1
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Depierre P, Ginet V, Truttmann AC, Puyal J. Neuronal autosis is Na +/K +-ATPase alpha 3-dependent and involved in hypoxic-ischemic neuronal death. Cell Death Dis 2024; 15:363. [PMID: 38796484 PMCID: PMC11127954 DOI: 10.1038/s41419-024-06750-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/28/2024]
Abstract
Macroautophagy (hereafter called autophagy) is an essential physiological process of degradation of organelles and long-lived proteins. The discovery of autosis, a Na+/K+-ATPase (ATP1)-dependent type of autophagic cell death with specific morphological and biochemical features, has strongly contributed to the acceptance of a pro-death role of autophagy. However, the occurrence and relevance of autosis in neurons has never been clearly investigated, whereas we previously provided evidence that autophagy mechanisms could be involved in neuronal death in different in vitro and in vivo rodent models of hypoxia-ischemia (HI) and that morphological features of autosis were observed in dying neurons following rat perinatal cerebral HI. In the present study, we demonstrated that neuronal autosis could occur in primary cortical neurons using two different stimulations enhancing autophagy flux and neuronal death: a neurotoxic concentration of Tat-BECN1 (an autophagy-inducing peptide) and a hypoxic/excitotoxic stimulus (mimicking neuronal death induced by cerebral HI). Both stimulations induce autophagic neuronal death (dependent on canonical autophagic genes and independent on apoptotic, necroptotic or ferroptotic pathways) with all morphological and biochemical (ATP1a-dependent) features of autosis. However, we demonstrated that autosis is not dependent on the ubiquitous subunit ATP1a1 in neurons, as in dividing cell types, but on the neuronal specific ATP1a3 subunit. We also provided evidence that, in different in vitro and in vivo models where autosis is induced, ATP1a3-BECN1 interaction is increased and prevented by cardiac glycosides treatment. Interestingly, an increase in ATP1a3-BECN1 interaction is also detected in dying neurons in the autoptic brains of human newborns with severe hypoxic-ischemic encephalopathy (HIE). Altogether, these results suggest that ATP1a3-BECN1-dependent autosis could play an important role in neuronal death in HI conditions, paving the way for the development of new neuroprotective strategies in hypoxic-ischemic conditions including in severe case of human HIE.
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Affiliation(s)
- Pauline Depierre
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Vanessa Ginet
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
- Clinic of Neonatology, Department of Women, Mother and Child, University Hospital Center of Vaud, Lausanne, Switzerland
| | - Anita C Truttmann
- Clinic of Neonatology, Department of Women, Mother and Child, University Hospital Center of Vaud, Lausanne, Switzerland
| | - Julien Puyal
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.
- CURML, University Center of Legal Medicine, Lausanne University Hospital, Lausanne, Switzerland.
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2
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Han Y, Tian X, Zhai J, Zhang Z. Clinical application of immunogenic cell death inducers in cancer immunotherapy: turning cold tumors hot. Front Cell Dev Biol 2024; 12:1363121. [PMID: 38774648 PMCID: PMC11106383 DOI: 10.3389/fcell.2024.1363121] [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: 12/29/2023] [Accepted: 04/23/2024] [Indexed: 05/24/2024] Open
Abstract
Immunotherapy has emerged as a promising cancer treatment option in recent years. In immune "hot" tumors, characterized by abundant immune cell infiltration, immunotherapy can improve patients' prognosis by activating the function of immune cells. By contrast, immune "cold" tumors are often less sensitive to immunotherapy owing to low immunogenicity of tumor cells, an immune inhibitory tumor microenvironment, and a series of immune-escape mechanisms. Immunogenic cell death (ICD) is a promising cellular process to facilitate the transformation of immune "cold" tumors to immune "hot" tumors by eliciting innate and adaptive immune responses through the release of (or exposure to) damage-related molecular patterns. Accumulating evidence suggests that various traditional therapies can induce ICD, including chemotherapy, targeted therapy, radiotherapy, and photodynamic therapy. In this review, we summarize the biological mechanisms and hallmarks of ICD and introduce some newly discovered and technologically innovative inducers that activate the immune system at the molecular level. Furthermore, we also discuss the clinical applications of combing ICD inducers with cancer immunotherapy. This review will provide valuable insights into the future development of ICD-related combination therapeutics and potential management for "cold" tumors.
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Affiliation(s)
| | | | | | - Zhenyong Zhang
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
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3
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Tokugawa M, Inoue Y, Aoki H, Miyajima C, Ishiuchi K, Tsurumi K, Kujirai C, Morishita D, Matsuno M, Mizukami H, Ri M, Iida S, Makino T, Aoyama M, Hayashi H. Involvement of cardiac glycosides targeting Na/K-ATPase in their inhibitory effects on c-Myc expression via its transcription, translation and proteasomal degradation. J Biochem 2024; 175:253-263. [PMID: 37948630 DOI: 10.1093/jb/mvad085] [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: 05/16/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/12/2023] Open
Abstract
Cardiac glycosides (CGs) have been used for decades to treat heart failure and arrhythmic diseases. Recent non-clinical and epidemiological findings have suggested that CGs exhibit anti-tumor activities. Therefore, CGs may be repositioned as drugs for the treatment of cancer. A detailed understanding of the anti-cancer mechanisms of CGs is essential for their application to the treatment of targetable cancer types. To elucidate the factors associated with the anti-tumor effects of CGs, we performed transcriptome profiling on human multiple myeloma AMO1 cells treated with periplocin, one of the CGs. Periplocin significantly down-regulated the transcription of MYC (c-Myc), a well-established oncogene. Periplocin also suppressed c-Myc expression at the protein levels. This repression of c-Myc was also observed in several cell lines. To identify target proteins for the inhibition of c-Myc, we generated CG-resistant (C9) cells using a sustained treatment with digoxin. We confirmed that C9 cells acquired resistance to the inhibition of c-Myc expression and cell proliferation by CGs. Moreover, the sequencing of genomic DNA in C9 cells revealed the mutation of D128N in α1-Na/K-ATPase, indicating the target protein. These results suggest that CGs suppress c-Myc expression in cancer cells via α1-Na/K-ATPase, which provides further support for the anti-tumor activities of CGs.
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Affiliation(s)
- Muneshige Tokugawa
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Yasumichi Inoue
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Hiromasa Aoki
- Department of Pathobiology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Chiharu Miyajima
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Kan'ichiro Ishiuchi
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Kento Tsurumi
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Chisane Kujirai
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Daisuke Morishita
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
- Chordia Therapeutics Inc., 26-1 Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-0012, Japan
| | - Michiyo Matsuno
- Plant research section, The Kochi Prefectural Makino Botanical Garden, 4200-6 Godaiyama, Kochi 781-8125, Japan
| | - Hajime Mizukami
- Plant research section, The Kochi Prefectural Makino Botanical Garden, 4200-6 Godaiyama, Kochi 781-8125, Japan
| | - Masaki Ri
- Department of Hematology and Oncology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Shinsuke Iida
- Department of Hematology and Oncology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Toshiaki Makino
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Mineyoshi Aoyama
- Department of Pathobiology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Hidetoshi Hayashi
- Department of Cell Signaling, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
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4
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Markov AG, Livanova AA, Fedorova AA, Kravtsova VV, Krivoi II. Chronic Ouabain Targets Pore-Forming Claudin-2 and Ameliorates Radiation-Induced Damage to the Rat Intestinal Tissue Barrier. Int J Mol Sci 2023; 25:278. [PMID: 38203449 PMCID: PMC10778734 DOI: 10.3390/ijms25010278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/15/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Ionizing radiation (IR) causes disturbances in the functions of the gastrointestinal tract. Given the therapeutic potential of ouabain, a specific ligand of the Na,K-ATPase, we tested its ability to protect against IR-induced disturbances in the barrier and transport properties of the jejunum and colon of rats. Male Wistar rats were subjected to 6-day intraperitoneal injections of vehicle or ouabain (1 µg/kg/day). On the fourth day of injections, rats were exposed to total-body X-ray irradiation (10 Gy) or a sham irradiation. Isolated tissues were examined 72 h post-irradiation. Electrophysiological characteristics and paracellular permeability for sodium fluorescein were measured in an Ussing chamber. Histological analysis and Western blotting were also performed. In the jejunum tissue, ouabain exposure did not prevent disturbances in transepithelial resistance, paracellular permeability, histological characteristics, as well as changes in the expression of claudin-1, -3, -4, tricellulin, and caspase-3 induced by IR. However, ouabain prevented overexpression of occludin and the pore-forming claudin-2. In the colon tissue, ouabain prevented electrophysiological disturbances and claudin-2 overexpression. These observations may reveal a mechanism by which circulating ouabain maintains tight junction integrity under IR-induced intestinal dysfunction.
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Affiliation(s)
- Alexander G. Markov
- Department of General Physiology, St. Petersburg State University, 199034 St. Petersburg, Russia; (A.A.L.); (A.A.F.); (V.V.K.); (I.I.K.)
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5
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Lopatina EV, Gavrichenko AV, Pasatetskaya NA. Involvement of Acetylcholine and Na+,K+-ATPase in the Regulation of Skeletal Muscle Growth in a Chicken Embryo. J EVOL BIOCHEM PHYS+ 2023. [DOI: 10.1134/s0022093023010234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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6
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Arystarkhova E, Toustrup-Jensen MS, Holm R, Ko JK, Lee KE, Feschenko P, Ozelius LJ, Brashear A, Vilsen B, Sweadner KJ. Temperature instability of a mutation at a multidomain junction in Na,K-ATPase isoform ATP1A3 (p.Arg756His) produces a fever-induced neurological syndrome. J Biol Chem 2023; 299:102758. [PMID: 36462665 PMCID: PMC9860391 DOI: 10.1016/j.jbc.2022.102758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 12/02/2022] Open
Abstract
ATP1A3 encodes the α3 isoform of Na,K-ATPase. In the brain, it is expressed only in neurons. Human ATP1A3 mutations produce a wide spectrum of phenotypes, but particular syndromes are associated with unique substitutions. For arginine 756, at the junction of membrane and cytoplasmic domains, mutations produce encephalopathy during febrile infections. Here we tested the pathogenicity of p.Arg756His (R756H) in isogenic mammalian cells. R756H protein had sufficient transport activity to support cells when endogenous ATP1A1 was inhibited. It had half the turnover rate of wildtype, reduced affinity for Na+, and increased affinity for K+. There was modest endoplasmic reticulum retention during biosynthesis at 37 °C but little benefit from the folding drug phenylbutyrate (4-PBA), suggesting a tolerated level of misfolding. When cells were incubated at just 39 °C, however, α3 protein level dropped without loss of β subunit, paralleled by an increase of endogenous α1. Elevated temperature resulted in internalization of α3 from the surface along with some β subunit, accompanied by cytoplasmic redistribution of a marker of lysosomes and endosomes, lysosomal-associated membrane protein 1. After return to 37 °C, α3 protein levels recovered with cycloheximide-sensitive new protein synthesis. Heating in vitro showed activity loss at a rate 20- to 30-fold faster than wildtype, indicating a temperature-dependent destabilization of protein structure. Arg756 appears to confer thermal resistance as an anchor, forming hydrogen bonds among four linearly distant parts of the Na,K-ATPase structure. Taken together, our observations are consistent with fever-induced symptoms in patients.
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Affiliation(s)
- Elena Arystarkhova
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
| | | | - Rikke Holm
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Jae-Kyun Ko
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Kyung Eun Lee
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Polina Feschenko
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Allison Brashear
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Bente Vilsen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Kathleen J Sweadner
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA.
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7
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Short-Term Mild Hypoxia Modulates Na,K-ATPase to Maintain Membrane Electrogenesis in Rat Skeletal Muscle. Int J Mol Sci 2022; 23:ijms231911869. [PMID: 36233169 PMCID: PMC9570130 DOI: 10.3390/ijms231911869] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/26/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
The Na,K-ATPase plays an important role in adaptation to hypoxia. Prolonged hypoxia results in loss of skeletal muscle mass, structure, and performance. However, hypoxic preconditioning is known to protect against a variety of functional impairments. In this study, we tested the possibility of mild hypoxia to modulate the Na,K-ATPase and to improve skeletal muscle electrogenesis. The rats were subjected to simulated high-altitude (3000 m above sea level) hypobaric hypoxia (HH) for 3 h using a hypobaric chamber. Isolated diaphragm and soleus muscles were tested. In the diaphragm muscle, HH increased the α2 Na,K-ATPase isozyme electrogenic activity and stably hyperpolarized the extrajunctional membrane for 24 h. These changes were accompanied by a steady increase in the production of thiobarbituric acid reactive substances as well as a decrease in the serum level of endogenous ouabain, a specific ligand of the Na,K-ATPase. HH also increased the α2 Na,K-ATPase membrane abundance without changing its total protein content; the plasma membrane lipid-ordered phase did not change. In the soleus muscle, HH protected against disuse (hindlimb suspension) induced sarcolemmal depolarization. Considering that the Na,K-ATPase is critical for maintaining skeletal muscle electrogenesis and performance, these findings may have implications for countermeasures in disuse-induced pathology and hypoxic therapy.
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8
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Mehrabian M, Wang X, Eid S, Yan BQ, Grinberg M, Siegner M, Sackmann C, Sulman M, Zhao W, Williams D, Schmitt-Ulms G. Cardiac glycoside-mediated turnover of Na, K-ATPases as a rational approach to reducing cell surface levels of the cellular prion protein. PLoS One 2022; 17:e0270915. [PMID: 35776750 PMCID: PMC9249225 DOI: 10.1371/journal.pone.0270915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/17/2022] [Indexed: 01/16/2023] Open
Abstract
It is widely anticipated that a reduction of brain levels of the cellular prion protein (PrPC) can prolong survival in a group of neurodegenerative diseases known as prion diseases. To date, efforts to decrease steady-state PrPC levels by targeting this protein directly with small molecule drug-like compounds have largely been unsuccessful. Recently, we reported Na,K-ATPases to reside in immediate proximity to PrPC in the brain, unlocking an opportunity for an indirect PrPC targeting approach that capitalizes on the availability of potent cardiac glycosides (CGs). Here, we report that exposure of human co-cultures of neurons and astrocytes to non-toxic nanomolar levels of CGs causes profound reductions in PrPC levels. The mechanism of action underpinning this outcome relies primarily on a subset of CGs engaging the ATP1A1 isoform, one of three α subunits of Na,K-ATPases expressed in brain cells. Upon CG docking to ATP1A1, the ligand receptor complex, and PrPC along with it, is internalized by the cell. Subsequently, PrPC is channeled to the lysosomal compartment where it is digested in a manner that can be rescued by silencing the cysteine protease cathepsin B. These data signify that the repurposing of CGs may be beneficial for the treatment of prion disorders.
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Affiliation(s)
- Mohadeseh Mehrabian
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Xinzhu Wang
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Shehab Eid
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Bei Qi Yan
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Mark Grinberg
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Murdock Siegner
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Christopher Sackmann
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Muhammad Sulman
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Wenda Zhao
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Declan Williams
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
| | - Gerold Schmitt-Ulms
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Krembil Discovery Centre, Toronto, Ontario, Canada
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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9
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Mann CN, Devi SS, Kersting CT, Bleem AV, Karch CM, Holtzman DM, Gallardo G. Astrocytic α2-Na +/K + ATPase inhibition suppresses astrocyte reactivity and reduces neurodegeneration in a tauopathy mouse model. Sci Transl Med 2022; 14:eabm4107. [PMID: 35171651 DOI: 10.1126/scitranslmed.abm4107] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most dominant form of dementia characterized by the deposition of extracellular amyloid plaques and intracellular neurofibrillary tau tangles (NFTs). In addition to these pathologies, an emerging pathophysiological mechanism that influences AD is neuroinflammation. Astrocytes are a vital type of glial cell that contribute to neuroinflammation, and reactive astrocytes, or astrogliosis, are a well-known pathological feature of AD. However, the mechanisms by which astrocytes contribute to the neurodegenerative process in AD have not been fully elucidated. Here, we showed that astrocytic α2-Na+/K+ adenosine triphosphatase (α2-NKA) is elevated in postmortem human brain tissue from AD and progressive nuclear palsy, a primary tauopathy. The increased astrocytic α2-NKA was also recapitulated in a mouse model of tauopathy. Pharmacological inhibition of α2-NKA robustly suppressed neuroinflammation and reduced brain atrophy. In addition, α2-NKA knockdown in tauopathy mice halted the accumulation of tau pathology. We also demonstrated that α2-NKA promoted tauopathy, in part, by regulating the proinflammatory protein lipocalin-2 (Lcn2). Overexpression of Lcn2 in tauopathy mice increased tau pathology, and prolonged Lcn2 exposure to primary neurons promoted tau uptake in vitro. These studies collectively highlight the contribution of reactive astrocytes to tau pathogenesis in mice and define α2-NKA as a major regulator of astrocytic-dependent neuroinflammation.
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Affiliation(s)
- Carolyn N Mann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA
| | - Shamulailatpam Shreedarshanee Devi
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA
| | - Corey T Kersting
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA
| | - Amber V Bleem
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA
| | - Celeste M Karch
- Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA.,Department of Psychiatry, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA.,Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO 63110, USA
| | - David M Holtzman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA.,Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University, St. Louis, MO 63110, USA
| | - Gilbert Gallardo
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110, USA
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10
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Wu D, Yu HQ, Xiong HJ, Zhang YJ, Lin XT, Zhang J, Wu W, Wang T, Liu XY, Xie CM. Elevated Sodium Pump α3 Subunit Expression Promotes Colorectal Liver Metastasis via the p53-PTEN/IGFBP3-AKT-mTOR Axis. Front Oncol 2021; 11:743824. [PMID: 34868940 PMCID: PMC8632823 DOI: 10.3389/fonc.2021.743824] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/26/2021] [Indexed: 11/25/2022] Open
Abstract
The sodium pump α3 subunit is associated with colorectal liver metastasis. However, the underlying mechanism involved in this effect is not yet known. In this study, we found that the expression levels of the sodium pump α3 subunit were positively associated with metastasis in colorectal cancer (CRC). Knockdown of the α3 subunit or inhibition of the sodium pump could significantly inhibit the migration of colorectal cancer cells, whereas overexpression of the α3 subunit promoted colorectal cancer cell migration. Mechanistically, the α3 subunit decreased p53 expression, which subsequently downregulated PTEN/IGFBP3 and activated mTOR, leading to the promotion of colorectal cancer cell metastasis. Reciprocally, knockdown of the α3 subunit or inhibition of the sodium pump dramatically blocked this effect in vitro and in vivo via the downregulation of mTOR activity. Furthermore, a positive correlation between α3 subunit expression and mTOR activity was observed in an aggressive CRC subtype. Conclusions: Elevated expression of the sodium pump α3 subunit promotes CRC liver metastasis via the PTEN/IGFBP3-mediated mTOR pathway, suggesting that sodium pump α3 could represent a critical prognostic marker and/or therapeutic target for this disease.
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Affiliation(s)
- Di Wu
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Hong-Qiang Yu
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Hao-Jun Xiong
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Yu-Jun Zhang
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiao-Tong Lin
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Jie Zhang
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Wu Wu
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China.,Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Teng Wang
- Department of Oncology, Affiliated Hospital of Jiangnan University, Wuxi, China
| | - Xiao-Yu Liu
- Department of Oncology, Affiliated Hospital of Jiangnan University, Wuxi, China.,School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Chuan-Ming Xie
- Key Laboratory of Hepatobiliary and Pancreatic Surgery, Institute of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
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11
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Nakamura K, Shiozaki A, Kosuga T, Shimizu H, Kudou M, Ohashi T, Arita T, Konishi H, Komatsu S, Kubota T, Fujiwara H, Okamoto K, Kishimoto M, Konishi E, Otsuji E. The expression of the alpha1 subunit of Na +/K +-ATPase is related to tumor development and clinical outcomes in gastric cancer. Gastric Cancer 2021; 24:1278-1292. [PMID: 34251542 DOI: 10.1007/s10120-021-01212-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 06/25/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND The Na+/K+-ATPase alpha1 subunit (ATP1A1) is a critical component of Na+/K+-ATPase (NKA), a membrane pump that maintains a low intracellular Na+/K+ ratio and retains cellular volume and osmolarity. ATP1A1 was recently implicated in tumor behavior. Therefore, the present study investigated the role of ATP1A1 in patients with gastric cancer (GC). METHODS Knockdown experiments were conducted on human GC cell lines using ATP1A1 siRNA, and its effects on proliferation, the cell cycle, apoptosis, and cellular movement were examined. Gene expression profiling was performed by a microarray analysis. Primary tumor samples from 192 GC patients who underwent gastrectomy were subjected to an immunohistochemical analysis. RESULTS High ATP1A1 expression levels were observed in NUGC4 and MKN74 cells. Cell proliferation was suppressed and apoptosis was induced by the siRNA-induced knockdown of ATP1A1. The microarray analysis showed that knockdown of ATP1A1 leads to the up-regulated expression of genes involved in the interferon (IFN) signaling pathway, such as STAT1, STAT2, IRF1, and IRF9. Furthermore, the depletion of ATP1A1 altered the phosphorylation of the MAPK pathway. The immunohistochemical analysis revealed that the expression of ATP1A1 was associated with the histological type, venous invasion, and the pathological T stage. Furthermore, the prognostic analysis showed a relationship between high ATP1A1 expression levels and poor postoperative survival. CONCLUSIONS ATP1A1 appears to regulate tumor progression by altering IFN signaling, and high ATP1A1 expression levels were associated with poor postoperative survival in GC patients. The present results provide novel insights into the function of ATP1A1 as a mediator and/or biomarker of GC.
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Affiliation(s)
- Kei Nakamura
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Atsushi Shiozaki
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan.
| | - Toshiyuki Kosuga
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Hiroki Shimizu
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Michihiro Kudou
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Takuma Ohashi
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Tomohiro Arita
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Hirotaka Konishi
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Shuhei Komatsu
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Takeshi Kubota
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Hitoshi Fujiwara
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Kazuma Okamoto
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Mitsuo Kishimoto
- Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.,Department of Pathology, Kyoto City Hospital, Kyoto, 604-8845, Japan
| | - Eiichi Konishi
- Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan
| | - Eigo Otsuji
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-8566, Japan
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12
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Kravtsova VV, Krivoi II. Molecular and Functional Heterogeneity of Na,K-ATPase in the Skeletal Muscle. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021040086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Li X, Zheng J, Chen S, Meng FD, Ning J, Sun SL. Oleandrin, a cardiac glycoside, induces immunogenic cell death via the PERK/elF2α/ATF4/CHOP pathway in breast cancer. Cell Death Dis 2021; 12:314. [PMID: 33762577 PMCID: PMC7990929 DOI: 10.1038/s41419-021-03605-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/08/2021] [Accepted: 03/10/2021] [Indexed: 12/22/2022]
Abstract
Chemotherapeutic agents have been linked to immunogenic cell death (ICD) induction that is capable of augmenting anti-tumor immune surveillance. The cardiac glycoside oleandrin, which inhibits Na+/K+-ATPase pump (NKP), has been shown to suppress breast cancer growth via inducing apoptosis. In the present study, we showed that oleandrin treatment triggered breast cancer cell ICD by inducing calreticulin (CRT) exposure on cell surface and the release of high-mobility group protein B1 (HMGB1), heat shock protein 70/90 (HSP70/90), and adenosine triphosphate (ATP). The maturation and activation of dendritic cells (DCs) were increased by co-culturing with the oleandrin-treated cancer cells, which subsequently enhanced CD8+ T cell cytotoxicity. Murine breast cancer cell line EMT6 was engrafted into BALB/c mice, and tumor-bearing mice were administered with oleandrin intraperitoneally every day. Oleandrin inhibited tumor growth and increased tumor infiltrating lymphocytes including DCs and T cells. Furthermore, the differential mRNA expression incurred by oleandrin was investigated by mRNA sequencing and subsequently confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting. Mechanistically, oleandrin induced endoplasmic reticulum (ER) stress-associated, caspase-independent ICD mainly through PERK/elF2α/ATF4/CHOP pathway. Pharmacological and genetic inhibition of protein kinase R-like ER kinase (PERK) suppressed oleandrin-triggered ICD. Taken together, our findings showed that oleandrin triggered ER stress and induced ICD-mediated immune destruction of breast cancer cells. Oleandrin combined with immune checkpoint inhibitors might improve the efficacy of immunotherapy.
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Affiliation(s)
- Xiaoxi Li
- Central Laboratory, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, Liaoning, 110042, People's Republic of China
| | - Jian Zheng
- Department of Thoracic Cancer, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, Liaoning, 110042, People's Republic of China
| | - Shi Chen
- Central Laboratory, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, Liaoning, 110042, People's Republic of China
| | - Fan-Dong Meng
- Molecular Oncology Laboratory of Cancer Research Institute, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110001, People's Republic of China
| | - Jing Ning
- Department of General Medicine (VIP ward) & Department of Tumor Supportive and Palliative Medicine, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, Liaoning, 110042, People's Republic of China
| | - Shu-Lan Sun
- Central Laboratory, Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, Shenyang, Liaoning, 110042, People's Republic of China.
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14
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Cytotoxicity of glucoevatromonoside alone and in combination with chemotherapy drugs and their effects on Na +,K +-ATPase and ion channels on lung cancer cells. Mol Cell Biochem 2021; 476:1825-1848. [PMID: 33459980 DOI: 10.1007/s11010-020-04040-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/22/2020] [Indexed: 12/16/2022]
Abstract
Cardiac glycosides (CGs) are useful drugs to treat cardiac illnesses and have potent cytotoxic and anticancer effects in cultured cells and animal models. Their receptor is the Na+,K+ ATPase, but other plasma membrane proteins might bind CGs as well. Herein, we evaluated the short- and long-lasting cytotoxic effects of the natural cardenolide glucoevatromonoside (GEV) on non-small-cell lung cancer H460 cells. We also tested GEV effects on Na+,K+ -ATPase activity and membrane currents, alone or in combination with selected chemotherapy drugs. GEV reduced viability, migration, and invasion of H460 cells spheroids. It also induced cell cycle arrest and death and reduced the clonogenic survival and cumulative population doubling. GEV inhibited Na+,K+-ATPase activity on A549 and H460 cells and purified pig kidney cells membrane. However, it showed no activity on the human red blood cell plasma membrane. Additionally, GEV triggered a Cl-mediated conductance on H460 cells without affecting the transient voltage-gated sodium current. The administration of GEV in combination with the chemotherapeutic drugs paclitaxel (PAC), cisplatin (CIS), irinotecan (IRI), and etoposide (ETO) showed synergistic antiproliferative effects, especially when combined with GEV + CIS and GEV + PAC. Taken together, our results demonstrate that GEV is a potential drug for cancer therapy because it reduces lung cancer H460 cell viability, migration, and invasion. Our results also reveal a link between the Na+,K+-ATPase and Cl- ion channels.
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15
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Pelin M, Stocco G, Florio C, Sosa S, Tubaro A. In Vitro Cell Sensitivity to Palytoxin Correlates with High Gene Expression of the Na +/K +-ATPase β2 Subunit Isoform. Int J Mol Sci 2020; 21:ijms21165833. [PMID: 32823835 PMCID: PMC7461505 DOI: 10.3390/ijms21165833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/03/2020] [Accepted: 08/13/2020] [Indexed: 01/13/2023] Open
Abstract
The marine polyether palytoxin (PLTX) is one of the most toxic natural compounds, and is involved in human poisonings after oral, inhalation, skin and/or ocular exposure. Epidemiological and molecular evidence suggest different inter-individual sensitivities to its toxic effects, possibly related to genetic-dependent differences in the expression of Na+/K+-ATPase, its molecular target. To identify Na+/K+-ATPase subunits, isoforms correlated with in vitro PLTX cytotoxic potency, sensitivity parameters (EC50: PLTX concentration reducing cell viability by 50%; Emax: maximum effect induced by the highest toxin concentration; 10-7 M) were assessed in 60 healthy donors' monocytes by the MTT (methylthiazolyl tetrazolium) assay. Sensitivity parameters, not correlated with donors' demographic variables (gender, age and blood group), demonstrated a high inter-individual variability (median EC50 = 2.7 × 10-10 M, interquartile range: 0.4-13.2 × 10-10 M; median Emax = 92.0%, interquartile range: 87.5-94.4%). Spearman's analysis showed significant positive correlations between the β2-encoding ATP1B2 gene expression and Emax values (rho = 0.30; p = 0.025) and between Emax and the ATP1B2/ATP1B3 expression ratio (rho = 0.38; p = 0.004), as well as a significant negative correlation between Emax and the ATP1B1/ATP1B2 expression ratio (rho = -0.30; p = 0.026). This toxicogenetic study represents the first approach to define genetic risk factors that may influence the onset of adverse effects in human PLTX poisonings, suggesting that individuals with high gene expression pattern of the Na+/K+-ATPase β2 subunit (alone or as β2/β1 and/or β2/β3 ratio) could be highly sensitive to PLTX toxic effects.
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16
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Influence of Endogenous Cardiac Glycosides, Digoxin, and Marinobufagenin in the Physiology of Epithelial Cells. Cardiol Res Pract 2019; 2019:8646787. [PMID: 32089875 PMCID: PMC7024086 DOI: 10.1155/2019/8646787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/20/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
Cardiac glycosides are a group of compounds widely known for their action in cardiac tissue, some of which have been found to be endogenously produced (ECG). We have previously studied the effect of ouabain, an endogenous cardiac glycoside, on the physiology of epithelial cells, and we have shown that in concentrations in the nanomolar range, it affects key properties of epithelial cells, such as tight junction, apical basolateral polarization, gap junctional intercellular communication (GJIC), and adherent junctions. In this work, we study the influence of digoxin and marinobufagenin, two other endogenously expressed cardiac glycosides, on GJIC as well as the degree of transepithelial tightness due to tight junction integrity (TJ). We evaluated GJIC by dye transfer assays and tight junction integrity by transepithelial electrical resistance (TER) measurements, as well as immunohistochemistry and western blot assays of expression of claudins 2 and 4. We found that both digoxin and marinobufagenin improve GJIC and significantly enhance the tightness of the tight junctions, as evaluated from TER measurements. Immunofluorescence assays show that both compounds promote enhanced basolateral localization of claudin-4 but not claudin 2, while densitometric analysis of western blot assays indicate a significantly increased expression of claudin 4. These changes, induced by digoxin and marinobufagenin on GJIC and TER, were not observed on MDCK-R, a modified MDCK cell line that has a genetically induced insensitive α1 subunit, indicating that Na-K-ATPase acts as a receptor mediating the actions of both ECG. Plus, the fact that the effect of both cardiac glycosides was suppressed by incubation with PP2, an inhibitor of c-Src kinase, PD98059, an inhibitor of mitogen extracellular kinase-1 and Y-27632, a selective inhibitor of ROCK, and a Rho-associated protein kinase, indicate altogether that the signaling pathways involved include c-Src and ERK1/2, as well as Rho-ROCK. These results widen and strengthen our general hypothesis that a very important physiological role of ECG is the control of the epithelial phenotype and the regulation of cell-cell contacts.
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17
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Munkert J, Gomes ER, Marostica LL, Cota BB, Lopes CLM, Andrade SF, Filho JDS, Alves RJ, Oliveira MC, Braga FC, Simões CO, Pádua RM, de Barros ALB. New 99mTc-Labeled Digitoxigenin Derivative for Cancer Cell Identification. ACS OMEGA 2019; 4:22048-22056. [PMID: 31891085 PMCID: PMC6933791 DOI: 10.1021/acsomega.9b03167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
In recent years, cardiac glycosides (CGs) have been investigated as potential antiviral and anticancer drugs. Digitoxigenin (DIG) and other CGs have been shown to bind and inhibit Na+/K+-adenosinetriphosphatase (ATPase). Tumor cells show a higher expression rate of the Na+/K+-ATPase protein or a stronger affinity towards the binding of CGs and are therefore more prone to CGs than non-tumor cells. Cancer imaging techniques using radiotracers targeted at specific receptors have yielded successful results. Technetium-99m (99mTc) is one of the radionuclides of choice to radiolabel pharmaceuticals because of its favorable physical and chemical properties along with reasonable costs. Herein, we describe a new Na+/K+-ATPase targeting radiotracer consisting of digitoxigenin and diethylenetriaminepentaacetic acid (DTPA), a bifunctional chelating ligand used to prepare 99mTc-labeled complexes, and its evaluation as an imaging probe. We report the synthesis and characterization of the radiolabeled compound including stability tests, blood clearance, and biodistribution in healthy mice. Additionally, we investigated the binding of the compound to A549 human non-small-cell lung cancer cells and the inhibition of the Na+/K+-ATPase by the labeled compound in vitro. The 99mTc-labeled DTPA-digitoxigenin (99mTc-DTPA-DIG) compound displayed high stability in vitro and in vivo, a fast renal excretion, and a specific binding towards A549 cancer cells in comparison to non-tumor cells. Therefore, 99mTc-DTPA-DIG could potentially be used for non-invasive visualization of tumor lesions by means of scintigraphic imaging.
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Affiliation(s)
- Jennifer Munkert
- Department
of Biology, Friedrich-Alexander-Universität
Erlangen-Nürnberg, Staudtstrasse 5, 91058 Erlangen, Germany
| | - Eliza R. Gomes
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - Lucas L. Marostica
- Department
of Pharmaceutical Sciences, Universidade
Federal de Santa Catarina, Florianópolis, SC 88040-970, Brazil
| | - Betânia B. Cota
- Laboratório
de Química de Produtos Naturais Bioativos, Centro de Pesquisa René Rachou, Fundação Oswaldo
Cruz, Av. Augusto de
Lima, 1715, Belo Horizonte, MG 30190-002, Brazil
| | - Cristina L. M. Lopes
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - Saulo F. Andrade
- Faculty
of
Pharmaceutical Sciences, Universidade Federal
de Rio Grande do Sul, Av. Ipiranga, 2752, Porto Alegre, RS 90610-000, Brazil
| | - José
D. de Souza Filho
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - Ricardo J. Alves
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - Monica C. Oliveira
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - Fernão C. Braga
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - Cláudia
M. O. Simões
- Department
of Pharmaceutical Sciences, Universidade
Federal de Santa Catarina, Florianópolis, SC 88040-970, Brazil
| | - Rodrigo M. Pádua
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
| | - André L. B. de Barros
- Faculty
of Pharmacy and Department of Chemistry, Universidade Federal
de Minas Gerais, Av. Pres. Antônio Carlos, 6627, Belo
Horizonte, MG 31270-901, Brazil
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18
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Potential anti-herpes and cytotoxic action of novel semisynthetic digitoxigenin-derivatives. Eur J Med Chem 2019; 167:546-561. [DOI: 10.1016/j.ejmech.2019.01.076] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 09/05/2018] [Accepted: 01/29/2019] [Indexed: 11/17/2022]
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19
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Deng K, Shen J, Wang W, Li M, Li H, Chen C, Zhao H, Zhang M, Xue T, Liu Q, Lui VWY, Hong B, Lin W. Sodium chloride (NaCl) potentiates digoxin-induced anti-tumor activity in small cell lung cancer. Cancer Biol Ther 2018; 20:52-64. [PMID: 30183476 DOI: 10.1080/15384047.2018.1504723] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Small cell lung cancer (SCLC) is a malignant neuroendocrine tumor with very high mortality. Effective new therapy for advanced SCLC patients is urgently needed. By screening a FDA-approved drug library, we identified a cardiac glycoside (CG), namely digoxin (an inhibitor of cellular Na+/K+ ATPase pump), which was highly effective in inhibiting SCLC cell growth. Intriguing findings showed that NaCl supplement markedly enhanced the anti-tumor activities of digoxin in both in vitro and in vivo models of SCLC. Subsequent analysis revealed that this novel combination of digoxin/NaCl caused an up-regulation of intracellular Na+ and Ca2+ levels with an induction of higher resting membrane potential of SCLC cells. We also found that this combination lead to morphological shrinking of SCLC cells, together with high levels of cytochrome C release. Lastly, our data revealed that NaCl supplement was able to induce the expression of ATP1A1 (a Na+/K+ ATPase subunit), in which contributes directly to the increased sensitivity of SCLC cells to digoxin. Thus, this is the first demonstration that NaCl is a potent supplement necessitating superior anti-cancer effects of digoxin for SCLC. Further, our study suggests that digoxin treatment could need to be combined with NaCl supplement in future clinical trial of SCLC, particularly where low Na+ is often present in SCLC patients.
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Affiliation(s)
- Ke Deng
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,b University of Science and Technology of China , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
| | - Jiawei Shen
- d School of Life Sciences , University of Science and Technology of China , Hefei , P. R. China
| | - Wei Wang
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
| | - Ming Li
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,b University of Science and Technology of China , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China.,e Department of Laboratory Diagnostics , Western Branch of The First Affiliated Hospital of University of Science and Technology of China , Hefei , P. R. China
| | - Hong Li
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
| | - Cheng Chen
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,b University of Science and Technology of China , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
| | - Huan Zhao
- d School of Life Sciences , University of Science and Technology of China , Hefei , P. R. China
| | - Mei Zhang
- d School of Life Sciences , University of Science and Technology of China , Hefei , P. R. China
| | - Tian Xue
- d School of Life Sciences , University of Science and Technology of China , Hefei , P. R. China
| | - Qingsong Liu
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
| | - Vivian Wai Yan Lui
- f School of Biomedical Sciences, Faculty of Medicine , The Chinese University of Hong Kong , Hong Kong SAR
| | - Bo Hong
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
| | - Wenchu Lin
- a High Magnetic Field Laboratory , Chinese Academy of Sciences , Hefei , P. R. China.,c Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science , Chinese Academy of Sciences , Hefei , P. R. China
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20
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Pessôa MTC, Alves SLG, Taranto AG, Villar JAFP, Blanco G, Barbosa LA. Selectivity analyses of γ-benzylidene digoxin derivatives to different Na,K-ATPase α isoforms: a molecular docking approach. J Enzyme Inhib Med Chem 2017; 33:85-97. [PMID: 29115894 PMCID: PMC6009882 DOI: 10.1080/14756366.2017.1380637] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Digoxin and other cardiotonic steroids (CTS) exert their effect by inhibiting Na,K-ATPase (NKA) activity. CTS bind to the various NKA isoforms that are expressed in different cell types, which gives CTS their narrow therapeutic index. We have synthesised a series of digoxin derivatives (γ-Benzylidene digoxin derivatives) with substitutions in the lactone ring (including non-oxygen and ether groups), to obtain CTS with better NKA isoform specificity. Some of these derivatives show some NKA isoform selective effects, with BD-3, BD-8, and BD-13 increasing NKA α2 activity, BD-5 inhibiting NKA α1 and NKA α3, BD-10 reducing NKA α1, but stimulating NKA α2 and α3; and BD-14, BD-15, and BD-16 enhancing NKA α3 activity. A molecular-docking approach favoured NKA isoform specific interactions for the compounds that supported their observed activity. These results show that BD compounds are a new type of CTS with the capacity to target NKA activity in an isoform-specific manner.
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Affiliation(s)
- Marco T C Pessôa
- a Laboratório de Bioquímica Celular , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - Silmara L G Alves
- b Laboratório de Síntese Orgânica e Nanoestruturas , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - Alex G Taranto
- c Laboratório de Modelagem Molecular , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - José A F P Villar
- b Laboratório de Síntese Orgânica e Nanoestruturas , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
| | - Gustavo Blanco
- d Department of Molecular and Integrative Physiology , Kansas University Medical Center , Kansas City , KS , USA
| | - Leandro A Barbosa
- a Laboratório de Bioquímica Celular , Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú , Divinópolis , Brazil
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21
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Elimination of undifferentiated human embryonic stem cells by cardiac glycosides. Sci Rep 2017; 7:5289. [PMID: 28706279 PMCID: PMC5509667 DOI: 10.1038/s41598-017-05616-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/05/2017] [Indexed: 12/14/2022] Open
Abstract
An important safety concern in the use of human pluripotent stem cells (hPSCs) is tumorigenic risk, because these cells can form teratomas after an in vivo injection at ectopic sites. Several thousands of undifferentiated hPSCs are sufficient to induce teratomas in a mouse model. Thus, it is critical to remove all residue-undifferentiated hPSCs that have teratoma potential before the clinical application of hPSC-derived cells. In this study, our data demonstrated the cytotoxic effects of cardiac glycosides, such as digoxin, lanatoside C, bufalin, and proscillaridin A, in human embryonic stem cells (hESCs). This phenomenon was not observed in human bone marrow mesenchymal stem cells (hBMMSCs). Most importantly, digoxin and lanatoside C did not affect the stem cells’ differentiation ability. Consistently, the viability of the hESC-derived MSCs, neurons, and endothelium cells was not affected by the digoxin and lanatoside C treatment. Furthermore, the in vivo experiments demonstrated that digoxin and lanatoside C prevented teratoma formation. To the best of our knowledge, this study is the first to describe the cytotoxicity and tumor prevention effects of cardiac glycosides in hESCs. Digoxin and lanatoside C are also the first FDA-approved drugs that demonstrated cytotoxicity in undifferentiated hESCs.
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Alpha 2 Na +,K +-ATPase silencing induces loss of inflammatory response and ouabain protection in glial cells. Sci Rep 2017; 7:4894. [PMID: 28687727 PMCID: PMC5501845 DOI: 10.1038/s41598-017-05075-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 05/24/2017] [Indexed: 12/12/2022] Open
Abstract
Ouabain (OUA) is a cardiac glycoside that binds to Na+,K+-ATPase (NKA), a conserved membrane protein that controls cell transmembrane ionic concentrations and requires ATP hydrolysis. At nM concentrations, OUA activates signaling pathways that are not related to its typical inhibitory effect on the NKA pump. Activation of these signaling pathways protects against some types of injury of the kidneys and central nervous system. There are 4 isoforms of the alpha subunit of NKA, which are differentially distributed across tissues and may have different physiological roles. Glial cells are important regulators of injury and inflammation in the brain and express the α1 and α2 NKA isoforms. This study investigated the role of α2 NKA in OUA modulation of the neuroinflammatory response induced by lipopolysaccharide (LPS) in mouse primary glial cell cultures. LPS treatment increased lactate dehydrogenase release, while OUA did not decrease cell viability and blocked LPS-induced NF-κB activation. Silencing α2 NKA prevented ERK and NF-κB activation by LPS. α2 NKA also regulates TNF-α and IL-1β levels. The data reported here indicate a significant role of α2 NKA in regulating central LPS effects, with implications in the associated neuroinflammatory processes.
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Na⁺ i,K⁺ i-Dependent and -Independent Signaling Triggered by Cardiotonic Steroids: Facts and Artifacts. Molecules 2017; 22:molecules22040635. [PMID: 28420099 PMCID: PMC6153942 DOI: 10.3390/molecules22040635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/31/2017] [Accepted: 04/11/2017] [Indexed: 11/17/2022] Open
Abstract
Na⁺,K⁺-ATPase is the only known receptor of cardiotonic steroids (CTS) whose interaction with catalytic α-subunits leads to inhibition of this enzyme. As predicted, CTS affect numerous cellular functions related to the maintenance of the transmembrane gradient of monovalent cations, such as electrical membrane potential, cell volume, transepithelial movement of salt and osmotically-obliged water, symport of Na⁺ with inorganic phosphate, glucose, amino acids, nucleotides, etc. During the last two decades, it was shown that side-by-side with these canonical Na⁺i/K⁺i-dependent cellular responses, long-term exposure to CTS affects transcription, translation, tight junction, cell adhesion and exhibits tissue-specific impact on cell survival and death. It was also shown that CTS trigger diverse signaling cascades via conformational transitions of the Na⁺,K⁺-ATPase α-subunit that, in turn, results in the activation of membrane-associated non-receptor tyrosine kinase Src, phosphatidylinositol 3-kinase and the inositol 1,4,5-triphosphate receptor. These findings allowed researchers to propose that endogenous CTS might be considered as a novel class of steroid hormones. We focus our review on the analysis of the relative impact Na⁺i,K⁺i-mediated and -independent pathways in cellular responses evoked by CTS.
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Nguyen CH, Huttary N, Atanasov AG, Chatuphonprasert W, Brenner S, Fristiohady A, Hong J, Stadler S, Holzner S, Milovanovic D, Dirsch VM, Kopp B, Saiko P, Krenn L, Jäger W, Krupitza G. Fenofibrate inhibits tumour intravasation by several independent mechanisms in a 3-dimensional co-culture model. Int J Oncol 2017; 50:1879-1888. [PMID: 28393180 DOI: 10.3892/ijo.2017.3956] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 01/16/2017] [Indexed: 11/06/2022] Open
Abstract
Lymph node metastasis of breast cancer is a clinical marker of poor prognosis. Yet, there exist no therapies targeting mechanisms of intravasation into lymphatics. Herein we report on an effect of the antidyslipidemic drug fenofibrate with vasoprotective activity, which attenuates breast cancer intravasation in vitro, and describe the potential mechanisms. To measure intravasation in a 3-dimensional co-culture model MDA-MB231 and MCF-7 breast cancer spheroids were placed on immortalised lymphendothelial cell (LEC) monolayers. This provokes the formation of circular chemorepellent induced defects (CCIDs) in the LEC barrier resembling entry ports for the intravasating tumour. Furthermore, the expression of adhesion molecules ICAM-1, CD31 and FAK was investigated in LECs by western blotting as well as cell-cell adhesion and NF-κB activity by respective assays. In MDA-MB231 cells the activity of CYP1A1 was measured by EROD assay. Fenofibrate inhibited CCID formation in the MDA-MB231/LEC- and MCF-7/LEC models and the activity of NF-κB, which in turn downregulated ICAM-1 in LECs and the adhesion of cancer cells to LECs. Furthermore, CD31 and the activity of FAK were inhibited. In MDA-MB231 cells, fenofibrate attenuated CYP1A1 activity. Combinations with other FDA-approved drugs, which reportedly inhibit different ion channels, attenuated CCID formation additively or synergistically. In summary, fenofibrate inhibited NF-κB and ICAM-1, and inactivated FAK, thereby attenuating tumour intravasation in vitro. A combination with other FDA-approved drugs further improved this effect. Our new concept may lead to a novel therapy for cancer patients.
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Affiliation(s)
- Chi Huu Nguyen
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Vienna, Austria
| | - Nicole Huttary
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | | | | | - Stefan Brenner
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Vienna, Austria
| | - Adryan Fristiohady
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Vienna, Austria
| | - Junli Hong
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Serena Stadler
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Silvio Holzner
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Daniela Milovanovic
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
| | - Verena M Dirsch
- Department of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Brigitte Kopp
- Department of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Philipp Saiko
- Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, Vienna, Austria
| | - Liselotte Krenn
- Department of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Walter Jäger
- Department of Clinical Pharmacy and Diagnostics, University of Vienna, Vienna, Austria
| | - Georg Krupitza
- Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria
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Diederich M, Muller F, Cerella C. Cardiac glycosides: From molecular targets to immunogenic cell death. Biochem Pharmacol 2017; 125:1-11. [DOI: 10.1016/j.bcp.2016.08.017] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 08/15/2016] [Indexed: 11/26/2022]
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26
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Patel S. Plant-derived cardiac glycosides: Role in heart ailments and cancer management. Biomed Pharmacother 2016; 84:1036-1041. [PMID: 27780131 DOI: 10.1016/j.biopha.2016.10.030] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/08/2016] [Accepted: 10/10/2016] [Indexed: 12/20/2022] Open
Abstract
Cardiac glycosides, the cardiotonic steroids such as digitalis have been in use as heart ailment remedy since ages. They manipulate the renin-angiotensin axis to improve cardiac output. However; their safety and efficacy have come under scrutiny in recent times, as poisoning and accidental mortalities have been observed. In order to better understand and exploit them as cardiac ionotropes, studies are being pursued using different cardiac glycosides such as digitoxin, digoxin, ouabain, oleandrin etc. Several cardiac glycosides as peruvoside have shown promise in cancer control, especially ovary cancer and leukemia. Functional variability of these glycosides has revealed that not all cardiac glycosides are alike. Apart from their specific affinity to sodium-potassium ATPase, their therapeutic dosage and behavior in poly-morbidity conditions needs to be considered. This review presents a concise account of the key findings in recent years with adequate elaboration of the mechanisms. This compilation is expected to contribute towards management of cardiac, cancer, even viral ailments.
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Affiliation(s)
- Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, 5500 Campanile Dr San Diego, CA 92182, USA.
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28
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Matchkov VV, Krivoi II. Specialized Functional Diversity and Interactions of the Na,K-ATPase. Front Physiol 2016; 7:179. [PMID: 27252653 PMCID: PMC4879863 DOI: 10.3389/fphys.2016.00179] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/04/2016] [Indexed: 12/22/2022] Open
Abstract
Na,K-ATPase is a protein ubiquitously expressed in the plasma membrane of all animal cells and vitally essential for their functions. A specialized functional diversity of the Na,K-ATPase isozymes is provided by molecular heterogeneity, distinct subcellular localizations, and functional interactions with molecular environment. Studies over the last decades clearly demonstrated complex and isoform-specific reciprocal functional interactions between the Na,K-ATPase and neighboring proteins and lipids. These interactions are enabled by a spatially restricted ion homeostasis, direct protein-protein/lipid interactions, and protein kinase signaling pathways. In addition to its "classical" function in ion translocation, the Na,K-ATPase is now considered as one of the most important signaling molecules in neuronal, epithelial, skeletal, cardiac and vascular tissues. Accordingly, the Na,K-ATPase forms specialized sub-cellular multimolecular microdomains which act as receptors to circulating endogenous cardiotonic steroids (CTS) triggering a number of signaling pathways. Changes in these endogenous cardiotonic steroid levels and initiated signaling responses have significant adaptive values for tissues and whole organisms under numerous physiological and pathophysiological conditions. This review discusses recent progress in the studies of functional interactions between the Na,K-ATPase and molecular microenvironment, the Na,K-ATPase-dependent signaling pathways and their significance for diversity of cell function.
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Affiliation(s)
| | - Igor I Krivoi
- Department of General Physiology, St. Petersburg State University St. Petersburg, Russia
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Liu CC, Teh R, Mozar CA, Baxter RC, Rasmussen HH. Silencing overexpression of FXYD3 protein in breast cancer cells amplifies effects of doxorubicin and γ-radiation on Na(+)/K(+)-ATPase and cell survival. Breast Cancer Res Treat 2016; 155:203-13. [PMID: 26740212 DOI: 10.1007/s10549-015-3667-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 12/18/2015] [Indexed: 12/01/2022]
Abstract
FXYD3, also known as mammary tumor protein 8, is overexpressed in several common cancers, including in many breast cancers. We examined if such overexpression might protect Na(+)/K(+)-ATPase and cancer cells against the high levels of oxidative stress characteristic of many tumors and often induced by cancer treatments. We measured FXYD3 expression, Na(+)/K(+)-ATPase activity and glutathionylation of the β1 subunit of Na(+)/K(+)-ATPase, a reversible oxidative modification that inhibits the ATPase, in MCF-7 and MDA-MB-468 cells. Expression of FXYD3 was suppressed by transfection with FXYD3 siRNA. A colorimetric end-point assay was used to estimate cell viability. Apoptosis was estimated by caspase 3/7 (DEVDase) activation using a Caspase fluorogenic substrate kit. Expression of FXYD3 in MCF-7 breast cancer cells was ~eightfold and ~twofold higher than in non-cancer MCF-10A cells and MDA-MB-468 cancer cells, respectively. A ~50 % reduction in FXYD3 expression increased glutathionylation of the β1 Na(+)/K(+)-ATPase subunit and reduced Na(+)/K(+)-ATPase activity by ~50 %, consistent with the role of FXYD3 to facilitate reversal of glutathionylation of the β1 subunit of Na(+)/K(+)-ATPase and glutathionylation-induced inhibition of Na(+)/K(+)-ATPase. Treatment of MCF-7 and MDA-MB- 468 cells with doxorubicin or γ-radiation decreased cell viability and induced apoptosis. The treatments upregulated FXYD3 expression in MCF-7 but not in MDA-MB-468 cells and suppression of FXYD3 in MCF-7 but not in MDA-MB-468 cells amplified effects of treatments on Na(+)/K(+)-ATPase activity and treatment-induced cell death and apoptosis. Overexpression of FXYD3 may be a marker of resistance to cancer treatments and a potentially important therapeutic target.
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Affiliation(s)
- Chia-Chi Liu
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Rachel Teh
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Christine A Mozar
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Robert C Baxter
- Hormones and Cancer Laboratories, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia
| | - Helge H Rasmussen
- North Shore Heart Research Group, Kolling Institute of Medical Research, University of Sydney, Sydney, Australia. .,The Department of Cardiology, Royal North Shore Hospital, St Leonards, NSW, 2065, Australia.
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