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Yeste M, Ahmad A, Viñolas E, Recuero S, Bonet S, Pinart E. Inhibition of forward and reverse transport of Ca 2+ via Na +/Ca 2+ exchangers (NCX) prevents sperm capacitation. Biol Res 2024; 57:57. [PMID: 39175101 PMCID: PMC11342557 DOI: 10.1186/s40659-024-00535-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 08/06/2024] [Indexed: 08/24/2024] Open
Abstract
BACKGROUND While calcium is known to play a crucial role in mammalian sperm physiology, how it flows in and out of the male gamete is not completely understood. Herein, we investigated the involvement of Na+/Ca2+ exchangers (NCX) in mammalian sperm capacitation. Using the pig as an animal model, we first confirmed the presence of NCX1 and NCX2 isoforms in the sperm midpiece. Next, we partially or totally blocked Ca2+ outflux (forward transport) via NCX1/NCX2 with different concentrations of SEA0400 (2-[4-[(2,5-difluorophenyl)methoxy]phenoxy]-5-ethoxyaniline; 0, 0.5, 5 and 50 µM) and Ca2+ influx (reverse transport) with SN6 (ethyl 2-[[4-[(4-nitrophenyl)methoxy]phenyl]methyl]-1,3-thiazolidine-4-carboxylate; 0, 0.3, 3 or 30 µM). Sperm were incubated under capacitating conditions for 180 min; after 120 min, progesterone was added to induce the acrosome reaction. At 0, 60, 120, 130, and 180 min, sperm motility, membrane lipid disorder, acrosome integrity, mitochondrial membrane potential (MMP), tyrosine phosphorylation of sperm proteins, and intracellular levels of Ca2+, reactive oxygen species (ROS) and superoxides were evaluated. RESULTS Partial and complete blockage of Ca2+ outflux and influx via NCX induced a significant reduction of sperm motility after progesterone addition. Early alterations on sperm kinematics were also observed, the effects being more obvious in totally blocked than in partially blocked samples. Decreased sperm motility and kinematics were related to both defective tyrosine phosphorylation and mitochondrial activity, the latter being associated to diminished MMP and ROS levels. As NCX blockage did not affect the lipid disorder of plasma membrane, the impaired acrosome integrity could result from reduced tyrosine phosphorylation. CONCLUSIONS Inhibition of outflux and influx of Ca2+ triggered similar effects, thus indicating that both forward and reverse Ca2+ transport through NCX exchangers are essential for sperm capacitation.
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Affiliation(s)
- Marc Yeste
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, ES-17003, Spain
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, ES-17003, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, ES-08010, Spain
| | - Adeel Ahmad
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, ES-17003, Spain
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, ES-17003, Spain
| | - Estel Viñolas
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, ES-17003, Spain
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, ES-17003, Spain
| | - Sandra Recuero
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, ES-17003, Spain
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, ES-17003, Spain
| | - Sergi Bonet
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, ES-17003, Spain
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, ES-17003, Spain
| | - Elisabeth Pinart
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, ES-17003, Spain.
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, ES-17003, Spain.
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Proteau S, Krossa I, Husser C, Guéguinou M, Sella F, Bille K, Irondelle M, Dalmasso M, Barouillet T, Cheli Y, Pisibon C, Arrighi N, Nahon‐Estève S, Martel A, Gastaud L, Lassalle S, Mignen O, Brest P, Mazure NM, Bost F, Baillif S, Landreville S, Turcotte S, Hasson D, Carcamo S, Vandier C, Bernstein E, Yvan‐Charvet L, Levesque MP, Ballotti R, Bertolotto C, Strub T. LKB1-SIK2 loss drives uveal melanoma proliferation and hypersensitivity to SLC8A1 and ROS inhibition. EMBO Mol Med 2023; 15:e17719. [PMID: 37966164 PMCID: PMC10701601 DOI: 10.15252/emmm.202317719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 10/16/2023] [Accepted: 10/23/2023] [Indexed: 11/16/2023] Open
Abstract
Metastatic uveal melanomas are highly resistant to all existing treatments. To address this critical issue, we performed a kinome-wide CRISPR-Cas9 knockout screen, which revealed the LKB1-SIK2 module in restraining uveal melanoma tumorigenesis. Functionally, LKB1 loss enhances proliferation and survival through SIK2 inhibition and upregulation of the sodium/calcium (Na+ /Ca2+ ) exchanger SLC8A1. This signaling cascade promotes increased levels of intracellular calcium and mitochondrial reactive oxygen species, two hallmarks of cancer. We further demonstrate that combination of an SLC8A1 inhibitor and a mitochondria-targeted antioxidant promotes enhanced cell death efficacy in LKB1- and SIK2-negative uveal melanoma cells compared to control cells. Our study also identified an LKB1-loss gene signature for the survival prognostic of patients with uveal melanoma that may be also predictive of response to the therapy combination. Our data thus identify not only metabolic vulnerabilities but also new prognostic markers, thereby providing a therapeutic strategy for particular subtypes of metastatic uveal melanoma.
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Affiliation(s)
- Sarah Proteau
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Imène Krossa
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Chrystel Husser
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | | | - Federica Sella
- Department of Dermatology, University Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Karine Bille
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | | | - Mélanie Dalmasso
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Thibault Barouillet
- Inserm, Hematometabolism and metainflammation, team 13, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Yann Cheli
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Céline Pisibon
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Nicole Arrighi
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Sacha Nahon‐Estève
- University Côte d'AzurNiceFrance
- Department of OphthalmologyCentre Hospitalier Universitaire of NiceNiceFrance
| | - Arnaud Martel
- University Côte d'AzurNiceFrance
- Department of OphthalmologyCentre Hospitalier Universitaire of NiceNiceFrance
| | | | - Sandra Lassalle
- University Côte d'AzurNiceFrance
- Laboratory of Clinical and Experimental Pathology, University Hospital of Nice, FHU OncoAge, Cote d'Azur University, Biobank BB‐0033‐00025, IRCAN team 4, OncoAge FHUNiceFrance
| | | | - Patrick Brest
- University Côte d'AzurNiceFrance
- IRCAN team 4, Inserm, CNRS, FHU‐oncoAge, IHU‐RESPIRera NiceNiceFrance
| | - Nathalie M Mazure
- University Côte d'AzurNiceFrance
- Inserm, Cancer, Metabolism and environment, team, Equipe labellisée Ligue 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Frédéric Bost
- University Côte d'AzurNiceFrance
- Inserm, Cancer, Metabolism and environment, team, Equipe labellisée Ligue 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Stéphanie Baillif
- University Côte d'AzurNiceFrance
- Department of OphthalmologyCentre Hospitalier Universitaire of NiceNiceFrance
| | - Solange Landreville
- Département d'ophtalmologie et d'ORL‐CCF, Faculté de médecineUniversité LavalQuebec CityQCCanada
- CUO‐Recherche and Axe médecine régénératriceCentre de recherche du CHU de Québec‐Université LavalQuebec CityQCCanada
- Centre de recherche sur le cancer de l'Université LavalQuebec CityQCCanada
- Centre de recherche en organogénèse expérimentale de l'Université Laval/LOEXQuebec CityQCCanada
| | - Simon Turcotte
- Cancer AxisCentre de recherche du Centre Hospitalier de l'Université de Montréal/Institut du cancer de MontréalMontréalQCCanada
- Hepato‐Pancreato‐Biliary Surgery and Liver Transplantation ServiceCentre hospitalier de l'Université de MontréalMontréalQCCanada
| | - Dan Hasson
- Department of Oncological Sciences, Tisch Cancer InstituteIcahn School of Medicine at Mount SinaiNew YorkNYUSA
- Tisch Cancer Institute Bioinformatics for Next Generation Sequencing (BiNGS) FacilityIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Saul Carcamo
- Department of Oncological Sciences, Tisch Cancer InstituteIcahn School of Medicine at Mount SinaiNew YorkNYUSA
- Tisch Cancer Institute Bioinformatics for Next Generation Sequencing (BiNGS) FacilityIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | | | - Emily Bernstein
- Department of Oncological Sciences, Tisch Cancer InstituteIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Laurent Yvan‐Charvet
- University Côte d'AzurNiceFrance
- Inserm, Hematometabolism and metainflammation, team 13, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Mitchell P Levesque
- Department of Dermatology, University Hospital ZurichUniversity of ZurichZurichSwitzerland
| | - Robert Ballotti
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Corine Bertolotto
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
| | - Thomas Strub
- University Côte d'AzurNiceFrance
- Inserm, Biology and Pathologies of melanocytes, team1, Equipe labellisée Ligue 2020, and Equipe labellisée ARC 2022, Mediterranean Centre for Molecular MedicineNiceFrance
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Takei GL, Ogura Y, Ujihara Y, Toyama F, Hayashi K, Fujita T. Hamster Sperm Possess Functional Na +/Ca 2+-Exchanger 1: Its Implication in Hyperactivation. Int J Mol Sci 2023; 24:ijms24108905. [PMID: 37240252 DOI: 10.3390/ijms24108905] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Previous studies demonstrated that hamster sperm hyperactivation is suppressed by extracellular Na+ by lowering intracellular Ca2+ levels, and Na+/Ca2+-exchanger (NCX) specific inhibitors canceled the suppressive effects of extracellular Na+. These results suggest the involvement of NCX in the regulation of hyperactivation. However, direct evidence of the presence and functionality of NCX in hamster spermatozoa is still lacking. This study aimed to reveal that NCX is present and is functional in hamster spermatozoa. First, NCX1 and NCX2 transcripts were detected via RNA-seq analyses of hamster testis mRNAs, but only the NCX1 protein was detected. Next, NCX activity was determined by measuring the Na+-dependent Ca2+ influx using the Ca2+ indicator Fura-2. The Na+-dependent Ca2+ influx was detected in hamster spermatozoa, notably in the tail region. The Na+-dependent Ca2+ influx was inhibited by the NCX inhibitor SEA0400 at NCX1-specific concentrations. NCX1 activity was reduced after 3 h of incubation in capacitating conditions. These results, together with authors' previous study, showed that hamster spermatozoa possesses functional NCX1 and that its activity was downregulated upon capacitation to trigger hyperactivation. This is the first study to successfully reveal the presence of NCX1 and its physiological function as a hyperactivation brake.
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Affiliation(s)
- Gen L Takei
- Department of Pharmacology and Toxicology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
| | - Yuhei Ogura
- Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | - Yoshihiro Ujihara
- Department of Electrical and Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | - Fubito Toyama
- School of Engineering, Utsunomiya University, Yoto 7-1-2, Utsunomiya 321-8585, Japan
| | - Keitaro Hayashi
- Department of Pharmacology and Toxicology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
| | - Tomoe Fujita
- Department of Pharmacology and Toxicology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Tochigi 321-0293, Japan
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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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5
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Elasmobranch Cardiovascular System. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/b978-0-12-801286-4.00001-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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6
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Towards Understanding the Role of the Na+-Ca2+ Exchanger Isoform 3. Rev Physiol Biochem Pharmacol 2015; 168:31-57. [DOI: 10.1007/112_2015_23] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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7
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Heijman J, Dewenter M, El-Armouche A, Dobrev D. Function and regulation of serine/threonine phosphatases in the healthy and diseased heart. J Mol Cell Cardiol 2013; 64:90-8. [PMID: 24051368 DOI: 10.1016/j.yjmcc.2013.09.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/03/2013] [Accepted: 09/08/2013] [Indexed: 12/20/2022]
Abstract
Protein phosphorylation is a major control mechanism of a wide range of physiological processes and plays an important role in cardiac pathophysiology. Serine/threonine protein phosphatases control the dephosphorylation of a variety of cardiac proteins, thereby fine-tuning cardiac electrophysiology and function. Specificity of protein phosphatases type-1 and type-2A is achieved by multiprotein complexes that target the catalytic subunits to specific subcellular domains. Here, we describe the composition, regulation and target substrates of serine/threonine phosphatases in the heart. In addition, we provide an overview of pharmacological tools and genetic models to study the role of cardiac phosphatases. Finally, we review the role of protein phosphatases in the diseased heart, particularly in ventricular arrhythmias and atrial fibrillation and discuss their role as potential therapeutic targets.
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Affiliation(s)
- Jordi Heijman
- Institute of Pharmacology, Faculty of Medicine, University Duisburg-Essen, 45122 Essen, Germany
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Tritsch E, Mallat Y, Lefebvre F, Diguet N, Escoubet B, Blanc J, De Windt LJ, Catalucci D, Vandecasteele G, Li Z, Mericskay M. An SRF/miR-1 axis regulates NCX1 and annexin A5 protein levels in the normal and failing heart. Cardiovasc Res 2013; 98:372-80. [PMID: 23436819 DOI: 10.1093/cvr/cvt042] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The expression of the sodium/calcium exchanger NCX1 increases during cardiac hypertrophy and heart failure, playing an important role in Ca(2+) extrusion. This increase is presumed to result from stress signalling induced changes in the interplay between transcriptional and post-transcriptional regulations. We aimed to determine the impact of the SRF transcription factor known to regulate the NCX1 promoter and microRNA genes, on the expression of NCX1 mRNA and protein and annexin A5 (AnxA5), a Ca(2+)-binding protein interacting with NCX1 and increased during HF. METHODS AND RESULTS NCX1 mRNA was decreased while the protein was increased in the failing heart of the cardiomyocyte-restricted SRF knock-out mice (SRF(HKO)). The induction of NCX1 mRNA by the pro-hypertrophic drug phenylephrine observed in control mice was abolished in the SRF(HKO) though the protein was strongly increased. AnxA5 protein expression profile paralleled the expression of NCX1 protein in the SRF(HKO). MiR-1, a microRNA regulated by SRF, was decreased in the SRF(HKO) and repressed by phenylephrine. In vitro and in vivo manipulation of miR-1 levels and site-directed mutagenesis showed that NCX1 and AnxA5 mRNAs are targets of miR-1. AnxA5 overexpression slowed down Ca(2+) extrusion during caffeine application in adult rat cardiomyocytes. CONCLUSION Our study reveals the existence of a complex regulatory loop where SRF regulates the transcription of NCX1 and miR-1, which in turn functions as a rheostat limiting the translation of NCX1 and AnxA5 proteins. The decrease of miR-1 and increase of AnxA5 appear as important modulators of NCX1 expression and activity during heart failure.
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Affiliation(s)
- Eva Tritsch
- Department of Aging, Stress and Inflammation , UPMC Univ Paris 6, 7, quai Saint Bernard - BP 256, Paris 75005, France
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9
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Zhang J. New insights into the contribution of arterial NCX to the regulation of myogenic tone and blood pressure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:329-43. [PMID: 23224892 DOI: 10.1007/978-1-4614-4756-6_28] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Plasma membrane protein Na(+)/Ca(2+) exchanger (NCX) in vascular smooth muscle (VSM) cells plays an important role in intracellular Ca(2+) homeostasis, Ca(2+) signaling, and arterial contractility. Recent evidence in intact animals reveals that VSM NCX type 1 (NCX1) is importantly involved in the control of arterial blood pressure (BP) in the normal state and in hypertension. Increased expression of vascular NCX1 has been implicated in human primary pulmonary hypertension and several salt-dependent hypertensive animal models. Our aim is to determine the molecular and physiological mechanisms by which vascular NCX influences vasoconstriction and BP normally and in salt-dependent hypertension. Here, we describe the relative contribution of VSM NCX1 to Ca(2+) signaling and arterial contraction, including recent data from transgenic mice (NCX1(smTg/Tg), overexpressors; NCX1(sm-/-), knockouts) that has begun to elucidate the specific contributions of NCX to BP regulation. Arterial contraction and BP correlate with the level of NCX1 expression in smooth muscle: NCX1(sm-/-) mice have decreased arterial myogenic tone (MT), vasoconstriction, and low BP. NCX1(smTg/Tg) mice have high BP and are more sensitive to salt; their arteries exhibit upregulated transient receptor potential canonical channel 6 (TRPC6) protein, increased MT, and vasoconstriction. These observations suggest that NCX is a key component of certain distinct signaling pathways that activate VSM contraction in response to stretch (i.e., myogenic response) and to activation of certain G-protein-coupled receptors. Arterial NCX expression and mechanisms that control the local (sub-plasma membrane) Na(+) gradient, including cation-selective receptor-operated channels containing TRPC6, regulate arterial Ca(2+) and constriction, and thus BP.
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Affiliation(s)
- Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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