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Røsand Ø, Wang J, Scrimgeour N, Marwarha G, Høydal MA. Exosomal Preconditioning of Human iPSC-Derived Cardiomyocytes Beneficially Alters Cardiac Electrophysiology and Micro RNA Expression. Int J Mol Sci 2024; 25:8460. [PMID: 39126028 PMCID: PMC11313350 DOI: 10.3390/ijms25158460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
Experimental evidence, both in vitro and in vivo, has indicated cardioprotective effects of extracellular vesicles (EVs) derived from various cell types, including induced pluripotent stem cell-derived cardiomyocytes. The biological effects of EV secretion, particularly in the context of ischemia and cardiac electrophysiology, remain to be fully explored. Therefore, the goal of this study was to unveil the effects of exosome (EXO)-mediated cell-cell signaling during hypoxia by employing a simulated preconditioning approach on human-induced pluripotent stem cell-derived cardiomyocytes (hIPSC-CMs). Electrophysiological activity of hIPSC-CMs was measured using a multielectrode array (MEA) system. A total of 16 h of hypoxic stress drastically increased the beat period. Moreover, hIPSC-CMs preconditioned with EXOs displayed significantly longer beat periods compared with non-treated cells after 16 h of hypoxia (+15.7%, p < 0.05). Furthermore, preconditioning with hypoxic EXOs resulted in faster excitation-contraction (EC) coupling compared with non-treated hIPSC-CMs after 16 h of hypoxia (-25.3%, p < 0.05). Additionally, microRNA (miR) sequencing and gene target prediction analysis of the non-treated and pre-conditioned hIPSC-CMs identified 10 differentially regulated miRs and 44 gene targets. These results shed light on the intricate involvement of miRs, emphasizing gene targets associated with cell survival, contraction, apoptosis, reactive oxygen species (ROS) regulation, and ion channel modulation. Overall, this study demonstrates that EXOs secreted by hIPSC-CM during hypoxia beneficially alter electrophysiological properties in recipient cells exposed to hypoxic stress, which could play a crucial role in the development of targeted interventions to improve outcomes in ischemic heart conditions.
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Affiliation(s)
| | | | | | | | - Morten Andre Høydal
- Group of Molecular and Cellular Cardiology, Department of Circulation and Medical Imaging, Faculty of Medicine and Health, Norwegian University of Science and Technology (NTNU), 7030 Trondheim, Norway; (Ø.R.); (J.W.); (N.S.); (G.M.)
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2
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Fraile A, Cebrián J, Thuissard-Vasallo I, Pérez-Martín S, Casado R, Gil-Fournier B, Alonso-Martín J, Tamargo J, Caballero R, Delpón E, Cosío FG. Coexistent HCN4 and GATA5 Rare Variants and Atrial Fibrillation in a Large Spanish Family. Can J Cardiol 2024; 40:1270-1280. [PMID: 38432398 DOI: 10.1016/j.cjca.2024.02.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 02/02/2024] [Accepted: 02/28/2024] [Indexed: 03/05/2024] Open
Abstract
BACKGROUND Familial association of atrial fibrillation (AF) can involve single gene variants related to known arrhythmogenic mechanisms; however, genome-wide association studies often disclose complex genetic variants in familial and nonfamilial AF, making it difficult to relate to known pathogenetic mechanisms. METHODS The finding of 4 siblings with AF led to studying 47 members of a family. Long-term Holter monitoring (average 298 hours) ruled out silent AF. Whole-exome sequencing was performed, and variants shared by the index cases were filtered and prioritised according to current recommendations. HCN4 currents (IHCN4) were recorded in Chinese hamster ovary cells expressing human p.P1163H or native HCN4 channels with the use of the patch-clamp technique, and topologically associating domain analyses of GATA5 variant were performed. RESULTS The clinical study diagnosed 2 more AF cases. Five family members carried the heterozygous p.P1163H HCN4 variant, 14 carried the intronic 20,61040536,G,A GATA5 rare variant, and 9 carried both variants (HCN4+GATA5). Five of the 6 AF cases (onset age ranging from 33 to 70 years) carried both variants and 1 carried the GATA5 variant alone. Multivariate analysis showed that the presence of HCN4+GATA5 variants significantly increased AF risk (odds ratio 32.7, 95% confidence interval 1.8-591.4) independently from age, hypertension, and overweight. Functional testing showed that IHCN4 generated by heterozygous p.P1163H were normal. Topologically associating domain analysis suggested that GATA5 could affect the expression of many genes, including those encoding microRNA-1. CONCLUSION The coincidence of 2 rare gene variants was independently associated with AF, but functional studies do not allow the postulation of the arrhythmogenic mechanisms involved.
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Affiliation(s)
- Alfonso Fraile
- Cardiology Department, Hospital Universitario de Getafe, Getafe, Spain.
| | - Jorge Cebrián
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain
| | | | - Sara Pérez-Martín
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain
| | - Raquel Casado
- Cardiology Department, Hospital Universitario de Getafe, Getafe, Spain
| | | | | | - Juan Tamargo
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain
| | - Ricardo Caballero
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain.
| | - Eva Delpón
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Centro de Investigación Biomédica en Red (CIBERCV), Madrid, Spain
| | - Francisco G Cosío
- Department of Biomedical and Health Sciences, Universidad Europea de Madrid, Madrid, Spain
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Vad OB, Olesen MS. Unlocking the Genetic Code: Novel Insights Into Familial Atrial Fibrillation and Gene-Variant Interactions. Can J Cardiol 2024; 40:1281-1282. [PMID: 38042338 DOI: 10.1016/j.cjca.2023.11.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/04/2023] Open
Affiliation(s)
- Oliver B Vad
- Department of Cardiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten S Olesen
- Department of Cardiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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4
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Kampka Z, Drabczyk M, Piłka N, Orszulak M, Rycyk M, Mizia-Stec K, Wybraniec MT. Wide Spectrum of Bradyarrhythmias and Supraventricular Tachyarrhythmias in Sportsmen: Run Forrest, Run?! Rev Cardiovasc Med 2024; 25:221. [PMID: 39076333 PMCID: PMC11270092 DOI: 10.31083/j.rcm2506221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/17/2024] [Accepted: 03/21/2024] [Indexed: 07/31/2024] Open
Abstract
The intricate relationship between sports participation and cardiac arrhythmias is a key focus of cardiovascular research. Physical activity, integral to preventing atherosclerotic cardiovascular disease, induces structural, functional, and electrical changes in the heart, potentially triggering arrhythmias, particularly atrial fibrillation (AF). Despite the cardiovascular benefits, the optimal exercise amount remains unclear, revealing a J-shaped association between AF and exercise. Endurance athletes, particularly males, face elevated AF risks, influenced by age. Risk factors vary among sports modalities, with unique physiological responses in swim training potentially elevating AF risk. Clinical management of AF in athletes necessitates a delicate balance between rhythm control, rate control, and anticoagulation therapy. Sport-induced bradyarrhythmias, including sinus bradycardia and conduction disturbances, are prevalent among athletes. Managing bradycardia in athletes proves challenging due to its complex and not fully understood pathophysiology. Careful consideration is required, particularly in symptomatic cases, where pacemaker implantation may be necessary for sinus node dysfunction. Although pacing is recommended for specific atrioventricular (AV) blocks, milder forms often prevail without restricting sports participation. This review explores the nuanced relationship between exercise and tachy- and bradyarrhythmia in athletes, addressing the challenges clinicians face when optimizing patient care in this distinctive population.
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Affiliation(s)
- Zofia Kampka
- First Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, 40-635 Katowice, Poland
| | - Mateusz Drabczyk
- First Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, 40-635 Katowice, Poland
| | - Nina Piłka
- First Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, 40-635 Katowice, Poland
| | - Michał Orszulak
- First Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, 40-635 Katowice, Poland
- First Department of Cardiology, Upper-Silesian Medical Center, 40-635 Katowice, Poland
| | | | - Katarzyna Mizia-Stec
- First Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, 40-635 Katowice, Poland
- First Department of Cardiology, Upper-Silesian Medical Center, 40-635 Katowice, Poland
- Member of the European Reference Network on Heart Diseases - ERN GUARD-HEART, 1105 AZ Amsterdam, Netherlands
| | - Maciej T. Wybraniec
- First Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, 40-635 Katowice, Poland
- First Department of Cardiology, Upper-Silesian Medical Center, 40-635 Katowice, Poland
- Member of the European Reference Network on Heart Diseases - ERN GUARD-HEART, 1105 AZ Amsterdam, Netherlands
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Kim D, Roh H, Lee HM, Kim SJ, Im M. Localization of hyperpolarization-activated cyclic nucleotide-gated channels in the vertebrate retinas across species and their physiological roles. Front Neuroanat 2024; 18:1385932. [PMID: 38562955 PMCID: PMC10982330 DOI: 10.3389/fnana.2024.1385932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
Transmembrane proteins known as hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control the movement of Na+ and K+ ions across cellular membranes. HCN channels are known to be involved in crucial physiological functions in regulating neuronal excitability and rhythmicity, and pacemaker activity in the heart. Although HCN channels have been relatively well investigated in the brain, their distribution and function in the retina have received less attention, remaining their physiological roles to be comprehensively understood. Also, because recent studies reported HCN channels have been somewhat linked with the dysfunction of photoreceptors which are affected by retinal diseases, investigating HCN channels in the retina may offer valuable insights into disease mechanisms and potentially contribute to identifying novel therapeutic targets for retinal degenerative disorders. This paper endeavors to summarize the existing literature on the distribution and function of HCN channels reported in the vertebrate retinas of various species and discuss the potential implications for the treatment of retinal diseases. Then, we recapitulate current knowledge regarding the function and regulation of HCN channels, as well as their relevance to various neurological disorders.
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Affiliation(s)
- Daniel Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Hyeonhee Roh
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Hyung-Min Lee
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Sang Jeong Kim
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science & Technology (UST), Seoul, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul, Republic of Korea
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Lee W, Lin Y, Shih J, Chen Z, Wu N, Chang W. Ivabradine could not decrease mitral regurgitation triggered atrial fibrosis and fibrillation compared with carvedilol. ESC Heart Fail 2024; 11:251-260. [PMID: 37963437 PMCID: PMC10804175 DOI: 10.1002/ehf2.14577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 10/07/2023] [Accepted: 10/19/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Ivabradine, a medical treatment for heart failure (HF), reduces heart rate (HR) and prolongs diastolic perfusion time. It is frequently prescribed to patients with HF who have a suboptimal response or intolerance to beta-blockers. Degenerative mitral regurgitation (MR) is a valvular heart disease often associated with the development of HF and atrial fibrillation (AF). However, studies comparing the effects of ivabradine and beta-blockers on MR are lacking. Therefore, this study aimed to explore the potential therapeutic effects of ivabradine and carvedilol on MR using a rat model. METHODS AND RESULTS Using a novel echo-guided mini-invasive surgery, MR was created in 12-weeks-old Sprague-Dawley rats. After 2 weeks, the rats were randomized to receive either ivabradine or carvedilol for 4 weeks. Echocardiography was performed at baseline and at two-week intervals. Following haemodynamic studies, postmortem tissues were analysed. Notably, the MR-induced myocardial dysfunction did not improve considerably after treatment with ivabradine or carvedilol. However, in haemodynamic studies, pharmacological therapies, particularly carvedilol, mitigated MR-induced chamber dilatation (end-systolic volume and end-diastolic volume; MR vs. MR + Carvedilol; P < 0.05) and decreased compliance (end-systolic pressure-volume relationship; MR vs. MR + Carvedilol; P < 0.05). Compared with ivabradine, a shorter duration (MR vs. MR + Carvedilol; P < 0.05) and reduced inducibility (MR vs. MR + Carvedilol and MR vs. MR + Ivabradine; P < 0.05) of AF were observed in MR rats treated with carvedilol. Similarly, reduced cardiac fibrosis and apoptosis were observed in the MR rat model in the treatment groups, especially in those treated with carvedilol (MR vs. MR + Carvedilol; P < 0.01). CONCLUSIONS Although both ivabradine and carvedilol, at least in part, mitigated MR-induced chamber dilatation and decreased compliance, carvedilol had a better effect on reversing MR-induced cardiac fibrosis, apoptosis, and arrhythmogenesis than ivabradine. When compared with Ivabradine, MR rats treated with carvedilol exhibited a shorter duration and reduced inducibility of AF, thus providing more effective suppression of HCN4. Further investigations are required to validate our findings.
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Affiliation(s)
- Wei‐Chieh Lee
- School of Medicine, College of MedicineNational Sun Yat‐sen UniversityKaohsiungTaiwan
- Department of Internal Medicine, Division of CardiologyChi Mei Medical CenterTainanTaiwan
- College of Medicine, Institute of Clinical MedicineNational Cheng Kung UniversityTainanTaiwan
| | - Yu‐Wen Lin
- Department of Internal Medicine, Division of CardiologyChi Mei Medical CenterTainanTaiwan
| | - Jhih‐Yuan Shih
- School of Medicine, College of MedicineNational Sun Yat‐sen UniversityKaohsiungTaiwan
- Department of Internal Medicine, Division of CardiologyChi Mei Medical CenterTainanTaiwan
| | - Zhih‐Cherng Chen
- School of Medicine, College of MedicineNational Sun Yat‐sen UniversityKaohsiungTaiwan
- Department of Internal Medicine, Division of CardiologyChi Mei Medical CenterTainanTaiwan
| | - Nan‐Chun Wu
- School of Medicine, College of MedicineNational Sun Yat‐sen UniversityKaohsiungTaiwan
- Department of Internal Medicine, Division of CardiologyChi Mei Medical CenterTainanTaiwan
- Department of Surgery, Division of Cardiovascular SurgeryChi Mei Medical CenterTainanTaiwan
- Department of Hospital and Health Care AdministrationChia Nan University of Pharmacy and ScienceTainanTaiwan
| | - Wei‐Ting Chang
- School of Medicine, College of MedicineNational Sun Yat‐sen UniversityKaohsiungTaiwan
- Department of Internal Medicine, Division of CardiologyChi Mei Medical CenterTainanTaiwan
- School of Medicine and Doctoral Program of Clinical and Experimental Medicine, College of Medicine and Center of Excellence for Metabolic Associated Fatty Liver DiseaseNational Sun Yat‐sen UniversityKaohsiungTaiwan
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7
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Verkerk AO, Wilders R. The Action Potential Clamp Technique as a Tool for Risk Stratification of Sinus Bradycardia Due to Loss-of-Function Mutations in HCN4: An In Silico Exploration Based on In Vitro and In Vivo Data. Biomedicines 2023; 11:2447. [PMID: 37760888 PMCID: PMC10525944 DOI: 10.3390/biomedicines11092447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
These days, in vitro functional analysis of gene variants is becoming increasingly important for risk stratification of cardiac ion channelopathies. So far, such risk stratification has been applied to SCN5A, KCNQ1, and KCNH2 gene variants associated with Brugada syndrome and long QT syndrome types 1 and 2, respectively, but risk stratification of HCN4 gene variants related to sick sinus syndrome has not yet been performed. HCN4 is the gene responsible for the hyperpolarization-activated 'funny' current If, which is an important modulator of the spontaneous diastolic depolarization underlying the sinus node pacemaker activity. In the present study, we carried out a risk classification assay on those loss-of-function mutations in HCN4 for which in vivo as well as in vitro data have been published. We used the in vitro data to compute the charge carried by If (Qf) during the diastolic depolarization phase of a prerecorded human sinus node action potential waveform and assessed the extent to which this Qf predicts (1) the beating rate of the comprehensive Fabbri-Severi model of a human sinus node cell with mutation-induced changes in If and (2) the heart rate observed in patients carrying the associated mutation in HCN4. The beating rate of the model cell showed a very strong correlation with Qf from the simulated action potential clamp experiments (R2 = 0.95 under vagal tone). The clinically observed minimum or resting heart rates showed a strong correlation with Qf (R2 = 0.73 and R2 = 0.71, respectively). While a translational perspective remains to be seen, we conclude that action potential clamp on transfected cells, without the need for further voltage clamp experiments and data analysis to determine individual biophysical parameters of If, is a promising tool for risk stratification of sinus bradycardia due to loss-of-function mutations in HCN4. In combination with an If blocker, this tool may also prove useful when applied to human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) obtained from mutation carriers and non-carriers.
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Affiliation(s)
- Arie O. Verkerk
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
- Department of Experimental Cardiology, Heart Center, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Ronald Wilders
- Department of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
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8
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Selewa A, Luo K, Wasney M, Smith L, Sun X, Tang C, Eckart H, Moskowitz IP, Basu A, He X, Pott S. Single-cell genomics improves the discovery of risk variants and genes of atrial fibrillation. Nat Commun 2023; 14:4999. [PMID: 37591828 PMCID: PMC10435551 DOI: 10.1038/s41467-023-40505-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/01/2023] [Indexed: 08/19/2023] Open
Abstract
Genome-wide association studies (GWAS) have linked hundreds of loci to cardiac diseases. However, in most loci the causal variants and their target genes remain unknown. We developed a combined experimental and analytical approach that integrates single cell epigenomics with GWAS to prioritize risk variants and genes. We profiled accessible chromatin in single cells obtained from human hearts and leveraged the data to study genetics of Atrial Fibrillation (AF), the most common cardiac arrhythmia. Enrichment analysis of AF risk variants using cell-type-resolved open chromatin regions (OCRs) implicated cardiomyocytes as the main mediator of AF risk. We then performed statistical fine-mapping, leveraging the information in OCRs, and identified putative causal variants in 122 AF-associated loci. Taking advantage of the fine-mapping results, our novel statistical procedure for gene discovery prioritized 46 high-confidence risk genes, highlighting transcription factors and signal transduction pathways important for heart development. In summary, our analysis provides a comprehensive map of AF risk variants and genes, and a general framework to integrate single-cell genomics with genetic studies of complex traits.
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Affiliation(s)
- Alan Selewa
- Biophysical Sciences Graduate Program, The University of Chicago, Chicago, IL, 60637, USA
| | - Kaixuan Luo
- Department of Human Genetics, The University of Chicago, Chicago, IL, 60637, USA
| | - Michael Wasney
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Linsin Smith
- Committee on Genetics, Genomics and Systems Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Xiaotong Sun
- Department of Human Genetics, The University of Chicago, Chicago, IL, 60637, USA
| | - Chenwei Tang
- The College, The University of Chicago, Chicago, IL, 60637, USA
| | - Heather Eckart
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Ivan P Moskowitz
- Department of Human Genetics, The University of Chicago, Chicago, IL, 60637, USA
- Department of Pediatrics, The University of Chicago, Chicago, IL, 60637, USA
| | - Anindita Basu
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, 60637, USA.
| | - Xin He
- Department of Human Genetics, The University of Chicago, Chicago, IL, 60637, USA.
| | - Sebastian Pott
- Department of Medicine, Section of Genetic Medicine, The University of Chicago, Chicago, IL, 60637, USA.
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9
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Pereira CH, Bare DJ, Rosas PC, Dias FAL, Banach K. The role of P21-activated kinase (Pak1) in sinus node function. J Mol Cell Cardiol 2023; 179:90-101. [PMID: 37086972 PMCID: PMC10294268 DOI: 10.1016/j.yjmcc.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 04/11/2023] [Accepted: 04/11/2023] [Indexed: 04/24/2023]
Abstract
Sinoatrial node (SAN) dysfunction (SND) and atrial arrhythmia frequently occur simultaneously with a hazard ratio of 4.2 for new onset atrial fibrillation (AF) in SND patients. In the atrial muscle attenuated activity of p21-activated kinase 1 (Pak1) increases the risk for AF by enhancing NADPH oxidase 2 dependent production of reactive oxygen species (ROS). However, the role of Pak1 dependent ROS regulation in SAN function has not yet been determined. We hypothesize that Pak1 activity maintains SAN activity by regulating the expression of the hyperpolarization activated cyclic nucleotide gated cation channel (HCN). To determine Pak1 dependent changes in heart rate (HR) regulation we quantified the intrinsic sinus rhythm in wild type (WT) and Pak1 deficient (Pak1-/-) mice of both sexes in vivo and in isolated Langendorff perfused hearts. Pak1-/- hearts displayed an attenuated HR in vivo after autonomic blockage and in isolated hearts. The contribution of the Ca2+ clock to pacemaker activity remained unchanged, but Ivabradine (3 μM), a blocker of HCN channels that are a membrane clock component, eliminated the differences in SAN activity between WT and Pak1-/- hearts. Reduced HCN4 expression was confirmed in Pak1-/- right atria. The reduced HCN activity in Pak1-/- could be rescued by class II HDAC inhibition (LMK235), ROS scavenging (TEMPOL) or attenuation of Extracellular Signal-Regulated Kinase (ERK) 1/2 activity (SCH772984). No sex specific differences in Pak1 dependent SAN regulation were determined. Our results establish Pak1 as a class II HDAC regulator and a potential therapeutic target to attenuate SAN bradycardia and AF susceptibility.
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Affiliation(s)
- Carlos H Pereira
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St., Chicago, IL 60612, USA; Biological Science Center, Department of Physiology, Av. Cel Francisco H. dos Santos 100, 19031 Centro Politécnico-Curitiba, Brazil.
| | - Dan J Bare
- Dept. of Physiology & Biophysics, The Ohio State University, 5018 Graves Hall, 333 W.10th Ave., Columbus, OH 4321, USA.
| | - Paola C Rosas
- Dept. of Pharmacy Practice, College of Pharmacy, 833 S Wood St., Chicago, IL 60612, USA.
| | - Fernando A L Dias
- Biological Science Center, Department of Physiology, Av. Cel Francisco H. dos Santos 100, 19031 Centro Politécnico-Curitiba, Brazil.
| | - Kathrin Banach
- Dept. of Internal Medicine/Cardiology, Rush University Medical Center, 1750 W. Harrison St., Chicago, IL 60612, USA.
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10
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Yu C, Deng XJ, Xu D. Gene mutations in comorbidity of epilepsy and arrhythmia. J Neurol 2023; 270:1229-1248. [PMID: 36376730 DOI: 10.1007/s00415-022-11430-2] [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: 07/31/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022]
Abstract
Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China.
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11
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Fan W, Sun X, Yang C, Wan J, Luo H, Liao B. Pacemaker activity and ion channels in the sinoatrial node cells: MicroRNAs and arrhythmia. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 177:151-167. [PMID: 36450332 DOI: 10.1016/j.pbiomolbio.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/13/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022]
Abstract
The primary pacemaking activity of the heart is determined by a spontaneous action potential (AP) within sinoatrial node (SAN) cells. This unique AP generation relies on two mechanisms: membrane clocks and calcium clocks. Nonhomologous arrhythmias are caused by several functional and structural changes in the myocardium. MicroRNAs (miRNAs) are essential regulators of gene expression in cardiomyocytes. These miRNAs play a vital role in regulating the stability of cardiac conduction and in the remodeling process that leads to arrhythmias. Although it remains unclear how miRNAs regulate the expression and function of ion channels in the heart, these regulatory mechanisms may support the development of emerging therapies. This study discusses the spread and generation of AP in the SAN as well as the regulation of miRNAs and individual ion channels. Arrhythmogenicity studies on ion channels will provide a research basis for miRNA modulation as a new therapeutic target.
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Affiliation(s)
- Wei Fan
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Xuemei Sun
- Department of Pharmacy, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Chao Yang
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Juyi Wan
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| | - Hongli Luo
- Department of Pharmacy, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| | - Bin Liao
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
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12
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Destici E, Zhu F, Tran S, Preissl S, Farah EN, Zhang Y, Hou X, Poirion OB, Lee AY, Grinstein JD, Bloomekatz J, Kim HS, Hu R, Evans SM, Ren B, Benner C, Chi NC. Human-gained heart enhancers are associated with species-specific cardiac attributes. NATURE CARDIOVASCULAR RESEARCH 2022; 1:830-843. [PMID: 36817700 PMCID: PMC9937543 DOI: 10.1038/s44161-022-00124-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 07/26/2022] [Indexed: 11/09/2022]
Abstract
The heart, a vital organ which is first to develop, has adapted its size, structure and function in order to accommodate the circulatory demands for a broad range of animals. Although heart development is controlled by a relatively conserved network of transcriptional/chromatin regulators, how the human heart has evolved species-specific features to maintain adequate cardiac output and function remains to be defined. Here, we show through comparative epigenomic analysis the identification of enhancers and promoters that have gained activity in humans during cardiogenesis. These cis-regulatory elements (CREs) are associated with genes involved in heart development and function, and may account for species-specific differences between human and mouse hearts. Supporting these findings, genetic variants that are associated with human cardiac phenotypic/disease traits, particularly those differing between human and mouse, are enriched in human-gained CREs. During early stages of human cardiogenesis, these CREs are also gained within genomic loci of transcriptional regulators, potentially expanding their role in human heart development. In particular, we discovered that gained enhancers in the locus of the early human developmental regulator ZIC3 are selectively accessible within a subpopulation of mesoderm cells which exhibits cardiogenic potential, thus possibly extending the function of ZIC3 beyond its conserved left-right asymmetry role. Genetic deletion of these enhancers identified a human gained enhancer that was required for not only ZIC3 and early cardiac gene expression at the mesoderm stage but also cardiomyocyte differentiation. Overall, our results illuminate how human gained CREs may contribute to human-specific cardiac attributes, and provide insight into how transcriptional regulators may gain cardiac developmental roles through the evolutionary acquisition of enhancers.
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Affiliation(s)
- Eugin Destici
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Fugui Zhu
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Shaina Tran
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Sebastian Preissl
- Ludwig Institute for Cancer Research, La Jolla, CA, 92093, USA
- Center for Epigenomics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Elie N. Farah
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Yanxiao Zhang
- Ludwig Institute for Cancer Research, La Jolla, CA, 92093, USA
| | - Xiameng Hou
- Center for Epigenomics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Olivier B. Poirion
- Center for Epigenomics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ah Young Lee
- Ludwig Institute for Cancer Research, La Jolla, CA, 92093, USA
| | - Jonathan D. Grinstein
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | | | - Hong Sook Kim
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Robert Hu
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Sylvia M. Evans
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Bing Ren
- Ludwig Institute for Cancer Research, La Jolla, CA, 92093, USA
- Center for Epigenomics, University of California, San Diego, La Jolla, CA, 92093, USA
- Institute of Genomic Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
- Moores Cancer Center, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Chris Benner
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Neil C. Chi
- Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
- Institute of Genomic Medicine, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
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13
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Young LJ, Antwi-Boasiako S, Ferrall J, Wold LE, Mohler PJ, El Refaey M. Genetic and non-genetic risk factors associated with atrial fibrillation. Life Sci 2022; 299:120529. [PMID: 35385795 PMCID: PMC9058231 DOI: 10.1016/j.lfs.2022.120529] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/08/2022] [Accepted: 03/31/2022] [Indexed: 12/15/2022]
Abstract
Atrial fibrillation (AF) is the most common arrhythmic disorder and its prevalence in the United States is projected to increase to more than twelve million cases in 2030. AF increases the risk of other forms of cardiovascular disease, including stroke. As the incidence of atrial fibrillation increases dramatically with age, it is paramount to elucidate risk factors underlying AF pathogenesis. Here, we review tissue and cellular pathways underlying AF, as well as critical components that impact AF susceptibility including genetic and environmental risk factors. Finally, we provide the latest information on potential links between SARS-CoV-2 and human AF. Improved understanding of mechanistic pathways holds promise in preventative care and early diagnostics, and also introduces novel targeted forms of therapy that might attenuate AF progression and maintenance.
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Affiliation(s)
- Lindsay J Young
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Steve Antwi-Boasiako
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | - Joel Ferrall
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Loren E Wold
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA; College of Nursing, The Ohio State University, Columbus, OH, USA
| | - Peter J Mohler
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA; Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH, USA
| | - Mona El Refaey
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Surgery, Division of Cardiac Surgery, The Ohio State University, Columbus, OH, USA.
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14
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Dogheim GM, Khairat I, Omran GA, El-Haggar SM, Amrawy AME, Werida RH. Clinical comparative study assessing the effect of ivabradine on neopterin and NT-Pro BNP against standard treatment in chronic heart failure patients. Eur J Clin Pharmacol 2022; 78:943-954. [PMID: 35238960 PMCID: PMC9107441 DOI: 10.1007/s00228-022-03290-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/01/2022] [Indexed: 12/11/2022]
Abstract
Purpose Heart rate reduction (HR) is a cornerstone in heart failure therapy as it improves patient outcomes. The aim of this study is to evaluate short-term effect of ivabradine on NT-Pro BNP and neopterin in heart failure patients and assess the association between HR and these biomarkers. Methods Sixty patients on standard heart failure therapy were randomly allocated into ivabradine group (n = 30) and non-ivabradine group (n = 30). Ivabradine 5 mg twice daily was given for 3 months. Lipid profile and kidney functions were performed and blood samples for NT-Pro BNP and neopterin were analysed at baseline and after 3 months of intervention in both groups. Results There was a significant improvement in NYHA class in ivabradine group (p < 0.001). Ejection fraction was improved in ivabradine and non-ivabradine groups after intervention (p < 0.001), with a greater improvement in ivabradine group (p = 0.026). Heart rate was reduced in ivabradine group (p < 0.001) and non-ivabradine group (p < 0.001) yet greater reduction was seen in ivabradine group (p < 0.001). Serum creatinine and blood urea nitrogen were reduced in ivabradine group (Scr: p = 0.001, BUN: p = 0.001). NT-Pro BNP and neopterin levels significantly decreased in ivabradine group (NT-Pro BNP: p < 0.001, neopterin p < 0.001). Significant positive correlation was found between HR and biomarker levels after intervention (NT-Pro BNP: r = 0.475, p < 0.001, neopterin: r = 0.384, p = 0.002). Conclusion Ivabradine therapy reduced levels of both biomarkers which correlated well with HR. Biomarker levels might provide a tool for assessing ivabradine effectiveness in HF. Trial registration Date: June 26, 2020. Identifier: NCT04448899. Link: Ivabradine in Patients with Congestive Heart Failure—Full Text View—ClinicalTrials.gov.
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Affiliation(s)
- Gaidaa M. Dogheim
- Pharmacy Practice Department, Faculty of Pharmacy, Alexandria University, Al Mesallah Sharq, Qism Bab Sharqi, Alexandria, Alexandria Governorate Egypt
| | - Ibtsam Khairat
- Cardiology Department, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Gamal A. Omran
- Biochemistry Department, Faculty of Pharmacy, Damanhour University, Damanhour, 22514 Egypt
| | - Sahar M. El-Haggar
- Clinical Pharmacy Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Ahmed M. El Amrawy
- Cardiology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Rehab H. Werida
- Clinical Pharmacy & Pharmacy Practice, Faculty of Pharmacy, Damanhour University, Damanhour, 22514 Egypt
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15
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Depuydt AS, Peigneur S, Tytgat J. Review: HCN Channels in the Heart. Curr Cardiol Rev 2022; 18:e040222200836. [PMID: 35125083 PMCID: PMC9893134 DOI: 10.2174/1573403x18666220204142436] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/13/2021] [Accepted: 12/23/2021] [Indexed: 11/22/2022] Open
Abstract
Pacemaker cells are the basis of rhythm in the heart. Cardiovascular diseases, and in particular, arrhythmias are a leading cause of hospital admissions and have been implicated as a cause of sudden death. The prevalence of people with arrhythmias will increase in the next years due to an increase in the ageing population and risk factors. The current therapies are limited, have a lot of side effects, and thus, are not ideal. Pacemaker channels, also called hyperpolarizationactivated cyclic nucleotide-gated (HCN) channels, are the molecular correlate of the hyperpolarization- activated current, called Ih (from hyperpolarization) or If (from funny), that contribute crucially to the pacemaker activity in cardiac nodal cells and impulse generation and transmission in neurons. HCN channels have emerged as interesting targets for the development of drugs, in particular, to lower the heart rate. Nonetheless, their pharmacology is still rather poorly explored in comparison to many other voltage-gated ion channels or ligand-gated ion channels. Ivabradine is the first and currently the only clinically approved compound that specifically targets HCN channels. The therapeutic indication of ivabradine is the symptomatic treatment of chronic stable angina pectoris in patients with coronary artery disease with a normal sinus rhythm. Several other pharmacological agents have been shown to exert an effect on heart rate, although this effect is not always desired. This review is focused on the pacemaking process taking place in the heart and summarizes the current knowledge on HCN channels.
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Affiliation(s)
- Anne-Sophie Depuydt
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
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16
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Regulation of sinoatrial funny channels by cyclic nucleotides: From adrenaline and I K2 to direct binding of ligands to protein subunits. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:12-21. [PMID: 34237319 DOI: 10.1016/j.pbiomolbio.2021.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 06/13/2021] [Accepted: 06/25/2021] [Indexed: 12/27/2022]
Abstract
The funny current, and the HCN channels that form it, are affected by the direct binding of cyclic nucleotides. Binding of these second messengers causes a depolarizing shift of the activation curve, which leads to greater availability of current at physiological membrane voltages. This review outlines a brief history on this regulation and provides some evidence that other cyclic nucleotides, especially cGMP, may be important for the regulation of the funny channel in the heart. Current understanding of the molecular mechanism of cyclic nucleotide regulation is also presented, which includes the notions that full and partial agonism occur as a consequence of negatively cooperative binding. Knowledge gaps, including a potential role of cyclic nucleotide-regulation of the funny current under pathophysiological conditions, are included. The work highlighted here is in dedication to Dario DiFrancesco on his retirement.
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17
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Ion channelopathies to bridge molecular lesions, channel function, and clinical therapies. Pflugers Arch 2021; 472:733-738. [PMID: 32607810 DOI: 10.1007/s00424-020-02424-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Giannetti F, Benzoni P, Campostrini G, Milanesi R, Bucchi A, Baruscotti M, Dell'Era P, Rossini A, Barbuti A. A detailed characterization of the hyperpolarization-activated "funny" current (I f) in human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes with pacemaker activity. Pflugers Arch 2021; 473:1009-1021. [PMID: 33934225 PMCID: PMC8245366 DOI: 10.1007/s00424-021-02571-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/01/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023]
Abstract
Properties of the funny current (If) have been studied in several animal and cellular models, but so far little is known concerning its properties in human pacemaker cells. This work provides a detailed characterization of If in human-induced pluripotent stem cell (iPSC)–derived pacemaker cardiomyocytes (pCMs), at different time points. Patch-clamp analysis showed that If density did not change during differentiation; however, after day 30, it activates at more negative potential and with slower time constants. These changes are accompanied by a slowing in beating rate. If displayed the voltage-dependent block by caesium and reversed (Erev) at − 22 mV, compatibly with the 3:1 K+/Na+ permeability ratio. Lowering [Na+]o (30 mM) shifted the Erev to − 39 mV without affecting conductance. Increasing [K+]o (30 mM) shifted the Erev to − 15 mV with a fourfold increase in conductance. pCMs express mainly HCN4 and HCN1 together with the accessory subunits CAV3, KCR1, MiRP1, and SAP97 that contribute to the context-dependence of If. Autonomic agonists modulated the diastolic depolarization, and thus rate, of pCMs. The adrenergic agonist isoproterenol induced rate acceleration and a positive shift of If voltage-dependence (EC50 73.4 nM). The muscarinic agonists had opposite effects (Carbachol EC50, 11,6 nM). Carbachol effect was however small but it could be increased by pre-stimulation with isoproterenol, indicating low cAMP levels in pCMs. In conclusion, we demonstrated that pCMs display an If with the physiological properties expected by pacemaker cells and may thus represent a suitable model for studying human If-related sinus arrhythmias.
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Affiliation(s)
- Federica Giannetti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Giulia Campostrini
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, The Netherlands
| | - Raffaella Milanesi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell'Università 6, 26900, Lodi, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Dell'Era
- Cellular Fate Reprogramming Unit, Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123, Brescia, Italy
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Viale Druso 1, 39100, Bolzano, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.
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19
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Amstetter D, Badt F, Rubi L, Bittner RE, Ebner J, Uhrin P, Hilber K, Koenig X, Todt H. The bradycardic agent ivabradine decreases conduction velocity in the AV node and in the ventricles in-vivo. Eur J Pharmacol 2021; 893:173818. [PMID: 33345856 DOI: 10.1016/j.ejphar.2020.173818] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 12/02/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Ivabradine blocks hyperpolarisation-activated cyclic nucleotide-gated (HCN) channels, thereby lowering the heart rate, an action that is used clinically for the treatment of heart failure and angina pectoris. We and others have shown previously that ivabradine, in addition to its HCN channel blocking activity, also inhibits voltage-gated Na channels in vitro at concentrations that may be clinically relevant. Such action may reduce conduction velocity in cardiac atria and ventricles. Here, we explore the effect of administration of ivabradine on parameters of ventricular conduction and repolarization in the surface ECG of anesthetized mice. We found that 5 min after i.p. administration of 10 mg/kg ivabradine spontaneous heart rate had declined by ~13%, which is within the range observed in human clinical studies. At the same time a significant increase in QRS duration by ~18% was observed, suggesting a reduction in ventricular conduction velocity. During transesophageal pacing at heart rates between 100 and 220 beats/min there was no obvious rate-dependence of ivabradine-induced QRS prolongation. On the other hand, ivabradine produced substantial rate-dependent slowing of AV nodal conduction. We conclude that ivabradine prolongs conduction in the AV-node and in the ventricles in vivo.
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Affiliation(s)
- Daniel Amstetter
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Florian Badt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Lena Rubi
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Janine Ebner
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Pavel Uhrin
- Department of Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Austria
| | - Karlheinz Hilber
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Xaver Koenig
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Center for Physiology and Pharmacology, Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria.
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20
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Gurusamy N, Rajasingh S, Sigamani V, Rajasingh R, Isai DG, Czirok A, Bittel D, Rajasingh J. Noonan syndrome patient-specific induced cardiomyocyte model carrying SOS1 gene variant c.1654A>G. Exp Cell Res 2021; 400:112508. [PMID: 33549576 DOI: 10.1016/j.yexcr.2021.112508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/19/2021] [Accepted: 01/26/2021] [Indexed: 12/13/2022]
Abstract
Noonan syndrome (NS) is a dominant autosomal genetic disorder, associated with mutations in several genes that exhibit multisystem abnormal development including cardiac defects. NS associated with the Son of Sevenless homolog 1 (SOS1) gene mutation attributes to the development of cardiomyopathy and congenital heart defects. Since the treatment option for NS is very limited, an in vitro disease model with SOS1 gene mutation would be beneficial for exploring therapeutic possibilities for NS. We reprogrammed cardiac fibroblasts obtained from a NS patient and normal control skin fibroblasts (C-SF) into induced pluripotent stem cells (iPSCs). We identified NS-iPSCs carry a heterozygous single nucleotide variation in the SOS1 gene at the c.1654A > G. Furthermore, the control and NS-iPSCs were differentiated into induced cardiomyocytes (iCMCs), and the electron microscopic analysis showed that the sarcomeres of the NS-iCMCs were highly disorganized. FACS analysis showed that 47.5% of the NS-iCMCs co-expressed GATA4 and cardiac troponin T proteins, and the mRNA expression levels of many cardiac related genes, studied by qRT-PCR array, were significantly reduced when compared to the control C-iCMCs. We report for the first time that NS-iPSCs carry a single nucleotide variation in the SOS1 gene at the c.1654A>G were showing significantly reduced cardiac genes and proteins expression as well as structurally and functionally compromised when compared to C-iCMCs. These iPSCs and iCMCs can be used as a modeling platform to unravel the pathologic mechanisms and also the development of novel drug for the cardiomyopathy in patients with NS.
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Affiliation(s)
- Narasimman Gurusamy
- Department of Bioscience Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Sheeja Rajasingh
- Department of Bioscience Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Vinoth Sigamani
- Department of Bioscience Research, University of Tennessee Health Science Center, Memphis, TN, USA
| | | | - Dona Greta Isai
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Andras Czirok
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | | | - Johnson Rajasingh
- Department of Bioscience Research, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Medicine-Cardiology, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Microbiology, Immunology & Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA.
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21
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Rivolta I, Binda A, Masi A, DiFrancesco JC. Cardiac and neuronal HCN channelopathies. Pflugers Arch 2020; 472:931-951. [PMID: 32424620 DOI: 10.1007/s00424-020-02384-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/31/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed as four different isoforms (HCN1-4) in the heart and in the central and peripheral nervous systems. In the voltage range of activation, HCN channels carry an inward current mediated by Na+ and K+, termed If in the heart and Ih in neurons. Altered function of HCN channels, mainly HCN4, is associated with sinus node dysfunction and other arrhythmias such as atrial fibrillation, ventricular tachycardia, and atrioventricular block. In recent years, several data have also shown that dysfunctional HCN channels, in particular HCN1, but also HCN2 and HCN4, can play a pathogenic role in epilepsy; these include experimental data from animal models, and data collected over genetic mutations of the channels identified and characterized in epileptic patients. In the central nervous system, alteration of the Ih current could predispose to the development of neurodegenerative diseases such as Parkinson's disease; since HCN channels are widely expressed in the peripheral nervous system, their dysfunctional behavior could also be associated with the pathogenesis of neuropathic pain. Given the fundamental role played by the HCN channels in the regulation of the discharge activity of cardiac and neuronal cells, the modulation of their function for therapeutic purposes is under study since it could be useful in various pathological conditions. Here we review the present knowledge of the HCN-related channelopathies in cardiac and neurological diseases, including clinical, genetic, therapeutic, and physiopathological aspects.
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Affiliation(s)
- Ilaria Rivolta
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Anna Binda
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Jacopo C DiFrancesco
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy. .,Department of Neurology, ASST San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi, 33, 20900, Monza, MB, Italy.
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22
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Abstract
This review is focusing on the understanding of various factors and components governing and controlling the occurrence of ventricular arrhythmias including (i) the role of various ion channel-related changes in the action potential (AP), (ii) electrocardiograms (ECGs), (iii) some important arrhythmogenic mediators of reperfusion, and pharmacological approaches to their attenuation. The transmembrane potential in myocardial cells is depending on the cellular concentrations of several ions including sodium, calcium, and potassium on both sides of the cell membrane and active or inactive stages of ion channels. The movements of Na+, K+, and Ca2+ via cell membranes produce various currents that provoke AP, determining the cardiac cycle and heart function. A specific channel has its own type of gate, and it is opening and closing under specific transmembrane voltage, ionic, or metabolic conditions. APs of sinoatrial (SA) node, atrioventricular (AV) node, and Purkinje cells determine the pacemaker activity (depolarization phase 4) of the heart, leading to the surface manifestation, registration, and evaluation of ECG waves in both animal models and humans. AP and ECG changes are key factors in arrhythmogenesis, and the analysis of these changes serve for the clarification of the mechanisms of antiarrhythmic drugs. The classification of antiarrhythmic drugs may be based on their electrophysiological properties emphasizing the connection between basic electrophysiological activities and antiarrhythmic properties. The review also summarizes some important mechanisms of ventricular arrhythmias in the ischemic/reperfused myocardium and permits an assessment of antiarrhythmic potential of drugs used for pharmacotherapy under experimental and clinical conditions.
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Affiliation(s)
- Arpad Tosaki
- Department of Pharmacology, School of Pharmacy, University of Debrecen, Debrecen, Hungary
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23
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Chen S, Ma Q, Xue Y, Zhang J, Yang G, Wang T, Ma A, Bai L. Comprehensive Analysis and Co-Expression Network of mRNAs and lncRNAs in Pressure Overload-Induced Heart Failure. Front Genet 2019; 10:1271. [PMID: 31921308 PMCID: PMC6920101 DOI: 10.3389/fgene.2019.01271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/18/2019] [Indexed: 01/16/2023] Open
Abstract
Aim: Heart failure (HF) is the end stage of various cardiovascular diseases. However, the precise regulation of gene expression profiles and functional mechanisms of long non-coding RNAs (lncRNAs) in HF remain to be elucidated. The present study aimed to identify the differentially expressed profiles and interaction of messenger RNAs (mRNAs) and lncRNAs in pressure overload-induced HF. Methods: Male Sprague-Dawley rats were randomly divided into the HF group and the sham-operated group. HF was induced by the transverse aortic constriction (TAC) surgery. The cardiac expression profiles of mRNAs and lncRNAs in HF were investigated using the microarray. Bioinformatics analyses and co-expression network construction were performed from the RNA sequencing data. Results: The expression profiles of mRNAs and lncRNAs showed significant differences between HF and controls. A total of 147 mRNAs and 162 lncRNAs were identified to be differentially expressed with a fold change of >2 in HF. The relative expression levels of several selected mRNAs and lncRNAs were validated by quantitative PCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that diverse pathways were involved in the molecular mechanisms of cardiac hypertrophy and HF including immune response, smooth muscle contraction, ion transmembrane transport. The mRNA-lncRNA and transcription factors (TFs)-lncRNA co-expression networks were constructed and several genes and TFs were identified as key regulators in the pathogenesis of HF. Further functional prediction showed that the lncRNA NONRATT013999 was predicted to cis-regulate mRNA CDH11, and NONRATT027756 was predicted to trans-regulate HCN4. Conclusion: This study revealed specific expression regulation and potential functions of mRNAs and lncRNAs in pressure overload-induced HF. These results will provide new insights into the underlying mechanisms and potential therapeutic targets for HF.
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Affiliation(s)
- Shuping Chen
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Qiong Ma
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Yanbo Xue
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Jingwen Zhang
- Department of Cardiology, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Guodong Yang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Tingzhong Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi Key Laboratory of Molecular Cardiology, Xi'an Jiaotong University, Xi’an, China
- Key Laboratory of Environment and Genes Related to Diseases (Xi’an Jiaotong University), Ministry of Education, Xi’an, China
| | - Aiqun Ma
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi Key Laboratory of Molecular Cardiology, Xi'an Jiaotong University, Xi’an, China
- Key Laboratory of Environment and Genes Related to Diseases (Xi’an Jiaotong University), Ministry of Education, Xi’an, China
- *Correspondence: Aiqun Ma, ; Ling Bai,
| | - Ling Bai
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- *Correspondence: Aiqun Ma, ; Ling Bai,
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24
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Abstract
The aim of this chapter is to discuss evidence concerning the many roles of calcium ions, Ca2+, in cell signaling pathways that control heart function. Before considering details of these signaling pathways, the control of contraction in ventricular muscle by Ca2+ transients accompanying cardiac action potentials is first summarized, together with a discussion of how myocytes from the atrial and pacemaker regions of the heart diverge from this basic scheme. Cell signaling pathways regulate the size and timing of the Ca2+ transients in the different heart regions to influence function. The simplest Ca2+ signaling elements involve enzymes that are regulated by cytosolic Ca2+. Particularly important examples to be discussed are those that are stimulated by Ca2+, including Ca2+-calmodulin-dependent kinase (CaMKII), Ca2+ stimulated adenylyl cyclases, Ca2+ stimulated phosphatase and NO synthases. Another major aspect of Ca2+ signaling in the heart concerns actions of the Ca2+ mobilizing agents, inositol trisphosphate (IP3), cADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate, (NAADP). Evidence concerning roles of these Ca2+ mobilizing agents in different regions of the heart is discussed in detail. The focus of the review will be on short term regulation of Ca2+ transients and contractile function, although it is recognized that Ca2+ regulation of gene expression has important long term functional consequences which will also be briefly discussed.
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25
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Chen J, Xu S, Li W, Wu L, Wang L, Li Y, Zhou W. Nkx2.5 insufficiency leads to atrial electrical remodeling through Wnt signaling in HL-1 cells. Exp Ther Med 2019; 18:4631-4636. [PMID: 31798700 PMCID: PMC6880433 DOI: 10.3892/etm.2019.8134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 09/26/2019] [Indexed: 12/12/2022] Open
Abstract
Homeobox protein Nxk-2.5 (Nkx2.5) is a homeobox transcription factor that promotes chamber-like myocardial gene expression. Data from a previous genome-wide association study suggested that Nkx2.5 may be associated with the genetic variation that underlies atrial fibrillation (AF). Nkx2.5 loss of function has been demonstrated to be associated with an increasing susceptibility of familial AF. Therefore, the aim of the present study was to investigate the effect of Nkx2.5 loss of function on electrophysiological substrates in HL-1 cells. To the best of our knowledge, the results demonstrated for the first time that Nkx2.5 expression was significantly decreased in a rat model exhibiting AF. The effect of silencing Nkx2.5 was assessed following transfection with adenoviral vectors with specific NKX2.5-shRNA. The effect of Nkx2.5 silencing on potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4), gap junction alpha-5 protein (Cx40), calcium handling proteins and protein Wnt-11 (Wnt11) expression levels was also assessed in HL-1 cells. The results revealed that Nkx2.5 silencing increased HCN4 expression, decreased Cx40 expression and disrupted the expression of calcium handling proteins. Additionally, Wnt11 signal protein expression was decreased following Nkx2.5 silencing. The results of the present study demonstrated that Nkx2.5 served as a transcriptional regulator of the electrophysiological substrates associated with AF.
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Affiliation(s)
- Jingjing Chen
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Shunen Xu
- Department of Orthopedics, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Wei Li
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Lirong Wu
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Long Wang
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Yongkang Li
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Wei Zhou
- Department of Cardiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
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26
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Li XH, Hu YM, Yin GL, Wu P. Correlation between HCN4 gene polymorphisms and lone atrial fibrillation risk. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2019; 47:2989-2993. [PMID: 31315459 DOI: 10.1080/21691401.2019.1637885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background and objective: Atrial electrical remodelling (AER) was significantly associated with atrial fibrillation (AF) development. Polymorphisms in hyperpolarization activated cyclic nucleotide gated potassium channel 4 (HCN4) gene might be correlated with AER. In the present study, we explored the association of HCN4 polymorphisms (rs498005 and rs7164883) with lone AF risk in a Chinese Han population. Methods: In this case-control study, the Sanger sequencing method was utilized to genotype the HCN4 polymorphisms. Relative risk of AF was assessed by the χ2 test, and presented by odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Logistic regression analysis was performed for multivariate analysis. The effects of HCN4 polymorphisms on AF clinical features were analyzed by the Mann-Whitney U test and adjusted by the Bonferroni method. Results: C allele of rs498005 was significantly correlated with increased risk of AF (OR = 1.412, 95%CI = 1.012-1.970), and the association still exited after adjustment by age, gender, the status of smoking and drinking, histories of diabetes, hyperlipidaemia and myocardial infarction (adjusted OR = 1.473, 95%CI = 1.043-2.081). G allele of rs7164883 SNP was marginally associated with enhanced AF risk after adjustment by the above clinical parameters (adjusted OR = 1.742, 95%CI = 1.019-2.980). Atrial late potential (ALP), including TP (P wave duration after filtering) and LP20 (the amplitude of superimposed potential in the final 20 ms of P wave) were significantly associated with rs498005 genotype (p < .001). Conclusion: HCN4 rs498005 and rs7164883 polymorphisms are significantly associated with AF risk.
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Affiliation(s)
- Xiao-Hong Li
- a Department of Cardiology, Cangzhou City Central Hospital , Cangzhou , China
| | - Ya-Min Hu
- a Department of Cardiology, Cangzhou City Central Hospital , Cangzhou , China
| | - Guang-Li Yin
- b Department of Cardiology, Hebei Provincial Hospital of Integrative Chinese and Western Medicine , Cangzhou , China
| | - Ping Wu
- a Department of Cardiology, Cangzhou City Central Hospital , Cangzhou , China
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27
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DiFrancesco JC, Castellotti B, Milanesi R, Ragona F, Freri E, Canafoglia L, Franceschetti S, Ferrarese C, Magri S, Taroni F, Costa C, Labate A, Gambardella A, Solazzi R, Binda A, Rivolta I, Di Gennaro G, Casciato S, D’Incerti L, Barbuti A, DiFrancesco D, Granata T, Gellera C. HCN ion channels and accessory proteins in epilepsy: genetic analysis of a large cohort of patients and review of the literature. Epilepsy Res 2019; 153:49-58. [DOI: 10.1016/j.eplepsyres.2019.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/01/2019] [Accepted: 04/08/2019] [Indexed: 11/28/2022]
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28
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Baruscotti M, Bucchi A, Milanesi R, Paina M, Barbuti A, Gnecchi-Ruscone T, Bianco E, Vitali-Serdoz L, Cappato R, DiFrancesco D. A gain-of-function mutation in the cardiac pacemaker HCN4 channel increasing cAMP sensitivity is associated with familial Inappropriate Sinus Tachycardia. Eur Heart J 2019; 38:280-288. [PMID: 28182231 DOI: 10.1093/eurheartj/ehv582] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/01/2015] [Accepted: 10/07/2015] [Indexed: 01/09/2023] Open
Affiliation(s)
- Mirko Baruscotti
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Raffaella Milanesi
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Manuel Paina
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | | | - Elisabetta Bianco
- Cardiovascular Department, 'Ospedali Riuniti di Trieste', University Hospital, Trieste, Italy
| | | | | | - Dario DiFrancesco
- Department of Biosciences, The PaceLab and 'Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata', Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
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29
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Development of a Rat Model of Sick Sinus Syndrome Using Pinpoint Press Permeation. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7487324. [PMID: 30581867 PMCID: PMC6276488 DOI: 10.1155/2018/7487324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/06/2018] [Indexed: 02/06/2023]
Abstract
Objective Sick sinus syndrome (SSS) is one of the most common causes of cardiac impairment necessitating pacemaker implantation. However, studies of SSS pathogenesis are neither comprehensive nor conclusive due to limited success in achieving a stable rat SSS model. Here, we modified pinpoint press permeation to establish a stable rat SSS model. Methods We randomly assigned 138 male Sprague-Dawley rats into three groups: normal control (n = 8), sham (n = 10), and SSS (n = 120). Postoperatively, the SSS group was further divided into SSSA (n = 40), SSSB (n = 40), and SSSC (n = 40), based on reduction in heart rates by 20–30%, 31–40%, and 41–50%, respectively. We also assessed histomorphological characteristics and hyperpolarization-activated cyclic nucleotide-gated cation channel 4 (HCN4) expression in the sinoatrial node (SAN) at 1, 2, 3, and 4 weeks after surgery. Results Mortality was statistically higher in SSSC compared to SSSA and SSSB (7.5% versus 90.0% and 87.5%; P < 0.05). Heart rate in SSSA was gradually restored to preoperative levels by week 4 after surgery. In contrast, heart rate in SSSB was stable at 2–3 weeks after surgery. However, we observed that the tissues and cells in SAN were severely injured and also found a time-dependent increase in collagen content and atrium myocardium in SSSB. HCN4 expression was significantly reduced at all 4 time points in SSSB, with statistically significant differences among the groups (P < 0.01). Conclusion We successfully developed a rat SSS model that was sustainable for up to 4 weeks.
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30
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Campostrini G, DiFrancesco JC, Castellotti B, Milanesi R, Gnecchi-Ruscone T, Bonzanni M, Bucchi A, Baruscotti M, Ferrarese C, Franceschetti S, Canafoglia L, Ragona F, Freri E, Labate A, Gambardella A, Costa C, Gellera C, Granata T, Barbuti A, DiFrancesco D. A Loss-of-Function HCN4 Mutation Associated With Familial Benign Myoclonic Epilepsy in Infancy Causes Increased Neuronal Excitability. Front Mol Neurosci 2018; 11:269. [PMID: 30127718 PMCID: PMC6089338 DOI: 10.3389/fnmol.2018.00269] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/16/2018] [Indexed: 01/03/2023] Open
Abstract
HCN channels are highly expressed and functionally relevant in neurons and increasing evidence demonstrates their involvement in the etiology of human epilepsies. Among HCN isoforms, HCN4 is important in cardiac tissue, where it underlies pacemaker activity. Despite being expressed also in deep structures of the brain, mutations of this channel functionally shown to be associated with epilepsy have not been reported yet. Using Next Generation Sequencing for the screening of patients with idiopathic epilepsy, we identified the p.Arg550Cys (c.1648C>T) heterozygous mutation on HCN4 in two brothers affected by benign myoclonic epilepsy of infancy. Functional characterization in heterologous expression system and in neurons showed that the mutation determines a loss of function of HCN4 contribution to activity and an increase of neuronal discharge, potentially predisposing to epilepsy. Expressed in cardiomyocytes, mutant channels activate at slightly more negative voltages than wild-type (WT), in accordance with borderline bradycardia. While HCN4 variants have been frequently associated with cardiac arrhythmias, these data represent the first experimental evidence that functional alteration of HCN4 can also be involved in human epilepsy through a loss-of-function effect and associated increased neuronal excitability. Since HCN4 appears to be highly expressed in deep brain structures only early during development, our data provide a potential explanation for a link between dysfunctional HCN4 and infantile epilepsy. These findings suggest that it may be useful to include HCN4 screening to extend the knowledge of the genetic causes of infantile epilepsies, potentially paving the way for the identification of innovative therapeutic strategies.
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Affiliation(s)
- Giulia Campostrini
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Jacopo C DiFrancesco
- Clinical Neurophysiology and Epilepsy Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Laboratory of Neurobiology, Department of Neurology, Milan Center for Neuroscience, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
| | - Barbara Castellotti
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Raffaella Milanesi
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | | | - Mattia Bonzanni
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Annalisa Bucchi
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Mirko Baruscotti
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Carlo Ferrarese
- Laboratory of Neurobiology, Department of Neurology, Milan Center for Neuroscience, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy
| | - Silvana Franceschetti
- Clinical Neurophysiology and Epilepsy Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Canafoglia
- Clinical Neurophysiology and Epilepsy Center, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Ragona
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Freri
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Angelo Labate
- Institute of Neurology, Università degli Studi Magna Græcia di Catanzaro, Catanzaro, Italy
| | - Antonio Gambardella
- Institute of Neurology, Università degli Studi Magna Græcia di Catanzaro, Catanzaro, Italy
| | - Cinzia Costa
- Neurology Unit, Ospedale S. Maria della Misericordia, Department of Medicine, University of Perugia, Perugia, Italy
| | - Cinzia Gellera
- Unit of Genetics of Neurodegenerative and Metabolic Diseases, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrea Barbuti
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Dario DiFrancesco
- Molecular Physiology and Neurobiology, The PaceLab, Department of Biosciences, Università degli Studi di Milano, Milan, Italy
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Yokoyama R, Kinoshita K, Hata Y, Abe M, Matsuoka K, Hirono K, Kano M, Nakazawa M, Ichida F, Nishida N, Tabata T. A mutant HCN4 channel in a family with bradycardia, left bundle branch block, and left ventricular noncompaction. Heart Vessels 2018; 33:802-819. [DOI: 10.1007/s00380-018-1116-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 01/05/2018] [Indexed: 01/09/2023]
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Semmler J, Kormann J, Srinivasan SP, Köster A, Sälzer D, Reppel M, Hescheler J, Plomann M, Nguemo F. Pacsin 2 is required for the maintenance of a normal cardiac function in the developing mouse heart. Pharmacol Res 2017; 128:200-210. [PMID: 29107716 DOI: 10.1016/j.phrs.2017.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 06/26/2017] [Accepted: 10/15/2017] [Indexed: 11/27/2022]
Abstract
The Pacsin proteins (Pacsin 1, 2 and 3) play an important role in intracellular trafficking and thereby signal transduction in many cells types. This study was designed to examine the role of Pacsin 2 in cardiac development and function. We investigated the development and electrophysiological properties of Pacsin 2 knockout (P2KO) hearts and single cardiomyocytes isolated from 11.5 and 15.5days old fetal mice. Immunofluorescence experiments confirmed the lack of Pacsin 2 protein expression in P2KO cardiac myocytes in comparison to wildtype (WT). Western blotting demonstrates low expression levels of connexin 43 and T-box 3 proteins in P2KO compared to wildtype (WT). Electrophysiology measurements including online Multi-Electrode Array (MEA) based field potential (FP) recordings on isolated whole heart of P2KO mice showed a prolonged AV-conduction time. Patch clamp measurements of P2KO cardiomyocytes revealed differences in action potential (AP) parameters and decreased pacemaker funny channel (If), as well as L-type Ca2+ channel (ICaL), and sodium channel (INa). These findings demonstrate that Pacsin 2 is necessary for cardiac development and function in mouse embryos, which will enhance our knowledge to better understand the genesis of cardiovascular diseases.
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Affiliation(s)
- Judith Semmler
- Institute of Neurophysiology, University of Cologne, 50931 Cologne, Germany
| | - Jan Kormann
- Institute of Biochemistry, University of Cologne, 50931 Cologne, Germany
| | | | - Annette Köster
- Institute of Neurophysiology, University of Cologne, 50931 Cologne, Germany
| | - Daniel Sälzer
- Institute of Biochemistry, University of Cologne, 50931 Cologne, Germany
| | - Michael Reppel
- Institute of Neurophysiology, University of Cologne, 50931 Cologne, Germany; Department of Cardiology, University of Lübeck, Lübeck, Germany
| | - Jürgen Hescheler
- Institute of Neurophysiology, University of Cologne, 50931 Cologne, Germany
| | - Markus Plomann
- Institute of Biochemistry, University of Cologne, 50931 Cologne, Germany
| | - Filomain Nguemo
- Institute of Neurophysiology, University of Cologne, 50931 Cologne, Germany.
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Hassinen M, Haverinen J, Vornanen M. Small functional If current in sinoatrial pacemaker cells of the brown trout ( Salmo trutta fario) heart despite strong expression of HCN channel transcripts. Am J Physiol Regul Integr Comp Physiol 2017; 313:R711-R722. [PMID: 28855177 DOI: 10.1152/ajpregu.00227.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/21/2017] [Accepted: 08/24/2017] [Indexed: 01/26/2023]
Abstract
Funny current (If), formed by hyperpolarization-activated cyclic nucleotide-gated channels (HCN channels), is supposed to be crucial for the membrane clock regulating the cardiac pacemaker mechanism. We examined the presence and activity of HCN channels in the brown trout (Salmo trutta fario) sinoatrial (SA) pacemaker cells and their putative role in heart rate (fH) regulation. Six HCN transcripts (HCN1, HCN2a, HCN2ba, HCN2bb, HCN3, and HCN4) were expressed in the brown trout heart. The total HCN transcript abundance was 4.0 and 4.9 times higher in SA pacemaker tissue than in atrium and ventricle, respectively. In the SA pacemaker, HCN3 and HCN4 were the main isoforms representing 35.8 ± 2.7 and 25.0 ± 1.5%, respectively, of the total HCN transcripts. Only a small If with a mean current density of -1.2 ± 0.37 pA/pF at -140 mV was found in 4 pacemaker cells out of 16 spontaneously beating cells examined, despite the optimization of recording conditions for If activity. If was not found in any of the 24 atrial myocytes and 21 ventricular myocytes examined. HCN4 coexpressed with the MinK-related peptide 1 (MiRP1) β-subunit in CHO cells generated large If currents. In contrast, HCN3 (+MiRP1) failed to produce If in the same expression system. Cs+ (2 mM), which blocked 84 ± 12% of the native If, reversibly reduced fH 19.2 ± 3.6% of the excised multicellular pacemaker tissue from 53 ± 5 to 44 ± 5 beats/min (P < 0.05). However, this effect was probably due to the reduction of IKr, which was also inhibited (63.5 ± 4.6%) by Cs+ These results strongly suggest that fH regulation in the brown trout heart is largely independent on If.
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Affiliation(s)
- Minna Hassinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Jaakko Haverinen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
| | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
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Tse G, Liu T, Li KHC, Laxton V, Wong AOT, Chan YWF, Keung W, Chan CW, Li RA. Tachycardia-bradycardia syndrome: Electrophysiological mechanisms and future therapeutic approaches (Review). Int J Mol Med 2017; 39:519-526. [PMID: 28204831 PMCID: PMC5360359 DOI: 10.3892/ijmm.2017.2877] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/09/2017] [Indexed: 02/07/2023] Open
Abstract
Sick sinus syndrome (SSS) encompasses a group of disorders whereby the heart is unable to perform its pacemaker function, due to genetic and acquired causes. Tachycardia‑bradycardia syndrome (TBS) is a complication of SSS characterized by alternating tachycardia and bradycardia. Techniques such as genetic screening and molecular diagnostics together with the use of pre-clinical models have elucidated the electrophysiological mechanisms of this condition. Dysfunction of ion channels responsible for initiation or conduction of cardiac action potentials may underlie both bradycardia and tachycardia; bradycardia can also increase the risk of tachycardia, and vice versa. The mainstay treatment option for SSS is pacemaker implantation, an effective approach, but has disadvantages such as infection, limited battery life, dislodgement of leads and catheters to be permanently implanted in situ. Alternatives to electronic pacemakers are gene‑based bio‑artificial sinoatrial node and cell‑based bio‑artificial pacemakers, which are promising techniques whose long-term safety and efficacy need to be established. The aim of this article is to review the different ion channels involved in TBS, examine the three‑way relationship between ion channel dysfunction, tachycardia and bradycardia in TBS and to consider its current and future therapies.
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Affiliation(s)
- Gary Tse
- Department of Medicine and Therapeutics, Chinese University of Hong Kong
- Li Ka Shing Institute of Health Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, SAR
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin 300211, P.R. China
| | | | - Victoria Laxton
- Intensive Care Department, Royal Brompton and Harefield NHS Foundation Trust, London SW3 6NP, UK
| | - Andy On-Tik Wong
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong Kong
- Li Dak-Sum Research Centre-HKU-Karolinska Institutet Collaboration on Regenerative Medicine, University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Yin Wah Fiona Chan
- School of Biological Sciences, University of Cambridge, Cambridge CB2 1AG, UK
| | - Wendy Keung
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong Kong
- Li Dak-Sum Research Centre-HKU-Karolinska Institutet Collaboration on Regenerative Medicine, University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Camie W.Y. Chan
- Stem Cell and Regenerative Medicine Consortium, Li Ka Shing Faculty of Medicine, The University of Hong Kong
| | - Ronald A. Li
- Li Dak-Sum Research Centre-HKU-Karolinska Institutet Collaboration on Regenerative Medicine, University of Hong Kong, Hong Kong, SAR, P.R. China
- Ming Wai Lau Centre for Reparative Medicine, Karolinska Institutet, Hong Kong, SAR, P.R. China
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Biel S, Aquila M, Hertel B, Berthold A, Neumann T, DiFrancesco D, Moroni A, Thiel G, Kauferstein S. Mutation in S6 domain of HCN4 channel in patient with suspected Brugada syndrome modifies channel function. Pflugers Arch 2016; 468:1663-71. [PMID: 27553229 DOI: 10.1007/s00424-016-1870-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/21/2016] [Accepted: 08/11/2016] [Indexed: 12/17/2022]
Abstract
Diseases such as the sick sinus and the Brugada syndrome are cardiac abnormalities, which can be caused by a number of genetic aberrances. Among them are mutations in HCN4, a gene, which encodes the hyperpolarization-activated, cyclic nucleotide-gated ion channel 4; this pacemaker channel is responsible for the spontaneous activity of the sinoatrial node. The present genetic screening of patients with suspected or diagnosed Brugada or sick sinus syndrome identified in 1 out of 62 samples the novel mutation V492F. It is located in a highly conserved site of hyperpolarization-activated cyclic nucleotide-gated (HCN)4 channel downstream of the filter at the start of the last transmembrane domain S6. Functional expression of mutant channels in HEK293 cells uncovered a profoundly reduced channel function but no appreciable impact on channel synthesis and trafficking compared to the wild type. The inward rectifying HCN4 current could be partially rescued by an expression of heteromeric channels comprising wt and mutant monomers. These heteromeric channels were responsive to cAMP but they required a more negative voltage for activation and they exhibited a lower current density than the wt channel. This suggests a dominant negative effect of the mutation in patients, which carry this heterozygous mutation. Such a modulation of HCN4 activity could be the cause of the diagnosed cardiac abnormality.
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Affiliation(s)
- Stephanie Biel
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596, Frankfurt am Main, Germany
| | - Marco Aquila
- Department of Biosciences and CNR IBF-Mi, University of Milano, Via Celoria 26, 20133, Milan, Italy
| | - Brigitte Hertel
- Department of Biology, Plant Membrane Biophysics, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany
| | - Anne Berthold
- Department of Biology, Plant Membrane Biophysics, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany
| | - Thomas Neumann
- Kerckhoff Heart and Thorax Center, University of Giessen, Benekestraße 2, 61231, Bad Nauheim, Germany
| | - Dario DiFrancesco
- The PaceLab, Department of Biosciences, University of Milano, via Celoria 26, 20133, Milan, Italy
| | - Anna Moroni
- Department of Biosciences and CNR IBF-Mi, University of Milano, Via Celoria 26, 20133, Milan, Italy
| | - Gerhard Thiel
- Department of Biology, Plant Membrane Biophysics, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287, Darmstadt, Germany.
| | - Silke Kauferstein
- Institute of Legal Medicine, University of Frankfurt, Kennedyallee 104, 60596, Frankfurt am Main, Germany
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Mesirca P, Bidaud I, Mangoni ME. Rescuing cardiac automaticity in L-type Cav1.3 channelopathies and beyond. J Physiol 2016; 594:5869-5879. [PMID: 27374078 DOI: 10.1113/jp270678] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 06/24/2016] [Indexed: 11/08/2022] Open
Abstract
Pacemaker activity of the sino-atrial node generates the heart rate. Disease of the sinus node and impairment of atrioventricular conduction induce an excessively low ventricular rate (bradycardia), which cannot meet the needs of the organism. Bradycardia accounts for about half of the total workload of clinical cardiologists. The 'sick sinus' syndrome (SSS) is characterized by sinus bradycardia and periods of intermittent atrial fibrillation. Several genetic or acquired risk factors or pathologies can lead to SSS. Implantation of an electronic pacemaker constitutes the only available therapy for SSS. The incidence of SSS is forecast to double over the next 50 years, with ageing of the general population thus urging the development of complementary or alternative therapeutic strategies. In recent years an increasing number of mutations affecting ion channels involved in sino-atrial automaticity have been reported to underlie inheritable SSS. L-type Cav 1.3 channels play a major role in the generation and regulation of sino-atrial pacemaker activity and atrioventricular conduction. Mutation in the CACNA1D gene encoding Cav 1.3 channels induces loss-of-function in channel activity and underlies the sino-atrial node dysfunction and deafness syndrome (SANDD). Mice lacking Cav 1.3 channels (Cav 1.3-/- ) fairly recapitulate SSS and constitute a precious model to test new therapeutic approaches to handle this disease. Work in our laboratory shows that targeting G protein-gated K+ (IKACh ) channels effectively rescues SSS of Cav 1.3-/- mice. This new concept of 'compensatory' ion channel targeting shines new light on the principles underlying the pacemaker mechanism and may open the way to new therapies for SSS.
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Affiliation(s)
- Pietro Mesirca
- Département de Physiologie, Institut de Genomique Fonctionnelle, LabEx ICST, UMR-5203, Centre national de la recherche scientifique, F-34094, Montpellier, France. .,INSERM U1191, F-34094, Montpellier, France. .,Université de Montpellier, F-34094, Montpellier, France.
| | - Isabelle Bidaud
- Département de Physiologie, Institut de Genomique Fonctionnelle, LabEx ICST, UMR-5203, Centre national de la recherche scientifique, F-34094, Montpellier, France.,INSERM U1191, F-34094, Montpellier, France.,Université de Montpellier, F-34094, Montpellier, France
| | - Matteo E Mangoni
- Département de Physiologie, Institut de Genomique Fonctionnelle, LabEx ICST, UMR-5203, Centre national de la recherche scientifique, F-34094, Montpellier, France. .,INSERM U1191, F-34094, Montpellier, France. .,Université de Montpellier, F-34094, Montpellier, France.
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Baruscotti M, Bianco E, Bucchi A, DiFrancesco D. Current understanding of the pathophysiological mechanisms responsible for inappropriate sinus tachycardia: role of the If "funny" current. J Interv Card Electrophysiol 2016; 46:19-28. [PMID: 26781742 DOI: 10.1007/s10840-015-0097-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 12/28/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND Together with the afferent branches of the autonomic nervous system, the sinoatrial node (SAN) forms a functional unit whose function is to fire rhythmic action potentials at a rate optimal for coping with the metabolic needs of the body. Dysfunctional behavior of this complex unit may thus result in SAN rhythm disorders. Among these disorders, there is the inappropriate sinus tachycardia (IST) which occurs when an unjustified fast SAN rate is present. METHODS We here present a critical review of the role of pacemaker f/HCN channels in cardiac rhythm generation and modulation and their involvement in IST. RESULTS Recent evidence demonstrates that a familial form of IST is associated with a gain-of-function mutation in the HCN4 pacemaker channel (R524Q) which confers an increased sensitivity to the second messenger cAMP, a key mediator in sympathetic modulation. CONCLUSIONS This finding is consistent with the general view that hypersympathetic tone is one of the causes of IST and introduces the novel concept of defective funny channel-dependent tachyarrhythmias.
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Affiliation(s)
- Mirko Baruscotti
- Department of Biosciences, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, via Celoria 26, 20133, Milano, Italy.
| | - Elisabetta Bianco
- Cardiovascular Department, "Ospedali Riuniti di Trieste", University Hospital, Trieste, Italy
| | - Annalisa Bucchi
- Department of Biosciences, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, via Celoria 26, 20133, Milano, Italy
| | - Dario DiFrancesco
- Department of Biosciences, Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata, University of Milano, via Celoria 26, 20133, Milano, Italy.
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Chaudhary R, Garg J, Krishnamoorthy P, Shah N, Lanier G, Martinez MW, Freudenberger R. Ivabradine: Heart Failure and Beyond. J Cardiovasc Pharmacol Ther 2015; 21:335-43. [PMID: 26721645 DOI: 10.1177/1074248415624157] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/16/2015] [Indexed: 11/16/2022]
Abstract
Heart failure affects over 5 million people in the United States and carries a high rate of mortality. Ivabradine, a new agent has been added to the current medical options for managing heart failure. It is a selective funny current (If) inhibitor in sinoatrial node and slows its firing rate, prolonging diastolic depolarization without a negative inotropic effect. Ivabradine was only recently approved by Food and Drug administration after the results of Systolic Heart Failure Treatment with the If Inhibitor Ivabradine (SHIFT) trial, for a reduction in rehospitalizations from chronic heart failure. This trial assessed patients with stable heart failure with reduced ejection fraction and a heart rate of at least 70 beats per minute at rest on maximally tolerated beta-blocker therapy and demonstrated statistically significant reduction in heart failure hospitalization and deaths. Additionally, ivabradine has been associated with reduced cardiac remodeling, reduced heart rate variability, improvement in exercise tolerance, improved heart failure class of New York Heart Association, and better quality of life. It has also been tried in other conditions, such as inappropriate sinus tachycardia and cardiogenic shock, and is currently in phase II trial for patients with newly diagnosed multiple organ dysfunction syndrome.
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Affiliation(s)
- Rahul Chaudhary
- Department of Medicine, Sinai Hospital of Baltimore, Johns Hopkins University, Baltimore, MD, USA
| | - Jalaj Garg
- Division of Cardiology, Lehigh Valley Health Network, Allentown, PA, USA
| | - Parasuram Krishnamoorthy
- Department of Medicine, Englewood Hospital and Medical Center, Mount Sinai School of Medicine, Englewood, NJ, USA
| | - Neeraj Shah
- Division of Cardiology, Lehigh Valley Health Network, Allentown, PA, USA
| | - Gregg Lanier
- Division of Cardiology, Westchester Medical Center, New York Medical College, Valhalla, NY, USA
| | - Mathew W Martinez
- Division of Cardiology, Lehigh Valley Health Network, Allentown, PA, USA
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