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Fan W, Sun X, Yang C, Wan J, Luo H, Liao B. Pacemaker activity and ion channels in the sinoatrial node cells: MicroRNAs and arrhythmia. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 177:151-167. [PMID: 36450332 DOI: 10.1016/j.pbiomolbio.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/13/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022]
Abstract
The primary pacemaking activity of the heart is determined by a spontaneous action potential (AP) within sinoatrial node (SAN) cells. This unique AP generation relies on two mechanisms: membrane clocks and calcium clocks. Nonhomologous arrhythmias are caused by several functional and structural changes in the myocardium. MicroRNAs (miRNAs) are essential regulators of gene expression in cardiomyocytes. These miRNAs play a vital role in regulating the stability of cardiac conduction and in the remodeling process that leads to arrhythmias. Although it remains unclear how miRNAs regulate the expression and function of ion channels in the heart, these regulatory mechanisms may support the development of emerging therapies. This study discusses the spread and generation of AP in the SAN as well as the regulation of miRNAs and individual ion channels. Arrhythmogenicity studies on ion channels will provide a research basis for miRNA modulation as a new therapeutic target.
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Affiliation(s)
- Wei Fan
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Xuemei Sun
- Department of Pharmacy, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Chao Yang
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China
| | - Juyi Wan
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| | - Hongli Luo
- Department of Pharmacy, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
| | - Bin Liao
- Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Jiangyang District, Luzhou, Sichuan Province, 646000, China.
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Mulvaney EP, Renzo F, Adão R, Dupre E, Bialesova L, Salvatore V, Reid HM, Conceição G, Grynblat J, Llucià-Valldeperas A, Michel JB, Brás-Silva C, Laurent CE, Howard LS, Montani D, Humbert M, Vonk Noordegraaf A, Perros F, Mendes-Ferreira P, Kinsella BT. The thromboxane receptor antagonist NTP42 promotes beneficial adaptation and preserves cardiac function in experimental models of right heart overload. Front Cardiovasc Med 2022; 9:1063967. [PMID: 36588576 PMCID: PMC9794752 DOI: 10.3389/fcvm.2022.1063967] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Background Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary artery pressure leading to right ventricular (RV) failure. While current PAH therapies improve patient outlook, they show limited benefit in attenuating RV dysfunction. Recent investigations demonstrated that the thromboxane (TX) A2 receptor (TP) antagonist NTP42 attenuates experimental PAH across key hemodynamic parameters in the lungs and heart. This study aimed to validate the efficacy of NTP42:KVA4, a novel oral formulation of NTP42 in clinical development, in preclinical models of PAH while also, critically, investigating its direct effects on RV dysfunction. Methods The effects of NTP42:KVA4 were evaluated in the monocrotaline (MCT) and pulmonary artery banding (PAB) models of PAH and RV dysfunction, respectively, and when compared with leading standard-of-care (SOC) PAH drugs. In addition, the expression of the TP, the target for NTP42, was investigated in cardiac tissue from several other related disease models, and from subjects with PAH and dilated cardiomyopathy (DCM). Results In the MCT-PAH model, NTP42:KVA4 alleviated disease-induced changes in cardiopulmonary hemodynamics, pulmonary vascular remodeling, inflammation, and fibrosis, to a similar or greater extent than the PAH SOCs tested. In the PAB model, NTP42:KVA4 improved RV geometries and contractility, normalized RV stiffness, and significantly increased RV ejection fraction. In both models, NTP42:KVA4 promoted beneficial RV adaptation, decreasing cellular hypertrophy, and increasing vascularization. Notably, elevated expression of the TP target was observed both in RV tissue from these and related disease models, and in clinical RV specimens of PAH and DCM. Conclusion This study shows that, through antagonism of TP signaling, NTP42:KVA4 attenuates experimental PAH pathophysiology, not only alleviating pulmonary pathologies but also reducing RV remodeling, promoting beneficial hypertrophy, and improving cardiac function. The findings suggest a direct cardioprotective effect for NTP42:KVA4, and its potential to be a disease-modifying therapy in PAH and other cardiac conditions.
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Affiliation(s)
- Eamon P. Mulvaney
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Fabiana Renzo
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Rui Adão
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal
| | | | - Lucia Bialesova
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Viviana Salvatore
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Helen M. Reid
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Glória Conceição
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Julien Grynblat
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France
| | - Aida Llucià-Valldeperas
- PHEniX Laboratory, Department of Pulmonary Medicine, Amsterdam UMC (Location VUMC), Amsterdam Cardiovascular Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands,Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Thrombosis, Amsterdam, Netherlands
| | | | - Carmen Brás-Silva
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal
| | - Charles E. Laurent
- IPS Therapeutique Inc., Sherbrooke, QC, Canada,ToxiPharm Laboratories Inc., Ste-Catherine-de-Hatley, QC, Canada
| | - Luke S. Howard
- Imperial College London, National Heart and Lung Institute, London, United Kingdom
| | - David Montani
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France,AP-HP, Dept of Respiratory and Intensive Care Medicine, Pulmonary Hypertension National Referral Centre, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Marc Humbert
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France,AP-HP, Dept of Respiratory and Intensive Care Medicine, Pulmonary Hypertension National Referral Centre, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Anton Vonk Noordegraaf
- PHEniX Laboratory, Department of Pulmonary Medicine, Amsterdam UMC (Location VUMC), Amsterdam Cardiovascular Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Frédéric Perros
- School of Medicine, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM UMR_S 999, Pulmonary Hypertension: Pathophysiology and Novel Therapies, Hôpital Marie Lannelongue, Le Plessis-Robinson, France,Paris-Porto Pulmonary Hypertension Collaborative Laboratory (3PH), INSERM UMR_S 999, Université Paris-Saclay, Le Kremlin-Bicêtre, France,INSERM, INRAE, CarMeN Laboratory and Centre de Recherche en Nutrition Humaine Rhône-Alpes (CRNH-RA), Claude Bernard University Lyon 1, University of Lyon, Lyon, France
| | - Pedro Mendes-Ferreira
- Department of Surgery and Physiology, Cardiovascular R&D Centre—UnIC@RISE, Faculty of Medicine of the University of Porto, Porto, Portugal,Paris-Porto Pulmonary Hypertension Collaborative Laboratory (3PH), INSERM UMR_S 999, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - B. Therese Kinsella
- ATXA Therapeutics Limited, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland,UCD School of Biomolecular and Biomedical Research, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland,*Correspondence: B. Therese Kinsella,
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3
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Ottolia M, John S, Hazan A, Goldhaber JI. The Cardiac Na + -Ca 2+ Exchanger: From Structure to Function. Compr Physiol 2021; 12:2681-2717. [PMID: 34964124 DOI: 10.1002/cphy.c200031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ca2+ homeostasis is essential for cell function and survival. As such, the cytosolic Ca2+ concentration is tightly controlled by a wide number of specialized Ca2+ handling proteins. One among them is the Na+ -Ca2+ exchanger (NCX), a ubiquitous plasma membrane transporter that exploits the electrochemical gradient of Na+ to drive Ca2+ out of the cell, against its concentration gradient. In this critical role, this secondary transporter guides vital physiological processes such as Ca2+ homeostasis, muscle contraction, bone formation, and memory to name a few. Herein, we review the progress made in recent years about the structure of the mammalian NCX and how it relates to function. Particular emphasis will be given to the mammalian cardiac isoform, NCX1.1, due to the extensive studies conducted on this protein. Given the degree of conservation among the eukaryotic exchangers, the information highlighted herein will provide a foundation for our understanding of this transporter family. We will discuss gene structure, alternative splicing, topology, regulatory mechanisms, and NCX's functional role on cardiac physiology. Throughout this article, we will attempt to highlight important milestones in the field and controversial topics where future studies are required. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.
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Affiliation(s)
- Michela Ottolia
- Department of Anesthesiology and Perioperative Medicine, Division of Molecular Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Scott John
- Department of Medicine (Cardiology), UCLA, Los Angeles, California, USA
| | - Adina Hazan
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California, USA
| | - Joshua I Goldhaber
- Smidt Heart Institute, Cedars Sinai Medical Center, Los Angeles, California, USA
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4
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Calpain-Mediated Mitochondrial Damage: An Emerging Mechanism Contributing to Cardiac Disease. Cells 2021; 10:cells10082024. [PMID: 34440793 PMCID: PMC8392834 DOI: 10.3390/cells10082024] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/19/2021] [Accepted: 08/06/2021] [Indexed: 12/13/2022] Open
Abstract
Calpains belong to the family of calcium-dependent cysteine proteases expressed ubiquitously in mammals and many other organisms. Activation of calpain is observed in diseased hearts and is implicated in cardiac cell death, hypertrophy, fibrosis, and inflammation. However, the underlying mechanisms remain incompletely understood. Recent studies have revealed that calpains target and impair mitochondria in cardiac disease. The objective of this review is to discuss the role of calpains in mediating mitochondrial damage and the underlying mechanisms, and to evaluate whether targeted inhibition of mitochondrial calpain is a potential strategy in treating cardiac disease. We expect to describe the wealth of new evidence surrounding calpain-mediated mitochondrial damage to facilitate future mechanistic studies and therapy development for cardiac disease.
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5
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Chelko SP, Keceli G, Carpi A, Doti N, Agrimi J, Asimaki A, Beti CB, Miyamoto M, Amat-Codina N, Bedja D, Wei AC, Murray B, Tichnell C, Kwon C, Calkins H, James CA, O'Rourke B, Halushka MK, Melloni E, Saffitz JE, Judge DP, Ruvo M, Kitsis RN, Andersen P, Di Lisa F, Paolocci N. Exercise triggers CAPN1-mediated AIF truncation, inducing myocyte cell death in arrhythmogenic cardiomyopathy. Sci Transl Med 2021; 13:13/581/eabf0891. [PMID: 33597260 DOI: 10.1126/scitranslmed.abf0891] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/27/2021] [Indexed: 12/15/2022]
Abstract
Myocyte death occurs in many inherited and acquired cardiomyopathies, including arrhythmogenic cardiomyopathy (ACM), a genetic heart disease plagued by the prevalence of sudden cardiac death. Individuals with ACM and harboring pathogenic desmosomal variants, such as desmoglein-2 (DSG2), often show myocyte necrosis with progression to exercise-associated heart failure. Here, we showed that homozygous Dsg2 mutant mice (Dsg2 mut/mut), a model of ACM, die prematurely during swimming and display myocardial dysfunction and necrosis. We detected calcium (Ca2+) overload in Dsg2 mut/mut hearts, which induced calpain-1 (CAPN1) activation, association of CAPN1 with mitochondria, and CAPN1-induced cleavage of mitochondrial-bound apoptosis-inducing factor (AIF). Cleaved AIF translocated to the myocyte nucleus triggering large-scale DNA fragmentation and cell death, an effect potentiated by mitochondrial-driven AIF oxidation. Posttranslational oxidation of AIF cysteine residues was due, in part, to a depleted mitochondrial thioredoxin-2 redox system. Hearts from exercised Dsg2 mut/mut mice were depleted of calpastatin (CAST), an endogenous CAPN1 inhibitor, and overexpressing CAST in myocytes protected against Ca2+ overload-induced necrosis. When cardiomyocytes differentiated from Dsg2 mut/mut embryonic stem cells (ES-CMs) were challenged with β-adrenergic stimulation, CAPN1 inhibition attenuated CAPN1-induced AIF truncation. In addition, pretreatment of Dsg2 mut/mut ES-CMs with an AIF-mimetic peptide, mirroring the cyclophilin-A (PPIA) binding site of AIF, blocked PPIA-mediated AIF-nuclear translocation, and reduced both apoptosis and necrosis. Thus, preventing CAPN1-induced AIF-truncation or barring binding of AIF to the nuclear chaperone, PPIA, may avert myocyte death and, ultimately, disease progression to heart failure in ACM and likely other forms of cardiomyopathies.
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Affiliation(s)
- Stephen P Chelko
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306, USA. .,Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Gizem Keceli
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Andrea Carpi
- Department of Biomedical Sciences, University of Padova, Padova 35122, Italy
| | - Nunzianna Doti
- Institute of Biostructures and Bioimaging, CNR, Naples 80134, Italy
| | - Jacopo Agrimi
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Angeliki Asimaki
- Molecular and Clinical Sciences Research Institute, St. George's, University of London, London WC1E 6BS, UK
| | - Carlos Bueno Beti
- Molecular and Clinical Sciences Research Institute, St. George's, University of London, London WC1E 6BS, UK
| | - Matthew Miyamoto
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Nuria Amat-Codina
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Djahida Bedja
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.,Australian School of Advanced Medicine, Macquarie University, Sydney, NSW 2109, Australia
| | - An-Chi Wei
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Brittney Murray
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Crystal Tichnell
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Chulan Kwon
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Hugh Calkins
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Cynthia A James
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Brian O'Rourke
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Marc K Halushka
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Edon Melloni
- Department of Medicine, University of Genova, Genova 16126, Italy
| | - Jeffrey E Saffitz
- Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA 20115, USA
| | - Daniel P Judge
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.,Medical University of South Carolina, Charleston, SC 29425, USA
| | - Menotti Ruvo
- Institute of Biostructures and Bioimaging, CNR, Naples 80134, Italy
| | - Richard N Kitsis
- Departments of Medicine and Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Peter Andersen
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Fabio Di Lisa
- Department of Biomedical Sciences, University of Padova, Padova 35122, Italy
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA. .,Department of Biomedical Sciences, University of Padova, Padova 35122, Italy
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Wanichawan P, Skogestad J, Lunde M, Støle TP, Stensland M, Nyman TA, Sjaastad I, Sejersted OM, Aronsen JM, Carlson CR. Design of a Proteolytically Stable Sodium-Calcium Exchanger 1 Activator Peptide for In Vivo Studies. Front Pharmacol 2021; 12:638646. [PMID: 34163352 PMCID: PMC8215385 DOI: 10.3389/fphar.2021.638646] [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: 12/15/2020] [Accepted: 05/14/2021] [Indexed: 11/13/2022] Open
Abstract
The cardiac sodium–calcium exchanger (NCX1) is important for normal Na+- and Ca2+-homeostasis and cardiomyocyte relaxation and contraction. It has been suggested that NCX1 activity is reduced by phosphorylated phospholemman (pSer68-PLM); however its direct interaction with PLM is debated. Disruption of the potentially inhibitory pSer68-PLM-NCX1 interaction might be a therapeutic strategy to increase NCX1 activity in cardiac disease. In the present study, we aimed to analyze the binding affinities and kinetics of the PLM-NCX1 and pSer68-PLM-NCX1 interactions by surface plasmon resonance (SPR) and to develop a proteolytically stable NCX1 activator peptide for future in vivo studies. The cytoplasmic parts of PLM (PLMcyt) and pSer68-PLM (pSer68-PLMcyt) were found to bind strongly to the intracellular loop of NCX1 (NCX1cyt) with similar KD values of 4.1 ± 1.0 nM and 4.3 ± 1.9 nM, but the PLMcyt-NCX1cyt interaction showed higher on/off rates. To develop a proteolytically stable NCX1 activator, we took advantage of a previously designed, high-affinity PLM binding peptide (OPT) that was derived from the PLM binding region in NCX1 and that reverses the inhibitory PLM (S68D)-NCX1 interaction in HEK293. We performed N- and C-terminal truncations of OPT and identified PYKEIEQLIELANYQV as the minimum sequence required for pSer68-PLM binding. To increase peptide stability in human serum, we replaced the proline with an N-methyl-proline (NOPT) after identification of N-terminus as substitution tolerant by two-dimensional peptide array analysis. Mass spectrometry analysis revealed that the half-life of NOPT was increased 17-fold from that of OPT. NOPT pulled down endogenous PLM from rat left ventricle lysate and exhibited direct pSer68-PLM binding in an ELISA-based assay and bound to pSer68-PLMcyt with a KD of 129 nM. Excess NOPT also reduced the PLMcyt-NCX1cyt interaction in an ELISA-based competition assay, but in line with that NCX1 and PLM form oligomers, NOPT was not able to outcompete the physical interaction between endogenous full length proteins. Importantly, cell-permeable NOPT-TAT increased NCX1 activity in cardiomyocytes isolated from both SHAM-operated and aorta banded heart failure (HF) mice, indicating that NOPT disrupted the inhibitory pSer68-PLM-NCX1 interaction. In conclusion, we have developed a proteolytically stable NCX1-derived PLM binding peptide that upregulates NCX1 activity in SHAM and HF cardiomyocytes.
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Affiliation(s)
- Pimthanya Wanichawan
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,The KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jonas Skogestad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Marianne Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,The KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Thea Parsberg Støle
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,The KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Maria Stensland
- Department of Immunology, Institute of Clinical Medicine, University of Oslo and Rikshospitalet Oslo, Oslo, Norway
| | - Tuula A Nyman
- Department of Immunology, Institute of Clinical Medicine, University of Oslo and Rikshospitalet Oslo, Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,The KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Ole M Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,The KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Pharmacology, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Cathrine Rein Carlson
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,The KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
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7
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Fross S, Mansel C, McCormick M, Vohra BPS. Tributyltin Alters Calcium Levels, Mitochondrial Dynamics, and Activates Calpains Within Dorsal Root Ganglion Neurons. Toxicol Sci 2021; 180:342-355. [PMID: 33481012 DOI: 10.1093/toxsci/kfaa193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Tributyltin (TBT) remains a global health concern. The primary route of human exposure to TBT is either through ingestion or skin absorption, but TBT's effects on the peripheral nervous system have still not been investigated. Therefore, we exposed in vitro sensory dorsal root ganglion (DRG) neurons to TBT at a concentration of 50-200 nM, which is similar to the observed concentrations of TBT in human blood samples. We observed that TBT causes extensive axon degeneration and neuronal death in the DRG neurons. Furthermore, we discovered that TBT causes an increase in both cytosolic and mitochondrial calcium levels, disrupts mitochondrial dynamics, decreases neuronal ATP levels, and leads to the activation of calpains. Additional experiments demonstrated that inhibition of calpain activation prevented TBT-induced fragmentation of neuronal cytoskeletal proteins and neuronal cell death. Thus, we conclude that calpain activation is the key executioner of TBT-induced peripheral neurodegeneration.
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Affiliation(s)
- Shaneann Fross
- Department of Biology, William Jewell College, Liberty, Missouri 64068, USA
| | - Clayton Mansel
- Department of Biology, William Jewell College, Liberty, Missouri 64068, USA
| | - Madison McCormick
- Department of Biology, William Jewell College, Liberty, Missouri 64068, USA
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8
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Xu X, Chen C, Lu WJ, Su YL, Shi JY, Liu YC, Wang L, Xiao CX, Wu X, Lu Q. Pyrroloquinoline quinone can prevent chronic heart failure by regulating mitochondrial function. Cardiovasc Diagn Ther 2020; 10:453-469. [PMID: 32695625 DOI: 10.21037/cdt-20-129] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Background Myocardial mitochondrial dysfunction is the leading cause of chronic heart failure (CHF). Increased reactive oxygen species (ROS) levels, disruption of mitochondrial biogenesis and mitochondrial Ca2+([Ca2+]m) homeostasis and reduction of the mitochondrial membrane potential (ΔΨm) cause myocardial mitochondrial dysfunction. Therefore, treating CHF by targeting mitochondrial function is a focus of current research. For the first time, this study investigated the effects of the strong antioxidant pyrroloquinoline quinone (PQQ) on mitochondrial function in a cardiac pressure overload model, and the mechanism by which PQQ regulates [Ca2+]m homeostasis was explored in depth. Methods After transaortic constriction (TAC), normal saline and PQQ (0.4, 2 and 10 mg/kg) were administered intragastrically to Sprague Dawley (SD) rats for 12 weeks. In vitro, neonatal rat left ventricle myocytes (NRVMs) were pretreated with 200 nm angiotensin II (Ang II) with or without PQQ (1, 10 and 100 μM). Rat heart remodelling was verified by assessment of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels (qRT-PCR), cell surface area (wheat germ agglutinin (WGA) staining in vivo and α-actin in vitro) and echocardiography. Myocardial mitochondrial morphology was assessed by transmission electron microscopy. Western blotting was used to assess mitochondrial biogenesis [peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and transcription factor A, mitochondrial (TFAM)]. The ΔΨm was determined by tetraethyl benzimidazolyl carbocyanine iodide (JC-1) staining and flow cytometry, and ROS levels were measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) and MitoSOX Red staining. [Ca2+]m was measured by isolating rat mitochondria, and mitochondrial Ca2+ channel proteins [the mitochondrial Na+/Ca2+ exchanger (NCLX) and mitochondrial Ca2+ uniporter (MCU)] were detected by Western blot. Results In vivo and in vitro, PQQ pretreatment improved pressure overload-induced cardiac remodelling and cell hypertrophy, thus preventing the occurrence of CHF. PQQ also prevented mitochondrial morphology damage and reduced the PGC-1α and TFAM downregulation caused by TAC or Ang II. In addition, in NRVMs treated with Ang II + PQQ, PQQ regulated ROS levels and increased the ΔΨm. PQQ also regulated [Ca2+]m homeostasis and prohibited [Ca2+]m overloading by increasing NCLX expression. Conclusions These results show that PQQ can prevent [Ca2+]m overload by increasing NCLX expression and thereby reducing ROS production and protecting the ΔΨm. At the same time, PQQ can increase PGC-1α and TFAM expression to regulate mitochondrial biogenesis. These factors can prevent mitochondrial dysfunction, thereby reducing cardiac damage caused by pressure overload and preventing the occurrence of CHF.
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Affiliation(s)
- Xuan Xu
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Chu Chen
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Wen-Jiang Lu
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Yi-Ling Su
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Jia-Yu Shi
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Yu-Chen Liu
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Li Wang
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Chen-Xi Xiao
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Xiang Wu
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
| | - Qi Lu
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong, China
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Cardiomyocyte calcium handling in health and disease: Insights from in vitro and in silico studies. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 157:54-75. [PMID: 32188566 DOI: 10.1016/j.pbiomolbio.2020.02.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/31/2019] [Accepted: 02/29/2020] [Indexed: 02/07/2023]
Abstract
Calcium (Ca2+) plays a central role in cardiomyocyte excitation-contraction coupling. To ensure an optimal electrical impulse propagation and cardiac contraction, Ca2+ levels are regulated by a variety of Ca2+-handling proteins. In turn, Ca2+ modulates numerous electrophysiological processes. Accordingly, Ca2+-handling abnormalities can promote cardiac arrhythmias via various mechanisms, including the promotion of afterdepolarizations, ion-channel modulation and structural remodeling. In the last 30 years, significant improvements have been made in the computational modeling of cardiomyocyte Ca2+ handling under physiological and pathological conditions. However, numerous questions involving the Ca2+-dependent regulation of different macromolecular complexes, cross-talk between Ca2+-dependent regulatory pathways operating over a wide range of time scales, and bidirectional interactions between electrophysiology and mechanics remain to be addressed by in vitro and in silico studies. A better understanding of disease-specific Ca2+-dependent proarrhythmic mechanisms may facilitate the development of improved therapeutic strategies. In this review, we describe the fundamental mechanisms of cardiomyocyte Ca2+ handling in health and disease, and provide an overview of currently available computational models for cardiomyocyte Ca2+ handling. Finally, we discuss important uncertainties and open questions about cardiomyocyte Ca2+ handling and highlight how synergy between in vitro and in silico studies may help to answer several of these issues.
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10
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Ottesen AH, Carlson CR, Eken OS, Sadredini M, Myhre PL, Shen X, Dalhus B, Laver DR, Lunde PK, Kurola J, Lunde M, Hoff JE, Godang K, Sjaastad I, Pettilä V, Stridsberg M, Lehnart SE, Edwards AG, Lunde IG, Omland T, Stokke MK, Christensen G, Røsjø H, Louch WE. Secretoneurin Is an Endogenous Calcium/Calmodulin-Dependent Protein Kinase II Inhibitor That Attenuates Ca 2+-Dependent Arrhythmia. Circ Arrhythm Electrophysiol 2020; 12:e007045. [PMID: 30943765 DOI: 10.1161/circep.118.007045] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Circulating SN (secretoneurin) concentrations are increased in patients with myocardial dysfunction and predict poor outcome. Because SN inhibits CaMKIIδ (Ca2+/calmodulin-dependent protein kinase IIδ) activity, we hypothesized that upregulation of SN in patients protects against cardiomyocyte mechanisms of arrhythmia. METHODS Circulating levels of SN and other biomarkers were assessed in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT; n=8) and in resuscitated patients after ventricular arrhythmia-induced cardiac arrest (n=155). In vivo effects of SN were investigated in CPVT mice (RyR2 [ryanodine receptor 2]-R2474S) using adeno-associated virus-9-induced overexpression. Interactions between SN and CaMKIIδ were mapped using pull-down experiments, mutagenesis, ELISA, and structural homology modeling. Ex vivo actions were tested in Langendorff hearts and effects on Ca2+ homeostasis examined by fluorescence (fluo-4) and patch-clamp recordings in isolated cardiomyocytes. RESULTS SN levels were elevated in patients with CPVT and following ventricular arrhythmia-induced cardiac arrest. In contrast to NT-proBNP (N-terminal pro-B-type natriuretic peptide) and hs-TnT (high-sensitivity troponin T), circulating SN levels declined after resuscitation, as the risk of a new arrhythmia waned. Myocardial pro-SN expression was also increased in CPVT mice, and further adeno-associated virus-9-induced overexpression of SN attenuated arrhythmic induction during stress testing with isoproterenol. Mechanistic studies mapped SN binding to the substrate binding site in the catalytic region of CaMKIIδ. Accordingly, SN attenuated isoproterenol induced autophosphorylation of Thr287-CaMKIIδ in Langendorff hearts and inhibited CaMKIIδ-dependent RyR phosphorylation. In line with CaMKIIδ and RyR inhibition, SN treatment decreased Ca2+ spark frequency and dimensions in cardiomyocytes during isoproterenol challenge, and reduced the incidence of Ca2+ waves, delayed afterdepolarizations, and spontaneous action potentials. SN treatment also lowered the incidence of early afterdepolarizations during isoproterenol; an effect paralleled by reduced magnitude of L-type Ca2+ current. CONCLUSIONS SN production is upregulated in conditions with cardiomyocyte Ca2+ dysregulation and offers compensatory protection against cardiomyocyte mechanisms of arrhythmia, which may underlie its putative use as a biomarker in at-risk patients.
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Affiliation(s)
- Anett H Ottesen
- Division of Medicine, Akershus University Hospital, Lørenskog, Norway (A.H.O., P.L.M., J.E.H., T.O., H.R.).,Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Cathrine R Carlson
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Olav Søvik Eken
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Mani Sadredini
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Peder L Myhre
- Division of Medicine, Akershus University Hospital, Lørenskog, Norway (A.H.O., P.L.M., J.E.H., T.O., H.R.).,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Xin Shen
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Bjørn Dalhus
- Department for Microbiology, Clinic for Laboratory Medicine (B.D.), Oslo University Hospital, Norway.,Department for Medical Biochemistry, Institute for Clinical Medicine (B.D.), University of Oslo, Norway
| | - Derek R Laver
- School of Biomedical Sciences and Pharmacy, University of Newcastle and Hunter Medical Research Institute, Callaghan, New South Wales, Australia (D.R.L.)
| | - Per Kristian Lunde
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Jouni Kurola
- Division of Intensive Care Medicine, Kuopio University Hospital, Finland (J.K.)
| | - Marianne Lunde
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Jon Erik Hoff
- Division of Medicine, Akershus University Hospital, Lørenskog, Norway (A.H.O., P.L.M., J.E.H., T.O., H.R.)
| | - Kristin Godang
- Section of Specialized Endocrinology, Department of Endocrinology (K.G.), Oslo University Hospital, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway.,K.G. Jebsen Center for Cardiac Research (I.S., G.C., W.E.L.), University of Oslo, Norway
| | - Ville Pettilä
- Division of Anesthesiology, Intensive Care and Pain Medicine, University of Helsinki & Helsinki University Hospital, Finland (V.P.)
| | - Mats Stridsberg
- Department of Medical Sciences, Uppsala University, Sweden (M. Stridsberg)
| | - Stephan E Lehnart
- Heart Research Center Goettingen, University Medicine Center Goettingen, Germany (S.E.L.)
| | - Andrew G Edwards
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway.,Simula Research Laboratory, Fornebu, Norway (A.G.E)
| | - Ida G Lunde
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Torbjørn Omland
- Division of Medicine, Akershus University Hospital, Lørenskog, Norway (A.H.O., P.L.M., J.E.H., T.O., H.R.).,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Mathis K Stokke
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - Geir Christensen
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway.,K.G. Jebsen Center for Cardiac Research (I.S., G.C., W.E.L.), University of Oslo, Norway
| | - Helge Røsjø
- Division of Medicine, Akershus University Hospital, Lørenskog, Norway (A.H.O., P.L.M., J.E.H., T.O., H.R.).,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research (A.H.O., C.R.C., O.S.E., M. Sadredini, X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., M.K.S., G.C., W.E.L.), Oslo University Hospital, Norway.,Center for Heart Failure Research (A.H.O., C.R.C., O.S.E., M. Sadredini, P.L.M., X.S., P.K.L., M.L., I.S., A.G.E., I.G.L., T.O., M.K.S., G.C., H.R., W.E.L.), University of Oslo, Norway.,K.G. Jebsen Center for Cardiac Research (I.S., G.C., W.E.L.), University of Oslo, Norway
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11
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TFAM overexpression reduces pathological cardiac remodeling. Mol Cell Biochem 2018; 454:139-152. [PMID: 30353496 DOI: 10.1007/s11010-018-3459-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 10/16/2018] [Indexed: 10/28/2022]
Abstract
Heart failure (HF) is a functional lack of myocardial performance due to a loss of molecular control over increases in calcium and ROS, resulting in proteolytic degradative advances and cardiac remodeling. Mitochondria are the molecular powerhouse of cells, shifting the sphere of cardiomyocyte stability and performance. Functional mitochondria rely on the molecular abilities of safety factors such as TFAM to maintain physiological parameters. Mitochondrial transcription factor A (TFAM) creates a mitochondrial nucleoid structure around mtDNA, protecting it from mutation, inhibiting NFAT (ROS activator/hypertrophic stimulator), and transcriptionally activates Serca2a to decrease calcium mishandling. Calpain1 and MMP9 are proteolytic degratory factors that play a major role in cardiomyocyte decline in HF. Current literature depicts major decreases in TFAM as HF progresses. We aim to assess TFAM function against Calpain1 and MMP9 proteolytic activity and its role in cardiac remodeling. To this date, no publication has surfaced describing the effects of aortic banding (AB) as a surgical HF model in TFAM-TG mice. HF models were created via AB in TFAM transgenic (TFAM-TG) and C57BLJ-6 (WT) mice. Eight weeks post AB, functional analysis revealed a successful banding procedure, resulting in cardiac hypertrophy as observed via echocardiography. Pulse wave and color doppler show increased aortic flow rates as well as turbulent flow at the banding site. Preliminary results of cardiac tissue immuno-histochemistry of HF-control mice show decreased TFAM and compensatory increases in Serca2a fluorescent expression, along with increased Calpain1 and MMP9 expression. Protein, RNA, and IHC analysis will further assess TFAM-TG results post-banding. Echocardiography shows more cardiac stability and functionality in HF-induced TFAM-TG mice than the control counterpart. These findings complement our published in vitro results. Overall, this suggests that TFAM has molecular therapeutic potential to reduce protease expression.
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12
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Røe ÅT, Aronsen JM, Skårdal K, Hamdani N, Linke WA, Danielsen HE, Sejersted OM, Sjaastad I, Louch WE. Increased passive stiffness promotes diastolic dysfunction despite improved Ca2+ handling during left ventricular concentric hypertrophy. Cardiovasc Res 2018; 113:1161-1172. [PMID: 28472418 PMCID: PMC5852536 DOI: 10.1093/cvr/cvx087] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/03/2017] [Indexed: 02/06/2023] Open
Abstract
Aims Concentric hypertrophy following pressure-overload is linked to preserved systolic function but impaired diastolic function, and is an important substrate for heart failure with preserved ejection fraction. While increased passive stiffness of the myocardium is a suggested mechanism underlying diastolic dysfunction in these hearts, the contribution of active diastolic Ca2+ cycling in cardiomyocytes remains unclear. In this study, we sought to dissect contributions of passive and active mechanisms to diastolic dysfunction in the concentrically hypertrophied heart following pressure-overload. Methods and results Rats were subjected to aortic banding (AB), and experiments were performed 6 weeks after surgery using sham-operated rats as controls. In vivo ejection fraction and fractional shortening were normal, confirming preservation of systolic function. Left ventricular concentric hypertrophy and diastolic dysfunction following AB were indicated by thickening of the ventricular wall, reduced peak early diastolic tissue velocity, and higher E/e' values. Slowed relaxation was also observed in left ventricular muscle strips isolated from AB hearts, during both isometric and isotonic stimulation, and accompanied by increases in passive tension, viscosity, and extracellular collagen. An altered titin phosphorylation profile was observed with hypophosphorylation of the phosphosites S4080 and S3991 sites within the N2Bus, and S12884 within the PEVK region. Increased titin-based stiffness was confirmed by salt-extraction experiments. In contrast, isolated, unloaded cardiomyocytes exhibited accelerated relaxation in AB compared to sham, and less contracture at high pacing frequencies. Parallel enhancement of diastolic Ca2+ handling was observed, with augmented NCX and SERCA2 activity and lowered resting cytosolic [Ca2+]. Conclusion In the hypertrophied heart with preserved systolic function, in vivo diastolic dysfunction develops as cardiac fibrosis and alterations in titin phosphorylation compromise left ventricular compliance, and despite compensatory changes in cardiomyocyte Ca2+ homeostasis.
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MESH Headings
- Adaptation, Physiological
- Animals
- Aorta/physiopathology
- Aorta/surgery
- Arterial Pressure
- Calcium/metabolism
- Calcium Signaling
- Collagen/metabolism
- Compliance
- Connectin/metabolism
- Constriction
- Diastole
- Disease Models, Animal
- Fibrosis
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Isolated Heart Preparation
- Male
- Myocardium/metabolism
- Myocardium/pathology
- Phosphorylation
- Rats, Wistar
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
- Sodium-Calcium Exchanger/metabolism
- Systole
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/pathology
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
- Ventricular Remodeling
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Affiliation(s)
- Åsmund T. Røe
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, NO-0407 Oslo, Norway
- Corresponding author. Tel: +47 23 01 68 00; fax: +47 23 01 67 99, E-mail:
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, NO-0407 Oslo, Norway
- Bjørknes College, Oslo, Norway
| | - Kristine Skårdal
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, NO-0407 Oslo, Norway
| | - Nazha Hamdani
- Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
| | - Wolfgang A. Linke
- Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
| | - Håvard E. Danielsen
- Institute for Cancer Genetics and Informatics, Oslo University Hospital, Oslo, Norway
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
- Nuffield Division of Clinical Laboratory Sciences, University of Oxford, Oxford, UK
| | - Ole M. Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, NO-0407 Oslo, Norway
| | - Ivar Sjaastad
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, NO-0407 Oslo, Norway
| | - William E. Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Ullevål, Kirkeveien 166, NO-0407 Oslo, Norway
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13
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Lubelwana Hafver T, Wanichawan P, Manfra O, de Souza GA, Lunde M, Martinsen M, Louch WE, Sejersted OM, Carlson CR. Mapping the in vitro interactome of cardiac sodium (Na + )-calcium (Ca 2+ ) exchanger 1 (NCX1). Proteomics 2017; 17. [PMID: 28755400 DOI: 10.1002/pmic.201600417] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 07/03/2017] [Accepted: 07/26/2017] [Indexed: 11/07/2022]
Abstract
The sodium (Na+ )-calcium (Ca2+ ) exchanger 1 (NCX1) is an antiporter membrane protein encoded by the SLC8A1 gene. In the heart, it maintains cytosolic Ca2+ homeostasis, serving as the primary mechanism for Ca2+ extrusion during relaxation. Dysregulation of NCX1 is observed in end-stage human heart failure. In this study, we used affinity purification coupled with MS in rat left ventricle lysates to identify novel NCX1 interacting proteins in the heart. Two screens were conducted using: (1) anti-NCX1 against endogenous NCX1 and (2) anti-His (where His is histidine) with His-trigger factor-NCX1cyt recombinant protein as bait. The respective methods identified 112 and 350 protein partners, of which several were known NCX1 partners from the literature, and 29 occurred in both screens. Ten novel protein partners (DYRK1A, PPP2R2A, SNTB1, DMD, RABGGTA, DNAJB4, BAG3, PDE3A, POPDC2, STK39) were validated for binding to NCX1, and two partners (DYRK1A, SNTB1) increased NCX1 activity when expressed in HEK293 cells. A cardiac NCX1 protein-protein interaction map was constructed. The map was highly connected, containing distinct clusters of proteins with different biological functions, where "cell communication" and "signal transduction" formed the largest clusters. The NCX1 interactome was also significantly enriched with proteins/genes involved in "cardiovascular disease" which can be explored as novel drug targets in future research.
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Affiliation(s)
- Tandekile Lubelwana Hafver
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Pimthanya Wanichawan
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Ornella Manfra
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Gustavo Antonio de Souza
- Department of Immunology and Centre for Immune Regulation, Oslo University Hospital HF Rikshospitalet, University of Oslo, Oslo, Norway.,The Brain Institute, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.,Bioinformatics Multidisciplinary Environment, Instituto Metrópole Digital, UFRN, Natal, RN, Brazil
| | - Marianne Lunde
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Marita Martinsen
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - William Edward Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Ole Mathias Sejersted
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Cathrine Rein Carlson
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
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14
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Zhao M, Jia HH, Liu LZ, Bi XY, Xu M, Yu XJ, He X, Zang WJ. Acetylcholine attenuated TNF-α-induced intracellular Ca 2+ overload by inhibiting the formation of the NCX1-TRPC3-IP3R1 complex in human umbilical vein endothelial cells. J Mol Cell Cardiol 2017; 107:1-12. [PMID: 28395930 DOI: 10.1016/j.yjmcc.2017.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/16/2017] [Accepted: 04/06/2017] [Indexed: 12/21/2022]
Abstract
The endoplasmic reticulum (ER) forms discrete junctions with the plasma membrane (PM) that play a critical role in the regulation of Ca2+ signaling during cellular bioenergetics, apoptosis and autophagy. We have previously confirmed that acetylcholine can inhibit ER stress and apoptosis after inflammatory injury. However, limited research has focused on the effects of acetylcholine on ER-PM junctions. In this work, we evaluated the structure and function of the supramolecular sodium-calcium exchanger 1 (NCX1)-transient receptor potential canonical 3 (TRPC3)-inositol 1,4,5-trisphosphate receptor 1 (IP3R1) complex, which is involved in regulating Ca2+ homeostasis during inflammatory injury. The width of the ER-PM junctions of human umbilical vein endothelial cells (HUVECs) was measured in nanometres using transmission electron microscopy and a fluorescent probe for Ca2+. Protein-protein interactions were assessed by immunoprecipitation. Ca2+ concentration was measured using a confocal microscope. An siRNA assay was employed to silence specific proteins. Our results demonstrated that the peripheral ER was translocated to PM junction sites when induced by tumour necrosis factor-alpha (TNF-α) and that NCX1-TRPC3-IP3R1 complexes formed at these sites. After down-regulating the protein expression of NCX1 or IP3R1, we found that the NCX1-mediated inflow of Ca2+ and the release of intracellular Ca2+ stores were reduced in TNF-α-treated cells. We also observed that acetylcholine attenuated the formation of NCX1-TRPC3-IP3R1 complexes and maintained calcium homeostasis in cells treated with TNF-α. Interestingly, the positive effects of acetylcholine were abolished by the selective M3AChR antagonist darifenacin and by AMPK siRNAs. These results indicate that acetylcholine protects endothelial cells from TNF-alpha-induced injury, [Ca2+]cyt overload and ER-PM interactions, which depend on the muscarinic 3 receptor/AMPK pathway, and that acetylcholine may be a new inhibitor for suppressing [Ca2+]cyt overload.
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Affiliation(s)
- Ming Zhao
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Hang-Huan Jia
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Long-Zhu Liu
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Xue-Yuan Bi
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Man Xu
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Xiao-Jiang Yu
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Xi He
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China
| | - Wei-Jin Zang
- Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, PR China.
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15
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Weber JJ, Golla M, Guaitoli G, Wanichawan P, Hayer SN, Hauser S, Krahl AC, Nagel M, Samer S, Aronica E, Carlson CR, Schöls L, Riess O, Gloeckner CJ, Nguyen HP, Hübener-Schmid J. A combinatorial approach to identify calpain cleavage sites in the Machado-Joseph disease protein ataxin-3. Brain 2017; 140:1280-1299. [DOI: 10.1093/brain/awx039] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/06/2017] [Indexed: 11/13/2022] Open
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16
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Xie Y, Gu ZJ, Wu MX, Huang TC, Ou JS, Ni HS, Lin MH, Yuan WL, Wang JF, Chen YX. Disruption of calcium homeostasis by cardiac-specific over-expression of PPAR-γ in mice: A role in ventricular arrhythmia. Life Sci 2016; 167:12-21. [DOI: 10.1016/j.lfs.2016.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/09/2016] [Accepted: 10/12/2016] [Indexed: 11/29/2022]
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17
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Development of a high-affinity peptide that prevents phospholemman (PLM) inhibition of the sodium/calcium exchanger 1 (NCX1). Biochem J 2016; 473:2413-23. [PMID: 27247424 PMCID: PMC4964977 DOI: 10.1042/bcj20160465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/31/2016] [Indexed: 11/17/2022]
Abstract
NCX1 (Na+/Ca2+ exchanger 1) is an important regulator of intracellular Ca2+ and a potential therapeutic target for brain ischaemia and for diastolic heart failure with preserved ejection fraction. PLM (phospholemman), a substrate for protein kinases A and C, has been suggested to regulate NCX1 activity. However, although several studies have demonstrated that binding of phosphorylated PLM (pSer68-PLM) leads to NCX1 inhibition, other studies have failed to demonstrate a functional interaction of these proteins. In the present study, we aimed to analyse the biological function of the pSer68-PLM–NCX1 interaction by developing high-affinity blocking peptides. PLM was observed to co-fractionate and co-immunoprecipitate with NCX1 in rat left ventricle, and in co-transfected HEK (human embryonic kidney)-293 cells. For the first time, the NCX1–PLM interaction was also demonstrated in the brain. PLM binding sites on NCX1 were mapped to two regions by peptide array assays, containing the previously reported PASKT and QKHPD motifs. Conversely, the two NCX1 regions bound identical sequences in the cytoplasmic domain of PLM, suggesting that NCX1-PASKT and NCX1-QKHPD might bind to each PLM monomer. Using two-dimensional peptide arrays of the native NCX1 sequence KHPDKEIEQLIELANYQVLS revealed that double substitution of tyrosine for positions 1 and 4 (K1Y and D4Y) enhanced pSer68-PLM binding 8-fold. The optimized peptide blocked binding of NCX1-PASKT and NCX1-QKHPD to PLM and reversed PLM(S68D) inhibition of NCX1 activity (both forward and reverse mode) in HEK-293 cells. Altogether our data indicate that PLM interacts directly with NCX1 and inhibits NCX1 activity when phosphorylated at Ser68.
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18
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Ujihara Y, Iwasaki K, Takatsu S, Hashimoto K, Naruse K, Mohri S, Katanosaka Y. Induced NCX1 overexpression attenuates pressure overload-induced pathological cardiac remodelling. Cardiovasc Res 2016; 111:348-61. [PMID: 27229460 DOI: 10.1093/cvr/cvw113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 05/22/2016] [Indexed: 11/12/2022] Open
Abstract
AIMS Although increased Na(+)/Ca(2+) exchanger 1 (NCX1) expression is observed during heart failure (HF), the pathological role of NCX1 during the progression of HF remains unclear. We examined alterations of NCX1 expression and activity in hearts after transverse aortic constriction (TAC) surgery and explored whether NCX1 influences pressure overload-induced pathological cardiac remodelling. METHODS AND RESULTS We generated novel transgenic mice in which NCX1 expression is controlled by a cardiac-specific, doxycycline (DOX)-dependent promoter. In the absence of DOX, TAC surgery caused substantial chamber dilation with a gradual decrease in contractility by 16 weeks. Cardiomyocytes showed a decline in contractility with abnormal Ca(2+) handling during excitation-contraction (E-C) coupling. Reduced NCX1 activity was observed 8 weeks after TAC and was still apparent at 17 weeks. Induced NCX1 overexpression by DOX treatment starting 8 weeks after TAC returned NCX1 activity to pre-TAC levels and prevented chamber dilation with cardiac dysfunction. DOX treatment not only upregulated NCX1 expression in TAC-operated hearts but also returned L-type Ca(2+) channel and sarcoplasmic reticulum (SR) Ca(2+) ATPase expression levels to those in sham-operated hearts. In DOX-treated myocytes, contractility, T-tubule integrity, synchrony of Ca(2+) release from the SR, and Ca(2+) handling during E-C coupling was preserved 16 weeks after TAC surgery. In addition, DOX treatment attenuated the down-regulation of survival signalling and up-regulation of apoptosis signalling 16 weeks after TAC surgery. CONCLUSION Induced overexpression of NCX1 attenuated pressure overload-induced pathological cardiac remodelling. Thus, maintaining NCX1 activity may be a potential therapeutic strategy for preventing the progression of HF.
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Affiliation(s)
- Yoshihiro Ujihara
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan Department of Physiology, Kawasaki Medical School, Kurashiki, Japan
| | - Keiichiro Iwasaki
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Satomi Takatsu
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Ken Hashimoto
- Department of Physiology, Kawasaki Medical School, Kurashiki, Japan
| | - Keiji Naruse
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Satoshi Mohri
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan Department of Physiology, Kawasaki Medical School, Kurashiki, Japan
| | - Yuki Katanosaka
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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19
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Lin X, He Y, Hou X, Zhang Z, Wang R, Wu Q. Endothelial Cells Can Regulate Smooth Muscle Cells in Contractile Phenotype through the miR-206/ARF6&NCX1/Exosome Axis. PLoS One 2016; 11:e0152959. [PMID: 27031991 PMCID: PMC4816502 DOI: 10.1371/journal.pone.0152959] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 03/22/2016] [Indexed: 01/08/2023] Open
Abstract
Active interactions between endothelial cells and smooth muscle cells (SMCs) are critical to maintaining the SMC phenotype. Exosomes play an important role in intercellular communication. However, little is known about the mechanisms that regulate endothelial cells and SMCs crosstalk. We aimed to determine the mechanisms underlying the regulation of the SMC phenotype by human umbilical vein endothelial cells (HUVECs) through exosomes. We found that HUVECs overexpressing miR-206 upregulated contractile marker (α-SMA, Smoothelin and Calponin) mRNA expression in SMCs. We also found that the expression of miR-206 by HUVECs reduced exosome production by regulating ADP-Ribosylation Factor 6 (ARF6) and sodium/calcium exchanger 1 (NCX1). Using real-time PCR and western blot analysis, we showed that HUVEC-derived exosomes decreased the expression of contractile phenotype marker genes (α-SMA, Smoothelin and Calponin) in SMCs. Furthermore, a reduction of the miR-26a-containing exosomes secreted from HUVECs affects the SMC phenotype. We propose a novel mechanism in which miR-206 expression in HUVECs maintains the contractile phenotype of SMCs by suppressing exosome secretion from HUVECs, particularly miR-26a in exosomes, through targeting ARF6 and NCX1.
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Affiliation(s)
- Xiao Lin
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yu He
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xue Hou
- Department of basic medicine, Medical College of Qinghai University, Xining 810016, China
| | - Zhenming Zhang
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Rui Wang
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Qiong Wu
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
- * E-mail:
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20
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Hafver TL, Hodne K, Wanichawan P, Aronsen JM, Dalhus B, Lunde PK, Lunde M, Martinsen M, Enger UH, Fuller W, Sjaastad I, Louch WE, Sejersted OM, Carlson CR. Protein Phosphatase 1c Associated with the Cardiac Sodium Calcium Exchanger 1 Regulates Its Activity by Dephosphorylating Serine 68-phosphorylated Phospholemman. J Biol Chem 2015; 291:4561-79. [PMID: 26668322 DOI: 10.1074/jbc.m115.677898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/06/2022] Open
Abstract
The sodium (Na(+))-calcium (Ca(2+)) exchanger 1 (NCX1) is an important regulator of intracellular Ca(2+) homeostasis. Serine 68-phosphorylated phospholemman (pSer-68-PLM) inhibits NCX1 activity. In the context of Na(+)/K(+)-ATPase (NKA) regulation, pSer-68-PLM is dephosphorylated by protein phosphatase 1 (PP1). PP1 also associates with NCX1; however, the molecular basis of this association is unknown. In this study, we aimed to analyze the mechanisms of PP1 targeting to the NCX1-pSer-68-PLM complex and hypothesized that a direct and functional NCX1-PP1 interaction is a prerequisite for pSer-68-PLM dephosphorylation. Using a variety of molecular techniques, we show that PP1 catalytic subunit (PP1c) co-localized, co-fractionated, and co-immunoprecipitated with NCX1 in rat cardiomyocytes, left ventricle lysates, and HEK293 cells. Bioinformatic analysis, immunoprecipitations, mutagenesis, pulldown experiments, and peptide arrays constrained PP1c anchoring to the K(I/V)FF motif in the first Ca(2+) binding domain (CBD) 1 in NCX1. This binding site is also partially in agreement with the extended PP1-binding motif K(V/I)FF-X5-8Φ1Φ2-X8-9-R. The cytosolic loop of NCX1, containing the K(I/V)FF motif, had no effect on PP1 activity in an in vitro assay. Dephosphorylation of pSer-68-PLM in HEK293 cells was not observed when NCX1 was absent, when the K(I/V)FF motif was mutated, or when the PLM- and PP1c-binding sites were separated (mimicking calpain cleavage of NCX1). Co-expression of PLM and NCX1 inhibited NCX1 current (both modes). Moreover, co-expression of PLM with NCX1(F407P) (mutated K(I/V)FF motif) resulted in the current being completely abolished. In conclusion, NCX1 is a substrate-specifying PP1c regulator protein, indirectly regulating NCX1 activity through pSer-68-PLM dephosphorylation.
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Affiliation(s)
- Tandekile Lubelwana Hafver
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Kjetil Hodne
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway, the Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences (NMBU), 0454 Oslo, Norway
| | - Pimthanya Wanichawan
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Jan Magnus Aronsen
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the Bjørknes College, Oslo, Norway
| | - Bjørn Dalhus
- the Department of Microbiology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway, the Department of Medical Biochemistry, Institute for Clinical Medicine, University of Oslo, 0424 Oslo, Norway and
| | - Per Kristian Lunde
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Marianne Lunde
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Marita Martinsen
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Ulla Helene Enger
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - William Fuller
- the Cardiovascular and Diabetes Medicine, School of Medicine, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
| | - Ivar Sjaastad
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - William Edward Louch
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Ole Mathias Sejersted
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Cathrine Rein Carlson
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway,
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21
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Michel LYM, Hoenderop JGJ, Bindels RJM. Calpain-3-mediated regulation of the Na⁺-Ca²⁺ exchanger isoform 3. Pflugers Arch 2015; 468:243-55. [PMID: 26503425 PMCID: PMC4713461 DOI: 10.1007/s00424-015-1747-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/05/2015] [Accepted: 10/07/2015] [Indexed: 12/27/2022]
Abstract
Ca2+ disturbances are observed when Ca2+-dependent cysteine proteases malfunction, causing muscle weakness and wasting. For example, loss of calpain-3 (CAPN3) activity leads to limb-girdle muscular dystrophy 2A (LGMD2A). In neuronal excitotoxicity, the cleavage of the Na+-Ca2+ exchanger isoform 3 (NCX3) has been associated with an increase in activity and elevation of the Ca2+ content in the endoplasmic reticulum (ER). Since NCX3 is expressed in skeletal muscle, we evaluated the cleavage of different NCX3 splice variants by CAPN1 and CAPN3. Using Fura-2-based cellular Ca2+ imaging, we showed for the first time that CAPN3 increases NCX3 activity and that only NCX3-AC, the variant predominantly expressed in skeletal muscle, is sensitive to calpain. The silencing of the endogenous CAPN1 and the expression of the inactive form of CAPN3 (C129S CAPN3) confirmed the specificity for CAPN1 and CAPN3. Functional studies revealed that cellular Ca2+ uptake through the reverse mode of NCX3 was significantly increased independently of the mode of activation of the exchanger by either a rise in intracellular Ca2+ ([Ca2+]i) or Na+ ([Na+]i). Subsequently, the sensitivity to CAPN1 and CAPN3 could be abrogated by removal of the six residues coded in exon C of NCX3-AC. Additionally, mutation of the Leu-600 and Leu-601 suggested the presence of a cleavage site at Leu-602. The increased Ca2+ uptake of NCX3 might participate in the Ca2+ refilling of the sarcoplasmic reticulum (SR) after the excitation-contraction uncoupling following exercise and therefore be implicated in the impaired reticular Ca2+ storage observed in LGMD2A.
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Affiliation(s)
- Lauriane Y M Michel
- From the Department of Physiology, Centre for System Biology and Bioenergetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- From the Department of Physiology, Centre for System Biology and Bioenergetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - René J M Bindels
- From the Department of Physiology, Centre for System Biology and Bioenergetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
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22
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Chen Q, Lesnefsky EJ. Heart mitochondria and calpain 1: Location, function, and targets. Biochim Biophys Acta Mol Basis Dis 2015; 1852:2372-8. [PMID: 26259540 DOI: 10.1016/j.bbadis.2015.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 07/17/2015] [Accepted: 08/06/2015] [Indexed: 12/22/2022]
Abstract
Calpain 1 is an ubiquitous Ca(2+)-dependent cysteine protease. Although calpain 1 has been found in cardiac mitochondria, the exact location within mitochondrial compartments and its function remain unclear. The aim of the current review is to discuss the localization of calpain 1 in different mitochondrial compartments in relationship to its function, especially in pathophysiological conditions. Briefly, mitochondrial calpain 1 (mit-CPN1) is located within the intermembrane space and mitochondrial matrix. Activation of the mit-CPN1 within intermembrane space cleaves apoptosis inducing factor (AIF), whereas the activated mit-CPN1 within matrix cleaves complex I subunits and metabolic enzymes. Inhibition of the mit-CPN1 could be a potential strategy to decrease cardiac injury during ischemia-reperfusion.
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Affiliation(s)
- Qun Chen
- Department of Medicine (Division of Cardiology, Pauley Heart Center), Virginia Commonwealth University, Richmond, VA 23298, United States.
| | - Edward J Lesnefsky
- Department of Medicine (Division of Cardiology, Pauley Heart Center), Virginia Commonwealth University, Richmond, VA 23298, United States; Department of Biochemistry, Virginia Commonwealth University, Richmond, VA 23298, United States; Department of Physiology, Virginia Commonwealth University, Richmond, VA 23298, United States; McGuire VA Medical Center, Richmond, VA 23249, United States
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