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Klocke B, Britzolaki A, Saurine J, Ott H, Krone K, Bahamonde K, Thelen C, Tzimas C, Sanoudou D, Kranias EG, Pitychoutis PM. A novel role for phospholamban in the thalamic reticular nucleus. Sci Rep 2024; 14:6376. [PMID: 38493225 PMCID: PMC10944534 DOI: 10.1038/s41598-024-56447-x] [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: 12/05/2023] [Accepted: 03/06/2024] [Indexed: 03/18/2024] Open
Abstract
The thalamic reticular nucleus (TRN) is a brain region that influences vital neurobehavioral processes, including executive functioning and the generation of sleep rhythms. TRN dysfunction underlies hyperactivity, attention deficits, and sleep disturbances observed across various neurodevelopmental disorders. A specialized sarco-endoplasmic reticulum calcium (Ca2+) ATPase 2 (SERCA2)-dependent Ca2+ signaling network operates in the dendrites of TRN neurons to regulate their bursting activity. Phospholamban (PLN) is a prominent regulator of SERCA2 with an established role in myocardial Ca2+-cycling. Our findings suggest that the role of PLN extends beyond the cardiovascular system to impact brain function. Specifically, we found PLN to be expressed in TRN neurons of the adult mouse brain, and utilized global constitutive and innovative conditional genetic knockout mouse models in concert with electroencephalography (EEG)-based somnography and the 5-choice serial reaction time task (5-CSRTT) to investigate the role of PLN in sleep and executive functioning, two complex behaviors that map onto thalamic reticular circuits. The results of the present study indicate that perturbed PLN function in the TRN results in aberrant TRN-dependent phenotypes in mice (i.e., hyperactivity, impulsivity and sleep deficits) and support a novel role for PLN as a critical regulator of SERCA2 in the TRN neurocircuitry.
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Affiliation(s)
- Benjamin Klocke
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Aikaterini Britzolaki
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Joseph Saurine
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Hayden Ott
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Kylie Krone
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Kiara Bahamonde
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Connor Thelen
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA
| | - Christos Tzimas
- Molecular Biology Department, Biomedical Research Foundation of the Academy of Athens, 11527, Athens, Greece
| | - Despina Sanoudou
- Molecular Biology Department, Biomedical Research Foundation of the Academy of Athens, 11527, Athens, Greece
- 4th Department of Internal Medicine, Clinical Genomics and Pharmacogenomics Unit, Medical School, "Attikon" Hospital, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Evangelia G Kranias
- Molecular Biology Department, Biomedical Research Foundation of the Academy of Athens, 11527, Athens, Greece
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Pothitos M Pitychoutis
- Department of Biology, University of Dayton, 300 College Park, Dayton, OH, 45469-2320, USA.
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Klocke B, Britzolaki A, Saurine J, Ott H, Krone K, Bahamonde K, Thelen C, Tzimas C, Sanoudou D, Kranias EG, Pitychoutis PM. A Novel Role for Phospholamban in the Thalamic Reticular Nucleus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.22.568306. [PMID: 38045420 PMCID: PMC10690257 DOI: 10.1101/2023.11.22.568306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
The thalamic reticular nucleus (TRN) is a critical brain region that greatly influences vital neurobehavioral processes, including executive functioning and the generation of sleep rhythms. Recently, TRN dysfunction was suggested to underlie hyperactivity, attention deficits, and sleep disturbances observed across various devastating neurodevelopmental disorders, including autism, schizophrenia and attention-deficit/hyperactivity disorder (ADHD). Notably, a highly specialized sarco- endoplasmic reticulum calcium (Ca 2+ ) ATPase 2 (SERCA2)-dependent Ca 2+ signaling network operates in the dendrites of TRN neurons to regulate their high-frequency bursting activity. Phospholamban (PLN) is a prominent regulator of the SERCA2 with an established role in maintaining Ca 2+ homeostasis in the heart; although the interaction of PLN with SERCA2 has been largely regarded as cardiac-specific, our findings challenge this view and suggest that the role of PLN extends beyond the cardiovascular system to impact brain function. Specifically, we found PLN to be expressed in the TRN neurons of the adult mouse brain and utilized global constitutive and innovative conditional genetic mouse models, in combination with 5-choice serial reaction time task (5-CSRTT) and electroencephalography (EEG)-based somnography to assess the role of PLN in regulating executive functioning and sleep, two complex behaviors that map onto thalamic reticular circuits. Overall, the results of the present study show that perturbed PLN function in the TRN results in aberrant thalamic reticular behavioral phenotypes in mice (i.e., hyperactivity, impulsivity and sleep deficits) and support a novel role for PLN as a critical regulator of the SERCA2 in the thalamic reticular neurocircuitry.
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van Lint FHM, Hassanzada F, Verstraelen TE, Wang W, Bosman LP, van der Zwaag PA, Oomen T, Calkins H, Murray B, Tichnell C, Beuren TMA, Asselbergs FW, Houweling A, van den Berg MP, Wilde AAM, James CA, van Tintelen JP. Exercise does not influence development of phenotype in PLN p.(Arg14del) cardiomyopathy. Neth Heart J 2023:10.1007/s12471-023-01800-4. [PMID: 37474840 PMCID: PMC10400740 DOI: 10.1007/s12471-023-01800-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2023] [Indexed: 07/22/2023] Open
Abstract
BACKGROUND Endurance and frequent exercise are associated with earlier onset of arrhythmogenic right ventricular cardiomyopathy (ARVC) and ventricular arrhythmias (VA) in desmosomal gene variant carriers. Individuals with the pathogenic c.40_42del; p.(Arg14del) variant in the PLN gene are frequently diagnosed with ARVC or dilated cardiomyopathy (DCM). The aim of this study was to evaluate the effect of exercise in PLN p.(Arg14del) carriers. METHODS In total, 207 adult PLN p.(Arg14del) carriers (39.1% male; mean age 53 ± 15 years) were interviewed on their regular physical activity since the age of 10 years. The association of exercise with diagnosis of ARVC, DCM, sustained VA and hospitalisation for heart failure (HF) was studied. RESULTS Individuals participated in regular physical activities with a median of 1661 metabolic equivalent of task (MET) hours per year (31.9 MET-hours per week) until clinical presentation. The 50% most and least active individuals had a similar frequency of sustained VA (18.3% vs 18.4%; p = 0.974) and hospitalisation for HF (9.6% vs 8.7%; p = 0.827). There was no relationship between exercise and survival free from (incident) sustained VA (p = 0.65), hospitalisation for HF (p = 0.81), diagnosis of ARVC (p = 0.67) or DCM (p = 0.39) during follow-up. In multivariate analyses, exercise was not associated with sustained VA or HF hospitalisation during follow-up in this relatively not-active cohort. CONCLUSION There was no association between the amount of exercise and the susceptibility to develop ARVC, DCM, VA or HF in PLN p.(Arg14del) carriers. This suggested unaffected PLN p.(Arg14del) carriers can safely perform mild-moderate exercise, in contrast to desmosomal variant carriers and ARVC patients.
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Affiliation(s)
- Freyja H M van Lint
- Department of Genetics, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
- Department of Human Genetics, Amsterdam University Medical Centres, location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
| | - Fahima Hassanzada
- Department of Genetics, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Tom E Verstraelen
- Heart Centre, Department of Cardiology, Amsterdam University Medical Centre, location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Weijia Wang
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Laurens P Bosman
- Netherlands Heart Institute, Utrecht, The Netherlands
- Department of Cardiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Paul A van der Zwaag
- University Medical Centre Groningen, Department of Genetics, University of Groningen, Groningen, The Netherlands
| | - Toon Oomen
- Department of Cardiology, St. Antonius Hospital, Sneek, The Netherlands
| | - Hugh Calkins
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Brittney Murray
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Crystal Tichnell
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Thais M A Beuren
- Department of Human Genetics, Amsterdam University Medical Centres, location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
| | - Folkert W Asselbergs
- Department of Cardiology, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Arjan Houweling
- Department of Human Genetics, Amsterdam University Medical Centres, location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Maarten P van den Berg
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Arthur A M Wilde
- Heart Centre, Department of Cardiology, Amsterdam University Medical Centre, location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Cynthia A James
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - J Peter van Tintelen
- Department of Genetics, University Medical Centre Utrecht, Utrecht University, Utrecht, The Netherlands.
- Department of Human Genetics, Amsterdam University Medical Centres, location Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
- Netherlands Heart Institute, Utrecht, The Netherlands.
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Vafiadaki E, Glijnis PC, Doevendans PA, Kranias EG, Sanoudou D. Phospholamban R14del disease: The past, the present and the future. Front Cardiovasc Med 2023; 10:1162205. [PMID: 37144056 PMCID: PMC10151546 DOI: 10.3389/fcvm.2023.1162205] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/03/2023] [Indexed: 05/06/2023] Open
Abstract
Arrhythmogenic cardiomyopathy affects significant number of patients worldwide and is characterized by life-threatening ventricular arrhythmias and sudden cardiac death. Mutations in multiple genes with diverse functions have been reported to date including phospholamban (PLN), a key regulator of sarcoplasmic reticulum (SR) Ca2+ homeostasis and cardiac contractility. The PLN-R14del variant in specific is recognized as the cause in an increasing number of patients worldwide, and extensive investigations have enabled rapid advances towards the delineation of PLN-R14del disease pathogenesis and discovery of an effective treatment. We provide a critical overview of current knowledge on PLN-R14del disease pathophysiology, including clinical, animal model, cellular and biochemical studies, as well as diverse therapeutic approaches that are being pursued. The milestones achieved in <20 years, since the discovery of the PLN R14del mutation (2006), serve as a paradigm of international scientific collaboration and patient involvement towards finding a cure.
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Affiliation(s)
- Elizabeth Vafiadaki
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Correspondence: Elizabeth Vafiadaki Despina Sanoudou
| | - Pieter C. Glijnis
- Stichting Genetische Hartspierziekte PLN, Phospholamban Foundation, Wieringerwerf, Netherlands
| | - Pieter A. Doevendans
- Netherlands Heart Institute, Utrecht, Netherlands
- Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Evangelia G. Kranias
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Despina Sanoudou
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Clinical Genomics and Pharmacogenomics Unit, 4th Department of Internal Medicine, Attikon Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Center for New Biotechnologies and Precision Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Correspondence: Elizabeth Vafiadaki Despina Sanoudou
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5
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de las Heras N, Galiana A, Ballesteros S, Olivares-Álvaro E, Fuller PJ, Lahera V, Martín-Fernández B. Proanthocyanidins Maintain Cardiac Ionic Homeostasis in Aldosterone-Induced Hypertension and Heart Failure. Int J Mol Sci 2021; 22:ijms22179602. [PMID: 34502509 PMCID: PMC8431754 DOI: 10.3390/ijms22179602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/31/2021] [Accepted: 08/31/2021] [Indexed: 11/16/2022] Open
Abstract
Excess aldosterone promotes pathological remodeling of the heart and imbalance in cardiac ion homeostasis of sodium, potassium and calcium. Novel treatment with proanthocyanidins in aldosterone-treated rats has resulted in downregulation of cardiac SGK1, the main genomic aldosterone-induced intracellular mediator of ion handling. It therefore follows that proanthocyanidins could be modulating cardiac ion homeostasis in aldosterone-treated rats. Male Wistar rats received aldosterone (1 mg kg−1 day−1) +1% NaCl for three weeks. Half of the animals in each group were simultaneously treated with the proanthocyanidins-rich extract (80% w/w) (PRO80, 5 mg kg−1 day−1). PRO80 prevented cardiac hypertrophy and decreased calcium content. Expression of ion channels (ROMK, NHE1, NKA and NCX1) and calcium transient mediators (CAV1.2, pCaMKII and oxCaMKII) were reduced by PRO80 treatment in aldosterone-treated rats. To conclude, our data indicate that PRO80 may offer an alternative treatment to conventional MR-blockade in the prevention of aldosterone-induced cardiac pathology.
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Affiliation(s)
- Natalia de las Heras
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Adrián Galiana
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Sandra Ballesteros
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Elena Olivares-Álvaro
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Peter J. Fuller
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia;
| | - Vicente Lahera
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Beatriz Martín-Fernández
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
- Department of Molecular Biology, Faculty of Biology, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
- Correspondence: ; Tel.: +34-987-291-000 (ext. 3650)
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6
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Arvanitis DA, Vafiadaki E, Johnson DM, Kranias EG, Sanoudou D. The Histidine-Rich Calcium Binding Protein in Regulation of Cardiac Rhythmicity. Front Physiol 2018; 9:1379. [PMID: 30319456 PMCID: PMC6171002 DOI: 10.3389/fphys.2018.01379] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 09/11/2018] [Indexed: 12/16/2022] Open
Abstract
Sudden unexpected cardiac death (SCD) accounts for up to half of all-cause mortality of heart failure patients. Standardized cardiology tools such as electrocardiography, cardiac imaging, electrophysiological and serum biomarkers cannot accurately predict which patients are at risk of life-threatening arrhythmic episodes. Recently, a common variant of the histidine-rich calcium binding protein (HRC), the Ser96Ala, was identified as a potent biomarker of malignant arrhythmia triggering in these patients. HRC has been shown to be involved in the regulation of cardiac sarcoplasmic reticulum (SR) Ca2+ cycling, by binding and storing Ca2+ in the SR, as well as interacting with the SR Ca2+ uptake and release complexes. The underlying mechanisms, elucidated by studies at the molecular, biochemical, cellular and intact animal levels, indicate that transversion of Ser96 to Ala results in abolishment of an HRC phosphorylation site by Fam20C kinase and dysregulation of SR Ca2+ cycling. This is mediated through aberrant SR Ca2+ release by the ryanodine receptor (RyR2) quaternary complex, due to the impaired HRC/triadin interaction, and depressed SR Ca2+ uptake by the sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2) pump, due to the impaired HRC/SERCA2 interaction. Pharmacological intervention with KN-93, an inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMKII), in the HRC Ser96Ala mouse model, reduced the occurrence of malignant cardiac arrhythmias. Herein, we summarize the current evidence on the pivotal role of HRC in the regulation of cardiac rhythmicity and the importance of HRC Ser96Ala as a genetic modifier for arrhythmias in the setting of heart failure.
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Affiliation(s)
- Demetrios A Arvanitis
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Daniel M Johnson
- Department of Cardiothoracic Surgery, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Evangelia G Kranias
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece.,Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Despina Sanoudou
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece.,Clinical Genomics and Pharmacogenomics Unit, 4th Department of Internal Medicine, Attikon Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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7
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Tzimas C, Johnson DM, Santiago DJ, Vafiadaki E, Arvanitis DA, Davos CH, Varela A, Athanasiadis NC, Dimitriou C, Katsimpoulas M, Sonntag S, Kryzhanovska M, Shmerling D, Lehnart SE, Sipido KR, Kranias EG, Sanoudou D. Impaired calcium homeostasis is associated with sudden cardiac death and arrhythmias in a genetic equivalent mouse model of the human HRC-Ser96Ala variant. Cardiovasc Res 2018; 113:1403-1417. [PMID: 28859293 DOI: 10.1093/cvr/cvx113] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 06/06/2017] [Indexed: 12/29/2022] Open
Abstract
Aims The histidine-rich calcium-binding protein (HRC) Ser96Ala variant has previously been identified as a potential biomarker for ventricular arrhythmias and sudden cardiac death in patients with idiopathic dilated cardiomyopathy. Herein, the role of this variant in cardiac pathophysiology is delineated through a novel mouse model, carrying the human mutation in the homologous mouse position. Methods and results The mouse HRC serine 81, homologous to human HRC serine 96, was mutated to alanine, using knock-in gene targeting. The HRC-Ser81Ala mice presented increased mortality in the absence of structural or histological abnormalities, indicating that early death may be arrhythmia-related. Indeed, under stress-but not baseline-conditions, the HRC-Ser81Ala mice developed ventricular arrhythmias, whilst at the cardiomyocyte level they exhibited increased occurrence of triggered activity. Cardiac contraction was decreased in vivo, ex vivo, and in vitro. Additionally, Ca2+ transients and SR Ca2+ load were both reduced suggesting that cytosolic Ca2+ overload is not the underlying proarrhythmic mechanism. Interestingly, total SR Ca2+ leak was increased in HRC-Ser81Ala cardiomyocytes, without an increase in Ca2+ spark and wave frequency. However, Ca2+ wave propagation was significantly slower and the duration of the associated Na/Ca exchange current was increased. Moreover, action potential duration was also increased. Notably, Ca2+/Calmodulin kinase II (CaMKII) phosphorylation of the ryanodine receptor was increased, whilst KN-93, an inhibitor of CaMKII, reduced the occurrence of arrhythmias. Conclusions The homologous mutation Ser81Ala in HRC in mice, corresponding to Ser96Ala in humans, is associated with sudden death and depressed cardiac function. Ventricular arrhythmias are related to abnormal Ca2+ cycling across the SR. The data further support a role for CaMKII with the perspective to treat arrhythmias through CaMKII inhibition.
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Affiliation(s)
- Christos Tzimas
- Department of Molecular Biology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Soranou Efessiou 4, 115 27, Athens, Greece
| | - Daniel M Johnson
- Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | | | - Elizabeth Vafiadaki
- Department of Molecular Biology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Soranou Efessiou 4, 115 27, Athens, Greece
| | - Demetrios A Arvanitis
- Department of Molecular Biology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Soranou Efessiou 4, 115 27, Athens, Greece
| | - Constantinos H Davos
- Department of Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Aimilia Varela
- Department of Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Nikolaos C Athanasiadis
- Department of Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Constantinos Dimitriou
- Department of Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Michalis Katsimpoulas
- Department of Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | | | | | | | - Stephan E Lehnart
- Department of Cardiology and Pulmonology, Heart Research Center Goettingen, University Medical Center Goettingen, Goettingen, Germany
| | - Karin R Sipido
- Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Evangelia G Kranias
- Department of Molecular Biology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Soranou Efessiou 4, 115 27, Athens, Greece.,Department of Pharmacology and Cell Biophysics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Despina Sanoudou
- Department of Molecular Biology, Center of Basic Research, Biomedical Research Foundation, Academy of Athens, Soranou Efessiou 4, 115 27, Athens, Greece.,4th Department of Internal Medicine, Clinical Genomics and Pharmacogenomics Unit, Medical School, National and Kapodistrian University of Athens, Attikon University Hospital, Rimini 1, Chaidari 124 62, Greece
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8
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Sasagawa S, Nishimura Y, Okabe S, Murakami S, Ashikawa Y, Yuge M, Kawaguchi K, Kawase R, Okamoto R, Ito M, Tanaka T. Downregulation of GSTK1 Is a Common Mechanism Underlying Hypertrophic Cardiomyopathy. Front Pharmacol 2016; 7:162. [PMID: 27378925 PMCID: PMC4905960 DOI: 10.3389/fphar.2016.00162] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/01/2016] [Indexed: 12/26/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and is associated with a number of potential outcomes, including impaired diastolic function, heart failure, and sudden cardiac death. Various etiologies have been described for HCM, including pressure overload and mutations in sarcomeric and non-sarcomeric genes. However, the molecular pathogenesis of HCM remains incompletely understood. In this study, we performed comparative transcriptome analysis to identify dysregulated genes common to five mouse HCM models of differing etiology: (i) mutation of myosin heavy chain 6, (ii) mutation of tropomyosin 1, (iii) expressing human phospholamban on a null background, (iv) knockout of frataxin, and (v) transverse aortic constriction. Gene-by-gene comparison identified five genes dysregulated in all five HCM models. Glutathione S-transferase kappa 1 (Gstk1) was significantly downregulated in the five models, whereas myosin heavy chain 7 (Myh7), connective tissue growth factor (Ctgf), periostin (Postn), and reticulon 4 (Rtn4) were significantly upregulated. Gene ontology comparison revealed that 51 cellular processes were significantly enriched in genes dysregulated in each transcriptome dataset. Among them, six processes (oxidative stress, aging, contraction, developmental process, cell differentiation, and cell proliferation) were related to four of the five genes dysregulated in all HCM models. GSTK1 was related to oxidative stress only, whereas the other four genes were related to all six cell processes except MYH7 for oxidative stress. Gene–gene functional interaction network analysis suggested correlative expression of GSTK1, MYH7, and actin alpha 2 (ACTA2). To investigate the implications of Gstk1 downregulation for cardiac function, we knocked out gstk1 in zebrafish using the clustered regularly interspaced short palindromic repeats/Cas9 system. We found that expression of the zebrafish homologs of MYH7, ACTA2, and actin alpha 1 were increased in the gstk1-knockout zebrafish. In vivo imaging of zebrafish expressing a fluorescent protein in cardiomyocytes showed that gstk1 deletion significantly decreased the end diastolic volume and, to a lesser extent, end systolic volume. These results suggest that downregulation of GSTK1 may be a common mechanism underlying HCM of various etiologies, possibly through increasing oxidative stress and the expression of sarcomere genes.
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Affiliation(s)
- Shota Sasagawa
- Department of Systems Pharmacology, Mie University Graduate School of Medicine, Tsu Japan
| | - Yuhei Nishimura
- Department of Systems Pharmacology, Mie University Graduate School of Medicine, TsuJapan; Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, TsuJapan; Mie University Medical Zebrafish Research Center, TsuJapan; Department of Omics Medicine, Mie University Industrial Technology Innovation Institute, TsuJapan; Department of Bioinformatics, Mie University Life Science Research Center, TsuJapan
| | - Shiko Okabe
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Tsu Japan
| | - Soichiro Murakami
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Tsu Japan
| | - Yoshifumi Ashikawa
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Tsu Japan
| | - Mizuki Yuge
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine, Tsu Japan
| | - Koki Kawaguchi
- Department of Systems Pharmacology, Mie University Graduate School of Medicine, Tsu Japan
| | - Reiko Kawase
- Department of Systems Pharmacology, Mie University Graduate School of Medicine, Tsu Japan
| | - Ryuji Okamoto
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu Japan
| | - Masaaki Ito
- Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu Japan
| | - Toshio Tanaka
- Department of Systems Pharmacology, Mie University Graduate School of Medicine, TsuJapan; Mie University Medical Zebrafish Research Center, TsuJapan; Department of Omics Medicine, Mie University Industrial Technology Innovation Institute, TsuJapan; Department of Bioinformatics, Mie University Life Science Research Center, TsuJapan
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Vostrikov VV, Soller KJ, Ha KN, Gopinath T, Veglia G. Effects of naturally occurring arginine 14 deletion on phospholamban conformational dynamics and membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:315-22. [PMID: 25251363 DOI: 10.1016/j.bbamem.2014.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/12/2014] [Accepted: 09/13/2014] [Indexed: 01/10/2023]
Abstract
Phospholamban (PLN) is a single-pass membrane protein that regulates the sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA). Phosphorylation of PLN at Ser16 reverses its inhibitory function under β-adrenergic stimulation, augmenting Ca²⁺ uptake in the sarcoplasmic reticulum and muscle contractility. PLN exists in two conformations; a T state, where the cytoplasmic domain is helical and adsorbed on the membrane surface, and an R state, where the cytoplasmic domain is unfolded and membrane detached. Previous studies have shown that the PLN conformational equilibrium is crucial to SERCA regulation. Here, we used a combination of solution and solid-state NMR to compare the structural topology and conformational dynamics of monomeric PLN (PLN(AFA)) with that of the PLN(R14del), a naturally occurring deletion mutant that is linked to the progression of dilated cardiomyopathy. We found that the behavior of the inhibitory transmembrane domain of PLN(R14del) is similar to that of the native sequence. Conversely, the conformational dynamics of R14del both in micelles and lipid membranes are enhanced. We conclude that the deletion of Arg14 in the cytoplasmic region weakens the interactions with the membrane and shifts the conformational equilibrium of PLN toward the disordered R state. This conformational transition is correlated with the loss-of-function character of this mutant and is corroborated by SERCA's activity assays. These findings support our hypothesis that SERCA function is fine-tuned by PLN conformational dynamics and begin to explain the aberrant regulation of SERCA by the R14del mutant.
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Affiliation(s)
- Vitaly V Vostrikov
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kailey J Soller
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kim N Ha
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Chemistry and Biochemistry, St. Catherine University, St. Paul, MN 55105, USA
| | - T Gopinath
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
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Beppu LY, Anilkumar AA, Newbury RO, Dohil R, Broide DH, Aceves SS. TGF-β1-induced phospholamban expression alters esophageal smooth muscle cell contraction in patients with eosinophilic esophagitis. J Allergy Clin Immunol 2014; 134:1100-1107.e4. [PMID: 24835503 DOI: 10.1016/j.jaci.2014.04.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 03/18/2014] [Accepted: 04/04/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Eosinophilic esophagitis (EoE) is a chronic antigen-mediated disease characterized by esophageal eosinophilia, remodeling, and fibrosis. TGF-β1 is a central regulator of EoE remodeling and increases esophageal smooth muscle (ESM) cell contraction. OBJECTIVE In this study we aimed to understand the molecular mechanisms by which TGF-β1 could induce ESM cell contraction. METHODS We used primary human ESM cells and esophageal myofibroblasts (EMFs) to assess the mechanisms of TGF-β1-induced contraction. We analyzed the expression, phosphorylation, and function of phospholamban (PLN), a sarcoendoplasmic reticulum regulatory protein induced by TGF-β1. Expression of PLN, phospho-PLN, and its regulatory pathway was analyzed in the ESM of biopsy specimens from patients with EoE and control subjects. Gene silencing in EMFs from patients with EoE was used to understand the role of PLN in contraction. RESULTS TGF-β1 induced and phosphorylated PLN in primary human ESM cells and EMFs from patients with EoE. PLN and phospho-PLN levels were increased in smooth muscle from patients with EoE compared with that seen in smooth muscle from control subjects in vivo. PLN inhibition significantly diminished TGF-β1-induced EMF contraction in patients with EoE. PLN expression and ESM/EMF contraction depended on TGF-β receptor I signals. CONCLUSION We describe a previously unrecognized mechanism for ESM cell contraction that depends on TGF-β1, its receptors, and PLN. Because PLN levels are increased in smooth muscle from patients with EoE and PLN silencing diminishes contraction, we provide a novel potential mechanistic framework and therapeutic target for ESM dysfunction in patients with EoE.
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Affiliation(s)
- Lisa Y Beppu
- Division of Allergy and Immunology, University of California, San Diego, Calif; Department of Pediatrics, University of California, San Diego, Calif
| | - Arjun A Anilkumar
- Division of Allergy and Immunology, University of California, San Diego, Calif; Department of Medicine, University of California, San Diego, Calif
| | - Robert O Newbury
- Department of Pediatrics, University of California, San Diego, Calif; Division of Pathology, University of California, San Diego, Calif
| | - Ranjan Dohil
- Department of Pediatrics, University of California, San Diego, Calif; Division of Gastroenterology, University of California, San Diego, Calif
| | - David H Broide
- Division of Allergy and Immunology, University of California, San Diego, Calif; Department of Medicine, University of California, San Diego, Calif
| | - Seema S Aceves
- Division of Allergy and Immunology, University of California, San Diego, Calif; Department of Pediatrics, University of California, San Diego, Calif; Department of Medicine, University of California, San Diego, Calif.
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Akin BL, Jones LR. Characterizing phospholamban to sarco(endo)plasmic reticulum Ca2+-ATPase 2a (SERCA2a) protein binding interactions in human cardiac sarcoplasmic reticulum vesicles using chemical cross-linking. J Biol Chem 2012; 287:7582-93. [PMID: 22247554 DOI: 10.1074/jbc.m111.334987] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Chemical cross-linking was used to study protein binding interactions between native phospholamban (PLB) and SERCA2a in sarcoplasmic reticulum (SR) vesicles prepared from normal and failed human hearts. Lys(27) of PLB was cross-linked to the Ca(2+) pump at the cytoplasmic extension of M4 (at or near Lys(328)) with the homobifunctional cross-linker, disuccinimidyl glutarate (7.7 Å). Cross-linking was augmented by ATP but abolished by Ca(2+) or thapsigargin, confirming in native SR vesicles that PLB binds preferentially to E2 (low Ca(2+) affinity conformation of the Ca(2+)-ATPase) stabilized by ATP. To assess the functional effects of PLB binding on SERCA2a activity, the anti-PLB antibody, 2D12, was used to disrupt the physical interactions between PLB and SERCA2a in SR vesicles. We observed a tight correlation between 2D12-induced inhibition of PLB cross-linking to SERCA2a and 2D12 stimulation of Ca(2+)-ATPase activity and Ca(2+) transport. The results suggest that the inhibitory effect of PLB on Ca(2+)-ATPase activity in SR vesicles results from mutually exclusive binding of PLB and Ca(2+) to the Ca(2+) pump, requiring PLB dissociation for catalytic activation. Importantly, the same result was obtained with SR vesicles prepared from normal and failed human hearts; therefore, we conclude that PLB binding interactions with the Ca(2+) pump are largely unchanged in failing myocardium.
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Affiliation(s)
- Brandy L Akin
- Krannert Institute of Cardiology and the Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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