1
|
Claessen G, De Bosscher R, Janssens K, Young P, Dausin C, Claeys M, Claus P, Goetschalckx K, Bogaert J, Mitchell AM, Flannery MD, Elliott AD, Yu C, Ghekiere O, Robyns T, Van De Heyning CM, Sanders P, Kalman JM, Ohanian M, Soka M, Rath E, Giannoulatou E, Johnson R, Lacaze P, Herbots L, Willems R, Fatkin D, Heidbuchel H, La Gerche A. Reduced Ejection Fraction in Elite Endurance Athletes: Clinical and Genetic Overlap With Dilated Cardiomyopathy. Circulation 2024; 149:1405-1415. [PMID: 38109351 PMCID: PMC11062611 DOI: 10.1161/circulationaha.122.063777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 10/30/2023] [Indexed: 12/20/2023]
Abstract
BACKGROUND Exercise-induced cardiac remodeling can be profound, resulting in clinical overlap with dilated cardiomyopathy, yet the significance of reduced ejection fraction (EF) in athletes is unclear. The aim is to assess the prevalence, clinical consequences, and genetic predisposition of reduced EF in athletes. METHODS Young endurance athletes were recruited from elite training programs and underwent comprehensive cardiac phenotyping and genetic testing. Those with reduced EF using cardiac magnetic resonance imaging (defined as left ventricular EF <50%, or right ventricular EF <45%, or both) were compared with athletes with normal EF. A validated polygenic risk score for indexed left ventricular end-systolic volume (LVESVi-PRS), previously associated with dilated cardiomyopathy, was assessed. Clinical events were recorded over a mean of 4.4 years. RESULTS Of the 281 elite endurance athletes (22±8 years, 79.7% male) undergoing comprehensive assessment, 44 of 281 (15.7%) had reduced left ventricular EF (N=12; 4.3%), right ventricular EF (N=14; 5.0%), or both (N=18; 6.4%). Reduced EF was associated with a higher burden of ventricular premature beats (13.6% versus 3.8% with >100 ventricular premature beats/24 h; P=0.008) and lower left ventricular global longitudinal strain (-17%±2% versus -19%±2%; P<0.001). Athletes with reduced EF had a higher mean LVESVi-PRS (0.57±0.13 versus 0.51±0.14; P=0.009) with athletes in the top decile of LVESVi-PRS having an 11-fold increase in the likelihood of reduced EF compared with those in the bottom decile (P=0.034). Male sex and higher LVESVi-PRS were the only significant predictors of reduced EF in a multivariate analysis that included age and fitness. During follow-up, no athletes developed symptomatic heart failure or arrhythmias. Two athletes died, 1 from trauma and 1 from sudden cardiac death, the latter having a reduced right ventricular EF and a LVESVi-PRS >95%. CONCLUSIONS Reduced EF occurs in approximately 1 in 6 elite endurance athletes and is related to genetic predisposition in addition to exercise training. Genetic and imaging markers may help identify endurance athletes in whom scrutiny about long-term clinical outcomes may be appropriate. REGISTRATION URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374976&isReview=true; Unique identifier: ACTRN12618000716268.
Collapse
Affiliation(s)
- Guido Claessen
- Faculty of Medicine and Life Sciences, Limburg Clinical Research Center (LCRC), Hasselt University, Biomedical Research Institute, Diepenbeek, Belgium (G.C., O.G., L.H.)
- Hartcentrum Hasselt (G.C., L.H.), KU Leuven, Belgium
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
| | - Ruben De Bosscher
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
- Department of Cardiovascular Diseases (R.D.B., K.G., T.R., R.W.), University Hospitals Leuven, Belgium
| | - Kristel Janssens
- HEART (Heart Exercise and Research Trials) Lab, St Vincent’s Institute of Medical Research, Fitzroy, Australia (K.J., A.M.M., A.L.G.)
- Exercise and Nutrition Research Program, The Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne Australia (K.J.)
| | - Paul Young
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
| | | | - Mathias Claeys
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
| | - Piet Claus
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
| | - Kaatje Goetschalckx
- Department of Cardiovascular Diseases (R.D.B., K.G., T.R., R.W.), University Hospitals Leuven, Belgium
| | - Jan Bogaert
- Department of Imaging and Pathology (J.B.), KU Leuven, Belgium
- Department of Radiology (J.B.), University Hospitals Leuven, Belgium
| | - Amy M. Mitchell
- HEART (Heart Exercise and Research Trials) Lab, St Vincent’s Institute of Medical Research, Fitzroy, Australia (K.J., A.M.M., A.L.G.)
| | - Michael D. Flannery
- Department of Medicine, University of Melbourne, Parkville, Australia (M.D.F., J.M.K., A.L.G.)
| | - Adrian D. Elliott
- Centre for Heart Rhythm Disorders, University of Adelaide and Royal Adelaide Hospital, Australia (A.D.E., P.S.)
| | - Chenglong Yu
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia (C.Y., P.L.)
| | - Olivier Ghekiere
- Faculty of Medicine and Life Sciences, Limburg Clinical Research Center (LCRC), Hasselt University, Biomedical Research Institute, Diepenbeek, Belgium (G.C., O.G., L.H.)
- Department of Radiology (O.G.), KU Leuven, Belgium
| | - Tomas Robyns
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
- Department of Cardiovascular Diseases (R.D.B., K.G., T.R., R.W.), University Hospitals Leuven, Belgium
| | - Caroline M. Van De Heyning
- Department of Cardiovascular Sciences, University of Antwerp, Belgium (C.M.V.D.H., H.H.)
- Department of Cardiology, University Hospital Antwerp, Belgium (C.M.V.D.H., H.H.)
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, University of Adelaide and Royal Adelaide Hospital, Australia (A.D.E., P.S.)
| | - Jonathan M. Kalman
- Department of Medicine, University of Melbourne, Parkville, Australia (M.D.F., J.M.K., A.L.G.)
- Department of Cardiology, Royal Melbourne Hospital, Australia (J.M.K.)
| | - Monique Ohanian
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
| | - Magdalena Soka
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
| | - Emma Rath
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
| | - Eleni Giannoulatou
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
| | - Renee Johnson
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington, Australia (R.J., D.F.)
| | - Paul Lacaze
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia (C.Y., P.L.)
| | - Lieven Herbots
- Faculty of Medicine and Life Sciences, Limburg Clinical Research Center (LCRC), Hasselt University, Biomedical Research Institute, Diepenbeek, Belgium (G.C., O.G., L.H.)
- Hartcentrum Hasselt (G.C., L.H.), KU Leuven, Belgium
| | - Rik Willems
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
- Department of Cardiovascular Diseases (R.D.B., K.G., T.R., R.W.), University Hospitals Leuven, Belgium
| | - Diane Fatkin
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
- School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington, Australia (R.J., D.F.)
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia (D.F.)
| | - Hein Heidbuchel
- Department of Cardiovascular Sciences, University of Antwerp, Belgium (C.M.V.D.H., H.H.)
- Department of Cardiology, University Hospital Antwerp, Belgium (C.M.V.D.H., H.H.)
| | - André La Gerche
- Jessa Ziekenhuis, Belgium. Department of Cardiovascular Sciences (G.C., R.D.B., M.C., P.C., T.R., R.W., A.L.G.), KU Leuven, Belgium
- HEART (Heart Exercise and Research Trials) Lab, St Vincent’s Institute of Medical Research, Fitzroy, Australia (K.J., A.M.M., A.L.G.)
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia (P.Y., M.O., M.S., E.R., E.G., R.J., D.F., A.L.G.)
- Department of Medicine, University of Melbourne, Parkville, Australia (M.D.F., J.M.K., A.L.G.)
- Cardiology Department, St Vincent’s Hospital Melbourne, Fitzroy, Australia (A.L.G.)
- National Centre for Sports Cardiology, Fitzroy, Australia (A.L.G.)
| |
Collapse
|
2
|
Johnson R, Otway R, Chin E, Horvat C, Ohanian M, Wilcox JA, Su Z, Prestes P, Smolnikov A, Soka M, Guo G, Rath E, Chakravorty S, Chrzanowski L, Hayward CS, Keogh AM, Macdonald PS, Giannoulatou E, Chang AC, Oates EC, Charchar F, Seidman JG, Seidman CE, Hegde M, Fatkin D. DMD-Associated Dilated Cardiomyopathy: Genotypes, Phenotypes, and Phenocopies. Circ Genom Precis Med 2023; 16:421-430. [PMID: 37671549 PMCID: PMC10592075 DOI: 10.1161/circgen.123.004221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 07/31/2023] [Indexed: 09/07/2023]
Abstract
BACKGROUND Variants in the DMD gene, that encodes the cytoskeletal protein, dystrophin, cause a severe form of dilated cardiomyopathy (DCM) associated with high rates of heart failure, heart transplantation, and ventricular arrhythmias. Improved early detection of individuals at risk is needed. METHODS Genetic testing of 40 male probands with a potential X-linked genetic cause of primary DCM was undertaken using multi-gene panel sequencing, multiplex polymerase chain reaction, and array comparative genomic hybridization. Variant location was assessed with respect to dystrophin isoform patterns and exon usage. Telomere length was evaluated as a marker of myocardial dysfunction in left ventricular tissue and blood. RESULTS Four pathogenic/likely pathogenic DMD variants were found in 5 probands (5/40: 12.5%). Only one rare variant was identified by gene panel testing with 3 additional multi-exon deletion/duplications found following targeted assays for structural variants. All of the pathogenic/likely pathogenic DMD variants involved dystrophin exons that had percent spliced-in scores >90, indicating high levels of constitutive expression in the human adult heart. Fifteen DMD variant-negative probands (15/40: 37.5%) had variants in autosomal genes including TTN, BAG3, LMNA, and RBM20. Myocardial telomere length was reduced in patients with DCM irrespective of genotype. No differences in blood telomere length were observed between genotype-positive family members with/without DCM and controls. CONCLUSIONS Primary genetic testing using multi-gene panels has a low yield and specific assays for structural variants are required if DMD-associated cardiomyopathy is suspected. Distinguishing X-linked causes of DCM from autosomal genes that show sex differences in clinical presentation is crucial for informed family management.
Collapse
Affiliation(s)
- Renee Johnson
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
| | - Robyn Otway
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
| | - Ephrem Chin
- Dept of Human Genetics, Emory Univ School of Medicine, Atlanta GA
- PerkinElmer Genomics, PerkinElmer, Waltham
| | | | | | | | - Zheng Su
- School of Biotechnology & Biomolecular Sciences, Faculty of Science, UNSW Sydney, Kensington, NSW, Australia
| | - Priscilla Prestes
- Health Innovation & Transformation Ctr, Federation Univ Australia, Ballarat, Victoria, Australia
| | - Andrei Smolnikov
- School of Biotechnology & Biomolecular Sciences, Faculty of Science, UNSW Sydney, Kensington, NSW, Australia
| | | | | | - Emma Rath
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
| | - Samya Chakravorty
- Dept of Human Genetics, Emory Univ School of Medicine, Atlanta GA
- Biocon Bristol Myers Squibb Rsrch & Development Ctr (BBRC), Bangalore, India
| | | | - Christopher S. Hayward
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- Cardiology Dept, St Vincent’s Hospital, Darlinghurst, NSW, Australia
| | - Anne M. Keogh
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- Cardiology Dept, St Vincent’s Hospital, Darlinghurst, NSW, Australia
| | - Peter S. Macdonald
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- Cardiology Dept, St Vincent’s Hospital, Darlinghurst, NSW, Australia
| | - Eleni Giannoulatou
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
| | - Alex C.Y. Chang
- Dept of Cardiology & Shanghai Inst of Precision Medicine, Ninth People’s Hospital, Shanghai Jiao Tong Univ School of Medicine, Shanghai, China
- Baxter Laboratory for Stem Cell Biology, Dept of Microbiology & Immunology, Inst for Stem Cell Biology & Regenerative Medicine, Stanford Univ School of Medicine, Stanford, CA
| | - Emily C. Oates
- School of Biotechnology & Biomolecular Sciences, Faculty of Science, UNSW Sydney, Kensington, NSW, Australia
| | - Fadi Charchar
- Health Innovation & Transformation Ctr, Federation Univ Australia, Ballarat, Victoria, Australia
| | - Jonathan G. Seidman
- Dept of Genetics, Harvard Medical School, Boston, MA
- Howard Hughes Medical Inst, Boston
| | - Christine E. Seidman
- Dept of Genetics, Harvard Medical School, Boston, MA
- Cardiovascular Division, Brigham and Women’s Hospital, Boston MA
| | - Madhuri Hegde
- Dept of Human Genetics, Emory Univ School of Medicine, Atlanta GA
- PerkinElmer Genomics, PerkinElmer, Waltham
| | - Diane Fatkin
- Victor Chang Cardiac Rsrch Inst, Darlinghurst
- School of Clinical Medicine, Faculty of Medicine & Health, UNSW Sydney, Kensington, NSW, Australia
- Cardiology Dept, St Vincent’s Hospital, Darlinghurst, NSW, Australia
| |
Collapse
|
3
|
Al-Kaisey A, Wong GR, Young P, Chieng D, Hawson J, Anderson R, Sugumar H, Nalliah C, Prabhu M, Johnson R, Soka M, Tarr I, Bakshi A, Yu C, Lacaze P, Giannoulatou E, McLellan A, Lee G, Kistler PM, Fatkin D, Kalman JM. Polygenic risk scores are associated with atrial electrophysiologic substrate abnormalities and outcomes after atrial fibrillation catheter ablation. Heart Rhythm 2023; 20:1188-1194. [PMID: 36804918 PMCID: PMC10522415 DOI: 10.1016/j.hrthm.2023.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/10/2023] [Accepted: 02/12/2023] [Indexed: 02/18/2023]
Affiliation(s)
- Ahmed Al-Kaisey
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Geoffrey R Wong
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Paul Young
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - David Chieng
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Heart Centre, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Joshua Hawson
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Robert Anderson
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Hariharan Sugumar
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Heart Centre, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Chrishan Nalliah
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | | | - Renee Johnson
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington, New South Wales, Australia
| | - Magdalena Soka
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Ingrid Tarr
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Andrew Bakshi
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Chenglong Yu
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Paul Lacaze
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Eleni Giannoulatou
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington, New South Wales, Australia
| | - Alex McLellan
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Geoffrey Lee
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter M Kistler
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Heart Centre, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Diane Fatkin
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; School of Clinical Medicine, Faculty of Medicine and Health, UNSW Sydney, Kensington, New South Wales, Australia; Cardiology Department, St Vincent's Hospital, Darlinghurst, New South Wales, Australia
| | - Jonathan M Kalman
- Department of Cardiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia.
| |
Collapse
|
4
|
Pineda S, Nikolova-Krstevski V, Leimena C, Atkinson AJ, Altekoester AK, Cox CD, Jacoby A, Huttner IG, Ju YK, Soka M, Ohanian M, Trivedi G, Kalvakuri S, Birker K, Johnson R, Molenaar P, Kuchar D, Allen DG, van Helden DF, Harvey RP, Hill AP, Bodmer R, Vogler G, Dobrzynski H, Ocorr K, Fatkin D. Conserved Role of the Large Conductance Calcium-Activated Potassium Channel, K Ca1.1, in Sinus Node Function and Arrhythmia Risk. Circ Genom Precis Med 2021; 14:e003144. [PMID: 33629867 DOI: 10.1161/circgen.120.003144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND KCNMA1 encodes the α-subunit of the large-conductance Ca2+-activated K+ channel, KCa1.1, and lies within a linkage interval for atrial fibrillation (AF). Insights into the cardiac functions of KCa1.1 are limited, and KCNMA1 has not been investigated as an AF candidate gene. METHODS The KCNMA1 gene was sequenced in 118 patients with familial AF. The role of KCa1.1 in normal cardiac structure and function was evaluated in humans, mice, zebrafish, and fly. A novel KCNMA1 variant was functionally characterized. RESULTS A complex KCNMA1 variant was identified in 1 kindred with AF. To evaluate potential disease mechanisms, we first evaluated the distribution of KCa1.1 in normal hearts using immunostaining and immunogold electron microscopy. KCa1.1 was seen throughout the atria and ventricles in humans and mice, with strong expression in the sinus node. In an ex vivo murine sinoatrial node preparation, addition of the KCa1.1 antagonist, paxilline, blunted the increase in beating rate induced by adrenergic receptor stimulation. Knockdown of the KCa1.1 ortholog, kcnma1b, in zebrafish embryos resulted in sinus bradycardia with dilatation and reduced contraction of the atrium and ventricle. Genetic inactivation of the Drosophila KCa1.1 ortholog, slo, systemically or in adult stages, also slowed the heartbeat and produced fibrillatory cardiac contractions. Electrophysiological characterization of slo-deficient flies revealed bursts of action potentials, reflecting increased events of fibrillatory arrhythmias. Flies with cardiac-specific overexpression of the human KCNMA1 mutant also showed increased heart period and bursts of action potentials, similar to the KCa1.1 loss-of-function models. CONCLUSIONS Our data point to a highly conserved role of KCa1.1 in sinus node function in humans, mice, zebrafish, and fly and suggest that KCa1.1 loss of function may predispose to AF.
Collapse
Affiliation(s)
- Santiago Pineda
- Development, Aging & Regeneration Program, Sanford-Burnham Prebys Medical Discovery Institute, La Jolla, CA (S.P., S.K., K.B., R.B., G.V., K.O.)
| | - Vesna Nikolova-Krstevski
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.).,Faculty of Medicine, UNSW Sydney, Kensington (V.N.-K., I.G.H., R.J., R.P.H., A.P.H., D.F.)
| | - Christiana Leimena
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Andrew J Atkinson
- Institute of Cardiovascular Sciences, University of Manchester, United Kingdom (A.J.A., H.D.)
| | - Ann-Kristin Altekoester
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Charles D Cox
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Arie Jacoby
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Inken G Huttner
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.).,Faculty of Medicine, UNSW Sydney, Kensington (V.N.-K., I.G.H., R.J., R.P.H., A.P.H., D.F.)
| | - Yue-Kun Ju
- Bosch Institute, University of Sydney, Camperdown (Y.-K.J., D.G.A.)
| | - Magdalena Soka
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Monique Ohanian
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Gunjan Trivedi
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.)
| | - Sreehari Kalvakuri
- Development, Aging & Regeneration Program, Sanford-Burnham Prebys Medical Discovery Institute, La Jolla, CA (S.P., S.K., K.B., R.B., G.V., K.O.)
| | - Katja Birker
- Development, Aging & Regeneration Program, Sanford-Burnham Prebys Medical Discovery Institute, La Jolla, CA (S.P., S.K., K.B., R.B., G.V., K.O.)
| | - Renee Johnson
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.).,Faculty of Medicine, UNSW Sydney, Kensington (V.N.-K., I.G.H., R.J., R.P.H., A.P.H., D.F.)
| | - Peter Molenaar
- Faculty of Health, Queensland University of Technology (P.M.).,School of Medicine, University of Queensland, Prince Charles Hospital, Brisbane, Queensland, Australia (P.M.)
| | - Dennis Kuchar
- Cardiology Department, St Vincent's Hospital, Darlinghurst (D.K., D.F.)
| | - David G Allen
- Bosch Institute, University of Sydney, Camperdown (Y.-K.J., D.G.A.)
| | - Dirk F van Helden
- University of Newcastle and Hunter Medical Research Institute, NSW, Australia (D.F.v.H.)
| | - Richard P Harvey
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.).,Faculty of Medicine, UNSW Sydney, Kensington (V.N.-K., I.G.H., R.J., R.P.H., A.P.H., D.F.)
| | - Adam P Hill
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.).,Faculty of Medicine, UNSW Sydney, Kensington (V.N.-K., I.G.H., R.J., R.P.H., A.P.H., D.F.)
| | - Rolf Bodmer
- Development, Aging & Regeneration Program, Sanford-Burnham Prebys Medical Discovery Institute, La Jolla, CA (S.P., S.K., K.B., R.B., G.V., K.O.)
| | - Georg Vogler
- Development, Aging & Regeneration Program, Sanford-Burnham Prebys Medical Discovery Institute, La Jolla, CA (S.P., S.K., K.B., R.B., G.V., K.O.)
| | - Halina Dobrzynski
- Institute of Cardiovascular Sciences, University of Manchester, United Kingdom (A.J.A., H.D.).,Jagiellonian University Medical College, Cracow, Poland (H.D.)
| | - Karen Ocorr
- Development, Aging & Regeneration Program, Sanford-Burnham Prebys Medical Discovery Institute, La Jolla, CA (S.P., S.K., K.B., R.B., G.V., K.O.)
| | - Diane Fatkin
- Victor Chang Cardiac Research Institute, Darlinghurst (V.N.-K., C.L., A.-K.A., C.D.C., A.J., I.G.H., M.S., M.O., G.T., R.J., R.P.H., A.P.H., D.F.).,Faculty of Medicine, UNSW Sydney, Kensington (V.N.-K., I.G.H., R.J., R.P.H., A.P.H., D.F.).,Cardiology Department, St Vincent's Hospital, Darlinghurst (D.K., D.F.)
| |
Collapse
|
5
|
Christensen AH, Chatelain FC, Huttner IG, Olesen MS, Soka M, Feliciangeli S, Horvat C, Santiago CF, Vandenberg JI, Schmitt N, Olesen SP, Lesage F, Fatkin D. The two-pore domain potassium channel, TWIK-1, has a role in the regulation of heart rate and atrial size. J Mol Cell Cardiol 2016; 97:24-35. [PMID: 27103460 DOI: 10.1016/j.yjmcc.2016.04.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/11/2016] [Accepted: 04/14/2016] [Indexed: 12/24/2022]
Abstract
The two-pore domain potassium (K(+)) channel TWIK-1 (or K2P1.1) contributes to background K(+) conductance in diverse cell types. TWIK-1, encoded by the KCNK1 gene, is present in the human heart with robust expression in the atria, however its physiological significance is unknown. To evaluate the cardiac effects of TWIK-1 deficiency, we studied zebrafish embryos after knockdown of the two KCNK1 orthologues, kcnk1a and kcnk1b. Knockdown of kcnk1a or kcnk1b individually caused bradycardia and atrial dilation (p<0.001 vs. controls), while ventricular stroke volume was preserved. Combined knockdown of both kcnk1a and kcnk1b resulted in a more severe phenotype, which was partially reversed by co-injection of wild-type human KCNK1 mRNA, but not by a dominant negative variant of human KCNK1 mRNA. To determine whether genetic variants in KCNK1 might cause atrial fibrillation (AF), we sequenced protein-coding regions in two independent cohorts of patients (373 subjects) and identified three non-synonymous variants, p.R171H, p.I198M and p.G236S, that were all located in highly conserved amino acid residues. In transfected mammalian cells, zebrafish and wild-type human TWIK-1 channels had a similar cellular distribution with predominant localization in the endosomal compartment. Two-electrode voltage-clamp experiments using Xenopus oocytes showed that both zebrafish and wild-type human TWIK-1 channels produced K(+) currents that are sensitive to external K(+) concentration as well as acidic pH. There were no effects of the three KCNK1 variants on cellular localization, current amplitude or reversal potential at pH7.4 or pH6. Our data indicate that TWIK-1 has a highly conserved role in cardiac function and is required for normal heart rate and atrial morphology. Despite the functional importance of TWIK-1 in the atrium, genetic variation in KCNK1 is not a common primary cause of human AF.
Collapse
Affiliation(s)
- Alex Hørby Christensen
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Franck C Chatelain
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, and Université de Nice Sophia-Antipolis, Sophia-Antipolis, Valbonne, France
| | - Inken G Huttner
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Morten Salling Olesen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Magdalena Soka
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Sylvain Feliciangeli
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, and Université de Nice Sophia-Antipolis, Sophia-Antipolis, Valbonne, France
| | - Claire Horvat
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Celine F Santiago
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Jamie I Vandenberg
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Nicole Schmitt
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Søren-Peter Olesen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Florian Lesage
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, and Université de Nice Sophia-Antipolis, Sophia-Antipolis, Valbonne, France
| | - Diane Fatkin
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia; Cardiology Department, St Vincent's Hospital, Darlinghurst, New South Wales, Australia.
| |
Collapse
|
6
|
Liang B, Soka M, Christensen AH, Olesen MS, Larsen AP, Knop FK, Wang F, Nielsen JB, Andersen MN, Humphreys D, Mann SA, Huttner IG, Vandenberg JI, Svendsen JH, Haunsø S, Preiss T, Seebohm G, Olesen SP, Schmitt N, Fatkin D. Genetic variation in the two-pore domain potassium channel, TASK-1, may contribute to an atrial substrate for arrhythmogenesis. J Mol Cell Cardiol 2013; 67:69-76. [PMID: 24374141 DOI: 10.1016/j.yjmcc.2013.12.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 12/09/2013] [Accepted: 12/17/2013] [Indexed: 12/22/2022]
Abstract
The two-pore domain potassium channel, K2P3.1 (TASK-1) modulates background conductance in isolated human atrial cardiomyocytes and has been proposed as a potential drug target for atrial fibrillation (AF). TASK-1 knockout mice have a predominantly ventricular phenotype however, and effects of TASK-1 inactivation on atrial structure and function have yet to be demonstrated in vivo. The extent to which genetic variation in KCNK3, that encodes TASK-1, might be a determinant of susceptibility to AF is also unknown. To address these questions, we first evaluated the effects of transient knockdown of the zebrafish kcnk3a and kcnk3b genes and cardiac phenotypes were evaluated using videomicroscopy. Combined kcnk3a and kcnk3b knockdown in 72 hour post fertilization embryos resulted in lower heart rate (p<0.001), marked increase in atrial diameter (p<0.001), and mild increase in end-diastolic ventricular diameter (p=0.01) when compared with control-injected embryos. We next performed genetic screening of KCNK3 in two independent AF cohorts (373 subjects) and identified three novel KCNK3 variants. Two of these variants, present in one proband with familial AF, were located at adjacent nucleotides in the Kozak sequence and reduced expression of an engineered reporter. A third missense variant, V123L, in a patient with lone AF, reduced resting membrane potential and altered pH sensitivity in patch-clamp experiments, with structural modeling predicting instability in the vicinity of the TASK-1 pore. These in vitro data suggest that the double Kozak variants and V123L will have loss-of-function effects on ITASK. Cardiac action potential modeling predicted that reduced ITASK prolongs atrial action potential duration, and that this is potentiated by reciprocal changes in activity of other ion channel currents. Our findings demonstrate the functional importance of ITASK in the atrium and suggest that inactivation of TASK-1 may have diverse effects on atrial size and electrophysiological properties that can contribute to an arrhythmogenic substrate.
Collapse
Affiliation(s)
- Bo Liang
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Magdalena Soka
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Alex Horby Christensen
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Morten S Olesen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Anders P Larsen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
| | - Filip K Knop
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Fan Wang
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Jonas B Nielsen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Martin N Andersen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - David Humphreys
- Molecular Genetics Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Stefan A Mann
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Inken G Huttner
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
| | - Jamie I Vandenberg
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia
| | - Jesper H Svendsen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Stig Haunsø
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Preiss
- John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Guiscard Seebohm
- Institute for Genetics of Heart Diseases (IfGH), Department of Cardiovascular Medicine, University Hospital Münster, Germany
| | - Søren-Peter Olesen
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | - Nicole Schmitt
- Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.
| | - Diane Fatkin
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia; Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia; Cardiology Department, St Vincent's Hospital, Darlinghurst, New South Wales, Australia
| |
Collapse
|
7
|
Olesen M, Liang B, Soka M, Larsen AP, Knop FK, Wang F, Nielsen JB, Andersen MN, Humphreys D, Mann SA, Vandenberg JI, Svendsen JH, Haunso S, Preiss T, Seebohm G, Olesen SP, Schmitt N, Fatkin D. TASK-1 potassium channel mutations in atrial fibrillation. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht309.3411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
8
|
Mann SA, Otway R, Guo G, Soka M, Karlsdotter L, Trivedi G, Ohanian M, Zodgekar P, Smith RA, Wouters MA, Subbiah R, Walker B, Kuchar D, Sanders P, Griffiths L, Vandenberg JI, Fatkin D. Epistatic effects of potassium channel variation on cardiac repolarization and atrial fibrillation risk. J Am Coll Cardiol 2012; 59:1017-25. [PMID: 22402074 DOI: 10.1016/j.jacc.2011.11.039] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/13/2011] [Accepted: 11/01/2011] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate the role of cardiac K(+) channel gene variants in families with atrial fibrillation (AF). BACKGROUND The K(+) channels play a major role in atrial repolarization but single mutations in cardiac K(+) channel genes are infrequently present in AF families. The collective effect of background K(+) channel variants of varying prevalence and effect size on the atrial substrate for AF is largely unexplored. METHODS Genes encoding the major cardiac K(+) channels were resequenced in 80 AF probands. Nonsynonymous coding sequence variants identified in AF probands were evaluated in 240 control subjects. Novel variants were characterized using patch-clamp techniques and in silico modeling was performed using the Courtemanche atrial cell model. RESULTS Nineteen nonsynonymous variants in 9 genes were found, including 11 rare variants. Rare variants were more frequent in AF probands (18.8% vs. 4.2%, p < 0.001), and the mean number of variants was greater (0.21 vs. 0.04, p < 0.001). The majority of K(+) channel variants individually had modest functional effects. Modeling simulations to evaluate combinations of K(+) channel variants of varying population frequency indicated that simultaneous small perturbations of multiple current densities had nonlinear interactions and could result in substantial (>30 ms) shortening or lengthening of action potential duration as well as increased dispersion of repolarization. CONCLUSIONS Families with AF show an excess of rare functional K(+) channel gene variants of varying phenotypic effect size that may contribute to an atrial arrhythmogenic substrate. Atrial cell modeling is a useful tool to assess epistatic interactions between multiple variants.
Collapse
Affiliation(s)
- Stefan A Mann
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW 2010, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|