1
|
Faienza S, Citterio L, Messaggio E, Zagato L, Lanzani C, Simonini M, Canciani B, Sanvito F, Rampoldi L, Pavlovic D, Manunta P. A novel mouse model recapitulates the effects of rs2254524 variant in the lanosterol synthase gene on salt sensitivity and organ damage. J Hypertens 2024:00004872-990000000-00523. [PMID: 39248148 DOI: 10.1097/hjh.0000000000003843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2024]
Abstract
OBJECTIVE The blood pressure (BP) response to salt intake (salt sensitivity) shows great variability among individuals and is more frequent in hypertensive patients. Elevated levels of the steroid hormone Endogenous Ouabain (EO) are associated with hypertension (HT) and salt sensitivity. The lanosterol synthase gene (LSS) plays a key role in the biosynthesis of steroids and its rs2254524 variant (Val642Leu) is linked to salt sensitivity in humans. This study aims to investigate the pathophysiological significance of the Lss missense variation in a new knock-in mouse model of salt-sensitive HT onset. METHODS We generated a mouse model carrying the murine homolog (Val643Leu) of the human LSS variant. C57BL/6N LssV643L/V643L were fed different NaCl diets (low-salt, LSD; normal-salt, NSD; high-salt, HSD) and were characterized at functional, histological, and molecular levels. RESULTS At baseline, mutant mice showed an enlarged kidney compared to the wild-type (WT) counterpart, but the Lss V643L variant did not affect EO biosynthesis nor systolic BP at 3 and 12 months. In HSD, we observed an increased systolic BP only in 12-month-old LssV643L/V643L mice, compared to NSD. Moreover, only the HSD LssV643L/V643L mice showed cardiac hypertrophy and a higher incidence of cardiac fibrosis compared to WT at 12 months. Finally, the Lss mRNA level was differentially regulated by HSD in the adrenal gland, liver, and heart of LssV643L/V643L mice compared to WT. CONCLUSIONS The novel Lss mouse model resembles the salt-sensitive HT phenotype observed in hypertensive patients and provides a good model of salt-sensitive HT and HT-mediated organ damage.
Collapse
Affiliation(s)
- Sipontina Faienza
- Genomics of Renal Diseases and Hypertension Unit, IRCCS Ospedale San Raffaele
- Università Vita-Salute San Raffaele
| | - Lorena Citterio
- Genomics of Renal Diseases and Hypertension Unit, IRCCS Ospedale San Raffaele
| | | | - Laura Zagato
- Genomics of Renal Diseases and Hypertension Unit, IRCCS Ospedale San Raffaele
| | - Chiara Lanzani
- Genomics of Renal Diseases and Hypertension Unit, IRCCS Ospedale San Raffaele
- Università Vita-Salute San Raffaele
| | - Marco Simonini
- Genomics of Renal Diseases and Hypertension Unit, IRCCS Ospedale San Raffaele
| | | | | | - Luca Rampoldi
- Università Vita-Salute San Raffaele
- Molecular Genetics of Renal Disorders Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Wolfson Drive, Birmingham, UK
| | - Paolo Manunta
- Genomics of Renal Diseases and Hypertension Unit, IRCCS Ospedale San Raffaele
- Università Vita-Salute San Raffaele
| |
Collapse
|
2
|
Fender J, Klöcker J, Boivin-Jahns V, Ravens U, Jahns R, Lorenz K. "Cardiac glycosides"-quo vaditis?-past, present, and future? NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03285-3. [PMID: 39007928 DOI: 10.1007/s00210-024-03285-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 07/03/2024] [Indexed: 07/16/2024]
Abstract
Up to date, digitalis glycosides, also known as "cardiac glycosides", are inhibitors of the Na+/K+-ATPase. They have a long-standing history as drugs used in patients suffering from heart failure and atrial fibrillation despite their well-known narrow therapeutic range and the intensive discussions on their raison d'être for these indications. This article will review the history and key findings in basic and clinical research as well as potentially overseen pros and cons of these drugs.
Collapse
Affiliation(s)
- Julia Fender
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Johanna Klöcker
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Valérie Boivin-Jahns
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany
| | - Ursula Ravens
- Institute of Experimental Cardiovascular Medicine, Faculty of Medicine, University of Freiburg, Elsässer Straße 2Q, 79110, Freiburg, Germany
| | - Roland Jahns
- Interdisciplinary Bank of Biological Materials and Data Würzburg (ibdw), University Hospital Würzburg, Straubmühlweg 2a, 97078, Würzburg, Germany
| | - Kristina Lorenz
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Würzburg, Germany.
- Leibniz-Institut für Analytische Wissenschaften-ISAS e.V., Bunsen-Kirchhoff-Straße 11, 44139, Dortmund, Germany.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Zhan Q, Liu B, Situ X, Luo Y, Fu T, Wang Y, Xie Z, Ren L, Zhu Y, He W, Ke Z. New insights into the correlations between circulating tumor cells and target organ metastasis. Signal Transduct Target Ther 2023; 8:465. [PMID: 38129401 PMCID: PMC10739776 DOI: 10.1038/s41392-023-01725-9] [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: 08/25/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
Organ-specific metastasis is the primary cause of cancer patient death. The distant metastasis of tumor cells to specific organs depends on both the intrinsic characteristics of the tumor cells and extrinsic factors in their microenvironment. During an intermediate stage of metastasis, circulating tumor cells (CTCs) are released into the bloodstream from primary and metastatic tumors. CTCs harboring aggressive or metastatic features can extravasate to remote sites for continuous colonizing growth, leading to further lesions. In the past decade, numerous studies demonstrated that CTCs exhibited huge clinical value including predicting distant metastasis, assessing prognosis and monitoring treatment response et al. Furthermore, increasingly numerous experiments are dedicated to identifying the key molecules on or inside CTCs and exploring how they mediate CTC-related organ-specific metastasis. Based on the above molecules, more and more inhibitors are being developed to target CTCs and being utilized to completely clean CTCs, which should provide promising prospects to administer advanced tumor. Recently, the application of various nanomaterials and microfluidic technologies in CTCs enrichment technology has assisted to improve our deep insights into the phenotypic characteristics and biological functions of CTCs as a potential therapy target, which may pave the way for us to make practical clinical strategies. In the present review, we mainly focus on the role of CTCs being involved in targeted organ metastasis, especially the latest molecular mechanism research and clinical intervention strategies related to CTCs.
Collapse
Affiliation(s)
- Qinru Zhan
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Bixia Liu
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Xiaohua Situ
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Yuting Luo
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Tongze Fu
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
- Institute of Precision Medicine, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Yanxia Wang
- Zhongshan School of Medicine, Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Zhongpeng Xie
- Zhongshan School of Medicine, Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Lijuan Ren
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China
| | - Ying Zhu
- Department of Radiology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China.
| | - Weiling He
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, 10065, USA.
- School of Medicine, Xiang'an Hospital of Xiamen University, Xiamen University, 361000, Xiamen, Fujian, P.R. China.
| | - Zunfu Ke
- Department of Pathology, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China.
- Institute of Precision Medicine, The First Affiliated Hospital of Sun Yat-sen University, 510000, Guangzhou, Guangdong, P.R. China.
| |
Collapse
|
5
|
Krampert L, Ossner T, Schröder A, Schatz V, Jantsch J. Simultaneous Increases in Intracellular Sodium and Tonicity Boost Antimicrobial Activity of Macrophages. Cells 2023; 12:2816. [PMID: 38132136 PMCID: PMC10741518 DOI: 10.3390/cells12242816] [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: 08/31/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
Inflamed and infected tissues can display increased local sodium (Na+) levels, which can have various effects on immune cells. In macrophages, high salt (HS) leads to a Na+/Ca2+-exchanger 1 (NCX1)-dependent increase in intracellular Na+ levels. This results in augmented osmoprotective signaling and enhanced proinflammatory activation, such as enhanced expression of type 2 nitric oxide synthase and antimicrobial function. In this study, the role of elevated intracellular Na+ levels in macrophages was investigated. Therefore, the Na+/K+-ATPase (NKA) was pharmacologically inhibited with two cardiac glycosides (CGs), ouabain (OUA) and digoxin (DIG), to raise intracellular Na+ without increasing extracellular Na+ levels. Exposure to HS conditions and treatment with both inhibitors resulted in intracellular Na+ accumulation and subsequent phosphorylation of p38/MAPK. The CGs had different effects on intracellular Ca2+ and K+ compared to HS stimulation. Moreover, the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) was not upregulated on RNA and protein levels upon OUA and DIG treatment. Accordingly, OUA and DIG did not boost nitric oxide (NO) production and showed heterogeneous effects toward eliminating intracellular bacteria. While HS environments cause hypertonic stress and ionic perturbations, cardiac glycosides only induce the latter. Cotreatment of macrophages with OUA and non-ionic osmolyte mannitol (MAN) partially mimicked the HS-boosted antimicrobial macrophage activity. These findings suggest that intracellular Na+ accumulation and hypertonic stress are required but not sufficient to mimic boosted macrophage function induced by increased extracellular sodium availability.
Collapse
Affiliation(s)
- Luka Krampert
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; (L.K.)
| | - Thomas Ossner
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; (L.K.)
| | - Agnes Schröder
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; (L.K.)
- Institute of Orthodontics, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany
| | - Valentin Schatz
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; (L.K.)
| | - Jonathan Jantsch
- Institute of Clinical Microbiology and Hygiene, University Hospital Regensburg and University of Regensburg, 93053 Regensburg, Germany; (L.K.)
- Institute for Medical Microbiology, Immunology, and Hygiene, Center for Molecular Medicine Cologne (CMMC), University Hospital Cologne and Faculty of Medicine, University of Cologne, 50935 Cologne, Germany
| |
Collapse
|
6
|
Rajanathan R, Riera CVI, Pedersen TM, Staehr C, Bouzinova EV, Nyengaard JR, Thomsen MB, Bøtker HE, Matchkov VV. Hypercontractile Cardiac Phenotype in Mice with Migraine-Associated Mutation in the Na +,K +-ATPase α 2-Isoform. Cells 2023; 12:cells12081108. [PMID: 37190017 DOI: 10.3390/cells12081108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
Two α-isoforms of the Na+,K+-ATPase (α1 and α2) are expressed in the cardiovascular system, and it is unclear which isoform is the preferential regulator of contractility. Mice heterozygous for the familial hemiplegic migraine type 2 (FHM2) associated mutation in the α2-isoform (G301R; α2+/G301R mice) have decreased expression of cardiac α2-isoform but elevated expression of the α1-isoform. We aimed to investigate the contribution of the α2-isoform function to the cardiac phenotype of α2+/G301R hearts. We hypothesized that α2+/G301R hearts exhibit greater contractility due to reduced expression of cardiac α2-isoform. Variables for contractility and relaxation of isolated hearts were assessed in the Langendorff system without and in the presence of ouabain (1 µM). Atrial pacing was performed to investigate rate-dependent changes. The α2+/G301R hearts displayed greater contractility than WT hearts during sinus rhythm, which was rate-dependent. The inotropic effect of ouabain was more augmented in α2+/G301R hearts than in WT hearts during sinus rhythm and atrial pacing. In conclusion, cardiac contractility was greater in α2+/G301R hearts than in WT hearts under resting conditions. The inotropic effect of ouabain was rate-independent and enhanced in α2+/G301R hearts, which was associated with increased systolic work.
Collapse
Affiliation(s)
| | - Clàudia Vilaseca I Riera
- Department of Basic Science, School of Medicine and Health Sciences, International University of Catalonia, 08195 Barcelona, Spain
| | | | - Christian Staehr
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | | | - Jens Randel Nyengaard
- Department of Clinical Medicine, Core Center for Molecular Morphology, Section for Stereology and Microscopy, Aarhus University, 8000 Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Morten B Thomsen
- Biomedical Sciences, University of Copenhagen, 1168 Copenhagen, Denmark
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital, 8200 Aarhus, Denmark
| | | |
Collapse
|
7
|
Rajanathan R, Pedersen TM, Guldbrandsen HO, Olesen LF, Thomsen MB, Bøtker HE, Matchkov VV. Augmented Ouabain-Induced Vascular Response Reduces Cardiac Efficiency in Mice with Migraine-Associated Mutation in the Na +, K +-ATPase α 2-Isoform. Biomedicines 2023; 11:biomedicines11020344. [PMID: 36830881 PMCID: PMC9953359 DOI: 10.3390/biomedicines11020344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/22/2023] [Accepted: 01/23/2023] [Indexed: 01/27/2023] Open
Abstract
Heterozygous mice (α2+/G301R mice) for the migraine-associated mutation (G301R) in the Na+,K+-ATPase α2-isoform have decreased expression of cardiovascular α2-isoform. The α2+/G301R mice exhibit a pro-contractile vascular phenotype associated with decreased left ventricular ejection fraction. However, the integrated functional cardiovascular consequences of this phenotype remain to be addressed in vivo. We hypothesized that the vascular response to α2-isoform-specific inhibition of the Na+,K+-ATPase by ouabain is augmented in α2+/G301R mice leading to reduced cardiac efficiency. Thus, we aimed to assess the functional contribution of the α2-isoform to in vivo cardiovascular function of wild-type (WT) and α2+/G301R mice. Blood pressure, stroke volume, heart rate, total peripheral resistance, arterial dP/dt, and systolic time intervals were assessed in anesthetized WT and α2+/G301R mice. To address rate-dependent cardiac changes, cardiovascular variables were compared before and after intraperitoneal injection of ouabain (1.5 mg/kg) or vehicle during atrial pacing. The α2+/G301R mice showed an enhanced ouabain-induced increase in total peripheral resistance associated with reduced efficiency of systolic development compared to WT. When the hearts were paced, ouabain reduced stroke volume in α2+/G301R mice. In conclusion, the ouabain-induced vascular response was augmented in α2+/G301R mice with consequent suppression of cardiac function.
Collapse
Affiliation(s)
- Rajkumar Rajanathan
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
- Correspondence:
| | | | | | | | - Morten B. Thomsen
- Department of Biomedical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital, 8000 Aarhus, Denmark
| | | |
Collapse
|
8
|
Forzano I, Mone P, Mottola G, Kansakar U, Salemme L, De Luca A, Tesorio T, Varzideh F, Santulli G. Efficacy of the New Inotropic Agent Istaroxime in Acute Heart Failure. J Clin Med 2022; 11:7503. [PMID: 36556120 PMCID: PMC9786901 DOI: 10.3390/jcm11247503] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Current therapeutic strategies for acute heart failure (AHF) are based on traditional inotropic agents that are often associated with untoward effects; therefore, finding new effective approaches with a safer profile is dramatically needed. Istaroxime is a novel compound, chemically unrelated to cardiac glycosides, that is currently being studied for the treatment of AHF. Its effects are essentially related to its inotropic and lusitropic positive properties exerted through a dual mechanism of action: activation of the sarcoplasmic reticulum Ca2+ ATPase isoform 2a (SERCA2a) and inhibition of the Na+/K+-ATPase (NKA) activity. The advantages of istaroxime over the available inotropic agents include its lower arrhythmogenic action combined with its capability of increasing systolic blood pressure without augmenting heart rate. However, it has a limited half-life (1 hour) and is associated with adverse effects including pain at the injection site and gastrointestinal issues. Herein, we describe the main mechanism of action of istaroxime and we present a systematic overview of both clinical and preclinical trials testing this drug, underlining the latest insights regarding its adoption in clinical practice for AHF.
Collapse
Affiliation(s)
- Imma Forzano
- Division of Cardiology, Department of Advanced Biomedical Sciences, “Federico II” University, 80131 Naples, Italy
| | - Pasquale Mone
- Division of Cardiology, Department of Medicine, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Gaetano Mottola
- Casa di Cura “Montevergine”, Mercogliano, 83013 Avellino, Italy
| | - Urna Kansakar
- Division of Cardiology, Department of Advanced Biomedical Sciences, “Federico II” University, 80131 Naples, Italy
| | - Luigi Salemme
- Casa di Cura “Montevergine”, Mercogliano, 83013 Avellino, Italy
| | - Antonio De Luca
- Department of Mental and Physical Health and Preventive Medicine, University of Campania “Vanvitelli”, 81100 Caserta, Italy
| | - Tullio Tesorio
- Casa di Cura “Montevergine”, Mercogliano, 83013 Avellino, Italy
| | - Fahimeh Varzideh
- Division of Cardiology, Department of Advanced Biomedical Sciences, “Federico II” University, 80131 Naples, Italy
| | - Gaetano Santulli
- Division of Cardiology, Department of Advanced Biomedical Sciences, “Federico II” University, 80131 Naples, Italy
- Division of Cardiology, Department of Medicine, Wilf Family Cardiovascular Research Institute, Einstein Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
- Department of Molecular Pharmacology, Einstein-Mount Sinai Diabetes Research Center (ES-DRC), Einstein Institute for Neuroimmunology and Inflammation (INI), Fleischer Institute for Diabetes and Metabolism (FIDAM), Albert Einstein College of Medicine, New York, NY 10461, USA
| |
Collapse
|
9
|
El-Mallakh RS, Sampath VP, Horesh N, Lichtstein D. Endogenous Cardiac Steroids in Bipolar Disorder: State of the Art. Int J Mol Sci 2022; 23:ijms23031846. [PMID: 35163766 PMCID: PMC8836531 DOI: 10.3390/ijms23031846] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 02/04/2023] Open
Abstract
Bipolar disorder (BD) is a severe psychiatric illness with a poor prognosis and problematic, suboptimal, treatments. Treatments, borne of an understanding of the pathoetiologic mechanisms, need to be developed in order to improve outcomes. Dysregulation of cationic homeostasis is the most reproducible aspect of BD pathophysiology. Correction of ionic balance is the universal mechanism of action of all mood stabilizing medications. Endogenous sodium pump modulators (collectively known as endogenous cardiac steroids, ECS) are steroids which are synthesized in and released from the adrenal gland and brain. These compounds, by activating or inhibiting Na+, K+-ATPase activity and activating intracellular signaling cascades, have numerous effects on cell survival, vascular tone homeostasis, inflammation, and neuronal activity. For the past twenty years we have addressed the hypothesis that the Na+, K+-ATPase-ECS system may be involved in the etiology of BD. This is a focused review that presents a comprehensive model pertaining to the role of ECS in the etiology of BD. We propose that alterations in ECS metabolism in the brain cause numerous biochemical changes that underlie brain dysfunction and mood symptoms. This is based on both animal models and translational human results. There are data that demonstrate that excess ECS induce abnormal mood and activity in animals, while a specific removal of ECS with antibodies normalizes mood. There are also data indicating that circulating levels of ECS are lower in manic individuals, and that patients with BD are unable to upregulate synthesis of ECS under conditions that increase their elaboration in non-psychiatric controls. There is strong evidence for the involvement of ion dysregulation and ECS function in bipolar illness. Additional research is required to fully characterize these abnormalities and define future clinical directions.
Collapse
Affiliation(s)
- Rif S. El-Mallakh
- Mood Disorders Research Program, Depression Center, Department of Psychiatry and Behavioral Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Correspondence: (R.S.E.-M.); (D.L.)
| | - Vishnu Priya Sampath
- Department of Medical Neurobiology, Faculty of Medicine, The Institute for Medical Research, Israel-Canada, Hadassah Medical School, The Hebrew University, Jerusalem 9112102, Israel; (V.P.S.); (N.H.)
| | - Noa Horesh
- Department of Medical Neurobiology, Faculty of Medicine, The Institute for Medical Research, Israel-Canada, Hadassah Medical School, The Hebrew University, Jerusalem 9112102, Israel; (V.P.S.); (N.H.)
| | - David Lichtstein
- Department of Medical Neurobiology, Faculty of Medicine, The Institute for Medical Research, Israel-Canada, Hadassah Medical School, The Hebrew University, Jerusalem 9112102, Israel; (V.P.S.); (N.H.)
- Correspondence: (R.S.E.-M.); (D.L.)
| |
Collapse
|
10
|
The Cardiac Glycoside Deslanoside Exerts Anticancer Activity in Prostate Cancer Cells by Modulating Multiple Signaling Pathways. Cancers (Basel) 2021; 13:cancers13225809. [PMID: 34830961 PMCID: PMC8616045 DOI: 10.3390/cancers13225809] [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: 09/28/2021] [Revised: 11/03/2021] [Accepted: 11/10/2021] [Indexed: 12/23/2022] Open
Abstract
Simple Summary Prostate cancer is a leading cause of cancer-related deaths among men, and novel therapies for advanced PCa are urgently needed. Cardiac glycosides are a group of attractive candidates for anticancer repurposing, but deslanoside has not been tested for a potential anticancer effect so far. This study aims to test the anticancer effect of deslanoside in PCa and investigate the underlying mechanisms. Deslanoside effectively inhibited colony formation and tumor growth in multiple prostate cancer cell lines. Such an inhibitory effect involved both the cell cycle arrest at G2/M and the induction of apoptosis. Deslanoside altered the expression of many genes, which belonged to various cancer-associated cellular processes and signaling pathways. Altered expression levels for 15 deslanoside-modulated genes correlate with recurrence-free survival or overall survival in PCa patients, some of which have not been implicated in cancer before. Therefore, deslanoside exerts anticancer activity in PCa cells by modulating gene expression. Abstract Prostate cancer (PCa) is a leading cause of cancer-related deaths among men worldwide, and novel therapies for advanced PCa are urgently needed. Cardiac glycosides represent an attractive group of candidates for anticancer repurposing, but the cardiac glycoside deslanoside has not been tested for potential anticancer activity so far. We found that deslanoside effectively inhibited colony formation in vitro and tumor growth in nude mice of PCa cell lines 22Rv1, PC-3, and DU 145. Such an anticancer activity was mediated by both the cell cycle arrest at G2/M and the induction of apoptosis, as demonstrated by different functional assays and the expression status of regulatory proteins of cell cycle and apoptosis in cultured cells. Moreover, deslanoside suppressed the invasion and migration of PCa cell lines. Genome-wide expression profiling and bioinformatic analyses revealed that 130 genes were either upregulated or downregulated by deslanoside in both 22Rv1 and PC-3 cell lines. These genes enriched multiple cellular processes, such as response to steroid hormones, regulation of lipid metabolism, epithelial cell proliferation and its regulation, and negative regulation of cell migration. They also enriched multiple signaling pathways, such as necroptosis, MAPK, NOD-like receptor, and focal adhesion. Survival analyses of the 130 genes in the TCGA PCa database revealed that 10 of the deslanoside-downregulated genes (ITG2B, CNIH2, FBF1, PABPC1L, MMP11, DUSP9, TMEM121, SOX18, CMPK2, and MAMDC4) inversely correlated, while one deslanoside-upregulated gene (RASD1) positively correlated, with disease-free survival in PCa patients. In addition, one deslanoside-downregulated gene (ENG) inversely correlated, while three upregulated genes (JUN, MXD1, and AQP3) positively correlated with overall survival in PCa patients. Some of the 15 genes have not been implicated in cancer before. These findings provide another candidate for repurposing cardiac glycosides for anticancer drugs. They also suggest that a diverse range of molecular events underlie deslanoside’s anticancer activity in PCa cells.
Collapse
|
11
|
Sadras F, Stewart TA, Robitaille M, Peters AA, Croft PKD, Soon PS, Saunus JM, Lakhani SR, Roberts-Thomson SJ, Monteith GR. Altered Calcium Influx Pathways in Cancer-Associated Fibroblasts. Biomedicines 2021; 9:biomedicines9060680. [PMID: 34208665 PMCID: PMC8234491 DOI: 10.3390/biomedicines9060680] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 06/10/2021] [Accepted: 06/12/2021] [Indexed: 11/16/2022] Open
Abstract
Cancer-associated fibroblasts (CAFs) represent an important component of the tumour microenvironment and are implicated in disease progression. Two outstanding questions in cancer biology are how CAFs arise and how they might be targeted therapeutically. The calcium signal also has an important role in tumorigenesis. To date, the role of calcium signalling pathways in the induction of the CAF phenotype remains unexplored. A CAF model was generated through exogenous transforming growth factor beta 1 (TGFβ1) stimulation of the normal human mammary fibroblast cell line, HMF3S (HMF3S-CAF), and changes in calcium signalling were investigated. Functional changes in HMF3S-CAF calcium signalling pathways were assessed using a fluorescent indicator, gene expression, gene-silencing and pharmacological approaches. HMF3S-CAF cells demonstrated functionally altered calcium influx pathways with reduced store-operated calcium entry. In support of a calcium signalling switch, two voltage-gated calcium channel (VGCC) family members, CaV1.2 and CaV3.2, were upregulated in HMF3S-CAFs and a subset of patient-derived breast CAFs. Both siRNA-mediated silencing and pharmacological inhibition of CaV1.2 or CaV3.2 significantly impaired CAF activation in HMF3S cells. Our findings show that VGCCs contribute to TGFβ1-mediated induction of HMF3S-CAF cells and both transcriptional interference and pharmacological antagonism of CaV1.2 and CaV3.2 inhibit CAF induction. This suggests a potential therapeutic role for targeting calcium signalling in breast CAFs.
Collapse
Affiliation(s)
- Francisco Sadras
- School of Pharmacy, The University of Queensland, Brisbane, QLD 4102, Australia; (F.S.); (M.R.); (A.A.P.); (S.J.R.-T.)
| | - Teneale A. Stewart
- Mater Research, Translational Research Institute, The University of Queensland, Brisbane, QLD 4102, Australia;
| | - Mélanie Robitaille
- School of Pharmacy, The University of Queensland, Brisbane, QLD 4102, Australia; (F.S.); (M.R.); (A.A.P.); (S.J.R.-T.)
| | - Amelia A. Peters
- School of Pharmacy, The University of Queensland, Brisbane, QLD 4102, Australia; (F.S.); (M.R.); (A.A.P.); (S.J.R.-T.)
| | - Priyakshi Kalita-de Croft
- Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD 4006, Australia; (P.K.-d.C.); (J.M.S.); (S.R.L.)
| | - Patsy S. Soon
- South Western Sydney Clinical School, University of New South Wales, Liverpool, NSW 2170, Australia;
- Department of Surgery, Bankstown Hospital, Bankstown, NSW 2200, Australia
- Medical Oncology Group, Ingham Institute for Applied Medical Research, Liverpool, NSW 2170, Australia
| | - Jodi M. Saunus
- Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD 4006, Australia; (P.K.-d.C.); (J.M.S.); (S.R.L.)
| | - Sunil R. Lakhani
- Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, QLD 4006, Australia; (P.K.-d.C.); (J.M.S.); (S.R.L.)
- Pathology Queensland, The Royal Brisbane and Women’s Hospital, Herston, QLD 4029, Australia
| | - Sarah J. Roberts-Thomson
- School of Pharmacy, The University of Queensland, Brisbane, QLD 4102, Australia; (F.S.); (M.R.); (A.A.P.); (S.J.R.-T.)
| | - Gregory R. Monteith
- School of Pharmacy, The University of Queensland, Brisbane, QLD 4102, Australia; (F.S.); (M.R.); (A.A.P.); (S.J.R.-T.)
- Mater Research, Translational Research Institute, The University of Queensland, Brisbane, QLD 4102, Australia;
- Correspondence:
| |
Collapse
|
12
|
Morotti S, Ni H, Peters CH, Rickert C, Asgari-Targhi A, Sato D, Glukhov AV, Proenza C, Grandi E. Intracellular Na + Modulates Pacemaking Activity in Murine Sinoatrial Node Myocytes: An In Silico Analysis. Int J Mol Sci 2021; 22:5645. [PMID: 34073281 PMCID: PMC8198068 DOI: 10.3390/ijms22115645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/19/2022] Open
Abstract
Background: The mechanisms underlying dysfunction in the sinoatrial node (SAN), the heart's primary pacemaker, are incompletely understood. Electrical and Ca2+-handling remodeling have been implicated in SAN dysfunction associated with heart failure, aging, and diabetes. Cardiomyocyte [Na+]i is also elevated in these diseases, where it contributes to arrhythmogenesis. Here, we sought to investigate the largely unexplored role of Na+ homeostasis in SAN pacemaking and test whether [Na+]i dysregulation may contribute to SAN dysfunction. Methods: We developed a dataset-specific computational model of the murine SAN myocyte and simulated alterations in the major processes of Na+ entry (Na+/Ca2+ exchanger, NCX) and removal (Na+/K+ ATPase, NKA). Results: We found that changes in intracellular Na+ homeostatic processes dynamically regulate SAN electrophysiology. Mild reductions in NKA and NCX function increase myocyte firing rate, whereas a stronger reduction causes bursting activity and loss of automaticity. These pathologic phenotypes mimic those observed experimentally in NCX- and ankyrin-B-deficient mice due to altered feedback between the Ca2+ and membrane potential clocks underlying SAN firing. Conclusions: Our study generates new testable predictions and insight linking Na+ homeostasis to Ca2+ handling and membrane potential dynamics in SAN myocytes that may advance our understanding of SAN (dys)function.
Collapse
Affiliation(s)
- Stefano Morotti
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA; (H.N.); (A.A.-T.); (D.S.)
| | - Haibo Ni
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA; (H.N.); (A.A.-T.); (D.S.)
| | - Colin H. Peters
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; (C.H.P.); (C.R.); (C.P.)
| | - Christian Rickert
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; (C.H.P.); (C.R.); (C.P.)
| | - Ameneh Asgari-Targhi
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA; (H.N.); (A.A.-T.); (D.S.)
| | - Daisuke Sato
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA; (H.N.); (A.A.-T.); (D.S.)
| | - Alexey V. Glukhov
- Department of Medicine, Cardiovascular Medicine, University of Wisconsin Madison School of Medicine and Public Health, Madison, WI 53705, USA;
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; (C.H.P.); (C.R.); (C.P.)
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Eleonora Grandi
- Department of Pharmacology, University of California Davis, Davis, CA 95616, USA; (H.N.); (A.A.-T.); (D.S.)
| |
Collapse
|
13
|
Cortassa S, Juhaszova M, Aon MA, Zorov DB, Sollott SJ. Mitochondrial Ca 2+, redox environment and ROS emission in heart failure: Two sides of the same coin? J Mol Cell Cardiol 2021; 151:113-125. [PMID: 33301801 PMCID: PMC7880885 DOI: 10.1016/j.yjmcc.2020.11.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 11/05/2020] [Accepted: 11/28/2020] [Indexed: 12/11/2022]
Abstract
Heart failure (HF) is a progressive, debilitating condition characterized, in part, by altered ionic equilibria, increased ROS production and impaired cellular energy metabolism, contributing to variable profiles of systolic and diastolic dysfunction with significant functional limitations and risk of premature death. We summarize current knowledge concerning changes of intracellular Na+ and Ca2+ control mechanisms during the disease progression and their consequences on mitochondrial Ca2+ homeostasis and the shift in redox balance. Absent existing biological data, our computational modeling studies advance a new 'in silico' analysis to reconcile existing opposing views, based on different experimental HF models, regarding variations in mitochondrial Ca2+ concentration that participate in triggering and perpetuating oxidative stress in the failing heart and their impact on cardiac energetics. In agreement with our hypothesis and the literature, model simulations demonstrate the possibility that the heart's redox status together with cytoplasmic Na+ concentrations act as regulators of mitochondrial Ca2+ levels in HF and of the bioenergetics response that will ultimately drive ATP supply and oxidative stress. The resulting model predictions propose future directions to study the evolution of HF as well as other types of heart disease, and to develop novel testable mechanistic hypotheses that may lead to improved therapeutics.
Collapse
Affiliation(s)
- Sonia Cortassa
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, United States.
| | - Magdalena Juhaszova
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, United States.
| | - Miguel A Aon
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, United States; Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, MD, United States.
| | - Dmitry B Zorov
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, United States; Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
| | - Steven J Sollott
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD, United States.
| |
Collapse
|
14
|
Barreca M, Spanò V, Montalbano A, Cueto M, Díaz Marrero AR, Deniz I, Erdoğan A, Lukić Bilela L, Moulin C, Taffin-de-Givenchy E, Spriano F, Perale G, Mehiri M, Rotter A, P. Thomas O, Barraja P, Gaudêncio SP, Bertoni F. Marine Anticancer Agents: An Overview with a Particular Focus on Their Chemical Classes. Mar Drugs 2020; 18:md18120619. [PMID: 33291602 PMCID: PMC7761941 DOI: 10.3390/md18120619] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 02/06/2023] Open
Abstract
The marine environment is a rich source of biologically active molecules for the treatment of human diseases, especially cancer. The adaptation to unique environmental conditions led marine organisms to evolve different pathways than their terrestrial counterparts, thus producing unique chemicals with a broad diversity and complexity. So far, more than 36,000 compounds have been isolated from marine micro- and macro-organisms including but not limited to fungi, bacteria, microalgae, macroalgae, sponges, corals, mollusks and tunicates, with hundreds of new marine natural products (MNPs) being discovered every year. Marine-based pharmaceuticals have started to impact modern pharmacology and different anti-cancer drugs derived from marine compounds have been approved for clinical use, such as: cytarabine, vidarabine, nelarabine (prodrug of ara-G), fludarabine phosphate (pro-drug of ara-A), trabectedin, eribulin mesylate, brentuximab vedotin, polatuzumab vedotin, enfortumab vedotin, belantamab mafodotin, plitidepsin, and lurbinectedin. This review focuses on the bioactive molecules derived from the marine environment with anticancer activity, discussing their families, origin, structural features and therapeutic use.
Collapse
Affiliation(s)
- Marilia Barreca
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90123 Palermo, Italy; (M.B.); (V.S.); (A.M.); (P.B.)
- Faculty of Biomedical Sciences, Institute of Oncology Research, USI, 6500 Bellinzona, Switzerland;
| | - Virginia Spanò
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90123 Palermo, Italy; (M.B.); (V.S.); (A.M.); (P.B.)
| | - Alessandra Montalbano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90123 Palermo, Italy; (M.B.); (V.S.); (A.M.); (P.B.)
| | - Mercedes Cueto
- Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), La Laguna, 38206 Tenerife, Spain;
| | - Ana R. Díaz Marrero
- Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), La Laguna, 38200 Tenerife, Spain;
| | - Irem Deniz
- Department of Bioengineering, Faculty of Engineering, Manisa Celal Bayar University, 45119 Manisa, Turkey;
| | - Ayşegül Erdoğan
- Research Center for Testing and Analysis (EGE MATAL), Ege University Application, 35100 İzmir, Turkey;
| | - Lada Lukić Bilela
- Department of Biology, Faculty of Science, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina;
| | - Corentin Moulin
- Marine Natural Products Team, UMR 7272, Institut de Chimie de Nice, Université Côte d’Azur, CNRS, 06108 Nice, France; (C.M.); (E.T.-d.-G.); (M.M.)
| | - Elisabeth Taffin-de-Givenchy
- Marine Natural Products Team, UMR 7272, Institut de Chimie de Nice, Université Côte d’Azur, CNRS, 06108 Nice, France; (C.M.); (E.T.-d.-G.); (M.M.)
| | - Filippo Spriano
- Faculty of Biomedical Sciences, Institute of Oncology Research, USI, 6500 Bellinzona, Switzerland;
| | - Giuseppe Perale
- Faculty of Biomedical Sciences, USI, 6900 Lugano, Switzerland;
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, 1200 Vienna, Austria
| | - Mohamed Mehiri
- Marine Natural Products Team, UMR 7272, Institut de Chimie de Nice, Université Côte d’Azur, CNRS, 06108 Nice, France; (C.M.); (E.T.-d.-G.); (M.M.)
| | - Ana Rotter
- Marine Biology Station Piran, National Institute of Biology, 1000 Ljubljana, Slovenia;
| | - Olivier P. Thomas
- Marine Biodiscovery Laboratory, School of Chemistry and Ryan Institute, National University of Ireland, Galway (NUI Galway), H91TK33 Galway, Ireland;
| | - Paola Barraja
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90123 Palermo, Italy; (M.B.); (V.S.); (A.M.); (P.B.)
| | - Susana P. Gaudêncio
- UCIBIO—Applied Biomolecular Sciences Unit, Department of Chemistry, Blue Biotechnology & Biomedicine Lab, Faculty of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal
- Correspondence: (S.P.G.); (F.B.); Tel.: +351-21-2948300 (S.P.G.); +41-91-8200367 (F.B.)
| | - Francesco Bertoni
- Faculty of Biomedical Sciences, Institute of Oncology Research, USI, 6500 Bellinzona, Switzerland;
- Oncology Institute of Southern Switzerland, 6500 Bellinzona, Switzerland
- Correspondence: (S.P.G.); (F.B.); Tel.: +351-21-2948300 (S.P.G.); +41-91-8200367 (F.B.)
| |
Collapse
|
15
|
Pederson PJ, Cai S, Carver C, Powell DR, Risinger AL, Grkovic T, O'Keefe BR, Mooberry SL, Cichewicz RH. Triple-Negative Breast Cancer Cells Exhibit Differential Sensitivity to Cardenolides from Calotropis gigantea. JOURNAL OF NATURAL PRODUCTS 2020; 83:2269-2280. [PMID: 32649211 PMCID: PMC7540184 DOI: 10.1021/acs.jnatprod.0c00423] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Triple-negative breast cancers (TNBC) are aggressive and heterogeneous cancers that lack targeted therapies. We implemented a screening program to identify new leads for subgroups of TNBC using diverse cell lines with different molecular drivers. Through this program, we identified an extract from Calotropis gigantea that caused selective cytotoxicity in BT-549 cells as compared to four other TNBC cell lines. Bioassay-guided fractionation of the BT-549 selective extract yielded nine cardenolides responsible for the selective activity. These included eight known cardenolides and a new cardenolide glycoside. Structure-activity relationships among the cardenolides demonstrated a correlation between their relative potencies toward BT-549 cells and Na+/K+ ATPase inhibition. Calotropin, the compound with the highest degree of selectivity for BT-549 cells, increased intracellular Ca2+ in sensitive cells to a greater extent than in the resistant MDA-MB-231 cells. Further studies identified a second TNBC cell line, Hs578T, that is also highly sensitive to the cardenolides, and mechanistic studies were conducted to identify commonalities among the sensitive cell lines. Experiments showed that both cardenolide-sensitive cell lines expressed higher mRNA levels of the Na+/Ca2+ exchanger NCX1 than resistant TNBC cells. This suggests that NCX1 could be a biomarker to identify TNBC patients that might benefit from the clinical administration of a cardiac glycoside for anticancer indications.
Collapse
Affiliation(s)
- Petra J Pederson
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
- Mays Cancer Center, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Shengxin Cai
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Chase Carver
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Douglas R Powell
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - April L Risinger
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
- Mays Cancer Center, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Tanja Grkovic
- Natural Products Support Group, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Barry R O'Keefe
- Natural Products Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Frederick, Maryland 21702, United States
- Molecular Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Susan L Mooberry
- Department of Pharmacology, University of Texas Health Science Center, San Antonio, Texas 78229, United States
- Mays Cancer Center, University of Texas Health Science Center, San Antonio, Texas 78229, United States
| | - Robert H Cichewicz
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States
| |
Collapse
|
16
|
Federico M, Valverde CA, Mattiazzi A, Palomeque J. Unbalance Between Sarcoplasmic Reticulum Ca 2 + Uptake and Release: A First Step Toward Ca 2 + Triggered Arrhythmias and Cardiac Damage. Front Physiol 2020; 10:1630. [PMID: 32038301 PMCID: PMC6989610 DOI: 10.3389/fphys.2019.01630] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/24/2019] [Indexed: 12/19/2022] Open
Abstract
The present review focusses on the regulation and interplay of cardiac SR Ca2+ handling proteins involved in SR Ca2+ uptake and release, i.e., SERCa2/PLN and RyR2. Both RyR2 and SERCA2a/PLN are highly regulated by post-translational modifications and/or different partners' proteins. These control mechanisms guarantee a precise equilibrium between SR Ca2+ reuptake and release. The review then discusses how disruption of this balance alters SR Ca2+ handling and may constitute a first step toward cardiac damage and malignant arrhythmias. In the last part of the review, this concept is exemplified in different cardiac diseases, like prediabetic and diabetic cardiomyopathy, digitalis intoxication and ischemia-reperfusion injury.
Collapse
Affiliation(s)
- Marilén Federico
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Carlos A Valverde
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Alicia Mattiazzi
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Julieta Palomeque
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", CCT-La Plata/CONICET, Facultad de Cs. Médicas, Universidad Nacional de La Plata, La Plata, Argentina.,Centro de Altos Estudios en Ciencias Humanas y de la Salud, Universidad Abierta Interamericana, Buenos Aires, Argentina
| |
Collapse
|
17
|
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.
Collapse
Affiliation(s)
- Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
| |
Collapse
|
18
|
Gkountela S, Castro-Giner F, Szczerba BM, Vetter M, Landin J, Scherrer R, Krol I, Scheidmann MC, Beisel C, Stirnimann CU, Kurzeder C, Heinzelmann-Schwarz V, Rochlitz C, Weber WP, Aceto N. Circulating Tumor Cell Clustering Shapes DNA Methylation to Enable Metastasis Seeding. Cell 2019; 176:98-112.e14. [PMID: 30633912 PMCID: PMC6363966 DOI: 10.1016/j.cell.2018.11.046] [Citation(s) in RCA: 532] [Impact Index Per Article: 106.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/31/2018] [Accepted: 11/28/2018] [Indexed: 01/01/2023]
Abstract
The ability of circulating tumor cells (CTCs) to form clusters has been linked to increased metastatic potential. Yet biological features and vulnerabilities of CTC clusters remain largely unknown. Here, we profile the DNA methylation landscape of single CTCs and CTC clusters from breast cancer patients and mouse models on a genome-wide scale. We find that binding sites for stemness- and proliferation-associated transcription factors are specifically hypomethylated in CTC clusters, including binding sites for OCT4, NANOG, SOX2, and SIN3A, paralleling embryonic stem cell biology. Among 2,486 FDA-approved compounds, we identify Na+/K+ ATPase inhibitors that enable the dissociation of CTC clusters into single cells, leading to DNA methylation remodeling at critical sites and metastasis suppression. Thus, our results link CTC clustering to specific changes in DNA methylation that promote stemness and metastasis and point to cluster-targeting compounds to suppress the spread of cancer.
Collapse
Affiliation(s)
- Sofia Gkountela
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland
| | - Francesc Castro-Giner
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland; SIB Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Barbara Maria Szczerba
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland
| | - Marcus Vetter
- Gynecologic Cancer Center, University Hospital Basel, 4056 Basel, Switzerland; Department of Medical Oncology, University Hospital Basel, 4056 Basel, Switzerland
| | - Julia Landin
- Department of Medical Oncology, University Hospital Basel, 4056 Basel, Switzerland; Breast Center, University Hospital Basel and University of Basel, 4031 Basel, Switzerland
| | - Ramona Scherrer
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland
| | - Ilona Krol
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland
| | - Manuel C Scheidmann
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland
| | - Christian Beisel
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | | | - Christian Kurzeder
- Gynecologic Cancer Center, University Hospital Basel, 4056 Basel, Switzerland; Breast Center, University Hospital Basel and University of Basel, 4031 Basel, Switzerland
| | | | - Christoph Rochlitz
- Department of Medical Oncology, University Hospital Basel, 4056 Basel, Switzerland
| | - Walter Paul Weber
- Breast Center, University Hospital Basel and University of Basel, 4031 Basel, Switzerland
| | - Nicola Aceto
- Cancer Metastasis Laboratory, Department of Biomedicine, University of Basel and University Hospital Basel, 4058 Basel, Switzerland.
| |
Collapse
|
19
|
Feric NT, Pallotta I, Singh R, Bogdanowicz DR, Gustilo M, Chaudhary K, Willette RN, Chendrimada T, Xu X, Graziano MP, Aschar-Sobbi R. Engineered Cardiac Tissues Generated in the Biowire™ II: A Platform for Human-Based Drug Discovery. Toxicol Sci 2019; 172:89-97. [PMID: 31385592 PMCID: PMC6813749 DOI: 10.1093/toxsci/kfz168] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/01/2019] [Accepted: 07/14/2019] [Indexed: 01/14/2023] Open
Abstract
Recent advances in techniques to differentiate human induced pluripotent stem cells (hiPSCs) hold the promise of an unlimited supply of human derived cardiac cells from both healthy and disease populations. That promise has been tempered by the observation that hiPSC-derived cardiomyocytes (hiPSC-CMs) typically retain a fetal-like phenotype, raising concern about the translatability of the in vitro data obtained to drug safety, discovery and development studies. The Biowire™ II platform was used to generate 3D engineered cardiac tissues (ECTs) from hiPSC-CMs and cardiac fibroblasts. Long term electrical stimulation was employed to obtain ECTs that possess a phenotype like that of adult human myocardium including a lack of spontaneous beating, the presence of a positive force-frequency response from 1-4Hz and prominent post-rest potentiation. Pharmacology studies were performed in the ECTs to confirm the presence and functionality of pathways that modulate cardiac contractility in humans. Canonical responses were observed for compounds that act via the β-adrenergic/cAMP-mediated pathway, e.g. isoproterenol and milrinone; the L-type calcium channel, e.g. FPL64176 and nifedipine; and indirectly effect intracellular Ca2+ concentrations, e.g. digoxin. Expected positive inotropic responses were observed for compounds that modulate proteins of the cardiac sarcomere, e.g. omecamtiv mecarbil and levosimendan. ECTs generated in the BiowireTM II platform display adult-like properties and have canonical responses to cardiotherapeutic and cardiotoxic agents that affect contractility in humans via a variety of mechanisms. These data demonstrate that this human-based model can be used to assess the effects of novel compounds on contractility early in the drug discovery and development process.
Collapse
|
20
|
Gonano LA, Sepúlveda M, Morell M, Toteff T, Racioppi MF, Lascano E, Negroni J, Fernández Ruocco MJ, Medei E, Neiman G, Miriuka SG, Back TG, Chen SRW, Mattiazzi A, Vila Petroff M. Non-β-Blocking Carvedilol Analog, VK-II-86, Prevents Ouabain-Induced Cardiotoxicity. Circ J 2018; 83:41-51. [DOI: 10.1253/circj.cj-18-0247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Luis A. Gonano
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Marisa Sepúlveda
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Malena Morell
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Tamara Toteff
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - María Florencia Racioppi
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Elena Lascano
- Instituto de Medicina Translacional, Transplante y Bioingeniería, Universidad Favaloro, CONICET
| | - Jorge Negroni
- Instituto de Medicina Translacional, Transplante y Bioingeniería, Universidad Favaloro, CONICET
| | - María Julieta Fernández Ruocco
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro
| | - Emiliano Medei
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro
| | | | | | | | - S. R. Wayne Chen
- Libin Cardiovascular Institute of Alberta, Department of Physiology and Pharmacology, University of Calgary
| | - Alicia Mattiazzi
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| | - Martin Vila Petroff
- Centro de Investigaciones Cardiovasculares, CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata
| |
Collapse
|
21
|
Bögeholz N, Pauls P, Bauer BK, Schulte JS, Frommeyer G, Dechering DG, Boknik P, Kirchhefer U, Müller FU, Pott C, Eckardt L. Overexpression of the Na + /Ca 2+ exchanger influences ouabain-mediated spontaneous Ca 2+ activity but not positive inotropy. Fundam Clin Pharmacol 2018; 33:43-51. [PMID: 30092622 DOI: 10.1111/fcp.12404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 07/16/2018] [Accepted: 08/01/2018] [Indexed: 12/01/2022]
Abstract
Administration of digitalis in heart failure (HF) increases quality of life but does not carry a prognostic benefit. Digitalis is an indirect inhibitor of the Na+ /Ca2+ exchanger (NCX), which is overexpressed in HF. We therefore used the cardiac glycoside ouabain in Ca2+ imaging experiments and patch-clamp experiments in isolated ventricular myocytes from nonfailing transgenic NCX overexpressor mice (OE). In field-stimulated myocytes, ouabain (1-100 μm) increased the amplitude of the Ca2+ transient in OE and wild-type (WT) similarly. Ouabain-mediated spontaneous Ca2+ -activity was significantly more pronounced in OE compared to WT myocytes at higher concentrations (100 μm). Also, at very high concentrations (1000 μm) of ouabain, the number of cells with hypercontraction leading to cell death was higher in OE. Ouabain (10 μm) shortened the action potential duration in both genotypes. Our findings suggest that the proarrhythmic but not the inotropic effects of cardiac glycosides are enhanced by increased NCX expression. This may offer an explanation for the observed lack of prognostic benefit but increased quality of life in HF, which is accompanied by NCX upregulation.
Collapse
Affiliation(s)
- Nils Bögeholz
- Klinik für Kardiologie II: Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany
| | - Paul Pauls
- Klinik für Kardiologie II: Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany.,Institut für Pharmakologie und Toxikologie, Universität Münster, Domagkstraße 12, 48149, Münster, Germany
| | - Bastian K Bauer
- Klinik für Kardiologie II: Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany
| | - Jan S Schulte
- Institut für Pharmakologie und Toxikologie, Universität Münster, Domagkstraße 12, 48149, Münster, Germany
| | - Gerrit Frommeyer
- Klinik für Kardiologie II: Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany
| | - Dirk G Dechering
- Klinik für Kardiologie II: Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany
| | - Peter Boknik
- Institut für Pharmakologie und Toxikologie, Universität Münster, Domagkstraße 12, 48149, Münster, Germany
| | - Uwe Kirchhefer
- Institut für Pharmakologie und Toxikologie, Universität Münster, Domagkstraße 12, 48149, Münster, Germany
| | - Frank U Müller
- Institut für Pharmakologie und Toxikologie, Universität Münster, Domagkstraße 12, 48149, Münster, Germany
| | - Christian Pott
- Department of Cardiology, Schüchtermann-Klinik, Ulmenallee 5-11, 49214, Bad Rothenfelde, Germany
| | - Lars Eckardt
- Klinik für Kardiologie II: Rhythmologie, Universitätsklinikum Münster, Albert-Schweitzer-Campus 1, Gebäude A1, 48149, Münster, Germany
| |
Collapse
|
22
|
Schmidt C, Wiedmann F, Gaubatz AR, Ratte A, Katus HA, Thomas D. New Targets for Old Drugs: Cardiac Glycosides Inhibit Atrial-Specific K 2P3.1 (TASK-1) Channels. J Pharmacol Exp Ther 2018; 365:614-623. [PMID: 29643254 DOI: 10.1124/jpet.118.247692] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/04/2018] [Indexed: 02/06/2023] Open
Abstract
Cardiac glycosides have been used in the treatment of arrhythmias for more than 200 years. Two-pore-domain (K2P) potassium channels regulate cardiac action potential repolarization. Recently, K2P3.1 [tandem of P domains in a weak inward rectifying K+ channel (TWIK)-related acid-sensitive K+ channel (TASK)-1] has been implicated in atrial fibrillation pathophysiology and was suggested as an atrial-selective antiarrhythmic drug target. We hypothesized that blockade of cardiac K2P channels contributes to the mechanism of action of digitoxin and digoxin. All functional human K2P channels were screened for interactions with cardiac glycosides. Human K2P channel subunits were expressed in Xenopus laevis oocytes, and voltage clamp electrophysiology was used to record K+ currents. Digitoxin significantly inhibited K2P3.1 and K2P16.1 channels. By contrast, digoxin displayed isolated inhibitory effects on K2P3.1. K2P3.1 outward currents were reduced by 80% (digitoxin, 1 Hz) and 78% (digoxin, 1 Hz). Digitoxin inhibited K2P3.1 currents with an IC50 value of 7.4 µM. Outward rectification properties of the channel were not affected. Mutagenesis studies revealed that amino acid residues located at the cytoplasmic site of the K2P3.1 channel pore form parts of a molecular binding site for cardiac glycosides. In conclusion, cardiac glycosides target human K2P channels. The antiarrhythmic significance of repolarizing atrial K2P3.1 current block by digoxin and digitoxin requires validation in translational and clinical studies.
Collapse
Affiliation(s)
- Constanze Schmidt
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Felix Wiedmann
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Anne-Rike Gaubatz
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Antonius Ratte
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Heidelberg, Germany (C.S., F.W., A.-R.G., A.R., H.A.K., D.T.); and German Centre for Cardiovascular Research, Heidelberg/Mannheim Partner Site, University of Heidelberg, Heidelberg, Germany (C.S., F.W., H.A.K., D.T.)
| |
Collapse
|
23
|
Hodes A, Lifschytz T, Rosen H, Cohen Ben-Ami H, Lichtstein D. Reduction in endogenous cardiac steroids protects the brain from oxidative stress in a mouse model of mania induced by amphetamine. Brain Res Bull 2018; 137:356-362. [PMID: 29374602 DOI: 10.1016/j.brainresbull.2018.01.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/10/2018] [Accepted: 01/19/2018] [Indexed: 02/08/2023]
Abstract
OBJECTIVES Bipolar disorder (BD) is a severe mental illness characterized by episodes of mania and depression. Numerous studies have implicated the involvement of endogenous cardiac steroids (CS), and their receptor, Na+, K+ -ATPase, in BD. The aim of the present study was to examine the role of brain oxidative stress in the CS-induced behavioral effects in mice. METHODS Amphetamine (AMPH)-induced hyperactivity, assessed in the open-field test, served as a model for manic-like behavior in mice. A reduction in brain CS was obtained by specific and sensitive anti-ouabain antibodies. The level of oxidative stress was tested in the hippocampus and frontal cortex by measuring the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), as well as the levels of antioxidant non-protein thiols (NPSH) and oxidative damage biomarkers thiobarbituric acid reactive substances (TBARS) and protein carbonyl (PC). RESULTS AMPH administration resulted in a marked hyperactivity and increased oxidative stress, as manifested by increased SOD activity, decreased activities of CAT and GPx, reduced levels of NPSH and increased levels of TBARS and PC. The administration of anti-ouabain antibodies, which reduced the AMPH-induced hyperactivity, protected against the concomitant oxidative stress in the brain. CONCLUSIONS Our results demonstrate that oxidative stress participates in the effects of endogenous CS on manic-like behavior induced by AMPH. These finding support the notion that CS and oxidative stress may be associated with the pathophysiology of mania and BD.
Collapse
Affiliation(s)
- Anastasia Hodes
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Tzuri Lifschytz
- Department of Psychiatry, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Haim Rosen
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Hagit Cohen Ben-Ami
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - David Lichtstein
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
| |
Collapse
|
24
|
Fernandez-Chas M, Curtis MJ, Niederer SA. Mechanism of doxorubicin cardiotoxicity evaluated by integrating multiple molecular effects into a biophysical model. Br J Pharmacol 2018; 175:763-781. [PMID: 29161764 DOI: 10.1111/bph.14104] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 10/20/2017] [Accepted: 10/23/2017] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Doxorubicin (DOX) is an effective cancer therapeutic agent but causes therapy-limiting cardiotoxicity. The effects of DOX and its metabolite doxorubicinol (DOXL) on individual channels have been well characterized in isolation. However, it is unknown how the action and interaction of affected channels combine to generate the phenotypic cardiotoxic outcome. We sought to develop an in silico model that links drug effects on channels to action potential duration (APD) and intracellular Ca2+ concentration in order to address this gap in knowledge. EXPERIMENTAL APPROACH We first propose two methods to obtain, from published values, consensus drug effects on the currents of individual channels, transporters and pumps. Separately, we obtained equivalent values for APD and Ca2+ concentration (the readouts used as surrogates for cardiotoxicity). Once derived, the consensus effects on the currents were incorporated into established biophysical models of the cardiac myocyte and were refined adjusting the sarcoplasmic reticulum Ca2+ leak current (ILeak ) until the consensus effects on APD and Ca2+ dynamics were replicated. Using factorial analysis, we then quantified the relative contribution of each channel to DOX and DOXL cardiotoxicity. KEY RESULTS The factorial analysis identified the rapid delayed rectifying K+ current, the L-type Ca2+ current and the sarcoplasmic reticulum ILeak as the targets primarily responsible for the cardiotoxic effects on APD and Ca2+ dynamics. CONCLUSIONS AND IMPLICATIONS This study provides insight into the mechanisms of DOX-induced cardiotoxicity and a framework for the development of future diagnostic and therapeutic strategies.
Collapse
Affiliation(s)
- M Fernandez-Chas
- Division of Imaging Sciences and Biomedical Engineering (MF, SAN) and Cardiovascular Division (MJC), King's College London, London, UK
| | - M J Curtis
- Division of Imaging Sciences and Biomedical Engineering (MF, SAN) and Cardiovascular Division (MJC), King's College London, London, UK
| | - S A Niederer
- Division of Imaging Sciences and Biomedical Engineering (MF, SAN) and Cardiovascular Division (MJC), King's College London, London, UK
| |
Collapse
|
25
|
Stewart BD, Scott CE, McCoy TP, Yin G, Despa F, Despa S, Kekenes-Huskey PM. Computational modeling of amylin-induced calcium dysregulation in rat ventricular cardiomyocytes. Cell Calcium 2017; 71:65-74. [PMID: 29604965 DOI: 10.1016/j.ceca.2017.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/30/2017] [Accepted: 11/30/2017] [Indexed: 01/08/2023]
Abstract
Hyperamylinemia is a condition that accompanies obesity and precedes type II diabetes, and it is characterized by above-normal blood levels of amylin, the pancreas-derived peptide. Human amylin oligomerizes easily and can deposit in the pancreas [1], brain [2], and heart [3], where they have been associated with calcium dysregulation. In the heart, accumulating evidence suggests that human amylin oligomers form moderately cation-selective [4,5] channels that embed in the cell sarcolemma (SL). The oligomers increase membrane conductance in a concentration-dependent manner [5], which is correlated with elevated cytosolic Ca2+. These findings motivate our core hypothesis that non-selective inward Ca2+ conduction afforded by human amylin oligomers increase cytosolic and sarcoplasmic reticulum (SR) Ca2+ load, which thereby magnifies intracellular Ca2+ transients. Questions remain however regarding the mechanism of amylin-induced Ca2+ dysregulation, including whether enhanced SL Ca2+ influx is sufficient to elevate cytosolic Ca2+ load [6], and if so, how might amplified Ca2+ transients perturb Ca2+-dependent cardiac pathways. To investigate these questions, we modified a computational model of cardiomyocytes Ca2+ signaling to reflect experimentally-measured changes in SL membrane permeation and decreased sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) function stemming from acute and transgenic human amylin peptide exposure. With this model, we confirmed the hypothesis that increasing SL permeation alone was sufficient to enhance Ca2+ transient amplitudes. Our model indicated that amplified cytosolic transients are driven by increased Ca2+ loading of the SR and that greater fractional release may contribute to the Ca2+-dependent activation of calmodulin, which could prime the activation of myocyte remodeling pathways. Importantly, elevated Ca2+ in the SR and dyadic space collectively drive greater fractional SR Ca2+ release for human amylin expressing rats (HIP) and acute amylin-exposed rats (+Amylin) mice, which contributes to the inotropic rise in cytosolic Ca2+ transients. These findings suggest that increased membrane permeation induced by oligomeratization of amylin peptide in cell sarcolemma contributes to Ca2+ dysregulation in pre-diabetes.
Collapse
Affiliation(s)
- Bradley D Stewart
- Department of Chemistry, University of Kentucky, 505 Rose St. Chemistry-Physics Building, Lexington, KY 40506, USA
| | - Caitlin E Scott
- Department of Chemistry, University of Kentucky, 505 Rose St. Chemistry-Physics Building, Lexington, KY 40506, USA
| | - Thomas P McCoy
- Department of Family & Community Nursing, University of North Carolina - Greensboro, 1008 Administration Dr. McIver Building, Greensboro, NC 27412, USA
| | - Guo Yin
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, UK Medical Center, MN 150, Lexington, KY 40536, USA
| | - Florin Despa
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, UK Medical Center, MN 150, Lexington, KY 40536, USA
| | - Sanda Despa
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, UK Medical Center, MN 150, Lexington, KY 40536, USA.
| | - Peter M Kekenes-Huskey
- Department of Chemistry, University of Kentucky, 505 Rose St. Chemistry-Physics Building, Lexington, KY 40506, USA.
| |
Collapse
|
26
|
Frommeyer G, Weller J, Ellermann C, Bögeholz N, Leitz P, Dechering DG, Kochhäuser S, Wasmer K, Eckardt L. Ivabradine Reduces Digitalis-induced Ventricular Arrhythmias. Basic Clin Pharmacol Toxicol 2017. [PMID: 28627809 DOI: 10.1111/bcpt.12829] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The I(f) channel inhibitor ivabradine is recommended for treatment of heart failure but also affects potassium currents and thereby prolongs ventricular repolarization. The aim of this study was to examine the electrophysiological effects of ivabradine on digitalis-induced ventricular arrhythmias. Thirteen rabbit hearts were isolated and Langendorff-perfused. After obtaining baseline data, the digitalis glycoside ouabain was infused (0.2 μM). Monophasic action potentials and ECG showed a significant abbreviation of QT interval (-34 ms, p < 0.05) and action potential duration (APD90 ; -27 ms, p < 0.05). The shortening of ventricular repolarization was accompanied by a reduction in effective refractory period (ERP; -27 ms, p < 0.05). Thereafter, hearts were additionally treated with ivabradine (5 μM). Of note, this did not exert significant effects on QT interval (-4 ms, p = ns) or APD90 (-15 ms, p = ns) but resulted in an increase in ERP (+17 ms, p < 0.05). This led to a significant increase in post-repolarization refractoriness (PRR, +32 ms, p < 0.01) as compared with sole ouabain treatment. Under baseline conditions, ventricular fibrillation (VF) was inducible by a standardized pacing protocol including programmed stimulation and burst stimulation in four of 13 hearts (31%; 15 episodes). After application of 0.2 μM ouabain, eight of 13 hearts were inducible (62%, 49 episodes). Additional infusion of 5 μM ivabradine led to a significant suppression of VF. Only four episodes could be induced in two of 13 hearts (15%). In this study, ivabradine reduced digitalis-induced ventricular arrhythmias. Ivabradine did not affect ventricular repolarization in the presence of digitalis treatment but demonstrated potent anti-arrhythmic properties based on an increase in both ERP and PRR. The study further characterizes the beneficial electrophysiological profile of ivabradine.
Collapse
Affiliation(s)
- Gerrit Frommeyer
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Jan Weller
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Christian Ellermann
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Nils Bögeholz
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Patrick Leitz
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Dirk G Dechering
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Simon Kochhäuser
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Kristina Wasmer
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| | - Lars Eckardt
- Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany
| |
Collapse
|
27
|
Identification of Na+/K+-ATPase inhibition-independent proarrhythmic ionic mechanisms of cardiac glycosides. Sci Rep 2017; 7:2465. [PMID: 28550304 PMCID: PMC5446409 DOI: 10.1038/s41598-017-02496-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 04/13/2017] [Indexed: 12/17/2022] Open
Abstract
The current study explored the Na+/K+-ATPase (NKA) inhibition-independent proarrhythmic mechanisms of cardiac glycosides (CGs) which are well-known NKA inhibitors. With the cytosolic Ca2+ chelated by EGTA and BAPTA or extracellular Ca2+ replaced by Ba2+, effects of bufadienolides (bufalin (BF) and cinobufagin (CBG)) and cardenolides (ouabain (Oua) and pecilocerin A (PEA)) on the L-type calcium current (ICa,L) were recorded in heterologous expression Cav1.2-CHO cells and human embryonic stem cell-derived cardiomyocytes (hESC-CMs). BF and CBG demonstrated a concentration-dependent (0.1 to 100 µM) ICa,L inhibition (maximal ≥50%) without and with the NKA activity blocked by 10 µM Oua. BF significantly shortened the action potential duration at 1.0 µM and shortened the extracellular field potential duration at 0.01~1.0 µM. On the other hand, BF and CBG at 100 µM demonstrated a strong inhibition (≥40%) of the rapidly activating component of the delayed rectifier K+ current (IKr) in heterologous expression HEK293 cells and prolonged the APD of the heart of day-3 Zebrafish larva with disrupted rhythmic contractions. Moreover, hESC-CMs treated with BF (10 nM) for 24 hours showed moderate yet significant prolongation in APD90. In conclusion, our data indicate that CGs particularly bufadienolides possess cytosolic [Ca2+]i- and NKA inhibition- independent proarrhythmic potential through ICa,L and IKr inhibitions.
Collapse
|
28
|
Himes RD, Smolin N, Kukol A, Bossuyt J, Bers DM, Robia SL. L30A Mutation of Phospholemman Mimics Effects of Cardiac Glycosides in Isolated Cardiomyocytes. Biochemistry 2016; 55:6196-6204. [PMID: 27718550 DOI: 10.1021/acs.biochem.6b00633] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
To determine if mutations introduced into phospholemman (PLM) could increase the level of PLM-Na,K-ATPase (NKA) binding, we performed scanning mutagenesis of the transmembrane domain of PLM and measured Förster resonance energy transfer (FRET) between each mutant and NKA. We observed an increased level of binding to NKA for several PLM mutants compared to that of the wild type (WT), including L27A, L30A, and I32A. In isolated cardiomyocytes, overexpression of WT PLM increased the amplitude of the Ca2+ transient compared to the GFP control. The Ca2+ transient amplitude was further increased by L30A PLM overexpression. The L30A mutation also delayed Ca2+ extrusion and increased the duration of cardiomyocyte contraction. This mimics aspects of the effect of cardiac glycosides, which are known to increase contractility through inhibition of NKA. No significant differences between WT and L30A PLM-expressing myocytes were observed after treatment with isoproterenol, suggesting that the superinhibitory effects of L30A are reversible with β-adrenergic stimulation. We also observed a decrease in the extent of PLM tetramerization with L30A compared to WT using FRET, suggesting that L30 is an important residue for mediating PLM-PLM binding. Molecular dynamics simulations revealed that the potential energy of the L30A tetramer is greater than that of the WT, and that the transmembrane α helix is distorted by the mutation. The results identify PLM residue L30 as an important determinant of PLM tetramerization and of functional inhibition of NKA by PLM.
Collapse
Affiliation(s)
- Ryan D Himes
- Department of Cell and Molecular Physiology, Loyola University Chicago , Maywood, Illinois 60153, United States
| | - Nikolai Smolin
- Department of Cell and Molecular Physiology, Loyola University Chicago , Maywood, Illinois 60153, United States
| | - Andreas Kukol
- School of Life and Medical Sciences, University of Hertfordshire , Hatfield, U.K
| | - Julie Bossuyt
- Department of Pharmacology, The University of California , Davis, California 95616, United States
| | - Donald M Bers
- Department of Pharmacology, The University of California , Davis, California 95616, United States
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago , Maywood, Illinois 60153, United States
| |
Collapse
|
29
|
Adams KF, Butler J, Patterson JH, Gattis Stough W, Bauman JL, van Veldhuisen DJ, Schwartz TA, Sabbah H, Mackowiak JI, Ventura HO, Ghali JK. Dose response characterization of the association of serum digoxin concentration with mortality outcomes in the Digitalis Investigation Group trial. Eur J Heart Fail 2016; 18:1072-81. [DOI: 10.1002/ejhf.584] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/17/2016] [Accepted: 04/19/2016] [Indexed: 12/25/2022] Open
Affiliation(s)
- Kirkwood F. Adams
- Departments of Medicine and Radiology, School of Medicine, Division of Cardiology; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Javed Butler
- Department of Medicine, Division of Cardiology; Emory University; Atlanta GA USA
| | - J. Herbert Patterson
- Division of Pharmacotherapy and Experimental Therapeutics; University of North Carolina at Chapel Hill Eshelman School of Pharmacy; Chapel Hill NC USA
| | - Wendy Gattis Stough
- Departments of Clinical Research and Pharmacy Practice; Campbell University College of Pharmacy and Health Sciences; Buies Creek NC USA
| | - Jerry L. Bauman
- Departments of Pharmacy Practice and Medicine, Section of Cardiology, Colleges of Pharmacy and Medicine; University of Illinois at Chicago; Chicago IL USA
| | - Dirk J. van Veldhuisen
- Department of Cardiology, University of Groningen; University Medical Center Groningen; Groningen The Netherlands
| | - Todd A. Schwartz
- Department of Biostatistics, Gillings School of Global Public Health; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Hani Sabbah
- Division of Cardiology, Wayne State University; Henry Ford Health System; Detroit MI USA
| | | | - Hector O. Ventura
- John Ochsner Heart and Vascular Institute, Ochsner Clinical School; The University of Queensland School of Medicine; New Orleans LA USA
| | - Jalal K. Ghali
- Division of Cardiology; Mercer University School of Medicine; Macon GA USA
| |
Collapse
|
30
|
Blaustein MP, Chen L, Hamlyn JM, Leenen FHH, Lingrel JB, Wier WG, Zhang J. Pivotal role of α2 Na + pumps and their high affinity ouabain binding site in cardiovascular health and disease. J Physiol 2016; 594:6079-6103. [PMID: 27350568 DOI: 10.1113/jp272419] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/18/2016] [Indexed: 12/13/2022] Open
Abstract
Reduced smooth muscle (SM)-specific α2 Na+ pump expression elevates basal blood pressure (BP) and increases BP sensitivity to angiotensin II (Ang II) and dietary NaCl, whilst SM-α2 overexpression lowers basal BP and decreases Ang II/salt sensitivity. Prolonged ouabain infusion induces hypertension in rodents, and ouabain-resistant mutation of the α2 ouabain binding site (α2R/R mice) confers resistance to several forms of hypertension. Pressure overload-induced heart hypertrophy and failure are attenuated in cardio-specific α2 knockout, cardio-specific α2 overexpression and α2R/R mice. We propose a unifying hypothesis that reconciles these apparently disparate findings: brain mechanisms, activated by Ang II and high NaCl, regulate sympathetic drive and a novel neurohumoral pathway mediated by both brain and circulating endogenous ouabain (EO). Circulating EO modulates ouabain-sensitive α2 Na+ pump activity and Ca2+ transporter expression and, via Na+ /Ca2+ exchange, Ca2+ homeostasis. This regulates sensitivity to sympathetic activity, Ca2+ signalling and arterial and cardiac contraction.
Collapse
Affiliation(s)
- Mordecai P Blaustein
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. .,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Ling Chen
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - John M Hamlyn
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Frans H H Leenen
- Hypertension Unit, University of Ottawa Heart Institute, Ottawa, ON, Canada, K1Y 4W7
| | - Jerry B Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267-0524, USA
| | - W Gil Wier
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jin Zhang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| |
Collapse
|
31
|
Sirenko SG, Maltsev VA, Yaniv Y, Bychkov R, Yaeger D, Vinogradova T, Spurgeon HA, Lakatta EG. Electrochemical Na+ and Ca2+ gradients drive coupled-clock regulation of automaticity of isolated rabbit sinoatrial nodal pacemaker cells. Am J Physiol Heart Circ Physiol 2016; 311:H251-67. [PMID: 27208164 DOI: 10.1152/ajpheart.00667.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 05/11/2016] [Indexed: 11/22/2022]
Abstract
Coupling of an intracellular Ca(2+) clock to surface membrane ion channels, i.e., a "membrane clock, " via coupling of electrochemical Na(+) and Ca(2+) gradients (ENa and ECa, respectively) has been theorized to regulate sinoatrial nodal cell (SANC) normal automaticity. To test this hypothesis, we measured responses of [Na(+)]i, [Ca(2+)]i, membrane potential, action potential cycle length (APCL), and rhythm in rabbit SANCs to Na(+)/K(+) pump inhibition by the digitalis glycoside, digoxigenin (DG, 10-20 μmol/l). Initial small but significant increases in [Na(+)]i and [Ca(2+)]i and reductions in ENa and ECa in response to DG led to a small reduction in maximum diastolic potential (MDP), significantly enhanced local diastolic Ca(2+) releases (LCRs), and reduced the average APCL. As [Na(+)]i and [Ca(2+)]i continued to increase at longer times following DG exposure, further significant reductions in MDP, ENa, and ECa occurred; LCRs became significantly reduced, and APCL became progressively and significantly prolonged. This was accompanied by increased APCL variability. We also employed a coupled-clock numerical model to simulate changes in ENa and ECa simultaneously with ion currents not measured experimentally. Numerical modeling predicted that, as the ENa and ECa monotonically reduced over time in response to DG, ion currents (ICaL, ICaT, If, IKr, and IbNa) monotonically decreased. In parallel with the biphasic APCL, diastolic INCX manifested biphasic changes; initial INCX increase attributable to enhanced LCR ensemble Ca(2+) signal was followed by INCX reduction as ENCX (ENCX = 3ENa - 2ECa) decreased. Thus SANC automaticity is tightly regulated by ENa, ECa, and ENCX via a complex interplay of numerous key clock components that regulate SANC clock coupling.
Collapse
Affiliation(s)
- Syevda G Sirenko
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Victor A Maltsev
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Yael Yaniv
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland; Biomedical Engineering Faculty, Technion-IIT, Haifa, Israel
| | - Rostislav Bychkov
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland; Universidad Central del Caribe, Santa Juanita, Bayamon Puerto Rico
| | - Daniel Yaeger
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Tatiana Vinogradova
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Harold A Spurgeon
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland;
| |
Collapse
|
32
|
Nánási P, Váczi K, Papp Z. The myosin activator omecamtiv mecarbil: a promising new inotropic agent. Can J Physiol Pharmacol 2016; 94:1033-1039. [PMID: 27322915 DOI: 10.1139/cjpp-2015-0573] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Heart failure became a leading cause of mortality in the past few decades with a progressively increasing prevalence. Its current therapy is restricted largely to the suppression of the sympathetic activity and the renin-angiotensin system in combination with diuretics. This restrictive strategy is due to the potential long-term adverse effects of inotropic agents despite their effective influence on cardiac function when employed for short durations. Positive inotropes include inhibitors of the Na+/K+ pump, β-receptor agonists, and phosphodiesterase inhibitors. Theoretically, Ca2+ sensitizers may also increase cardiac contractility without resulting in Ca2+ overload; nevertheless, their mechanism of action is frequently complicated by other pleiotropic effects. Recently, a new positive inotropic agent, the myosin activator omecamtiv mecarbil, has been developed. Omecamtiv mecarbil binds directly to β-myosin heavy chain and enhances cardiac contractility by increasing the number of the active force-generating cross-bridges, presumably without major off-target effects. This review focuses on recent in vivo and in vitro results obtained with omecamtiv mecarbil, and discusses its mechanism of action at a molecular level. Based on clinical data, omecamtiv mecarbil is a promising new tool in the treatment of systolic heart failure.
Collapse
Affiliation(s)
- Péter Nánási
- a Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Krisztina Váczi
- b Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Papp
- c Division of Clinical Physiology, Department of Cardiology, Research Center for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| |
Collapse
|
33
|
Peng LQ, Li P, Zhang QL, Hong L, Liu LP, Cui X, Cui BR. cAMP induction by ouabain promotes endothelin-1 secretion via MAPK/ERK signaling in beating rabbit atria. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 20:9-14. [PMID: 26807018 PMCID: PMC4722196 DOI: 10.4196/kjpp.2016.20.1.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/31/2015] [Accepted: 04/16/2015] [Indexed: 11/20/2022]
Abstract
Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the Na+-K+-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain (3.0 µmol/L) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 (3.0 µmol/L), an inhibitor for reverse mode of Na+-Ca2+ exchangers (NCX), but did not by L-type Ca2+ channel blocker nifedipine (1.0 µmol/L) or protein kinase A (PKA) selective inhibitor H-89 (3.0 µmol/L). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline (100.0 µmol/L), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP (0.5 µmol/L) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 (30 µmol/L), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.
Collapse
Affiliation(s)
- Li-Qun Peng
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China.; KeErQinQu First People's Hospital, Tongliao, Neimenggu 028050, China
| | - Ping Li
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China
| | - Qiu-Li Zhang
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China
| | - Lan Hong
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China
| | - Li-Ping Liu
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China
| | - Xun Cui
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China.; Key Laboratory of Organism Functional Factors of the Changbai Mountain, Ministry of Education, Yanbian University, Yanji 133-002, China.; Cellular Function Research Center, Yanbian University, Yanji 133-002, China
| | - Bai-Ri Cui
- Department of Physiology, School of Medicine, Yanbian University, Yanji 133-002, China.; Institue of Clinical Medicine, Yanbian University, Yanji 133000, China
| |
Collapse
|
34
|
Xie J, Ye Q, Cui X, Madan N, Yi Q, Pierre SV, Xie Z. Expression of rat Na-K-ATPase α2 enables ion pumping but not ouabain-induced signaling in α1-deficient porcine renal epithelial cells. Am J Physiol Cell Physiol 2015; 309:C373-82. [PMID: 26108663 DOI: 10.1152/ajpcell.00103.2015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/13/2015] [Indexed: 11/22/2022]
Abstract
Na-K-ATPase is a fundamental component of ion transport. Four α isoforms of the Na-K-ATPase catalytic α subunit are expressed in human cells. The ubiquitous Na-K-ATPase α1 was recently discovered to also mediate signal transduction through Src kinase. In contrast, α2 expression is limited to a few cell types including myocytes, where it is coupled to the Na(+)/Ca(2+) exchanger. To test whether rat Na-K-ATPase α2 is capable of cellular signaling like its α1 counterpart in a recipient mammalian system, we used an α1 knockdown pig renal epithelial cell (PY-17) to create an α2-expressing cell line with no detectable level of α1 expression. These cells exhibited normal ouabain-sensitive ATPase, but failed to effectively regulate Src. In contrast to α1-expressing cells, ouabain did not stimulate Src kinase or downstream effectors such as ERK and Akt in α2 cells, although their signaling apparatus was intact as evidenced by EGF-mediated signal transduction. Additionally, α2 cells were unable to rescue caveolin-1. Unlike the NaKtide sequence derived from Na-K-ATPase α1, which downregulates basal Src activity, the corresponding α2 NaKtide was unable to inhibit Src in vitro. Finally, coimmunoprecipitation of cellular Src was diminished in α2 cells. These findings indicate that Na-K-ATPase α2 does not regulate Src and, therefore, may not serve the same role in signal transduction as α1. This further implies that the signaling mechanism of Na-K-ATPase is isoform specific, thereby supporting a model where α1 and α2 isoforms play distinct roles in mediating contraction and signaling in myocytes.
Collapse
Affiliation(s)
- Joe Xie
- Department of Medicine, University of Colorado, Aurora, Colorado
| | - Qiqi Ye
- Department of Physiology and Pharmacology, University of Toledo, Toledo, Ohio
| | - Xiaoyu Cui
- Department of Physiology and Pharmacology, University of Toledo, Toledo, Ohio
| | - Namrata Madan
- Department of Physiology and Pharmacology, University of Toledo, Toledo, Ohio
| | - Qiying Yi
- Laboratory Animal Center, Chongqing Medical University, Chongqing, PR China; and
| | - Sandrine V Pierre
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, West Virginia
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, West Virginia
| |
Collapse
|
35
|
Role of phosphoinositide 3-kinase IA (PI3K-IA) activation in cardioprotection induced by ouabain preconditioning. J Mol Cell Cardiol 2015; 80:114-25. [PMID: 25575882 DOI: 10.1016/j.yjmcc.2014.12.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/06/2014] [Accepted: 12/26/2014] [Indexed: 11/23/2022]
Abstract
Acute myocardial infarction, the clinical manifestation of ischemia-reperfusion (IR) injury, is a leading cause of death worldwide. Like ischemic preconditioning (IPC) induced by brief episodes of ischemia and reperfusion, ouabain preconditioning (OPC) mediated by Na/K-ATPase signaling protects the heart against IR injury. Class I PI3K activation is required for IPC, but its role in OPC has not been investigated. While PI3K-IB is critical to IPC, studies have suggested that ouabain signaling is PI3K-IA-specific. Hence, a pharmacological approach was used to test the hypothesis that OPC and IPC rely on distinct PI3K-I isoforms. In Langendorff-perfused mouse hearts, OPC was initiated by 4 min of ouabain 10 μM and IPC was triggered by 4 cycles of 5 min ischemia and reperfusion prior to 40 min of global ischemia and 30 min of reperfusion. Without affecting PI3K-IB, ouabain doubled PI3K-IA activity and Akt phosphorylation at Ser(473). IPC and OPC significantly preserved cardiac contractile function and tissue viability as evidenced by left ventricular developed pressure and end-diastolic pressure recovery, reduced lactate dehydrogenase release, and decreased infarct size. OPC protection was blunted by the PI3K-IA inhibitor PI-103, but not by the PI3K-IB inhibitor AS-604850. In contrast, IPC-mediated protection was not affected by PI-103 but was blocked by AS-604850, suggesting that PI3K-IA activation is required for OPC while PI3K-IB activation is needed for IPC. Mechanistically, PI3K-IA activity is required for ouabain-induced Akt activation but not PKCε translocation. However, in contrast to PKCε translocation which is critical to protection, Akt activity was not required for OPC. Further studies shall reveal the identity of the downstream targets of this new PI3K IA-dependent branch of OPC. These findings may be of clinical relevance in patients at risk for myocardial infarction with underlying diseases and/or medication that could differentially affect the integrity of cardiac PI3K-IA and IB pathways.
Collapse
|
36
|
Gonano LA, Petroff MV. Subcellular Mechanisms Underlying Digitalis-Induced Arrhythmias: Role of Calcium/Calmodulin-Dependent Kinase II (CaMKII) in the Transition from an Inotropic to an Arrhythmogenic Effect. Heart Lung Circ 2014; 23:1118-24. [DOI: 10.1016/j.hlc.2014.07.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/03/2014] [Accepted: 07/23/2014] [Indexed: 11/27/2022]
|
37
|
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.
Collapse
Affiliation(s)
- Davor Pavlovic
- Cardiovascular Division, King's College London, Rayne Institute, St. Thomas' Hospital, London, UK
| |
Collapse
|
38
|
Grandi E, Herren AW. CaMKII-dependent regulation of cardiac Na(+) homeostasis. Front Pharmacol 2014; 5:41. [PMID: 24653702 PMCID: PMC3948048 DOI: 10.3389/fphar.2014.00041] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 02/21/2014] [Indexed: 01/01/2023] Open
Abstract
Na+ homeostasis is a key regulator of cardiac excitation and contraction. The cardiac voltage-gated Na+ channel, NaV1.5, critically controls cell excitability, and altered channel gating has been implicated in both inherited and acquired arrhythmias. Ca2+/calmodulin-dependent protein kinase II (CaMKII), a serine/threonine kinase important in cardiac physiology and disease, phosphorylates NaV1.5 at multiple sites within the first intracellular linker loop to regulate channel gating. Although CaMKII sites on the channel have been identified (S516, T594, S571), the relative role of each of these phospho-sites in channel gating properties remains unclear, whereby both loss-of-function (reduced availability) and gain-of-function (late Na+ current, INaL) effects have been reported. Our review highlights investigating the complex multi-site phospho-regulation of NaV1.5 gating is crucial to understanding the genesis of acquired arrhythmias in heart failure (HF) and CaMKII activated conditions. In addition, the increased Na+ influx accompanying INaL may also indirectly contribute to arrhythmia by promoting Ca2+ overload. While the precise mechanisms of Na+ loading during HF remain unclear, and quantitative analyses of the contribution of INaL are lacking, disrupted Na+ homeostasis is a consistent feature of HF. Computational and experimental observations suggest that both increased diastolic Na+ influx and action potential prolongation due to systolic INaL contribute to disruption of Ca2+ handling in failing hearts. Furthermore, simulations reveal a synergistic interaction between perturbed Na+ fluxes and CaMKII, and confirm recent experimental findings of an arrhythmogenic feedback loop, whereby CaMKII activation is at once a cause and a consequence of Na+ loading.
Collapse
Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California at Davis Davis, CA, USA
| | - Anthony W Herren
- Department of Pharmacology, University of California at Davis Davis, CA, USA
| |
Collapse
|
39
|
Adams KF, Ghali JK, Herbert Patterson J, Stough WG, Butler J, Bauman JL, Ventura HO, Sabbah H, Mackowiak JI, van Veldhuisen DJ. A perspective on re-evaluating digoxin's role in the current management of patients with chronic systolic heart failure: targeting serum concentration to reduce hospitalization and improve safety profile. Eur J Heart Fail 2014; 16:483-93. [DOI: 10.1002/ejhf.64] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/07/2013] [Accepted: 01/20/2014] [Indexed: 01/11/2023] Open
Affiliation(s)
- Kirkwood F. Adams
- Departments of Medicine and Radiology, School of Medicine, Division of Cardiology; University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - Jalal K. Ghali
- Division of Cardiology; Mercer University School of Medicine; Macon GA USA
| | - J. Herbert Patterson
- Division of Pharmacotherapy and Experimental Therapeutics; University of North Carolina at Chapel Hill Eshelman School of Pharmacy; Chapel Hill NC USA
| | - Wendy Gattis Stough
- Department of Clinical Research; Campbell University College of Pharmacy and Health Sciences; Buies Creek NC USA
| | - Javed Butler
- Department of Medicine, Division of Cardiology; Emory University; Atlanta GA USA
| | - Jerry L. Bauman
- Departments of Pharmacy Practice and Medicine, Section of Cardiology, Colleges of Pharmacy and Medicine; University of Illinois at Chicago; Chicago IL USA
| | - Hector O. Ventura
- John Ochsner Heart and Vascular Institute, Ochsner Clinical School; The University of Queensland School of Medicine; New Orleans LA USA
| | - Hani Sabbah
- Division of Cardiology; Wayne State University, Henry Ford Health System; Detroit MI USA
| | | | - Dirk J. van Veldhuisen
- Department of Cardiology; University of Groningen, University Medical Center Groningen; Groningen the Netherlands
| |
Collapse
|
40
|
Morotti S, Edwards AG, McCulloch AD, Bers DM, Grandi E. A novel computational model of mouse myocyte electrophysiology to assess the synergy between Na+ loading and CaMKII. J Physiol 2014; 592:1181-97. [PMID: 24421356 DOI: 10.1113/jphysiol.2013.266676] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) hyperactivity in heart failure causes intracellular Na(+) ([Na(+)]i) loading (at least in part by enhancing the late Na(+) current). This [Na(+)]i gain promotes intracellular Ca(2+) ([Ca(2+)]i) overload by altering the equilibrium of the Na(+)-Ca(2+) exchanger to impair forward-mode (Ca(2+) extrusion), and favour reverse-mode (Ca(2+) influx) exchange. In turn, this Ca(2+) overload would be expected to further activate CaMKII and thereby form a pathological positive feedback loop of ever-increasing CaMKII activity, [Na(+)]i, and [Ca(2+)]i. We developed an ionic model of the mouse ventricular myocyte to interrogate this potentially arrhythmogenic positive feedback in both control conditions and when CaMKIIδC is overexpressed as in genetically engineered mice. In control conditions, simulation of increased [Na(+)]i causes the expected increases in [Ca(2+)]i, CaMKII activity, and target phosphorylation, which degenerate into unstable Ca(2+) handling and electrophysiology at high [Na(+)]i gain. Notably, clamping CaMKII activity to basal levels ameliorates but does not completely offset this outcome, suggesting that the increase in [Ca(2+)]i per se plays an important role. The effect of this CaMKII-Na(+)-Ca(2+)-CaMKII feedback is more striking in CaMKIIδC overexpression, where high [Na(+)]i causes delayed afterdepolarizations, which can be prevented by imposing low [Na(+)]i, or clamping CaMKII phosphorylation of L-type Ca(2+) channels, ryanodine receptors and phospholamban to basal levels. In this setting, Na(+) loading fuels a vicious loop whereby increased CaMKII activation perturbs Ca(2+) and membrane potential homeostasis. High [Na(+)]i is also required to produce instability when CaMKII is further activated by increased Ca(2+) loading due to β-adrenergic activation. Our results support recent experimental findings of a synergistic interaction between perturbed Na(+) fluxes and CaMKII, and suggest that pharmacological inhibition of intracellular Na(+) loading can contribute to normalizing Ca(2+) and membrane potential dynamics in heart failure.
Collapse
Affiliation(s)
- S Morotti
- Department of Pharmacology, University of California Davis, 451 Health Sciences Drive, GBSF rm 3502, Davis, CA 95616, USA.
| | | | | | | | | |
Collapse
|
41
|
Ho HT, Liu B, Snyder JS, Lou Q, Brundage EA, Velez-Cortes F, Wang H, Ziolo MT, Anderson ME, Sen CK, Wehrens XHT, Fedorov VV, Biesiadecki BJ, Hund TJ, Györke S. Ryanodine receptor phosphorylation by oxidized CaMKII contributes to the cardiotoxic effects of cardiac glycosides. Cardiovasc Res 2013; 101:165-74. [PMID: 24104877 DOI: 10.1093/cvr/cvt233] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIMS Recent studies suggest that proarrhythmic effects of cardiac glycosides (CGs) on cardiomyocyte Ca(2+) handling involve generation of reactive oxygen species (ROS). However, the specific pathway(s) of ROS production and the subsequent downstream molecular events that mediate CG-dependent arrhythmogenesis remain to be defined. METHODS AND RESULTS We examined the effects of digitoxin (DGT) on Ca(2+) handling and ROS production in cardiomyocytes using a combination of pharmacological approaches and genetic mouse models. Myocytes isolated from mice deficient in NADPH oxidase type 2 (NOX2KO) and mice transgenically overexpressing mitochondrial superoxide dismutase displayed markedly increased tolerance to the proarrhythmic action of DGT as manifested by the inhibition of DGT-dependent ROS and spontaneous Ca(2+) waves (SCW). Additionally, DGT-induced mitochondrial membrane potential depolarization was abolished in NOX2KO cells. DGT-dependent ROS was suppressed by the inhibition of PI3K, PKC, and the mitochondrial KATP channel, suggesting roles for these proteins, respectively, in activation of NOX2 and in mitochondrial ROS generation. Western blot analysis revealed increased levels of oxidized CaMKII in WT but not in NOX2KO hearts treated with DGT. The DGT-induced increase in SCW frequency was abolished in myocytes isolated from mice in which the Ser 2814 CaMKII phosphorylation site on RyR2 is constitutively inactivated. CONCLUSION These results suggest that the arrhythmogenic adverse effects of CGs on Ca(2+) handling involve PI3K- and PKC-mediated stimulation of NOX2 and subsequent NOX2-dependent ROS release from the mitochondria; mitochondria-derived ROS then activate CaMKII with consequent phosphorylation of RyR2 at Ser 2814.
Collapse
Affiliation(s)
- Hsiang-Ting Ho
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Ottolia M, Torres N, Bridge JHB, Philipson KD, Goldhaber JI. Na/Ca exchange and contraction of the heart. J Mol Cell Cardiol 2013; 61:28-33. [PMID: 23770352 DOI: 10.1016/j.yjmcc.2013.06.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/30/2013] [Accepted: 06/04/2013] [Indexed: 12/19/2022]
Abstract
Sodium-calcium exchange (NCX) is the major calcium (Ca) efflux mechanism of ventricular cardiomyocytes. Consequently the exchanger plays a critical role in the regulation of cellular Ca content and hence contractility. Reductions in Ca efflux by the exchanger, such as those produced by elevated intracellular sodium (Na) in response to cardiac glycosides, raise sarcoplasmic reticulum (SR) Ca stores. The result is an increased Ca transient and cardiac contractility. Enhanced Ca efflux activity by the exchanger, for example during heart failure, may reduce diadic cleft Ca and excitation-contraction (EC) coupling gain. This aggravates the impaired contractility associated with SR Ca ATPase dysfunction and reduced SR Ca load in failing heart muscle. Recent data from our laboratories indicate that NCX can also impact the efficiency of EC coupling and contractility independent of SR Ca load through diadic cleft priming with Ca during the upstroke of the action potential. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes".
Collapse
Affiliation(s)
- Michela Ottolia
- Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | | | | | | |
Collapse
|
43
|
Saini-Chohan HK, Hryshko L, Xu YJ, Dhalla NS. Modification of Ca(2+)-handling in cardiomyocytes by redox sensitive mechanisms in response to ouabain. Can J Physiol Pharmacol 2013; 91:45-55. [PMID: 23367872 DOI: 10.1139/cjpp-2012-0215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We examined the role of redox-sensitive signal transduction mechanisms in modifying the changes in [Ca(2+)](i) produced by ouabain upon incubating adult rat cardiomyocytes with antioxidants or inhibitors of different protein kinases and monitoring alterations in fura-2 fluorescence. Ouabain increased basal [Ca(2+)](i), augmented the KCl-induced increase in [Ca(2+)](i), and promoted oxyradical production in cardiomyocytes. These actions of ouabain were attenuated by an oxyradical scavenging mixture (superoxide dismutase plus catalase), and the antioxidants (N-acetyl-L-cysteine and N-(2-mercaptoproprionyl)glycine). An inhibitor of MAP kinase (PD98059) depressed the ouabain-induced increase in [Ca(2+)], whereas inhibitors of tyrosine kinase (tyrphostin and genistein) and PI3 kinase (Wortmannin and LV294002) enhanced the ouabain-induced increase in [Ca(2+)](i). Inhibitors of protein kinase C (calphostin and bisindolylmalaimide) augmented the ouabain-induced increase in [Ca(2+)](i), whereas stimulation of protein kinase C by a phorbol ester (phorbol 12-myristate 13-acetate) depressed the action of ouabain. These results suggest that ouabain-induced inhibition of Na (+)-K(+) ATPase may alter the redox status of cardiomyocytes through the production of oxyradicals, and increase the activities of various protein kinases. Thus, these redox-sensitive signal transduction mechanisms involving different protein kinases may modify Ca(2+)-handling sites in cardiomyocytes and determine the magnitude of net increase in [Ca(2+)](i) in response to ouabain.
Collapse
Affiliation(s)
- Harjot K Saini-Chohan
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research and Department of Physiology, Faculty of Medicine, University of Manitoba, 351 Tache Avenue, Winnipeg, MB R2H 2A6, Canada
| | | | | | | |
Collapse
|
44
|
2′-Epi-2′-O-acetylthevetin B induces apoptosis partly via Ca2+-mediated mitochondrial pathway in human hepatocellular carcinoma HepG2 cells. Cell Biol Int 2013; 33:918-25. [DOI: 10.1016/j.cellbi.2009.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 04/02/2009] [Accepted: 06/03/2009] [Indexed: 11/23/2022]
|
45
|
Blaustein MP. Livin' with NCX and lovin' it: a 45 year romance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 961:3-15. [PMID: 23224865 PMCID: PMC3884827 DOI: 10.1007/978-1-4614-4756-6_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
This conference commemorates, almost to the day, the 45th anniversary of the discovery of the Na(+)/Ca(2+) exchanger (NCX). The discovery was serendipitous, as is so often the case with scientific breakthroughs. Indeed, that is what is so fascinating and romantic about scientific research. I will describe the discovery of NCX, but will begin by explaining how I got there, and will then discuss how the discovery influenced my career path.
Collapse
|
46
|
Bai Y, Morgan EE, Giovannucci DR, Pierre SV, Philipson KD, Askari A, Liu L. Different roles of the cardiac Na+/Ca2+-exchanger in ouabain-induced inotropy, cell signaling, and hypertrophy. Am J Physiol Heart Circ Physiol 2012. [PMID: 23203972 DOI: 10.1152/ajpheart.00462.2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have shown that digitalis drugs, acting as specific inhibitors of cardiac Na(+)/K(+)-ATPase, not only cause positive inotropic effects, but also activate cell signaling pathways that lead to cardiac myocyte hypertrophy. A major aim of this work was to assess the role of Na(+)/Ca(2+)-exchanger, NCX1, in the above two seemingly related drug effects. Using a mouse with ventricular-specific knockout (KO) of NCX1, ouabain-induced positive inotropy that was evident in isolated wild-type (Wt) hearts was clearly reduced in KO hearts. Ouabain also increased Ca(2+) transient amplitudes in Wt myocytes, but not in KO myocytes. Ouabain-induced activations of ERK 1/2 were noted in Wt myocytes, but not in KO myocytes; however, ouabain activated PI3K1A and Akt in both Wt and KO myocytes. Protein synthesis rate, as a measure of hypertrophy, was increased by ouabain in Wt and KO myocytes; these drug effects were prevented by a PI3K inhibitor but not by a MEK/ERK inhibitor. Hypertrophy caused by ET-1, but not that induced by ouabain, was accompanied by upregulation of BNP gene in Wt and KO myocytes. The findings indicate 1) the necessity of NCX1 for positive inotropic action of ouabain; 2) the irrelevance of NCX1 and ERK 1/2 activation to ouabain-induced hypertrophy; and 3) that hypertrophy caused by ouabain through the activation of PI3K1A/Akt pathway is likely to be beneficial to the heart.
Collapse
Affiliation(s)
- Yan Bai
- Department of Biochemistry and Cancer Biology, College of Medicine and Life Sciences, Univ. of Toledo, 3000 Arlington Ave., MS 1010, Toledo, Ohio 43614, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Cuozzo F, Raciti M, Bertelli L, Parente R, Di Renzo L. Pro-death and pro-survival properties of ouabain in U937 lymphoma derived cells. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2012; 31:95. [PMID: 23153195 PMCID: PMC3541998 DOI: 10.1186/1756-9966-31-95] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 11/12/2012] [Indexed: 12/17/2022]
Abstract
BACKGROUND Epidemiological studies revealed significantly lower mortality rates in cancer patients receiving cardiac glycosides, which turned on interest in the anticancer properties of these drugs. However, cardiac glycosides have also been shown to stimulate cell growth in several cell types. In the present investigation we analyzed the pro-death and pro-survival properties of ouabain in the human lymphoma derived cell line U937. METHODS ROS, intracellular Ca++, cell cycle were evaluated by loading the cells with fluorescent probes under cytofluorimetry. Cell counts and evaluation of trypan blue-excluding cells were performed under optic microscope. Protein detection was done by specific antibodies after protein separation from cellular lysates by SDS-PAGE and transfer blot. RESULTS High doses of ouabain cause ROS generation, elevation of [Ca++]i and death of lymphoma derived U937 cells. Lower doses of OUA activate a survival pathway in which plays a role the Na+/Ca++-exchanger (NCX), active in the Ca++ influx mode rather than in the Ca++ efflux mode. Also p38 MAPK plays a pro-survival role. However, the activation of this MAPK does not appear to depend on NCX. CONCLUSION This investigation shows that the cardiac glycoside OUA is cytotoxic also for the lymphoma derived cell line U937 and that can activate a survival pathway in which are involved NCX and p38 MAPK. These molecules can represent potential targets of combined therapy.
Collapse
Affiliation(s)
- Francesca Cuozzo
- Department of Experimental Medicine, University of Rome La Sapienza, Viale Regina Elena 324, Rome 00161, Italy
| | | | | | | | | |
Collapse
|
48
|
Gillespie D, Chen H, Fill M. Is ryanodine receptor a calcium or magnesium channel? Roles of K+ and Mg2+ during Ca2+ release. Cell Calcium 2012; 51:427-33. [PMID: 22387011 DOI: 10.1016/j.ceca.2012.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 01/30/2012] [Accepted: 02/01/2012] [Indexed: 11/19/2022]
Abstract
The ryanodine receptor (RyR) is a poorly selective channel that mediates Ca(2+) release from intracellular Ca(2+) stores. How RyR's selectivity between the physiological cations K(+), Mg(2+), and Ca(2+) affects single-channel Ca(2+) current amplitude is examined using a recent model of RyR permeation. It is found that K(+) provides the vast majority of the countercurrent (through RyR itself) that is needed to prevent the sarcoplasmic reticulum (SR) membrane potential from changing and stopping Ca(2+) release. Moreover, intra-pore competition between Ca(2+) and Mg(2+) defines single RyR Ca(2+) current amplitude. Since both [Mg(2+)] and [Ca(2+)](SR) can change during pathophysiological conditions, the RyR unitary Ca(2+) current amplitude during Ca(2+) release may change significantly due to this Ca(2+)/Mg(2+) competition. Compared to the classic action of Mg(2+) on RyR open probability, these Ca(2+) current amplitude changes have as large or larger effects on overall RyR Ca(2+) mobilization. A new aspect of RyR divalent versus monovalent selectivity is also identified where this kind of selectivity decreases as divalent concentration increases.
Collapse
Affiliation(s)
- Dirk Gillespie
- Department of Molecular Biophysics and Physiology, Section of Cellular Signaling, Rush University Medical Center, Chicago, IL 60612, United States.
| | | | | |
Collapse
|
49
|
Gonano LA, Sepúlveda M, Rico Y, Kaetzel M, Valverde CA, Dedman J, Mattiazzi A, Vila Petroff M. Calcium-calmodulin kinase II mediates digitalis-induced arrhythmias. Circ Arrhythm Electrophysiol 2011; 4:947-57. [PMID: 22009705 DOI: 10.1161/circep.111.964908] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Digitalis-induced Na(+) accumulation results in an increase in Ca(2+)(i) via the Na(+)/Ca(2+) exchanger, leading to enhanced sarcoplasmic reticulum (SR) Ca(2+) load, responsible for the positive inotropic and toxic arrhythmogenic effects of glycosides. A digitalis-induced increase in Ca(2+)(i) could also activate calcium-calmodulin kinase II (CaMKII), which has been shown to have proarrhythmic effects. Here, we investigate whether CaMKII underlies digitalis-induced arrhythmias and the subcellular mechanisms involved. METHODS AND RESULTS In paced rat ventricular myocytes (0.5 Hz), 50 μmol/L ouabain increased contraction amplitude by 160 ± 5%. In the absence of electric stimulation, ouabain promoted spontaneous contractile activity and Ca(2+) waves. Ouabain activated CaMKII (p-CaMKII), which phosphorylated its downstream targets, phospholamban (PLN) (Thr17) and ryanodine receptor (RyR) (Ser2814). Ouabain-induced spontaneous activity was prevented by inhibiting CaMKII with 2.5 μmol/L KN93 but not by 2.5 μmol/L of the inactive analog, KN92. Similar results were obtained using the CaMKII inhibitor, autocamtide-2 related inhibitory peptide (AIP) (1 to 2.5 μmol/L), and in myocytes from transgenic mice expressing SR-targeted AIP. Consistently, CaMKII overexpression exacerbated ouabain-induced spontaneous contractile activity. Ouabain was associated with an increase in SR Ca(2+) content and Ca(2+) spark frequency, indicative of enhanced SR Ca(2+) leak. KN93 suppressed the ouabain-induced increase in Ca(2+) spark frequency without affecting SR Ca(2+) content. Similar results were obtained with digoxin. In vivo, ouabain-induced arrhythmias were prevented by KN93 and absent in SR-AIP mice. CONCLUSIONS These results show for the first time that CaMKII mediates ouabain-induced arrhythmic/toxic effects. We suggest that CaMKII-dependent phosphorylation of the RyR, resulting in Ca(2+) leak from the SR, is the underlying mechanism involved.
Collapse
Affiliation(s)
- Luis A Gonano
- Centro de Investigaciones Cardiovasculares, Conicet La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Feldmann T, Shahar M, Baba A, Matsuda T, Lichtstein D, Rosen H. The Na(+)/Ca(2+)-exchanger: an essential component in the mechanism governing cardiac steroid-induced slow Ca(2+) oscillations. Cell Calcium 2011; 50:424-32. [PMID: 21930298 DOI: 10.1016/j.ceca.2011.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 07/05/2011] [Accepted: 07/07/2011] [Indexed: 02/07/2023]
Abstract
Plasma membrane (PM) Na(+), K(+)-ATPase, plays crucial roles in numerous physiological processes. Cardiac steroids (CS), such as ouabain and bufalin, specifically bind to the Na(+), K(+)-ATPase and affect ionic homeostasis, signal transduction, and endocytosed membrane traffic. CS-like compounds, synthesized in and released from the adrenal gland, are considered a new family of steroid hormones. Previous studies showed that ouabain induces slow Ca(2+) oscillations in COS-7 cells by enhancing the interactions between Na(+), K(+)-ATPase, inositol 1,4,5-trisphosphate receptor (IP(3)R) and Ankyrin B (Ank-B) to form a Ca(2+) signaling micro-domain. The activation of this micro-domain, however, is independent of InsP3 generation. Thus, the mechanism underlying the induction of these slow Ca(2+) oscillations remained largely unclear. We now show that other CS, such as bufalin, can also induce Ca(2+) oscillations. These oscillations depend on extracellular Ca(2+) concentrations [Ca(2+)](out) and are inhibited by Ni(2+). Furthermore, we found that these slow oscillations are Na(+)(out) dependent, abolished by Na(+)/Ca(2+) exchanger1 (NCX1)-specific inhibitors and markedly attenuated by NCX1 siRNA knockdown. Based on these results, a model is presented for the CS-induced slow Ca(2+) oscillations in COS-7 cells.
Collapse
Affiliation(s)
- Tomer Feldmann
- The Kuvin Center for the Study of Infectious and Tropical Diseases, Department of Microbiology and Molecular Genetics, Institute for Medical Research-Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | | | | | | | | | | |
Collapse
|