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Fabri LM, Moraes CM, Garçon DP, McNamara JC, Faria SC, Leone FA. Primary amino acid sequences of decapod (Na +, K +)-ATPase provide evolutionary insights into osmoregulatory mechanisms. Comp Biochem Physiol A Mol Integr Physiol 2024; 296:111696. [PMID: 39004301 DOI: 10.1016/j.cbpa.2024.111696] [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: 04/29/2024] [Revised: 07/08/2024] [Accepted: 07/08/2024] [Indexed: 07/16/2024]
Abstract
Decapod Crustacea exhibit a marine origin, but many taxa have occupied environments ranging from brackish to fresh water and terrestrial habitats, overcoming their inherent osmotic challenges. Osmotic and ionic regulation is achieved by the gill epithelia, driven by two active ATP-hydrolyzing ion transporters, the basal (Na+, K+)-ATPase and the apical V(H+)-ATPase. The kinetic characteristic of gill (Na+, K+)-ATPase and the mRNA expression of its α subunit have been widely studied in various decapod species under different salinity challenges. However, the evolution of the primary structure has not been explored, especially considering the functional modifications associated with decapod phylogeny. Here, we proposed a model for the topology of the decapod α subunit, identifying the sites and motifs involved in its function and regulation, as well as the patterns of its evolution assuming a decapod phylogeny. We also examined both the amino acid substitutions and their functional implications within the context of biochemical and physiological adaptation. The α-subunit of decapod crustaceans shows greater conservation (∼94% identity) compared to the β-subunit (∼40%). While the binding sites for ATP and modulators are conserved in the decapod enzyme, the residues involved in the α-β interaction are only partially conserved. In the phylogenetic context of the complete sequence of (Na+, K+)-ATPase α-subunit, most substitutions appear to be characteristic of the entire group, with specific changes for different subgroups, especially among brachyuran crabs. Interestingly, there was no consistent separation of α-subunit partial sequences related to habitat, suggesting that the convergent evolution for freshwater or terrestrial modes of life is not correlated with similar changes in the enzyme's primary amino acid sequence.
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Affiliation(s)
- Leonardo M Fabri
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Cintya M Moraes
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - John C McNamara
- Departamento de Biologia Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil; Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, São Paulo, Brazil
| | - Samuel C Faria
- Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, São Paulo, Brazil
| | - Francisco A Leone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.
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2
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Fender J, Klöcker J, Boivin-Jahns V, Ravens U, Jahns R, Lorenz K. "Cardiac glycosides"-quo vaditis?-past, present, and future? NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03285-3. [PMID: 39007928 DOI: 10.1007/s00210-024-03285-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024]
Abstract
Up to date, digitalis glycosides, also known as "cardiac glycosides", are inhibitors of the Na+/K+-ATPase. They have a long-standing history as drugs used in patients suffering from heart failure and atrial fibrillation despite their well-known narrow therapeutic range and the intensive discussions on their raison d'être for these indications. This article will review the history and key findings in basic and clinical research as well as potentially overseen pros and cons of these drugs.
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Affiliation(s)
- Julia Fender
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Johanna Klöcker
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Valérie Boivin-Jahns
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Ursula Ravens
- Institute of Experimental Cardiovascular Medicine, Faculty of Medicine, University of Freiburg, Elsässer Straße 2Q, 79110, Freiburg, Germany
| | - Roland Jahns
- Interdisciplinary Bank of Biological Materials and Data Würzburg (ibdw), University Hospital Würzburg, Straubmühlweg 2a, 97078, Würzburg, Germany
| | - Kristina Lorenz
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany.
- Leibniz-Institut für Analytische Wissenschaften-ISAS e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany.
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3
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Contreras RG, Torres-Carrillo A, Flores-Maldonado C, Shoshani L, Ponce A. Na +/K +-ATPase: More than an Electrogenic Pump. Int J Mol Sci 2024; 25:6122. [PMID: 38892309 PMCID: PMC11172918 DOI: 10.3390/ijms25116122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
The sodium pump, or Na+/K+-ATPase (NKA), is an essential enzyme found in the plasma membrane of all animal cells. Its primary role is to transport sodium (Na+) and potassium (K+) ions across the cell membrane, using energy from ATP hydrolysis. This transport creates and maintains an electrochemical gradient, which is crucial for various cellular processes, including cell volume regulation, electrical excitability, and secondary active transport. Although the role of NKA as a pump was discovered and demonstrated several decades ago, it remains the subject of intense research. Current studies aim to delve deeper into several aspects of this molecular entity, such as describing its structure and mode of operation in atomic detail, understanding its molecular and functional diversity, and examining the consequences of its malfunction due to structural alterations. Additionally, researchers are investigating the effects of various substances that amplify or decrease its pumping activity. Beyond its role as a pump, growing evidence indicates that in various cell types, NKA also functions as a receptor for cardiac glycosides like ouabain. This receptor activity triggers the activation of various signaling pathways, producing significant morphological and physiological effects. In this report, we present the results of a comprehensive review of the most outstanding studies of the past five years. We highlight the progress made regarding this new concept of NKA and the various cardiac glycosides that influence it. Furthermore, we emphasize NKA's role in epithelial physiology, particularly its function as a receptor for cardiac glycosides that trigger intracellular signals regulating cell-cell contacts, proliferation, differentiation, and adhesion. We also analyze the role of NKA β-subunits as cell adhesion molecules in glia and epithelial cells.
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Affiliation(s)
| | | | | | | | - Arturo Ponce
- Department of Physiology, Biophysics and Neurosciences, CINVESTAV-IPN, Mexico City 07360, Mexico; (R.G.C.); (A.T.-C.); (C.F.-M.); (L.S.)
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4
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Depierre P, Ginet V, Truttmann AC, Puyal J. Neuronal autosis is Na +/K +-ATPase alpha 3-dependent and involved in hypoxic-ischemic neuronal death. Cell Death Dis 2024; 15:363. [PMID: 38796484 PMCID: PMC11127954 DOI: 10.1038/s41419-024-06750-2] [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: 11/07/2023] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/28/2024]
Abstract
Macroautophagy (hereafter called autophagy) is an essential physiological process of degradation of organelles and long-lived proteins. The discovery of autosis, a Na+/K+-ATPase (ATP1)-dependent type of autophagic cell death with specific morphological and biochemical features, has strongly contributed to the acceptance of a pro-death role of autophagy. However, the occurrence and relevance of autosis in neurons has never been clearly investigated, whereas we previously provided evidence that autophagy mechanisms could be involved in neuronal death in different in vitro and in vivo rodent models of hypoxia-ischemia (HI) and that morphological features of autosis were observed in dying neurons following rat perinatal cerebral HI. In the present study, we demonstrated that neuronal autosis could occur in primary cortical neurons using two different stimulations enhancing autophagy flux and neuronal death: a neurotoxic concentration of Tat-BECN1 (an autophagy-inducing peptide) and a hypoxic/excitotoxic stimulus (mimicking neuronal death induced by cerebral HI). Both stimulations induce autophagic neuronal death (dependent on canonical autophagic genes and independent on apoptotic, necroptotic or ferroptotic pathways) with all morphological and biochemical (ATP1a-dependent) features of autosis. However, we demonstrated that autosis is not dependent on the ubiquitous subunit ATP1a1 in neurons, as in dividing cell types, but on the neuronal specific ATP1a3 subunit. We also provided evidence that, in different in vitro and in vivo models where autosis is induced, ATP1a3-BECN1 interaction is increased and prevented by cardiac glycosides treatment. Interestingly, an increase in ATP1a3-BECN1 interaction is also detected in dying neurons in the autoptic brains of human newborns with severe hypoxic-ischemic encephalopathy (HIE). Altogether, these results suggest that ATP1a3-BECN1-dependent autosis could play an important role in neuronal death in HI conditions, paving the way for the development of new neuroprotective strategies in hypoxic-ischemic conditions including in severe case of human HIE.
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Affiliation(s)
- Pauline Depierre
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Vanessa Ginet
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
- Clinic of Neonatology, Department of Women, Mother and Child, University Hospital Center of Vaud, Lausanne, Switzerland
| | - Anita C Truttmann
- Clinic of Neonatology, Department of Women, Mother and Child, University Hospital Center of Vaud, Lausanne, Switzerland
| | - Julien Puyal
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.
- CURML, University Center of Legal Medicine, Lausanne University Hospital, Lausanne, Switzerland.
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Samolej J, White IJ, Strang BL, Mercer J. Cardiac glycosides inhibit early and late vaccinia virus protein expression. J Gen Virol 2024; 105:001971. [PMID: 38546099 PMCID: PMC10995631 DOI: 10.1099/jgv.0.001971] [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: 02/13/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024] Open
Abstract
Cardiac glycosides (CGs) are natural steroid glycosides, which act as inhibitors of the cellular sodium-potassium ATPase pump. Although traditionally considered toxic to human cells, CGs are widely used as drugs for the treatment of cardiovascular-related medical conditions. More recently, CGs have been explored as potential anti-viral drugs and inhibit replication of a range of RNA and DNA viruses. Previously, a compound screen identified CGs that inhibited vaccinia virus (VACV) infection. However, no further investigation of the inhibitory potential of these compounds was performed, nor was there investigation of the stage(s) of the poxvirus lifecycle they impacted. Here, we investigated the anti-poxvirus activity of a broad panel of CGs. We found that all CGs tested were potent inhibitors of VACV replication. Our virological experiments showed that CGs did not impact virus infectivity, binding, or entry. Rather, experiments using recombinant viruses expressing reporter proteins controlled by VACV promoters and arabinoside release assays demonstrated that CGs inhibited early and late VACV protein expression at different concentrations. Lack of virus assembly in the presence of CGs was confirmed using electron microscopy. Thus, we expand our understanding of compounds with anti-poxvirus activity and highlight a yet unrecognized mechanism by which poxvirus replication can be inhibited.
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Affiliation(s)
- Jerzy Samolej
- Insititute of Microbiology and Infection, University of Birmingham, Birmingham, UK
- Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Ian J. White
- Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Blair L. Strang
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Jason Mercer
- Insititute of Microbiology and Infection, University of Birmingham, Birmingham, UK
- Laboratory for Molecular Cell Biology, University College London, London, UK
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Choi M, Yun JW. β-Carotene induces UCP1-independent thermogenesis via ATP-consuming futile cycles in 3T3-L1 white adipocytes. Arch Biochem Biophys 2023; 739:109581. [PMID: 36948352 DOI: 10.1016/j.abb.2023.109581] [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: 12/07/2022] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 03/24/2023]
Abstract
The activation of brown fat and induction of beige adipocytes, so-called non-shivering thermogenesis, is emerging as a promising target for therapeutic intervention in obesity management. Our previous report demonstrated that β-carotene (BC) induces beige adipocytes to increase UCP1-dependent thermogenic activity. However, the UCP1-independent thermogenic effect of BC on adipose tissues remains unexplored. In this study, we examined the effects of BC on UCP1-independent thermogenic activity with a focus on the ATP-consuming futile cycles in 3T3-L1 adipocytes. BC increased intracellular calcium levels and stimulated the expression of calcium cycling-related proteins, including sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) 2b, ryanodine receptor 2 (RyR2), voltage-dependent anion channel (VDAC), mitochondrial calcium uniporter (MCU), and Ca2+/calmodulin-dependent protein kinase 2 (CaMK2) in 3T3-L1 white adipocytes. In addition, BC stimulated thermogenesis by activating the creatine metabolism-related thermogenic pathway. Moreover, BC activated β-carotene oxygenase 1 (BCO1), which efficiently cleaved BC to retinal and consequently converted to its transcriptionally active form retinoic acid. These BC conversion products also exhibited thermogenic effects comparable to a similar level of BC. The mechanistic study revealed that retinal exhibited thermogenic activity independently of retinoic acid and retinoic acid-mediated thermogenesis was resulted partly from conversion of retinal. Moreover, BC activated α1-AR and UCP1-independent thermogenic effectors independently of UCP1 expression. In conclusion, the thermogenic response to BC and its conversion products in 3T3-L1 white adipocytes involves two interacting pathways, one mediated via β3-adrenergic receptors (β3-AR) and cyclic adenosine monophosphate (cAMP) and the other via α1-AR and increases in cytosolic Ca2+ levels activated by calcium regulatory proteins.
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Affiliation(s)
- Minji Choi
- Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea
| | - Jong Won Yun
- Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea.
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7
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Manoj KM, Gideon DA, Bazhin NM, Tamagawa H, Nirusimhan V, Kavdia M, Jaeken L. Na,K-ATPase: A murzyme facilitating thermodynamic equilibriums at the membrane-interface. J Cell Physiol 2023; 238:109-136. [PMID: 36502470 DOI: 10.1002/jcp.30925] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 12/14/2022]
Abstract
The redox metabolic paradigm of murburn concept advocates that diffusible reactive species (DRS, particularly oxygen-centric radicals) are mainstays of physiology, and not mere pathological manifestations. The murburn purview of cellular function also integrates the essential principles of bioenergetics, thermogenesis, homeostasis, electrophysiology, and coherence. In this context, any enzyme that generates/modulates/utilizes/sustains DRS functionality is called a murzyme. We have demonstrated that several water-soluble (peroxidases, lactate dehydrogenase, hemogoblin, etc.) and membrane-embedded (Complexes I-V in mitochondria, Photosystems I/II in chloroplasts, rhodopsin/transducin in rod cells, etc.) proteins serve as murzymes. The membrane protein of Na,K-ATPase (NKA, also known as sodium-potassium pump) is the focus of this article, owing to its centrality in neuro-cardio-musculo electrophysiology. Herein, via a series of critical queries starting from the geometric/spatio-temporal considerations of diffusion/mass transfer of solutes in cells to an update on structural/distributional features of NKA in diverse cellular systems, and from various mechanistic aspects of ion-transport (thermodynamics, osmoregulation, evolutionary dictates, etc.) to assays/explanations of inhibitory principles like cardiotonic steroids (CTS), we first highlight some unresolved problems in the field. Thereafter, we propose and apply a minimalist murburn model of trans-membrane ion-differentiation by NKA to address the physiological inhibitory effects of trans-dermal peptide, lithium ion, volatile anesthetics, confirmed interfacial DRS + proton modulators like nitrophenolics and unsaturated fatty acid, and the diverse classes of molecules like CTS, arginine, oximes, etc. These explanations find a pan-systemic connectivity with the inhibitions/uncouplings of other membrane proteins in cells.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2, Kerala, India
| | - Daniel A Gideon
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2, Kerala, India
| | - Nikolai M Bazhin
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, Russia
| | - Hirohisa Tamagawa
- Department of Mechanical Engineering, Gifu University, Gifu City, Japan
| | - Vijay Nirusimhan
- Satyamjayatu: The Science & Ethics Foundation, Kulappully, Shoranur-2, Kerala, India
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Laurent Jaeken
- Department of Industrial Sciences and Technology, Karel de Grote-Hogeschool, Antwerp University Association, Antwerp, Belgium
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8
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Curcumin Stimulates UCP1-independent Thermogenesis in 3T3-L1 White Adipocytes but Suppresses in C2C12 Muscle Cells. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-022-0319-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Identification of a Cardiac Glycoside Exhibiting Favorable Brain Bioavailability and Potency for Reducing Levels of the Cellular Prion Protein. Int J Mol Sci 2022; 23:ijms232314823. [PMID: 36499150 PMCID: PMC9736291 DOI: 10.3390/ijms232314823] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/19/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022] Open
Abstract
Several strands of investigation have established that a reduction in the levels of the cellular prion protein (PrPC) is a promising avenue for the treatment of prion diseases. We recently described an indirect approach for reducing PrPC levels that targets Na,K-ATPases (NKAs) with cardiac glycosides (CGs), causing cells to respond with the degradation of these pumps and nearby molecules, including PrPC. Because the therapeutic window of widely used CGs is narrow and their brain bioavailability is low, we set out to identify a CG with improved pharmacological properties for this indication. Starting with the CG known as oleandrin, we combined in silico modeling of CG binding poses within human NKA folds, CG structure-activity relationship (SAR) data, and predicted blood-brain barrier (BBB) penetrance scores to identify CG derivatives with improved characteristics. Focusing on C4'-dehydro-oleandrin as a chemically accessible shortlisted CG derivative, we show that it reaches four times higher levels in the brain than in the heart one day after subcutaneous administration, exhibits promising pharmacological properties, and suppresses steady-state PrPC levels by 84% in immortalized human cells that have been differentiated to acquire neural or astrocytic characteristics. Finally, we validate that the mechanism of action of this approach for reducing cell surface PrPC levels requires C4'-dehydro-oleandrin to engage with its cognate binding pocket within the NKA α subunit. The improved brain bioavailability of C4'-dehydro-oleandrin, combined with its relatively low toxicity, make this compound an attractive lead for brain CG indications and recommends its further exploration for the treatment of prion diseases.
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Meneses-Sagrero SE, Rascón-Valenzuela LA, García-Ramos JC, Vilegas W, Arvizu-Flores AA, Sotelo-Mundo RR, Robles-Zepeda RE. Calotropin and corotoxigenin 3-O-glucopyranoside from the desert milkweed Asclepias subulata inhibit the Na +/K +-ATPase activity. PeerJ 2022; 10:e13524. [PMID: 35673388 PMCID: PMC9167584 DOI: 10.7717/peerj.13524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/10/2022] [Indexed: 01/17/2023] Open
Abstract
Na+/K+-ATPase is an essential transmembrane enzyme found in all mammalian cells with critical functions for cell ion homeostasis. The inhibition of this enzyme by several cardiotonic steroids (CTS) has been associated with the cytotoxic effect on cancer cell lines of phytochemicals such as ouabain and digitoxin. This study evaluated the inhibitory capacity of cardenolides calotropin and corotoxigenin 3-O-glucopyranoside (C3OG) from Asclepias subulata over the Na+/K+-ATPase activity in vitro and silico. The inhibitory assays showed that calotropin and C3OG decreased the Na+/K+-ATPase activity with IC50 values of 0.27 and 0.87 μM, respectively. Furthermore, the molecules presented an uncompetitive inhibition on Na+/K+-ATPase activity, with Ki values of 0.2 μM to calotropin and 0.5 μM to C3OG. Furthermore, the molecular modeling indicated that calotropin and C3OG might interact with the Thr797 and Gln111 residues, considered essential to the interaction with the Na+/K+-ATPase. Besides, these cardenolides can interact with amino acid residues such as Phe783, Leu125, and Ala323, to establish hydrophobic interactions on the binding site. Considering the results, these provide novel evidence about the mechanism of action of cardenolides from A. subulata, proposing that C3OG is a novel cardenolide that deserves further consideration for in vitro cellular antiproliferative assays and in vivo studies as an anticancer molecule.
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Affiliation(s)
| | | | - Juan C. García-Ramos
- Escuela de Ciencias de la Salud, Universidad Autónoma de Baja California, Ensenada, Baja California, México
| | - Wagner Vilegas
- Instituto de Biociências, São Paulo State University, Sao Paulo, Brasil
| | | | - Rogerio R. Sotelo-Mundo
- Laboratorio de Estructura Molecular, Centro de Investigación en Alimentación y Desarrollo AC, Hermosillo, Sonora, México
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Small Molecule Arranged Thermal Proximity Co aggregation (smarTPCA)-A Novel Approach to Characterize Protein-Protein Interactions in Living Cells by Similar Isothermal Dose-Responses. Int J Mol Sci 2022; 23:ijms23105605. [PMID: 35628420 PMCID: PMC9147192 DOI: 10.3390/ijms23105605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/17/2022] Open
Abstract
Chemical biology and the application of small molecules has proven to be a potent perturbation strategy, especially for the functional elucidation of proteins, their networks, and regulators. In recent years, the cellular thermal shift assay (CETSA) and its proteome-wide extension, thermal proteome profiling (TPP), have proven to be effective tools for identifying interactions of small molecules with their target proteins, as well as off-targets in living cells. Here, we asked the question whether isothermal dose-response (ITDR) CETSA can be exploited to characterize secondary effects downstream of the primary binding event, such as changes in post-translational modifications or protein-protein interactions (PPI). By applying ITDR-CETSA to MAPK14 kinase inhibitor treatment of living HL-60 cells, we found similar dose-responses for the direct inhibitor target and its known interaction partners MAPKAPK2 and MAPKAPK3. Extension of the dose-response similarity comparison to the proteome wide level using TPP with compound concentration range (TPP-CCR) revealed not only the known MAPK14 interaction partners MAPKAPK2 and MAPKAPK3, but also the potentially new intracellular interaction partner MYLK. We are confident that dose-dependent small molecule treatment in combination with ITDR-CETSA or TPP-CCR similarity assessment will not only allow discrimination between primary and secondary effects, but will also provide a novel method to study PPI in living cells without perturbation by protein modification, which we named "small molecule arranged thermal proximity coaggregation" (smarTPCA).
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Fedosova NU, Habeck M, Nissen P. Structure and Function of Na,K-ATPase-The Sodium-Potassium Pump. Compr Physiol 2021; 12:2659-2679. [PMID: 34964112 DOI: 10.1002/cphy.c200018] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Na,K-ATPase is an ubiquitous enzyme actively transporting Na-ions out of the cell in exchange for K-ions, thereby maintaining their concentration gradients across the cell membrane. Since its discovery more than six decades ago the Na-pump has been studied extensively and its vital physiological role in essentially every cell has been established. This article aims at providing an overview of well-established biochemical properties with a focus on Na,K-ATPase isoforms, its transport mechanism and principle conformations, inhibitors, and insights gained from crystal structures. © 2021 American Physiological Society. Compr Physiol 11:1-21, 2021.
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Affiliation(s)
| | - Michael Habeck
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
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13
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Role of Na +/K +-ATPase in ischemic stroke: in-depth perspectives from physiology to pharmacology. J Mol Med (Berl) 2021; 100:395-410. [PMID: 34839371 DOI: 10.1007/s00109-021-02143-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/27/2021] [Accepted: 09/20/2021] [Indexed: 12/26/2022]
Abstract
Na+/K+-ATPase (NKA) is a large transmembrane protein expressed in all cells. It is well studied for its ion exchanging function, which is indispensable for the maintenance of electrochemical gradients across the plasma membrane and herein neuronal excitability. The widely recognized pump function of NKA closely depends on its unique structure features and conformational changes upon binding of specific ions. Various Na+-dependent secondary transport systems are rigorously controlled by the ionic gradients generated by NKA and are essential for multiple physiological processes. In addition, roles of NKA as a signal transducer have also been unveiled nowadays. Plethora of signaling cascades are defined including Src-Ras-MAPK signaling, IP3R-mediated calcium oscillation, inflammation, and autophagy though most underlying mechanisms remain elusive. Ischemic stroke occurs when the blood flow carrying nutrients and oxygen into the brain is disrupted by blood clots, which is manifested by excitotoxicity, oxidative stress, inflammation, etc. The protective effect of NKA against ischemic stress is emerging gradually with the application of specific NKA inhibitor. However, NKA-related research is limited due to the opposite effects caused by NKA inhibitor at lower doses. The present review focuses on the recent progression involving different aspects about NKA in cellular homeostasis to present an in-depth understanding of this unique protein. Moreover, essential roles of NKA in ischemic pathology are discussed to provide a platform and bright future for the improvement in clinical research on ischemic stroke.
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Meneses-Sagrero SE, Rascón-Valenzuela LA, Sotelo-Mundo R, Vilegas W, Velazquez C, García-Ramos JC, Robles-Zepeda RE. Antiproliferative activity of cardenolides on cell line A549: structure-activity relationship analysis. Mol Divers 2021; 25:2289-2305. [PMID: 32627094 DOI: 10.1007/s11030-020-10119-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 06/19/2020] [Indexed: 01/22/2023]
Abstract
Since the beginning, natural products have represented an important source of bioactive molecules for cancer treatment. Among them, cardenolides attract the attention of different research groups due to their cardiotonic and antitumor activity. The observed biological activity is closely related to their Na+/K+-ATPase inhibition potency. Currently, the discovery of new compounds against cancer is an urgent need in modern pharmaceutical research. Thus, the aim of this work is to determine the physicochemical properties and substituent effects that module the antiproliferative activity of cardenolides on the human lung cancer cell line A549. We build and curate a library with results obtained from literature; molecular descriptors were calculated in PaDEL software, and SAR/QSAR analysis was performed. The SAR results showed that cardenolides were sensitive to modifications in C and D steroidal ring and required substituent groups with the function of hydrogen bond acceptor at the C3 position. QSAR models to doubly linked-type cardenolides indicated that properties as lipoaffinity and atoms with the capacity to be hydrogen bond acceptors are involved in the increment of antiproliferative activity on A549 cell line. In contrast, the presence and position of very electro-negative atoms on the molecule decreased the antiproliferative effect on A549 cells. These results suggest that the antiproliferative capacity of cardenolides on the cell line A549 is strongly related to substituent groups on the C3 position, which must not be carbohydrate. Additionally, the steroidal rings C and D must remain without modifications.
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Affiliation(s)
| | - Luisa Alondra Rascón-Valenzuela
- Unidad Regional Centro, Departamento de Ciencias, Químico Biológicas y de la Salud, Universidad de Sonora, Blvd. Encinas y Rosales S/N, Hermosillo, Sonora, Mexico
| | - Rogerio Sotelo-Mundo
- Centro de Investigación de Alimentos y Desarrollo A. C, Hermosillo, Sonora, Mexico
| | - Wagner Vilegas
- UNESP, São Paolo State University, Coastal Campus of São Vicente, São Paulo, Brazil
| | - Carlos Velazquez
- Unidad Regional Centro, Departamento de Ciencias, Químico Biológicas y de la Salud, Universidad de Sonora, Blvd. Encinas y Rosales S/N, Hermosillo, Sonora, Mexico
| | - Juan Carlos García-Ramos
- Escuela de Ciencias de la Salud, Universidad Autonoma de Baja California, Blvd. Zartuche y Blvd. Los Lagos, Fraccionamiento Valle Dorado, Ensenada, Baja California, Mexico.
| | - Ramón Enrique Robles-Zepeda
- Unidad Regional Centro, Departamento de Ciencias, Químico Biológicas y de la Salud, Universidad de Sonora, Blvd. Encinas y Rosales S/N, Hermosillo, Sonora, Mexico.
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Liu J, Tian J, Sodhi K, Shapiro JI. The Na/K-ATPase Signaling and SGLT2 Inhibitor-Mediated Cardiorenal Protection: A Crossed Road? J Membr Biol 2021; 254:513-529. [PMID: 34297135 PMCID: PMC8595165 DOI: 10.1007/s00232-021-00192-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/06/2021] [Indexed: 12/17/2022]
Abstract
In different large-scale clinic outcome trials, sodium (Na+)/glucose co-transporter 2 (SGLT2) inhibitors showed profound cardiac- and renal-protective effects, making them revolutionary treatments for heart failure and kidney disease. Different theories are proposed according to the emerging protective effects other than the original purpose of glucose-lowering in diabetic patients. As the ATP-dependent primary ion transporter providing the Na+ gradient to drive other Na+-dependent transporters, the possible role of the sodium–potassium adenosine triphosphatase (Na/K-ATPase) as the primary ion transporter and its signaling function is not explored.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA.
| | - Jiang Tian
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Komal Sodhi
- Department of Surgery, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Joseph I Shapiro
- Departments of Medicine, JCE School of Medicine, Marshall University, Huntington, WV, USA
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Structural Insights into the Interactions of Digoxin and Na +/K +-ATPase and Other Targets for the Inhibition of Cancer Cell Proliferation. Molecules 2021; 26:molecules26123672. [PMID: 34208576 PMCID: PMC8234910 DOI: 10.3390/molecules26123672] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/01/2021] [Accepted: 06/09/2021] [Indexed: 12/12/2022] Open
Abstract
Digoxin is a cardiac glycoside long used to treat congestive heart failure and found recently to show antitumor potential. The hydroxy groups connected at the C-12, C-14, and C-3′a positions; the C-17 unsaturated lactone unit; the conformation of the steroid core; and the C-3 saccharide moiety have been demonstrated as being important for digoxin’s cytotoxicity and interactions with Na+/K+-ATPase. The docking profiles for digoxin and several derivatives and Na+/K+-ATPase were investigated; an additional small Asn130 side pocket was revealed, which could be useful in the design of novel digoxin-like antitumor agents. In addition, the docking scores for digoxin and its derivatives were found to correlate with their cytotoxicity, indicating a potential use of these values in the prediction of the cancer cell cytotoxicity of other cardiac glycosides. Moreover, in these docking studies, digoxin was found to bind to FIH-1 and NF-κB but not HDAC, IAP, and PI3K, suggesting that this cardiac glycoside directly targets FIH-1, Na+/K+-ATPase, and NF-κB to mediate its antitumor potential. Differentially, digoxigenin, the aglycon of digoxin, binds to HDAC and PI3K, but not FIH-1, IAP, Na+/K+-ATPase, and NF-κB, indicating that this compound may target tumor autophagy and metabolism to mediate its antitumor propensity.
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17
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Na,K-ATPase α4, and Not Na,K-ATPase α1, is the Main Contributor to Sperm Motility, But its High Ouabain Binding Affinity Site is Not Required for Male Fertility in Mice. J Membr Biol 2021; 254:549-561. [PMID: 34129092 DOI: 10.1007/s00232-021-00181-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 04/28/2021] [Indexed: 01/05/2023]
Abstract
Mammalian sperm express two Na,K-ATPase (NKA) isoforms, Na,K-ATPase α4 (NKAα4) and Na,K-ATPase α1 (NKAα1). While NKAα4 is critical to sperm motility, the role of NKAα1 in sperm movement remains unknown. We determined this here using a genetic and pharmacological approach, modifying the affinity of NKAα1 and NKAα4 for the inhibitor ouabain to selectively block the function of each isoform. Sperm from wild-type (WT) mice (naturally containing ouabain-resistant NKAα1 and ouabain-sensitive NKAα4) and three newly generated mouse lines, expressing both NKAα1 and NKAα4 ouabain resistant (OR), ouabain sensitive (OS), and with their ouabain affinity switched (SW) were used. All mouse lines produced normal sperm numbers and were fertile. All sperm types showed NKAα isoform expression levels and activity comparable to WT, and kinetics for ouabain inhibition confirming the expected changes in ouabain affinity for each NKA isoform. Ouabain at 1 μM, which only block ouabain-sensitive NKA, significantly inhibited total, progressive, and hyperactivated sperm motility in WT and OS, but had no significant effect on OR or SW sperm. Higher ouabain (1 mM), which inhibits both ouabain-sensitive and ouabain-resistant NKA, had little additional effect on sperm motility in all mouse lines, including the OR and SW. A similar pattern was found for the effect of ouabain on sperm intracellular sodium ([Na+]i). These results indicate that NKAα4, but not NKAα1 is the main contributor to sperm motility and that the ouabain affinity site in NKA is not an essential requirement for male fertility.
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Geometry and water accessibility of the inhibitor binding site of Na +-pump: Pulse- and CW-EPR study. Biophys J 2021; 120:2679-2690. [PMID: 34087213 PMCID: PMC8390900 DOI: 10.1016/j.bpj.2021.05.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 05/07/2021] [Accepted: 05/19/2021] [Indexed: 11/22/2022] Open
Abstract
Spin labels based on cinobufagin, a specific inhibitor of the Na,K-ATPase, have proved valuable tools to characterize the binding site of cardiotonic steroids (CTSs), which also constitutes the extracellular cation pathway. Because existing literature suggests variations in the physiological responses caused by binding of different CTSs, we extended the original set of spin-labeled inhibitors to the more potent bufalin derivatives. Positioning of the spin labels within the Na,K-ATPase site was defined and visualized by molecular docking. Although the original cinobufagin labels exhibited lower affinity, continuous-wave electron paramagnetic resonance spectra of spin-labeled bufalins and cinobufagins revealed a high degree of pairwise similarity, implying that these two types of CTS bind in the same way. Further analysis of the spectral lineshapes of bound spin labels was performed with emphasis on their structure (PROXYL vs. TEMPO), as well as length and rigidity of the linkers. For comparable structures, the dynamic flexibility increased in parallel with linker length, with the longest linker placing the spin label at the entrance to the binding site. Temperature-related changes in spectral lineshapes indicate that six-membered nitroxide rings undergo boat-chair transitions, showing that the binding-site cross section can accommodate the accompanying changes in methyl-group orientation. D2O-electron spin echo envelope modulation in pulse-electron paramagnetic resonance measurements revealed high water accessibilities and similar polarity profiles for all bound spin labels, implying that the vestibule leading to steroid-binding site and cation-binding sites is relatively wide and water-filled.
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Abstract
The sodium pump (Na+, K+-ATPase, NKA) is vital for animal cells, as it actively maintains Na+ and K+ electrochemical gradients across the cell membrane. It is a target of cardiotonic steroids (CTSs) such as ouabain and digoxin. As CTSs are almost unique strong inhibitors specific to NKA, a wide range of derivatives has been developed for potential therapeutic use. Several crystal structures have been published for NKA-CTS complexes, but they fail to explain the largely different inhibitory properties of the various CTSs. For instance, although CTSs are thought to inhibit ATPase activity by binding to NKA in the E2P state, we do not know if large conformational changes accompany binding, as no crystal structure is available for the E2P state free of CTS. Here, we describe crystal structures of the BeF3 - complex of NKA representing the E2P ground state and then eight crystal structures of seven CTSs, including rostafuroxin and istaroxime, two new members under clinical trials, in complex with NKA in the E2P state. The conformations of NKA are virtually identical in all complexes with and without CTSs, showing that CTSs bind to a preformed cavity in NKA. By comparing the inhibitory potency of the CTSs measured under four different conditions, we elucidate how different structural features of the CTSs result in different inhibitory properties. The crystal structures also explain K+-antagonism and suggest a route to isoform specific CTSs.
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Ladefoged LK, Schiøtt B, Fedosova NU. Beneficent and Maleficent Effects of Cations on Bufadienolide Binding to Na +,K +-ATPase. J Chem Inf Model 2021; 61:976-986. [PMID: 33502848 DOI: 10.1021/acs.jcim.0c01396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Kinetic properties and crystal structures of the Na+,K+-ATPase in complex with cardiotonic steroids (CTS) revealed significant differences between CTS subfamilies (Laursen et al.). Thus, we found beneficial effects of K+ on bufadienolide binding, which strongly contrasted with the well-known antagonism between K+ and cardenolides. In order to understand this peculiarity of bufalin interactions, we used docking and molecular dynamics simulations of the complexes involving Na+,K+-ATPase, bufadienolides (bufalin, cinobufagin), and ions (K+, Na+, Mg2+). The results revealed that bufadienolide binding is affected by (i) electrostatic attraction of the lactone ring by a cation and (ii) the ability of a cation to stabilize and "shape" the site constituted by transmembrane helices of the α-subunit (αM1-6). The latter effect was due to varying coordination patterns involving amino acid residues from helix bundles αM1-4 and αM5-10. Substituents on the steroid core of a bufadienolide add to and modify the cation effects. The above rationale is fully consistent with the ion effects on the kinetics of Na+,K+-ATPase/bufadienolide interactions.
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Affiliation(s)
- Lucy Kate Ladefoged
- Department of Biomedicine, Aarhus University, Høegh-Guldbergsgade 10, 8000 Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Natalya U Fedosova
- Department of Biomedicine, Aarhus University, Høegh-Guldbergsgade 10, 8000 Aarhus C, Denmark
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21
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Xu Y, Marck P, Huang M, Xie JX, Wang T, Shapiro JI, Cai L, Feng F, Xie Z. Biased Effect of Cardiotonic Steroids on Na/K-ATPase-Mediated Signal Transduction. Mol Pharmacol 2021; 99:217-225. [PMID: 33495275 DOI: 10.1124/molpharm.120.000101] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 12/24/2020] [Indexed: 01/13/2023] Open
Abstract
Recent studies have revealed that Na/K-ATPase (NKA) can transmit signals through ion-pumping-independent activation of pathways relayed by distinct intracellular protein/lipid kinases, and endocytosis challenges the traditional definition that cardiotonic steroids (CTS) are NKA inhibitors. Although additional effects of CTS have long been suspected, revealing its agonist impact through the NKA receptor could be a novel mechanism in understanding the basic biology of NKA. In this study, we tested whether different structural CTS could trigger different sets of NKA/effector interactions, resulting in biased signaling responses without compromising ion-pumping capacity. Using purified NKA, we found that ouabain, digitoxigenin, and somalin cause comparable levels of NKA inhibition. However, although endogenous ouabain stimulates both protein kinases and NKA endocytosis, digitoxigenin and somalin bias to protein kinases and endocytosis, respectively, in LLC-PK1 cells. The positive inotropic effects of CTS are traditionally regarded as NKA inhibitors. However, CTS-induced signaling occurs at concentrations at least one order of magnitude lower than that of inotropy, which eliminates their well known toxic actions on the heart. The current study adds a novel mechanism that CTS could exert its biased signaling properties through the NKA signal transducer. SIGNIFICANCE STATEMENT: Although it is now well accepted that NKA has an ion-pumping-independent signaling function, it is still debated whether direct and conformation-dependent NKA/effector interaction is a key to this function. Therefore, this investigation is significant in advancing our understanding of the basic biology of NKA-mediated signal transduction and gaining molecular insight into the structural elements that are important for cardiotonic steroid's biased action.
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Affiliation(s)
- Yunhui Xu
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Pauline Marck
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Minqi Huang
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Jeffrey X Xie
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Tong Wang
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Joseph I Shapiro
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Liquan Cai
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Feng Feng
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Huntington, West Virginia (Y.X., P.M., M.H., T.W., L.C., Z.X.); University of Toledo College of Medicine and Life Sciences, Toledo, Ohio (J.X.X.); Joan C. Edwards School of Medicine at Marshall University, Huntington, West Virginia (J.I.S.); and Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, P. R. China, and Jiangsu Food and Pharmaceutical Science College, Huai'an, P. R. China (F.F.)
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Cytotoxicity of glucoevatromonoside alone and in combination with chemotherapy drugs and their effects on Na +,K +-ATPase and ion channels on lung cancer cells. Mol Cell Biochem 2021; 476:1825-1848. [PMID: 33459980 DOI: 10.1007/s11010-020-04040-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/22/2020] [Indexed: 12/16/2022]
Abstract
Cardiac glycosides (CGs) are useful drugs to treat cardiac illnesses and have potent cytotoxic and anticancer effects in cultured cells and animal models. Their receptor is the Na+,K+ ATPase, but other plasma membrane proteins might bind CGs as well. Herein, we evaluated the short- and long-lasting cytotoxic effects of the natural cardenolide glucoevatromonoside (GEV) on non-small-cell lung cancer H460 cells. We also tested GEV effects on Na+,K+ -ATPase activity and membrane currents, alone or in combination with selected chemotherapy drugs. GEV reduced viability, migration, and invasion of H460 cells spheroids. It also induced cell cycle arrest and death and reduced the clonogenic survival and cumulative population doubling. GEV inhibited Na+,K+-ATPase activity on A549 and H460 cells and purified pig kidney cells membrane. However, it showed no activity on the human red blood cell plasma membrane. Additionally, GEV triggered a Cl-mediated conductance on H460 cells without affecting the transient voltage-gated sodium current. The administration of GEV in combination with the chemotherapeutic drugs paclitaxel (PAC), cisplatin (CIS), irinotecan (IRI), and etoposide (ETO) showed synergistic antiproliferative effects, especially when combined with GEV + CIS and GEV + PAC. Taken together, our results demonstrate that GEV is a potential drug for cancer therapy because it reduces lung cancer H460 cell viability, migration, and invasion. Our results also reveal a link between the Na+,K+-ATPase and Cl- ion channels.
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Schmid V, Plössl K, Schmid C, Bernklau S, Weber BHF, Friedrich U. Retinoschisin and Cardiac Glycoside Crosstalk at the Retinal Na/K-ATPase. Invest Ophthalmol Vis Sci 2020; 61:1. [PMID: 32392309 PMCID: PMC7405613 DOI: 10.1167/iovs.61.5.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Purpose Mutations in the RS1 gene, which encodes retinoschisin, cause X-linked juvenile retinoschisis, a retinal dystrophy in males. Retinoschisin specifically interacts with the retinal sodium–potassium adenosine triphosphatase (Na/K-ATPase), a transmembrane ion pump. Na/K-ATPases also bind cardiac glycosides, which control the activity of the pump and have been linked to disturbances in retinal homeostasis. In this study, we investigated the crosstalk between retinoschisin and cardiac glycosides at the retinal Na/K-ATPase and the consequences of this interplay on retinal integrity. Methods The effect of cardiac glycosides (ouabain and digoxin) on the binding of retinoschisin to the retinal Na/K-ATPase was investigated via western blot and immunocytochemistry. Also, the influence of retinoschisin on the binding of cardiac glycosides was analyzed via enzymatic assays, which quantified cardiac glycoside-sensitive Na/K-ATPase pump activity. Moreover, retinoschisin-dependent binding of tritium-labeled ouabain to the Na/K-ATPase was determined. Finally, a reciprocal effect of retinoschisin and cardiac glycosides on Na/K-ATPase localization and photoreceptor degeneration was addressed using immunohistochemistry in retinoschisin-deficient murine retinal explants. Results Cardiac glycosides displaced retinoschisin from the retinal Na/K-ATPase; however, retinoschisin did not affect cardiac glycoside binding. Notably, cardiac glycosides reduced the capacity of retinoschisin to regulate Na/K-ATPase localization and to protect against photoreceptor degeneration. Conclusions Our findings reveal opposing effects of retinoschisin and cardiac glycosides on retinal Na/K-ATPase binding and on retinal integrity, suggesting that a fine-tuned interplay between both components is required to maintain retinal homeostasis. This observation provides new insight into the mechanisms underlying the pathological effects of cardiac glycoside treatment on retinal integrity.
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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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Azalim P, do Monte FM, Rendeiro MM, Liu X, O'Doherty GA, Fontes CF, Leitão SG, Quintas LEM, Noël F. Conformational states of the pig kidney Na+/K+-ATPase differently affect bufadienolides and cardenolides: A directed structure-activity and structure-kinetics study. Biochem Pharmacol 2020; 171:113679. [DOI: 10.1016/j.bcp.2019.113679] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
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26
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Ding T, Wang S, Gao Y, Li C, Wan F, Zhang B. Toxicity and effects of four insecticides on Na +, K +-ATPase of western flower thrips, Frankliniella occidentalis. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:58-64. [PMID: 31784922 DOI: 10.1007/s10646-019-02139-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/12/2019] [Indexed: 06/10/2023]
Abstract
Western flower thrips (WFT), Frankliniella occidentalis, has become an important pest of vegetables worldwide, due to its economic damage to crop production. In order to control WFT, chemical insecticides are widely used. However, WFT has developed a high resistance against many kinds of insecticides. Na+, K+-ATPase, playing an important role in the ionic transmission across the membrane, is commonly considered to be the target of several xenobiotic compounds. However, whether the Na+, K+-ATPase can be used as one of the target sites for controlling WFT is still unknown. In this study, resistance levels of WFT to four insecticides (chlorpyrifos, beta cypermethrin, abamectin, and thiamethoxam) were measured. It was found that all four insecticides exhibited significant inhibitory effects on WFT, especially on nymphs. The activity of Na+, K+-ATPase was estimated after the treatment of four insecticides. Additionally, mRNA expression levels of three Na+, K+-ATPase α-subunit isoforms (X1, X2 and X3) were detected using RT-qPCR. The transcription profile of three Na+, K+-ATPase α-subunit isoforms were diverse after treatment by these four insecticides, which indicated that these isoforms might play different roles in the tolerance to insecticides. The results suggested that Na+, K+-ATPase can obviously be inhibited by these four classes of insecticide, and may serve as the new target for controlling WFT.
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Affiliation(s)
- Tianbo Ding
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
| | - Sifang Wang
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
| | - Yulin Gao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, PR China
| | - Changyou Li
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
| | - Fanghao Wan
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, PR China
| | - Bin Zhang
- Key Lab of Integrated Crop Pest Management of Shandong, College of Agronomy and Plant Protection, Qingdao Agricultural University, Qingdao, 266109, PR China.
- China-Australia Joint Institute of Agricultural and Environmental Health, Qingdao Agricultural University, Qingdao, 266109, PR China.
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Patel CN, Kumar SP, Modi KM, Soni MN, Modi NR, Pandya HA. Cardiotonic steroids as potential Na +/K +-ATPase inhibitors - a computational study. J Recept Signal Transduct Res 2019; 39:226-234. [PMID: 31509043 DOI: 10.1080/10799893.2019.1660893] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cardiotonic steroids (CTS) are steroidal drugs, processed from the seeds and dried leaves of the genus Digitalis as well as from the skin and parotid gland of amphibians. The most commonly known CTS are ouabain, digoxin, digoxigenin and bufalin. CTS can be used for safer medication of congestive heart failure and other related conditions due to promising pharmacological and medicinal properties. Ouabain isolated from plants is widely utilized in in vitro studies to specifically block the sodium potassium (Na+/K+-ATPase) pump. For checking, whether ouabain derivatives are robust inhibitors of Na+/K+-ATPase pump, molecular docking simulation was performed between ouabain and its derivatives using YASARA software. The docking energy falls within the range of 8.470 kcal/mol to 7.234 kcal/mol, in which digoxigenin was found to be the potential ligand with the best docking energy of 8.470 kcal/mol. Furthermore, pharmacophore modeling was applied to decipher the electronic features of CTS. Molecular dynamics simulation was also employed to determine the conformational properties of Na+/K+-ATPase-ouabain and Na+/K+-ATPase-digoxigenin complexes with the plausible structural integrity through conformational ensembles for 100 ns which promoted digoxigenin as the most promising CTS for treating conditions of congestive heart failure patients.
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Affiliation(s)
- Chirag N Patel
- Department of Botany, Bioinformatics and Climate Change Impacts Management, University School of Science, Gujarat University , Ahmedabad , India
| | | | - Krunal M Modi
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova , Czech Republic
| | - Mehul N Soni
- Department of Botany, Bioinformatics and Climate Change Impacts Management, University School of Science, Gujarat University , Ahmedabad , India
| | - Nainesh R Modi
- Department of Botany, Bioinformatics and Climate Change Impacts Management, University School of Science, Gujarat University , Ahmedabad , India
| | - Himanshu A Pandya
- Department of Botany, Bioinformatics and Climate Change Impacts Management, University School of Science, Gujarat University , Ahmedabad , India
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Dobler S, Wagschal V, Pietsch N, Dahdouli N, Meinzer F, Romey-Glüsing R, Schütte K. New ways to acquire resistance: imperfect convergence in insect adaptations to a potent plant toxin. Proc Biol Sci 2019; 286:20190883. [PMID: 31387508 PMCID: PMC6710594 DOI: 10.1098/rspb.2019.0883] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/17/2019] [Indexed: 12/22/2022] Open
Abstract
Evolution of insensitivity to the toxic effects of cardiac glycosides has become a model in the study of convergent evolution, as five taxonomic orders of insects use the same few similar amino acid substitutions in the otherwise highly conserved Na,K-ATPase α. We show here that insensitivity in pyrgomorphid grasshoppers evolved along a slightly divergent path. As in other lineages, duplication of the Na,K-ATPase α gene paved the way for subfunctionalization: one copy maintains the ancestral, sensitive state, while the other copy is resistant. Nonetheless, in contrast with all other investigated insects, the grasshoppers' resistant copy shows length variation by two amino acids in the first extracellular loop, the main part of the cardiac glycoside-binding pocket. RT-qPCR analyses confirmed that this copy is predominantly expressed in tissues exposed to the toxins, while the ancestral copy predominates in the nervous tissue. Functional tests with genetically engineered Drosophila Na,K-ATPases bearing the first extracellular loop of the pyrgomorphid genes showed the derived form to be highly resistant, while the ancestral state is sensitive. Thus, we report convergence in gene duplication and in the gene targets for toxin insensitivity; however, the means to the phenotypic end have been novel in pyrgomorphid grasshoppers.
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Affiliation(s)
- Susanne Dobler
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Hamburg, Germany
| | - Vera Wagschal
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Hamburg, Germany
| | - Niels Pietsch
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Hamburg, Germany
| | - Nadja Dahdouli
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Hamburg, Germany
| | - Fee Meinzer
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Hamburg, Germany
| | - Renja Romey-Glüsing
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Hamburg, Germany
| | - Kai Schütte
- Animal Ecology and Conservation, Institute of Zoology, Universität Hamburg, Hamburg, Germany
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El-Mallakh RS, Brar KS, Yeruva RR. Cardiac Glycosides in Human Physiology and Disease: Update for Entomologists. INSECTS 2019; 10:E102. [PMID: 30974764 PMCID: PMC6523104 DOI: 10.3390/insects10040102] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 12/12/2022]
Abstract
Cardiac glycosides, cardenolides and bufadienolides, are elaborated by several plant or animal species to prevent grazing or predation. Entomologists have characterized several insect species that have evolved the ability to sequester these glycosides in their tissues to reduce their palatability and, thus, reduce predation. Cardiac glycosides are known to interact with the sodium- and potassium-activated adenosine triphosphatase, or sodium pump, through a specific receptor-binding site. Over the last couple of decades, and since entomologic studies, it has become clear that mammals synthesize endogenous cardenolides that closely resemble or are identical to compounds of plant origin and those sequestered by insects. The most important of these are ouabain-like compounds. These compounds are essential for the regulation of normal ionic physiology in mammals. Importantly, at physiologic picomolar or nanomolar concentrations, endogenous ouabain, a cardenolide, stimulates the sodium pump, activates second messengers, and may even function as a growth factor. This is in contrast to the pharmacologic or toxic micromolar or milimolar concentrations achieved after consumption of exogenous cardenolides (by consuming medications, plants, or insects), which inhibit the pump and result in either a desired medical outcome, or the toxic consequence of sodium pump inhibition.
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Affiliation(s)
- Rif S El-Mallakh
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
| | - Kanwarjeet S Brar
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
| | - Rajashekar Reddy Yeruva
- Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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Lan YL, Zou YJ, Lou JC, Xing JS, Wang X, Zou S, Ma BB, Ding Y, Zhang B. The sodium pump α1 subunit regulates bufalin sensitivity of human glioblastoma cells through the p53 signaling pathway. Cell Biol Toxicol 2019; 35:521-539. [DOI: 10.1007/s10565-019-09462-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022]
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Faraj SE, Centeno M, Rossi RC, Montes MR. A kinetic comparison between E2P and the E2P-like state induced by a beryllium fluoride complex in the Na,K-ATPase. Interactions with Rb+. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:355-365. [DOI: 10.1016/j.bbamem.2018.10.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/24/2018] [Accepted: 10/30/2018] [Indexed: 10/27/2022]
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Noël F, Azalim P, do Monte FM, Quintas LEM, Katz A, Karlish SJ. Revisiting the binding kinetics and inhibitory potency of cardiac glycosides on Na+,K+-ATPase (α1β1): Methodological considerations. J Pharmacol Toxicol Methods 2018; 94:64-72. [DOI: 10.1016/j.vascn.2018.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/30/2018] [Accepted: 09/18/2018] [Indexed: 12/12/2022]
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Petschenka G, Fei CS, Araya JJ, Schröder S, Timmermann BN, Agrawal AA. Relative Selectivity of Plant Cardenolides for Na +/K +-ATPases From the Monarch Butterfly and Non-resistant Insects. FRONTIERS IN PLANT SCIENCE 2018; 9:1424. [PMID: 30323822 PMCID: PMC6172315 DOI: 10.3389/fpls.2018.01424] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/07/2018] [Indexed: 05/31/2023]
Abstract
A major prediction of coevolutionary theory is that plants may target particular herbivores with secondary compounds that are selectively defensive. The highly specialized monarch butterfly (Danaus plexippus) copes well with cardiac glycosides (inhibitors of animal Na+/K+-ATPases) from its milkweed host plants, but selective inhibition of its Na+/K+-ATPase by different compounds has not been previously tested. We applied 17 cardiac glycosides to the D. plexippus-Na+/K+-ATPase and to the more susceptible Na+/K+-ATPases of two non-adapted insects (Euploea core and Schistocerca gregaria). Structural features (e.g., sugar residues) predicted in vitro inhibitory activity and comparison of insect Na+/K+-ATPases revealed that the monarch has evolved a highly resistant enzyme overall. Nonetheless, we found evidence for relative selectivity of individual cardiac glycosides reaching from 4- to 94-fold differences of inhibition between non-adapted Na+/K+-ATPase and D. plexippus-Na+/K+-ATPase. This toxin receptor specificity suggests a mechanism how plants could target herbivores selectively and thus provides a strong basis for pairwise coevolutionary interactions between plants and herbivorous insects.
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Affiliation(s)
- Georg Petschenka
- Institute for Insect Biotechnology, Justus-Liebig-Universität, Giessen, Germany
| | - Colleen S. Fei
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
| | - Juan J. Araya
- Centro de Investigaciones en Productos Naturales, Escuela de Química, Instituto de Investigaciones Farmacéuticas, Facultad de Farmacia, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Susanne Schröder
- Institut für Medizinische Biochemie und Molekularbiologie, Universität Rostock, Rostock, Germany
| | - Barbara N. Timmermann
- Department of Medicinal Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Anurag A. Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
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Lan YL, Yu ZL, Lou JC, Ma XC, Zhang B. Update on the effects of the sodium pump α1 subunit on human glioblastoma: from the laboratory to the clinic. Expert Opin Investig Drugs 2018; 27:753-763. [PMID: 30130132 DOI: 10.1080/13543784.2018.1512582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Glioblastoma is a debilitating disease that is associated with poor prognosis and a very limited response to therapies; thus, molecularly targeted therapeutics and personalized therapy are urgently needed. The Na+/K+-ATPase sodium pump is a transmembrane protein complex that has recently been recognized as an important transducer and integrator of various signals. The sodium pump α1 subunit, which is highly expressed in most glioblastomas compared with that in normal brain tissues, is an emerging cancer target that merits further investigation. AREAS COVERED The purpose of this narrative review is to explore the important roles of the sodium pump α1 subunit in glioblastoma and analyze its potential therapeutic applications. EXPERT OPINION Expression of the sodium pump α1 subunit in glioblastoma tissues is generally higher than that in normal tissues. Sodium pump α1 subunit-mediated pivotal antiglioblastoma signaling pathways have been reviewed, and their impact on the sensitivity of glioblastoma cells to anticancer drugs has recently been clarified. In addition, various pharmacologically optimized sodium pump inhibitors have recently reached early clinical trials, and explorations of sodium pump α1 subunit inhibitors may hold promise for the development of stratification strategies in which patients are treated based on their isoform expression status.
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Affiliation(s)
- Yu-Long Lan
- a Department of Neurosurgery , The Second Affiliated Hospital of Dalian Medical University , Dalian , China.,b Department of Pharmacy , Dalian Medical University , Dalian , China.,c Department of Physiology , Dalian Medical University , Dalian , China
| | - Zhen-Long Yu
- b Department of Pharmacy , Dalian Medical University , Dalian , China
| | - Jia-Cheng Lou
- a Department of Neurosurgery , The Second Affiliated Hospital of Dalian Medical University , Dalian , China
| | - Xiao-Chi Ma
- b Department of Pharmacy , Dalian Medical University , Dalian , China
| | - Bo Zhang
- a Department of Neurosurgery , The Second Affiliated Hospital of Dalian Medical University , Dalian , China
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Silva IT, Munkert J, Nolte E, Schneider NFZ, Rocha SC, Ramos ACP, Kreis W, Braga FC, de Pádua RM, Taranto AG, Cortes V, Barbosa LA, Wach S, Taubert H, Simões CMO. Cytotoxicity of AMANTADIG - a semisynthetic digitoxigenin derivative - alone and in combination with docetaxel in human hormone-refractory prostate cancer cells and its effect on Na +/K +-ATPase inhibition. Biomed Pharmacother 2018; 107:464-474. [PMID: 30107342 DOI: 10.1016/j.biopha.2018.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/26/2018] [Accepted: 08/06/2018] [Indexed: 01/29/2023] Open
Abstract
Cardiac glycosides (CGs) are natural compounds used to treat congestive heart failure. They have garnered attention as a potential cancer treatment option, especially because they bind to Na+/K+-ATPase as a target and activate intracellular signaling pathways leading to a variety of cellular responses. In this study we evaluated AMANTADIG, a semisynthetic cardenolide derivative, for its cytotoxic activity in two human androgen-insensitive prostate carcinoma cell lines, and the potential synergistic effects with docetaxel. AMANTADIG induced cytotoxic effects in both cell lines, and a combination with docetaxel showed a moderate and strong synergism in DU145 and PC-3 cells, respectively, at concentrations considerably lower than their IC50 values. Cell cycle analyses showed that AMANTADIG and its synergistic combination induced G2/M arrest of DU145 and PC-3 cells by modulating Cyclin B1, CDK1, p21 and, mainly, survivin expression, a promising target in cancer therapy. Furthermore, AMANTADIG presented reduced toxicity toward non-cancerous cell type (PBMC), and computational docking studies disclosed high-affinity binding to the Na+/K+-ATPase α subunit, a result that was experimentally confirmed by Na+/K+-ATPase inhibition assays. Hence, AMANTADIG inhibited Na+/K+-ATPase activity in PC-3 cells, as well as in purified pig kidney at nanomolar range. Altogether, these data highlight the potent effects of AMANTADIG in combination with docetaxel and offer important insights for the development of more effective and selective therapies against prostate cancer.
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Affiliation(s)
- Izabella Thaís Silva
- Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Jennifer Munkert
- Department of Biology, Chair of Pharmaceutical Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Elke Nolte
- Department of Urology and Pediatric Urology, University Hospital Erlangen, Erlangen, Germany
| | | | - Sayonarah Carvalho Rocha
- Laboratório de Bioquímica Celular, Faculdade de Bioquímica, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, Brazil
| | - Ana Carolina Pacheco Ramos
- Laboratório de Bioquímica Celular, Faculdade de Bioquímica, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, Brazil
| | - Wolfgang Kreis
- Department of Biology, Chair of Pharmaceutical Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Fernão Castro Braga
- Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Maia de Pádua
- Departamento de Produtos Farmacêuticos, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Alex G Taranto
- Laboratório de Química Farmacêutica Medicinal, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, Brazil
| | - Vanessa Cortes
- Laboratório de Bioquímica Celular, Faculdade de Bioquímica, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, Brazil
| | - Leandro Augusto Barbosa
- Laboratório de Bioquímica Celular, Faculdade de Bioquímica, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindu, Divinópolis, Brazil
| | - Sven Wach
- Department of Urology and Pediatric Urology, University Hospital Erlangen, Erlangen, Germany
| | - Helge Taubert
- Department of Urology and Pediatric Urology, University Hospital Erlangen, Erlangen, Germany
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Wu H, Shabala L, Azzarello E, Huang Y, Pandolfi C, Su N, Wu Q, Cai S, Bazihizina N, Wang L, Zhou M, Mancuso S, Chen Z, Shabala S. Na+ extrusion from the cytosol and tissue-specific Na+ sequestration in roots confer differential salt stress tolerance between durum and bread wheat. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3987-4001. [PMID: 29897491 PMCID: PMC6054258 DOI: 10.1093/jxb/ery194] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 05/21/2018] [Indexed: 05/25/2023]
Abstract
The progress in plant breeding for salinity stress tolerance is handicapped by the lack of understanding of the specificity of salt stress signalling and adaptation at the cellular and tissue levels. In this study, we used electrophysiological, fluorescence imaging, and real-time quantitative PCR tools to elucidate the essentiality of the cytosolic Na+ extrusion in functionally different root zones (elongation, meristem, and mature) in a large number of bread and durum wheat accessions. We show that the difference in the root's ability for vacuolar Na+ sequestration in the mature zone may explain differential salinity stress tolerance between salt-sensitive durum and salt-tolerant bread wheat species. Bread wheat genotypes also had on average 30% higher capacity for net Na+ efflux from the root elongation zone, providing the first direct evidence for the essentiality of the root salt exclusion trait at the cellular level. At the same time, cytosolic Na+ accumulation in the root meristem was significantly higher in bread wheat, leading to the suggestion that this tissue may harbour a putative salt sensor. This hypothesis was then tested by investigating patterns of Na+ distribution and the relative expression level of several key genes related to Na+ transport in leaves in plants with intact roots and in those in which the root meristems were removed. We show that tampering with this sensing mechanism has resulted in a salt-sensitive phenotype, largely due to compromising the plant's ability to sequester Na+ in mesophyll cell vacuoles. The implications of these findings for plant breeding for salinity stress tolerance are discussed.
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Affiliation(s)
- Honghong Wu
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
| | - Lana Shabala
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
| | - Elisa Azzarello
- Department of Horticulture, University of Florence, Sesto Fiorentino, Italy
| | - Yuqing Huang
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Camilla Pandolfi
- Department of Horticulture, University of Florence, Sesto Fiorentino, Italy
| | - Nana Su
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
| | - Qi Wu
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
| | - Shengguan Cai
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Nadia Bazihizina
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
- Department of Horticulture, University of Florence, Sesto Fiorentino, Italy
| | - Lu Wang
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
| | - Stefano Mancuso
- Department of Horticulture, University of Florence, Sesto Fiorentino, Italy
| | - Zhonghua Chen
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag, Hobart, Tasmania, Australia
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Lohr JN, Meinzer F, Dalla S, Romey-Glüsing R, Dobler S. The function and evolutionary significance of a triplicated Na,K-ATPase gene in a toxin-specialized insect. BMC Evol Biol 2017; 17:256. [PMID: 29246105 PMCID: PMC5732401 DOI: 10.1186/s12862-017-1097-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/27/2017] [Indexed: 01/27/2023] Open
Abstract
Background The Na,K-ATPase is a vital animal cell-membrane protein that maintains the cell’s resting potential, among other functions. Cardenolides, a group of potent plant toxins, bind to and inhibit this pump. The gene encoding the α-subunit of the pump has undergone duplication events in some insect species known to feed on plants containing cardenolides. Here we test the function of these duplicated gene copies in the cardenolide-adapted milkweed bug, Oncopeltus fasciatus, which has three known copies of the gene: α1A, α1B and α1C. Results Using RT-qPCR analyses we demonstrate that the α1C is highly expressed in neural tissue, where the pump is generally thought to be most important for neuron excitability. With the use of in vivo RNAi in adult bugs we found that α1C knockdowns suffered high mortality, where as α1A and α1B did not, supporting that α1C is most important for effective ion pumping. Next we show a role for α1A and α1B in the handling of cardenolides: expression results find that both copies are primarily expressed in the Malpighian tubules, the primary insect organ responsible for excretion, and when we injected either α1A or α1B knockdowns with cardenolides this proved fatal (whereas not in controls). Conclusions These results show that the Na,K-ATPα gene-copies have taken on diverse functions. Having multiple copies of this gene appears to have allowed the newly arisen duplicates to specialize on resistance to cardenolides, whereas the ancestral copy of the pump remains comparatively sensitive, but acts as a more efficient ion carrier. Interestingly both the α1A and α1B were required for cardenolide handling, suggesting that these two copies have separate and vital functions. Gene duplications of the Na,K-ATPase thus represent an excellent example of subfunctionalization in response to a new environmental challenge. Electronic supplementary material The online version of this article (10.1186/s12862-017-1097-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jennifer N Lohr
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany. .,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, WC1E 6BT, London, UK.
| | - Fee Meinzer
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| | - Safaa Dalla
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| | - Renja Romey-Glüsing
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
| | - Susanne Dobler
- Universität Hamburg, Biozentrum Grindel, Zoologisches Institut, Martin-Luther-King Pl. 3, 20146, Hamburg, Germany
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Pessôa MTC, Alves SLG, Taranto AG, Villar JAFP, Blanco G, Barbosa LA. Selectivity analyses of γ-benzylidene digoxin derivatives to different Na,K-ATPase α isoforms: a molecular docking approach. J Enzyme Inhib Med Chem 2017; 33:85-97. [PMID: 29115894 PMCID: PMC6009882 DOI: 10.1080/14756366.2017.1380637] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Digoxin and other cardiotonic steroids (CTS) exert their effect by inhibiting Na,K-ATPase (NKA) activity. CTS bind to the various NKA isoforms that are expressed in different cell types, which gives CTS their narrow therapeutic index. We have synthesised a series of digoxin derivatives (γ-Benzylidene digoxin derivatives) with substitutions in the lactone ring (including non-oxygen and ether groups), to obtain CTS with better NKA isoform specificity. Some of these derivatives show some NKA isoform selective effects, with BD-3, BD-8, and BD-13 increasing NKA α2 activity, BD-5 inhibiting NKA α1 and NKA α3, BD-10 reducing NKA α1, but stimulating NKA α2 and α3; and BD-14, BD-15, and BD-16 enhancing NKA α3 activity. A molecular-docking approach favoured NKA isoform specific interactions for the compounds that supported their observed activity. These results show that BD compounds are a new type of CTS with the capacity to target NKA activity in an isoform-specific manner.
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Affiliation(s)
- Marco T C Pessôa
- a Laboratório de Bioquímica Celular , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - Silmara L G Alves
- b Laboratório de Síntese Orgânica e Nanoestruturas , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - Alex G Taranto
- c Laboratório de Modelagem Molecular , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - José A F P Villar
- b Laboratório de Síntese Orgânica e Nanoestruturas , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - Gustavo Blanco
- d Department of Molecular and Integrative Physiology , Kansas University Medical Center , Kansas City , KS , USA
| | - Leandro A Barbosa
- a Laboratório de Bioquímica Celular , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
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39
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Anticancer and Immunogenic Properties of Cardiac Glycosides. Molecules 2017; 22:molecules22111932. [PMID: 29117117 PMCID: PMC6150164 DOI: 10.3390/molecules22111932] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/29/2017] [Accepted: 11/04/2017] [Indexed: 12/25/2022] Open
Abstract
Cardiac glycosides (CGs) are natural compounds widely used in the treatment of several cardiac conditions and more recently have been recognized as potential antitumor compounds. They are known to be ligands for Na/K-ATPase, which is a promising drug target in cancer. More recently, in addition to their antitumor effects, it has been suggested that CGs activate tumor-specific immune responses. This review summarizes the anticancer aspects of CGs as new strategies for immunotherapy and drug repositioning (new horizons for old players), and the possible new targets for CGs in cancer cells.
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40
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Blaustein MP. The pump, the exchanger, and the holy spirit: origins and 40-year evolution of ideas about the ouabain-Na + pump endocrine system. Am J Physiol Cell Physiol 2017; 314:C3-C26. [PMID: 28971835 DOI: 10.1152/ajpcell.00196.2017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Two prescient 1953 publications set the stage for the elucidation of a novel endocrine system: Schatzmann's report that cardiotonic steroids (CTSs) are all Na+ pump inhibitors, and Szent-Gyorgi's suggestion that there is an endogenous "missing screw" in heart failure that CTSs like digoxin may replace. In 1977 I postulated that an endogenous Na+ pump inhibitor acts as a natriuretic hormone and simultaneously elevates blood pressure (BP) in salt-dependent hypertension. This hypothesis was based on the idea that excess renal salt retention promoted the secretion of a CTS-like hormone that inhibits renal Na+ pumps and salt reabsorption. The hormone also inhibits arterial Na+ pumps, elevates myocyte Na+ and promotes Na/Ca exchanger-mediated Ca2+ gain. This enhances vasoconstriction and arterial tone-the hallmark of hypertension. Here I describe how those ideas led to the discovery that the CTS-like hormone is endogenous ouabain (EO), a key factor in the pathogenesis of hypertension and heart failure. Seminal observations that underlie the still-emerging picture of the EO-Na+ pump endocrine system in the physiology and pathophysiology of multiple organ systems are summarized. Milestones include: 1) cloning the Na+ pump isoforms and physiological studies of mutated pumps in mice; 2) discovery that Na+ pumps are also EO-triggered signaling molecules; 3) demonstration that ouabain, but not digoxin, is hypertensinogenic; 4) elucidation of EO's roles in kidney development and cardiovascular and renal physiology and pathophysiology; 5) discovery of "brain ouabain", a component of a novel hypothalamic neuromodulatory pathway; and 6) finding that EO and its brain receptors modulate behavior and learning.
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Affiliation(s)
- Mordecai P Blaustein
- Departments of Physiology and Medicine, University of Maryland School of Medicine , Baltimore, Maryland
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41
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Blaustein MP. How does pressure overload cause cardiac hypertrophy and dysfunction? High-ouabain affinity cardiac Na + pumps are crucial. Am J Physiol Heart Circ Physiol 2017; 313:H919-H930. [PMID: 28733446 PMCID: PMC5792198 DOI: 10.1152/ajpheart.00131.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022]
Abstract
Left ventricular hypertrophy is frequently observed in hypertensive patients and is believed to be due to the pressure overload and cardiomyocyte stretch. Three recent reports on mice with genetically engineered Na+ pumps, however, have demonstrated that cardiac ouabain-sensitive α2-Na+ pumps play a key role in the pathogenesis of transaortic constriction-induced hypertrophy. Hypertrophy was delayed/attenuated in mice with mutant, ouabain-resistant α2-Na+ pumps and in mice with cardiac-selective knockout or transgenic overexpression of α2-Na+ pumps. The latter, seemingly paradoxical, findings can be explained by comparing the numbers of available (ouabain-free) high-affinity (α2) ouabain-binding sites in wild-type, knockout, and transgenic hearts. Conversely, hypertrophy was accelerated in α2-ouabain-resistant (R) mice in which the normally ouabain-resistant α1-Na+ pumps were mutated to an ouabain-sensitive (S) form (α1S/Sα2R/R or "SWAP" vs. wild-type or α1R/R α2S/S mice). Furthermore, transaortic constriction-induced hypertrophy in SWAP mice was prevented/reversed by immunoneutralizing circulating endogenous ouabain (EO). These findings show that EO and its receptor, ouabain-sensitive α2, are critical factors in pressure overload-induced cardiac hypertrophy. This complements reports linking elevated plasma EO to hypertension, cardiac hypertrophy, and failure in humans and elucidates the underappreciated role of the EO-Na+ pump pathway in cardiovascular disease.
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Affiliation(s)
- Mordecai P. Blaustein
- Departments of Physiology and Medicine, University of Maryland School of Medicine, Baltimore, Maryland
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42
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Dalla S, Baum M, Dobler S. Substitutions in the cardenolide binding site and interaction of subunits affect kinetics besides cardenolide sensitivity of insect Na,K-ATPase. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2017; 89:43-50. [PMID: 28866054 DOI: 10.1016/j.ibmb.2017.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/20/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Substitutions within the cardenolide target site of several insects' Na,K-ATPase α-subunits may confer resistance against toxic cardenolides. However, to which extent these substitutions alter the Na,K-ATPase's kinetic properties and how they interact with different β-subunits is not clear. The cardenolide-adapted milkweed bug Oncopeltus fasciatus possesses three paralogs of the α-subunit (A, B, and C) that differ in number and identity of resistance-conferring substitutions. We introduced these substitutions into the α-subunit of Drosophila melanogaster and combined them with the β-subunits Nrv2.2 and Nrv3. The substitutions Q111T-N122H-F786N-T797A (A-copy mimic) and Q111T-N122H-F786N (B-copy mimic) mediated high insensitivity to ouabain, yet they drastically lowered ATPase activity. Remarkably, the identity of the β-subunit was decisive and all α-subunits were less active when combined with Nrv3 than when combined with Nrv2.2. Both the substitutions and the co-expressed β-subunit strongly affected the enyzme's affinity for Na+ and K+. Na+ affinity was considerably higher for all enzymes expressed with nrv3 while expression with nrv2.2 mostly increased K+ affinity. Our results provide the first evidence that resistance against cardenolides comes at the cost of significantly altered kinetic properties of the Na,K-ATPase. The β-subunit can strongly modulate these properties but cannot fully compensate for the effect of the substitutions.
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Affiliation(s)
- Safaa Dalla
- Institute of Zoology, Universität Hamburg, Martin-Luther-King Pl. 3, 20146 Hamburg, Germany
| | - Michael Baum
- Institute of Zoology, Universität Hamburg, Martin-Luther-King Pl. 3, 20146 Hamburg, Germany
| | - Susanne Dobler
- Institute of Zoology, Universität Hamburg, Martin-Luther-King Pl. 3, 20146 Hamburg, Germany.
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43
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Petschenka G, Wagschal V, von Tschirnhaus M, Donath A, Dobler S. Convergently Evolved Toxic Secondary Metabolites in Plants Drive the Parallel Molecular Evolution of Insect Resistance. Am Nat 2017; 190:S29-S43. [DOI: 10.1086/691711] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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44
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Gable M, Ellis L, Fedorova OV, Bagrov AY, Askari A. Comparison of Digitalis Sensitivities of Na +/K +-ATPases from Human and Pig Kidneys. ACS OMEGA 2017; 2:3610-3615. [PMID: 28782051 PMCID: PMC5537699 DOI: 10.1021/acsomega.7b00591] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/06/2017] [Indexed: 05/16/2023]
Abstract
Digitalis drugs are selective inhibitors of the plasma membrane Na+/K+-ATPase. There are many studies on molecular mechanisms of digitalis interaction with purified pig kidney enzyme, with the tacit assumption that it is a good model of human kidney enzyme. However, previous studies on crude or recombinant human kidney enzymes are limited, and have not resulted in consistent findings on their digitalis sensitivities. Hence, we prepared comparably purified enzymes from human and pig kidneys and determined inhibitory constants of digoxin, ouabain, ouabagenin, bufalin, and marinobufagenin (MBG) on enzyme activity under optimal turnover conditions. We found that each compound had the same potency against the two enzymes, indicating that (i) the pig enzyme is an appropriate model of the human enzyme, and (ii) prior discrepant findings on human kidney enzymes were either due to structural differences between the natural and recombinant enzymes or because potencies were determined using binding constants of digitalis for enzymes under nonphysiological conditions. In conjunction with previous findings, our newly determined inhibitory constants of digitalis compounds for human kidney enzymes indicate that (i) of the compounds that have long been advocated to be endogenous hormones, only bufalin and MBG may act as such at kidney tubules, and (ii) beneficial effects of digoxin, the only digitalis with extensive clinical use, does not involve its inhibitory effect on renal tubular Na+/K+-ATPase.
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Affiliation(s)
- Marjorie
E. Gable
- Department
Biochemistry & Cancer Biology, College of Medicine & Life
Sciences, University of Toledo, 3000 Arlington Avenue, MS 1010, Toledo, Ohio 43614, United States
| | - Linda Ellis
- Department
Biochemistry & Cancer Biology, College of Medicine & Life
Sciences, University of Toledo, 3000 Arlington Avenue, MS 1010, Toledo, Ohio 43614, United States
| | - Olga V. Fedorova
- Laboratory
of Cardiovascular Science, National Institute of Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Alexei Y. Bagrov
- Laboratory
of Cardiovascular Science, National Institute of Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
- Sechenov
Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg 194223, Russia
| | - Amir Askari
- Department
Biochemistry & Cancer Biology, College of Medicine & Life
Sciences, University of Toledo, 3000 Arlington Avenue, MS 1010, Toledo, Ohio 43614, United States
- E-mail: . Phone: 419-383-3982
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45
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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: 100] [Impact Index Per Article: 14.3] [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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Abstract
Besides its essential role in the activation of HIV-1 gene expression, the viral Tat protein has the unusual property of trafficking in and out of cells. In contrast to Tat internalization, the mechanism involved in extracellular Tat release has so far remained elusive. Here we show that Tat secretion occurs through a Golgi-independent pathway requiring binding of Tat with three short, non-consecutive intracytoplasmic loops at the C-terminus of the cellular Na+,K+-ATPase pump alpha subunit. Ouabain, a pump inhibitor, blocked this interaction and prevented Tat secretion; virions produced in the presence of this drug were less infectious, consistent the capacity of virion-associated Tat to increase HIV-1 infectivity. Treatment of CD4+ T-cells with short peptides corresponding to the Tat-binding regions of the pump alpha subunit impaired extracellular Tat release and blocked HIV-1 replication. Thus, non canonical, extracellular Tat secretion is essential for viral infectivity.
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47
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Focht D, Croll TI, Pedersen BP, Nissen P. Improved Model of Proton Pump Crystal Structure Obtained by Interactive Molecular Dynamics Flexible Fitting Expands the Mechanistic Model for Proton Translocation in P-Type ATPases. Front Physiol 2017; 8:202. [PMID: 28443028 PMCID: PMC5387105 DOI: 10.3389/fphys.2017.00202] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/20/2017] [Indexed: 11/22/2022] Open
Abstract
The plasma membrane H+-ATPase is a proton pump of the P-type ATPase family and essential in plants and fungi. It extrudes protons to regulate pH and maintains a strong proton-motive force that energizes e.g., secondary uptake of nutrients. The only crystal structure of a H+-ATPase (AHA2 from Arabidopsis thaliana) was reported in 2007. Here, we present an improved atomic model of AHA2, obtained by a combination of model rebuilding through interactive molecular dynamics flexible fitting (iMDFF) and structural refinement based on the original data, but using up-to-date refinement methods. More detailed map features prompted local corrections of the transmembrane domain, in particular rearrangement of transmembrane helices 7 and 8, and the cytoplasmic N- and P-domains, and the new model shows improved overall quality and reliability scores. The AHA2 structure shows similarity to the Ca2+-ATPase E1 state, and provides a valuable starting point model for structural and functional analysis of proton transport mechanism of P-type H+-ATPases. Specifically, Asp684 protonation associated with phosphorylation and occlusion of the E1P state may result from hydrogen bond interaction with Asn106. A subsequent deprotonation associated with extracellular release in the E2P state may result from an internal salt bridge formation to an Arg655 residue, which in the present E1 state is stabilized in a solvated pocket. A release mechanism based on an in-built counter-cation was also later proposed for Zn2+-ATPase, for which structures have been determined in Zn2+ released E2P-like states with the salt bridge interaction formed.
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Affiliation(s)
- Dorota Focht
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark.,DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus UniversityAarhus, Denmark.,PUMPkin, Danish National Research Foundation, Aarhus UniversityAarhus, Denmark
| | - Tristan I Croll
- Institute of Health Biomedical Innovation, Queensland University of TechnologyBrisbane, QLD, Australia
| | - Bjorn P Pedersen
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark.,PUMPkin, Danish National Research Foundation, Aarhus UniversityAarhus, Denmark.,Aarhus Institute of Advanced Studies, Aarhus UniversityAarhus, Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Aarhus UniversityAarhus, Denmark.,DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus UniversityAarhus, Denmark.,PUMPkin, Danish National Research Foundation, Aarhus UniversityAarhus, Denmark
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48
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Tejral G, Sopko B, Necas A, Schoner W, Amler E. Computer modelling reveals new conformers of the ATP binding loop of Na +/K +-ATPase involved in the transphosphorylation process of the sodium pump. PeerJ 2017; 5:e3087. [PMID: 28316890 PMCID: PMC5354106 DOI: 10.7717/peerj.3087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/14/2017] [Indexed: 01/02/2023] Open
Abstract
Hydrolysis of ATP by Na+/K+-ATPase, a P-Type ATPase, catalyzing active Na+ and K+ transport through cellular membranes leads transiently to a phosphorylation of its catalytical α-subunit. Surprisingly, three-dimensional molecular structure analysis of P-type ATPases reveals that binding of ATP to the N-domain connected by a hinge to the P-domain is much too far away from the Asp369 to allow the transfer of ATP’s terminal phosphate to its aspartyl-phosphorylation site. In order to get information for how the transfer of the γ-phosphate group of ATP to the Asp369 is achieved, analogous molecular modeling of the M4–M5 loop of ATPase was performed using the crystal data of Na+/K+-ATPase of different species. Analogous molecular modeling of the cytoplasmic loop between Thr338 and Ile760 of the α2-subunit of Na+/K+-ATPase and the analysis of distances between the ATP binding site and phosphorylation site revealed the existence of two ATP binding sites in the open conformation; the first one close to Phe475 in the N-domain, the other one close to Asp369 in the P-domain. However, binding of Mg2+•ATP to any of these sites in the “open conformation” may not lead to phosphorylation of Asp369. Additional conformations of the cytoplasmic loop were found wobbling between “open conformation” <==> “semi-open conformation <==> “closed conformation” in the absence of 2Mg2+•ATP. The cytoplasmic loop’s conformational change to the “semi-open conformation”—characterized by a hydrogen bond between Arg543 and Asp611—triggers by binding of 2Mg2+•ATP to a single ATP site and conversion to the “closed conformation” the phosphorylation of Asp369 in the P-domain, and hence the start of Na+/K+-activated ATP hydrolysis.
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Affiliation(s)
- Gracian Tejral
- Department of Biophysics, 2nd Faculty of Medicine, Charles University Prague, Prague, Czech Republic; Laboratory of Tissue Engineering, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Bruno Sopko
- Department of Medical Chemistry and Clinical Biochemistry, 2nd Faculty of Medicine, Charles University Prague , Prague , Czech Republic
| | - Alois Necas
- Small Animal Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Science , Brno , Czech Republic
| | - Wilhelm Schoner
- Institute of Biochemistry and Endocrinology, University of Giessen , Giessen , Germany
| | - Evzen Amler
- Department of Biophysics, 2nd Faculty of Medicine, Charles University Prague, Prague, Czech Republic; Laboratory of Tissue Engineering, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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49
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Abstract
Na+/K+-ATPase (NKA) is an essential cation pump protein responsible for the maintenance of the sodium and potassium gradients across the plasma membrane. Recently published high-resolution structures revealed amino acids forming the cation binding sites (CBS) in the transmembrane domain and variable position of the domains in the cytoplasmic headpiece. Here we report molecular dynamic simulations of the human NKA α1β1 isoform embedded into DOPC bilayer. We have analyzed the NKA conformational changes in the presence of Na+- or K+-cations in the CBS, for various combinations of the cytoplasmic ligands, and the two major enzyme conformations in the 100 ns runs (more than 2.5 μs of simulations in total). We identified two novel cytoplasmic pathways along the pairs of transmembrane helices TM3/TM7 or TM6/TM9 that allow hydration of the CBS or transport of cations from/to the bulk. These findings can provide a structural explanation for previous mutagenesis studies, where mutation of residues that are distal from the CBS resulted in the alteration of the enzyme affinity to the transported cations or change in the enzyme activity.
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Affiliation(s)
- Petra Čechová
- Department of Biophysics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacký University , Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Karel Berka
- Department of Physical Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University , 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Martin Kubala
- Department of Biophysics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacký University , Šlechtitelů 27, 783 71, Olomouc, Czech Republic
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50
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Dalla S, Dobler S. Gene duplications circumvent trade-offs in enzyme function: Insect adaptation to toxic host plants. Evolution 2016; 70:2767-2777. [DOI: 10.1111/evo.13077] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 01/20/2023]
Affiliation(s)
- Safaa Dalla
- Molecular Evolutionary Biology, Zoological Institute, Biocenter Grindel; University of Hamburg; 20146 Hamburg Germany
| | - Susanne Dobler
- Molecular Evolutionary Biology, Zoological Institute, Biocenter Grindel; University of Hamburg; 20146 Hamburg Germany
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