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Chatham JC, Patel RP. Protein glycosylation in cardiovascular health and disease. Nat Rev Cardiol 2024; 21:525-544. [PMID: 38499867 DOI: 10.1038/s41569-024-00998-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/13/2024] [Indexed: 03/20/2024]
Abstract
Protein glycosylation, which involves the attachment of carbohydrates to proteins, is one of the most abundant protein co-translational and post-translational modifications. Advances in technology have substantially increased our knowledge of the biosynthetic pathways involved in protein glycosylation, as well as how changes in glycosylation can affect cell function. In addition, our understanding of the role of protein glycosylation in disease processes is growing, particularly in the context of immune system function, infectious diseases, neurodegeneration and cancer. Several decades ago, cell surface glycoproteins were found to have an important role in regulating ion transport across the cardiac sarcolemma. However, with very few exceptions, our understanding of how changes in protein glycosylation influence cardiovascular (patho)physiology remains remarkably limited. Therefore, in this Review, we aim to provide an overview of N-linked and O-linked protein glycosylation, including intracellular O-linked N-acetylglucosamine protein modification. We discuss our current understanding of how all forms of protein glycosylation contribute to normal cardiovascular function and their roles in cardiovascular disease. Finally, we highlight potential gaps in our knowledge about the effects of protein glycosylation on the heart and vascular system, highlighting areas for future research.
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Affiliation(s)
- John C Chatham
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Rakesh P Patel
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
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2
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Simonson BT, Jegla M, Ryan JF, Jegla T. Functional analysis of ctenophore Shaker K + channels: N-type inactivation in the animal roots. Biophys J 2024; 123:2038-2049. [PMID: 38291751 DOI: 10.1016/j.bpj.2024.01.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/16/2023] [Accepted: 01/24/2024] [Indexed: 02/01/2024] Open
Abstract
Here we explore the evolutionary origins of fast N-type ball-and-chain inactivation in Shaker (Kv1) K+ channels by functionally characterizing Shaker channels from the ctenophore (comb jelly) Mnemiopsis leidyi. Ctenophores are the sister lineage to other animals and Mnemiopsis has >40 Shaker-like K+ channels, but they have not been functionally characterized. We identified three Mnemiopsis channels (MlShak3-5) with N-type inactivation ball-like sequences at their N termini and functionally expressed them in Xenopus oocytes. Two of the channels, MlShak4 and MlShak5, showed rapid inactivation similar to cnidarian and bilaterian Shakers with rapid N-type inactivation, whereas MlShak3 inactivated ∼100-fold more slowly. Fast inactivation in MlShak4 and MlShak5 required the putative N-terminal inactivation ball sequences. Furthermore, the rate of fast inactivation in these channels depended on the number of inactivation balls/channel, but the rate of recovery from inactivation did not. These findings closely match the mechanism of N-type inactivation first described for Drosophila Shaker in which 1) inactivation balls on the N termini of each subunit can independently block the pore, and 2) only one inactivation ball occupies the pore binding site at a time. These findings suggest classical N-type activation evolved in Shaker channels at the very base of the animal phylogeny in a common ancestor of ctenophores, cnidarians, and bilaterians and that fast-inactivating Shakers are therefore a fundamental type of animal K+ channel. Interestingly, we find evidence from functional co-expression experiments and molecular dynamics that MlShak4 and MlShak5 do not co-assemble, suggesting that Mnemiopsis has at least two functionally independent N-type Shaker channels.
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Affiliation(s)
- Benjamin T Simonson
- Department of Biology and Huck Institutes of the Life Sciences, Penn State University, University Park, Pennsylvania
| | - Max Jegla
- Department of Biology and Huck Institutes of the Life Sciences, Penn State University, University Park, Pennsylvania
| | - Joseph F Ryan
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL; Department of Biology, University of Florida, Gainesville, FL
| | - Timothy Jegla
- Department of Biology and Huck Institutes of the Life Sciences, Penn State University, University Park, Pennsylvania.
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3
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Saito K, Yoshida H, Hirota K. Sustained mitigation of ST-segment elevation in a patient with Brugada syndrome type 1 during sevoflurane and remifentanil anesthesia: a case report. JA Clin Rep 2024; 10:18. [PMID: 38467908 PMCID: PMC10928048 DOI: 10.1186/s40981-024-00702-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/19/2024] [Accepted: 03/03/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND During general anesthesia, patients with Brugada syndrome are at risk of malignant arrhythmias following worsened ST-segment elevation, potentially leading to sudden cardiac death. The protocol for safe anesthetic management of patients with Brugada syndrome has not yet been established. CASE PRESENTATION A 63-year-old man, diagnosed with a spontaneous Brugada type 1 pattern, was scheduled for a pleural biopsy using video-assisted thoracoscopic surgery under general anesthesia. We planned general anesthesia using volatile induction and maintenance anesthesia with sevoflurane and remifentanil. We monitored ST-segment morphology and observed sustained mitigation of ST-segment elevation throughout general anesthesia. CONCLUSION The present case may indicate that safe anesthetic management of patients with Brugada syndrome depends on whether the anesthetics used can reduce ST-segment elevation.
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Affiliation(s)
- Kurumi Saito
- Department of Anesthesiology, Hirosaki General Medical Center, 1 Tomino-Cho, Hirosaki, 036-8174, Japan.
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, 5 Zaifu-Cho, Hirosaki, 036-8562, Japan.
| | - Hitoshi Yoshida
- Department of Anesthesiology, Hirosaki General Medical Center, 1 Tomino-Cho, Hirosaki, 036-8174, Japan
| | - Kazuyoshi Hirota
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, 5 Zaifu-Cho, Hirosaki, 036-8562, Japan
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4
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Yang C, Li Q, Hu F, Liu Y, Wang K. Inhibition of Cardiac Kv4.3/KChIP2 Channels by Sulfonylurea Drug Gliquidone. Mol Pharmacol 2024; 105:224-232. [PMID: 38164605 DOI: 10.1124/molpharm.123.000787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/09/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024] Open
Abstract
The Kv4.3 channel features fast N-type inactivation and also undergoes a slow C-type inactivation. The gain-of-function mutations of Kv4.3 channels cause an inherited disease called Brugada syndrome (BrS), characterized by a shortened duration of cardiac action potential repolarization and ventricular arrhythmia. The sulfonylurea drug gliquidone, an ATP-dependent K+ channel antagonist, is widely used for the treatment of type 2 diabetes. Here, we report a novel role of gliquidone in inhibiting Kv4.3 and Kv4.3/KChIP2 channels that encode the cardiac transient outward K+ currents responsible for the initial phase of action potential repolarization. Gliquidone results in concentration-dependent inhibition of both Kv4.3 and Kv4.3/KChIP2 fast or steady-state inactivation currents with an IC50 of approximately 8 μM. Gliquidone also accelerates Kv4.3 channel inactivation and shifts the steady-state activation to a more depolarizing direction. Site-directed mutagenesis and molecular docking reveal that the residues S301 in the S4 and Y312A and L321A in the S4-S5 linker are critical for gliquidone-mediated inhibition of Kv4.3 currents, as mutating those residues to alanine significantly reduces the potency for gliquidone-mediated inhibition. Furthermore, gliquidone also inhibits a gain-of-function Kv4.3 V392I mutant identified in BrS patients in voltage- and concentration-dependent manner. Taken together, our findings demonstrate that gliquidone inhibits Kv4.3 channels by acting on the residues in the S4 and the S4-S5 linker. Therefore, gliquidone may hold repurposing potential for the therapy of Brugada syndrome. SIGNIFICANCE STATEMENT: We describe a novel role of gliquidone in inhibiting cardiac Kv4.3 currents and the channel gain-of-function mutation identified from patients with Brugada syndrome, suggesting its repurposing potential for therapy for the heart disease.
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Affiliation(s)
- Chenxia Yang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (C.Y., Q.L., F.H., Y.L., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Qinqin Li
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (C.Y., Q.L., F.H., Y.L., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Fang Hu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (C.Y., Q.L., F.H., Y.L., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Yani Liu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (C.Y., Q.L., F.H., Y.L., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - KeWei Wang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (C.Y., Q.L., F.H., Y.L., K.W.) and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
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Cumberland MJ, Euchner J, Azad AJ, T N Vo N, Kirchhof P, Holmes AP, Denning C, Gehmlich K. Generation of a human iPSC-derived cardiomyocyte/fibroblast engineered heart tissue model. F1000Res 2024; 12:1224. [PMID: 38298530 PMCID: PMC10828555 DOI: 10.12688/f1000research.139482.1] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/09/2024] [Indexed: 02/02/2024] Open
Abstract
Animal models have proven integral to broadening our understanding of complex cardiac diseases but have been hampered by significant species-dependent differences in cellular physiology. Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have shown great promise in the modelling of cardiac diseases despite limitations in functional and structural maturity. 3D stem cell-derived cardiac models represent a step towards mimicking the intricate microenvironment present in the heart as an in vitro model. Incorporation of non-myocyte cell types, such as cardiac fibroblasts, into engineered heart tissue models (EHTs) can help better recapitulate the cell-to-cell and cell-to-matrix interactions present in the human myocardium. Integration of human-induced pluripotent stem cell-derived cardiac fibroblasts (hiPSC-CFs) and hiPSC-CM into EHT models enables the generation of a genetically homogeneous modelling system capable of exploring the abstruse structural and electrophysiological interplay present in cardiac pathophysiology. Furthermore, the construction of more physiologically relevant 3D cardiac models offers great potential in the replacement of animals in heart disease research. Here we describe efficient and reproducible protocols for the differentiation of hiPSC-CMs and hiPSC-CFs and their subsequent assimilation into EHTs. The resultant EHT consists of longitudinally arranged iPSC-CMs, incorporated alongside hiPSC-CFs. EHTs with both hiPSC-CMs and hiPSC-CFs exhibit slower beating frequencies and enhanced contractile force compared to those composed of hiPSC-CMs alone. The modified protocol may help better characterise the interplay between different cell types in the myocardium and their contribution to structural remodelling and cardiac fibrosis.
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Affiliation(s)
- Max J Cumberland
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
| | - Jonas Euchner
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham, Birmingham, England, B15 2TT, UK
| | - Amar J Azad
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
| | - Nguyen T N Vo
- Biodiscovery Institute, University of Nottingham, Nottingham, England, NG7 2RD, UK
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
- Department of Cardiology, University Heart and Vascular Center Hamburg, Universitat Hamburg, Hamburg, Hamburg, 20251, Germany
| | - Andrew P Holmes
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
- Institute of Clinical Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
| | - Chris Denning
- Biodiscovery Institute, University of Nottingham, Nottingham, England, NG7 2RD, UK
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, England, B15 2TT, UK
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, England, OX3 9DU, UK
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Ye T, Zhou Y, Yang J, Yu F, Song Z, Shi J, Wang L, Huang Z, Yang B, Wang X. P2X7 receptor inhibition prevents atrial fibrillation in rodent models of depression. Europace 2024; 26:euae022. [PMID: 38261756 PMCID: PMC10873709 DOI: 10.1093/europace/euae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 12/07/2023] [Indexed: 01/25/2024] Open
Abstract
AIMS Depression, the most prevalent psychiatric disorder, is associated with the occurrence and development of atrial fibrillation (AF). P2X7 receptor (P2X7R) activation participates in the development of depression, but little attention has been given to its role in AF. This study was to investigate the effects of P2X7R on AF in depression models. METHODS AND RESULTS Lipopolysaccharide (LPS) and chronic unpredictable stress (CUS) were carried out to induce depression in rodents. Behavioural assessments, atrial electrophysiological parameters, electrocardiogram (ECG) parameters, western blot, and histology were performed. Atrial fibrillation inducibility was increased in both LPS- and CUS-induced depression, along with the up-regulation of P2X7R in atria. CUS facilitated atrial fibrosis. CUS reduced heart rate variability (HRV) and increased the expression of TH and GAP43, representing autonomic dysfunction. Down-regulation of Nav1.5, Cav1.2, Kv1.5, Kv4.3, Cx40, and Cx43 in CUS indicated the abnormalities in ion channels. In addition, the expression levels of TLR4, P65, P-P65, NLRP3, ASC, caspase-1, and IL-1β were elevated in depression models. Pharmacological inhibitor (Brilliant Blue G, BBG) or genetic deficiency of P2X7R significantly mitigated depressive-like behaviours; ameliorated electrophysiological deterioration and autonomic dysfunction; improved ion channel expression and atrial fibrosis; and prevented atrial NLRP3 inflammasome activation in the pathophysiological process of AF in depression models. CONCLUSION LPS or CUS induces AF and promotes P2X7R-dependent activation of NLRP3 inflammasome, whereas pharmacological P2X7R inhibition or P2X7R genetic deficiency prevents atrial remodelling without interrupting normal atrial physiological functions. Our results point to P2X7R as an important factor in the pathology of AF in depression.
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Affiliation(s)
- Tianxin Ye
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Yunping Zhou
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Jinxiu Yang
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Fangcong Yu
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Zhuonan Song
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Jiaran Shi
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Longbo Wang
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
| | - Zhouqing Huang
- Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, 2 Fuxue Road, Wenzhou, Zhejiang Province 325000, PR China
| | - Bo Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan 430060, PR China
- Cardiovascular Research Institute, Wuhan University, 238 Jiefang Road, Wuchang District, Wuhan 430060, PR China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, PR China
| | - Xingxiang Wang
- Department of Cardiology, The First Affiliated Hospital, Zhejiang University School of Medicine, #79 Qingchun Road, Hangzhou, Zhejiang Province 310003, PR China
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7
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Kanithi M, Kumari L, Yalakaturi K, Munjal K, Jimitreddy S, Kandamuri M, Veeramachineni P, Chopra H, Junapudi S. Nanoparticle Polymers Influence on Cardiac Health: Good or Bad for Cardiac Physiology? Curr Probl Cardiol 2024; 49:102145. [PMID: 37852559 DOI: 10.1016/j.cpcardiol.2023.102145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 10/14/2023] [Indexed: 10/20/2023]
Abstract
Cardiovascular diseases (CVD) are one of the leading causes of death and morbidity worldwide. Lifestyle modifications, medications, and addressing epidemiological factors have long been at the forefront of targeting therapeutics for CVD. Treatments can be further complicated given the intersection of gender, age, unique comorbidities, and healthcare access, among many other factors. Therefore, expanding treatment and diagnostic modalities for CVD is absolutely necessary. Nanoparticles and nanomaterials are increasingly being used as therapeutic and diagnostic modalities in various disciplines of biomedicine. Nanoparticles have multiple ways of interacting with the cardiovascular system. Some of them alter cardiac physiology by impacting ion channels, whereas others influence ions directly or indirectly, improving cellular death via decreasing oxidative stress. While embedding nanoparticles into therapeutics can help enhance healthy cardiovascular function in other scenarios, they can also impair physiology by increasing reactive oxidative species and leading to cardiotoxicity. This review explores different types of nanoparticles, their effects, and the applicable dosages to create a better foundation for understanding the current research findings.
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Affiliation(s)
- Manasa Kanithi
- Michigan State University College of Osteopathic Medicine, East Lansing, MI
| | - Lata Kumari
- People University of Medical and Health Sciences, Nawab Shah, Sindh, Pakistan
| | | | - Kavita Munjal
- Amity Institute of Pharmacy, Amity University, Noida, Uttar Pradesh, India
| | | | | | | | - Hitesh Chopra
- Department of Biosciences, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India.
| | - Sunil Junapudi
- Geethanjali College of Pharmacy, Hyderabad, Telangana, India.
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8
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Steinberg C. Short-Coupled Ventricular Fibrillation. Card Electrophysiol Clin 2023; 15:331-341. [PMID: 37558303 DOI: 10.1016/j.ccep.2023.05.004] [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] [Indexed: 08/11/2023]
Abstract
Short-coupled ventricular fibrillation (SCVF) is a distinct phenotype among individuals with unexplained cardiac arrest accounting for 7% to 14% of cases of idiopathic ventricular fibrillation (IVF). VF is typically initiated by a trigger premature ventricular contraction with a short-coupling interval of less than 350 milliseconds. In the absence of specific electrocardiographic features or provocative tests, the diagnosis remains challenging and requires documentation of VF onset. Most cases are diagnosed during follow-up at the time of VF recurrence. SCVF is characterized by a high risk of VF recurrence. Insertion of an implantable cardioverter-defibrillator and quinidine are the keystones of SCVF management.
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Affiliation(s)
- Christian Steinberg
- Institut universitaire de cardiologie et pneumologie de Québec (IUCPQ-UL), Laval University, 2725 Chemin Ste-Foy, Quebec, QC, G1V 4G5, Canada.
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Li M, Liu F, Hao X, Fan Y, Li J, Hu Z, Shi J, Fan L, Zhang S, Ma D, Guo M, Xu Y, Shi C. Rare KCND3 Loss-of-Function Mutation Associated With the SCA19/22. Front Mol Neurosci 2022; 15:919199. [PMID: 35813061 PMCID: PMC9261871 DOI: 10.3389/fnmol.2022.919199] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/19/2022] [Indexed: 12/15/2022] Open
Abstract
Spinocerebellar ataxia 19/22 (SCA19/22) is a rare neurodegenerative disorder caused by mutations of the KCND3 gene, which encodes the Kv4. 3 protein. Currently, only 22 KCND3 single-nucleotide mutation sites of SCA19/22 have been reported worldwide, and detailed pathogenesis remains unclear. In this study, Sanger sequencing was used to screen 115 probands of cerebellar ataxia families in 67 patients with sporadic cerebellar ataxia and 200 healthy people to identify KCND3 mutations. Mutant gene products showed pathogenicity damage, and the polarity was changed. Next, we established induced pluripotent stem cells (iPSCs) derived from SCA19/22 patients. Using a transcriptome sequencing technique, we found that protein processing in the endoplasmic reticulum was significantly enriched in SCA19/22-iPS-derived neurons and was closely related to endoplasmic reticulum stress (ERS) and apoptosis. In addition, Western blotting of the SCA19/22-iPS-derived neurons showed a reduction in Kv4.3; but, activation of transcription factor 4 (ATF4) and C/EBP homologous protein was increased. Therefore, the c.1130 C>T (p.T377M) mutation of the KCND3 gene may mediate misfold and aggregation of Kv4.3, which activates the ERS and further induces neuron apoptosis involved in SCA19/22.
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Affiliation(s)
- Mengjie Li
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Fen Liu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Xiaoyan Hao
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Yu Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Jiadi Li
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Zhengwei Hu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Jingjing Shi
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Department of Cell Biology and Medical Genetics, Basic Medical College of Zhengzhou University, Zhengzhou, China
| | - Liyuan Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Shuo Zhang
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Dongrui Ma
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Mengnan Guo
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Yuming Xu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Department of Cell Biology and Medical Genetics, Basic Medical College of Zhengzhou University, Zhengzhou, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, China
- The Henan Medical Key Laboratory of Hereditary Neurodegenerative Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- The Key Laboratory of Cerebrovascular Diseases Prevention and Treatment, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Changhe Shi
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Henan Key Laboratory of Cerebrovascular Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- Institute of Neuroscience, Zhengzhou University, Zhengzhou, China
- The Henan Medical Key Laboratory of Hereditary Neurodegenerative Diseases, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- The Key Laboratory of Cerebrovascular Diseases Prevention and Treatment, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- *Correspondence: Changhe Shi
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10
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Wang M, Tu X. The Genetics and Epigenetics of Ventricular Arrhythmias in Patients Without Structural Heart Disease. Front Cardiovasc Med 2022; 9:891399. [PMID: 35783865 PMCID: PMC9240357 DOI: 10.3389/fcvm.2022.891399] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/25/2022] [Indexed: 12/19/2022] Open
Abstract
Ventricular arrhythmia without structural heart disease is an arrhythmic disorder that occurs in structurally normal heart and no transient or reversible arrhythmia factors, such as electrolyte disorders and myocardial ischemia. Ventricular arrhythmias without structural heart disease can be induced by multiple factors, including genetics and environment, which involve different genetic and epigenetic regulation. Familial genetic analysis reveals that cardiac ion-channel disorder and dysfunctional calcium handling are two major causes of this type of heart disease. Genome-wide association studies have identified some genetic susceptibility loci associated with ventricular tachycardia and ventricular fibrillation, yet relatively few loci associated with no structural heart disease. The effects of epigenetics on the ventricular arrhythmias susceptibility genes, involving non-coding RNAs, DNA methylation and other regulatory mechanisms, are gradually being revealed. This article aims to review the knowledge of ventricular arrhythmia without structural heart disease in genetics, and summarizes the current state of epigenetic regulation.
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Abramochkin DV, Filatova TS, Pustovit KB, Voronina YA, Kuzmin VS, Vornanen M. Ionic currents underlying different patterns of electrical activity in working cardiac myocytes of mammals and non-mammalian vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111204. [PMID: 35346823 DOI: 10.1016/j.cbpa.2022.111204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 12/19/2022]
Abstract
The orderly contraction of the vertebrate heart is determined by generation and propagation of cardiac action potentials (APs). APs are generated by the integrated activity of time- and voltage-dependent ionic channels which carry inward Na+ and Ca2+ currents, and outward K+ currents. This review compares atrial and ventricular APs and underlying ion currents between different taxa of vertebrates. We have collected literature data and attempted to find common electrophysiological features for two or more vertebrate groups, show differences between taxa and cardiac chambers, and indicate gaps in the existing data. Although electrical excitability of the heart in all vertebrates is based on the same superfamily of channels, there is a vast variability of AP waveforms between atrial and ventricular myocytes, between different species of the same vertebrate class and between endothermic and ectothermic animals. The wide variability of AP shapes is related to species-specific differences in animal size, heart rate, stage of ontogenetic development, excitation-contraction coupling, temperature and oxygen availability. Some of the differences between taxa are related to evolutionary development of genomes, which appear e.g. in the expression of different Na+ and K+ channel orthologues in cardiomyocytes of vertebrates. There is a wonderful variability of AP shapes and underlying ion currents with which electrical excitability of vertebrate heart can be generated depending on the intrinsic and extrinsic conditions of animal body. This multitude of ionic mechanisms provides excellent material for studying how the function of the vertebrate heart can adapt or acclimate to prevailing physiological and environmental conditions.
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Affiliation(s)
- Denis V Abramochkin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia.
| | - Tatiana S Filatova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Ksenia B Pustovit
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Yana A Voronina
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia; Laboratory of Cardiac Electrophysiology, National Medical Research Center for Cardiology, 3(rd) Cherepkovskaya str., 15A, Moscow, Russia
| | - Vladislav S Kuzmin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia; Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova str., 1, Moscow, Russia
| | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
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12
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Li Y, Duan H, Yi J, Wang G, Cheng W, Feng L, Liu J. Kv4.2 phosphorylation by PKA drives Kv4.2 - KChIP2 dissociation, leading to Kv4.2 out of lipid rafts and internalization. Am J Physiol Cell Physiol 2022; 323:C190-C201. [PMID: 35508186 DOI: 10.1152/ajpcell.00307.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sympathetic regulation of the Kv4.2 transient outward potassium current is critical for the acute electrical and contractile response of the myocardium under physiological and pathological conditions. Previous studies have suggested that KChIP2, the key auxiliary subunit of Kv4 channels, is required for the sympathetic regulation of Kv4.2 current densities. Of interest, Kv4.2 and KChIP2, and key components mediating acute sympathetic signaling transduction are present in lipid rafts, which are profoundly involved in regulation of Ito densities in rat ventricular myocytes. However, little is known about the mechanisms of Kv4.2-raft association and its connection with acute sympathetic regulation. With the aid of high-resolution fluorescent microscope, we demonstrate that KChIP2 assists Kv4.2 localization in lipid rafts in HEK293 cells. Moreover, PKA-mediated Kv4.2 phosphorylation, the downstream signaling event of acute sympathetic stimulation, induced dissociation between Kv4.2 and KChIP2, resulting in Kv4.2 shifting out of lipid rafts in KChIP2-expressed HEK293.The mutation that mimics Kv4.2 phosphorylation by PKA similarly disrupted Kv4.2 interaction with KChIP2 and also decreased the surface stability of Kv4.2. The attenuated Kv4.2-KChIP2 interaction was also observed in native neonatal rat ventricular myocytes (NRVMs) upon acute adrenergic stimulation with phenylephrine (PE). Furthermore, PE accelerated internalization of Kv4.2 in native NRVMs, but disruption of lipid rafts dampens this reaction. In conclusion, KChIP2 contributes to targeting Kv4.2 to lipid rafts. Acute adrenergic stimulation induces Kv4.2 - KChIP2 dissociation, leading to Kv4.2 out of lipid rafts and internalization, reinforcing the critical role of Kv4.2-lipid raft association in the essential physiological response of Ito to acute sympathetic regulation.
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Affiliation(s)
- Ying Li
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, Guangdong, China
| | - Haixia Duan
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, Guangdong, China
| | - Jing Yi
- Department of Hepatobiliary and Pancreatic Surgery, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Gang Wang
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, Guangdong, China
| | - Wanwen Cheng
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, Guangdong, China
| | - Li Feng
- Department of Cardiology, Zhongshan People's Hospital, Zhongshan, Guangdong, China
| | - Jie Liu
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, Guangdong, China
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13
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Sanghvi S, Szteyn K, Ponnalagu D, Sridharan D, Lam A, Hansra I, Chaudhury A, Majumdar U, Kohut AR, Gururaja Rao S, Khan M, Garg V, Singh H. Inhibition of BK Ca channels protects neonatal hearts against myocardial ischemia and reperfusion injury. Cell Death Dis 2022; 8:175. [PMID: 35393410 PMCID: PMC8989942 DOI: 10.1038/s41420-022-00980-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/15/2022] [Accepted: 03/23/2022] [Indexed: 11/30/2022]
Abstract
BKCa channels are large-conductance calcium and voltage-activated potassium channels that are heterogeneously expressed in a wide array of cells. Activation of BKCa channels present in mitochondria of adult ventricular cardiomyocytes is implicated in cardioprotection against ischemia-reperfusion (IR) injury. However, the BKCa channel’s activity has never been detected in the plasma membrane of adult ventricular cardiomyocytes. In this study, we report the presence of the BKCa channel in the plasma membrane and mitochondria of neonatal murine and rodent cardiomyocytes, which protects the heart on inhibition but not activation. Furthermore, K+ currents measured in neonatal cardiomyocyte (NCM) was sensitive to iberiotoxin (IbTx), suggesting the presence of BKCa channels in the plasma membrane. Neonatal hearts subjected to IR when post-conditioned with NS1619 during reoxygenation increased the myocardial infarction whereas IbTx reduced the infarct size. In agreement, isolated NCM also presented increased apoptosis on treatment with NS1619 during hypoxia and reoxygenation, whereas IbTx reduced TUNEL-positive cells. In NCMs, activation of BKCa channels increased the intracellular reactive oxygen species post HR injury. Electrophysiological characterization of NCMs indicated that NS1619 increased the beat period, field, and action potential duration, and decreased the conduction velocity and spike amplitude. In contrast, IbTx had no impact on the electrophysiological properties of NCMs. Taken together, our data established that inhibition of plasma membrane BKCa channels in the NCM protects neonatal heart/cardiomyocytes from IR injury. Furthermore, the functional disparity observed towards the cardioprotective activity of BKCa channels in adults compared to neonatal heart could be attributed to their differential localization.
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Affiliation(s)
- Shridhar Sanghvi
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, USA
| | - Kalina Szteyn
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Devasena Ponnalagu
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Divya Sridharan
- Department of Emergency Medicine, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Alexander Lam
- Department of Internal Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Inderjot Hansra
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ankur Chaudhury
- Department of Internal Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Uddalak Majumdar
- Center for Cardiovascular Research and The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - Andrew R Kohut
- Department of Internal Medicine, Drexel University College of Medicine, Philadelphia, PA, USA.,Division of Cardiology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Shubha Gururaja Rao
- Department of Pharmaceutical and Biomedical Sciences, The Raabe College of Pharmacy, Ohio Northern University, Ada, OH, USA
| | - Mahmood Khan
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.,Department of Emergency Medicine, Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Vidu Garg
- Center for Cardiovascular Research and The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Harpreet Singh
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA. .,Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, USA.
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14
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Yang J, Li H, Zhang C, Zhou Y. Indoxyl sulfate reduces Ito,f by activating ROS/MAPK and NF-κB signaling pathways. JCI Insight 2022; 7:145475. [PMID: 35132967 PMCID: PMC8855797 DOI: 10.1172/jci.insight.145475] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/08/2021] [Indexed: 12/17/2022] Open
Abstract
There is a high prevalence of ventricular arrhythmias related to sudden cardiac death in patients with chronic kidney disease (CKD). To explored the possible mechanism of CKD-related ventricular arrhythmias, a CKD rat model was created, and indoxyl sulfate (IS) was further used in vivo and in vitro. This project used the following methods: patch clamp, electrocardiogram, and some molecular biology experimental techniques. IS was found to be significantly elevated in the serum of CKD rats. Interestingly, the expression levels of the fast transient outward potassium current-related (Ito,f-related) proteins (Kv4.2, Kv4.3, and KChIP2) in the heart of CKD rats and rats treated with IS decreased. IS dose-dependently reduced Ito,f density, accompanied by the decreases in Kv4.2, Kv4.3, and KChIP2 proteins in vitro. IS also prolonged the action potential duration and QT interval, and paroxysmal ventricular tachycardia could be induced by IS. In-depth studies have shown that ROS/p38MAPK, ROS-p44/42 MAPK, and NF-κB signaling pathways play key roles in the reduction of Ito,f density and Ito,f-related proteins caused by IS. These data suggest that IS reduces Ito,f-related proteins and Ito,f density by activating ROS/MAPK and NF-κB signaling pathways, and the action potential duration and QT interval are subsequently prolonged, which contributes to increasing the susceptibility to arrhythmia in CKD.
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Affiliation(s)
- Jing Yang
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Hongxia Li
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Chi Zhang
- Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yafeng Zhou
- Department of Cardiology, Dushu Public Hospital Affiliated to Soochow University, Suzhou, Jiangsu, China
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15
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Cumberland MJ, Riebel LL, Roy A, O’Shea C, Holmes AP, Denning C, Kirchhof P, Rodriguez B, Gehmlich K. Basic Research Approaches to Evaluate Cardiac Arrhythmia in Heart Failure and Beyond. Front Physiol 2022; 13:806366. [PMID: 35197863 PMCID: PMC8859441 DOI: 10.3389/fphys.2022.806366] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 01/10/2022] [Indexed: 12/20/2022] Open
Abstract
Patients with heart failure often develop cardiac arrhythmias. The mechanisms and interrelations linking heart failure and arrhythmias are not fully understood. Historically, research into arrhythmias has been performed on affected individuals or in vivo (animal) models. The latter however is constrained by interspecies variation, demands to reduce animal experiments and cost. Recent developments in in vitro induced pluripotent stem cell technology and in silico modelling have expanded the number of models available for the evaluation of heart failure and arrhythmia. An agnostic approach, combining the modalities discussed here, has the potential to improve our understanding for appraising the pathology and interactions between heart failure and arrhythmia and can provide robust and validated outcomes in a variety of research settings. This review discusses the state of the art models, methodologies and techniques used in the evaluation of heart failure and arrhythmia and will highlight the benefits of using them in combination. Special consideration is paid to assessing the pivotal role calcium handling has in the development of heart failure and arrhythmia.
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Affiliation(s)
- Max J. Cumberland
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Leto L. Riebel
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Ashwin Roy
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Christopher O’Shea
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Andrew P. Holmes
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Chris Denning
- Stem Cell Biology Unit, Biodiscovery Institute, British Heart Foundation Centre for Regenerative Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford and British Heart Foundation Centre of Research Excellence Oxford, Oxford, United Kingdom
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16
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Knockout of interleukin-17A diminishes ventricular arrhythmia susceptibility in diabetic mice via inhibiting NF-κB-mediated electrical remodeling. Acta Pharmacol Sin 2022; 43:307-315. [PMID: 33911193 PMCID: PMC8791974 DOI: 10.1038/s41401-021-00659-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/16/2021] [Indexed: 02/03/2023] Open
Abstract
Interleukin-17A (IL-17), a potent proinflammatory cytokine, has been shown to participate in cardiac electrical disorders. Diabetes mellitus is an independent risk factor for ventricular arrhythmia. In this study, we investigated the role of IL-17 in ventricular arrhythmia of diabetic mice. Diabetes was induced in both wild-type and IL-17 knockout mice by intraperitoneal injection of streptozotocin (STZ). High-frequency electrical stimuli were delivered into the right ventricle to induce ventricular arrhythmias. We showed that the occurrence rate of ventricular tachycardia was significantly increased in diabetic mice, which was attenuated by IL-17 knockout. We conducted optical mapping on perfused mouse hearts and found that cardiac conduction velocity (CV) was significantly decreased, and action potential duration (APD) was prolonged in diabetic mice, which were mitigated by IL-17 knockout. We performed whole-cell patch clamp recordings from isolated ventricular myocytes, and found that the densities of Ito, INa and ICa,L were reduced, the APDs at 50% and 90% repolarization were increased, and early afterdepolarization (EAD) was markedly increased in diabetic mice. These alterations were alleviated by the knockout of IL-17. Moreover, knockout of IL-17 alleviated the downregulation of Nav1.5 (the pore forming subunit of INa), Cav1.2 (the main component subunit of ICa,L) and KChIP2 (potassium voltage-gated channel interacting protein 2, the regulatory subunit of Ito) in the hearts of diabetic mice. The expression of NF-κB was significantly upregulated in the hearts of diabetic mice, which was suppressed by IL-17 knockout. In neonatal mouse ventricular myocytes, knockdown of NF-κB significantly increased the expression of Nav1.5, Cav1.2 and KChIP2. These results imply that IL-17 may represent a potential target for the development of agents against diabetes-related ventricular arrhythmias.
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17
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Lu YY, Cheng CC, Huang SY, Chen YC, Kao YH, Lin YK, Higa S, Chen SA, Chen YJ. Fibroblast Growth Factor 1 Reduces Pulmonary Vein and Atrium Arrhythmogenesis via Modification of Oxidative Stress and Sodium/Calcium Homeostasis. Front Cardiovasc Med 2022; 8:813589. [PMID: 35118146 PMCID: PMC8804298 DOI: 10.3389/fcvm.2021.813589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/21/2021] [Indexed: 11/13/2022] Open
Abstract
Rationale Atrial fibrillation is a critical health burden. Targeting calcium (Ca2+) dysregulation and oxidative stress are potential upstream therapeutic strategies. Fibroblast growth factor (FGF) 1 can modulate Ca2+ homeostasis and has antioxidant activity. The aim of this study was to investigate whether FGF1 has anti-arrhythmic potential through modulating Ca2+ homeostasis and antioxidant activity of pulmonary vein (PV) and left atrium (LA) myocytes. Methods Patch clamp, western blotting, confocal microscopy, cellular and mitochondrial oxidative stress studies were performed in isolated rabbit PV and LA myocytes treated with or without FGF1 (1 and 10 ng/mL). Conventional microelectrodes were used to record electrical activity in isolated rabbit PV and LA tissue preparations with and without FGF1 (3 μg/kg, i.v.). Results FGF1-treated rabbits had a slower heart rate than that observed in controls. PV and LA tissues in FGF1-treated rabbits had slower beating rates and longer action potential duration than those observed in controls. Isoproterenol (1 μM)-treated PV and LA tissues in the FGF1-treated rabbits showed less changes in the increased beating rate and a lower incidence of tachypacing (20 Hz)-induced burst firing than those observed in controls. FGF1 (10 ng/mL)-treated PV and LA myocytes had less oxidative stress and Ca2+ transient than those observed in controls. Compared to controls, FGF1 (10 ng/mL) decreased INa−L in PV myocytes and lowered Ito, IKr−tail in LA myocytes. Protein kinase C (PKC)ε inhibition abolished the effects of FGF1 on the ionic currents of LA and PV myocytes. Conclusion FGF1 changes PV and LA electrophysiological characteristics possibly via modulating oxidative stress, Na+/Ca2+ homeostasis, and the PKCε pathway.
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Affiliation(s)
- Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan
- School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Chen-Chuan Cheng
- Division of Cardiology, Chi-Mei Medical Center, Tainan City, Taiwan
| | - Shih-Yu Huang
- School of Medicine, College of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
- Division of Cardiac Electrophysiology, Cardiovascular Center, Cathay General Hospital, Taipei, Taiwan
- Post-Baccalaureate Medicine, College of Life Science, National Tsing Hua University, Hsinchu City, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yung-Kuo Lin
- Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Satoshi Higa
- Cardiac Electrophysiology and Pacing Laboratory, Division of Cardiovascular Medicine, Makiminato Central Hospital, Okinawa, Japan
| | - Shih-Ann Chen
- Heart Rhythm Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
- *Correspondence: Yi-Jen Chen
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Sanghvi S, Szteyn K, Ponnalagu D, Sridharan D, Lam A, Hansra I, Chaudhury A, Majumdar U, Kohut AR, Rao SG, Khan M, Garg V, Singh H. Inhibition of BK Ca channels protects neonatal hearts against myocardial ischemia and reperfusion injury.. [DOI: 10.1101/2021.11.02.466585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
AbstractBKCa channels are large-conductance calcium and voltage-activated potassium channels that are heterogeneously expressed in a wide array of cells. Activation of BKCa channels present in mitochondria of adult ventricular cardiomyocytes is implicated in cardioprotection against ischemia-reperfusion (IR) injury. However, the BKCa channel’s activity has never been detected in the plasma membrane of adult ventricular cardiomyocytes. In this study, we report the presence of the BKCa channel in the plasma membrane and mitochondria of neonatal murine and rodent cardiomyocytes which protects the heart on inhibition but not activation. Furthermore, K+ currents measured in neonatal cardiomyocyte (NCM) was sensitive to iberiotoxin (IbTx), suggesting the presence of BKCa channels in the plasma membrane. Neonatal hearts subjected to IR when post-conditioned with NS1619 during reoxygenation increased the myocardial infarction whereas IbTx reduced the infarct size. In agreement, isolated NCM also presented increased apoptosis on treatment with NS1619 during hypoxia and reoxygenation, whereas IbTx reduced TUNEL positive cells. In NCMs, activation of BKCa channels increased the intracellular reactive oxygen species post HR injury. Electrophysiological characterization of NCMs indicated that NS1619 increased the beat period, field, and action potential duration, and decreased the conduction velocity and spike amplitude. In contrast, IbTx had no impact on the electrophysiological properties of NCMs. Taken together, our data established that inhibition of plasma membrane BKCa channels in the NCM protects neonatal heart/cardiomyocytes from IR injury. Furthermore, the functional disparity observed towards the cardioprotective activity of BKCa channels in adults compared to neonatal heart could be attributed to their differential localization.
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19
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Yang L, Deng N, He J, Xia G, Yang Y, Zhao Y, Huo Z, Guo C. Calcineurin Aβ gene knockdown inhibits transient outward potassium current ion channel remodeling in hypertrophic ventricular myocyte. Open Life Sci 2021; 16:1010-1021. [PMID: 34632071 PMCID: PMC8473944 DOI: 10.1515/biol-2021-0107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 08/05/2021] [Accepted: 08/16/2021] [Indexed: 12/23/2022] Open
Abstract
It has been shown that the activation of calcineurin is involved in regulating ion channel remodeling in hypertrophic cardiomyocytes. But the precise role of calcineurin in the regulation of transient outward potassium current (I to), an ion channel associated with fatal arrhythmia, remains controversial. This study aimed to examine the effects of calcineurin Aβ (CnAβ) gene knockdown on I to channel remodeling and action potential duration (APD) in the hypertrophic ventricular myocytes of neonatal rats. Results showed that phenylephrine stimulation caused hypertrophy of ventricular myocytes, upregulation of CnAβ protein expression, downregulation of Kv4.2 mRNA and protein expression, a decrease in I to current density, and prolongation of APD. CnAβ gene knockdown significantly inhibited the effects of phenylephrine stimulation. Our data indicate that CnAβ gene knockdown can inhibit I to channel remodeling and APD prolongation in hypertrophic neonatal rat ventricular myocytes. This finding suggests that calcineurin may be a potential target for the prevention of malignant ventricular arrhythmia in a hypertrophic heart.
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Affiliation(s)
- Long Yang
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
| | - Na Deng
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang 550025, China
| | - Jionghong He
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
| | - Guiling Xia
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
| | - Ying Yang
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
| | - Yidong Zhao
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
| | - Zhaomei Huo
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
| | - Chuxian Guo
- Department of Cardiology, Guizhou Provincial People's Hospital, No. 83 Zhongshandong Road, Guiyang 550002, China
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20
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Chen L, He Y, Wang X, Ge J, Li H. Ventricular voltage-gated ion channels: Detection, characteristics, mechanisms, and drug safety evaluation. Clin Transl Med 2021; 11:e530. [PMID: 34709746 PMCID: PMC8516344 DOI: 10.1002/ctm2.530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac voltage-gated ion channels (VGICs) play critical roles in mediating cardiac electrophysiological signals, such as action potentials, to maintain normal heart excitability and contraction. Inherited or acquired alterations in the structure, expression, or function of VGICs, as well as VGIC-related side effects of pharmaceutical drug delivery can result in abnormal cellular electrophysiological processes that induce life-threatening cardiac arrhythmias or even sudden cardiac death. Hence, to reduce possible heart-related risks, VGICs must be acknowledged as important targets in drug discovery and safety studies related to cardiac disease. In this review, we first summarize the development and application of electrophysiological techniques that are employed in cardiac VGIC studies alone or in combination with other techniques such as cryoelectron microscopy, optical imaging and optogenetics. Subsequently, we describe the characteristics, structure, mechanisms, and functions of various well-studied VGICs in ventricular myocytes and analyze their roles in and contributions to both physiological cardiac excitability and inherited cardiac diseases. Finally, we address the implications of the structure and function of ventricular VGICs for drug safety evaluation. In summary, multidisciplinary studies on VGICs help researchers discover potential targets of VGICs and novel VGICs in heart, enrich their knowledge of the properties and functions, determine the operation mechanisms of pathological VGICs, and introduce groundbreaking trends in drug therapy strategies, and drug safety evaluation.
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Affiliation(s)
- Lulan Chen
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
| | - Yue He
- Department of CardiologyShanghai Xuhui District Central Hospital & Zhongshan‐xuhui HospitalShanghaiChina
| | - Xiangdong Wang
- Institute of Clinical Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Junbo Ge
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
| | - Hua Li
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
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21
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Gao X, Yu S, Guan Y, Shen Y, Xu L. Nucleoporin 50 mediates Kcna4 transcription to regulate cardiac electrical activity. J Cell Sci 2021; 134:271877. [PMID: 34409458 DOI: 10.1242/jcs.256818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 08/12/2021] [Indexed: 11/20/2022] Open
Abstract
Emerging evidence has demonstrated that nucleoporins (Nups) play a pivotal role in cell-type-specific gene regulation, but how they control the expression and activity of ion channel genes in the heart remains unclear. Here, we show that Nup50, which is localized in the nucleus of cardiomyocytes, selectively induces an increase in the transcription and translation of Kcna4. The Kcna4 gene encodes a K+ voltage-gated channel of shaker-related subfamily member 4 and is essential for regulating the action potential in cardiac membranes. Using immunofluorescence imaging, luciferase assays and chromatin immunoprecipitation assays, we identified that the direct binding of the FG-repeat domain within Nup50 to the proximity of the Kcna4 promoter was required to activate the transcription and subsequent translation of Kcna4. Functionally, Nup50 overexpression increased the currents of KCNA4-encoded Ito,s channels, and reverse knockdown of Nup50 resulted in a remarkable decrease in the amplitude of Ito,s currents in cardiomyocytes. Moreover, a positive correlation between Nup50 and Kcna4 mRNA and protein expression was observed in heart tissues subjected to ischemic insults. These findings provide insights into the homeostatic control of cardiac electrophysiology through Nup-mediated regulation.
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Affiliation(s)
- Xueting Gao
- Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai 200120, China.,Institute of Medical Genetics, Tongji University, Shanghai 200092, China
| | - Shuai Yu
- Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai 200120, China.,Institute of Medical Genetics, Tongji University, Shanghai 200092, China
| | - Yi Guan
- Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai 200120, China.,Institute of Medical Genetics, Tongji University, Shanghai 200092, China
| | - Yunli Shen
- Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai 200120, China
| | - Liang Xu
- Department of Cardiology, East Hospital, Tongji University School of Medicine, Shanghai 200120, China.,Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai 200120, China.,Institute of Medical Genetics, Tongji University, Shanghai 200092, China
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22
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Mangold KE, Wang W, Johnson EK, Bhagavan D, Moreno JD, Nerbonne JM, Silva JR. Identification of structures for ion channel kinetic models. PLoS Comput Biol 2021; 17:e1008932. [PMID: 34398881 PMCID: PMC8389848 DOI: 10.1371/journal.pcbi.1008932] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 08/26/2021] [Accepted: 07/16/2021] [Indexed: 12/22/2022] Open
Abstract
Markov models of ion channel dynamics have evolved as experimental advances have improved our understanding of channel function. Past studies have examined limited sets of various topologies for Markov models of channel dynamics. We present a systematic method for identification of all possible Markov model topologies using experimental data for two types of native voltage-gated ion channel currents: mouse atrial sodium currents and human left ventricular fast transient outward potassium currents. Successful models identified with this approach have certain characteristics in common, suggesting that aspects of the model topology are determined by the experimental data. Incorporating these channel models into cell and tissue simulations to assess model performance within protocols that were not used for training provided validation and further narrowing of the number of acceptable models. The success of this approach suggests a channel model creation pipeline may be feasible where the structure of the model is not specified a priori. Markov models of ion channel dynamics have evolved as experimental advances have improved our understanding of channel function. Past studies have examined limited sets of various structures for Markov models of channel dynamics. Here, we present a computational routine designed to thoroughly search for Markov model topologies for simulating whole-cell currents. We tested this method on two distinct types of voltage-gated cardiac ion channels and found the number of states and connectivity required to recapitulate experimentally observed kinetics. Successful models identified with this approach have certain characteristics in common, suggesting that model structures are determined by the experimental data. Incorporation of these models into higher scale action potential and cable (an approximation of one-dimensional action potential propagation) simulations, identified key channel phenomena that were required for proper function. These methods provide a route to create functional channel models that can be used for action potential simulation without pre-defining their structure ahead of time.
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Affiliation(s)
- Kathryn E. Mangold
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Wei Wang
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis Missouri, United States of America
| | - Eric K. Johnson
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis Missouri, United States of America
| | - Druv Bhagavan
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Jonathan D. Moreno
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States of America
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis Missouri, United States of America
| | - Jeanne M. Nerbonne
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis Missouri, United States of America
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jonathan R. Silva
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States of America
- * E-mail:
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23
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Canine Myocytes Represent a Good Model for Human Ventricular Cells Regarding Their Electrophysiological Properties. Pharmaceuticals (Basel) 2021; 14:ph14080748. [PMID: 34451845 PMCID: PMC8398821 DOI: 10.3390/ph14080748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022] Open
Abstract
Due to the limited availability of healthy human ventricular tissues, the most suitable animal model has to be applied for electrophysiological and pharmacological studies. This can be best identified by studying the properties of ion currents shaping the action potential in the frequently used laboratory animals, such as dogs, rabbits, guinea pigs, or rats, and comparing them to those of human cardiomyocytes. The authors of this article with the experience of three decades of electrophysiological studies, performed in mammalian and human ventricular tissues and isolated cardiomyocytes, summarize their results obtained regarding the major canine and human cardiac ion currents. Accordingly, L-type Ca2+ current (ICa), late Na+ current (INa-late), rapid and slow components of the delayed rectifier K+ current (IKr and IKs, respectively), inward rectifier K+ current (IK1), transient outward K+ current (Ito1), and Na+/Ca2+ exchange current (INCX) were characterized and compared. Importantly, many of these measurements were performed using the action potential voltage clamp technique allowing for visualization of the actual current profiles flowing during the ventricular action potential. Densities and shapes of these ion currents, as well as the action potential configuration, were similar in human and canine ventricular cells, except for the density of IK1 and the recovery kinetics of Ito. IK1 displayed a largely four-fold larger density in canine than human myocytes, and Ito recovery from inactivation displayed a somewhat different time course in the two species. On the basis of these results, it is concluded that canine ventricular cells represent a reasonably good model for human myocytes for electrophysiological studies, however, it must be borne in mind that due to their stronger IK1, the repolarization reserve is more pronounced in canine cells, and moderate differences in the frequency-dependent repolarization patterns can also be anticipated.
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24
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Non-Coding RNAs in the Cardiac Action Potential and Their Impact on Arrhythmogenic Cardiac Diseases. HEARTS 2021. [DOI: 10.3390/hearts2030026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cardiac arrhythmias are prevalent among humans across all age ranges, affecting millions of people worldwide. While cardiac arrhythmias vary widely in their clinical presentation, they possess shared complex electrophysiologic properties at cellular level that have not been fully studied. Over the last decade, our current understanding of the functional roles of non-coding RNAs have progressively increased. microRNAs represent the most studied type of small ncRNAs and it has been demonstrated that miRNAs play essential roles in multiple biological contexts, including normal development and diseases. In this review, we provide a comprehensive analysis of the functional contribution of non-coding RNAs, primarily microRNAs, to the normal configuration of the cardiac action potential, as well as their association to distinct types of arrhythmogenic cardiac diseases.
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25
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Zayas-Arrabal J, Alquiza A, Tuncay E, Turan B, Gallego M, Casis O. Molecular and Electrophysiological Role of Diabetes-Associated Circulating Inflammatory Factors in Cardiac Arrhythmia Remodeling in a Metabolic-Induced Model of Type 2 Diabetic Rat. Int J Mol Sci 2021; 22:ijms22136827. [PMID: 34202017 PMCID: PMC8268936 DOI: 10.3390/ijms22136827] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 12/29/2022] Open
Abstract
Background: Diabetic patients have prolonged cardiac repolarization and higher risk of arrhythmia. Besides, diabetes activates the innate immune system, resulting in higher levels of plasmatic cytokines, which are described to prolong ventricular repolarization. Methods: We characterize a metabolic model of type 2 diabetes (T2D) with prolonged cardiac repolarization. Sprague-Dawley rats were fed on a high-fat diet (45% Kcal from fat) for 6 weeks, and a low dose of streptozotozin intraperitoneally injected at week 2. Body weight and fasting blood glucose were measured and electrocardiograms of conscious animals were recorded weekly. Plasmatic lipid profile, insulin, cytokines, and arrhythmia susceptibility were determined at the end of the experimental period. Outward K+ currents and action potentials were recorded in isolated ventricular myocytes by patch-clamp. Results: T2D animals showed insulin resistance, hyperglycemia, and elevated levels of plasma cholesterol, triglycerides, TNFα, and IL-1b. They also developed bradycardia and prolonged QTc-interval duration that resulted in increased susceptibility to severe ventricular tachycardia under cardiac challenge. Action potential duration (APD) was prolonged in control cardiomyocytes incubated 24 h with plasma isolated from diabetic rats. However, adding TNFα and IL-1b receptor blockers to the serum of diabetic animals prevented the increased APD. Conclusions: The elevation of the circulating levels of TNFα and IL-1b are responsible for impaired ventricular repolarization and higher susceptibility to cardiac arrhythmia in our metabolic model of T2D.
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Affiliation(s)
- Julian Zayas-Arrabal
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
| | - Amaia Alquiza
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100 Ankara, Turkey;
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, 06510 Ankara, Turkey;
| | - Monica Gallego
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
| | - Oscar Casis
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
- Correspondence: ; Tel.: +34-945013033
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26
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Chaumont C, Suffee N, Gandjbakhch E, Balse E, Anselme F, Hatem SN. Epicardial origin of cardiac arrhythmias: clinical evidences and pathophysiology. Cardiovasc Res 2021; 118:1693-1702. [PMID: 34152392 PMCID: PMC9215195 DOI: 10.1093/cvr/cvab213] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
Recent developments in imaging, mapping, and ablation techniques have shown that the epicardial region of the heart is a key player in the occurrence of ventricular arrhythmic events in several cardiac diseases, such as Brugada syndrome, arrhythmogenic cardiomyopathy, or dilated cardiomyopathy. At the atrial level as well, the epicardial region has emerged as an important determinant of the substrate of atrial fibrillation, pointing to common underlying pathophysiological mechanisms. Alteration in the gradient of repolarization between myocardial layers favouring the occurrence of re-entry circuits has largely been described. The fibro-fatty infiltration of the subepicardium is another shared substrate between ventricular and atrial arrhythmias. Recent data have emphasized the role of the epicardial reactivation in the formation of this arrhythmogenic substrate. There are new evidences supporting this structural remodelling process to be regulated by the recruitment of epicardial progenitor cells that can differentiate into adipocytes or fibroblasts under various stimuli. In addition, immune-inflammatory processes can also contribute to fibrosis of the subepicardial layer. A better understanding of such ‘electrical fragility’ of the epicardial area will open perspectives for novel biomarkers and therapeutic strategies. In this review article, a pathophysiological scheme of epicardial-driven arrhythmias will be proposed.
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Affiliation(s)
- Corentin Chaumont
- Cardiology Department, Rouen University Hospital, Rouen, France.,FHU REMOD-VHF, UNIROUEN, INSERM U1096, F76000, France
| | - Nadine Suffee
- INSERM UMRS1166, ICAN-Institute of CardioMetabolism and Nutrition, Sorbonne University, Institute of Cardiology, Pitié-Salpêtrière Hospital, Paris, France
| | - Estelle Gandjbakhch
- INSERM UMRS1166, ICAN-Institute of CardioMetabolism and Nutrition, Sorbonne University, Institute of Cardiology, Pitié-Salpêtrière Hospital, Paris, France
| | - Elise Balse
- INSERM UMRS1166, ICAN-Institute of CardioMetabolism and Nutrition, Sorbonne University, Institute of Cardiology, Pitié-Salpêtrière Hospital, Paris, France
| | - Frédéric Anselme
- Cardiology Department, Rouen University Hospital, Rouen, France.,FHU REMOD-VHF, UNIROUEN, INSERM U1096, F76000, France
| | - Stéphane N Hatem
- INSERM UMRS1166, ICAN-Institute of CardioMetabolism and Nutrition, Sorbonne University, Institute of Cardiology, Pitié-Salpêtrière Hospital, Paris, France
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27
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Xiao Z, Zhao P, Wu X, Kong X, Wang R, Liang S, Tang C, Liu Z. Variation of Two S3b Residues in K V4.1-4.3 Channels Underlies Their Different Modulations by Spider Toxin κ-LhTx-1. Front Pharmacol 2021; 12:692076. [PMID: 34177600 PMCID: PMC8222713 DOI: 10.3389/fphar.2021.692076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/27/2021] [Indexed: 11/13/2022] Open
Abstract
The naturally occurred peptide toxins from animal venoms are valuable pharmacological tools in exploring the structure-function relationships of ion channels. Herein we have identified the peptide toxin κ-LhTx-1 from the venom of spider Pandercetes sp (the Lichen huntsman spider) as a novel selective antagonist of the KV4 family potassium channels. κ-LhTx-1 is a gating-modifier toxin impeded KV4 channels' voltage sensor activation, and mutation analysis has confirmed its binding site on channels' S3b region. Interestingly, κ-LhTx-1 differently modulated the gating of KV4 channels, as revealed by toxin inhibiting KV4.2/4.3 with much more stronger voltage-dependence than that for KV4.1. We proposed that κ-LhTx-1 trapped the voltage sensor of KV4.1 in a much more stable resting state than that for KV4.2/4.3 and further explored the underlying mechanism. Swapping the non-conserved S3b segments between KV4.1(280FVPK283) and KV4.3(275VMTN278) fully reversed their voltage-dependence phenotypes in inhibition by κ-LhTx-1, and intensive mutation analysis has identified P282 in KV4.1, D281 in KV4.2 and N278 in KV4.3 being the key residues. Furthermore, the last two residues in this segment of each KV4 channel (P282/K283 in KV4.1, T280/D281 in KV4.2 and T277/N278 in KV4.3) likely worked synergistically as revealed by our combinatorial mutations analysis. The present study has clarified the molecular basis in KV4 channels for their different modulations by κ-LhTx-1, which have advanced our understanding on KV4 channels' structure features. Moreover, κ-LhTx-1 might be useful in developing anti-arrhythmic drugs given its high affinity, high selectivity and unique action mode in interacting with the KV4.2/4.3 channels.
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Affiliation(s)
- Zhen Xiao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Piao Zhao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiangyue Wu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiangjin Kong
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Ruiwen Wang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Songping Liang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Cheng Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Zhonghua Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
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28
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Nakajima T, Tamura S, Kurabayashi M, Kaneko Y. Towards Mutation-Specific Precision Medicine in Atypical Clinical Phenotypes of Inherited Arrhythmia Syndromes. Int J Mol Sci 2021; 22:ijms22083930. [PMID: 33920294 PMCID: PMC8069124 DOI: 10.3390/ijms22083930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/08/2021] [Indexed: 12/19/2022] Open
Abstract
Most causal genes for inherited arrhythmia syndromes (IASs) encode cardiac ion channel-related proteins. Genotype-phenotype studies and functional analyses of mutant genes, using heterologous expression systems and animal models, have revealed the pathophysiology of IASs and enabled, in part, the establishment of causal gene-specific precision medicine. Additionally, the utilization of induced pluripotent stem cell (iPSC) technology have provided further insights into the pathophysiology of IASs and novel promising therapeutic strategies, especially in long QT syndrome. It is now known that there are atypical clinical phenotypes of IASs associated with specific mutations that have unique electrophysiological properties, which raises a possibility of mutation-specific precision medicine. In particular, patients with Brugada syndrome harboring an SCN5A R1632C mutation exhibit exercise-induced cardiac events, which may be caused by a marked activity-dependent loss of R1632C-Nav1.5 availability due to a marked delay of recovery from inactivation. This suggests that the use of isoproterenol should be avoided. Conversely, the efficacy of β-blocker needs to be examined. Patients harboring a KCND3 V392I mutation exhibit both cardiac (early repolarization syndrome and paroxysmal atrial fibrillation) and cerebral (epilepsy) phenotypes, which may be associated with a unique mixed electrophysiological property of V392I-Kv4.3. Since the epileptic phenotype appears to manifest prior to cardiac events in this mutation carrier, identifying KCND3 mutations in patients with epilepsy and providing optimal therapy will help prevent sudden unexpected death in epilepsy. Further studies using the iPSC technology may provide novel insights into the pathophysiology of atypical clinical phenotypes of IASs and the development of mutation-specific precision medicine.
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29
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Romanowicz J, Guerrelli D, Dhari Z, Mulvany C, Reilly M, Swift L, Vasandani N, Ramadan M, Leatherbury L, Ishibashi N, Posnack NG. Chronic perinatal hypoxia delays cardiac maturation in a mouse model for cyanotic congenital heart disease. Am J Physiol Heart Circ Physiol 2021; 320:H1873-H1886. [PMID: 33739154 DOI: 10.1152/ajpheart.00870.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Compared with acyanotic congenital heart disease (CHD), cyanotic CHD has an increased risk of lifelong mortality and morbidity. These adverse outcomes may be attributed to delayed cardiomyocyte maturation, since the transition from a hypoxic fetal milieu to oxygen-rich postnatal environment is disrupted. We established a rodent model to replicate hypoxic myocardial conditions spanning perinatal development, and tested the hypothesis that chronic hypoxia impairs cardiac development. Pregnant mice were housed in hypoxia beginning at embryonic day 16. Pups stayed in hypoxia until postnatal day (P)8 when cardiac development is nearly complete. Global gene expression was quantified at P8 and at P30, after recovering in normoxia. Phenotypic testing included electrocardiogram, echocardiogram, and ex vivo electrophysiology study. Hypoxic P8 animals were 47% smaller than controls with preserved heart size. Gene expression was grossly altered by hypoxia at P8 (1,427 genes affected), but normalized after recovery (P30). Electrocardiograms revealed bradycardia and slowed conduction velocity in hypoxic animals at P8, with noticeable resolution after recovery (P30). Notable differences that persisted after recovery (P30) included a 65% prolongation in ventricular effective refractory period, sinus node dysfunction, 23% reduction in ejection fraction, and 16% reduction in fractional shortening in animals exposed to hypoxia. We investigated the impact of chronic hypoxia on the developing heart. Perinatal hypoxia was associated with changes in gene expression and cardiac function. Persistent changes to the electrophysiological substrate and contractile function warrant further investigation and may contribute to adverse outcomes observed in the cyanotic CHD population.NEW & NOTEWORTHY We utilized a new mouse model of chronic perinatal hypoxia to simulate the hypoxic myocardial conditions present in cyanotic congenital heart disease. Hypoxia caused numerous abnormalities in cardiomyocyte gene expression, the electrophysiologic substrate of the heart, and contractile function. Taken together, alterations observed in the neonatal period suggest delayed cardiac development immediately following hypoxia.
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Affiliation(s)
- Jennifer Romanowicz
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia
| | - Devon Guerrelli
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia.,Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | - Zaenab Dhari
- Center for Neuroscience Research, Children's National Research Institute, Washington, District of Columbia
| | - Colm Mulvany
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia
| | - Marissa Reilly
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia
| | - Luther Swift
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia
| | - Nimisha Vasandani
- Center for Neuroscience Research, Children's National Research Institute, Washington, District of Columbia
| | - Manelle Ramadan
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia
| | - Linda Leatherbury
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia
| | - Nobuyuki Ishibashi
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia.,Center for Neuroscience Research, Children's National Research Institute, Washington, District of Columbia.,Department of Pediatrics, George Washington University, Washington, District of Columbia.,Department of Pharmacology & Physiology, George Washington University, Washington, District of Columbia
| | - Nikki Gillum Posnack
- Children's National Heart Institute, Children's National Hospital, Washington, District of Columbia.,Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Research Institute, Washington, District of Columbia.,Department of Pediatrics, George Washington University, Washington, District of Columbia.,Department of Pharmacology & Physiology, George Washington University, Washington, District of Columbia
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30
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KLF15 Loss-of-Function Mutation Underlying Atrial Fibrillation as well as Ventricular Arrhythmias and Cardiomyopathy. Genes (Basel) 2021; 12:genes12030408. [PMID: 33809104 PMCID: PMC8001991 DOI: 10.3390/genes12030408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/27/2021] [Accepted: 03/09/2021] [Indexed: 12/04/2022] Open
Abstract
Atrial fibrillation (AF) represents the most common type of clinical cardiac arrhythmia and substantially increases the risks of cerebral stroke, heart failure and death. Accumulating evidence has convincingly demonstrated the strong genetic basis of AF, and an increasing number of pathogenic variations in over 50 genes have been causally linked to AF. Nevertheless, AF is of pronounced genetic heterogeneity, and the genetic determinants underpinning AF in most patients remain obscure. In the current investigation, a Chinese pedigree with AF as well as ventricular arrhythmias and hypertrophic cardiomyopathy was recruited. Whole exome sequencing and bioinformatic analysis of the available family members were conducted, and a novel heterozygous variation in the KLF15 gene (encoding Krüppel-like factor 15, a transcription factor critical for cardiac electrophysiology and structural remodeling), NM_014079.4: c.685A>T; p.(Lys229*), was identified. The variation was verified by Sanger sequencing and segregated with autosomal dominant AF in the family with complete penetrance. The variation was absent from 300 unrelated healthy subjects used as controls. In functional assays using a dual-luciferase assay system, mutant KLF15 showed neither transcriptional activation of the KChIP2 promoter nor transcriptional inhibition of the CTGF promoter, alone or in the presence of TGFB1, a key player in the pathogenesis of arrhythmias and cardiomyopathies. The findings indicate KLF15 as a new causative gene responsible for AF as well as ventricular arrhythmias and hypertrophic cardiomyopathy, and they provide novel insight into the molecular mechanisms underlying cardiac arrhythmias and hypertrophic cardiomyopathy.
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31
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Saraf A, Rampoldi A, Chao M, Li D, Armand L, Hwang H, Liu R, Jha R, Fu H, Maxwell JT, Xu C. Functional and molecular effects of TNF-α on human iPSC-derived cardiomyocytes. Stem Cell Res 2021; 52:102218. [PMID: 33592567 PMCID: PMC8080119 DOI: 10.1016/j.scr.2021.102218] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 01/02/2021] [Accepted: 01/25/2021] [Indexed: 12/17/2022] Open
Abstract
Proinflammatory molecule tumor necrosis factor alpha (TNF-α) is predominantly elevated in cytokine storm as well as worsening cardiac function. Here we model the molecular and functional effects of TNF-α in cardiomyocytes (CMs) derived from human induced pluripotent stem cells (hiPSC). We found that treatment of hiPSC-CMs with TNF-α increased reactive oxygen species (ROS) and caspase 3/7 activity and caused cell death and apoptosis. TNF-α treatment also resulted in dysregulation of cardiomyocyte function with respect to the increased abnormal calcium handling, calcium wave propagation between cells and excitation–contraction coupling. We also uncovered significant changes in gene expression and protein localization caused by TNF-α treatment. Notably, TNF-α treatment altered the expression of ion channels, dysregulated cadherins, and affected the localization of gap-junction protein connexin-43. In addition, TNF-α treatment up-regulated IL-32 (a human specific cytokine, not present in rodents and an inducer of TNF-α) and IL-34 and down-regulated glutamate receptors and cardiomyocyte contractile proteins. These findings provide insights into the molecular and functional consequences from the exposure of human cardiomyocytes to TNF-α. Our study provides a model to incorporate inflammatory factors into hiPSC-CM-based studies to evaluate mechanistic aspects of heart disease.
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Affiliation(s)
- Anita Saraf
- Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA; University of Pittsburgh, Department of Medicine and Pediatrics and McGowan Regenerative Institute, 200 Lothorop Street, PUH, Pittsburgh, PA 15213, USA.
| | - Antonio Rampoldi
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Myra Chao
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Dong Li
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Lawrence Armand
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Hyun Hwang
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Rui Liu
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Rajnesh Jha
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Haian Fu
- Emory Chemical Biology Discovery Center and the Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Joshua T Maxwell
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Chunhui Xu
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA 30322, USA; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA.
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DNA Methylation Analysis Identifies Patterns in Progressive Glioma Grades to Predict Patient Survival. Int J Mol Sci 2021; 22:ijms22031020. [PMID: 33498463 PMCID: PMC7864199 DOI: 10.3390/ijms22031020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/15/2021] [Accepted: 01/17/2021] [Indexed: 12/15/2022] Open
Abstract
DNA methylation is an epigenetic change to the genome that impacts gene activities without modification to the DNA sequence. Alteration in the methylation pattern is a naturally occurring event throughout the human life cycle which may result in the development of diseases such as cancer. In this study, we analyzed methylation data from The Cancer Genome Atlas, under the Lower-Grade Glioma (LGG) and Glioblastoma Multiforme (GBM) projects, to identify methylation markers that exhibit unique changes in DNA methylation pattern along with tumor grade progression, to predict patient survival. We found ten glioma grade-associated Cytosine-phosphate-Guanine (CpG) sites that targeted four genes (SMOC1, KCNA4, SLC25A21, and UPP1) and the methylation pattern is strongly associated with glioma specific molecular alterations, primarily isocitrate dehydrogenase (IDH) mutation and chromosome 1p/19q codeletion. The ten CpG sites collectively distinguished a cohort of diffuse glioma patients with remarkably poor survival probability. Our study highlights genes (KCNA4 and SLC25A21) that were not previously associated with gliomas to have contributed to the poorer patient outcome. These CpG sites can aid glioma tumor progression monitoring and serve as prognostic markers to identify patients diagnosed with less aggressive and malignant gliomas that exhibit similar survival probability to GBM patients.
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Kabakov AY, Sengun E, Lu Y, Roder K, Bronk P, Baggett B, Turan NN, Moshal KS, Koren G. Three-Week-Old Rabbit Ventricular Cardiomyocytes as a Novel System to Study Cardiac Excitation and EC Coupling. Front Physiol 2021; 12:672360. [PMID: 34867432 PMCID: PMC8637404 DOI: 10.3389/fphys.2021.672360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/06/2021] [Indexed: 01/14/2023] Open
Abstract
Cardiac arrhythmias significantly contribute to cardiovascular morbidity and mortality. The rabbit heart serves as an accepted model system for studying cardiac cell excitation and arrhythmogenicity. Accordingly, primary cultures of adult rabbit ventricular cardiomyocytes serve as a preferable model to study molecular mechanisms of human cardiac excitation. However, the use of adult rabbit cardiomyocytes is often regarded as excessively costly. Therefore, we developed and characterized a novel low-cost rabbit cardiomyocyte model, namely, 3-week-old ventricular cardiomyocytes (3wRbCMs). Ventricular myocytes were isolated from whole ventricles of 3-week-old New Zealand White rabbits of both sexes by standard enzymatic techniques. Using wheat germ agglutinin, we found a clear T-tubule structure in acutely isolated 3wRbCMs. Cells were adenovirally infected (multiplicity of infection of 10) to express Green Fluorescent Protein (GFP) and cultured for 48 h. The cells showed action potential duration (APD90 = 253 ± 24 ms) and calcium transients similar to adult rabbit cardiomyocytes. Freshly isolated and 48-h-old-cultured cells expressed critical ion channel proteins: calcium voltage-gated channel subunit alpha1 C (Cavα1c), sodium voltage-gated channel alpha subunit 5 (Nav1.5), potassium voltage-gated channel subfamily D member 3 (Kv4.3), and subfamily A member 4 (Kv1.4), and also subfamily H member 2 (RERG. Kv11.1), KvLQT1 (K7.1) protein and inward-rectifier potassium channel (Kir2.1). The cells displayed an appropriate electrophysiological phenotype, including fast sodium current (I Na), transient outward potassium current (I to), L-type calcium channel peak current (I Ca,L), rapid and slow components of the delayed rectifier potassium current (I Kr and I Ks), and inward rectifier (I K1). Although expression of the channel proteins and some currents decreased during the 48 h of culturing, we conclude that 3wRbCMs are a new, low-cost alternative to the adult-rabbit-cardiomyocytes system, which allows the investigation of molecular mechanisms of cardiac excitation on morphological, biochemical, genetic, physiological, and biophysical levels.
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Affiliation(s)
- Anatoli Y Kabakov
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Elif Sengun
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Department of Pharmacology, Institute of Graduate Studies in Health Sciences, Istanbul University, Istanbul, Türkiye
| | - Yichun Lu
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Karim Roder
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Peter Bronk
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Brett Baggett
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Nilüfer N Turan
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Karni S Moshal
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Gideon Koren
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
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Kuzmin VS, Potekhina VM, Odnoshivkina YG, Chelombitko MA, Fedorov AV, Averina OA, Borodkov AS, Shevtsova AA, Lovat ML, Petrov AM. Proarrhythmic atrial ectopy associated with heart sympathetic innervation dysfunctions is specific for murine B6CBAF1 hybrid strain. Life Sci 2020; 266:118887. [PMID: 33316264 DOI: 10.1016/j.lfs.2020.118887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/25/2020] [Accepted: 12/04/2020] [Indexed: 11/20/2022]
Abstract
A lot of animal models are developed with aim to advance in atrial fibrillation (AF) understanding. The hybrid B6CBAF1 mice are used extensively as a background to create manifestation of various diseases, however, their atrial electrophysiology, autonomic sympathetic innervation of the heart and potential for AF investigation is poorly characterized. In the present study we used ECG and microelectrode recordings from multicellular atrial preparations to reveal attributes of atrial electrical activity in B6CBAF1. Also, experiments with a fluorescent false monoamine neurotransmitter and glyoxylic acid-based staining were carried out to characterize functionally and morphologically catecholaminergic innervation of the B6CBAF1 atria. Atrial myocardium of B6CBAF1 is highly prone to ectopic automaticity and exhibits abnormal spontaneous action potential accompanied by multiple postdepolarizations that result in proarrhythmic triggered activity unlike two parental C57Bl/6 and CBA strains. In vivo experiments revealed that B6CBAF1 hybrids are more susceptible to the norepinephrine induced AF. Also, sympathetic nerve terminals are partially dysfunctional in B6CBAF1 revealing lower ability to accumulate and release neurotransmitters unlike two parental strains. The analysis of the heart rate variability revealed suppressed sympathetic component of the autonomic heart control in B6CBAF1. The organization of sympathetic innervation is very similar morphologically in all three murine strains however the abundance of non-bifurcated catecholamine-positive fibers in B6CBAF1 was increased. These results suggest that B6CBAF1 mice exhibit enhanced intrinsic atrial proarrhythmicity, while the abnormalities of sympathetic neurotransmitter cycling probably underlie disturbed autonomic heart control.
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Affiliation(s)
- Vlad S Kuzmin
- Lomonosov Moscow State University, Biological Faculty, Department of Human and Animal Physiology, Leninskie gory 1, building 12, 119991 Moscow, Russia; Pirogov Russian National Research Medical University (RNRMU), Ostrovitjanova 1, 117997 Moscow, Russia
| | - Viktoriia M Potekhina
- Lomonosov Moscow State University, Biological Faculty, Department of Human and Animal Physiology, Leninskie gory 1, building 12, 119991 Moscow, Russia.
| | | | - Maria A Chelombitko
- The A.N. Belozersky Institute of Physico-Chemical Biology, MSU, Moscow, Russia
| | - Artem V Fedorov
- Lomonosov Moscow State University, Biological Faculty, Department of Human and Animal Physiology, Leninskie gory 1, building 12, 119991 Moscow, Russia
| | - Olga A Averina
- The A.N. Belozersky Institute of Physico-Chemical Biology, MSU, Moscow, Russia; Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, Russia
| | - Alexey S Borodkov
- Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academу of Sciences, Moscow, Russia
| | - Anna A Shevtsova
- Lomonosov Moscow State University, Faculty of Biology, Department of Genetics, Moscow, Russia
| | - Maxim L Lovat
- Lomonosov Moscow State University, Biological Faculty, Department of Human and Animal Physiology, Leninskie gory 1, building 12, 119991 Moscow, Russia
| | - Alexey M Petrov
- Institute of Neuroscience, Kazan State Medial University, Kazan, Russia; Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center "Kazan Scientific Center of RAS", Kazan, Russia
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35
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Trum M, Islam MMT, Lebek S, Baier M, Hegner P, Eaton P, Maier LS, Wagner S. Inhibition of cardiac potassium currents by oxidation-activated protein kinase A contributes to early afterdepolarizations in the heart. Am J Physiol Heart Circ Physiol 2020; 319:H1347-H1357. [PMID: 33035439 PMCID: PMC7792712 DOI: 10.1152/ajpheart.00182.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species (ROS) have been shown to prolong cardiac action potential duration resulting in afterdepolarizations, the cellular basis of triggered arrhythmias. As previously shown, protein kinase A type I (PKA I) is readily activated by oxidation of its regulatory subunits. However, the relevance of this mechanism of activation for cardiac pathophysiology is still elusive. In this study, we investigated the effects of oxidation-activated PKA I on cardiac electrophysiology. Ventricular cardiomyocytes were isolated from redox-dead PKA-RI Cys17Ser knock-in (KI) and wild-type (WT) mice and exposed to H2O2 (200 µmol/L) or vehicle (Veh) solution. In WT myocytes, exposure to H2O2 significantly increased oxidation of the regulatory subunit I (RI) and thus its dimerization (threefold increase in PKA RI dimer). Whole cell current clamp and voltage clamp were used to measure cardiac action potentials (APs), transient outward potassium current (Ito) and inward rectifying potassium current (IK1), respectively. In WT myocytes, H2O2 exposure significantly prolonged AP duration due to significantly decreased Ito and IK1 resulting in frequent early afterdepolarizations (EADs). Preincubation with the PKA-specific inhibitor Rp-8-Br-cAMPS (10 µmol/L) completely abolished the H2O2-dependent decrease in Ito and IK1 in WT myocytes. Intriguingly, H2O2 exposure did not prolong AP duration, nor did it decrease Ito, and only slightly enhanced EAD frequency in KI myocytes. Treatment of WT and KI cardiomyocytes with the late INa inhibitor TTX (1 µmol/L) completely abolished EAD formation. Our results suggest that redox-activated PKA may be important for H2O2-dependent arrhythmias and could be important for the development of specific antiarrhythmic drugs.NEW & NOTEWORTHY Oxidation-activated PKA type I inhibits transient outward potassium current (Ito) and inward rectifying potassium current (IK1) and contributes to ROS-induced APD prolongation as well as generation of early afterdepolarizations in murine ventricular cardiomyocytes.
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Affiliation(s)
- M. Trum
- 1Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - M. M. T. Islam
- 2Department of Biochemistry and Molecular Biology, University of Dhaka, Bangladesh
- 3Department of Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - S. Lebek
- 1Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - M. Baier
- 1Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - P. Hegner
- 1Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - P. Eaton
- 4The William Harvey Research Institute, Charterhouse Square, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - L. S. Maier
- 1Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - S. Wagner
- 1Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
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36
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Lipovsky CE, Jimenez J, Guo Q, Li G, Yin T, Hicks SC, Bhatnagar S, Takahashi K, Zhang DM, Brumback BD, Goldsztejn U, Nadadur RD, Perez-Cervantez C, Moskowitz IP, Liu S, Zhang B, Rentschler SL. Chamber-specific transcriptional responses in atrial fibrillation. JCI Insight 2020; 5:135319. [PMID: 32841220 PMCID: PMC7526559 DOI: 10.1172/jci.insight.135319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 08/19/2020] [Indexed: 12/30/2022] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia, yet the molecular signature of the vulnerable atrial substrate is not well understood. Here, we delineated a distinct transcriptional signature in right versus left atrial cardiomyocytes (CMs) at baseline and identified chamber-specific gene expression changes in patients with a history of AF in the setting of end-stage heart failure (AF+HF) that are not present in heart failure alone (HF). We observed that human left atrial (LA) CMs exhibited Notch pathway activation and increased ploidy in AF+HF but not in HF alone. Transient activation of Notch signaling within adult CMs in a murine genetic model is sufficient to increase ploidy in both atrial chambers. Notch activation within LA CMs generated a transcriptomic fingerprint resembling AF, with dysregulation of transcription factor and ion channel genes, including Pitx2, Tbx5, Kcnh2, Kcnq1, and Kcnip2. Notch activation also produced distinct cellular electrophysiologic responses in LA versus right atrial CMs, prolonging the action potential duration (APD) without altering the upstroke velocity in the left atrium and reducing the maximal upstroke velocity without altering the APD in the right atrium. Our results support a shared human/murine model of increased Notch pathway activity predisposing to AF. Distinct transcriptional changes occur in human left versus right atrial cardiomyocytes in atrial fibrillation, including Notch pathway activation, which alters electric properties and ploidy in murine models.
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Affiliation(s)
- Catherine E Lipovsky
- Department of Medicine, Cardiovascular Division.,Department of Developmental Biology, and
| | | | - Qiusha Guo
- Department of Medicine, Cardiovascular Division
| | - Gang Li
- Department of Medicine, Cardiovascular Division.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Tiankai Yin
- Department of Medicine, Cardiovascular Division
| | | | - Somya Bhatnagar
- Department of Medicine, Cardiovascular Division.,Department of Developmental Biology, and
| | | | | | - Brittany D Brumback
- Department of Medicine, Cardiovascular Division.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Uri Goldsztejn
- Department of Medicine, Cardiovascular Division.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Rangarajan D Nadadur
- Departments of Pediatrics, Pathology, and Human Genetics, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA
| | - Carlos Perez-Cervantez
- Departments of Pediatrics, Pathology, and Human Genetics, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA
| | - Ivan P Moskowitz
- Departments of Pediatrics, Pathology, and Human Genetics, Biological Sciences Division, University of Chicago, Chicago, Illinois, USA
| | | | - Bo Zhang
- Department of Developmental Biology, and
| | - Stacey L Rentschler
- Department of Medicine, Cardiovascular Division.,Department of Developmental Biology, and.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
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37
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Gunawan MG, Sangha SS, Shafaattalab S, Lin E, Heims-Waldron DA, Bezzerides VJ, Laksman Z, Tibbits GF. Drug screening platform using human induced pluripotent stem cell-derived atrial cardiomyocytes and optical mapping. Stem Cells Transl Med 2020; 10:68-82. [PMID: 32927497 PMCID: PMC7780813 DOI: 10.1002/sctm.19-0440] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 07/13/2020] [Accepted: 08/03/2020] [Indexed: 12/17/2022] Open
Abstract
Current drug development efforts for the treatment of atrial fibrillation are hampered by the fact that many preclinical models have been unsuccessful in reproducing human cardiac physiology and its response to medications. In this study, we demonstrated an approach using human induced pluripotent stem cell-derived atrial and ventricular cardiomyocytes (hiPSC-aCMs and hiPSC-vCMs, respectively) coupled with a sophisticated optical mapping system for drug screening of atrial-selective compounds in vitro. We optimized differentiation of hiPSC-aCMs by modulating the WNT and retinoid signaling pathways. Characterization of the transcriptome and proteome revealed that retinoic acid pushes the differentiation process into the atrial lineage and generated hiPSC-aCMs. Functional characterization using optical mapping showed that hiPSC-aCMs have shorter action potential durations and faster Ca2+ handling dynamics compared with hiPSC-vCMs. Furthermore, pharmacological investigation of hiPSC-aCMs captured atrial-selective effects by displaying greater sensitivity to atrial-selective compounds 4-aminopyridine, AVE0118, UCL1684, and vernakalant when compared with hiPSC-vCMs. These results established that a model system incorporating hiPSC-aCMs combined with optical mapping is well-suited for preclinical drug screening of novel and targeted atrial selective compounds.
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Affiliation(s)
- Marvin G Gunawan
- Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.,Tibbits Research Team, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Sarabjit S Sangha
- Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.,Tibbits Research Team, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Sanam Shafaattalab
- Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.,Tibbits Research Team, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Eric Lin
- Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | | | - Zachary Laksman
- Division of Cardiology, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.,Centre for Heart and Lung Innovation, St. Paul's Hospital, Vancouver, British Columbia, Canada
| | - Glen F Tibbits
- Molecular Cardiac Physiology Group, Departments of Biomedical Physiology and Kinesiology and Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.,Tibbits Research Team, British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
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38
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Li X, Li Z, Wang DWW, Wang DW, Wang Y. A Novel Gain-of-Function KCND3 Variant Associated with Brugada Syndrome. Cardiology 2020; 145:623-632. [PMID: 32818936 DOI: 10.1159/000508033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 04/06/2020] [Indexed: 11/19/2022]
Abstract
Brugada syndrome (BrS) is a known cause of sudden cardiac death (SCD) characterized by abnormal electrocardiograms and fatal arrhythmias. The variants in KCND3 encoding the KV4.3 potassium-channel (the α-subunit of the Ito) have seldom been reported in BrS. This study aimed to identify novel KCND3 variants associated with BrS and elucidate BrS pathogenesis. High-depth targeted sequencing was performed and the electrophysiological properties of the variants were detected by whole-cell patch-clamp methods in a cultured-cell expressing system. The transcriptional levels of KV4.3 in different genotypes were studied by real-time PCR. Western blot was used to assess channel protein expression. A novel KCND3heterozygous variant, c.1292G>A (Arg431His, R431H), was found in the proband. Whole-cell patch-clamp results revealed a gain-of-function phenotype in the variant, with peak Ito current density increased and faster recovery from inactivation. The expression of mutant Kv4.3 membrane protein increased and the cytoplasmic protein decreased, demonstrating that the membrane/cytoplasm ratio was significantly different. In conclusion, a novel KCND3 heterozygous variant was associated with BrS. The increased Ito current explained the critical role of KCND3 in the pathogenesis of BrS. Genetic screening for KCND3 could be useful for understanding the pathogenesis of BrS and providing effective risk stratification in the clinic.
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Affiliation(s)
- Xianqing Li
- Division of Cardiology, Departments of Internal Medicine and Genetic Diagnosis Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Zongzhe Li
- Division of Cardiology, Departments of Internal Medicine and Genetic Diagnosis Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Dao Wen Wen Wang
- Division of Cardiology, Departments of Internal Medicine and Genetic Diagnosis Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Dao Wu Wang
- State Key Laboratory of Reproductive Medicine, the Center for Clinical Reproductive Medicine and Department of Cardiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yan Wang
- Division of Cardiology, Departments of Internal Medicine and Genetic Diagnosis Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, .,Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan, China,
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39
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Deng M, Jiang L, Luo X, Tao H, Liang S. Jingzhaotoxin-X, a gating modifier of Kv4.2 and Kv4.3 potassium channels purified from the venom of the Chinese tarantula Chilobrachys jingzhao. J Venom Anim Toxins Incl Trop Dis 2020; 26:e20190043. [PMID: 32536941 PMCID: PMC7269146 DOI: 10.1590/1678-9199-jvatitd-2019-0043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background The tarantula Chilobrachys jingzhao is one of the largest venomous spiders in China. In previous studies, we purified and characterized at least eight peptides from C. jingzhao venom. In this report, we describe the purification and characterization of Jingzhaotoxin-X (JZTX-X), which selectively blocks Kv4.2 and Kv4.3 potassium channels. Methods JZTX-X was purified using a combination of cation-exchange HPLC and reverse-phase HPLC. The amino-acid sequence was determined by automated Edman degradation and confirmed by mass spectrometry (MS). Voltage-gated ion channel currents were recorded in HEK293t cells transiently transfected with a variety of ion channel constructs. In addition, the hyperalgesic activity of JZTX-X and the toxin´s effect on motor function were assessed in mice. Results JZTX-X contained 31 amino acids, with six cysteine residues that formed three disulfide bonds within an inhibitory cysteine knot (ICK) topology. In whole-cell voltage-clamp experiments, JZTX-X inhibited Kv4.2 and Kv4.3 potassium channels in a concentration- and voltage-dependent manner, without affecting other ion channels (Kv1.1, 1.2, 1.3, 2.1, delayed rectifier potassium channels, high- and low-voltage-activated Ca2+ channels, and voltage-gated sodium channels Nav1.5 and 1.7). JZTX-X also shifted the voltage-dependent channel activation to more depolarized potentials, whereas extreme depolarization caused reversible toxin binding to Kv4.2 channels. JZTX-X shifted the Kv4.2 and Kv4.3 activities towards a resting state, since at the resting potential the toxin completely inhibited the channels, even in the absence of an applied physical stimulus. Intrathecal or intraplantar injection of JZTX-X caused a long-lasting decrease in the mechanical nociceptive threshold (hyperalgesia) but had no effect on motor function as assessed in the rotarod test. Conclusions JZTX-X selectively suppresses Kv4.2 and Kv4.3 potassium channel activity in a concentration- and voltage-dependent manner and causes long-lasting mechanical hyperalgesia.
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Affiliation(s)
- Meichun Deng
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Central South University, Changsha, Hunan 410013, China
| | - Liping Jiang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Xuan Luo
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
| | - Huai Tao
- Department of Biochemistry and Molecular Biology, Hunan University of Chinese Medicine, Changsha 410208, Hunan, China
| | - Songping Liang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
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40
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Abstract
This review is focusing on the understanding of various factors and components governing and controlling the occurrence of ventricular arrhythmias including (i) the role of various ion channel-related changes in the action potential (AP), (ii) electrocardiograms (ECGs), (iii) some important arrhythmogenic mediators of reperfusion, and pharmacological approaches to their attenuation. The transmembrane potential in myocardial cells is depending on the cellular concentrations of several ions including sodium, calcium, and potassium on both sides of the cell membrane and active or inactive stages of ion channels. The movements of Na+, K+, and Ca2+ via cell membranes produce various currents that provoke AP, determining the cardiac cycle and heart function. A specific channel has its own type of gate, and it is opening and closing under specific transmembrane voltage, ionic, or metabolic conditions. APs of sinoatrial (SA) node, atrioventricular (AV) node, and Purkinje cells determine the pacemaker activity (depolarization phase 4) of the heart, leading to the surface manifestation, registration, and evaluation of ECG waves in both animal models and humans. AP and ECG changes are key factors in arrhythmogenesis, and the analysis of these changes serve for the clarification of the mechanisms of antiarrhythmic drugs. The classification of antiarrhythmic drugs may be based on their electrophysiological properties emphasizing the connection between basic electrophysiological activities and antiarrhythmic properties. The review also summarizes some important mechanisms of ventricular arrhythmias in the ischemic/reperfused myocardium and permits an assessment of antiarrhythmic potential of drugs used for pharmacotherapy under experimental and clinical conditions.
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Affiliation(s)
- Arpad Tosaki
- Department of Pharmacology, School of Pharmacy, University of Debrecen, Debrecen, Hungary
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41
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Deng M, Jiang L, Luo X, Tao H, Liang S. Jingzhaotoxin-X, a gating modifier of Kv4.2 and Kv4.3 potassium channels purified from the venom of the Chinese tarantula Chilobrachys jingzhao. J Venom Anim Toxins Incl Trop Dis 2020. [DOI: 10.1590//1678-9199-jvatitd-2019-0043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
| | | | | | - Huai Tao
- Hunan University of Chinese Medicine, China
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Zhang H, Zhang H, Wang C, Wang Y, Zou R, Shi C, Guan B, Gamper N, Xu Y. Auxiliary subunits control biophysical properties and response to compound NS5806 of the Kv4 potassium channel complex. FASEB J 2019; 34:807-821. [PMID: 31914636 PMCID: PMC6972550 DOI: 10.1096/fj.201902010rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 12/19/2022]
Abstract
Kv4 pore‐forming subunits co‐assemble with β‐subunits including KChIP2 and DPP6 and the resultant complexes conduct cardiac transient outward K+ current (Ito). Compound NS5806 has been shown to potentate Ito in canine cardiomyocytes; however, its effects on Ito in other species yet to be determined. We found that NS5806 inhibited native Ito in a concentration‐dependent manner (0.1~30 μM) in both mouse ventricular cardiomyocytes and human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs), but potentiated Ito in the canine cardiomyocytes. In HEK293 cells co‐transfected with cloned Kv4.3 (or Kv4.2) and β‐subunit KChIP2, NS5806 significantly increased the peak current amplitude and slowed the inactivation. In contrast, NS5806 suppressed the current and accelerated inactivation of the channels when cells were co‐transfected with Kv4.3 (or Kv4.2), KChIP2 and another β‐subunit, DPP6‐L (long isoform). Western blot analysis showed that DPP6‐L was dominantly expressed in both mouse ventricular myocardium and hiPSC‐CMs, while it was almost undetectable in canine ventricular myocardium. In addition, low level of DPP6‐S expression was found in canine heart, whereas levels of KChIP2 expression were comparable among all three species. siRNA knockdown of DPP6 antagonized the Ito inhibition by NS5806 in hiPSC‐CMs. Molecular docking simulation suggested that DPP6‐L may associate with KChIP2 subunits. Mutations of putative KChIP2‐interacting residues of DPP6‐L reversed the inhibitory effect of NS5806 into potentiation of the current. We conclude that a pharmacological modulator can elicit opposite regulatory effects on Kv4 channel complex among different species, depending on the presence of distinct β‐subunits. These findings provide novel insight into the molecular design and regulation of cardiac Ito. Since Ito is a potential therapeutic target for treatment of multiple cardiovascular diseases, our data will facilitate the development of new therapeutic Ito modulators.
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Affiliation(s)
- Hongxue Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Hua Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Chanjuan Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Yuhong Wang
- Institute of Masteria Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ruya Zou
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Chenxia Shi
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Bingcai Guan
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Nikita Gamper
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Yanfang Xu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
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Potekhina VM, Averina OA, Razumov AA, Kuzmin VS, Rozenshtraukh LV. The local repolarization heterogeneity in the murine pulmonary veins myocardium contributes to the spatial distribution of the adrenergically induced ectopic foci. J Physiol Sci 2019; 69:1041-1055. [PMID: 31724110 PMCID: PMC10717041 DOI: 10.1007/s12576-019-00724-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 10/23/2019] [Indexed: 12/11/2022]
Abstract
An atrial tachyarrhythmias is predominantly triggered by a proarrhythmic activity originate from the pulmonary veins (PV) myocardial sleeves; sympathetic or adrenergic stimulation facilitates PV proarrhythmia. In the present study the electrophysiological inhomogeneity, spatiotemporal characteristics of the adrenergically induced ectopic firing and sympathetic nerves distribution have been investigated in a murine PV myocardium to clarify mechanisms of adrenergic PV ectopy. Electrically paced murine PV demonstrate atrial-like pattern of conduction and atrial-like action potentials (AP) with longest duration in the mouth of PV. The application of norepinephrine (NE), agonists of α- and β-adrenergic receptors (ARs) or intracardiac nerves stimulation induced spontaneous AP in a form of periodical bursts or continuous firing. NE- or ARs agonists-induced SAP originated from unifocal ectopic foci with predominant localization in the region surrounding PV mouth, but not in the distal portions of a murine PV myocardium. A higher level of catecholamine content and catecholamine fiber network density was revealed in the PV myocardial sleeves relative to LA appendage. However, no significant local variation of catecholamine content and fiber density was observed in the murine PV. In conclusion, PV mouth region appear to be a most susceptible to adrenergic proarrhythmia in mice. Intrinsic spatial heterogeneity of AP duration can be considered as a factor influencing localization of the ectopic foci in PV.
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Affiliation(s)
- V M Potekhina
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, 1-12 Leninskie Gory, 119234, Moscow, Russia.
| | - O A Averina
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, Russia
| | - A A Razumov
- Institute of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg, Russia
| | - V S Kuzmin
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, 1-12 Leninskie Gory, 119234, Moscow, Russia
- Pirogov Russian National Research Medical University (RNRMU), Moscow, Russia
| | - L V Rozenshtraukh
- Institute of Experimental Cardiology, National Medicine Research Cardiological Complex, Moscow, Russia
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Ji CC, Yao FJ, Cheng YJ, Yao H, Fan J, Chen XM, Zheng ZH, Dong YG, Wu SH. A novel DPP6 variant in Chinese families causes early repolarization syndrome. Exp Cell Res 2019; 384:111561. [PMID: 31476289 DOI: 10.1016/j.yexcr.2019.111561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/15/2019] [Accepted: 08/17/2019] [Indexed: 11/15/2022]
Abstract
Previous studies demonstrated that variants in dipeptidyl aminopeptidase-like protein-6 (DPP6) are involved in idiopathic ventricular fibrillation. However, its role in early repolarization syndrome (ERS) remains largely elusive. The aim of this study is to determine whether the novel DPP6-L747P variant is associated with ERS, and explore the underlying mechanisms. In our study, whole genome sequencing was used to identify a genetic variant in 4 Chinese families with sudden cardiac arrest induced by ERS. Then, wild-type (WT) DPP6 or mutant (c.2240T > C/p.L747P) DPP6 were respectively expressed in HEK293 cells, co-expressed with KV4.3 and KChIP2. Western blotting, immunofluorescence, and whole-cell patch clamp experiments were performed to reveal possible underlying mechanisms. A novel missense variant (c.2240T > C/p.L747P) in DPP6 was identified in the 4 families. Both DPP6-WT and DPP6-L747P were mainly located on the cell membrane. Compared with DPP6-WT, the intensity of DPP6 protein bands was downregulated in DPP6-L747P. Functional experiments showed that macroscopic currents exhibited an increase in DPP6-L747P, and the current intensity of DPP6-L747P was increased more than that of DPP6-WT (63.1 ± 8.2 pA/pF vs.86.5 ± 15.1 pA/pF at +50 mV, P < 0.05). Compared with DPP6-WT, the slope of the activation curve of DPP6-L747P was slightly decreased (15.49 ± 0.56 mV vs. 13.88 ± 0.54 mV, P < 0.05), the slope of the inactivation curve was increased (13.65 ± 1.57 mV, vs. 24.44 ± 2.79 mV, P < 0.05) and the recovery time constant was significantly reduced (216.81 ± 18.59 ms vs. 102.11 ± 32.03 ms, P < 0.05). In conclusion, we identified a novel missense variant (c.2240T > C/p. L747P) in DPP6 in 4 Chinese families with sudden cardiac arrest induced by ERS. Patch clamp experiments revealed that this variant could generate a gain of function of Ito and affect the potassium current. These results demonstrated that changes caused by the variant may be the underlying mechanisms of malignant arrhythmias in the individuals with ERS.
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Affiliation(s)
- Cheng-Cheng Ji
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Feng-Juan Yao
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Yun-Jiu Cheng
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Hao Yao
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Jun Fan
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Xu-Miao Chen
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Zi-Heng Zheng
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China
| | - Yu-Gang Dong
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China.
| | - Su-Hua Wu
- Department of Cardiology and Department of Medical Ultrasonics (Feng-Juan, Yao), the First Affiliated Hospital, Sun Yat-Sen University, and Key Laboratory of Assisted Circulation, NHC, Guangzhou, China.
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Martínez-Milla J, Raposeiras-Roubín S, Pascual-Figal DA, Ibáñez B. Papel de los bloqueadores beta en la enfermedad cardiovascular en 2019. Rev Esp Cardiol 2019. [DOI: 10.1016/j.recesp.2019.02.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Garg P, Garg V, Shrestha R, Sanguinetti MC, Kamp TJ, Wu JC. Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes as Models for Cardiac Channelopathies: A Primer for Non-Electrophysiologists. Circ Res 2019; 123:224-243. [PMID: 29976690 DOI: 10.1161/circresaha.118.311209] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Life threatening ventricular arrhythmias leading to sudden cardiac death are a major cause of morbidity and mortality. In the absence of structural heart disease, these arrhythmias, especially in the younger population, are often an outcome of genetic defects in specialized membrane proteins called ion channels. In the heart, exceptionally well-orchestrated activity of a diversity of ion channels mediates the cardiac action potential. Alterations in either the function or expression of these channels can disrupt the configuration of the action potential, leading to abnormal electrical activity of the heart that can sometimes initiate an arrhythmia. Understanding the pathophysiology of inherited arrhythmias can be challenging because of the complexity of the disorder and lack of appropriate cellular and in vivo models. Recent advances in human induced pluripotent stem cell technology have provided remarkable progress in comprehending the underlying mechanisms of ion channel disorders or channelopathies by modeling these complex arrhythmia syndromes in vitro in a dish. To fully realize the potential of induced pluripotent stem cells in elucidating the mechanistic basis and complex pathophysiology of channelopathies, it is crucial to have a basic knowledge of cardiac myocyte electrophysiology. In this review, we will discuss the role of the various ion channels in cardiac electrophysiology and the molecular and cellular mechanisms of arrhythmias, highlighting the promise of human induced pluripotent stem cell-cardiomyocytes as a model for investigating inherited arrhythmia syndromes and testing antiarrhythmic strategies. Overall, this review aims to provide a basic understanding of the electrical activity of the heart and related channelopathies, especially to clinicians or research scientists in the cardiovascular field with limited electrophysiology background.
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Affiliation(s)
- Priyanka Garg
- From the Stanford Cardiovascular Institute (P.G., R.S., J.C.W.).,Department of Medicine, Division of Cardiology (P.G., R.S., J.C.W.).,Institute for Stem Cell Biology and Regenerative Medicine (P.G., R.S., J.C.W.)
| | - Vivek Garg
- Stanford University School of Medicine, CA; Department of Physiology, University of California San Francisco (V.G.)
| | - Rajani Shrestha
- From the Stanford Cardiovascular Institute (P.G., R.S., J.C.W.).,Department of Medicine, Division of Cardiology (P.G., R.S., J.C.W.).,Institute for Stem Cell Biology and Regenerative Medicine (P.G., R.S., J.C.W.)
| | | | - Timothy J Kamp
- Department of Medicine, University of Wisconsin-Madison (T.J.K.)
| | - Joseph C Wu
- From the Stanford Cardiovascular Institute (P.G., R.S., J.C.W.) .,Department of Medicine, Division of Cardiology (P.G., R.S., J.C.W.).,Institute for Stem Cell Biology and Regenerative Medicine (P.G., R.S., J.C.W.)
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Drabkin M, Zilberberg N, Menahem S, Mulla W, Halperin D, Yogev Y, Wormser O, Perez Y, Kadir R, Etzion Y, Katz A, Birk OS. Nocturnal Atrial Fibrillation Caused by Mutation in KCND2, Encoding Pore-Forming (α) Subunit of the Cardiac Kv4.2 Potassium Channel. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 11:e002293. [PMID: 30571183 DOI: 10.1161/circgen.118.002293] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Paroxysmal atrial fibrillation (AF) can be caused by gain-of-function mutations in genes, encoding the cardiac potassium channel subunits KCNJ2, KCNE1, and KCNH2 that mediate the repolarizing potassium currents Ik1, Iks, and Ikr, respectively. METHODS Linkage analysis, whole-exome sequencing, and Xenopus oocyte electrophysiology studies were used in this study. RESULTS Through genetic studies, we showed that autosomal dominant early-onset nocturnal paroxysmal AF is caused by p.S447R mutation in KCND2, encoding the pore-forming (α) subunit of the Kv4.2 cardiac potassium channel. Kv4.2, along with Kv4.3, contributes to the cardiac fast transient outward K+ current, Ito. Ito underlies the early phase of repolarization in the cardiac action potential, thereby setting the initial potential of the plateau phase and governing its duration and amplitude. In Xenopus oocytes, the mutation increased the channel's inactivation time constant and affected its regulation: p.S447 resides in a protein kinase C (PKC) phosphorylation site, which normally allows attenuation of Kv4.2 membrane expression. The mutant Kv4.2 exhibited impaired response to PKC; hence, Kv4.2 membrane expression was augmented, enhancing potassium currents. Coexpression of mutant and wild-type channels (recapitulating heterozygosity in affected individuals) showed results similar to the mutant channel alone. Finally, in a hybrid channel composed of Kv4.3 and Kv4.2, simulating the mature endogenous heterotetrameric channel underlying Ito, the p.S447R Kv4.2 mutation exerted a gain-of-function effect on Kv4.3. CONCLUSIONS The mutation alters Kv4.2's kinetic properties, impairs its inhibitory regulation, and exerts gain-of-function effect on both Kv4.2 homotetramers and Kv4.2-Kv4.3 heterotetramers. These effects presumably increase the repolarizing potassium current Ito, thereby abbreviating action potential duration, creating arrhythmogenic substrate for nocturnal AF. Interestingly, Kv4.2 expression was previously shown to demonstrate circadian variation, with peak expression at daytime in murine hearts (human nighttime), with possible relevance to the nocturnal onset of paroxysmal AF symptoms in our patients. The atrial-specific phenotype suggests that targeting Kv4.2 might be effective in the treatment of nocturnal paroxysmal AF, avoiding adverse ventricular effects.
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Affiliation(s)
- Max Drabkin
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.)
| | - Noam Zilberberg
- Department of Life Sciences and Zlotowski Center for Neuroscience, Ben-Gurion University, Beer-Sheva, Israel (N.Z.)
| | - Sasson Menahem
- Department of Family Medicine, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (S.M.)
| | - Wesam Mulla
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.).,Regenerative Medicine and Stem Cell Research Center and Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (W.M., Y.E.)
| | - Daniel Halperin
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.)
| | - Yuval Yogev
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.)
| | - Ohad Wormser
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.)
| | - Yonatan Perez
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.)
| | - Rotem Kadir
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.)
| | - Yoram Etzion
- Regenerative Medicine and Stem Cell Research Center and Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (W.M., Y.E.)
| | - Amos Katz
- Department of Cardiology, Barzilai University Medical Center, Ashkelon, Israel (A.K.).,affiliated to the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (A.K., O.S.B.)
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (M.D., W.M., D.H., Y.Y., O.W., Y.P., R.K., O.S.B.).,The Genetics Institute, Soroka University Medical Center, Beer-Sheva, Israel (O.S.B.).,affiliated to the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. (A.K., O.S.B.)
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Ohya S, Ito K, Hatano N, Ohno A, Muraki K, Imaizumi Y. Castration Induces Down-Regulation of A-Type K + Channel in Rat Vas Deferens Smooth Muscle. Int J Mol Sci 2019; 20:ijms20174073. [PMID: 31438481 PMCID: PMC6747096 DOI: 10.3390/ijms20174073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/03/2019] [Accepted: 08/19/2019] [Indexed: 01/20/2023] Open
Abstract
A-type K+ channels contribute to regulating the propagation and frequency of action potentials in smooth muscle cells (SMCs). The present study (i) identified the molecular components of A-type K+ channels in rat vas deferens SMs (VDSMs) and (ii) showed the long-term, genomic effects of testosterone on their expression in VDSMs. Transcripts of the A-type K+ channel α subunit, Kv4.3L and its regulatory β subunits, KChIP3, NCS1, and DPP6-S were predominantly expressed in rat VDSMs over the other related subtypes (Kv4.2, KChIP1, KChIP2, KChIP4, and DPP10). A-type K+ current (IA) density in VDSM cells (VDSMCs) was decreased by castration without changes in IA kinetics, and decreased IA density was compensated for by an oral treatment with 17α-methyltestosterone (MET). Correspondingly, in the VDSMs of castrated rats, Kv4.3L and KChIP3 were down-regulated at both the transcript and protein expression levels. Changes in Kv4.3L and KChIP3 expression levels were compensated for by the treatment with MET. These results suggest that testosterone level changes in testosterone disorders and growth processes control the functional expression of A-type K+ channels in VDSMCs.
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Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan.
| | - Katsunori Ito
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmacological Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Noriyuki Hatano
- Laboratory of Cellular Pharmacology, Aichi Gakuin University, Nagoya 464-8650, Japan
| | - Akitoshi Ohno
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmacological Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, Aichi Gakuin University, Nagoya 464-8650, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmacological Sciences, Nagoya City University, Nagoya 467-8603, Japan.
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Martínez-Milla J, Raposeiras-Roubín S, Pascual-Figal DA, Ibáñez B. Role of Beta-blockers in Cardiovascular Disease in 2019. ACTA ACUST UNITED AC 2019; 72:844-852. [PMID: 31402328 DOI: 10.1016/j.rec.2019.04.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/24/2019] [Indexed: 11/17/2022]
Abstract
Beta-blockers are the cornerstone of treatment for various cardiovascular conditions. Although their effects have classically been considered to be driven by their antagonistic and competitive action on beta-adrenergic receptors, nowadays it is known that their effect goes beyond that of mere competition with catecholamines on these receptors. Beta-blockers were discovered as antianginal drugs in the 1960s and are currently widely used in heart failure, arrhythmias, and ischemic heart disease. In this article, we review the evidence for the beneficial effects of beta-blockers in these conditions, as well as the current recommendations in clinical practice guidelines for their use. Surprisingly, despite having been prescribed for more than 4 decades, new, previously unnoticed mechanisms of action on cellular compartments are still being discovered, which continues to open up new horizons for their use. All in all, beta-blockers are one of the most fascinating drug groups in our therapeutic armamentarium.
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Affiliation(s)
- Juan Martínez-Milla
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Servicio de Cardiología, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz (IIS-FJD), Madrid, Spain
| | | | - Domingo A Pascual-Figal
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Servicio de Cardiología, Hospital Clínico Universitario Virgen de la Arrixaca, Instituto Murciano de Investigación Biosanitaria (IMIB-Arrixaca), Universidad de Murcia, El Palmar, Murcia, Spain; Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Borja Ibáñez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain; Servicio de Cardiología, Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz (IIS-FJD), Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.
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50
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El-Abassi R, Soliman MY, Villemarette-Pittman N, England JD. SPS: Understanding the complexity. J Neurol Sci 2019; 404:137-149. [PMID: 31377632 DOI: 10.1016/j.jns.2019.06.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 05/31/2019] [Accepted: 06/17/2019] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Stiff-person syndrome (SPS), first described in 1956 by Moersch and Woltman, is a progressive autoimmune disorder with core features of chronic fluctuating progressive truncal and limb rigidity and painful muscle spasms leading to gait difficulties, falls and an appearance that resembles tin soldiers. The syndrome is a rare, highly disabling disorder of the central nervous and frequently results in significant disability. Understanding of the etiology, clinical spectrum, diagnostic workup and therapeutic modalities for this painful and disabling disorder has vastly evolved over the past few years with more confidence in classifying and treating the patients. The purpose of this review is to increase the awareness, early detection, and treatment of this disabling disease. METHOD PubMed was searched, all date inclusive, using the following phrases: stiff person syndrome,anti-Glutamic acid decarboxylase (Anti-GAD) antibody syndrome, Progressive encephalomyelitis with rigidity and myoclonus (PERM), and Paraneoplastic Stiff Person syndrome. No filters or restrictions were used. A total of 888 articles were identified. RESULTS The results were narrowed to 190 citations after excluding non-English and duplicate reports. Clinical presentation, laboratory testing, treatment, and prognosis were categorized and summarized. DISCUSSION In this article we will discuss the epidemiology, presentation and classification. Explain the pathophysiology of SPS and the autoimmune mechanisms involved. Discuss the diagnostic approach and treatments available, as well as, the prognosis and outcome.
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Affiliation(s)
- Rima El-Abassi
- Department of Neurology, Louisiana State University School of medicine, New Orleans, USA.
| | - Michael Y Soliman
- Department of Neurology, Louisiana State University School of medicine, New Orleans, USA
| | | | - John D England
- Department of Neurology, Louisiana State University School of medicine, New Orleans, USA
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