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Blaustein MP, Hamlyn JM. Sensational site: the sodium pump ouabain-binding site and its ligands. Am J Physiol Cell Physiol 2024; 326:C1120-C1177. [PMID: 38223926 PMCID: PMC11193536 DOI: 10.1152/ajpcell.00273.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/22/2023] [Accepted: 01/10/2024] [Indexed: 01/16/2024]
Abstract
Cardiotonic steroids (CTS), used by certain insects, toads, and rats for protection from predators, became, thanks to Withering's trailblazing 1785 monograph, the mainstay of heart failure (HF) therapy. In the 1950s and 1960s, we learned that the CTS receptor was part of the sodium pump (NKA) and that the Na+/Ca2+ exchanger was critical for the acute cardiotonic effect of digoxin- and ouabain-related CTS. This "settled" view was upended by seven revolutionary observations. First, subnanomolar ouabain sometimes stimulates NKA while higher concentrations are invariably inhibitory. Second, endogenous ouabain (EO) was discovered in the human circulation. Third, in the DIG clinical trial, digoxin only marginally improved outcomes in patients with HF. Fourth, cloning of NKA in 1985 revealed multiple NKA α and β subunit isoforms that, in the rodent, differ in their sensitivities to CTS. Fifth, the NKA is a cation pump and a hormone receptor/signal transducer. EO binding to NKA activates, in a ligand- and cell-specific manner, several protein kinase and Ca2+-dependent signaling cascades that have widespread physiological effects and can contribute to hypertension and HF pathogenesis. Sixth, all CTS are not equivalent, e.g., ouabain induces hypertension in rodents while digoxin is antihypertensinogenic ("biased signaling"). Seventh, most common rodent hypertension models require a highly ouabain-sensitive α2 NKA and the elevated blood pressure is alleviated by EO immunoneutralization. These numerous phenomena are enabled by NKA's intricate structure. We have just begun to understand the endocrine role of the endogenous ligands and the broad impact of the ouabain-binding site on physiology and pathophysiology.
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Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, United States
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Tomazelli CA, Ishikawa FM, Couto GK, Parente JM, Castro MMD, Xavier FE, Rossoni LV. Small artery remodeling and stiffening in deoxycorticosterone acetate-salt hypertensive rats involves the interaction between endogenous ouabain/Na + K + -ATPase/cSrc signaling. J Hypertens 2023; 41:1554-1564. [PMID: 37432904 DOI: 10.1097/hjh.0000000000003502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
OBJECTIVE Endogenous ouabain (EO) increases in some patients with hypertension and in rats with volume-dependent hypertension. When ouabain binds to Na + K + -ATPase, cSrc is activated, which leads to multieffector signaling activation and high blood pressure (BP). In mesenteric resistance arteries (MRA) from deoxycorticosterone acetate (DOCA)-salt rats, we have demonstrated that the EO antagonist rostafuroxin blocks downstream cSrc activation, enhancing endothelial function and lowering oxidative stress and BP. Here, we examined the possibility that EO is involved in the structural and mechanical alterations that occur in MRA from DOCA-salt rats. METHODS MRA were taken from control, vehicle-treated DOCA-salt or rostafuroxin (1 mg/kg per day, for 3 weeks)-treated DOCA-salt rats. Pressure myography and histology were used to evaluate the mechanics and structure of the MRA, and western blotting to assess protein expression. RESULTS DOCA-salt MRA exhibited signs of inward hypertrophic remodeling and increased stiffness, with a higher wall:lumen ratio, which were reduced by rostafuroxin treatment. The enhanced type I collagen, TGFβ1, pSmad2/3 Ser465/457 /Smad2/3 ratio, CTGF, p-Src Tyr418 , EGFR, c-Raf, ERK1/2 and p38MAPK protein expression in DOCA-salt MRA were all recovered by rostafuroxin. CONCLUSION A process combining Na + K + -ATPase/cSrc/EGFR/Raf/ERK1/2/p38MAPK activation and a Na + K + -ATPase/cSrc/TGF-1/Smad2/3/CTGF-dependent mechanism explains how EO contributes to small artery inward hypertrophic remodeling and stiffening in DOCA-salt rats. This result supports the significance of EO as a key mediator for end-organ damage in volume-dependent hypertension and the efficacy of rostafuroxin in avoiding remodeling and stiffening of small arteries.
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Affiliation(s)
| | | | | | | | | | - Fabiano Elias Xavier
- Department of Physiology and Pharmacology, Biosciences Center, Federal University of Pernambuco, Recife, Brazil
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Pereira‐Acácio A, Veloso‐Santos JPM, Alves‐Bezerra D, Costa‐Sarmento G, Muzi‐Filho H, Vieyra A. Different antihypertensive and metabolic responses to rostafuroxin in undernourished and normonourished male rats: Outcomes on bodily Na + handling. Physiol Rep 2023; 11:e15820. [PMID: 37667414 PMCID: PMC10477346 DOI: 10.14814/phy2.15820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/06/2023] Open
Abstract
Hypertension is a pandemic nowadays. We aimed to investigate whether chronic undernutrition modifies the response to the antihypertensive drug rostafuroxin in juvenile hypertensive rats. Chronic undernutrition was induced in male rats using a multideficient diet known as the Regional Basic Diet (RBD), mimicking alimentary habits in impoverished regions worldwide. Animals were given RBD-or a control/CTRL normal diet for rodents-from weaning to 90 days, and rostafuroxin (1 mg/kg body mass) was orally administered from day 60 onwards. For the last 2 days, the rats were hosted in metabolic cages to measure food/energy, water, Na+ ingestion, and urinary volume. Rostafuroxin increased food/energy/Na+ intake in CTRL and RBD rats but had opposite effects on Na+ balance (intake minus urinary excretion). The drug normalized the decreased plasma Na+ concentration in RBD rats, increased urinary volume in RBD but not in CTRL, and decreased and increased urinary Na+ concentration in the RBD and CTRL groups, respectively. Rostafuroxin decreased the ouabain-sensitive (Na+ +K+ )ATPase and increased the ouabain-resistant Na+ -ATPase from proximal tubule cells in both groups and normalized the systolic blood pressure in RBD without effect in CTRL rats. We conclude that chronic undernutrition modifies the response of blood pressure and metabolic responses to rostafuroxin.
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Affiliation(s)
- Amaury Pereira‐Acácio
- Graduate Program of Translational Biomedicine/BIOTRANSUniversity of Grande RioDuque de CaxiasBrazil
- Carlos Chagas Filho Institute of BiophysicsFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Center for Structural Biology and Bioimaging/CENABIOFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERARio de JaneiroBrazil
| | - João P. M. Veloso‐Santos
- Carlos Chagas Filho Institute of BiophysicsFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Center for Structural Biology and Bioimaging/CENABIOFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERARio de JaneiroBrazil
| | - Danilo Alves‐Bezerra
- Graduate Program of Translational Biomedicine/BIOTRANSUniversity of Grande RioDuque de CaxiasBrazil
- National Center for Structural Biology and Bioimaging/CENABIOFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERARio de JaneiroBrazil
| | - Glória Costa‐Sarmento
- Carlos Chagas Filho Institute of BiophysicsFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Center for Structural Biology and Bioimaging/CENABIOFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERARio de JaneiroBrazil
| | - Humberto Muzi‐Filho
- Carlos Chagas Filho Institute of BiophysicsFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Center for Structural Biology and Bioimaging/CENABIOFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERARio de JaneiroBrazil
| | - Adalberto Vieyra
- Graduate Program of Translational Biomedicine/BIOTRANSUniversity of Grande RioDuque de CaxiasBrazil
- Carlos Chagas Filho Institute of BiophysicsFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Center for Structural Biology and Bioimaging/CENABIOFederal University of Rio de JaneiroRio de JaneiroBrazil
- National Institute of Science and Technology for Regenerative Medicine/REGENERARio de JaneiroBrazil
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Kemp BA, Howell NL, Gildea JJ, Hinkle JD, Shabanowitz J, Hunt DF, Conaway MR, Keller SR, Carey RM. Evidence That Binding of Cyclic GMP to the Extracellular Domain of NKA (Sodium-Potassium ATPase) Mediates Natriuresis. Circ Res 2023; 132:1127-1140. [PMID: 36919600 PMCID: PMC10171454 DOI: 10.1161/circresaha.122.321693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 03/07/2023] [Indexed: 03/16/2023]
Abstract
BACKGROUND Extracellular renal interstitial guanosine cyclic 3',5'-monophosphate (cGMP) inhibits renal proximal tubule (RPT) sodium (Na+) reabsorption via Src (Src family kinase) activation. Through which target extracellular cGMP acts to induce natriuresis is unknown. We hypothesized that cGMP binds to the extracellular α1-subunit of NKA (sodium-potassium ATPase) on RPT basolateral membranes to inhibit Na+ transport similar to ouabain-a cardiotonic steroid. METHODS Urine Na+ excretion was measured in uninephrectomized 12-week-old female Sprague-Dawley rats that received renal interstitial infusions of vehicle (5% dextrose in water), cGMP (18, 36, and 72 μg/kg per minute; 30 minutes each), or cGMP+rostafuroxin (12 ng/kg per minute) or were subjected to pressure-natriuresis±rostafuroxin infusion. Rostafuroxin is a digitoxigenin derivative that displaces ouabain from NKA. RESULTS Renal interstitial cGMP and raised renal perfusion pressure induced natriuresis and increased phosphorylated SrcTyr416 and Erk 1/2 (extracellular signal-regulated protein kinase 1/2)Thr202/Tyr204; these responses were abolished with rostafuroxin coinfusion. To assess cGMP binding to NKA, we performed competitive binding studies with isolated rat RPTs using bodipy-ouabain (2 μM)+cGMP (10 µM) or rostafuroxin (10 µM) and 8-biotin-11-cGMP (2 μM)+ouabain (10 μM) or rostafuroxin (10 µM). cGMP or rostafuroxin reduced bodipy-ouabain fluorescence intensity, and ouabain or rostafuroxin reduced 8-biotin-11-cGMP staining. We cross-linked isolated rat RPTs with 4-N3-PET-8-biotin-11-cGMP (2 μM); 8-N3-6-biotin-10-cAMP served as negative control. Precipitation with streptavidin beads followed by immunoblot analysis showed that RPTs after cross-linking with 4-N3-PET-8-biotin-11-cGMP exhibited a significantly stronger signal for NKA than non-cross-linked samples and cross-linked or non-cross-linked 8-N3-6-biotin-10-cAMP RPTs. Ouabain (10 μM) reduced NKA in cross-linked 4-N3-PET-8-biotin-11-cGMP RPTs confirming fluorescence staining. 4-N3-PET-8-biotin-11-cGMP cross-linked samples were separated by SDS gel electrophoresis and slices corresponding to NKA molecular weight excised and processed for mass spectrometry. NKA was the second most abundant protein with 50 unique NKA peptides covering 47% of amino acids in NKA. Molecular modeling demonstrated a potential cGMP docking site in the ouabain-binding pocket of NKA. CONCLUSIONS cGMP can bind to NKA and thereby mediate natriuresis.
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Affiliation(s)
- Brandon A Kemp
- Department of Medicine, Division of Endocrinology and Metabolism (B.A.K., N.L.H., S.R.K., R.M.C.), University of Virginia, Charlottesville
| | - Nancy L Howell
- Department of Medicine, Division of Endocrinology and Metabolism (B.A.K., N.L.H., S.R.K., R.M.C.), University of Virginia, Charlottesville
| | - John J Gildea
- Department of Pathology (J.J.G.), University of Virginia, Charlottesville
| | - Josh D Hinkle
- Department of Chemistry (J.D.H., J.S., D.F.H.), University of Virginia, Charlottesville
| | - Jeffrey Shabanowitz
- Department of Chemistry (J.D.H., J.S., D.F.H.), University of Virginia, Charlottesville
| | - Donald F Hunt
- Department of Chemistry (J.D.H., J.S., D.F.H.), University of Virginia, Charlottesville
| | - Mark R Conaway
- Division of Translational Research and Applied Statistics, Department of Public Health Sciences (M.R.C.), University of Virginia, Charlottesville
| | - Susanna R Keller
- Department of Medicine, Division of Endocrinology and Metabolism (B.A.K., N.L.H., S.R.K., R.M.C.), University of Virginia, Charlottesville
| | - Robert M Carey
- Department of Medicine, Division of Endocrinology and Metabolism (B.A.K., N.L.H., S.R.K., R.M.C.), University of Virginia, Charlottesville
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Ren J, Gao X, Guo X, Wang N, Wang X. Research Progress in Pharmacological Activities and Applications of Cardiotonic Steroids. Front Pharmacol 2022; 13:902459. [PMID: 35721110 PMCID: PMC9205219 DOI: 10.3389/fphar.2022.902459] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/11/2022] [Indexed: 12/21/2022] Open
Abstract
Cardiotonic steroids (CTS) are a group of compounds existing in animals and plants. CTS are commonly referred to cardiac glycosides (CGs) which are composed of sugar residues, unsaturated lactone rings and steroid cores. Their traditional mechanism of action is to inhibit sodium-potassium ATPase to strengthen the heart and regulate heart rate, so it is currently widely used in the treatment of cardiovascular diseases such as heart failure and tachyarrhythmia. It is worth noticing that recent studies have found an avalanche of inestimable values of CTS applications in many fields such as anti-tumor, anti-virus, neuroprotection, and immune regulation through multi-molecular mechanisms. Thus, the pharmacological activities and applications of CTS have extensive prospects, which would provide a direction for new drug research and development. Here, we review the potential applications of CTS in cardiovascular system and other systems. We also provide suggestions for new clinical practical strategies of CTS, for many diseases. Four main themes will be discussed, in relation to the impact of CTS, on 1) tumors, 2) viral infections, 3) nervous system diseases and 4) immune-inflammation-related diseases.
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Affiliation(s)
- Junwei Ren
- Key Laboratory of Cardiovascular Medicine Research, Department of Pharmacology, Ministry of Education, Harbin Medical University, Harbin, China
| | - Xinyuan Gao
- Key Laboratory of Cardiovascular Medicine Research, Department of Pharmacology, Ministry of Education, Harbin Medical University, Harbin, China
| | - Xi Guo
- Thyroid Surgery, Affiliated Cancer Hospital, Harbin Medical University, Harbin, China
| | - Ning Wang
- Key Laboratory of Cardiovascular Medicine Research, Department of Pharmacology, Ministry of Education, Harbin Medical University, Harbin, China
| | - Xin Wang
- Department of Pharmacy, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
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Healthy eating index 2015 and major dietary patterns in relation to incident hypertension; a prospective cohort study. BMC Public Health 2022; 22:734. [PMID: 35418042 PMCID: PMC9006467 DOI: 10.1186/s12889-022-13166-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/05/2022] [Indexed: 01/11/2023] Open
Abstract
Background Since hypertension (HTN) is responsible for more than half of all deaths from cardiovascular disease, it is vital to understand the nutritional factors that reduce its risk. Little information, however, is known about it in the Kurdish population. This study was aimed to evaluate the healthy eating index (HEI) 2015 and major dietary patterns concerning incident HTN. Methods This case-cohort study was designed using Ravansar non-communicable diseases (RaNCD) cohort study data (294 participants with incident HTN and 1295 participants as representative random sub-cohort). HEI 2015 and major dietary patterns were extracted using data from their dietary intake, and three major dietary patterns were identified, including plant-based, high protein, and unhealthy dietary patterns. To analyses the association between HEI 2015 and major dietary patterns with incident HTN Cox proportional hazards regression models were applied. Results There was a significant positive correlation between HEI 2015 and plant-based diet (r = 0.492). The participants in the highest quartile of HEI-2015 had a 39% and 30% lower risk of incident HTN, compared to participants in the first quartile in both crude and adjusted model (HR: 0.61; 95% CI: 0.46–0.82) and (HR: 0.70; 95% CI: 0.51–0.97), respectively. Furthermore, participants with the highest tertile of the plant-based dietary pattern were at lower risk of incident HTN in both crude and adjusted models (HR: 0.69; 95% CI: 0.54–0.9) and (HR: 0.70; 95% CI: 0.53–0.94), respectively. However, the other two identified dietary patterns showed no significant association with incident HTN. Conclusions We found evidence indicating higher adherence to HEI 2015 and plant- based diet had protective effects on incident HTN. The HEI 2015 emphasizes limited sodium intake and adequate intake of vegetables and fruits.
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Liu J, Tian J, Sodhi K, Shapiro JI. The Na/K-ATPase Signaling and SGLT2 Inhibitor-Mediated Cardiorenal Protection: A Crossed Road? J Membr Biol 2021; 254:513-529. [PMID: 34297135 PMCID: PMC8595165 DOI: 10.1007/s00232-021-00192-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/06/2021] [Indexed: 12/17/2022]
Abstract
In different large-scale clinic outcome trials, sodium (Na+)/glucose co-transporter 2 (SGLT2) inhibitors showed profound cardiac- and renal-protective effects, making them revolutionary treatments for heart failure and kidney disease. Different theories are proposed according to the emerging protective effects other than the original purpose of glucose-lowering in diabetic patients. As the ATP-dependent primary ion transporter providing the Na+ gradient to drive other Na+-dependent transporters, the possible role of the sodium–potassium adenosine triphosphatase (Na/K-ATPase) as the primary ion transporter and its signaling function is not explored.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA.
| | - Jiang Tian
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Komal Sodhi
- Department of Surgery, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Joseph I Shapiro
- Departments of Medicine, JCE School of Medicine, Marshall University, Huntington, WV, USA
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Abstract
The sodium pump (Na+, K+-ATPase, NKA) is vital for animal cells, as it actively maintains Na+ and K+ electrochemical gradients across the cell membrane. It is a target of cardiotonic steroids (CTSs) such as ouabain and digoxin. As CTSs are almost unique strong inhibitors specific to NKA, a wide range of derivatives has been developed for potential therapeutic use. Several crystal structures have been published for NKA-CTS complexes, but they fail to explain the largely different inhibitory properties of the various CTSs. For instance, although CTSs are thought to inhibit ATPase activity by binding to NKA in the E2P state, we do not know if large conformational changes accompany binding, as no crystal structure is available for the E2P state free of CTS. Here, we describe crystal structures of the BeF3 - complex of NKA representing the E2P ground state and then eight crystal structures of seven CTSs, including rostafuroxin and istaroxime, two new members under clinical trials, in complex with NKA in the E2P state. The conformations of NKA are virtually identical in all complexes with and without CTSs, showing that CTSs bind to a preformed cavity in NKA. By comparing the inhibitory potency of the CTSs measured under four different conditions, we elucidate how different structural features of the CTSs result in different inhibitory properties. The crystal structures also explain K+-antagonism and suggest a route to isoform specific CTSs.
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Canale MP, Noce A, Di Lauro M, Marrone G, Cantelmo M, Cardillo C, Federici M, Di Daniele N, Tesauro M. Gut Dysbiosis and Western Diet in the Pathogenesis of Essential Arterial Hypertension: A Narrative Review. Nutrients 2021; 13:nu13041162. [PMID: 33915885 PMCID: PMC8066853 DOI: 10.3390/nu13041162] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Metabolic syndrome is a cluster of the most dangerous cardiovascular (CV) risk factors including visceral obesity, insulin resistance, hyperglycemia, alterations in lipid metabolism and arterial hypertension (AH). In particular, AH plays a key role in the complications associated with metabolic syndrome. High salt intake is a well-known risk factor for AH and CV diseases. Vasoconstriction, impaired vasodilation, extracellular volume expansion, inflammation, and an increased sympathetic nervous system (SNS) activity are the mechanisms involved in the pathogenesis of AH, induced by Western diet. Gut dysbiosis in AH is associated with reduction of short chain fatty acid-producing bacteria: acetate, butyrate and propionate, which activate different pathways, causing vasoconstriction, impaired vasodilation, salt and water retention and a consequent high blood pressure. Moreover, increased trimethylamine N-oxide and lipopolysaccharides trigger chronic inflammation, which contributes to endothelial dysfunction and target organs damage. Additionally, a high salt-intake diet impacts negatively on gut microbiota composition. A bidirectional neuronal pathway determines the “brain–gut” axis, which, in turn, influences blood pressure levels. Then, we discuss the possible adjuvant novel treatments related to gut microbiota modulation for AH control.
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Affiliation(s)
- Maria Paola Canale
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.P.C.); (M.F.)
| | - Annalisa Noce
- UOC of Internal Medicine-Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.D.L.); (G.M.); (N.D.D.)
- Correspondence: (A.N.); (M.T.); Tel.: +39-06-2090-2194 (A.N.); +39-06-2090-2982 (M.T.)
| | - Manuela Di Lauro
- UOC of Internal Medicine-Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.D.L.); (G.M.); (N.D.D.)
| | - Giulia Marrone
- UOC of Internal Medicine-Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.D.L.); (G.M.); (N.D.D.)
- PhD School of Applied Medical, Surgical Sciences, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Maria Cantelmo
- School of Specialization in Geriatrics, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - Carmine Cardillo
- Department of Internal Medicine and Geriatrics, Policlinico A. Gemelli IRCCS, 00168 Roma, Italy;
| | - Massimo Federici
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.P.C.); (M.F.)
| | - Nicola Di Daniele
- UOC of Internal Medicine-Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.D.L.); (G.M.); (N.D.D.)
| | - Manfredi Tesauro
- UOC of Internal Medicine-Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (M.D.L.); (G.M.); (N.D.D.)
- Correspondence: (A.N.); (M.T.); Tel.: +39-06-2090-2194 (A.N.); +39-06-2090-2982 (M.T.)
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Citterio L, Bianchi G, Scioli GA, Glorioso N, Bigazzi R, Cusi D, Staessen JA, Cavuto S, Ferrandi M, Lanzani C, Li X, Lau LF, Chiang CE, Wang TD, Wang KL, Ferrari P, Manunta P. Antihypertensive treatment guided by genetics: PEARL-HT, the randomized proof-of-concept trial comparing rostafuroxin with losartan. THE PHARMACOGENOMICS JOURNAL 2021; 21:346-358. [PMID: 33649520 PMCID: PMC8159753 DOI: 10.1038/s41397-021-00214-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 01/14/2021] [Accepted: 01/27/2021] [Indexed: 12/22/2022]
Abstract
We compared a standard antihypertensive losartan treatment with a pharmacogenomics-guided rostafuroxin treatment in never-treated Caucasian and Chinese patients with primary hypertension. Rostafuroxin is a digitoxigenin derivative that selectively disrupts the binding to the cSrc-SH2 domain of mutant α-adducin and of the ouabain-activated Na-K pump at 10-11 M. Of 902 patients screened, 172 were enrolled in Italy and 107 in Taiwan. After stratification for country and genetic background, patients were randomized to rostafuroxin or losartan, being the difference in the fall in office systolic blood pressure (OSBP) after 2-month treatment the primary endpoint. Three pharmacogenomic profiles (P) were examined, considering: P1, adding to the gene variants included in the subsequent P2, the variants detected by post-hoc analysis of a previous trial; P2, variants of genes encoding enzymes for endogenous ouabain (EO) synthesis (LSS and HSD3B1), EO transport (MDR1/ABCB1), adducin (ADD1 and ADD3); P3, variants of the LSS gene only. In Caucasians, the group differences (rostafuroxin 50 μg minus losartan 50 mg in OSBP mmHg) were significant both in P2 adjusted for genetic heterogeneity (P2a) and P3 LSS rs2254524 AA [9.8 (0.6-19.0), P = 0.038 and 13.4 (25.4-2.5), P = 0.031, respectively]. In human H295R cells transfected with LSS A and LSS C variants, the EO production was greater in the former (P = 0.038); this difference was abolished by rostafuroxin at 10-11 M. Chinese patients had a similar drop in OSBP to Caucasians with losartan but no change in OSBP with rostafuroxin. These results show that genetics may guide drug treatment for primary hypertension in Caucasians.
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Affiliation(s)
- Lorena Citterio
- Genomics of Renal Diseases and Hypertension Unit, IRCCS San Raffaele Scientific Institute, Università Vita Salute San Raffaele, Milano, Italy.,Università Vita Salute San Raffaele, Milan, Italy
| | | | - Giuseppe A Scioli
- Hypertension and Cardiovascular Prevention Center, Ospedale Ferdinando Veneziale, Isernia, Italy
| | - Nicola Glorioso
- Hypertension and Related Diseases Center, Department of Clinical and Experimental Medicine, University of Sassari, Sassari, Italy
| | | | - Daniele Cusi
- Institute of Biomedical Technologies Milano National Research Council of Italy (CNR), Segrate, Milano, Italy.,Bio4Dreams Scientific Unit, Bio4Dreams-Business Nursery for Life Sciences, Milano, Italy
| | - Jan A Staessen
- Research Unit Hypertension and Cardiovascular Epidemiology KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Silvio Cavuto
- Clinical Trials and Statistics Unit, Azienda USL-IRCCS di Reggio Emilia, Reggio Emilia, Italy
| | | | - Chiara Lanzani
- Genomics of Renal Diseases and Hypertension Unit, IRCCS San Raffaele Scientific Institute, Università Vita Salute San Raffaele, Milano, Italy.,Università Vita Salute San Raffaele, Milan, Italy
| | | | - Lit-Fui Lau
- Zhaoke (Guangzhou) Ophthalmology Pharmaceutical Limited, Guangzhou, China
| | - Chern-En Chiang
- General Clinical Research Center, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
| | - Tzung-Dau Wang
- Cardiovascular Center and Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Kang-Ling Wang
- General Clinical Research Center, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
| | | | - Paolo Manunta
- Genomics of Renal Diseases and Hypertension Unit, IRCCS San Raffaele Scientific Institute, Università Vita Salute San Raffaele, Milano, Italy.,Università Vita Salute San Raffaele, Milan, Italy
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11
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Yang CW, Hsu HY, Chang HY, Lee YZ, Lee SJ. Natural cardenolides suppress coronaviral replication by downregulating JAK1 via a Na +/K +-ATPase independent proteolysis. Biochem Pharmacol 2020; 180:114122. [PMID: 32592721 PMCID: PMC7314687 DOI: 10.1016/j.bcp.2020.114122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/18/2020] [Accepted: 06/22/2020] [Indexed: 12/21/2022]
Abstract
Natural cardenolides suppress coronaviral activity via downregulating JAK1. Natural cardenolides downregulate JAK1 in a Na+/K+-ATPase independent manner. Ouabain (cardenolides) activates Ndfip1/2 and NEDD4 to mediate JAK1 proteolysis. Ndfip1/2 and NEDD4 mediated JAK1 proteolysis attenuates coronaviral activity.
An unprecedented biological function of natural cardenolides independent of their membrane target Na+/K+-ATPase is disclosed. Previously, we reported that cardenolides impart anti-transmissible gastroenteritis coronavirus (anti-TGEV) activity through the targeting of Na+/K+-ATPase and its associated PI3K_PDK1_RSK2 signaling. Swine testis cells with Na+/K+-ATPase α1 knocked down exhibited decreased susceptibility to TGEV infectivity and attenuated PI3K_PDK1_RSK2 signaling. Herein, we further explored a Na+/K+-ATPase-independent signaling axis induced by natural cardenolides that also afforded significant anti-coronaviral activity for porcine TGEV and human HCoV-OC43. Using pharmacological inhibition and gene silencing techniques, we found that this anti-TGEV or anti-HCoV-OC43 activity was caused by JAK1 proteolysis and mediated through upstream activation of Ndfip1/2 and its effector NEDD4. This study provides novel insights into the pharmacological effects of natural cardenolides, and is expected to inform their future development as antiviral agents.
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Affiliation(s)
- Cheng-Wei Yang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli 35053, Taiwan, ROC
| | - Hsing-Yu Hsu
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli 35053, Taiwan, ROC
| | - Hsin-Yu Chang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli 35053, Taiwan, ROC
| | - Yue-Zhi Lee
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli 35053, Taiwan, ROC
| | - Shiow-Ju Lee
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli 35053, Taiwan, ROC.
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12
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Pavlovic D. Endogenous cardiotonic steroids and cardiovascular disease, where to next? Cell Calcium 2019; 86:102156. [PMID: 31896530 PMCID: PMC7031694 DOI: 10.1016/j.ceca.2019.102156] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/24/2019] [Accepted: 12/24/2019] [Indexed: 11/18/2022]
Abstract
Ever since British Physician William Withering first described the use of foxglove extract for treatment of patients with congestive heart failure in 1785, cardiotonic steroids have been used clinically to treat heart failure and more recently atrial fibrillation. Due to their ability to bind and inhibit the ubiquitous transport enzyme sodium potassium pump, thus regulating intracellular Na+ concentration in every living cell, they are also an essential tool for research into the sodium potassium pump structure and function. Exogenous CTS have been clearly demonstrated to affect cardiovascular system through modulation of vagal tone, cardiac contraction (via ionic changes) and altered natriuresis. Reports of a number of endogenous CTS, since the 1980s, have intensified research into their physiologic and pathophysiologic roles and opened up novel therapeutic targets. Substantive evidence pointing to the role of endogenous ouabain and marinobufagenin, the two most prominent CTS, in development of cardiovascular disease has accumulated. Nevertheless, their presence, structure, biosynthesis pathways and even mechanism of action remain unclear or controversial. In this review the current state-of-the-art, the controversies and the remaining questions surrounding the role of endogenous cardiotonic steroids in health and disease are discussed.
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Affiliation(s)
- Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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13
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Lingemann M, McCarty T, Liu X, Buchholz UJ, Surman S, Martin SE, Collins PL, Munir S. The alpha-1 subunit of the Na+,K+-ATPase (ATP1A1) is required for macropinocytic entry of respiratory syncytial virus (RSV) in human respiratory epithelial cells. PLoS Pathog 2019; 15:e1007963. [PMID: 31381610 PMCID: PMC6695199 DOI: 10.1371/journal.ppat.1007963] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/15/2019] [Accepted: 07/05/2019] [Indexed: 01/07/2023] Open
Abstract
Human respiratory syncytial virus (RSV) is the leading viral cause of acute pediatric lower respiratory tract infections worldwide, with no available vaccine or effective antiviral drug. To gain insight into virus-host interactions, we performed a genome-wide siRNA screen. The expression of over 20,000 cellular genes was individually knocked down in human airway epithelial A549 cells, followed by infection with RSV expressing green fluorescent protein (GFP). Knockdown of expression of the cellular ATP1A1 protein, which is the major subunit of the Na+,K+-ATPase of the plasma membrane, had one of the strongest inhibitory effects on GFP expression and viral titer. Inhibition was not observed for vesicular stomatitis virus, indicating that it was RSV-specific rather than a general effect. ATP1A1 formed clusters in the plasma membrane very early following RSV infection, which was independent of replication but dependent on the attachment glycoprotein G. RSV also triggered activation of ATP1A1, resulting in signaling by c-Src-kinase activity that transactivated epidermal growth factor receptor (EGFR) by Tyr845 phosphorylation. ATP1A1 signaling and activation of both c-Src and EGFR were found to be required for efficient RSV uptake. Signaling events downstream of EGFR culminated in the formation of macropinosomes. There was extensive uptake of RSV virions into macropinosomes at the beginning of infection, suggesting that this is a major route of RSV uptake, with fusion presumably occurring in the macropinosomes rather than at the plasma membrane. Important findings were validated in primary human small airway epithelial cells (HSAEC). In A549 cells and HSAEC, RSV uptake could be inhibited by the cardiotonic steroid ouabain and the digitoxigenin derivative PST2238 (rostafuroxin) that bind specifically to the ATP1A1 extracellular domain and block RSV-triggered EGFR Tyr845 phosphorylation. In conclusion, we identified ATP1A1 as a host protein essential for macropinocytic entry of RSV into respiratory epithelial cells, and identified PST2238 as a potential anti-RSV drug. RSV continues to be the most important viral cause of severe bronchiolitis and pneumonia in infants and young children, and also has a substantial impact in the elderly. It is estimated to claim the lives of ~118,000 children under five years of age annually. No vaccine or antiviral drug suitable for general use is available. The involvement of host factors in RSV infection and replication is not well understood, but this knowledge might lead to intervention strategies to prevent infection. Using a genome-wide siRNA screen to knock down the expression of over 20,000 individual cellular genes, we identified ATP1A1, the major subunit of the Na+,K+-ATPase, as an important host protein for RSV entry. We showed that ATP1A1 activation by RSV resulted in transactivation of EGFR by Src-kinase activity, resulting in the uptake of RSV particles into the host cell through macropinocytosis. We also showed that the cardiotonic steroid ouabain and the synthetic digitoxigenin derivative PST2238, which bind specifically to the extracellular domain of ATP1A1, significantly reduced RSV entry. Taken together, we describe a novel ATP1A1-enabled mechanism used by RSV to enter the host cell, and describe candidate antiviral drugs that block this entry.
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Affiliation(s)
- Matthias Lingemann
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Thomas McCarty
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Xueqiao Liu
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ursula J. Buchholz
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sonja Surman
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Scott E. Martin
- Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America
| | - Peter L. Collins
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Shirin Munir
- RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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14
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A Review of the Epidemiological Evidence for Adducin Family Gene Polymorphisms and Hypertension. Cardiol Res Pract 2019; 2019:7135604. [PMID: 31275642 PMCID: PMC6589276 DOI: 10.1155/2019/7135604] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/11/2019] [Accepted: 04/17/2019] [Indexed: 12/31/2022] Open
Abstract
Hypertension is one of the most common cardiovascular diseases that seriously endangers human health and has become a significant public health problem worldwide. In the vast majority of patients, the cause of hypertension is unknown, called essential hypertension (EH), accounting for more than 95% of total hypertension. Epidemiological and genetic studies of humans and animals provide strong evidence of a causal relationship between high salt intake and hypertension. Adducin is one of the important candidate genes for essential hypertension. Adducin is a heterodimeric or heterotetrameric protein that consists of α, β, and γ subunits; the three subunits are encoded by genes (ADD1, ADD2, and ADD3) that map to three different chromosomes. Animal model experiments and clinical studies suggest that changes in single-nucleotide polymorphisms (SNPs) at part of the adducin family gene increase the Na+-K+-ATPase activity of the renal tubular basement membrane and increase the reabsorption of Na+ by renal tubular epithelial cells, which may cause hypertension. This review makes a summary on the structure, function, and mechanism of adducin and the role of adducin on the onset of EH, providing a basis for the early screening, prevention, and treatment of EH.
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15
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Regioselective single pot C3-glycosylation of strophanthidol using methylboronic acid as a transient protecting group. J Antibiot (Tokyo) 2019; 72:437-448. [PMID: 30948784 DOI: 10.1038/s41429-019-0172-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/09/2019] [Accepted: 02/18/2019] [Indexed: 12/15/2022]
Abstract
This manuscript describes a single pot protocol for the selective introduction of unprotected sugars to the C3 position of the cardiotonic steroid strophanthidol. These reactions proceed with high levels of regiocontrol (>20:1 rr) in the presence of three other hydroxyl functionalities including the C19 primary hydroxyl group and could be applied to different sugars to provide the deprotected cardiac glycosides upon work up (5 examples, 77-69% yield per single operation). The selective glycosylation of the less reactive C3 position is accomplished by the use of traceless protection with methylboronic acid that blocks the C5 and C19 hydroxyls by forming a cyclic boronic ester, followed by in situ glycosylation and a work up with ammonia in methanol to remove the boronic ester and the carbohydrate ester protecting groups.
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16
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Khatri HR, Bhattarai B, Kaplan W, Li Z, Curtis Long MJ, Aye Y, Nagorny P. Modular Total Synthesis and Cell-Based Anticancer Activity Evaluation of Ouabagenin and Other Cardiotonic Steroids with Varying Degrees of Oxygenation. J Am Chem Soc 2019; 141:4849-4860. [PMID: 30802047 PMCID: PMC6516474 DOI: 10.1021/jacs.8b12870] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A Cu(II)-catalyzed diastereoselective Michael/aldol cascade approach is used to accomplish concise total syntheses of cardiotonic steroids with varying degrees of oxygenation including cardenolides ouabagenin, sarmentologenin, 19-hydroxysarmentogenin, and 5- epi-panogenin. These syntheses enabled the subsequent structure activity relationship (SAR) studies on 37 synthetic and natural steroids to elucidate the effect of oxygenation, stereochemistry, C3-glycosylation, and C17-heterocyclic ring. Based on this parallel evaluation of synthetic and natural steroids and their derivatives, glycosylated steroids cannogenol-l-α-rhamnoside (79a), strophanthidol-l-α-rhamnoside (92), and digitoxigenin-l-α-rhamnoside (97) were identified as the most potent steroids demonstrating broad anticancer activity at 10-100 nM concentrations and selectivity (nontoxic at 3 μM against NIH-3T3, MEF, and developing fish embryos). Further analyses indicate that these molecules show a general mode of anticancer activity involving DNA-damage upregulation that subsequently induces apoptosis.
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Affiliation(s)
- Hem Raj Khatri
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109 USA
| | - Bijay Bhattarai
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109 USA
| | - Will Kaplan
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109 USA
| | - Zhongzheng Li
- Department of Chemistry, Nankai University, Nankai, People Republic of China
| | | | - Yimon Aye
- École Polytechnique Fédérale de Lausanne, Institute of Chemical Sciences and Engineering, 1015, Lausanne, Switzerland
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853 USA
| | - Pavel Nagorny
- Chemistry Department, University of Michigan, Ann Arbor, MI 48109 USA
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17
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Chao PK, Chang HF, Ou LC, Chuang JY, Lee PT, Chang WT, Chen SC, Ueng SH, Hsu JTA, Tao PL, Law PY, Loh HH, Yeh SH. Convallatoxin enhance the ligand-induced mu-opioid receptor endocytosis and attenuate morphine antinociceptive tolerance in mice. Sci Rep 2019; 9:2405. [PMID: 30787373 PMCID: PMC6382827 DOI: 10.1038/s41598-019-39555-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/07/2019] [Indexed: 11/29/2022] Open
Abstract
Morphine is a unique opioid analgesic that activates the mu-opioid receptor (MOR) without efficiently promoting its endocytosis that may underlie side effects. Our objective was to discover a novel enhancer of ligand-induced MOR endocytosis and determine its effects on analgesia, tolerance and dependence. We used high-throughput screening to identify convallatoxin as an enhancer of ligand-induced MOR endocytosis with high potency and efficacy. Treatment of cells with convallatoxin enhanced morphine-induced MOR endocytosis through an adaptor protein 2 (AP2)/clathrin-dependent mechanism, attenuated morphine-induced phosphorylation of MOR, and diminished desensitization of membrane hyperpolarization. Furthermore, co-treatment with chronic convallatoxin reduced morphine tolerance in animal models of acute thermal pain and chronic inflammatory pain. Acute convallatoxin administration reversed morphine tolerance and dependence in morphine-tolerant mice. These findings suggest convallatoxin are potentially therapeutic for morphine side effects and open a new avenue to study MOR trafficking.
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Affiliation(s)
- Po-Kuan Chao
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - Hsiao-Fu Chang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - Li-Chin Ou
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - Jian-Ying Chuang
- The PhD Program for Neural Regenerative Medicine, Taipei Medical University, Taipei, 110, Taiwan
| | - Pin-Tse Lee
- Cellular Pathobiology Section, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, Baltimore, MD, 21224, USA
| | - Wan-Ting Chang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - Shu-Chun Chen
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - Shau-Hua Ueng
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - John Tsu-An Hsu
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan
| | - Pao-Luh Tao
- Center for Neuropsychiatric Research, National Heath Research Institutes, Zhunan, 35053, Taiwan
| | - Ping-Yee Law
- Department of Pharmacology, Medical School University of Minnesota, Minneapolis, MN, 55455-0217, USA
| | - Horace H Loh
- Department of Pharmacology, Medical School University of Minnesota, Minneapolis, MN, 55455-0217, USA
| | - Shiu-Hwa Yeh
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, 35053, Taiwan.
- The PhD Program for Neural Regenerative Medicine, Taipei Medical University, Taipei, 110, Taiwan.
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18
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Nakashima A, Kawamoto T, Noshiro M, Ueno T, Doi S, Honda K, Maruhashi T, Noma K, Honma S, Masaki T, Higashi Y, Kato Y. Dec1 and CLOCK Regulate Na +/K +-ATPase β1 Subunit Expression and Blood Pressure. Hypertension 2018; 72:746-754. [PMID: 30012868 DOI: 10.1161/hypertensionaha.118.11075] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Blood pressure shows a circadian rhythm, and recent studies have suggested the involvement of a molecular clock system in its control. In the clock system, the CLOCK (circadian locomotor output cycles kaput):BMAL1 (brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein-1) heterodimer enhances promoter activity of clock genes, and DEC1 (BHLHE40/STRA13/SHARP-2) represses CLOCK/BMAL1-enhanced promoter activity through competition for binding to the clock element, CACGTG E-box. However, the molecular mechanisms by which this system regulates blood pressure remain unclear. Here, we show that DEC1 suppressed the expression of ATP1B1, which encodes the β1 subunit of the Na+/K+-ATPase and elevated blood pressure. Using chromatin immunoprecipitation and chromatin immunoprecipitation-on-chip analyses, we found that DEC1 and CLOCK bound to E-boxes in the ATP1B1 promoter. Luciferase assays revealed that CLOCK:BMAL1 heterodimer enhanced transcription from the ATP1B1 promoter, whereas DEC1 suppressed this transactivation. Accordingly, Atp1b1 mRNA and protein levels in mouse kidney, aorta, and heart showed a circadian rhythm that was antiphasic to the blood pressure rhythm. Furthermore, Dec1-deficient mice showed enhanced Atp1b1 expression in these tissues and reduced blood pressure. In contrast, Clock-mutant mice showed reduced Atp1b1 expression and elevated blood pressure. Our results raise the possibility that transcriptional regulation of Atp1b1 by DEC1 and CLOCK:BMAL1 contributes to blood pressure.
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Affiliation(s)
- Ayumu Nakashima
- From the Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine (A.N., K.N., Y.H.)
- Department of Stem Cell Biology and Medicine (A.N.)
- Department of Nephrology (A.N., T.U., S.D., T. Masaki)
| | - Takeshi Kawamoto
- Department of Dental and Medical Biochemistry (T.K., M.N., K.H., Y.K.)
| | - Mitsuhide Noshiro
- Department of Dental and Medical Biochemistry (T.K., M.N., K.H., Y.K.)
| | | | - Shigehiro Doi
- Department of Nephrology (A.N., T.U., S.D., T. Masaki)
| | - Kiyomasa Honda
- Department of Dental and Medical Biochemistry (T.K., M.N., K.H., Y.K.)
| | - Tatsuya Maruhashi
- Department of Cardiovascular Medicine (T. Maruhashi), Graduate School of Biomedical & Health Sciences, Hiroshima University, Japan
| | - Kensuke Noma
- From the Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine (A.N., K.N., Y.H.)
- Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research (K.N., Y.H.), Hiroshima University Hospital, Japan
| | - Sato Honma
- Department of Chronomedicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan (S.H.)
| | - Takao Masaki
- Department of Nephrology (A.N., T.U., S.D., T. Masaki)
| | - Yukihito Higashi
- From the Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine (A.N., K.N., Y.H.)
- Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research (K.N., Y.H.), Hiroshima University Hospital, Japan
| | - Yukio Kato
- Department of Dental and Medical Biochemistry (T.K., M.N., K.H., Y.K.)
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19
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Endogenous Ouabain and Related Genes in the Translation from Hypertension to Renal Diseases. Int J Mol Sci 2018; 19:ijms19071948. [PMID: 29970843 PMCID: PMC6073363 DOI: 10.3390/ijms19071948] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 01/22/2023] Open
Abstract
The endogenous ouabain (EO) is a steroid hormone secreted by the adrenal gland with cardio-tonic effects. In this article, we have reviewed and summarized the most recent reports about EO, particularly with regard to how it may interact with specific genetic backgrounds. We have focused our attention on the EO’s potential pathogenic role in several diseases, including renal failure, essential hypertension and heart failure. Notably, these reports have demonstrated that EO acts as a pro-hypertrophic and growth-promoting hormone, which might lead to a cardiac remodeling affecting cardiovascular functions and structures. In addition, a possible role of EO in the development of acute kidney injury has been hypothesized. During the last decays, many important improvements permitted a deeper understanding of EO’s metabolisms and functions, including the characteristics of its receptor and the effects of its activation. Such progresses indicated that EO has significant implications in the pathogenesis of many common diseases. The patho-physiological role of EO in the development of hypertension and other cardiac and renal complications have laid the basis for the development of a new selective compound that could selectively modulate the genetic and molecular mechanisms involved in EO’s action. It is evident that the knowledge of EO has incredibly increased; however, many important areas remain to be further investigated.
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20
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX
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21
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Aldosterone and Mineralocorticoid Receptors-Physiology and Pathophysiology. Int J Mol Sci 2017; 18:ijms18051032. [PMID: 28492512 PMCID: PMC5454944 DOI: 10.3390/ijms18051032] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/02/2017] [Accepted: 05/04/2017] [Indexed: 12/11/2022] Open
Abstract
Aldosterone is a uniquely terrestrial hormone, first appearing in lungfish, which have both gills and lungs. Mineralocorticoid receptors (MRs), on the other hand, evolved much earlier, and are found in cartilaginous and bony fish, presumptive ligand cortisol. MRs have equivalent high affinity for aldosterone, progesterone, and cortisol; in epithelia, despite much higher cortisol circulating levels, aldosterone selectively activates MRs by co-expression of the enzyme 11β-hydroxysteroid dehydrogenase, Type 11. In tissues in which the enzyme is not expressed, MRs are overwhelmingly occupied but not activated by cortisol, which normally thus acts as an MR antagonist; in tissue damage, however, cortisol mimics aldosterone and acts as an MR agonist. The risk profile for primary aldosteronism (PA) is much higher than that in age-, sex-, and blood pressure-matched essential hypertensives. High levels of aldosterone per se are not the problem: in chronic sodium deficiency, as seen in the monsoon season in the highlands of New Guinea, plasma aldosterone levels are extraordinarily high, but cause neither hypertension nor cardiovascular damage. Such damage occurs when aldosterone levels are out of the normal feedback control, and are inappropriately elevated for the salt status of the individual (or experimental animal). The question thus remains of how excess salt can synergize with elevated aldosterone levels to produce deleterious cardiovascular effects. One possible mechanism is through the agency of the elusive ouabain-like factors (OLFs). Such factors are secreted from the adrenal in response to ACTH (adrenalocortical tropic hormone), to angiotensin via AT2R, and-the polar opposite of aldosterone-to sodium loading. They act on blood vessels to cause vasoconstriction and thus elevate blood pressure to dump excess sodium through pressure natriuresis. Their levels are chronically elevated in PA in response to the continually elevated sodium status, and they thus act to constrict coronary and systemic arteries. In the context of the elevated blood volume and total body sodium in a PA patient, this raises blood pressure and acts as the proximate cause of cardiovascular damage. If this is the case, it would appear to offer new insights into therapy for PA. One would be the use of digibindin, or its more recent successors as antagonists of OLFs acting on Na/K ATPase at the vessel wall. A second would be to routinely combine a low dose MR antagonist, an ENaC inhibitor, and sodium restriction as first-line therapy for bilateral aldosterone overproduction. Finally, for unilateral cases post-surgery, there is good reason to include low-dose MRs in drug therapy if required, given the ability of cortisol in damaged blood vessels to mimic aldosterone vasoconstrictor action.
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Abstract
During the past 20 years, the studies on genetics or pharmacogenomics of primary hypertension provided interesting results supporting the role of genetics, but no actionable finding ready to be translated into personalized medicine. Two types of approaches have been applied: a "hypothesis-driven" approach on the candidate genes, coding for proteins involved in the biochemical machinery underlying the regulation of BP, and an "unbiased hypothesis-free" approach with GWAS, based on the randomness principles of frequentist statistics. During the past 10-15 years, the application of the latter has overtaken the application of the former leading to an enlargement of the number of previously unknown candidate loci or genes but without any actionable result for the therapy of hypertension. In the present review, we summarize the results of our hypothesis-driven approach based on studies carried out in rats with genetic hypertension and in humans with essential hypertension at the pre-hypertensive and early hypertensive stages. These studies led to the identification of mutant adducin and endogenous ouabain as candidate genetic-molecular mechanisms in both species. Rostafuroxin has been developed for its ability to selectively correct Na(+) pump abnormalities sustained by the two abovementioned mechanisms and to selectively reduce BP in rats and in humans carrying the gene variants underlying the mutant adducin and endogenous ouabain (EO) effects. A clinical trial is ongoing to substantiate these findings. Future studies should apply both the candidate gene and GWAS approaches to fully exploit the potential of genetics in optimizing the personalized therapy.
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Cao C, Zhao X, Fan R, Zhao J, Luan Y, Zhang Z, Xu S. Dietary selenium increases the antioxidant levels and ATPase activity in the arteries and veins of poultry. Biol Trace Elem Res 2016; 172:222-227. [PMID: 26637493 DOI: 10.1007/s12011-015-0584-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 11/30/2015] [Indexed: 12/25/2022]
Abstract
Selenium (Se) deficiency is associated with the pathogenesis of vascular diseases. It has been shown that oxidative levels and ATPase activity were involved in Se deficiency diseases in humans and mammals; however, the mechanism by how Se influences the oxidative levels and ATPase activity in the poultry vasculature is unclear. We assessed the effects of dietary Se deficiency on the oxidative stress parameters (superoxide dismutase, catalase, and hydroxyl radical) and ATPase (Na(+)K(+)-ATPase, Ca(++)-ATPase, Mg(++)-ATPase, and Ca(++)Mg(++)-ATPase) activity in broiler poultry. A total of 40 broilers (1-day old) were randomly divided into a Se-deficient group (L group, fed a Se-deficient diet containing 0.08 mg/kg Se) and a control group (C group, fed a diet containing sodium selenite at 0.20 mg/kg Se). Then, arteries and veins were collected following euthanasia when typical symptoms of Se deficiency appeared. Antioxidant indexes and ATPase activity were evaluated using standard assays in arteries and veins. The results indicated that superoxide dismutase activity in the artery according to dietary Se deficiency was significantly lower (p < 0.05) compared with the C group. The catalase activity in the veins and hydroxyl radical inhibition in the arteries and veins by dietary Se deficiency were significantly higher (p < 0.05) compared with the C group. The Se-deficient group showed a significantly lower (p < 0.05) tendency in Na(+)K(+)-ATPase activity, Ca(++)-ATPase activity, and Ca(++)Mg(++)-ATPase activity. There were strong correlations between antioxidant indexes and Ca(++)-ATPase activity. Thus, these results indicate that antioxidant indexes and ATPases may have special roles in broiler artery and vein injuries under Se deficiency.
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Affiliation(s)
- Changyu Cao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xia Zhao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Ruifeng Fan
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Jinxin Zhao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Yilin Luan
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Ziwei Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
| | - Shiwen Xu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
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Yosef E, Katz A, Peleg Y, Mehlman T, Karlish SJD. Do Src Kinase and Caveolin Interact Directly with Na,K-ATPase? J Biol Chem 2016; 291:11736-50. [PMID: 27022017 DOI: 10.1074/jbc.m116.721084] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Indexed: 12/14/2022] Open
Abstract
Much evidence points to a role of Na,K-ATPase in ouabain-dependent signal transduction. Based on experiments with different cell lines and native tissue membranes, a current hypothesis postulates direct interactions between the Na,K-ATPase and Src kinase (non-receptor tyrosine kinase). Na,K-ATPase is proposed to bind Src kinase and inhibit its activity, whereas ouabain, the specific Na,K-ATPase inhibitor, binds and stabilizes the E2 conformation, thus exposing the Src kinase domain and its active site Tyr-418 for activation. Ouabain-dependent signaling is thought to be mediated within caveolae by a complex consisting of Na,K-ATPase, caveolin, and Src kinase. In the current work, we have looked for direct interactions utilizing purified recombinant Na,K-ATPase (human α1β1FXYD1 or porcine α1D369Nβ1FXYD1) and purified human Src kinase and human caveolin 1 or interactions between these proteins in native membrane vesicles isolated from rabbit kidney. By several independent criteria and techniques, no stable interactions were detected between Na,K-ATPase and purified Src kinase. Na,K-ATPase was found to be a substrate for Src kinase phosphorylation at Tyr-144. Clear evidence for a direct interaction between purified human Na,K-ATPase and human caveolin was obtained, albeit with a low molar stoichiometry (1:15-30 caveolin 1/Na,K-ATPase). In native renal membranes, a specific caveolin 14-5 oligomer (95 kDa) was found to be in direct interaction with Na,K-ATPase. We inferred that a small fraction of the renal Na,K-ATPase molecules is in a ∼1:1 complex with a caveolin 14-5 oligomer. Thus, overall, whereas a direct caveolin 1/Na,K-ATPase interaction is confirmed, the lack of direct Src kinase/Na,K-ATPase binding requires reassessment of the mechanism of ouabain-dependent signaling.
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Affiliation(s)
| | | | - Yoav Peleg
- the Israel Structural Proteomics Center, and
| | - Tevie Mehlman
- the Biological Services Department-Mass Spectrometry unit, Weizmann Institute of Science, Rehovot 7610001, Israel
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Shattock MJ, Ottolia M, Bers DM, Blaustein MP, Boguslavskyi A, Bossuyt J, Bridge JHB, Chen-Izu Y, Clancy CE, Edwards A, Goldhaber J, Kaplan J, Lingrel JB, Pavlovic D, Philipson K, Sipido KR, Xie ZJ. Na+/Ca2+ exchange and Na+/K+-ATPase in the heart. J Physiol 2015; 593:1361-82. [PMID: 25772291 PMCID: PMC4376416 DOI: 10.1113/jphysiol.2014.282319] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/30/2014] [Indexed: 12/17/2022] Open
Abstract
This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field.
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Affiliation(s)
- Michael J Shattock
- King's College London BHF Centre of Excellence, The Rayne Institute, St Thomas' Hospital, London, SE1 7EH, UK
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Lupoli S, Salvi E, Barcella M, Barlassina C. Pharmacogenomics considerations in the control of hypertension. Pharmacogenomics 2015; 16:1951-64. [PMID: 26555875 DOI: 10.2217/pgs.15.131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The response to antihypertensive therapy is very heterogeneous and the need by the physicians to account for it has driven much interest in pharmacogenomics of antihypertensive drugs. The Human Genome Project and the initiatives in genomics that followed, generated a huge number of genetic data that furnished the tools to explore the genotype-phenotype association in candidate genes and at genome-wide level. In spite of the efforts and the great number of publications, pharmacogenomics of antihypertensive drugs is far from being used in clinical practice. In this review, we analyze the main findings available in PubMed from 2010 to 2015, in relation to the major classes of antihypertensive drugs. We also describe a new Phase II drug that targets two specific hypertension predisposing mechanisms.
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Affiliation(s)
- Sara Lupoli
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
| | - Erika Salvi
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
| | - Matteo Barcella
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
| | - Cristina Barlassina
- Department of Health Sciences, Milan University, Via Rudinì 8, 20142 Milan & Filarete Foundation, Viale Ortles 22/4, 20139 Milan, Italy
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Buckalew VM. Endogenous digitalis-like factors: an overview of the history. Front Endocrinol (Lausanne) 2015; 6:49. [PMID: 25918512 PMCID: PMC4394700 DOI: 10.3389/fendo.2015.00049] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 03/24/2015] [Indexed: 12/22/2022] Open
Abstract
The sodium pump is a ubiquitous cell surface enzyme, a Na, K ATPase, which maintains ion gradients between cells and the extracellular fluid (ECF). The extracellular domain of this enzyme contains a highly conserved binding site, a receptor for a plant derived family of compounds, the digitalis glycosides. These compounds inhibit the enzyme and are used in the treatment of congestive heart failure and certain cardiac arrhythmias. The highly conserved nature of this enzyme and its digitalis receptor led to early suggestions that endogenous regulators might exist. Recent examination of this hypothesis emerged from research in two separate areas: the regulation of ECF volume by a natriuretic hormone (NH), and the regulation of peripheral vascular resistance by a circulating inhibitor of vascular Na, K ATPase. These two areas merged with the hypothesis that NH and the vascular Na, K ATPase inhibitor were in fact the same entity, and that it played a causative role in the pathophysiology of certain types of hypertension. The possibility that multiple endogenous digitalis-like factors (EDLFs) exist emerged from efforts to characterize the circulating enzyme inhibitory activity. In this review, the development of this field from its beginnings is traced, the current status of the structure of EDLFs is briefly discussed, and areas for future development are suggested.
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Affiliation(s)
- Vardaman M. Buckalew
- Medical Center Boulevard, Wake Forest School of Medicine, Winston Salem, NC, USA
- *Correspondence: Vardaman M. Buckalew, Medical Center Boulevard, Wake Forest School of Medicine, Winston Salem, NC 27157, USA e-mail:
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Pavlovic D. The role of cardiotonic steroids in the pathogenesis of cardiomyopathy in chronic kidney disease. Nephron Clin Pract 2014; 128:11-21. [PMID: 25341357 DOI: 10.1159/000363301] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cardiotonic steroids (CTS) are a new class of hormones that circulate in the blood and are divided into two distinct groups, cardenolides, such as ouabain and digoxin, and bufadienolides, such as marinobufagenin, telocinobufagin and bufalin. They have the ability to bind and inhibit the ubiquitous transport enzyme sodium potassium pump, thus regulating intracellular Na(+) concentration in every living cell. Although digoxin has been prescribed to heart failure patients for at least 200 years, the realization that CTS are endogenously produced has intensified research into their physiological and pathophysiological roles. Over the last two decades, substantial evidence has accumulated demonstrating the effects of endogenously synthesised CTS on the kidneys, vasculature and the heart. In this review, the current state of art and the controversies surrounding the manner in which CTS mediate their pathophysiological effects are discussed. Several potential therapeutic strategies have emerged as a result of our increased understanding of the role CTS play in health and disease.
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Affiliation(s)
- Davor Pavlovic
- Cardiovascular Division, King's College London, Rayne Institute, St. Thomas' Hospital, London, UK
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29
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Rostafuroxin ameliorates endothelial dysfunction and oxidative stress in resistance arteries from deoxycorticosterone acetate-salt hypertensive rats: the role of Na+K+-ATPase/ cSRC pathway. J Hypertens 2014; 32:542-54. [PMID: 24309491 DOI: 10.1097/hjh.0000000000000059] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIMS Endogenous ouabain is elevated in patients and experimental models of hypertension and is associated with elevated mortality. In this context, it is reasonable to assume that a new antihypertensive drug that inhibits the deleterious effects of endogenous ouabain may be a specific pharmacological tool for hypertension treatment. Here, we investigated the effects of rostafuroxin (ROSTA), an ouabain inhibitor, on SBP, endothelial dysfunction and oxidative stress in deoxycorticosterone acetate (DOCA)-salt rats. METHODS AND RESULTS A hypertensive model was established in uninephrectomized Wistar rats using DOCA-salt. After SBP stabilization, DOCA-salt rats were divided into two groups: DOCA-salt (control) and DOCA-salt treatment with ROSTA (1 mg/kg per day gavage, 3 weeks). The SBP was measured using the tail-cuff method, and vascular function was assessed in mesenteric-resistance arteries (MRAs) using a wire myograph. Nitric oxide and reactive oxygen species production were investigated. Western blot was performed to quantify protein expression. Our results indicated that ROSTA treatment decreased SBP, improved acetylcholine-induced relaxation via enhanced nitric oxide synthesis and bioavailability, decreased superoxide anion generation from NAD(P)H oxidase and cyclooxygenase-2 and reduced cytoplasmic tyrosine kinase Src phosphorylation without changes in NaKATPase activity in MRA from DOCA-salt rats. CONCLUSION This study reports the critical role of endogenous ouabain in volume-dependent hypertension. In MRA from DOCA-salt rats, the binding of endogenous ouabain to NaK-ATPase results in downstream c-SRC activation, oxidative stress and endothelial dysfunction. Endogenous ouabain is a putative target for the treatment of hypertension, and ROSTA may represent a novel therapeutic approach.
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Lewis LK, Yandle TG, Hilton PJ, Jensen BP, Begg EJ, Nicholls MG. Endogenous ouabain is not ouabain. Hypertension 2014; 64:680-3. [PMID: 25001271 DOI: 10.1161/hypertensionaha.114.03919] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Lynley K Lewis
- From the Christchurch Heart Institute (L.K.L., T.G.Y.) and Department of Medicine (E.J.B., M.G.N.), University of Otago-Christchurch, Christchurch, New Zealand; Department of Medicine, St Thomas' Hospital, London, United Kingdom (P.J.H.); and Division of Toxicology, Canterbury Health Laboratories, Christchurch, New Zealand (B.P.J.)
| | - Timothy G Yandle
- From the Christchurch Heart Institute (L.K.L., T.G.Y.) and Department of Medicine (E.J.B., M.G.N.), University of Otago-Christchurch, Christchurch, New Zealand; Department of Medicine, St Thomas' Hospital, London, United Kingdom (P.J.H.); and Division of Toxicology, Canterbury Health Laboratories, Christchurch, New Zealand (B.P.J.)
| | - Philip J Hilton
- From the Christchurch Heart Institute (L.K.L., T.G.Y.) and Department of Medicine (E.J.B., M.G.N.), University of Otago-Christchurch, Christchurch, New Zealand; Department of Medicine, St Thomas' Hospital, London, United Kingdom (P.J.H.); and Division of Toxicology, Canterbury Health Laboratories, Christchurch, New Zealand (B.P.J.)
| | - Berit P Jensen
- From the Christchurch Heart Institute (L.K.L., T.G.Y.) and Department of Medicine (E.J.B., M.G.N.), University of Otago-Christchurch, Christchurch, New Zealand; Department of Medicine, St Thomas' Hospital, London, United Kingdom (P.J.H.); and Division of Toxicology, Canterbury Health Laboratories, Christchurch, New Zealand (B.P.J.)
| | - Evan J Begg
- From the Christchurch Heart Institute (L.K.L., T.G.Y.) and Department of Medicine (E.J.B., M.G.N.), University of Otago-Christchurch, Christchurch, New Zealand; Department of Medicine, St Thomas' Hospital, London, United Kingdom (P.J.H.); and Division of Toxicology, Canterbury Health Laboratories, Christchurch, New Zealand (B.P.J.)
| | - M Gary Nicholls
- From the Christchurch Heart Institute (L.K.L., T.G.Y.) and Department of Medicine (E.J.B., M.G.N.), University of Otago-Christchurch, Christchurch, New Zealand; Department of Medicine, St Thomas' Hospital, London, United Kingdom (P.J.H.); and Division of Toxicology, Canterbury Health Laboratories, Christchurch, New Zealand (B.P.J.).
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Song D, Du T. Ammonium activates ouabain-activated signalling pathway in astrocytes: therapeutic potential of ouabain antagonist. Curr Neuropharmacol 2014; 12:334-41. [PMID: 25342941 PMCID: PMC4207073 DOI: 10.2174/1570159x12666140828222115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/18/2014] [Accepted: 06/25/2014] [Indexed: 01/16/2023] Open
Abstract
The causal role of ammonium in hepatic encephalopathy was identified in 1930s. Astroglial cells are primary cellular elements of hepatic encephalopathy which conceptually, can be considered a toxic astrogliopathology. Previously we have reported that acute exposure to ammonium activated ouabain/Na,K-ATPase signalling pathway, which includes Src, EGF receptor, Raf, Ras, MEK and ERK1/2. Chronic incubation of astrocytes with ammonium increased production of endogenous ouabain-like compound. Ouabain antagonist canrenone abolished effects of ammonium on astrocytic swelling, ROS production, and upregulation of gene expression and function of TRPC1 and Cav1.2. However, ammonium induces multiple pathological modifications in astrocytes, and some of them may be not related to this signalling pathway. In this review, we focus on the effect of ammonium on ouabain/Na,K-ATPase signalling pathway and its involvement in ammonium-induced ROS production, cell swelling and aberration of Ca(2+) signals in astrocytes. We also briefly discuss Na,K-ATPase, EGF receptor, endogenous ouabain and ouabain antagonist.
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Affiliation(s)
- Dan Song
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
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Khundmiri SJ. Advances in understanding the role of cardiac glycosides in control of sodium transport in renal tubules. J Endocrinol 2014; 222:R11-24. [PMID: 24781255 DOI: 10.1530/joe-13-0613] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cardiotonic steroids have been used for the past 200 years in the treatment of congestive heart failure. As specific inhibitors of membrane-bound Na(+)/K(+) ATPase, they enhance cardiac contractility through increasing myocardial cell calcium concentration in response to the resulting increase in intracellular Na concentration. The half-minimal concentrations of cardiotonic steroids required to inhibit Na(+)/K(+) ATPase range from nanomolar to micromolar concentrations. In contrast, the circulating levels of cardiotonic steroids under physiological conditions are in the low picomolar concentration range in healthy subjects, increasing to high picomolar levels under pathophysiological conditions including chronic kidney disease and heart failure. Little is known about the physiological function of low picomolar concentrations of cardiotonic steroids. Recent studies have indicated that physiological concentrations of cardiotonic steroids acutely stimulate the activity of Na(+)/K(+) ATPase and activate an intracellular signaling pathway that regulates a variety of intracellular functions including cell growth and hypertrophy. The effects of circulating cardiotonic steroids on renal salt handling and total body sodium homeostasis are unknown. This review will focus on the role of low picomolar concentrations of cardiotonic steroids in renal Na(+)/K(+) ATPase activity, cell signaling, and blood pressure regulation.
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Affiliation(s)
- Syed Jalal Khundmiri
- Division of Nephrology and HypertensionDepartment of MedicineDepartment of Physiology and BiophysicsUniversity of Louisville, 570 S. Preston Street, Louisville, Kentucky 40202, USADivision of Nephrology and HypertensionDepartment of MedicineDepartment of Physiology and BiophysicsUniversity of Louisville, 570 S. Preston Street, Louisville, Kentucky 40202, USA
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Hertz L, Peng L, Song D. Ammonia, like K(+), stimulates the Na(+), K(+), 2 Cl(-) cotransporter NKCC1 and the Na(+),K(+)-ATPase and interacts with endogenous ouabain in astrocytes. Neurochem Res 2014; 40:241-57. [PMID: 24929663 DOI: 10.1007/s11064-014-1352-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/31/2014] [Accepted: 06/03/2014] [Indexed: 12/12/2022]
Abstract
Brain edema during hepatic encephalopathy or acute liver failure as well as following brain ischemia has a multifactorial etiology, but it is a dangerous and occasionally life-threatening complication because the brain is enclosed in the rigid skull. During ischemia the extracellular K(+) concentration increases to very high levels, which when energy becomes available during reperfusion stimulate NKCC1, a cotransporter driven by the transmembrane ion gradients established by the Na(+),K(+)-ATPase and accumulating Na(+), K(+) and 2 Cl(-) together with water. This induces pronounced astrocytic swelling under pathologic conditions, but NKCC1 is probably also activated, although to a lesser extent, during normal brain function. Redistribution of ions and water between extra- and intracellular phases does not create brain edema, which in addition requires uptake across the blood-brain barrier. During hepatic encephalopathy and acute liver failure a crucial factor is the close resemblance between K(+) and NH4(+) in their effects not only on NKCC1 and Na(+),K(+)-ATPase but also on Na(+),K(+)-ATPase-induced signaling by endogenous ouabains. These in turn activate production of ROS and nitrosactive agents which slowly sensitize NKCC1, explaining why cell swelling and brain edema generally are delayed under hyperammonemic conditions, although very high ammonia concentrations can cause immediate NKCC1 activation.
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Affiliation(s)
- Leif Hertz
- Laboratory of Brain Metabolic Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, No. 92 Beier Road, Heping District, Shenyang, People's Republic of China
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Heinzen EL, Arzimanoglou A, Brashear A, Clapcote SJ, Gurrieri F, Goldstein DB, Jóhannesson SH, Mikati MA, Neville B, Nicole S, Ozelius LJ, Poulsen H, Schyns T, Sweadner KJ, van den Maagdenberg A, Vilsen B. Distinct neurological disorders with ATP1A3 mutations. Lancet Neurol 2014; 13:503-14. [PMID: 24739246 DOI: 10.1016/s1474-4422(14)70011-0] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Genetic research has shown that mutations that modify the protein-coding sequence of ATP1A3, the gene encoding the α3 subunit of Na(+)/K(+)-ATPase, cause both rapid-onset dystonia parkinsonism and alternating hemiplegia of childhood. These discoveries link two clinically distinct neurological diseases to the same gene, however, ATP1A3 mutations are, with one exception, disease-specific. Although the exact mechanism of how these mutations lead to disease is still unknown, much knowledge has been gained about functional consequences of ATP1A3 mutations using a range of in-vitro and animal model systems, and the role of Na(+)/K(+)-ATPases in the brain. Researchers and clinicians are attempting to further characterise neurological manifestations associated with mutations in ATP1A3, and to build on the existing molecular knowledge to understand how specific mutations can lead to different diseases.
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Affiliation(s)
- Erin L Heinzen
- Center for Human Genome Variation, Duke University, School of Medicine, Durham, NC, USA; Department of Medicine, Section of Medical Genetics, Duke University, School of Medicine, Durham, NC, USA.
| | - Alexis Arzimanoglou
- Epilepsy, Sleep and Pediatric Neurophysiology Department, HFME, University Hospitals of Lyon, France; Centre de Recherche en Neurosciences de Lyon, Centre National de la Recherche Scientifique, UMR 5292, INSERM U1028, Lyon, France
| | - Allison Brashear
- Department of Neurology, Wake Forest School of Medicine, Winston Salem, NC, USA
| | | | - Fiorella Gurrieri
- Istituto di Genetica Medica, Università Cattolica S Cuore, Rome, Italy
| | - David B Goldstein
- Center for Human Genome Variation, Duke University, School of Medicine, Durham, NC, USA; Department of Molecular Genetics and Microbiology, Duke University, School of Medicine, Durham, NC, USA
| | | | - Mohamad A Mikati
- Division of Pediatric Neurology, Duke University, School of Medicine, Durham, NC, USA; Department of Neurobiology, Duke University, School of Medicine, Durham, NC, USA
| | - Brian Neville
- Institute of Child Health, University College London, London, UK
| | - Sophie Nicole
- Institut National de la Santé et de la Recherche Médicale, U975, Centre de Recherche de l'Institut du Cerveau et de la Moelle, Paris, France; Centre National de la Recherche Scientifique, UMR7225, Paris, France; Université Pierre et Marie Curie Paris VI, UMRS975, Paris, France
| | - Laurie J Ozelius
- Department of Genetics and Genomic Sciences and Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hanne Poulsen
- Danish Research Institute for Translational Neuroscience, Nordic-EMBL Partnership of Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Aarhus, Denmark
| | - Tsveta Schyns
- European Network for Research on Alternating Hemiplegia (ENRAH), Brussels, Belgium
| | | | - Arn van den Maagdenberg
- Department of Human Genetics and Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands
| | - Bente Vilsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Xie JX, Shapiro AP, Shapiro JI. The Trade-Off between Dietary Salt and Cardiovascular Disease; A Role for Na/K-ATPase Signaling? Front Endocrinol (Lausanne) 2014; 5:97. [PMID: 25101054 PMCID: PMC4101451 DOI: 10.3389/fendo.2014.00097] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 06/07/2014] [Indexed: 12/12/2022] Open
Abstract
It has been postulated for some time that endogenous digitalis-like substances, also called cardiotonic steroids (CTS), exist, and that these substances are involved in sodium handling. Within the past 20 years, these substances have been unequivocally identified and measurements of circulating and tissue concentrations have been made. More recently, it has been identified that CTS also mediate signal transduction through the Na/K-ATPase, and consequently been implicated in profibrotic pathways. This review will discuss the mechanism of CTS in renal sodium handling and a potential "trade-off" effect from their role in inducing tissue fibrosis.
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Affiliation(s)
- Joe X. Xie
- Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anna Pearl Shapiro
- Department of Medicine, University of Toledo College of Medicine, Toledo, OH, USA
| | - Joseph Isaac Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
- *Correspondence: Joseph Isaac Shapiro, Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, 1600 Medical Center Drive Suite 3408, Huntington, WV 25701, USA e-mail:
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Dai H, Song D, Xu J, Li B, Hertz L, Peng L. Ammonia-induced Na,K-ATPase/ouabain-mediated EGF receptor transactivation, MAPK/ERK and PI3K/AKT signaling and ROS formation cause astrocyte swelling. Neurochem Int 2013; 63:610-25. [PMID: 24044899 DOI: 10.1016/j.neuint.2013.09.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 12/13/2022]
Abstract
Ammonia toxicity is clinically important and biologically poorly understood. We reported previously that 3mM ammonia chloride (ammonia), a relevant concentration for hepatic encephalopathy studies, increases production of endogenous ouabain and activity of Na,K-ATPase in astrocytes. In addition, ammonia-induced upregulation of gene expression of α2 isoform of Na,K-ATPase in astrocytes could be inhibited by AG1478, an inhibitor of the EGF receptor (EGFR), and by PP1, an inhibitor of Src, but not by GM6001, an inhibitor of metalloproteinase and shedding of growth factor, suggesting the involvement of endogenous ouabain-induced EGF receptor transactivation. In the present cell culture study, we investigated ammonia effects on phosphorylation of EGF receptor and its intracellular signal pathway towards MAPK/ERK1/2 and PI3K/AKT; interaction between EGF receptor, α1, and α2 isoforms of Na,K-ATPase, Src, ERK1/2, AKT and caveolin-1; and relevance of these signal pathways for ammonia-induced cell swelling, leading to brain edema, an often fatal complication of ammonia toxicity. We found that (i) ammonia increases EGF receptor phosphorylation at EGFR(845) and EGFR(1068); (ii) ammonia-induced ERK1/2 and AKT phosphorylation depends on the activity of EGF receptor and Src, but not on metalloproteinase; (iii) AKT phosphorylation occurs upstream of ERK1/2 phosphorylation; (iv) ammonia stimulates association between the α1 Na,K-ATPase isoform, Src, EGF receptor, ERK1/2, AKT and caveolin-1; (v) ammonia-induced ROS production might occur later than EGFR transactivation; (vi) both ammonia induced ERK phosphorylation and ROS production can be abolished by canrenone, an inhibitor of ouabain, and (vii) ammonia-induced cell swelling depends on signaling via the Na,K-ATPase/ouabain/Src/EGF receptor/PI3K-AKT/ERK1/2, but in response to 3mM ammonia it does not appear until after 12h. Based on literature data it is suggested that the delayed appearance of the ammonia-induced swelling at this concentration reflects required ouabain-induced oxidative damage of the ion and water cotransporter NKCC1. This information may provide new therapeutic targets for treatment of hyperammonic brain disorders.
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Affiliation(s)
- Hongliang Dai
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Dan Song
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Junnan Xu
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Baoman Li
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Leif Hertz
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
| | - Liang Peng
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China.
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Fox MOB, Gutiérrez EB. Role of the glomerular–tubular imbalance with tubular predominance in the arterial hypertension pathophysiology. Med Hypotheses 2013; 81:397-9. [DOI: 10.1016/j.mehy.2013.05.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 05/21/2013] [Indexed: 10/26/2022]
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Kirshenbaum GS, Dawson N, Mullins JGL, Johnston TH, Drinkhill MJ, Edwards IJ, Fox SH, Pratt JA, Brotchie JM, Roder JC, Clapcote SJ. Alternating hemiplegia of childhood-related neural and behavioural phenotypes in Na+,K+-ATPase α3 missense mutant mice. PLoS One 2013; 8:e60141. [PMID: 23527305 PMCID: PMC3603922 DOI: 10.1371/journal.pone.0060141] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 02/21/2013] [Indexed: 12/29/2022] Open
Abstract
Missense mutations in ATP1A3 encoding Na+,K+-ATPase α3 have been identified as the primary cause of alternating hemiplegia of childhood (AHC), a motor disorder with onset typically before the age of 6 months. Affected children tend to be of short stature and can also have epilepsy, ataxia and learning disability. The Na+,K+-ATPase has a well-known role in maintaining electrochemical gradients across cell membranes, but our understanding of how the mutations cause AHC is limited. Myshkin mutant mice carry an amino acid change (I810N) that affects the same position in Na+,K+-ATPase α3 as I810S found in AHC. Using molecular modelling, we show that the Myshkin and AHC mutations display similarly severe structural impacts on Na+,K+-ATPase α3, including upon the K+ pore and predicted K+ binding sites. Behavioural analysis of Myshkin mice revealed phenotypic abnormalities similar to symptoms of AHC, including motor dysfunction and cognitive impairment. 2-DG imaging of Myshkin mice identified compromised thalamocortical functioning that includes a deficit in frontal cortex functioning (hypofrontality), directly mirroring that reported in AHC, along with reduced thalamocortical functional connectivity. Our results thus provide validation for missense mutations in Na+,K+-ATPase α3 as a cause of AHC, and highlight Myshkin mice as a starting point for the exploration of disease mechanisms and novel treatments in AHC.
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Affiliation(s)
- Greer S. Kirshenbaum
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Neil Dawson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Jonathan G. L. Mullins
- Institute of Life Science, College of Medicine, Swansea University, Swansea, United Kingdom
| | - Tom H. Johnston
- Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, Toronto, Ontario, Canada
| | - Mark J. Drinkhill
- Division of Cardiovascular and Neuronal Remodelling, Leeds Institute for Genetics, Health and Therapeutics, University of Leeds, Leeds, United Kingdom
| | - Ian J. Edwards
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Susan H. Fox
- Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, Toronto, Ontario, Canada
| | - Judith A. Pratt
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Jonathan M. Brotchie
- Division of Brain, Imaging and Behaviour – Systems Neuroscience, Toronto Western Research Institute, Toronto, Ontario, Canada
| | - John C. Roder
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Steven J. Clapcote
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
- * E-mail:
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Reinhard L, Tidow H, Clausen MJ, Nissen P. Na(+),K (+)-ATPase as a docking station: protein-protein complexes of the Na(+),K (+)-ATPase. Cell Mol Life Sci 2013; 70:205-22. [PMID: 22695678 PMCID: PMC11113973 DOI: 10.1007/s00018-012-1039-9] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 05/13/2012] [Accepted: 05/23/2012] [Indexed: 12/13/2022]
Abstract
The Na(+),K(+)-ATPase, or sodium pump, is well known for its role in ion transport across the plasma membrane of animal cells. It carries out the transport of Na(+) ions out of the cell and of K(+) ions into the cell and thus maintains electrolyte and fluid balance. In addition to the fundamental ion-pumping function of the Na(+),K(+)-ATPase, recent work has suggested additional roles for Na(+),K(+)-ATPase in signal transduction and biomembrane structure. Several signaling pathways have been found to involve Na(+),K(+)-ATPase, which serves as a docking station for a fast-growing number of protein interaction partners. In this review, we focus on Na(+),K(+)-ATPase as a signal transducer, but also briefly discuss other Na(+),K(+)-ATPase protein-protein interactions, providing a comprehensive overview of the diverse signaling functions ascribed to this well-known enzyme.
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Affiliation(s)
- Linda Reinhard
- Danish National Research Foundation, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Molecular Biology and Genetics, 8000 Aarhus C, Denmark
| | - Henning Tidow
- Danish National Research Foundation, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Molecular Biology and Genetics, 8000 Aarhus C, Denmark
| | - Michael J. Clausen
- Danish National Research Foundation, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Molecular Biology and Genetics, 8000 Aarhus C, Denmark
| | - Poul Nissen
- Danish National Research Foundation, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Molecular Biology and Genetics, 8000 Aarhus C, Denmark
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Systemic hypertension: the roles of salt, vascular Na+/K+ ATPase and the endogenous glycosides, ouabain and marinobufagenin. Cardiol Rev 2012; 20:130-8. [PMID: 22183064 DOI: 10.1097/crd.0b013e31823c835c] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Essential hypertension has been shown to be significantly associated with an increased risk for cardiovascular disease and is not well controlled in many patients. In a large portion of people with essential hypertension, sodium intake has been shown to play a significant role in the production of their hypertension. The mechanism through which increased sodium intake manifests hypertension is unresolved and likely multifactorial. Endogenous cardiac glycosides such as endogenous ouabain (EO) and marinobufagenin have been proposed to play a role in salt-sensitive essential hypertension through their inhibition of Na/K ATPase (NKA). The normal function of the NKA pump is to extrude Na from the intracellular environment and import K. Blocking the NKA disrupts its normal maintenance function. EO is proposed to produce alteration in smooth muscle cell contractility by inhibiting the α2-isoform of NKA, altering Na in a microdomain of the cell. In this region of the plasma membrane the α2-isoform of the NKA colocalizes with another transmembrane protein, the Na/Ca exchanger (NCX). The normal function of NCX is to extrude Ca and import Na. Inhibition of NKA produces an increase in Na within the microdomain, which in turn alters the function of the NCX so that less Ca is extruded, leading to increased intracellular Ca and increased vascular contraction. EO has been shown to be synthesized and secreted by the adrenal cortex in response to chronically elevated sodium intake. The levels of EO have been shown to be significantly elevated in 40% of all untreated hypertensive patients. Marinobufagenin, another cardiac glycoside, has also been implicated as a possible cause of essential hypertension through its preferential inhibition of the α1-isoform of NKA. Antagonism of the endogenous inhibitors of NKA is currently a target of clinical research for the development of innovative antihypertensive treatments.
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DOCA-salt hypertension does not require the ouabain-sensitive binding site of the α2 Na,K-ATPase. Am J Hypertens 2012; 25:421-9. [PMID: 22258333 DOI: 10.1038/ajh.2011.255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND We have shown that the ouabain-sensitive α2 Na,K-ATPase is required for adrenocorticotropic hormone (ACTH)-induced hypertension and gestational blood pressure regulation. It is therefore of interest to explore whether this binding site participates in the development of other forms of hypertension, such as deoxycorticosterone acetate (DOCA)-salt using mutant mice with altered sensitivity to ouabain. METHODS Wild-type (α1 ouabain-resistant, α2 ouabain-sensitive: α(R/R)α2(S/S)), α1-resistant, α2-resistant (α1(R/R)α2(R/R)) and α1-sensitive, α2-resistant (α1(S/S)α2(R/R)) mice were uninephrectomized and implanted with DOCA pellets. The animals were given either tap water or 1% NaCl, and blood pressure was measured before and after DOCA. RESULTS DOCA-salt-treated α1(R/R)α2(R/R) mice developed hypertension to the same extent as α1(R/R)α2(S/S) mice (wild type), and the α1(S/S)α2(R/R) mice given DOCA-salt also showed no difference from the other two genotypes. The expression of the α1 isoform was not changed by DOCA-salt treatment in either α1(R/R)α2(S/S) or α1(R/R)α2(R/R) mice. However, the α2 subunit was expressed at substantially higher levels in the hearts of α1(R/R)α2(R/R) than α1(R/R)α2(S/S) mice, regardless of treatment. Plasma levels of ouabain did not change consistently, but those of marinobufagenin were modestly higher in DOCA-salt treated mice relatively to those without salt. CONCLUSIONS The ouabain-binding site of either the α1 or α2 Na,K-ATPase subunit does not play an essential role in the development of DOCA-salt hypertension in this mouse model. These findings indicate that the underlying mechanisms of hypertension induced by DOCA-salt treatment are different from those of ACTH-induced hypertension.
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Heasley B. Chemical synthesis of the cardiotonic steroid glycosides and related natural products. Chemistry 2012; 18:3092-120. [PMID: 22354477 DOI: 10.1002/chem.201103733] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The active components from the extracts of Digitalis, cardiotonic steroid glycosides, have been ingested by humans for more than 200 years as a medicinal therapy for heart failure and abnormal heart rhythms. The positive inotropic activity of the cardiotonic steroids that mediates clinically useful physiological effects in patients has been attributed largely to a high affinity inhibitory interaction with the extracellular surface of the membrane-bound sodium pump (Na(+)/K(+)-ATPase). However, previously unrecognized intracellular signaling pathways continue to be uncovered. This Review examines both partial and de novo synthetic approaches to the medicinally important and structurally captivating cardenolide and bufadienolide steroid families, with an emphasis on the stereocontrolled construction of the pharmacophoric aglycone (genin) framework.
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Affiliation(s)
- Brian Heasley
- Scynexis, Inc. P. O. Box 12878, Research Triangle Park, NC 27709-2878, USA.
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Mania-like behavior induced by genetic dysfunction of the neuron-specific Na+,K+-ATPase α3 sodium pump. Proc Natl Acad Sci U S A 2011; 108:18144-9. [PMID: 22025725 DOI: 10.1073/pnas.1108416108] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Bipolar disorder is a debilitating psychopathology with unknown etiology. Accumulating evidence suggests the possible involvement of Na(+),K(+)-ATPase dysfunction in the pathophysiology of bipolar disorder. Here we show that Myshkin mice carrying an inactivating mutation in the neuron-specific Na(+),K(+)-ATPase α3 subunit display a behavioral profile remarkably similar to bipolar patients in the manic state. Myshkin mice show increased Ca(2+) signaling in cultured cortical neurons and phospho-activation of extracellular signal regulated kinase (ERK) and Akt in the hippocampus. The mood-stabilizing drugs lithium and valproic acid, specific ERK inhibitor SL327, rostafuroxin, and transgenic expression of a functional Na(+),K(+)-ATPase α3 protein rescue the mania-like phenotype of Myshkin mice. These findings establish Myshkin mice as a unique model of mania, reveal an important role for Na(+),K(+)-ATPase α3 in the control of mania-like behavior, and identify Na(+),K(+)-ATPase α3, its physiological regulators and downstream signal transduction pathways as putative targets for the design of new antimanic therapies.
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Ferrandi M, Molinari I, Torielli L, Padoani G, Salardi S, Rastaldi MP, Ferrari P, Bianchi G. Adducin- and ouabain-related gene variants predict the antihypertensive activity of rostafuroxin, part 1: experimental studies. Sci Transl Med 2011; 2:59ra86. [PMID: 21106940 DOI: 10.1126/scitranslmed.3001815] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Essential hypertension is a complex, multifactorial disease associated with a high cardiovascular risk and whose genetic-molecular basis is heterogeneous and largely unknown. Although multiple antihypertensive therapies are available, the large individual variability in drug response results in only a modest reduction of the cardiovascular risk and unsatisfactory control of blood pressure in the hypertensive population as a whole. Two mechanisms, among others, are associated with essential hypertension and related organ damage: mutant α-adducin variants and high concentrations of endogenous ouabain. An antihypertensive agent, rostafuroxin, selectively inhibits these mechanisms in rodents. We investigated the molecular and functional effects of mutant α-adducin, ouabain, and rostafuroxin in hypertensive rats, human cells, and cell-free systems and demonstrated that both mutant α-adducin variants and the ouabain-Na,K-ATPase (Na(+)- and K(+)-dependent adenosine triphosphatase) complex can interact with the Src-SH2 (Src homology 2) domain, increasing Src activity and the Src-dependent Na,K-ATPase phosphorylation and activity. Wild-type α-adducin or Na,K-ATPase in the absence of ouabain showed no interaction with the Src-SH2 domain. Rostafuroxin disrupted the interactions between the Src-SH2 domain and mutant α-adducin or the ouabain-Na,K-ATPase complex and blunted Src activation and Na,K-ATPase phosphorylation, resulting in blood pressure normalization in the hypertensive rats. We have also shown the translatability of these data to humans in a pharmacogenomic clinical trial, as described in the companion paper.
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Affiliation(s)
- Mara Ferrandi
- Prassis sigma-tau Research Institute, Settimo Milanese, Milan 20019, Italy
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Staessen JA, Thijs L, Stolarz-Skrzypek K, Bacchieri A, Barton J, Espositi ED, de Leeuw PW, Dłużniewski M, Glorioso N, Januszewicz A, Manunta P, Milyagin V, Nikitin Y, Souček M, Lanzani C, Citterio L, Timio M, Tykarski A, Ferrari P, Valentini G, Kawecka-Jaszcz K, Bianchi G. Main results of the ouabain and adducin for Specific Intervention on Sodium in Hypertension Trial (OASIS-HT): a randomized placebo-controlled phase-2 dose-finding study of rostafuroxin. Trials 2011; 12:13. [PMID: 21235787 PMCID: PMC3031200 DOI: 10.1186/1745-6215-12-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 01/14/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Ouabain and Adducin for Specific Intervention on Sodium in Hypertension (OASIS-HT) Trial was a phase-2 dose-finding study of rostafuroxin, a digitoxygenin derivative, which selectively antagonizes the effects of endogenous ouabain (EO) on Na+,K+-ATPase and mutated adducin. Rostafuroxin lowered blood pressure (BP) in some animal models and in humans. METHODS OASIS-HT consisted of 5 concurrently running double-blind cross-over studies. After 4 weeks without treatment, 435 patients with uncomplicated systolic hypertension (140-169 mm Hg) were randomized to rostafuroxin (0.05, 0.15, 0.5, 1.5 or 5.0 mg/d) or matching placebo, each treatment period lasting 5 weeks. The primary endpoint was the reduction in systolic office BP. Among the secondary endpoints were diastolic office BP, 24-h ambulatory BP, plasma EO concentration and renin activity, 24-h urinary sodium and aldosterone excretion, and safety. ANOVA considered treatment sequence (fixed effect), subjects nested within sequence (random), period (fixed), and treatment (fixed). RESULTS Among 410 analyzable patients (40.5% women; mean age, 48.4 years), the differences in the primary endpoint (rostafuroxin minus placebo) ranged from -0.18 mm Hg (P = 0.90) on 0.15 mg/d rostafuroxin to 2.72 mm Hg (P = 0.04) on 0.05 mg/d. In the 5 dosage arms combined, the treatment effects averaged 1.30 mm Hg (P = 0.03) for systolic office BP; 0.70 mm Hg (P = 0.08) for diastolic office BP; 0.36 mm Hg (P = 0.49) for 24-h systolic BP; and 0.05 mm Hg (P = 0.88) for 24-h diastolic BP. In the 2 treatment groups combined, systolic (-1.36 mm Hg) and diastolic (-0.97 mm Hg) office BPs decreased from week 5 to 10 (P for period effect ≤ 0.028), but carry-over effects were not significant (P ≥ 0.11). All other endpoints were not different on rostafuroxin and placebo. Minor side-effects occurred with similarly low frequency on rostafuroxin and placebo. CONCLUSIONS In 5 concurrently running double-blind cross-over studies rostafuroxin did not reduce BP at any dose. TRIAL REGISTRATION ClinicalTrials (NCT): NCT00415038.
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Affiliation(s)
- Jan A Staessen
- The Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, Department of Cardiovascular Research, University of Leuven, Leuven, Belgium
- The Department of Epidemiology, Maastricht University, Maastricht, The Netherlands
| | - Lutgarde Thijs
- The Studies Coordinating Centre, Division of Hypertension and Cardiovascular Rehabilitation, Department of Cardiovascular Research, University of Leuven, Leuven, Belgium
| | - Katarzyna Stolarz-Skrzypek
- The First Department of Cardiology and Hypertension, Jagiellonian University Medical College, Kraków, Poland
| | | | - John Barton
- Cardiac Research Department, Portiuncula Hospital, Galway, Ireland
| | - Ezio degli Espositi
- Unità di Valutazione dell' Efficacia Clinica, Ospedale San Maria delle Croci, Ravenna, Italy
| | - Peter W de Leeuw
- Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | | | - Andrzej Januszewicz
- Department of Internal Medicine and Hypertension, Medical Academy Warsaw, Warsaw, Poland
| | - Paolo Manunta
- Divisione di Nefrologia Dialisi e Ipertensione, Ospedale San Raffaele, Dipartimento di Scienze e Techologie Biomediche, Universitá Vita-Salute, Milan, Italy
| | - Viktor Milyagin
- Department of Internal Medicine, Smolensk State Medical Academy, Smolensk, Russian Federation
| | - Yuri Nikitin
- Institute of Internal Medicine, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, the Russian Federation
| | - Miroslav Souček
- Department of Internal Medicine 2, Saint Anna Hospital, University of Brno, Brno, The Czech Republic
| | - Chiara Lanzani
- Divisione di Nefrologia Dialisi e Ipertensione, Ospedale San Raffaele, Dipartimento di Scienze e Techologie Biomediche, Universitá Vita-Salute, Milan, Italy
| | - Lorena Citterio
- Divisione di Nefrologia Dialisi e Ipertensione, Ospedale San Raffaele, Dipartimento di Scienze e Techologie Biomediche, Universitá Vita-Salute, Milan, Italy
| | - Mario Timio
- Department of Internal Medicine, Nephrology, and Dialysis, Hospital San Giovanni Battista, Perugia, Italy
| | | | | | | | - Kalina Kawecka-Jaszcz
- The First Department of Cardiology and Hypertension, Jagiellonian University Medical College, Kraków, Poland
| | - Giuseppe Bianchi
- Divisione di Nefrologia Dialisi e Ipertensione, Ospedale San Raffaele, Dipartimento di Scienze e Techologie Biomediche, Universitá Vita-Salute, Milan, Italy
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Shapiro JI, Tian J. Signaling through the Na/K-ATPase: implications for cardiac fibrosis. Am J Physiol Heart Circ Physiol 2010; 300:H29-30. [PMID: 20971770 DOI: 10.1152/ajpheart.01038.2010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Puschett JB, Agunanne E, Uddin MN. Emerging Role of the Bufadienolides in Cardiovascular and Kidney Diseases. Am J Kidney Dis 2010; 56:359-70. [DOI: 10.1053/j.ajkd.2010.01.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 01/05/2010] [Indexed: 01/11/2023]
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Xue Z, Li B, Gu L, Hu X, Li M, Butterworth RF, Peng L. Increased Na, K-ATPase alpha2 isoform gene expression by ammonia in astrocytes and in brain in vivo. Neurochem Int 2010; 57:395-403. [PMID: 20447429 DOI: 10.1016/j.neuint.2010.04.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 03/28/2010] [Accepted: 04/27/2010] [Indexed: 10/19/2022]
Abstract
In mouse astrocyte cultures identical to those used in the present study ammonia increases the production of ouabain-like compounds and Na, K-ATPase activity (Kala et al., 2000). Increased activity of Na, K-ATPase could be the result of enhanced production of ouabain-like compounds, since cultured rat astrocytes react to prolonged exposure to a high concentration of ouabain with an upregulation of the Na, K-ATPase alpha(1) isoform (Hosoi et al., 1997). However, unlike astrocytes in brain in vivo and mouse primary cultures, cultured rat astrocytes do not express the astrocyte-specific alpha(2) isoform, which shows a higher affinity for ouabain (EC(50) approximately 0.1 microM) than the alpha(1) isoform (EC(50) approximately 10 microM). In the present study we have investigated (i) effects of ammonia on mRNA and protein expression of alpha(1) and alpha(2) isoforms in primary cultures of mouse astrocytes; (ii) effects of hyperammonia obtained by urease injection on mRNA and protein expression of alpha(1) and alpha(2) isoforms in the brain in vivo; and (iii) effect on observed upregulation of gene expression of AG1478, an inhibitor of the EGF receptor-tyrosine kinase, PP1, an inhibitor of Src, and GM6001, an inhibitor of Zn(2+)-dependent metalloproteinases in the cultured cells. It was established that alpha(2) mRNA and protein expression, but not alpha(1) expression, was upregulated in cultured astrocytes by 1-4 days of exposure to 3 or 5 mM ammonia and that similar upregulation, contrasted by a downregulation of the neuronal alpha(3) subunit occurred in the hyperammonemic brain. Based on the effects of the inhibitors and literature data it is concluded that ammonia activates formation of an endogenous ouabain-like compound, which binds to the Na, K-ATPase, activating Src, which in turn stimulates the receptor-tyrosine kinase of the EGF receptor, leading to activation of the Ras, Raf, MEK pathway and phosphorylation of ERK(1/2), which eventually causes upregulation of alpha(2) gene expression.
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Affiliation(s)
- Zhanxia Xue
- Department of Clinical Pharmacology, China Medical University, Shenyang, PR China
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50
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Holthouser KA, Mandal A, Merchant ML, Schelling JR, Delamere NA, Valdes RR, Tyagi SC, Lederer ED, Khundmiri SJ. Ouabain stimulates Na-K-ATPase through a sodium/hydrogen exchanger-1 (NHE-1)-dependent mechanism in human kidney proximal tubule cells. Am J Physiol Renal Physiol 2010; 299:F77-90. [PMID: 20427472 DOI: 10.1152/ajprenal.00581.2009] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recent investigations demonstrate increased Na/H exchanger-1 (NHE-1) activity and plasma levels of ouabain-like factor in spontaneously hypertensive rats. At nanomolar concentrations, ouabain increases Na-K-ATPase activity, induces cell proliferation, and activates complex signaling cascades. We hypothesize that the activity of NHE-1 and Na-K-ATPase are interdependent. To test whether treatment with picomolar ouabain regulates Na-K-ATPase through an NHE-1-dependent mechanism, we examined the role of NHE-1 in ouabain-mediated stimulation of Na-K-ATPase in kidney proximal tubule cell lines [opossum kidney (OK), HK-2, HKC-5, and HKC-11] and rat kidney basolateral membranes. Ouabain stimulated Na-K-ATPase activity and tyrosine phosphorylation in cells that express NHE-1 (OK, HKC-5, and HKC-11) but not in HK-2 cells that express very low levels of NHE-1. Inhibition of NHE-1 with 5 microM EIPA, a NHE-1-specific inhibitor, prevented ouabain-mediated stimulation of (86)Rb uptake and Na-K-ATPase phosphorylation in OK, HKC-5, and HKC-11 cells. Expression of wild-type NHE-1 in HK2 cells restored regulation of Na-K-ATPase by picomolar ouabain. Treatment with picomolar ouabain increased membrane expression of Na-K-ATPase and enhanced NHE-1-Na-K-ATPase alpha1-subunit association. Treatment with ouabain (1 microg x kg body wt(-1) x day(-1)) increased Na-K-ATPase activity, expression, phosphorylation, and association with NHE-1 increased in rat kidney cortical basolateral membranes. Eight days' treatment with ouabain (1 microg x kg body wt(-1) x day(-1)) resulted in increased blood pressure in these rats. These results suggest that the association of NHE-1 with Na-K-ATPase is critical for ouabain-mediated regulation of Na-K-ATPase and that these effects may play a role in cardioglycoside-stimulated hypertension.
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Affiliation(s)
- Kristine A Holthouser
- Department of Medicine/Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA
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