
- Laboratory of Biological Motility, Institute of Immunology and Physiology, Ural Branch of Russian Academy of Sciences, 106 Pervomayskaya St., Yekaterinburg, 620049, Russian Federation
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36
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Song J, Yang R, Yang J, Zhou L. Mitochondrial Dysfunction-Associated Arrhythmogenic Substrates in Diabetes Mellitus. Front Physiol 2018; 9:1670. [PMID: 30574091 PMCID: PMC6291470 DOI: 10.3389/fphys.2018.01670] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/07/2018] [Indexed: 12/15/2022] Open
Abstract
There is increasing evidence that diabetic cardiomyopathy increases the risk of cardiac arrhythmia and sudden cardiac death. While the detailed mechanisms remain incompletely understood, the loss of mitochondrial function, which is often observed in the heart of patients with diabetes, has emerged as a key contributor to the arrhythmogenic substrates. In this mini review, the pathophysiology of mitochondrial dysfunction in diabetes mellitus is explored in detail, followed by descriptions of several mechanisms potentially linking mitochondria to arrhythmogenesis in the context of diabetic cardiomyopathy.
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Affiliation(s)
- Jiajia Song
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ruilin Yang
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States.,Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin, China
| | - Jing Yang
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Lufang Zhou
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
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37
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Ng KM, Lau YM, Dhandhania V, Cai ZJ, Lee YK, Lai WH, Tse HF, Siu CW. Empagliflozin Ammeliorates High Glucose Induced-Cardiac Dysfuntion in Human iPSC-Derived Cardiomyocytes. Sci Rep 2018; 8:14872. [PMID: 30291295 PMCID: PMC6173708 DOI: 10.1038/s41598-018-33293-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 09/03/2018] [Indexed: 12/12/2022] Open
Abstract
Empagliflozin, a sodium-glucose co-transporter (SGLT) inhibitor, reduces heart failure and sudden cardiac death but the underlying mechanisms remain elusive. In cardiomyocytes, SGLT1 and SGLT2 expression is upregulated in diabetes mellitus, heart failure, and myocardial infarction. We hypothesise that empagliflozin exerts direct effects on cardiomyocytes that attenuate diabetic cardiomyopathy. To test this hypothesis, cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) were used to test the potential effects of empagliflozin on neutralization of cardiac dysfunction induced by diabetic-like cultures. Our results indicated that insulin-free high glucose culture significantly increased the size of and NPPB, SGLT1 and SGLT2 expression of hiPSC-derived cardiomyocytes. In addition, high glucose-treated hiPSC-derived cardiomyocytes exhibited reduced contractility regardless of the increased calcium transient capacity. Interestingly, application of empagliflozin before or after high glucose treatment effectively reduced the high glucose-induced cardiac abnormalities. Since application of empagliflozin did not significantly alter viability or glycolytic capacity of the hiPSC-derived cardiomyocytes, it is plausible that empagliflozin exerts its effects via the down-regulation of SGLT1, SGLT2 and GLUT1 expression. These observations provide supportive evidence that may help explain its unexpected benefit observed in the EMPA-REG trial.
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Affiliation(s)
- Kwong-Man Ng
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Yee-Man Lau
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Vidhu Dhandhania
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Zhu-Jun Cai
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Yee-Ki Lee
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Wing-Hon Lai
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Hung-Fat Tse
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China
| | - Chung-Wah Siu
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, Hong Kong, China.
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38
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Carro J, Pueyo E, Rodríguez Matas JF. A response surface optimization approach to adjust ionic current conductances of cardiac electrophysiological models. Application to the study of potassium level changes. PLoS One 2018; 13:e0204411. [PMID: 30281636 PMCID: PMC6169915 DOI: 10.1371/journal.pone.0204411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 09/07/2018] [Indexed: 01/23/2023] Open
Abstract
Cardiac electrophysiological computational models are often developed from previously published models. The new models may incorporate additional features to adapt the model to a different species or may upgrade a specific ionic formulation based on newly available experimental data. A relevant challenge in the development of a new model is the estimation of certain ionic current conductances that cannot be reliably identified from experiments. A common strategy to estimate those conductances is by means of constrained non-linear least-squares optimization. In this work, a novel methodology is proposed for estimation of ionic current conductances of cardiac electrophysiological models by using a response surface approximation-based constrained optimization with trust region management. Polynomial response surfaces of a number of electrophysiological markers were built using statistical sampling methods. These markers included action potential duration (APD), triangulation, diastolic and systolic intracellular calcium concentration, and time constants of APD rate adaptation. The proposed methodology was applied to update the Carro et al. human ventricular action potential model after incorporation of intracellular potassium ([K+]i) dynamics. While the Carro et al. model was well suited for investigation of arrhythmogenesis, it did not allow simulation of [K+]i changes. With the methodology proposed in this study, the updated Carro et al. human ventricular model could be used to simulate [K+]i changes in response to varying extracellular potassium ([K+]o) levels. Additionally, it rendered values of evaluated electrophysiological markers within physiologically plausible ranges. The optimal values of ionic current conductances in the updated model were found in a notably shorter time than with previously proposed methodologies. As a conclusion, the response surface optimization-based approach proposed in this study allows estimating ionic current conductances of cardiac electrophysiological computational models while guaranteeing replication of key electrophysiological features and with an important reduction in computational cost with respect to previously published approaches. The updated Carro et al. model developed in this study is thus suitable for the investigation of arrhythmic risk-related conditions, including those involving large changes in potassium concentration.
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Affiliation(s)
- Jesús Carro
- Universidad San Jorge, Villanueva de Gállego, Zaragoza, Spain
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Spain
- CIBER in Bioengineering, Biomaterials & Nanomedicne (CIBER-BBN), Spain
- * E-mail:
| | - Esther Pueyo
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Spain
- CIBER in Bioengineering, Biomaterials & Nanomedicne (CIBER-BBN), Spain
| | - José F. Rodríguez Matas
- Aragón Institute for Engineering Research, University of Zaragoza, IIS Aragón, Spain
- LaBS, Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Italy
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39
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Human iPSC-Derived Cardiomyocytes for Investigation of Disease Mechanisms and Therapeutic Strategies in Inherited Arrhythmia Syndromes: Strengths and Limitations. Cardiovasc Drugs Ther 2018; 31:325-344. [PMID: 28721524 PMCID: PMC5550530 DOI: 10.1007/s10557-017-6735-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
During the last two decades, significant progress has been made in the identification of genetic defects underlying inherited arrhythmia syndromes, which has provided some clinical benefit through elucidation of gene-specific arrhythmia triggers and treatment. However, for most arrhythmia syndromes, clinical management is hindered by insufficient knowledge of the functional consequences of the mutation in question, the pro-arrhythmic mechanisms involved, and hence the most optimal treatment strategy. Moreover, disease expressivity and sensitivity to therapeutic interventions often varies between mutations and/or patients, underlining the need for more individualized strategies. The development of the induced pluripotent stem cell (iPSC) technology now provides the opportunity for generating iPSC-derived cardiomyocytes (CMs) from human material (hiPSC-CMs), enabling patient- and/or mutation-specific investigations. These hiPSC-CMs may furthermore be employed for identification and assessment of novel therapeutic strategies for arrhythmia syndromes. However, due to their relative immaturity, hiPSC-CMs also display a number of essential differences as compared to adult human CMs, and hence there are certain limitations in their use. We here review the electrophysiological characteristics of hiPSC-CMs, their use for investigating inherited arrhythmia syndromes, and their applicability for identification and assessment of (novel) anti-arrhythmic treatment strategies.
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40
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Li ZY, Lin J, Sun F, Li H, Xia J, Li XN, Ge J, Zhang C, Li JL. Transport stress induces weight loss and heart injury in chicks: disruption of ionic homeostasis via modulating ion transporting ATPases. Oncotarget 2018; 8:24142-24153. [PMID: 28445983 PMCID: PMC5421834 DOI: 10.18632/oncotarget.15903] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 02/24/2017] [Indexed: 11/25/2022] Open
Abstract
Transportation is inevitable in the poultry industry, and it can induce stress to chicks in varying degrees, such as mild discomfort, sometimes even death. However, the research about the effects of transport stress on the weight loss and heart injury of chicks is lacking. To elucidate the underlying mechanism of transport stress-induced effects, chicks were transported for 2h, 4h and 8h. The creatinine kinase (CK) activities, the ionic contents, the ATPases activities and the transcription of the ATPase associated subunits in chick heart were detected. The results showed that transport stress increased the weight loss and the CK activity, disturbed the ionic (K+, Ca2+, Mg2+) homeostasis and inhibited the ATPase (Na+-K+-ATPase, Ca2+-ATPase, Mg2+-ATPase and Ca2+-Mg2+-ATPase) activities, increased the ATP content and downregulated the gene expression levels of the ATPase associated subunits in heart. In conclusion, transport stress disturbed the ionic homeostasis via modulating ion transporting ATPases and the transcriptions of the associated subunits, and ultimately induced weight loss and heart injury in chicks.
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Affiliation(s)
- Zhao-Yang Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China
| | - Jia Lin
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China
| | - Feng Sun
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China
| | - Hui Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China.,Harbin Sport University, Harbin, P. R. China
| | - Jun Xia
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China.,Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Key Laboratory of the Provincial Education Northeast Agricultural University, Harbin, P. R. China
| | - Xue-Nan Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China.,Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Northeast Agricultural University, Harbin, P. R. China
| | - Jing Ge
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China.,Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Northeast Agricultural University, Harbin, P. R. China
| | - Cong Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China.,Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Key Laboratory of the Provincial Education Northeast Agricultural University, Harbin, P. R. China
| | - Jin-Long Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, P. R. China.,Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Key Laboratory of the Provincial Education Northeast Agricultural University, Harbin, P. R. China.,Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Northeast Agricultural University, Harbin, P. R. China
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41
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Meraviglia V, Bocchi L, Sacchetto R, Florio MC, Motta BM, Corti C, Weichenberger CX, Savi M, D'Elia Y, Rosato-Siri MD, Suffredini S, Piubelli C, Pompilio G, Pramstaller PP, Domingues FS, Stilli D, Rossini A. HDAC Inhibition Improves the Sarcoendoplasmic Reticulum Ca 2+-ATPase Activity in Cardiac Myocytes. Int J Mol Sci 2018; 19:ijms19020419. [PMID: 29385061 PMCID: PMC5855641 DOI: 10.3390/ijms19020419] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/23/2018] [Accepted: 01/29/2018] [Indexed: 02/06/2023] Open
Abstract
SERCA2a is the Ca2+ ATPase playing the major contribution in cardiomyocyte (CM) calcium removal. Its activity can be regulated by both modulatory proteins and several post-translational modifications. The aim of the present work was to investigate whether the function of SERCA2 can be modulated by treating CMs with the histone deacetylase (HDAC) inhibitor suberanilohydroxamic acid (SAHA). The incubation with SAHA (2.5 µM, 90 min) of CMs isolated from rat adult hearts resulted in an increase of SERCA2 acetylation level and improved ATPase activity. This was associated with a significant improvement of calcium transient recovery time and cell contractility. Previous reports have identified K464 as an acetylation site in human SERCA2. Mutants were generated where K464 was substituted with glutamine (Q) or arginine (R), mimicking constitutive acetylation or deacetylation, respectively. The K464Q mutation ameliorated ATPase activity and calcium transient recovery time, thus indicating that constitutive K464 acetylation has a positive impact on human SERCA2a (hSERCA2a) function. In conclusion, SAHA induced deacetylation inhibition had a positive impact on CM calcium handling, that, at least in part, was due to improved SERCA2 activity. This observation can provide the basis for the development of novel pharmacological approaches to ameliorate SERCA2 efficiency.
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Affiliation(s)
- Viviana Meraviglia
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Leonardo Bocchi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Roberta Sacchetto
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020 Legnaro (Padova), Italy.
| | - Maria Cristina Florio
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Benedetta M Motta
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Corrado Corti
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Christian X Weichenberger
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Monia Savi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Yuri D'Elia
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Marcelo D Rosato-Siri
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Silvia Suffredini
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Chiara Piubelli
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Giulio Pompilio
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino, IRCCS, 20138 Milano, Italy.
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, 20122 Milano, Italy.
| | - Peter P Pramstaller
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Francisco S Domingues
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Donatella Stilli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
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42
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Abstract
Supplemental Digital Content is available in the text. Rationale: The development of a refractory period for Ca2+ spark initiation after Ca2+ release in cardiac myocytes should inhibit further Ca2+ release during the action potential plateau. However, Ca2+ release sites that did not initially activate or which have prematurely recovered from refractoriness might release Ca2+ later during the action potential and alter the cell-wide Ca2+ transient. Objective: To investigate the possibility of late Ca2+ spark (LCS) activity in intact isolated cardiac myocytes using fast confocal line scanning with improved confocality and signal to noise. Methods and Results: We recorded Ca2+ transients from cardiac ventricular myocytes isolated from rabbit hearts. Action potentials were produced by electric stimulation, and rapid solution changes were used to modify the L-type Ca2+ current. After the upstroke of the Ca2+ transient, LCSs were detected which had increased amplitude compared with diastolic Ca2+ sparks. LCS are triggered by both L-type Ca2+ channel activity during the action potential plateau, as well as by the increase of cytosolic Ca2+ associated with the Ca2+ transient itself. Importantly, a mismatch between sarcoplasmic reticulum load and L-type Ca2+ trigger can increase the number of LCS. The likelihood of triggering an LCS also depends on recovery from refractoriness that appears after prior activation. Consequences of LCS include a reduced rate of decline of the Ca2+ transient and, if frequent, formation of microscopic propagating Ca2+ release events (Ca2+ ripples). Ca2+ ripples resemble Ca2+ waves in terms of local propagation velocity but spread for only a short distance because of limited regeneration. Conclusions: These new types of Ca2+ signaling behavior extend our understanding of Ca2+-mediated signaling. LCS may provide an arrhythmogenic substrate by slowing the Ca2+ transient decline, as well as by amplifying maintained Ca2+ current effects on intracellular Ca2+ and consequently Na+/Ca2+ exchange current.
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Affiliation(s)
- Ewan D Fowler
- From the School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Sciences, University of Bristol, University Walk, United Kingdom
| | - Cherrie H T Kong
- From the School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Sciences, University of Bristol, University Walk, United Kingdom
| | - Jules C Hancox
- From the School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Sciences, University of Bristol, University Walk, United Kingdom
| | - Mark B Cannell
- From the School of Physiology, Pharmacology & Neuroscience, Faculty of Biomedical Sciences, University of Bristol, University Walk, United Kingdom.
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43
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Blaustein MP. The pump, the exchanger, and the holy spirit: origins and 40-year evolution of ideas about the ouabain-Na + pump endocrine system. Am J Physiol Cell Physiol 2017; 314:C3-C26. [PMID: 28971835 DOI: 10.1152/ajpcell.00196.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Two prescient 1953 publications set the stage for the elucidation of a novel endocrine system: Schatzmann's report that cardiotonic steroids (CTSs) are all Na+ pump inhibitors, and Szent-Gyorgi's suggestion that there is an endogenous "missing screw" in heart failure that CTSs like digoxin may replace. In 1977 I postulated that an endogenous Na+ pump inhibitor acts as a natriuretic hormone and simultaneously elevates blood pressure (BP) in salt-dependent hypertension. This hypothesis was based on the idea that excess renal salt retention promoted the secretion of a CTS-like hormone that inhibits renal Na+ pumps and salt reabsorption. The hormone also inhibits arterial Na+ pumps, elevates myocyte Na+ and promotes Na/Ca exchanger-mediated Ca2+ gain. This enhances vasoconstriction and arterial tone-the hallmark of hypertension. Here I describe how those ideas led to the discovery that the CTS-like hormone is endogenous ouabain (EO), a key factor in the pathogenesis of hypertension and heart failure. Seminal observations that underlie the still-emerging picture of the EO-Na+ pump endocrine system in the physiology and pathophysiology of multiple organ systems are summarized. Milestones include: 1) cloning the Na+ pump isoforms and physiological studies of mutated pumps in mice; 2) discovery that Na+ pumps are also EO-triggered signaling molecules; 3) demonstration that ouabain, but not digoxin, is hypertensinogenic; 4) elucidation of EO's roles in kidney development and cardiovascular and renal physiology and pathophysiology; 5) discovery of "brain ouabain", a component of a novel hypothalamic neuromodulatory pathway; and 6) finding that EO and its brain receptors modulate behavior and learning.
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Affiliation(s)
- Mordecai P Blaustein
- Departments of Physiology and Medicine, University of Maryland School of Medicine , Baltimore, Maryland
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44
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Botelho AFM, Santos-Miranda A, Joca HC, Mattoso CRS, de Oliveira MS, Pierezan F, Cruz JS, Soto-Blanco B, Melo MM. Hydroalcoholic extract from Nerium oleander L. (Apocynaceae) elicits arrhythmogenic activity. JOURNAL OF ETHNOPHARMACOLOGY 2017; 206:170-177. [PMID: 28564584 DOI: 10.1016/j.jep.2017.05.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 04/24/2017] [Accepted: 05/27/2017] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nerium oleander L. (OLE) has been used medicinally and is reported to possess a wide range of pharmacological activities. OLE effects are caused by different cardiac glycosides (CG), primarily oleandrin, found within the plant. CG can potentially impair sodium-potassium ATPase (NKA) pump activity and cause positive inotropic effects on the heart. AIM OF THE STUDY The aim of this study was to investigate the potential arrhythmogenic effects of hydroalcoholic extracts from N. oleander (OLE). MATERIALS AND METHODS OLE hydroalcoholic extracts were obtained from N. oleander leaves and analyzed by HPLC. In vivo experiments with guinea pigs consisted if oral administration of water, 150mg/kg and 300mg/kg OLE extract. Clinical signs and ECG analysis were evaluated. Sample tissues from the heart were processed for histopathological and ultra-structural analysis. Autonomic effects were assessed through pharmacological blockade and ECG monitoring. In vitro experiments were conducted with isolated ventricular myocytes from adult mice. The effects of OLE extract on cardiac excitability, Na+/K+ pump current and global Ca2+ transients were evaluated. RESULTS Our results demonstrated that OLE hydroalcoholic extract elicited severe cardiac arrhythmias that can lead to death with minimal tissue damage. In vitro experiments suggest that OLE causes electromechanical disturbances in the heart due to inhibition of Na+/K+ pump, mitochondrial swelling, and modulation of the sarco(endo)plasmic Ca2+ ATPase without interfering with the autonomic nervous system. Thus, arrhythmias and electrical conduction disturbances promoted by OLE are mainly associated with impaired cardiomyocyte dysfunction, rather than anatomical tissue remodeling and/or autonomic modulation. CONCLUSION Our data revealed the potential cardiotoxicity and positive inotropic effect of OLE and its important role in modulation of electrophysiology in cardiomyocytes.
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Affiliation(s)
- Ana Flávia Machado Botelho
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Artur Santos-Miranda
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Humberto Cavalcante Joca
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Cláudio Roberto Scabelo Mattoso
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Maira Souza de Oliveira
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Felipe Pierezan
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Jader Santos Cruz
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Benito Soto-Blanco
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marília Martins Melo
- Department of Veterinary Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Vieira FF, Olivoto RR, Silva POD, Francisco JC, Fogaça RTH. Functional Effects of Hyperthyroidism on Cardiac Papillary Muscle in Rats. Arq Bras Cardiol 2017; 107:542-549. [PMID: 28558076 PMCID: PMC5210458 DOI: 10.5935/abc.20160179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/27/2016] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Hyperthyroidism is currently recognized to affect the cardiovascular system, leading to a series of molecular and functional changes. However, little is known about the functional influence of hyperthyroidism in the regulation of cytoplasmic calcium and on the sodium/calcium exchanger (NCX) in the cardiac muscle. OBJECTIVES To evaluate the functional changes in papillary muscles isolated from animals with induced hyperthyroidism. METHODS We divided 36 Wistar rats into a group of controls and another of animals with hyperthyroidism induced by intraperitoneal T3 injection. We measured in the animals' papillary muscles the maximum contraction force, speed of contraction (+df/dt) and relaxation (-df/dt), contraction and relaxation time, contraction force at different concentrations of extracellular sodium, post-rest potentiation (PRP), and contraction force induced by caffeine. RESULTS In hyperthyroid animals, we observed decreased PRP at all rest times (p < 0.05), increased +df/dt and -df/dt (p < 0.001), low positive inotropic response to decreased concentration of extracellular sodium (p < 0.001), reduction of the maximum force in caffeine-induced contraction (p < 0.003), and decreased total contraction time (p < 0.001). The maximal contraction force did not differ significantly between groups (p = 0.973). CONCLUSION We hypothesize that the changes observed are likely due to a decrease in calcium content in the sarcoplasmic reticulum, caused by calcium leakage, decreased expression of NCX, and increased expression of a-MHC and SERCA2.
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Affiliation(s)
| | - Robson Ruiz Olivoto
- Laboratório de Fisiologia da Contração Muscular, Universidade Federal do Paraná, Brazil
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46
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Cai L, Wang Y, Gao H, Li Y, Luo X. A mathematical model for active contraction in healthy and failing myocytes and left ventricles. PLoS One 2017; 12:e0174834. [PMID: 28406991 PMCID: PMC5391010 DOI: 10.1371/journal.pone.0174834] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/15/2017] [Indexed: 02/07/2023] Open
Abstract
Cardiovascular disease is one of the leading causes of death worldwide, in particular myocardial dysfunction, which may lead to heart failure eventually. Understanding the electro-mechanics of the heart will help in developing more effective clinical treatments. In this paper, we present a multi-scale electro-mechanics model of the left ventricle (LV). The Holzapfel-Ogden constitutive law was used to describe the passive myocardial response in tissue level, a modified Grandi-Pasqualini-Bers model was adopted to model calcium dynamics in individual myocytes, and the active tension was described using the Niederer-Hunter-Smith myofilament model. We first studied the electro-mechanics coupling in a single myocyte in the healthy and diseased left ventricle, and then the single cell model was embedded in a dynamic LV model to investigate the compensation mechanism of LV pump function due to myocardial dysfunction caused by abnormality in cellular calcium dynamics. The multi-scale LV model was solved using an in-house developed hybrid immersed boundary method with finite element extension. The predictions of the healthy LV model agreed well with the clinical measurements and other studies, and likewise, the results in the failing states were also consistent with clinical observations. In particular, we found that a low level of intracellular Ca2+ transient in myocytes can result in LV pump function failure even with increased myocardial contractility, decreased systolic blood pressure, and increased diastolic filling pressure, even though they will increase LV stroke volume. Our work suggested that treatments targeted at increased contractility and lowering the systolic blood pressure alone are not sufficient in preventing LV pump dysfunction, restoring a balanced physiological Ca2+ handling mechanism is necessary.
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Affiliation(s)
- Li Cai
- NPU-UoG International Cooperative Lab for Computation & Application in Cardiology, Northwestern Polytechnical University, Xi’an, Shanxi Province, China
| | - Yongheng Wang
- NPU-UoG International Cooperative Lab for Computation & Application in Cardiology, Northwestern Polytechnical University, Xi’an, Shanxi Province, China
| | - Hao Gao
- School of Mathematics and Statistics, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Yiqiang Li
- NPU-UoG International Cooperative Lab for Computation & Application in Cardiology, Northwestern Polytechnical University, Xi’an, Shanxi Province, China
| | - Xiaoyu Luo
- School of Mathematics and Statistics, University of Glasgow, Glasgow, Scotland, United Kingdom
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Different Densities of Na-Ca Exchange Current in T-Tubular and Surface Membranes and Their Impact on Cellular Activity in a Model of Rat Ventricular Cardiomyocyte. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6343821. [PMID: 28321411 PMCID: PMC5340987 DOI: 10.1155/2017/6343821] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/18/2016] [Accepted: 01/04/2017] [Indexed: 01/13/2023]
Abstract
The ratio of densities of Na-Ca exchanger current (INaCa) in the t-tubular and surface membranes (INaCa-ratio) computed from the values of INaCa and membrane capacitances (Cm) measured in adult rat ventricular cardiomyocytes before and after detubulation ranges between 1.7 and 25 (potentially even 40). Variations of action potential waveform and of calcium turnover within this span of the INaCa-ratio were simulated employing previously developed model of rat ventricular cell incorporating separate description of ion transport systems in the t-tubular and surface membranes. The increase of INaCa-ratio from 1.7 to 25 caused a prolongation of APD (duration of action potential at 90% repolarisation) by 12, 9, and 6% and an increase of peak intracellular Ca2+ transient by 45, 19, and 6% at 0.1, 1, and 5 Hz, respectively. The prolonged APD resulted from the increase of INaCa due to the exposure of a larger fraction of Na-Ca exchangers to higher Ca2+ transients under the t-tubular membrane. The accompanying rise of Ca2+ transient was a consequence of a higher Ca2+ load in sarcoplasmic reticulum induced by the increased Ca2+ cycling between the surface and t-tubular membranes. However, the reason for large differences in the INaCa-ratio assessed from measurements in adult rat cardiomyocytes remains to be explained.
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Namekata I, Hamaguchi S, Iida-Tanaka N, Kusakabe T, Kato K, Kawanishi T, Tanaka H. Fluorescence Analysis of the Mitochondrial Effect of a Plasmalemmal Na +/Ca 2+ Exchanger Inhibitor, SEA0400, in Permeabilized H9c2 Cardiomyocytes. Biol Pharm Bull 2017; 40:1551-1555. [DOI: 10.1248/bpb.b17-00079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Iyuki Namekata
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Shogo Hamaguchi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Naoko Iida-Tanaka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
- Department of Food Science, Otsuma Women’s University
| | - Taichi Kusakabe
- Department of Organic Chemistry, Faculty of Pharmaceutical Sciences, Toho University
| | - Keisuke Kato
- Department of Organic Chemistry, Faculty of Pharmaceutical Sciences, Toho University
| | | | - Hikaru Tanaka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
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50
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Revealing calcium fluxes by analyzing inhibition dynamics in action potential clamp. J Mol Cell Cardiol 2016; 100:93-108. [DOI: 10.1016/j.yjmcc.2016.08.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 07/19/2016] [Accepted: 08/22/2016] [Indexed: 11/29/2022]
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