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Blaustein MP, Hamlyn JM. Sensational site: the sodium pump ouabain-binding site and its ligands. Am J Physiol Cell Physiol 2024; 326:C1120-C1177. [PMID: 38223926 PMCID: PMC11193536 DOI: 10.1152/ajpcell.00273.2023] [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: 06/22/2023] [Revised: 12/22/2023] [Accepted: 01/10/2024] [Indexed: 01/16/2024]
Abstract
Cardiotonic steroids (CTS), used by certain insects, toads, and rats for protection from predators, became, thanks to Withering's trailblazing 1785 monograph, the mainstay of heart failure (HF) therapy. In the 1950s and 1960s, we learned that the CTS receptor was part of the sodium pump (NKA) and that the Na+/Ca2+ exchanger was critical for the acute cardiotonic effect of digoxin- and ouabain-related CTS. This "settled" view was upended by seven revolutionary observations. First, subnanomolar ouabain sometimes stimulates NKA while higher concentrations are invariably inhibitory. Second, endogenous ouabain (EO) was discovered in the human circulation. Third, in the DIG clinical trial, digoxin only marginally improved outcomes in patients with HF. Fourth, cloning of NKA in 1985 revealed multiple NKA α and β subunit isoforms that, in the rodent, differ in their sensitivities to CTS. Fifth, the NKA is a cation pump and a hormone receptor/signal transducer. EO binding to NKA activates, in a ligand- and cell-specific manner, several protein kinase and Ca2+-dependent signaling cascades that have widespread physiological effects and can contribute to hypertension and HF pathogenesis. Sixth, all CTS are not equivalent, e.g., ouabain induces hypertension in rodents while digoxin is antihypertensinogenic ("biased signaling"). Seventh, most common rodent hypertension models require a highly ouabain-sensitive α2 NKA and the elevated blood pressure is alleviated by EO immunoneutralization. These numerous phenomena are enabled by NKA's intricate structure. We have just begun to understand the endocrine role of the endogenous ligands and the broad impact of the ouabain-binding site on physiology and pathophysiology.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States
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2
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Horesh N, Pelov I, Pogodin I, Zannadeh H, Rosen H, Mikhrina AL, Dvela-Levitt M, Sampath VP, Lichtstein D. Involvement of the Na +, K +-ATPase α1 Isoform and Endogenous Cardiac Steroids in Depression- and Manic-like Behaviors. Int J Mol Sci 2024; 25:1644. [PMID: 38338921 PMCID: PMC10855204 DOI: 10.3390/ijms25031644] [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: 11/23/2023] [Revised: 01/18/2024] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
Bipolar disorder (BD) is a severe and common chronic mental illness characterized by recurrent mood swings between depression and mania. The biological basis of the disease is poorly understood, and its treatment is unsatisfactory. Na+, K+-ATPase is a major plasma membrane transporter and signal transducer. The catalytic α subunit of this enzyme is the binding site for cardiac steroids. Three α isoforms of the Na+, K+-ATPase are present in the brain. Previous studies have supported the involvement of the Na+, K+-ATPase and endogenous cardiac steroids (ECS) in the etiology of BD. Decreased brain ECS has been found to elicit anti-manic and anti-depressive-like behaviors in mice and rats. However, the identity of the specific α isoform involved in these behavioral effects is unknown. Here, we demonstrated that decreasing ECS through intracerebroventricular (i.c.v.) administration of anti-ouabain antibodies (anti-Ou-Ab) decreased the activity of α1+/- mice in forced swimming tests but did not change the activity in wild type (wt) mice. This treatment also affected exploratory and anxiety behaviors in α1+/- but not wt mice, as measured in open field tests. The i.c.v. administration of anti-Ou-Ab decreased brain ECS and increased brain Na+, K+-ATPase activity in wt and α1+/- mice. The serum ECS was lower in α1+/- than wt mice. In addition, a study in human participants demonstrated that serum ECS significantly decreased after treatment. These results suggest that the Na+, K+-ATPase α1 isoform is involved in depressive- and manic-like behaviors and support that the Na+, K+-ATPase/ECS system participates in the etiology of BD.
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Affiliation(s)
- Noa Horesh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Ilana Pelov
- Jerusalem Mental Health Center, Eitanim Psychiatric Hospital, Jerusalem 91060, Israel;
| | - Ilana Pogodin
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Hiba Zannadeh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Haim Rosen
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel;
| | - Anastasiia Leonidovna Mikhrina
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - Moran Dvela-Levitt
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel;
| | - Vishnu Priya Sampath
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
| | - David Lichtstein
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91905, Israel; (N.H.); (I.P.); (H.Z.); (A.L.M.); (V.P.S.)
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3
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Jahanshahi S, Ouyang H, Ahmed C, Zahedi Amiri A, Dahal S, Mao YQ, Van Ommen DAJ, Malty R, Duan W, Been T, Hernandez J, Mangos M, Nurtanto J, Babu M, Attisano L, Houry WA, Moraes TJ, Cochrane A. Broad spectrum post-entry inhibitors of coronavirus replication: Cardiotonic steroids and monensin. Virology 2024; 589:109915. [PMID: 37931588 DOI: 10.1016/j.virol.2023.109915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/10/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
A small molecule screen identified several cardiotonic steroids (digitoxin and ouabain) and the ionophore monensin as potent inhibitors of HCoV-229E, HCoV-OC43, and SARS-CoV-2 replication with EC50s in the low nM range. Subsequent tests confirmed antiviral activity in primary cell models including human nasal epithelial cells and lung organoids. Addition of digitoxin, ouabain, or monensin strongly reduced viral gene expression as measured by both viral protein and RNA accumulation. Furthermore, the compounds acted post virus entry. While the antiviral activity of digitoxin was dependent upon activation of the MEK and JNK signaling pathways but not signaling through GPCRs, the antiviral effect of monensin was reversed upon inhibition of several signaling pathways. Together, the data demonstrates the potent anti-coronavirus properties of two classes of FDA approved drugs that function by altering the properties of the infected cell, rendering it unable to support virus replication.
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Affiliation(s)
- Shahrzad Jahanshahi
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada; Dept. of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Hong Ouyang
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Choudhary Ahmed
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Ali Zahedi Amiri
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Subha Dahal
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Yu-Qian Mao
- Dept. of Biochemistry, University of Toronto, Toronto, ON, Canada
| | | | - Ramy Malty
- Dept. of Biochemistry, University of Toronto, Toronto, ON, Canada; Research and Innovation Centre, Department of Biochemistry, University of Regina, Regina, SK, Canada
| | - Wenming Duan
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Terek Been
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Maria Mangos
- Donnelly Center, University of Toronto, Ontario, Canada
| | | | - Mohan Babu
- Research and Innovation Centre, Department of Biochemistry, University of Regina, Regina, SK, Canada
| | - Liliana Attisano
- Dept. of Biochemistry, University of Toronto, Toronto, ON, Canada; Donnelly Center, University of Toronto, Ontario, Canada
| | - Walid A Houry
- Dept. of Biochemistry, University of Toronto, Toronto, ON, Canada; Dept. of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Theo J Moraes
- Program in Translational Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Alan Cochrane
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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4
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Staehr C, Aalkjaer C, Matchkov V. The vascular Na,K-ATPase: clinical implications in stroke, migraine, and hypertension. Clin Sci (Lond) 2023; 137:1595-1618. [PMID: 37877226 PMCID: PMC10600256 DOI: 10.1042/cs20220796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/26/2023]
Abstract
In the vascular wall, the Na,K-ATPase plays an important role in the control of arterial tone. Through cSrc signaling, it contributes to the modulation of Ca2+ sensitivity in vascular smooth muscle cells. This review focuses on the potential implication of Na,K-ATPase-dependent intracellular signaling pathways in severe vascular disorders; ischemic stroke, familial migraine, and arterial hypertension. We propose similarity in the detrimental Na,K-ATPase-dependent signaling seen in these pathological conditions. The review includes a retrospective proteomics analysis investigating temporal changes after ischemic stroke. The analysis revealed that the expression of Na,K-ATPase α isoforms is down-regulated in the days and weeks following reperfusion, while downstream Na,K-ATPase-dependent cSrc kinase is up-regulated. These results are important since previous studies have linked the Na,K-ATPase-dependent cSrc signaling to futile recanalization and vasospasm after stroke. The review also explores a link between the Na,K-ATPase and migraine with aura, as reduced expression or pharmacological inhibition of the Na,K-ATPase leads to cSrc kinase signaling up-regulation and cerebral hypoperfusion. The review discusses the role of an endogenous cardiotonic steroid-like compound, ouabain, which binds to the Na,K-ATPase and initiates the intracellular cSrc signaling, in the pathophysiology of arterial hypertension. Currently, our understanding of the precise control mechanisms governing the Na,K-ATPase/cSrc kinase regulation in the vascular wall is limited. Understanding the role of vascular Na,K-ATPase signaling is essential for developing targeted treatments for cerebrovascular disorders and hypertension, as the Na,K-ATPase is implicated in the pathogenesis of these conditions and may contribute to their comorbidity.
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Affiliation(s)
- Christian Staehr
- Department of Biomedicine, Aarhus University, Høegh-Guldbergsgade 10, 8000 Aarhus, Denmark
- Department of Renal Medicine, Aarhus University Hospital, Palle Juul-Jensens Boulevard 35, Aarhus, Denmark
| | - Christian Aalkjaer
- Department of Biomedicine, Aarhus University, Høegh-Guldbergsgade 10, 8000 Aarhus, Denmark
- Danish Cardiovascular Academy, Høegh-Guldbergsgade 10, 8000 Aarhus, Denmark
| | - Vladimir V. Matchkov
- Department of Biomedicine, Aarhus University, Høegh-Guldbergsgade 10, 8000 Aarhus, Denmark
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Carullo N, Fabiano G, D'Agostino M, Zicarelli MT, Musolino M, Presta P, Michael A, Andreucci M, Bolignano D, Coppolino G. New Insights on the Role of Marinobufagenin from Bench to Bedside in Cardiovascular and Kidney Diseases. Int J Mol Sci 2023; 24:11186. [PMID: 37446363 DOI: 10.3390/ijms241311186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
Marinobufagenin (MBG) is a member of the bufadienolide family of compounds, which are natural cardiac glycosides found in a variety of animal species, including man, which have different physiological and biochemical functions but have a common action on the inhibition of the adenosine triphosphatase sodium-potassium pump (Na+/K+-ATPase). MBG acts as an endogenous cardiotonic steroid, and in the last decade, its role as a pathogenic factor in various human diseases has emerged. In this paper, we have collated major evidence regarding the biological characteristics and functions of MBG and its implications in human pathology. This review focused on MBG involvement in chronic kidney disease, including end-stage renal disease, cardiovascular diseases, sex and gender medicine, and its actions on the nervous and immune systems. The role of MBG in pathogenesis and the development of a wide range of pathological conditions indicate that this endogenous peptide could be used in the future as a diagnostic biomarker and/or therapeutic target, opening important avenues of scientific research.
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Affiliation(s)
- Nazareno Carullo
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Giuseppe Fabiano
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Mario D'Agostino
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | | | - Michela Musolino
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Pierangela Presta
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Ashour Michael
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Michele Andreucci
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Davide Bolignano
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
| | - Giuseppe Coppolino
- Renal Unit, "Magna Graecia" University of Catanzaro, 88100 Catanzaro, Italy
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6
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Zheng J, Lan P, Li M, Kang MC, Xun M, Ma X, Yan M, Sun D, Shen Y, Fu X, Ding X, Yan X, Xue WJ. Anti-Na +/K +-ATPase DR antibody attenuates UUO-induced renal fibrosis through inhibition of Na +/K +-ATPase α1-dependent HMGB1 release. Int Immunopharmacol 2023; 116:109826. [PMID: 36764269 DOI: 10.1016/j.intimp.2023.109826] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/10/2023] [Accepted: 01/29/2023] [Indexed: 02/11/2023]
Abstract
Reduced Na+/K+-ATPase (NKA) activity and NKAα1 expression are engaged in the pathologies of renal diseases. NKA-mediated Src activation is not the only reason for NKA-related renal fibrosis. In this study, we found that genetic reduction of NKAα1 exhibited exacerbated tubulointerstitial lesions and fibrosis in the UUO mice model. Activation of NKAα1 with an antibody against the extracellular DR region of the NKAα1 subunit (DRm217) prevented UUO-induced tubulointerstitial lesions, preserved kidney function, and decrease renal fibrosis. Further studies revealed that NKAα1 deficiency mice exhibited high inflammation factors expression when they suffered UUO surgery, compared with NKAα1+/+ (WT) mice. DRm217 alleviated inflammatory cell infiltration, suppress NF-κB phosphorylation, and decreased inflammatory factors expression in the UUO mice model. Released HMGB1 can trigger the inflammatory response and contribute to renal fibrosis. Knockdown of NKA in renal tubular cells or in NKAα1+/- mice was associated with more susceptibility to HMGB1 release in the UUO mice model. DRm217 exerted its antifibrotic effect via inhibiting HMGB1 release. Furthermore, AMPK activation participates in the effect of DRm217 on inhibiting HMGB1 release. Our findings suggest that NKAα1 is a regulator of renal fibrosis and its DR-region is a novel target on it.
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Affiliation(s)
- Jin Zheng
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Ping Lan
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Meihe Li
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China
| | - Min-Chao Kang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Meng Xun
- Department of Microbiology and Immunology, Xi'an Jiaotong University, Xi'an 710061, China
| | - Xiangyun Ma
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Mengyao Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Dan Sun
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Yu Shen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Xinyi Fu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Xiaoming Ding
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China; Department of Microbiology and Immunology, Xi'an Jiaotong University, Xi'an 710061, China
| | - Xiaofei Yan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University, Xi'an, 710061, China.
| | - Wu-Jun Xue
- Hospital of Nephrology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, China.
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7
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Leite JA, Cavalcante-Silva LHA, Ribeiro MR, de Morais Lima G, Scavone C, Rodrigues-Mascarenhas S. Neuroinflammation and Neutrophils: Modulation by Ouabain. Front Pharmacol 2022; 13:824907. [PMID: 35173621 PMCID: PMC8841582 DOI: 10.3389/fphar.2022.824907] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/10/2022] [Indexed: 12/12/2022] Open
Abstract
Cardiotonic steroids are natural compounds that present many physiological and pharmacological functions. They bind Na+/K+-ATPase (NKA) modifying cellular ion concentration and trigger cell signaling mechanisms without altering ion balance. These steroids are known to modulate some immune responses, including cytokine production, neutrophil migration, and inflammation (peripherally and in the nervous system). Inflammation can occur in response to homeostasis perturbations and is related to the development of many diseases, including immune-mediated diseases and neurodegenerative disorders. Considering the neutrophils role in the general neuroinflammatory response and that these cells can be modulated by cardiac steroids, this work aims to review the possible regulation of neutrophilic neuroinflammation by the cardiac steroid ouabain.
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Affiliation(s)
- Jacqueline Alves Leite
- Department of Pharmacology, Institute of Biomedical Science, Federal University of Goiás, Goiânia, Brazil
| | | | - Martina Raissa Ribeiro
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Geovanni de Morais Lima
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Cristoforo Scavone
- Laboratory of Molecular Neuropharmacology, Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
- *Correspondence: Cristoforo Scavone,
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8
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Marck PV, Pessoa MT, Xu Y, Kutz LC, Collins DM, Yan Y, King C, Wang X, Duan Q, Cai L, Xie JX, Lingrel JB, Xie Z, Tian J, Pierre SV. Cardiac Oxidative Signaling and Physiological Hypertrophy in the Na/K-ATPase α1 s/sα2 s/s Mouse Model of High Affinity for Cardiotonic Steroids. Int J Mol Sci 2021; 22:ijms22073462. [PMID: 33801629 PMCID: PMC8036649 DOI: 10.3390/ijms22073462] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 11/25/2022] Open
Abstract
The Na/K-ATPase is the specific receptor for cardiotonic steroids (CTS) such as ouabain and digoxin. At pharmacological concentrations used in the treatment of cardiac conditions, CTS inhibit the ion-pumping function of Na/K-ATPase. At much lower concentrations, in the range of those reported for endogenous CTS in the blood, they stimulate hypertrophic growth of cultured cardiac myocytes through initiation of a Na/K-ATPase-mediated and reactive oxygen species (ROS)-dependent signaling. To examine a possible effect of endogenous concentrations of CTS on cardiac structure and function in vivo, we compared mice expressing the naturally resistant Na/K-ATPase α1 and age-matched mice genetically engineered to express a mutated Na/K-ATPase α1 with high affinity for CTS. In this model, total cardiac Na/K-ATPase activity, α1, α2, and β1 protein content remained unchanged, and the cardiac Na/K-ATPase dose–response curve to ouabain shifted to the left as expected. In males aged 3–6 months, increased α1 sensitivity to CTS resulted in a significant increase in cardiac carbonylated protein content, suggesting that ROS production was elevated. A moderate but significant increase of about 15% of the heart-weight-to-tibia-length ratio accompanied by an increase in the myocyte cross-sectional area was detected. Echocardiographic analyses did not reveal any change in cardiac function, and there was no fibrosis or re-expression of the fetal gene program. RNA sequencing analysis indicated that pathways related to energy metabolism were upregulated, while those related to extracellular matrix organization were downregulated. Consistent with a functional role of the latter, an angiotensin-II challenge that triggered fibrosis in the α1r/rα2s/s mouse failed to do so in the α1s/sα2s/s. Taken together, these results are indicative of a link between circulating CTS, Na/K-ATPase α1, ROS, and physiological cardiac hypertrophy in mice under baseline laboratory conditions.
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Affiliation(s)
- Pauline V. Marck
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Marco T. Pessoa
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Yunhui Xu
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Laura C. Kutz
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Dominic M. Collins
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Yanling Yan
- Department of Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25755, USA;
| | - Cierra King
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Xiaoliang Wang
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Qiming Duan
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA;
| | - Liquan Cai
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Jeffrey X. Xie
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Jerry B. Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Jiang Tian
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
| | - Sandrine V. Pierre
- Marshall Institute for Interdisciplinary Research, Huntington, WV 25703, USA; (P.V.M.); (M.T.P.); (Y.X.); (L.C.K.); (D.M.C.); (C.K.); (X.W.); (L.C.); (Z.X.); (J.T.)
- Correspondence: ; Tel.: +1-(304)-696-3505
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9
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Pillai SS, Lakhani HV, Zehra M, Wang J, Dilip A, Puri N, O’Hanlon K, Sodhi K. Predicting Nonalcoholic Fatty Liver Disease through a Panel of Plasma Biomarkers and MicroRNAs in Female West Virginia Population. Int J Mol Sci 2020; 21:ijms21186698. [PMID: 32933141 PMCID: PMC7554851 DOI: 10.3390/ijms21186698] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/04/2020] [Accepted: 09/11/2020] [Indexed: 02/07/2023] Open
Abstract
(1) Background: Nonalcoholic fatty liver disease (NAFLD) is primarily characterized by the presence of fatty liver, hepatic inflammation and fibrogenesis eventually leading to nonalcoholic steatohepatitis (NASH) or cirrhosis. Obesity and diabetes are common risk factors associated with the development and progression of NAFLD, with one of the highest prevalence of these diseased conditions in the West Virginia population. Currently, the diagnosis of NAFLD is limited to radiologic studies and biopsies, which are not cost-effective and highly invasive. Hence, this study aimed to develop a panel and assess the progressive levels of circulatory biomarkers and miRNA expression in patients at risk for progression to NASH to allow early intervention strategies. (2) Methods: In total, 62 female patients were enrolled and blood samples were collected after 8–10 h of fasting. Computed tomography was performed on abdomen/pelvis following IV contrast administration. The patients were divided into the following groups: Healthy subjects with normal BMI and normal fasting blood glucose (Control, n = 20), Obese with high BMI and normal fasting blood glucose (Obese, n = 20) and Obese with high fasting blood glucose (Obese + DM, n = 22). Based on findings from CT, another subset was created from Obese + DM group with patients who showed signs of fatty liver infiltration (Obese + DM(FI), n = 10). ELISA was performed for measurement of plasma biomarkers and RT-PCR was performed for circulating miRNA expression. (3) Results: Our results show significantly increased levels of plasma IL-6, Leptin and FABP-1, while significantly decreased level of adiponectin in Obese, Obese + DM and Obese + DM(FI) group, as compared to healthy controls. The level of CK-18 was significantly increased in Obese + DM(FI) group as compared to control. Subsequently, the expression of miR-122, miR-34a, miR-375, miR-16 and miR-21 was significantly increased in Obese + DM and Obese + DM(FI) group as compared to healthy control. Our results also show distinct correlation of IL-6, FABP-1 and adiponectin levels with the expression of miRNAs in relation to the extent of NAFLD progression. (4) Conclusion: Our results support the clinical application of these biomarkers and miRNAs in monitoring the progression of NAFLD, suggesting a more advanced diagnostic potential of this panel than conventional methods. This panel may provide an appropriate method for early prognosis and management of NAFLD and subsequent adverse hepatic pathophysiology, potentially reducing the disease burden on the West Virginia population.
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Affiliation(s)
- Sneha S. Pillai
- Departments of Surgery and Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA; (S.S.P.); (H.V.L.); (M.Z.); (J.W.); (A.D.)
| | - Hari Vishal Lakhani
- Departments of Surgery and Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA; (S.S.P.); (H.V.L.); (M.Z.); (J.W.); (A.D.)
| | - Mishghan Zehra
- Departments of Surgery and Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA; (S.S.P.); (H.V.L.); (M.Z.); (J.W.); (A.D.)
| | - Jiayan Wang
- Departments of Surgery and Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA; (S.S.P.); (H.V.L.); (M.Z.); (J.W.); (A.D.)
| | - Anum Dilip
- Departments of Surgery and Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA; (S.S.P.); (H.V.L.); (M.Z.); (J.W.); (A.D.)
| | - Nitin Puri
- Departments of Biomedical Sciences and Medical Education, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA;
| | - Kathleen O’Hanlon
- Departments of Family Medicine, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA;
| | - Komal Sodhi
- Departments of Surgery and Biomedical Sciences, Marshall University Joan C. Edwards School of Medicine, Huntington, WV 25701, USA; (S.S.P.); (H.V.L.); (M.Z.); (J.W.); (A.D.)
- Correspondence: ; Tel.: +1-(304)-691-1704; Fax: +1-(914)-347-4956
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10
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Lopina OD, Tverskoi AM, Klimanova EA, Sidorenko SV, Orlov SN. Ouabain-Induced Cell Death and Survival. Role of α1-Na,K-ATPase-Mediated Signaling and [Na +] i/[K +] i-Dependent Gene Expression. Front Physiol 2020; 11:1060. [PMID: 33013454 PMCID: PMC7498651 DOI: 10.3389/fphys.2020.01060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/31/2020] [Indexed: 12/12/2022] Open
Abstract
Ouabain is of cardiotonic steroids (CTS) family that is plant-derived compounds and is known for many years as therapeutic and cytotoxic agents. They are specific inhibitors of Na,K-ATPase, the enzyme, which pumps Na+ and K+ across plasma membrane of animal cells. Treatment of cells by CTS affects various cellular functions connected with the maintenance of the transmembrane gradient of Na+ and K+. Numerous studies demonstrated that binding of CTS to Na,K-ATPase not only suppresses its activity but also induces some signal pathways. This review is focused on different mechanisms of two ouabain effects: their ability (1) to protect rodent cells from apoptosis through the expression of [Na+]i-sensitive genes and (2) to trigger death of non-rodents cells (so-called «oncosis»), possessing combined markers of «classic» necrosis and «classic» apoptosis. Detailed study of oncosis demonstrated that the elevation of the [Na+]i/[K+]i ratio is not a sufficient for its triggering. Non-rodent cell death is determined by the characteristic property of "sensitive" to ouabain α1-subunit of Na,K-ATPase. In this case, ouabain binding leads to enzyme conformational changes triggering the activation of p38 mitogen-activated protein kinases (MAPK) signaling. The survival of rodent cells with ouabain-«resistant» α1-subunit is connected with another conformational transition induced by ouabain binding that results in the activation of ERK 1/2 signaling pathway.
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Affiliation(s)
- Olga Dmitrievna Lopina
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Artem Mikhaylovich Tverskoi
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences (RAS), Moscow, Russia
- Laboratory of Biological Membranes, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | | | - Sergei Nikolaevich Orlov
- Laboratory of Biological Membranes, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
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11
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Leite JA, Isaksen TJ, Heuck A, Scavone C, Lykke-Hartmann K. The α 2 Na +/K +-ATPase isoform mediates LPS-induced neuroinflammation. Sci Rep 2020; 10:14180. [PMID: 32843655 PMCID: PMC7447643 DOI: 10.1038/s41598-020-71027-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/16/2020] [Indexed: 12/12/2022] Open
Abstract
Na+/K+-ATPase is a transmembrane ion pump that is essential for the maintenance of ion gradients and regulation of multiple cellular functions. Na+/K+-ATPase has been associated with nuclear factor kappa B (NFκB) signalling, a signal associated with lipopolysaccharides (LPSs)-induced immune response in connection with activated Toll-like receptor 4 (TLR4) signalling. However, the contribution of Na+/K+-ATPase to regulating inflammatory responses remains elusive. We report that mice haploinsufficient for the astrocyte-enriched α2Na+/K+-ATPase isoform (α2+/G301R mice) have a reduced proinflammatory response to LPS, accompanied by a reduced hypothermic reaction compared to wild type litter mates. Following intraperitoneal injection of LPS, gene expressions of Tnf-α, Il-1β, and Il-6 was reduced in the hypothalamus and hippocampus from α2+/G301R mice compared to α2+/+ littermates. The α2+/G301R mice experienced increased expression of the gene encoding an antioxidant enzyme, NRF2, in hippocampal astrocytes. Our findings indicate that α2Na+/K+-ATPase haploinsufficiency negatively modulates LPS-induced immune responses, highlighting a rational pharmacological target for reducing LPS-induced inflammation.
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Affiliation(s)
- J A Leite
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Pharmacology, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.,Department of Pharmacology, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Brazil
| | - T J Isaksen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - A Heuck
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - C Scavone
- Department of Pharmacology, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - K Lykke-Hartmann
- Department of Biomedicine, Aarhus University, Aarhus, Denmark. .,Department of Clinical Medicine, Aarhus University, 8000, Aarhus C, Denmark. .,Department of Clinical Genetics, Aarhus University Hospital, 8200, Aarhus N, Denmark.
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12
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Apical periodontitis induces changes on oxidative stress parameters and increases Na +/K +-ATPase activity in adult rats. Arch Oral Biol 2020; 118:104849. [PMID: 32847752 DOI: 10.1016/j.archoralbio.2020.104849] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/01/2020] [Accepted: 07/21/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Endodontic infection can cause systemic alterations. The involvement of oxidative stress (OS) and transmembrane enzymes compose the pathogenesis of various systemic diseases. However, the relation among apical periodontitis (AP), OS parameters, and Na+/K+-ATPase (NKA) pump was not reported in the literature. This study evaluated the AP influence on OS parameters and NKA activity in adult rats. METHODS Adult male Wistar rats (sixteen weeks old) were randomly assigned to two experimental groups: control (CT group; n = 8) and AP (AP group; n = 9), which was induced in the first right mandibular molar tooth. After 21 days of AP induction, mandibles were dissected for radiographic analysis. In addition, the heart, liver, pancreas, and kidney were collected for analysis of endogenous OS parameters and NKA activity. Data were analyzed by Student's T-test. Values of p < 0.05 were considered statistically significant. RESULTS AP presence increased reactive species (RS) generation only in the heart, while the other analyzed organs did not have this parameter modified. Heart and pancreas had a decreased endogenous antioxidant system (catalase activity and vitamin C levels), liver and kidney had an increased one. AP increased NKA activity in the heart, liver, and pancreas, but not in the kidney. CONCLUSION The modulation of both endogenous antioxidant defense system and NKA activity in vital organs suggested that alterations in the antioxidant status and cellular electrochemical gradient may be involved in the AP pathophysiology.
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13
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Elucidating Potential Profibrotic Mechanisms of Emerging Biomarkers for Early Prognosis of Hepatic Fibrosis. Int J Mol Sci 2020; 21:ijms21134737. [PMID: 32635162 PMCID: PMC7369895 DOI: 10.3390/ijms21134737] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
Hepatic fibrosis has been associated with a series of pathophysiological processes causing excessive accumulation of extracellular matrix proteins. Several cellular processes and molecular mechanisms have been implicated in the diseased liver that augments fibrogenesis, fibrogenic cytokines and associated liver complications. Liver biopsy remains an essential diagnostic tool for histological evaluation of hepatic fibrosis to establish a prognosis. In addition to being invasive, this methodology presents with several limitations including poor cost-effectiveness, prolonged hospitalizations, and risks of peritoneal bleeding, while the clinical use of this method does not reveal underlying pathogenic mechanisms. Several alternate noninvasive diagnostic strategies have been developed, to determine the extent of hepatic fibrosis, including the use of direct and indirect biomarkers. Immediate diagnosis of hepatic fibrosis by noninvasive means would be more palatable than a biopsy and could assist clinicians in taking early interventions timely, avoiding fatal complications, and improving prognosis. Therefore, we sought to review some common biomarkers of liver fibrosis along with some emerging candidates, including the oxidative stress-mediated biomarkers, epigenetic and genetic markers, exosomes, and miRNAs that needs further evaluation and would have better sensitivity and specificity. We also aim to elucidate the potential role of cardiotonic steroids (CTS) and evaluate the pro-inflammatory and profibrotic effects of CTS in exacerbating hepatic fibrosis. By understanding the underlying pathogenic processes, the efficacy of these biomarkers could allow for early diagnosis and treatment of hepatic fibrosis in chronic liver diseases, once validated.
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14
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Aperia A, Brismar H, Uhlén P. Mending Fences: Na,K-ATPase signaling via Ca 2+ in the maintenance of epithelium integrity. Cell Calcium 2020; 88:102210. [PMID: 32380435 DOI: 10.1016/j.ceca.2020.102210] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/18/2022]
Abstract
Na,K-ATPase is a ubiquitous multifunctional protein that acts both as an ion pump and as a signal transducer. The signaling function is activated by ouabain in non-toxic concentrations. In epithelial cells the ouabain-bound Na,K-ATPase connects with the inositol 1,4,5-trisphosphate receptor via a short linear motif to activate low frequency Ca2+ oscillations. Within a couple of minutes this ouabain mediated signal has resulted in phosphorylation or dephosphorylation of 2580 phospho-sites. Proteins that control cell proliferation and cell adhesion and calmodulin regulated proteins are enriched among the ouabain phosphor-regulated proteins. The inositol 1,4,5-trisphosphate receptor and the stromal interaction molecule, which are both essential for the initiation of Ca2+ oscillations, belong to the ouabain phosphor-regulated proteins. Downstream effects of the ouabain-evoked Ca2+ signal in epithelial cells include interference with the intrinsic mitochondrial apoptotic process and stimulation of embryonic growth processes. The dual function of Na,K-ATPase as an ion pump and a signal transducer is now well established and evaluation of the physiological and pathophysiological consequences of this universal signal emerges as an urgent topic for future studies.
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Affiliation(s)
- Anita Aperia
- Science for Life Laboratory, Dept of Women's and Children's Health, Karolinska Institutet, Sweden
| | - Hjalmar Brismar
- Science for Life Laboratory, Dept of Women's and Children's Health, Karolinska Institutet, Sweden; Science for Life Laboratory, Dept of Applied Physics, KTH Royal Institute of Technology, Sweden.
| | - Per Uhlén
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
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15
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The Na/K-ATPase α1 and c-Src form signaling complex under native condition: A crosslinking approach. Sci Rep 2020; 10:6006. [PMID: 32265464 PMCID: PMC7138855 DOI: 10.1038/s41598-020-61920-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 03/04/2020] [Indexed: 11/09/2022] Open
Abstract
The protein-protein interactions amongst the Na/K-ATPase α1 subunit, c-Src, and caveolin-1 (cav-1) are essential for the Na/K-ATPase signaling functions. However, there are arguments concerning the interaction model. The present study aims to clarify the interactions amongst the endogenous native proteins in live cells under native resting condition. Under native condition, Blue Native-PAGE and Blue Native-PAGE/SDS-PAGE 2D analyses demonstrated co-existence of the α1 subunit and c-Src in same protein complex, as well as a direct interaction between the α1 subunit and c-Src. By comparison of cleavable and non-cleavable cysteine-cysteine crosslinked samples, capillary immunoblotting analysis demonstrated that depletion of Src kinase family members (c-Src, Yes, and Fyn) or cav-1 clearly reduced the interactions of the α1 subunit with proteins, but depletion of cav-1 did not affect the interaction of c-Src with the α1 subunit. The data indicated that there are direct interactions between the α1 subunit and c-Src as well as between the α1 subunit and cav-1, but argued about the interaction between c-Src and cav-1 under the condition. Furthermore, the data also indicated the existence of different protein complexes containing the α1 subunit and c-Src, which might have different signaling functions.
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16
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Orlov SN, Tverskoi AM, Sidorenko SV, Smolyaninova LV, Lopina OD, Dulin NO, Klimanova EA. Na,K-ATPase as a target for endogenous cardiotonic steroids: What's the evidence? Genes Dis 2020; 8:259-271. [PMID: 33997173 PMCID: PMC8093582 DOI: 10.1016/j.gendis.2020.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/24/2019] [Accepted: 01/09/2020] [Indexed: 12/17/2022] Open
Abstract
With an exception of few reports, the plasma concentration of ouabain and marinobufagenin, mostly studied cardiotonic steroids (CTS) assessed by immunoassay techniques, is less than 1 nM. During the last 3 decades, the implication of these endogenous CTS in the pathogenesis of hypertension and other volume-expanded disorders is widely disputed. The threshold for inhibition by CTS of human and rodent α1-Na,K-ATPase is ∼1 and 1000 nM, respectively, that rules out the functioning of endogenous CTS (ECTS) as natriuretic hormones and regulators of cell adhesion, cell-to-cell communication, gene transcription and translation, which are mediated by dissipation of the transmembrane gradients of monovalent cations. In several types of cells ouabain and marinobufagenin at concentrations corresponding to its plasma level activate Na,K-ATPase, decrease the [Na+]i/[K+]i-ratio and increase cell proliferation. Possible physiological significance and mechanism of non-canonical Na+i/K+i-dependent and Na+i/K+i-independent cell responses to CTS are discussed.
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Affiliation(s)
- Sergei N Orlov
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia.,Siberian State Medical University, Tomsk, 634050, Russia
| | | | - Svetlana V Sidorenko
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
| | - Larisa V Smolyaninova
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
| | - Olga D Lopina
- MV Lomonosov Moscow State University, Moscow, 119234, Russia
| | | | - Elizaveta A Klimanova
- MV Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
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17
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Reddy D, Ghosh P, Kumavath R. Strophanthidin Attenuates MAPK, PI3K/AKT/mTOR, and Wnt/β-Catenin Signaling Pathways in Human Cancers. Front Oncol 2020; 9:1469. [PMID: 32010609 PMCID: PMC6978703 DOI: 10.3389/fonc.2019.01469] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 12/09/2019] [Indexed: 12/16/2022] Open
Abstract
Lung cancer is the most prevalent in cancer-related deaths, while breast carcinoma is the second most dominant cancer in women, accounting for the most number of deaths worldwide. Cancers are heterogeneous diseases that consist of several subtypes based on the presence or absence of hormone receptors and human epidermal growth factor receptor 2. Several drugs have been developed targeting cancer biomarkers; nonetheless, their efficiency are not adequate due to the high reemergence rate of cancers and fundamental or acquired resistance toward such drugs, which leads to partial therapeutic possibilities. Recent studies on cardiac glycosides (CGs) positioned them as potent cytotoxic agents that target multiple pathways to initiate apoptosis and autophagic cell death in many cancers. In the present study, our aim is to identify the anticancer activity of a naturally available CG (strophanthidin) in human breast (MCF-7), lung (A549), and liver cancer (HepG2) cells. Our results demonstrate a dose-dependent cytotoxic effect of strophanthidin in MCF-7, A549, and HepG2 cells, which was further supported by DNA damage on drug treatment. Strophanthidin arrested the cell cycle at the G2/M phase; this effect was further validated by checking the inhibited expressions of checkpoint and cyclin-dependent kinases in strophanthidin-induced cells. Moreover, strophanthidin inhibited the expression of several key proteins such as MEK1, PI3K, AKT, mTOR, Gsk3α, and β-catenin from MAPK, PI3K/AKT/mTOR, and Wnt/β-catenin signaling. The current study adequately exhibits the role of strophanthidin in modulating the expression of various key proteins involved in cell cycle arrest, apoptosis, and autophagic cell death. Our in silico studies revealed that strophanthidin can interact with several key proteins from various pathways. Taken together, this study demonstrates the viability of strophanthidin as a promising anticancer agent, which may serve as a new anticancer drug.
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Affiliation(s)
- Dhanasekhar Reddy
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Kasaragod, India
| | - Preetam Ghosh
- Department of Computer Science, Virginia Commonwealth University, Richmond, VA, United States
| | - Ranjith Kumavath
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Kasaragod, India
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18
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Blaustein MP, Hamlyn JM. Ouabain, endogenous ouabain and ouabain-like factors: The Na + pump/ouabain receptor, its linkage to NCX, and its myriad functions. Cell Calcium 2020; 86:102159. [PMID: 31986323 DOI: 10.1016/j.ceca.2020.102159] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/01/2020] [Accepted: 01/03/2020] [Indexed: 12/12/2022]
Abstract
In this brief review we discuss some aspects of the Na+ pump and its roles in mediating the effects of ouabain and endogenous ouabain (EO): i) in regulating the cytosolic Ca2+ concentration ([Ca2+]CYT) via Na/Ca exchange (NCX), and ii) in activating a number of protein kinase (PK) signaling cascades that control a myriad of cell functions. Importantly, [Ca2+]CYT and the other signaling pathways intersect at numerous points because of the influence of Ca2+ and calmodulin in modulating some steps in those other pathways. While both mechanisms operate in virtually all cells and tissues, this article focuses primarily on their functions in the cardiovascular system, the central nervous system (CNS) and the kidneys.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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19
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Smolyaninova LV, Shiyan AA, Kapilevich LV, Lopachev AV, Fedorova TN, Klementieva TS, Moskovtsev AA, Kubatiev AA, Orlov SN. Transcriptomic changes triggered by ouabain in rat cerebellum granule cells: Role of α3- and α1-Na+,K+-ATPase-mediated signaling. PLoS One 2019; 14:e0222767. [PMID: 31557202 PMCID: PMC6762055 DOI: 10.1371/journal.pone.0222767] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 09/06/2019] [Indexed: 12/15/2022] Open
Abstract
It was shown previously that inhibition of the ubiquitous α1 isoform of Na+,K+-ATPase by ouabain sharply affects gene expression profile via elevation of intracellular [Na+]i/[K+]i ratio. Unlike other cells, neurons are abundant in the α3 isoform of Na+,K+-ATPase, whose affinity in rodents to ouabain is 104-fold higher compared to the α1 isoform. With these sharp differences in mind, we compared transcriptomic changes in rat cerebellum granule cells triggered by inhibition of α1- and α3-Na+,K+-ATPase isoforms. Inhibition of α1- and α3-Na+,K+-ATPase isoforms by 1 mM ouabain resulted in dissipation of transmembrane Na+ and K+ gradients and differential expression of 994 transcripts, whereas selective inhibition of α3-Na+,K+-ATPase isoform by 100 nM ouabain affected expression of 144 transcripts without any impact on the [Na+]i/[K+]i ratio. The list of genes whose expression was affected by 1 mM ouabain by more than 2-fold was abundant in intermediates of intracellular signaling and transcription regulators, including augmented content of Npas4, Fos, Junb, Atf3, and Klf4 mRNAs, whose upregulated expression was demonstrated in neurons subjected to electrical and glutamatergic stimulation. The role [Na+]i/[K+]i-mediated signaling in transcriptomic changes involved in memory formation and storage should be examined further.
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Affiliation(s)
- Larisa V. Smolyaninova
- Department of Biomembranes, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
- Department of Sports Tourism Sports Physiology and Medicine, National Research Tomsk State University, Tomsk, Russia
- * E-mail: (LVS); (SNO)
| | - Alexandra A. Shiyan
- Department of Biomembranes, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Leonid V. Kapilevich
- Department of Sports Tourism Sports Physiology and Medicine, National Research Tomsk State University, Tomsk, Russia
| | - Alexander V. Lopachev
- Laboratory of Clinical and Experimental Neurochemistry, Research Center of Neurology, Moscow, Russia
| | - Tatiana N. Fedorova
- Laboratory of Clinical and Experimental Neurochemistry, Research Center of Neurology, Moscow, Russia
| | - Tatiana S. Klementieva
- Department of Molecular and Cell Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Aleksey A. Moskovtsev
- Department of Molecular and Cell Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Aslan A. Kubatiev
- Department of Molecular and Cell Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Sergei N. Orlov
- Department of Biomembranes, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
- Department of Sports Tourism Sports Physiology and Medicine, National Research Tomsk State University, Tomsk, Russia
- Central Research Laboratory, Siberian Medical State University, Tomsk, Russia
- * E-mail: (LVS); (SNO)
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20
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Transcriptomic changes triggered by ouabain in rat cerebellum granule cells: Role of α3- and α1-Na+,K+-ATPase-mediated signaling. PLoS One 2019. [DOI: 10.1371/journal.pone.0222767
expr 919876128 + 853282961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
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21
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The Adipocyte Na/K-ATPase Oxidant Amplification Loop is the Central Regulator of Western Diet-Induced Obesity and Associated Comorbidities. Sci Rep 2019; 9:7927. [PMID: 31138824 PMCID: PMC6538745 DOI: 10.1038/s41598-019-44350-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/10/2019] [Indexed: 12/29/2022] Open
Abstract
Obesity has become a worldwide epidemic. We have previously reported that systemic administration of pNaKtide which targets the Na/K-ATPase oxidant amplification loop (NKAL) was able to decrease systemic oxidative stress and adiposity in mice fed a high fat and fructose supplemented western diet (WD). As adipocytes are believed to play a central role in the development of obesity and its related comorbidities, we examined whether lentiviral-mediated adipocyte-specific expression of NaKtide, a peptide derived from the N domain of the alpha1 Na/K-ATPase subunit, could ameliorate the effects of the WD. C57BL6 mice were fed a WD, which activated Na/K-ATPase signaling in the adipocytes and induced an obese phenotype and caused an increase in plasma levels of leptin, IL-6 and TNFα. WD also decreased locomotor activity, expression of the D2 receptor and tyrosine hydroxylase in brain tissue, while markers of neurodegeneration and neuronal apoptosis were increased following the WD. Selective adipocyte expression of NaKtide in these mice fed a WD attenuated all of these changes including the brain biochemical alterations and behavioral adaptations. These data suggest that adipocyte derived cytokines play an essential role in the development of obesity induced by a WD and that targeting the adipocyte NKAL loop may serve as an effective therapeutic strategy.
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Yu Y, Chen C, Huo G, Deng J, Zhao H, Xu R, Jiang L, Chen S, Wang S. ATP1A1 Integrates AKT and ERK Signaling via Potential Interaction With Src to Promote Growth and Survival in Glioma Stem Cells. Front Oncol 2019; 9:320. [PMID: 31114755 PMCID: PMC6503087 DOI: 10.3389/fonc.2019.00320] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 04/09/2019] [Indexed: 02/02/2023] Open
Abstract
Glioma stem cells (GSCs) have been considered to be responsible for treatment failure due to their self-renewal and limitless proliferative property. Recently, the Na+/K+-ATPase a1 (ATP1A1) subunit was described as a novel therapeutic target for gliomas. Interestingly, our previous proteomics study revealed that ATP1A1 is remarkably overexpressed in GSCs. In the current study, we investigated the role of ATP1A1 in regulating growth, survival, and tumorigenicity of primary human GSCs and the underlying molecular mechanism. We tested RNA and protein expression of ATP1A1 in glioma tissues and GSCs. In addition, we knocked down ATP1A1 in GSCs and assessed the effects thereof on growth, survival, and apoptosis. The role of ATP1A1 in signaling pathways was investigated in vitro. We found that the ATP1A1 expression level was associated with the grade of glioma. Knockdown of ATP1A1 in GSCs in vitro inhibited cell proliferation and survival, increased apoptosis, and halted cell-cycle progression at the G1 phase. Cell proliferation and survival were resumed upon rescue of ATP1A1 expression in ATP1A1-knockdown GSCs. The ERK1/2 and AKT pathways were inhibited through suppression of Src phosphorylation by ATP1A1 knockdown. Collectively, our findings suggest that ATP1A1 overexpression promotes GSC growth and proliferation by affecting Src phosphorylation to activate the ERK1/2 and AKT signaling pathways.
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Affiliation(s)
- Yang Yu
- Institute of Neuroscience, Basic Medical College, Chongqing Medical University, Chongqing, China
| | - Chen Chen
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Gang Huo
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jinmu Deng
- Department of Neurosurgery, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Hongxin Zhao
- Department of Neurosurgery, First Affiliated Hospital, Zunyi Medical College, Zunyi, China
| | - Rui Xu
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Li Jiang
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Song Chen
- Department of Neurosurgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Shali Wang
- Institute of Neuroscience, Basic Medical College, Chongqing Medical University, Chongqing, China
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Abstract
Myofibroblast activation is a critical process in the pathogenesis of tissue fibrosis accounting for 45% of all deaths. No effective therapies are available for the treatment of fibrotic diseases. We focus our mini-review on recent data showing that cardiotonic steroids (CTS) that are known as potent inhibitors of Na+,K+-ATPase affect myofibroblast differentiation in a cell type-specific manner. In cultured human lung fibroblasts (HLF), epithelial cells, and cancer-associated fibroblasts, CTS blocked myofibroblast differentiation triggered by profibrotic cytokine TGF-β. In contrast, in the absence of TGF-β, CTS augmented myofibroblast differentiation of cultured cardiac fibroblasts. The cell type-specific action of CTS in myofibroblast differentiation is consistent with data obtained in in vivo studies. Thus, infusion of ouabain via osmotic mini-pumps attenuated the development of lung fibrosis in bleomycintreated mice, whereas marinobufagenin stimulated renal and cardiac fibrosis in rats with experimental renal injury. In TGF-β-treated HLF, suppression of myofibroblast differentiation by ouabain is mediated by elevation of the [Na+]i/[K+]i ratio and is accompanied by upregulation of cyclooxygenase COX-2 and downregulation of TGF-β receptor TGFBR2. Augmented expression of COX-2 is abolished by inhibition of Na+/Ca2+ exchanger, suggesting a key role of [Ca2+]i-mediated signaling. What is the relative impact in tissue fibrosis of [Na+]i,[K+]iindependent signaling documented in several types of CTS-treated cells? Do the different conformational transitions of Na+,K+-ATPase α1 subunit in the presence of ouabain and marinobufagenin contribute to their distinct involvement in myofibroblast differentiation? Additional experiments should be done to answer these questions and to develop novel pharmacological approaches for the treatment of fibrosis-related disorders.
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Affiliation(s)
- Sergei N. Orlov
- Faculty of Biology, Lomonosov Moscow State University, Russian Federation
| | - Jennifer La
- Department of Medicine, The University of Chicago, IL, United States
| | | | - Nickolai O. Dulin
- Department of Medicine, The University of Chicago, IL, United States
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24
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Interaction of ouabain and progesterone on induction of bull sperm capacitation. Theriogenology 2019; 126:191-198. [DOI: 10.1016/j.theriogenology.2018.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 11/06/2018] [Accepted: 12/01/2018] [Indexed: 01/16/2023]
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Paczula A, Wiecek A, Piecha G. Cardiotonic Steroids-A Possible Link Between High-Salt Diet and Organ Damage. Int J Mol Sci 2019; 20:ijms20030590. [PMID: 30704040 PMCID: PMC6386955 DOI: 10.3390/ijms20030590] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/24/2019] [Accepted: 01/28/2019] [Indexed: 02/07/2023] Open
Abstract
High dietary salt intake has been listed among the top ten risk factors for disability-adjusted life years. We discuss the role of endogenous cardiotonic steroids in mediating the dietary salt-induced hypertension and organ damage.
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Affiliation(s)
- Aneta Paczula
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Francuska 20-24, 40-027 Katowice, Poland.
| | - Andrzej Wiecek
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Francuska 20-24, 40-027 Katowice, Poland.
| | - Grzegorz Piecha
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Francuska 20-24, 40-027 Katowice, Poland.
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Smolyaninova LV, Shiyan AA, Kapilevich LV, Lopachev AV, Fedorova TN, Klementieva TS, Moskovtsev AA, Kubatiev AA, Orlov SN. Transcriptomic changes triggered by ouabain in rat cerebellum granule cells: Role of α3- and α1-Na+,K+-ATPase-mediated signaling. PLoS One 2019; 14:e0222767. [PMID: 31557202 PMCID: PMC6762055 DOI: 10.1371/journal.pone.0222767&set/a 820829471+911750583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
It was shown previously that inhibition of the ubiquitous α1 isoform of Na+,K+-ATPase by ouabain sharply affects gene expression profile via elevation of intracellular [Na+]i/[K+]i ratio. Unlike other cells, neurons are abundant in the α3 isoform of Na+,K+-ATPase, whose affinity in rodents to ouabain is 104-fold higher compared to the α1 isoform. With these sharp differences in mind, we compared transcriptomic changes in rat cerebellum granule cells triggered by inhibition of α1- and α3-Na+,K+-ATPase isoforms. Inhibition of α1- and α3-Na+,K+-ATPase isoforms by 1 mM ouabain resulted in dissipation of transmembrane Na+ and K+ gradients and differential expression of 994 transcripts, whereas selective inhibition of α3-Na+,K+-ATPase isoform by 100 nM ouabain affected expression of 144 transcripts without any impact on the [Na+]i/[K+]i ratio. The list of genes whose expression was affected by 1 mM ouabain by more than 2-fold was abundant in intermediates of intracellular signaling and transcription regulators, including augmented content of Npas4, Fos, Junb, Atf3, and Klf4 mRNAs, whose upregulated expression was demonstrated in neurons subjected to electrical and glutamatergic stimulation. The role [Na+]i/[K+]i-mediated signaling in transcriptomic changes involved in memory formation and storage should be examined further.
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Affiliation(s)
- Larisa V. Smolyaninova
- Department of Biomembranes, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
- Department of Sports Tourism Sports Physiology and Medicine, National Research Tomsk State University, Tomsk, Russia
- * E-mail: (LVS); (SNO)
| | - Alexandra A. Shiyan
- Department of Biomembranes, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Leonid V. Kapilevich
- Department of Sports Tourism Sports Physiology and Medicine, National Research Tomsk State University, Tomsk, Russia
| | - Alexander V. Lopachev
- Laboratory of Clinical and Experimental Neurochemistry, Research Center of Neurology, Moscow, Russia
| | - Tatiana N. Fedorova
- Laboratory of Clinical and Experimental Neurochemistry, Research Center of Neurology, Moscow, Russia
| | - Tatiana S. Klementieva
- Department of Molecular and Cell Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Aleksey A. Moskovtsev
- Department of Molecular and Cell Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Aslan A. Kubatiev
- Department of Molecular and Cell Pathophysiology, Institute of General Pathology and Pathophysiology, Moscow, Russia
| | - Sergei N. Orlov
- Department of Biomembranes, Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, Russia
- Department of Sports Tourism Sports Physiology and Medicine, National Research Tomsk State University, Tomsk, Russia
- Central Research Laboratory, Siberian Medical State University, Tomsk, Russia
- * E-mail: (LVS); (SNO)
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Amarelle L, Lecuona E. A Nonhospitable Host: Targeting Cellular Factors as an Antiviral Strategy for Respiratory Viruses. Am J Respir Cell Mol Biol 2018; 59:666-667. [PMID: 30230347 PMCID: PMC6293076 DOI: 10.1165/rcmb.2018-0268ed] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Luciano Amarelle
- 1 Facultad de Medicina Universidad de la República Montevideo, Uruguay and
| | - Emilia Lecuona
- 2 Feinberg School of Medicine Northwestern University Chicago, Illinois
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Telocinobufagin and Marinobufagin Produce Different Effects in LLC-PK1 Cells: A Case of Functional Selectivity of Bufadienolides. Int J Mol Sci 2018; 19:ijms19092769. [PMID: 30223494 PMCID: PMC6163863 DOI: 10.3390/ijms19092769] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/09/2018] [Accepted: 09/13/2018] [Indexed: 12/24/2022] Open
Abstract
Bufadienolides are cardiotonic steroids (CTS) identified in mammals. Besides Na+/K+-ATPase inhibition, they activate signal transduction via protein–protein interactions. Diversity of endogenous bufadienolides and mechanisms of action may indicate the presence of functional selectivity and unique cellular outcomes. We evaluated whether the bufadienolides telocinobufagin and marinobufagin induce changes in proliferation or viability of pig kidney (LLC-PK1) cells and the mechanisms involved in these changes. In some experiments, ouabain was used as a positive control. CTS exhibited an inhibitory IC50 of 0.20 (telocinobufagin), 0.14 (ouabain), and 3.40 μM (marinobufagin) for pig kidney Na+/K+-ATPase activity and concentrations that barely inhibited it were tested in LLC-PK1 cells. CTS induced rapid ERK1/2 phosphorylation, but corresponding proliferative response was observed for marinobufagin and ouabain instead of telocinobufagin. Telocinobufagin increased Bax:Bcl-2 expression ratio, sub-G0 cell cycle phase and pyknotic nuclei, indicating apoptosis. Src and MEK1/2 inhibitors blunted marinobufagin but not telocinobufagin effect, which was also not mediated by p38, JNK1/2, and PI3K. However, BIO, a GSK-3β inhibitor, reduced proliferation and, as telocinobufagin, phosphorylated GSK-3β at inhibitory Ser9. Combination of both drugs resulted in synergistic antiproliferative effect. Wnt reporter activity assay showed that telocinobufagin impaired Wnt/β-catenin pathway by acting upstream to β-catenin stabilization. Our findings support that mammalian endogenous bufadienolides may exhibit functional selectivity.
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The Na/K-ATPase Signaling: From Specific Ligands to General Reactive Oxygen Species. Int J Mol Sci 2018; 19:ijms19092600. [PMID: 30200500 PMCID: PMC6163532 DOI: 10.3390/ijms19092600] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/10/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022] Open
Abstract
The signaling function of the Na/K-ATPase has been established for 20 years and is widely accepted in the field, with many excellent reports and reviews not cited here. Even though there is debate about the underlying mechanism, the signaling function is unquestioned. This short review looks back at the evolution of Na/K-ATPase signaling, from stimulation by cardiotonic steroids (also known as digitalis-like substances) as specific ligands to stimulation by reactive oxygen species (ROS) in general. The interplay of cardiotonic steroids and ROS in Na/K-ATPase signaling forms a positive-feedback oxidant amplification loop that has been implicated in some pathophysiological conditions.
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30
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Kennedy DJ, Khalaf FK, Sheehy B, Weber ME, Agatisa-Boyle B, Conic J, Hauser K, Medert CM, Westfall K, Bucur P, Fedorova OV, Bagrov AY, Tang WHW. Telocinobufagin, a Novel Cardiotonic Steroid, Promotes Renal Fibrosis via Na⁺/K⁺-ATPase Profibrotic Signaling Pathways. Int J Mol Sci 2018; 19:ijms19092566. [PMID: 30158457 PMCID: PMC6164831 DOI: 10.3390/ijms19092566] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 08/26/2018] [Accepted: 08/27/2018] [Indexed: 12/24/2022] Open
Abstract
Cardiotonic steroids (CTS) are Na+/K+-ATPase (NKA) ligands that are elevated in volume-expanded states and associated with cardiac and renal dysfunction in both clinical and experimental settings. We test the hypothesis that the CTS telocinobufagin (TCB) promotes renal dysfunction in a process involving signaling through the NKA α-1 in the following studies. First, we infuse TCB (4 weeks at 0.1 µg/g/day) or a vehicle into mice expressing wild-type (WT) NKA α-1, as well as mice with a genetic reduction (~40%) of NKA α-1 (NKA α-1+/−). Continuous TCB infusion results in increased proteinuria and cystatin C in WT mice which are significantly attenuated in NKA α-1+/− mice (all p < 0.05), despite similar increases in blood pressure. In a series of in vitro experiments, 24-h treatment of HK2 renal proximal tubular cells with TCB results in significant dose-dependent increases in both Collagens 1 and 3 mRNA (2-fold increases at 10 nM, 5-fold increases at 100 nM, p < 0.05). Similar effects are seen in primary human renal mesangial cells. TCB treatment (100 nM) of SYF fibroblasts reconstituted with cSrc results in a 1.5-fold increase in Collagens 1 and 3 mRNA (p < 0.05), as well as increases in both Transforming Growth factor beta (TGFb, 1.5 fold, p < 0.05) and Connective Tissue Growth Factor (CTGF, 2 fold, p < 0.05), while these effects are absent in SYF cells without Src kinase. In a patient study of subjects with chronic kidney disease, TCB is elevated compared to healthy volunteers. These studies suggest that the pro-fibrotic effects of TCB in the kidney are mediated though the NKA-Src kinase signaling pathway and may have relevance to volume-overloaded conditions, such as chronic kidney disease where TCB is elevated.
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Affiliation(s)
- David J Kennedy
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA.
| | - Fatimah K Khalaf
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH 43614, USA.
| | - Brendan Sheehy
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Malory E Weber
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Brendan Agatisa-Boyle
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Julijana Conic
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Kayla Hauser
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Charles M Medert
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Kristen Westfall
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Philip Bucur
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
| | - Olga V Fedorova
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
| | - Alexei Y Bagrov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg 194223, Russia.
| | - W H Wilson Tang
- Department of Cellular and Molecular Medicine, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
- Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute Cleveland Clinic, Cleveland, OH 44106, USA.
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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31
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Lichtstein D, Ilani A, Rosen H, Horesh N, Singh SV, Buzaglo N, Hodes A. Na⁺, K⁺-ATPase Signaling and Bipolar Disorder. Int J Mol Sci 2018; 19:E2314. [PMID: 30087257 PMCID: PMC6121236 DOI: 10.3390/ijms19082314] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 02/07/2023] Open
Abstract
Bipolar disorder (BD) is a severe and common chronic mental illness characterized by recurrent mood swings between depression and mania. The biological basis of the disease is poorly understood and its treatment is unsatisfactory. Although in past decades the "monoamine hypothesis" has dominated our understanding of both the pathophysiology of depressive disorders and the action of pharmacological treatments, recent studies focus on the involvement of additional neurotransmitters/neuromodulators systems and cellular processes in BD. Here, evidence for the participation of Na⁺, K⁺-ATPase and its endogenous regulators, the endogenous cardiac steroids (ECS), in the etiology of BD is reviewed. Proof for the involvement of brain Na⁺, K⁺-ATPase and ECS in behavior is summarized and it is hypothesized that ECS-Na⁺, K⁺-ATPase-induced activation of intracellular signaling participates in the mechanisms underlying BD. We propose that the activation of ERK, AKT, and NFκB, resulting from ECS-Na⁺, K⁺-ATPase interaction, modifies neuronal activity and neurotransmission which, in turn, participate in the regulation of behavior and BD. These observations suggest Na⁺, K⁺-ATPase-mediated signaling is a potential target for drug development for the treatment of BD.
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Affiliation(s)
- David Lichtstein
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
| | - Asher Ilani
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
| | - Haim Rosen
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
| | - Noa Horesh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
| | - Shiv Vardan Singh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
| | - Nahum Buzaglo
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
| | - Anastasia Hodes
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
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32
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Ruthenium(II)-N-alkyl phenothiazine complexes as potential anticancer agents. J Biol Inorg Chem 2018; 23:689-704. [DOI: 10.1007/s00775-018-1560-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 04/08/2018] [Indexed: 12/20/2022]
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Wong RW, Lingwood CA, Ostrowski MA, Cabral T, Cochrane A. Cardiac glycoside/aglycones inhibit HIV-1 gene expression by a mechanism requiring MEK1/2-ERK1/2 signaling. Sci Rep 2018; 8:850. [PMID: 29339801 PMCID: PMC5770468 DOI: 10.1038/s41598-018-19298-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 11/07/2017] [Indexed: 12/14/2022] Open
Abstract
The capacity of HIV-1 to develop resistance to current drugs calls for innovative strategies to control this infection. We aimed at developing novel inhibitors of HIV-1 replication by targeting viral RNA processing—a stage dependent on conserved host processes. We previously reported that digoxin is a potent inhibitor of this stage. Herein, we identify 12 other cardiac glycoside/aglycones or cardiotonic steroids (CSs) that impede HIV growth in HIV-infected T cells from clinical patients at IC50s (1.1–1.3 nM) that are 2–26 times below concentrations used in patients with heart conditions. We subsequently demonstrate that CSs inhibit HIV-1 gene expression in part through modulation of MEK1/2-ERK1/2 signaling via interaction with the Na+/K+-ATPase, independent of alterations in intracellular Ca2+. Supporting this hypothesis, depletion of the Na+/K+-ATPase or addition of a MEK1/2-ERK1/2 activator also impairs HIV-1 gene expression. Similar to digoxin, all CSs tested induce oversplicing of HIV-1 RNAs, reducing unspliced (Gag) and singly spliced RNAs (Env/p14-Tat) encoding essential HIV-1 structural/regulatory proteins. Furthermore, all CSs cause nuclear retention of genomic/unspliced RNAs, supporting viral RNA processing as the underlying mechanism for their disruption of HIV-1 replication. These findings call for further in vivo validation and supports the targeting of cellular processes to control HIV-1 infection.
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Affiliation(s)
- Raymond W Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Clifford A Lingwood
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S1A8, Canada.,Division of Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, M5G1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S1A8, Canada
| | - Mario A Ostrowski
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital Toronto, Toronto, ON, M5B1W8, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, M5S1A8, Canada.,Department of Immunology, University of Toronto, Toronto, ON, M5S1A8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Tyler Cabral
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Alan Cochrane
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S1A8, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada.
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Liu J, Lilly MN, Shapiro JI. Targeting Na/K-ATPase Signaling: A New Approach to Control Oxidative Stress. Curr Pharm Des 2018; 24:359-364. [PMID: 29318961 PMCID: PMC6052765 DOI: 10.2174/1381612824666180110101052] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 12/27/2017] [Accepted: 01/04/2017] [Indexed: 01/13/2023]
Abstract
Renal and cardiac function are greatly affected by chronic oxidative stress which can cause many pathophysiological states. The Na/K-ATPase is well-described as an ion pumping enzyme involved in maintaining cellular ion homeostasis; however, in the past two decades, extensive research has been done to understand the signaling function of the Na/K-ATPase and determine its role in physiological and pathophysiological states. Our lab has shown that the Na/K-ATPase signaling cascade can function as an amplifier of reactive oxygen species (ROS) which can be initiated by cardiotonic steroids or increases in ROS. Regulation of systemic oxidative stress by targeting Na/K-ATPase signaling mediated oxidant amplification improves 5/6th partial nephrectomy (PNx) mediated uremic cardiomyopathy, renal sodium handling, as well as ameliorates adipogenesis. This review will present this new concept of Na/K-ATPase signaling mediated oxidant amplification loop and its clinic implication.
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Affiliation(s)
- Jiang Liu
- Dept. of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | - Megan N. Lilly
- Dept. of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | - Joseph I. Shapiro
- Dept. of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
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35
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Smolyaninova LV, Koltsova SV, Sidorenko SV, Orlov SN. Augmented gene expression triggered by Na + ,K + -ATPase inhibition: Role of Ca 2+ i -mediated and −independent excitation-transcription coupling. Cell Calcium 2017; 68:5-13. [DOI: 10.1016/j.ceca.2017.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/28/2017] [Accepted: 10/07/2017] [Indexed: 11/16/2022]
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Ellman DG, Isaksen TJ, Lund MC, Dursun S, Wirenfeldt M, Jørgensen LH, Lykke-Hartmann K, Lambertsen KL. The loss-of-function disease-mutation G301R in the Na +/K +-ATPase α 2 isoform decreases lesion volume and improves functional outcome after acute spinal cord injury in mice. BMC Neurosci 2017; 18:66. [PMID: 28886701 PMCID: PMC5590116 DOI: 10.1186/s12868-017-0385-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 09/01/2017] [Indexed: 12/12/2022] Open
Abstract
Background The Na+/K+-ATPases are transmembrane ion pumps important for maintenance of ion gradients across the plasma membrane that serve to support multiple cellular functions, such as membrane potentials, regulation of cellular volume and pH, and co-transport of signaling transmitters in all animal cells. The α2Na+/K+-ATPase subunit isoform is predominantly expressed in astrocytes, which us the sharp Na+-gradient maintained by the sodium pump necessary for astroglial metabolism. Prolonged ischemia induces an elevation of [Na+]i, decreased ATP levels and intracellular pH owing to anaerobic metabolism and lactate accumulation. During ischemia, Na+/K+-ATPase-related functions will naturally increase the energy demand of the Na+/K+-ATPase ion pump. However, the role of the α2Na+/K+-ATPase in contusion injury to the spinal cord remains unknown. We used mice heterozygous mice for the loss-of-function disease-mutation G301R in the Atp1a2 gene (α2+/G301R) to study the effect of reduced α2Na+/K+-ATPase expression in a moderate contusion spinal cord injury (SCI) model. Results We found that α2+/G301R mice display significantly improved functional recovery and decreased lesion volume compared to littermate controls (α2+/+) 7 days after SCI. The protein level of the α1 isoform was significantly increased, in contrast to the α3 isoform that significantly decreased 3 days after SCI in both α2+/G301R and α2+/+ mice. The level of the α2 isoform was significantly decreased in α2+/G301R mice both under naïve conditions and 3 days after SCI compared to α2+/+ mice. We found no differences in astroglial aquaporin 4 levels and no changes in the expression of chemokines (CCL2, CCL5 and CXCL1) and cytokines (TNF, IL-6, IL-1β, IL-10 and IL-5) between genotypes, just as no apparent differences were observed in location and activation of CD45 and F4/80 positive microglia and infiltrating leukocytes. Conclusion Our proof of concept study demonstrates that reduced expression of the α2 isoform in the spinal cord is protective following SCI. Importantly, the BMS and lesion volume were assessed at 7 days after SCI, and longer time points after SCI were not evaluated. However, the α2 isoform is a potential possible target of therapeutic strategies for the treatment of SCI.
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Affiliation(s)
- Ditte Gry Ellman
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000, Odense C, Denmark
| | - Toke Jost Isaksen
- Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark.,Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Aarhus University, 8000, Aarhus C, Denmark
| | - Minna Christiansen Lund
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000, Odense C, Denmark
| | - Safinaz Dursun
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000, Odense C, Denmark
| | - Martin Wirenfeldt
- Department of Pathology, University of Southern Denmark/Odense University Hospital, Odense, 5000, Odense C, Denmark.,Department of Clinical Research, University of Southern Denmark/Odense University Hospital, Odense, 5000, Odense C, Denmark
| | - Louise Helskov Jørgensen
- Department of Pathology, University of Southern Denmark/Odense University Hospital, Odense, 5000, Odense C, Denmark.,Department of Clinical Research, University of Southern Denmark/Odense University Hospital, Odense, 5000, Odense C, Denmark
| | - Karin Lykke-Hartmann
- Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark. .,Department of Clinical Medicine, Aarhus University, 8000, Aarhus C, Denmark. .,Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Aarhus University, 8000, Aarhus C, Denmark. .,Department of Clinical Genetics, Aarhus University Hospital, 8000, Aarhus C, Denmark.
| | - Kate Lykke Lambertsen
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000, Odense C, Denmark. .,Department of Neurology, Odense University Hospital, 5000, Odense C, Denmark. .,BRIDGE, Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, 5000, Odense C, Denmark.
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The type IV pilus assembly ATPase PilB functions as a signaling protein to regulate exopolysaccharide production in Myxococcus xanthus. Sci Rep 2017; 7:7263. [PMID: 28779124 PMCID: PMC5544727 DOI: 10.1038/s41598-017-07594-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/28/2017] [Indexed: 12/12/2022] Open
Abstract
Myxococcus xanthus possesses a form of surface motility powered by the retraction of the type IV pilus (T4P). Additionally, exopolysaccharide (EPS), the major constituent of bacterial biofilms, is required for this T4P-mediated motility in M. xanthus as the putative trigger of T4P retraction. The results here demonstrate that the T4P assembly ATPase PilB functions as an intermediary in the EPS regulatory pathway composed of the T4P upstream of the Dif signaling proteins in M. xanthus. A suppressor screen isolated a pilB mutation that restored EPS production to a T4P− mutant. An additional PilB mutant variant, which is deficient in ATP hydrolysis and T4P assembly, supports EPS production without the T4P, indicating PilB can regulate EPS production independently of its function in T4P assembly. Further analysis confirms that PilB functions downstream of the T4P filament but upstream of the Dif proteins. In vitro studies suggest that the nucleotide-free form of PilB assumes the active signaling conformation in EPS regulation. Since M. xanthus PilB possesses conserved motifs with high affinity for c-di-GMP binding, the findings here suggest that c-di-GMP can regulate both motility and biofilm formation through a single effector in this surface-motile bacterium.
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Lubarski-Gotliv I, Dey K, Kuznetsov Y, Kalchenco V, Asher C, Garty H. FXYD5 (dysadherin) may mediate metastatic progression through regulation of the β-Na+-K+-ATPase subunit in the 4T1 mouse breast cancer model. Am J Physiol Cell Physiol 2017; 313:C108-C117. [DOI: 10.1152/ajpcell.00206.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 04/24/2017] [Accepted: 05/06/2017] [Indexed: 11/22/2022]
Abstract
FXYD5 is a Na+-K+-ATPase regulator, expressed in a variety of normal epithelia. In parallel, it has been found to be associated with several types of cancer and effect lethal outcome by promoting metastasis. However, the molecular mechanism underlying FXYD5 mediated invasion has not yet been identified. In this study, using in vivo 4T1 murine breast cancer model, we found that FXYD5-specific shRNA significantly inhibited lung cancer metastasis, without having a substantial effect on primary tumor growth. Our study reveals that FXYD5 participates in multiple stages of metastatic development and exhibits more than one mode of E-cadherin regulation. We provide the first evidence that FXYD5-related morphological changes are mediated through its interaction with Na+-K+-ATPase. Experiments in cultured 4T1 cells have indicated that FXYD5 expression may downregulate the β1 isoform of the pump. This behavior could have implications on both transcellular interactions and intracellular events. Further studies suggest that differential localization of the adaptor protein Annexin A2 in FXYD5-expressing cells may correlate with matrix metalloproteinase 9 secretion and adhesion changes in 4T1 wild-type cells.
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Affiliation(s)
- Irina Lubarski-Gotliv
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel; and
| | - Kuntal Dey
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel; and
| | - Yuri Kuznetsov
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Vecheslav Kalchenco
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Carol Asher
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel; and
| | - Haim Garty
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel; and
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Cui X, Xie Z. Protein Interaction and Na/K-ATPase-Mediated Signal Transduction. Molecules 2017; 22:molecules22060990. [PMID: 28613263 PMCID: PMC6152704 DOI: 10.3390/molecules22060990] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/01/2017] [Accepted: 06/02/2017] [Indexed: 02/05/2023] Open
Abstract
The Na/K-ATPase (NKA), or Na pump, is a member of the P-type ATPase superfamily. In addition to pumping ions across cell membrane, it is engaged in assembly of multiple protein complexes in the plasma membrane. This assembly allows NKA to perform many non-pumping functions including signal transduction that are important for animal physiology and disease progression. This article will focus on the role of protein interaction in NKA-mediated signal transduction, and its potential utility as target for developing new therapeutics.
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Affiliation(s)
- Xiaoyu Cui
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV 25703, USA.
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV 25703, USA.
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On the Many Actions of Ouabain: Pro-Cystogenic Effects in Autosomal Dominant Polycystic Kidney Disease. Molecules 2017; 22:molecules22050729. [PMID: 28467389 PMCID: PMC5688955 DOI: 10.3390/molecules22050729] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/19/2017] [Accepted: 04/30/2017] [Indexed: 02/07/2023] Open
Abstract
Ouabain and other cardenolides are steroidal compounds originally discovered in plants. Cardenolides were first used as poisons, but after finding their beneficial cardiotonic effects, they were rapidly included in the medical pharmacopeia. The use of cardenolides to treat congestive heart failure remained empirical for centuries and only relatively recently, their mechanisms of action became better understood. A breakthrough came with the discovery that ouabain and other cardenolides exist as endogenous compounds that circulate in the bloodstream of mammals. This elevated these compounds to the category of hormones and opened new lines of investigation directed to further study their biological role. Another important discovery was the finding that the effect of ouabain was mediated not only by inhibition of the activity of the Na,K-ATPase (NKA), but by the unexpected role of NKA as a receptor and a signal transducer, which activates a complex cascade of intracellular second messengers in the cell. This broadened the interest for ouabain and showed that it exerts actions that go beyond its cardiotonic effect. It is now clear that ouabain regulates multiple cell functions, including cell proliferation and hypertrophy, apoptosis, cell adhesion, cell migration, and cell metabolism in a cell and tissue type specific manner. This review article focuses on the cardenolide ouabain and discusses its various in vitro and in vivo effects, its role as an endogenous compound, its mechanisms of action, and its potential use as a therapeutic agent; placing especial emphasis on our findings of ouabain as a pro-cystogenic agent in autosomal dominant polycystic kidney disease (ADPKD).
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Na⁺ i,K⁺ i-Dependent and -Independent Signaling Triggered by Cardiotonic Steroids: Facts and Artifacts. Molecules 2017; 22:molecules22040635. [PMID: 28420099 PMCID: PMC6153942 DOI: 10.3390/molecules22040635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/31/2017] [Accepted: 04/11/2017] [Indexed: 11/17/2022] Open
Abstract
Na⁺,K⁺-ATPase is the only known receptor of cardiotonic steroids (CTS) whose interaction with catalytic α-subunits leads to inhibition of this enzyme. As predicted, CTS affect numerous cellular functions related to the maintenance of the transmembrane gradient of monovalent cations, such as electrical membrane potential, cell volume, transepithelial movement of salt and osmotically-obliged water, symport of Na⁺ with inorganic phosphate, glucose, amino acids, nucleotides, etc. During the last two decades, it was shown that side-by-side with these canonical Na⁺i/K⁺i-dependent cellular responses, long-term exposure to CTS affects transcription, translation, tight junction, cell adhesion and exhibits tissue-specific impact on cell survival and death. It was also shown that CTS trigger diverse signaling cascades via conformational transitions of the Na⁺,K⁺-ATPase α-subunit that, in turn, results in the activation of membrane-associated non-receptor tyrosine kinase Src, phosphatidylinositol 3-kinase and the inositol 1,4,5-triphosphate receptor. These findings allowed researchers to propose that endogenous CTS might be considered as a novel class of steroid hormones. We focus our review on the analysis of the relative impact Na⁺i,K⁺i-mediated and -independent pathways in cellular responses evoked by CTS.
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42
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Liu J, Yan Y, Nie Y, Shapiro JI. Na/K-ATPase Signaling and Salt Sensitivity: The Role of Oxidative Stress. Antioxidants (Basel) 2017; 6:E18. [PMID: 28257114 PMCID: PMC5384181 DOI: 10.3390/antiox6010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/10/2017] [Accepted: 02/22/2017] [Indexed: 02/07/2023] Open
Abstract
Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Yanling Yan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Ying Nie
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Joseph I Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
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Yan Y, Shapiro AP, Mopidevi BR, Chaudhry MA, Maxwell K, Haller ST, Drummond CA, Kennedy DJ, Tian J, Malhotra D, Xie ZJ, Shapiro JI, Liu J. Protein Carbonylation of an Amino Acid Residue of the Na/K-ATPase α1 Subunit Determines Na/K-ATPase Signaling and Sodium Transport in Renal Proximal Tubular Cells. J Am Heart Assoc 2016; 5:e003675. [PMID: 27613772 PMCID: PMC5079028 DOI: 10.1161/jaha.116.003675] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/12/2016] [Indexed: 01/12/2023]
Abstract
BACKGROUND We have demonstrated that cardiotonic steroids, such as ouabain, signaling through the Na/K-ATPase, regulate sodium reabsorption in the renal proximal tubule. By direct carbonylation modification of the Pro222 residue in the actuator (A) domain of pig Na/K-ATPase α1 subunit, reactive oxygen species are required for ouabain-stimulated Na/K-ATPase/c-Src signaling and subsequent regulation of active transepithelial (22)Na(+) transport. In the present study we sought to determine the functional role of Pro222 carbonylation in Na/K-ATPase signaling and sodium handling. METHODS AND RESULTS Stable pig α1 knockdown LLC-PK1-originated PY-17 cells were rescued by expressing wild-type rat α1 and rat α1 with a single mutation of Pro224 (corresponding to pig Pro222) to Ala. This mutation does not affect ouabain-induced inhibition of Na/K-ATPase activity, but abolishes the effects of ouabain on Na/K-ATPase/c-Src signaling, protein carbonylation, Na/K-ATPase endocytosis, and active transepithelial (22)Na(+) transport. CONCLUSIONS Direct carbonylation modification of Pro224 in the rat α1 subunit determines ouabain-mediated Na/K-ATPase signal transduction and subsequent regulation of renal proximal tubule sodium transport.
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Affiliation(s)
- Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV
| | - Anna P Shapiro
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Brahma R Mopidevi
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Muhammad A Chaudhry
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV
| | - Kyle Maxwell
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV
| | - Steven T Haller
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | | | - David J Kennedy
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Jiang Tian
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Deepak Malhotra
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Zi-Jian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
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Liu L, Wu J, Kennedy DJ. Regulation of Cardiac Remodeling by Cardiac Na(+)/K(+)-ATPase Isoforms. Front Physiol 2016; 7:382. [PMID: 27667975 PMCID: PMC5016610 DOI: 10.3389/fphys.2016.00382] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/22/2016] [Indexed: 12/20/2022] Open
Abstract
Cardiac remodeling occurs after cardiac pressure/volume overload or myocardial injury during the development of heart failure and is a determinant of heart failure. Preventing or reversing remodeling is a goal of heart failure therapy. Human cardiomyocyte Na+/K+-ATPase has multiple α isoforms (1–3). The expression of the α subunit of the Na+/K+-ATPase is often altered in hypertrophic and failing hearts. The mechanisms are unclear. There are limited data from human cardiomyocytes. Abundant evidences from rodents show that Na+/K+-ATPase regulates cardiac contractility, cell signaling, hypertrophy and fibrosis. The α1 isoform of the Na+/K+-ATPase is the ubiquitous isoform and possesses both pumping and signaling functions. The α2 isoform of the Na+/K+-ATPase regulates intracellular Ca2+ signaling, contractility and pathological hypertrophy. The α3 isoform of the Na+/K+-ATPase may also be a target for cardiac hypertrophy. Restoration of cardiac Na+/K+-ATPase expression may be an effective approach for prevention of cardiac remodeling. In this article, we will overview: (1) the distribution and function of isoform specific Na+/K+-ATPase in the cardiomyocytes. (2) the role of cardiac Na+/K+-ATPase in the regulation of cell signaling, contractility, cardiac hypertrophy and fibrosis in vitro and in vivo. Selective targeting of cardiac Na+/K+-ATPase isoform may offer a new target for the prevention of cardiac remodeling.
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Affiliation(s)
- Lijun Liu
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo Toledo, OH, USA
| | - Jian Wu
- Center for Craniofacial Molecular Biology, University of Southern California Los Angeles, CA, USA
| | - David J Kennedy
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo Toledo, OH, USA
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Upmanyu N, Dietze R, Kirch U, Scheiner-Bobis G. Ouabain interactions with the α4 isoform of the sodium pump trigger non-classical steroid hormone signaling and integrin expression in spermatogenic cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2809-2819. [PMID: 27599714 DOI: 10.1016/j.bbamcr.2016.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/22/2016] [Accepted: 09/01/2016] [Indexed: 01/18/2023]
Abstract
In addition to the ubiquitous α1 isoform of the sodium pump, sperm cells also express a male-specific α4 isoform whose function has been associated with sperm motility, fertility, and capacitation. Here we investigate in the murine spermatogenic cell line GC-2 interactions of the α4 isoform with the cardiotonic steroid ouabain in signaling cascades involved in the non-classical action of steroid hormones. Exposure of GC-2 cells to low concentrations of ouabain stimulates the phosphorylation of Erk1/2 and of the transcription factors CREB and ATF-1. As a consequence of this signaling cascade, ouabain stimulates on the mRNA level the expression of integrins αv, β3 and α5, whose expression is also modulated by the cAMP response element. Increased expression of integrins αv and β3 is also seen in cultures of seminiferous tubules exposed to 10nM ouabain. At the protein level we observed a significant stimulation of β3 integrin expression by ouabain. Abrogation of α4 isoform expression by siRNA leads to the complete suppression of all ouabain-induced signaling mentioned above, including its stimulatory effect on the expression of β3 integrin. The results presented here demonstrate for the first time the induction of signaling cascades through the interaction of ouabain with the α4 isoform in a germ-cell derived cell line. The novel finding that these interactions lead to increased expression of integrins in GC-2 cells and the confirmation of these results in the ex vivo experiments indicate that hormone/receptor-like interactions of ouabain with the α4 isoform might be of significance for male physiology.
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Affiliation(s)
- Neha Upmanyu
- Institut für Veterinär-Physiologie und -Biochemie, Fachbereich Veterinärmedizin, Justus-Liebig Universität Giessen, Giessen, Germany
| | - Raimund Dietze
- Institut für Veterinär-Physiologie und -Biochemie, Fachbereich Veterinärmedizin, Justus-Liebig Universität Giessen, Giessen, Germany
| | - Ulrike Kirch
- Institut für Veterinär-Physiologie und -Biochemie, Fachbereich Veterinärmedizin, Justus-Liebig Universität Giessen, Giessen, Germany
| | - Georgios Scheiner-Bobis
- Institut für Veterinär-Physiologie und -Biochemie, Fachbereich Veterinärmedizin, Justus-Liebig Universität Giessen, Giessen, Germany.
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Tverskoi AM, Sidorenko SV, Klimanova EA, Akimova OA, Smolyaninova LV, Lopina OD, Orlov SN. Effects of ouabain on proliferation of human endothelial cells correlate with Na+,K+-ATPase activity and intracellular ratio of Na+ and K+. BIOCHEMISTRY (MOSCOW) 2016; 81:876-83. [DOI: 10.1134/s0006297916080083] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Blaustein MP, Chen L, Hamlyn JM, Leenen FHH, Lingrel JB, Wier WG, Zhang J. Pivotal role of α2 Na + pumps and their high affinity ouabain binding site in cardiovascular health and disease. J Physiol 2016; 594:6079-6103. [PMID: 27350568 DOI: 10.1113/jp272419] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/18/2016] [Indexed: 12/13/2022] Open
Abstract
Reduced smooth muscle (SM)-specific α2 Na+ pump expression elevates basal blood pressure (BP) and increases BP sensitivity to angiotensin II (Ang II) and dietary NaCl, whilst SM-α2 overexpression lowers basal BP and decreases Ang II/salt sensitivity. Prolonged ouabain infusion induces hypertension in rodents, and ouabain-resistant mutation of the α2 ouabain binding site (α2R/R mice) confers resistance to several forms of hypertension. Pressure overload-induced heart hypertrophy and failure are attenuated in cardio-specific α2 knockout, cardio-specific α2 overexpression and α2R/R mice. We propose a unifying hypothesis that reconciles these apparently disparate findings: brain mechanisms, activated by Ang II and high NaCl, regulate sympathetic drive and a novel neurohumoral pathway mediated by both brain and circulating endogenous ouabain (EO). Circulating EO modulates ouabain-sensitive α2 Na+ pump activity and Ca2+ transporter expression and, via Na+ /Ca2+ exchange, Ca2+ homeostasis. This regulates sensitivity to sympathetic activity, Ca2+ signalling and arterial and cardiac contraction.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Ling Chen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Frans H H Leenen
- Hypertension Unit, University of Ottawa Heart Institute, Ottawa, ON, Canada, K1Y 4W7
| | - Jerry B Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267-0524, USA
| | - W Gil Wier
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Shah PT, Martin R, Yan Y, Shapiro JI, Liu J. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis. Front Physiol 2016; 7:256. [PMID: 27445847 PMCID: PMC4923243 DOI: 10.3389/fphys.2016.00256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/11/2016] [Indexed: 01/01/2023] Open
Abstract
Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT).
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Affiliation(s)
- Preeya T Shah
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Rebecca Martin
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
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Matchkov VV, Krivoi II. Specialized Functional Diversity and Interactions of the Na,K-ATPase. Front Physiol 2016; 7:179. [PMID: 27252653 PMCID: PMC4879863 DOI: 10.3389/fphys.2016.00179] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/04/2016] [Indexed: 12/22/2022] Open
Abstract
Na,K-ATPase is a protein ubiquitously expressed in the plasma membrane of all animal cells and vitally essential for their functions. A specialized functional diversity of the Na,K-ATPase isozymes is provided by molecular heterogeneity, distinct subcellular localizations, and functional interactions with molecular environment. Studies over the last decades clearly demonstrated complex and isoform-specific reciprocal functional interactions between the Na,K-ATPase and neighboring proteins and lipids. These interactions are enabled by a spatially restricted ion homeostasis, direct protein-protein/lipid interactions, and protein kinase signaling pathways. In addition to its "classical" function in ion translocation, the Na,K-ATPase is now considered as one of the most important signaling molecules in neuronal, epithelial, skeletal, cardiac and vascular tissues. Accordingly, the Na,K-ATPase forms specialized sub-cellular multimolecular microdomains which act as receptors to circulating endogenous cardiotonic steroids (CTS) triggering a number of signaling pathways. Changes in these endogenous cardiotonic steroid levels and initiated signaling responses have significant adaptive values for tissues and whole organisms under numerous physiological and pathophysiological conditions. This review discusses recent progress in the studies of functional interactions between the Na,K-ATPase and molecular microenvironment, the Na,K-ATPase-dependent signaling pathways and their significance for diversity of cell function.
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Affiliation(s)
| | - Igor I Krivoi
- Department of General Physiology, St. Petersburg State University St. Petersburg, Russia
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Isaksen TJ, Lykke-Hartmann K. Insights into the Pathology of the α2-Na(+)/K(+)-ATPase in Neurological Disorders; Lessons from Animal Models. Front Physiol 2016; 7:161. [PMID: 27199775 PMCID: PMC4854887 DOI: 10.3389/fphys.2016.00161] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/15/2016] [Indexed: 12/12/2022] Open
Abstract
A functional Na+/K+-ATPase consists of a catalytic α subunit and a regulatory β subunit. Four α isoforms of the Na+/K+-ATPase are found in mammals, each with a unique expression pattern and catalytic activity. The α2 isoform, encoded by the ATP1A2 gene, is primarily found in the central nervous system (CNS) and in heart-, skeletal- and smooth muscle tissues. In the CNS, the α2 isoform is mainly expressed in glial cells. In particular, the α2 isoform is found in astrocytes, important for astrocytic K+ clearance and, consequently, the indirect uptake of neurotransmitters. Both processes are essential for proper brain activity, and autosomal dominantly mutations in the ATP1A2 gene cause the neurological disorder Familial hemiplegic migraine type 2 (FHM2). FHM2 is a severe subtype of migraine with aura including temporary numbness or weakness, and affecting only one side of the body. FHM2 patients often suffer from neurological comorbidities such as seizures, sensory disturbances, cognitive impairment, and psychiatric manifestations. The functional consequences of FHM2 disease mutations leads to a partial or complete loss of function of pump activity; however, a clear phenotype-genotype correlation has yet to be elucidated. Gene-modified mouse models targeting the Atp1a2 gene have proved instrumental in the understanding of the pathology of FHM2. Several Atp1a2 knockout (KO) mice targeting different exons have been reported. Homozygous Atp1a2 KO mice die shortly after birth due to respiratory malfunction resulting from abnormal Cl− homeostasis in brainstem neurons. Heterozygous KO mice are viable, but display altered behavior and neurological deficits such as altered spatial learning, decreased motor activity and enhanced fear/anxiety compared to wild type mice. FHM2 knock-in (KI) mouse models carrying the human in vivo disease mutations W887R and G301R have also been reported. Both models display altered cortical spreading depression (CSD) and point to deficits in the glutamatergic system as the main underlying mechanism of FHM2.
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Affiliation(s)
- Toke J Isaksen
- Department of Biomedicine, Aarhus UniversityAarhus, Denmark; Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark
| | - Karin Lykke-Hartmann
- Department of Biomedicine, Aarhus UniversityAarhus, Denmark; Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark; Aarhus Institute of Advanced Studies, Aarhus UniversityAarhus, Denmark
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