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Suarez PZ, Natali AJ, Mill JG, de Rezende LMT, Soares LL, Drummond FR, Cardoso LCC, Reis ECC, Lavorato VN, Carneiro-Júnior MA. Effects of moderate-continuous and high-intensity interval aerobic training on cardiac function of spontaneously hypertensive rats. Exp Biol Med (Maywood) 2022; 247:1691-1700. [PMID: 35880885 PMCID: PMC9597206 DOI: 10.1177/15353702221110823] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The aim of this study was to verify the effects of moderate-intensity continuous (MICT) and high-intensity interval (HIIT) aerobic training on cardiac morphology and function and the mechanical properties of single cardiomyocytes in spontaneously hypertensive rats (SHR) in the compensated phase of hypertension. Sixteen-week-old male SHR and normotensive Wistar (WIS) rats were allocated to six groups of six animals each: SHR CONT or WIS CONT (control); SHR MICT or WIS MICT (underwent MICT, 30 min/day, five days per week for eight weeks); and SHR HIIT or WIS HIIT (underwent HIIT, 30 min/day, five days per week for eight weeks). Total exercise time until fatigue and maximum running speed were determined using a maximal running test before and after the experimental period. Systolic (SAP), diastolic (DAP), and mean (MAP) blood pressures were measured using tail plethysmography before and after the experimental period. Echocardiographic evaluations were performed at the end of the experimental period. The rats were euthanized after in vivo assessments, and left ventricular myocytes were isolated to evaluate global intracellular Ca2+ transient ([Ca2+]i) and contractile function. Cellular measurements were performed at basal temperature (~37°C) at 3, 5, and 7 Hz. The results showed that both training programs increased total exercise time until fatigue and, consequently, maximum running speed. In hypertensive rats, MICT decreased SAP, DAP, MAP, interventricular septal thickness during systole and diastole, and the contraction amplitude at 5 Hz. HIIT increased heart weight and left ventricular wall thickness during systole and diastole and reduced SAP, MAP, and the time to peak [Ca2+]i at all pacing frequencies. In conclusion, both aerobic training protocols promoted beneficial adaptations to cardiac morphology, function, and mechanical properties of single cardiomyocytes in SHR.
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Affiliation(s)
- Pedro Z Suarez
- Laboratory of Exercise Biology,
Department of Physical Education, Universidade Federal de Viçosa (UFV), Viçosa
36570-000, Brazil
| | - Antônio J Natali
- Laboratory of Exercise Biology,
Department of Physical Education, Universidade Federal de Viçosa (UFV), Viçosa
36570-000, Brazil
| | - José G Mill
- Department of Physiological Sciences,
Universidade Federal do Espírito Santo (UFES), Vitória 29075-210, Brazil
| | - Leonardo MT de Rezende
- Laboratory of Exercise Biology,
Department of Physical Education, Universidade Federal de Viçosa (UFV), Viçosa
36570-000, Brazil
| | - Leôncio L Soares
- Laboratory of Exercise Biology,
Department of Physical Education, Universidade Federal de Viçosa (UFV), Viçosa
36570-000, Brazil
| | - Filipe R Drummond
- Department of General Biology,
Universidade Federal de Viçosa (UFV), Viçosa 36570-000, Brazil
| | - Lucas CC Cardoso
- Laboratory of Exercise Biology,
Department of Physical Education, Universidade Federal de Viçosa (UFV), Viçosa
36570-000, Brazil
| | - Emily CC Reis
- Department of Veterinary Medicine,
Universidade Federal de Viçosa (UFV), Viçosa 36570-000, Brazil
| | - Victor N Lavorato
- Department of Physical Education,
Centro Universitário Governador Ozanam Coelho (UNIFAGOC), Ubá 36506-022,
Brazil
| | - Miguel A Carneiro-Júnior
- Laboratory of Exercise Biology,
Department of Physical Education, Universidade Federal de Viçosa (UFV), Viçosa
36570-000, Brazil,Miguel A Carneiro-Júnior.
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Al Kury LT, Sydorenko V, Smail MMA, Qureshi MA, Shmygol A, Papandreou D, Singh J, Howarth FC. Calcium signaling in endocardial and epicardial ventricular myocytes from streptozotocin-induced diabetic rats. J Diabetes Investig 2021; 12:493-500. [PMID: 33112506 PMCID: PMC8015823 DOI: 10.1111/jdi.13451] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/08/2020] [Accepted: 10/22/2020] [Indexed: 12/16/2022] Open
Abstract
AIMS/INTRODUCTION Abnormalities in Ca2+ signaling have a key role in hemodynamic dysfunction in diabetic heart. The purpose of this study was to explore the effects of streptozotocin (STZ)-induced diabetes on Ca2+ signaling in epicardial (EPI) and endocardial (ENDO) cells of the left ventricle after 5-6 months of STZ injection. MATERIALS AND METHODS Whole-cell patch clamp was used to measure the L-type Ca2+ channel (LTCC) and Na+ /Ca2+ exchanger currents. Fluorescence photometry techniques were used to measure intracellular free Ca2+ concentration. RESULTS Although the LTCC current was not significantly altered, the amplitude of Ca2+ transients increased significantly in EPI-STZ and ENDO-STZ compared with controls. Time to peak LTCC current, time to peak Ca2+ transient, time to half decay of LTCC current and time to half decay of Ca2+ transients were not significantly changed in EPI-STZ and ENDO-STZ myocytes compared with controls. The Na+ /Ca2+ exchanger current was significantly smaller in EPI-STZ and in ENDO-STZ compared with controls. CONCLUSIONS STZ-induced diabetes resulted in an increase in amplitude of Ca2+ transients in EPI and ENDO myocytes that was independent of the LTCC current. Such an effect can be attributed, at least in part, to the dysfunction of the Na+ /Ca2+ exchanger. Additional studies are warranted to improve our understanding of the regional impact of diabetes on Ca2+ signaling, which will facilitate the discovery of new targeted treatments for diabetic cardiomyopathy.
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Affiliation(s)
- Lina T Al Kury
- Department of Health SciencesCollege of Natural and Health SciencesZayed UniversityAbu DhabiUnited Arab Emirates
| | - Vadym Sydorenko
- Department of Cellular MembranologyBogomoletz Institute of PhysiologyKievUkraine
| | - Manal MA Smail
- Department of PhysiologyCollege of Medicine and Health SciencesUAE UniversityAl AinUnited Arab Emirates
| | - Muhammad A Qureshi
- Department of PhysiologyCollege of Medicine and Health SciencesUAE UniversityAl AinUnited Arab Emirates
| | - Anatoly Shmygol
- Department of PhysiologyCollege of Medicine and Health SciencesUAE UniversityAl AinUnited Arab Emirates
| | - Dimitrios Papandreou
- Department of Health SciencesCollege of Natural and Health SciencesZayed UniversityAbu DhabiUnited Arab Emirates
| | - Jaipaul Singh
- School of Forensic and Applied SciencesUniversity of Central LancashirePrestonUK
| | - Frank Christopher Howarth
- Department of PhysiologyCollege of Medicine and Health SciencesUAE UniversityAl AinUnited Arab Emirates
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3
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Wacker C, Dams N, Schauer A, Ritzer A, Volk T, Wagner M. Region-specific mechanisms of corticosteroid-mediated inotropy in rat cardiomyocytes. Sci Rep 2020; 10:11604. [PMID: 32665640 PMCID: PMC7360564 DOI: 10.1038/s41598-020-68308-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/23/2020] [Indexed: 11/09/2022] Open
Abstract
Regional differences in ion channel activity in the heart control the sequence of repolarization and may contribute to differences in contraction. Corticosteroids such as aldosterone or corticosterone increase the L-type Ca2+ current (ICaL) in the heart via the mineralocorticoid receptor (MR). Here, we investigate the differential impact of corticosteroid-mediated increase in ICaL on action potentials (AP), ion currents, intracellular Ca2+ handling and contractility in endo- and epicardial myocytes of the rat left ventricle. Dexamethasone led to a similar increase in ICaL in endocardial and epicardial myocytes, while the K+ currents Ito and IK were unaffected. However, AP duration (APD) and AP-induced Ca2+ influx (QCa) significantly increased exclusively in epicardial myocytes, thus abrogating the normal differences between the groups. Dexamethasone increased Ca2+ transients, contractility and SERCA activity in both regions, the latter possibly due to a decrease in total phospholamban (PLB) and an increase PLBpThr17. These results suggest that corticosteroids are powerful modulators of ICaL, Ca2+ transients and contractility in both endo- and epicardial myocytes, while APD and QCa are increased in epicardial myocytes only. This indicates that increased ICaL and SERCA activity rather than QCa are the primary drivers of contractility by adrenocorticoids.
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Affiliation(s)
- Caroline Wacker
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstraße 6, 91054, Erlangen, Germany
| | - Niklas Dams
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstraße 6, 91054, Erlangen, Germany
| | - Alexander Schauer
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstraße 6, 91054, Erlangen, Germany
| | - Anne Ritzer
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstraße 6, 91054, Erlangen, Germany
| | - Tilmann Volk
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstraße 6, 91054, Erlangen, Germany. .,Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| | - Michael Wagner
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstraße 6, 91054, Erlangen, Germany. .,Abteilung für Rhythmologie, Herzzentrum Dresden, Fetscherstraße 76, 01307, Dresden, Germany.
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Smail M, Al Kury L, Qureshi MA, Shmygol A, Oz M, Singh J, Howarth FC. Cell shortening and calcium dynamics in epicardial and endocardial myocytes from the left ventricle of Goto-Kakizaki type 2 diabetic rats. Exp Physiol 2018; 103:502-511. [PMID: 29363193 DOI: 10.1113/ep086542] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 01/17/2018] [Indexed: 01/18/2023]
Abstract
NEW FINDINGS What is the central question of this study? To investigate haemodynamic dysfunction in the type 2 diabetic Goto-Kakizaki (GK) rat, we measured shortening and Ca2+ transport in ventricular myocytes from epicardial (EPI) and endocardial (ENDO) regions. What is the main finding and its importance? EPI and ENDO GK myocytes displayed similar hypertrophy. Time to peak (TPK) and time to half (THALF) relaxation were prolonged in EPI GK myocytes. TPK Ca2+ transient was prolonged and THALF decay of the Ca2+ transient was shortened in EPI GK myocytes. Amplitude of shortening, Ca2+ transient and sarcoplasmic reticulum Ca2+ were unaltered in EPI and ENDO myocytes from Goto-Kakizaki compared with control rats. We demostrated regional differences in shortening and Ca2+ transport in Goto-Kakizaki rats. ABSTRACT Diabetic cardiomyopathy is considered to be one of the major diabetes-associated complications, and the pathogenesis of cardiac dysfunction is not well understood. The electromechanical properties of cardiac myocytes vary across the walls of the chambers. The aim of this study was to investigate shortening and Ca2+ transport in epicardial (EPI) and endocardial (ENDO) left ventricular myocytes in the Goto-Kakizaki (GK) type 2 diabetic rat heart. Shortening and intracellular Ca2+ transients were measured by video edge detection and fluorescence photometry. Myocyte surface area was increased in EPI-GK and ENDO-GK compared with control EPI-CON and ENDO-CON myocytes. Time to peak shortening was prolonged in EPI-GK compared with EPI-CON and in ENDO-CON compared with EPI-CON myocytes. Time to half-relaxation of shortening and time to peak Ca2+ transient were prolonged in EPI-GK compared with EPI-CON myocytes. Time to half-decay of the Ca2+ transient was prolonged in EPI-CON compared with EPI-GK and in EPI-CON compared with ENDO-CON myocytes. The amplitude of shortening and the Ca2+ transient were unaltered in EPI-GK and ENDO-GK compared with their respective controls. Sarcoplasmic reticulum Ca2+ and myofilament sensitivity to Ca2+ were unaltered in EPI-GK and ENDO-GK compared with their respective controls. Regional differences in Ca2+ signalling in healthy and diabetic myocytes might account for variation in the dynamics of myocyte shortening. Further studies will be required to clarify the mechanisms underlying regional differences in the time course of shortening and the Ca2+ transient in EPI and ENDO myocytes from diabetic and control hearts.
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Affiliation(s)
- Manal Smail
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Lina Al Kury
- College of Natural and Health Sciences, Zayed University, Abu Dhabi, United Arab Emirates
| | - Muhammad Anwar Qureshi
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Anatoliy Shmygol
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Murat Oz
- Department of Basic Medical Sciences, College of Medicine, Qatar University, Doha, Qatar
| | - Jaipaul Singh
- School of Forensic & Applied Sciences, University of Central Lancashire, Preston, UK
| | - Frank Christopher Howarth
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, United Arab Emirates
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Smail MMA, Qureshi MA, Shmygol A, Oz M, Singh J, Sydorenko V, Arabi A, Howarth FC, Al Kury L. Regional effects of streptozotocin-induced diabetes on shortening and calcium transport in epicardial and endocardial myocytes from rat left ventricle. Physiol Rep 2017; 4:4/22/e13034. [PMID: 27884956 PMCID: PMC5357996 DOI: 10.14814/phy2.13034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/17/2016] [Accepted: 10/17/2016] [Indexed: 11/24/2022] Open
Abstract
In the heart, the left ventricle pumps blood at higher pressure than the right ventricle. Within the left ventricle, the electromechanical properties of ventricular cardiac myocytes vary transmurally and this may be related to the gradients of stress and strain experienced in vivo across the ventricular wall. Diabetes is also associated with alterations in hemodynamic function. The aim of this study was to investigate shortening and Ca2+ transport in epicardial (EPI) and endocardial (ENDO) left ventricular myocytes in the streptozotocin (STZ)‐induced diabetic rat. Shortening, intracellular Ca2+ and L‐type Ca2+ current (ICa,L) were measured by video detection, fura‐2 microfluorimetry, and whole‐cell patch clamp techniques, respectively. Time to peak (TPK) shortening was prolonged to similar extents in ENDO and EPI myocytes from STZ‐treated rats compared to ENDO and EPI myocytes from controls. Time to half (THALF) relaxation of shortening was prolonged in ENDO myocytes from STZ‐treated rats compared to ENDO controls. TPK Ca2+ transient was prolonged in ENDO myocytes from STZ‐treated rats compared to ENDO controls. THALF decay of the Ca2+ transient was prolonged in ENDO myocytes from STZ‐treated rats compared to ENDO controls. Sarcoplasmic reticulum (SR) fractional release of Ca2+ was reduced in EPI myocytes from STZ‐treated rats compared to EPI controls. ICa,L activation, inactivation, and recovery from inactivation were not significantly altered in EPI and ENDO myocytes from STZ‐treated rats or controls. Regional differences in Ca2+ transport may partly underlie differences in ventricular myocyte shortening across the wall of the healthy and the STZ‐treated rat left ventricle.
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Affiliation(s)
- Manal M A Smail
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Muhammad A Qureshi
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Anatoliy Shmygol
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Murat Oz
- Department of Pharmacology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Jaipaul Singh
- School of Forensic & Applied Sciences, University of Central Lancashire, Preston, UK
| | - Vadym Sydorenko
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Alya Arabi
- College of Natural & Health Sciences, Zayed University, Abu Dhabi, UAE
| | - Frank C Howarth
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Lina Al Kury
- College of Natural & Health Sciences, Zayed University, Abu Dhabi, UAE
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Bai XJ, Hao JT, Wang J, Zhang WF, Yan CP, Zhao JH, Zhao ZQ. Curcumin inhibits cardiac hypertrophy and improves cardiovascular function via enhanced Na +/Ca 2+ exchanger expression after transverse abdominal aortic constriction in rats. Pharmacol Rep 2017; 70:60-68. [PMID: 29331788 DOI: 10.1016/j.pharep.2017.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 07/08/2017] [Accepted: 07/13/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND This study tested the hypothesis that inhibition of cardiac hypertrophy and preservation of cardiac/endothelial function by the natural yellow pigment curcumin are associated with upregulated expression of Na+/Ca2+ exchanger (NCX) after transverse aortic constriction (TAC). METHODS Male Wistar rats were subjected to TAC for 10 weeks and curcumin (50 mg/kg/day) was fed by gastric gavage during TAC. Expression of NCX and endothelial nitric oxide synthase (eNOS) was analyzed by Western blot and immunohistochemistry. RESULTS Compared with the animals in the TAC group, curcumin significantly increased the survival rate and reduced the ratio of heart or left ventricle (LV) to body weight and the cross sectional area of cardiomyocytes. In coincidence with improved LV systolic pressure and reduced LV end-diastolic pressure, curcumin significantly reduced LV end-systolic and diastolic diameter/dimension, and enhanced LV ejection fraction and LV fractional shortening as measured by echocardiography. Furthermore, endothelium-dependent relaxation of aortic rings in response to acetylcholine was significantly improved by curcumin. Along with these modifications, the expression and localization of NCX and eNOS in the myocardium and vascular endothelium were significantly upregulated by curcumin. The protective effect of curcumin on endothelium-dependent relaxation was partly blocked by pretreatment with the NCX inhibitor, KB-R7943. CONCLUSIONS These results demonstrate that inhibition of cardiac hypertrophy, improvement of cardiac systolic/diastolic function and preservation of vascular endothelium by curcumin might be associated with upregulated NCX expression level in response to increased afterload.
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Affiliation(s)
- Xiao-Jie Bai
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China.
| | - Jun-Tao Hao
- Department of Thoracic Surgery, Shanxi Provincial People's Hospital, Taiyuan, Shanxi, People's Republic of China
| | - Jin Wang
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Wei-Fang Zhang
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Cai-Ping Yan
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Jia-Hui Zhao
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, People's Republic of China
| | - Zhi-Qing Zhao
- Cardiovascular Research Laboratory, Mercer University School of Medicine, Savannah, GA, USA
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Enhanced nucleoplasmic Ca2+ signaling in ventricular myocytes from young hypertensive rats. J Mol Cell Cardiol 2016; 101:58-68. [DOI: 10.1016/j.yjmcc.2016.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 10/31/2016] [Accepted: 11/01/2016] [Indexed: 11/20/2022]
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8
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N-3 vs. n-6 fatty acids differentially influence calcium signalling and adhesion of inflammatory activated monocytes: impact of lipid rafts. Inflamm Res 2016; 65:881-894. [DOI: 10.1007/s00011-016-0971-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 04/01/2016] [Accepted: 06/28/2016] [Indexed: 11/30/2022] Open
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Asensio-López MC, Soler F, Sánchez-Más J, Pascual-Figal D, Fernández-Belda F, Lax A. Early oxidative damage induced by doxorubicin: Source of production, protection by GKT137831 and effect on Ca(2+) transporters in HL-1 cardiomyocytes. Arch Biochem Biophys 2016; 594:26-36. [PMID: 26906075 DOI: 10.1016/j.abb.2016.02.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 02/04/2016] [Accepted: 02/18/2016] [Indexed: 01/26/2023]
Abstract
In atrial-derived HL-1 cells, ryanodine receptor and Na(+)/Ca(2+)-exchanger were altered early by 5 μM doxorubicin. The observed effects were an increase of cytosolic Ca(2+) at rest, ensuing ryanodine receptor phosphorylation, and the slowing of Ca(2+) transient decay after caffeine addition. Doxorubicin triggered a linear rise of reactive oxygen species (ROS) with no early effect on mitochondrial inner membrane potential. Doxorubicin and ROS were both detected in mitochondria by colocalization with fluorescence probes and doxorubicin-induced ROS was totally blocked by mitoTEMPO. The NADPH oxidase activity in the mitochondrial fraction was sensitive to inhibition by GKT137831, and doxorubicin-induced ROS decreased gradually as the GKT137831 concentration added in preincubation was increased. When doxorubicin-induced ROS was prevented by GKT137831, the kinetic response revealed a permanent degree of protection that was consistent with mitochondrial NADPH oxidase inhibition. In contrast, the ROS induction by doxorubicin after melatonin preincubation was totally eliminated at first but the effect was completely reversed with time. Limiting the source of ROS production is a better alternative for dealing with oxidative damage than using ROS scavengers. The short-term effect of doxorubicin on Ca(2+) transporters involved in myocardiac contractility was dependent on oxidative damage, and so the impairment was subsequent to ROS production.
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Affiliation(s)
- Mari C Asensio-López
- Cardiología Clínica y Experimental, Departamento de Medicina Interna, Facultad de Medicina, Universidad de Murcia, Campus de El Palmar, 30120, Murcia, Spain
| | - Fernando Soler
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia, Campus de Espinardo, 30071, Murcia, Spain
| | - Jesús Sánchez-Más
- Cardiología Clínica y Experimental, Departamento de Medicina Interna, Facultad de Medicina, Universidad de Murcia, Campus de El Palmar, 30120, Murcia, Spain
| | - Domingo Pascual-Figal
- Cardiología Clínica y Experimental, Departamento de Medicina Interna, Facultad de Medicina, Universidad de Murcia, Campus de El Palmar, 30120, Murcia, Spain; Servicio de Cardiología, Hospital Clínico Universitario Virgen de la Arrixaca, 30120, El Palmar, Murcia, Spain
| | - Francisco Fernández-Belda
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia, Campus de Espinardo, 30071, Murcia, Spain.
| | - Antonio Lax
- Cardiología Clínica y Experimental, Departamento de Medicina Interna, Facultad de Medicina, Universidad de Murcia, Campus de El Palmar, 30120, Murcia, Spain
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Rodriguez JS, Velez Rueda JO, Salas M, Becerra R, Di Carlo MN, Said M, Vittone L, Rinaldi G, Portiansky EL, Mundiña-Weilenmann C, Palomeque J, Mattiazzi A. Increased Na⁺/Ca²⁺ exchanger expression/activity constitutes a point of inflection in the progression to heart failure of hypertensive rats. PLoS One 2014; 9:e96400. [PMID: 24781001 PMCID: PMC4004550 DOI: 10.1371/journal.pone.0096400] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 04/07/2014] [Indexed: 11/19/2022] Open
Abstract
UNLABELLED Spontaneously hypertensive rat (SHR) constitutes a genetic model widely used to study the natural evolution of hypertensive heart disease. Ca²⁺-handling alterations are known to occur in SHR. However, the putative modifications of Ca²⁺-handling proteins during the progression to heart failure (HF) are not well established. Moreover, the role of apoptosis in SHR is controversial. We investigated intracellular Ca²⁺, Ca²⁺-handling proteins and apoptosis in SHR vs. control Wistar rats (W) from 3 to 15 months (mo). Changes associated with the transition to HF (i.e. lung edema and decrease in midwall fractional shortening), occurred at 15 mo in 38% of SHR (SHRF). In SHRF, twitch and caffeine-induced Ca²⁺ transients, significantly decreased relative to 6/9 mo and 15 mo without HF signs. This decrease occurred in association with a decrease in the time constant of caffeine-Ca²⁺ transient decay and an increase in Na⁺/Ca²⁺ exchanger (NCX) abundance (p<0.05) with no changes in SERCA2a expression/activity. An increased Ca²⁺-calmodulin-kinase II activity, associated with an enhancement of apoptosis (TUNEL and Bax/Bcl2) was observed in SHR relative to W from 3 to 15 mo. CONCLUSIONS 1. Apoptosis is an early and persistent event that may contribute to hypertrophic remodeling but would not participate in the contractile impairment of SHRF. 2. The increase in NCX expression/activity, associated with an increase in Ca²⁺ efflux from the cell, constitutes a primary alteration of Ca²⁺-handling proteins in the evolution to HF. 3. No changes in SERCA2a expression/activity are observed when HF signs become evident.
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Affiliation(s)
- Jesica S. Rodriguez
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - J. Omar Velez Rueda
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Margarita Salas
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Romina Becerra
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Mariano N. Di Carlo
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Matilde Said
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Leticia Vittone
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Gustavo Rinaldi
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
| | - Enrique L. Portiansky
- Laboratorio de Análisis de Imágenes, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina
| | - Cecilia Mundiña-Weilenmann
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
- * E-mail: (CM-W); (JP)
| | - Julieta Palomeque
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
- * E-mail: (CM-W); (JP)
| | - Alicia Mattiazzi
- Centro de Investigaciones Cardiovasculares, CONICET-La Plata, Facultad de Medicina, Universidad Nacional de La Plata, La Plata, Argentina
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Sacherer M, Sedej S, Wakuła P, Wallner M, Vos MA, Kockskämper J, Stiegler P, Sereinigg M, von Lewinski D, Antoons G, Pieske BM, Heinzel FR. JTV519 (K201) reduces sarcoplasmic reticulum Ca²⁺ leak and improves diastolic function in vitro in murine and human non-failing myocardium. Br J Pharmacol 2013; 167:493-504. [PMID: 22509897 DOI: 10.1111/j.1476-5381.2012.01995.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Ca²⁺ leak from the sarcoplasmic reticulum (SR) via ryanodine receptors (RyR2s) contributes to cardiomyocyte dysfunction. RyR2 Ca²⁺ leak has been related to RyR2 phosphorylation. In these conditions, JTV519 (K201), a 1,4-benzothiazepine derivative and multi-channel blocker, stabilizes RyR2s and decrease SR Ca²⁺ leak. We investigated whether JTV519 stabilizes RyR2s without increasing RyR2 phosphorylation in mice and in non-failing human myocardium and explored underlying mechanisms. EXPERIMENTAL APPROACH SR Ca²⁺ leak was induced by ouabain in murine cardiomyocytes. [Ca²⁺]-transients, SR Ca²⁺ load and RyR2-mediated Ca²⁺ leak (sparks/waves) were quantified, with or without JTV519 (1 µmol·L⁻¹). Contribution of Ca²⁺ -/calmodulin-dependent kinase II (CaMKII) was assessed by KN-93 and Western blot (RyR2-Ser(2814) phosphorylation). Effects of JTV519 on contractile force were investigated in non-failing human ventricular trabeculae. KEY RESULTS Ouabain increased systolic and diastolic cytosolic [Ca²⁺](i) , SR [Ca²⁺], and SR Ca²⁺ leak (Ca²⁺ spark (SparkF) and Ca²⁺ wave frequency), independently of CaMKII and RyR-Ser(2814) phosphorylation. JTV519 decreased SparkF but also SR Ca²⁺ load. At matched SR [Ca²⁺], Ca²⁺ leak was significantly reduced by JTV519, but it had no effect on fractional Ca²⁺ release or Ca²⁺ wave propagation velocity. In human muscle, JTV519 was negatively inotropic at baseline but significantly enhanced ouabain-induced force and reduced its deleterious effects on diastolic function. CONCLUSIONS AND IMPLICATIONS JTV519 was effective in reducing SR Ca²⁺ leak by specifically regulating RyR2 opening at diastolic [Ca²⁺](i) in the absence of increased RyR2 phosphorylation at Ser(2814) , extending the potential use of JTV519 to conditions of acute cellular Ca²⁺ overload.
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Affiliation(s)
- M Sacherer
- Division of Cardiology, Medical University of Graz, Austria
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12
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Takagaki Y, Yamagishi H, Matsuoka R. Factors Involved in Signal Transduction During Vertebrate Myogenesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 296:187-272. [DOI: 10.1016/b978-0-12-394307-1.00004-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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13
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Xu L, Chen J, Li XY, Ren S, Huang CX, Wu G, Li XY, Jiang XJ. Analysis of Na(+)/Ca (2+) exchanger (NCX) function and current in murine cardiac myocytes during heart failure. Mol Biol Rep 2011; 39:3847-52. [PMID: 21750914 DOI: 10.1007/s11033-011-1163-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Accepted: 06/30/2011] [Indexed: 11/29/2022]
Abstract
Na(+)/Ca(2+) exchanger (NCX) plays important roles in cardiac electrical activity and calcium homeostasis. NCX current (I(NCX)) shows transmural gradient across left ventricle in many species. Previous studies demonstrated that NCX expression was increased and transmural gradient of I(NCX) was disrupted in failing heart, but the mechanisms underlying I(NCX) remodeling still remain unknown. In present study, we used patch clamp technique to record I(NCX) from subepicardial (EPI) myocytes and subendocardial (ENDO) myocytes isolated from sham operation (SO) mice and heart failure (HF) mice. Our results showed that I(NCX) was higher in normal EPI cells compared with that in ENDO, whatever for forward mode or reverse mode. In HF group, I(NCX) was significantly up-regulated, but EPI-ENDO difference was disrupted because of a more increase of I(NCX) in ENDO myocytes. In order to explore the molecular mechanism underlying remodeling of I(NCX) in failing heart, we detected the protein expression of NCX1 and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) by Western blot. We found that CaMKII activity was dramatically enhanced and parallel with the expression of NCX1 in failing heart. Our study demonstrated that transmural gradient of I(NCX) existed in murine left ventricle, and increased activity of CaMKII should account for I(NCX) remodeling in failing heart.
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Affiliation(s)
- Lin Xu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, People's Republic of China.
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14
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Bondarenko VE, Rasmusson RL. Transmural heterogeneity of repolarization and Ca2+ handling in a model of mouse ventricular tissue. Am J Physiol Heart Circ Physiol 2010; 299:H454-69. [PMID: 20525874 DOI: 10.1152/ajpheart.00907.2009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mouse hearts have a diversity of action potentials (APs) generated by the cardiac myocytes from different regions. Recent evidence shows that cells from the epicardial and endocardial regions of the mouse ventricle have a diversity in Ca(2+) handling properties as well as K(+) current expression. To examine the mechanisms of AP generation, propagation, and stability in transmurally heterogeneous tissue, we developed a comprehensive model of the mouse cardiac cells from the epicardial and endocardial regions of the heart. Our computer model simulates the following differences between epicardial and endocardial myocytes: 1) AP duration is longer in endocardial and shorter in epicardial myocytes, 2) diastolic and systolic intracellular Ca(2+) concentration and intracellular Ca(2+) concentration transients are higher in paced endocardial and lower in epicardial myocytes, 3) Ca(2+) release rate is about two times larger in endocardial than in epicardial myocytes, and 4) Na(+)/Ca(2+) exchanger rate is greater in epicardial than in endocardial myocytes. Isolated epicardial cells showed a higher threshold for stability of AP generation but more complex patterns of AP duration at fast pacing rates. AP propagation velocities in the model of two-dimensional tissue are close to those measured experimentally. Simulations show that heterogeneity of repolarization and Ca(2+) handling are sustained across the mouse ventricular wall. Stability analysis of AP propagation in the two-dimensional model showed the generation of Ca(2+) alternans and more complex transmurally heterogeneous irregular structures of repolarization and intracellular Ca(2+) transients at fast pacing rates.
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Affiliation(s)
- Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, USA
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15
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Affiliation(s)
- Mark R. Fowler
- Faculty of Biomedical & Life Sciences, West Medical Building, University of Glasgow, United Kingdom
| | - Godfrey L. Smith
- Faculty of Biomedical & Life Sciences, West Medical Building, University of Glasgow, United Kingdom
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16
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Guo A, Yang HT. Ca2+removal mechanisms in mouse embryonic stem cell-derived cardiomyocytes. Am J Physiol Cell Physiol 2009; 297:C732-41. [DOI: 10.1152/ajpcell.00025.2009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In mammalian adult cardiomyocytes, sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) plays a major role in controlling the decline of cytosolic free Ca2+concentration ([Ca2+]i) in comparison with sarcolemmal Na+/Ca2+exchanger (NCX). However, the functional importance of SERCA and NCX in cytosolic Ca2+removal during early cardiomyogenesis is still debated. In this study, the functional contributions of Ca2+transporters to [Ca2+]idecline in mouse embryonic stem cell-derived cardiomyocytes (mESCMs), a suitable model for investigation of early cardiogenesis, at various differentiation stages were investigated. We estimated that even at early differentiation stages of mESCMs, SERCA was responsible for ∼76% of total Ca2+removal, while NCX was responsible for ∼21%. The contributions of SERCA and NCX to cytosolic Ca2+clearance were increased to ∼88% and decreased to ∼10%, respectively, at the late differentiation stage. Dynamical analysis of the transient decay phases in normal and Na+-free solutions suggests that the contribution of NCX to [Ca2+]idecline is more apparent in the terminal slow decay phase than that in the initial fast phase. When SR function was suppressed in type 2 ryanodine receptor-null mESCMs or with ryanodine receptor and SERCA inhibitors (ryanodine and thapsigargin), NCX acted as the main pathway for [Ca2+]idecline. We conclude that the rapid [Ca2+]idecline is mainly achieved by the SR uptake even at the early differentiation stage of mESCMs, while NCX acts as the main Ca2+remover when SR function is suppressed. These findings suggest a critical role of SR in the regulation of [Ca2+]ihomeostasis even in differentiating cardiomyocytes.
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Affiliation(s)
- Ang Guo
- Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, and Shanghai Jiao Tong University School of Medicine
| | - Huang-Tian Yang
- Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, and Shanghai Jiao Tong University School of Medicine
- Shanghai Stem Cell Institute, Shanghai Jiao Tong University School of Medicine; and
- Shanghai Key Laboratory of Vascular Biology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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17
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Calcium in the heart: when it's good, it's very very good, but when it's bad, it's horrid. Biochem Soc Trans 2008; 35:957-61. [PMID: 17956254 DOI: 10.1042/bst0350957] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ca(2+) increases in the heart control both contraction and transcription. To accommodate a short-term increased cardiovascular demand, neurohormonal modulators acting on the cardiac pacemaker and individual myocytes induce an increase in frequency and magnitude of myocyte contraction respectively. Prolonged, enhanced function results in hypertrophic growth of the heart, which is initially also associated with greater Ca(2+) signals and cardiac contraction. As a result of disease, however, hypertrophy progresses to a decompensated state and Ca(2+) signalling capacity and cardiac output are reduced. Here, the role that Ca(2+) plays in the induction of hypertrophy as well as the impact that cardiac hypertrophy and failure has on Ca(2+) fluxes will be discussed.
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18
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Cingolani E, Ramirez Correa GA, Kizana E, Murata M, Cho HC, Marbán E. Gene Therapy to Inhibit the Calcium Channel β Subunit. Circ Res 2007; 101:166-75. [PMID: 17556655 DOI: 10.1161/circresaha.107.155721] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Calcium cycling figures prominently in excitation-contraction coupling and in various signaling cascades involved in the development of left ventricular hypertrophy. We hypothesized that genetic suppression of the L-type calcium channel accessory beta-subunit would modulate calcium current and suppress cardiac hypertrophy. A short hairpin RNA template sequence capable of mediating the knockdown of the L-type calcium channel accessory beta-subunit gene was incorporated into a lentiviral vector (PPT.CG.H1.beta(2)). Transduction of ventricular myocytes in vivo with the active short hairpin RNA partially inhibited the L-type calcium current. In neonatal rat cardiomyocytes, L-type calcium channel accessory beta-subunit gene knockdown reduced calcium transient amplitude. Similarly, [(3)H]leucine incorporation was attenuated in PPT.CG.H1.beta(2)-transduced neonatal rat cardiomyocytes compared with nonsilencing controls in a phenylephrine-induced hypertrophy model. In vivo gene transfer attenuated the hypertrophic response in an aortic-banded rat model of left ventricular hypertrophy, with reduced left ventricular wall thickness and heart weight/body weight ratios in PPT.CG.H1.beta(2)-injected rats at four weeks post transduction. Fractional shortening was preserved in rats treated with PPT.CG.H1.beta(2). These findings indicate that knockdown of L-type calcium channel accessory beta-subunit is capable of attenuating the hypertrophic response both in vitro and in vivo without compromising systolic performance. Suppression of the calcium channel beta subunit may represent a novel and useful therapeutic strategy for left ventricular hypertrophy.
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MESH Headings
- Animals
- Animals, Newborn
- Calcium Channels, L-Type/deficiency
- Calcium Channels, L-Type/metabolism
- Disease Models, Animal
- Gene Silencing
- Genetic Therapy
- Humans
- Hypertrophy, Left Ventricular/genetics
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Hypertrophy, Left Ventricular/therapy
- Lentivirus
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Organ Size/genetics
- Protein Subunits/deficiency
- Protein Subunits/metabolism
- Rats
- Transduction, Genetic
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Affiliation(s)
- Eugenio Cingolani
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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19
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Kapur N, Banach K. Inositol-1,4,5-trisphosphate-mediated spontaneous activity in mouse embryonic stem cell-derived cardiomyocytes. J Physiol 2007; 581:1113-27. [PMID: 17379641 PMCID: PMC2170837 DOI: 10.1113/jphysiol.2006.125955] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Embryonic stem cell-derived cardiomyocytes (ESdCs) have been proposed as a source for cardiac cell-replacement therapy. The aim of this study was to determine the Ca2+-handling mechanisms that determine the frequency and duration of spontaneous Ca2+ transients in single ESdCs. With laser scanning confocal microscopy using the Ca2+-sensitive dye Fluo-4/AM, we determined that spontaneous Ca2+ transients in ESdCs at the onset of beating (day 9) depend on Ca2+ entry across the plasma membrane (50%) whereas Ca2+-induced Ca2+ release is the major contributor to Ca2+ transients in ESdCs after 16 days (72%). Likewise, Ca2+ extrusion in 9-day-old ESdCs depends on Na+-Ca2+ exchange (50.0+/-8%) whereas Ca2+ reuptake by the sarco(endo)plasmic Ca2+ ATPase (72+/-5%) dominates in further differentiated cells. Spontaneous Ca2+ transients were suppressed by the inositol-1,4,5-trisphosphate (IP3) receptor (IP3R) blocker 2-aminoethoxydiphenyl borate (2-APB) and the phospholipase C blocker U73122 but continued in the presence of caffeine. Stimulation of IP3 production by phenylephrine or endothelin-1 had a positive chronotropic effect that could be reversed by U73122 and 2-APB. The presence of Ca2+-free solution and block of L-type Ca2+ channels by nifedipine also resulted in a cessation of spontaneous activity. Overall, IP3R-mediated Ca2+ release in ESdCs is translated into a depolarization of the plasma membrane and a whole-cell Ca2+ transient is subsequently induced by voltage-dependent Ca2+ influx. Although ryanodine receptor-mediated Ca2+ release amplifies the IP3R-induced trigger for the Ca2+ transients and modulates its frequencies, it is not a prerequisite for spontaneous activity. The results of this study offer important insight into the role of IP3R-mediated Ca2+ release for pacemaker activity in differentiating cardiomyocytes.
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MESH Headings
- Action Potentials
- Aniline Compounds
- Animals
- Boron Compounds/pharmacology
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/metabolism
- Calcium Signaling/drug effects
- Cell Differentiation
- Cell Line
- Embryonic Stem Cells/drug effects
- Embryonic Stem Cells/metabolism
- Endothelin-1/metabolism
- Enzyme Inhibitors/pharmacology
- Estrenes/pharmacology
- Fluorescent Dyes
- Heart Rate/drug effects
- Heart Rate/physiology
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/antagonists & inhibitors
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Mice
- Microscopy, Confocal
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Nifedipine/pharmacology
- Phenylephrine/metabolism
- Pyrrolidinones/pharmacology
- Ryanodine Receptor Calcium Release Channel/metabolism
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
- Sodium-Calcium Exchanger/metabolism
- Time Factors
- Type C Phospholipases/antagonists & inhibitors
- Type C Phospholipases/metabolism
- Xanthenes
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Affiliation(s)
- Nidhi Kapur
- Department of Physiology, Stritch School of Medicine, Loyola University Chicago, 2160 South First Avenue, Maywood, IL 60153, USA
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20
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Duncan DJ, Hopkins PM, Harrison SM. Negative inotropic effects of tumour necrosis factor-alpha and interleukin-1beta are ameliorated by alfentanil in rat ventricular myocytes. Br J Pharmacol 2007; 150:720-6. [PMID: 17279089 PMCID: PMC2013863 DOI: 10.1038/sj.bjp.0707147] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Serum levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) increase during an inflammatory response and have been reported to induce a negative inotropic effect on the myocardium. Alfentanil, an opioid analgesic often used in the critical care of patients with sepsis, has been shown to enhance ventricular contractility. This study characterised the effects of TNF-alpha and IL-1beta on contraction and the Ca(2+) transient and investigated whether depressed ventricular function was ameliorated by alfentanil. EXPERIMENTAL APPROACH Isolated rat ventricular myocytes were loaded with fura-2 and electrically stimulated at 1 Hz. Contraction and Ca(2+) transients were measured after 60, 120 and 180 min incubations in TNF-alpha (0.05 ng ml(-1)) and IL-1beta (2 ng ml(-1)). The effects of 10 microM alfentanil on contractility and Ca(2+) transients of TNF-alpha and IL-1beta treated cells were determined. KEY RESULTS After 180 min of TNF-alpha and IL-1beta treatment, the amplitude of contraction, the Ca(2+) transient and sarcoplasmic reticulum (SR) Ca(2+) content were significantly reduced. Alfentanil significantly increased contraction of TNF-alpha and IL-1beta treated cells via a small increase in the Ca(2+) transient and a larger increase in myofilament Ca(2+) sensitivity, effects that were not blocked by 10 microM naloxone, a broad spectrum opioid receptor antagonist. CONCLUSIONS AND IMPLICATIONS TNF-alpha and IL-1beta induce a significant negative inotropic effect on ventricular myocytes in a time dependent manner through disruption of SR Ca(2+) handling and the Ca(2+) transient. This negative inotropic effect was ameliorated by alfentanil, but this response may not be mediated via opioid receptors.
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Affiliation(s)
- D J Duncan
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds Leeds, UK
| | - P M Hopkins
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds Leeds, UK
| | - S M Harrison
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, University of Leeds Leeds, UK
- Author for correspondence:
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Dilly KW, Rossow CF, Votaw VS, Meabon JS, Cabarrus JL, Santana LF. Mechanisms underlying variations in excitation-contraction coupling across the mouse left ventricular free wall. J Physiol 2006; 572:227-41. [PMID: 16423856 PMCID: PMC1779645 DOI: 10.1113/jphysiol.2005.102020] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Ca(2+) release during excitation-contraction (EC) coupling varies across the left ventricular free wall. Here, we investigated the mechanisms underlying EC coupling differences between mouse left ventricular epicardial (Epi) and endocardial (Endo) myocytes. We found that diastolic and systolic [Ca(2+)](i) was higher in paced Endo than in Epi myocytes. Our data indicated that differences in action potential (AP) waveform between Epi and Endo cells only partially accounted for differences in [Ca(2+)](i). Rather, we found that the amplitude of the [Ca(2+)](i) transient, but not its trigger - the Ca(2+) current - was larger in Endo than in Epi cells. We also found that spontaneous Ca(2+) spark activity was about 2.8-fold higher in Endo than in Epi cells. Interestingly, ryanodine receptor type 2 (RyR2) protein expression was nearly 2-fold higher in Endo than in Epi myocytes. Finally, we observed less Na(+)-Ca(2+) exchanger function in Endo than in Epi cells, which was associated with decreased Ca(2+) efflux during the AP; this contributed to higher diastolic [Ca(2+)](i) and SR Ca(2+) in Endo than in Epi cells during pacing. We propose that transmural differences in AP waveform, SR Ca(2+) release, and Na(+)-Ca(2+) exchanger function underlie differences in [Ca(2+)](i) and EC coupling across the left ventricular free wall.
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Affiliation(s)
- Keith W Dilly
- Department of Physiology and Biophysics, University of Washington, Box 357290, Seattle, WA 98195, USA
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