201
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Venugopal J, McDermott J, Sanchez G, Sharma M, Barbosa L, Reif GA, Wallace DP, Blanco G. Ouabain promotes partial epithelial to mesenchymal transition (EMT) changes in human autosomal dominant polycystic kidney disease (ADPKD) cells. Exp Cell Res 2017; 355:142-152. [PMID: 28385574 DOI: 10.1016/j.yexcr.2017.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/31/2017] [Accepted: 04/01/2017] [Indexed: 12/13/2022]
Abstract
The hormone ouabain has been shown to enhance the cystic phenotype of autosomal dominant polycystic kidney disease (ADPKD). Among other characteristics, the ADPKD phenotype includes cell de-differentiation and epithelial to mesenchymal transition (EMT). Here, we determined whether physiological concentrations of ouabain induces EMT in human renal epithelial cells from patients with ADPKD. We found that ADPKD cells respond to ouabain with a decrease in expression of the epithelial marker E-cadherin and increase in the expression of the mesenchymal markers N-cadherin, α smooth muscle actin (αSMA) and collagen-I; and the tight junction protein occludin and claudin-1. Other adhesion molecules, such as ZO-1, β-catenin and vinculin were not significantly modified by ouabain. At the cellular level, ouabain stimulated ADPKD cell migration, reduced cell-cell interaction, and the ability of ADPKD cells to form aggregates. Moreover, ouabain increased the transepithelial electrical resistance of ADPKD cell monolayers, suggesting that the paracellular transport pathway was preserved in the cells. These effects of ouabain were not observed in normal human kidney (NHK) cells. Altogether these results show a novel role for ouabain in ADPKD, inducing changes that lead to a partial EMT phenotype in the cells. These effects further support the key role that ouabain has as a factor that promotes the cystic characteristics of ADPKD cells.
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Affiliation(s)
- Jessica Venugopal
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Jeffrey McDermott
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Gladis Sanchez
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Madhulika Sharma
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Leandro Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Divinopolis, Brazil
| | - Gail A Reif
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Darren P Wallace
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - Gustavo Blanco
- Departments of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States; The Kidney Institute, University of Kansas Medical Center, Kansas City, Kansas, United States.
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202
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Klimanova EA, Tverskoi AM, Koltsova SV, Sidorenko SV, Lopina OD, Tremblay J, Hamet P, Kapilevich LV, Orlov SN. Time- and dose dependent actions of cardiotonic steroids on transcriptome and intracellular content of Na + and K +: a comparative analysis. Sci Rep 2017; 7:45403. [PMID: 28345607 PMCID: PMC5366943 DOI: 10.1038/srep45403] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/17/2017] [Indexed: 01/07/2023] Open
Abstract
Recent studies demonstrated that in addition to Na+,K+-ATPase inhibition cardiotonic steroids (CTSs) affect diverse intracellular signaling pathways. This study examines the relative impact of [Na+]i/[K+]i-mediated and -independent signaling in transcriptomic changes triggered by the endogenous CTSs ouabain and marinobufagenin (MBG) in human umbilical vein endothelial cells (HUVEC). We noted that prolongation of incubation increased the apparent affinity for ouabain estimated by the loss of [K+]i and gain of [Na+]i. Six hour exposure of HUVEC to 100 and 3,000 nM ouabain resulted in elevation of the [Na+]i/[K+]i ratio by ~15 and 80-fold and differential expression of 258 and 2185 transcripts, respectively. Neither [Na+]i/[K+]i ratio nor transcriptome were affected by 6-h incubation with 30 nM ouabain. The 96-h incubation with 3 nM ouabain or 30 nM MBG elevated the [Na+]i/[K+]i ratio by ~14 and 3-fold and led to differential expression of 880 and 484 transcripts, respectively. These parameters were not changed after 96-h incubation with 1 nM ouabain or 10 nM MBG. Thus, our results demonstrate that elevation of the [Na+]i/[K+]i ratio is an obligatory step for transcriptomic changes evoked by CTS in HUVEC. The molecular origin of upstream [Na+]i/[K+]i sensors involved in transcription regulation should be identified in forthcoming studies.
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Affiliation(s)
| | - Artem M Tverskoi
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Svetlana V Koltsova
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Svetlana V Sidorenko
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Olga D Lopina
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Johanne Tremblay
- Research Centre, University of Montreal Hospital (CRCHUM), Montreal, H2X 0A9, Canada
| | - Pavel Hamet
- Research Centre, University of Montreal Hospital (CRCHUM), Montreal, H2X 0A9, Canada
| | | | - Sergei N Orlov
- Faculty of Biology, M. V. Lomonosov Moscow State University, Moscow, 119234, Russia.,National Research Tomsk State University, Tomsk, 634050, Russia
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203
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Landfried B, Samardzija M, Barben M, Schori C, Klee K, Storti F, Grimm C. Digoxin-induced retinal degeneration depends on rhodopsin. Cell Death Dis 2017; 8:e2670. [PMID: 28300845 PMCID: PMC5386584 DOI: 10.1038/cddis.2017.94] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 02/09/2017] [Accepted: 02/10/2017] [Indexed: 12/13/2022]
Abstract
Na,K-ATPases are energy consuming ion pumps that are required for maintaining ion homeostasis in most cells. In the retina, Na,K-ATPases are especially important to sustain the dark current in photoreceptor cells needed for rapid hyperpolarization of rods and cones in light. Cardiac glycosides like digoxin inhibit the activity of Na,K-ATPases by targeting their catalytic alpha subunits. This leads to a disturbed ion balance, which can affect cellular function and survival. Here we show that the treatment of wild-type mice with digoxin leads to severe retinal degeneration and loss of vision. Digoxin induced cell death specifically in photoreceptor cells with no or only minor effects in other retinal cell types. Photoreceptor-specific cytotoxicity depended on the presence of bleachable rhodopsin. Photoreceptors of Rpe65 knockouts, which have no measurable rhodopsin and photoreceptors of Rpe65R91W mice that have <10% of the rhodopsin found in retinas of wild-type mice were not sensitive to digoxin treatment. Similarly, cones in the all-cone retina of Nrl knockout mice were also not affected. Digoxin induced expression of several genes involved in stress signaling and inflammation. It also activated proteins such as ERK1/2, AKT, STAT1, STAT3 and CASP1 during a period of up to 10 days after treatment. Activation of signaling genes and proteins, as well as the dependency on bleachable rhodopsin resembles mechanisms of light-induced photoreceptor degeneration. Digoxin-mediated photoreceptor cell death may thus be used as an inducible model system to study molecular mechanisms of retinal degeneration.
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Affiliation(s)
- Britta Landfried
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland
| | - Marijana Samardzija
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland
| | - Maya Barben
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland.,Neuroscience Center Zürich (ZNZ), University of Zürich, Zürich, Switzerland
| | - Christian Schori
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
| | - Katrin Klee
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
| | - Federica Storti
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland
| | - Christian Grimm
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zürich, Zürich, Switzerland.,Neuroscience Center Zürich (ZNZ), University of Zürich, Zürich, Switzerland.,Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland
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204
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Liu J, Yan Y, Nie Y, Shapiro JI. Na/K-ATPase Signaling and Salt Sensitivity: The Role of Oxidative Stress. Antioxidants (Basel) 2017; 6:E18. [PMID: 28257114 PMCID: PMC5384181 DOI: 10.3390/antiox6010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/10/2017] [Accepted: 02/22/2017] [Indexed: 02/07/2023] Open
Abstract
Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Yanling Yan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Ying Nie
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA.
| | - Joseph I Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
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205
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Fan X, Xie J, Tian J. Reducing Cardiac Fibrosis: Na/K-ATPase Signaling Complex as a Novel Target. ACTA ACUST UNITED AC 2017; 6. [PMID: 29034264 DOI: 10.4172/2329-6607.1000204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cardiac fibrosis is a common pathological process in cardiac disease and may lead to heart failure. It can also cause sudden death even in those without cardiac symptoms. Tissue fibrosis can be categorized into two categories: replacement fibrosis (also called reparative fibrosis) and reactive fibrosis. In replacement fibrosis, infiltration of inflammatory cells and accumulation of Extracellular Matrix (ECM) proteins are the initial steps in forming scarlike fibrotic tissue after acute cardiac injury and cardiac cell necrosis. Reactive fibrosis can be formed in response to hormonal change and pressure or volume overload. Experimental studies in animals have identified important pathways such as the Renin-Angiotensin-Aldosterone System (RAAS) and the endothelin pathway that contribute to fibrosis formation. Despite the fact that clinical trials using RAAS inhibitors as therapies for reducing cardiac fibrosis and improving cardiac function have been promising, heart failure is still the leading cause of deaths in the United States. Intensive efforts have been made to find novel targets and to develop new treatments for cardiac fibrosis and heart failure in the past few decades. The Na/K-ATPase, a canonical ion transporter, has been shown to also function as a signal transducer and prolonged activation of Na/K-ATPase signaling has been found to promote the formation of cardiac fibrosis. Novel tools that block the activation of Na/K-ATPase signaling have been developed and have shown promise in reducing cardiac fibrosis. This review will discuss the recent development of novel molecular targets, focusing on the Na/K-ATPase signaling complex as a therapeutic target in treatment of cardiac fibrosis.
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Affiliation(s)
- X Fan
- Department of Medicine, Center for Hypertension and Personalized Medicine, University of Toledo, Ohio 43614, USA
| | - J Xie
- Department of Medicine, Center for Hypertension and Personalized Medicine, University of Toledo, Ohio 43614, USA
| | - J Tian
- Department of Medicine, Center for Hypertension and Personalized Medicine, University of Toledo, Ohio 43614, USA
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206
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Bufadienolides from amphibians: A promising source of anticancer prototypes for radical innovation, apoptosis triggering and Na +/K +-ATPase inhibition. Toxicon 2017; 127:63-76. [PMID: 28069354 DOI: 10.1016/j.toxicon.2017.01.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/27/2016] [Accepted: 01/05/2017] [Indexed: 12/22/2022]
Abstract
Amphibians present pharmacologically active aliphatic, aromatic and heterocyclic molecules in their skin as defense against microorganisms, predators and infections, such as steroids, alkaloids, biogenic amines, guanidine derivatives, proteins and peptides. Based on the discovered bioactive potential of bufadienolides, this work reviewed the contribution of amphibians, especially from members of Bufonidae family, as source of new cytotoxic and antitumor molecules, highlighting the mechanisms responsible for such amazing biological potentialities. Bufonidae species produce bufadienolides related to cholesterol through the mevalonate-independent and acidic bile acid pathways as polyhydroxy steroids with 24 carbons. In vitro antitumor studies performed with skin secretions and its isolated components (specially marinobufagin, telocinobufagin, bufalin and cinobufagin) from Rhinella, Bufo and Rhaebo species have shown remarkable biological action on hematological, solid, sensitive and/or resistant human tumor cell lines. Some compounds revealed higher selectivity against neoplastic lines when compared to dividing normal cells and some molecules may biochemically associate with Na+/K+-ATPase and there is structural similarity to the digoxin- and ouabain-Na+/K+-ATPase complexs, implying a similar mechanism of the Na+/K+-ATPase inhibition by cardenolides and bufadienolides. Some bufadienolides also reduce levels of antiapoptotic proteins and DNA synthesis, cause morphological changes (chromatin condensation, nuclear fragmentation, cytoplasm shrinkage, cytoplasmic vacuoles, stickiness reduction and apoptotic bodies), cell cycle arrest in G2/M or S phases, mitochondrial depolarization, PARP [poly (ADPribose) polymerase] and Bid cleavages, cytochrome c release, activation of Bax and caspases (-3, -9, -8 and -10), increased expression of the Fas-Associated protein with Death Domain (FADD), induce topoisomerase II inhibition, DNA fragmentation, cell differentiation, angiogenesis inhibition, multidrug resistance reversion, and also regulate immune responses. Then, bufadienolides isolated from amphibians, some of them at risk of extinction, emerge as a natural class of incredible chemical biodiversity, has moderate selectivity against human tumor cells and weak activity on murine cells, probably due to structural differences between subunits of human and mice Na+/K+-ATPases.
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207
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Abstract
Significant hemodynamic changes ensue with aging, leading to an ever-growing epidemic of hypertension. Alterations in central arterial properties play a major role in these hemodynamic changes. These alterations are characterized by an initial decline in aortic distensibility and an increase of diastolic blood pressure, followed by a sharp increase in pulse wave velocity (PWV), and an increase in pulse pressure (PP) beyond the sixth decade. However, the trajectories of PWV and PP diverge with advancing age. There is an increased prevalence of salt-sensitive hypertension with advancing age that is, in part, mediated by marinobufagenin, an endogenous sodium pump ligand.
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Affiliation(s)
- Majd AlGhatrif
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA; Department of Medicine, Johns Hopkins Bayview Medical Center, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA
| | - Olga V Fedorova
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA
| | - Alexei Y Bagrov
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, NIA, NIH, Baltimore, MD, USA.
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208
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Buchanan C, Mohammed A, Cox E, Köhler K, Canaud B, Taal MW, Selby NM, Francis S, McIntyre CW. Intradialytic Cardiac Magnetic Resonance Imaging to Assess Cardiovascular Responses in a Short-Term Trial of Hemodiafiltration and Hemodialysis. J Am Soc Nephrol 2016; 28:1269-1277. [PMID: 28122851 DOI: 10.1681/asn.2016060686] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/11/2016] [Indexed: 12/15/2022] Open
Abstract
Hemodynamic stress during hemodialysis (HD) results in recurrent segmental ischemic injury (myocardial stunning) that drives cumulative cardiac damage. We performed a fully comprehensive study of the cardiovascular effect of dialysis sessions using intradialytic cardiac magnetic resonance imaging (MRI) to examine the comparative acute effects of standard HD versus hemodiafiltration (HDF) in stable patients. We randomly allocated 12 patients on HD (ages 32-72 years old) to either HD or HDF. Patients were stabilized on a modality for 2 weeks before undergoing serial cardiac MRI assessment during dialysis. Patients then crossed over to the other modality and were rescanned after 2 weeks. Cardiac MRI measurements included cardiac index, stroke volume index, global and regional contractile function (myocardial strain), coronary artery flow, and myocardial perfusion. Patients had mean±SEM ultrafiltration rates of 3.8±2.9 ml/kg per hour during HD and 4.4±2.5 ml/kg per hour during HDF (P=0.29), and both modalities provided a similar degree of cooling. All measures of systolic contractile function fell during HD and HDF, with partial recovery after dialysis. All patients experienced some degree of segmental left ventricular dysfunction, with severity proportional to ultrafiltration rate and BP reduction. Myocardial perfusion decreased significantly during HD and HDF. Treatment modality did not influence any of the cardiovascular responses to dialysis. In conclusion, in this randomized, crossover study, there was no significant difference in the cardiovascular response to HDF or HD with cooled dialysate as assessed with intradialytic MRI.
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Affiliation(s)
| | - Azharuddin Mohammed
- Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, University of Nottingham, Nottingham, United Kingdom
| | | | - Katrin Köhler
- Center of Excellence Medical Europe, Middle East and Africa, Fresenius Medical Care, Bad Homburg, Germany; and
| | - Bernard Canaud
- Center of Excellence Medical Europe, Middle East and Africa, Fresenius Medical Care, Bad Homburg, Germany; and
| | - Maarten W Taal
- Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Nicholas M Selby
- Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, University of Nottingham, Nottingham, United Kingdom
| | | | - Chris W McIntyre
- Departments of Medicine and .,Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Canada
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209
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Drummond CA, Crotty Alexander LE, Haller ST, Fan X, Xie JX, Kennedy DJ, Liu J, Yan Y, Hernandez DA, Mathew DP, Cooper CJ, Shapiro JI, Tian J. Cigarette smoking causes epigenetic changes associated with cardiorenal fibrosis. Physiol Genomics 2016; 48:950-960. [PMID: 27789733 DOI: 10.1152/physiolgenomics.00070.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 10/22/2016] [Indexed: 12/14/2022] Open
Abstract
Clinical studies indicate that smoking combustible cigarettes promotes progression of renal and cardiac injury, leading to functional decline in the setting of chronic kidney disease (CKD). However, basic studies using in vivo small animal models that mimic clinical pathology of CKD are lacking. To address this issue, we evaluated renal and cardiac injury progression and functional changes induced by 4 wk of daily combustible cigarette smoke exposure in the 5/6th partial nephrectomy (PNx) CKD model. Molecular evaluations revealed that cigarette smoke significantly (P < 0.05) decreased renal and cardiac expression of the antifibrotic microRNA miR-29b-3 and increased expression of molecular fibrosis markers. In terms of cardiac and renal organ structure and function, exposure to cigarette smoke led to significantly increased systolic blood pressure, cardiac hypertrophy, cardiac and renal fibrosis, and decreased renal function. These data indicate that decreased expression of miR-29b-3p is a novel mechanism wherein cigarette smoke promotes accelerated cardiac and renal tissue injury in CKD. (155 words).
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Affiliation(s)
- Christopher A Drummond
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio;
| | - Laura E Crotty Alexander
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System and Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego Health Sciences, San Diego, California; and
| | - Steven T Haller
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio
| | - Xiaoming Fan
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio
| | - Jeffrey X Xie
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio
| | - David J Kennedy
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio
| | - Jiang Liu
- Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia
| | - Yanling Yan
- Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia
| | - Dawn-Alita Hernandez
- Division of Pulmonary Medicine (Critical Care and Sleep Medicine), University of Toledo, Toledo, Ohio
| | - Denzil P Mathew
- Pulmonary Critical Care Section, Veterans Affairs San Diego Healthcare System and Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego Health Sciences, San Diego, California; and
| | - Christopher J Cooper
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio
| | - Joseph I Shapiro
- Joan C. Edwards School of Medicine, Marshall University, Huntington, West Virginia
| | - Jiang Tian
- College of Medicine and Life Sciences, Department of Medicine, Division of Cardiovascular Medicine and Center for Hypertension and Personalized Medicine, University of Toledo, Toledo, Ohio
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210
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Haller ST, Yan Y, Drummond CA, Xie J, Tian J, Kennedy DJ, Shilova VY, Xie Z, Liu J, Cooper CJ, Malhotra D, Shapiro JI, Fedorova OV, Bagrov AY. Rapamycin Attenuates Cardiac Fibrosis in Experimental Uremic Cardiomyopathy by Reducing Marinobufagenin Levels and Inhibiting Downstream Pro-Fibrotic Signaling. J Am Heart Assoc 2016; 5:JAHA.116.004106. [PMID: 27694325 PMCID: PMC5121507 DOI: 10.1161/jaha.116.004106] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Experimental uremic cardiomyopathy causes cardiac fibrosis and is causally related to the increased circulating levels of the cardiotonic steroid, marinobufagenin (MBG), which signals through Na/K-ATPase. Rapamycin is an inhibitor of the serine/threonine kinase mammalian target of rapamycin (mTOR) implicated in the progression of many different forms of renal disease. Given that Na/K-ATPase signaling is known to stimulate the mTOR system, we speculated that the ameliorative effects of rapamycin might influence this pathway. METHODS AND RESULTS Biosynthesis of MBG by cultured human JEG-3 cells is initiated by CYP27A1, which is also a target for rapamycin. It was demonstrated that 1 μmol/L of rapamycin inhibited production of MBG in human JEG-2 cells. Male Sprague-Dawley rats were subjected to either partial nephrectomy (PNx), infusion of MBG, and/or infusion of rapamycin through osmotic minipumps. PNx animals showed marked increase in plasma MBG levels (1025±60 vs 377±53 pmol/L; P<0.01), systolic blood pressure (169±1 vs 111±1 mm Hg; P<0.01), and cardiac fibrosis compared to controls. Plasma MBG levels were significantly decreased in PNx-rapamycin animals compared to PNx (373±46 vs 1025±60 pmol/L; P<0.01), and cardiac fibrosis was substantially attenuated by rapamycin treatment. CONCLUSIONS Rapamycin treatment in combination with MBG infusion significantly attenuated cardiac fibrosis. Our results suggest that rapamycin may have a dual effect on cardiac fibrosis through (1) mTOR inhibition and (2) inhibiting MBG-mediated profibrotic signaling and provide support for beneficial effect of a novel therapy for uremic cardiomyopathy.
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Affiliation(s)
- Steven T Haller
- University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - Yanling Yan
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | | | - Joe Xie
- University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - Jiang Tian
- University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - David J Kennedy
- University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - Victoria Y Shilova
- Laboratory of Cardiovascular Science, National Institute on Aging, Baltimore, MD
| | - Zijian Xie
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | - Jiang Liu
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | | | - Deepak Malhotra
- University of Toledo College of Medicine and Life Sciences, Toledo, OH
| | - Joseph I Shapiro
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV
| | - Olga V Fedorova
- Laboratory of Cardiovascular Science, National Institute on Aging, Baltimore, MD
| | - Alexei Y Bagrov
- Laboratory of Cardiovascular Science, National Institute on Aging, Baltimore, MD
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211
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Kärkäs M, Porco JA, Stephenson CRJ. Photochemical Approaches to Complex Chemotypes: Applications in Natural Product Synthesis. Chem Rev 2016; 116:9683-747. [PMID: 27120289 PMCID: PMC5025835 DOI: 10.1021/acs.chemrev.5b00760] [Citation(s) in RCA: 674] [Impact Index Per Article: 84.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Indexed: 01/29/2023]
Abstract
The use of photochemical transformations is a powerful strategy that allows for the formation of a high degree of molecular complexity from relatively simple building blocks in a single step. A central feature of all light-promoted transformations is the involvement of electronically excited states, generated upon absorption of photons. This produces transient reactive intermediates and significantly alters the reactivity of a chemical compound. The input of energy provided by light thus offers a means to produce strained and unique target compounds that cannot be assembled using thermal protocols. This review aims at highlighting photochemical transformations as a tool for rapidly accessing structurally and stereochemically diverse scaffolds. Synthetic designs based on photochemical transformations have the potential to afford complex polycyclic carbon skeletons with impressive efficiency, which are of high value in total synthesis.
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Affiliation(s)
- Markus
D. Kärkäs
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - John A. Porco
- Department
of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Corey R. J. Stephenson
- Department
of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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212
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Habeck M, Tokhtaeva E, Nadav Y, Ben Zeev E, Ferris SP, Kaufman RJ, Bab-Dinitz E, Kaplan JH, Dada LA, Farfel Z, Tal DM, Katz A, Sachs G, Vagin O, Karlish SJD. Selective Assembly of Na,K-ATPase α2β2 Heterodimers in the Heart: DISTINCT FUNCTIONAL PROPERTIES AND ISOFORM-SELECTIVE INHIBITORS. J Biol Chem 2016; 291:23159-23174. [PMID: 27624940 DOI: 10.1074/jbc.m116.751735] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Indexed: 12/31/2022] Open
Abstract
The Na,K-ATPase α2 subunit plays a key role in cardiac muscle contraction by regulating intracellular Ca2+, whereas α1 has a more conventional role of maintaining ion homeostasis. The β subunit differentially regulates maturation, trafficking, and activity of α-β heterodimers. It is not known whether the distinct role of α2 in the heart is related to selective assembly with a particular one of the three β isoforms. We show here by immunofluorescence and co-immunoprecipitation that α2 is preferentially expressed with β2 in T-tubules of cardiac myocytes, forming α2β2 heterodimers. We have expressed human α1β1, α2β1, α2β2, and α2β3 in Pichia pastoris, purified the complexes, and compared their functional properties. α2β2 and α2β3 differ significantly from both α2β1 and α1β1 in having a higher K0.5K+ and lower K0.5Na+ for activating Na,K-ATPase. These features are the result of a large reduction in binding affinity for extracellular K+ and shift of the E1P-E2P conformational equilibrium toward E1P. A screen of perhydro-1,4-oxazepine derivatives of digoxin identified several derivatives (e.g. cyclobutyl) with strongly increased selectivity for inhibition of α2β2 and α2β3 over α1β1 (range 22-33-fold). Molecular modeling suggests a possible basis for isoform selectivity. The preferential assembly, specific T-tubular localization, and low K+ affinity of α2β2 could allow an acute response to raised ambient K+ concentrations in physiological conditions and explain the importance of α2β2 for cardiac muscle contractility. The high sensitivity of α2β2 to digoxin derivatives explains beneficial effects of cardiac glycosides for treatment of heart failure and potential of α2β2-selective digoxin derivatives for reducing cardiotoxicity.
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Affiliation(s)
| | - Elmira Tokhtaeva
- the Department of Physiology, School of Medicine, UCLA and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California 90073
| | - Yotam Nadav
- From the Department of Biomolecular Sciences and
| | - Efrat Ben Zeev
- Israel National Centre for Personalized Medicine, Weizmann Institute of Science, Rehovoth 7610001, Israel
| | - Sean P Ferris
- the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109
| | - Randal J Kaufman
- the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109
| | | | - Jack H Kaplan
- the Department of Biochemistry and Molecular Genetics, University of Illinois, Chicago, Illinois 60607, and
| | - Laura A Dada
- the Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Zvi Farfel
- From the Department of Biomolecular Sciences and.,the School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Daniel M Tal
- From the Department of Biomolecular Sciences and
| | - Adriana Katz
- From the Department of Biomolecular Sciences and
| | - George Sachs
- the Department of Physiology, School of Medicine, UCLA and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California 90073
| | - Olga Vagin
- the Department of Physiology, School of Medicine, UCLA and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California 90073,
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213
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Yan Y, Shapiro AP, Mopidevi BR, Chaudhry MA, Maxwell K, Haller ST, Drummond CA, Kennedy DJ, Tian J, Malhotra D, Xie ZJ, Shapiro JI, Liu J. Protein Carbonylation of an Amino Acid Residue of the Na/K-ATPase α1 Subunit Determines Na/K-ATPase Signaling and Sodium Transport in Renal Proximal Tubular Cells. J Am Heart Assoc 2016; 5:e003675. [PMID: 27613772 PMCID: PMC5079028 DOI: 10.1161/jaha.116.003675] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/12/2016] [Indexed: 01/12/2023]
Abstract
BACKGROUND We have demonstrated that cardiotonic steroids, such as ouabain, signaling through the Na/K-ATPase, regulate sodium reabsorption in the renal proximal tubule. By direct carbonylation modification of the Pro222 residue in the actuator (A) domain of pig Na/K-ATPase α1 subunit, reactive oxygen species are required for ouabain-stimulated Na/K-ATPase/c-Src signaling and subsequent regulation of active transepithelial (22)Na(+) transport. In the present study we sought to determine the functional role of Pro222 carbonylation in Na/K-ATPase signaling and sodium handling. METHODS AND RESULTS Stable pig α1 knockdown LLC-PK1-originated PY-17 cells were rescued by expressing wild-type rat α1 and rat α1 with a single mutation of Pro224 (corresponding to pig Pro222) to Ala. This mutation does not affect ouabain-induced inhibition of Na/K-ATPase activity, but abolishes the effects of ouabain on Na/K-ATPase/c-Src signaling, protein carbonylation, Na/K-ATPase endocytosis, and active transepithelial (22)Na(+) transport. CONCLUSIONS Direct carbonylation modification of Pro224 in the rat α1 subunit determines ouabain-mediated Na/K-ATPase signal transduction and subsequent regulation of renal proximal tubule sodium transport.
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Affiliation(s)
- Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV
| | - Anna P Shapiro
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Brahma R Mopidevi
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Muhammad A Chaudhry
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV
| | - Kyle Maxwell
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV
| | - Steven T Haller
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | | | - David J Kennedy
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Jiang Tian
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Deepak Malhotra
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Zi-Jian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV Department of Medicine, University of Toledo College of Medicine, Toledo, OH
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine, Marshall University, Huntington, WV Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, WV
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214
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Liu L, Wu J, Kennedy DJ. Regulation of Cardiac Remodeling by Cardiac Na(+)/K(+)-ATPase Isoforms. Front Physiol 2016; 7:382. [PMID: 27667975 PMCID: PMC5016610 DOI: 10.3389/fphys.2016.00382] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/22/2016] [Indexed: 12/20/2022] Open
Abstract
Cardiac remodeling occurs after cardiac pressure/volume overload or myocardial injury during the development of heart failure and is a determinant of heart failure. Preventing or reversing remodeling is a goal of heart failure therapy. Human cardiomyocyte Na+/K+-ATPase has multiple α isoforms (1–3). The expression of the α subunit of the Na+/K+-ATPase is often altered in hypertrophic and failing hearts. The mechanisms are unclear. There are limited data from human cardiomyocytes. Abundant evidences from rodents show that Na+/K+-ATPase regulates cardiac contractility, cell signaling, hypertrophy and fibrosis. The α1 isoform of the Na+/K+-ATPase is the ubiquitous isoform and possesses both pumping and signaling functions. The α2 isoform of the Na+/K+-ATPase regulates intracellular Ca2+ signaling, contractility and pathological hypertrophy. The α3 isoform of the Na+/K+-ATPase may also be a target for cardiac hypertrophy. Restoration of cardiac Na+/K+-ATPase expression may be an effective approach for prevention of cardiac remodeling. In this article, we will overview: (1) the distribution and function of isoform specific Na+/K+-ATPase in the cardiomyocytes. (2) the role of cardiac Na+/K+-ATPase in the regulation of cell signaling, contractility, cardiac hypertrophy and fibrosis in vitro and in vivo. Selective targeting of cardiac Na+/K+-ATPase isoform may offer a new target for the prevention of cardiac remodeling.
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Affiliation(s)
- Lijun Liu
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo Toledo, OH, USA
| | - Jian Wu
- Center for Craniofacial Molecular Biology, University of Southern California Los Angeles, CA, USA
| | - David J Kennedy
- Department of Medicine, College of Medicine and Life Sciences, University of Toledo Toledo, OH, USA
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215
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216
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Bogdanova A, Petrushanko IY, Hernansanz-Agustín P, Martínez-Ruiz A. "Oxygen Sensing" by Na,K-ATPase: These Miraculous Thiols. Front Physiol 2016; 7:314. [PMID: 27531981 PMCID: PMC4970491 DOI: 10.3389/fphys.2016.00314] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/12/2016] [Indexed: 12/16/2022] Open
Abstract
Control over the Na,K-ATPase function plays a central role in adaptation of the organisms to hypoxic and anoxic conditions. As the enzyme itself does not possess O2 binding sites its "oxygen-sensitivity" is mediated by a variety of redox-sensitive modifications including S-glutathionylation, S-nitrosylation, and redox-sensitive phosphorylation. This is an overview of the current knowledge on the plethora of molecular mechanisms tuning the activity of the ATP-consuming Na,K-ATPase to the cellular metabolic activity. Recent findings suggest that oxygen-derived free radicals and H2O2, NO, and oxidized glutathione are the signaling messengers that make the Na,K-ATPase "oxygen-sensitive." This very ancient signaling pathway targeting thiols of all three subunits of the Na,K-ATPase as well as redox-sensitive kinases sustains the enzyme activity at the "optimal" level avoiding terminal ATP depletion and maintaining the transmembrane ion gradients in cells of anoxia-tolerant species. We acknowledge the complexity of the underlying processes as we characterize the sources of reactive oxygen and nitrogen species production in hypoxic cells, and identify their targets, the reactive thiol groups which, upon modification, impact the enzyme activity. Structured accordingly, this review presents a summary on (i) the sources of free radical production in hypoxic cells, (ii) localization of regulatory thiols within the Na,K-ATPase and the role reversible thiol modifications play in responses of the enzyme to a variety of stimuli (hypoxia, receptors' activation) (iii) redox-sensitive regulatory phosphorylation, and (iv) the role of fine modulation of the Na,K-ATPase function in survival success under hypoxic conditions. The co-authors attempted to cover all the contradictions and standing hypotheses in the field and propose the possible future developments in this dynamic area of research, the importance of which is hard to overestimate. Better understanding of the processes underlying successful adaptation strategies will make it possible to harness them and use for treatment of patients with stroke and myocardial infarction, sleep apnoea and high altitude pulmonary oedema, and those undergoing surgical interventions associated with the interruption of blood perfusion.
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Affiliation(s)
- Anna Bogdanova
- Institute of Veterinary Physiology, Vetsuisse Faculty and the Zurich Center for Integrative Human Physiology (ZIHP), University of ZurichZurich, Switzerland
| | - Irina Y. Petrushanko
- Engelhardt Institute of Molecular Biology, Russian Academy of SciencesMoscow, Russia
| | - Pablo Hernansanz-Agustín
- Servicio de Inmunología, Instituto de Investigación Sanitaria Princesa (IIS-IP), Hospital Universitario de La PrincesaMadrid, Spain
- Departamento de Bioquímica, Universidad Autónoma de MadridMadrid, Spain
| | - Antonio Martínez-Ruiz
- Servicio de Inmunología, Instituto de Investigación Sanitaria Princesa (IIS-IP), Hospital Universitario de La PrincesaMadrid, Spain
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217
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Blaustein MP, Chen L, Hamlyn JM, Leenen FHH, Lingrel JB, Wier WG, Zhang J. Pivotal role of α2 Na + pumps and their high affinity ouabain binding site in cardiovascular health and disease. J Physiol 2016; 594:6079-6103. [PMID: 27350568 DOI: 10.1113/jp272419] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/18/2016] [Indexed: 12/13/2022] Open
Abstract
Reduced smooth muscle (SM)-specific α2 Na+ pump expression elevates basal blood pressure (BP) and increases BP sensitivity to angiotensin II (Ang II) and dietary NaCl, whilst SM-α2 overexpression lowers basal BP and decreases Ang II/salt sensitivity. Prolonged ouabain infusion induces hypertension in rodents, and ouabain-resistant mutation of the α2 ouabain binding site (α2R/R mice) confers resistance to several forms of hypertension. Pressure overload-induced heart hypertrophy and failure are attenuated in cardio-specific α2 knockout, cardio-specific α2 overexpression and α2R/R mice. We propose a unifying hypothesis that reconciles these apparently disparate findings: brain mechanisms, activated by Ang II and high NaCl, regulate sympathetic drive and a novel neurohumoral pathway mediated by both brain and circulating endogenous ouabain (EO). Circulating EO modulates ouabain-sensitive α2 Na+ pump activity and Ca2+ transporter expression and, via Na+ /Ca2+ exchange, Ca2+ homeostasis. This regulates sensitivity to sympathetic activity, Ca2+ signalling and arterial and cardiac contraction.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Ling Chen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Frans H H Leenen
- Hypertension Unit, University of Ottawa Heart Institute, Ottawa, ON, Canada, K1Y 4W7
| | - Jerry B Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267-0524, USA
| | - W Gil Wier
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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218
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Pirkmajer S, Chibalin AV. Na,K-ATPase regulation in skeletal muscle. Am J Physiol Endocrinol Metab 2016; 311:E1-E31. [PMID: 27166285 DOI: 10.1152/ajpendo.00539.2015] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 05/02/2016] [Indexed: 12/17/2022]
Abstract
Skeletal muscle contains one of the largest and the most dynamic pools of Na,K-ATPase (NKA) in the body. Under resting conditions, NKA in skeletal muscle operates at only a fraction of maximal pumping capacity, but it can be markedly activated when demands for ion transport increase, such as during exercise or following food intake. Given the size, capacity, and dynamic range of the NKA pool in skeletal muscle, its tight regulation is essential to maintain whole body homeostasis as well as muscle function. To reconcile functional needs of systemic homeostasis with those of skeletal muscle, NKA is regulated in a coordinated manner by extrinsic stimuli, such as hormones and nerve-derived factors, as well as by local stimuli arising in skeletal muscle fibers, such as contractions and muscle energy status. These stimuli regulate NKA acutely by controlling its enzymatic activity and/or its distribution between the plasma membrane and the intracellular storage compartment. They also regulate NKA chronically by controlling NKA gene expression, thus determining total NKA content in skeletal muscle and its maximal pumping capacity. This review focuses on molecular mechanisms that underlie regulation of NKA in skeletal muscle by major extrinsic and local stimuli. Special emphasis is given to stimuli and mechanisms linking regulation of NKA and energy metabolism in skeletal muscle, such as insulin and the energy-sensing AMP-activated protein kinase. Finally, the recently uncovered roles for glutathionylation, nitric oxide, and extracellular K(+) in the regulation of NKA in skeletal muscle are highlighted.
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Affiliation(s)
- Sergej Pirkmajer
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; and
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
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219
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Kulikov AV, Slobodkina EA, Alekseev AV, Gogvadze V, Zhivotovsky B. Contrasting effects of cardiac glycosides on cisplatin- and etoposide-induced cell death. Biol Chem 2016; 397:661-70. [DOI: 10.1515/hsz-2016-0101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 01/28/2016] [Indexed: 11/15/2022]
Abstract
Abstract
Cardiac glycosides (CGs) or cardiotonic steroids, which constitute a group of naturally occurring compounds with a steroid-like structure, can act on Na+/K+-ATPase as a receptor and activate intracellular signaling messengers leading to a variety of cellular responses. Epidemiological studies have revealed that CGs, used for the treatment of cardiac disorders, may also be beneficial as anti-cancer agents. CGs, acting in combination with other chemotherapeutic agents, may significantly alter their efficiency in relation to cancer cell elimination, causing both sensitization and an increase in cancer cell death, and in some cases resistance to chemotherapy. Here we show the ability of CGs to modulate apoptotic response to conventionally used anti-cancer drugs. In combination with etoposide, CGs digoxin may enhance cytotoxic potential, thereby allowing the chemotherapeutic dose to be decreased and minimizing toxicity and adverse reactions. Mechanisms behind this event are discussed.
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220
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Shah PT, Martin R, Yan Y, Shapiro JI, Liu J. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis. Front Physiol 2016; 7:256. [PMID: 27445847 PMCID: PMC4923243 DOI: 10.3389/fphys.2016.00256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/11/2016] [Indexed: 01/01/2023] Open
Abstract
Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT).
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Affiliation(s)
- Preeya T Shah
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Rebecca Martin
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
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221
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Direct interaction of beta-amyloid with Na,K-ATPase as a putative regulator of the enzyme function. Sci Rep 2016; 6:27738. [PMID: 27296892 PMCID: PMC4906314 DOI: 10.1038/srep27738] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 05/23/2016] [Indexed: 11/13/2022] Open
Abstract
By maintaining the Na+ and K+ transmembrane gradient mammalian Na,K-ATPase acts as a key regulator of neuronal electrotonic properties. Na,K-ATPase has an important role in synaptic transmission and memory formation. Accumulation of beta-amyloid (Aβ) at the early stages of Alzheimer’s disease is accompanied by reduction of Na,K-ATPase functional activity. The molecular mechanism behind this phenomenon is not known. Here we show that the monomeric Aβ(1-42) forms a tight (Kd of 3 μM), enthalpy-driven equimolar complex with α1β1 Na,K-ATPase. The complex formation results in dose-dependent inhibition of the enzyme hydrolytic activity. The binding site of Aβ(1-42) is localized in the “gap” between the alpha- and beta-subunits of Na,K-ATPase, disrupting the enzyme functionality by preventing the subunits from shifting towards each other. Interaction of Na,K-ATPase with exogenous Aβ(1-42) leads to a pronounced decrease of the enzyme transport and hydrolytic activity and Src-kinase activation in neuroblastoma cells SH-SY5Y. This interaction allows regulation of Na,K-ATPase activity by short-term increase of the Aβ(1-42) level. However prolonged increase of Aβ(1-42) level under pathological conditions could lead to chronical inhibition of Na,K-ATPase and disruption of neuronal function. Taken together, our data suggest the role of beta-amyloid as a novel physiological regulator of Na,K-ATPase.
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222
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Matchkov VV, Krivoi II. Specialized Functional Diversity and Interactions of the Na,K-ATPase. Front Physiol 2016; 7:179. [PMID: 27252653 PMCID: PMC4879863 DOI: 10.3389/fphys.2016.00179] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/04/2016] [Indexed: 12/22/2022] Open
Abstract
Na,K-ATPase is a protein ubiquitously expressed in the plasma membrane of all animal cells and vitally essential for their functions. A specialized functional diversity of the Na,K-ATPase isozymes is provided by molecular heterogeneity, distinct subcellular localizations, and functional interactions with molecular environment. Studies over the last decades clearly demonstrated complex and isoform-specific reciprocal functional interactions between the Na,K-ATPase and neighboring proteins and lipids. These interactions are enabled by a spatially restricted ion homeostasis, direct protein-protein/lipid interactions, and protein kinase signaling pathways. In addition to its "classical" function in ion translocation, the Na,K-ATPase is now considered as one of the most important signaling molecules in neuronal, epithelial, skeletal, cardiac and vascular tissues. Accordingly, the Na,K-ATPase forms specialized sub-cellular multimolecular microdomains which act as receptors to circulating endogenous cardiotonic steroids (CTS) triggering a number of signaling pathways. Changes in these endogenous cardiotonic steroid levels and initiated signaling responses have significant adaptive values for tissues and whole organisms under numerous physiological and pathophysiological conditions. This review discusses recent progress in the studies of functional interactions between the Na,K-ATPase and molecular microenvironment, the Na,K-ATPase-dependent signaling pathways and their significance for diversity of cell function.
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Affiliation(s)
| | - Igor I Krivoi
- Department of General Physiology, St. Petersburg State University St. Petersburg, Russia
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223
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Afroze SH, Kalagiri RR, Reyes M, Zimmerman JD, Beeram MR, Drever N, Zawieja DC, Kuehl TJ, Uddin MN. Apoptotic and stress signaling markers are augmented in preeclamptic placenta and umbilical cord. BBA CLINICAL 2016; 6:25-30. [PMID: 27335802 PMCID: PMC4906135 DOI: 10.1016/j.bbacli.2016.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/10/2016] [Accepted: 05/23/2016] [Indexed: 12/22/2022]
Abstract
Objective Preeclampsia (preE) has a significant link to alterations of placental function leading to stress and apoptotic signaling, which pass the placental barrier and leave persistent defect in the circulation of the offspring. We assessed apoptotic signaling in placentas and umbilical cords from patients with and without preE. Methods We collected placental and cord tissues from 27 normal pregnant (NP) women and 20 preE consenting patients after delivery in an IRB approved prospective study. p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation, pro-apoptotic Bcl-2-associated X (Bax), anti-apoptotic Bcl-2, caspase-9, and pro-inflammatory cyclooxygenase-2 (Cox-2) were evaluated by western blot and immunohistochemistry. Comparisons were performed using Student's t-test. Results p38 phosphorylation (Placenta: 1.5 fold, Cord: 1.7 fold), ratio of Bax/Bcl-2 (Placenta: 1.7 fold, Cord: 2.2 fold), caspase-9 (Placenta: 1.5 fold, Cord: 1.8 fold) and Cox-2 (Placenta: 2.5 fold, Cord: 2.3 fold) were up-regulated (p < 0.05) in preE compared to NP patients. Average hospital stays for preE babies were longer than NP babies. No complications were reported for NP babies; however, all of preE babies had multiple complications. Conclusions Apoptotic and stress signaling are augmented in preE placenta and cord tissue that alter the intrauterine environment and activates the detrimental signaling that is transported to fetus.
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Affiliation(s)
- Syeda H Afroze
- Department of Medical Physiology, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Ram R Kalagiri
- Department of Pediatrics, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Michelle Reyes
- Department of Obstetrics and Gynecology, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Jacqueline D Zimmerman
- Department of Obstetrics and Gynecology, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Madhava R Beeram
- Department of Pediatrics, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Nathan Drever
- Department of Obstetrics and Gynecology, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - David C Zawieja
- Department of Medical Physiology, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Thomas J Kuehl
- Department of Pediatrics, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA; Department of Obstetrics and Gynecology, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
| | - Mohammad N Uddin
- Department of Pediatrics, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA; Department of Obstetrics and Gynecology, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA; Department of Internal Medicine, Baylor Scott & White Health, Texas A&M Health Science Center College of Medicine, Temple, TX, USA
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Grigorova YN, Juhasz O, Zernetkina V, Fishbein KW, Lakatta EG, Fedorova OV, Bagrov AY. Aortic Fibrosis, Induced by High Salt Intake in the Absence of Hypertensive Response, is Reduced by a Monoclonal Antibody to Marinobufagenin. Am J Hypertens 2016; 29:641-6. [PMID: 26350300 DOI: 10.1093/ajh/hpv155] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 08/13/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Marinobufagenin (MBG) is an endogenous Na/K-ATPase inhibitor, a natriuretic and a vasoconstrictor. MBG is implicated in salt-sensitive hypertension, cardiac hypertrophy, and initiate the pro-fibrotic signaling. Previously it was demonstrated that immunoneutralization of an endogenous MBG by 3E9 anti-MBG-antibody (mAb) in vivo lowered blood pressure (BP) and reversed cardiac fibrosis in salt-sensitive, and in partially nephrectomized rats. In the present study, we investigated whether mAb alleviates vascular remodeling induced in normotensive rats on high salt intake. METHODS Wistar rats (5 months old) received normal (CTRL; n = 8) or high salt intake (2% NaCl in drinking water) for 4 weeks ( n = 16). Rats from the group on a high salt intake were administered vehicle (SALT; n = 8) or mAb (50 µg/kg) (SALT-AB; n = 8) during the last week of high salt diet. BP, erythrocyte Na/K-ATPase activity, levels of MBG in plasma and 24-hour urine, and sensitivity of aortic explants to the vasorelaxant effect of sodium nitroprusside (SNP) were measured. Aortic collagen abundance was determined immunohistochemically. RESULTS In SALT vs. CTRL, heightened levels of MBG were associated with inhibition of erythrocyte Na/K-ATPase in the absence of BP changes. High salt intake was accompanied by a 2.5-fold increase in aortic collagen abundance and by a reduction of sensitivity of aortic explants to the vasorelaxant effect of SNP following endothelin-1-induced constriction. In the SALT-AB group, all NaCl-mediated effects were reversed by immunoneutralization of MBG. CONCLUSIONS High salt intake in young normotensive rats can induce vascular fibrosis via pressure-independent/MBG-dependent mechanisms, and this remodeling is reduced by immunoneutralization of MBG.
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Affiliation(s)
- Yulia N Grigorova
- National Institute on Aging, NIH, Baltimore, Maryland, USA; Federal Almazov Medical Research Centre, and Sechenov Institute of Evolutionary Physiology and Biochemistry, St Petersburg, Russia
| | - Ondrej Juhasz
- National Institute on Aging, NIH, Baltimore, Maryland, USA
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Yoneda JS, Scanavachi G, Sebinelli HG, Borges JC, Barbosa LRS, Ciancaglini P, Itri R. Multimeric species in equilibrium in detergent-solubilized Na,K-ATPase. Int J Biol Macromol 2016; 89:238-45. [PMID: 27109755 DOI: 10.1016/j.ijbiomac.2016.04.058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 12/29/2022]
Abstract
In this work, we find an equilibrium between different Na,K-ATPase (NKA) oligomeric species solubilized in a non-ionic detergent C12E8 by means of Dynamic Light Scattering (DLS), Analytical Ultracentrifugation (AUC), Small Angle X-ray Scattering (SAXS), Spectrophotometry (absorption at 280/350nm) and enzymatic activity assay. The NKA sample after chromatography purification presented seven different populations as identified by AUC, with monomers and tetramers amounting to ∼55% of the total protein mass in solution. These two species constituted less than 40% of the total protein mass after increasing the NKA concentration. Removal of higher-order oligomer/aggregate species from the NKA solution using 220nm-pore filter resulted in an increase of the specific enzymatic activity. Nevertheless, the enzyme forms new large aggregates over an elapsed time of 20h. The results thus point out that C12E8-solubilized NKA is in a dynamic equilibrium of monomers, tetramers and high-order oligomers/subunit aggregates. These latter have low or null activity. High amount of detergent leads to the dissociation of NKA into smaller aggregates with no enzymatic activity.
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Affiliation(s)
- Juliana Sakamoto Yoneda
- Instituto de Física da Universidade de São Paulo, IF USP, 05508-090 São Paulo, Brazil; Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, FFCLRP USP, 14040-901 Ribeirão Preto, SP, Brazil
| | - Gustavo Scanavachi
- Instituto de Física da Universidade de São Paulo, IF USP, 05508-090 São Paulo, Brazil
| | - Heitor Gobbi Sebinelli
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, FFCLRP USP, 14040-901 Ribeirão Preto, SP, Brazil
| | - Júlio Cesar Borges
- Instituto de Química de São Carlos, IQSC-USP, 13560-970 São Carlos, SP, Brazil
| | - Leandro R S Barbosa
- Instituto de Física da Universidade de São Paulo, IF USP, 05508-090 São Paulo, Brazil
| | - Pietro Ciancaglini
- Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, FFCLRP USP, 14040-901 Ribeirão Preto, SP, Brazil
| | - Rosangela Itri
- Instituto de Física da Universidade de São Paulo, IF USP, 05508-090 São Paulo, Brazil.
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226
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Marinobufagenin-induced vascular fibrosis is a likely target for mineralocorticoid antagonists. J Hypertens 2016; 33:1602-10. [PMID: 26136067 DOI: 10.1097/hjh.0000000000000591] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Endogenous cardiotonic steroids, including marinobufagenin (MBG), stimulate vascular synthesis of collagen. Because mineralocorticoid antagonists competitively antagonize effect of cardiotonic steroids on the Na/K-ATPase, we hypothesized that spironolactone would reverse the profibrotic effects of MBG. METHODS Experiment 1: Explants of thoracic aortae and aortic vascular smooth muscle cells from Wistar rats were cultured for 24 h in the presence of vehicle or MBG (100 nmol/l) with or without canrenone (10 μmol/l), an active metabolite of spironolactone. Experiment 2: In 16 patients (56 ± 2 years) with resistant hypertension on a combined (lisinopril/amlodipine/hydrochlorothiazide) therapy, we determined arterial pressure, pulse wave velocity, plasma MBG, and erythrocyte Na/K-ATPase before and 6 months after addition of placebo (n = 8) or spironolactone (50 mg/day; n = 8) to the therapy. RESULTS In rat aortic explants and in vascular smooth muscle cells, pretreatment with MBG resulted in a two-fold rise in collagen-1, and a marked reduction in the sensitivity of the aortic rings to the vasorelaxant effect of sodium nitroprusside following endothelin-1-induced constriction (EC50 = 480 ± 67 vs. 23 ± 3 nmol/l in vehicle-treated rings; P < 0.01). Canrenone blocked effects of MBG on collagen synthesis and restored sensitivity of vascular rings to sodium nitroprusside (EC50 = 17 ± 1 nmol/l). Resistant hypertension patients exhibited elevated plasma MBG (0.42 ± 0.07 vs. 0.24 ± 0.03 nmol/l; P = 0.01) and reduced Na/K-ATPase activity (1.9 ± 0.15 vs. 2.8 ± 0.2 μmol Pi/ml per h, P < 0.01) vs. seven healthy individuals. Six-month administration of spironolactone, unlike placebo treatment, was associated with a decrease in pulse wave velocity and arterial pressure, and with restoration of Na/K-ATPase activity in the presence of unchanged MBG levels. CONCLUSION MBG-induced vascular fibrosis is a likely target for spironolactone.
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Plasma level of the endogenous sodium pump ligand marinobufagenin is related to the salt-sensitivity in men. J Hypertens 2016; 33:534-41; discussion 541. [PMID: 25479026 DOI: 10.1097/hjh.0000000000000437] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE Salt-induced elevation of the endogenous digitalis like sodium pump ligand marinobufagenin (MBG) in the Dahl salt-sensitive rats resulted in elevated blood pressure (BP). Here, we tested, in humans, whether MBG levels are related to ambulatory 24-h BP (ABP), controlled long-term increase of salt-intake induces changes in MBG and any salt-induced change in MBG is related to salt sensitivity. METHODS Thirty-nine healthy individuals (53 ± 11 years old; 20 men and 19 women) had a total daily NaCl intake of 50 mmol (low-salt) and 150 mmol (high-salt) for 4 weeks each, in a random order. ABP and MBG in plasma and urine were measured at baseline (unstandardized salt intake) and after high and low-salt intake. RESULTS At baseline, plasma MBG (P-MBG) was related to 24-h SBP (r = 0.43, P = 0.007) and DBP (r = 0.32, P = 0.047), whereas 24-h urinary excretion of MBG (UE-MBG) was related to 24-h DBP only (r = 0.42, P = 0.008). Sex-specific analyses revealed that these relationships were significant in men only. Compared with low-salt, high-salt diet increased P-MBG (P = 0.029), mainly driven by results in men. Male P-MBG responders vs. nonresponders (above vs. below median of high-salt induced P-MBG increase) had markedly enhanced SBP (10.4 ± 6.4 vs. 1.0 ± 6.0 mmHg; P = 0.003) and DBP (6.7 ± 5.0 vs. -0.6 ± 3.6 mmHg; P = 0.001) salt sensitivity. CONCLUSION In men, MBG increases with 24-h ABP, and similar to Dahl salt-sensitive rats, 4 weeks of high-salt induced MBG response is accompanied by marked salt sensitivity. However, these patterns seem to be sex-specific and are not observed in women.
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228
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Yan Y, Shapiro JI. The physiological and clinical importance of sodium potassium ATPase in cardiovascular diseases. Curr Opin Pharmacol 2016; 27:43-9. [PMID: 26891193 PMCID: PMC5161351 DOI: 10.1016/j.coph.2016.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/14/2016] [Accepted: 01/29/2016] [Indexed: 12/14/2022]
Abstract
The Na/K-ATPase has been extensively studied, but it is only recently that its role as a scaffolding and signaling protein has been identified. It has been identified that cardiotonic steroids (CTS) such as digitalis mediate signal transduction through the Na/K-ATPase in a process found to result in the generation of reactive oxygen species (ROS). As these ROS also appear capable of initiating this signal cascade, a feed forward amplification process has been postulated and subsequently implicated in some disease pathways including uremic cardiomyopathy.
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Affiliation(s)
- Yanling Yan
- Joan C. Edwards School of Medicine, Marshall University, Department of Medicine, USA
| | - Joseph I Shapiro
- Joan C. Edwards School of Medicine, Marshall University, Department of Medicine, USA.
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Milutinovic S, Heynen-Genel S, Chao E, Dewing A, Solano R, Milan L, Barron N, He M, Diaz PW, Matsuzawa SI, Reed JC, Hassig CA. Cardiac Glycosides Activate the Tumor Suppressor and Viral Restriction Factor Promyelocytic Leukemia Protein (PML). PLoS One 2016; 11:e0152692. [PMID: 27031987 PMCID: PMC4816303 DOI: 10.1371/journal.pone.0152692] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/17/2016] [Indexed: 02/05/2023] Open
Abstract
Cardiac glycosides (CGs), inhibitors of Na+/K+-ATPase (NKA), used clinically to treat heart failure, have garnered recent attention as potential anti-cancer and anti-viral agents. A high-throughput phenotypic screen designed to identify modulators of promyelocytic leukemia protein (PML) nuclear body (NB) formation revealed the CG gitoxigenin as a potent activator of PML. We demonstrate that multiple structurally distinct CGs activate the formation of PML NBs and induce PML protein SUMOylation in an NKA-dependent fashion. CG effects on PML occur at the post-transcriptional level, mechanistically distinct from previously described PML activators and are mediated through signaling events downstream of NKA. Curiously, genomic deletion of PML in human cancer cells failed to abrogate the cytotoxic effects of CGs and other apoptotic stimuli such as ceramide and arsenic trioxide that were previously shown to function through PML in mice. These findings suggest that alternative pathways can compensate for PML loss to mediate apoptosis in response to CGs and other apoptotic stimuli.
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Affiliation(s)
- Snezana Milutinovic
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Susanne Heynen-Genel
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Elizabeth Chao
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Antimone Dewing
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Ricardo Solano
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Loribelle Milan
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Nikki Barron
- Bemer USA, LLC, Carlsbad, CA, United States of America
| | - Min He
- National Cancer Institute (NCI), Bethesda, MD, United States of America
| | - Paul W. Diaz
- P.William Diaz, Pharmaceutical Consulting, Riverside, CA, United States of America
| | - Shu-ichi Matsuzawa
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - John C. Reed
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
| | - Christian A. Hassig
- Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Road, La Jolla, CA 92037, United States of America
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Venugopal J, Blanco G. Ouabain Enhances ADPKD Cell Apoptosis via the Intrinsic Pathway. Front Physiol 2016; 7:107. [PMID: 27047392 PMCID: PMC4805603 DOI: 10.3389/fphys.2016.00107] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/07/2016] [Indexed: 11/13/2022] Open
Abstract
Progression of autosomal dominant polycystic kidney disease (ADPKD) is highly influenced by factors circulating in blood. We have shown that the hormone ouabain enhances several characteristics of the ADPKD cystic phenotype, including the rate of cell proliferation, fluid secretion and the capacity of the cells to form cysts. In this work, we found that physiological levels of ouabain (3 nM) also promote programmed cell death of renal epithelial cells obtained from kidney cysts of patients with ADPKD (ADPKD cells). This was determined by Alexa Fluor 488 labeled-Annexin-V staining and TUNEL assay, both biochemical markers of apoptosis. Ouabain-induced apoptosis also takes place when ADPKD cell growth is blocked; suggesting that the effect is not secondary to the stimulatory actions of ouabain on cell proliferation. Ouabain alters the expression of BCL family of proteins, reducing BCL-2 and increasing BAX expression levels, anti- and pro-apoptotic mediators respectively. In addition, ouabain caused the release of cytochrome c from mitochondria. Moreover, ouabain activates caspase-3, a key “executioner” caspase in the cell apoptotic pathway, but did not affect caspase-8. This suggests that ouabain triggers ADPKD cell apoptosis by stimulating the intrinsic, but not the extrinsic pathway of programmed cell death. The apoptotic effects of ouabain are specific for ADPKD cells and do not occur in normal human kidney cells (NHK cells). Taken together with our previous observations, these results show that ouabain causes an imbalance in cell growth/death, to favor growth of the cystic cells. This event, characteristic of ADPKD, further suggests the importance of ouabain as a circulating factor that promotes ADPKD progression.
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Affiliation(s)
- Jessica Venugopal
- Department of Molecular and Integrative Physiology and The Kidney Institute, University of Kansas Medical Center Kansas City, KS, USA
| | - Gustavo Blanco
- Department of Molecular and Integrative Physiology and The Kidney Institute, University of Kansas Medical Center Kansas City, KS, USA
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Carvalho FB, Boligon AA, Athayde ML, Rubin MA, Ferreira J, Trevisan G. Inhibitory effect of Scutia buxifolia extracts, fractions, and ursolic acid on Na(+), K(+)-ATPase activity in vitro in membranes purified from rat hearts. JOURNAL OF ETHNOPHARMACOLOGY 2016; 179:45-54. [PMID: 26719288 DOI: 10.1016/j.jep.2015.12.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/19/2015] [Accepted: 12/20/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Scutia buxifolia is a tree native to South America and is used as a cardiotonic agent; however, this property has not been associated with a clear mechanism or a specific compound. AIM OF THE STUDY Given the importance of Na(+),K(+)-ATPase as a drug target in the treatment of heart failure, this study aimed to investigate the possible inhibitory effect of S. buxifolia crude extract and fractions (dichloromethane, ethyl acetate, and butanolic fractions), and identified compounds with effects on the activity of Na(+),K(+)-ATPase in vitro. MATERIALS AND METHODS First, we characterized the crude extract and fractions by high-performance liquid chromatography, and then monitored their effects on the activity of Na(+),K(+)-ATPase obtained from heart muscle and brain membranes of adult male Wistar rats. RESULTS We identified gallic acid, chlorogenic acid, caffeic acid, rutin, quercitrin, quercetin, and ursolic acid in S. buxifolia stem bark and leaves; quercitrin and ursolic acid were the main compounds in the ethyl acetate and dichloromethane fractions from leaves and stem bark. The crude extract (3 and 30mg/ml), and the ethyl acetate and dichloromethane fractions (0.1 and 1mg/ml) of both the stem bark and leaves inhibited Na(+),K(+)-ATPase activity in heart and brain samples. We found that, of the identified compounds, only ursolic acid (0.1mg/ml) was able to diminish Na(+), K(+)-ATPase activity in heart and brain samples. CONCLUSIONS These data indicated that the cardiotonic effects of S. buxifolia may be due to the inhibition of Na(+),K(+)-ATPase activity in heart muscle, supporting the popular use of this plant as a treatment for heart failure.
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Affiliation(s)
- Fabiano B Carvalho
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil
| | - Aline A Boligon
- Programa de Pós-graduação em Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal de Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil
| | - Margareth L Athayde
- Programa de Pós-graduação em Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal de Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil
| | - Maribel A Rubin
- Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria (UFSM), 97105-900 Santa Maria, RS, Brazil
| | - Juliano Ferreira
- Programa de Pós-graduação em Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), 88049-900 Florianópolis, SC, Brazil
| | - Gabriela Trevisan
- Programa de Pós-graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense (Unesc), 88806-000 Criciúma, SC, Brazil.
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Critical role of the α1-Na(+), K(+)-ATPase subunit in insensitivity of rodent cells to cytotoxic action of ouabain. Apoptosis 2016; 20:1200-10. [PMID: 26067145 DOI: 10.1007/s10495-015-1144-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In rodents, ubiquitous α1-Na(+), K(+)-ATPase is inhibited by ouabain and other cardiotonic steroids (CTS) at ~10(3)-fold higher concentrations than those effective in other mammals. To examine the specific roles of the CTS-sensitive α1S- and CTS-resistant α1R-Na(+), K(+)-ATPase isoforms, we compared the effects of ouabain on intracellular Na(+) and K(+) content, cell survival, and mitogen-activated protein kinases (MAPK) in human and rat vascular smooth muscle cells (HASMC and RASMC), human and rat endothelial cells (HUVEC and RAEC), and human and rat brain astrocytes. 6-h exposure of HASMC and HUVEC to 3 μM ouabain dramatically increased the intracellular [Na(+)]/[K(+)] ratio to the same extend as in RASMC and RAEC treated with 3000 μM ouabain. In 24, 3 μM ouabain triggered the death of all types of human cells used in this study. Unlike human cells, we did not detect any effect of 3000-5000 μM ouabain on the survival of rat cells, or smooth muscle cells from mouse aorta (MASMC). Unlike in the wild-type α1(R/R) mouse, ouabain triggered death of MASMC from α1(S/S) mouse expressing human α1-Na(+), K(+)-ATPase. Furthermore, transfection of HUVEC with rat α1R-Na(+), K(+)-ATPase protected them from the ouabain-induced death. In HUVEC, ouabain led to phosphorylation of p38 MAPK, whereas in RAEC it stimulated phosphorylation of ERK1/2. Overall, our results, demonstrate that the drastic differences in cytotoxic action of ouabain on human and rodent cells are caused by unique features of α1S/α1R-Na(+), K(+)-ATPase, rather than by any downstream CTS-sensitive/resistant components of the cell death machinery.
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Aperia A, Akkuratov EE, Fontana JM, Brismar H. Na+-K+-ATPase, a new class of plasma membrane receptors. Am J Physiol Cell Physiol 2016; 310:C491-5. [PMID: 26791490 DOI: 10.1152/ajpcell.00359.2015] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Na(+)-K(+)-ATPase (NKA) differs from most other ion transporters, not only in its capacity to maintain a steep electrochemical gradient across the plasma membrane, but also as a receptor for a family of cardiotonic steroids, to which ouabain belongs. Studies from many groups, performed during the last 15 years, have demonstrated that ouabain, a member of the cardiotonic steroid family, can activate a network of signaling molecules, and that NKA will also serve as a signal transducer that can provide a feedback loop between NKA and the mitochondria. This brief review summarizes the current knowledge and controversies with regard to the understanding of NKA signaling.
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Affiliation(s)
- Anita Aperia
- Science for Life Laboratory, Department of Women and Children's Health, Karolinska Institutet, Stockholm, Sweden; and
| | - Evgeny E Akkuratov
- Science for Life Laboratory, Department of Women and Children's Health, Karolinska Institutet, Stockholm, Sweden; and
| | - Jacopo Maria Fontana
- Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | - Hjalmar Brismar
- Science for Life Laboratory, Department of Women and Children's Health, Karolinska Institutet, Stockholm, Sweden; and Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
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Yang S, Sun J, Zhu C, He P, Peng Z, Ding G. Supramolecular recognition control of polyethylene glycol modified N-doped graphene quantum dots: tunable selectivity for alkali and alkaline-earth metal ions. Analyst 2016; 141:1052-9. [PMID: 26730814 DOI: 10.1039/c5an02270c] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The graphene quantum dot based fluorescent probe community needs unambiguous evidence about the control on the ion selectivity. In this paper, polyethylene glycol modified N-doped graphene quantum dots (PN-GQDs) were synthesized by alkylation reaction between graphene quantum dots and organic halides. We demonstrate the tunable selectivity and sensitivity by controlling the supramolecular recognition through the length and the end group size of the polyether chain on PN-GQDs. The relationship formulae between the selectivity/detection limit and polyether chains are experimentally deduced. The polyether chain length determines the interaction between the PN-GQDs and ions with different ratios of charge to radius, which in turn leads to a good selectivity control. Meanwhile the detection limit shows an exponential growth with the size of end groups of the polyether chain. The PN-GQDs can be used as ultrasensitive and selective fluorescent probes for Li(+), Na(+), K(+), Mg(2+), Ca(2+) and Sr(2+), respectively.
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Affiliation(s)
- Siwei Yang
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Science, Shanghai, 200500, China.
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Orellana AM, Kinoshita PF, Leite JA, Kawamoto EM, Scavone C. Cardiotonic Steroids as Modulators of Neuroinflammation. Front Endocrinol (Lausanne) 2016; 7:10. [PMID: 26909067 PMCID: PMC4754428 DOI: 10.3389/fendo.2016.00010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/22/2016] [Indexed: 01/13/2023] Open
Abstract
Cardiotonic steroids (CTS) are a class of specific ligands of the Na(+), K(+)- ATPase (NKA). NKA is a P-type ATPase that is ubiquitously expressed and although well known to be responsible for the maintenance of the cell electrochemical gradient through active transport, NKA can also act as a signal transducer in the presence of CTS. Inflammation, in addition to importantly driving organism defense and survival mechanisms, can also modulate NKA activity and memory formation, as well as being relevant to many chronic illnesses, neurodegenerative diseases, and mood disorders. The aim of the current review is to highlight the recent advances as to the role of CTS and NKA in inflammatory process, with a particular focus in the central nervous system.
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Affiliation(s)
- Ana Maria Orellana
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Paula Fernanda Kinoshita
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Jacqueline Alves Leite
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Elisa Mitiko Kawamoto
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Cristoforo Scavone
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
- *Correspondence: Cristoforo Scavone,
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Obradovic M, Zafirovic S, Jovanovic A, Milovanovic ES, Mousa SA, Labudovic-Borovic M, Isenovic ER. Effects of 17β-estradiol on cardiac Na(+)/K(+)-ATPase in high fat diet fed rats. Mol Cell Endocrinol 2015; 416:46-56. [PMID: 26284496 DOI: 10.1016/j.mce.2015.08.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/28/2015] [Accepted: 08/14/2015] [Indexed: 01/04/2023]
Abstract
The aim of this study was to investigate in vivo effects of estradiol on Na(+)/K(+)-ATPase activity/expression in high fat (HF) diet fed rats. Adult male Wistar rats were fed normally (Control, n = 7) or with a HF diet (Obese, n = 14) for 10 weeks. After 10 weeks, half of the obese rats were treated with estradiol (Obese + Estradiol, n = 7, 40 μg/kg, i.p.) as a bolus injection and 24 h after treatment all the rats were sacrificed. Estradiol in vivo in obese rats in comparison with obese non-treated rats led to a statistically significant increase in concentration of serum Na(+) (p < 0.05), Na(+)/K(+)-ATPase activity (p < 0.01), expression of α1 (p < 0.01) and α2 (p < 0.05) subunit of Na(+)/K(+)-ATPase, both PI3K subunits p85 (p < 0.01), p110 (p < 0.05), and association of IRS-1 with p85 (p < 0.05), while significantly decrease expression of AT1 (p < 0.05) and Rho A (p < 0.01) proteins. Our results suggest that estradiol in vivo in pathophysiological conditions, such as obesity accompanied with insulin resistance stimulates activity and expression of Na(+)/K(+)-ATPase by a mechanism that involves the participation of IRS-1/PI3K/Akt signaling. In addition, the decreasing level of AT1 and Rho A proteins estradiol probably attenuates the detrimental effect of obesity to decreased IRS-1/PI3K association and consequently reduce Na(+)/K(+)-ATPase activity/expression.
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Affiliation(s)
- Milan Obradovic
- Institute of Nuclear Sciences Vinca, University of Belgrade, Laboratory of Radiobiology and Molecular Genetics, Mike Petrovica Alasa 12-14, 11000 Belgrade, Serbia.
| | - Sonja Zafirovic
- Institute of Nuclear Sciences Vinca, University of Belgrade, Laboratory of Radiobiology and Molecular Genetics, Mike Petrovica Alasa 12-14, 11000 Belgrade, Serbia.
| | - Aleksandra Jovanovic
- Institute of Nuclear Sciences Vinca, University of Belgrade, Laboratory of Radiobiology and Molecular Genetics, Mike Petrovica Alasa 12-14, 11000 Belgrade, Serbia.
| | - Emina Sudar Milovanovic
- Institute of Nuclear Sciences Vinca, University of Belgrade, Laboratory of Radiobiology and Molecular Genetics, Mike Petrovica Alasa 12-14, 11000 Belgrade, Serbia.
| | - Shaker A Mousa
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, 1 Discovery Drive, Rensselaer, NY 12144, USA.
| | - Milica Labudovic-Borovic
- Institute of Histology and Embryology "Aleksandar Đ. Kostić", Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
| | - Esma R Isenovic
- Institute of Nuclear Sciences Vinca, University of Belgrade, Laboratory of Radiobiology and Molecular Genetics, Mike Petrovica Alasa 12-14, 11000 Belgrade, Serbia.
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237
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High-salt diets during pregnancy increases renal vascular reactivity due to altered soluble guanylyl cyclase-related pathways in rat offspring. J Nutr Biochem 2015; 28:121-8. [PMID: 26878789 DOI: 10.1016/j.jnutbio.2015.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 10/09/2015] [Accepted: 10/13/2015] [Indexed: 12/29/2022]
Abstract
Adverse prenatal factors such as overtake of salt or fat food are potential risks for cardiovascular diseases in offspring. This study tested the hypothesis that prenatal high-salt (HS) diets may influence renal vascular tone and attenuates signaling pathways related to soluble guanylyl cyclase (sGC) or/and large-conductance Ca(2+)-activated K(+) (BKCa) channels in the offspring. Pregnant rats were fed either normal salt (NS) (1% NaCl) or HS (8% NaCl) diet for the whole gestation. Offspring were maintained on NS diets. Renal interlobar arteries in offspring were tested for vascular responses to phenylephrine (Phe), K(+) channels and signal pathways related to sGC. Phe induced higher vessel tension in interlobar arteries of the HS offspring. Following pretreatment with BKCa channel inhibitor iberiotoxin, Phe-mediated vasoconstrictions were decreased in HS offspring compared to NS. Phe-mediated constrictions following pretreatment with NO synthase inhibitor N(G)-nitro-l-arginine methyl ester or sGC inhibitor 1H-1,2,4-oxadiazolo-4,3-quinoxalin-1-one in the HS offspring were less sensitive than NS. The whole-cell K(+) currents and the component of BKCa channels were not changed in smooth muscle cells from interlobar arteries, whereas the K(+) currents stimulated by sGC activator BAY41-2272 were reduced in the HS offspring. The protein expressions of sGC β1 and β2 in the interlobar arteries of HS offspring were reduced. The results showed that chronic overintake of salt during pregnancy could increase renal vascular tone in the offspring. The affected signal pathways included down-regulation of sGC function and expression.
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238
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Ehrig JC, Afroze SH, Reyes M, Allen SR, Drever NS, Pilkinton KA, Kuehl TJ, Uddin MN. A p38 mitogen-activated protein kinase inhibitor attenuates cardiotonic steroids-induced apoptotic and stress signaling in a Sw-71 cytotrophoblast cell line. Placenta 2015; 36:1276-82. [DOI: 10.1016/j.placenta.2015.08.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 08/27/2015] [Accepted: 08/28/2015] [Indexed: 12/14/2022]
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239
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Sodhi K, Maxwell K, Yan Y, Liu J, Chaudhry MA, Getty M, Xie Z, Abraham NG, Shapiro JI. RETRACTED: pNaKtide inhibits Na/K-ATPase reactive oxygen species amplification and attenuates adipogenesis. SCIENCE ADVANCES 2015; 1:e1500781. [PMID: 26601314 PMCID: PMC4646828 DOI: 10.1126/sciadv.1500781] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/03/2015] [Indexed: 06/05/2023]
Abstract
Obesity has become a worldwide epidemic and is a major risk factor for metabolic syndrome. Oxidative stress is known to play a role in the generation and maintenance of an obesity phenotype in both isolated adipocytes and intact animals. Because we had identified that the Na/K-ATPase can amplify oxidant signaling, we speculated that a peptide designed to inhibit this pathway, pNaKtide, might ameliorate an obesity phenotype. To test this hypothesis, we first performed studies in isolated murine preadipocytes (3T3L1 cells) and found that pNaKtide attenuated oxidant stress and lipid accumulation in a dose-dependent manner. Complementary experiments in C57Bl6 mice fed a high-fat diet corroborated our in vitro observations. Administration of pNaKtide in these mice reduced body weight gain, restored systemic redox and inflammatory milieu, and, crucially, improved insulin sensitivity. Thus, we propose that inhibition of Na/K-ATPase amplification of oxidative stress may ultimately be a novel way to combat obesity, insulin resistance, and metabolic syndrome.
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Affiliation(s)
- Komal Sodhi
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Kyle Maxwell
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Yanling Yan
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Jiang Liu
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Muhammad A. Chaudhry
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Morghan Getty
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Zijian Xie
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
| | - Nader G. Abraham
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
- Department of Medicine, New York Medical College, Valhalla, NY 10595, USA
| | - Joseph I. Shapiro
- Departments of Medicine, Pharmacology, and Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA
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240
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Cherniavsky Lev M, Karlish SJD, Garty H. Cardiac glycosides induced toxicity in human cells expressing α1-, α2-, or α3-isoforms of Na-K-ATPase. Am J Physiol Cell Physiol 2015; 309:C126-35. [PMID: 25994790 DOI: 10.1152/ajpcell.00089.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Na+-K+-ATPase is specifically inhibited by cardiac glycosides, some of which may also function as endogenous mammalian hormones. Previous studies using Xenopus oocytes, yeast cells, or purified isoforms demonstrated that affinities of various cardiac glycosides for three isoforms of the Na+-K+-ATPase (α1-α3β1) may differ, a finding with potential clinical implication. The present study investigates isoform selectivity and effects of cardiac glycosides on cultured mammalian cells under more physiological conditions. H1299 cells (non-small cell lung carcinoma) were engineered to express only one α-isoform (α1, α2, or α3) by combining stable transfection of isoforms and silencing endogenous α1. Cardiac glycoside binding was measured by displacement of bound 3H-ouabain. The experiments confirm moderate α1/α3:α2 selectivity of ouabain, moderate α2:α1 selectivity of digoxin, and enhanced α2:α1 selectivity of synthetic derivatives (Katz A, Tal DM, Heller D, Haviv H, Rabah B, Barkana Y, Marcovich AL, Karlish SJD. J Biol Chem 289: 21153-21162, 2014). Relative α2:α1 selectivity of digoxin vs. ouabain was also manifested by enhanced internalization of α2 in response to digoxin. Cellular proliferation assays of H1299 cells confirmed the patterns of α2:α1 selectivity for ouabain, digoxin, and a synthetic derivative and reveal a crucial role of surface pump density on sensitivity to cardiac glycosides. Because cardiac glycosides are being considered as drugs for treatment of cancer, effects of ouabain on proliferation of 12 cancer and noncancer cell lines, with variable plasma membrane expression of α1, have been tested. These demonstrated that sensitivity to ouabain indeed depends linearly on the plasma membrane surface density of Na+-K+-ATPase irrespective of status, malignant or nonmalignant.
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241
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Fedorova OV, Zernetkina VI, Shilova VY, Grigorova YN, Juhasz O, Wei W, Marshall CA, Lakatta EG, Bagrov AY. Synthesis of an Endogenous Steroidal Na Pump Inhibitor Marinobufagenin, Implicated in Human Cardiovascular Diseases, Is Initiated by CYP27A1 via Bile Acid Pathway. ACTA ACUST UNITED AC 2015; 8:736-45. [PMID: 26374826 DOI: 10.1161/circgenetics.115.001217] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 08/31/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND The bioactive steroid, marinobufagenin, is an endogenous Na/K-ATPase bufadienolide inhibitor that is synthesized by adrenocortical and placental cells. Marinobufagenin binding to Na/K-ATPase initiates profibrotic cell signaling, and heightened marinobufagenin levels are implicated in the pathogenesis of hypertension, preeclampsia, and chronic kidney disease. Steroids are derived from cholesterol through the traditional steroidogenesis pathway initiated by enzyme CYP11A1, and via the acidic bile acid pathway, which is controlled by enzyme CYP27A1. The mechanism of marinobufagenin biosynthesis in mammals, however, remains unknown. METHODS AND RESULTS Here, we show that post-transcriptional silencing of the CYP27A1 gene in human trophoblast and rat adrenocortical cells reduced the expression of CYP27A1 mRNA by 70%, reduced total bile acids 2-fold, and marinobufagenin levels by 67% when compared with nontreated cells or cells transfected with nontargeting siRNA. In contrast, silencing of the CYP11A1 gene did not affect marinobufagenin production in either cell culture, but suppressed production of progesterone 2-fold in human trophoblast cells and of corticosterone by 90% in rat adrenocortical cells when compared with cells transfected with nontargeting siRNA. In vivo, in a high-salt administration experiment, male and female Dahl salt-sensitive rats became hypertensive after 4 weeks on a high-NaCl diet, their plasma marinobufagenin levels doubled, and adrenocortical CYP27A1 mRNA and protein increased 1.6-fold and 2.0-fold. CONCLUSIONS Therefore, the endogenous steroidal Na/K-ATPase inhibitor, marinobufagenin, is synthesized in mammalian placenta and adrenal cortex from cholesterol through the novel acidic bile acid pathway. These findings will help to understand the role of marinobufagenin in highly prevalent human cardiovascular diseases.
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Affiliation(s)
- Olga V Fedorova
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD.
| | - Valentina I Zernetkina
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Victoria Y Shilova
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Yulia N Grigorova
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Ondrej Juhasz
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Wen Wei
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Courtney A Marshall
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Edward G Lakatta
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Alexei Y Bagrov
- From the Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD.
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242
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Chen Y, Kennedy DJ, Ramakrishnan DP, Yang M, Huang W, Li Z, Xie Z, Chadwick AC, Sahoo D, Silverstein RL. Oxidized LDL-bound CD36 recruits an Na⁺/K⁺-ATPase-Lyn complex in macrophages that promotes atherosclerosis. Sci Signal 2015; 8:ra91. [PMID: 26350901 DOI: 10.1126/scisignal.aaa9623] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
One characteristic of atherosclerosis is the accumulation of lipid-laden macrophage foam cells in the arterial wall. We have previously shown that the binding of oxidized low-density lipoprotein (oxLDL) to the scavenger receptor CD36 activates the kinase Lyn, initiating a cascade that inhibits macrophage migration and is necessary for foam cell generation. We identified the plasma membrane ion transporter Na(+)/K(+)-ATPase as a key component in the macrophage oxLDL-CD36 signaling axis. Using peritoneal macrophages isolated from Atp1a1 heterozygous or Cd36-null mice, we demonstrated that CD36 recruited an Na(+)/K(+)-ATPase-Lyn complex for Lyn activation in response to oxLDL. Macrophages deficient in the α1 Na(+)/K(+)-ATPase catalytic subunit did not respond to activation of CD36, showing attenuated oxLDL uptake and foam cell formation, and oxLDL failed to inhibit migration of these macrophages. Furthermore, Apoe-null mice, which are a model of atherosclerosis, were protected from diet-induced atherosclerosis by global deletion of a single allele encoding the α1 Na(+)/K(+)-ATPase subunit or reconstitution with macrophages that lacked an allele encoding the α1 Na(+)/K(+)-ATPase subunit. These findings identify Na(+)/K(+)-ATPase as a potential target for preventing or treating atherosclerosis.
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Affiliation(s)
- Yiliang Chen
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
| | - David J Kennedy
- Department of Medicine, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
| | - Devi Prasadh Ramakrishnan
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA. Department of Molecular Medicine, Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA
| | - Moua Yang
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA. Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Wenxin Huang
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA
| | - Zhichuan Li
- Department of Physiology and Pharmacology, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
| | - Zijian Xie
- Department of Physiology and Pharmacology, University of Toledo, Health Science Campus, Toledo, OH 43614, USA
| | - Alexandra C Chadwick
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daisy Sahoo
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA. Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA. Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Roy L Silverstein
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53226, USA. Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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243
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Chauvet S, Boonen M, Chevallet M, Jarvis L, Abebe A, Benharouga M, Faller P, Jadot M, Bouron A. The Na+/K+-ATPase and the amyloid-beta peptide aβ1-40 control the cellular distribution, abundance and activity of TRPC6 channels. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2957-65. [PMID: 26348127 DOI: 10.1016/j.bbamcr.2015.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 08/31/2015] [Accepted: 09/03/2015] [Indexed: 11/19/2022]
Abstract
The Na(+)/K(+)-ATPase interacts with the non-selective cation channels TRPC6 but the functional consequences of this association are unknown. Experiments performed with HEK cells over-expressing TRPC6 channels showed that inhibiting the activity of the Na(+)/K(+)-ATPase with ouabain reduced the amount of TRPC6 proteins and depressed Ca(2+) entry through TRPC6. This effect, not mimicked by membrane depolarization with KCl, was abolished by sucrose and bafilomycin-A, and was partially sensitive to the intracellular Ca(2+) chelator BAPTA/AM. Biotinylation and subcellular fractionation experiments showed that ouabain caused a multifaceted redistribution of TRPC6 to the plasma membrane and to an endo/lysosomal compartment where they were degraded. The amyloid beta peptide Aβ(1-40), another inhibitor of the Na(+)/K(+)-ATPase, but not the shorter peptide Aβ1-16, reduced TRPC6 protein levels and depressed TRPC6-mediated responses. In cortical neurons from embryonic mice, ouabain, veratridine (an opener of voltage-gated Na(+) channel), and Aβ(1-40) reduced TRPC6-mediated Ca(2+) responses whereas Aβ(1-16) was ineffective. Furthermore, when Aβ(1-40) was co-added together with zinc acetate it could no longer control TRPC6 activity. Altogether, this work shows the existence of a functional coupling between the Na(+)/K(+)-ATPase and TRPC6. It also suggests that the abundance, distribution and activity of TRPC6 can be regulated by cardiotonic steroids like ouabain and the naturally occurring peptide Aβ(1-40) which underlines the pathophysiological significance of these processes.
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Affiliation(s)
- Sylvain Chauvet
- Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France
| | - Marielle Boonen
- URPhyM-Laboratoire de Chimie Physiologique, University of Namur, Belgium
| | - Mireille Chevallet
- Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France
| | - Louis Jarvis
- Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France
| | - Addis Abebe
- Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France
| | - Mohamed Benharouga
- Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France
| | - Peter Faller
- CNRS, Laboratoire de Chimie de Coordination, Toulouse, France
| | - Michel Jadot
- URPhyM-Laboratoire de Chimie Physiologique, University of Namur, Belgium
| | - Alexandre Bouron
- Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France.
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244
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Mutsaers HAM, Stribos EGD, Glorieux G, Vanholder R, Olinga P. Chronic Kidney Disease and Fibrosis: The Role of Uremic Retention Solutes. Front Med (Lausanne) 2015; 2:60. [PMID: 26380262 PMCID: PMC4553389 DOI: 10.3389/fmed.2015.00060] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 08/17/2015] [Indexed: 12/20/2022] Open
Abstract
Chronic kidney disease (CKD) is a major global health concern, and the uremic state is highly associated with fibrogenesis in several organs and tissues. Fibrosis is characterized by excessive production and deposition of extracellular matrix proteins with a detrimental impact on organ function. Another key feature of CKD is the retention and subsequent accumulation of solutes that are normally cleared by the healthy kidney. Several of these uremic retention solutes, including indoxyl sulfate and p-cresyl sulfate, have been suggested to be CKD-specific triggers for the development and perpetuation of fibrosis. The purpose of this brief review is to gather and discuss the current body of evidence linking uremic retention solutes to the fibrotic response during CKD, with a special emphasis on the pathophysiological mechanisms in the kidney.
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Affiliation(s)
- Henricus A M Mutsaers
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen , Groningen , Netherlands
| | - Elisabeth G D Stribos
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen , Groningen , Netherlands ; Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen , Groningen , Netherlands
| | - Griet Glorieux
- Renal Division, Department of Internal Medicine, Ghent University Hospital , Ghent , Belgium
| | - Raymond Vanholder
- Renal Division, Department of Internal Medicine, Ghent University Hospital , Ghent , Belgium
| | - Peter Olinga
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen , Groningen , Netherlands
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245
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Delebinski CI, Georgi S, Kleinsimon S, Twardziok M, Kopp B, Melzig MF, Seifert G. Analysis of proliferation and apoptotic induction by 20 steroid glycosides in 143B osteosarcoma cells in vitro. Cell Prolif 2015; 48:600-10. [PMID: 26300346 DOI: 10.1111/cpr.12208] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/04/2015] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES Osteosarcoma is the most common type of malignant bone tumour in children and adolescents; it has poor prognosis, is highly metastatic and is resistant to current therapeutic approaches. In this study, different herbal extracts used in phytotherapy have been screened after searching innovative natural anti-cancer components. MATERIALS AND METHODS Twenty steroid glycosides were examined for accordance to their potential of inhibiting cell proliferation and inducing apoptosis in the osteosarcoma cell line 143B. Cell proliferation was examined using a CASY counter. Effects of cardiac glycosides on induction of apoptosis were evaluated by Annexin V-APC and flow cytometry, caspase activity assay and measurement of mitochondrial membrane potential. RESULTS The study revealed that various steroid glycosides suppress cell proliferation in a concentration-dependent manner. Further investigations indicated apoptotic induction by 17 of the 20 tested cardenolides and bufadienolides. Bufadienolide proscillaridin A, arenobufagin, and cardenolides evomonoside, convallatoxol and ouabain waged strongest apoptotic induction, associated with breakdown of mitochondrial membrane potential and activation of caspases -8 and -9. In contrast, the bufadienolide resibufogenin and cardenolide uzarin had no effect on proliferation inhibition, apoptotic induction or change in mitochondrial membrane potential. CONCLUSION These results indicate that bufadienolides proscillaridin A and arenobufagin and cardenolide evomonoside, or related natural compounds might be promising new starting points for development of novel anti-cancer agents for treatment of osteosarcoma.
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Affiliation(s)
- C I Delebinski
- Department of Paediatric Oncology/Haematology, Otto-Heubner-Centre for Paediatric and Adolescent Medicine (OHC), Charité, Universitaetsmedizin Berlin, Berlin, 13353, Germany
| | - S Georgi
- FU Berlin, Institute for Pharmacy, Berlin, 14195, Germany
| | - S Kleinsimon
- Department of Paediatric Oncology/Haematology, Otto-Heubner-Centre for Paediatric and Adolescent Medicine (OHC), Charité, Universitaetsmedizin Berlin, Berlin, 13353, Germany
| | - M Twardziok
- Department of Paediatric Oncology/Haematology, Otto-Heubner-Centre for Paediatric and Adolescent Medicine (OHC), Charité, Universitaetsmedizin Berlin, Berlin, 13353, Germany
| | - B Kopp
- Department of Pharmacognosy, University of Vienna, Vienna, A-1090, Austria
| | - M F Melzig
- FU Berlin, Institute for Pharmacy, Berlin, 14195, Germany
| | - G Seifert
- Department of Paediatric Oncology/Haematology, Otto-Heubner-Centre for Paediatric and Adolescent Medicine (OHC), Charité, Universitaetsmedizin Berlin, Berlin, 13353, Germany
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246
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Jansson K, Venugopal J, Sánchez G, Magenheimer BS, Reif GA, Wallace DP, Calvet JP, Blanco G. Ouabain Regulates CFTR-Mediated Anion Secretion and Na,K-ATPase Transport in ADPKD Cells. J Membr Biol 2015; 248:1145-57. [PMID: 26289599 DOI: 10.1007/s00232-015-9832-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/06/2015] [Indexed: 01/16/2023]
Abstract
Cyst enlargement in autosomal dominant polycystic kidney disease (ADPKD) requires the transepithelial secretion of fluid into the cyst lumen. We previously showed that physiological amounts of ouabain enhance cAMP-dependent fluid secretion and cyst growth of human ADPKD cyst epithelial cells in culture and formation of cyst-like dilations in metanephric kidneys from Pkd1 mutant mice. Here, we investigated the mechanisms by which ouabain promotes cAMP-dependent fluid secretion and cystogenesis. Ouabain (3 nM) enhanced cAMP-induced cyst-like dilations in embryonic kidneys from Pkd1 (m1Bei) mice, but had no effect on metanephroi from Pkd1 (m1Bei) mice that lack expression of the cystic fibrosis transmembrane conductance regulator (CFTR). Similarly, ouabain stimulation of cAMP-induced fluid secretion and in vitro cyst growth of ADPKD cells were abrogated by CFTR inhibition, showing that CFTR is required for ouabain effects on ADPKD fluid secretion. Moreover, ouabain directly enhanced the cAMP-dependent Cl(-) efflux mediated by CFTR in ADPKD monolayers. Ouabain increased the trafficking of CFTR to the plasma membrane and up-regulated the expression of the CFTR activator PDZK1. Finally, ouabain decreased plasma membrane expression and activity of the Na,K-ATPase in ADPKD cells. Altogether, these results show that ouabain enhances net fluid secretion and cyst formation by activating apical anion secretion via CFTR and decreasing basolateral Na(+) transport via Na,K-ATPase. These results provide new information on the mechanisms by which ouabain affects ADPKD cells and further highlight the importance of ouabain as a non-genomic stimulator of cystogenesis in ADPKD.
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Affiliation(s)
- Kyle Jansson
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jessica Venugopal
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Gladis Sánchez
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Brenda S Magenheimer
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Gail A Reif
- Department of Medicine, University of Kansas Medical Center, Kansas City, KS, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Darren P Wallace
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA.,Department of Medicine, University of Kansas Medical Center, Kansas City, KS, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - James P Calvet
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA.,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA
| | - Gustavo Blanco
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS, 66160, USA. .,The Kidney Institute, University of Kansas Medical Center, Kansas City, KS, USA.
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Klimanova EA, Petrushanko IY, Mitkevich VA, Anashkina AA, Orlov SN, Makarov AA, Lopina OD. Binding of ouabain and marinobufagenin leads to different structural changes in Na,K-ATPase and depends on the enzyme conformation. FEBS Lett 2015; 589:2668-74. [PMID: 26297827 DOI: 10.1016/j.febslet.2015.08.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/20/2015] [Accepted: 08/06/2015] [Indexed: 01/18/2023]
Abstract
Ion pump, Na,K-ATPase specifically binds cardiotonic steroids (CTS), which leads to inhibition of the enzyme activity and activation of signaling network in the cell. We have studied interaction of Na,K-ATPase with CTS of two different types - marinobufagenin and ouabain. We have shown that both CTS inhibit activity of Na,K-ATPase with the same Ki values, but binding of ouabain is sensitive to the conformation of Na,K-ATPase while binding of marinobufagenin is not. Furthermore, binding of ouabain and marinobufagenin results in different structural changes in Na,K-ATPase. Our data allow to explain the diversity of effects on the receptor function of Na,K-ATPase caused by different types of CTS.
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Affiliation(s)
- Elizaveta A Klimanova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Vavilov Str. 32, Moscow, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Irina Yu Petrushanko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Vavilov Str. 32, Moscow, Russia
| | - Vladimir A Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Vavilov Str. 32, Moscow, Russia
| | - Anastasia A Anashkina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Vavilov Str. 32, Moscow, Russia
| | - Sergey N Orlov
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Vavilov Str. 32, Moscow, Russia.
| | - Olga D Lopina
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
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248
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Dan C, Jinjun B, Zi-Chun H, Lin M, Wei C, Xu Z, Ri Z, Shun C, Wen-Zhu S, Qing-Cai J, Wu Y. Modulation of TNF-α mRNA stability by human antigen R and miR181s in sepsis-induced immunoparalysis. EMBO Mol Med 2015; 7:140-57. [PMID: 25535255 PMCID: PMC4328645 DOI: 10.15252/emmm.201404797] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Immunoparalysis is an important pathological mechanism in sepsis. However, an effective small molecule therapy is lacking. Here, we show that ouabain, a Na+,K+-ATPase ligand, can reverse immunoparalysis in vitro, in vivo, and in clinical samples. Notably, the effect of ouabain was critically dependent on TNF-α expression. However, ouabain had opposing effects on the stability of TNF-α mRNA: Ouabain triggered miR-181 transcription, which promoted TNF-α mRNA degradation and induced immunoparalysis, and ouabain triggered the nuclear export of human antigen R (HuR), which stabilized TNF-α mRNA and suppressed immuno-paralysis. Interestingly, because the miR-181 binding site is located within the HuR binding site in the 3′-untranslated region of TNF-α, in ouabain-treated cells, HuR competed with miR-181 for binding to TNF-α mRNA and recruited TNF-α mRNA to stress granules, thereby stabilizing TNF-α mRNA and reversing immunoparalysis. Ouabain also induced GM-CSF and interferon-γ expression in a HuR-dependent manner. Hence, the fine-tuning of TNF-α mRNA stability by HuR and miR181 plays a crucial role in immunoparalysis, and Na+,K+-ATPase ligands are promising agents for immunoparalysis therapy.
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Affiliation(s)
- Cao Dan
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Bian Jinjun
- Department of Anesthesiology and Intensive Care Unit, Changhai Hospital Affiliated Hospital of the Second Military Medical University, Shanghai, China
| | - Hua Zi-Chun
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Ma Lin
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Chen Wei
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Zhang Xu
- Department of Anesthesiology and Intensive Care Unit, Changhai Hospital Affiliated Hospital of the Second Military Medical University, Shanghai, China
| | - Zhou Ri
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Cheng Shun
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Sun Wen-Zhu
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Jiao Qing-Cai
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China
| | - Yin Wu
- The State Key Lab of Pharmaceutical Biotechnology, College of life Sciences Nanjing University, Nanjing, China The State Key Lab of Natural Medicine, China Pharmaceutical University, Nanjing, China Jiangsu Key Lab of Pediatric Respiratory Disease, Nanjing University of Chinese Medicine, Nanjing, China
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249
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Kennedy DJ, Shrestha K, Sheehey B, Li XS, Guggilam A, Wu Y, Finucan M, Gabi A, Medert CM, Westfall K, Borowski A, Fedorova O, Bagrov AY, Tang WHW. Elevated Plasma Marinobufagenin, An Endogenous Cardiotonic Steroid, Is Associated With Right Ventricular Dysfunction and Nitrative Stress in Heart Failure. Circ Heart Fail 2015; 8:1068-76. [PMID: 26276886 DOI: 10.1161/circheartfailure.114.001976] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 08/05/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Plasma levels of cardiotonic steroids are elevated in volume-expanded states, such as chronic kidney disease, but the role of these natriuretic hormones in subjects with heart failure (HF) is unclear. We sought to determine the prognostic role of the cardiotonic steroids marinobufagenin (MBG) in HF, particularly in relation to long-term outcomes. METHODS AND RESULTS We first measured plasma MBG levels and performed comprehensive clinical, laboratory, and echocardiographic assessment in 245 patients with HF. All-cause mortality, cardiac transplantation, and HF hospitalization were tracked for 5 years. In our study cohort, median (interquartile range) MBG was 583 (383-812) pM. Higher MBG was associated with higher myeloperoxidase (r=0.42, P<0.0001), B-type natriuretic peptide (r=0.25, P=0.001), and asymmetrical dimethylarginine (r=0.32, P<0.001). Elevated levels of MBG were associated with measures of worse right ventricular function (RV s', r=-0.39, P<0.0001) and predicted increased risk of adverse clinical outcomes (MBG≥574 pmol/L: hazard ratio 1.58 [1.10-2.31], P=0.014) even after adjustment for age, sex, diabetes mellitus, and ischemic pathogenesis. In mice, a left anterior descending coronary artery ligation model of HF lead to increases in MBG, whereas infusion of MBG into mice for 4 weeks lead to significant increases in myeloperoxidase, asymmetrical dimethylarginine, and cardiac fibrosis. CONCLUSIONS In the setting of HF, elevated plasma levels of MBG are associated with right ventricular dysfunction and predict worse long-term clinical outcomes in multivariable models adjusting for established clinical and biochemical risk factors. Infusion of MBG seems to directly contribute to increased nitrative stress and cardiac fibrosis.
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Affiliation(s)
- David J Kennedy
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Kevin Shrestha
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Brendan Sheehey
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Xinmin S Li
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Anuradha Guggilam
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Yuping Wu
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Michael Finucan
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Alaa Gabi
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Charles M Medert
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Kristen Westfall
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Allen Borowski
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Olga Fedorova
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Alexei Y Bagrov
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - W H Wilson Tang
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.).
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Penniyaynen VA, Kipenko AV, Lopatina EV, Bagrov AY, Krylov BV. The effect of marinobufagenin on the growth and proliferation of cells in the organotypic culture. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2015; 462:164-166. [PMID: 26164341 DOI: 10.1134/s0012496615030096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Indexed: 06/04/2023]
Abstract
In recent years, a substantial interest has been aroused in investigating Na(+),K(+) ATPase as a membrane structure which not only performs its direct function in maintaining the gradients of Na(+) and K(+) concentrations, but also may participate in the intracellular signal transduction processes in response to various physiological stimuli. The effect of marinobufagenin, a digitalislike factor, on the growth and proliferation of sensory ganglia, cardiac, retina, skin, and liver tissue explants of 10-12day old chicken embryos was investigated by the organotypic culture method in a wide range of concentrations (10(-10) to 10(-4) M). It was first demonstrated that marinobufagenin inhibited the growth of the investigated tissue explants in the dosedependent but not tissuespecific manner. The experimental data obtained allow us to suggest that the mechanism of regulation of tissue growth by marinobufagenin during the embryonic period of ontogenesis is associated with the modulation of the pump function of Na(+),K(+) ATPase but not its transducing function.
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Affiliation(s)
- V A Penniyaynen
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, 199034, Russia
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