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Herbertz M, Dalla S, Wagschal V, Turjalei R, Heiser M, Dobler S. Coevolutionary escalation led to differentially adapted paralogs of an insect's Na,K-ATPase optimizing resistance to host plant toxins. Mol Ecol 2024; 33:e17041. [PMID: 37296537 DOI: 10.1111/mec.17041] [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: 02/05/2023] [Revised: 04/24/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
Cardiac glycosides are chemical defence toxins known to fatally inhibit the Na,K-ATPase (NKA) throughout the animal kingdom. Several animals, however, have evolved target-site insensitivity through substitutions in the otherwise highly conserved cardiac glycoside binding pocket of the NKA. The large milkweed bug, Oncopeltus fasciatus, shares a long evolutionary history with cardiac glycoside containing plants that led to intricate adaptations. Most strikingly, several duplications of the bugs' NKA1α gene provided the opportunity for differential resistance-conferring substitutions and subsequent sub-functionalization of the enzymes. Here, we analysed cardiac glycoside resistance and ion pumping activity of nine functional NKA α/β-combinations of O. fasciatus expressed in cell culture. We tested the enzymes with two structurally distinct cardiac glycosides, calotropin, a host plant compound, and ouabain, a standard cardiac glycoside. The identity and number of known resistance-conferring substitutions in the cardiac glycoside binding site significantly impacted activity and toxin resistance in the three α-subunits. The β-subunits also influenced the enzymes' characteristics, yet to a lesser extent. Enzymes containing the more ancient αC-subunit were inhibited by both compounds but much more strongly by the host plant toxin calotropin than by ouabain. The sensitivity to calotropin was diminished in enzymes containing the more derived αB and αA, which were only marginally inhibited by both cardiac glycosides. This trend culminated in αAβ1 having higher resistance against calotropin than against ouabain. These results support the coevolutionary escalation of plant defences and herbivore tolerance mechanisms. The possession of multiple paralogs additionally mitigates pleiotropic effects by compromising between ion pumping activity and resistance.
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Affiliation(s)
- Marlena Herbertz
- Institute of Cell and Systems Biology of Animals, Molecular Evolutionary Biology, Universität Hamburg, Hamburg, Germany
| | - Safaa Dalla
- Institute of Cell and Systems Biology of Animals, Molecular Evolutionary Biology, Universität Hamburg, Hamburg, Germany
| | - Vera Wagschal
- Institute of Cell and Systems Biology of Animals, Molecular Evolutionary Biology, Universität Hamburg, Hamburg, Germany
| | - Rohin Turjalei
- Institute of Cell and Systems Biology of Animals, Molecular Evolutionary Biology, Universität Hamburg, Hamburg, Germany
| | - Marlies Heiser
- Institute of Cell and Systems Biology of Animals, Molecular Evolutionary Biology, Universität Hamburg, Hamburg, Germany
| | - Susanne Dobler
- Institute of Cell and Systems Biology of Animals, Molecular Evolutionary Biology, Universität Hamburg, Hamburg, Germany
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2
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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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3
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Barathi VA, Katz A, Chaudhary S, Li HL, Tal DM, Marcovich A, Do CW, Karlish SJD. A digoxin derivative that potently reduces intraocular pressure: efficacy and mechanism of action in different animal models. Am J Physiol Cell Physiol 2024; 326:C1505-C1519. [PMID: 38557355 DOI: 10.1152/ajpcell.00617.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/04/2024]
Abstract
Glaucoma is a blinding disease. Reduction of intraocular pressure (IOP) is the mainstay of treatment, but current drugs show side effects or become progressively ineffective, highlighting the need for novel compounds. We have synthesized a family of perhydro-1,4-oxazepine derivatives of digoxin, the selective inhibitor of Na,K-ATPase. The cyclobutyl derivative (DcB) displays strong selectivity for the human α2 isoform and potently reduces IOP in rabbits. These observations appeared consistent with a hypothesis that in ciliary epithelium DcB inhibits the α2 isoform of Na,K-ATPase, which is expressed strongly in nonpigmented cells, reducing aqueous humor (AH) inflow. This paper extends assessment of efficacy and mechanism of action of DcB using an ocular hypertensive nonhuman primate model (OHT-NHP) (Macaca fascicularis). In OHT-NHP, DcB potently lowers IOP, in both acute (24 h) and extended (7-10 days) settings, accompanied by increased aqueous humor flow rate (AFR). By contrast, ocular normotensive animals (ONT-NHP) are poorly responsive to DcB, if at all. The mechanism of action of DcB has been analyzed using isolated porcine ciliary epithelium and perfused enucleated eyes to study AH inflow and AH outflow facility, respectively. 1) DcB significantly stimulates AH inflow although prior addition of 8-Br-cAMP, which raises AH inflow, precludes additional effects of DcB. 2) DcB significantly increases AH outflow facility via the trabecular meshwork (TM). Taken together, the data indicate that the original hypothesis on the mechanism of action must be revised. In the OHT-NHP, and presumably other species, DcB lowers IOP by increasing AH outflow facility rather than by decreasing AH inflow.NEW & NOTEWORTHY When applied topically, a cyclobutyl derivative of digoxin (DcB) potently reduces intraocular pressure in an ocular hypertensive nonhuman primate model (Macaca fascicularis), associated with increased aqueous humor (AH) flow rate (AFR). The mechanism of action of DcB involves increased AH outflow facility as detected in enucleated perfused porcine eyes and, in parallel, increased (AH) inflow as detected in isolated porcine ciliary epithelium. DcB might have potential as a drug for the treatment of open-angle human glaucoma.
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Affiliation(s)
- Veluchamy Amutha Barathi
- Translational Pre-Clinical Model Platform, Singapore Institute of Eye Research (SERI)
- ACP in Ophthalmology & Visual Sciences, DUKE-NUS Graduate Medical School, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Adriana Katz
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Shashikant Chaudhary
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China
| | - Hoi-Lam Li
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China
| | - Daniel M Tal
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Arie Marcovich
- Opthalmology Department, Kaplan Medical Center, Rehovot, Israel
- Hebrew University Medical School, Jerusalem, Israel
| | - Chi-Wai Do
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China
- Centre for Eye and Vision Research (CEVR), Hong Kong, People's Republic of China
- Research Institute for Smart Ageing (RISA), The Hong Kong Polytechnic University, Hong Kong, People's Republic of China
| | - Steven J D Karlish
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
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4
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Markov AG, Livanova AA, Fedorova AA, Kravtsova VV, Krivoi II. Chronic Ouabain Targets Pore-Forming Claudin-2 and Ameliorates Radiation-Induced Damage to the Rat Intestinal Tissue Barrier. Int J Mol Sci 2023; 25:278. [PMID: 38203449 PMCID: PMC10778734 DOI: 10.3390/ijms25010278] [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: 11/04/2023] [Revised: 12/15/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Ionizing radiation (IR) causes disturbances in the functions of the gastrointestinal tract. Given the therapeutic potential of ouabain, a specific ligand of the Na,K-ATPase, we tested its ability to protect against IR-induced disturbances in the barrier and transport properties of the jejunum and colon of rats. Male Wistar rats were subjected to 6-day intraperitoneal injections of vehicle or ouabain (1 µg/kg/day). On the fourth day of injections, rats were exposed to total-body X-ray irradiation (10 Gy) or a sham irradiation. Isolated tissues were examined 72 h post-irradiation. Electrophysiological characteristics and paracellular permeability for sodium fluorescein were measured in an Ussing chamber. Histological analysis and Western blotting were also performed. In the jejunum tissue, ouabain exposure did not prevent disturbances in transepithelial resistance, paracellular permeability, histological characteristics, as well as changes in the expression of claudin-1, -3, -4, tricellulin, and caspase-3 induced by IR. However, ouabain prevented overexpression of occludin and the pore-forming claudin-2. In the colon tissue, ouabain prevented electrophysiological disturbances and claudin-2 overexpression. These observations may reveal a mechanism by which circulating ouabain maintains tight junction integrity under IR-induced intestinal dysfunction.
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Affiliation(s)
- Alexander G. Markov
- Department of General Physiology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.A.L.); (A.A.F.); (V.V.K.); (I.I.K.)
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5
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Baloglu E. Hypoxic Stress-Dependent Regulation of Na,K-ATPase in Ischemic Heart Disease. Int J Mol Sci 2023; 24:ijms24097855. [PMID: 37175562 PMCID: PMC10177966 DOI: 10.3390/ijms24097855] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023] Open
Abstract
In cardiomyocytes, regular activity of the Na,K-ATPase (NKA) and its Na/K pump activity is essential for maintaining ion gradients, excitability, propagation of action potentials, electro-mechanical coupling, trans-membrane Na+ and Ca2+ gradients and, thus, contractility. The activity of NKA is impaired in ischemic heart disease and heart failure, which has been attributed to decreased expression of the NKA subunits. Decreased NKA activity leads to intracellular Na+ and Ca2+ overload, diastolic dysfunction and arrhythmias. One signal likely related to these events is hypoxia, where hypoxia-inducible factors (HIF) play a critical role in the adaptation of cells to low oxygen tension. HIF activity increases in ischemic heart, hypertension, heart failure and cardiac fibrosis; thus, it might contribute to the impaired function of NKA. This review will mainly focus on the regulation of NKA in ischemic heart disease in the context of stressed myocardium and the hypoxia-HIF axis and argue on possible consequences of treatment.
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Affiliation(s)
- Emel Baloglu
- Department of Medical Pharmacology, School of Medicine, Acibadem Mehmet Ali Aydinlar University, 34752 Istanbul, Turkey
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6
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Sirirungruang S, Barnum CR, Tang SN, Shih PM. Plant glycosyltransferases for expanding bioactive glycoside diversity. Nat Prod Rep 2023. [PMID: 36853278 DOI: 10.1039/d2np00077f] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Glycosylation is a successful strategy to alter the pharmacological properties of small molecules, and it has emerged as a unique approach to expand the chemical space of natural products that can be explored in drug discovery. Traditionally, most glycosylation events have been carried out chemically, often requiring many protection and deprotection steps to achieve a target molecule. Enzymatic glycosylation by glycosyltransferases could provide an alternative strategy for producing new glycosides. In particular, the glycosyltransferase family has greatly expanded in plants, representing a rich enzymatic resource to mine and expand the diversity of glycosides with novel bioactive properties. This article highlights previous and prospective uses for plant glycosyltransferases in generating bioactive glycosides and altering their pharmacological properties.
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Affiliation(s)
- Sasilada Sirirungruang
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.,Feedstocks Division, Joint BioEnergy Institute, Emeryville, CA, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Center for Biomolecular Structure, Function and Application, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Collin R Barnum
- Department of Plant Biology, University of California, Davis, CA, USA
| | - Sophia N Tang
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, CA, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Patrick M Shih
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.,Feedstocks Division, Joint BioEnergy Institute, Emeryville, CA, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Innovative Genomics Institute, University of California, Berkeley, CA, USA
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7
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Vinod M, Berthier A, Maréchal X, Gheeraert C, Boutry R, Delhaye S, Annicotte JS, Duez H, Hovasse A, Cianférani S, Montaigne D, Eeckhoute J, Staels B, Lefebvre P. Timed use of digoxin prevents heart ischemia-reperfusion injury through a REV-ERBα-UPS signaling pathway. NATURE CARDIOVASCULAR RESEARCH 2022; 1:990-1005. [PMID: 38229609 PMCID: PMC7615528 DOI: 10.1038/s44161-022-00148-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 09/16/2022] [Indexed: 01/18/2024]
Abstract
Myocardial ischemia-reperfusion injury (MIRI) induces life-threatening damages to the cardiac tissue and pharmacological means to achieve cardioprotection are sorely needed. MIRI severity varies along the day-night cycle and is molecularly linked to components of the cellular clock including the nuclear receptor REV-ERBα, a transcriptional repressor. Here we show that digoxin administration in mice is cardioprotective when timed to trigger REV-ERBα protein degradation. In cardiomyocytes, digoxin increases REV-ERBα ubiquitinylation and proteasomal degradation, which depend on REV-ERBα ability to bind its natural ligand, heme. Inhibition of the membrane-bound Src tyrosine-kinase partially alleviated digoxin-induced REV-ERBα degradation. In untreated cardiomyocytes, REV-ERBα proteolysis is controlled by known (HUWE1, FBXW7, SIAH2) or novel (CBL, UBE4B) E3 ubiquitin ligases and the proteasome subunit PSMB5. Only SIAH2 and PSMB5 contributed to digoxin-induced degradation of REV-ERBα. Thus, controlling REV-ERBα proteostasis through the ubiquitin-proteasome system is an appealing cardioprotective strategy. Our data support the timed use of clinically-approved cardiotonic steroids in prophylactic cardioprotection.
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Affiliation(s)
- Manjula Vinod
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Alexandre Berthier
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Xavier Maréchal
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Céline Gheeraert
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Raphaёl Boutry
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 – RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000 Lille, France
| | - Stéphane Delhaye
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Jean-Sébastien Annicotte
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1167 – RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000 Lille, France
| | - Hélène Duez
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Agnès Hovasse
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), IPHC, Université de Strasbourg, CNRS, UMR7178, 25 Rue Becquerel, F-67087 Strasbourg, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), IPHC, Université de Strasbourg, CNRS, UMR7178, 25 Rue Becquerel, F-67087 Strasbourg, France
| | - David Montaigne
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Jérôme Eeckhoute
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Bart Staels
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
| | - Philippe Lefebvre
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000 Lille, France
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8
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Short-Term Mild Hypoxia Modulates Na,K-ATPase to Maintain Membrane Electrogenesis in Rat Skeletal Muscle. Int J Mol Sci 2022; 23:ijms231911869. [PMID: 36233169 PMCID: PMC9570130 DOI: 10.3390/ijms231911869] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/26/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
The Na,K-ATPase plays an important role in adaptation to hypoxia. Prolonged hypoxia results in loss of skeletal muscle mass, structure, and performance. However, hypoxic preconditioning is known to protect against a variety of functional impairments. In this study, we tested the possibility of mild hypoxia to modulate the Na,K-ATPase and to improve skeletal muscle electrogenesis. The rats were subjected to simulated high-altitude (3000 m above sea level) hypobaric hypoxia (HH) for 3 h using a hypobaric chamber. Isolated diaphragm and soleus muscles were tested. In the diaphragm muscle, HH increased the α2 Na,K-ATPase isozyme electrogenic activity and stably hyperpolarized the extrajunctional membrane for 24 h. These changes were accompanied by a steady increase in the production of thiobarbituric acid reactive substances as well as a decrease in the serum level of endogenous ouabain, a specific ligand of the Na,K-ATPase. HH also increased the α2 Na,K-ATPase membrane abundance without changing its total protein content; the plasma membrane lipid-ordered phase did not change. In the soleus muscle, HH protected against disuse (hindlimb suspension) induced sarcolemmal depolarization. Considering that the Na,K-ATPase is critical for maintaining skeletal muscle electrogenesis and performance, these findings may have implications for countermeasures in disuse-induced pathology and hypoxic therapy.
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9
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Fabri LM, Moraes CM, Costa MIC, Garçon DP, Fontes CFL, Pinto MR, McNamara JC, Leone FA. Salinity-dependent modulation by protein kinases and the FXYD2 peptide of gill (Na +, K +)-ATPase activity in the freshwater shrimp Macrobrachium amazonicum (Decapoda, Palaemonidae). BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183982. [PMID: 35671812 DOI: 10.1016/j.bbamem.2022.183982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 05/16/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
The geographical distribution of aquatic crustaceans is determined by ambient factors like salinity that modulate their biochemistry, physiology, behavior, reproduction, development and growth. We investigated the effects of exogenous pig FXYD2 peptide and endogenous protein kinases A and C on gill (Na+, K+)-ATPase activity, and characterized enzyme kinetic properties in a freshwater population of Macrobrachium amazonicum in fresh water (<0.5 ‰ salinity) or acclimated to 21 ‰S. Stimulation by FXYD2 peptide and inhibition by endogenous kinase phosphorylation are salinity-dependent. While without effect in shrimps in fresh water, the FXYD2 peptide stimulated activity in salinity-acclimated shrimps by ≈50 %. PKA-mediated phosphorylation inhibited gill (Na+, K+)-ATPase activity by 85 % in acclimated shrimps while PKC phosphorylation markedly inhibited enzyme activity in freshwater- and salinity-acclimated shrimps. The (Na+, K+)-ATPase in salinity-acclimated shrimp gills hydrolyzed ATP at a Vmax of 54.9 ± 1.8 nmol min-1 mg-1 protein, corresponding to ≈60 % that of freshwater shrimps. Mg2+ affinity increased with salinity acclimation while K+ affinity decreased. (Ca2+, Mg2+)-ATPase activity increased while V(H+)- and Na+- or K+-stimulated activities decreased on salinity acclimation. The 120-kDa immunoreactive band expressed in salinity-acclimated shrimps suggests nonspecific α-subunit phosphorylation by PKA and/or PKC. These alterations in (Na+, K+)-ATPase kinetics in salinity-acclimated M. amazonicum may result from regulatory mechanisms mediated by phosphorylation via protein kinases A and C and the FXYD2 peptide rather than through the expression of a different α-subunit isoform. This is the first demonstration of gill (Na+, K+)-ATPase regulation by protein kinases in freshwater shrimps during salinity challenge.
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Affiliation(s)
- Leonardo M Fabri
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Brazil
| | - Cintya M Moraes
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Brazil
| | - Maria I C Costa
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | | | - Carlos F L Fontes
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Brazil
| | - Marcelo R Pinto
- Laboratório de Biopatologia e Biologia Molecular, Universidade de Uberaba, Uberaba, Brazil
| | - John C McNamara
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil; Centro de Biologia Marinha, Universidade de São Paulo, São Sebastião, Brazil
| | - Francisco A Leone
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
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10
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Lindholm H, Ejeskär K, Szekeres F. Na +/K +‑ATPase subunit α3 expression is associated with the efficacy of digitoxin treatment in pancreatic cancer cells. MEDICINE INTERNATIONAL 2022; 2:27. [PMID: 36698913 PMCID: PMC9829214 DOI: 10.3892/mi.2022.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/01/2022] [Indexed: 01/28/2023]
Abstract
The alpha subunits (ATP1A1-3) of Na+/K+-ATPase binds digitoxin with varying affinity. The expression levels of these subunits dictate the anticancer effects of digitoxin. In the present study, three pancreatic cancer cell lines, AsPC-1, Panc-1 and CFPAC-1, were used to investigate the effects of digitoxin in relation to the expression of the subunits ATP1A1 and ATP1A3. Cell viability and intracellular calcium concentrations was measured in relation to the gene and protein expression of ATP1A1 and ATP1A3. Digitoxin was used to treat the cells at concentrations of 1-100 nM, and the intracellular calcium concentrations increased in a concentration-dependent manner in the Panc-1 and in the CFPAC-1 cells with treatment at 100 nM. In the AsPC-1 cells only the supraphysiological concentration of digitoxin (100 nM) resulted in a decrease in the number of viable cells (unviable cells increased to 22%), whereas it had no effect on intracellular calcium levels. The number of viable Panc-1 and CFPAC-1 cells decreased after digitoxin treatment at 25-100 nM (unviable Panc-1 cells increased to 33-59%; unviable CFPAC-1 cells increased to 22-56%). Digitoxin treatment also affected the transcriptional expression of the ATP1A1 and ATP1A3 subunits. In Panc-1 cells, ATP1A3 gene expression was negatively associated with the digitoxin concentration (25-100 nM). In the AsPC-1 and CFPAC-1 cells, the expression of the ATP1A1 gene increased in the cells treated with the 100 nM digitoxin concentration. The protein expression of ATP1A1 and ATP1A3 was not altered with digitoxin treatment. The basal protein expression of ATP1A1 was high in the AsPC-1 and CFPAC-1 cells, compared to the Panc-1 cells, in contrast to the basal expression of ATP1A3, which was higher in the Panc-1 cells, compared to the other pancreatic cancer cells used. On the whole, the present study demonstrates that the high expression of ATP1A3 renders pancreatic cancer cells more susceptible to digitoxin-induced cell death. The findings suggest that the expression of ATP1A3 may be used as a marker for tumor sensitivity to digitoxin treatment, where a high expression of ATP1A3 is favorable for the anticancer effects of digitoxin.
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Affiliation(s)
- Heléne Lindholm
- Department of Biomedicine, Translational Medicine, School of Health Sciences, University of Skövde, 54145 Skövde, Sweden
| | - Katarina Ejeskär
- Department of Biomedicine, Translational Medicine, School of Health Sciences, University of Skövde, 54145 Skövde, Sweden
| | - Ferenc Szekeres
- Department of Biomedicine, Translational Medicine, School of Health Sciences, University of Skövde, 54145 Skövde, Sweden,Correspondence to: Dr Ferenc Szekeres, Department of Biomedicine, Translational Medicine, School of Health Sciences, University of Skövde, Högskolevägen 1, 54145 Skövde, Sweden
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11
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Mehrabian M, Wang X, Eid S, Yan BQ, Grinberg M, Siegner M, Sackmann C, Sulman M, Zhao W, Williams D, Schmitt-Ulms G. Cardiac glycoside-mediated turnover of Na, K-ATPases as a rational approach to reducing cell surface levels of the cellular prion protein. PLoS One 2022; 17:e0270915. [PMID: 35776750 PMCID: PMC9249225 DOI: 10.1371/journal.pone.0270915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/17/2022] [Indexed: 01/16/2023] Open
Abstract
It is widely anticipated that a reduction of brain levels of the cellular prion protein (PrPC) can prolong survival in a group of neurodegenerative diseases known as prion diseases. To date, efforts to decrease steady-state PrPC levels by targeting this protein directly with small molecule drug-like compounds have largely been unsuccessful. Recently, we reported Na,K-ATPases to reside in immediate proximity to PrPC in the brain, unlocking an opportunity for an indirect PrPC targeting approach that capitalizes on the availability of potent cardiac glycosides (CGs). Here, we report that exposure of human co-cultures of neurons and astrocytes to non-toxic nanomolar levels of CGs causes profound reductions in PrPC levels. The mechanism of action underpinning this outcome relies primarily on a subset of CGs engaging the ATP1A1 isoform, one of three α subunits of Na,K-ATPases expressed in brain cells. Upon CG docking to ATP1A1, the ligand receptor complex, and PrPC along with it, is internalized by the cell. Subsequently, PrPC is channeled to the lysosomal compartment where it is digested in a manner that can be rescued by silencing the cysteine protease cathepsin B. These data signify that the repurposing of CGs may be beneficial for the treatment of prion disorders.
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Affiliation(s)
- Mohadeseh Mehrabian
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Xinzhu Wang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Shehab Eid
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Bei Qi Yan
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Mark Grinberg
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Murdock Siegner
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Christopher Sackmann
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Muhammad Sulman
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Wenda Zhao
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Declan Williams
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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12
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Skogestad J, Aronsen JM. Regulation of Cardiac Contractility by the Alpha 2 Subunit of the Na+/K+-ATPase. Front Physiol 2022; 13:827334. [PMID: 35812308 PMCID: PMC9258780 DOI: 10.3389/fphys.2022.827334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/16/2022] [Indexed: 11/14/2022] Open
Abstract
Cytosolic Na + concentrations regulate cardiac excitation-contraction coupling and contractility. Inhibition of the Na+/K+-ATPase (NKA) activity increases cardiac contractility by increasing cytosolic Ca2+ levels, as increased cytosolic Na+ levels are coupled to less Ca2+ extrusion and/or increased Ca2+ influx from the Na+/Ca2+-exchanger. NKA consists of one α subunit and one β subunit, with α1 and α2 being the main α isoforms in cardiomyocytes. Substantial evidence suggests that NKAα2 is the primary regulator of cardiac contractility despite being outnumbered by NKAα1 in cardiomyocytes. This review will mainly focus on differential regulation and subcellular localization of the NKAα1 and NKAα2 isoforms, and their relation to the proposed concept of subcellular gradients of Na+ in cardiomyocytes. We will also discuss the potential roles of NKAα2 in mediating cardiac hypertrophy and ventricular arrhythmias.
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Affiliation(s)
- Jonas Skogestad
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Jan Magnus Aronsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Pharmacology, Oslo University Hospital, Oslo, Norway
- *Correspondence: Jan Magnus Aronsen,
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13
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Fujii T, Katoh M, Ootsubo M, Nguyen OTT, Iguchi M, Shimizu T, Tabuchi Y, Shimizu Y, Takeshima H, Sakai H. Cardiac glycosides stimulate endocytosis of GLUT1 via intracellular Na + ,K + -ATPase α3-isoform in human cancer cells. J Cell Physiol 2022; 237:2980-2991. [PMID: 35511727 DOI: 10.1002/jcp.30762] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/23/2022] [Accepted: 04/11/2022] [Indexed: 01/20/2023]
Abstract
Glucose transporter GLUT1 plays a primary role in the glucose metabolism of cancer cells. Here, we found that cardiac glycosides (CGs) such as ouabain, oleandrin, and digoxin, which are Na+ ,K+ -ATPase inhibitors, decreased the GLUT1 expression in the plasma membrane of human cancer cells (liver cancer HepG2, colon cancer HT-29, gastric cancer MKN45, and oral cancer KB cells). The effective concentration of ouabain was lower than that for inhibiting the activity of Na+ ,K+ -ATPase α1-isoform (α1NaK) in the plasma membrane. The CGs also inhibited [3 H]2-deoxy- d-glucose uptake, lactate secretion, and proliferation of the cancer cells. In intracellular vesicles of human cancer cells, Na+ ,K+ -ATPase α3-isoform (α3NaK) is abnormally expressed. Here, a low concentration of ouabain inhibited the activity of α3NaK. Knockdown of α3NaK significantly inhibited the ouabain-decreased GLUT1 expression in HepG2 cells, while the α1NaK knockdown did not. Consistent with the results in human cancer cells, CGs had no effect on GLUT1 expression in rat liver cancer dRLh-84 cells where α3NaK was not endogenously expressed. Interestingly, CGs decreased GLUT expression in the dRLh-84 cells exogenously expressing α3NaK. In HepG2 cells, α3NaK was found to be colocalized with TPC1, a Ca2+ -releasing channel activated by nicotinic acid adenine dinucleotide phosphate (NAADP). The CGs-decreased GLUT1 expression was significantly inhibited by a Ca2+ chelator, a Ca2+ -ATPase inhibitor, and a NAADP antagonist. The GLUT1 decrease was also attenuated by inhibitors of dynamin and phosphatidylinositol-3 kinases (PI3Ks). In conclusion, the binding of CGs to intracellular α3NaK elicits the NAADP-mediated Ca2+ mobilization followed by the dynamin-dependent GLUT1 endocytosis in human cancer cells.
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Affiliation(s)
- Takuto Fujii
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Mizuki Katoh
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Manami Ootsubo
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Oanh T T Nguyen
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Mayumi Iguchi
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Takahiro Shimizu
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Yoshiaki Tabuchi
- Division of Molecular Genetics Research, Life Science Research Center, University of Toyama, Toyama, Japan
| | - Yasuharu Shimizu
- Tokyo Research Center, Kyushin Pharmaceutical Co, Ltd., Tokyo, Japan
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Hideki Sakai
- Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, University of Toyama, Toyama, Japan
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14
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Dorgau B, Georgiou M, Chaudhary A, Moya-Molina M, Collin J, Queen R, Hilgen G, Davey T, Hewitt P, Schmitt M, Kustermann S, Pognan F, Steel DH, Sernagor E, Armstrong L, Lako M. Human Retinal Organoids Provide a Suitable Tool for Toxicological Investigations: A Comprehensive Validation Using Drugs and Compounds Affecting the Retina. Stem Cells Transl Med 2022; 11:159-177. [PMID: 35298655 PMCID: PMC8929478 DOI: 10.1093/stcltm/szab010] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/13/2021] [Indexed: 12/04/2022] Open
Abstract
Retinal drug toxicity screening is essential for the development of safe treatment strategies for a large number of diseases. To this end, retinal organoids derived from human pluripotent stem cells (hPSCs) provide a suitable screening platform due to their similarity to the human retina and the ease of generation in large-scale formats. In this study, two hPSC cell lines were differentiated to retinal organoids, which comprised all key retinal cell types in multiple nuclear and synaptic layers. Single-cell RNA-Seq of retinal organoids indicated the maintenance of retinal ganglion cells and development of bipolar cells: both cell types segregated into several subtypes. Ketorolac, digoxin, thioridazine, sildenafil, ethanol, and methanol were selected as key compounds to screen on retinal organoids because of their well-known retinal toxicity profile described in the literature. Exposure of the hPSC-derived retinal organoids to digoxin, thioridazine, and sildenafil resulted in photoreceptor cell death, while digoxin and thioridazine additionally affected all other cell types, including Müller glia cells. All drug treatments caused activation of astrocytes, indicated by dendrites sprouting into neuroepithelium. The ability to respond to light was preserved in organoids although the number of responsive retinal ganglion cells decreased after drug exposure. These data indicate similar drug effects in organoids to those reported in in vivo models and/or in humans, thus providing the first robust experimental evidence of their suitability for toxicological studies.
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Affiliation(s)
- Birthe Dorgau
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
- Newcells Biotech, Biosphere, Newcastle Helix, Newcastle upon Tyne, UK
| | - Maria Georgiou
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
| | - Alexander Chaudhary
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
| | - Marina Moya-Molina
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
- Newcells Biotech, Biosphere, Newcastle Helix, Newcastle upon Tyne, UK
| | - Joseph Collin
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
| | - Rachel Queen
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
| | - Gerrit Hilgen
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
- Northumbria University, Applied Sciences, Faculty of Health and Life Science, Newcastle upon Tyne, UK
| | - Tracey Davey
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
- Electron Microscopy Research Services, Newcastle University, Newcastle upon Tyne, UK
| | | | | | - Stefan Kustermann
- Pharmaceutical Sciences, F. Hoffmann-La Roche, Pharma Research and Early Development, Roche Innovation Center Basel, Switzerland
| | | | - David H Steel
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
| | - Evelyne Sernagor
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
| | - Lyle Armstrong
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
- Newcells Biotech, Biosphere, Newcastle Helix, Newcastle upon Tyne, UK
| | - Majlinda Lako
- Newcastle University, Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, UK
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15
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Shandell MA, Capatina AL, Lawrence SM, Brackenbury WJ, Lagos D. Inhibition of the Na +/K +-ATPase by cardiac glycosides suppresses expression of the IDO1 immune checkpoint in cancer cells by reducing STAT1 activation. J Biol Chem 2022; 298:101707. [PMID: 35150740 PMCID: PMC8902613 DOI: 10.1016/j.jbc.2022.101707] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 12/18/2022] Open
Abstract
Despite extensive basic and clinical research on immune checkpoint regulatory pathways, little is known about the effects of the ionic tumor microenvironment on immune checkpoint expression and function. Here we describe a mechanistic link between Na+/K+-ATPase (NKA) inhibition and activity of the immune checkpoint protein indoleamine-pyrrole 2',3'-dioxygenase 1 (IDO1). We found that IDO1 was necessary and sufficient for production of kynurenine, a downstream tryptophan metabolite, in cancer cells. We developed a spectrophotometric assay to screen a library of 31 model ion transport-targeting compounds for potential effects on IDO1 function in A549 lung and MDA-MB-231 breast cancer cells. This revealed that the cardiac glycosides ouabain and digoxin inhibited kynurenine production at concentrations that did not affect cell survival. NKA inhibition by ouabain and digoxin resulted in increased intracellular Na+ levels and downregulation of IDO1 mRNA and protein levels, which was consistent with the reduction in kynurenine levels. Knockdown of ATP1A1, the ɑ1 subunit of the NKA and target of cardiac glycosides, increased Na+ levels to a lesser extent than cardiac glycoside treatment and did not affect IDO1 expression. However, ATP1A1 knockdown significantly enhanced the effect of cardiac glycosides on IDO1 expression and kynurenine production. Mechanistically, we show that cardiac glycoside treatment resulted in curtailing the length of phosphorylation-mediated stabilization of STAT1, a transcriptional regulator of IDO1 expression, an effect enhanced by ATP1A1 knockdown. Our findings reveal cross talk between ionic modulation via cardiac glycosides and immune checkpoint protein expression in cancer cells with broad mechanistic and clinical implications.
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Affiliation(s)
- Mia A Shandell
- Department of Biology, University of York, York, United Kingdom; Hull York Medical School, University of York, York, United Kingdom; York Biomedical Research Institute, University of York, York, United Kingdom
| | - Alina L Capatina
- Department of Biology, University of York, York, United Kingdom; York Biomedical Research Institute, University of York, York, United Kingdom
| | | | - William J Brackenbury
- Department of Biology, University of York, York, United Kingdom; York Biomedical Research Institute, University of York, York, United Kingdom
| | - Dimitris Lagos
- Hull York Medical School, University of York, York, United Kingdom; York Biomedical Research Institute, University of York, York, United Kingdom.
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16
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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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17
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Ygberg S, Akkuratov EE, Howard RJ, Taylan F, Jans DC, Mahato DR, Katz A, Kinoshita PF, Portal B, Nennesmo I, Lindskog M, Karlish SJD, Andersson M, Lindstrand A, Brismar H, Aperia A. A missense mutation converts the Na +,K +-ATPase into an ion channel and causes therapy-resistant epilepsy. J Biol Chem 2021; 297:101355. [PMID: 34717959 PMCID: PMC8637647 DOI: 10.1016/j.jbc.2021.101355] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/14/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
The ion pump Na+,K+-ATPase is a critical determinant of neuronal excitability; however, its role in the etiology of diseases of the central nervous system (CNS) is largely unknown. We describe here the molecular phenotype of a Trp931Arg mutation of the Na+,K+-ATPase catalytic α1 subunit in an infant diagnosed with therapy-resistant lethal epilepsy. In addition to the pathological CNS phenotype, we also detected renal wasting of Mg2+. We found that membrane expression of the mutant α1 protein was low, and ion pumping activity was lost. Arginine insertion into membrane proteins can generate water-filled pores in the plasma membrane, and our molecular dynamic (MD) simulations of the principle states of Na+,K+-ATPase transport demonstrated massive water inflow into mutant α1 and destabilization of the ion-binding sites. MD simulations also indicated that a water pathway was created between the mutant arginine residue and the cytoplasm, and analysis of oocytes expressing mutant α1 detected a nonspecific cation current. Finally, neurons expressing mutant α1 were observed to be depolarized compared with neurons expressing wild-type protein, compatible with a lowered threshold for epileptic seizures. The results imply that Na+,K+-ATPase should be considered a neuronal locus minoris resistentia in diseases associated with epilepsy and with loss of plasma membrane integrity.
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Affiliation(s)
- Sofia Ygberg
- Neuropediatric Unit, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden; Centre for Inherited Metabolic Diseases (CMMS), Karolinska University Hospital, Stockholm, Sweden
| | - Evgeny E Akkuratov
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | - Rebecca J Howard
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Fulya Taylan
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Daniel C Jans
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | | | - Adriana Katz
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovoth, Israel
| | - Paula F Kinoshita
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Benjamin Portal
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Inger Nennesmo
- Department of Pathology, Karolinska University Hospital, Stockholm, Sweden
| | - Maria Lindskog
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Steven J D Karlish
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovoth, Israel
| | | | - Anna Lindstrand
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Hjalmar Brismar
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden; Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.
| | - Anita Aperia
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
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18
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Jiang H, Qin X, Wang Q, Xu Q, Wang J, Wu Y, Chen W, Wang C, Zhang T, Xing D, Zhang R. Application of carbohydrates in approved small molecule drugs: A review. Eur J Med Chem 2021; 223:113633. [PMID: 34171659 DOI: 10.1016/j.ejmech.2021.113633] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 12/24/2022]
Abstract
Carbohydrates are an important energy source and play numerous key roles in all living organisms. Carbohydrates chemistry involved in diagnosis and treatment of diseases has been attracting increasing attention. Carbohydrates could be one of the major focuses of new drug discovery. Currently, however, carbohydrate-containing drugs account for only a small percentage of all drugs in clinical use, which does not match the important roles of carbohydrates in the organism. In other words, carbohydrates are a relatively untapped source of new drugs and therefore may offer exciting novel therapeutic opportunities. Here, we presented an overview of the application of carbohydrates in approved small molecule drugs and emphasized and evaluated the roles of carbohydrates in those drugs. The potential development direction of carbohydrate-containing drugs was presented after summarizing the advantages and challenges of carbohydrates in the development of new drugs.
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Affiliation(s)
- Hongfei Jiang
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China; Cancer Institute, Qingdao University, Qingdao, 266071, China
| | - Xiaofei Qin
- Department of Bioengineering, Zhuhai Campus of Zunyi Medical University, Zhuhai, 519041, China
| | - Qi Wang
- Department of Critical Medicine, Hainan Maternal and Children's Medical Center, Haikou, 570312, China
| | - Qi Xu
- Laboratory of Immunology for Environment and Health, Shandong Analysis and Test Center, Qilu University of Technology Shandong Academy of Sciences, Jinan, China
| | - Jie Wang
- Cancer Institute, Qingdao University, Qingdao, 266071, China
| | - Yudong Wu
- Cancer Institute, Qingdao University, Qingdao, 266071, China
| | - Wujun Chen
- Cancer Institute, Qingdao University, Qingdao, 266071, China
| | - Chao Wang
- Cancer Institute, Qingdao University, Qingdao, 266071, China
| | - Tingting Zhang
- Cancer Institute, Qingdao University, Qingdao, 266071, China
| | - Dongming Xing
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China; Cancer Institute, Qingdao University, Qingdao, 266071, China; School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Renshuai Zhang
- The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, 266071, China; Cancer Institute, Qingdao University, Qingdao, 266071, China.
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19
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Quo vadis Cardiac Glycoside Research? Toxins (Basel) 2021; 13:toxins13050344. [PMID: 34064873 PMCID: PMC8151307 DOI: 10.3390/toxins13050344] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 12/16/2022] Open
Abstract
Cardiac glycosides (CGs), toxins well-known for numerous human and cattle poisoning, are natural compounds, the biosynthesis of which occurs in various plants and animals as a self-protective mechanism to prevent grazing and predation. Interestingly, some insect species can take advantage of the CG’s toxicity and by absorbing them, they are also protected from predation. The mechanism of action of CG’s toxicity is inhibition of Na+/K+-ATPase (the sodium-potassium pump, NKA), which disrupts the ionic homeostasis leading to elevated Ca2+ concentration resulting in cell death. Thus, NKA serves as a molecular target for CGs (although it is not the only one) and even though CGs are toxic for humans and some animals, they can also be used as remedies for various diseases, such as cardiovascular ones, and possibly cancer. Although the anticancer mechanism of CGs has not been fully elucidated, yet, it is thought to be connected with the second role of NKA being a receptor that can induce several cell signaling cascades and even serve as a growth factor and, thus, inhibit cancer cell proliferation at low nontoxic concentrations. These growth inhibitory effects are often observed only in cancer cells, thereby, offering a possibility for CGs to be repositioned for cancer treatment serving not only as chemotherapeutic agents but also as immunogenic cell death triggers. Therefore, here, we report on CG’s chemical structures, production optimization, and biological activity with possible use in cancer therapy, as well as, discuss their antiviral potential which was discovered quite recently. Special attention has been devoted to digitoxin, digoxin, and ouabain.
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20
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Zhang W, Tao WW, Zhou J, Wu CY, Long F, Shen H, Zhu H, Mao Q, Xu J, Li SL, Wu QN. Structural analogues in herbal medicine ginseng hit a shared target to achieve cumulative bioactivity. Commun Biol 2021; 4:549. [PMID: 33972672 PMCID: PMC8110997 DOI: 10.1038/s42003-021-02084-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/07/2021] [Indexed: 12/13/2022] Open
Abstract
By a pilot trial on investigating immunomodulatory activity and target of ginsenosides, the major bioactive components of ginseng, here we report that structural analogues in herbal medicines hit a shared target to achieve cumulative bioactivity. A ginsenoside analogues combination with definite immunomodulatory activity in vivo was designed by integrating pharmacodynamics, serum pharmacochemistry and pharmacokinetics approaches. The cumulative bioactivity of the ginsenoside analogues was validated on LPS/ATP-induced RAW264.7 macrophages. The potentially shared target NLRP3 involved in this immunomodulatory activity was predicted by systems pharmacology. The steady binding affinity between each ginsenoside and NLRP3 was defined by molecular docking and bio-layer interferometry assay. The activation of NLRP3 inflammasomes in LPS/ATP-induced RAW264.7 was significantly suppressed by the combination, but not by any individual, and the overexpression of NLRP3 counteracted the immunomodulatory activity of the combination. All these results demonstrate that the ginsenoside analogues jointly hit NLRP3 to achieve cumulative immunomodulatory activity. Zhang et al. design ginsenoside structural analogues and demonstrate that their combination shows more potent immunomodulatory activities than individual ginsenosides used alone at the same dosages. They predict that these analogues act on the joint target NLRP3 and consequently suggest that structural analogues hit a shared target to achieve cumulative bioactivity.
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Affiliation(s)
- Wei Zhang
- Department of Pharmaceutical Analysis, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, People's Republic of China.,College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, People's Republic of China
| | - Wei-Wei Tao
- School of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, 210023, Nanjing, People's Republic of China
| | - Jing Zhou
- Department of Metabolomics, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, People's Republic of China
| | - Cheng-Ying Wu
- Department of Pharmaceutical Analysis, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, People's Republic of China
| | - Fang Long
- Department of Metabolomics, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, People's Republic of China
| | - Hong Shen
- Department of Pharmaceutical Analysis, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, People's Republic of China
| | - He Zhu
- Department of Metabolomics, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, People's Republic of China
| | - Qian Mao
- Department of Pharmaceutical Analysis, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, People's Republic of China
| | - Jun Xu
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, People's Republic of China.
| | - Song-Lin Li
- Department of Pharmaceutical Analysis, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210028, People's Republic of China. .,Department of Metabolomics, Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028, People's Republic of China.
| | - Qi-Nan Wu
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, People's Republic of China. .,Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Nanjing University of Chinese Medicine, Nanjing, 210023, People's Republic of China.
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21
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Tokugawa M, Inoue Y, Ishiuchi K, Kujirai C, Matsuno M, Ri M, Itoh Y, Miyajima C, Morishita D, Ohoka N, Iida S, Mizukami H, Makino T, Hayashi H. Periplocin and cardiac glycosides suppress the unfolded protein response. Sci Rep 2021; 11:9528. [PMID: 33947921 PMCID: PMC8097017 DOI: 10.1038/s41598-021-89074-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/20/2021] [Indexed: 12/23/2022] Open
Abstract
The unfolded protein response (UPR) controls protein homeostasis through transcriptional and translational regulation. However, dysregulated UPR signaling has been associated with the pathogenesis of many human diseases. Therefore, the compounds modulating UPR may provide molecular insights for these pathologies in the context of UPR. Here, we screened small-molecule compounds that suppress UPR, using a library of Myanmar wild plant extracts. The screening system to track X-box binding protein 1 (XBP1) splicing activity revealed that the ethanol extract of the Periploca calophylla stem inhibited the inositol-requiring enzyme 1 (IRE1)-XBP1 pathway. We isolated and identified periplocin as a potent inhibitor of the IRE1-XBP1 axis. Periplocin also suppressed other UPR axes, protein kinase R-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Examining the structure–activity relationship of periplocin revealed that cardiac glycosides also inhibited UPR. Moreover, periplocin suppressed the constitutive activation of XBP1 and exerted cytotoxic effects in the human multiple myeloma cell lines, AMO1 and RPMI8226. These results reveal a novel suppressive effect of periplocin or the other cardiac glycosides on UPR regulation, suggesting that these compounds will contribute to our understanding of the pathological or physiological importance of UPR.
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Affiliation(s)
- Muneshige Tokugawa
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
| | - Yasumichi Inoue
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan. .,Department of Innovative Therapeutic Sciences, Cooperative Major in Nanopharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan.
| | - Kan'ichiro Ishiuchi
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
| | - Chisane Kujirai
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
| | - Michiyo Matsuno
- The Kochi Prefectural Makino Botanical Garden, Kochi, 781-8125, Japan
| | - Masaki Ri
- Department of Hematology and Oncology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Yuka Itoh
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
| | - Chiharu Miyajima
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan.,Department of Innovative Therapeutic Sciences, Cooperative Major in Nanopharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
| | - Daisuke Morishita
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan.,Chordia Therapeutics Inc., Kanagawa, 251-0012, Japan
| | - Nobumichi Ohoka
- Division of Molecular Target and Gene Therapy Products, National Institute of Health Sciences, Kawasaki, 210-9501, Japan
| | - Shinsuke Iida
- Department of Hematology and Oncology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, 467-8601, Japan
| | - Hajime Mizukami
- The Kochi Prefectural Makino Botanical Garden, Kochi, 781-8125, Japan
| | - Toshiaki Makino
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan
| | - Hidetoshi Hayashi
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan. .,Department of Innovative Therapeutic Sciences, Cooperative Major in Nanopharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, 467-8603, Japan.
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22
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Škubník J, Pavlíčková V, Rimpelová S. Cardiac Glycosides as Immune System Modulators. Biomolecules 2021; 11:biom11050659. [PMID: 33947098 PMCID: PMC8146282 DOI: 10.3390/biom11050659] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/11/2022] Open
Abstract
Cardiac glycosides (CGs) are natural steroid compounds occurring both in plants and animals. They are known for long as cardiotonic agents commonly used for various cardiac diseases due to inhibition of Na+/K+-ATPase (NKA) pumping activity and modulating heart muscle contractility. However, recent studies show that the portfolio of diseases potentially treatable with CGs is much broader. Currently, CGs are mostly studied as anticancer agents. Their antiproliferative properties are based on the induction of multiple signaling pathways in an NKA signalosome complex. In addition, they are strongly connected to immunogenic cell death, a complex mechanism of induction of anticancer immune response. Moreover, CGs exert various immunomodulatory effects, the foremost of which are connected with suppressing the activity of T-helper cells or modulating transcription of many immune response genes by inhibiting nuclear factor kappa B. The resulting modulations of cytokine and chemokine levels and changes in immune cell ratios could be potentially useful in treating sundry autoimmune and inflammatory diseases. This review aims to summarize current knowledge in the field of immunomodulatory properties of CGs and emphasize the large area of potential clinical use of these compounds.
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23
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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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24
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Bejček J, Spiwok V, Kmoníčková E, Rimpelová S. Na +/K +-ATPase Revisited: On Its Mechanism of Action, Role in Cancer, and Activity Modulation. Molecules 2021; 26:molecules26071905. [PMID: 33800655 PMCID: PMC8061769 DOI: 10.3390/molecules26071905] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 01/08/2023] Open
Abstract
Maintenance of Na+ and K+ gradients across the cell plasma membrane is an essential process for mammalian cell survival. An enzyme responsible for this process, sodium-potassium ATPase (NKA), has been currently extensively studied as a potential anticancer target, especially in lung cancer and glioblastoma. To date, many NKA inhibitors, mainly of natural origin from the family of cardiac steroids (CSs), have been reported and extensively studied. Interestingly, upon CS binding to NKA at nontoxic doses, the role of NKA as a receptor is activated and intracellular signaling is triggered, upon which cancer cell death occurs, which lies in the expression of different NKA isoforms than in healthy cells. Two major CSs, digoxin and digitoxin, originally used for the treatment of cardiac arrhythmias, are also being tested for another indication—cancer. Such drug repositioning has a big advantage in smoother approval processes. Besides this, novel CS derivatives with improved performance are being developed and evaluated in combination therapy. This article deals with the NKA structure, mechanism of action, activity modulation, and its most important inhibitors, some of which could serve not only as a powerful tool to combat cancer, but also help to decipher the so-far poorly understood NKA regulation.
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Affiliation(s)
- Jiří Bejček
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic; (J.B.); (V.S.)
| | - Vojtěch Spiwok
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic; (J.B.); (V.S.)
| | - Eva Kmoníčková
- Department of Pharmacology, Second Faculty of Medicine, Charles University, Plzeňská 311, 150 00 Prague, Czech Republic;
| | - Silvie Rimpelová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 3, 166 28 Prague 6, Czech Republic; (J.B.); (V.S.)
- Faculty of Medicine in Pilsen, Charles University, Alej Svobody 76, 323 00 Pilsen, Czech Republic
- Correspondence: ; Tel.: +420-220-444-360
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25
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Nah J, Zhai P, Huang CY, Fernández ÁF, Mareedu S, Levine B, Sadoshima J. Upregulation of Rubicon promotes autosis during myocardial ischemia/reperfusion injury. J Clin Invest 2021; 130:2978-2991. [PMID: 32364533 DOI: 10.1172/jci132366] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/20/2020] [Indexed: 12/29/2022] Open
Abstract
Although autophagy is generally protective, uncontrolled or excessive activation of autophagy can be detrimental. However, it is often difficult to distinguish death by autophagy from death with autophagy, and whether autophagy contributes to death in cardiomyocytes (CMs) is still controversial. Excessive activation of autophagy induces a morphologically and biochemically defined form of cell death termed autosis. Whether autosis is involved in tissue injury induced under pathologically relevant conditions is poorly understood. In the present study, myocardial ischemia/reperfusion (I/R) induced autosis in CMs, as evidenced by cell death with numerous vacuoles and perinuclear spaces, and depleted intracellular membranes. Autosis was observed frequently after 6 hours of reperfusion, accompanied by upregulation of Rubicon, attenuation of autophagic flux, and marked accumulation of autophagosomes. Genetic downregulation of Rubicon inhibited autosis and reduced I/R injury, whereas stimulation of autosis during the late phase of I/R with Tat-Beclin 1 exacerbated injury. Suppression of autosis by ouabain, a cardiac glycoside, in humanized Na+,K+-ATPase-knockin mice reduced I/R injury. Taken together, these results demonstrate that autosis is significantly involved in I/R injury in the heart and triggered by dysregulated accumulation of autophagosomes due to upregulation of Rubicon.
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Affiliation(s)
- Jihoon Nah
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Peiyong Zhai
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Chun-Yang Huang
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | | | - Satvik Mareedu
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Beth Levine
- Center for Autophagy Research, Department of Internal Medicine, and.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Junichi Sadoshima
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA
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26
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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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27
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Steroid Glycosides Hyrcanoside and Deglucohyrcanoside: On Isolation, Structural Identification, and Anticancer Activity. Foods 2021; 10:foods10010136. [PMID: 33440629 PMCID: PMC7827417 DOI: 10.3390/foods10010136] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 12/31/2020] [Accepted: 01/03/2021] [Indexed: 12/20/2022] Open
Abstract
Cardiac glycosides (CGs) represent a group of sundry compounds of natural origin. Most CGs are potent inhibitors of Na+/K+-ATPase, and some are routinely utilized in the treatment of various cardiac conditions. Biological activities of other lesser known CGs have not been fully explored yet. Interestingly, the anticancer potential of some CGs was revealed and thereby, some of these compounds are now being evaluated for drug repositioning. However, high systemic toxicity and low cancer cell selectivity of the clinically used CGs have severely limited their utilization in cancer treatment so far. Therefore, in this study, we have focused on two poorly described CGs: hyrcanoside and deglucohyrcanoside. We elaborated on their isolation, structural identification, and cytotoxicity evaluation in a panel of cancerous and noncancerous cell lines, and on their potential to induce cell cycle arrest in the G2/M phase. The activity of hyrcanoside and deglucohyrcanoside was compared to three other CGs: ouabain, digitoxin, and cymarin. Furthermore, by in silico modeling, interaction of these CGs with Na+/K+-ATPase was also studied. Hopefully, these compounds could serve not only as a research tool for Na+/K+-ATPase inhibition, but also as novel cancer therapeutics.
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28
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Kongkham B, Prabakaran D, Puttaswamy H. Opportunities and challenges in managing antibiotic resistance in bacteria using plant secondary metabolites. Fitoterapia 2020; 147:104762. [PMID: 33069839 DOI: 10.1016/j.fitote.2020.104762] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 10/08/2020] [Accepted: 10/12/2020] [Indexed: 12/11/2022]
Abstract
Development of antibiotic resistance (ABR) in bacteria and its multidimensional spread is an emerging global threat that needs immediate attention. Extensive antibiotics (AB) usage results in development of ABR in bacteria by target modification, production of AB degrading enzymes, porin modifications, efflux pumps overexpression, etc. To counter this, apart from strict regulation of AB use and behavioural changes, research and development (R&D) of newer antimicrobials are in place. One such emerging approach to combat ABR is the use of structurally and functionally diverse plant secondary metabolites (PSMs) in combination with the conventional AB. Either the PSMs are themselves antimicrobial or they potentiate the activity of the AB through a range of mechanisms. However, their use is lagging due to poor knowledge of mode of action, structure-activity relationships, pharmacokinetics, etc. This review paper discussed the opportunities and challenges in managing ABR using PSMs. Mechanisms of ABR development in bacteria and current strategies to counter them were studied and the areas where PSMs can play an important role were highlighted. The use of PSMs, both as an anti-resistance and anti-virulence agent in combination therapy to counter multi-drug resistance along with their mechanisms of action, has been discussed in detail. The difficulties in the commercialisation of PSMs and strategies to overcome them along with future priority areas of research have also been given. Following the given R&D path will definitely help in better understanding and utilising the full potential of PSMs in solving the problem of antimicrobial resistance (AMR).
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Affiliation(s)
- Bhani Kongkham
- Environmental Biotechnology Laboratory, Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Delhi 110016, India
| | - Duraivadivel Prabakaran
- Environmental Biotechnology Laboratory, Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Delhi 110016, India
| | - Hariprasad Puttaswamy
- Environmental Biotechnology Laboratory, Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Delhi 110016, India.
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29
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Petrushanko IY, Mitkevich VA, Makarov AA. Molecular Mechanisms of the Redox Regulation of the Na,K-ATPase. Biophysics (Nagoya-shi) 2020. [DOI: 10.1134/s0006350920050139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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30
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Pelin M, Stocco G, Florio C, Sosa S, Tubaro A. In Vitro Cell Sensitivity to Palytoxin Correlates with High Gene Expression of the Na +/K +-ATPase β2 Subunit Isoform. Int J Mol Sci 2020; 21:ijms21165833. [PMID: 32823835 PMCID: PMC7461505 DOI: 10.3390/ijms21165833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/03/2020] [Accepted: 08/13/2020] [Indexed: 01/13/2023] Open
Abstract
The marine polyether palytoxin (PLTX) is one of the most toxic natural compounds, and is involved in human poisonings after oral, inhalation, skin and/or ocular exposure. Epidemiological and molecular evidence suggest different inter-individual sensitivities to its toxic effects, possibly related to genetic-dependent differences in the expression of Na+/K+-ATPase, its molecular target. To identify Na+/K+-ATPase subunits, isoforms correlated with in vitro PLTX cytotoxic potency, sensitivity parameters (EC50: PLTX concentration reducing cell viability by 50%; Emax: maximum effect induced by the highest toxin concentration; 10-7 M) were assessed in 60 healthy donors' monocytes by the MTT (methylthiazolyl tetrazolium) assay. Sensitivity parameters, not correlated with donors' demographic variables (gender, age and blood group), demonstrated a high inter-individual variability (median EC50 = 2.7 × 10-10 M, interquartile range: 0.4-13.2 × 10-10 M; median Emax = 92.0%, interquartile range: 87.5-94.4%). Spearman's analysis showed significant positive correlations between the β2-encoding ATP1B2 gene expression and Emax values (rho = 0.30; p = 0.025) and between Emax and the ATP1B2/ATP1B3 expression ratio (rho = 0.38; p = 0.004), as well as a significant negative correlation between Emax and the ATP1B1/ATP1B2 expression ratio (rho = -0.30; p = 0.026). This toxicogenetic study represents the first approach to define genetic risk factors that may influence the onset of adverse effects in human PLTX poisonings, suggesting that individuals with high gene expression pattern of the Na+/K+-ATPase β2 subunit (alone or as β2/β1 and/or β2/β3 ratio) could be highly sensitive to PLTX toxic effects.
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31
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Pederson PJ, Cai S, Carver C, Powell DR, Risinger AL, Grkovic T, O'Keefe BR, Mooberry SL, Cichewicz RH. Triple-Negative Breast Cancer Cells Exhibit Differential Sensitivity to Cardenolides from Calotropis gigantea. JOURNAL OF NATURAL PRODUCTS 2020; 83:2269-2280. [PMID: 32649211 PMCID: PMC7540184 DOI: 10.1021/acs.jnatprod.0c00423] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Triple-negative breast cancers (TNBC) are aggressive and heterogeneous cancers that lack targeted therapies. We implemented a screening program to identify new leads for subgroups of TNBC using diverse cell lines with different molecular drivers. Through this program, we identified an extract from Calotropis gigantea that caused selective cytotoxicity in BT-549 cells as compared to four other TNBC cell lines. Bioassay-guided fractionation of the BT-549 selective extract yielded nine cardenolides responsible for the selective activity. These included eight known cardenolides and a new cardenolide glycoside. Structure-activity relationships among the cardenolides demonstrated a correlation between their relative potencies toward BT-549 cells and Na+/K+ ATPase inhibition. Calotropin, the compound with the highest degree of selectivity for BT-549 cells, increased intracellular Ca2+ in sensitive cells to a greater extent than in the resistant MDA-MB-231 cells. Further studies identified a second TNBC cell line, Hs578T, that is also highly sensitive to the cardenolides, and mechanistic studies were conducted to identify commonalities among the sensitive cell lines. Experiments showed that both cardenolide-sensitive cell lines expressed higher mRNA levels of the Na+/Ca2+ exchanger NCX1 than resistant TNBC cells. This suggests that NCX1 could be a biomarker to identify TNBC patients that might benefit from the clinical administration of a cardiac glycoside for anticancer indications.
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Affiliation(s)
- Petra J Pederson
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
- Mays Cancer Center, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Shengxin Cai
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Chase Carver
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Douglas R Powell
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - April L Risinger
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
- Mays Cancer Center, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Tanja Grkovic
- Natural Products Support Group, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Barry R O'Keefe
- Natural Products Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Frederick, Maryland 21702, United States
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Susan L Mooberry
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
- Mays Cancer Center, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Robert H Cichewicz
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
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32
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Klimanova EA, Fedorov DA, Sidorenko SV, Abramicheva PA, Lopina OD, Orlov SN. Ouabain and Marinobufagenin: Physiological Effects on Human Epithelial and Endothelial Cells. BIOCHEMISTRY (MOSCOW) 2020; 85:507-515. [PMID: 32569558 DOI: 10.1134/s0006297920040112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Long-term study on the identification of Na,K-ATPase endogenous inhibitors in mammalian tissues has resulted in the discovery of ouabain, marinobufagenin (MBG), and other cardiotonic steroids (CTS) in the blood plasma. Production of ouabain and MBG is increased in essential hypertension and other diseases associated with hypervolemia. Here, we compared the effects of ouabain and MBG on the Na,K-ATPase activity (measured as the transport of Na+, K+, and Rb+ ions) and proliferation and death of human renal epithelial cells (HRECs) and human umbilical vein endothelial cells (HUVEC) expressing α1-Na,K-ATPase. Ouabain concentration that provided the half-maximal inhibition of the Rb+ influx (IC50) into HRECs and HUVECs was 0.07 μM. In both types of cells, the IC50 values for MBG were 10 times higher than for ouabain. Incubation of HREC and HUVEC with 0.001-0.01 μM ouabain for 30 h resulted in 40% increase in the [3H]thymidine incorporation into DNA; further elevation of ouabain concentration to 0.1 μM completely suppressed DNA synthesis. MBG at the concentration of 0.1 μM activated DNA synthesis by 25% in HRECs, but not in HUVECs; 1 μM MBG completely inhibited DNA synthesis in HRECs and by 50% in HUVECs. In contrast to HRECs, incubation of HUVECs in the serum-free medium induced apoptosis, which was almost completely suppressed by ouabain and MBG at the concentrations of 0.1 and 3 μM, respectively. Based on these data, we can conclude that (i) the effect of MBG at the concentrations detected in the blood plasma (<0.01 μM) on HRECs and HUVECs was not due to the changes in the [Na+]i/[K+]i ratio; (ii) the effect of physiological concentrations of ouabain on these cells might be mediated by the activation of Na,K-ATPase, leading to cell proliferation.
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Affiliation(s)
- E A Klimanova
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia.
| | - D A Fedorov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - S V Sidorenko
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - P A Abramicheva
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - O D Lopina
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
| | - S N Orlov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119234, Russia
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Slenter IJM, Djajadiningrat-Laanen SC, de Vries I, Dijkman MA. Intoxication with Ornithogalum arabicum is a potential cause of visual impairment and irreversible blindness in dogs. Toxicon X 2020; 4:100014. [PMID: 32550571 PMCID: PMC7286106 DOI: 10.1016/j.toxcx.2019.100014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/21/2019] [Accepted: 09/01/2019] [Indexed: 01/04/2023] Open
Abstract
We describe two dogs with persistent visual impairment after initially mild intoxication signs following ingestion of Ornithogalum arabicum plant material. Additionally, a 12-year analysis of the Dutch Poisons Information Centre database additionally reveals that ingestion of Ornithogalum plant material can be potentially life-threatening to companion animals. Further studies are necessary to confirm the involvement of cardiac glycoside-like toxins present in Ornithogalum arabicum and the toxicity of these substances to the retina. Intoxication with Ornithogalum arabicum leads to visual impairment and irreversible blindness in dogs. Intoxication with Ornithogalum arabicum may be life-threatening in companion animals. Ornithogalum arabicum and other species are suspected to contain heart glycosides.
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Affiliation(s)
- Inge J M Slenter
- Ophthalmology Section, Department of Clinical Sciences of Companion Animals, Utrecht University, the Netherlands
| | | | - Irma de Vries
- Dutch Poisons Information Centre (DPIC), University Medical Centre Utrecht, Utrecht University, the Netherlands
| | - Marieke A Dijkman
- Dutch Poisons Information Centre (DPIC), University Medical Centre Utrecht, Utrecht University, the Netherlands
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Cardiac glycosides with target at direct and indirect interactions with nuclear receptors. Biomed Pharmacother 2020; 127:110106. [PMID: 32248001 DOI: 10.1016/j.biopha.2020.110106] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/15/2022] Open
Abstract
Cardiac glycosides are compounds isolated from plants and animals and have been known since ancient times. These compounds inhibit the activity of the sodium potassium pump in eukaryotic cells. Cardiac glycosides were used as drugs in heart ailments to increase myocardial contraction force and, at the same time, to lower frequency of this contraction. An increasing number of studies have indicated that the biological effects of these compounds are not limited to inhibition of sodium-potassium pump activity. Furthermore, an increasing number of data have shown that they are synthesized in tissues of mammals, where they may act as a new class of steroid hormones or other hormones by mimicry to modulate various signaling pathways and influence whole organisms. Thus, we discuss the interactions of cardiac glycosides with the nuclear receptor superfamily of transcription factors activated by low-weight molecular ligands (including hormones) that regulate many functions of cells and organisms. Cardiac glycosides of endogenous and exogenous origin by interacting with nuclear receptors can affect the processes regulated by these transcription factors, including hormonal management, immune system, body defense, and carcinogenesis. They can also be treated as initial structures for combinatorial chemistry to produce new compounds (including drugs) with the desired properties.
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Influence of Endogenous Cardiac Glycosides, Digoxin, and Marinobufagenin in the Physiology of Epithelial Cells. Cardiol Res Pract 2019; 2019:8646787. [PMID: 32089875 PMCID: PMC7024086 DOI: 10.1155/2019/8646787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/20/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
Cardiac glycosides are a group of compounds widely known for their action in cardiac tissue, some of which have been found to be endogenously produced (ECG). We have previously studied the effect of ouabain, an endogenous cardiac glycoside, on the physiology of epithelial cells, and we have shown that in concentrations in the nanomolar range, it affects key properties of epithelial cells, such as tight junction, apical basolateral polarization, gap junctional intercellular communication (GJIC), and adherent junctions. In this work, we study the influence of digoxin and marinobufagenin, two other endogenously expressed cardiac glycosides, on GJIC as well as the degree of transepithelial tightness due to tight junction integrity (TJ). We evaluated GJIC by dye transfer assays and tight junction integrity by transepithelial electrical resistance (TER) measurements, as well as immunohistochemistry and western blot assays of expression of claudins 2 and 4. We found that both digoxin and marinobufagenin improve GJIC and significantly enhance the tightness of the tight junctions, as evaluated from TER measurements. Immunofluorescence assays show that both compounds promote enhanced basolateral localization of claudin-4 but not claudin 2, while densitometric analysis of western blot assays indicate a significantly increased expression of claudin 4. These changes, induced by digoxin and marinobufagenin on GJIC and TER, were not observed on MDCK-R, a modified MDCK cell line that has a genetically induced insensitive α1 subunit, indicating that Na-K-ATPase acts as a receptor mediating the actions of both ECG. Plus, the fact that the effect of both cardiac glycosides was suppressed by incubation with PP2, an inhibitor of c-Src kinase, PD98059, an inhibitor of mitogen extracellular kinase-1 and Y-27632, a selective inhibitor of ROCK, and a Rho-associated protein kinase, indicate altogether that the signaling pathways involved include c-Src and ERK1/2, as well as Rho-ROCK. These results widen and strengthen our general hypothesis that a very important physiological role of ECG is the control of the epithelial phenotype and the regulation of cell-cell contacts.
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Michalak K, Rárová L, Kubala M, Čechová P, Strnad M, Wicha J. Synthesis and evaluation of cytotoxic and Na+/K+-ATP-ase inhibitory activity of selected 5α-oleandrigenin derivatives. Eur J Med Chem 2019; 180:417-429. [DOI: 10.1016/j.ejmech.2019.07.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/08/2019] [Accepted: 07/08/2019] [Indexed: 12/28/2022]
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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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Zatloukalova M, Nazaruk E, Bilewicz R. Electrogenic transport of Na+/K+-ATPase incorporated in lipidic cubic phases as a model biomimetic membrane. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.04.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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39
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Huang W, Wen C, Zhou Z, Fu Z, Katz A, Plotnikov A, Karlish SJD, Jiang R. An Efficient One‐Pot Enzymatic Synthesis of Cardiac Glycosides with Varied Sugar Chain Lengths. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900227] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Wei Huang
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, and International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of EducationJinan University Guangzhou 510632 People's Republic of China
| | - Chao Wen
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, and International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of EducationJinan University Guangzhou 510632 People's Republic of China
| | - Zhen‐Ru Zhou
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, and International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of EducationJinan University Guangzhou 510632 People's Republic of China
| | - Zhi‐Hao Fu
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, and International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of EducationJinan University Guangzhou 510632 People's Republic of China
| | - Adriana Katz
- Department of Biomolecular SciencesWeizmann Institute of Science Rehovot Israel
| | - Alexander Plotnikov
- Department of Biomolecular SciencesWeizmann Institute of Science Rehovot Israel
| | | | - Ren‐Wang Jiang
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, and International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of EducationJinan University Guangzhou 510632 People's Republic of China
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40
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Potential anti-herpes and cytotoxic action of novel semisynthetic digitoxigenin-derivatives. Eur J Med Chem 2019; 167:546-561. [DOI: 10.1016/j.ejmech.2019.01.076] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 09/05/2018] [Accepted: 01/29/2019] [Indexed: 11/17/2022]
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41
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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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42
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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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44
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Ding B, Walton JP, Zhu X, Frisina RD. Age-related changes in Na, K-ATPase expression, subunit isoform selection and assembly in the stria vascularis lateral wall of mouse cochlea. Hear Res 2018; 367:59-73. [PMID: 30029086 DOI: 10.1016/j.heares.2018.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/02/2018] [Accepted: 07/06/2018] [Indexed: 11/26/2022]
Abstract
Due to the critical role of cochlear ion channels for hearing, the focus of the present study was to examine age-related changes of Na, K-ATPase (NKA) subunits in the lateral wall of mouse cochlea. We combined qRT-PCR, western blot and immunocytochemistry methodologies in order to determine gene and protein expression levels in the lateral wall of young and aged CBA/CaJ mice. Of the seven NKA subunits, only the mRNA expressions of α1, β1 and β2 subunit isoforms were detected in the lateral wall of CBA/CaJ mice. Aging was accompanied by dys-regulation of gene and protein expression of all three subunits detected. Hematoxylin and eosin (H&E) staining revealed atrophy of the cochlear stria vascularis (SV). The SV atrophy rate (20%) was much less than the ∼80% decline in expression of all three NKA isoforms, indicating lateral wall atrophy and NKA dys-regulation are independent factors and that there is a combination of changes involving the morphology of SV and NKA expression in the aging cochlea which may concomitantly affect cochlear function. Immunoprecipitation assays showed that the α1-β1 heterodimer is the selective preferential heterodimer over the α1-β2 heterodimer in cochlea lateral wall. Interestingly, in vitro pathway experiments utilizing cultured mouse cochlear marginal cells from the SV (SV-K1 cells) indicated that decreased mRNA and protein expressions of α1, β1 and β2 subunit isoforms are not associated with reduction of NKA activity following in vitro application of ouabain, but ouabain did disrupt the α1-β1 heterodimer interaction. Lastly, the association between the α1 and β1 subunit isoforms was present in the cochlear lateral wall of young adult mice, but this interaction could not be detected in old mice. Taken together, these data suggest that in the young adult mouse there is a specific, functional selection and assembly of NKA subunit isoforms in the SV lateral wall, which is disrupted and dys-regulated with age. Interventions for this age-linked ion channel disruption may have the potential to help diagnose, prevent, or treat age-related hearing loss.
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Affiliation(s)
- Bo Ding
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| | - Joseph P Walton
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA.
| | - Xiaoxia Zhu
- Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| | - Robert D Frisina
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Medical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
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45
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Guo J, Jiang R, Andersen JL, Esmann M, Fedosova NU. Spin‐labeled derivatives of cardiotonic steroids as tools for characterization of the extracellular entrance to the binding site on Na
+
,K
+
‐
ATP
ase. FEBS J 2018; 285:2292-2305. [DOI: 10.1111/febs.14480] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 03/13/2018] [Accepted: 04/18/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Jin‐Hua Guo
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research College of Pharmacy Jinan University Guangzhou City Guangdong Province China
| | - Ren‐Wang Jiang
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research College of Pharmacy Jinan University Guangzhou City Guangdong Province China
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Lenaerts C, Bond L, Tuytten R, Blankert B. Revealing of endogenous Marinobufagin by an ultra-specific and sensitive UHPLC-MS/MS assay in pregnant women. Talanta 2018; 187:193-199. [PMID: 29853035 DOI: 10.1016/j.talanta.2018.05.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 01/24/2023]
Abstract
Marinobufagenin (MBG) is a bufadienolide cardiac inotrope implicated in volume expansion-mediated hypertensive states including essential hypertension and preeclampsia (PE). Endogenous MBG is an inhibitor of the α1-isoform of Na+,K+-ATPase with vasoconstrictive and cardiotonic properties, causing hypertension and natriuresis. Elevated endogenous MBG-like material levels have been described by immunoassays in salt-sensitive pregnant and preeclamptic rats as well as in preeclamptic human patients. The rise of endogenous MBG-like material appears prior the development of the main symptoms of PE, leading us to consider MBG as one of the potential biomarkers for PE. The weak specificity and the high variability of the published immunoassays gives no certification about endogenous MBG existence. This led us to set-up a highly specific and sensitive analytical method to detect MBG in plasma at low levels relying on liquid chromatography combined to mass spectrometry (UHPLC-MS/MS) with recording of 7 highly specific MRM transitions for MBG. Pure MBG standard used in the method development was obtained by purification from the Bufo marinus toad venom. d3-25-hydroxyvitamin D3 was used as internal standard. An increasing organic gradient with mobile phase A and B composed of 97:3 (v/v) H2O: MeOH and 50:45:5 (v/v/v) MeOH:IPA:H2O at pH 4.5 respectively was used on a Pursuit 3 PFP column (100 mm × 3 mm; 3 µm) to allow elution and separation of the plasmatic compounds. Chromatographic analyses of plasma samples were preceded by a precipitation of proteins pretreatment. The developed UHPLC-MS/MS assay has been applied to early-pregnant women plasma samples allowing us to investigate MBG plasma levels. Thanks to the high specificity of the assay we were able to authenticate and certify the presence of endogenous MBG in early-pregnant women plasma with the use of the 7 selected specific mass transitions. These pioneering preliminary results are giving a promising perspective for early preeclampsia risk assessment in pregnant women.
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Affiliation(s)
- Charline Lenaerts
- Laboratory of Pharmaceutical Analysis, Faculty of medicine and pharmacy, Research Institute for Health Sciences and Technology, University of Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Liz Bond
- Metabolomic Diagnostics, Little Island, Cork, Ireland
| | - Robin Tuytten
- Metabolomic Diagnostics, Little Island, Cork, Ireland
| | - Bertrand Blankert
- Laboratory of Pharmaceutical Analysis, Faculty of medicine and pharmacy, Research Institute for Health Sciences and Technology, University of Mons, Place du Parc 20, 7000 Mons, Belgium.
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Lopachev AV, Abaimov DA, Fedorova TN, Lopacheva OM, Akkuratova NV, Akkuratov EE. Cardiotonic Steroids as Potential Endogenous Regulators in the Nervous System. NEUROCHEM J+ 2018. [DOI: 10.1134/s1819712418010087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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48
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Lopachev AV, Lopacheva OM, Nikiforova KA, Filimonov IS, Fedorova TN, Akkuratov EE. Comparative Action of Cardiotonic Steroids on Intracellular Processes in Rat Cortical Neurons. BIOCHEMISTRY (MOSCOW) 2018; 83:140-151. [DOI: 10.1134/s0006297918020062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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49
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Zhu XL, Wen C, Ye QM, Xu W, Zou DL, Liang GP, Zhang F, Chen WN, Jiang RW. Probing the stereoselectivity of OleD-catalyzed glycosylation of cardiotonic steroids. RSC Adv 2018; 8:5071-5078. [PMID: 35542447 PMCID: PMC9078122 DOI: 10.1039/c7ra11979h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/16/2018] [Indexed: 01/26/2023] Open
Abstract
The glycosyltransferase OleD variant as a catalyst for the glycosylation of four pairs of epimers of cardiotonic steroids (CTS) are assessed. The results of this study demonstrated that the OleD-catalyze glycosylation of CTS is significantly influenced by the configuration at C-3 and the A/B fusion mode. 3β-OH and A/B ring cis fusion are favoured by OleD (ASP). An epoxide ring at C-14 and C-15 further increases the bioconversion rate; while an acetyl group at C-16 and lactone ring type at C-17 did not influence the biotransformation. A high conversion rate corresponded to a low K m value. A molecular docking simulation showed that filling of hydrophobic pocket II and interaction with residue Tyr115 may play an important role in the glycosylation reactions catalyzed by OleD glycosyltransferases. Furthermore, the glycosylation products showed a stronger inhibitory activity for Na+, K+-ATPase than the corresponding aglycones. This study provides the first stereoselective properties for OleD (ASP) catalyzed glycosylation.
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Affiliation(s)
- Xue-Lin Zhu
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Chao Wen
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Qing-Mei Ye
- Department of Pharmacy, Hainan General Hospital Haikou 570311 P. R. China
| | - Wei Xu
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Deng-Lang Zou
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Guang-Ping Liang
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Fan Zhang
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Wan-Na Chen
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
| | - Ren-Wang Jiang
- Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University Guangzhou 510632 P. R. China
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50
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Wong RW, Lingwood CA, Ostrowski MA, Cabral T, Cochrane A. Cardiac glycoside/aglycones inhibit HIV-1 gene expression by a mechanism requiring MEK1/2-ERK1/2 signaling. Sci Rep 2018; 8:850. [PMID: 29339801 PMCID: PMC5770468 DOI: 10.1038/s41598-018-19298-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 11/07/2017] [Indexed: 12/14/2022] Open
Abstract
The capacity of HIV-1 to develop resistance to current drugs calls for innovative strategies to control this infection. We aimed at developing novel inhibitors of HIV-1 replication by targeting viral RNA processing—a stage dependent on conserved host processes. We previously reported that digoxin is a potent inhibitor of this stage. Herein, we identify 12 other cardiac glycoside/aglycones or cardiotonic steroids (CSs) that impede HIV growth in HIV-infected T cells from clinical patients at IC50s (1.1–1.3 nM) that are 2–26 times below concentrations used in patients with heart conditions. We subsequently demonstrate that CSs inhibit HIV-1 gene expression in part through modulation of MEK1/2-ERK1/2 signaling via interaction with the Na+/K+-ATPase, independent of alterations in intracellular Ca2+. Supporting this hypothesis, depletion of the Na+/K+-ATPase or addition of a MEK1/2-ERK1/2 activator also impairs HIV-1 gene expression. Similar to digoxin, all CSs tested induce oversplicing of HIV-1 RNAs, reducing unspliced (Gag) and singly spliced RNAs (Env/p14-Tat) encoding essential HIV-1 structural/regulatory proteins. Furthermore, all CSs cause nuclear retention of genomic/unspliced RNAs, supporting viral RNA processing as the underlying mechanism for their disruption of HIV-1 replication. These findings call for further in vivo validation and supports the targeting of cellular processes to control HIV-1 infection.
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Affiliation(s)
- Raymond W Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Clifford A Lingwood
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S1A8, Canada.,Division of Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, M5G1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S1A8, Canada
| | - Mario A Ostrowski
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital Toronto, Toronto, ON, M5B1W8, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, M5S1A8, Canada.,Department of Immunology, University of Toronto, Toronto, ON, M5S1A8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Tyler Cabral
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Alan Cochrane
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S1A8, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada.
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