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Ren AJ, Wei C, Liu YJ, Liu M, Wang P, Fan J, Wang K, Zhang S, Qin Z, Ren QX, Zheng Y, Chen YX, Xie Z, Gao L, Zhu Y, Zhang Y, Yang HT, Zhang WJ. ZBTB20 Regulates SERCA2a Activity and Myocardial Contractility Through Phospholamban. Circ Res 2024; 134:252-265. [PMID: 38166470 DOI: 10.1161/circresaha.123.323798] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/20/2023] [Indexed: 01/04/2024]
Abstract
BACKGROUND Intracellular Ca2+ cycling determines myocardial contraction and relaxation in response to physiological demands. SERCA2a (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2a) is responsible for the sequestration of cytosolic Ca2+ into intracellular stores during cardiac relaxation, and its activity is reversibly inhibited by PLN (phospholamban). However, the regulatory hierarchy of SERCA2a activity remains unclear. METHODS Cardiomyocyte-specific ZBTB20 knockout mice were generated by crossing ZBTB20flox mice with Myh6-Cre mice. Echocardiography, blood pressure measurements, Langendorff perfusion, histological analysis and immunohistochemistry, quantitative reverse transcription-PCR, Western blot analysis, electrophysiological measurements, and chromatin immunoprecipitation assay were performed to clarify the phenotype and elucidate the molecular mechanisms. RESULTS Specific ablation of ZBTB20 in cardiomyocyte led to a significant increase in basal myocardial contractile parameters both in vivo and in vitro, accompanied by an impairment in cardiac reserve and exercise capacity. Moreover, the cardiomyocytes lacking ZBTB20 showed an increase in sarcoplasmic reticular Ca2+ content and exhibited a remarkable enhancement in both SERCA2a activity and electrically stimulated contraction. Mechanistically, PLN expression was dramatically reduced in cardiomyocytes at the mRNA and protein levels by ZBTB20 deletion or silencing, and PLN overexpression could largely restore the basal contractility in ZBTB20-deficient cardiomyocytes. CONCLUSIONS These data point to ZBTB20 as a fine-tuning modulator of PLN expression and SERCA2a activity, thereby offering new perspective on the regulation of basal contractility in the mammalian heart.
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Affiliation(s)
- An-Jing Ren
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
- Experimental Teaching Center, College of Basic Medical Sciences, Naval Medical University, Shanghai, China (A.-J.R., J.F.)
| | - Chunchun Wei
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Ya-Jin Liu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Institute of Endocrinology and Chu Hsien-I Memorial Hospital, Tianjin Medical University Tianjin, China (Y.-J.L., Y. Zhu, W.J.Z.)
| | - Mengna Liu
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Ping Wang
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Juan Fan
- Experimental Teaching Center, College of Basic Medical Sciences, Naval Medical University, Shanghai, China (A.-J.R., J.F.)
| | - Kai Wang
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Sha Zhang
- Department of Cardiovascular Diseases, Changhai Hospital, Naval Medical University, Shanghai, China (S.Z.)
| | - Zhenbang Qin
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Qiu-Xiao Ren
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Yanjun Zheng
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Laboratory of Molecular Cardiology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, China (Y. Zheng, H.-T.Y.)
| | - Yu-Xia Chen
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
| | - Zhifang Xie
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Institute of Early Life Health, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, China (Z.X.)
| | - Ling Gao
- Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital, Tongji University School of Medicine, China (L.G.)
| | - Yi Zhu
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Institute of Endocrinology and Chu Hsien-I Memorial Hospital, Tianjin Medical University Tianjin, China (Y.-J.L., Y. Zhu, W.J.Z.)
| | - Youyi Zhang
- Institute of Vascular Medicine, National Key Laboratory of Cardiovascular Homeostasis and Remodeling, Peking University Third Hospital, Beijing, China (Y. Zhang)
| | - Huang-Tian Yang
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Laboratory of Molecular Cardiology, Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences, China (Y. Zheng, H.-T.Y.)
| | - Weiping J Zhang
- Department of Pathophysiology, Naval Medical University, Shanghai, China (A.-J.R., C.W., M.L., P.W., K.W., Z.Q., Q.-X.R., Y.-X.C., W.J.Z.)
- NHC Key Laboratory of Hormones and Development, Tianjin Key Laboratory of Metabolic Diseases, Tianjin Institute of Endocrinology and Chu Hsien-I Memorial Hospital, Tianjin Medical University Tianjin, China (Y.-J.L., Y. Zhu, W.J.Z.)
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Hu C, Ma L, Gao S, Yang MY, Mu MD, Chang L, Huang P, Ye X, Wang W, Tao X, Zhou BH, Chen W, Tang KL. PPP1R3A inhibits osteogenesis and negatively regulates intracellular calcium levels in calcific tendinopathy. iScience 2023; 26:107784. [PMID: 37876608 PMCID: PMC10590817 DOI: 10.1016/j.isci.2023.107784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/25/2023] [Accepted: 08/28/2023] [Indexed: 10/26/2023] Open
Abstract
Calcific tendinopathy (CT) is defined by the progressive accumulation of calcium crystals in tendonic regions that results in severe pain in patients. The etiology of CT is not fully elucidated. In this study, we elucidate the role of PPP1R3A in CT. A significant decrease in PPP1R3A expression was observed in CT patient tissues, which was further confirmed in tissues from a CT-induced rat model. Overexpression of PPP1R3A ex vivo reduced the expression of osteo/chondrogenic markers OCN and Sox9, improved tendon tissue architecture, and reduced intracellular Ca2+ levels. Overexpression of SERCA2 and knockdown of Piezo1 decreased expression of osteo/chondrogenic markers and intracellular calcium in PPP1R3A-knockdown tendon cells. Lastly, PPP1R3A expression was regulated at the posttranscriptional level by binding of HuR. Collectively, the present study indicates that PPP1R3A plays an important role in regulating calcium homeostasis in tendon cells via Piezo1/SERCA2, rendering it a promising target for therapeutic interventions of CT.
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Affiliation(s)
- Chao Hu
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
- Department of Orthopedics, 904 Hospital of PLA, Wuxi 214000 Jiangsu, China
| | - Lin Ma
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Shang Gao
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Ming-Yu Yang
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Mi-Duo Mu
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Le Chang
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Pan Huang
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Xiao Ye
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Wei Wang
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Xu Tao
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Bing-Hua Zhou
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Wan Chen
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
| | - Kang-Lai Tang
- Department of Sports Medicine Center, Southwest Hospital, Army Medical University, Chongqing 400000, China
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Papp B, Launay S, Gélébart P, Arbabian A, Enyedi A, Brouland JP, Carosella ED, Adle-Biassette H. Endoplasmic Reticulum Calcium Pumps and Tumor Cell Differentiation. Int J Mol Sci 2020; 21:ijms21093351. [PMID: 32397400 PMCID: PMC7247589 DOI: 10.3390/ijms21093351] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/01/2020] [Accepted: 05/02/2020] [Indexed: 12/21/2022] Open
Abstract
Endoplasmic reticulum (ER) calcium homeostasis plays an essential role in cellular calcium signaling, intra-ER protein chaperoning and maturation, as well as in the interaction of the ER with other organelles. Calcium is accumulated in the ER by sarco/endoplasmic reticulum calcium ATPases (SERCA enzymes) that generate by active, ATP-dependent transport, a several thousand-fold calcium ion concentration gradient between the cytosol (low nanomolar) and the ER lumen (high micromolar). SERCA enzymes are coded by three genes that by alternative splicing give rise to several isoforms, which can display isoform-specific calcium transport characteristics. SERCA expression levels and isoenzyme composition vary according to cell type, and this constitutes a mechanism whereby ER calcium homeostasis is adapted to the signaling and metabolic needs of the cell, depending on its phenotype, its state of activation and differentiation. As reviewed here, in several normal epithelial cell types including bronchial, mammary, gastric, colonic and choroid plexus epithelium, as well as in mature cells of hematopoietic origin such as pumps are simultaneously expressed, whereas in corresponding tumors and leukemias SERCA3 expression is selectively down-regulated. SERCA3 expression is restored during the pharmacologically induced differentiation of various cancer and leukemia cell types. SERCA3 is a useful marker for the study of cell differentiation, and the loss of SERCA3 expression constitutes a previously unrecognized example of the remodeling of calcium homeostasis in tumors.
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Affiliation(s)
- Bela Papp
- Institut National de la Santé et de la Recherche Médicale, UMR U976, Institut Saint-Louis, 75010 Paris, France
- Institut de Recherche Saint-Louis, Hôpital Saint-Louis, Université de Paris, 75010 Paris, France
- CEA, DRF-Institut Francois Jacob, Department of Hemato-Immunology Research, Hôpital Saint-Louis, 75010 Paris, France;
- Correspondence: or
| | - Sophie Launay
- EA481, UFR Santé, Université de Bourgogne Franche-Comté, 25000 Besançon, France;
| | - Pascal Gélébart
- Department of Clinical Science-Hematology Section, Haukeland University Hospital, University of Bergen, 5021 Bergen, Norway;
| | - Atousa Arbabian
- Laboratoire d’Innovation Vaccins, Institut Pasteur de Paris, 75015 Paris, France;
| | - Agnes Enyedi
- Second Department of Pathology, Semmelweis University, 1091 Budapest, Hungary;
| | - Jean-Philippe Brouland
- Institut Universitaire de Pathologie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland;
| | - Edgardo D. Carosella
- CEA, DRF-Institut Francois Jacob, Department of Hemato-Immunology Research, Hôpital Saint-Louis, 75010 Paris, France;
| | - Homa Adle-Biassette
- AP-HP, Service d’Anatomie et Cytologie Pathologiques, Hôpital Lariboisière, 75010 Paris, France;
- Université de Paris, NeuroDiderot, Inserm UMR 1141, 75019 Paris, France
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Sarcoplasmic reticulum and calcium signaling in muscle cells: Homeostasis and disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 350:197-264. [PMID: 32138900 DOI: 10.1016/bs.ircmb.2019.12.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The sarco/endoplasmic reticulum is an extensive, dynamic and heterogeneous membranous network that fulfills multiple homeostatic functions. Among them, it compartmentalizes, stores and releases calcium within the intracellular space. In the case of muscle cells, calcium released from the sarco/endoplasmic reticulum in the vicinity of the contractile machinery induces cell contraction. Furthermore, sarco/endoplasmic reticulum-derived calcium also regulates gene transcription in the nucleus, energy metabolism in mitochondria and cytosolic signaling pathways. These diverse and overlapping processes require a highly complex fine-tuning that the sarco/endoplasmic reticulum provides by means of its numerous tubules and cisternae, specialized domains and contacts with other organelles. The sarco/endoplasmic reticulum also possesses a rich calcium-handling machinery, functionally coupled to both contraction-inducing stimuli and the contractile apparatus. Such is the importance of the sarco/endoplasmic reticulum for muscle cell physiology, that alterations in its structure, function or its calcium-handling machinery are intimately associated with the development of cardiometabolic diseases. Cardiac hypertrophy, insulin resistance and arterial hypertension are age-related pathologies with a common mechanism at the muscle cell level: the accumulation of damaged proteins at the sarco/endoplasmic reticulum induces a stress response condition termed endoplasmic reticulum stress, which impairs proper organelle function, ultimately leading to pathogenesis.
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Wang J, Zhang QJ, Pirolli TJ, Liu ZP, Powell L, Thorp EB, Jessen M, Forbess JM. Cardio-omentopexy Reduces Cardiac Fibrosis and Heart Failure After Experimental Pressure Overload. Ann Thorac Surg 2019; 107:1448-1455. [PMID: 30552887 PMCID: PMC6478504 DOI: 10.1016/j.athoracsur.2018.11.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 11/21/2022]
Abstract
BACKGROUND The pedicled greater omentum has been shown to offer benefit in ischemic heart disease for both animal models and human patients. The impact of cardio-omentopexy in a pressure overload model of left ventricular hypertrophy (LVH) is unknown. METHODS LVH was created in rats by banding the ascending aorta after right thoracotomy (n = 23). Sham surgery was performed in 12 additional rats. Six weeks after banding, surviving LVH rats were assigned to cardio-omentopexy by left thoracotomy (LVH+Om, n = 8) or sham left thoracotomy (LVH, n = 8). Sham rats also underwent left thoracotomy for cardio-omentopexy (Sham+Om, n = 6); the remaining rats underwent sham left thoracotomy (Sham, n = 6). RESULTS Echocardiography 10 weeks after cardio-omentopexy revealed LV end-systolic diameter, cardiomyocyte diamter, and myocardial fibrosis in the LVH group were significantly increased compared with the LVH+Om, Sham+Om, and Sham groups (p < 0.01). LV ejection fraction of the LVH group was lower than the LVH+Om group (p < 0.01). Gene expression analysis revealed significantly lower levels of sarcoendoplasmic reticulum calcium adenosine triphosphatase 2b in LVH rats than in the LVH+Om, Sham+Om, and Sham groups (p < 0.01). In contrast, collagen type 1 α 1 chain, lysyl oxidase-like protein 1, nuclear protein-1, and transforming growth factor- β1 in the LVH group were significantly higher than in the LVH+Om cohort (p < 0.01), consistent with a reduced fibrotic phenotype after omentopexy. Lectin staining showed myocardial capillary density of the LVH group was significantly lower than all other groups (p < 0.01). CONCLUSIONS Cardio-omentopexy reduced cardiac dilation, contractile dysfunction, cardiomyocyte hypertrophy, and myocardial fibrosis, while maintaining other molecular indicators of contractile function in this LVH model.
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Affiliation(s)
- Jian Wang
- Department of Thoracic and Cardiovascular Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Qing-Jun Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Timothy J Pirolli
- Department of Thoracic and Cardiovascular Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Zhi-Ping Liu
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - LaShondra Powell
- Department of Thoracic and Cardiovascular Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Edward B Thorp
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Michael Jessen
- Department of Thoracic and Cardiovascular Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Joseph M Forbess
- Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Division of Cardiovascular-Thoracic Surgery, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois.
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Desmond PF, Labuza A, Muriel J, Markwardt ML, Mancini AE, Rizzo MA, Bloch RJ. Interactions between small ankyrin 1 and sarcolipin coordinately regulate activity of the sarco(endo)plasmic reticulum Ca 2+-ATPase (SERCA1). J Biol Chem 2017; 292:10961-10972. [PMID: 28487373 PMCID: PMC5491780 DOI: 10.1074/jbc.m117.783613] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/08/2017] [Indexed: 11/06/2022] Open
Abstract
SERCA1, the sarco(endo)plasmic reticulum Ca2+-ATPase of skeletal muscle, is essential for muscle relaxation and maintenance of low resting Ca2+ levels in the myoplasm. We recently reported that small ankyrin 1 (sAnk1) interacts with the sarco(endo)plasmic reticulum Ca2+-ATPase in skeletal muscle (SERCA1) to inhibit its activity. We also showed that this interaction is mediated at least in part through sAnk1's transmembrane domain in a manner similar to that of sarcolipin (SLN). Earlier studies have shown that SLN and phospholamban, the other well studied small SERCA-regulatory proteins, oligomerize either alone or together. As sAnk1 is coexpressed with SLN in muscle, we sought to determine whether these two proteins interact with one another when coexpressed exogenously in COS7 cells. Coimmunoprecipitation (coIP) and anisotropy-based FRET (AFRET) assays confirmed this interaction. Our results indicated that sAnk1 and SLN can associate in the sarcoplasmic reticulum membrane and after exogenous expression in COS7 cells in vitro but that their association did not require endogenous SERCA2. Significantly, SLN promoted the interaction between sAnk1 and SERCA1 when the three proteins were coexpressed, and both coIP and AFRET experiments suggested the formation of a complex consisting of all three proteins. Ca2+-ATPase assays showed that sAnk1 ablated SLN's inhibition of SERCA1 activity. These results suggest that sAnk1 interacts with SLN both directly and in complex with SERCA1 and reduces SLN's inhibitory effect on SERCA1 activity.
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Affiliation(s)
- Patrick F Desmond
- From the Department of Physiology and
- Programs in Biochemistry and Molecular Biology
| | - Amanda Labuza
- From the Department of Physiology and
- Neuroscience, and
| | | | | | - Allison E Mancini
- Molecular Medicine, University of Maryland, Baltimore, Maryland 21201
| | - Megan A Rizzo
- From the Department of Physiology and
- Neuroscience, and
- Molecular Medicine, University of Maryland, Baltimore, Maryland 21201
| | - Robert J Bloch
- From the Department of Physiology and
- Programs in Biochemistry and Molecular Biology
- Neuroscience, and
- Molecular Medicine, University of Maryland, Baltimore, Maryland 21201
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Wang Q, Wang D, Yan G, Qiao Y, Sun L, Zhu B, Wang X, Tang C. SERCA2a was serotonylated and may regulate sino-atrial node pacemaker activity. Biochem Biophys Res Commun 2016; 480:492-497. [DOI: 10.1016/j.bbrc.2016.10.082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 10/22/2016] [Indexed: 10/20/2022]
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Li LH, Tian XR, Jiang Z, Zeng LW, He WF, Hu ZP. The Golgi Apparatus: Panel Point of Cytosolic Ca(2+) Regulation. Neurosignals 2016; 21:272-84. [PMID: 23796968 DOI: 10.1159/000350471] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 03/05/2013] [Indexed: 12/21/2022] Open
Abstract
The Golgi apparatus (GA), an intermediate organelle of the cell inner membrane system, plays a key role in protein glycosylation and secretion. In recent years, this organelle has been found to act as a vital intracellular Ca(2+) store because different Ca (2+) regulators, such as the inositol-1,4,5-triphosphate receptor, sarco/endoplasmic reticulum Ca(2+) -ATPase and secretory pathway Ca 2+ -ATPase, were demonstrated to localize on their membrane. The mechanisms involved in Ca(2+) release and uptake in the GA have now been established.Here, based on careful backward looking on compartments and patterns in GA Ca (2+) regulation, we review neurological diseases related to GA calcium remodeling and propose a modified cytosolic Ca(2+) adjustment model, in which GA acts as part of the panel point.
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Affiliation(s)
- Li-Hua Li
- Department of Neurology, Second Xiangya Hospital, Central-South University, Changsha; School of Medicine, Jishou University, Jishou , PR China
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9
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Desmond PF, Muriel J, Markwardt ML, Rizzo MA, Bloch RJ. Identification of Small Ankyrin 1 as a Novel Sarco(endo)plasmic Reticulum Ca2+-ATPase 1 (SERCA1) Regulatory Protein in Skeletal Muscle. J Biol Chem 2015; 290:27854-67. [PMID: 26405035 DOI: 10.1074/jbc.m115.676585] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Indexed: 01/06/2023] Open
Abstract
Small ankyrin 1 (sAnk1) is a 17-kDa transmembrane (TM) protein that binds to the cytoskeletal protein, obscurin, and stabilizes the network sarcoplasmic reticulum in skeletal muscle. We report that sAnk1 shares homology in its TM amino acid sequence with sarcolipin, a small protein inhibitor of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA). Here we investigate whether sAnk1 and SERCA1 interact. Our results indicate that sAnk1 interacts specifically with SERCA1 in sarcoplasmic reticulum vesicles isolated from rabbit skeletal muscle, and in COS7 cells transfected to express these proteins. This interaction was demonstrated by co-immunoprecipitation and an anisotropy-based FRET method. Binding was reduced ~2-fold by the replacement of all of the TM amino acids of sAnk1 with leucines by mutagenesis. This suggests that, like sarcolipin, sAnk1 interacts with SERCA1 at least in part via its TM domain. Binding of the cytoplasmic domain of sAnk1 to SERCA1 was also detected in vitro. ATPase activity assays show that co-expression of sAnk1 with SERCA1 leads to a reduction of the apparent Ca(2+) affinity of SERCA1 but that the effect of sAnk1 is less than that of sarcolipin. The sAnk1 TM mutant has no effect on SERCA1 activity. Our results suggest that sAnk1 interacts with SERCA1 through its TM and cytoplasmic domains to regulate SERCA1 activity and modulate sequestration of Ca(2+) in the sarcoplasmic reticulum lumen. The identification of sAnk1 as a novel regulator of SERCA1 has significant implications for muscle physiology and the development of therapeutic approaches to treat heart failure and muscular dystrophies linked to Ca(2+) misregulation.
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Affiliation(s)
- Patrick F Desmond
- From the Department of Physiology and Program in Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland 21230
| | | | | | | | - Robert J Bloch
- From the Department of Physiology and Program in Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland 21230
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10
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Yang X, Koltes JE, Park CA, Chen D, Reecy JM. Gene co-expression network analysis provides novel insights into myostatin regulation at three different mouse developmental timepoints. PLoS One 2015; 10:e0117607. [PMID: 25695797 PMCID: PMC4335066 DOI: 10.1371/journal.pone.0117607] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 12/29/2014] [Indexed: 12/03/2022] Open
Abstract
Myostatin (Mstn) knockout mice exhibit large increases in skeletal muscle mass. However, relatively few of the genes that mediate or modify MSTN effects are known. In this study, we performed co-expression network analysis using whole transcriptome microarray data from MSTN-null and wild-type mice to identify genes involved in important biological processes and pathways related to skeletal muscle and adipose development. Genes differentially expressed between wild-type and MSTN-null mice were further analyzed for shared DNA motifs using DREME. Differentially expressed genes were identified at 13.5 d.p.c. during primary myogenesis and at d35 during postnatal muscle development, but not at 17.5 d.p.c. during secondary myogenesis. In total, 283 and 2034 genes were differentially expressed at 13.5 d.p.c. and d35, respectively. Over-represented transcription factor binding sites in differentially expressed genes included SMAD3, SP1, ZFP187, and PLAGL1. The use of regulatory (RIF) and phenotypic (PIF) impact factor and differential hubbing co-expression analyses identified both known and potentially novel regulators of skeletal muscle growth, including Apobec2, Atp2a2, and Mmp13 at d35 and Sox2, Tmsb4x, and Vdac1 at 13.5 d.p.c. Among the genes with the highest PIF scores were many fiber type specifying genes. The use of RIF, PIF, and differential hubbing analyses identified both known and potentially novel regulators of muscle development. These results provide new details of how MSTN may mediate transcriptional regulation as well as insight into novel regulators of MSTN signal transduction that merit further study regarding their physiological roles in muscle and adipose development.
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Affiliation(s)
- Xuerong Yang
- Animal Nutrition Institute, Sichuan Agricultural University, Ya’an, Sichuan, China
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
| | - James E. Koltes
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
| | - Carissa A. Park
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
| | - Daiwen Chen
- Animal Nutrition Institute, Sichuan Agricultural University, Ya’an, Sichuan, China
| | - James M. Reecy
- Department of Animal Science, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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Chan YH, Tsai WC, Song Z, Ko CY, Qu Z, Weiss JN, Lin SF, Chen PS, Jones LR, Chen Z. Acute reversal of phospholamban inhibition facilitates the rhythmic whole-cell propagating calcium waves in isolated ventricular myocytes. J Mol Cell Cardiol 2015; 80:126-35. [PMID: 25596331 DOI: 10.1016/j.yjmcc.2014.12.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 12/08/2014] [Accepted: 12/30/2014] [Indexed: 02/01/2023]
Abstract
Phospholamban (PLB) inhibits the activity of cardiac sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a). Phosphorylation of PLB during sympathetic activation reverses SERCA2a inhibition, increasing SR Ca(2+) uptake. However, sympathetic activation also modulates multiple other intracellular targets in ventricular myocytes (VMs), making it impossible to determine the specific effects of the reversal of PLB inhibition on the spontaneous SR Ca(2+) release. Therefore, it remains unclear how PLB regulates rhythmic activity in VMs. Here, we used the Fab fragment of 2D12, a monoclonal anti-PLB antibody, to test how acute reversal of PLB inhibition affects the spontaneous SR Ca(2+) release in normal VMs. Ca(2+) sparks and spontaneous Ca(2+) waves (SCWs) were recorded in the line-scan mode of confocal microscopy using the Ca(2+) fluorescent dye Fluo-4 in isolated permeabilized mouse VMs. Fab, which reverses PLB inhibition, significantly increased the frequency, amplitude, and spatial/temporal spread of Ca(2+) sparks in VMs exposed to 50 nM free [Ca(2+)]. At physiological diastolic free [Ca(2+)] (100-200 nM), Fab facilitated the formation of whole-cell propagating SCWs. At higher free [Ca(2+)], Fab increased the frequency and velocity, but decreased the decay time of the SCWs. cAMP had little additional effect on the frequency or morphology of Ca(2+) sparks or SCWs after Fab addition. These findings were complemented by computer simulations. In conclusion, acute reversal of PLB inhibition alone significantly increased the spontaneous SR Ca(2+) release, leading to the facilitation and organization of whole-cell propagating SCWs in normal VMs. PLB thus plays a key role in subcellular Ca(2+) dynamics and rhythmic activity of VMs.
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Affiliation(s)
- Yi-Hsin Chan
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Linkou, Taoyuan, Taiwan
| | - Wei-Chung Tsai
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung University College of Medicine, Kaohsiung, Taiwan
| | - Zhen Song
- Division of Cardiology, Department of Medicine, University of California, Los Angeles, CA, USA
| | - Christopher Y Ko
- Division of Cardiology, Department of Medicine, University of California, Los Angeles, CA, USA
| | - Zhilin Qu
- Division of Cardiology, Department of Medicine, University of California, Los Angeles, CA, USA
| | - James N Weiss
- Division of Cardiology, Department of Medicine, University of California, Los Angeles, CA, USA
| | - Shien-Fong Lin
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; Institute of Biomedical Engineering, National Chiao-Tung University, Hsin-Chu, Taiwan
| | - Peng-Sheng Chen
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Larry R Jones
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Zhenhui Chen
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
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12
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Locatelli J, de Assis LVM, Isoldi MC. Calcium handling proteins: structure, function, and modulation by exercise. Heart Fail Rev 2014; 19:207-25. [PMID: 23436107 DOI: 10.1007/s10741-013-9373-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Heart failure is a serious public health issue with a growing prevalence, and it is related with the aging of the population. Hypertension is identified as the main precursor of left ventricular hypertrophy and therefore can lead to diastolic dysfunction and heart failure. Scientific studies have confirmed the beneficial effects of the physical exercise by reducing the blood pressure and improving the functional status of the heart in hypertension. Several proteins are involved in the mobilization of calcium during the coupling excitation-contraction process in the heart among those are sarcoplasmic reticulum Ca(2+)-ATPase, phospholamban, calsequestrin, sodium-calcium exchanger, L-type calcium's channel, and ryanodine receptors. Our goal is to address the beneficial effects of exercise on the calcium handling proteins in a heart with hypertension.
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Affiliation(s)
- Jamille Locatelli
- Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Prêto, Brazil
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13
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Loffredo FS, Nikolova AP, Pancoast JR, Lee RT. Heart failure with preserved ejection fraction: molecular pathways of the aging myocardium. Circ Res 2014; 115:97-107. [PMID: 24951760 DOI: 10.1161/circresaha.115.302929] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Age-related diastolic dysfunction is a major factor in the epidemic of heart failure. In patients hospitalized with heart failure, HFpEF is now as common as heart failure with reduced ejection fraction. We now have many successful treatments for heart failure with reduced ejection fraction, while specific treatment options for HFpEF patients remain elusive. The lack of treatments for HFpEF reflects our very incomplete understanding of this constellation of diseases. There are many pathophysiological factors in HFpEF, but aging appears to play an important role. Here, we propose that aging of the myocardium is itself a specific pathophysiological process. New insights into the aging heart, including hormonal controls and specific molecular pathways, such as microRNAs, are pointing to myocardial aging as a potentially reversible process. While the overall process of aging remains mysterious, understanding the molecular pathways of myocardial aging has never been more important. Unraveling these pathways could lead to new therapies for the enormous and growing problem of HFpEF.
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Affiliation(s)
- Francesco S Loffredo
- From the Department of Stem Cell and Regenerative Biology, Harvard University, Brigham Regenerative Medicine Center, Cambridge, MA; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA; and Harvard Stem Cell Institute, Cambridge, MA
| | - Andriana P Nikolova
- From the Department of Stem Cell and Regenerative Biology, Harvard University, Brigham Regenerative Medicine Center, Cambridge, MA; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA; and Harvard Stem Cell Institute, Cambridge, MA
| | - James R Pancoast
- From the Department of Stem Cell and Regenerative Biology, Harvard University, Brigham Regenerative Medicine Center, Cambridge, MA; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA; and Harvard Stem Cell Institute, Cambridge, MA
| | - Richard T Lee
- From the Department of Stem Cell and Regenerative Biology, Harvard University, Brigham Regenerative Medicine Center, Cambridge, MA; Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA; and Harvard Stem Cell Institute, Cambridge, MA.
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14
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Vandecaetsbeek I, Holemans T, Wuytack F, Vangheluwe P. High-throughput measurement of the Ca2+-dependent ATPase activity in COS microsomes. Cold Spring Harb Protoc 2014; 2014:865-75. [PMID: 25086012 DOI: 10.1101/pdb.prot076885] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We provide a detailed procedure to determine the Ca(2+)-dependent ATPase activity in COS or HEK293 cells overexpressing a Ca(2+) pump. The ATPase activity is determined by the Baginsky method, which allows measurement of the steady-state production of inorganic phosphate (Pi). We have adapted this widely applied method into a sensitive, fast, and semi-high-throughput protocol suitable for use in a 96-well plate format.
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Affiliation(s)
- Ilse Vandecaetsbeek
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
| | - Tine Holemans
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
| | - Frank Wuytack
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
| | - Peter Vangheluwe
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
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15
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Holemans T, Vandecaetsbeek I, Wuytack F, Vangheluwe P. Measuring Ca2+-dependent Ca2+-uptake activity in the mouse heart. Cold Spring Harb Protoc 2014; 2014:876-86. [PMID: 25086013 DOI: 10.1101/pdb.prot076893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The apparent Ca(2+) affinity of the isoforms of the sarco/endoplasmic reticulum Ca(2+) ATPase SERCA2 is controlled primarily by two proteins, phospholamban (PLB) and sarcolipin (SLN). The rate of ATP-driven Ca(2+) uptake into sarcoplasmic reticulum (SR)-derived vesicles can be monitored by a technique in which the net uptake of (45)Ca(2+) in the form of an intravesicular calcium oxalate precipitate is recorded. Here, we present details of a modification of such a protocol for determining the apparent Ca(2+) affinity of the Ca(2+) pump, and its control by various regulators, in crude homogenates of mouse heart.
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Affiliation(s)
- Tine Holemans
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
| | - Ilse Vandecaetsbeek
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
| | - Frank Wuytack
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
| | - Peter Vangheluwe
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, KU Leuven, B3000 Leuven, Belgium
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16
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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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17
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Louch WE, Vangheluwe P, Bito V, Raeymaekers L, Wuytack F, Sipido KR. Phospholamban ablation in hearts expressing the high affinity SERCA2b isoform normalizes global Ca²⁺ homeostasis but not Ca²⁺-dependent hypertrophic signaling. Am J Physiol Heart Circ Physiol 2012; 302:H2574-82. [PMID: 22505640 DOI: 10.1152/ajpheart.01166.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiomyocytes from failing hearts exhibit reduced levels of the sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA) and/or increased activity of the endogenous SERCA inhibitor phospholamban. The resulting reduction in the Ca(2+) affinity of SERCA impairs SR Ca(2+) cycling in this condition. We have previously investigated the physiological impact of increasing the Ca(2+) affinity of SERCA by substituting SERCA2a with the higher affinity SERCA2b pump. When phospholamban was also ablated, these double knockouts (DKO) exhibited a dramatic reduction in total SERCA levels, severe hypertrophy, and diastolic dysfunction. We presently examined the role of cardiomyocyte Ca(2+) homeostasis in both functional and structural remodeling in these hearts. Despite the low SERCA levels in DKO, we observed near-normal Ca(2+) homeostasis with rapid Ca(2+) reuptake even at high Ca(2+) loads and stimulation frequencies. Well-preserved global Ca(2+) homeostasis in DKO was paradoxically associated with marked activation of the Ca(2+)-dependent nuclear factor of activated T-cell-calcineurin pathway known to trigger hypertrophy. No activation of the MAP kinase signaling pathway was detected. These findings suggest that local changes in Ca(2+) homeostasis may play an important signaling role in DKO, perhaps due to reduced microdomain Ca(2+) buffering by SERCA2b. Furthermore, alterations in global Ca(2+) homeostasis can also not explain impaired in vivo diastolic function in DKO. Taken together, our results suggest that normalizing global cardiomyocyte Ca(2+) homeostasis does not necessarily protect against hypertrophy and heart failure development and that excessively increasing SERCA Ca(2+) affinity may be detrimental.
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Affiliation(s)
- William E Louch
- Laboratory for Experimental Cardiology, University of Leuven, Leuven, Belgium
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18
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Improving cardiac Ca⁺² transport into the sarcoplasmic reticulum in heart failure: lessons from the ubiquitous SERCA2b Ca⁺² pump. Biochem Soc Trans 2011; 39:781-7. [PMID: 21599649 DOI: 10.1042/bst0390781] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As a major Ca2+ pump in the sarcoplasmic reticulum of the cardiomyocyte, SERCA2a (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 2a) controls the relaxation and contraction of the cardiomyocyte. It is meticulously regulated by adapting its expression levels and affinity for Ca2+ ions to the physiological demand of the heart. Dysregulation of the SERCA2a activity entails poor cardiomyocyte contractility, resulting in heart failure. Conversely, improving cardiac SERCA2a activity, e.g. by boosting its expression level or by increasing its affinity for Ca2+, is a promising strategy to rescue contractile dysfunction of the failing heart. The structures of the related SERCA1a Ca2+ pump and the Na+/K+-ATPase of the plasma membrane exposed the pumping mechanism and conserved domain architecture of these ion pumps. However, how the Ca2+ affinity of SERCA2a is regulated at the molecular level remained unclear. A structural and functional analysis of the closely related SERCA2b Ca2+ pump, i.e. the housekeeping Ca2+ pump found in the endoplasmic reticulum and the only SERCA isoform characterized by a high Ca2+ affinity, aimed to fill this gap. We demonstrated the existence of a novel and highly conserved site on the SERCA2 pump mediating Ca2+ affinity regulation by the unique C-terminus of SERCA2b (2b-tail). It differs from the earlier-described target site of the affinity regulator phospholamban. Targeting this novel site may provide a new approach to improve SERCA2a function in the failing heart. Strikingly, the intramembrane interaction site of the 2b-tail in SERCA2b shares sequence and structural homology with the binding site of the β-subunit on the α Na+/K+-ATPase. Thus P-type ATPases seem to have developed related mechanisms of regulation, and it is a future challenge for us to discover these general principles of P-type regulation.
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19
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Raeymaekers L, Vandecaetsbeek I, Wuytack F, Vangheluwe P. Modeling Ca2+ dynamics of mouse cardiac cells points to a critical role of SERCA's affinity for Ca2+. Biophys J 2011; 100:1216-25. [PMID: 21354394 DOI: 10.1016/j.bpj.2011.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 01/14/2011] [Indexed: 11/19/2022] Open
Abstract
The SERCA2a isoform of the sarco/endoplasmic reticulum Ca(2+) pumps is specifically expressed in the heart, whereas SERCA2b is the ubiquitously expressed variant. It has been shown previously that replacement of SERCA2a by SERCA2b in mice (SERCA2(b/b) mice) results in only a moderate functional impairment, whereas SERCA activity is decreased by a 40% lower SERCA protein expression and by increased inhibition by phospholamban. To find out whether the documented kinetic differences in SERCA2b relative to SERCA2a (i.e., a twofold higher apparent Ca(2+) affinity, but twofold lower maximal turnover rate) can explain these compensatory changes, we simulated Ca(2+) dynamics in mouse ventricular myocytes. The model shows that the relative Ca(2+) transport capacity of SERCA2a and SERCA2b depends on the SERCA concentration. The simulations point to a dominant effect of SERCA2b's higher Ca(2+) affinity over its lower maximal turnover rate. The results suggest that increased systolic and decreased diastolic Ca(2+) levels in unstimulated conditions could contribute to the downregulation of SERCA in SERCA2(b/b) mice. In stress conditions, Ca(2+) handling is less efficient by SERCA2b than by SERCA2a, which might contribute to the observed hypertrophy in SERCA2(b/b) mice. Altogether, SERCA2a might be a better compromise between performance in basal conditions and performance during β-adrenergic stress.
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Affiliation(s)
- Luc Raeymaekers
- Laboratory of Cellular Transport Systems, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Campus Gasthuisberg, Leuven, Belgium.
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20
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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: 154] [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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21
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Thapsigargin affinity purification of intracellular P2A-type Ca2+ ATPases. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1118-27. [DOI: 10.1016/j.bbamcr.2010.12.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/22/2010] [Accepted: 12/23/2010] [Indexed: 11/23/2022]
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22
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Abstract
RNA viruses are the champions of evolution due to high frequency mutations and genetic recombination occurring during virus replication. These genetic events are due to the error-prone nature of viral RNA-dependent RNA polymerases (RdRp). Recently emerging models on viral RNA recombination, however, also include key roles for host and environmental factors. Accordingly, genome-wide screens and global proteomics approaches with Tomato bushy stunt virus (TBSV) and yeast (Saccharomyces cerevisiae) as a model host have identified 38 host proteins affecting viral RNA recombination. Follow-up studies have identified key host proteins and cellular pathways involved in TBSV RNA recombination. In addition, environmental factors, such as salt stress, have been shown to affect TBSV recombination via influencing key host or viral factors involved in the recombination process. These advances will help build more accurate models on viral recombination, evolution, and adaptation.
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23
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Shanmugam M, Gao S, Hong C, Fefelova N, Nowycky MC, Xie LH, Periasamy M, Babu GJ. Ablation of phospholamban and sarcolipin results in cardiac hypertrophy and decreased cardiac contractility. Cardiovasc Res 2010; 89:353-61. [PMID: 20833651 DOI: 10.1093/cvr/cvq294] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
AIMS Improving the sarco(endo)plasmic reticulum (SR) Ca(2+)-ATPase (SERCA) function has clinical implications in treating heart failure. The present study aimed to determine the effect of constitutive activation of the SERCA pump on cardiac contractility in normal mice and during pressure-overload-induced cardiac hypertrophy. METHODS AND RESULTS The SERCA pump was constitutively activated in both atrial and ventricular chambers of the mouse heart by ablating its key regulators, phospholamban (PLN) and sarcolipin (SLN). The double-knockout (dKO) mice for PLN and SLN showed increased SERCA pump activity, Ca(2+) transients and SR Ca(2+) load, and developed cardiac hypertrophy. Echocardiographic measurements showed that the basal cardiac function was not affected in the young dKO mice. However, the cardiac function worsened upon ageing and when subjected to pressure overload. CONCLUSION Our studies suggest that the constitutive activation of the SERCA pump is detrimental to cardiac function. Our findings also emphasize the need for dynamic regulation of the SERCA pump by PLN and/or SLN to maintain cardiac contractility in normal conditions and during pathophysiological states.
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Affiliation(s)
- Mayilvahanan Shanmugam
- Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, 185 South Orange Avenue, MSB, G609, Newark, NJ 07103, USA
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24
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Serra AJ, Santos MHH, Bocalini DS, Antônio EL, Levy RF, Santos AA, Higuchi ML, Silva JA, Magalhães FC, Baraúna VG, Krieger JE, Tucci PJF. Exercise training inhibits inflammatory cytokines and more than prevents myocardial dysfunction in rats with sustained beta-adrenergic hyperactivity. J Physiol 2010; 588:2431-42. [PMID: 20442263 DOI: 10.1113/jphysiol.2010.187310] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Myocardial hypertrophy and dysfunction occur in response to excessive catecholaminergic drive. Adverse cardiac remodelling is associated with activation of proinflammatory cytokines in the myocardium. To test the hypothesis that exercise training can prevent myocardial dysfunction and production of proinflammatory cytokines induced by beta-adrenergic hyperactivity, male Wistar rats were assigned to one of the following four groups: sedentary non-treated (Con); sedentary isoprenaline treated (Iso); exercised non-treated (Ex); and exercised plus isoprenaline (Iso+Ex). Echocardiography, haemodynamic measurements and isolated papillary muscle were used for functional evaluations. Real-time RT-PCR and Western blot were used to quantify tumour necrosis factor alpha, interleukin-6, interleukin-10 and transforming growth factor beta(1) (TGF-beta(1)) in the tissue. NF-B expression in the nucleus was evaluated by immunohistochemical staining. The Iso rats showed a concentric hypertrophy of the left ventricle (LV). These animals exhibited marked increases in LV end-diastolic pressure and impaired myocardial performance in vitro, with a reduction in the developed tension and maximal rate of tension increase and decrease, as well as worsened recruitment of the Frank-Starling mechanism. Both gene and protein levels of tumour necrosis factor alpha and interleukin-6, as well as TGF-beta(1) mRNA, were increased. In addition, the NF-B expression in the Iso group was significantly raised. In the Iso+Ex group, the exercise training had the following effects: (1) it prevented LV hypertrophy; (ii) it improved myocardial contractility; (3) it avoided the increase of proinflammatory cytokines and improved interleukin-10 levels; and (4) it attenuated the increase of TGF-beta(1) mRNA. Thus, exercise training in a model of beta-adrenergic hyperactivity can avoid the adverse remodelling of the LV and inhibit inflammatory cytokines. Moreover, the cardioprotection is related to beneficial effects on myocardial performance.
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Affiliation(s)
- Andrey J Serra
- Department of Medicine, Cardiology Division, Federal University of São Paulo, (UNIFESP), São Paulo, SP, Brazil.
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25
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Dally S, Corvazier E, Bredoux R, Bobe R, Enouf J. Multiple and diverse coexpression, location, and regulation of additional SERCA2 and SERCA3 isoforms in nonfailing and failing human heart. J Mol Cell Cardiol 2010; 48:633-44. [DOI: 10.1016/j.yjmcc.2009.11.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 11/02/2009] [Accepted: 11/22/2009] [Indexed: 11/27/2022]
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27
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Jaag HM, Pogany J, Nagy PD. A host Ca2+/Mn2+ ion pump is a factor in the emergence of viral RNA recombinants. Cell Host Microbe 2010; 7:74-81. [PMID: 20114029 DOI: 10.1016/j.chom.2009.12.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 10/16/2009] [Accepted: 12/21/2009] [Indexed: 10/19/2022]
Abstract
Viruses change rapidly due to genetic mutations, and viral RNA recombination in RNA viruses can lead to the emergence of drug-resistant or highly virulent strains. Here, we report that host Pmr1p, an ion pump that controls Ca2+/Mn2+ influx into the Golgi from the cytosol, affects the frequency of viral RNA recombination and the efficiency of replication. Inactivation of PMR1 leads to an approximately 160-fold increase in RNA recombination of Tomato bushy stunt virus (TBSV) in yeast, a model host. Expression of separation-of-function mutants of Pmr1p reveals that the ability of Pmr1p to control the Mn2+ concentration in the cytosol is a key factor in viral RNA recombination. Indeed, a high Mn2+ concentration in a cell-free TBSV replication system increases the recombination frequency, and knockdown of Ca2+/Mn2+ exporters in plants increases virus replication and RNA recombination. Thus, a conserved host protein could affect the adaptive evolution of RNA viruses.
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Affiliation(s)
- Hannah M Jaag
- Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546, USA
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28
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Lipskaia L, Chemaly ER, Hadri L, Lompre AM, Hajjar RJ. Sarcoplasmic reticulum Ca(2+) ATPase as a therapeutic target for heart failure. Expert Opin Biol Ther 2010; 10:29-41. [PMID: 20078230 PMCID: PMC3001226 DOI: 10.1517/14712590903321462] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The cardiac isoform of the sarco/endoplasmic reticulum Ca(2+)ATPase (SERCA2a) plays a major role in controlling excitation/contraction coupling. In both experimental and clinical heart failure, SERCA2a expression is significantly reduced which leads to abnormal Ca(2+) handling and deficient contractility. A large number of studies in isolated cardiac myocytes and in small and large animal models of heart failure showed that restoring SERCA2a expression by gene transfer corrects the contractile abnormalities and improves energetics and electrical remodeling. Following a long line of investigation, a clinical trial is underway to restore SERCA2a expression in patients with heart failure using adeno-associated virus type 1. This review addresses the following issues regarding heart failure gene therapy: i) new insights on calcium regulation by SERCA2a; ii) SERCA2a as a gene therapy target in animal models of heart failure; iii) advances in the development of viral vectors and gene delivery; and iv) clinical trials on heart failure using SERCA2a. This review focuses on the new advances in SERCA2a- targeted gene therapy made in the last three years. In conclusion, SERCA2a is an important therapeutic target in various cardiovascular disorders. Ongoing clinical gene therapy trials will provide answers on its safety and applicability.
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Affiliation(s)
- Larissa Lipskaia
- Cardiovascular Research Center, Mount Sinai School of Medicine, New York, NY 10029, USA
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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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30
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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: 54] [Impact Index Per Article: 3.6] [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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Vangheluwe P, Sepúlveda MR, Missiaen L, Raeymaekers L, Wuytack F, Vanoevelen J. Intracellular Ca2+- and Mn2+-Transport ATPases. Chem Rev 2009; 109:4733-59. [DOI: 10.1021/cr900013m] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Peter Vangheluwe
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - M. Rosario Sepúlveda
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Ludwig Missiaen
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Luc Raeymaekers
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Frank Wuytack
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Jo Vanoevelen
- Laboratory of Ca2+-transport ATPases and Laboratory of Molecular and Cellular Signaling, Department of Molecular Cell Biology, Katholieke Universiteit Leuven, Leuven, Belgium
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Bupha-Intr T, Laosiripisan J, Wattanapermpool J. Moderate intensity of regular exercise improves cardiac SR Ca2+ uptake activity in ovariectomized rats. J Appl Physiol (1985) 2009; 107:1105-12. [PMID: 19679745 DOI: 10.1152/japplphysiol.00407.2009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The impact of regular exercise in protecting cardiac deteriorating results of female sex hormone deprivation was evaluated by measuring changes in intracellular Ca2+ removal activity of sarcoplasmic reticulum (SR) in ovariectomized rats following 9-wk treadmill running exercise at moderate intensity. Despite induction of cardiac hypertrophy in exercised groups of both sham-operated and ovariectomized rats, exercise training had no effect on SR Ca2+ uptake and SR Ca(2+)-ATPase (SERCA) in hormone intact rat heart. However, exercise training normalized the suppressed maximum SR Ca2+ uptake and SERCA activity in ovariectomized rat heart. While exercise training normalized the leftward shift in pCa (-log[Ca2+])-SR Ca2+ uptake relation in ovariectomized rats, no effect was detected in exercised sham-operated rats. Similar phenomena were also observed on SERCA and on phospholamban (PLB) phosphorylation levels; exercise training in ovariectomized rats enhanced SERCA expression to reach the level as that in sham-operated rats, in which there were no differences in SERCA and phospho-PLB levels between sedentary and exercised groups. In addition, the reduction in phospho-Thr(17) PLB in myocardium of ovariectomized rats was abolished by exercise training. These results showed that regular exercise maintains the molecular activation of cardiac SR Ca2+ uptake under normal physiological conditions and is able to induce a protective impact on cardiac SR Ca2+ uptake in ovarian sex hormone-deprived status.
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Affiliation(s)
- Tepmanas Bupha-Intr
- Department of Physiology, Faculty of Science, Mahidol Univ., Rama 6 Road, Bangkok 10400, Thailand
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O'Donnell JM, Fields A, Xu X, Chowdhury SAK, Geenen DL, Bi J. Limited functional and metabolic improvements in hypertrophic and healthy rat heart overexpressing the skeletal muscle isoform of SERCA1 by adenoviral gene transfer in vivo. Am J Physiol Heart Circ Physiol 2008; 295:H2483-94. [PMID: 18952713 DOI: 10.1152/ajpheart.01023.2008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adenoviral gene transfer of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a to the hypertrophic heart in vivo has been consistently reported to lead to enhanced myocardial contractility. It is unknown if the faster skeletal muscle isoform, SERCA1, expressed in the whole heart in early failure, leads to similar improvements and whether metabolic requirements are maintained during an adrenergic challenge. In this study, Ad.cmv.SERCA1 was delivered in vivo to aortic banded and sham-operated Sprague-Dawley rat hearts. The total SERCA content increased 34%. At 48-72 h posttransfer, echocardiograms were acquired, hearts were excised and retrograded perfused, and hemodynamics were measured parallel to NMR measures of the phosphocreatine (PCr)-to-ATP ratio (PCr/ATP) and energy substrate selection at basal and high workloads (isoproterenol). In the Langendorff mode, the rate-pressure product was enhanced 27% with SERCA1 in hypertrophic hearts and 10% in shams. The adrenergic response to isoproterenol was significantly potentiated in both groups with SERCA1. 31P NMR analysis of PCr/ATP revealed that the ratio remained low in the hypertrophic group with SERCA1 overexpression and was not further compromised with adrenergic challenge. 13C NMR analysis revealed fat and carbohydrate oxidation were unaffected at basal with SERCA1 expression; however, there was a shift from fats to carbohydrates at higher workloads with SERCA1 in both groups. Transport of NADH-reducing equivalents into the mitochondria via the alpha-ketoglutamate-malate transporter was not affected by either SERCA1 overexpression or adrenergic challenge in both groups. Echocardiograms revealed an important distinction between in vivo versus ex vivo data. In contrast to previous SERCA2a studies, the echocardiogram data revealed that SERCA1 expression compromised function (fractional shortening) in the hypertrophic group. Shams were unaffected. While our ex vivo findings support much of the earlier cardiomyocyte and transgenic data, the in vivo data challenge previous reports of improved cardiac function in heart failure models after SERCA intervention.
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Affiliation(s)
- J Michael O'Donnell
- Department of Physiology and Biophysics M/C 901 College of Medicine, University of Illinois, 835 S. Wolcott Ave., Chicago, IL 60612, USA.
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Compartmentalized expression of three novel sarco/endoplasmic reticulum Ca2+ATPase 3 isoforms including the switch to ER stress, SERCA3f, in non-failing and failing human heart. Cell Calcium 2008; 45:144-54. [PMID: 18947868 DOI: 10.1016/j.ceca.2008.08.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 08/04/2008] [Indexed: 11/24/2022]
Abstract
The human sarco/endoplasmic reticulum (ER) Ca(2+)ATPase 3 (SERCA3) gene gives rise to SERCA3a-3f isoforms, the latter inducing ER stress in vitro. Here, we first demonstrated the co-expression of SERCA3a, -3d and -3f proteins in the heart. Evidence for endogenous proteins was obtained by using isoform-specific antibodies including a new SERCA3d-specific antibody, and either Western blotting of protein lysates or immunoprecipitation of membrane proteins. An immunolocalization study of both left ventricle tissue and isolated cardiomyocytes showed a distinct compartmentalization of the SERCA3 isoforms, as a uniform distribution of SERCA3a was detected while -3d and -3f isoforms were observed around the nucleus and in close vicinity of plasma membrane, respectively. Second, we studied their expressions in failing hearts including mixed (MCM) (n=1) and idiopathic dilated (IDCM) cardiomyopathies (n=4). Compared with controls (n=5), similar expressions of SERCA3a and -3d mRNAs were observed in all patients. In contrast, SERCA3f mRNA was found to be up-regulated in failing hearts (125+/-7%). Remarkably, overexpression of SERCA3f paralleled an increase in ER stress markers including processing of X-box-binding protein-1 (XBP-1) mRNA (176+/-24%), and expression of XBP-1 protein and glucose-regulated protein (GRP)78 (232+/-21%). These findings revisit the human heart's Ca(2+)ATPase system and indicate that SERCA3f may account for the mechanism of ER stress in vivo in heart failure.
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35
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Rocchetti M, Alemanni M, Mostacciuolo G, Barassi P, Altomare C, Chisci R, Micheletti R, Ferrari P, Zaza A. Modulation of Sarcoplasmic Reticulum Function by PST2744 [Istaroxime; (E,Z)-3-((2-Aminoethoxy)imino) Androstane-6,17-dione Hydrochloride)] in a Pressure-Overload Heart Failure Model. J Pharmacol Exp Ther 2008; 326:957-65. [DOI: 10.1124/jpet.108.138701] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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36
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Ikeda Y, Hoshijima M, Chien KR. Toward biologically targeted therapy of calcium cycling defects in heart failure. Physiology (Bethesda) 2008; 23:6-16. [PMID: 18268360 DOI: 10.1152/physiol.00033.2007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A growing body of evidence indicates that heart failure progression is tightly associated with dysregulation of phosphorylation of Ca2+ regulators localized in the sub-cellular microdomain of the sarcoplasmic reticulum. Chemical or genetic correction of abnormalities in cardiac phosphorylation cascades is emerging as a potential target in the treatment of heart failure. Here, we review how specific kinases and phosphatases finely tune Ca2+ cycling and regulate excitation-contraction (E-C) coupling in cardiomyocytes.
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Affiliation(s)
- Yasuhiro Ikeda
- Department of Molecular Cardiovascular Biology, Yamaguchi University School of Medicine, Ube, Japan.
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37
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Ottenheijm CAC, Fong C, Vangheluwe P, Wuytack F, Babu GJ, Periasamy M, Witt CC, Labeit S, Granzier H. Sarcoplasmic reticulum calcium uptake and speed of relaxation are depressed in nebulin-free skeletal muscle. FASEB J 2008; 22:2912-9. [PMID: 18434434 DOI: 10.1096/fj.07-104372] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previous work suggested that altered Ca(2+) homeostasis might contribute to dysfunction of nebulin-free muscle, as gene expression analysis revealed that the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)-inhibitor sarcolipin (SLN) is up-regulated >70-fold in nebulin knockout mice, and here we tested this proposal. We investigated SLN protein expression in nebulin-free and wild-type skeletal muscle, as well as expression of other Ca(2+)-handling proteins. Ca(2+) uptake capacity was determined in isolated sarcoplasmic reticulum vesicles and in intact myofibers by measuring Ca(2+) transients. Muscle contractile performance was determined in skinned muscle activated with exogenous Ca(2+), as well as in electrically stimulated intact muscle. We found profound up-regulation of SLN protein in nebulin-free skeletal muscle, whereas expression of other Ca(2+)-handling proteins was not (calsequestrin and phospholamban) or was minimally (SERCA) affected. Speed of Ca(2+) uptake was >3-fold decreased in sarcoplasmic reticulum vesicles isolated from nebulin-free muscle as well as in nebulin-free intact myofibers. Ca(2+)-activated stress in skinned muscle and stress produced by intact nebulin-free muscle were reduced to a similar extent compared with wild type. Half-relaxation time was significantly longer in nebulin-free compared with wild-type muscle. Thus, the present study demonstrates for the first time that nebulin might also be involved in physiological Ca(2+) handling of the SR-myofibrillar system.
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Affiliation(s)
- Coen A C Ottenheijm
- Dept. of Molecular and Cellular Biology, University of Arizona, PO Box 245217, Tucson, AZ 85724, USA
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38
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Role of sarco/endoplasmic reticulum calcium content and calcium ATPase activity in the control of cell growth and proliferation. Pflugers Arch 2008; 457:673-85. [PMID: 18188588 DOI: 10.1007/s00424-007-0428-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 12/11/2007] [Indexed: 12/11/2022]
Abstract
Ca(2+), the main second messenger, is central to the regulation of cellular growth. There is increasing evidence that cellular growth and proliferation are supported by a continuous store-operated Ca(2+) influx. By controlling store refilling, the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) also controls store-operated calcium entry and, thus, cell growth. In this review, we discuss data showing the involvement of SERCA in the regulation of proliferation and hypertrophy. First, we describe the Ca(2+)-related signaling pathways involved in cell growth. Then, we present evidence that SERCA controls proliferation of differentiated cells and hypertrophic growth of cardiomyocytes, and discuss the role of SERCA isoforms. Last, we consider the potential therapeutic applications of increasing SERCA activity for the treatment of cardiovascular diseases and of modulating SERCA and SR content for the treatment of cancer.
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39
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Inesi G, Prasad AM, Pilankatta R. The Ca2+ ATPase of cardiac sarcoplasmic reticulum: Physiological role and relevance to diseases. Biochem Biophys Res Commun 2007; 369:182-7. [PMID: 18068669 DOI: 10.1016/j.bbrc.2007.11.161] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Accepted: 11/22/2007] [Indexed: 01/24/2023]
Abstract
The Ca(2+) ATPase of sarcoplasmic reticulum has a prominent role in excitation/contraction coupling of cardiac muscle, as it induces relaxation by sequestering Ca(2+) from the cytoplasm. The stored Ca(2+) is in turn released to trigger contraction. We review here experiments demonstrating that in cardiac myocytes Ca(2+) signaling and contractile activation are strongly altered by pharmacological inhibition or transcriptional down-regulation of SERCA. On the other hand, kinetics, and intensity of Ca(2+) signaling are improved by SERCA overexpression following delivery of exogenous cDNA by adenovirus vectors. Experiments on adrenergic hypertrophy demonstrate SERCA down-regulation, consistent with its pathogenetic involvement in cardiac hypertrophy and failure, as also shown in other experimental models and clinical studies. Compensation by alternate Ca(2+) signaling proteins, including functional activation and increased expression of Na(+)/Ca(2+) exchanger and TRPC proteins has been observed. These compensatory mechanisms, including calcineurin activation, remain to be clarified and are a most important subject of current studies.
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Affiliation(s)
- Giuseppe Inesi
- California Pacific Medical Center Research Institute, 475 Brannan Street, San Francisco, CA 94107, USA
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40
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Vangheluwe P, Schuermans M, Raeymaekers L, Wuytack F. Tight interplay between the Ca2+ affinity of the cardiac SERCA2 Ca2+ pump and the SERCA2 expression level. Cell Calcium 2007; 42:281-9. [PMID: 17306367 DOI: 10.1016/j.ceca.2007.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Revised: 11/27/2006] [Indexed: 10/23/2022]
Abstract
A reduced activity of the sarcoplasmic reticulum Ca2+ pump SERCA2a is a hallmark of cardiac dysfunction in heart failure. In SERCA2b/b mice, the normal SERCA2a isoform is replaced by SERCA2b, displaying a higher Ca2+ affinity. This elicited decreased cardiac SERCA2 expression and cardiac hypertrophy. Here, the interplay was studied between the increased Ca2+ affinity and a reduced expression of the pump and its role in the cardiac remodeling was investigated. First, SERCA2b/b mice were crossed with SERCA2b transgenes to boost cardiac SERCA2b expression. However, the enforced expression of SERCA2b was spontaneously countered by an increased inhibition by phospholamban (PLB), reducing the pump's Ca2+ affinity. Moreover, the higher SERCA2 content did not prevent hypertrophy. Second, we studied heterozygous SERCA2b/WT mice, which also express lower SERCA2 levels compared to wild-type. Hypertrophy was not observed. In heterozygotes, SERCA2b expression was specifically suppressed, explaining the reduced SERCA2 content. The SERCA2b/WT model strikingly differs from the homozygote models because SERCA2a (not SERCA2b) is the major isoform and because the inhibition of the pump by PLB is decreased instead of being increased. Thus, a tight correlation exists between the SERCA2 levels and Ca2+ affinity (controlled by PLB). This compensatory response may be important to prevent cardiac remodeling.
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Affiliation(s)
- Peter Vangheluwe
- Laboratory of Physiology, University of Leuven, Herestraat 49, Bus 802 B-3000 Leuven, Belgium
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41
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Mørk HK, Sjaastad I, Sande JB, Periasamy M, Sejersted OM, Louch WE. Increased cardiomyocyte function and Ca2+ transients in mice during early congestive heart failure. J Mol Cell Cardiol 2007; 43:177-86. [PMID: 17574269 DOI: 10.1016/j.yjmcc.2007.05.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 03/30/2007] [Accepted: 05/09/2007] [Indexed: 10/23/2022]
Abstract
End-stage heart failure is believed to involve depressed cardiomyocyte contractility and Ca2+ transients. However, the time course of these alterations is poorly understood. We examined alterations in myocyte excitation-contraction coupling in a mouse model of early congestive heart failure (CHF) following myocardial infarction. One week after myocardial infarction was induced by ligation of the left coronary artery, CHF mice were selected based on established criteria (increased left atrial diameter, increased lung weight). Sham-operated animals (SHAM) served as controls. Echocardiographic measurements showed decreased global function in early CHF relative to SHAM, but increased local function in viable regions of the myocardium which deteriorated with time. Cardiomyocytes isolated from the non-infarcted septum also exhibited larger contractions in early CHF than SHAM (CHF=219.6+/-15.3% of SHAM values, P<0.05; 1 Hz field stimulation), and relaxation was more rapid (time to 50% relaxation=82.9+/-5.5% of SHAM values, P<0.05). Ca2+ transients (fluo-4 AM) were larger and decayed more rapidly in CHF than SHAM during both field stimulation (1 Hz) and voltage-clamp steps. Sarcoplasmic reticulum (SR) Ca2+ content was increased. Western blots showed that while SR Ca2+ ATPase (SERCA) expression was unaltered in CHF, phospholamban (PLB) was downregulated (60+/-11% of SHAM values, P<0.05). Thus, an increased SERCA/PLB ratio in CHF may promote SR Ca2+ re-uptake. Additionally, peak L-type Ca2+ current and Na+/Ca2+ exchanger expression were increased in CHF, suggesting increased sarcolemmal Ca2+ flux. Thus, in early CHF, alterations in Ca2+ homeostasis improve cardiomyocyte contractility which may compensate for loss of function in the infarction area.
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Affiliation(s)
- Halvor K Mørk
- Institute for Experimental Medical Research, Ullevaal University Hospital, Oslo, Norway.
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42
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Stenoien DL, Knyushko TV, Londono MP, Opresko LK, Mayer MU, Brady ST, Squier TC, Bigelow DJ. Cellular trafficking of phospholamban and formation of functional sarcoplasmic reticulum during myocyte differentiation. Am J Physiol Cell Physiol 2007; 292:C2084-94. [PMID: 17287364 DOI: 10.1152/ajpcell.00523.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholamban (PLB) associates with the Ca(2+)-ATPase in sarcoplasmic reticulum (SR) membranes to permit the modulation of contraction in response to beta-adrenergic signaling. To understand how coordinated changes in the abundance and intracellular trafficking of PLB and the Ca(2+)-ATPase contribute to the maturation of functional muscle, we measured changes in abundance, location, and turnover of endogenous and tagged proteins in myoblasts and during their differentiation. We found that PLB is constitutively expressed in both myoblasts and differentiated myotubes, whereas abundance increases of the Ca(2+)-ATPase coincide with the formation of differentiated myotubes. We observed that PLB is primarily present in highly mobile vesicular structures outside the endoplasmic reticulum, irrespective of the expression of the Ca(2+)-ATPase, indicating that PLB targeting is regulated through vesicle trafficking. Moreover, using pulse-chase methods, we observed that in myoblasts, PLB is trafficked through directed transport through the Golgi to the plasma membrane before endosome-mediated internalization. The observed trafficking of PLB to the plasma membrane suggests an important role for PLB during muscle differentiation, which is distinct from its previously recognized role in the regulation of the Ca(2+)-ATPase.
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Affiliation(s)
- David L Stenoien
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA
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44
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Vangheluwe P, Sipido KR, Raeymaekers L, Wuytack F. New perspectives on the role of SERCA2's Ca2+ affinity in cardiac function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1216-28. [PMID: 17005265 DOI: 10.1016/j.bbamcr.2006.08.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Accepted: 08/10/2006] [Indexed: 11/21/2022]
Abstract
Cardiomyocyte relaxation and contraction are tightly controlled by the activity of the cardiac sarco(endo)plasmic reticulum (SR) Ca2+ transport ATPase (SERCA2a). The SR Ca2+ -uptake activity not only determines the speed of Ca(2+) removal during relaxation, but also the SR Ca2+ content and therefore the amount of Ca2+ released for cardiomyocyte contraction. The Ca2+ affinity is the major determinant of the pump's activity in the physiological Ca2+ concentration range. In the heart, the affinity of the pump for Ca2+ needs to be controlled between narrow borders, since an imbalanced affinity may evoke hypertrophic cardiomyopathy. Several small proteins (phospholamban, sarcolipin) adjust the Ca2+ affinity of the pump to the physiological needs of the cardiomyocyte. It is generally accepted that a chronically reduced Ca2+ affinity of the pump contributes to depressed SR Ca2+ handling in heart failure. Moreover, a persistently lower Ca2+ affinity is sufficient to impair cardiomyocyte SR Ca2+ handling and contractility inducing dilated cardiomyopathy in mice and humans. Conversely, the expression of SERCA2a, a pump with a lower Ca2+ affinity than the housekeeping isoform SERCA2b, is crucial to maintain normal cardiac function and growth. Novel findings demonstrated that a chronically increased Ca2+ affinity also may trigger cardiac hypertrophy in mice and humans. In addition, recent studies suggest that some models of heart failure are marked by a higher affinity of the pump for Ca2+, and hence by improved cardiomyocyte relaxation and contraction. Depressed cardiomyocyte SR Ca2+ uptake activity may therefore not be a universal hallmark of heart failure.
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Affiliation(s)
- P Vangheluwe
- Laboratory of Physiology, University of Leuven, Herestraat 49, bus 802, B-3000 Leuven, Belgium.
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