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Yao ZJ, Jiang YP, Yuan D, Hong P, He MJ, Li FX, Xu SY, Lin HB, Zhang HF. Decreased connexin 40 expression of the sinoatrial node mediates ischemic stroke-induced arrhythmia in mice. Exp Neurol 2024; 376:114773. [PMID: 38599368 DOI: 10.1016/j.expneurol.2024.114773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/23/2024] [Accepted: 04/06/2024] [Indexed: 04/12/2024]
Abstract
BACKGROUND Arrhythmia is the most common cardiac complication after ischemic stroke. Connexin 40 is the staple component of gap junctions, which influences the propagation of cardiac electrical signals in the sinoatrial node. However, the role of connexin 40 in post-stroke arrhythmia remains unclear. METHODS In this study, a permanent middle cerebral artery occlusion model was used to simulate the occurrence of an ischemic stroke. Subsequently, an electrocardiogram was utilized to record and assess variations in electrocardiogram measures. In addition, optical tissue clearing and whole-mount immunofluorescence staining were used to confirm the anatomical localization of the sinoatrial node, and the sinoatrial node tissue was collected for RNA sequencing to screen for potential pathological mechanisms. Lastly, the rAAV9-Gja5 virus was injected with ultrasound guidance into the heart to increase Cx40 expression in the sinoatrial node. RESULTS We demonstrated that the mice suffering from a permanent middle cerebral artery occlusion displayed significant arrhythmia, including atrial fibrillation, premature ventricular contractions, atrioventricular block, and abnormal electrocardiogram parameters. Of note, we observed a decrease in connexin 40 expression within the sinoatrial node after the ischemic stroke via RNA sequencing and western blot. Furthermore, rAAV9-Gja5 treatment ameliorated the occurrence of arrhythmia following stroke. CONCLUSIONS In conclusion, decreased connexin 40 expression in the sinoatrial node contributed to the ischemic stroke-induced cardiac arrhythmia. Therefore, enhancing connexin 40 expression holds promise as a potential therapeutic approach for ischemic stroke-induced arrhythmia.
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Affiliation(s)
- Zhi-Jun Yao
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Yan-Pin Jiang
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Department of Anesthesiology, The First Hospital Affiliated to the Army Medical University, Chongqing 400038, China
| | - Dan Yuan
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Pu Hong
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Meng-Jiao He
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Feng-Xian Li
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Shi-Yuan Xu
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Hong-Bin Lin
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
| | - Hong-Fei Zhang
- Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
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2
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Ganea G, Cinteză EE, Filip C, Iancu MA, Balta MD, Vătășescu R, Vasile CM, Cîrstoveanu C, Bălgrădean M. Postoperative Cardiac Arrhythmias in Pediatric and Neonatal Patients with Congenital Heart Disease-A Narrative Review. Life (Basel) 2023; 13:2278. [PMID: 38137879 PMCID: PMC10744555 DOI: 10.3390/life13122278] [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: 10/06/2023] [Revised: 11/14/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023] Open
Abstract
Cardiac arrhythmias are a frequent complication in the evolution of patients with congenital heart disease. Corrective surgery for these malformations is an additional predisposition to the appearance of arrhythmias. Several factors related to the patient, as well as to the therapeutic management, are involved in the etiopathogenesis of cardiac arrhythmias occurring post-operatively. The risk of arrhythmias in the immediate postoperative period is correlated with the patient's young age and low weight at surgery. The change in heart geometry, hemodynamic stress, and post-surgical scars represent the main etiopathogenic factors that can contribute to the occurrence of cardiac arrhythmias in the population of patients with operated-on congenital heart malformations. Clinical manifestations differ depending on the duration of the arrhythmia, underlying structural defects, hemodynamic conditions, and comorbidities. The accurate diagnosis and the establishment of specific management options strongly influence the morbidity and mortality associated with arrhythmias. As such, identifying the risk factors for the occurrence of cardiac arrhythmias in the case of each patient is essential to establish a specific follow-up and management plan to improve the life expectancy and quality of life of children.
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Affiliation(s)
- Gabriela Ganea
- Department of Pediatrics, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (G.G.); (E.E.C.); (C.F.); (M.B.)
- “Marie Skolodowska Curie” Emergency Children’s Hospital, 041451 Bucharest, Romania
| | - Eliza Elena Cinteză
- Department of Pediatrics, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (G.G.); (E.E.C.); (C.F.); (M.B.)
- “Marie Skolodowska Curie” Emergency Children’s Hospital, 041451 Bucharest, Romania
| | - Cristina Filip
- Department of Pediatrics, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (G.G.); (E.E.C.); (C.F.); (M.B.)
- “Marie Skolodowska Curie” Emergency Children’s Hospital, 041451 Bucharest, Romania
| | - Mihaela Adela Iancu
- Department of Internal Medicine, Family Medicine and Labor Medicine, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania;
- “Alessandrescu-Rusescu” National Institute for Mother and Child Health, 20382 Bucharest, Romania
| | - Mihaela Daniela Balta
- Department of Internal Medicine, Family Medicine and Labor Medicine, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania;
- “Alessandrescu-Rusescu” National Institute for Mother and Child Health, 20382 Bucharest, Romania
| | - Radu Vătășescu
- Emergency Clinical Hospital, 014461 Bucharest, Romania
- Cardio-Thoracic Department, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Corina Maria Vasile
- Pediatric and Adult Congenital Cardiology Department, Centre Hospitalier Universitaire de Bordeaux, 33000 Bordeaux, France;
| | - Cătălin Cîrstoveanu
- Department of Neonatal Intensive Care, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania;
- Neonatal Intensive Care Unit, M.S. Curie Children’s Clinical Hospital, 041451 Bucharest, Romania
| | - Mihaela Bălgrădean
- Department of Pediatrics, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (G.G.); (E.E.C.); (C.F.); (M.B.)
- “Marie Skolodowska Curie” Emergency Children’s Hospital, 041451 Bucharest, Romania
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3
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Jičínský M, Kubuš P, Pavlíková M, Ložek M, Janoušek J. Natural History of Nonsurgical Complete Atrioventricular Block in Children and Predictors of Pacemaker Implantation. JACC Clin Electrophysiol 2023; 9:1379-1389. [PMID: 37086232 DOI: 10.1016/j.jacep.2023.02.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/02/2023] [Accepted: 02/15/2023] [Indexed: 04/23/2023]
Abstract
BACKGROUND Data on the natural history of complete atrioventricular block (CAVB) in children are scarce, and criteria for pacemaker (PM) implantation are based on low levels of evidence. OBJECTIVES This study aimed to evaluate the natural course and predictors of PM implantation in a nationwide cohort of pediatric patients with nonsurgical CAVB. METHODS All children with CAVB in the absence of structural heart disease presenting from 1977 to 2016 were retrospectively identified, yielding 95 subjects with a mean age of 4.05 years at the first presentation with a follow-up median of 0.80 years (IQR: 0.02-6.82 years). PM implantation was performed according to the available guidelines. Serial 24-hour Holter recordings and echocardiograms were reviewed. Predictors of PM implantation performed >1 month after the first presentation were evaluated. RESULTS The minimum and mean 24-hour heart rates and maximum RR intervals had a nonlinear correlation with age (P < 0.0001 for all). The left ventricular (LV) size was moderately increased, and the shortening fraction was normal in the majority throughout follow-up. PM implantation was performed in 62 patients (65.3%) reaching guideline criteria. The mean 24-hour heart rate at presentation was a predictor of subsequent PM implantation (HR: 0.938; 95% CI: 0.894-0.983; P = 0.003 per unit increase) regardless of age at presentation. Patients presenting with a mean 24-hour heart rate >58 beats/min (>75th percentile) had a high probability of freedom from PM within the subsequent 5 years (91.7% vs 44.4%; P < 0.001). CONCLUSIONS Pediatric patients with CAVB showed an age-dependent decrease in heart rate, moderate LV dilation, and preserved LV function. The probability of subsequent PM implantation could be predicted by the heart rate profile at presentation, defining a low-risk group and allowing for individualized follow-up.
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Affiliation(s)
- Michal Jičínský
- Children's Heart Centre, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic.
| | - Peter Kubuš
- Children's Heart Centre, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
| | - Markéta Pavlíková
- Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
| | - Miroslav Ložek
- Children's Heart Centre, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic; 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jan Janoušek
- Children's Heart Centre, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
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4
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Kikano S, Kannankeril PJ. Precision Medicine in Pediatric Cardiology. Pediatr Ann 2022; 51:e390-e395. [PMID: 36215086 DOI: 10.3928/19382359-20220803-05] [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] [Indexed: 11/05/2022]
Abstract
Precision medicine is a developing strategy for individualized treatment of a wide range of diseases. Congenital heart disease is the most common of all congenital defects and carries a high degree of variability in outcomes because of unidentified causes. Advances have identified individual genetic and environmental factors that have helped understand variations in morbidity and mortality in pediatric cardiology. A focus on genomics and pharmacogenetics has also been key to risk prediction and improvement in drug safety and efficacy in the pediatric population. With the rapidly evolving understanding of these individual factors, there also come challenges in implementation of personalized medicine into our health care model. This review outlines the key features of precision medicine in pediatric cardiology and highlights the clinical effects of these findings in patients with congenital heart disease. [Pediatr Ann. 2022;51(10):e390-e395.].
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5
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Tang J, Wei L, Li Y. Single Cell RNA Sequencing Reveals the Association Between a Novel GJA5 Variant and Trifascicular Block. JACC Clin Electrophysiol 2022; 8:939-941. [PMID: 35643807 DOI: 10.1016/j.jacep.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/08/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Affiliation(s)
- Jie Tang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Li Wei
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.
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Haywood ME, Cocciolo A, Porter KF, Dobrinskikh E, Slavov D, Graw SL, Reece TB, Ambardekar AV, Bristow MR, Mestroni L, Taylor MRG. Transcriptome signature of ventricular arrhythmia in dilated cardiomyopathy reveals increased fibrosis and activated TP53. J Mol Cell Cardiol 2020; 139:124-134. [PMID: 31958463 PMCID: PMC7144813 DOI: 10.1016/j.yjmcc.2019.12.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 12/19/2019] [Accepted: 12/29/2019] [Indexed: 12/21/2022]
Abstract
AIMS One-third of DCM patients experience ventricular tachycardia (VT), but a clear biological basis for this has not been established. The purpose of this study was to identify transcriptome signatures and enriched pathways in the hearts of dilated cardiomyopathy (DCM) patients with VT. METHODS AND RESULTS We used RNA-sequencing in explanted heart tissue from 49 samples: 19 DCM patients with VT, 16 DCM patients without VT, and 14 non-failing controls. We compared each DCM cohort to the controls and identified the genes that were differentially expressed in DCM patients with VT but not without VT. Differentially expressed genes were evaluated using pathway analysis, and pathways of interest were investigated by qRT-PCR validation, Western blot, and microscopy. There were 590 genes differentially expressed in DCM patients with VT that are not differentially expressed in patients without VT. These genes were enriched for genes in the TGFß1 and TP53 signaling pathways. Increased fibrosis and activated TP53 signaling was demonstrated in heart tissue of DCM patients with VT. CONCLUSIONS Our study supports that distinct biological mechanisms distinguish ventricular arrhythmia in DCM patients.
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Affiliation(s)
- Mary E Haywood
- Human Medical Genetics and Genomics, University of Colorado, Aurora, CO, USA.
| | - Andrea Cocciolo
- Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado, Aurora, CO, USA
| | - Kadijah F Porter
- Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado, Aurora, CO, USA.
| | - Evgenia Dobrinskikh
- Division of Renal Diseases and Hypertension, Department of Medicine University of Colorado, Aurora, CO, USA.
| | - Dobromir Slavov
- Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado, Aurora, CO, USA.
| | - Sharon L Graw
- Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado, Aurora, CO, USA.
| | - T Brett Reece
- Department of Cardiothoracic Surgery, University of Colorado Hospital, Aurora, CO, USA.
| | - Amrut V Ambardekar
- Division of Cardiology, Department of Medicine, University of Colorado, Aurora, CO, USA.
| | - Michael R Bristow
- Division of Cardiology, Department of Medicine, University of Colorado, Aurora, CO, USA.
| | - Luisa Mestroni
- Human Medical Genetics and Genomics, University of Colorado, Aurora, CO, USA; Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado, Aurora, CO, USA.
| | - Matthew R G Taylor
- Human Medical Genetics and Genomics, University of Colorado, Aurora, CO, USA; Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado, Aurora, CO, USA.
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7
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Mao Z, Wang Y, Peng H, He F, Zhu L, Huang H, Huang X, Lu X, Tan X. A newly identified missense mutation in CLCA2 is associated with autosomal dominant cardiac conduction block. Gene 2019; 714:143990. [PMID: 31326550 DOI: 10.1016/j.gene.2019.143990] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 07/15/2019] [Accepted: 07/17/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND Progressive cardiac conduction defect (PCCD), also known as Lenegre-Lev disease, is one of the most common heart conduction abnormalities. Previous studies have screened for known mutation sites that cause heart block in a 68-person family with a history of PCCD, revealed no mutations. OBJECTIVE To screen pathogenic genes of the PCCD family and to study the function of the gene mutations related to heart block diseases. METHODS Whole exome sequencing (WES) was performed on two PCCD patients and one non-PCCD family member to find the related pathogenic gene. After family co-segregation and preliminary functional analysis, we identified the mutant gene CLCA2. To study the function of this gene, we constructed mutant-gene mice using CRISPR-Cas9 technology, and electrocardiogram monitoring was performed after genotype verification. RESULTS The CLCA2 c.G1725T mutation was identified and co-segregated with the phenotype. The analysis showed that the CLCA2 c.G1725T mutation is harmful and mainly affects protein glycosylation. Immunofluorescence staining revealed that CLCA2 was highly expressed in the sinoatrial node (SAN) tissues. Electrocardiogram monitoring of the mice revealed that CLCA2 point mutations induced mild conduction block and ectopic pacemakers. CONCLUSION Our findings indicate that a novel heterozygous missense mutation c.G1725T of the CLCA2 gene may be associated with heart block disease and the mutation in this gene may lead to sinus node lesions and conduction blocking.
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Affiliation(s)
- Zhuo Mao
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Yi Wang
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Hao Peng
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Fang He
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Li Zhu
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - He Huang
- Cardiovascular Medicine of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Xianghong Huang
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Xiaowei Lu
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China
| | - Xiaojun Tan
- Reproductive and Genetic Center of Central Hospital of Xiangtan, 120 Heping Road, Yuhu District, Xiangtan City 411100, Hunan Province, China.
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8
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Asatryan B, Medeiros-Domingo A. Molecular and genetic insights into progressive cardiac conduction disease. Europace 2019; 21:1145-1158. [DOI: 10.1093/europace/euz109] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/27/2019] [Indexed: 12/14/2022] Open
Abstract
Abstract
Progressive cardiac conduction disease (PCCD) is often a primarily genetic disorder, with clinical and genetic overlaps with other inherited cardiac and metabolic diseases. A number of genes have been implicated in PCCD pathogenesis with or without structural heart disease or systemic manifestations. Precise genetic diagnosis contributes to risk stratification, better selection of specific therapy and allows familiar cascade screening. Cardiologists should be aware of the different phenotypes emerging from different gene-mutations and the potential risk of sudden cardiac death. Genetic forms of PCCD often overlap or coexist with other inherited heart diseases or manifest in the context of multisystem syndromes. Despite the significant advances in the knowledge of the genetic architecture of PCCD and overlapping diseases, in a measurable fraction of PCCD cases, including in familial clustering of disease, investigations of known cardiac disease-associated genes fail to reveal the underlying substrate, suggesting that new causal genes are yet to be discovered. Here, we provide insight into genetics and molecular mechanisms of PCCD and related diseases. We also highlight the phenotypic overlaps of PCCD with other inherited cardiac and metabolic diseases, present unmet challenges in clinical practice, and summarize the available therapeutic options for affected patients.
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Affiliation(s)
- Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, Freiburgstrasse 8, Bern, Switzerland
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9
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Pruetz JD, Miller JC, Loeb GE, Silka MJ, Bar-Cohen Y, Chmait RH. Prenatal diagnosis and management of congenital complete heart block. Birth Defects Res 2019; 111:380-388. [PMID: 30821931 DOI: 10.1002/bdr2.1459] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/04/2019] [Indexed: 01/03/2023]
Abstract
Congenital complete heart block (CCHB) is a life-threatening medical condition in the unborn fetus with insufficiently validated prenatal interventions. Maternal administration of medications aimed at decreasing the immune response in the fetus and beta-agonists intended to increase fetal cardiac output have shown only marginal benefits. Anti-inflammatory therapies cannot reverse CCHB, but may decrease myocarditis and improve heart function. Advances in prenatal diagnosis and use of strict surveillance protocols for delivery timing have demonstrated small improvements in morbidity and mortality. Ambulatory surveillance programs and wearable fetal heart rate monitors may afford early identification of evolving fetal heart block allowing for emergent treatment. There is also preliminary data suggesting a roll for prevention of CCHB with hydroxychloroquine, but the efficacy and safety is still being studied. To date, intrauterine fetal pacing has not been successful due to the high-risk invasive placement techniques and potential problems with lead dislodgement. The development of a fully implantable micropacemaker via a minimally invasive approach has the potential to pace fetal patients with CCHB and thus delay delivery and allow fetal hydrops to resolve. The challenge remains to establish accepted prenatal interventions capable of successfully managing CCHB in utero until postnatal pacemaker placement is successfully achieved.
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Affiliation(s)
- Jay D Pruetz
- Department of Pediatrics/Division of Pediatric Cardiology, Children's Hospital Los Angeles, Los Angeles, California.,Keck School of Medicine of USC, Los Angeles, California
| | - Jennifer C Miller
- Department of Pediatrics/Division of Pediatric Cardiology, Children's Hospital Los Angeles, Los Angeles, California.,Keck School of Medicine of USC, Los Angeles, California
| | - Gerald E Loeb
- Department of Biomedical Engineering, University of Southern California (USC), Los Angeles, California
| | - Michael J Silka
- Department of Pediatrics/Division of Pediatric Cardiology, Children's Hospital Los Angeles, Los Angeles, California.,Keck School of Medicine of USC, Los Angeles, California
| | - Yaniv Bar-Cohen
- Department of Pediatrics/Division of Pediatric Cardiology, Children's Hospital Los Angeles, Los Angeles, California.,Keck School of Medicine of USC, Los Angeles, California
| | - Ramen H Chmait
- Department of Obstetrics and Gynecology/Division of Maternal Fetal Medicine, Keck School of Medicine of USC, Los Angeles, California
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11
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Yuan SM. Fetal arrhythmias: Surveillance and management. Hellenic J Cardiol 2018; 60:72-81. [PMID: 30576831 DOI: 10.1016/j.hjc.2018.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 12/04/2018] [Accepted: 12/11/2018] [Indexed: 10/27/2022] Open
Abstract
Fetal arrhythmias warrant sophisticated surveillance and management, especially for the high-risk pregnancies. Clinically, fetal arrhythmias can be categorized into 3 types: premature contractions, tachyarrhythmias, and bradyarrhythmias. Fetal arrhythmias include electrocardiography, cardiotocography, echocardiography and magnetocardiography. Oxygen saturation monitoring can be an effective way of fetal surveillance for congenital complete AV block or SVT during labor. Genetic surveillance of fetal arrhythmias may facilitate the understanding of the mechanisms of the arrhythmias and provide theoretical basis for diagnosis and treatment. For fetal benign arrhythmias, usually no treatment but a close follow-up is need, while persistant fetal arrhythmias with congestive heart dysfunction or hydrops fetalis, intrauterine or postnatal treatments are required. The prognoses of fetal arrhythmias depend on the type and severity of fetal arrhythmias and the associated fetal conditions. Responses of fetal arrhythmias to individual treatments and clinical schemes are heterogeneous, and the prognoses are poor particularly under such circumstances.
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Affiliation(s)
- Shi-Min Yuan
- Department of Cardiothoracic Surgery, The First Hospital of Putian, Teaching Hospital, Fujian Medical University, Putian, Fujian Province, People's Republic of China.
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12
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Boyden PA. Purkinje physiology and pathophysiology. J Interv Card Electrophysiol 2018; 52:255-262. [PMID: 30056516 DOI: 10.1007/s10840-018-0414-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/17/2018] [Indexed: 01/08/2023]
Abstract
There has always been an appreciation of the role of Purkinje fibers in the fast conduction of the normal cardiac impulse. Here, we briefly update our knowledge of this important set of cardiac cells. We discuss the anatomy of a Purkinje fiber strand, the importance of longitudinal conduction within a strand, circus movement within a strand, conduction, and excitability properties of Purkinjes. At the cell level, we discuss the important components of the ion channel makeup in the nonremodeled Purkinjes of healthy hearts. Finally, we discuss the role of the Purkinjes in forming the heritable arrhythmogenic substrates such as long QT, heritable conduction slowing, CPVT, sQT, and Brugada syndromes.
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Affiliation(s)
- Penelope A Boyden
- Department of Pharmacology, Columbia University, New York, NY, 10032, USA.
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13
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van Deventer BS, du Toit-Prinsloo L, van Niekerk C. Feasibility of analysis of the SCN5A gene in paraffin embedded samples in sudden infant death cases at the Pretoria Medico-Legal Laboratory, South Africa. Forensic Sci Med Pathol 2018; 14:276-284. [PMID: 29907895 DOI: 10.1007/s12024-018-9995-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2018] [Indexed: 12/19/2022]
Abstract
To determine variations in the SCN5A gene linked to inherited cardiac arrhythmogenic disorders in sudden, unexplained infant death (SUID) cases examined at the Pretoria Medico-Legal Laboratory, South Africa. A retrospective study was conducted on SUID cases and controls, analyzing DNA extracted from archived formalin-fixed, paraffin-embedded (FFPE) myocardial tissue samples as well as blood samples. A total of 48 FFPE tissue samples (cases), 10 control FFPE tissue samples and nine control blood samples were included. DNA extracted from all samples was used to test for variations in the SCN5A gene by using high resolution melt (HRM) real-time PCR and sequencing. Genetic analysis showed 31 different single nucleotide variants in the entire study population (n = 67). Five previously reported variants of known pathogenic significance, and 14 variants of benign clinical significance, were identified. The study found 12 different variants in the cases that were not published in any database or literature and were considered novel. Of these novel variants, two were predicted as "probably damaging" with a high level of certainty (found in four case samples), one (identified in another case sample) was predicted to be "possibly damaging" with a 50% chance of being disease-causing, and nine were predicted to be benign. This study shows the significant added value of using genetic testing in determining the cause of death in South African SUID cases. Considering the high heritability of these arrhythmic disorders, post mortem genetic testing could play an important role in the understanding of the pathogenesis thereof and could also aid in the diagnosis and treatment of family members at risk, ultimately preventing similar future cases.
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Affiliation(s)
| | - Lorraine du Toit-Prinsloo
- Department of Forensic Medicine, University of Pretoria, Pretoria, South Africa.,Department of Forensic Medicine, Sydney, Forensic & Analytical Science Services (FASS), NSW Health Pathology, Sydney, New South Wales, Australia
| | - Chantal van Niekerk
- Department of Chemical Pathology, University of Pretoria, R3-43 Pathology Building, Prinshof Campus, Pretoria, 0002, Republic of South Africa. .,Department of Chemical Pathology, National Health Laboratory Services (NHLS), Tshwane Academic Division, Pretoria, South Africa.
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14
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Garcia RU, Safa R, Karpawich PP. Postoperative complete heart block among congenital heart disease patients: Contributing risk factors, therapies and long-term sequelae in the current era. PROGRESS IN PEDIATRIC CARDIOLOGY 2018. [DOI: 10.1016/j.ppedcard.2018.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Leybaert L, Lampe PD, Dhein S, Kwak BR, Ferdinandy P, Beyer EC, Laird DW, Naus CC, Green CR, Schulz R. Connexins in Cardiovascular and Neurovascular Health and Disease: Pharmacological Implications. Pharmacol Rev 2017; 69:396-478. [PMID: 28931622 PMCID: PMC5612248 DOI: 10.1124/pr.115.012062] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Connexins are ubiquitous channel forming proteins that assemble as plasma membrane hemichannels and as intercellular gap junction channels that directly connect cells. In the heart, gap junction channels electrically connect myocytes and specialized conductive tissues to coordinate the atrial and ventricular contraction/relaxation cycles and pump function. In blood vessels, these channels facilitate long-distance endothelial cell communication, synchronize smooth muscle cell contraction, and support endothelial-smooth muscle cell communication. In the central nervous system they form cellular syncytia and coordinate neural function. Gap junction channels are normally open and hemichannels are normally closed, but pathologic conditions may restrict gap junction communication and promote hemichannel opening, thereby disturbing a delicate cellular communication balance. Until recently, most connexin-targeting agents exhibited little specificity and several off-target effects. Recent work with peptide-based approaches has demonstrated improved specificity and opened avenues for a more rational approach toward independently modulating the function of gap junctions and hemichannels. We here review the role of connexins and their channels in cardiovascular and neurovascular health and disease, focusing on crucial regulatory aspects and identification of potential targets to modify their function. We conclude that peptide-based investigations have raised several new opportunities for interfering with connexins and their channels that may soon allow preservation of gap junction communication, inhibition of hemichannel opening, and mitigation of inflammatory signaling.
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Affiliation(s)
- Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Paul D Lampe
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Stefan Dhein
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Brenda R Kwak
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Peter Ferdinandy
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Eric C Beyer
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Dale W Laird
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Christian C Naus
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Colin R Green
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium (L.L.); Translational Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington (P.D.L.); Institute for Pharmacology, University of Leipzig, Leipzig, Germany (S.D.); Department of Pathology and Immunology, Department of Medical Specialization-Cardiology, University of Geneva, Geneva, Switzerland (B.R.K.); Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Department of Pediatrics, University of Chicago, Chicago, Illinois (E.C.B.); Department of Anatomy and Cell Biology, University of Western Ontario, Dental Science Building, London, Ontario, Canada (D.W.L.); Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada (C.C.N.); Department of Ophthalmology and The New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand (C.R.G.); and Physiologisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany (R.S.)
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16
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Seki A, Ishikawa T, Daumy X, Mishima H, Barc J, Sasaki R, Nishii K, Saito K, Urano M, Ohno S, Otsuki S, Kimoto H, Baruteau AE, Thollet A, Fouchard S, Bonnaud S, Parent P, Shibata Y, Perrin JP, Le Marec H, Hagiwara N, Mercier S, Horie M, Probst V, Yoshiura KI, Redon R, Schott JJ, Makita N. Progressive Atrial Conduction Defects Associated With Bone Malformation Caused by a Connexin-45 Mutation. J Am Coll Cardiol 2017; 70:358-370. [PMID: 28705318 DOI: 10.1016/j.jacc.2017.05.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/29/2017] [Accepted: 05/09/2017] [Indexed: 02/09/2023]
Abstract
BACKGROUND Inherited cardiac conduction disease is a rare bradyarrhythmia associated with mutations in various genes that affect action potential propagation. It is often characterized by isolated conduction disturbance of the His-Purkinje system, but it is rarely described as a syndromic form. OBJECTIVES The authors sought to identify the genetic defect in families with a novel bradyarrhythmia syndrome associated with bone malformation. METHODS The authors genetically screened 15 European cases with genotype-negative de novo atrioventricular (AV) block and their parents by trio whole-exome sequencing, plus 31 Japanese cases with genotype-negative familial AV block or sick sinus syndrome by targeted exon sequencing of 457 susceptibility genes. Functional consequences of the mutation were evaluated using an in vitro cell expression system and in vivo knockout mice. RESULTS The authors identified a connexin-45 (Cx45) mutation (p.R75H) in 2 unrelated families (a de novo French case and a 3-generation Japanese family) who presented with progressive AV block, which resulted in atrial standstill without ventricular conduction abnormalities. Affected individuals shared a common extracardiac phenotype: a brachyfacial pattern, finger deformity, and dental dysplasia. Mutant Cx45 expressed in Neuro-2a cells showed normal hemichannel assembly and plaque formation. However, Lucifer yellow dye transfer and gap junction conductance between cell pairs were severely impaired, which suggested that mutant Cx45 impedes gap junction communication in a dominant-negative manner. Tamoxifen-induced, cardiac-specific Cx45 knockout mice showed sinus node dysfunction and atrial arrhythmia, recapitulating the intra-atrial disturbance. CONCLUSIONS Altogether, the authors showed that Cx45 mutant p.R75H is responsible for a novel disease entity of progressive atrial conduction system defects associated with craniofacial and dentodigital malformation.
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Affiliation(s)
- Akiko Seki
- Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan; Support Center for Women Health Care Professionals and Researchers, Tokyo Women's Medical University, Tokyo, Japan
| | - Taisuke Ishikawa
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Xavier Daumy
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France
| | - Hiroyuki Mishima
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Julien Barc
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France
| | - Ryo Sasaki
- Department of Oral and Maxillofacial Surgery, Tokyo Women's Medical University, Tokyo, Japan
| | - Kiyomasa Nishii
- Department of Anatomy and Neurobiology, National Defense Medical College, Tokorozawa, Japan
| | - Kayoko Saito
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | - Mari Urano
- Institute of Medical Genetics, Tokyo Women's Medical University, Tokyo, Japan
| | - Seiko Ohno
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Saki Otsuki
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Hiroki Kimoto
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Alban-Elouen Baruteau
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France; Department of Congenital Cardiology, Evelina London Children's Hospital, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Aurelie Thollet
- CHU Nantes, L'institut du thorax, Service de Cardiologie, Nantes, France
| | - Swanny Fouchard
- CHU Nantes, L'institut du thorax, Service de Cardiologie, Nantes, France
| | | | | | | | - Jean-Philippe Perrin
- CHU Nantes, Service de Chirurgie Maxillo-Faciale et Stomatologie, Nantes, France
| | - Hervé Le Marec
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France; CHU Nantes, L'institut du thorax, Service de Cardiologie, Nantes, France
| | - Nobuhisa Hagiwara
- Department of Cardiology, Tokyo Women's Medical University, Tokyo, Japan
| | - Sandra Mercier
- CHU Nantes, Service de Génétique Médicale, Nantes, France
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Vincent Probst
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France; CHU Nantes, L'institut du thorax, Service de Cardiologie, Nantes, France
| | - Koh-Ichiro Yoshiura
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Richard Redon
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France; CHU Nantes, L'institut du thorax, Service de Cardiologie, Nantes, France
| | - Jean-Jacques Schott
- INSERM, CNRS, UNIV Nantes, L'Institut du Thorax, Nantes, France; CHU Nantes, L'institut du thorax, Service de Cardiologie, Nantes, France.
| | - Naomasa Makita
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
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17
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Postmortem genetic analysis of sudden unexpected death in infancy: neonatal genetic screening may enable the prevention of sudden infant death. J Hum Genet 2017; 62:989-995. [DOI: 10.1038/jhg.2017.79] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 11/08/2022]
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18
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Bai D, Yue B, Aoyama H. Crucial motifs and residues in the extracellular loops influence the formation and specificity of connexin docking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:9-21. [PMID: 28693896 DOI: 10.1016/j.bbamem.2017.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/25/2017] [Accepted: 07/03/2017] [Indexed: 12/19/2022]
Abstract
Most of the early studies on gap junction (GJ) channel function and docking compatibility were on rodent connexins, while recent research on GJ channels gradually shifted from rodent to human connexins largely due to the fact that mutations in many human connexin genes are found to associate with inherited human diseases. The studies on human connexins have revealed some key differences from those found in rodents, calling for a comprehensive characterization of human GJ channels. Functional studies revealed that docking and formation of functional GJ channels between two hemichannels are possible only between docking-compatible connexins. Two groups of docking-compatible rodent connexins have been identified. Compatibility is believed to be due to their amino acid residue differences at the extracellular loop domains (E1 and E2). Sequence alignment of the E1 and E2 domains of all connexins known to make GJs revealed that they are highly conserved and show high sequence identity with human Cx26, which is the only connexin with near atomic resolution GJ structure. We hypothesize that different connexins have a similar structure as that of Cx26 at the E1 and E2 domains and use the corresponding residues in their E1 and E2 domains for docking. Based on the Cx26 GJ structure and sequence analysis of well-studied connexins, we propose that the E1-E1 docking interactions are staggered with each E1 interacting with two E1s on the docked connexon. The putative E1 docking residues are conserved in both docking-compatible and -incompatible connexins, indicating that E1 does not likely serve a role in docking compatibility. However, in the case of E2-E2 docking interactions, the putative docking residues are only conserved within the docking-compatible connexins, suggesting the E2 is likely to serve the function of docking compatibility. Docking compatibility studies on human connexins have attracted a lot of attention due to the fact that putative docking residues are mutational hotspots for several connexin-linked human diseases. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Donglin Bai
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
| | - Benny Yue
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Hiroshi Aoyama
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
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19
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Abstract
The generation and propagation of the cardiac impulse is the central function of the cardiac conduction system (CCS). Impulse initiation occurs in nodal tissues that have high levels of automaticity, but slow conduction properties. Rapid impulse propagation is a feature of the ventricular conduction system, which is essential for synchronized contraction of the ventricular chambers. When functioning properly, the CCS produces ~2.4 billion heartbeats during a human lifetime and orchestrates the flow of cardiac impulses, designed to maximize cardiac output. Abnormal impulse initiation or propagation can result in brady- and tachy-arrhythmias, producing an array of symptoms, including syncope, heart failure or sudden cardiac death. Underlying the functional diversity of the CCS are gene regulatory networks that direct cell fate towards a nodal or a fast conduction gene program. In this review, we will discuss our current understanding of the transcriptional networks that dictate the components of the CCS, the growth factor-dependent signaling pathways that orchestrate some of these transcriptional hierarchies and the effect of aberrant transcription factor expression on mammalian conduction disease.
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20
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Garcia-Bustos V, Sebastian R, Izquierdo M, Molina P, Chorro FJ, Ruiz-Sauri A. A quantitative structural and morphometric analysis of the Purkinje network and the Purkinje-myocardial junctions in pig hearts. J Anat 2017; 230:664-678. [PMID: 28256093 DOI: 10.1111/joa.12594] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2016] [Indexed: 12/20/2022] Open
Abstract
The morpho-functional properties of the distal section of the cardiac Purkinje network (PN) and the Purkinje-myocardial junctions (PMJs) are fundamental to understanding the sequence of electrical activation in the heart. The overall structure of the system has already been described, and several computational models have been developed to gain insight into its involvement in cardiac arrhythmias or its interaction with implantable devices, such as pacemakers. However, anatomical descriptions of the PN in the literature have not enabled enough improvements in the accuracy of anatomical-based electrophysiological simulations of the PN in 3D hearts models. In this work, we study the global distribution and morphological properties of the PN, with special emphasis on the cellular and architectural characterization of its intramural branching structure, mesh-like sub-endocardial network, and the PMJs in adult pig hearts by both histopathological and morphometric evaluation. We have defined three main patterns of PMJ: contact through cell bodies, contact through cell prolongations either thick or piliform, and contact through transitional cells. Moreover, from hundreds of micrographs, we quantified the density of PMJs and provided data for the basal/medial/apical regions, anterior/posterior/septal/lateral regions and myocardial/sub-endocardial distribution. Morphometric variables, such as Purkinje cell density and thickness of the bundles, were also analyzed. After combining the results of these parameters, a different septoanterior distribution in the Purkinje cell density was observed towards the cardiac apex, which is associated with a progressive thinning of the conduction bundles and the posterolateral ascension of intramyocardial terminal scattered fibers. The study of the PMJs revealed a decreasing trend towards the base that may anatomically explain the early apical activation. The anterolateral region contains the greatest number of contacts, followed by the anterior and septal regions. This supports the hypothesis that thin distal Purkinje bundles create a junction-rich network that may be responsible for the quick apical depolarization. The PN then ascends laterally and spreads through the anterior and medial walls up to the base. We have established the first morphometric study of the Purkinje system, and provided quantitative and objective data that facilitate its incorporation into the development of models beyond gross and variable pathological descriptions, and which, after further studies, could be useful in the characterization of pathological processes or therapeutic procedures.
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Affiliation(s)
- V Garcia-Bustos
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain
| | - R Sebastian
- Computational Multiscale Simulation Lab, Universitat de Valencia, Valencia, Spain
| | - M Izquierdo
- INCLIVA Biomedical Research Institute, Valencia, Spain.,Cardiology Unit, Hospital Clinico Universitario de Valencia, Valencia, Spain
| | - P Molina
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain
| | - F J Chorro
- INCLIVA Biomedical Research Institute, Valencia, Spain.,Cardiology Unit, Hospital Clinico Universitario de Valencia, Valencia, Spain
| | - A Ruiz-Sauri
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain.,INCLIVA Biomedical Research Institute, Valencia, Spain
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21
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Murray LE, Smith AH, Flack EC, Crum K, Owen J, Kannankeril PJ. Genotypic and phenotypic predictors of complete heart block and recovery of conduction after surgical repair of congenital heart disease. Heart Rhythm 2017; 14:402-409. [PMID: 27826129 PMCID: PMC5345747 DOI: 10.1016/j.hrthm.2016.11.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Complete heart block (CHB) is a major complication that occurs after congenital heart surgery. We hypothesized that genetic and clinical factors are associated with the development of postoperative CHB and recovery of atrioventricular (AV) conduction. OBJECTIVE The purpose of this study was to identify predictors of CHB and recovery after congenital heart surgery. METHODS Patients undergoing congenital heart surgery at our institution from September 2007 through June 2015 were prospectively enrolled in a parent study of postoperative arrhythmias. Patients with onset of CHB within 48 hours postoperatively were included in the study. Daily rhythm assessment was performed until demonstration of 1:1 conduction or pacemaker implantation. RESULTS Of 1199 subjects enrolled, 56 (4.7%) developed postoperative CHB. In multivariate analysis, preoperative digoxin exposure (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.3-4.4), aortic cross-clamp time (OR 1.08, 95% CI 1.04-1.11), ventricular septal defect closure (OR 2.2, 95% CI 1.2-4.1), and a common polymorphism in the gene encoding connexin-40 (GJA5 rs10465885 TT genotype; OR 2.1, 95% CI 1.2-3.8) were independently associated with postoperative CHB. Junctional acceleration (JA) (OR 4.0, 95% CI 1.1-15.1) and intermittent conduction noted during complete AV block (OR 9.1, 95% CI 1.0-80) were independently associated with 1:1 AV conduction recovery. Use of a multivariate model including both JA and intermittent conduction demonstrated good discrimination with a positive predictive value of 86% (95% CI 67%-96%) in predicting 1:1 conduction recovery. CONCLUSION Preoperative factors, including a missense polymorphism in GJA5, are independently associated with increased risk for CHB. JA and intermittent conduction may prove useful in predicting recovery of AV conduction among patients with CHB after congenital heart surgery.
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Affiliation(s)
- Laura E Murray
- Vanderbilt University Medical Center, Nashville, Tennessee.
| | - Andrew H Smith
- Department of Pediatrics, Thomas P. Graham Jr. Division of Cardiology, Nashville, Tennessee,; Division of Critical Care Medicine, Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee
| | - English C Flack
- Department of Pediatrics, Thomas P. Graham Jr. Division of Cardiology, Nashville, Tennessee
| | - Kim Crum
- Department of Pediatrics, Thomas P. Graham Jr. Division of Cardiology, Nashville, Tennessee
| | - Jill Owen
- Department of Pediatrics, Thomas P. Graham Jr. Division of Cardiology, Nashville, Tennessee
| | - Prince J Kannankeril
- Department of Pediatrics, Thomas P. Graham Jr. Division of Cardiology, Nashville, Tennessee
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22
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HD Physiology Project-Japanese efforts to promote multilevel integrative systems biology and physiome research. NPJ Syst Biol Appl 2017. [PMID: 28649429 PMCID: PMC5445586 DOI: 10.1038/s41540-016-0001-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The HD Physiology Project is a Japanese research consortium that aimed to develop methods and a computational platform in which physiological and pathological information can be described in high-level definitions across multiple scales of time and size. During the 5 years of this project, an appropriate software platform for multilevel functional simulation was developed and a whole-heart model including pharmacokinetics for the assessment of the proarrhythmic risk of drugs was developed. In this article, we outline the description and scientific strategy of this project and present the achievements and influence on multilevel integrative systems biology and physiome research.
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Progressive cardiac conduction disease associated with a DSP gene mutation. Int J Cardiol 2016; 216:188-9. [DOI: 10.1016/j.ijcard.2016.04.164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 04/29/2016] [Indexed: 11/19/2022]
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Karademir LB, Aoyama H, Yue B, Chen H, Bai D. Engineered Cx26 variants established functional heterotypic Cx26/Cx43 and Cx26/Cx40 gap junction channels. Biochem J 2016; 473:1391-403. [PMID: 26987811 DOI: 10.1042/bcj20160200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/16/2016] [Indexed: 12/16/2023]
Abstract
Gap junction (GJ) channels mediate direct intercellular communication and are composed of two docked hemichannels (connexin oligomers). It is well documented that the docking and formation of GJs are possible only between compatible hemichannels (or connexins). The mechanisms of heterotypic docking compatibility are not fully clear. We aligned the protein sequences of docking-compatible and -incompatible connexins with that of connexin26 (Cx26). We found that two docking hydrogen bond (HB)-forming residues on the second extracellular domain (E2) of Cx26 and their equivalent residues are well conserved within docking-compatible connexins, but different between docking-incompatible connexins. Replacing one or both of these residues of Cx26 into the corresponding residues in the docking incompatible connexins (K168V, N176H or K168V-N176H) increased the formation of morphological and functional heterotypic GJs with connexin43 (Cx43) or connexin40 (Cx40), indicating that these two residues are important for docking incompatibility between Cx26 and these connexins. Our homology structure models predict that both HBs and hydrophobic interactions at the E2 docking interface are important docking mechanisms in heterotypic Cx26 K168V-N176H/Cx43 GJs and probably other docking compatible connexins. Revealing the key residues and mechanisms of heterotypic docking compatibility will assist us in understanding why these putative docking residues are hotspots of disease-linked mutants.
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Affiliation(s)
- Levent B Karademir
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada, N6A 5C1
| | - Hiroshi Aoyama
- Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Benny Yue
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada, N6A 5C1
| | - Honghong Chen
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada, N6A 5C1
| | - Donglin Bai
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada, N6A 5C1
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Savi M, Bocchi L, Rossi S, Frati C, Graiani G, Lagrasta C, Miragoli M, Di Pasquale E, Stirparo GG, Mastrototaro G, Urbanek K, De Angelis A, Macchi E, Stilli D, Quaini F, Musso E. Antiarrhythmic effect of growth factor-supplemented cardiac progenitor cells in chronic infarcted heart. Am J Physiol Heart Circ Physiol 2016; 310:H1622-48. [PMID: 26993221 DOI: 10.1152/ajpheart.00035.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/10/2016] [Indexed: 12/12/2022]
Abstract
c-Kit(pos) cardiac progenitor cells (CPCs) represent a successful approach in healing the infarcted heart and rescuing its mechanical function, but electrophysiological consequences are uncertain. CPC mobilization promoted by hepatocyte growth factor (HGF) and IGF-1 improved electrogenesis in myocardial infarction (MI). We hypothesized that locally delivered CPCs supplemented with HGF + IGF-1 (GFs) can concur in ameliorating electrical stability of the regenerated heart. Adult male Wistar rats (139 rats) with 4-wk-old MI or sham conditions were randomized to receive intramyocardial injection of GFs, CPCs, CPCs + GFs, or vehicle (V). Enhanced green fluorescent protein-tagged CPCs were used for cell tracking. Vulnerability to stress-induced arrhythmia was assessed by telemetry-ECG. Basic cardiac electrophysiological properties were examined by epicardial multiple-lead recording. Hemodynamic function was measured invasively. Hearts were subjected to anatomical, morphometric, immunohistochemical, and molecular biology analyses. Compared with V and at variance with individual CPCs, CPCs + GFs approximately halved arrhythmias in all animals, restoring cardiac anisotropy toward sham values. GFs alone reduced arrhythmias by less than CPCs + GFs, prolonging ventricular refractoriness without affecting conduction velocity. Concomitantly, CPCs + GFs reactivated the expression levels of Connexin-43 and Connexin-40 as well as channel proteins of key depolarizing and repolarizing ion currents differently than sole GFs. Mechanical function and anatomical remodeling were equally improved by all regenerative treatments, thus exhibiting a divergent behavior relative to electrical aspects. Conclusively, we provided evidence of distinctive antiarrhythmic action of locally injected GF-supplemented CPCs, likely attributable to retrieval of Connexin-43, Connexin-40, and Cav1.2 expression, favoring intercellular coupling and spread of excitation in mended heart.
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Affiliation(s)
- Monia Savi
- Department of Life Sciences, University of Parma, Italy
| | | | - Stefano Rossi
- Department of Life Sciences, University of Parma, Italy
| | - Caterina Frati
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Italy
| | - Gallia Graiani
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Italy
| | - Costanza Lagrasta
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Italy; Cardiac Stem Cell Interdepartmental Center "CISTAC," University of Parma, Italy
| | | | - Elisa Di Pasquale
- Humanitas Clinical and Research Center, Rozzano (MI), Italy; Institute of Genetic and Biomedical Research-UOS Milan-National Research Council, Milan, Italy
| | | | | | - Konrad Urbanek
- Department of Experimental Medicine, Section of Pharmacology, Second University of Naples, Italy
| | - Antonella De Angelis
- Department of Experimental Medicine, Section of Pharmacology, Second University of Naples, Italy
| | - Emilio Macchi
- Department of Life Sciences, University of Parma, Italy; Cardiac Stem Cell Interdepartmental Center "CISTAC," University of Parma, Italy
| | - Donatella Stilli
- Department of Life Sciences, University of Parma, Italy; Cardiac Stem Cell Interdepartmental Center "CISTAC," University of Parma, Italy
| | - Federico Quaini
- Department of Clinical and Experimental Medicine, University of Parma, Italy; Cardiac Stem Cell Interdepartmental Center "CISTAC," University of Parma, Italy
| | - Ezio Musso
- Department of Life Sciences, University of Parma, Italy; Cardiac Stem Cell Interdepartmental Center "CISTAC," University of Parma, Italy
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Daumy X, Amarouch MY, Lindenbaum P, Bonnaud S, Charpentier E, Bianchi B, Nafzger S, Baron E, Fouchard S, Thollet A, Kyndt F, Barc J, Le Scouarnec S, Makita N, Le Marec H, Dina C, Gourraud JB, Probst V, Abriel H, Redon R, Schott JJ. Targeted resequencing identifies TRPM4 as a major gene predisposing to progressive familial heart block type I. Int J Cardiol 2016; 207:349-58. [PMID: 26820365 DOI: 10.1016/j.ijcard.2016.01.052] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/05/2015] [Accepted: 01/01/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Progressive cardiac conduction disease (PCCD) is one of the most common cardiac conduction disturbances. It has been causally related to rare mutations in several genes including SCN5A, SCN1B, TRPM4, LMNA and GJA5. METHODS AND RESULTS In this study, by applying targeted next-generation sequencing (NGS) in 95 unrelated patients with PCCD, we have identified 13 rare variants in the TRPM4 gene, two of which are currently absent from public databases. This gene encodes a cardiac calcium-activated cationic channel which precise role and importance in cardiac conduction and disease is still debated. One novel variant, TRPM4-p.I376T, is carried by the proband of a large French 4-generation pedigree. Systematic familial screening showed that a total of 13 family members carry the mutation, including 10 out of the 11 tested affected individuals versus only 1 out of the 21 unaffected ones. Functional and biochemical analyses were performed using HEK293 cells, in whole-cell patch-clamp configuration and Western blotting. TRPM4-p.I376T results in an increased current density concomitant to an augmented TRPM4 channel expression at the cell surface. CONCLUSIONS This study is the first extensive NGS-based screening of TRPM4 coding variants in patients with PCCD. It reports the third largest pedigree diagnosed with isolated Progressive Familial Heart Block type I and confirms that this subtype of PCCD is caused by mutation-induced gain-of-expression and function of the TRPM4 ion channel.
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Affiliation(s)
- Xavier Daumy
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France
| | - Mohamed-Yassine Amarouch
- Department of Clinical Research, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Switzerland
| | - Pierre Lindenbaum
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Stéphanie Bonnaud
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Eric Charpentier
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France
| | - Beatrice Bianchi
- Department of Clinical Research, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Switzerland
| | - Sabine Nafzger
- Department of Clinical Research, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Switzerland
| | - Estelle Baron
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France
| | - Swanny Fouchard
- Department of Clinical Research, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Switzerland
| | - Aurélie Thollet
- Department of Clinical Research, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Switzerland
| | - Florence Kyndt
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Julien Barc
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France
| | - Solena Le Scouarnec
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France
| | - Naomasa Makita
- Molecular Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Hervé Le Marec
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Christian Dina
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Jean-Baptiste Gourraud
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Vincent Probst
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Hugues Abriel
- Department of Clinical Research, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, Switzerland.
| | - Richard Redon
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France
| | - Jean-Jacques Schott
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1087, l'institut du thorax, Nantes, France; Centre National de la Recherche Scientifique (CNRS) UMR 6291, l'institut du thorax, Nantes, France; Université de Nantes, l'institut du thorax, Nantes, France; Centre Hospitalier Universitaire (CHU) de Nantes, l'institut du thorax, Service de Cardiologie, Nantes, France.
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Baruteau AE, Pass RH, Thambo JB, Behaghel A, Le Pennec S, Perdreau E, Combes N, Liberman L, McLeod CJ. Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management. Eur J Pediatr 2016; 175:1235-1248. [PMID: 27351174 PMCID: PMC5005411 DOI: 10.1007/s00431-016-2748-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 06/13/2016] [Accepted: 06/16/2016] [Indexed: 02/07/2023]
Abstract
UNLABELLED Atrioventricular block is classified as congenital if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental passage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive cardiac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe permanent cardiac pacing in almost all patients, including those with structural heart abnormalities. CONCLUSION Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death, and this review critically assesses our current understanding of the pathogenetic mechanisms, clinical course, and optimal management of congenital and childhood AV block. WHAT IS KNOWN • Prevalence of congenital heart block of 1 per 15,000 to 20,000 live births. AV block is defined as congenital if diagnosed in utero, at birth, or within the first month of life, whereas childhood AV block is diagnosed between the first month and the 18th year of life. As a result of several different etiologies, congenital and childhood atrioventricular block may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease. Cardiac pacing is indicated in symptomatic patients and has several prophylactic indications in asymptomatic patients to prevent sudden death. • Autoimmune, congenital AV block is associated with a high neonatal mortality rate and development of dilated cardiomyopathy in 5 to 30 % cases. What is New: • Several genes including SCN5A have been implicated in autosomal dominant forms of familial progressive cardiac conduction disorders. • Leadless pacemaker technology and gene therapy for biological pacing are promising research fields. In utero percutaneous pacing appears to be at high risk and needs further development before it can be adopted into routine clinical practice. Cardiac resynchronization therapy is of proven value in case of pacing-induced cardiomyopathy.
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Affiliation(s)
- Alban-Elouen Baruteau
- Cardiovascular and Cell Sciences Research Center, St George's University of London, London, UK. .,LIRYC Institute, CHU Bordeaux, Department of Pediatric Cardiology, Bordeaux-II University, Bordeaux, France. .,Service de Cardiologie Pédiatrique, Hôpital du Haut Lévèque, Institut Hospitalo-Universitaire LIRYC (Electrophysiology and Heart Modeling Institute), 5 avenue de Magellan, 33600, Pessac, France.
| | - Robert H. Pass
- Division of Pediatric Electrophysiology, Albert Einstein College of Medicine, Montefiore Children’s Hospital, Bronx, NY USA
| | - Jean-Benoit Thambo
- LIRYC Institute, CHU Bordeaux, Department of Pediatric Cardiology, Bordeaux-II University, Bordeaux, France
| | - Albin Behaghel
- CHU Rennes, Department of Cardiology, LTSI, INSERM 1099, Rennes-1 University, Rennes, France
| | - Solène Le Pennec
- CHU Rennes, Department of Cardiology, LTSI, INSERM 1099, Rennes-1 University, Rennes, France
| | - Elodie Perdreau
- LIRYC Institute, CHU Bordeaux, Department of Pediatric Cardiology, Bordeaux-II University, Bordeaux, France
| | - Nicolas Combes
- Department of Cardiology, Clinique Pasteur, Toulouse, France
| | - Leonardo Liberman
- Morgan Stanley Children’s Hospital, Division of Pediatric Cardiology, New York Presbyterian Hospital, Columbia University Medical Center, New York, NY USA
| | - Christopher J. McLeod
- Mayo Clinic, Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Rochester, MN USA
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Ishikawa T, Tsuji Y, Makita N. Inherited bradyarrhythmia: A diverse genetic background. J Arrhythm 2015; 32:352-358. [PMID: 27761158 PMCID: PMC5063261 DOI: 10.1016/j.joa.2015.09.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/03/2015] [Accepted: 09/16/2015] [Indexed: 12/31/2022] Open
Abstract
Bradyarrhythmia is a common heart rhythm abnormality comprising number of diseases and is associated with decreased heart rate due to the failure of action potential generation and propagation at the sinus node. Permanent pacemaker implantation is often used therapeutically to compensate for decreased heart rate and cardiac output. The vast majority of bradyarrhythmia cases are attributable either to aging or to structural abnormalities of the cardiac conduction system, caused by underlying structural heart disease. However, there is a subset of bradyarrhythmia primarily caused by genetic defects in the absence of aging or underlying structural heart disease. These include several genes that play principal roles in cardiac electrophysiology, heart development, cardioprotection, and the structural integrity of the membrane and sarcomere. Recent advances in the functional analysis of mutations using a heterologous expression system and genetically engineered animal models have provided significant insights into the underlying molecular mechanisms responsible for inherited arrhythmia. In this review, current understandings of the genetic and molecular basis of inherited bradyarrhythmia are presented.
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Affiliation(s)
- Taisuke Ishikawa
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Yukiomi Tsuji
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Naomasa Makita
- Department of Molecular Physiology, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
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Chaston DJ, Haddock RE, Howitt L, Morton SK, Brown RD, Matthaei KI, Hill CE. Perturbation of chemical coupling by an endothelial Cx40 mutant attenuates endothelium-dependent vasodilation by KCa channels and elevates blood pressure in mice. Pflugers Arch 2015; 467:1997-2009. [PMID: 25369777 DOI: 10.1007/s00424-014-1640-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/16/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
Mutant forms of connexin40 (Cx40) exist in the human population and predispose carriers to atrial fibrillation. Since endothelial expression of Cx40 is important for electrical and chemical communication within the arterial wall, carriers of mutant Cx40 proteins may be predisposed to peripheral arterial dysfunction and dysregulation of blood pressure. We have therefore studied mice expressing either a chemically dysfunctional mutant, Cx40T202S, or wild-type Cx40, with native Cx40, specifically in the endothelium. Blood pressure was measured by telemetry under normal conditions and during cardiovascular stress induced by locomotor activity, phenylephrine or nitric oxide blockade (N(ɷ)-nitro-L-arginine methyl ester hydroxide, L-NAME). Blood pressure of Cx40T202STg mice was significantly elevated at night when compared with wild-type or Cx40Tg mice, without change in mean heart rate, pulse pressure or locomotor activity. Analysis over 24 h showed that blood pressure of Cx40T202STg mice was significantly elevated at rest and additionally during locomotor activity. In contrast, neither plasma renin concentration nor pressor responses to phenylephrine or L-NAME were altered, the latter indicating that nitric oxide bioavailability was normal. In isolated, pressurised mesenteric arteries, hyperpolarisation and vasodilation evoked by SKA-31, the selective modulator of SKCa and IKCa channels, was significantly reduced in Cx40T202STg mice, due to attenuation of the SKCa component. Acetylcholine-induced ascending vasodilation in vivo was also significantly attenuated in cremaster muscle arterioles of Cx40T202STg mice, compared to wild-type and Cx40Tg mice. We conclude that endothelial expression of the chemically dysfunctional Cx40T202S reduces peripheral vasodilator capacity mediated by SKCa-dependent hyperpolarisation and also increases blood pressure.
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Affiliation(s)
- Daniel J Chaston
- John Curtin School of Medical Research, Australian National University, Canberra, ACT, 0200, Australia
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Abstract
PURPOSE OF REVIEW Progressive cardiac conduction disorder (PCCD) is an inherited cardiac disease that may present as a primary electrical disease or be associated with structural heart disease. In this brief review, we present recent clinical, genetic, and molecular findings relating to PCCD. RECENT FINDINGS Inherited PCCD in structurally normal hearts has been found to be linked to genetic variants in the ion channel genes SCN5A, SCN1B, SCN10A, TRPM4, and KCNK17, as well as in genes coding for cardiac connexin proteins. In addition, several SCN5A mutations lead to 'cardiac sodium channelopathy overlap syndrome'. Other genes coding for cardiac transcription factors, such as NKX2.5 and TBX5, are involved in the development of the cardiac conduction system and in the morphogenesis of the heart. Mutations in these two genes have been shown to cause cardiac conduction disorders associated with various congenital heart defects. SUMMARY PCCD is a hereditary syndrome, and genetic variants in multiple genes have been described to date. Genetic screening and identification of the causal mutation are crucial for risk stratification and family counselling.
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31
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Daimi H, Khelil AH, Ben Hamda K, Aranega A, Chibani JBE, Franco D. Absence of family history and phenotype-genotype correlation in pediatric Brugada syndrome: more burden to bear in clinical and genetic diagnosis. Pediatr Cardiol 2015; 36:1090-6. [PMID: 25758664 DOI: 10.1007/s00246-015-1133-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 03/04/2015] [Indexed: 11/29/2022]
Abstract
Brugada syndrome (BrS) is an autosomal-dominant genetic cardiac disorder caused in 18-30 % of the cases by SCN5A gene mutations and manifested by an atypical right bundle block pattern with ST segment elevation and T wave inversion in the right precordial leads. The syndrome is usually detected after puberty. The identification of BrS in pediatric patients is thus a rare occurrence, and most of the reported cases are unmasked after febrile episodes. Usually, having a family history of sudden death represents the first reason to perform an ECG in febrile children. However, this practice makes the sporadic cases of cardiac disease and specially the asymptomatic ones excluded from this diagnosis. Here, we report a sporadic case of a 2-month-old male patient presented with vaccination-related fever and ventricular tachycardia associated with short breathing, palpitation and cold sweating. ECG changes were consistent with type 1 BrS. SCN5A gene analysis of the proband and his family revealed a set of mutations and polymorphisms differentially distributed among family members, however, without any clear genotype-phenotype correlation. Based on our findings, we think that genetic testing should be pursued as a routine practice in symptomatic and asymptomatic pediatric cases of BrS, with or without family history of sudden cardiac death. Similarly, our study suggests that pediatrician should be encouraged to perform an ECG profiling in suspicious febrile children and quickly manage fever since it is the most important factor unmasking BrS in children.
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Affiliation(s)
- Houria Daimi
- Department of Experimental Biology, University of Jaen, 23071, Jaén, Spain
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Aburawi EH, Aburawi HE, Bagnall KM, Bhuiyan ZA. Molecular insight into heart development and congenital heart disease: An update review from the Arab countries. Trends Cardiovasc Med 2014; 25:291-301. [PMID: 25541328 DOI: 10.1016/j.tcm.2014.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 11/14/2014] [Accepted: 11/14/2014] [Indexed: 02/07/2023]
Abstract
Congenital heart defect (CHD) has a major influence on affected individuals as well as on the supportive and associated environment such as the immediate family. Unfortunately, CHD is common worldwide with an incidence of approximately 1% and consequently is a major health concern. The Arab population has a high rate of consanguinity, fertility, birth, and annual population growth, in addition to a high incidence of diabetes mellitus and obesity. All these factors may lead to a higher incidence and prevalence of CHD within the Arab population than in the rest of the world, making CHD of even greater concern. Sadly, most Arab countries lack appropriate public health measures directed toward the control and prevention of congenital malformations and so the importance of CHD within the population remains unknown but is thought to be high. In approximately 85% of CHD patients, the multifactorial theory is considered as the pathologic basis. The genetic risk factors for CHD can be attributed to large chromosomal aberrations, copy number variations (CNV) of particular regions in the chromosome, and gene mutations in specific nuclear transcription pathways and in the genes that are involved in cardiac structure and development. The application of modern molecular biology techniques such as high-throughput nucleotide sequencing and chromosomal array and methylation array all have the potential to reveal more genetic defects linked to CHD. Exploring the genetic defects in CHD pathology will improve our knowledge and understanding about the diverse pathways involved and also about the progression of this disease. Ultimately, this will link to more efficient genetic diagnosis and development of novel preventive therapeutic strategies, as well as gene-targeted clinical management. This review summarizes our current understanding of the molecular basis of normal heart development and the pathophysiology of a wide range of CHD. The risk factors that might account for the high prevalence of CHD within the Arab population and the measures required to be undertaken for conducting research into CHD in Arab countries will also be discussed.
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Affiliation(s)
- Elhadi H Aburawi
- Department of Pediatrics, United Arab Emirates University, Al-Ain, UAE
| | - Hanan E Aburawi
- Department of Biology, Faculty of Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Keith M Bagnall
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, UAE
| | - Zahurul A Bhuiyan
- Laboratoire de Diagnostic Moléculaire, Service de Génétique Médicale, BH19_512, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, Lausanne CH-1011, Switzerland.
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Molica F, Meens MJP, Morel S, Kwak BR. Mutations in cardiovascular connexin genes. Biol Cell 2014; 106:269-93. [PMID: 24966059 DOI: 10.1111/boc.201400038] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/20/2014] [Indexed: 12/25/2022]
Abstract
Connexins (Cxs) form a family of transmembrane proteins comprising 21 members in humans. Cxs differ in their expression patterns, biophysical properties and ability to combine into homomeric or heteromeric gap junction channels between neighbouring cells. The permeation of ions and small metabolites through gap junction channels or hemichannels confers a crucial role to these proteins in intercellular communication and in maintaining tissue homeostasis. Among others, Cx37, Cx40, Cx43, Cx45 and Cx47 are found in heart, blood and lymphatic vessels. Mutations or polymorphisms in the genes coding for these Cxs have not only been implicated in cardiovascular pathologies but also in a variety of other disorders. While mutations in Cx43 are mostly linked to oculodentodigital dysplasia, Cx47 mutations are associated with Pelizaeus-Merzbacher-like disease and lymphoedema. Cx40 mutations are principally linked to atrial fibrillation. Mutations in Cx37 have not yet been described, but polymorphisms in the Cx37 gene have been implicated in the development of arterial disease. This review addresses current knowledge on gene mutations in cardiovascular Cxs systematically and links them to alterations in channel properties and disease.
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Affiliation(s)
- Filippo Molica
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland; Department of Medical Specializations - Cardiology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Kusumoto S, Kawano H, Makita N, Ichimaru S, Kaku T, Haruta D, Hida A, Sera N, Imaizumi M, Nakashima E, Maemura K, Akahoshi M. Right bundle branch block without overt heart disease predicts higher risk of pacemaker implantation: The study of atomic-bomb survivors. Int J Cardiol 2014; 174:77-82. [DOI: 10.1016/j.ijcard.2014.03.152] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 02/14/2014] [Accepted: 03/22/2014] [Indexed: 11/26/2022]
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Bai D. Atrial fibrillation-linked GJA5/connexin40 mutants impaired gap junctions via different mechanisms. FEBS Lett 2014; 588:1238-43. [PMID: 24656738 DOI: 10.1016/j.febslet.2014.02.064] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/05/2014] [Accepted: 02/06/2014] [Indexed: 01/08/2023]
Abstract
The gap junctions (GJs) formed by Cx40 and Cx43 provide a low resistance passage allowing for rapid propagation of action potentials. Sporadic somatic mutations in GJA5 (encoding Cx40) have been identified in lone atrial fibrillation (AF) patients. More recently germline autosomal dominantly inherited mutations in GJA5 have been found in early onset lone AF patients in several families over generations. Characterizations of these AF-linked Cx40 mutants in model cells and in patient tissues revealed that some of the mutants reduced GJ channel function due to an impaired trafficking or channel formation. While others showed a gain-of-function in hemichannels. These functional alterations in GJs or hemichannel may play an important role in the pathogenesis of AF in the mutant carriers.
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Affiliation(s)
- Donglin Bai
- Department of Physiology and Pharmacology, Western University, London, Ontario N6A 5C1, Canada.
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Mezzano V, Pellman J, Sheikh F. Cell junctions in the specialized conduction system of the heart. ACTA ACUST UNITED AC 2014; 21:149-59. [PMID: 24738884 DOI: 10.3109/15419061.2014.905928] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Anchoring cell junctions are integral in maintaining electro-mechanical coupling of ventricular working cardiomyocytes; however, their role in cardiomyocytes of the cardiac conduction system (CCS) remains less clear. Recent studies in genetic mouse models and humans highlight the appearance of these cell junctions alongside gap junctions in the CCS and also show that defects in these structures and their components are associated with conduction impairments in the CCS. Here we outline current evidence supporting an integral relationship between anchoring and gap junctions in the CCS. Specifically we focus on (1) molecular and ultrastructural evidence for cell-cell junctions in specialized cardiomyocytes of the CCS, (2) genetic mouse models specifically targeting cell-cell junction components in the heart which exhibit CCS conduction defects and (3) human clinical studies from patients with cell-cell junction-based diseases that exhibit CCS electrophysiological defects.
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Affiliation(s)
- Valeria Mezzano
- Leon H. Charney Division of Cardiology, New York University School of Medicine , New York , New York
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Extracellular domains play different roles in gap junction formation and docking compatibility. Biochem J 2014; 458:1-10. [PMID: 24438327 DOI: 10.1042/bj20131162] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
GJ (gap junction) channels mediate direct intercellular communication and play an important role in many physiological processes. Six connexins oligomerize to form a hemichannel and two hemichannels dock together end-to-end to form a GJ channel. Connexin extracellular domains (E1 and E2) have been shown to be important for the docking, but the molecular mechanisms behind the docking and formation of GJ channels are not clear. Recent developments in atomic GJ structure and functional studies on a series of connexin mutants revealed that E1 and E2 are likely to play different roles in the docking. Non-covalent interactions at the docking interface, including hydrogen bonds, are predicted to form between interdocked extracellular domains. Protein sequence alignment analysis on the docking compatible/incompatible connexins indicate that the E1 domain is important for the formation of the GJ channel and the E2 domain is important in the docking compatibility in heterotypic channels. Interestingly, the hydrogen-bond forming or equivalent residues in both E1 and E2 domains are mutational hot spots for connexin-linked human diseases. Understanding the molecular mechanisms of GJ docking can assist us to develop novel strategies in rescuing the disease-linked connexin mutants.
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Exome analysis–based molecular autopsy in cases of sudden unexplained death in the young. Heart Rhythm 2014; 11:655-62. [DOI: 10.1016/j.hrthm.2014.01.017] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Indexed: 11/20/2022]
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Kawakami H, Aiba T, Yamada T, Okayama H, Kazatani Y, Konishi K, Nakajima I, Miyamoto K, Yamada Y, Okamura H, Noda T, Satomi K, Kamakura S, Makita N, Shimizu W. Variable phenotype expression with a frameshift mutation of the cardiac sodium channel gene SCN5A. J Arrhythm 2013. [DOI: 10.1016/j.joa.2013.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Current perspectives in genetic cardiovascular disorders: from basic to clinical aspects. Heart Vessels 2013; 29:129-41. [PMID: 23907713 DOI: 10.1007/s00380-013-0391-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 06/27/2013] [Indexed: 12/18/2022]
Abstract
We summarize recent advances in the clinical genetics of hypercholesterolemia, hypertrophic cardiomyopathy (HCM), and lethal arrhythmia, all of which are monogenic cardiovascular diseases being essential to understanding the heart and circulatory pathophysiology. Among the issues of hypercholesterolemia which play a pivotal role in development of vascular damages, familial hypercholesterolemia is the common genetic cardiovascular disease; in addition to identifying the gene mutation coding low-density lipoprotein receptor, lipid kinetics in autosomal recessive hypercholesterolemia as well as in proprotein convertase subtilisin/kexin 9 gene mutation were recently demonstrated. As for HCM, some gene mutations were identified to correlate with clinical manifestations. Additionally, a gene polymorphism of the renin-angiotensin system in development of heart failure was identified as a modifier gene. The lethal arrhythmias such as sudden death syndromes, QT prolongation, and Brugada syndrome were found to exhibit gene mutation coding potassium and/or sodium ion channels. Interestingly, functional analysis of these gene mutations helped to identify the role of each gene mutation in developing these cardiovascular disorders. We suggest considering the genetic mechanisms of cardiovascular diseases associated with hyperlipidemia, myocardial hypertrophy, or lethal arrhythmia in terms of not only clinical diagnosis but also understanding pathophysiology of each disease with therapeutic aspects.
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Chaston DJ, Baillie BK, Grayson TH, Courjaret RJ, Heisler JM, Lau KA, Machaca K, Nicholson BJ, Ashton A, Matthaei KI, Hill CE. Polymorphism in endothelial connexin40 enhances sensitivity to intraluminal pressure and increases arterial stiffness. Arterioscler Thromb Vasc Biol 2013; 33:962-70. [PMID: 23471232 DOI: 10.1161/atvbaha.112.300957] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To determine whether impairment of endothelial connexin40 (Cx40), an effect that can occur in hypertension and aging, contributes to the arterial dysfunction and stiffening in these conditions. APPROACH AND RESULTS A new transgenic mouse strain, expressing a mutant Cx40, (Cx40T202S), specifically in the vascular endothelium, has been developed and characterized. This mutation produces nonfunctional hemichannels, whereas gap junctions containing the mutant are electrically, but not chemically, patent. Mesenteric resistance arteries from Cx40T202S mice showed increased sensitivity of the myogenic response to intraluminal pressure in vitro, compared with wild-type mice, whereas transgenic mice overexpressing native Cx40 (Cx40Tg) showed reduced sensitivity. In control and Cx40Tg mice, the sensitivity to pressure of myogenic constriction was modulated by both NO and endothelium-derived hyperpolarization; however, the endothelium-derived hyperpolarization component was absent in Cx40T202S arteries. Analysis of passive mechanical properties revealed that arterial stiffness was enhanced in vessels from Cx40T202S mice, but not in wild-type or Cx40Tg mice. CONCLUSIONS Introduction of a mutant form of Cx40 in the endogenous endothelial Cx40 population prevents endothelium-derived hyperpolarization activation during myogenic constriction, enhancing sensitivity to intraluminal pressure and increasing arterial stiffness. We conclude that genetic polymorphisms in endothelial Cx40 can contribute to the pathogenesis of arterial disease.
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Affiliation(s)
- Daniel J Chaston
- John Curtin School of Medical Research, The Australian National University, Bldg 131 Garran Rd, Acton Australian Capital Territory 0200 Australia.
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