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Li E, van der Heyden MAG. The network of cardiac K IR2.1: its function, cellular regulation, electrical signaling, diseases and new drug avenues. Naunyn Schmiedebergs Arch Pharmacol 2024:10.1007/s00210-024-03116-5. [PMID: 38683369 DOI: 10.1007/s00210-024-03116-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
The functioning of the human heart relies on complex electrical and communication systems that coordinate cardiac contractions and sustain rhythmicity. One of the key players contributing to this intricate system is the KIR2.1 potassium ion channel, which is encoded by the KCNJ2 gene. KIR2.1 channels exhibit abundant expression in both ventricular myocytes and Purkinje fibers, exerting an important role in maintaining the balance of intracellular potassium ion levels within the heart. And by stabilizing the resting membrane potential and contributing to action potential repolarization, these channels have an important role in cardiac excitability also. Either gain- or loss-of-function mutations, but also acquired impairments of their function, are implicated in the pathogenesis of diverse types of cardiac arrhythmias. In this review, we aim to elucidate the system functions of KIR2.1 channels related to cellular electrical signaling, communication, and their contributions to cardiovascular disease. Based on this knowledge, we will discuss existing and new pharmacological avenues to modulate their function.
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Affiliation(s)
- Encan Li
- Department of Medical Physiology, Division Heart & Lungs, University Medical Center Utrecht, Yalelaan 50, 3584 CM, Utrecht, Netherlands
| | - Marcel A G van der Heyden
- Department of Medical Physiology, Division Heart & Lungs, University Medical Center Utrecht, Yalelaan 50, 3584 CM, Utrecht, Netherlands.
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2
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Yu W, Wang Z, Yu X, Zhao Y, Xie Z, Zhang K, Chi Z, Chen S, Xu T, Jiang D, Guo X, Li M, Zhang J, Fang H, Yang D, Guo Y, Yang X, Zhang X, Wu Y, Yang W, Wang D. Kir2.1-mediated membrane potential promotes nutrient acquisition and inflammation through regulation of nutrient transporters. Nat Commun 2022; 13:3544. [PMID: 35729093 PMCID: PMC9213538 DOI: 10.1038/s41467-022-31149-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 05/26/2022] [Indexed: 12/22/2022] Open
Abstract
Immunometabolism contributes to inflammation, but how activated macrophages acquire extracellular nutrients to fuel inflammation is largely unknown. Here, we show that the plasma membrane potential (Vm) of macrophages mediated by Kir2.1, an inwardly-rectifying K+ channel, is an important determinant of nutrient acquisition and subsequent metabolic reprogramming promoting inflammation. In the absence of Kir2.1 activity, depolarized macrophage Vm lead to a caloric restriction state by limiting nutrient uptake and concomitant adaptations in nutrient conservation inducing autophagy, AMPK (Adenosine 5'-monophosphate-activated protein kinase), and GCN2 (General control nonderepressible 2), which subsequently depletes epigenetic substrates feeding histone methylation at loci of a cluster of metabolism-responsive inflammatory genes, thereby suppressing their transcription. Kir2.1-mediated Vm supports nutrient uptake by facilitating cell-surface retention of nutrient transporters such as 4F2hc and GLUT1 by its modulation of plasma membrane phospholipid dynamics. Pharmacological targeting of Kir2.1 alleviated inflammation triggered by LPS or bacterial infection in a sepsis model and sterile inflammation in human samples. These findings identify an ionic control of macrophage activation and advance our understanding of the immunomodulatory properties of Vm that links nutrient inputs to inflammatory diseases.
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Affiliation(s)
- Weiwei Yu
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China.,Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, P. R. China
| | - Zhen Wang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China.,Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, P. R. China
| | - Xiafei Yu
- Department of Biophysics, and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Yonghui Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, P. R. China
| | - Zili Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, P. R. China
| | - Kailian Zhang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Zhexu Chi
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Sheng Chen
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Ting Xu
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Danlu Jiang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Xingchen Guo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, P. R. China
| | - Mobai Li
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Jian Zhang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Hui Fang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Dehang Yang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Yuxian Guo
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Xuyan Yang
- Department of Rheumatology of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Xue Zhang
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, P. R. China
| | - Wei Yang
- Department of Biophysics, and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China.
| | - Di Wang
- Institute of Immunology and Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, P. R. China. .,Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, P. R. China.
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3
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Li E, Loen V, van Ham WB, Kool W, van der Heyden MAG, Takanari H. Quantitative Analysis of the Cytoskeleton's Role in Inward Rectifier K IR 2.1 Forward and Backward Trafficking. Front Physiol 2022; 12:812572. [PMID: 35145427 PMCID: PMC8821923 DOI: 10.3389/fphys.2021.812572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/23/2021] [Indexed: 11/13/2022] Open
Abstract
Alteration of the inward rectifier current IK1, carried by KIR2.1 channels, affects action potential duration, impacts resting membrane stability and associates with cardiac arrhythmias. Congenital and acquired KIR2.1 malfunction frequently associates with aberrant ion channel trafficking. Cellular processes underlying trafficking are intertwined with cytoskeletal function. The extent to which the cytoskeleton is involved in KIR2.1 trafficking processes is unknown. We aimed to quantify the dependence of KIR2.1 trafficking on cytoskeleton function. GFP or photoconvertible Dendra2 tagged KIR2.1 constructs were transfected in HEK293 or HeLa cells. Photoconversion of the Dendra2 probe at the plasma membrane and subsequent live imaging of trafficking processes was performed by confocal laser-scanning microscopy. Time constant of green fluorescent recovery (τg,s) represented recruitment of new KIR2.1 at the plasma membrane. Red fluorescent decay (τr,s) represented internalization of photoconverted KIR2.1. Patch clamp electrophysiology was used to quantify IKIR2.1. Biochemical methods were used for cytoskeleton isolation and detection of KIR2.1-cytoskeleton interactions. Cytochalasin B (20 μM), Nocodazole (30 μM) and Dyngo-4a (10 nM) were used to modify the cytoskeleton. Chloroquine (10 μM, 24 h) was used to impair KIR2.1 breakdown. Cytochalasin B and Nocodazole, inhibitors of actin and tubulin filament formation respectively, strongly inhibited the recovery of green fluorescence at the plasma membrane suggestive for inhibition of KIR2.1 forward trafficking [τg,s 13 ± 2 vs. 131 ± 31* and 160 ± 40* min, for control, Cytochalasin B and Nocodazole, respectively (*p < 0.05 vs. control)]. Dyngo-4a, an inhibitor of dynamin motor proteins, strongly slowed the rate of photoconverted channel internalization, whereas Nocodazole and Cytochalasin B had less effect [τr,s 20 ± 2 vs. 87 ± 14*, 60 ± 16 and 64 ± 20 min (*p < 0.05 vs. control)]. Cytochalasin B treatment (20 μM, 24 h) inhibited IKIR2.1. Chloroquine treatment (10 μM, 24 h) induced intracellular aggregation of KIR2.1 channels and enhanced interaction with the actin/intermediate filament system (103 ± 90 fold; p < 0.05 vs. control). Functional actin and tubulin cytoskeleton systems are essential for forward trafficking of KIR2.1 channels, whereas initial backward trafficking relies on a functional dynamin system. Chronic disturbance of the actin system inhibits KIR2.1 currents. Internalized KIR2.1 channels become recruited to the cytoskeleton, presumably in lysosomes.
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Affiliation(s)
- Encan Li
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Vera Loen
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Willem B van Ham
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Willy Kool
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marcel A G van der Heyden
- Department of Medical Physiology, Division of Heart & Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Hiroki Takanari
- Department of Interdisciplinary Researches for Medicine and Photonics, Institute of Post-LED Photonics, University of Tokushima, Tokushima, Japan
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Lagoutte-Renosi J, Allemand F, Ramseyer C, Yesylevskyy S, Davani S. Molecular modeling in cardiovascular pharmacology: Current state of the art and perspectives. Drug Discov Today 2021; 27:985-1007. [PMID: 34863931 DOI: 10.1016/j.drudis.2021.11.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 11/02/2021] [Accepted: 11/25/2021] [Indexed: 01/10/2023]
Abstract
Molecular modeling in pharmacology is a promising emerging tool for exploring drug interactions with cellular components. Recent advances in molecular simulations, big data analysis, and artificial intelligence (AI) have opened new opportunities for rationalizing drug interactions with their pharmacological targets. Despite the obvious utility and increasing impact of computational approaches, their development is not progressing at the same speed in different fields of pharmacology. Here, we review current in silico techniques used in cardiovascular diseases (CVDs), cardiological drug discovery, and assessment of cardiotoxicity. In silico techniques are paving the way to a new era in cardiovascular medicine, but their use somewhat lags behind that in other fields.
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Affiliation(s)
- Jennifer Lagoutte-Renosi
- EA 3920 Université Bourgogne Franche-Comté, 25000 Besançon, France; Laboratoire de Pharmacologie Clinique et Toxicologie-CHU de Besançon, 25000 Besançon, France
| | - Florentin Allemand
- EA 3920 Université Bourgogne Franche-Comté, 25000 Besançon, France; Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France
| | - Christophe Ramseyer
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France
| | - Semen Yesylevskyy
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25000 Besançon, France; Department of Physics of Biological Systems, Institute of Physics of The National Academy of Sciences of Ukraine, Nauky Sve. 46, Kyiv, Ukraine; Receptor.ai inc, 16192 Coastal Highway, Lewes, DE, USA
| | - Siamak Davani
- EA 3920 Université Bourgogne Franche-Comté, 25000 Besançon, France; Laboratoire de Pharmacologie Clinique et Toxicologie-CHU de Besançon, 25000 Besançon, France.
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Lacalle-Aurioles M, Trigiani LJ, Bourourou M, Lecrux C, Hamel E. Alzheimer's disease and cerebrovascular pathology alter brain endothelial inward rectifier potassium (K IR 2.1) channels. Br J Pharmacol 2021; 179:2259-2274. [PMID: 34820829 PMCID: PMC9304142 DOI: 10.1111/bph.15751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 11/27/2022] Open
Abstract
Background and Purpose Inward rectifier potassium (KIR) channels are key effectors of vasodilatation in neurovascular coupling (NVC). KIR channels expressed in cerebral endothelial cells (ECs) have been confirmed as essential modulators of NVC. Alzheimer's disease (AD) and cerebrovascular disease (CVD) impact on EC‐KIR channel function, but whether oxidative stress or inflammation explains this impairment remains elusive. Experimental Approach We evaluated KIR channel function in intact and EC‐denuded pial arteries of wild‐type (WT) and transgenic mice overexpressing a mutated form of the human amyloid precursor protein (APP mice, recapitulating amyloid β‐induced oxidative stress seen in AD) or a constitutively active form of TGF‐β1 (TGF mice, recapitulating inflammation seen in cerebrovascular pathology). The benefits of antioxidant (catalase) or anti‐inflammatory (indomethacin) drugs also were investigated. Vascular and neuronal components of NVC were assessed in vivo. Key Results Our findings show that (i) KIR channel‐mediated maximal vasodilatation in APP and TGF mice reaches only 37% and 10%, respectively, of the response seen in WT mice; (ii) KIR channel dysfunction results from KIR2.1 subunit impairment; (iii) about 50% of K+‐induced artery dilatation is mediated by EC‐KIR channels; (iv) oxidative stress and inflammation impair KIR channel function, which can be restored by antioxidant and anti‐inflammatory drugs; and (v) inflammation induces KIR2.1 overexpression and impairs NVC in TGF mice. Conclusion and Implications Therapies targeting both oxidative stress and inflammation are necessary for full recovery of KIR2.1 channel function in cerebrovascular pathology caused by AD and CVD.
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Affiliation(s)
- María Lacalle-Aurioles
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Lianne J Trigiani
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Miled Bourourou
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Clotilde Lecrux
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Edith Hamel
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
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Fan X, Yang G, Kowitz J, Duru F, Saguner AM, Akin I, Zhou X, El-Battrawy I. Preclinical short QT syndrome models: studying the phenotype and drug-screening. Europace 2021; 24:481-493. [PMID: 34516623 DOI: 10.1093/europace/euab214] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 09/05/2021] [Indexed: 11/14/2022] Open
Abstract
Cardiovascular diseases are the main cause of sudden cardiac death (SCD) in developed and developing countries. Inherited cardiac channelopathies are linked to 5-10% of SCDs, mainly in the young. Short QT syndrome (SQTS) is a rare inherited channelopathy, which leads to both atrial and ventricular tachyarrhythmias, syncope, and even SCD. International European Society of Cardiology guidelines include as diagnostic criteria: (i) QTc ≤ 340 ms on electrocardiogram, (ii) QTc ≤ 360 ms plus one of the follwing, an affected short QT syndrome pathogenic gene mutation, or family history of SQTS, or aborted cardiac arrest, or family history of cardiac arrest in the young. However, further evaluation of the QTc ranges seems to be required, which might be possible by assembling large short QT cohorts and considering genetic screening of the newly described pathogenic mutations. Since the mechanisms underlying the arrhythmogenesis of SQTS is unclear, optimal therapy for SQTS is still lacking. The disease is rare, unclear genotype-phenotype correlations exist in a bevy of cases and the absence of an international short QT registry limit studies on the pathophysiological mechanisms of arrhythmogenesis and therapy of SQTS. This leads to the necessity of experimental models or platforms for studying SQTS. Here, we focus on reviewing preclinical SQTS models and platforms such as animal models, heterologous expression systems, human-induced pluripotent stem cell-derived cardiomyocyte models and computer models as well as three-dimensional engineered heart tissues. We discuss their usefulness for SQTS studies to examine genotype-phenotype associations, uncover disease mechanisms and test drugs. These models might be helpful for providing novel insights into the exact pathophysiological mechanisms of this channelopathy and may offer opportunities to improve the diagnosis and treatment of patients with SQT syndrome.
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Affiliation(s)
- Xuehui Fan
- University of Mannheim, University of Heidelberg, Germany.,Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention of Cardiovascular Diseases, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Guoqiang Yang
- Department of Acupuncture and Rehabilitation, Hospital (T.CM.) Affiliated to Southwest Medical University, Luzhou, Sichuan, China.,Research Unit of Molecular Imaging Probes, Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | | | - Firat Duru
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Ardan M Saguner
- Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland
| | - Ibrahim Akin
- University of Mannheim, University of Heidelberg, Germany.,DZHK (German Center for Cardiovascular Research) Partner Site, Heidelberg-Mannheim, Germany
| | - Xiaobo Zhou
- University of Mannheim, University of Heidelberg, Germany.,Key Laboratory of Medical Electrophysiology, Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Collaborative Innovation Center for Prevention of Cardiovascular Diseases, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China.,DZHK (German Center for Cardiovascular Research) Partner Site, Heidelberg-Mannheim, Germany
| | - Ibrahim El-Battrawy
- University of Mannheim, University of Heidelberg, Germany.,Department of Cardiology, University Heart Centre, University Hospital Zurich, Zurich, Switzerland
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Qile M, Ji Y, Houtman MJC, Veldhuis M, Romunde F, Kok B, van der Heyden MAG. Identification of a PEST Sequence in Vertebrate K IR2.1 That Modifies Rectification. Front Physiol 2019; 10:863. [PMID: 31333502 PMCID: PMC6624654 DOI: 10.3389/fphys.2019.00863] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/20/2019] [Indexed: 11/13/2022] Open
Abstract
KIR2.1 potassium channels, producing inward rectifier potassium current (IK1), are important for final action potential repolarization and a stable resting membrane potential in excitable cells like cardiomyocytes. Abnormal KIR2.1 function, either decreased or increased, associates with diseases such as Andersen-Tawil syndrome, long and short QT syndromes. KIR2.1 ion channel protein trafficking and subcellular anchoring depends on intrinsic specific short amino acid sequences. We hypothesized that combining an evolutionary based sequence comparison and bioinformatics will identify new functional domains within the C-terminus of the KIR2.1 protein, which function could be determined by mutation analysis. We determined PEST domain signatures, rich in proline (P), glutamic acid (E), serine (S), and threonine (T), within KIR2.1 sequences using the “epestfind” webtool. WT and ΔPEST KIR2.1 channels were expressed in HEK293T and COS-7 cells. Patch-clamp electrophysiology measurements were performed in the inside-out mode on excised membrane patches and the whole cell mode using AxonPatch 200B amplifiers. KIR2.1 protein expression levels were determined by western blot analysis. Immunofluorescence microscopy was used to determine KIR2.1 subcellular localization. An evolutionary conserved PEST domain was identified in the C-terminus of the KIR2.1 channel protein displaying positive PEST scores in vertebrates ranging from fish to human. No similar PEST domain was detected in KIR2.2, KIR2.3, and KIR2.6 proteins. Deletion of the PEST domain in California kingsnake and human KIR2.1 proteins (ΔPEST), did not affect plasma membrane localization. Co-expression of WT and ΔPEST KIR2.1 proteins resulted in heterotetrameric channel formation. Deletion of the PEST domain did not increase protein stability in cycloheximide assays [T½ from 2.64 h (WT) to 1.67 h (ΔPEST), n.s.]. WT and ΔPEST channels, either from human or snake, produced typical IK1, however, human ΔPEST channels displayed stronger intrinsic rectification. The current observations suggest that the PEST sequence of KIR2.1 is not associated with rapid protein degradation, and has a role in the rectification behavior of IK1 channels.
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Affiliation(s)
- Muge Qile
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Yuan Ji
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marien J C Houtman
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marlieke Veldhuis
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Fee Romunde
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Bart Kok
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marcel A G van der Heyden
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
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Hancox JC, Whittaker DG, Zhang H, Stuart AG. Learning from studying very rare cardiac conditions: the example of short QT syndrome. J Congenit Heart Dis 2019. [DOI: 10.1186/s40949-019-0024-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Sanson C, Schombert B, Filoche-Rommé B, Partiseti M, Bohme GA. Electrophysiological and Pharmacological Characterization of Human Inwardly Rectifying K ir2.1 Channels on an Automated Patch-Clamp Platform. Assay Drug Dev Technol 2019; 17:89-99. [PMID: 30835490 PMCID: PMC6479253 DOI: 10.1089/adt.2018.882] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Inwardly rectifying IK1 potassium currents of the heart control the resting membrane potential of ventricular cardiomyocytes during diastole and contribute to their repolarization after each action potential. Mutations in the gene encoding Kir2.1 channels, which primarily conduct ventricular IK1, are associated with inheritable forms of arrhythmias and sudden cardiac death. Therefore, potential iatrogenic inhibition of Kir2.1-mediated IK1 currents is a cardiosafety concern during new drug discovery and development. Kir2.1 channels are part of the panel of cardiac ion channels currently considered for refined early compound risk assessment within the Comprehensive in vitro Proarrhythmia Assay initiative. In this study, we have validated a cell-based assay allowing functional quantification of Kir2.1 inhibitors using whole-cell recordings of Chinese hamster ovary cells stably expressing human Kir2.1 channels. We reproduced key electrophysiological and pharmacological features known for native IK1, including current enhancement by external potassium and voltage- and concentration-dependent blockade by external barium. Furthermore, the Kir inhibitors ML133, PA-6, and chloroquine, as well as the multichannel inhibitors chloroethylclonidine, chlorpromazine, SKF-96365, and the class III antiarrhythmic agent terikalant demonstrated slowly developing inhibitory activity in the low micromolar range. The robustness of this assay authorizes medium throughput screening for cardiosafety purposes and could help to enrich the currently limited Kir2.1 pharmacology.
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Affiliation(s)
- Camille Sanson
- 1 Integrated Drug Discovery, High-Content Biology, Sanofi Research and Development, Vitry-sur-Seine, France
| | - Brigitte Schombert
- 1 Integrated Drug Discovery, High-Content Biology, Sanofi Research and Development, Vitry-sur-Seine, France
| | - Bruno Filoche-Rommé
- 2 Integrated Drug Discovery, Medicinal Chemistry, Sanofi Research and Development, Vitry-sur-Seine, France
| | - Michel Partiseti
- 1 Integrated Drug Discovery, High-Content Biology, Sanofi Research and Development, Vitry-sur-Seine, France
| | - G Andrees Bohme
- 1 Integrated Drug Discovery, High-Content Biology, Sanofi Research and Development, Vitry-sur-Seine, France
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10
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Affiliation(s)
- Jules C Hancox
- School of Physiology, Pharmacology and Neuroscience, Medical Sciences Building, University Walk, Bristol, United Kingdom
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
| | - Dominic G Whittaker
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Chunyun Du
- School of Physiology, Pharmacology and Neuroscience, Medical Sciences Building, University Walk, Bristol, United Kingdom
| | - A. Graham Stuart
- Cardiology, Bristol Heart Institute, University of Bristol, Bristol, United Kingdom
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
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Abstract
PURPOSE OF REVIEW Atrial fibrillation is a common cardiac arrhythmia with a high morbidity and mortality affecting 34 million worldwide. Current therapies are inadequate and often fail to directly address molecular mechanisms of the disease. In this review, we will provide an overview of recent advances in our understanding of the genetic underpinnings of atrial fibrillation. RECENT FINDINGS Large-scale genetic association studies have more than doubled the number of genetic loci associated with atrial fibrillation during the last year. Studies examining how genes at or near these loci can affect the pathogenesis of atrial fibrillation are ongoing in cellular, animal, and computational models. In addition, several recent clinical studies have also demonstrated that variants at these loci can aid in risk stratification of patients. SUMMARY There are now over 30 genetic loci associated with atrial fibrillation. A better understanding of how these loci relate to disease pathogenesis may provide insight into novel therapeutic targets and ultimately lead to improved clinical care.
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12
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Abstract
Short QT syndrome (SQTS) is a myocardial conduction disorder characterized by a short QT interval on electrocardiogram and predisposition to familial atrial fibrillation and/or sudden cardiac death. Genetic SQTS is primarily caused by one or more cardiac ion channelopathies, in which either impaired depolarization currents, or enhanced repolarization currents, shorten cardiac action potential duration. Given that QT interval duration is not always predictive of arrhythmia burden and risk of death in SQTS, there is a need to understand the molecular mechanisms of the condition to improve risk prognostication and potential pharmacologic treatment. In the last decade, several computational advances and in vitro preclinical studies have provided insight into the molecular mechanisms underlying congenital SQTS. In this review, we discuss recent findings in SQTS molecular mechanisms and correlate these advances with clinical guidelines for SQTS diagnosis and treatment.
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Affiliation(s)
- Srikanth Perike
- Department of Medicine, Section of Cardiology, Department of Bioengineering, Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL
| | - Mark D McCAULEY
- Department of Medicine, Section of Cardiology, Department of Bioengineering, Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL
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Abstract
Degradation of cellular material by lysosomes is known as autophagy, and its main function is to maintain cellular homeostasis for growth, proliferation and survival of the cell. In recent years, research has focused on the characterization of autophagy pathways. Targeting of autophagy mediators has been described predominantly in cancer treatment, but also in neurological and cardiovascular diseases. Although the number of studies is still limited, there are indications that activity of autophagy pathways increases under arrhythmic conditions. Moreover, an increasing number of antiarrhythmic and non-cardiac drugs are found to affect autophagy pathways. We, therefore, suggest that future work should recognize the largely unaddressed effects of antiarrhythmic agents and other classes of drugs on autophagy pathway activation and inhibition.
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Affiliation(s)
- Joanne J A van Bavel
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marc A Vos
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
| | - Marcel A G van der Heyden
- Department of Medical Physiology, Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, Netherlands
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