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Horváth B, Kovács Z, Dienes C, Barta Z, Óvári J, Szentandrássy N, Magyar J, Bányász T, Nánási PP. Relationship between ion currents and membrane capacitance in canine ventricular myocytes. Sci Rep 2024; 14:11241. [PMID: 38755246 PMCID: PMC11099174 DOI: 10.1038/s41598-024-61736-6] [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: 02/21/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024] Open
Abstract
Current density, the membrane current value divided by membrane capacitance (Cm), is widely used in cellular electrophysiology. Comparing current densities obtained in different cell populations assume that Cm and ion current magnitudes are linearly related, however data is scarce about this in cardiomyocytes. Therefore, we statistically analyzed the distributions, and the relationship between parameters of canine cardiac ion currents and Cm, and tested if dividing original parameters with Cm had any effect. Under conventional voltage clamp conditions, correlations were high for IK1, moderate for IKr and ICa,L, while negligible for IKs. Correlation between Ito1 peak amplitude and Cm was negligible when analyzing all cells together, however, the analysis showed high correlations when cells of subepicardial, subendocardial or midmyocardial origin were analyzed separately. In action potential voltage clamp experiments IK1, IKr and ICa,L parameters showed high correlations with Cm. For INCX, INa,late and IKs there were low-to-moderate correlations between Cm and these current parameters. Dividing the original current parameters with Cm reduced both the coefficient of variation, and the deviation from normal distribution. The level of correlation between ion currents and Cm varies depending on the ion current studied. This must be considered when evaluating ion current densities in cardiac cells.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary.
| | - Zsigmond Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zalán Barta
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - József Óvári
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
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Naveed M, Mohammed ASA, Topal L, Kovács ZM, Dienes C, Ovári J, Szentandrássy N, Magyar J, Bányász T, Prorok J, Jost N, Virág L, Baczkó I, Varró A, Nánási PP, Horváth B. Selective Inhibition of Cardiac Late Na + Current Is Based on Fast Offset Kinetics of the Inhibitor. Biomedicines 2023; 11:2383. [PMID: 37760824 PMCID: PMC10525890 DOI: 10.3390/biomedicines11092383] [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: 07/23/2023] [Revised: 08/11/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
The present study was designed to test the hypothesis that the selectivity of blocking the late Na+ current (INaL) over the peak Na+ current (INaP) is related to the fast offset kinetics of the Na+ channel inhibitor. Therefore, the effects of 1 µM GS967 (INaL inhibitor), 20 µM mexiletine (I/B antiarrhythmic) and 10 µM quinidine (I/A antiarrhythmic) on INaL and INaP were compared in canine ventricular myocardium. INaP was estimated as the maximum velocity of action potential upstroke (V+max). Equal amounts of INaL were dissected by the applied drug concentrations under APVC conditions. The inhibition of INaL by mexiletine and quinidine was comparable under a conventional voltage clamp, while both were smaller than the inhibitory effect of GS967. Under steady-state conditions, the V+max block at the physiological cycle length of 700 ms was 2.3% for GS967, 11.4% for mexiletine and 26.2% for quinidine. The respective offset time constants were 110 ± 6 ms, 456 ± 284 ms and 7.2 ± 0.9 s. These results reveal an inverse relationship between the offset time constant and the selectivity of INaL over INaP inhibition without any influence of the onset rate constant. It is concluded that the selective inhibition of INaL over INaP is related to the fast offset kinetics of the Na+ channel inhibitor.
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Affiliation(s)
- Muhammad Naveed
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
| | - Aiman Saleh A. Mohammed
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
| | - Leila Topal
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
| | - Zsigmond Máté Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
| | - Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
| | - József Ovári
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, H-6720 Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
- Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
| | - János Prorok
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Loránd Eötvös Research Network, 1097 Szeged, Hungary;
| | - Norbert Jost
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Loránd Eötvös Research Network, 1097 Szeged, Hungary;
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (M.N.); (A.S.A.M.); (L.T.); (N.J.); (L.V.); (I.B.); (A.V.)
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Loránd Eötvös Research Network, 1097 Szeged, Hungary;
| | - Péter P. Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
- Division of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, H-6720 Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-6720 Debrecen, Hungary; (Z.M.K.); (C.D.); (J.O.); (N.S.); (J.M.); (T.B.); (B.H.)
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Sun XY, Jia LY, Rong Z, Zhou X, Cao LQ, Li AH, Guo M, Jin J, Wang YD, Huang L, Li YH, He ZJ, Li L, Ma RK, Lv YF, Shao KK, Zhang J, Cao HL. Research Advances on Matrine. Front Chem 2022; 10:867318. [PMID: 35433636 PMCID: PMC9010661 DOI: 10.3389/fchem.2022.867318] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 11/13/2022] Open
Abstract
Matrine is an alkaloid extracted from traditional Chinese herbs including Sophora flavescentis, Sophora alopecuroides, Sophora root, etc. It has the dual advantages of traditional Chinese herbs and chemotherapy drugs. It exhibits distinct benefits in preventing and improving chronic diseases such as cardiovascular disease and tumors. The review introduced recent research progresses on extraction, synthesis and derivatization of Matrine. The summary focused on the latest research advances of Matrine on anti-atherosclerosis, anti-hypertension, anti-ischemia reperfusion injury, anti-arrhythmia, anti-diabetic cardiovascular complications, anti-tumor, anti-inflammatory, anti-bacterium, anti-virus, which would provide new core structures and new insights for new drug development in related fields.
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Affiliation(s)
- Xiao-Ying Sun
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Li-Yi Jia
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Zheng Rong
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Xin Zhou
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
| | - Lu-Qi Cao
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
| | - Ai-Hong Li
- Shaanxi Key Laboratory of Chinese Herb and Natural Drug Development, Medicine Research Institute, Shaanxi Pharmaceutical Holding Group Co., LTD, Xi’an, China
| | - Meng Guo
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Jie Jin
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Yin-Di Wang
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Ling Huang
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
| | - Yi-Heng Li
- College of Life Sciences, Northwest University, Xi’an, China
| | - Zhong-Jing He
- College of Life Sciences, Northwest University, Xi’an, China
| | - Long Li
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
| | - Rui-Kang Ma
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
| | - Yi-Fan Lv
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
| | - Ke-Ke Shao
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
| | - Juan Zhang
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
- *Correspondence: Juan Zhang, ; Hui-Ling Cao,
| | - Hui-Ling Cao
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, China
- Xi’an Key Laboratory of Basic and Translation of Cardiovascular Metabolic Disease, Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, China
- Shaanxi Key Laboratory of Chinese Herb and Natural Drug Development, Medicine Research Institute, Shaanxi Pharmaceutical Holding Group Co., LTD, Xi’an, China
- College of Life Sciences, Northwest University, Xi’an, China
- *Correspondence: Juan Zhang, ; Hui-Ling Cao,
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Kiss D, Horváth B, Hézső T, Dienes C, Kovács Z, Topal L, Szentandrássy N, Almássy J, Prorok J, Virág L, Bányász T, Varró A, Nánási PP, Magyar J. Late Na + Current Is [Ca 2+] i-Dependent in Canine Ventricular Myocytes. Pharmaceuticals (Basel) 2021; 14:ph14111142. [PMID: 34832924 PMCID: PMC8623624 DOI: 10.3390/ph14111142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022] Open
Abstract
Enhancement of the late sodium current (INaL) increases arrhythmia propensity in the heart, whereas suppression of the current is antiarrhythmic. In the present study, we investigated INaL in canine ventricular cardiomyocytes under action potential voltage-clamp conditions using the selective Na+ channel inhibitors GS967 and tetrodotoxin. Both 1 µM GS967 and 10 µM tetrodotoxin dissected largely similar inward currents. The amplitude and integral of the GS967-sensitive current was significantly smaller after the reduction of intracellular Ca2+ concentration ([Ca2+]i) either by superfusion of the cells with 1 µM nisoldipine or by intracellular application of 10 mM BAPTA. Inhibiting calcium/calmodulin-dependent protein kinase II (CaMKII) by KN-93 or the autocamtide-2-related inhibitor peptide similarly reduced the amplitude and integral of INaL. Action potential duration was shortened in a reverse rate-dependent manner and the plateau potential was depressed by GS967. This GS967-induced depression of plateau was reduced by pretreatment of the cells with BAPTA-AM. We conclude that (1) INaL depends on the magnitude of [Ca2+]i in canine ventricular cells, (2) this [Ca2+]i-dependence of INaL is mediated by the Ca2+-dependent activation of CaMKII, and (3) INaL is augmented by the baseline CaMKII activity.
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Affiliation(s)
- Dénes Kiss
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
- Faculty of Pharmacy, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
| | - Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
| | - Zsigmond Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
| | - Leila Topal
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary; (L.T.); (J.P.); (L.V.); (A.V.)
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - János Almássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
| | - János Prorok
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary; (L.T.); (J.P.); (L.V.); (A.V.)
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Eötvös Loránd Research Network, 6725 Szeged, Hungary
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary; (L.T.); (J.P.); (L.V.); (A.V.)
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6725 Szeged, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, 6725 Szeged, Hungary; (L.T.); (J.P.); (L.V.); (A.V.)
- ELKH-SZTE Research Group for Cardiovascular Pharmacology, Eötvös Loránd Research Network, 6725 Szeged, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, 6725 Szeged, Hungary
| | - Péter P. Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
- Correspondence: ; Tel.: +36-52255575; Fax: +36-52255116
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (D.K.); (B.H.); (T.H.); (C.D.); (Z.K.); (N.S.); (J.A.); (T.B.); (J.M.)
- Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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Canine Myocytes Represent a Good Model for Human Ventricular Cells Regarding Their Electrophysiological Properties. Pharmaceuticals (Basel) 2021; 14:ph14080748. [PMID: 34451845 PMCID: PMC8398821 DOI: 10.3390/ph14080748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022] Open
Abstract
Due to the limited availability of healthy human ventricular tissues, the most suitable animal model has to be applied for electrophysiological and pharmacological studies. This can be best identified by studying the properties of ion currents shaping the action potential in the frequently used laboratory animals, such as dogs, rabbits, guinea pigs, or rats, and comparing them to those of human cardiomyocytes. The authors of this article with the experience of three decades of electrophysiological studies, performed in mammalian and human ventricular tissues and isolated cardiomyocytes, summarize their results obtained regarding the major canine and human cardiac ion currents. Accordingly, L-type Ca2+ current (ICa), late Na+ current (INa-late), rapid and slow components of the delayed rectifier K+ current (IKr and IKs, respectively), inward rectifier K+ current (IK1), transient outward K+ current (Ito1), and Na+/Ca2+ exchange current (INCX) were characterized and compared. Importantly, many of these measurements were performed using the action potential voltage clamp technique allowing for visualization of the actual current profiles flowing during the ventricular action potential. Densities and shapes of these ion currents, as well as the action potential configuration, were similar in human and canine ventricular cells, except for the density of IK1 and the recovery kinetics of Ito. IK1 displayed a largely four-fold larger density in canine than human myocytes, and Ito recovery from inactivation displayed a somewhat different time course in the two species. On the basis of these results, it is concluded that canine ventricular cells represent a reasonably good model for human myocytes for electrophysiological studies, however, it must be borne in mind that due to their stronger IK1, the repolarization reserve is more pronounced in canine cells, and moderate differences in the frequency-dependent repolarization patterns can also be anticipated.
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Shemer Y, Mekies LN, Ben Jehuda R, Baskin P, Shulman R, Eisen B, Regev D, Arbustini E, Gerull B, Gherghiceanu M, Gottlieb E, Arad M, Binah O. Investigating LMNA-Related Dilated Cardiomyopathy Using Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Int J Mol Sci 2021; 22:ijms22157874. [PMID: 34360639 PMCID: PMC8346174 DOI: 10.3390/ijms22157874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 01/09/2023] Open
Abstract
LMNA-related dilated cardiomyopathy is an inherited heart disease caused by mutations in the LMNA gene encoding for lamin A/C. The disease is characterized by left ventricular enlargement and impaired systolic function associated with conduction defects and ventricular arrhythmias. We hypothesized that LMNA-mutated patients' induced Pluripotent Stem Cell-derived cardiomyocytes (iPSC-CMs) display electrophysiological abnormalities, thus constituting a suitable tool for deciphering the arrhythmogenic mechanisms of the disease, and possibly for developing novel therapeutic modalities. iPSC-CMs were generated from two related patients (father and son) carrying the same E342K mutation in the LMNA gene. Compared to control iPSC-CMs, LMNA-mutated iPSC-CMs exhibited the following electrophysiological abnormalities: (1) decreased spontaneous action potential beat rate and decreased pacemaker current (If) density; (2) prolonged action potential duration and increased L-type Ca2+ current (ICa,L) density; (3) delayed afterdepolarizations (DADs), arrhythmias and increased beat rate variability; (4) DADs, arrhythmias and cessation of spontaneous firing in response to β-adrenergic stimulation and rapid pacing. Additionally, compared to healthy control, LMNA-mutated iPSC-CMs displayed nuclear morphological irregularities and gene expression alterations. Notably, KB-R7943, a selective inhibitor of the reverse-mode of the Na+/Ca2+ exchanger, blocked the DADs in LMNA-mutated iPSC-CMs. Our findings demonstrate cellular electrophysiological mechanisms underlying the arrhythmias in LMNA-related dilated cardiomyopathy.
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Affiliation(s)
- Yuval Shemer
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
| | - Lucy N. Mekies
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
| | - Ronen Ben Jehuda
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
- Department of Biotechnology, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Polina Baskin
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
| | - Rita Shulman
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
| | - Binyamin Eisen
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
| | - Danielle Regev
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
| | - Eloisa Arbustini
- Centre for Inherited Cardiovascular Diseases, IRCCS Foundation, Policlinico San Matteo, 27100 Pavia, Italy;
| | - Brenda Gerull
- Comprehensive Heart Failure Center and Department of Internal Medicine I, University Hospital Würzburg, 97080 Würzburg, Germany;
| | | | - Eyal Gottlieb
- Department of Cell Biology and Cancer Science, Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 31096, Israel;
| | - Michael Arad
- Leviev Heart Center, Sheba Medical Center, Ramat Gan 52621, Israel;
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ofer Binah
- Department of Physiology, Biophysics and Systems Biology, Rappaport Faculty of Medicine and Rappaport Research Institute, Technion—Israel Institute of Technology, Haifa 31096, Israel; (Y.S.); (L.N.M.); (R.B.J.); (P.B.); (R.S.); (B.E.); (D.R.)
- Correspondence: ; Tel.: +972-4-8295262; Fax: +972-4-8513919
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7
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Ion current profiles in canine ventricular myocytes obtained by the "onion peeling" technique. J Mol Cell Cardiol 2021; 158:153-162. [PMID: 34089737 DOI: 10.1016/j.yjmcc.2021.05.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/05/2021] [Accepted: 05/21/2021] [Indexed: 02/07/2023]
Abstract
The profiles of ion currents during the cardiac action potential can be visualized by the action potential voltage clamp technique. To obtain multiple ion current data from the same cell, the "onion peeling" technique, based on sequential pharmacological dissection of ion currents, has to be applied. Combination of the two methods allows recording of several ion current profiles from the same myocyte under largely physiological conditions. Using this approach, we have studied the densities and integrals of the major cardiac inward (ICa, INCX, INa-late) and outward (IKr, IKs, IK1) currents in canine ventricular cells and studied the correlation between them. For this purpose, canine ventricular cardiomyocytes were chosen because their electrophysiological properties are similar to those of human ones. Significant positive correlation was observed between the density and integral of ICa and IKr, and positive correlation was found also between the integral of ICa and INCX. No further correlations were detected. The Ca2+-sensitivity of K+ currents was studied by comparing their parameters in the case of normal calcium homeostasis and following blockade of ICa. Out of the three K+ currents studied, only IKs was Ca2+-sensitive. The density and integral of IKs was significantly greater, while its time-to-peak value was shorter at normal Ca2+ cycling than following ICa blockade. No differences were detected for IKr or IK1 in this regard. Present results indicate that the positive correlation between ICa and IKr prominently contribute to the balance between inward and outward fluxes during the action potential plateau in canine myocytes. The results also suggest that the profiles of cardiac ion currents have to be studied under physiological conditions, since their behavior may strongly be influenced by the intracellular Ca2+ homeostasis and the applied membrane potential protocol.
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8
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Hézső T, Naveed M, Dienes C, Kiss D, Prorok J, Árpádffy-Lovas T, Varga R, Fujii E, Mercan T, Topal L, Kistamás K, Szentandrássy N, Almássy J, Jost N, Magyar J, Bányász T, Baczkó I, Varró A, Nánási PP, Virág L, Horváth B. Mexiletine-like cellular electrophysiological effects of GS967 in canine ventricular myocardium. Sci Rep 2021; 11:9565. [PMID: 33953276 PMCID: PMC8100105 DOI: 10.1038/s41598-021-88903-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/26/2021] [Indexed: 12/14/2022] Open
Abstract
Enhancement of the late Na+ current (INaL) increases arrhythmia propensity in the heart, while suppression of the current is antiarrhythmic. GS967 is an agent considered as a selective blocker of INaL. In the present study, effects of GS967 on INaL and action potential (AP) morphology were studied in canine ventricular myocytes by using conventional voltage clamp, action potential voltage clamp and sharp microelectrode techniques. The effects of GS967 (1 µM) were compared to those of the class I/B antiarrhythmic compound mexiletine (40 µM). Under conventional voltage clamp conditions, INaL was significantly suppressed by GS967 and mexiletine, causing 80.4 ± 2.2% and 59.1 ± 1.8% reduction of the densities of INaL measured at 50 ms of depolarization, and 79.0 ± 3.1% and 63.3 ± 2.7% reduction of the corresponding current integrals, respectively. Both drugs shifted the voltage dependence of the steady-state inactivation curve of INaL towards negative potentials. GS967 and mexiletine dissected inward INaL profiles under AP voltage clamp conditions having densities, measured at 50% of AP duration (APD), of −0.37 ± 0.07 and −0.28 ± 0.03 A/F, and current integrals of −56.7 ± 9.1 and −46.6 ± 5.5 mC/F, respectively. Drug effects on peak Na+ current (INaP) were assessed by recording the maximum velocity of AP upstroke (V+max) in multicellular preparations. The offset time constant was threefold faster for GS967 than mexiletine (110 ms versus 289 ms), while the onset of the rate-dependent block was slower in the case of GS967. Effects on beat-to-beat variability of APD was studied in isolated myocytes. Beat-to-beat variability was significantly decreased by both GS967 and mexiletine (reduction of 42.1 ± 6.5% and 24.6 ± 12.8%, respectively) while their shortening effect on APD was comparable. It is concluded that the electrophysiological effects of GS967 are similar to those of mexiletine, but with somewhat faster offset kinetics of V+max block. However, since GS967 depressed V+max and INaL at the same concentration, the current view that GS967 represents a new class of drugs that selectively block INaL has to be questioned and it is suggested that GS967 should be classified as a class I/B antiarrhythmic agent.
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Affiliation(s)
- Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - Muhammad Naveed
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary
| | - Csaba Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - Dénes Kiss
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - János Prorok
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary.,MTA-SZTE Research Group for Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary
| | - Tamás Árpádffy-Lovas
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary
| | - Richárd Varga
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary
| | - Erika Fujii
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - Tanju Mercan
- Department of Biophysics, School of Medicine, Akdeniz University, Antalya, Turkey
| | - Leila Topal
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary
| | - Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary.,Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - János Almássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - Norbert Jost
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary.,MTA-SZTE Research Group for Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary.,Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Szeged, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary. .,MTA-SZTE Research Group for Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary. .,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Szeged, Hungary.
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary. .,Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary.
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Dóm tér 12, 6701, Szeged, Hungary.,Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Szeged, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, 4012, Debrecen, Hungary.,Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
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9
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Nakao S, Ihara D, Hasegawa K, Kawamura T. Applications for Induced Pluripotent Stem Cells in Disease Modelling and Drug Development for Heart Diseases. Eur Cardiol 2020; 15:1-10. [PMID: 32180835 PMCID: PMC7066852 DOI: 10.15420/ecr.2019.03] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/09/2019] [Indexed: 12/22/2022] Open
Abstract
Induced pluripotent stem cells (iPSCs) are derived from reprogrammed somatic cells by the introduction of defined transcription factors. They are characterised by a capacity for self-renewal and pluripotency. Human (h)iPSCs are expected to be used extensively for disease modelling, drug screening and regenerative medicine. Obtaining cardiac tissue from patients with mutations for genetic studies and functional analyses is a highly invasive procedure. In contrast, disease-specific hiPSCs are derived from the somatic cells of patients with specific genetic mutations responsible for disease phenotypes. These disease-specific hiPSCs are a better tool for studies of the pathophysiology and cellular responses to therapeutic agents. This article focuses on the current understanding, limitations and future direction of disease-specific hiPSC-derived cardiomyocytes for further applications.
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Affiliation(s)
- Shu Nakao
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan.,Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan.,Division of Translational Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan
| | - Dai Ihara
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan.,Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan
| | - Koji Hasegawa
- Division of Translational Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan
| | - Teruhisa Kawamura
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu, Japan.,Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan.,Division of Translational Research, Kyoto Medical Center, National Hospital Organization, Kyoto, Japan
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10
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Late sodium current in human, canine and guinea pig ventricular myocardium. J Mol Cell Cardiol 2020; 139:14-23. [DOI: 10.1016/j.yjmcc.2019.12.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/18/2019] [Accepted: 12/25/2019] [Indexed: 02/06/2023]
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11
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Abi-Gerges N, Miller PE, Ghetti A. Human Heart Cardiomyocytes in Drug Discovery and Research: New Opportunities in Translational Sciences. Curr Pharm Biotechnol 2019; 21:787-806. [PMID: 31820682 DOI: 10.2174/1389201021666191210142023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/14/2019] [Accepted: 10/28/2019] [Indexed: 12/28/2022]
Abstract
In preclinical drug development, accurate prediction of drug effects on the human heart is critically important, whether in the context of cardiovascular safety or for the purpose of modulating cardiac function to treat heart disease. Current strategies have significant limitations, whereby, cardiotoxic drugs can escape detection or potential life-saving therapies are abandoned due to false positive toxicity signals. Thus, new and more reliable translational approaches are urgently needed to help accelerate the rate of new therapy development. Renewed efforts in the recovery of human donor hearts for research and in cardiomyocyte isolation methods, are providing new opportunities for preclinical studies in adult primary cardiomyocytes. These cells exhibit the native physiological and pharmacological properties, overcoming the limitations presented by artificial cellular models, animal models and have great potential for providing an excellent tool for preclinical drug testing. Adult human primary cardiomyocytes have already shown utility in assessing drug-induced cardiotoxicity risk and helping in the identification of new treatments for cardiac diseases, such as heart failure and atrial fibrillation. Finally, strategies with actionable decision-making trees that rely on data derived from adult human primary cardiomyocytes will provide the holistic insights necessary to accurately predict human heart effects of drugs.
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Affiliation(s)
- Najah Abi-Gerges
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA 92109, United States
| | - Paul E Miller
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA 92109, United States
| | - Andre Ghetti
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA 92109, United States
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12
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Li N, Zhou H, Tang Q. miR-133: A Suppressor of Cardiac Remodeling? Front Pharmacol 2018; 9:903. [PMID: 30174600 PMCID: PMC6107689 DOI: 10.3389/fphar.2018.00903] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/23/2018] [Indexed: 01/28/2023] Open
Abstract
Cardiac remodeling, which is characterized by mechanical and electrical remodeling, is a significant pathophysiological process involved in almost all forms of heart diseases. MicroRNAs (miRNAs) are a group of non-coding RNAs of 20–25 nucleotides in length that primarily regulate gene expression by promoting mRNA degradation or post-transcriptional repression in a sequence-specific manner. Three miR-133 genes have been identified in the human genome, miR-133a-1, miR-133a-2, and miR-133b, which are located on chromosomes 18, 20, and 6, respectively. These miRNAs are mainly expressed in muscle tissues and appear to repress the expression of non-muscle genes. Based on accumulating evidence, miR-133 participates in the proliferation, differentiation, survival, hypertrophic growth, and electrical conduction of cardiac cells, which are essential for cardiac fibrosis, cardiac hypertrophy, and arrhythmia. Nevertheless, the roles of miR-133 in cardiac remodeling are ambiguous, and the mechanisms are also sophisticated, involving many target genes and signaling pathways, such as RhoA, MAPK, TGFβ/Smad, and PI3K/Akt. Therefore, in this review, we summarize the critical roles of miR-133 and its potential mechanisms in cardiac remodeling.
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Affiliation(s)
- Ning Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Heng Zhou
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
| | - Qizhu Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Cardiovascular Research Institute, Wuhan University, Wuhan, China.,Hubei Key Laboratory of Cardiology, Wuhan, China
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13
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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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14
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Nánási P, Gaburjakova M, Gaburjakova J, Almássy J. Omecamtiv mecarbil activates ryanodine receptors from canine cardiac but not skeletal muscle. Eur J Pharmacol 2017; 809:73-79. [PMID: 28506910 DOI: 10.1016/j.ejphar.2017.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/01/2017] [Accepted: 05/12/2017] [Indexed: 01/10/2023]
Abstract
Due to the limited results achieved in the clinical treatment of heart failure, a new inotropic strategy of myosin motor activation has been developed. The lead molecule of myosin activator agents is omecamtiv mecarbil, which binds directly to the heavy chain of the cardiac β-myosin and enhances cardiac contractility by lengthening the lifetime of the acto-myosin complex and increasing the number of the active force-generating cross-bridges. In the absence of relevant data, the effect of omecamtiv mecarbil on canine cardiac ryanodine receptors (RyR 2) has been investigated in the present study by measuring the electrical activity of single RyR 2 channels incorporated into planar lipid bilayer. When applying 100nM Ca2+ concentration on the cis side ([Ca2+]cis) omecamtiv mecarbil (1-10µM) significantly increased the open probability and opening frequency of RyR 2, while the mean closed time was reduced. Mean open time was increased moderately by 10µM omecamtiv mecarbil. When [Ca2+]cis was elevated to 322 and 735nM, the effect of omecamtiv mecarbil on open probability was evident only at higher (3-10µM) concentrations. All effects of omecamtiv mecarbil were fully reversible upon washout. Omecamtiv mecarbil (up to 10µM) had no effect on the open probability of RyR 1, isolated from either canine or rabbit skeletal muscles. It is concluded that the direct stimulatory action of omecamtiv mecarbil on RyR 2 has to be taken into account when discussing the mechanism of action or the potential side effects of the compound.
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Affiliation(s)
- Péter Nánási
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Marta Gaburjakova
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Jana Gaburjakova
- Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - János Almássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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15
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Sun X, Nunes SS. Bioengineering Approaches to Mature Human Pluripotent Stem Cell-Derived Cardiomyocytes. Front Cell Dev Biol 2017; 5:19. [PMID: 28337437 PMCID: PMC5343210 DOI: 10.3389/fcell.2017.00019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/21/2017] [Indexed: 11/26/2022] Open
Abstract
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) represent a potential unlimited cell supply for cardiac tissue engineering and possibly regenerative medicine applications. However, hPSC-CMs produced by current protocols are not representative of native adult human cardiomyocytes as they display immature gene expression profile, structure and function. In order to improve hPSC-CM maturity and function, various approaches have been developed, including genetic manipulations to induce gene expression, delivery of biochemical factors, such as triiodothyronine and alpha-adrenergic agonist phenylephrine, induction of cell alignment in 3D tissues, mechanical stress as a mimic of cardiac load and electrical stimulation/pacing or a combination of these. In this mini review, we discuss biomimetic strategies for the maturation for hPSC-CMs with a particular focus on electromechanical conditioning methods.
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Affiliation(s)
- Xuetao Sun
- Toronto General Research Institute, University Health Network Toronto, ON, Canada
| | - Sara S Nunes
- Toronto General Research Institute, University Health NetworkToronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of TorontoToronto, ON, Canada; Heart & Stroke/Richard Lewar Centre of Excellence, University of TorontoToronto, ON, Canada
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16
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Bezzerides VJ, Zhang D, Pu WT. Modeling Inherited Arrhythmia Disorders Using Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Circ J 2016; 81:12-21. [PMID: 27916777 DOI: 10.1253/circj.cj-16-1113] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inherited arrhythmia disorders (IADs) are a group of potentially lethal diseases that remain diagnostic and management challenges. Although the genetic basis for many of these disorders is well known, the pathogenicity of individual mutations and the resulting clinical outcomes are difficult to predict. Treatment options remain imperfect, and optimizing therapy for individual patients can be difficult. Recent advances in the derivation of induced pluripotent stem cells (iPSCs) from patients and creation of genetically engineered human models using CRISPR/Cas9 has the potential to dramatically advance translational arrhythmia research. In this review, we discuss the current state of modeling IADs using human iPSC-derived cardiomyocytes. We also discuss current limitations and areas for further study.
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17
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Barbuti A, Benzoni P, Campostrini G, Dell'Era P. Human derived cardiomyocytes: A decade of knowledge after the discovery of induced pluripotent stem cells. Dev Dyn 2016; 245:1145-1158. [DOI: 10.1002/dvdy.24455] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 12/27/2022] Open
Affiliation(s)
- Andrea Barbuti
- Department of Biosciences; Università degli Studi di Milano; Milan Italy
| | - Patrizia Benzoni
- Department of Biosciences; Università degli Studi di Milano; Milan Italy
| | - Giulia Campostrini
- Department of Biosciences; Università degli Studi di Milano; Milan Italy
| | - Patrizia Dell'Era
- Cellular Fate Reprogramming Unit, Department of Molecular and Translational Medicine; Università degli Studi di Brescia; Brescia Italy
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18
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Rajamohan D, Kalra S, Duc Hoang M, George V, Staniforth A, Russell H, Yang X, Denning C. Automated Electrophysiological and Pharmacological Evaluation of Human Pluripotent Stem Cell-Derived Cardiomyocytes. Stem Cells Dev 2016; 25:439-52. [PMID: 26906236 PMCID: PMC4790208 DOI: 10.1089/scd.2015.0253] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Automated planar patch clamp systems are widely used in drug evaluation studies because of their ability to provide accurate, reliable, and reproducible data in a high-throughput manner. Typically, CHO and HEK tumorigenic cell lines overexpressing single ion channels are used since they can be harvested as high-density, homogenous, single-cell suspensions. While human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) are physiologically more relevant, these cells are fragile, have complex culture requirements, are inherently heterogeneous, and are expensive to produce, which has restricted their use on automated patch clamp (APC) devices. Here, we used high efficiency differentiation protocols to produce cardiomyocytes from six different hPSC lines for analysis on the Patchliner (Nanion Technologies GmbH) APC platform. We developed a two-step cell preparation protocol that yielded cell catch rates and whole-cell breakthroughs of ∼80%, with ∼40% of these cells allowing electrical activity to be recorded. The protocol permitted formation of long-lasting (>15 min), high quality seals (>2 GΩ) in both voltage- and current-clamp modes. This enabled density of sodium, calcium, and potassium currents to be evaluated, along with dose–response curves to their respective channel inhibitors, tetrodotoxin, nifedipine, and E-4031. Thus, we show the feasibility of using the Patchliner platform for automated evaluation of the electrophysiology and pharmacology of hPSC-CMs, which will enable considerable increase in throughput for reliable and efficient drug evaluation.
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Affiliation(s)
- Divya Rajamohan
- 1 Division of Cancer and Stem Cells, School of Medicine, Wolfson Centre for Stem Cells, Tissue Engineering & Modelling, University of Nottingham , Nottingham, United Kingdom
| | - Spandan Kalra
- 1 Division of Cancer and Stem Cells, School of Medicine, Wolfson Centre for Stem Cells, Tissue Engineering & Modelling, University of Nottingham , Nottingham, United Kingdom
| | - Minh Duc Hoang
- 1 Division of Cancer and Stem Cells, School of Medicine, Wolfson Centre for Stem Cells, Tissue Engineering & Modelling, University of Nottingham , Nottingham, United Kingdom
| | - Vinoj George
- 1 Division of Cancer and Stem Cells, School of Medicine, Wolfson Centre for Stem Cells, Tissue Engineering & Modelling, University of Nottingham , Nottingham, United Kingdom
| | - Andrew Staniforth
- 2 Nottingham University Hospitals NHS Trust , Department of Cardiology, Nottingham, United Kingdom
| | - Hugh Russell
- 3 Biomaterials and Tissue Engineering Group, Department of Oral Biology, University of Leeds, St. James's University Hospital , Leeds, United Kingdom
| | - Xuebin Yang
- 3 Biomaterials and Tissue Engineering Group, Department of Oral Biology, University of Leeds, St. James's University Hospital , Leeds, United Kingdom
| | - Chris Denning
- 1 Division of Cancer and Stem Cells, School of Medicine, Wolfson Centre for Stem Cells, Tissue Engineering & Modelling, University of Nottingham , Nottingham, United Kingdom
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19
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Winter J, Shattock MJ. Geometrical considerations in cardiac electrophysiology and arrhythmogenesis. Europace 2015; 18:320-31. [PMID: 26585597 DOI: 10.1093/europace/euv307] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/14/2015] [Indexed: 11/14/2022] Open
Abstract
The rate of repolarization (RRepol) and so the duration of the cardiac action potential are determined by the balance of inward and outward currents across the cardiac membrane (net ionic current). Plotting action potential duration (APD) as a function of the RRepol reveals an inverse non-linear relationship, arising from the geometric association between these two factors. From the RRepol-APD relationship, it can be observed that a longer action potential will exhibit a greater propensity to shorten, or prolong, for a given change in the RRepol (i.e. net ionic current), when compared with one that is initially shorter. This observation has recently been used to explain why so many interventions that prolong the action potential exert a greater effect at slow rates (reverse rate-dependence). In this article, we will discuss the broader implications of this simple principle and examine how common experimental observations on the electrical behaviour of the myocardium may be explained in terms of the RRepol-APD relationship. An argument is made, with supporting published evidence, that the non-linear relationship between the RRepol and APD is a fundamental, and largely overlooked, property of the myocardium. The RRepol-APD relationship appears to explain why interventions and disease with seemingly disparate mechanisms of action have similar electrophysiological consequences. Furthermore, the RRepol-APD relationship predicts that prolongation of the action potential, by slowing repolarization, will promote conditions of dynamic electrical instability, exacerbating several electrophysiological phenomena associated with arrhythmogenesis, namely, the rate dependence of dispersion of repolarization, APD restitution, and electrical alternans.
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Affiliation(s)
- James Winter
- Cardiovascular Division, The Rayne Institute, 4th Floor, Lambeth Wing, St Thomas' Hospital, King's College London, London SE1 7EH, UK
| | - Michael J Shattock
- Cardiovascular Division, The Rayne Institute, 4th Floor, Lambeth Wing, St Thomas' Hospital, King's College London, London SE1 7EH, UK
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Liu QN, Trudeau MC. Eag Domains Regulate LQT Mutant hERG Channels in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. PLoS One 2015; 10:e0123951. [PMID: 25923442 PMCID: PMC4414485 DOI: 10.1371/journal.pone.0123951] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 03/09/2015] [Indexed: 01/08/2023] Open
Abstract
Human Ether á go-go Related Gene potassium channels form the rapid component of the delayed-rectifier (IKr) current in the heart. The N-terminal 'eag' domain, which is composed of a Per-Arnt-Sim (PAS) domain and a short PAS-cap region, is a critical regulator of hERG channel function. In previous studies, we showed that isolated eag (i-eag) domains rescued the dysfunction of long QT type-2 associated mutant hERG R56Q channels, by substituting for defective eag domains, when the channels were expressed in Xenopus oocytes or HEK 293 cells.Here, our goal was to determine whether the rescue of hERG R56Q channels by i-eag domains could be translated into the environment of cardiac myocytes. We expressed hERG R56Q channels in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and measured electrical properties of the cells with whole-cell patch-clamp recordings. We found that, like in non-myocyte cells, hERG R56Q had defective, fast closing (deactivation) kinetics when expressed in hiPSC-CMs. We report here that i-eag domains slowed the deactivation kinetics of hERG R56Q channels in hiPSC-CMs. hERG R56Q channels prolonged the AP of hiPSCs, and the AP was shortened by co-expression of i-eag domains and hERG R56Q channels. We measured robust Förster Resonance Energy Transfer (FRET) between i-eag domains tagged with Cyan fluorescent protein (CFP) and hERG R56Q channels tagged with Citrine fluorescent proteins (Citrine), indicating their close proximity at the cell membrane in live iPSC-CMs. Together, functional regulation and FRET spectroscopy measurements indicated that i-eag domains interacted directly with hERG R56Q channels in hiPSC-CMs. These results mean that the regulatory role of i-eag domains is conserved in the cellular environment of human cardiomyocytes, indicating that i-eag domains may be useful as a biological therapeutic.
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Affiliation(s)
- Qiang-ni Liu
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Matthew C. Trudeau
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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21
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Meijer van Putten RME, Mengarelli I, Guan K, Zegers JG, van Ginneken ACG, Verkerk AO, Wilders R. Ion channelopathies in human induced pluripotent stem cell derived cardiomyocytes: a dynamic clamp study with virtual IK1. Front Physiol 2015; 6:7. [PMID: 25691870 PMCID: PMC4315032 DOI: 10.3389/fphys.2015.00007] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/07/2015] [Indexed: 12/11/2022] Open
Abstract
Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are widely used in studying basic mechanisms of cardiac arrhythmias that are caused by ion channelopathies. Unfortunately, the action potential profile of hiPSC-CMs-and consequently the profile of individual membrane currents active during that action potential-differs substantially from that of native human cardiomyocytes, largely due to almost negligible expression of the inward rectifier potassium current (IK1). In the present study, we attempted to "normalize" the action potential profile of our hiPSC-CMs by inserting a voltage dependent in silico IK1 into our hiPSC-CMs, using the dynamic clamp configuration of the patch clamp technique. Recordings were made from single hiPSC-CMs, using the perforated patch clamp technique at physiological temperature. We assessed three different models of IK1, with different degrees of inward rectification, and systematically varied the magnitude of the inserted IK1. Also, we modified the inserted IK1 in order to assess the effects of loss- and gain-of-function mutations in the KCNJ2 gene, which encodes the Kir2.1 protein that is primarily responsible for the IK1 channel in human ventricle. For our experiments, we selected spontaneously beating hiPSC-CMs, with negligible IK1 as demonstrated in separate voltage clamp experiments, which were paced at 1 Hz. Upon addition of in silico IK1 with a peak outward density of 4-6 pA/pF, these hiPSC-CMs showed a ventricular-like action potential morphology with a stable resting membrane potential near -80 mV and a maximum upstroke velocity >150 V/s (n = 9). Proarrhythmic action potential changes were observed upon injection of both loss-of-function and gain-of-function IK1, as associated with Andersen-Tawil syndrome type 1 and short QT syndrome type 3, respectively (n = 6). We conclude that injection of in silico IK1 makes the hiPSC-CM a more reliable model for investigating mechanisms underlying cardiac arrhythmias.
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Affiliation(s)
- Rosalie M E Meijer van Putten
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Isabella Mengarelli
- Department of Experimental Cardiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Kaomei Guan
- Department of Cardiology and Pneumology, Georg-August-University of Göttingen Göttingen, Germany
| | - Jan G Zegers
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Antoni C G van Ginneken
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Arie O Verkerk
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
| | - Ronald Wilders
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
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22
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Khan JM, Lyon AR, Harding SE. The case for induced pluripotent stem cell-derived cardiomyocytes in pharmacological screening. Br J Pharmacol 2014; 169:304-17. [PMID: 22845396 DOI: 10.1111/j.1476-5381.2012.02118.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The current drug screening models are deficient, particularly in detecting cardiac side effects. Human stem cell-derived cardiomyocytes could aid both early cardiotoxicity detection and novel drug discovery. Work over the last decade has generated human embryonic stem cells as potentially accurate sources of human cardiomyocytes, but ethical constraints and poor efficacy in establishing cell lines limit their use. Induced pluripotent stem cells do not require the use of human embryos and have the added advantage of producing patient-specific cardiomyocytes, allowing both generic and disease- and patient-specific pharmacological screening, as well as drug development through disease modelling. A critical question is whether sufficient standards have been achieved in the reliable and reproducible generation of 'adult-like' cardiomyocytes from human fibroblast tissue to progress from validation to safe use in practice and drug discovery. This review will highlight the need for a new experimental system, assess the validity of human induced pluripotent stem cell-derived cardiomyocytes and explore what the future may hold for their use in pharmacology.
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Affiliation(s)
- Jaffar M Khan
- Royal Brompton and Harefield NHS Trust, London, UK National Heart and Lung Institute, Imperial College, London, UK
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23
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Ruzsnavszky F, Hegyi B, Kistamás K, Váczi K, Horváth B, Szentandrássy N, Bányász T, Nánási PP, Magyar J. Asynchronous activation of calcium and potassium currents by isoproterenol in canine ventricular myocytes. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:457-67. [PMID: 24566722 DOI: 10.1007/s00210-014-0964-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/13/2014] [Indexed: 11/25/2022]
Abstract
Adrenergic activation of L-type Ca(2+) and various K(+) currents is a crucial mechanism of cardiac adaptation; however, it may carry a substantial proarrhythmic risk as well. The aim of the present work was to study the timing of activation of Ca(2+) and K(+) currents in isolated canine ventricular cells in response to exposure to isoproterenol (ISO). Whole cell configuration of the patch-clamp technique in either conventional voltage clamp or action potential voltage clamp modes were used to monitor I(Ca), I(Ks), and I(Kr), while action potentials were recorded using sharp microelectrodes. ISO (10 nM) elevated the plateau potential and shortened action potential duration (APD) in subepicardial and mid-myocardial cells, which effects were associated with multifold enhancement of I(Ca) and I(Ks) and moderate stimulation of I(Kr). The ISO-induced plateau shift and I(Ca) increase developed faster than the shortening of APD and stimulation of I(Ks) and I(Kr). Blockade of β1-adrenoceptors (using 300 nM CGP-20712A) converted the ISO-induced shortening of APD to lengthening, decreased its latency, and reduced the plateau shift. In contrast, blockade of β2-adrenoceptors (by 50 nM ICI 118,551) augmented the APD-shortening effect and increased the latency of plateau shift without altering its magnitude. All effects of ISO were prevented by simultaneous blockade of both receptor types. Inhibition of phosphodiesterases decreased the differences observed in the turn on of the ISO-induced plateau shift and APD shortening. ISO-induced activation of I(Ca) is turned on faster than the stimulation of I(Ks) and I(Kr) in canine ventricular cells due to the involvement of different adrenergic pathways and compartmentalization.
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Affiliation(s)
- Ferenc Ruzsnavszky
- Department of Physiology, Medical and Health Science Center, University of Debrecen, Debrecen, Nagyerdei krt 98, 4012, Hungary
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24
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Lessons from the heart: mirroring electrophysiological characteristics during cardiac development to in vitro differentiation of stem cell derived cardiomyocytes. J Mol Cell Cardiol 2013; 67:12-25. [PMID: 24370890 DOI: 10.1016/j.yjmcc.2013.12.011] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/14/2013] [Accepted: 12/13/2013] [Indexed: 01/12/2023]
Abstract
The ability of human pluripotent stem cells (hPSCs) to differentiate into any cell type of the three germ layers makes them a very promising cell source for multiple purposes, including regenerative medicine, drug discovery, and as a model to study disease mechanisms and progression. One of the first specialized cell types to be generated from hPSC was cardiomyocytes (CM), and differentiation protocols have evolved over the years and now allow for robust and large-scale production of hPSC-CM. Still, scientists are struggling to achieve the same, mainly ventricular, phenotype of the hPSC-CM in vitro as their adult counterpart in vivo. In vitro generated cardiomyocytes are generally described as fetal-like rather than adult. In this review, we compare the in vivo development of cardiomyocytes to the in vitro differentiation of hPSC into CM with focus on electrophysiology, structure and contractility. Furthermore, known epigenetic changes underlying the differences between adult human CM and CM differentiated from pluripotent stem cells are described. This should provide the reader with an extensive overview of the current status of human stem cell-derived cardiomyocyte phenotype and function. Additionally, the reader will gain insight into the underlying signaling pathways and mechanisms responsible for cardiomyocyte development.
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25
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Townsend C, Brown BS. Predicting drug-induced QT prolongation and torsades de pointes: a review of preclinical endpoint measures. ACTA ACUST UNITED AC 2013; Chapter 10:Unit 10.16. [PMID: 23744708 DOI: 10.1002/0471141755.ph1016s61] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Compound-induced prolongation of the cardiac QT interval is a major concern in drug development and this unit discusses approaches that can predict QT effects prior to undertaking clinical trials. The majority of compounds that prolong the QT interval block the cardiac rapid delayed rectifier potassium current, IKr (hERG). Described in this overview are different ways to measure hERG, from recent advances in automated electrophysiology to the quantification of channel protein trafficking and binding. The contribution of other cardiac ion channels to hERG data interpretation is also discussed. In addition, endpoint measures of the integrated activity of cardiac ion channels at the single-cell, tissue, and whole-animal level, including for example the well-established action potential to the more recent beat-to-beat variability, transmural dispersion of repolarization, and field potential duration, are described in the context of their ability to predict QT prolongation and torsadogenicity in humans.
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Affiliation(s)
- Claire Townsend
- GlaxoSmithKline Biological Reagents and Assay Development, Research Triangle Park, NC, USA
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26
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Szuts V, Ménesi D, Varga-Orvos Z, Zvara Á, Houshmand N, Bitay M, Bogáts G, Virág L, Baczkó I, Szalontai B, Geramipoor A, Cotella D, Wettwer E, Ravens U, Deák F, Puskás LG, Papp JG, Kiss I, Varró A, Jost N. Altered expression of genes for Kir ion channels in dilated cardiomyopathy. Can J Physiol Pharmacol 2013; 91:648-56. [PMID: 23889090 DOI: 10.1139/cjpp-2012-0413] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dilated cardiomyopathy (DCM) is a multifactorial disease characterized by left ventricular dilation that is associated with systolic dysfunction and increased action potential duration. The Kir2.x K⁺ channels (encoded by KCNJ genes) regulate the inward rectifier current (IK1) contributing to the final repolarization in cardiac muscle. Here, we describe the transitions in the gene expression profiles of 4 KCNJ genes from healthy or dilated cardiomyopathic human hearts. In the healthy adult ventricles, KCNJ2, KCNJ12, and KCNJ4 (Kir2.1-2.3, respectively) genes were expressed at high levels, while expression of the KCNJ14 (Kir2.4) gene was low. In DCM ventricles, the levels of Kir2.1 and Kir2.3 were upregulated, but those of Kir2.2 channels were downregulated. Additionally, the expression of the DLG1 gene coding for the synapse-associated protein 97 (SAP97) anchoring molecule exhibited a 2-fold decline with increasing age in normal hearts, and it was robustly downregulated in young DCM patients. These adaptations could offer a new aspect for the explanation of the generally observed physiological and molecular alterations found in DCM.
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Affiliation(s)
- Viktoria Szuts
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
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Szentandrássy N, Farkas V, Bárándi L, Hegyi B, Ruzsnavszky F, Horváth B, Bányász T, Magyar J, Márton I, Nánási PP. Role of action potential configuration and the contribution of C²⁺a and K⁺ currents to isoprenaline-induced changes in canine ventricular cells. Br J Pharmacol 2013; 167:599-611. [PMID: 22563726 DOI: 10.1111/j.1476-5381.2012.02015.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca²⁺ current (I(Ca)), slow delayed rectifier K⁺ current (I(Ks)) and fast delayed rectifier K⁺ current (I(Kr)) were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from various transmural locations. EXPERIMENTAL APPROACH Action potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques. KEY RESULTS In myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the I(Kr) blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the I(Ks) blocker HMR-1556. Both action potential shortening and elevation of the plateau were prevented by pretreatment with the I(Ca) blocker nisoldipine. Action potential voltage clamp experiments revealed a prominent slowly inactivating I(Ca) followed by a rise in I(Ks) , both currents increased with increasing the cycle length. CONCLUSIONS AND IMPLICATIONS The effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of I(Ks) - but not I(Kr) - may be responsible for the observed shortening of action potentials.
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Hoekstra M, Mummery CL, Wilde AAM, Bezzina CR, Verkerk AO. Induced pluripotent stem cell derived cardiomyocytes as models for cardiac arrhythmias. Front Physiol 2012; 3:346. [PMID: 23015789 PMCID: PMC3449331 DOI: 10.3389/fphys.2012.00346] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 08/09/2012] [Indexed: 12/20/2022] Open
Abstract
Cardiac arrhythmias are a major cause of morbidity and mortality. In younger patients, the majority of sudden cardiac deaths have an underlying Mendelian genetic cause. Over the last 15 years, enormous progress has been made in identifying the distinct clinical phenotypes and in studying the basic cellular and genetic mechanisms associated with the primary Mendelian (monogenic) arrhythmia syndromes. Investigation of the electrophysiological consequences of an ion channel mutation is ideally done in the native cardiomyocyte (CM) environment. However, the majority of such studies so far have relied on heterologous expression systems in which single ion channel genes are expressed in non-cardiac cells. In some cases, transgenic mouse models have been generated, but these also have significant shortcomings, primarily related to species differences. The discovery that somatic cells can be reprogrammed to pluripotency as induced pluripotent stem cells (iPSC) has generated much interest since it presents an opportunity to generate patient- and disease-specific cell lines from which normal and diseased human CMs can be obtained These genetically diverse human model systems can be studied in vitro and used to decipher mechanisms of disease and identify strategies and reagents for new therapies. Here, we review the present state of the art with respect to cardiac disease models already generated using IPSC technology and which have been (partially) characterized. Human iPSC (hiPSC) models have been described for the cardiac arrhythmia syndromes, including LQT1, LQT2, LQT3-Brugada Syndrome, LQT8/Timothy syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT). In most cases, the hiPSC-derived cardiomyoctes recapitulate the disease phenotype and have already provided opportunities for novel insight into cardiac pathophysiology. It is expected that the lines will be useful in the development of pharmacological agents for the management of these disorders.
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Affiliation(s)
- Maaike Hoekstra
- Department of Clinical and Experimental Cardiology, Heart Failure Research Center, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
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29
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O'Hara T, Rudy Y. Quantitative comparison of cardiac ventricular myocyte electrophysiology and response to drugs in human and nonhuman species. Am J Physiol Heart Circ Physiol 2011; 302:H1023-30. [PMID: 22159993 DOI: 10.1152/ajpheart.00785.2011] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Explanations for arrhythmia mechanisms at the cellular level are usually based on experiments in nonhuman myocytes. However, subtle electrophysiological differences between species may lead to different rhythmic or arrhythmic cellular behaviors and drug response given the nonlinear and highly interactive cellular system. Using detailed and quantitatively accurate mathematical models for human, dog, and guinea pig ventricular action potentials (APs), we simulated and compared cell electrophysiology mechanisms and response to drugs. Under basal conditions (absence of β-adrenergic stimulation), Na(+)/K(+)-ATPase changes secondary to Na(+) accumulation determined AP rate dependence for human and dog but not for guinea pig where slow delayed rectifier current (I(Ks)) was the major rate-dependent current. AP prolongation with reduction of rapid delayed rectifier current (I(Kr)) and I(Ks) (due to mutations or drugs) showed strong species dependence in simulations, as in experiments. For humans, AP prolongation was 80% following I(Kr) block. It was 30% for dog and 20% for guinea pig. Under basal conditions, I(Ks) block was of no consequence for human and dog, but for guinea pig, AP prolongation after I(Ks) block was severe. However, with β-adrenergic stimulation, I(Ks) played an important role in all species, particularly in AP shortening at fast rate. Quantitative comparison of AP repolarization, rate-dependence mechanisms, and drug response in human, dog, and guinea pig revealed major species differences (e.g., susceptibility to arrhythmogenic early afterdepolarizations). Extrapolation from animal to human electrophysiology and drug response requires great caution.
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Affiliation(s)
- Thomas O'Hara
- Cardiac Bioelectricity and Arrhythmia Center, Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130-4899, USA
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30
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Ma J, Guo L, Fiene SJ, Anson BD, Thomson JA, Kamp TJ, Kolaja KL, Swanson BJ, January CT. High purity human-induced pluripotent stem cell-derived cardiomyocytes: electrophysiological properties of action potentials and ionic currents. Am J Physiol Heart Circ Physiol 2011; 301:H2006-17. [PMID: 21890694 DOI: 10.1152/ajpheart.00694.2011] [Citation(s) in RCA: 558] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human-induced pluripotent stem cells (hiPSCs) can differentiate into functional cardiomyocytes; however, the electrophysiological properties of hiPSC-derived cardiomyocytes have yet to be fully characterized. We performed detailed electrophysiological characterization of highly pure hiPSC-derived cardiomyocytes. Action potentials (APs) were recorded from spontaneously beating cardiomyocytes using a perforated patch method and had atrial-, nodal-, and ventricular-like properties. Ventricular-like APs were more common and had maximum diastolic potentials close to those of human cardiac myocytes, AP durations were within the range of the normal human electrocardiographic QT interval, and APs showed expected sensitivity to multiple drugs (tetrodotoxin, nifedipine, and E4031). Early afterdepolarizations (EADs) were induced with E4031 and were bradycardia dependent, and EAD peak voltage varied inversely with the EAD take-off potential. Gating properties of seven ionic currents were studied including sodium (I(Na)), L-type calcium (I(Ca)), hyperpolarization-activated pacemaker (I(f)), transient outward potassium (I(to)), inward rectifier potassium (I(K1)), and the rapidly and slowly activating components of delayed rectifier potassium (I(Kr) and I(Ks), respectively) current. The high purity and large cell numbers also enabled automated patch-clamp analysis. We conclude that these hiPSC-derived cardiomyocytes have ionic currents and channel gating properties underlying their APs and EADs that are quantitatively similar to those reported for human cardiac myocytes. These hiPSC-derived cardiomyocytes have the added advantage that they can be used in high-throughput assays, and they have the potential to impact multiple areas of cardiovascular research and therapeutic applications.
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Affiliation(s)
- Junyi Ma
- Cellular Dynamics International, Madison, Wisconsin, USA
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31
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O'Hara T, Virág L, Varró A, Rudy Y. Simulation of the undiseased human cardiac ventricular action potential: model formulation and experimental validation. PLoS Comput Biol 2011; 7:e1002061. [PMID: 21637795 PMCID: PMC3102752 DOI: 10.1371/journal.pcbi.1002061] [Citation(s) in RCA: 704] [Impact Index Per Article: 54.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 04/05/2011] [Indexed: 11/19/2022] Open
Abstract
Cellular electrophysiology experiments, important for understanding cardiac arrhythmia mechanisms, are usually performed with channels expressed in non myocytes, or with non-human myocytes. Differences between cell types and species affect results. Thus, an accurate model for the undiseased human ventricular action potential (AP) which reproduces a broad range of physiological behaviors is needed. Such a model requires extensive experimental data, but essential elements have been unavailable. Here, we develop a human ventricular AP model using new undiseased human ventricular data: Ca(2+) versus voltage dependent inactivation of L-type Ca(2+) current (I(CaL)); kinetics for the transient outward, rapid delayed rectifier (I(Kr)), Na(+)/Ca(2+) exchange (I(NaCa)), and inward rectifier currents; AP recordings at all physiological cycle lengths; and rate dependence and restitution of AP duration (APD) with and without a variety of specific channel blockers. Simulated APs reproduced the experimental AP morphology, APD rate dependence, and restitution. Using undiseased human mRNA and protein data, models for different transmural cell types were developed. Experiments for rate dependence of Ca(2+) (including peak and decay) and intracellular sodium ([Na(+)](i)) in undiseased human myocytes were quantitatively reproduced by the model. Early afterdepolarizations were induced by I(Kr) block during slow pacing, and AP and Ca(2+) alternans appeared at rates >200 bpm, as observed in the nonfailing human ventricle. Ca(2+)/calmodulin-dependent protein kinase II (CaMK) modulated rate dependence of Ca(2+) cycling. I(NaCa) linked Ca(2+) alternation to AP alternans. CaMK suppression or SERCA upregulation eliminated alternans. Steady state APD rate dependence was caused primarily by changes in [Na(+)](i), via its modulation of the electrogenic Na(+)/K(+) ATPase current. At fast pacing rates, late Na(+) current and I(CaL) were also contributors. APD shortening during restitution was primarily dependent on reduced late Na(+) and I(CaL) currents due to inactivation at short diastolic intervals, with additional contribution from elevated I(Kr) due to incomplete deactivation.
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Affiliation(s)
- Thomas O'Hara
- Cardiac Bioelectricity and Arrhythmia Center, Department of Biomedical
Engineering, Washington University in St. Louis, St. Louis, Missouri, United
States of America
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, University of Szeged,
Szeged, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged,
Szeged, Hungary
- Division of Cardiovascular Pharmacology, Hungarian Academy of Sciences,
Szeged, Hungary
| | - Yoram Rudy
- Cardiac Bioelectricity and Arrhythmia Center, Department of Biomedical
Engineering, Washington University in St. Louis, St. Louis, Missouri, United
States of America
- * E-mail:
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32
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Liu J, Kim KH, London B, Morales MJ, Backx PH. Dissection of the voltage-activated potassium outward currents in adult mouse ventricular myocytes: I to,f, I to,s, I K,slow1, I K,slow2, and I ss. Basic Res Cardiol 2011; 106:189-204. [DOI: 10.1007/s00395-010-0134-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 10/27/2010] [Accepted: 11/04/2010] [Indexed: 11/30/2022]
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33
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Functional role of TASK-1 in the heart: studies in TASK-1-deficient mice show prolonged cardiac repolarization and reduced heart rate variability. Basic Res Cardiol 2010; 106:75-87. [DOI: 10.1007/s00395-010-0128-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 10/01/2010] [Accepted: 10/11/2010] [Indexed: 01/23/2023]
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34
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Reverse rate-dependent changes are determined by baseline action potential duration in mammalian and human ventricular preparations. Basic Res Cardiol 2010; 105:315-23. [DOI: 10.1007/s00395-009-0082-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 12/10/2009] [Accepted: 12/21/2009] [Indexed: 11/26/2022]
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35
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Bányász T, Horváth B, Virág L, Bárándi L, Szentandrássy N, Harmati G, Magyar J, Marangoni S, Zaza A, Varró A, Nánási PP. Reverse rate dependency is an intrinsic property of canine cardiac preparations. Cardiovasc Res 2009; 84:237-44. [DOI: 10.1093/cvr/cvp213] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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