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Ebner A, Kuerbis N, Brandt A, Zatschler B, Weinert S, Poitz DM, Ebner B, Augstein A, Wunderlich C, El-Armouche A, Strasser RH. Endothelial Nitric Oxide Synthase-Induced Hypertrophy and Vascular Dysfunction Contribute to the Left Ventricular Dysfunction in Caveolin-1−/− Mice. Can J Cardiol 2017; 33:1716-1724. [DOI: 10.1016/j.cjca.2017.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 02/02/2023] Open
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Uzun AU, Mannhardt I, Breckwoldt K, Horváth A, Johannsen SS, Hansen A, Eschenhagen T, Christ T. Ca(2+)-Currents in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Effects of Two Different Culture Conditions. Front Pharmacol 2016; 7:300. [PMID: 27672365 PMCID: PMC5018497 DOI: 10.3389/fphar.2016.00300] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 08/25/2016] [Indexed: 11/13/2022] Open
Abstract
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) provide a unique opportunity to study human heart physiology and pharmacology and repair injured hearts. The suitability of hiPSC-CM critically depends on how closely they share physiological properties of human adult cardiomyocytes (CM). Here we investigated whether a 3D engineered heart tissue (EHT) culture format favors maturation and addressed the L-type Ca2+-current (ICa,L) as a readout. The results were compared with hiPSC-CM cultured in conventional monolayer (ML) and to our previous data from human adult atrial and ventricular CM obtained when identical patch-clamp protocols were used. HiPSC-CM were two- to three-fold smaller than adult CM, independently of culture format [capacitance ML 45 ± 1 pF (n = 289), EHT 45 ± 1 pF (n = 460), atrial CM 87 ± 3 pF (n = 196), ventricular CM 126 ± 8 pF (n = 50)]. Only 88% of ML cells showed ICa, but all EHT. Basal ICa density was 10 ± 1 pA/pF (n = 207) for ML and 12 ± 1 pA/pF (n = 361) for EHT and was larger than in adult CM [7 ± 1 pA/pF (p < 0.05, n = 196) for atrial CM and 6 ± 1 pA/pF (p < 0.05, n = 47) for ventricular CM]. However, ML and EHT showed robust T-type Ca2+-currents (ICa,T). While (−)-Bay K 8644, that activates ICa,L directly, increased ICa,Lto the same extent in ML and EHT, β1- and β2-adrenoceptor effects were marginal in ML, but of same size as (−)-Bay K 8644 in EHT. The opposite was true for serotonin receptors. Sensitivity to β1 and β2-adrenoceptor stimulation was the same in EHT as in adult CM (−logEC50: 5.9 and 6.1 for norepinephrine (NE) and epinephrine (Epi), respectively), but very low concentrations of Rp-8-Br-cAMPS were sufficient to suppress effects (−logEC50: 5.3 and 5.3 respectively for NE and Epi). Taken together, hiPSC-CM express ICa,L at the same density as human adult CM, but, in contrast, possess robust ICa,T. Increased effects of catecholamines in EHT suggest more efficient maturation.
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Affiliation(s)
- Ahmet U Uzun
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Ingra Mannhardt
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Kaja Breckwoldt
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - András Horváth
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany; Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of SzegedSzeged, Hungary
| | - Silke S Johannsen
- Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany; Department of General and Interventional Cardiology, University Heart Center HamburgHamburg, Germany
| | - Arne Hansen
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Thomas Eschenhagen
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
| | - Torsten Christ
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-EppendorfHamburg, Germany; Partner Site Hamburg/Kiel/Lübeck, German Centre for Cardiovascular Research (DZHK)Hamburg, Germany
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Koivumäki JT, Seemann G, Maleckar MM, Tavi P. In silico screening of the key cellular remodeling targets in chronic atrial fibrillation. PLoS Comput Biol 2014; 10:e1003620. [PMID: 24853123 PMCID: PMC4031057 DOI: 10.1371/journal.pcbi.1003620] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 03/30/2014] [Indexed: 02/07/2023] Open
Abstract
Chronic atrial fibrillation (AF) is a complex disease with underlying changes in electrophysiology, calcium signaling and the structure of atrial myocytes. How these individual remodeling targets and their emergent interactions contribute to cell physiology in chronic AF is not well understood. To approach this problem, we performed in silico experiments in a computational model of the human atrial myocyte. The remodeled function of cellular components was based on a broad literature review of in vitro findings in chronic AF, and these were integrated into the model to define a cohort of virtual cells. Simulation results indicate that while the altered function of calcium and potassium ion channels alone causes a pronounced decrease in action potential duration, remodeling of intracellular calcium handling also has a substantial impact on the chronic AF phenotype. We additionally found that the reduction in amplitude of the calcium transient in chronic AF as compared to normal sinus rhythm is primarily due to the remodeling of calcium channel function, calcium handling and cellular geometry. Finally, we found that decreased electrical resistance of the membrane together with remodeled calcium handling synergistically decreased cellular excitability and the subsequent inducibility of repolarization abnormalities in the human atrial myocyte in chronic AF. We conclude that the presented results highlight the complexity of both intrinsic cellular interactions and emergent properties of human atrial myocytes in chronic AF. Therefore, reversing remodeling for a single remodeled component does little to restore the normal sinus rhythm phenotype. These findings may have important implications for developing novel therapeutic approaches for chronic AF.
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Affiliation(s)
- Jussi T. Koivumäki
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical Computing, Oslo, Norway
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Gunnar Seemann
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Mary M. Maleckar
- Simula Research Laboratory, Center for Cardiological Innovation and Center for Biomedical Computing, Oslo, Norway
| | - Pasi Tavi
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- * E-mail:
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Wuest M, Christ T, Hiller N, Braeter M, Ravens U. Effects of three metabolites of propiverine on voltage-dependent L-type calcium currents in human atrial myocytes. Eur J Pharmacol 2008; 598:94-7. [PMID: 18796302 DOI: 10.1016/j.ejphar.2008.08.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 08/06/2008] [Accepted: 08/21/2008] [Indexed: 11/17/2022]
Abstract
The non-selective muscarinic receptor antagonist propiverine impairs L-type Ca(2+) currents (I(Ca,L)) in human detrusor smooth muscle cells and atrial cardiomyocytes. Here, we have investigated the effects of three metabolites of propiverine on human cardiac I(Ca,L). Propiverine reduced I(Ca)(,L) with a -logIC(50) [M] value of 4.1, M-5 only showed minor effect on I(Ca)(,L) at high concentrations, M-6 did not influence I(Ca)(,L) at all. Like the parent compound M-14 also reduced I(Ca)(,L) (-logIC(50) [M]=4.6). We conclude, that propiverine and M-14 reduce cardiac I(Ca)(,L) at higher concentrations than in detrusor cells and therefore preferentially reduce I(Ca)(,L) in the urinary bladder than in the heart.
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Affiliation(s)
- Melinda Wuest
- Department of Pharmacology and Toxicology, Dresden University of Technology, Dresden, Germany.
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Christ T, Wettwer E, Wuest M, Braeter M, Donath F, Champeroux P, Richard S, Ravens U. Electrophysiological profile of propiverine--relationship to cardiac risk. Naunyn Schmiedebergs Arch Pharmacol 2007; 376:431-40. [PMID: 18092154 DOI: 10.1007/s00210-007-0231-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 11/22/2007] [Indexed: 10/22/2022]
Abstract
Drugs that prolong the QT interval by blocking human ether-a-go-go (HERG) channels may enhance the risk of ventricular arrhythmia. The spasmolytic drug propiverine is widely used for the therapy of overactive bladder (OAB). Here, we have investigated the effects of propiverine on cardiac ion channels and action potentials as well as on contractile properties of cardiac tissue, in order to estimate its cardiac safety profile, because other drugs used in this indication had to be withdrawn due to safety reasons. Whole-cell patch clamp technique was used to record the following cardiac ion currents: rapidly and slowly activating delayed rectifier K+ current (I(Kr), I(Ks)), ultra rapidly activating delayed rectifier K+ current (I(Kur)), inwardly rectifying K+ current I(K1), transient outward K+ current (I(to)), and L-type Ca2+ current (I(Ca,L)). Action potentials in cardiac tissue biopsies were recorded with conventional microelectrodes. The torsade de pointes screening assay (TDPScreen) was used for drug scoring. Propiverine blocked in a concentration-dependent manner HERG channels expressed in HEK293 cells, as well as native I(Kr) current in ventricular myocytes of guinea pig (IC50 values: 10 microM and 1.8 microM respectively). At high concentrations (100 microM), propiverine suppressed I(Ks). I(K1) and the transient outward current I(to) and I(Kur) were not affected. In guinea-pig ventricular and human atrial myocytes, propiverine also blocked I(Ca,L) (IC50 values: 34.7 microM and 41.7 microM, respectively) and reduced force of contraction. Despite block of I(Kr), action potential duration was not prolonged in guinea-pig and human ventricular tissue, but decreased progressively until excitation failed altogether. Similar effects were observed in dog Purkinje fibers. Propiverine obtained a low score in the TDPScreen. In conclusion, in vitro and in vivo studies of propiverine do not provide evidence for an enhanced cardiovascular safety risk. We propose that lack of torsadogenic risk of propiverine is related to enhancement of repolarization reserve by block of I(Ca,L).
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Affiliation(s)
- Torsten Christ
- Department of Pharmacology and Toxicology, Medical Faculty, Dresden University of Technology, Fetscherstrasse 74, 01307 Dresden, Germany
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Christ T, Wettwer E, Ravens U. Risperidone-induced action potential prolongation is attenuated by increased repolarization reserve due to concomitant block of ICa,L. Naunyn Schmiedebergs Arch Pharmacol 2005; 371:393-400. [PMID: 15959721 DOI: 10.1007/s00210-005-1063-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Accepted: 04/13/2005] [Indexed: 11/26/2022]
Abstract
The neuroleptic risperidone is an effective blocker of the rapidly activating component of the delayed rectifier current (I(Kr)) and hence is expected to prolong cardiac action potential duration (APD). However, unlike with other typical I(Kr) blockers we failed to demonstrate a marked prolongation of late repolarization with risperidone. It is hypothesized that the APD-prolonging effect of risperidone is masked by the high repolarization reserve due to the prominent delayed rectifier currents I(Kr) and I(Ks) in guinea pig papillary muscle. Action potentials and force of contraction were recorded in isolated guinea pig papillary muscles. L-type calcium current I(Ca,L) and I(Kr) were measured using the standard patch clamp technique in single ventricular cardiomyocytes. Reduction of the repolarization reserve by the blocking of I(Ks) with chromanol 239B augmented the effect of the selective I(Kr) blocker E-4031, but not of risperidone, although both drugs completely blocked I(Kr). In contrast to E-4031 risperidone markedly reduced the force of contraction due to the partial blocking of I(Ca,L) in the same concentration range as required for block of I(Kr). Reduction of the repolarization reserve by the blocking of I(Ks) cannot exacerbate the APD-prolonging effect of risperidone. However, even incomplete concomitant blocking of I(Ca,L) attenuates the APD-prolonging effect of the complete blocking of I(Kr). This behaviour may explain the small APD-prolonging effect of risperidone despite the drug's robust blocking of I(Kr).
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Affiliation(s)
- Torsten Christ
- Department of Pharmacology and Toxicology, Medical Faculty, University of Technology, Dresden, Germany
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