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Katsaras D, Sanjeev Kumar BT, Patel B, Chalil S, Abozguia K. A 59-Year-Old Woman with Familial Brugada Syndrome and the c.664C>T Variant of the Sodium Voltage-Gated Channel Alpha Subunit 5 (SCN5A) Gene, Accompanied by Congenital Absence of the Right Coronary Artery, Patent Foramen Ovale, and Ischemic Stroke. AMERICAN JOURNAL OF CASE REPORTS 2021; 22:e931535. [PMID: 34446689 PMCID: PMC8409454 DOI: 10.12659/ajcr.931535] [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] [Indexed: 11/20/2022]
Abstract
Patient: Female, 59-year-old
Final Diagnosis: Absence of right coronary artery • patent foramen ovale • positive for Brugada-related gene variant
Symptoms: Angina
Medication:—
Clinical Procedure: —
Specialty: Cardiology
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Affiliation(s)
- Dimitrios Katsaras
- Department of Cardiology, Lancashire Cardiac Centre, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, United Kingdom
| | | | - Billal Patel
- Department of Cardiology, Lancashire Cardiac Centre, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, United Kingdom
| | - Shajil Chalil
- Department of Cardiology, Lancashire Cardiac Centre, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, United Kingdom
| | - Khalid Abozguia
- Department of Cardiology, Lancashire Cardiac Centre, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, United Kingdom
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52
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Yin J, Zhou J, Chen J, Xu T, Zhang Z, Zhang H, Yuan C, Cheng X, Qin Y, Zheng B, Wang C, Yang S, Jia Z. Case Report: A Novel Variant c.2262+3A>T of the SCN5A Gene Results in Intron Retention Associated With Incessant Ventricular Tachycardias. Front Med (Lausanne) 2021; 8:659119. [PMID: 34422849 PMCID: PMC8371685 DOI: 10.3389/fmed.2021.659119] [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: 01/27/2021] [Accepted: 06/30/2021] [Indexed: 11/18/2022] Open
Abstract
Objective: Voltage-gated sodium channel Nav1.5 encoded by the SCN5A gene plays crucial roles in cardiac electrophysiology. Previous genetic studies have shown that mutations in SCN5A are associated with multiple inherited cardiac arrhythmias. Here, we investigated the molecular defect in a Chinese boy with clinical manifestations of arrhythmias. Methods: Gene variations were screened using whole-exome sequencing and validated by direct Sanger sequencing. A minigene assay and reverse transcription PCR (RT-PCR) were performed to confirm the effects of splice variants in vitro. Western blot analysis was carried out to determine whether the c.2262+3A>T variant produced a truncated protein. Results: By genetic analysis, we identified a novel splice variant c.2262+3A>T in SCN5A gene in a Chinese boy with incessant ventricular tachycardias (VT). This variant was predicted to activate a new cryptic splice donor site and was identified by in silico analysis. The variant retained 79 bp at the 5′ end of intron 14 in the mature mRNA. Furthermore, the mutant transcript that created a premature stop codon at 818 amino acids [p.(R818*)] could be produced as a truncated protein. Conclusion: We verified the pathogenic effect of splicing variant c.2262+3A>T, which disturbed the normal mRNA splicing and caused a truncated protein, suggesting that splice variants play an important role in the molecular basis of early onset incessant ventricular tachycardias, and careful molecular profiling of these patients will be essential for future effective personalized treatment options.
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Affiliation(s)
- Jie Yin
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jia Zhou
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jinlong Chen
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Ting Xu
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhongman Zhang
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Han Zhang
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Chang Yuan
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xueying Cheng
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Yuming Qin
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Bixia Zheng
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Chunli Wang
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Shiwei Yang
- Department of Cardiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Zhanjun Jia
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, Nanjing, China
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53
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Elfatih A, Mifsud B, Syed N, Badii R, Mbarek H, Abbaszadeh F, Estivill X. Actionable genomic variants in 6045 participants from the Qatar Genome Program. Hum Mutat 2021; 42:1584-1601. [PMID: 34428338 DOI: 10.1002/humu.24278] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 01/26/2023]
Abstract
In a clinical setting, DNA sequencing can uncover findings unrelated to the purpose of genetic evaluation. The American College of Medical Genetics and Genomics (ACMG) recommends the evaluation and reporting of 59 genes from clinic genomic sequencing. While the prevalence of secondary findings is available from large population studies, these data lack Arab and other Middle Eastern populations. The Qatar Genome Program (QGP) generates whole-genome sequencing (WGS) data and combines it with phenotypic information to create a comprehensive database for studying the Qatari and wider Arab and Middle Eastern populations at the molecular level. This study identified and analyzed medically actionable variants in the 59 ACMG genes using WGS data from 6045 QGP participants. Our results identified a total of 60 pathogenic and likely pathogenic variants in 25 ACMG genes in 141 unique individuals. Overall, 2.3% of the QGP sequenced participants carried a pathogenic or likely pathogenic variant in one of the 59 ACMG genes. We evaluated the QGP phenotype-genotype association of additional nonpathogenic ACMG variants. These variants were found in patients from the Hamad Medical Corporation or reported incidental findings data in Qatar. We found a significant phenotype association for two variants, c.313+3A>C in LDLR, and c.58C>T (p.Gln20*) in the TPM1.
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Affiliation(s)
- Amal Elfatih
- Genomics and Precision Medicine, College of Health and Life Science, Hamad Bin Khalifa University, Doha, Qatar
| | - Borbala Mifsud
- Genomics and Precision Medicine, College of Health and Life Science, Hamad Bin Khalifa University, Doha, Qatar
- William Harvey Research Institute, Queen Mary University London, London, UK
| | - Najeeb Syed
- Applied Bioinformatics Core, Integrated Genomics Services, Research Branch, Sidra Medicine, Doha, Qatar
| | - Ramin Badii
- Molecular Genetics Laboratory, Hamad Medical Corporation, Doha, Qatar
| | - Hamdi Mbarek
- Qatar Genome Program, Qatar Foundation Research, Development and Innovation, Qatar Foundation, Doha, Qatar
| | | | - Xavier Estivill
- Research Department, T'havia Quantitative Genomics Laboratories (qGenomics), Barcelona, Spain
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Giri P, Mukhopadhyay A, Gupta M, Mohapatra B. Dilated cardiomyopathy: a new insight into the rare but common cause of heart failure. Heart Fail Rev 2021; 27:431-454. [PMID: 34245424 DOI: 10.1007/s10741-021-10125-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/25/2021] [Indexed: 12/26/2022]
Abstract
Heart failure is a global health burden responsible for high morbidity and mortality with a prevalence of greater than 60 million individuals worldwide. One of the major causes of heart failure is dilated cardiomyopathy (DCM), characterized by associated systolic dysfunction. During the last few decades, there have been remarkable advances in our understanding about the genetics of dilated cardiomyopathy. The genetic causes were initially thought to be associated with mutations in genes encoding proteins that are localized to cytoskeleton and sarcomere only; however, with the advancement in mechanistic understanding, the roles of ion channels, Z-disc, mitochondria, nuclear proteins, cardiac transcription factors (e.g., NKX-2.5, TBX20, GATA4), and the factors involved in calcium homeostasis have also been identified and found to be implicated in both familial and sporadic DCM cases. During past few years, next-generation sequencing (NGS) has been established as a diagnostic tool for genetic analysis and it has added significantly to the existing candidate gene list for DCM. The animal models have also provided novel insights to develop a better treatment strategy based on phenotype-genotype correlation, epigenetic and phenomic profiling. Most of the DCM biomarkers that are used in routine genetic and clinical testing are structural proteins, but during the last few years, the role of mi-RNA has also emerged as a biomarker due to their accessibility through noninvasive methods. Our increasing genetic knowledge can improve the clinical management of DCM by bringing clinicians and geneticists on one platform, thereby influencing the individualized clinical decision making and leading to precision medicine.
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Affiliation(s)
- Prerna Giri
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Uttar Pradesh, Varanasi-5, India
| | - Amrita Mukhopadhyay
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Uttar Pradesh, Varanasi-5, India
| | - Mohini Gupta
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Uttar Pradesh, Varanasi-5, India
| | - Bhagyalaxmi Mohapatra
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Uttar Pradesh, Varanasi-5, India.
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55
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Decroocq M, Rousselet L, Riant M, Norberciak L, Viart G, Guyomar Y, Graux P, Maréchaux S, Germain M, Menet A. Periprocedural, early, and long-term risks of pacemaker implantation after atrioventricular nodal re-entry tachycardia ablation: a French nationwide cohort. Europace 2021; 22:1526-1536. [PMID: 32785702 DOI: 10.1093/europace/euaa151] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/13/2020] [Indexed: 01/22/2023] Open
Abstract
AIMS Pacemaker implantation (PI) after atrioventricular nodal re-entry tachycardia (AVNRT) ablation is a dreadful complication. We aimed to assess periprocedural, early, and late risks for PI. METHODS AND RESULTS All 27 022 patients who underwent latest AVNRT ablation in France from 2009 to 2017, were identified in the nationwide medicalization database. A control group of 305 152 patients hospitalized for arm, leg, or skin injuries with no history of AVNRT or supraventricular tachycardia were selected. After propensity score matching, both groups had mean age of 53 ± 18 years and were predominantly female (64%). During this 9-year period, 822 of 27 022 (3.0%) AVNRT patients underwent PI, with significant higher risk in propensity-matched AVNRT patients compared to propensity-matched controls [2.9% vs. 0.9%; hazard ratio 3.4 (2.9-3.9), P < 0.0001]. This excess risk was significant during all follow-up, including periprocedural (1st month), early (1-6 months), and late (>6 months) risk periods. Annualized late risk per 100 AVNRT patients was 0.2%. In comparison to controls, excess risk was 0.2% in <30-year-old AVNRT patients; 0.7% in 30-50-year-old; 1.1% in 50-70-year-old and 6.5% over 70-year-olds. Risk for PI was also significantly different according to three procedural factors: centres, experience, and ablation date, with a 30% decrease since 2015. CONCLUSION Periprocedural, early, and late risks for PI were higher after AVNRT ablation compared to propensity-matched controls. Longer follow-up is needed as the excess risk seems to persist late after AVNRT ablation.
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Affiliation(s)
- Marie Decroocq
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Cardiologie, Université Catholique de Lille, F-59000 Lille, France
| | - Louis Rousselet
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département d'Information Médicale, Université Catholique de Lille, F-59000 Lille, France
| | - Margaux Riant
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Recherche Médicale, Université Catholique de Lille, F-59000 Lille, France
| | - Laurène Norberciak
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Recherche Médicale, Université Catholique de Lille, F-59000 Lille, France
| | - Guillaume Viart
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Cardiologie, Université Catholique de Lille, F-59000 Lille, France
| | - Yves Guyomar
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Cardiologie, Université Catholique de Lille, F-59000 Lille, France
| | - Pierre Graux
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Cardiologie, Université Catholique de Lille, F-59000 Lille, France
| | - Sylvestre Maréchaux
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Cardiologie, Université Catholique de Lille, F-59000 Lille, France
| | - Marysa Germain
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département d'Information Médicale, Université Catholique de Lille, F-59000 Lille, France
| | - Aymeric Menet
- GCS-Groupement des hôpitaux de l'institut Catholique de Lille/Faculté Libre de Médecine, Département de Cardiologie, Université Catholique de Lille, F-59000 Lille, France
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56
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Lopes‐Marques M, Pacheco AR, Peixoto MJ, Cardoso AR, Serrano C, Amorim A, Prata MJ, Cooper DN, Azevedo L. Common polymorphic OTC variants can act as genetic modifiers of enzymatic activity. Hum Mutat 2021; 42:978-989. [PMID: 34015158 PMCID: PMC8362079 DOI: 10.1002/humu.24221] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 05/05/2021] [Accepted: 05/18/2021] [Indexed: 12/24/2022]
Abstract
Understanding the role of common polymorphisms in modulating the clinical phenotype when they co‐occur with a disease‐causing lesion is of critical importance in medical genetics. We explored the impact of apparently neutral common polymorphisms, using the gene encoding the urea cycle enzyme, ornithine transcarbamylase (OTC), as a model system. Distinct combinations of genetic backgrounds embracing two missense polymorphisms were created in cis with the pathogenic p.Arg40His replacement. In vitro enzymatic assays revealed that the polymorphic variants were able to modulate OTC activity both in the presence or absence of the pathogenic lesion. First, we found that the combination of the minor alleles of polymorphisms p.Lys46Arg and p.Gln270Arg significantly enhanced enzymatic activity in the wild‐type protein. Second, enzymatic assays revealed that the minor allele of the p.Gln270Arg polymorphism was capable of ameliorating OTC activity when combined in cis with the pathogenic p.Arg40His replacement. Structural analysis predicted that the minor allele of the p.Gln270Arg polymorphism would serve to stabilize the OTC wild‐type protein, thereby corroborating the results of the experimental assays. Our findings demonstrate the potential importance of cis‐interactions between common polymorphic variants and pathogenic missense mutations and illustrate how standing genetic variation can modulate protein function.
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Affiliation(s)
- Mónica Lopes‐Marques
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
- Faculty of Sciences, Department of BiologyUniversity of PortoPortoPortugal
| | - Ana Rita Pacheco
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
| | - Maria João Peixoto
- ICVS‐ Life and Health Sciences Research Institute, School of MedicineUniversity of MinhoBragaPortugal
- ICVS/3B's‐PT Government Associate LaboratoryBragaGuimarãesPortugal
| | - Ana Rita Cardoso
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
- Faculty of Sciences, Department of BiologyUniversity of PortoPortoPortugal
| | - Catarina Serrano
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
- Faculty of Sciences, Department of BiologyUniversity of PortoPortoPortugal
| | - António Amorim
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
- Faculty of Sciences, Department of BiologyUniversity of PortoPortoPortugal
| | - Maria João Prata
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
- Faculty of Sciences, Department of BiologyUniversity of PortoPortoPortugal
| | - David N. Cooper
- Institute of Medical Genetics; School of MedicineCardiff UniversityCardiffUK
| | - Luísa Azevedo
- i3S‐Instituto de Investigação e Inovação em Saúde, Population Genetics and Evolution GroupUniversidade do PortoPortoPortugal
- IPATIMUP‐Institute of Molecular Pathology and Immunology, Population Genetics and Evolution GroupUniversity of PortoPortoPortugal
- Faculty of Sciences, Department of BiologyUniversity of PortoPortoPortugal
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Deng Y, Yang Q, Yang Y, Li Y, Peng H, Wu S, Zhang S, Yao B, Li S, Gao Y, Li X, Li L, Deng Y. Conditional knockout of Tsc1 in RORγt-expressing cells induces brain damage and early death in mice. J Neuroinflammation 2021; 18:107. [PMID: 33957945 PMCID: PMC8101034 DOI: 10.1186/s12974-021-02153-8] [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: 01/15/2021] [Accepted: 04/15/2021] [Indexed: 11/23/2022] Open
Abstract
Background Tuberous sclerosis complex 1 (Tsc1) is known to regulate the development and function of various cell types, and RORγt is a critical transcription factor in the immune system. However, whether Tsc1 participates in regulating RORγt-expressing cells remains unknown. Methods We generated a mouse model in which Tsc1 was conditionally deleted from RORγt-expressing cells (Tsc1RORγt) to study the role of RORγt-expressing cells with Tsc1 deficiency in brain homeostasis. Results Type 3 innate lymphoid cells (ILC3s) in Tsc1RORγt mice displayed normal development and function, and the mice showed normal Th17 cell differentiation. However, Tsc1RORγt mice exhibited spontaneous tonic-clonic seizures and died between 4 and 6 weeks after birth. At the age of 4 weeks, mice in which Tsc1 was specifically knocked out in RORγt-expressing cells had cortical neuron defects and hippocampal structural abnormalities. Notably, over-activation of neurons and astrogliosis were observed in the cortex and hippocampus of Tsc1RORγt mice. Moreover, expression of the γ-amino butyric acid (GABA) receptor in the brains of Tsc1RORγt mice was decreased, and GABA supplementation prolonged the lifespan of the mice to some extent. Further experiments revealed the presence of a group of rare RORγt-expressing cells with high metabolic activity in the mouse brain. Conclusions Our study verifies the critical role of previously unnoticed RORγt-expressing cells in the brain and demonstrates that the Tsc1 signaling pathway in RORγt-expressing cells is important for maintaining brain homeostasis. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02153-8.
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Affiliation(s)
- Yafei Deng
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Qinglan Yang
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Yao Yang
- Institute of Materia Medica, College of Pharmacy, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Yana Li
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Hongyan Peng
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Shuting Wu
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Shuju Zhang
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Baige Yao
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, 410000, China
| | - Shuhui Li
- Department of Clinical Biochemistry, Faculty of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Yuan Gao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Xiaohui Li
- Institute of Materia Medica, College of Pharmacy, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
| | - Liping Li
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China.
| | - Youcai Deng
- Institute of Materia Medica, College of Pharmacy, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
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Re-evaluation of single nucleotide variants and identification of structural variants in a cohort of 45 sudden unexplained death cases. Int J Legal Med 2021; 135:1341-1349. [PMID: 33895855 PMCID: PMC8205883 DOI: 10.1007/s00414-021-02580-5] [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: 01/02/2021] [Accepted: 03/16/2021] [Indexed: 12/30/2022]
Abstract
Sudden unexplained death (SUD) takes up a considerable part in overall sudden death cases, especially in adolescents and young adults. During the past decade, many channelopathy- and cardiomyopathy-associated single nucleotide variants (SNVs) have been identified in SUD studies by means of postmortem molecular autopsy, yet the number of cases that remain inconclusive is still high. Recent studies had suggested that structural variants (SVs) might play an important role in SUD, but there is no consensus on the impact of SVs on inherited cardiac diseases. In this study, we searched for potentially pathogenic SVs in 244 genes associated with cardiac diseases. Whole-exome sequencing and appropriate data analysis were performed in 45 SUD cases. Re-analysis of the exome data according to the current ACMG guidelines identified 14 pathogenic or likely pathogenic variants in 10 (22.2%) out of the 45 SUD cases, whereof 2 (4.4%) individuals had variants with likely functional effects in the channelopathy-associated genes SCN5A and TRDN and 1 (2.2%) individual in the cardiomyopathy-associated gene DTNA. In addition, 18 structural variants (SVs) were identified in 15 out of the 45 individuals. Two SVs with likely functional impairment were found in the coding regions of PDSS2 and TRPM4 in 2 SUD cases (4.4%). Both were identified as heterozygous deletions, which were confirmed by multiplex ligation-dependent probe amplification. In conclusion, our findings support that SVs could contribute to the pathology of the sudden death event in some of the cases and therefore should be investigated on a routine basis in suspected SUD cases.
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Kohli U, Sriram CS, Nayak HM. A novel familial SCN5A exon 20 deletion is associated with a heterogeneous phenotype. J Electrocardiol 2021; 66:131-135. [PMID: 33951591 DOI: 10.1016/j.jelectrocard.2021.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 01/23/2023]
Abstract
The SCN5A gene, located on chromosome 3p21, has 28 exons and is a member of the human voltage-gated sodium channel gene family. Genetic variation in SCN5A is associated with a diverse range of phenotypes. Due to incomplete penetrance, delayed expression, inherent low signal-to-noise ratio, and marked phenotypic heterogeneity, rare novel variants in SCN5A could be misinterpreted. Hence, defining the phenotypic characteristics of these rare SCN5A variants in humans is of importance. We describe the phenotypic heterogeneity noted in 4 familial carriers of a rare, previously unreported, large deletion in exon 20 of SCN5A (c.3667-?_c.3840C +?del) and discuss the mechanisms that underlie this heterogeneity.
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Affiliation(s)
- Utkarsh Kohli
- Division of Pediatric Cardiology, Department of Pediatrics, Comer Children's Hospital and the Pritzker School of Medicine of the University of Chicago, Chicago, IL, USA; Division of Pediatric Cardiology/Electrophysiology, Department of Pediatrics, West Virginia School of Medicine, Morgantown, WV, USA.
| | - Chenni S Sriram
- Division of Pediatric Cardiology, Department of Pediatrics, Children's Hospital of Michigan, Central Michigan University, Detroit, MI, USA
| | - Hemal M Nayak
- Center for Arrhythmia Care, Heart & Vascular Center, Pritzker School of Medicine of the University of Chicago, Chicago, IL, USA
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60
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Arrhythmogenic Cardiomyopathy: Mechanisms, Genetics, and Their Clinical Implications. CURRENT CARDIOVASCULAR RISK REPORTS 2021. [DOI: 10.1007/s12170-021-00669-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Xu L, Shi R. Generation of functional Na V1.5 current by endogenous transcriptional activation of SCN5A. BIOTECHNOL BIOTEC EQ 2021. [DOI: 10.1080/13102818.2021.1892524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Liang Xu
- Research Center for Translational Medicine, East Hospital, Tongji University School of Medicine, Shanghai, PR China
| | - Rui Shi
- Department of Gynaecology and Obstetrics, East Hospital, Tongji University School of Medicine, Shanghai, PR China
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Turan NN, Moshal KS, Roder K, Baggett BC, Kabakov AY, Dhakal S, Teramoto R, Chiang DYE, Zhong M, Xie A, Lu Y, Dudley SC, MacRae CA, Karma A, Koren G. The endosomal trafficking regulator LITAF controls the cardiac Nav1.5 channel via the ubiquitin ligase NEDD4-2. J Biol Chem 2020; 295:18148-18159. [PMID: 33093176 PMCID: PMC7939464 DOI: 10.1074/jbc.ra120.015216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/20/2020] [Indexed: 01/14/2023] Open
Abstract
The QT interval is a recording of cardiac electrical activity. Previous genome-wide association studies identified genetic variants that modify the QT interval upstream of LITAF (lipopolysaccharide-induced tumor necrosis factor-α factor), a protein encoding a regulator of endosomal trafficking. However, it was not clear how LITAF might impact cardiac excitation. We investigated the effect of LITAF on the voltage-gated sodium channel Nav1.5, which is critical for cardiac depolarization. We show that overexpressed LITAF resulted in a significant increase in the density of Nav1.5-generated voltage-gated sodium current INa and Nav1.5 surface protein levels in rabbit cardiomyocytes and in HEK cells stably expressing Nav1.5. Proximity ligation assays showed co-localization of endogenous LITAF and Nav1.5 in cardiomyocytes, whereas co-immunoprecipitations confirmed they are in the same complex when overexpressed in HEK cells. In vitro data suggest that LITAF interacts with the ubiquitin ligase NEDD4-2, a regulator of Nav1.5. LITAF overexpression down-regulated NEDD4-2 in cardiomyocytes and HEK cells. In HEK cells, LITAF increased ubiquitination and proteasomal degradation of co-expressed NEDD4-2 and significantly blunted the negative effect of NEDD4-2 on INa We conclude that LITAF controls cardiac excitability by promoting degradation of NEDD4-2, which is essential for removal of surface Nav1.5. LITAF-knockout zebrafish showed increased variation in and a nonsignificant 15% prolongation of action potential duration. Computer simulations using a rabbit-cardiomyocyte model demonstrated that changes in Ca2+ and Na+ homeostasis are responsible for the surprisingly modest action potential duration shortening. These computational data thus corroborate findings from several genome-wide association studies that associated LITAF with QT interval variation.
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Affiliation(s)
- Nilüfer N Turan
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Karni S Moshal
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Karim Roder
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Brett C Baggett
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Anatoli Y Kabakov
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Saroj Dhakal
- Physics Department and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts, USA
| | - Ryota Teramoto
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - David Yi-Eng Chiang
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Mingwang Zhong
- Physics Department and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts, USA
| | - An Xie
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Yichun Lu
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA
| | - Samuel C Dudley
- Cardiovascular Division, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Calum A MacRae
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Alain Karma
- Physics Department and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts, USA
| | - Gideon Koren
- Cardiovascular Research Center, Division of Cardiology, Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School, Brown University, Providence, Rhode Island, USA.
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63
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Dong C, Wang Y, Ma A, Wang T. Life Cycle of the Cardiac Voltage-Gated Sodium Channel Na V1.5. Front Physiol 2020; 11:609733. [PMID: 33391024 PMCID: PMC7773603 DOI: 10.3389/fphys.2020.609733] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/12/2020] [Indexed: 12/13/2022] Open
Abstract
Cardiac voltage-gated sodium channel NaV1.5, encoded by SCN5A, is crucial for the upstroke of action potential and excitation of cardiomyocytes. NaV1.5 undergoes complex processes before it reaches the target membrane microdomains and performs normal functions. A variety of protein partners are needed to achieve the balance between SCN5A transcription and mRNA decay, endoplasmic reticulum retention and export, Golgi apparatus retention and export, selective anchoring and degradation, activation, and inactivation of sodium currents. Subtle alterations can impair NaV1.5 in terms of expression or function, eventually leading to NaV1.5-associated diseases such as lethal arrhythmias and cardiomyopathy.
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Affiliation(s)
- Caijuan Dong
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Ya Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Aiqun Ma
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Molecular Cardiology, Shaanxi Province, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education, Xi'an, China
| | - Tingzhong Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Molecular Cardiology, Shaanxi Province, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education, Xi'an, China
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64
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Solé L, Tamkun MM. Trafficking mechanisms underlying Na v channel subcellular localization in neurons. Channels (Austin) 2020; 14:1-17. [PMID: 31841065 PMCID: PMC7039628 DOI: 10.1080/19336950.2019.1700082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 11/13/2019] [Indexed: 01/06/2023] Open
Abstract
Voltage gated sodium channels (Nav) play a crucial role in action potential initiation and propagation. Although the discovery of Nav channels dates back more than 65 years, and great advances in understanding their localization, biophysical properties, and links to disease have been made, there are still many questions to be answered regarding the cellular and molecular mechanisms involved in Nav channel trafficking, localization and regulation. This review summarizes the different trafficking mechanisms underlying the polarized Nav channel localization in neurons, with an emphasis on the axon initial segment (AIS), as well as discussing the latest advances regarding how neurons regulate their excitability by modifying AIS length and location. The importance of Nav channel localization is emphasized by the relationship between mutations, impaired trafficking and disease. While this review focuses on Nav1.6, other Nav isoforms are also discussed.
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Affiliation(s)
- Laura Solé
- Molecular, Cellular and Integrative Neurosciences Graduate Program, Colorado State University, Fort Collins, CO, USA
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Michael M. Tamkun
- Molecular, Cellular and Integrative Neurosciences Graduate Program, Colorado State University, Fort Collins, CO, USA
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
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65
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66
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Zakrzewska-Koperska J, Bilińska ZT, Truszkowska GT, Franaszczyk M, Elikowski W, Warmiński G, Kalin K, Urbanek P, Bodalski R, Orczykowski M, Szumowski Ł, Płoski R, Bilińska M. A combination of quinidine/mexiletine reduces arrhythmia in dilated cardiomyopathy in two patients with R814W SCN5A mutation. ESC Heart Fail 2020; 7:4326-4335. [PMID: 33084224 PMCID: PMC7754730 DOI: 10.1002/ehf2.12993] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/03/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022] Open
Abstract
SCN5A gene mutations are described in 2% of patients with dilated cardiomyopathy (DCM) and different rhythm disturbances, including multifocal ectopic Purkinje‐related premature contractions. Recent data indicate that sodium channel blockers are particularly effective monotherapy in carriers of the R222Q SCN5A variant. Our purpose is to describe the effectiveness of antiarrhythmic treatment in a family with genetically determined arrhythmogenic DCM associated with the R814W variant in the SCN5A gene. We examined a family with arrhythmogenic DCM (multifocal ectopic Purkinje‐related premature contractions phenotype, atrial tachyarrhythmias, automatism, and conduction disorders) and described antiarrhythmic treatment efficacy in heart failure symptoms reduction and myocardial function improvement. We found a heterozygotic mutation R814W in SCN5A by whole exome sequencing in the proband and confirmed its presence in all affected subjects. There were two sudden cardiac deaths and one heart transplantation among first‐degree relatives. The 58‐year‐old father and his 37‐year‐old daughter had full spectrum of symptoms associated with R814W SCN5A mutation. Both had implanted cardioverter defibrillator. In the father, adding mexiletine to quinidine therapy reduced ventricular arrhythmia (50–60% → 6–8% of whole rhythm) and reverted long‐standing atrial fibrillation to sinus rhythm. In the daughter, mexiletine and overdrive pacing were effective in ventricular arrhythmia reduction (25% → 0.01%). Because of a growing number of atrial fibrillation recurrences, a reduced dose of quinidine (subsequently flecainide) was added, resulting in arrhythmia significant reduction. In both cases, antiarrhythmic effectiveness correlated with clinical improvement. In SCN5A R814W‐associated DCM, a combination of Class I antiarrhythmics and overdrive pacing is an effective treatment of severe ventricular and atrial arrhythmias.
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Affiliation(s)
| | - Zofia T Bilińska
- Unit for Screening Studies in Inherited Cardiovascular Diseases, National Institute of Cardiology, ul. Alpejska 42, Warsaw, 04-628, Poland
| | - Grażyna T Truszkowska
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | - Maria Franaszczyk
- Molecular Biology Laboratory, Department of Medical Biology, National Institute of Cardiology, Warsaw, Poland
| | | | - Grzegorz Warmiński
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Katarzyna Kalin
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Piotr Urbanek
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Robert Bodalski
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Michał Orczykowski
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Łukasz Szumowski
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
| | - Rafał Płoski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Maria Bilińska
- 1st Department of Arrhythmia, National Institute of Cardiology, Warsaw, Poland
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67
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Machine learning-based QSAR models to predict sodium ion channel (Na v 1.5) blockers. Future Med Chem 2020; 12:1829-1843. [PMID: 33034205 DOI: 10.4155/fmc-2020-0156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Aim: Conventional experimental approaches used for the evaluation of the proarrhythmic potential of compounds in the drug discovery process are expensive and time consuming but an integral element in the safety profile required for a new drug to be approved. The voltage-gated sodium ion channel 1.5 (Nav 1.5), a target known for arrhythmic drugs, causes adverse cardiac complications when the channel is blocked. Results: Machine learning classification and regression models were built to predict the possibility of blocking these channels by small molecules. The finalized models tested with balanced accuracies of 0.88, 0.93 and 0.94 at three thresholds (1, 10 and 30 µmol, respectively). The regression model built to predict the pIC50 of compounds had q2 of 0.84 (root-mean-square error = 0.46). Conclusion: The machine learning models that have been built can act as effective filters to screen out the potentially toxic compounds in the early stages of drug discovery.
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68
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Tse G, Lee S, Liu T, Yuen HC, Wong ICK, Mak C, Mok NS, Wong WT. Identification of Novel SCN5A Single Nucleotide Variants in Brugada Syndrome: A Territory-Wide Study From Hong Kong. Front Physiol 2020; 11:574590. [PMID: 33071830 PMCID: PMC7531256 DOI: 10.3389/fphys.2020.574590] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022] Open
Abstract
Background The aim of this study is to report on the genetic composition of Brugada syndrome (BrS) patients undergoing genetic testing in Hong Kong. Methods Patients with suspected BrS who presented to the Hospital Authority of Hong Kong between 1997 and 2019, and underwent genetic testing, were analyzed retrospectively. Results A total of 65 subjects were included (n = 65, 88% male, median presenting age 42 [30–54] years old, 58% type 1 pattern). Twenty-two subjects (34%) showed abnormal genetic test results, identifying the following six novel, pathogenic or likely pathogenic mutations in SCN5A: c.674G > A, c.2024-11T > A, c.2042A > C, c.4279G > T, c.5689C > T, c.429del. Twenty subjects (31%) in the cohort suffered from spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF) and 18 (28%) had incident VT/VF over a median follow-up of 83 [Q1–Q3: 52–112] months. Univariate Cox regression demonstrated that syncope (hazard ratio [HR]: 4.27 [0.95–19.30]; P = 0.059), prior VT/VF (HR: 21.34 [5.74–79.31; P < 0.0001) and T-wave axis (HR: 0.970 [0.944–0.998]; P = 0.036) achieved P < 0.10 for predicting incident VT/VF. After multivariate adjustment, only prior VT/VF remained a significant predictor (HR: 12.39 [2.97–51.67], P = 0.001). Conclusion This study identified novel mutations in SCN5A in a Chinese cohort of BrS patients.
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Affiliation(s)
- Gary Tse
- Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China.,Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Sharen Lee
- Laboratory of Cardiovascular Physiology, Li Ka Shing Institute of Health Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Ho Chuen Yuen
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Kowloon, China
| | - Ian Chi Kei Wong
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, China.,School of Pharmacy, University College London, London, United Kingdom
| | - Chloe Mak
- Department of Pathology, Hong Kong Children's Hospital, Kowloon, China
| | - Ngai Shing Mok
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Kowloon, China
| | - Wing Tak Wong
- State Key Laboratory of Agrobiotechnology (CUHK), School of Life Sciences, The Chinese University of Hong Kong, Shatin, China
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69
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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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70
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Abstract
Cardiac fibrosis is associated with non-ischemic dilated cardiomyopathy, increasing its morbidity and mortality. Cardiac fibroblast is the keystone of fibrogenesis, being activated by numerous cellular and humoral factors. Macrophages, CD4+ and CD8+ T cells, mast cells, and endothelial cells stimulate fibrogenesis directly by activating cardiac fibroblasts and indirectly by synthetizing various profibrotic molecules. The synthesis of type 1 and type 3 collagen, fibronectin, and α-smooth muscle actin is rendered by various mechanisms like transforming growth factor-beta/small mothers against decapentaplegic pathway, renin angiotensin system, and estrogens, which in turn alter the extracellular matrix. Investigating the underlying mechanisms will allow the development of diagnostic and prognostic tools and discover novel specific therapies. Serum biomarkers aid in the diagnosis and tracking of cardiac fibrosis progression. The diagnostic gold standard is cardiac magnetic resonance with gadolinium administration that allows quantification of cardiac fibrosis either by late gadolinium enhancement assessment or by T1 mapping. Therefore, the goal is to stop and even reverse cardiac fibrosis by developing specific therapies that directly target fibrogenesis, in addition to the drugs used to treat heart failure. Cardiac resynchronization therapy had shown to revert myocardial remodeling and to reduce cardiac fibrosis. The purpose of this review is to provide an overview of currently available data.
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71
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Monasky MM, Micaglio E, Ciconte G, Pappone C. Brugada Syndrome: Oligogenic or Mendelian Disease? Int J Mol Sci 2020; 21:ijms21051687. [PMID: 32121523 PMCID: PMC7084676 DOI: 10.3390/ijms21051687] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 02/06/2023] Open
Abstract
Brugada syndrome (BrS) is diagnosed by a coved-type ST-segment elevation in the right precordial leads on the electrocardiogram (ECG), and it is associated with an increased risk of sudden cardiac death (SCD) compared to the general population. Although BrS is considered a genetic disease, its molecular mechanism remains elusive in about 70-85% of clinically-confirmed cases. Variants occurring in at least 26 different genes have been previously considered causative, although the causative effect of all but the SCN5A gene has been recently challenged, due to the lack of systematic, evidence-based evaluations, such as a variant's frequency among the general population, family segregation analyses, and functional studies. Also, variants within a particular gene can be associated with an array of different phenotypes, even within the same family, preventing a clear genotype-phenotype correlation. Moreover, an emerging concept is that a single mutation may not be enough to cause the BrS phenotype, due to the increasing number of common variants now thought to be clinically relevant. Thus, not only the complete list of genes causative of the BrS phenotype remains to be determined, but also the interplay between rare and common multiple variants. This is particularly true for some common polymorphisms whose roles have been recently re-evaluated by outstanding works, including considering for the first time ever a polygenic risk score derived from the heterozygous state for both common and rare variants. The more common a certain variant is, the less impact this variant might have on heart function. We are aware that further studies are warranted to validate a polygenic risk score, because there is no mutated gene that connects all, or even a majority, of BrS cases. For the same reason, it is currently impossible to create animal and cell line genetic models that represent all BrS cases, which would enable the expansion of studies of this syndrome. Thus, the best model at this point is the human patient population. Further studies should first aim to uncover genetic variants within individuals, as well as to collect family segregation data to identify potential genetic causes of BrS.
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Affiliation(s)
| | | | | | - Carlo Pappone
- Correspondence: ; Tel.: +39-0252-774260; Fax: +39-0252-774306
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72
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Wang R, Hopping G, Al Othman B, Tabba S, Kini A, Lee AG. Simultanagnosia as the presenting symptom in neuro-ophthalmology. Proc (Bayl Univ Med Cent) 2020; 33:105-107. [PMID: 32063790 DOI: 10.1080/08998280.2019.1656013] [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: 07/11/2019] [Revised: 08/04/2019] [Accepted: 08/12/2019] [Indexed: 10/25/2022] Open
Abstract
Simultanagnosia is a well-known neurologic symptom characterized by the inability to conceptualize the whole picture despite being able to see individual elements within a visual scene. The pathophysiology involves a lesion to the bilateral parieto-occipital lobe. We report two unusual cases of simultanagnosia and juxtaposed homonymous visual field loss involving aqueductal stenosis-related obstructive hydrocephalus and cardiac arrest due to Brugada syndrome. Clinicians should be aware that simultanagnosia can be the presenting symptom of neuro-ophthalmic disease.
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Affiliation(s)
- Rui Wang
- Department of Medicine, Texas A&M College of MedicineBryanTexas
| | | | - Bayan Al Othman
- Department of Ophthalmology, Blanton Eye Institute, Houston Methodist HospitalHoustonTexas
| | | | - Ashwini Kini
- Department of Ophthalmology, Blanton Eye Institute, Houston Methodist HospitalHoustonTexas
| | - Andrew G Lee
- McGovern Medical SchoolHoustonTexas.,Department of Ophthalmology, Blanton Eye Institute, Houston Methodist HospitalHoustonTexas.,Houston Methodist Hospital Research Institute, Houston Methodist HospitalHoustonTexas.,Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell MedicineNew YorkNew York.,Department of Ophthalmology, University of Texas Medical BranchGalvestonTexas.,University of Texas MD Anderson Cancer CenterHoustonTexas.,Department of Ophthalmology, The University of Iowa Hospitals and ClinicsIowa CityIowa
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73
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Ge Y, Ding D, Zhu G, Kwan P, Wang W, Hong Z, Sander JW. Genetic variants in incident SUDEP cases from a community-based prospective cohort with epilepsy. J Neurol Neurosurg Psychiatry 2020; 91:126-131. [PMID: 31776209 DOI: 10.1136/jnnp-2019-321983] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/21/2019] [Accepted: 11/05/2019] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is a leading cause of epilepsy-related mortality in young adults. It has been suggested that SUDEP may kill over 20 000 people with epilepsy in China yearly. The aetiology of SUDEP is unclear. Little is known about candidate genes for SUDEP in people of Chinese origin as most studies have ascertained this in Caucasians. No candidate genes for SUDEP in Chinese people have been identified. METHODS We performed whole exome sequencing (WES) in DNA samples collected from five incident cases of SUDEP identified in a large epilepsy cohort in rural China. We filtered rare variants identified from these cases as well as screened for SUDEP, epilepsy, heart disease or respiratory disease-related genes from previous published reports and compared them with publicly available data, living epilepsy controls and ethnicity-match non-epilepsy controls, to identify potential candidate genes for SUDEP. RESULTS After the filtering process, the five cases carried 168 qualified mutations in 167 genes. Among these genetic anomalies, we identified rare variants in SCN5A (1/5:20% in our cases), KIF6 (1/5:20% in our cases) and TBX18 (1/5:20% in our cases) which were absent in 330 living epilepsy control alleles from the same original cohort and 320 ethnicity-match non-epilepsy control alleles. CONCLUSIONS These three genes were previously related to heart disease, providing support to the hypothesis that underlying heart disorder may be a driver of SUDEP risk.
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Affiliation(s)
- Yan Ge
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Ding Ding
- Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Fudan University, Shanghai, China
| | - Guoxing Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Patrick Kwan
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Wenzhi Wang
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Zhen Hong
- Institute of Neurology, WHO Collaborating Center for Research and Training in Neurosciences, Huashan Hospital, Fudan University, Shanghai, China
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London, United Kingdom.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, the Netherlands
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74
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Glazer AM, Kroncke BM, Matreyek KA, Yang T, Wada Y, Shields T, Salem JE, Fowler DM, Roden DM. Deep Mutational Scan of an SCN5A Voltage Sensor. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2020; 13:e002786. [PMID: 31928070 DOI: 10.1161/circgen.119.002786] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Variants in ion channel genes have classically been studied in low throughput by patch clamping. Deep mutational scanning is a complementary approach that can simultaneously assess function of thousands of variants. METHODS We have developed and validated a method to perform a deep mutational scan of variants in SCN5A, which encodes the major voltage-gated sodium channel in the heart. We created a library of nearly all possible variants in a 36 base region of SCN5A in the S4 voltage sensor of domain IV and stably integrated the library into HEK293T cells. RESULTS In preliminary experiments, challenge with 3 drugs (veratridine, brevetoxin, and ouabain) could discriminate wild-type channels from gain- and loss-of-function pathogenic variants. High-throughput sequencing of the pre- and postdrug challenge pools was used to count the prevalence of each variant and identify variants with abnormal function. The deep mutational scan scores identified 40 putative gain-of-function and 33 putative loss-of-function variants. For 8 of 9 variants, patch clamping data were consistent with the scores. CONCLUSIONS These experiments demonstrate the accuracy of a high-throughput in vitro scan of SCN5A variant function, which can be used to identify deleterious variants in SCN5A and other ion channel genes.
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Affiliation(s)
- Andrew M Glazer
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Brett M Kroncke
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Kenneth A Matreyek
- Department of Genome Sciences, University of Washington, Seattle (K.A.M., D.M.F.)
| | - Tao Yang
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Yuko Wada
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Tiffany Shields
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN
| | - Joe-Elie Salem
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN.,Department of Clinical Pharmacology, APHP, Sorbonne Université, INSERM, CIC-1421, Hôpital Pitié-Salpêtrière, Paris, France (J.-E.S.)
| | - Douglas M Fowler
- Department of Genome Sciences, University of Washington, Seattle (K.A.M., D.M.F.)
| | - Dan M Roden
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt Center for Arrhythmia Research and Therapeutics (A.M.G., B.M.K., T.Y., Y.W., T.S., J.-E.S., D.M.R.), Vanderbilt University Medical Center, Nashville, TN.,Department of Biomedical Informatics (D.M.R.), Vanderbilt University Medical Center, Nashville, TN.,Department of Pharmacology (D.M.R.), Vanderbilt University Medical Center, Nashville, TN
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75
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Synnergren J, Vukusic K, Dönnes P, Jonsson M, Lindahl A, Dellgren G, Jeppsson A, Asp J. Transcriptional sex and regional differences in paired human atrial and ventricular cardiac biopsies collected in vivo. Physiol Genomics 2019; 52:110-120. [PMID: 31869284 DOI: 10.1152/physiolgenomics.00036.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Transcriptional studies of the human heart provide insight into physiological and pathophysiological mechanisms, essential for understanding the fundamental mechanisms of normal cardiac function and how they are altered by disease. To improve the understanding of why men and women may respond differently to the same therapeutic treatment it is crucial to learn more about sex-specific transcriptional differences. In this study the transcriptome of right atrium and left ventricle was compared across sex and regional location. Paired biopsies from five male and five female patients undergoing aortic valve replacement or coronary artery bypass grafting were included. Gene expression analysis identified 620 differentially expressed transcripts in atrial and ventricular tissue in men and 471 differentially expressed transcripts in women. In total 339 of these transcripts overlapped across sex but notably, 281 were unique in the male tissue and 162 in the female tissue, displaying marked sex differences in the transcriptional machinery. The transcriptional activity was significantly higher in atrias than in ventricles as 70% of the differentially expressed genes were upregulated in the atrial tissue. Furthermore, pathway- and functional annotation analyses performed on the differentially expressed genes showed enrichment for a more heterogeneous composition of biological processes in atrial compared with the ventricular tissue, and a dominance of differentially expressed genes associated with infection disease was observed. The results reported here provide increased insights about transcriptional differences between the cardiac atrium and ventricle but also reveal transcriptional differences in the human heart that can be attributed to sex.
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Affiliation(s)
- Jane Synnergren
- Systems Biology Research Center, School of Bioscience, University of Skövde, Skövde, Sweden
| | - Kristina Vukusic
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Marianne Jonsson
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Lindahl
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Göran Dellgren
- Department of Cardiothoracic Surgery, Sahlgrenska University Hospital Gothenburg, Sweden and Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anders Jeppsson
- Department of Cardiothoracic Surgery, Sahlgrenska University Hospital Gothenburg, Sweden and Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Julia Asp
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
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76
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Jiang D, Shi H, Tonggu L, Gamal El-Din TM, Lenaeus MJ, Zhao Y, Yoshioka C, Zheng N, Catterall WA. Structure of the Cardiac Sodium Channel. Cell 2019; 180:122-134.e10. [PMID: 31866066 DOI: 10.1016/j.cell.2019.11.041] [Citation(s) in RCA: 180] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/18/2019] [Accepted: 11/27/2019] [Indexed: 12/19/2022]
Abstract
Voltage-gated sodium channel Nav1.5 generates cardiac action potentials and initiates the heartbeat. Here, we report structures of NaV1.5 at 3.2-3.5 Å resolution. NaV1.5 is distinguished from other sodium channels by a unique glycosyl moiety and loss of disulfide-bonding capability at the NaVβ subunit-interaction sites. The antiarrhythmic drug flecainide specifically targets the central cavity of the pore. The voltage sensors are partially activated, and the fast-inactivation gate is partially closed. Activation of the voltage sensor of Domain III allows binding of the isoleucine-phenylalanine-methionine (IFM) motif to the inactivation-gate receptor. Asp and Ala, in the selectivity motif DEKA, line the walls of the ion-selectivity filter, whereas Glu and Lys are in positions to accept and release Na+ ions via a charge-delocalization network. Arrhythmia mutation sites undergo large translocations during gating, providing a potential mechanism for pathogenic effects. Our results provide detailed insights into Nav1.5 structure, pharmacology, activation, inactivation, ion selectivity, and arrhythmias.
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Affiliation(s)
- Daohua Jiang
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Hui Shi
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Lige Tonggu
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | | | - Michael J Lenaeus
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Division of General Internal Medicine, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Yan Zhao
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Craig Yoshioka
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
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