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Ferreira G, Cardozo R, Sastre S, Costa C, Santander A, Chavarría L, Guizzo V, Puglisi J, Nicolson GL. Bacterial toxins and heart function: heat-labile Escherichia coli enterotoxin B promotes changes in cardiac function with possible relevance for sudden cardiac death. Biophys Rev 2023; 15:447-473. [PMID: 37681088 PMCID: PMC10480140 DOI: 10.1007/s12551-023-01100-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 07/11/2023] [Indexed: 09/09/2023] Open
Abstract
Bacterial toxins can cause cardiomyopathy, though it is not its most common cause. Some bacterial toxins can form pores in the membrane of cardiomyocytes, while others can bind to membrane receptors. Enterotoxigenic E. coli can secrete enterotoxins, including heat-resistant (ST) or labile (LT) enterotoxins. LT is an AB5-type toxin that can bind to specific cell receptors and disrupt essential host functions, causing several common conditions, such as certain diarrhea. The pentameric B subunit of LT, without A subunit (LTB), binds specifically to certain plasma membrane ganglioside receptors, found in lipid rafts of cardiomyocytes. Isolated guinea pig hearts and cardiomyocytes were exposed to different concentrations of purified LTB. In isolated hearts, mechanical and electrical alternans and an increment of heart rate variability, with an IC50 of ~0.2 μg/ml LTB, were observed. In isolated cardiomyocytes, LTB promoted significant decreases in the amplitude and the duration of action potentials. Na+ currents were inhibited whereas L-type Ca2+ currents were augmented at their peak and their fast inactivation was promoted. Delayed rectifier K+ currents decreased. Measurements of basal Ca2+ or Ca2+ release events in cells exposed to LTB suggest that LTB impairs Ca2+ homeostasis. Impaired calcium homeostasis is linked to sudden cardiac death. The results are consistent with the recent view that the B subunit is not merely a carrier of the A subunit, having a role explaining sudden cardiac death in children (SIDS) infected with enterotoxigenic E. coli, explaining several epidemiological findings that establish a strong relationship between SIDS and ETEC E. coli. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-023-01100-6.
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Affiliation(s)
- Gonzalo Ferreira
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics, Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - Romina Cardozo
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics, Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - Santiago Sastre
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics and Centro de Investigaciones Biomédicas (CeInBio), Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - Carlos Costa
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics, Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - Axel Santander
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics, Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - Luisina Chavarría
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics, Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - Valentina Guizzo
- Ion Channels, Biological Membranes and Cell Signaling Laboratory, Dept. Of Biophysics, Facultad de Medicina, Universidad de la Republica, Gral Flores 2125, 11800 Montevideo, CP Uruguay
| | - José Puglisi
- College of Medicine, California North State University, 9700 West Taron Drive, Elk Grove, CA 95757 USA
| | - G. L. Nicolson
- Institute for Molecular Medicine, Beach, Huntington, CA USA
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2
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Sanchez-Sandoval AL, Hernández-Plata E, Gomora JC. Voltage-gated sodium channels: from roles and mechanisms in the metastatic cell behavior to clinical potential as therapeutic targets. Front Pharmacol 2023; 14:1206136. [PMID: 37456756 PMCID: PMC10348687 DOI: 10.3389/fphar.2023.1206136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/21/2023] [Indexed: 07/18/2023] Open
Abstract
During the second half of the last century, the prevalent knowledge recognized the voltage-gated sodium channels (VGSCs) as the proteins responsible for the generation and propagation of action potentials in excitable cells. However, over the last 25 years, new non-canonical roles of VGSCs in cancer hallmarks have been uncovered. Their dysregulated expression and activity have been associated with aggressive features and cancer progression towards metastatic stages, suggesting the potential use of VGSCs as cancer markers and prognostic factors. Recent work has elicited essential information about the signalling pathways modulated by these channels: coupling membrane activity to transcriptional regulation pathways, intracellular and extracellular pH regulation, invadopodia maturation, and proteolytic activity. In a promising scenario, the inhibition of VGSCs with FDA-approved drugs as well as with new synthetic compounds, reduces cancer cell invasion in vitro and cancer progression in vivo. The purpose of this review is to present an update regarding recent advances and ongoing efforts to have a better understanding of molecular and cellular mechanisms on the involvement of both pore-forming α and auxiliary β subunits of VGSCs in the metastatic processes, with the aim at proposing VGSCs as new oncological markers and targets for anticancer treatments.
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Affiliation(s)
- Ana Laura Sanchez-Sandoval
- Departamento de Neuropatología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Medicina Genómica, Hospital General de México “Dr Eduardo Liceaga”, Mexico City, Mexico
| | - Everardo Hernández-Plata
- Consejo Nacional de Humanidades, Ciencias y Tecnologías and Instituto Nacional de Medicina Genómica, Mexico City, Mexico
| | - Juan Carlos Gomora
- Departamento de Neuropatología Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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3
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Li S, Lin Z, Xiao H, Xu Z, Li C, Zeng J, Xie X, Deng L, Huang H. Fyn deficiency inhibits oxidative stress by decreasing c-Cbl-mediated ubiquitination of Sirt1 to attenuate diabetic renal fibrosis. Metabolism 2023; 139:155378. [PMID: 36538986 DOI: 10.1016/j.metabol.2022.155378] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/15/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Oxidative stress (OS) is the main cause leading to diabetic renal fibrosis. Recently, Fyn was paid much attention on OS and emerged as a pivotal player in acute kidney injury, while whether Fyn regulates oxidative stress in chronic diabetes nephropathy (DN) has not been clarified yet. The purpose of this study was to identify the role of Fyn in DN and elucidated its regulatory mechanism. METHODS The db/db mice and littermate control C57BKS/J mice were injected by tail vein with Fyn interfering adenovirus or Fyn overexpressing adenovirus to investigate the role of Fyn in vivo. Primary glomerular mesangial cells (GMCs) were used for in vitro studies. RESULTS Fyn was up-regulated in high glucose (HG)-induced GMCs and kidneys of diabetic mice. Additionally, Fyn knockdown reduced the level of OS in HG-induced GMCs and kidneys of diabetic mice, thereby ameliorating diabetic renal fibrosis. While overexpression of Fyn significantly increased the level of OS in GMCs and kidney tissues, resulting in renal damage. Moreover, Fyn deficiency exerted antioxidant effects by activating the Sirt1/Foxo3a pathway. Mechanistically, Fyn facilitated the combination of c-Cbl and Sirt1 by phosphorylating c-Cbl at Tyr731, which triggered K48-linked polyubiquitination of Sirt1 at Lys377 and Lys513 by c-Cbl and promoted Sirt1 degradation, impairing the antioxidant effects of Foxo3a. CONCLUSIONS Fyn deficiency promoted Foxo3a nuclear transcription via reducing the ubiquitination of Sirt1 by c-Cbl, thereby alleviating renal oxidative damage in diabetic mice. These results identified Fyn as a potential therapeutic target against DN.
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Affiliation(s)
- Shanshan Li
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zeyuan Lin
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Haiming Xiao
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhanchi Xu
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Chuting Li
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jingran Zeng
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xi Xie
- School of Pharmaceutical Sciences, Hainan University, Haikou 570228, China.
| | - Li Deng
- College of Traditional Chinese Medicine, Jinan University, Guangzhou 510632, China.
| | - Heqing Huang
- Laboratory of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
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4
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Proteomics analysis in myocardium of spontaneously hypertensive rats. Sci Rep 2023; 13:276. [PMID: 36609626 PMCID: PMC9822958 DOI: 10.1038/s41598-023-27590-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023] Open
Abstract
Hypertension-related left ventricular hypertrophy is recognized as a good predictor of adverse cardiovascular events. However, the underlying mechanism of left ventricular hypertrophy is still not fully understood. This study employed liquid chromatography coupled with tandem mass spectrometry to investigate global changes in protein profile in myocardium of spontaneously hypertensive rat, a classical animal model of essential hypertension. There were 369 differentially expressed proteins in myocardium between spontaneously hypertensive rats and normotensive rats. Xenobiotic catabolic process, cholesterol binding and mitochondrial proton-transporting ATP synthase were found to be the most significantly enriched biological process, molecular function and cellular component terms of Gene Ontology, respectively. Drug metabolism-cytochrome P450 was revealed to be the most significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways. FYN proto-oncogene, Src family tyrosine kinase was found to have the most interactions with other proteins. Differentially expressed proteins involved in xenobiotic catabolic process, lipid transport and metabolism, mitochondrial function might be targets for further study of hypertension-related left ventricular hypertrophy.
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Chen YT, Masbuchin AN, Fang YH, Hsu LW, Wu SN, Yen CJ, Liu YW, Hsiao YW, Wang JM, Rohman MS, Liu PY. Pentraxin 3 regulates tyrosine kinase inhibitor-associated cardiomyocyte contraction and mitochondrial dysfunction via ERK/JNK signalling pathways. Biomed Pharmacother 2023; 157:113962. [PMID: 36370523 DOI: 10.1016/j.biopha.2022.113962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 10/28/2022] [Accepted: 11/01/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Hepatocellular carcinoma (HCC) patients suffer varying degrees of heart dysfunction after tyrosine kinase inhibitor (TKI) treatment. Interestingly, HCC patients often have higher levels of pentraxin 3 (PTX3), and PTX3 inhibition was found to improve left ventricular dysfunction in animal models. OBJECTIVES We sought to assess the therapeutic potential of PTX3 inhibition on TKI-associated cardiotoxicity. METHODS We used a human embryonic stem cell line, RUES2, to generate cardiomyocyte cultures (RUES2-CM) for functional testing. We also assessed heart function and PTX3 expression levels in 16 HCC patients who received TKI treatment, 3 HCC patients who did not receive TKIs, and 7 healthy volunteers. RESULTS Significantly higher PTX3 expression was noted in HCC patients with TKI treatment versus those without, and 38% of male and 33% of female patients had QTc prolongation after TKI treatment. Treatment of cardiomyocyte cultures with sorafenib also increased PTX3 expression and induced cytoskeletal remodelling, contraction reduction, sodium current inhibition, and mitochondrial respiratory dysfunction. PTX3 colocalised with CD44 in cardiomyocytes, and cardiomyocyte contraction, mitochondrial respiratory function, and regular cytoskeletal and apoptotic protein expression were restored with PTX3 inhibition. CD44 knockdown confirmed PTX3/CD44 signalling. These results suggest a possible mechanism in which sorafenib treatment increases PTX3 expression, thereby resulting in reduced extracellular signal-regulated kinase (ERK) 1/2 expression that affects cardiomyocyte contraction, while also activating c-Jun N-terminal kinase (JNK) downstream pathways to disrupt mitochondrial respiration and trigger apoptosis. CONCLUSIONS TKI-induced cardiotoxicity may be partly mediated by the upregulation of PTX3, and thus PTX3 inhibition has potential as a therapeutic strategy.
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Affiliation(s)
- Yan-Ting Chen
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC.
| | - Ainun Nizar Masbuchin
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC; Department of Cardiology and Vascular Medicine, Faculty of Medicine, Universitas Brawijaya, Malang 65145, Indonesia.
| | - Yi-Hsien Fang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC.
| | - Ling-Wei Hsu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC.
| | - Sheng-Nan Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan, ROC; Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan, ROC.
| | - Chia-Jui Yen
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC; Department of Oncology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan, ROC; Center of Cell Therapy, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan, ROC.
| | - Yen-Wen Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC; Center of Cell Therapy, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan, ROC; Division of Cardiology, Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan, ROC.
| | - Yu-Wei Hsiao
- Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan, ROC.
| | - Ju-Ming Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan, ROC; Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan, ROC; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.
| | - Mohammad Saifur Rohman
- Department of Cardiology and Vascular Medicine, Faculty of Medicine, Universitas Brawijaya, Malang 65145, Indonesia.
| | - Ping-Yen Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC; Center of Cell Therapy, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan, ROC; Division of Cardiology, Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70403, Taiwan, ROC; Center of Clinical Medical Research, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70457, Taiwan, ROC.
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6
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Gamal El-Din TM. When the Gates Swing Open Only: Arrhythmia Mutations That Target the Fast Inactivation Gate of Na v1.5. Cells 2022; 11:cells11233714. [PMID: 36496974 PMCID: PMC9735811 DOI: 10.3390/cells11233714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/17/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Nav1.5 is the main voltage-gated sodium channel found in cardiac muscle, where it facilitates the fast influx of Na+ ions across the cell membrane, resulting in the fast depolarization phase-phase 0 of the cardiac action potential. As a result, it plays a major role in determining the amplitude and the upstroke velocity of the cardiac impulse. Quantitively, cardiac sodium channel activates in less than a millisecond to trigger the cardiac action potential and inactivates within 2-3 ms to facilitate repolarization and return to the resting state in preparation for firing the next action potential. Missense mutations in the gene that encodes Nav1.5 (SCN5A), change these time constants which leads to a wide spectrum of cardiac diseases ranging from long QT syndrome type 3 (LQT3) to sudden cardiac death. In this mini-review I will focus on the missense mutations in the inactivation gate of Nav1.5 that results in arrhythmia, attempting to correlate the location of the missense mutation to their specific phenotype.
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7
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Daimi H, Lozano-Velasco E, Aranega A, Franco D. Genomic and Non-Genomic Regulatory Mechanisms of the Cardiac Sodium Channel in Cardiac Arrhythmias. Int J Mol Sci 2022; 23:1381. [PMID: 35163304 PMCID: PMC8835759 DOI: 10.3390/ijms23031381] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/30/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
Nav1.5 is the predominant cardiac sodium channel subtype, encoded by the SCN5A gene, which is involved in the initiation and conduction of action potentials throughout the heart. Along its biosynthesis process, Nav1.5 undergoes strict genomic and non-genomic regulatory and quality control steps that allow only newly synthesized channels to reach their final membrane destination and carry out their electrophysiological role. These regulatory pathways are ensured by distinct interacting proteins that accompany the nascent Nav1.5 protein along with different subcellular organelles. Defects on a large number of these pathways have a tremendous impact on Nav1.5 functionality and are thus intimately linked to cardiac arrhythmias. In the present review, we provide current state-of-the-art information on the molecular events that regulate SCN5A/Nav1.5 and the cardiac channelopathies associated with defects in these pathways.
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Affiliation(s)
- Houria Daimi
- Biochemistry and Molecular Biology Laboratory, Faculty of Pharmacy, University of Monastir, Monastir 5000, Tunisia
| | - Estefanía Lozano-Velasco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
| | - Amelia Aranega
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
| | - Diego Franco
- Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain; (E.L.-V.); (A.A.); (D.F.)
- Medina Foundation, Technology Park of Health Sciences, Av. del Conocimiento, 34, 18016 Granada, Spain
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8
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Functional cross-talk between phosphorylation and disease-causing mutations in the cardiac sodium channel Na v1.5. Proc Natl Acad Sci U S A 2021; 118:2025320118. [PMID: 34373326 PMCID: PMC8379932 DOI: 10.1073/pnas.2025320118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The cardiac sodium channel (Nav1.5) is crucial for generating a regular heartbeat. It is thus not surprising that Nav1.5 mutations have been linked to life-threatening arrhythmias. Interestingly, Nav1.5 activity can also be altered by posttranslational modifications, such as tyrosine phosphorylation. Our combination of protein engineering and molecular modeling has revealed that the detrimental effect of a long QT3 patient mutation is only exposed when a proximal tyrosine is phosphorylated. This suggests a dynamic cross-talk between the genetic mutation and a neighboring phosphorylation, a phenomenon that could be important in other classes of proteins. Additionally, we show that phosphorylation can affect the channel’s sensitivity toward clinically relevant drugs, a finding that may prove important when devising patient-specific treatment plans. The voltage-gated sodium channel Nav1.5 initiates the cardiac action potential. Alterations of its activation and inactivation properties due to mutations can cause severe, life-threatening arrhythmias. Yet despite intensive research efforts, many functional aspects of this cardiac channel remain poorly understood. For instance, Nav1.5 undergoes extensive posttranslational modification in vivo, but the functional significance of these modifications is largely unexplored, especially under pathological conditions. This is because most conventional approaches are unable to insert metabolically stable posttranslational modification mimics, thus preventing a precise elucidation of the contribution by these modifications to channel function. Here, we overcome this limitation by using protein semisynthesis of Nav1.5 in live cells and carry out complementary molecular dynamics simulations. We introduce metabolically stable phosphorylation mimics on both wild-type (WT) and two pathogenic long-QT mutant channel backgrounds and decipher functional and pharmacological effects with unique precision. We elucidate the mechanism by which phosphorylation of Y1495 impairs steady-state inactivation in WT Nav1.5. Surprisingly, we find that while the Q1476R patient mutation does not affect inactivation on its own, it enhances the impairment of steady-state inactivation caused by phosphorylation of Y1495 through enhanced unbinding of the inactivation particle. We also show that both phosphorylation and patient mutations can impact Nav1.5 sensitivity toward the clinically used antiarrhythmic drugs quinidine and ranolazine, but not flecainide. The data highlight that functional effects of Nav1.5 phosphorylation can be dramatically amplified by patient mutations. Our work is thus likely to have implications for the interpretation of mutational phenotypes and the design of future drug regimens.
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9
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Arribas-Blázquez M, Piniella D, Olivos-Oré LA, Bartolomé-Martín D, Leite C, Giménez C, Artalejo AR, Zafra F. Regulation of the voltage-dependent sodium channel Na V1.1 by AKT1. Neuropharmacology 2021; 197:108745. [PMID: 34375627 DOI: 10.1016/j.neuropharm.2021.108745] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/09/2021] [Accepted: 08/02/2021] [Indexed: 11/28/2022]
Abstract
The voltage-sensitive sodium channel NaV1.1 plays a critical role in regulating excitability of GABAergic neurons and mutations in the corresponding gene are associated to Dravet syndrome and other forms of epilepsy. The activity of this channel is regulated by several protein kinases. To identify novel regulatory kinases we screened a library of activated kinases and we found that AKT1 was able to directly phosphorylate NaV1.1. In vitro kinase assays revealed that the phosphorylation site was located in the C-terminal part of the large intracellular loop connecting domains I and II of NaV1.1, a region that is known to be targeted by other kinases like PKA and PKC. Electrophysiological recordings revealed that activated AKT1 strongly reduced peak Na+ currents and displaced the inactivation curve to more negative potentials in HEK-293 cell stably expressing NaV1.1. These alterations in current amplitude and steady-state inactivation were mimicked by SC79, a specific activator of AKT1, and largely reverted by triciribine, a selective inhibitor. Neurons expressing endogenous NaV1.1 in primary cultures were identified by expressing a fluorescent protein under the NaV1.1 promoter. There, we also observed a strong decrease in the current amplitude after addition of SC79, but small effects on the inactivation parameters. Altogether, we propose a novel mechanism that might regulate the excitability of neural networks in response to AKT1, a kinase that plays a pivotal role under physiological and pathological conditions, including epileptogenesis.
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Affiliation(s)
- Marina Arribas-Blázquez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Dolores Piniella
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Luis A Olivos-Oré
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, 28040, Madrid, Spain; Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - David Bartolomé-Martín
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristiana Leite
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Cecilio Giménez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Antonio R Artalejo
- Department of Pharmacology and Toxicology, Veterinary Faculty, Universidad Complutense de Madrid, 28040, Madrid, Spain; Instituto Universitario de Investigación en Neuroquímica, Universidad Complutense de Madrid, 28040, Madrid, Spain
| | - Francisco Zafra
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain; IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain.
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10
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Lorenzini M, Burel S, Lesage A, Wagner E, Charrière C, Chevillard PM, Evrard B, Maloney D, Ruff KM, Pappu RV, Wagner S, Nerbonne JM, Silva JR, Townsend RR, Maier LS, Marionneau C. Proteomic and functional mapping of cardiac NaV1.5 channel phosphorylation sites. J Gen Physiol 2021; 153:211660. [PMID: 33410863 PMCID: PMC7797897 DOI: 10.1085/jgp.202012646] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 10/23/2020] [Accepted: 12/03/2020] [Indexed: 12/16/2022] Open
Abstract
Phosphorylation of the voltage-gated Na+ (NaV) channel NaV1.5 regulates cardiac excitability, yet the phosphorylation sites regulating its function and the underlying mechanisms remain largely unknown. Using a systematic, quantitative phosphoproteomic approach, we analyzed NaV1.5 channel complexes purified from nonfailing and failing mouse left ventricles, and we identified 42 phosphorylation sites on NaV1.5. Most sites are clustered, and three of these clusters are highly phosphorylated. Analyses of phosphosilent and phosphomimetic NaV1.5 mutants revealed the roles of three phosphosites in regulating NaV1.5 channel expression and gating. The phosphorylated serines S664 and S667 regulate the voltage dependence of channel activation in a cumulative manner, whereas the nearby S671, the phosphorylation of which is increased in failing hearts, regulates cell surface NaV1.5 expression and peak Na+ current. No additional roles could be assigned to the other clusters of phosphosites. Taken together, our results demonstrate that ventricular NaV1.5 is highly phosphorylated and that the phosphorylation-dependent regulation of NaV1.5 channels is highly complex, site specific, and dynamic.
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Affiliation(s)
- Maxime Lorenzini
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
| | - Sophie Burel
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
| | - Adrien Lesage
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
| | - Emily Wagner
- Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, MO
| | - Camille Charrière
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
| | - Pierre-Marie Chevillard
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
| | - Bérangère Evrard
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
| | - Dan Maloney
- Bioinformatics Solutions Inc., Waterloo, Ontario, Canada
| | - Kiersten M Ruff
- Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, MO
| | - Rohit V Pappu
- Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, MO
| | - Stefan Wagner
- Department of Internal Medicine II, University Heart Center, University Hospital Regensburg, Regensburg, Germany
| | - Jeanne M Nerbonne
- Department of Developmental Biology, Washington University Medical School, St. Louis, MO.,Department of Medicine, Washington University Medical School, St. Louis, MO
| | - Jonathan R Silva
- Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, MO
| | - R Reid Townsend
- Department of Medicine, Washington University Medical School, St. Louis, MO.,Department of Cell Biology and Physiology, Washington University Medical School, St. Louis, MO
| | - Lars S Maier
- Department of Internal Medicine II, University Heart Center, University Hospital Regensburg, Regensburg, Germany
| | - Céline Marionneau
- Université de Nantes, Centre national de la recherche scientifique, Institut National de la Santé et de la Recherche Médicale, l'Institut du thorax, Nantes, France
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11
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Xiao L, Salem JE, Clauss S, Hanley A, Bapat A, Hulsmans M, Iwamoto Y, Wojtkiewicz G, Cetinbas M, Schloss MJ, Tedeschi J, Lebrun-Vignes B, Lundby A, Sadreyev RI, Moslehi J, Nahrendorf M, Ellinor PT, Milan DJ. Ibrutinib-Mediated Atrial Fibrillation Attributable to Inhibition of C-Terminal Src Kinase. Circulation 2020; 142:2443-2455. [PMID: 33092403 DOI: 10.1161/circulationaha.120.049210] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Ibrutinib is a Bruton tyrosine kinase inhibitor with remarkable efficacy against B-cell cancers. Ibrutinib also increases the risk of atrial fibrillation (AF), which remains poorly understood. METHODS We performed electrophysiology studies on mice treated with ibrutinib to assess inducibility of AF. Chemoproteomic analysis of cardiac lysates identified candidate ibrutinib targets, which were further evaluated in genetic mouse models and additional pharmacological experiments. The pharmacovigilance database, VigiBase, was queried to determine whether drug inhibition of an identified candidate kinase was associated with increased reporting of AF. RESULTS We demonstrate that treatment of mice with ibrutinib for 4 weeks results in inducible AF, left atrial enlargement, myocardial fibrosis, and inflammation. This effect was reproduced in mice lacking Bruton tyrosine kinase, but not in mice treated with 4 weeks of acalabrutinib, a more specific Bruton tyrosine kinase inhibitor, demonstrating that AF is an off-target side effect. Chemoproteomic profiling identified a short list of candidate kinases that was narrowed by additional experimentation leaving CSK (C-terminal Src kinase) as the strongest candidate for ibrutinib-induced AF. Cardiac-specific Csk knockout in mice led to increased AF, left atrial enlargement, fibrosis, and inflammation, phenocopying ibrutinib treatment. Disproportionality analyses in VigiBase confirmed increased reporting of AF associated with kinase inhibitors blocking Csk versus non-Csk inhibitors, with a reporting odds ratio of 8.0 (95% CI, 7.3-8.7; P<0.0001). CONCLUSIONS These data identify Csk inhibition as the mechanism through which ibrutinib leads to AF. Registration: URL: https://ww.clinicaltrials.gov; Unique identifier: NCT03530215.
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Affiliation(s)
- Ling Xiao
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Joe-Elie Salem
- Clinical Pharmacology, Sorbonne University, INSERM, APHP, UNICO-GRECO Cardio-oncology Program (J-E.S., B.L-V.), Sorbonne University, ISERM, APHP, UNICO-GRECO Cardio-oncology Program, Hospital Pitié-Salpêtrière, Paris, France.,Clinical Investigation Center, Paris, France (J-E.S.).,Vanderbilt University Medical Center, Cardio-Oncology Program, Division of Cardiovascular Medicine, Nashville, TN (J-E.S., J.M.)
| | - Sebastian Clauss
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA.,Department of Medicine I, Klinikum Grosshadern, University of Munich, Germany (S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance, Germany (S.C.)
| | - Alan Hanley
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Aneesh Bapat
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Maarten Hulsmans
- Center for Systems Biology, Department of Radiology (M.H., Y.I., G.W., M.J.S., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Yoshiko Iwamoto
- Center for Systems Biology, Department of Radiology (M.H., Y.I., G.W., M.J.S., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Gregory Wojtkiewicz
- Center for Systems Biology, Department of Radiology (M.H., Y.I., G.W., M.J.S., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Murat Cetinbas
- Department of Molecular Biology(M.C.), Massachusetts General Hospital and Harvard Medical School, Boston, MA.,Department of Genetics, Harvard Medical School, Boston, MA (M.C.)
| | - Maximilian J Schloss
- Center for Systems Biology, Department of Radiology (M.H., Y.I., G.W., M.J.S., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Justin Tedeschi
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Bénédicte Lebrun-Vignes
- Clinical Pharmacology, Sorbonne University, INSERM, APHP, UNICO-GRECO Cardio-oncology Program (J-E.S., B.L-V.), Sorbonne University, ISERM, APHP, UNICO-GRECO Cardio-oncology Program, Hospital Pitié-Salpêtrière, Paris, France.,Clinical Pharmacology and Regional Pharmacovigilance Center (B.L-V.), Sorbonne University, ISERM, APHP, UNICO-GRECO Cardio-oncology Program, Hospital Pitié-Salpêtrière, Paris, France.,Université Paris Est (UPEC), IRMB- EA 7379 EpiDermE (Epidemiology in Dermatology and Evaluation of Therapeutics), F-94010, Créteil, France (B.L-V.)
| | - Alicia Lundby
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences and NNF Center for Protein Research, Københavns Universitet, Copenhagen, Denmark (A.L.)
| | - Ruslan I Sadreyev
- Department of Pathology (R.I.S.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Javid Moslehi
- Vanderbilt University Medical Center, Cardio-Oncology Program, Division of Cardiovascular Medicine, Nashville, TN (J-E.S., J.M.)
| | - Matthias Nahrendorf
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA.,Center for Systems Biology, Department of Radiology (M.H., Y.I., G.W., M.J.S., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Patrick T Ellinor
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA.,Cardiovascular Disease Initiative, Broad Institute of Harvard and MIT, Cambridge, MA (P.T.E.)
| | - David J Milan
- Cardiovascular Research Center (L.X., S.C., A.H., A.B., J.T., M.N., P.T.E., D.J.M.), Massachusetts General Hospital and Harvard Medical School, Boston, MA.,Leducq Foundation, Boston, MA (D.J.M.)
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12
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Salvage SC, Huang CLH, Jackson AP. Cell-Adhesion Properties of β-Subunits in the Regulation of Cardiomyocyte Sodium Channels. Biomolecules 2020; 10:biom10070989. [PMID: 32630316 PMCID: PMC7407995 DOI: 10.3390/biom10070989] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 12/17/2022] Open
Abstract
Voltage-gated sodium (Nav) channels drive the rising phase of the action potential, essential for electrical signalling in nerves and muscles. The Nav channel α-subunit contains the ion-selective pore. In the cardiomyocyte, Nav1.5 is the main Nav channel α-subunit isoform, with a smaller expression of neuronal Nav channels. Four distinct regulatory β-subunits (β1–4) bind to the Nav channel α-subunits. Previous work has emphasised the β-subunits as direct Nav channel gating modulators. However, there is now increasing appreciation of additional roles played by these subunits. In this review, we focus on β-subunits as homophilic and heterophilic cell-adhesion molecules and the implications for cardiomyocyte function. Based on recent cryogenic electron microscopy (cryo-EM) data, we suggest that the β-subunits interact with Nav1.5 in a different way from their binding to other Nav channel isoforms. We believe this feature may facilitate trans-cell-adhesion between β1-associated Nav1.5 subunits on the intercalated disc and promote ephaptic conduction between cardiomyocytes.
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Affiliation(s)
- Samantha C. Salvage
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
- Correspondence: (S.C.S.); (A.P.J.); Tel.: +44-1223-765950 (S.C.S.); +44-1223-765951 (A.P.J.)
| | - Christopher L.-H. Huang
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Antony P. Jackson
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
- Correspondence: (S.C.S.); (A.P.J.); Tel.: +44-1223-765950 (S.C.S.); +44-1223-765951 (A.P.J.)
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13
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Khoo KK, Galleano I, Gasparri F, Wieneke R, Harms H, Poulsen MH, Chua HC, Wulf M, Tampé R, Pless SA. Chemical modification of proteins by insertion of synthetic peptides using tandem protein trans-splicing. Nat Commun 2020; 11:2284. [PMID: 32385250 PMCID: PMC7210297 DOI: 10.1038/s41467-020-16208-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/20/2020] [Indexed: 12/20/2022] Open
Abstract
Manipulation of proteins by chemical modification is a powerful way to decipher their function. However, most ribosome-dependent and semi-synthetic methods have limitations in the number and type of modifications that can be introduced, especially in live cells. Here, we present an approach to incorporate single or multiple post-translational modifications or non-canonical amino acids into proteins expressed in eukaryotic cells. We insert synthetic peptides into GFP, NaV1.5 and P2X2 receptors via tandem protein trans-splicing using two orthogonal split intein pairs and validate our approach by investigating protein function. We anticipate the approach will overcome some drawbacks of existing protein enigineering methods.
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Affiliation(s)
- K K Khoo
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - I Galleano
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - F Gasparri
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - R Wieneke
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Strasse 9, 60438, Frankfurt/Main, Germany
| | - H Harms
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - M H Poulsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - H C Chua
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - M Wulf
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - R Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Strasse 9, 60438, Frankfurt/Main, Germany
| | - S A Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.
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14
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Horváth B, Hézső T, Kiss D, Kistamás K, Magyar J, Nánási PP, Bányász T. Late Sodium Current Inhibitors as Potential Antiarrhythmic Agents. Front Pharmacol 2020; 11:413. [PMID: 32372952 PMCID: PMC7184885 DOI: 10.3389/fphar.2020.00413] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/18/2020] [Indexed: 12/19/2022] Open
Abstract
Based on recent findings, an increased late sodium current (INa,late) plays an important pathophysiological role in cardiac diseases, including rhythm disorders. The article first describes what is INa,late and how it functions under physiological circumstances. Next, it shows the wide range of cellular mechanisms that can contribute to an increased INa,late in heart diseases, and also discusses how the upregulated INa,late can play a role in the generation of cardiac arrhythmias. The last part of the article is about INa,late inhibiting drugs as potential antiarrhythmic agents, based on experimental and preclinical data as well as in the light of clinical trials.
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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
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dénes Kiss
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Division of Sport Physiology, 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
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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15
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El Refaey M, Musa H, Murphy NP, Lubbers ER, Skaf M, Han M, Cavus O, Koenig SN, Wallace MJ, Gratz D, Bradley E, Alsina KM, Wehrens XHT, Hund TJ, Mohler PJ. Protein Phosphatase 2A Regulates Cardiac Na + Channels. Circ Res 2019; 124:737-746. [PMID: 30602331 DOI: 10.1161/circresaha.118.314350] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
RATIONALE Voltage-gated Na+ channel ( INa) function is critical for normal cardiac excitability. However, the Na+ channel late component ( INa,L) is directly associated with potentially fatal forms of congenital and acquired human arrhythmia. CaMKII (Ca2+/calmodulin-dependent kinase II) enhances INa,L in response to increased adrenergic tone. However, the pathways that negatively regulate the CaMKII/Nav1.5 axis are unknown and essential for the design of new therapies to regulate the pathogenic INa,L. OBJECTIVE To define phosphatase pathways that regulate INa,L in vivo. METHODS AND RESULTS A mouse model lacking a key regulatory subunit (B56α) of the PP (protein phosphatase) 2A holoenzyme displayed aberrant action potentials after adrenergic stimulation. Unbiased computational modeling of B56α KO (knockout) mouse myocyte action potentials revealed an unexpected role of PP2A in INa,L regulation that was confirmed by direct INa,L recordings from B56α KO myocytes. Further, B56α KO myocytes display decreased sensitivity to isoproterenol-induced induction of arrhythmogenic INa,L, and reduced CaMKII-dependent phosphorylation of Nav1.5. At the molecular level, PP2A/B56α complex was found to localize and coimmunoprecipitate with the primary cardiac Nav channel, Nav1.5. CONCLUSIONS PP2A regulates Nav1.5 activity in mouse cardiomyocytes. This regulation is critical for pathogenic Nav1.5 late current and requires PP2A-B56α. Our study supports B56α as a novel target for the treatment of arrhythmia.
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Affiliation(s)
- Mona El Refaey
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Hassan Musa
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Nathaniel P Murphy
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Ellen R Lubbers
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Michel Skaf
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Mei Han
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Omer Cavus
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Sara N Koenig
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Michael J Wallace
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
| | - Daniel Gratz
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Biomedical Engineering, Ohio State University College of Engineering, Columbus (D.G., T.J.H.)
| | - Elisa Bradley
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Internal Medicine, Ohio State University College of Medicine, Columbus (E.B., T.J.H., P.J.M.)
| | - Katherina M Alsina
- Department of Molecular Physiology and Biophysics (K.M.A.), Baylor College of Medicine, Houston, TX.,Division of Cardiology, Department of Medicine (K.M.A.), Baylor College of Medicine, Houston, TX.,Division of Cardiology, Department of Pediatrics (K.M.A.), Baylor College of Medicine, Houston, TX
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX (X.H.T.W.)
| | - Thomas J Hund
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Internal Medicine, Ohio State University College of Medicine, Columbus (E.B., T.J.H., P.J.M.).,Department of Biomedical Engineering, Ohio State University College of Engineering, Columbus (D.G., T.J.H.)
| | - Peter J Mohler
- From the Ohio State University College of Medicine and Wexner Medical Center, The Frick Center for Heart Failure and Arrhythmia, The Dorothy M. Davis Heart and Lung Research Institute, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., D.G., E.B., T.J.H., P.J.M.).,Department of Internal Medicine, Ohio State University College of Medicine, Columbus (E.B., T.J.H., P.J.M.).,Department of Physiology and Cell Biology, Ohio State University, Columbus (M.E.R., H.M., N.P.M., E.R.L., M.S., M.H., O.C., S.N.K., M.J.W., P.J.M.)
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16
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Sun XD, Wang A, Ma P, Gong S, Tao J, Yu XM, Jiang X. Regulation of the firing activity by PKA-PKC-Src family kinases in cultured neurons of hypothalamic arcuate nucleus. J Neurosci Res 2019; 98:384-403. [PMID: 31407399 PMCID: PMC6916362 DOI: 10.1002/jnr.24516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 07/18/2019] [Accepted: 07/30/2019] [Indexed: 12/19/2022]
Abstract
The cAMP‐dependent protein kinase A family (PKAs), protein kinase C family (PKCs), and Src family kinases (SFKs) are found to play important roles in pain hypersensitivity. However, more detailed investigations are still needed in order to understand the mechanisms underlying the actions of PKAs, PKCs, and SFKs. Neurons in the hypothalamic arcuate nucleus (ARC) are found to be involved in the regulation of pain hypersensitivity. Here we report that the action potential (AP) firing activity of ARC neurons in culture was up‐regulated by application of the adenylate cyclase activator forskolin or the PKC activator PMA, and that the forskolin or PMA application‐induced up‐regulation of AP firing activity could be blocked by pre‐application of the SFK inhibitor PP2. SFK activation also up‐regulated the AP firing activity and this effect could be prevented by pre‐application of the inhibitors of PKCs, but not of PKAs. Furthermore, we identified that forskolin or PMA application caused increases in the phosphorylation not only in PKAs at T197 or PKCs at S660 and PKCα/βII at T638/641, but also in SFKs at Y416. The forskolin or PMA application‐induced increase in the phosphorylation of PKAs or PKCs was not affected by pre‐treatment with PP2. The regulations of the SFK and AP firing activities by PKCs were independent upon the translocation of either PKCα or PKCβII. Thus, it is demonstrated that PKAs may act as an upstream factor(s) to enhance SFKs while PKCs and SFKs interact reciprocally, and thereby up‐regulate the AP firing activity in hypothalamic ARC neurons.
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Affiliation(s)
- Xiao-Dong Sun
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
| | - Anqi Wang
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
| | - Peng Ma
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
| | - Shan Gong
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
| | - Jin Tao
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
| | - Xian-Min Yu
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
| | - Xinghong Jiang
- Key Laboratory of Pain Basic Research and Clinical Therapy, Department of Physiology and Neurobiology, Medical College of Soochow University, Suzhou, China
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17
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Iqbal SM, Lemmens‐Gruber R. Phosphorylation of cardiac voltage-gated sodium channel: Potential players with multiple dimensions. Acta Physiol (Oxf) 2019; 225:e13210. [PMID: 30362642 PMCID: PMC6590314 DOI: 10.1111/apha.13210] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 10/14/2018] [Accepted: 10/14/2018] [Indexed: 12/11/2022]
Abstract
Cardiomyocytes are highly coordinated cells with multiple proteins organized in micro domains. Minor changes or interference in subcellular proteins can cause major disturbances in physiology. The cardiac sodium channel (NaV1.5) is an important determinant of correct electrical activity in cardiomyocytes which are localized at intercalated discs, T‐tubules and lateral membranes in the form of a macromolecular complex with multiple interacting protein partners. The channel is tightly regulated by post‐translational modifications for smooth conduction and propagation of action potentials. Among regulatory mechanisms, phosphorylation is an enzymatic and reversible process which modulates NaV1.5 channel function by attaching phosphate groups to serine, threonine or tyrosine residues. Phosphorylation of NaV1.5 is implicated in both normal physiological and pathological processes and is carried out by multiple kinases. In this review, we discuss and summarize recent literature about the (a) structure of NaV1.5 channel, (b) formation and subcellular localization of NaV1.5 channel macromolecular complex, (c) post‐translational phosphorylation and regulation of NaV1.5 channel, and (d) how these phosphorylation events of NaV1.5 channel alter the biophysical properties and affect the channel during disease status. We expect, by reviewing these aspects will greatly improve our understanding of NaV1.5 channel biology, physiology and pathology, which will also provide an insight into the mechanism of arrythmogenesis at molecular level.
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Affiliation(s)
- Shahid M. Iqbal
- Department of Pharmacology and Toxicology University of Vienna Vienna Austria
- Drugs Regulatory Authority of Pakistan Telecom Foundation (TF) Complex Islamabad Pakistan
| | - Rosa Lemmens‐Gruber
- Department of Pharmacology and Toxicology University of Vienna Vienna Austria
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18
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Li Y, Zhu T, Yang H, Dib-Hajj SD, Waxman SG, Yu Y, Xu TL, Cheng X. Nav1.7 is phosphorylated by Fyn tyrosine kinase which modulates channel expression and gating in a cell type-dependent manner. Mol Pain 2018; 14:1744806918782229. [PMID: 29790812 PMCID: PMC6024516 DOI: 10.1177/1744806918782229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Voltage-gated sodium channel Nav1.7 is a key molecule in nociception, and its dysfunction has been associated with various pain disorders. Here, we investigated the regulation of Nav1.7 biophysical properties by Fyn, an Src family tyrosine kinase. Nav1.7 was coexpressed with either constitutively active (FynCA) or dominant negative (FynDN) variants of Fyn kinase. FynCA elevated protein expression and tyrosine phosphorylation of Nav1.7 channels. Site-directed mutagenesis analysis identified two tyrosine residues (Y1470 and Y1471) located within the Nav1.7 DIII-DIV linker (L3) as phosphorylation sites of Fyn. Whole-cell recordings revealed that FynCA evoked larger changes in Nav1.7 biophysical properties when expressed in ND7/23 cells than in Human Embryonic Kidney (HEK) 293 cells, suggesting a cell type-specific modulation of Nav1.7 by Fyn kinase. In HEK 293 cells, substitution of both tyrosine residues with phenylalanine dramatically reduced current amplitude of mutant channels, which was partially rescued by expressing mutant channels in ND7/23 cells. Phenylalanine substitution showed little effect on FynCA-induced changes in Nav1.7 activation and inactivation, suggesting additional modifications in the channel or modulation by interaction with extrinsic factor(s). Our study demonstrates that Nav1.7 is a substrate for Fyn kinase, and the effect of the channel phosphorylation depends on the cell background. Fyn-mediated modulation of Nav1.7 may regulate DRG neuron excitability and contribute to pain perception. Whether this interaction could serve as a target for developing new pain therapeutics requires future study.
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Affiliation(s)
- Yangyang Li
- 1 Discipline of Neuroscience and Department of Anatomy and Physiology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tengteng Zhu
- 1 Discipline of Neuroscience and Department of Anatomy and Physiology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huan Yang
- 1 Discipline of Neuroscience and Department of Anatomy and Physiology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Sulayman D Dib-Hajj
- 2 Department of Neurology, Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.,3 Rehabilitation Research Center, Veterans Administration Connecticut Healthcare System, West Haven, CT, USA
| | - Stephen G Waxman
- 2 Department of Neurology, Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.,3 Rehabilitation Research Center, Veterans Administration Connecticut Healthcare System, West Haven, CT, USA
| | - Ye Yu
- 4 Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tian-Le Xu
- 1 Discipline of Neuroscience and Department of Anatomy and Physiology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoyang Cheng
- 1 Discipline of Neuroscience and Department of Anatomy and Physiology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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19
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Iqbal SM, Aufy M, Shabbir W, Lemmens-Gruber R. Identification of phosphorylation sites and binding pockets for modulation of Na V 1.5 channel by Fyn tyrosine kinase. FEBS J 2018; 285:2520-2530. [PMID: 29734505 DOI: 10.1111/febs.14496] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/05/2018] [Accepted: 04/30/2018] [Indexed: 11/26/2022]
Abstract
Cardiac sodium channel NaV 1.5 is the predominant form of sodium channels in cardiomyocytes, which exists as a macromolecular complex and interacts with multiple protein partners. Fyn kinase is one of the interacting proteins which colocalize, phosphorylate and modulate the NaV 1.5 channel. To elaborate this interaction we created expression vectors for the N-terminal, intracellular loop, and C-terminal regions of the NaV 1.5 channel, to express in HEK-293 cells. By co-immunoprecipitation and anti-phosphotyrosine blotting, we identified proline-rich binding sites for Fyn kinase in the N-terminal, IC-loopi-ii and C-terminal. After binding, Fyn kinase phosphorylates tyrosine residues present in the N- and C-terminal, which produce a depolarizing shift of 7 mV in fast inactivation. The functional relevance of these binding and phosphorylation sites was further underpinned by creating full length mutants masking these sites sequentially. An activation and inactivation curves were recorded with or without co-expressed Fyn kinase which indicates that phosphorylation of tyrosine residues at positions 68, 87, 112 in the N-terminal and at positions 1811 and 1889 in the C-terminal creates a depolarizing shift in fast inactivation of NaV 1.5 channel.
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Affiliation(s)
- Shahid Muhammad Iqbal
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria.,Drugs Regulatory Authority of Pakistan, Islamabad, Pakistan
| | - Mohammed Aufy
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Waheed Shabbir
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
| | - Rosa Lemmens-Gruber
- Department of Pharmacology and Toxicology, University of Vienna, Vienna, Austria
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20
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Edokobi N, Isom LL. Voltage-Gated Sodium Channel β1/β1B Subunits Regulate Cardiac Physiology and Pathophysiology. Front Physiol 2018; 9:351. [PMID: 29740331 PMCID: PMC5924814 DOI: 10.3389/fphys.2018.00351] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/20/2018] [Indexed: 12/19/2022] Open
Abstract
Cardiac myocyte contraction is initiated by a set of intricately orchestrated electrical impulses, collectively known as action potentials (APs). Voltage-gated sodium channels (NaVs) are responsible for the upstroke and propagation of APs in excitable cells, including cardiomyocytes. NaVs consist of a single, pore-forming α subunit and two different β subunits. The β subunits are multifunctional cell adhesion molecules and channel modulators that have cell type and subcellular domain specific functional effects. Variants in SCN1B, the gene encoding the Nav-β1 and -β1B subunits, are linked to atrial and ventricular arrhythmias, e.g., Brugada syndrome, as well as to the early infantile epileptic encephalopathy Dravet syndrome, all of which put patients at risk for sudden death. Evidence over the past two decades has demonstrated that Nav-β1/β1B subunits play critical roles in cardiac myocyte physiology, in which they regulate tetrodotoxin-resistant and -sensitive sodium currents, potassium currents, and calcium handling, and that Nav-β1/β1B subunit dysfunction generates substrates for arrhythmias. This review will highlight the role of Nav-β1/β1B subunits in cardiac physiology and pathophysiology.
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Affiliation(s)
| | - Lori L. Isom
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
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21
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DeMarco KR, Clancy CE. Cardiac Na Channels: Structure to Function. CURRENT TOPICS IN MEMBRANES 2016; 78:287-311. [PMID: 27586288 DOI: 10.1016/bs.ctm.2016.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heart rhythms arise from electrical activity generated by precisely timed opening and closing of ion channels in individual cardiac myocytes. Opening of the primary cardiac voltage-gated sodium (NaV1.5) channel initiates cellular depolarization and the propagation of an electrical action potential that promotes coordinated contraction of the heart. The regularity of these contractile waves is critically important since it drives the primary function of the heart: to act as a pump that delivers blood to the brain and vital organs. When electrical activity goes awry during a cardiac arrhythmia, the pump does not function, the brain does not receive oxygenated blood, and death ensues. Perturbations to NaV1.5 may alter the structure, and hence the function, of the ion channel and are associated downstream with a wide variety of cardiac conduction pathologies, such as arrhythmias.
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Affiliation(s)
- K R DeMarco
- University of California, Davis, Davis, CA, United States
| | - C E Clancy
- University of California, Davis, Davis, CA, United States
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22
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Chen H, Zeng Q, Yao C, Cai Z, Wei T, Huang Z, Su J. Src family tyrosine kinase inhibitors suppress Nav1.1 expression in cultured rat spiral ganglion neurons. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2016; 202:185-93. [PMID: 26790420 DOI: 10.1007/s00359-016-1066-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/22/2015] [Accepted: 01/01/2016] [Indexed: 11/25/2022]
Abstract
Src family kinases regulate neuronal voltage-gated Na(+) channels, which generate action potentials. The mechanisms of action, however, remain poorly understood. The aim of the present study was to further elucidate the effects of Src family kinases on Nav1.1 mRNA and protein expression in spiral ganglion neurons. Immunofluorescence staining techniques detected Nav1.1 expression in the spiral ganglion neurons. Additionally, quantitative PCR and western blot techniques were used to analyze Nav1.1 mRNA and protein expression, respectively, in spiral ganglion neurons following exposure to Src family kinase inhibitors PP2 (1 and 10 μM) and SU6656 (0.1 and 1 μM) for different lengths of time (6 and 24 h). In the spiral ganglion neurons, Nav1.1 protein expression was detected in the somas and axons. The Src family kinase inhibitors PP2 and SU6665 significantly decreased Nav1.1 mRNA and protein expression (p < 0.05), respectively, in the spiral ganglion neurons, and changes in expression were not dependent on time or dose (p > 0.05).
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Affiliation(s)
- Huiying Chen
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Qingjiao Zeng
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Chen Yao
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Zheng Cai
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Tingjia Wei
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Zhihui Huang
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China
| | - Jiping Su
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021, Guangxi, China.
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Onwuli DO, Beltran-Alvarez P. An update on transcriptional and post-translational regulation of brain voltage-gated sodium channels. Amino Acids 2015; 48:641-651. [PMID: 26503606 PMCID: PMC4752963 DOI: 10.1007/s00726-015-2122-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 11/29/2022]
Abstract
Voltage-gated sodium channels are essential proteins in brain physiology, as they generate the sodium currents that initiate neuronal action potentials. Voltage-gated sodium channels expression, localisation and function are regulated by a range of transcriptional and post-translational mechanisms. Here, we review our understanding of regulation of brain voltage-gated sodium channels, in particular SCN1A (NaV1.1), SCN2A (NaV1.2), SCN3A (NaV1.3) and SCN8A (NaV1.6), by transcription factors, by alternative splicing, and by post-translational modifications. Our focus is strongly centred on recent research lines, and newly generated knowledge.
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Affiliation(s)
- Donatus O Onwuli
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hardy Building Cottingham Road, Hull, HU6 7RX, UK
| | - Pedro Beltran-Alvarez
- School of Biological, Biomedical and Environmental Sciences, University of Hull, Hardy Building Cottingham Road, Hull, HU6 7RX, UK.
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24
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Besson P, Driffort V, Bon É, Gradek F, Chevalier S, Roger S. How do voltage-gated sodium channels enhance migration and invasiveness in cancer cells? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2493-501. [PMID: 25922224 DOI: 10.1016/j.bbamem.2015.04.013] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 04/13/2015] [Accepted: 04/20/2015] [Indexed: 11/16/2022]
Abstract
Voltage-gated sodium channels are abnormally expressed in tumors, often as neonatal isoforms, while they are not expressed, or only at a low level, in the matching normal tissue. The level of their expression and their activity is related to the aggressiveness of the disease and to the formation of metastases. A vast knowledge on the regulation of their expression and functioning has been accumulated in normal excitable cells. This helped understand their regulation in cancer cells. However, how voltage-gated sodium channels impose a pro-metastatic behavior to cancer cells is much less documented. This aspect will be addressed in the review. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
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Affiliation(s)
- Pierre Besson
- Inserm UMR1069 "Nutrition, Croissance et Cancer", Faculté de Médecine, Université François Rabelais de Tours, France; Faculté de Sciences Pharmaceutiques, Université François Rabelais de Tours, France.
| | - Virginie Driffort
- Inserm UMR1069 "Nutrition, Croissance et Cancer", Faculté de Médecine, Université François Rabelais de Tours, France
| | - Émeline Bon
- Inserm UMR1069 "Nutrition, Croissance et Cancer", Faculté de Médecine, Université François Rabelais de Tours, France
| | - Frédéric Gradek
- Inserm UMR1069 "Nutrition, Croissance et Cancer", Faculté de Médecine, Université François Rabelais de Tours, France
| | - Stéphan Chevalier
- Inserm UMR1069 "Nutrition, Croissance et Cancer", Faculté de Médecine, Université François Rabelais de Tours, France; Faculté de Sciences Pharmaceutiques, Université François Rabelais de Tours, France
| | - Sébastien Roger
- Inserm UMR1069 "Nutrition, Croissance et Cancer", Faculté de Médecine, Université François Rabelais de Tours, France; Faculté des Sciences et Techniques, Université François Rabelais de Tours, France
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25
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Regulation of the cardiac Na+ channel NaV1.5 by post-translational modifications. J Mol Cell Cardiol 2015; 82:36-47. [PMID: 25748040 DOI: 10.1016/j.yjmcc.2015.02.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/28/2015] [Accepted: 02/17/2015] [Indexed: 02/07/2023]
Abstract
The cardiac voltage-gated Na(+) channel, Na(V)1.5, is responsible for the upstroke of the action potential in cardiomyocytes and for efficient propagation of the electrical impulse in the myocardium. Even subtle alterations of Na(V)1.5 function, as caused by mutations in its gene SCN5A, may lead to many different arrhythmic phenotypes in carrier patients. In addition, acquired malfunctions of Na(V)1.5 that are secondary to cardiac disorders such as heart failure and cardiomyopathies, may also play significant roles in arrhythmogenesis. While it is clear that the regulation of Na(V)1.5 protein expression and function tightly depends on genetic mechanisms, recent studies have demonstrated that Na(V)1.5 is the target of various post-translational modifications that are pivotal not only in physiological conditions, but also in disease. In this review, we examine the recent literature demonstrating glycosylation, phosphorylation by Protein Kinases A and C, Ca(2+)/Calmodulin-dependent protein Kinase II, Phosphatidylinositol 3-Kinase, Serum- and Glucocorticoid-inducible Kinases, Fyn and Adenosine Monophosphate-activated Protein Kinase, methylation, acetylation, redox modifications, and ubiquitylation of Na(V)1.5. Modern and sensitive mass spectrometry approaches, applied directly to channel proteins that were purified from native cardiac tissues, have enabled the determination of the precise location of post-translational modification sites, thus providing essential information for understanding the mechanistic details of these regulations. The current challenge is first, to understand the roles of these modifications on the expression and the function of Na(V)1.5, and second, to further identify other chemical modifications. It is postulated that the diversity of phenotypes observed with Na(V)1.5-dependent disorders may partially arise from the complex post-translational modifications of channel protein components.
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26
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Nav1.5 channels can reach the plasma membrane through distinct N-glycosylation states. Biochim Biophys Acta Gen Subj 2015; 1850:1215-23. [PMID: 25721215 DOI: 10.1016/j.bbagen.2015.02.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 01/26/2015] [Accepted: 02/16/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Like many voltage-gated sodium channels, the cardiac isoform Nav1.5 is well known as a glycoprotein which necessarily undergoes N-glycosylation processing during its transit to the plasma membrane. In some cardiac disorders, especially the Brugada syndrome (BrS), mutations in Nav1.5 encoding gene lead to intracellular retention and consequently trafficking defect of these proteins. We used two BrS mutants as tools to clarify both Nav1.5 glycosylation states and associated secretory behaviors. METHODS Patch-clamp recordings and surface biotinylation assays of HEK293T cells expressing wild-type (WT) and/or mutant Nav1.5 proteins were performed to assess the impact of mutant co-expression on the membrane activity and localization of WT channels. Enzymatic deglycosylation assays and brefeldin A (BFA) treatments were also employed to further characterize recombinant and native Nav1.5 maturation. RESULTS The present data demonstrate that Nav1.5 channels mainly exist as two differentially glycosylated forms. We reveal that dominant negative effects induced by BrS mutants upon WT channel current result from the abnormal surface expression of the fully-glycosylated forms exclusively. Furthermore, we show that core-glycosylated channels can be found at the surface membrane of BFA-treated or untreated cells, but obviously without generating any sodium current. CONCLUSIONS Our findings provide evidence that native and recombinant Nav1.5 subunits are expressed as two distinct matured forms. Fully-glycosylated state of Nav1.5 seems to determine its functionality whereas core-glycosylated forms might be transported to the plasma membrane through an unconventional Golgi-independent secretory route. GENERAL SIGNIFICANCE This work highlights that N-linked glycosylation processing would be critical for Nav1.5 membrane trafficking and function.
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Abstract
One of the main strategies for cancer therapy is to use tyrosine kinase inhibitors for inhibiting tumor proliferation. Increasing evidence has demonstrated the potential risks of cardiac arrhythmias (such as prolonged QT interval) of these drugs. We report here that a widely used selective inhibitor of Src tyrosine kinases, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2), can inhibit and prevent β-adrenergic stimulation of cardiac pacemaker activity. First, in dissected rat sinus node, PP2 inhibited and prevented the isoproterenol-induced increase of spontaneous beating rate. Second, in isolated rat sinus node myocytes, PP2 suppressed the hyperpolarization-activated "funny" current (traditionally called cardiac pacemaker current, I(f)) by negatively shifting the activation curve and decelerating activation kinetics. Third, in isolated rat sinus node myocytes, PP2 decreased the Src kinase activity, the cell surface expression, and tyrosine phosphorylation of hyperpolarization-activated, cyclic nucleotide-modulated channel 4 (HCN4) channel proteins. Finally, in human embryonic kidney 293 cells overexpressing recombinant human HCN4 channels, PP2 reversed the enhancement of HCN4 channels by isoproterenol and inhibited 573x, a cyclic adenosine momophosphate-insensitive human HCN4 mutant. These results demonstrated that inhibition of Src kinase activity in heart by PP2 decreased and prevented β-adrenergic stimulation of cardiac pacemaker activity. These effects are mediated, at least partially, by a cAMP-independent attenuation of channel activity and cell surface expression of HCN4, the main channel protein that controls the heart rate.
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28
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SRC tyrosine kinases regulate neuronal differentiation of mouse embryonic stem cells via modulation of voltage-gated sodium channel activity. Neurochem Res 2015; 40:674-87. [PMID: 25577147 DOI: 10.1007/s11064-015-1514-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 12/10/2014] [Accepted: 01/07/2015] [Indexed: 12/19/2022]
Abstract
Voltage-gated Na(+) channel activity is vital for the proper function of excitable cells and has been indicated in nervous system development. Meanwhile, the Src family of non-receptor tyrosine kinases (SFKs) has been implicated in the regulation of Na(+) channel activity. The present investigation tests the hypothesis that Src family kinases influence neuronal differentiation via a chronic regulation of Na(+) channel functionality. In cultured mouse embryonic stem (ES) cells undergoing neural induction and terminal neuronal differentiation, SFKs showed distinct stage-specific expression patterns during the differentiation process. ES cell-derived neuronal cells expressed multiple voltage-gated Na(+) channel proteins (Nav) and underwent a gradual increase in Na(+) channel activity. While acute inhibition of SFKs using the Src family inhibitor PP2 suppressed the Na(+) current, chronic inhibition of SFKs during early neuronal differentiation of ES cells did not change Nav expression. However, a long-lasting block of SFK significantly altered electrophysiological properties of the Na(+) channels, shown as a right shift of the current-voltage relationship of the Na(+) channels, and reduced the amplitude of Na(+) currents recorded in drug-free solutions. Immunocytochemical staining of differentiated cells subjected to the chronic exposure of a SFK inhibitor, or the Na(+) channel blocker tetrodotoxin, showed no changes in the number of NeuN-positive cells; however, both treatments significantly hindered neurite outgrowth. These findings suggest that SFKs not only modulate the Na(+) channel activation acutely, but the tonic activity of SFKs is also critical for normal development of functional Na(+) channels and neuronal differentiation or maturation of ES cells.
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29
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Horvath B, Bers DM. The late sodium current in heart failure: pathophysiology and clinical relevance. ESC Heart Fail 2014; 1:26-40. [PMID: 28834665 DOI: 10.1002/ehf2.12003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 07/13/2014] [Accepted: 07/14/2014] [Indexed: 12/19/2022] Open
Abstract
Large and growing body of data suggest that an increased late sodium current (INa,late ) can have a significant pathophysiological role in heart failure and other heart diseases. The first goal of this article is to describe how INa,late functions under physiological circumstances. The second goal is to show the wide range of cellular mechanisms that can increase INa,late in cardiac disease, and also to describe how the up-regulated INa,late contributes to the pathophysiology of heart failure. The final section of the article discusses the possible use of INa,late -modifying drugs in heart failure, on the basis of experimental and preclinical data.
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Affiliation(s)
- Balazs Horvath
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Donald M Bers
- Department of Pharmacology, School of Medicine, University of California, Davis, CA, USA
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30
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Fraser SP, Ozerlat-Gunduz I, Brackenbury WJ, Fitzgerald EM, Campbell TM, Coombes RC, Djamgoz MBA. Regulation of voltage-gated sodium channel expression in cancer: hormones, growth factors and auto-regulation. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130105. [PMID: 24493753 PMCID: PMC3917359 DOI: 10.1098/rstb.2013.0105] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Although ion channels are increasingly being discovered in cancer cells in vitro and in vivo, and shown to contribute to different aspects and stages of the cancer process, much less is known about the mechanisms controlling their expression. Here, we focus on voltage-gated Na+ channels (VGSCs) which are upregulated in many types of carcinomas where their activity potentiates cell behaviours integral to the metastatic cascade. Regulation of VGSCs occurs at a hierarchy of levels from transcription to post-translation. Importantly, mainstream cancer mechanisms, especially hormones and growth factors, play a significant role in the regulation. On the whole, in major hormone-sensitive cancers, such as breast and prostate cancer, there is a negative association between genomic steroid hormone sensitivity and functional VGSC expression. Activity-dependent regulation by positive feedback has been demonstrated in strongly metastatic cells whereby the VGSC is self-sustaining, with its activity promoting further functional channel expression. Such auto-regulation is unlike normal cells in which activity-dependent regulation occurs mostly via negative feedback. Throughout, we highlight the possible clinical implications of functional VGSC expression and regulation in cancer.
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Affiliation(s)
- Scott P Fraser
- Neuroscience Solutions to Cancer Research Group, Department of Life Sciences, Imperial College London, , South Kensington Campus, London SW7 2AZ, UK
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Mick E, McGough J, Deutsch CK, Frazier JA, Kennedy D, Goldberg RJ. Genome-wide association study of proneness to anger. PLoS One 2014; 9:e87257. [PMID: 24489884 PMCID: PMC3905014 DOI: 10.1371/journal.pone.0087257] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 12/27/2013] [Indexed: 11/19/2022] Open
Abstract
Background Community samples suggest that approximately 1 in 20 children and adults exhibit clinically significant anger, hostility, and aggression. Individuals with dysregulated emotional control have a greater lifetime burden of psychiatric morbidity, severe impairment in role functioning, and premature mortality due to cardiovascular disease. Methods With publically available data secured from dbGaP, we conducted a genome-wide association study of proneness to anger using the Spielberger State-Trait Anger Scale in the Atherosclerosis Risk in Communities (ARIC) study (n = 8,747). Results Subjects were, on average, 54 (range 45–64) years old at baseline enrollment, 47% (n = 4,117) were male, and all were of European descent by self-report. The mean Angry Temperament and Angry Reaction scores were 5.8±1.8 and 7.6±2.2. We observed a nominally significant finding (p = 2.9E-08, λ = 1.027 - corrected pgc = 2.2E-07, λ = 1.0015) on chromosome 6q21 in the gene coding for the non-receptor protein-tyrosine kinase, Fyn. Conclusions Fyn interacts with NDMA receptors and inositol-1,4,5-trisphosphate (IP3)-gated channels to regulate calcium influx and intracellular release in the post-synaptic density. These results suggest that signaling pathways regulating intracellular calcium homeostasis, which are relevant to memory, learning, and neuronal survival, may in part underlie the expression of Angry Temperament.
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Affiliation(s)
- Eric Mick
- Department of Quantitative Health Sciences and the Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
| | - James McGough
- Division of Child and Adolescent Psychiatry, University of California, Los Angeles Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, Los Angeles California, United States of America
| | - Curtis K. Deutsch
- Eunice Kennedy Shriver Center, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Jean A. Frazier
- Psychiatry Department, Division of Child and Adolescent Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - David Kennedy
- Psychiatry Department, Division of Neuroinformatics and the Child and Adolescent NeuroDevelopment Initiative, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Robert J. Goldberg
- Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
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Abstract
The pedigree of voltage-gated sodium channels spans the millennia from eukaryotic members that initiate the action potential firing in excitable tissues to primordial ancestors that act as enviro-protective complexes in bacterial extremophiles. Eukaryotic sodium channels (eNavs) are central to electrical signaling throughout the cardiovascular and nervous systems in animals and are established clinical targets for the therapeutic management of epilepsy, cardiac arrhythmia, and painful syndromes as they are inhibited by local anesthetic compounds. Alternatively, bacterial voltage-gated sodium channels (bNavs) likely regulate the survival response against extreme pH conditions, electrophiles, and hypo-osmotic shock and may represent a founder of the voltage-gated cation channel family. Despite apparent differences between eNav and bNav channel physiology, gating, and gene structure, the discovery that bNavs are amenable to crystallographic study opens the door for the possibility of structure-guided rational design of the next generation of therapeutics that target eNavs. Here we summarize the gating behavior of these disparate channel members and discuss mechanisms of local anesthetic inhibition in light of the growing number of bNav structures.
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Affiliation(s)
- Ben Corry
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
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Abstract
Late I Na is an integral part of the sodium current, which persists long after the fast-inactivating component. The magnitude of the late I Na is relatively small in all species and in all types of cardiomyocytes as compared with the amplitude of the fast sodium current, but it contributes significantly to the shape and duration of the action potential. This late component had been shown to increase in several acquired or congenital conditions, including hypoxia, oxidative stress, and heart failure, or due to mutations in SCN5A, which encodes the α-subunit of the sodium channel, as well as in channel-interacting proteins, including multiple β subunits and anchoring proteins. Patients with enhanced late I Na exhibit the type-3 long QT syndrome (LQT3) characterized by high propensity for the life-threatening ventricular arrhythmias, such as Torsade de Pointes (TdP), as well as for atrial fibrillation. There are several distinct mechanisms of arrhythmogenesis due to abnormal late I Na, including abnormal automaticity, early and delayed after depolarization-induced triggered activity, and dramatic increase of ventricular dispersion of repolarization. Many local anesthetic and antiarrhythmic agents have a higher potency to block late I Na as compared with fast I Na. Several novel compounds, including ranolazine, GS-458967, and F15845, appear to be the most selective inhibitors of cardiac late I Na reported to date. Selective inhibition of late I Na is expected to be an effective strategy for correcting these acquired and congenital channelopathies.
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Xi Y, Wu G, Ai T, Cheng N, Kalisnik JM, Sun J, Abbasi S, Yang D, Fan C, Yuan X, Wang S, Elayda M, Gregoric ID, Kantharia BK, Lin SF, Cheng J. Ionic Mechanisms Underlying the Effects of Vasoactive Intestinal Polypeptide on Canine Atrial Myocardium. Circ Arrhythm Electrophysiol 2013; 6:976-83. [DOI: 10.1161/circep.113.000518] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Yutao Xi
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Geru Wu
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Tomohiko Ai
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Nancy Cheng
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Jurij Matija Kalisnik
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Junping Sun
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Shahrzad Abbasi
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Donghui Yang
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Christopher Fan
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Xiaojing Yuan
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Suwei Wang
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - MacArthur Elayda
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Igor D. Gregoric
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Bharat K. Kantharia
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Shien-Fong Lin
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
| | - Jie Cheng
- From the Texas Heart Institute/St. Luke’s Episcopal Hospital, Houston (Y.X., G.W., N.C., J.M.K., J.S., S.A., D.Y., C.F., S.W., M.E., J.C.); Krannert Institute of Cardiology, Indiana University, Indianapolis (T.A., S.-F.L.); Engineering Technology Department, University of Houston, TX (X.Y.); and Center for Advanced Heart Failure (I.D.G.) and Section of Cardiology (Y.X., B.K.K., J.C.), University of Texas Health Science Center at Houston
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Van Petegem F, Lobo PA, Ahern CA. Seeing the forest through the trees: towards a unified view on physiological calcium regulation of voltage-gated sodium channels. Biophys J 2013; 103:2243-51. [PMID: 23283222 DOI: 10.1016/j.bpj.2012.10.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 09/26/2012] [Accepted: 10/18/2012] [Indexed: 12/23/2022] Open
Abstract
Voltage-gated sodium channels (Na(V)s) underlie the upstroke of the action potential in the excitable tissues of nerve and muscle. After opening, Na(V)s rapidly undergo inactivation, a crucial process through which sodium conductance is negatively regulated. Disruption of inactivation by inherited mutations is an established cause of lethal cardiac arrhythmia, epilepsy, or painful syndromes. Intracellular calcium ions (Ca(2+)) modulate sodium channel inactivation, and multiple players have been suggested in this process, including the cytoplasmic Na(V) C-terminal region including two EF-hands and an IQ motif, the Na(V) domain III-IV linker, and calmodulin. Calmodulin can bind to the IQ domain in both Ca(2+)-bound and Ca(2+)-free conditions, but only to the DIII-IV linker in a Ca(2+)-loaded state. The mechanism of Ca(2+) regulation, and its composite effect(s) on channel gating, has been shrouded in much controversy owing to numerous apparent experimental inconsistencies. Herein, we attempt to summarize these disparate data and propose a novel, to our knowledge, physiological mechanism whereby calcium ions promote sodium current facilitation due to Ca(2+) memory at high-action-potential frequencies where Ca(2+) levels may accumulate. The available data suggest that this phenomenon may be disrupted in diseases where cytoplasmic calcium ion levels are chronically high and where targeted phosphorylation may decouple the Ca(2+) regulatory machinery. Many Na(V) disease mutations associated with electrical dysfunction are located in the Ca(2+)-sensing machinery and misregulation of Ca(2+)-dependent channel modulation is likely to contribute to disease phenotypes.
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Affiliation(s)
- Filip Van Petegem
- The Department of Biochemistry and Molecular Biology, Vancouver, British Columbia, Canada.
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EGFR tyrosine kinase regulates human small-conductance Ca2+-activated K+ (hSKCa1) channels expressed in HEK-293 cells. Biochem J 2013; 452:121-9. [PMID: 23496660 DOI: 10.1042/bj20121324] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
SKCa (small-conductance Ca(2+)-activated K(+)) channels are widely distributed in different tissues, including the brain, pancreatic islets and myocardium and play an important role in controlling electrical activity and cellular functions. However, intracellular signal modulation of SKCa channels is not fully understood. The present study was designed to investigate the potential regulation of hSKCa1 (human SKCa1) channels by PTKs (protein tyrosine kinases) in HEK (human embryonic kidney)-293 cells expressing the hSKCa1 (KCNN1) gene using approaches of whole-cell patch voltage-clamp, immunoprecipitation, Western blotting and mutagenesis. We found that the hSKCa1 current was inhibited by the broad-spectrum PTK inhibitor genistein, the selective EGFR (epidermal growth factor receptor) kinase inhibitors T25 (tyrphostin 25) and AG556 (tyrphostin AG 556), but not by the Src-family kinases inhibitor PP2. The inhibitory effect of these PTK inhibitors was significantly antagonized by the PTP (protein tyrosine phosphatase) inhibitor orthovanadate. The tyrosine phosphorylation level of hSKCa1 channels was reduced by genistein, T25 or AG556. The reduced tyrosine phosphorylation was countered by orthovanadate. Interestingly, the Y109F mutant hSKCa1 channel lost the inhibitory response to T25 or AG556, and showed a dramatic reduction in tyrosine phosphorylation levels and a reduced current density. These results demonstrate the novel information that hSKCa1 channels are inhibited by genistein, T25 and AG556 via EGFR tyrosine kinase inhibition, which is related to the phosphorylation of Tyr(109) in the N-terminus. This effect may affect electrical activity and cellular functions in brain, pancreatic islets and myocardium.
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Marionneau C, Lichti CF, Lindenbaum P, Charpentier F, Nerbonne JM, Townsend RR, Mérot J. Mass spectrometry-based identification of native cardiac Nav1.5 channel α subunit phosphorylation sites. J Proteome Res 2012; 11:5994-6007. [PMID: 23092124 DOI: 10.1021/pr300702c] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Cardiac voltage-gated Na+ (Nav) channels are key determinants of action potential waveforms, refractoriness and propagation, and Nav1.5 is the main Nav pore-forming (α) subunit in the mammalian heart. Although direct phosphorylation of the Nav1.5 protein has been suggested to modulate various aspects of Nav channel physiology and pathophysiology, native Nav1.5 phosphorylation sites have not been identified. In the experiments here, a mass spectrometry (MS)-based proteomic approach was developed to identify native Nav1.5 phosphorylation sites directly. Using an anti-NavPAN antibody, Nav channel complexes were immunoprecipitated from adult mouse cardiac ventricles. The MS analyses revealed that this antibody immunoprecipitates several Nav α subunits in addition to Nav1.5, as well as several previously identified Nav channel associated/regulatory proteins. Label-free comparative and data-driven phosphoproteomic analyses of purified cardiac Nav1.5 protein identified 11 phosphorylation sites, 8 of which are novel. All the phosphorylation sites identified except one in the N-terminus are in the first intracellular linker loop, suggesting critical roles for this region in phosphorylation-dependent cardiac Nav channel regulation. Interestingly, commonly used prediction algorithms did not reliably predict these newly identified in situ phosphorylation sites. Taken together, the results presented provide the first in situ map of basal phosphorylation sites on the mouse cardiac Nav1.5 α subunit.
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Feng S, Pflueger M, Lin SX, Groveman BR, Su J, Yu XM. Regulation of voltage-gated sodium current by endogenous Src family kinases in cochlear spiral ganglion neurons in culture. Pflugers Arch 2012; 463:571-84. [PMID: 22297656 DOI: 10.1007/s00424-012-1072-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 12/09/2011] [Accepted: 01/02/2012] [Indexed: 01/28/2023]
Abstract
Voltage-gated sodium (Na+) and potassium (K+)channels have been found to be regulated by Src family kinases(SFKs).However, how these channels are regulated by SFKs in cochlear spiral ganglion neurons (SGNs) remains unknown.Here, we report that altering the activity of endogenous SFKs modulated voltage-gated Na+, but not K+, currents recorded in embryonic SGNs in culture. Voltage-gated Na+ current was suppressed by inhibition of endogenous SFKs or just Src and potentiated by the activation of these enzymes. Detailed investigations showed that under basal conditions, SFK inhibitor application did not significantly affect the voltage-dependent activation, but shifted the steady-state inactivation curves of Na+ currents and delayed the recovery of Na+ currents from inactivation. Application of Src specific inhibitor, Src40–58,not only shifted the inactivation curve but also delayed the recovery of Na+ currents and moved the voltage-dependent activation curve towards the left. The pre-inhibition of SFKs occluded all the effects induced by Src40–58 application, except the left shift of the activation curve. The activation of SFKs did not change either steady-state inactivation or recovery of Na+ currents, but caused the left shift of the activation curve.SFK inhibitor application effectively prevented all the effects induced by SFK activation, suggesting that both the voltage-dependent activation and steady-state inactivation of Na+ current are subjects of SFK regulation. The different effects induced by activation versus inhibition of SFKs implied that under basal conditions, endogenously active and inactive SFKs might be differentially involved in the regulation of voltage-gated Na+ channels in SGNs.
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Affiliation(s)
- Shuang Feng
- Department of Otolaryngology—Head and Neck Surgery, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, People’s Republic of China
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Beyder A, Farrugia G. Targeting ion channels for the treatment of gastrointestinal motility disorders. Therap Adv Gastroenterol 2012; 5:5-21. [PMID: 22282704 PMCID: PMC3263980 DOI: 10.1177/1756283x11415892] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Gastrointestinal (GI) functional and motility disorders are highly prevalent and responsible for long-term morbidity and sometimes mortality in the affected patients. It is estimated that one in three persons has a GI functional or motility disorder. However, diagnosis and treatment of these widespread conditions remains challenging. This partly stems from the multisystem pathophysiology, including processing abnormalities in the central and peripheral (enteric) nervous systems and motor dysfunction in the GI wall. Interstitial cells of Cajal (ICCs) are central to the generation and propagation of the cyclical electrical activity and smooth muscle cells (SMCs) are responsible for electromechanical coupling. In these and other excitable cells voltage-sensitive ion channels (VSICs) are the main molecular units that generate and regulate electrical activity. Thus, VSICs are potential targets for intervention in GI motility disorders. Research in this area has flourished with advances in the experimental methods in molecular and structural biology and electrophysiology. However, our understanding of the molecular mechanisms responsible for the complex and variable electrical behavior of ICCs and SMCs remains incomplete. In this review, we focus on the slow waves and action potentials in ICCs and SMCs. We describe the constituent VSICs, which include voltage-gated sodium (Na(V)), calcium (Ca(V)), potassium (K(V), K(Ca)), chloride (Cl(-)) and nonselective ion channels (transient receptor potentials [TRPs]). VSICs have significant structural homology and common functional mechanisms. We outline the approaches and limitations and provide examples of targeting VSICs at the pores, voltage sensors and alternatively spliced sites. Rational drug design can come from an integrated view of the structure and mechanisms of gating and activation by voltage or mechanical stress.
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Affiliation(s)
- Arthur Beyder
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
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40
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Zhang YH, Wu W, Sun HY, Deng XL, Cheng LC, Li X, Tse HF, Lau CP, Li GR. Modulation of human cardiac transient outward potassium current by EGFR tyrosine kinase and Src-family kinases. Cardiovasc Res 2011; 93:424-33. [PMID: 22198508 DOI: 10.1093/cvr/cvr347] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
AIMS The human cardiac transient outward K(+) current I(to) (encoded by Kv4.3 or KCND3) plays an important role in phase 1 rapid repolarization of cardiac action potentials in the heart. However, modulation of I(to) by intracellular signal transduction is not fully understood. The present study was therefore designed to determine whether/how human atrial I(to) and hKv4.3 channels stably expressed in HEK 293 cells are regulated by protein tyrosine kinases (PTKs). METHODS AND RESULTS Whole-cell patch voltage-clamp, immunoprecipitation, western blotting, and site-directed mutagenesis approaches were employed in the present study. We found that human atrial I(to) was inhibited by the broad-spectrum PTK inhibitor genistein, the selective epidermal growth factor receptor (EGFR) kinase inhibitor AG556, and the Src-family kinases inhibitor PP2. The inhibitory effect was countered by the protein tyrosine phosphatase inhibitor orthovanadate. In HEK 293 cells stably expressing human KCND3, genistein, AG556, and PP2 significantly reduced the hKv4.3 current, and the reduction was antagonized by orthovanadate. Interestingly, orthovanadate also reversed the reduced tyrosine phosphorylation level of hKv4.3 channels by genistein, AG556, or PP2. Mutagenesis revealed that the hKv4.3 mutant Y136F lost the inhibitory response to AG556, while Y108F lost response to PP2. The double-mutant Y108F-Y136F hKv4.3 channels showed no response to either AG556 or PP2. CONCLUSION Our results demonstrate that human atrial I(to) and cloned hKv4.3 channels are modulated by EGFR kinase via phosphorylation of the Y136 residue and by Src-family kinases via phosphorylation of the Y108 residue; tyrosine phosphorylation of the channel may be involved in regulating cardiac electrophysiology.
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Affiliation(s)
- Yan-Hui Zhang
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, L4-59, Laboratory Block, FMB, 21 Sassoon Road, Pokfulam, Hong Kong, China
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Wang T, Lang GD, Moreno-Vinasco L, Huang Y, Goonewardena SN, Peng YJ, Svensson EC, Natarajan V, Lang RM, Linares JD, Breysse PN, Geyh AS, Samet JM, Lussier YA, Dudley S, Prabhakar NR, Garcia JGN. Particulate matter induces cardiac arrhythmias via dysregulation of carotid body sensitivity and cardiac sodium channels. Am J Respir Cell Mol Biol 2011; 46:524-31. [PMID: 22108299 DOI: 10.1165/rcmb.2011-0213oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The mechanistic links between exposure to airborne particulate matter (PM) pollution and the associated increases in cardiovascular morbidity and mortality, particularly in people with congestive heart failure (CHF), have not been identified. To advance understanding of this issue, genetically engineered mice (CREB(A133)) exhibiting severe dilated cardiomyopathic changes were exposed to ambient PM collected in Baltimore. CREB(A133) mice, which display aberrant cardiac physiology and anatomy reminiscent of human CHF, displayed evidence of basal autonomic aberrancies (compared with wild-type mice) with PM exposure via aspiration, producing significantly reduced heart rate variability, respiratory dysynchrony, and increased ventricular arrhythmias. Carotid body afferent nerve responses to hypoxia and hyperoxia-induced respiratory depression were pronounced in PM-challenged CREB(A133) mice, and denervation of the carotid bodies significantly reduced PM-mediated cardiac arrhythmias. Genome-wide expression analyses of CREB(A133) left ventricular tissues demonstrated prominent Na(+) and K(+) channel pathway gene dysregulation. Subsequent PM challenge increased tyrosine phosphorylation and nitration of the voltage-gated type V cardiac muscle α-subunit of the Na(+) channel encoded by SCN5A. Ranolazine, a Na(+) channel modulator that reduces late cardiac Na(+) channel currents, attenuated PM-mediated cardiac arrhythmias and shortened PM-elongated QT intervals in vivo. These observations provide mechanistic insights into the epidemiologic findings in susceptibility of human CHF populations to PM exposure. Our results suggest a multiorgan pathobiology inherent to the CHF phenotype that is exaggerated by PM exposure via heightened carotid body sensitivity and cardiac Na(+) channel dysfunction.
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Affiliation(s)
- Ting Wang
- Section of Pulmonary, Critical Care, Sleep & Allergy, Department of Medicine, University of Illinois at Chicago, Illinois, USA
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Zhang DY, Zhang YH, Sun HY, Lau CP, Li GR. Epidermal growth factor receptor tyrosine kinase regulates the human inward rectifier potassium K(IR)2.3 channel, stably expressed in HEK 293 cells. Br J Pharmacol 2011; 164:1469-78. [PMID: 21486282 PMCID: PMC3221101 DOI: 10.1111/j.1476-5381.2011.01424.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 03/05/2011] [Accepted: 04/04/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The detailed molecular modulation of inward rectifier potassium channels (including the K(IR) 2.3 channel) is not fully understood. The present study was designed to determine whether human K(IR) 2.3 (K(IR) 2.3) channels were regulated by protein tyrosine kinases (PTKs). EXPERIMENTAL APPROACH Whole-cell patch voltage-clamp, immunoprecipitation, Western blot analysis and site-directed mutagenesis were employed to determine the potential PTK phosphorylation of Kir2.3 current in HEK 293 cells stably expressing Kir2.3 gene. KEY RESULTS The broad-spectrum PTK inhibitor genistein (10 µM) and the selective epidermal growth factor (EGF) kinase inhibitor AG556 (10 µM) reversibly decreased K(IR) 2.3 current and the effect was reversed by the protein tyrosine phosphatase inhibitor, orthovanadate (1 mM). Although EGF (100 ng·mL(-1) ) and orthovanadate enhanced K(IR) 2.3 current, this effect was antagonized by AG556. However, the Src-family tyrosine kinase inhibitor PP2 (10 µM) did not inhibit K(IR) 2.3 current. Tyrosine phosphorylation of K(IR) 2.3 channels was decreased by genistein or AG556, and was increased by EGF or orthovanadate. The decrease of tyrosine phosphorylation of K(IR) 2.3 channels by genistein or AG556 was reversed by orthovanadate or EGF. Interestingly, the response of K(IR) 2.3 channels to EGF or AG556 was lost in the K(IR) 2.3 Y234A mutant channel. CONCLUSION AND IMPLICATIONS These results demonstrate that the EGF receptor tyrosine kinase up-regulates the K(IR) 2.3 channel via phosphorylation of the Y234 residue of the WT protein. This effect may be involved in the endogenous regulation of cellular electrical activity.
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Affiliation(s)
- De-Yong Zhang
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong SAR, China
| | - Yan-Hui Zhang
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong SAR, China
| | - Hai-Ying Sun
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong SAR, China
| | - Chu-Pak Lau
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong SAR, China
| | - Gui-Rong Li
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong SAR, China
- Department of Physiology, Li Ka Shing Faculty of Medicine, The University of Hong KongPokfulam, Hong Kong SAR, China
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Rook MB, Evers MM, Vos MA, Bierhuizen MFA. Biology of cardiac sodium channel Nav1.5 expression. Cardiovasc Res 2011; 93:12-23. [PMID: 21937582 DOI: 10.1093/cvr/cvr252] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Na(v)1.5, the pore forming α-subunit of the voltage-dependent cardiac Na(+) channel, is an integral membrane protein involved in the initiation and conduction of action potentials. Mutations in the gene-encoding Na(v)1.5, SCN5A, have been associated with a variety of arrhythmic disorders, including long QT, Brugada, and sick sinus syndromes as well as progressive cardiac conduction defect and atrial standstill. Moreover, alterations in the Na(v)1.5 expression level and/or sodium current density have been frequently noticed in acquired cardiac disorders, such as heart failure. The molecular mechanisms underlying these alterations are poorly understood, but are considered essential for conception of arrhythmogenesis and the development of therapeutic strategies for prevention or treatment of arrhythmias. The unravelling of such mechanisms requires critical molecular insight into the biology of Na(v)1.5 expression and function. Therefore, the aim of this review is to provide an up-to-date account of molecular determinants of normal Na(v)1.5 expression and function. The parts of the Na(v)1.5 life cycle that are discussed include (i) regulatory aspects of the SCN5A gene and transcript structure, (ii) the nature, molecular determinants, and functional consequences of Na(v)1.5 post-translational modifications, and (iii) the role of Na(v)1.5 interacting proteins in cellular trafficking. The reviewed studies have provided valuable information on how the Na(v)1.5 expression level, localization, and biophysical properties are regulated, but also revealed that our understanding of the underlying mechanisms is still limited.
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Affiliation(s)
- Martin B Rook
- Department of Medical Physiology, Division Heart & Lungs, University Medical Center Utrecht, The Netherlands
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Zhang DY, Wu W, Deng XL, Lau CP, Li GR. Genistein and tyrphostin AG556 inhibit inwardly-rectifying Kir2.1 channels expressed in HEK 293 cells via protein tyrosine kinase inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1993-9. [DOI: 10.1016/j.bbamem.2011.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 04/13/2011] [Accepted: 04/29/2011] [Indexed: 11/28/2022]
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Beltran-Alvarez P, Pagans S, Brugada R. The cardiac sodium channel is post-translationally modified by arginine methylation. J Proteome Res 2011; 10:3712-9. [PMID: 21726068 DOI: 10.1021/pr200339n] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The α subunit of the cardiac sodium channel (Na(v)1.5) is an essential protein in the initial depolarization phase of the cardiomyocyte action potential. Post-translational modifications such as phosphorylation are known to regulate Na(v)1.5 function. Here, we used a proteomic approach for the study of the post-translational modifications of Na(v)1.5 using tsA201 cells as a model system. We generated a stable cell line expressing Na(v)1.5, purified the sodium channel, and analyzed Na(v)1.5 by MALDI-TOF and LC-MS/MS. We report the identification of arginine methylation as a novel post-translational modification of Na(v)1.5. R513, R526, and R680, located in the linker between domains I and II in Na(v)1.5, were found in mono- or dimethylated states. The functional relevance of arginine methylation in Na(v)1.5 is underscored by the fact that R526H and R680H are known Na(v)1.5 mutations causing Brugada and long QT type 3 syndromes, respectively. Our work describes for the first time arginine methylation in the voltage-gated ion channel superfamily.
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Affiliation(s)
- Pedro Beltran-Alvarez
- Cardiovascular Genetics Center, Institut d'Investigació Biomèdica de Girona, Hospital Dr. Josep Trueta, Girona, Spain
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Affiliation(s)
- T Jespersen
- Department of Biomedical Sciences 16.5, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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Gershome C, Lin E, Kashihara H, Hove-Madsen L, Tibbits GF. Colocalization of voltage-gated Na+ channels with the Na+/Ca2+ exchanger in rabbit cardiomyocytes during development. Am J Physiol Heart Circ Physiol 2011; 300:H300-11. [DOI: 10.1152/ajpheart.00798.2010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Reverse-mode activity of the Na+/Ca2+ exchanger (NCX) has been previously shown to play a prominent role in excitation-contraction coupling in the neonatal rabbit heart, where we have proposed that a restricted subsarcolemmal domain allows a Na+ current to cause an elevation in the Na+ concentration sufficiently large to bring Ca2+ into the myocyte through reverse-mode NCX. In the present study, we tested the hypothesis that there is an overlapping expression and distribution of voltage-gated Na+ (Nav) channel isoforms and the NCX in the neonatal heart. For this purpose, Western blot analysis, immunocytochemistry, confocal microscopy, and image analyses were used. Here, we report the robust expression of skeletal Nav1.4 and cardiac Nav1.5 in neonatal myocytes. Both isoforms colocalized with the NCX, and Nav1.5-NCX colocalization was not statistically different from Nav1.4-NCX colocalization in the neonatal group. Western blot analysis also showed that Nav1.4 expression decreased by sixfold in the adult ( P < 0.01) and Nav1.1 expression decreased by ninefold ( P < 0.01), whereas Nav1.5 expression did not change. Although Nav1.4 underwent large changes in expression levels, the Nav1.4-NCX colocalization relationship did not change with age. In contrast, Nav1.5-NCX colocalization decreased ∼50% with development. Distance analysis indicated that the decrease in Nav1.5-NCX colocalization occurs due to a statistically significant increase in separation distances between Nav1.5 and NCX objects. Taken together, the robust expression of both Nav1.4 and Nav1.5 isoforms and their colocalization with the NCX in the neonatal heart provides structural support for Na+ current-induced Ca2+ entry through reverse-mode NCX. In contrast, this mechanism is likely less efficient in the adult heart because the expression of Nav1.4 and NCX is lower and the separation distance between Nav1.5 and NCX is larger.
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Affiliation(s)
- Cynthia Gershome
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby
- Child and Family Research Institute, Vancouver, British Columbia, Canada; and
| | - Eric Lin
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby
- Child and Family Research Institute, Vancouver, British Columbia, Canada; and
| | - Haruyo Kashihara
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby
- Child and Family Research Institute, Vancouver, British Columbia, Canada; and
| | - Leif Hove-Madsen
- Centro de Investigación Cardiovascular CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Glen F. Tibbits
- Molecular Cardiac Physiology Group, Simon Fraser University, Burnaby
- Child and Family Research Institute, Vancouver, British Columbia, Canada; and
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Scheuer T. Regulation of sodium channel activity by phosphorylation. Semin Cell Dev Biol 2010; 22:160-5. [PMID: 20950703 DOI: 10.1016/j.semcdb.2010.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 10/04/2010] [Accepted: 10/05/2010] [Indexed: 12/24/2022]
Abstract
Voltage-gated sodium channels carry the major inward current responsible for action potential depolarization in excitable cells as well as providing additional inward current that modulates overall excitability. Both their expression and function is under tight control of protein phosphorylation by specific kinases and phosphatases and this control is particular to each type of sodium channel. This article examines the impact and mechanism of phosphorylation for isoforms where it has been studied in detail in an attempt to delineate common features as well as differences.
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Affiliation(s)
- Todd Scheuer
- Department of Pharmacology, University of Washington School of Medicine, Seattle, WA 98195-7280, United States.
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Regulation of human cardiac KCNQ1/KCNE1 channel by epidermal growth factor receptor kinase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:995-1001. [DOI: 10.1016/j.bbamem.2010.01.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/12/2010] [Accepted: 01/13/2010] [Indexed: 11/19/2022]
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Tfelt-Hansen J, Winkel BG, Grunnet M, Jespersen T. Inherited cardiac diseases caused by mutations in the Nav1.5 sodium channel. J Cardiovasc Electrophysiol 2009; 21:107-15. [PMID: 19845816 DOI: 10.1111/j.1540-8167.2009.01633.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A prerequisite for a normal cardiac function is a proper generation and propagation of electrical impulses. Contraction of the heart is obtained through a delicate matched transmission of the electrical impulses. A pivotal element of the impulse propagation is the depolarizing sodium current, responsible for the initial depolarization of the cardiomyocytes. Recent research has shown that mutations in the SCN5A gene, encoding the cardiac sodium channel Nav1.5, are associated with both rare forms of ventricular arrhythmia, as well as the most frequent form of arrhythmia, atrial fibrillation (AF). In this comprehensive review, we describe the functional role of Nav1.5 and its associated proteins in propagation and depolarization both in a normal- and in a pathophysiological setting. Furthermore, several of the arrhythmogenic diseases, such as long-QT syndrome, Brugada syndrome, and AF, reported to be associated with mutations in SCN5A, are thoroughly described.
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Affiliation(s)
- Jacob Tfelt-Hansen
- The Danish National Research Foundation Centre for Cardiac Arrhythmia (DARC), Copenhagen, Denmark.
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