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Duse DA, Schröder NH, Srivastava T, Benkhoff M, Vogt J, Nowak MK, Funk F, Semleit N, Wollnitzke P, Erkens R, Kötter S, Meuth SG, Keul P, Santos W, Polzin A, Kelm M, Krüger M, Schmitt J, Levkau B. Deficiency of the sphingosine-1-phosphate (S1P) transporter Mfsd2b protects the heart against hypertension-induced cardiac remodeling by suppressing the L-type-Ca 2+ channel. Basic Res Cardiol 2024; 119:853-868. [PMID: 39110173 PMCID: PMC11461684 DOI: 10.1007/s00395-024-01073-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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 07/26/2024] [Accepted: 07/29/2024] [Indexed: 10/09/2024]
Abstract
The erythrocyte S1P transporter Mfsd2b is also expressed in the heart. We hypothesized that S1P transport by Mfsd2b is involved in cardiac function. Hypertension-induced cardiac remodeling was induced by 4-weeks Angiotensin II (AngII) administration and assessed by echocardiography. Ca2+ transients and sarcomere shortening were examined in adult cardiomyocytes (ACM) from Mfsd2b+/+ and Mfsd2b-/- mice. Tension and force development were measured in skinned cardiac fibers. Myocardial gene expression was determined by real-time PCR, Protein Phosphatase 2A (PP2A) by enzymatic assay, and S1P by LC/MS, respectively. Msfd2b was expressed in the murine and human heart, and its deficiency led to higher cardiac S1P. Mfsd2b-/- mice had regular basal cardiac function but were protected against AngII-induced deterioration of left-ventricular function as evidenced by ~ 30% better stroke volume and cardiac index, and preserved ejection fraction despite similar increases in blood pressure. Mfsd2b-/- ACM exhibited attenuated Ca2+ mobilization in response to isoprenaline whereas contractility was unchanged. Mfsd2b-/- ACM showed no changes in proteins responsible for Ca2+ homeostasis, and skinned cardiac fibers exhibited reduced passive tension generation with preserved contractility. Verapamil abolished the differences in Ca2+ mobilization between Mfsd2b+/+ and Mfsd2b-/- ACM suggesting that S1P inhibits L-type-Ca2+ channels (LTCC). In agreement, intracellular S1P activated the inhibitory LTCC phosphatase PP2A in ACM and PP2A activity was increased in Mfsd2b-/- hearts. We suggest that myocardial S1P protects from hypertension-induced left-ventricular remodeling by inhibiting LTCC through PP2A activation. Pharmacologic inhibition of Mfsd2b may thus offer a novel approach to heart failure.
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Affiliation(s)
- Dragos Andrei Duse
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
- Department of Cardiology, Pneumology, and Vascular Medicine, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany
| | - Nathalie Hannelore Schröder
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Tanu Srivastava
- Institute of Pharmacology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Marcel Benkhoff
- Department of Cardiology, Pneumology, and Vascular Medicine, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Jens Vogt
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Melissa Kim Nowak
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Florian Funk
- Institute of Pharmacology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Nina Semleit
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Philipp Wollnitzke
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Ralf Erkens
- Department of Cardiology, Pneumology, and Vascular Medicine, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany
| | - Sebastian Kötter
- Institute of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sven Günther Meuth
- Department of Neurology, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Petra Keul
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany
| | - Webster Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA, 24060, USA
| | - Amin Polzin
- Department of Cardiology, Pneumology, and Vascular Medicine, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany
| | - Malte Kelm
- Department of Cardiology, Pneumology, and Vascular Medicine, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany
| | - Martina Krüger
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany
- Institute of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Joachim Schmitt
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany
- Institute of Pharmacology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Bodo Levkau
- Institute for Molecular Medicine III, University Hospital Düsseldorf and Heinrich Heine University, Düsseldorf, Germany.
- Cardiovascular Research Institute Düsseldorf (CARID), Düsseldorf, Germany.
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Zhao R, Yan Y, Dong Y, Wang X, Li X, Qiao R, Zhang H, Cui N, Han Y, Wang C, Han J, Ma Q, Liu D, Yang J, Gu G, Wang C. FGF13 deficiency ameliorates calcium signaling abnormality in heart failure by regulating microtubule stability. Biochem Pharmacol 2024; 225:116329. [PMID: 38821375 DOI: 10.1016/j.bcp.2024.116329] [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: 02/09/2024] [Revised: 05/17/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Calcium signaling abnormality in cardiomyocytes, as a key mechanism, is closely associated with developing heart failure. Fibroblast growth factor 13 (FGF13) demonstrates important regulatory roles in the heart, but its association with cardiac calcium signaling in heart failure remains unknown. This study aimed to investigate the role and mechanism of FGF13 on calcium mishandling in heart failure. Mice underwent transaortic constriction to establish a heart failure model, which showed decreased ejection fraction, fractional shortening, and contractility. FGF13 deficiency alleviated cardiac dysfunction. Heart failure reduces calcium transients in cardiomyocytes, which were alleviated by FGF13 deficiency. Meanwhile, FGF13 deficiency restored decreased Cav1.2 and Serca2α expression and activity in heart failure. Furthermore, FGF13 interacted with microtubules in the heart, and FGF13 deficiency inhibited the increase of microtubule stability during heart failure. Finally, in isoproterenol-stimulated FGF13 knockdown neonatal rat ventricular myocytes (NRVMs), wildtype FGF13 overexpression, but not FGF13 mutant, which lost the binding site of microtubules, promoted calcium transient abnormality aggravation and Cav1.2 downregulation compared with FGF13 knockdown group. Generally, FGF13 deficiency improves abnormal calcium signaling by inhibiting the increased microtubule stability in heart failure, indicating the important role of FGF13 in cardiac calcium homeostasis and providing new avenues for heart failure prevention and treatment.
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Affiliation(s)
- Ran Zhao
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China
| | - Yingke Yan
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China
| | - Yiming Dong
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China
| | - Xiangchong Wang
- Department of Pharmacology, Hebei International Cooperation Center for Ion Channel Function and Innovative Traditional Chinese Medicine, Hebei Higher Education Institute Applied Technology Research Center on TCM Formula Preparation, Hebei University of Chinese Medicine, Shijiazhuang 050091, China
| | - Xuyan Li
- College of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Ruoyang Qiao
- College of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China
| | - Huaxing Zhang
- Core Facilities and Centers, Hebei Medical University, Shijiazhuang 050017, China
| | - Nanqi Cui
- Department of Vascular Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Yanxue Han
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China
| | - Cong Wang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China
| | - Jiabing Han
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China
| | - Qianli Ma
- Department of Cardiac Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Demin Liu
- Department of Cardiology, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Jing Yang
- Department of Pathology and Pathophysiology, Hangzhou Normal University, Hangzhou 311121, China.
| | - Guoqiang Gu
- Department of Cardiology, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China.
| | - Chuan Wang
- Department of Pharmacology, The Key Laboratory of Neural and Vascular Biology, Ministry of Education, The Key Laboratory of New Drug Pharmacology and Toxicology, The Hebei Collaboration Innovation Center for Mechanism, Diagnosis and Treatment of Neurological and Psychiatric Disease, Hebei Medical University, Shijiazhuang 050017, China.
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Yu Q, Barndt RJ, Shen Y, Sallam K, Tang Y, Chan SY, Wu JC, Liu Q, Wu H. Mitigation of Stress-induced Structural Remodeling and Functional Deficiency in iPSC-CMs with PLN R9C Mutation by Promoting Autophagy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.17.589921. [PMID: 38659742 PMCID: PMC11042320 DOI: 10.1101/2024.04.17.589921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Background Phospholamban (PLN) is a key regulator of cardiac function connecting adrenergic signaling and calcium homeostasis. The R9C mutation of PLN is known to cause early onset dilated cardiomyopathy (DCM) and premature death, yet the detailed mechanisms underlie the pathologic remodeling process are not well defined in human cardiomyocytes. The aim of this study is to unravel the role of PLN R9C in DCM and identify potential therapeutic targets. Methods PLN R9C knock-in (KI) and patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) were generated and comprehensively examined for their expression profile, contractile function, and cellular signaling under both baseline conditions and following functional challenges. Results PLN R9C KI iPSC-CMs exhibited near-normal morphology and calcium handling, slightly increased contractility, and an attenuated response to β-adrenergic activation compared to wild-type (WT) cells. However, treatment with a maturation medium (MM) has induced fundamentally different remodeling in the two groups: while it improved the structural integrity and functional performance of WT cells, the same treatment result in sarcomere disarrangement, calcium handling deficiency, and further disrupted adrenergic signaling in PLN R9C KI cells. To understand the mechanism, transcriptomic analysis showed the enrichment of protein homeostasis signaling pathways specifically in PLN R9C KI cells in response to the MM treatment and increased contractile demands. Further studies also indicated elevated ROS levels, interrupted autophagic flux, and increased pentamer PLN aggregation in functionally challenged KI cells. These results were further confirmed in patient-specific iPSC-CM models, suggesting that functional stresses exacerbate the deficiencies in PLN R9C cells through disrupting protein homeostasis. Indeed, treating stressed patient cells with autophagy-accelerating reagents, such as metformin and rapamycin, has restored autophagic flux, mitigated sarcomere disarrangement, and partially rescued β-adrenergic signaling and cardiac function. Conclusions PLN R9C leads to a mild increase of calcium recycling and contractility. Functional challenges further enhanced contractile and proteostasis stress, leading to autophagic overload, structural remodeling, and functional deficiencies in PLN R9C cardiomyocytes. Activation of autophagy signaling partially rescues these effects, revealing a potential therapeutic target for DCM patients with the PLN R9C mutation. Graphic abstracts A graphic abstract is available for this article.
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Maniezzi C, Eskandr M, Florindi C, Ferrandi M, Barassi P, Sacco E, Pasquale V, Maione AS, Pompilio G, Teixeira VON, de Boer RA, Silljé HHW, Lodola F, Zaza A. Early consequences of the phospholamban mutation PLN-R14del +/- in a transgenic mouse model. Acta Physiol (Oxf) 2024; 240:e14082. [PMID: 38214033 DOI: 10.1111/apha.14082] [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: 07/07/2023] [Revised: 12/11/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024]
Abstract
AIMS The heterozygous phospholamban (PLN) mutation R14del (PLN R14del+/- ) is associated with a severe arrhythmogenic cardiomyopathy (ACM) developing in the adult. "Superinhibition" of SERCA2a by PLN R14del is widely assumed to underlie the pathogenesis, but alternative mechanisms such abnormal energy metabolism have also been reported. This work aims to (1) to evaluate Ca2+ dynamics and energy metabolism in a transgenic (TG) mouse model of the mutation prior to cardiomyopathy development; (2) to test whether they are causally connected. METHODS Ca2+ dynamics, energy metabolism parameters, reporters of mitochondrial integrity, energy, and redox homeostasis were measured in ventricular myocytes of 8-12 weeks-old, phenotypically silent, TG mice. Mutation effects were compared to pharmacological PLN antagonism and analyzed during modulation of sarcoplasmic reticulum (SR) and cytosolic Ca2+ compartments. Transcripts and proteins of relevant signaling pathways were evaluated. RESULTS The mutation was characterized by hyperdynamic Ca2+ handling, compatible with a loss of SERCA2a inhibition by PLN. All components of energy metabolism were depressed; myocyte energy charge was preserved under quiescence but reduced during stimulation. Cytosolic Ca2+ buffering or SERCA2a blockade reduced O2 consumption with larger effect in the mutant. Signaling changes suggest cellular adaptation to perturbed Ca2+ dynamics and response to stress. CONCLUSIONS (1) PLN R14del+/- loses its ability to inhibit SERCA2a, which argues against SERCA2a superinhibition as a pathogenetic mechanism; (2) depressed energy metabolism, its enhanced dependency on Ca2+ and activation of signaling responses point to an early involvement of metabolic stress in the pathogenesis of this ACM model.
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Affiliation(s)
- Claudia Maniezzi
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Marem Eskandr
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Chiara Florindi
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Mara Ferrandi
- Windtree Therapeutics Inc., Warrington, Pennsylvania, USA
| | - Paolo Barassi
- Windtree Therapeutics Inc., Warrington, Pennsylvania, USA
| | - Elena Sacco
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Valentina Pasquale
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Angela S Maione
- Unit of Vascular Biology and Regenerative Medicine, Centro Cardiologico Monzino IRCCS, Milan, Italy
| | - Giulio Pompilio
- Unit of Vascular Biology and Regenerative Medicine, Centro Cardiologico Monzino IRCCS, Milan, Italy
- Department of Biomedical, Surgical and Dentist Sciences, University of Milano, Milan, Italy
| | | | - Rudolf A de Boer
- Department of Cardiology, Erasmus University Medical Center, University of Rotterdam, Rotterdam, Netherlands
| | - Herman H W Silljé
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Francesco Lodola
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Antonio Zaza
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
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Cleary SR, Teng ACT, Kongmeneck AD, Fang X, Phillips TA, Cho EE, Kekenes-Huskey P, Gramolini AO, Robia SL. Dilated cardiomyopathy variant R14del increases phospholamban pentamer stability, blunting dynamic regulation of cardiac calcium handling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.26.542463. [PMID: 37292897 PMCID: PMC10245957 DOI: 10.1101/2023.05.26.542463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The sarco(endo)plasmic reticulum Ca 2+ ATPase (SERCA) is a membrane transporter that creates and maintains intracellular Ca 2+ stores. In the heart, SERCA is regulated by an inhibitory interaction with the monomeric form of the transmembrane micropeptide phospholamban (PLB). PLB also forms avid homo-pentamers, and dynamic exchange of PLB between pentamers and the regulatory complex with SERCA is an important determinant of cardiac responsiveness to exercise. Here, we investigated two naturally occurring pathogenic mutations of PLB, a cysteine substitution of arginine 9 (R9C) and an in-frame deletion of arginine 14 (R14del). Both mutations are associated with dilated cardiomyopathy. We previously showed that the R9C mutation causes disulfide crosslinking and hyperstabilization of pentamers. While the pathogenic mechanism of R14del is unclear, we hypothesized that this mutation may also alter PLB homo-oligomerization and disrupt the PLB-SERCA regulatory interaction. SDS-PAGE revealed a significantly increased pentamer:monomer ratio for R14del-PLB when compared to WT-PLB. In addition, we quantified homo-oligomerization and SERCA-binding in live cells using fluorescence resonance energy transfer (FRET) microscopy. R14del-PLB showed an increased affinity for homo-oligomerization and decreased binding affinity for SERCA compared to WT, suggesting that, like R9C, the R14del mutation stabilizes PLB in its pentameric form, decreasing its ability to regulate SERCA. Moreover, the R14del mutation reduces the rate of PLB unbinding from the pentamer after a transient Ca 2+ elevation, limiting the rate of re-binding to SERCA. A computational model predicted that hyperstabilization of PLB pentamers by R14del impairs the ability of cardiac Ca 2+ handling to respond to changing heart rates between rest and exercise. We postulate that impaired responsiveness to physiological stress contributes to arrhythmogenesis in human carriers of the R14del mutation.
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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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7
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Funk F, Kronenbitter A, Isić M, Flocke V, Gorreßen S, Semmler D, Brinkmann M, Beck K, Steinhoff O, Srivastava T, Barbosa DM, Voigt K, Wang L, Bottermann K, Kötter S, Grandoch M, Flögel U, Krüger M, Schmitt JP. Diabetes disturbs functional adaptation of the remote myocardium after ischemia/reperfusion. J Mol Cell Cardiol 2022; 173:47-60. [PMID: 36150524 DOI: 10.1016/j.yjmcc.2022.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 07/01/2022] [Accepted: 09/16/2022] [Indexed: 01/06/2023]
Abstract
Diabetes mellitus type 2 is associated with adverse clinical outcome after myocardial infarction. To better understand the underlying causes we here investigated sarcomere protein function and its calcium-dependent regulation in the non-ischemic remote myocardium (RM) of diabetic mice (db/db) after transient occlusion of the left anterior descending coronary artery. Before and 24 h after surgery db/db and non-diabetic db/+ underwent magnetic resonance imaging followed by histological and biochemical analyses of heart tissue. Intracellular calcium transients and sarcomere function were measured in isolated cardiomyocytes. Active and passive force generation was assessed in skinned fibers and papillary muscle preparations. Before ischemia and reperfusion (I/R), beat-to-beat calcium cycling was depressed in diabetic cardiomyocytes. Nevertheless, contractile function was preserved owing to increased myofilament calcium sensitivity and higher responsiveness of myocardial force production to β-adrenergic stimulation in db/db compared to db/+. In addition, protein kinase C activity was elevated in db/db hearts leading to strong phosphorylation of the titin PEVK region and increased titin-based tension of myofilaments. I/R impaired the function of whole hearts and RM sarcomeres in db/db to a larger extent than in non-diabetic db/+, and we identified several reasons. First, the amplitude and the kinetics of cardiomyocyte calcium transients were further reduced in the RM of db/db. Underlying causes involved altered expression of calcium regulatory proteins. Diabetes and I/R additively reduced phospholamban S16-phosphorylation by 80% (P < 000.1) leading to strong inhibition of the calcium ATPase SERCA2a. Second, titin stiffening was only observed in the RM of db/+, but not in the RM of db/db. Finally, db/db myofilament calcium sensitivity and force generation upon β-adrenergic stimulation were no longer enhanced over db/+ in the RM. The findings demonstrate that impaired cardiomyocyte calcium cycling of db/db hearts is compensated by increased myofilament calcium sensitivity and increased titin-based stiffness prior to I/R. In contrast, sarcomere function of the RM 24 h after I/R is poor because both these compensatory mechanisms fail and myocyte calcium handling is further depressed.
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Affiliation(s)
- Florian Funk
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Annette Kronenbitter
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Malgorzata Isić
- Institute of Cardiovascular Physiology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Vera Flocke
- Institute of Molecular Cardiology, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Simone Gorreßen
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Dominik Semmler
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Maximilian Brinkmann
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Katharina Beck
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Oliver Steinhoff
- Institute of Translational Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Tanu Srivastava
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - David Monteiro Barbosa
- Institute of Cardiovascular Physiology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Katharina Voigt
- Institute of Cardiovascular Physiology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Luzhou Wang
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Katharina Bottermann
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Sebastian Kötter
- Institute of Cardiovascular Physiology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Maria Grandoch
- Institute of Translational Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Ulrich Flögel
- Institute of Molecular Cardiology, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Martina Krüger
- Institute of Cardiovascular Physiology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
| | - Joachim P Schmitt
- Institute of Pharmacology, University Hospital Düsseldorf, and Cardiovascular Research Institute Düsseldorf (CARID), Universitätsstraße 1, 40225 Düsseldorf, Germany.
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8
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Qin J, Zhang J, Lin L, Haji-Ghassemi O, Lin Z, Woycechowsky KJ, Van Petegem F, Zhang Y, Yuchi Z. Structures of PKA-phospholamban complexes reveal a mechanism of familial dilated cardiomyopathy. eLife 2022; 11:75346. [PMID: 35297759 PMCID: PMC8970585 DOI: 10.7554/elife.75346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/16/2022] [Indexed: 01/07/2023] Open
Abstract
Several mutations identified in phospholamban (PLN) have been linked to familial dilated cardiomyopathy (DCM) and heart failure, yet the underlying molecular mechanism remains controversial. PLN interacts with sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) and regulates calcium uptake, which is modulated by the protein kinase A (PKA)-dependent phosphorylation of PLN during the fight-or-flight response. Here, we present the crystal structures of the catalytic domain of mouse PKA in complex with wild-type and DCM-mutant PLNs. Our structures, combined with the results from other biophysical and biochemical assays, reveal a common disease mechanism: the mutations in PLN reduce its phosphorylation level by changing its conformation and weakening its interactions with PKA. In addition, we demonstrate that another more ubiquitous SERCA-regulatory peptide, called another-regulin (ALN), shares a similar mechanism mediated by PKA in regulating SERCA activity.
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Affiliation(s)
- Juan Qin
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin UniversityTianjinChina
| | - Jingfeng Zhang
- Wuhan Institute of Physics and Mathematics, Chinese Academy of SciencesWuhanChina
| | - Lianyun Lin
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin UniversityTianjinChina
| | - Omid Haji-Ghassemi
- Department of Biochemistry and Molecular Biology, The Life Sciences Centre, University of British ColumbiaVancouverCanada
| | - Zhi Lin
- School of Life Sciences, Tianjin UniversityTianjinChina
| | - Kenneth J Woycechowsky
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin UniversityTianjinChina
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The Life Sciences Centre, University of British ColumbiaVancouverCanada
| | - Yan Zhang
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin UniversityTianjinChina
| | - Zhiguang Yuchi
- Tianjin Key Laboratory for Modern Drug Delivery & High-Efficiency; Collaborative Innovation Center of Chemical Science and Engineering; School of Pharmaceutical Science and Technology, Tianjin UniversityTianjinChina,Department of Molecular Pharmacology, Tianjin Medical University Cancer Institute & Hospital; National Clinical Research Center for Cancer; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Tianjin’s Clinical Research Center for CancerTianjinChina
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9
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Koch D, Alexandrovich A, Funk F, Kho AL, Schmitt JP, Gautel M. Molecular noise filtering in the β-adrenergic signaling network by phospholamban pentamers. Cell Rep 2021; 36:109448. [PMID: 34320358 PMCID: PMC8333238 DOI: 10.1016/j.celrep.2021.109448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/16/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Phospholamban (PLN) is an important regulator of cardiac calcium handling due to its ability to inhibit the calcium ATPase SERCA. β-Adrenergic stimulation reverses SERCA inhibition via PLN phosphorylation and facilitates fast calcium reuptake. PLN also forms pentamers whose physiological significance has remained elusive. Using mathematical modeling combined with biochemical and cell biological experiments, we show that pentamers regulate both the dynamics and steady-state levels of monomer phosphorylation. Substrate competition by pentamers and a feed-forward loop involving inhibitor-1 can delay monomer phosphorylation by protein kinase A (PKA), whereas cooperative pentamer dephosphorylation enables bistable PLN steady-state phosphorylation. Simulations show that phosphorylation delay and bistability act as complementary filters that reduce the effect of random fluctuations in PKA activity, thereby ensuring consistent monomer phosphorylation and SERCA activity despite noisy upstream signals. Preliminary analyses suggest that the PLN mutation R14del could impair noise filtering, offering a new perspective on how this mutation causes cardiac arrhythmias.
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Affiliation(s)
- Daniel Koch
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK.
| | | | - Florian Funk
- Institute of Pharmacology and Clinical Pharmacology, and Cardiovascular Research Institute Düsseldorf (CARID), University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical Pharmacology, and Cardiovascular Research Institute Düsseldorf (CARID), University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK
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10
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Cao S, Deng Q, Wang Y, Zhou Y, Zhou Q. Ultrasound-targeted microbubble destruction-mediated Ang1 gene transfection improves left ventricular structural and sympathetic nerve remodeling in canines with myocardial infarction. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:221. [PMID: 33708848 PMCID: PMC7940881 DOI: 10.21037/atm-20-839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Background The present study aimed to determine whether ultrasound-targeted microbubble destruction (UTMD)-mediated angiopoietin 1 (Ang1) gene transfection can improve angiogenesis and potentially reverse left ventricular (LV) structural and sympathetic nerve remodeling in canines with myocardial infarction (MI). Methods Thirty dogs were randomly divided into groups (n=10/group) as follows: the MI group (MI dogs without UTMD treatment), the UTMD group (MI dogs with UTMD-mediated negative control plasmid treatment), and the UTMD-Ang1 group (MI dogs with UTMD-mediated Ang1 plasmid treatment). LV dimensions, systolic function, and synchrony were used to reflect the structural remodeling. The density of tyrosine hydroxylase (TH)- and growth-associated protein 43 (GAP43)-positive nerve fibers were calculated to assess the sympathetic nerve remodeling. Results One month after treatment, the UTMD-Ang1 group showed lower LV end-diastolic dimension (LVEDD: 31.2±2.3 mm) and higher LV ejection fraction (LVEF: 44.6%±4.3%) than the MI group (LVEDD: 34.5±2.2 mm, t=2.282, P=0.014; LVEF: 37.3%±3.1%, t=3.718, P=0.003) and the UTMD group (LVEDD: 34.1±2.8 mm, t=2.264, P=0.040; LVEF: 39.3%±4.5%, t=2.408, P=0.030). LV synchrony was higher in the UTMD-Ang1 group compared with the MI group by 2-dimensional speckle-tracking echocardiography. Angiogenic density was higher in the UTMD group than the MI group but was highest in the UTMD-Ang1 group according to immunohistochemistry of CD31 and α-smooth muscle actin staining. The density of TH- and GAP43-positive nerve fibers were decreased in the UTMD-Ang1 group (TH: 1,928.2±376.6 μm2/mm2; GAP43: 2,090.8±329.2 μm2/mm2) compared with the MI group (TH: 2916.5±558.4 μm2/mm2, t=4.069, P=0.001; GAP43: 3,275.4±548.6 μm2/mm2, t=5.153, P=0.000) and the UTMD group (TH: 2,552.7±408.1 μm2/mm2, t=3.181, P=0.007; GAP43: 2,630.5±419.3 μm2/mm2, t=2.863, P=0.013). The relative Ang1 and sarcoplasmic reticulum Ca2+-ATPase 2a protein levels were significantly higher in the UTMD-Ang1 group than the UTMD and MI groups by Western blot, while the phospholamban levels exhibited the opposite trend. Plasma norepinephrine and N-terminal pro-B-type-natriuretic peptide were significantly reduced in the UTMD-Ang1 group from day 1 to 1 month after MI. Conclusions UTMD-mediated Ang1 transfection can promote angiogenesis, reverse LV structural and sympathetic nerve remodeling, and improve LV synchrony after MI.
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Affiliation(s)
- Sheng Cao
- Department of Ultrasound Imaging, Renmin Hospital of Wuhan University, Wuhan, China
| | - Qing Deng
- Department of Ultrasound Imaging, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yijia Wang
- Department of Ultrasound Imaging, Renmin Hospital of Wuhan University, Wuhan, China
| | - Yanxiang Zhou
- Department of Ultrasound Imaging, Renmin Hospital of Wuhan University, Wuhan, China
| | - Qing Zhou
- Department of Ultrasound Imaging, Renmin Hospital of Wuhan University, Wuhan, China
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11
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Li Z, Guo J, Bian Y, Zhang M. Intermedin protects thapsigargin‑induced endoplasmic reticulum stress in cardiomyocytes by modulating protein kinase A and sarco/endoplasmic reticulum Ca 2+‑ATPase. Mol Med Rep 2020; 23:107. [PMID: 33300086 PMCID: PMC7723158 DOI: 10.3892/mmr.2020.11746] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022] Open
Abstract
Intermedin (IMD) is a calcitonin/calcitonin-related peptide that elicits cardioprotective effects in a variety of heart diseases, such as cardiac hypertrophy and heart failure. However, the molecular mechanism of IMD remains unclear. The present study investigated the effects of IMD on neonatal rat ventricular myocytes treated with thapsigargin. The results of the present study demonstrated that thapsigargin induced apoptosis in cardiomyocytes in a dose- and time-dependent manner. Thapsigargin induced endoplasmic reticulum stress, as determined by increased expression levels of 78-kDa glucose-regulated protein, C/EBP-homologous protein and caspase-12, which were dose-dependently attenuated by pretreatment with IMD. In addition, IMD treatment counteracted the thapsigargin-induced suppression of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity and protein expression levels, and cytoplasmic Ca2+ overload. IMD treatment also augmented the phosphorylation of phospholamban, which is a crucial regulator of SERCA. Additionally, treatment with the protein kinase A antagonist H-89 inhibited the IMD-mediated cardioprotective effects, including SERCA activity restoration, anti-Ca2+ overload, endoplasmic reticulum stress inhibition and antiapoptosis effects. In conclusion, the results of the present study suggested that IMD may protect cardiomyocytes against thapsigargin-induced endoplasmic reticulum stress and the associated apoptosis at least partly by activating the protein kinase A/SERCA pathway.
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Affiliation(s)
- Zhidong Li
- Department of Pharmacology, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
| | - Jia Guo
- Department of Cardiology, Shanxi Medical University First Hospital, Taiyuan, Shanxi 030001, P.R. China
| | - Yunfei Bian
- Department of Cardiology, Shanxi Medical University Second Hospital, Taiyuan, Shanxi 030001, P.R. China
| | - Mingsheng Zhang
- Department of Pharmacology, Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China
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12
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Jiang X, Xu Y, Sun J, Wang L, Guo X, Chen Y. The phenotypic characteristic observed by cardiac magnetic resonance in a PLN-R14del family. Sci Rep 2020; 10:16478. [PMID: 33020536 PMCID: PMC7536202 DOI: 10.1038/s41598-020-73359-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 09/03/2020] [Indexed: 02/05/2023] Open
Abstract
Phospholamban (PLN) is an important regulator for sarcoendoplasmic reticulum (SR) calcium transport ATPase (SERCA), which uptakes Ca2+ to SR during the diastolic phase of cardiomyocytes to maintain intracellular calcium homeostasis. Mutations on PLN result in intracellular calcium disorder, myocardial contraction defect, and eventually heart failure and/or malignant ventricular arrhythmia. Since 2003, several kinds of PLN mutations have been identified in familial dilated cardiomyopathy (DCM) patients, illustrating a few clinical characteristics that differs from classical DCM patients. Herein, we report a large PLN-R14del family with typical clinical characteristics reported including relatively late-onset clinical symptoms, low-voltage in ECG, as well as frequent ventricular arrythmias. Moreover, members underwent cardiac magnetic resonance (CMR) examination showed a strikingly similar pattern of late gadolinium enhancement (LGE)—Sub-epicardial involvement in the left ventricular (LV) lateral wall with or without linear mid-wall enhancement in the interventricular septum. The former one can also present in younger PLN-R14del carriers despite completely normal LV structure and function. Meanwhile, T1 mapping also found significantly increased extracellular volume (ECV) in PLN-R14del carriers. These findings highlight the special role of CMR to phenotyping PLN-induced cardiomyopathy patients and distinguish them from other types of cardiomyopathy.
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Affiliation(s)
- Xincheng Jiang
- Department of Cardiology, West China Hospital, Sichuan University, Guoxue Xiang No. 37, Chengdu, Sichuan, 610041, People's Republic of China
| | - Yuanwei Xu
- Department of Cardiology, West China Hospital, Sichuan University, Guoxue Xiang No. 37, Chengdu, Sichuan, 610041, People's Republic of China
| | - Jiayu Sun
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lili Wang
- Department of Cardiology, West China Hospital, Sichuan University, Guoxue Xiang No. 37, Chengdu, Sichuan, 610041, People's Republic of China
| | - Xinli Guo
- Department of Cardiology, West China Hospital, Sichuan University, Guoxue Xiang No. 37, Chengdu, Sichuan, 610041, People's Republic of China
| | - Yucheng Chen
- Department of Cardiology, West China Hospital, Sichuan University, Guoxue Xiang No. 37, Chengdu, Sichuan, 610041, People's Republic of China.
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13
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Braun JL, Hamstra SI, Messner HN, Fajardo VA. SERCA2a tyrosine nitration coincides with impairments in maximal SERCA activity in left ventricles from tafazzin-deficient mice. Physiol Rep 2020; 7:e14215. [PMID: 31444868 PMCID: PMC6708055 DOI: 10.14814/phy2.14215] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 07/31/2019] [Accepted: 08/07/2019] [Indexed: 12/12/2022] Open
Abstract
The sarco/endoplasmic reticulum Ca2+‐ATPase (SERCA) is imperative for normal cardiac function regulating both muscle relaxation and contractility. SERCA2a is the predominant isoform in cardiac muscles and is inhibited by phospholamban (PLN). Under conditions of oxidative stress, SERCA2a may also be impaired by tyrosine nitration. Tafazzin (Taz) is a mitochondrial‐specific transacylase that regulates mature cardiolipin (CL) formation, and its absence leads to mitochondrial dysfunction and excessive production of reactive oxygen/nitrogen species (ROS/RNS). In the present study, we examined SERCA function, SERCA2a tyrosine nitration, and PLN expression/phosphorylation in left ventricles (LV) obtained from young (3‐5 months) and old (10‐12 months) wild‐type (WT) and Taz knockdown (TazKD) male mice. These mice are a mouse model for Barth syndrome, which is characterized by mitochondrial dysfunction, excessive ROS/RNS production, and dilated cardiomyopathy (DCM). Here, we show that maximal SERCA activity was impaired in both young and old TazKD LV, a result that correlated with elevated SERCA2a tyrosine nitration. In addition PLN protein was decreased, and its phosphorylation was increased in TazKD LV compared with control, which suggests that PLN may not contribute to the impairments in SERCA function. These changes in expression and phosphorylation of PLN may be an adaptive response aimed to improve SERCA function in TazKD mice. Nonetheless, we demonstrate for the first time that SERCA function is impaired in LVs obtained from young and old TazKD mice likely due to elevated ROS/RNS production. Future studies should determine whether improving SERCA function can improve cardiac contractility and pathology in TazKD mice.
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Affiliation(s)
- Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Sophie I Hamstra
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Holt N Messner
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
| | - Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, ON, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada
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14
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Zhao J, Lei Y, Yang Y, Gao H, Gai Z, Li X. Metoprolol alleviates arginine vasopressin-induced cardiomyocyte hypertrophy by upregulating the AKT1-SERCA2 cascade in H9C2 cells. Cell Biosci 2020; 10:72. [PMID: 32489586 PMCID: PMC7247229 DOI: 10.1186/s13578-020-00434-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/16/2020] [Indexed: 12/20/2022] Open
Abstract
Background Arginine vasopressin (AVP) is elevated in patients with heart failure, and the increase in the AVP concentration in plasma is positively correlated with disease severity and mortality. Metoprolol (Met) is a beta blocker that is widely used in the clinic to treat pathological cardiac hypertrophy and to improve heart function. However, the specific mechanism by which Met alleviates AVP-induced pathological cardiac hypertrophy is still unknown. Our current study aimed to evaluate the inhibitory effects of Met on AVP-induced cardiomyocyte hypertrophy and the underlying mechanisms. Methods AVP alone or AVP plus Met was added to the wild type or AKT1-overexpressing rat cardiac H9C2 cell line. The cell surface areas and ANP/BNP/β-MHC expressions were used to evaluate the levels of hypertrophy. Western bolting was used to analyze AKT1/P-AKT1, AKT2/P-AKT2, total AKT, SERCA2, and Phospholamban (PLN) expression. Fluo3-AM was used to measure the intracellular Ca2+ stores. Results In the current study, we found that AKT1 but not AKT2 mediated the pathogenesis of AVP-induced cardiomyocyte hypertrophy. Sustained stimulation (48 h) with AVP led to hypertrophy in the H9C2 rat cardiomyocytes, resulting in the downregulation of AKT1 (0.48 fold compared to control) and SERCA2 (0.62 fold), the upregulation of PLN (1.32 fold), and the increase in the cytoplasmic calcium concentration (1.52 fold). In addition, AKT1 overexpression increased the expression of SERCA2 (1.34 fold) and decreased the expression of PLN (0.48 fold) in the H9C2 cells. Moreover, we found that Met could attenuate the AVP-induced changes in AKT1, SERCA2 and PLN expression and decreased the cytoplasmic calcium concentration in the H9C2 cells. Conclusions Our results demonstrated that the AKT1-SERCA2 cascade served as an important regulatory pathway in AVP-induced pathological cardiac hypertrophy.
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Affiliation(s)
- Jieqiong Zhao
- Department of Cardiology, Tangdu Hospital, Air Force Medical University, Xi'an, 710038 Shaanxi People's Republic of China
| | - Yonghong Lei
- Department of Plastic Surgery, General Hospital of Chinese PLA, Beijing, 100853 People's Republic of China
| | - Yanping Yang
- Department of Cardiology, Tangdu Hospital, Air Force Medical University, Xi'an, 710038 Shaanxi People's Republic of China
| | - Haibo Gao
- Department of Cardiology, Tangdu Hospital, Air Force Medical University, Xi'an, 710038 Shaanxi People's Republic of China
| | - Zhongchao Gai
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021 Shaanxi People's Republic of China
| | - Xue Li
- Department of Cardiology, Tangdu Hospital, Air Force Medical University, Xi'an, 710038 Shaanxi People's Republic of China
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15
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Zhao J, Xu T, Zhou Y, Zhou Y, Xia Y, Li D. B-type natriuretic peptide and its role in altering Ca 2+-regulatory proteins in heart failure-mechanistic insights. Heart Fail Rev 2019; 25:861-871. [PMID: 31820203 DOI: 10.1007/s10741-019-09883-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heart failure (HF) is a worldwide disease with high levels of morbidity and mortality. The pathogenesis of HF is complicated and involves imbalances in hormone and electrolyte. B-type natriuretic peptide (BNP) has served as a biomarker of HF severity, and in recent years, it has been used to treat the disease, thanks to its cardio-protective effects, such as diuresis, natriuresis, and vasodilatation. In stage C/D HF, symptoms are severe despite elevated BNP. Disturbances in Ca2+ homeostasis are often a dominating feature of the disease, causing Ca2+-regulatory protein dysfunction, including reduced expression and activity of sarcoplasmic reticulum Ca2+-ATPase2a (SERCA2a), impaired ryanodine receptors (RYRs) function, intensive Na+-Ca2+ exchanger (NCX), and downregulation of S100A1. The relationship between natriuretic peptides (NPs) and Ca2+-regulatory proteins has been widely studied and represents important mechanisms in the etiology of HF. In this review, we present evidence that BNP may regulate Ca2+-regulatory proteins, in particular, suppressing SERCA2a and S100A1 expression. However, relationships between BNP and other Ca2+-regulatory proteins remain vague.
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Affiliation(s)
- Jiaqi Zhao
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China
| | - Tongda Xu
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China
| | - Yao Zhou
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China
| | - You Zhou
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China
| | - Yong Xia
- Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China.
| | - Dongye Li
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China. .,Department of Cardiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, People's Republic of China.
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16
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Machuki JO, Zhang HY, Geng J, Fu L, Adzika GK, Wu L, Shang W, Wu J, Kexue L, Zhao Z, Sun H. Estrogen regulation of cardiac cAMP-L-type Ca 2+ channel pathway modulates sex differences in basal contraction and responses to β 2AR-mediated stress in left ventricular apical myocytes. Cell Commun Signal 2019; 17:34. [PMID: 30987657 PMCID: PMC6466778 DOI: 10.1186/s12964-019-0346-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/27/2019] [Indexed: 12/16/2022] Open
Abstract
Backgrounds/Aim Male and female hearts have many structural and functional differences. Here, we investigated the role of estrogen (E2) in the mechanisms of sex differences in contraction through the cAMP-L-type Ca2+channel pathway in adult mice left ventricular (LV) apical myocytes at basal and stress state. Methods Isolated LV apical myocytes from male, female (Sham) and ovariectomised mice (OVX) were used to investigate contractility, Ca2+ transients and L-type Ca2+ channel (LTCC) function. The levels of β2AR, intracellular cAMP, phosphodiesterase (PDE 3 and PDE 4), RyR2, PLB, SLN, and SERCA2a were compared among the experimental groups. Results We found that (1) intracellular cAMP, ICaL density, contraction and Ca2+ transient amplitudes were larger in Sham and OVX + E2 myocytes compared to male and OVX. (2) The mRNA expression of PDE 3 and 4 were lower in Sham and OVX + E2 groups compared with male and OVX groups. Treatment of myocytes with IBMX (100 μM) increased contraction and Ca2+ transient amplitude in both sexes and canceled differences between them. (3) β2AR-mediated stress decreased cAMP concentration and peak contraction and Ca2+ transient amplitude only in male and OVX groups but not in Sham or OVX + E2 groups suggesting a cardioprotective role of E2 in female mice. (4) Pretreatment of OVX myocytes with GPR30 antagonist G15 (100 nM) abolished the effects of E2, but ERα and ERβ antagonist ICI 182,780 (1 μM) did not. Moreover, activation of GPR30 with G1 (100 nM) replicated the effects of E2 on cAMP, contraction and Ca2+ transient amplitudes suggesting that the acute effects of E2 were mediated by GPR30 via non-genomic signaling. (5) mRNA expression of RyR2 was higher in myocytes from Sham than those of male while PLB and SLN were higher in male than Sham but no sex differences were observed in the mRNA of SERCA2a. Conclusion Collectively, these results demonstrate that E2 modulates the expression of genes related to the cAMP-LTCC pathway and contributes to sex differences in cardiac contraction and responses to stress. We also show that estrogen confers cardioprotection against cardiac stress by non-genomic acute signaling via GPR30.
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Affiliation(s)
| | - Hong-Yuan Zhang
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.,Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, 221002, China
| | - Juan Geng
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.,Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, 221002, China
| | - Lu Fu
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Gabriel Komla Adzika
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Lijuan Wu
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.,Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, 221002, China
| | - Wenkang Shang
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, 221002, China
| | - Jinxia Wu
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Li Kexue
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China
| | - Zhiwei Zhao
- Institute of Cardiovascular Disease Research, Xuzhou Medical University, Xuzhou, 221002, China
| | - Hong Sun
- Physiology Department, Xuzhou Medical University, Xuzhou, 221004, Jiangsu, China.
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17
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Saad NS, Elnakish MT, Ahmed AAE, Janssen PML. Protein Kinase A as a Promising Target for Heart Failure Drug Development. Arch Med Res 2018; 49:530-537. [PMID: 30642654 PMCID: PMC6451668 DOI: 10.1016/j.arcmed.2018.12.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 12/13/2018] [Indexed: 12/24/2022]
Abstract
Heart failure (HF) is a clinical syndrome characterized by impaired ability of the heart to fill or eject blood. HF is rather prevalent and it represents the foremost reason of hospitalization in the United States. The costs linked to HF overrun those of all other causes of disabilities, and death in the United States and all over the developed as well as the developing countries which amplify the supreme significance of its prevention. Protein kinase (PK) A plays multiple roles in heart functions including, contraction, metabolism, ion fluxes, and gene transcription. Altered PKA activity is likely to cause the progression to cardiomyopathy and HF. Thus, this review is intended to focus on the roles of PKA and PKA-mediated signal transduction in the healthy heart as well as during the development of HF. Furthermore, the impact of cardiac PKA inhibition/activation will be highlighted to identify PKA as a potential target for the HF drug development.
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Affiliation(s)
- Nancy S Saad
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Mohammad T Elnakish
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Amany A E Ahmed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Paul M L Janssen
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA.
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Ceholski DK, Turnbull IC, Kong CW, Koplev S, Mayourian J, Gorski PA, Stillitano F, Skodras AA, Nonnenmacher M, Cohen N, Björkegren JLM, Stroik DR, Cornea RL, Thomas DD, Li RA, Costa KD, Hajjar RJ. Functional and transcriptomic insights into pathogenesis of R9C phospholamban mutation using human induced pluripotent stem cell-derived cardiomyocytes. J Mol Cell Cardiol 2018; 119:147-154. [PMID: 29752948 DOI: 10.1016/j.yjmcc.2018.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 12/27/2022]
Abstract
Dilated cardiomyopathy (DCM) can be caused by mutations in the cardiac protein phospholamban (PLN). We used CRISPR/Cas9 to insert the R9C PLN mutation at its endogenous locus into a human induced pluripotent stem cell (hiPSC) line from an individual with no cardiovascular disease. R9C PLN hiPSC-CMs display a blunted β-agonist response and defective calcium handling. In 3D human engineered cardiac tissues (hECTs), a blunted lusitropic response to β-adrenergic stimulation was observed with R9C PLN. hiPSC-CMs harboring the R9C PLN mutation showed activation of a hypertrophic phenotype, as evidenced by expression of hypertrophic markers and increased cell size and capacitance of cardiomyocytes. RNA-seq suggests that R9C PLN results in an altered metabolic state and profibrotic signaling, which was confirmed by gene expression analysis and picrosirius staining of R9C PLN hECTs. The expression of several miRNAs involved in fibrosis, hypertrophy, and cardiac metabolism were also perturbed in R9C PLN hiPSC-CMs. This study contributes to better understanding of the pathogenic mechanisms of the hereditary R9C PLN mutation in the context of human cardiomyocytes.
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Affiliation(s)
- Delaine K Ceholski
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Irene C Turnbull
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Chi-Wing Kong
- Department of Paediatrics and Adolescent Medicine, Hong Kong University, Pokfulam, Hong Kong
| | - Simon Koplev
- Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Joshua Mayourian
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Przemek A Gorski
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Francesca Stillitano
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Angelos A Skodras
- Microscopy Core, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mathieu Nonnenmacher
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Ninette Cohen
- Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Johan L M Björkegren
- Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Daniel R Stroik
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - Ronald A Li
- Department of Paediatrics and Adolescent Medicine, Hong Kong University, Pokfulam, Hong Kong; Ming Wai Lau Centre for Reparative Medicine, Karolinska Institutet, Solna SE-171, Sweden
| | - Kevin D Costa
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Roger J Hajjar
- Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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19
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Kronenbitter A, Funk F, Hackert K, Gorreßen S, Glaser D, Boknik P, Poschmann G, Stühler K, Isić M, Krüger M, Schmitt JP. Impaired Ca 2+ cycling of nonischemic myocytes contributes to sarcomere dysfunction early after myocardial infarction. J Mol Cell Cardiol 2018; 119:28-39. [PMID: 29674140 DOI: 10.1016/j.yjmcc.2018.04.004] [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: 02/19/2018] [Revised: 04/05/2018] [Accepted: 04/08/2018] [Indexed: 12/15/2022]
Abstract
Changes in the nonischemic remote myocardium of the heart contribute to left ventricular dysfunction after ischemia and reperfusion (I/R). Understanding the underlying mechanisms early after I/R is crucial to improve the adaptation of the viable myocardium to increased mechanical demands. Here, we investigated the role of myocyte Ca2+ handling in the remote myocardium 24 h after 60 min LAD occlusion. Cardiomyocytes isolated from the basal noninfarct-related parts of wild type mouse hearts demonstrated depressed beat-to-beat Ca2+ handling. The amplitude of the Ca2+ transients as well as the kinetics of Ca2+ transport were reduced by up to 25%. These changes were associated with impaired sarcomere contraction. While expression levels of Ca2+ regulatory proteins were unchanged in remote myocardium compared to the corresponding regions of sham-operated hearts, mobility shift analyses of phosphorylated protein showed 2.9 ± 0.4-fold more unphosphorylated phospholamban (PLN) monomers, the PLN species that inhibits the Ca2+ ATPase SERCA2a (P ≤ 0.001). Phospho-specific antibodies revealed normal phosphorylation of PLN at T17 in remote myocardium, but markedly reduced phosphorylation at its PKA-dependent phosphorylation site, S16 (P ≤ 0.01). The underlying cause involved enhanced activity of protein phosphatases, particularly PP2A (P ≤ 0.01). In contrast, overall PKA activity was normal. The PLN interactome, as determined by co-immunoprecipitation and mass spectrometry, and the phosphorylation state of PKA targets other than PLN were also unchanged. Isoproterenol enhanced cellular Ca2+ cycling much stronger in remote myocytes than in healthy controls and improved sarcomere function. We conclude that the reduced phosphorylation state of PLN at S16 impairs myocyte Ca2+ cycling in the remote myocardium 24 h after I/R and contributes to contractile dysfunction.
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Affiliation(s)
- Annette Kronenbitter
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Florian Funk
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Katarzyna Hackert
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Simone Gorreßen
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Dennis Glaser
- Institute of Pharmacology and Toxicology, University Hospital Münster, Germany
| | - Peter Boknik
- Institute of Pharmacology and Toxicology, University Hospital Münster, Germany
| | - Gereon Poschmann
- Molecular Proteomics Laboratory, Biological and Medical Research Center (BMFZ), Institute of Molecular Medicine, University Hospital Düsseldorf, Germany
| | - Kai Stühler
- Molecular Proteomics Laboratory, Biological and Medical Research Center (BMFZ), Institute of Molecular Medicine, University Hospital Düsseldorf, Germany
| | - Malgorzata Isić
- Institute of Cardiovascular Physiology, University of Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Martina Krüger
- Institute of Cardiovascular Physiology, University of Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical Pharmacology, University Hospital Düsseldorf, Germany; Cardiovascular Research Institute Düsseldorf (CARID), Heinrich-Heine-University, Düsseldorf, Germany.
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20
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Kraev A. Insertional Mutagenesis Confounds the Mechanism of the Morbid Phenotype of a PLN R9C Transgenic Mouse Line. J Card Fail 2018; 24:115-125. [PMID: 29325795 DOI: 10.1016/j.cardfail.2017.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 12/18/2017] [Accepted: 12/21/2017] [Indexed: 12/29/2022]
Abstract
BACKGROUND A mouse line with heterozygous transgenic expression of phospholamban carrying a substitution of cysteine for arginine 9 (TgPLNR9C) under the control of α-myosin heavy chain (αMHC) promoter features dilated cardiomyopathy, heart failure, and premature death. METHODS AND RESULTS Determination of transgene chromosomal localization by conventional methods shows that in this line the transgenic array of 13 PLNR9C expression cassettes, arranged in a head-to-tail tandem orientation, have integrated into the bidirectional promoter of the αMHC (Myh6) gene and the gene for the regulatory noncoding RNA Myheart (Mhrt), both of which are known to be involved in cardiac development and pathology. Expression of the noncoding RNA Mhrt in TgPLNR9C mice exhibits profound deregulation, despite the presence of the second, intact allele. CONCLUSIONS The TgPLNR9C mouse strain is, in the best case, a functionally ambiguous phenocopy of the human PLNR9C heterozygote, because a similar constellation of genetically programmed events can not occur in a patient. Publications featuring "cardiac-specific overexpression" are focused on the phenotype and typically forgo the definition of the transgene integration site or transgene temporal expression profile, so caution should be exercised in attributing clinical relevance to pathologic phenomena observed in αMHC-driven transgenes.
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Affiliation(s)
- Alexander Kraev
- University of Toronto, 27 King's College Circle, Toronto, Ontario M5S 1A1, Canada.
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21
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Abstract
The calcium pump (a.k.a. Ca2+-ATPase or SERCA) is a membrane transport protein ubiquitously found in the endoplasmic reticulum (ER) of all eukaryotic cells. As a calcium transporter, SERCA maintains the low cytosolic calcium level that enables a vast array of signaling pathways and physiological processes (e.g. synaptic transmission, muscle contraction, fertilization). In muscle cells, SERCA promotes relaxation by pumping calcium ions from the cytosol into the lumen of the sarcoplasmic reticulum (SR), the main storage compartment for intracellular calcium. X-ray crystallographic studies have provided an extensive understanding of the intermediate states that SERCA populates as it progresses through the calcium transport cycle. Historically, SERCA is also known to be regulated by small transmembrane peptides, phospholamban (PLN) and sarcolipin (SLN). PLN is expressed in cardiac muscle, whereas SLN predominates in skeletal and atrial muscle. These two regulatory subunits play critical roles in cardiac contractility. While our understanding of these regulatory mechanisms are still developing, SERCA and PLN are one of the best understood examples of peptide-transporter regulatory interactions. Nonetheless, SERCA appeared to have only two regulatory subunits, while the related sodium pump (a.k.a. Na+, K+-ATPase) has at least nine small transmembrane peptides that provide tissue specific regulation. The last few years have seen a renaissance in our understanding of SERCA regulatory subunits. First, structures of the SERCA-SLN and SERCA-PLN complexes revealed molecular details of their interactions. Second, an array of micropeptides concealed within long non-coding RNAs have been identified as new SERCA regulators. This chapter will describe our current understanding of SERCA structure, function, and regulation.
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22
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Lorenz K, Rosner MR, Brand T, Schmitt JP. Raf kinase inhibitor protein: lessons of a better way for β-adrenergic receptor activation in the heart. J Physiol 2017; 595:4073-4087. [PMID: 28444807 PMCID: PMC5471367 DOI: 10.1113/jp274064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 02/27/2017] [Indexed: 12/13/2022] Open
Abstract
Stimulation of β-adrenergic receptors (βARs) provides the most efficient physiological mechanism to enhance contraction and relaxation of the heart. Activation of βARs allows rapid enhancement of myocardial function in order to fuel the muscles for running and fighting in a fight-or-flight response. Likewise, βARs become activated during cardiovascular disease in an attempt to counteract the restrictions of cardiac output. However, long-term stimulation of βARs increases the likelihood of cardiac arrhythmias, adverse ventricular remodelling, decline of cardiac performance and premature death, thereby limiting the use of βAR agonists in the treatment of heart failure. Recently the endogenous Raf kinase inhibitor protein (RKIP) was found to activate βAR signalling of the heart without adverse effects. This review will summarize the current knowledge on RKIP-driven compared to receptor-mediated signalling in cardiomyocytes. Emphasis is given to the differential effects of RKIP on β1 - and β2 -ARs and their downstream targets, the regulation of myocyte calcium cycling and myofilament activity.
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Affiliation(s)
- Kristina Lorenz
- Comprehensive Heart Failure CenterUniversity of WürzburgVersbacher Straße 997078WürzburgGermany
- West German Heart and Vascular Center EssenUniversity Hospital EssenHufelandstraße 5545147EssenGermany
- Leibniz‐Institut für Analytische Wissenschaften – ISAS – e.V.Bunsen‐Kirchhoff‐Straße 1144139DortmundGermany
- Institute of Pharmacology and ToxicologyUniversity of WürzburgVersbacher Straße 997078WürzburgGermany
| | - Marsha Rich Rosner
- Ben May Department for Cancer ResearchUniversity of ChicagoChicagoIL 60637USA
| | - Theresa Brand
- Leibniz‐Institut für Analytische Wissenschaften – ISAS – e.V.Bunsen‐Kirchhoff‐Straße 1144139DortmundGermany
- Institute of Pharmacology and ToxicologyUniversity of WürzburgVersbacher Straße 997078WürzburgGermany
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical PharmacologyDüsseldorf University HospitalUniverstitätsstraße 140225DüsseldorfGermany
- Cardiovascular Research Institute Düsseldorf (CARID)Heinrich‐Heine‐UniversityUniverstitätsstraße 140225DüsseldorfGermany
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23
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Structure-Function Relationship of the SERCA Pump and Its Regulation by Phospholamban and Sarcolipin. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:77-119. [DOI: 10.1007/978-3-319-55858-5_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Phospholamban pentamers attenuate PKA-dependent phosphorylation of monomers. J Mol Cell Cardiol 2015; 80:90-7. [DOI: 10.1016/j.yjmcc.2014.12.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 11/29/2014] [Accepted: 12/23/2014] [Indexed: 11/18/2022]
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25
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Abrol N, de Tombe PP, Robia SL. Acute inotropic and lusitropic effects of cardiomyopathic R9C mutation of phospholamban. J Biol Chem 2015; 290:7130-40. [PMID: 25593317 DOI: 10.1074/jbc.m114.630319] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A naturally occurring R9C mutation of phospholamban (PLB) triggers cardiomyopathy and premature death by altering regulation of sarco/endoplasmic reticulum calcium-ATPase (SERCA). The goal of this study was to investigate the acute physiological consequences of the R9C-PLB mutation on cardiomyocyte calcium kinetics and contractility. We measured the physiological consequences of R9C-PLB mutation on calcium transients and sarcomere shortening in adult cardiomyocytes. In contrast to studies of chronic R9C-PLB expression in transgenic mice, we found that acute expression of R9C-PLB exerts a positively inotropic and lusitropic effect in cardiomyocytes. Importantly, R9C-PLB exhibited blunted sensitivity to frequency potentiation and β-adrenergic stimulation, two major physiological mechanisms for the regulation of cardiac performance. To identify the molecular mechanism of R9C pathology, we quantified the effect of R9C on PLB oligomerization and PLB-SERCA binding. FRET measurements in live cells revealed that R9C-PLB exhibited an increased propensity for oligomerization, and this was further increased by oxidative stress. The R9C also decreased PLB binding to SERCA and altered the structure of the PLB-SERCA regulatory complex. The structural change after oxidative modification of R9C-PLB was similar to that observed after PLB phosphorylation. We conclude that R9C mutation of PLB decreases SERCA inhibition by decreasing the amount of the regulatory complex and altering its conformation. This has an acute inotropic/lusitropic effect but yields negative consequences of impaired frequency potentiation and blunted β-adrenergic responsiveness. We envision a self-reinforcing mechanism beginning with phosphomimetic R9C-PLB oxidation and loss of SERCA inhibition, leading to impaired calcium regulation and heart failure.
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Affiliation(s)
- Neha Abrol
- From the Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois 60163
| | - Pieter P de Tombe
- From the Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois 60163
| | - Seth L Robia
- From the Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, Illinois 60163
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26
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Young HS, Ceholski DK, Trieber CA. Deception in simplicity: hereditary phospholamban mutations in dilated cardiomyopathy. Biochem Cell Biol 2014; 93:1-7. [PMID: 25563649 DOI: 10.1139/bcb-2014-0080] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The sarcoplasmic reticulum (SR) calcium pump (SERCA) and its regulator phospholamban are required for cardiovascular function. Phospholamban alters the apparent calcium affinity of SERCA in a process that is modulated by phosphorylation via the β-adrenergic pathway. This regulatory axis allows for the dynamic control of SR calcium stores and cardiac contractility. Herein we focus on hereditary mutants of phospholamban that are associated with heart failure, such as Arg(9)-Cys, Arg(9)-Leu, Arg(9)-His, and Arg(14)-deletion. Each mutant has a distinct effect on PLN function and SR calcium homeostasis. Arg(9)-Cys and Arg(9)-Leu do not inhibit SERCA, Arg(14)-deletion is a partial inhibitor, and Arg(9)-His is comparable to wild-type. While the mutants have distinct functional effects on SERCA, they have in common that they cannot be phosphorylated by protein kinase A (PKA). Arg(9) and Arg(14) are required for PKA recognition and phosphorylation of PLN. Thus, mutations at these positions eliminate β-adrenergic control and dynamic cardiac contractility. Hydrophobic mutations of Arg(9) cause more complex changes in function, including loss of PLN function and dominant negative interaction with SERCA in heterozygous individuals. In addition, aberrant interaction with PKA may prevent phosphorylation of wild-type PLN and sequester PKA from other local subcellular targets. Herein we consider what is known about each mutant and how the synergistic changes in SR calcium homeostasis lead to impaired cardiac contractility and dilated cardiomyopathy.
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Affiliation(s)
- Howard S Young
- a Department of Biochemistry, University of Alberta, 327 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
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27
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Hughes E, Middleton DA. Comparison of the structure and function of phospholamban and the arginine-14 deficient mutant associated with dilated cardiomyopathy. PLoS One 2014; 9:e106746. [PMID: 25225809 PMCID: PMC4165587 DOI: 10.1371/journal.pone.0106746] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 08/01/2014] [Indexed: 12/20/2022] Open
Abstract
Phospholamban (PLB) is a pentameric protein that plays an important role in regulating cardiac contractility via a reversible inhibitory association with the sarcoplasmic reticulum Ca2+ATPase (SERCA), the enzyme responsible for maintaining correct calcium homeostasis. Here we study the functional and biophysical characteristics of a PLB mutant associated with human dilated cardiomyopathy (DCM), with a deletion of arginine at position 14 (PLBR14Δ). In agreement with recent findings, we find that PLBR14Δ has a reduced inhibitory effect on SERCA compared to wild type PLB (PLBWT) when reconstituted into lipid membranes. The mutation also leads to a large reduction in the protein kinase A-catalysed phosphorylation of Ser-16 in the cytoplasmic domain of PLBR14Δ. Measurements on SERCA co-reconstituted with an equimolar mixture of PLBWT and PLBR14Δ (representing the lethal heterozygous state associated with DCM) indicates that the loss-of-function mutation has a dominant effect on PLBWT functionality and phosphorylation capacity, suggesting that mixed PLBWT/PLBR14Δ pentamers are formed that have characteristics typical of the mutant protein. Structural and biophysical analysis of PLBR14Δ indicates that the mutation perturbs slightly the helical structure of the PLB cytoplasmic domain and reduces its affinity for the phospholipid bilayer surface, thereby altering the orientation of the cytoplasmic domain relative to the wild-type protein. These results indicate that the structure and function consequences of the R14 deletion have profound effects on the regulation of SERCA which may contribute to the aetiology of DCM.
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Affiliation(s)
- Eleri Hughes
- Department of Chemistry, Lancaster University, Lancaster, United Kingdom
| | - David A Middleton
- Department of Chemistry, Lancaster University, Lancaster, United Kingdom
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28
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El-Ani D, Philipchik I, Stav H, Levi M, Zerbib J, Shainberg A. Tumor necrosis factor alpha protects heart cultures against hypoxic damage via activation of PKA and phospholamban to prevent calcium overload. Can J Physiol Pharmacol 2014; 92:917-25. [PMID: 25349921 DOI: 10.1139/cjpp-2014-0092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
This study aims to elucidate the mechanisms by which tumor necrosis factor alpha (TNFα) provides protection from hypoxic damage to neonatal rat cardiomyocyte cultures. We show that when intracellular Ca(2+) ([Ca(2+)]i) levels are elevated by extracellular Ca(2+) ([Ca(2+)]o) or by hypoxia, then TNFα decreased [Ca(2+)]i in individual cardiomyocytes. However, TNFα did not reduce [Ca(2+)]i after its increase by thapsigargin, (a SERCA2a inhibitor), indicating that TNFα attenuates Ca(2+) overload through Ca(2+) uptake by SERCA2a. TNFα did not reduce [Ca(2+)]i, following its elevation when [Ca(2+)]o levels were elevated in TNFα receptor knock-out mice. H-89, a protein kinase A (PKA) inhibitor, attenuated the protective effect of TNFα when the cardiomyoctyes were subjected to hypoxia, as determined by lactate dehydrogenase (LDH) and creatine kinase (CK) released and from the cardiomyocytes. Moreover, when the levels of [Ca(2+)]i were increased by hypoxia, H-89, but not KN93, (a calmodulin kinase II inhibitor), prevented the reduction in [Ca(2+)]i by TNFα. TNFα increased the phosphorylation of PKA in normoxic and hypoxic cardiomyoctes, indicating that the cardioprotective effect of TNFα against hypoxic damage was via PKA activation. Hypoxia decreased phosphorylated phospholamban levels; however, TNFα attenuated this decrease following hypoxia. It is suggested that TNFα activates phospholamban phosphorylation in hypoxic heart cultures via PKA to stimulate SERCA2a activity to limit Ca(2+) overload.
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Affiliation(s)
- Dalia El-Ani
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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29
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Tilgmann C, Pollesello P, Ovaska M, Kaivola J, Pystynen J, Tiainen E, Yliperttula M, Annila A, Levijoki J. Discovery and Structural Characterization of a Phospholamban-Binding Cyclic Peptide and Design of Novel Inhibitors of Phospholamban. Chem Biol Drug Des 2012; 81:463-73. [DOI: 10.1111/j.1747-0285.2012.01409.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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30
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Medeiros A, Biagi DG, Sobreira TJP, de Oliveira PSL, Negrão CE, Mansur AJ, Krieger JE, Brum PC, Pereira AC. Mutations in the human phospholamban gene in patients with heart failure. Am Heart J 2011; 162:1088-1095.e1. [PMID: 22137083 DOI: 10.1016/j.ahj.2011.07.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 07/21/2011] [Indexed: 11/28/2022]
Abstract
BACKGROUND Phospholamban (PLN) is a crucial Ca(2+) cycling protein and a primary mediator of the β-adrenergic effects resulting in enhanced cardiac output. Mutations in the gene encoding PLN have been associated with idiopathic dilated cardiomyopathy; however, no systematic search for PLN mutations in heart failure has been conducted. METHODS We screened a cohort of 1,014 Brazilian patients with heart failure for mutations in the PLN gene. Molecular modeling studies of the mutations found were developed. Different disease etiologies were present in our sample: idiopathic, ischemic, Chagas, valvular, hypertensive, and others. RESULTS We identified 4 unrelated patients with PLN mutations (prevalence of 0.4%), 3 of them in the same amino acid residue (R9). Two patients presented a G-T missense mutation at the G26 nucleotide, which encodes an Arg-Leu substitution at codon 9 (R9L). One patient presented a G-A missense mutation at the same nucleotide, which encodes an Arg-His substitution at codon 9 (R9H). The fourth affected patient presented a T-G nonsense mutation at the nucleotide 116, substituting a termination codon for Leu-39 (L39stop). Molecular modeling studies suggested that R9L and R9H mutations might affect the region involved in protein kinase A docking and probably affect the mechanism modulating the release of phosphorylated PLN from the substrate binding site of protein kinase A. CONCLUSIONS Mutations in the PLN gene are a rare cause of heart failure, present almost exclusively in patients with dilated cardiomyopathy etiology. The Arg9 and Leu39 residues are the leading location of mutations described at this locus to date. Despite the few mutated residues described to date, the clinical spectrum of presentation appears to vary considerably.
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31
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Vandecaetsbeek I, Vangheluwe P, Raeymaekers L, Wuytack F, Vanoevelen J. The Ca2+ pumps of the endoplasmic reticulum and Golgi apparatus. Cold Spring Harb Perspect Biol 2011; 3:cshperspect.a004184. [PMID: 21441596 DOI: 10.1101/cshperspect.a004184] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The various splice variants of the three SERCA- and the two SPCA-pump genes in higher vertebrates encode P-type ATPases of the P(2A) group found respectively in the membranes of the endoplasmic reticulum and the secretory pathway. Of these, SERCA2b and SPCA1a represent the housekeeping isoforms. The SERCA2b form is characterized by a luminal carboxy terminus imposing a higher affinity for cytosolic Ca(2+) compared to the other SERCAs. This is mediated by intramembrane and luminal interactions of this extension with the pump. Other known affinity modulators like phospholamban and sarcolipin decrease the affinity for Ca(2+). The number of proteins reported to interact with SERCA is rapidly growing. Here, we limit the discussion to those for which the interaction site with the ATPase is specified: HAX-1, calumenin, histidine-rich Ca(2+)-binding protein, and indirectly calreticulin, calnexin, and ERp57. The role of the phylogenetically older and structurally simpler SPCAs as transporters of Ca(2+), but also of Mn(2+), is also addressed.
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Affiliation(s)
- Ilse Vandecaetsbeek
- Laboratory of Ca-transport ATPases, Department of Molecular Cell Biology, K.U. Leuven, Leuven, Belgium
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32
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Gustavsson M, Traaseth NJ, Karim CB, Lockamy EL, Thomas DD, Veglia G. Lipid-mediated folding/unfolding of phospholamban as a regulatory mechanism for the sarcoplasmic reticulum Ca2+-ATPase. J Mol Biol 2011; 408:755-65. [PMID: 21419777 DOI: 10.1016/j.jmb.2011.03.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 01/10/2011] [Accepted: 03/07/2011] [Indexed: 10/18/2022]
Abstract
The integral membrane protein complex between phospholamban (PLN) and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) regulates cardiac contractility. In the unphosphorylated form, PLN binds SERCA and inhibits Ca(2+) flux. Upon phosphorylation of PLN at Ser16, the inhibitory effect is reversed. Although structural details on both proteins are emerging from X-ray crystallography, cryo-electron microscopy, and NMR studies, the molecular mechanisms of their interactions and regulatory process are still lacking. It has been speculated that SERCA regulation depends on PLN structural transitions (order to disorder, i.e., folding/unfolding). Here, we investigated PLN conformational changes upon chemical unfolding by a combination of electron paramagnetic resonance and NMR spectroscopies, revealing that the conformational transitions involve mostly the cytoplasmic regions, with two concomitant phenomena: (1) membrane binding and folding of the amphipathic domain Ia and (2) folding/unfolding of the juxtamembrane domain Ib of PLN. Analysis of phosphorylated and unphosphorylated PLN with two phosphomimetic mutants of PLN (S16E and S16D) shows that the population of an unfolded state in domains Ia and Ib (T' state) is linearly correlated to the extent of SERCA inhibition measured by activity assays. Inhibition of SERCA is carried out by the folded ground state (T state) of the protein (PLN), while the relief of inhibition involves promotion of PLN to excited conformational states (Ser16 phosphorylated PLN). We propose that PLN population shifts (folding/unfolding) are a key regulatory mechanism for SERCA.
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Affiliation(s)
- Martin Gustavsson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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Lethal Arg9Cys phospholamban mutation hinders Ca2+-ATPase regulation and phosphorylation by protein kinase A. Proc Natl Acad Sci U S A 2011; 108:2735-40. [PMID: 21282613 DOI: 10.1073/pnas.1013987108] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The regulatory interaction of phospholamban (PLN) with Ca(2+)-ATPase controls the uptake of calcium into the sarcoplasmic reticulum, modulating heart muscle contractility. A missense mutation in PLN cytoplasmic domain (R9C) triggers dilated cardiomyopathy in humans, leading to premature death. Using a combination of biochemical and biophysical techniques both in vitro and in live cells, we show that the R9C mutation increases the stability of the PLN pentameric assembly via disulfide bridge formation, preventing its binding to Ca(2+)-ATPase as well as phosphorylation by protein kinase A. These effects are enhanced under oxidizing conditions, suggesting that oxidative stress may exacerbate the cardiotoxic effects of the PLN(R9C) mutant. These results reveal a regulatory role of the PLN pentamer in calcium homeostasis, going beyond the previously hypothesized role of passive storage for active monomers.
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Dhalla NS, Müller AL. Protein Kinases as Drug Development Targets for Heart Disease Therapy. Pharmaceuticals (Basel) 2010; 3:2111-2145. [PMID: 27713345 PMCID: PMC4036665 DOI: 10.3390/ph3072111] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 06/03/2010] [Accepted: 06/23/2010] [Indexed: 02/07/2023] Open
Abstract
Protein kinases are intimately integrated in different signal transduction pathways for the regulation of cardiac function in both health and disease. Protein kinase A (PKA), Ca²⁺-calmodulin-dependent protein kinase (CaMK), protein kinase C (PKC), phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) are not only involved in the control of subcellular activities for maintaining cardiac function, but also participate in the development of cardiac dysfunction in cardiac hypertrophy, diabetic cardiomyopathy, myocardial infarction, and heart failure. Although all these kinases serve as signal transducing proteins by phosphorylating different sites in cardiomyocytes, some of their effects are cardioprotective whereas others are detrimental. Such opposing effects of each signal transduction pathway seem to depend upon the duration and intensity of stimulus as well as the type of kinase isoform for each kinase. In view of the fact that most of these kinases are activated in heart disease and their inhibition has been shown to improve cardiac function, it is suggested that these kinases form excellent targets for drug development for therapy of heart disease.
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Affiliation(s)
- Naranjan S Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R2H 2A6, Canada.
| | - Alison L Müller
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, MB R2H 2A6, Canada.
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Lompré AM, Hajjar RJ, Harding SE, Kranias EG, Lohse MJ, Marks AR. Ca2+ cycling and new therapeutic approaches for heart failure. Circulation 2010; 121:822-30. [PMID: 20124124 DOI: 10.1161/circulationaha.109.890954] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Anne-Marie Lompré
- INSERM UMRS956/Université Pierre et Marie Curie, Faculté de Médecine, 91 Boulevard de l'Hôpital, 75013 Paris, France.
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Vandecaetsbeek I, Raeymaekers L, Wuytack F, Vangheluwe P. Factors controlling the activity of the SERCA2a pump in the normal and failing heart. Biofactors 2009; 35:484-99. [PMID: 19904717 DOI: 10.1002/biof.63] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Heart failure is the leading cause of death in western countries and is often associated with impaired Ca(2+) handling in the cardiomyocyte. In fact, cardiomyocyte relaxation and contraction are tightly controlled by the activity of the cardiac sarco(endo)plasmic reticulum (ER/SR) Ca(2+) pump SERCA2a, pumping Ca(2+) from the cytosol into the lumen of the ER/SR. This review addresses three important facets that control the SERCA2 activity in the heart. First, we focus on the alternative splicing of the SERCA2 messenger, which is strictly regulated in the developing heart. This splicing controls the formation of three SERCA2 splice variants with different enzymatic properties. Second, we will discuss the role and regulation of SERCA2a activity in the normal and failing heart. The two well-studied Ca(2+) affinity modulators phospholamban and sarcolipin control the activity of SERCA2a within a narrow window. An aberrantly high or low Ca(2+) affinity is often observed in and may even trigger cardiac failure. Correcting SERCA2a activity might therefore constitute a therapeutic approach to improve the contractility of the failing heart. Finally, we address the controversies and unanswered questions of other putative regulators of the cardiac Ca(2+) pump, such as sarcalumenin, HRC, S100A1, Bcl-2, HAX-1, calreticulin, calnexin, ERp57, IRS-1, and -2.
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Affiliation(s)
- Ilse Vandecaetsbeek
- Department of Molecular Cell Biology, Laboratory of Ca(2+)-transport ATPases, K.U.Leuven, Leuven, Belgium
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Structural basis for the high Ca2+ affinity of the ubiquitous SERCA2b Ca2+ pump. Proc Natl Acad Sci U S A 2009; 106:18533-8. [PMID: 19846779 DOI: 10.1073/pnas.0906797106] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sarco(endo)plasmic reticulum Ca(2+) ATPase (SERCA) Ca(2+) transporters pump cytosolic Ca(2+) into the endoplasmic reticulum, maintaining a Ca(2+) gradient that controls vital cell functions ranging from proliferation to death. To meet the physiological demand of the cell, SERCA activity is regulated by adjusting the affinity for Ca(2+) ions. Of all SERCA isoforms, the housekeeping SERCA2b isoform displays the highest Ca(2+) affinity because of a unique C-terminal extension (2b-tail). Here, an extensive structure-function analysis of SERCA2b mutants and SERCA1a2b chimera revealed how the 2b-tail controls Ca(2+) affinity. Its transmembrane (TM) segment (TM11) and luminal extension functionally cooperate and interact with TM7/TM10 and luminal loops of SERCA2b, respectively. This stabilizes the Ca(2+)-bound E1 conformation and alters Ca(2+)-transport kinetics, which provides the rationale for the higher apparent Ca(2+) affinity. Based on our NMR structure of TM11 and guided by mutagenesis results, a structural model was developed for SERCA2b that supports the proposed 2b-tail mechanism and is reminiscent of the interaction between the alpha- and beta-subunits of Na(+),K(+)-ATPase. The 2b-tail interaction site may represent a novel target to increase the Ca(2+) affinity of malfunctioning SERCA2a in the failing heart to improve contractility.
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