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Luczak MW, Krawic C, Zhitkovich A. NAD + metabolism controls growth inhibition by HIF1 in normoxia and determines differential sensitivity of normal and cancer cells. Cell Cycle 2021; 20:1812-1827. [PMID: 34382917 DOI: 10.1080/15384101.2021.1959988] [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] [Indexed: 12/14/2022] Open
Abstract
The hypoxia-induced transcription factor HIF1 inhibits cell growth in normoxia through poorly understood mechanisms. A constitutive upregulation of hypoxia response is associated with increased malignancy, indicating a loss of antiproliferative effects of HIF1 in cancer cells. To understand these differences, we examined a control of cell cycle in primary human cells with activated hypoxia response in normoxia. Activated HIF1 caused a global slowdown of cell cycle progression through G1, S and G2 phases leading to the loss of mitotic cells. Cell cycle inhibition required a prolonged HIF1 activation and was not associated with upregulation of p53 or the CDK inhibitors p16, p21 or p27. Growth inhibition by HIF1 was independent of its Asn803 hydroxylation or the presence of HIF2. Antiproliferative effects of hypoxia response were alleviated by inhibition of lactate dehydrogenase and more effectively, by boosting cellular production of NAD+, which was decreased by HIF1 activation. In comparison to normal cells, various cancer lines showed several fold-higher expression of NAMPT which is a rate-limiting enzyme in the main biosynthetic pathway for NAD+. Inhibition of NAMPT activity in overexpressor cancer cells sensitized them to antigrowth effects of HIF1. Thus, metabolic changes in cancer cells, such as enhanced NAD+ production, create resistance to growth-inhibitory activity of HIF1 permitting manifestation of its tumor-promoting properties.AbbreviationsDMOG: dimethyloxalylglycine, DM-NOFD: dimethyl N-oxalyl-D-phenylalanine, NMN: β-nicotinamide mononucleotide.
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Affiliation(s)
- Michal W Luczak
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Casey Krawic
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Anatoly Zhitkovich
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
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2
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Raudenska M, Balvan J, Fojtu M, Gumulec J, Masarik M. Unexpected therapeutic effects of cisplatin. Metallomics 2020; 11:1182-1199. [PMID: 31098602 DOI: 10.1039/c9mt00049f] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cisplatin is a widely used chemotherapeutic agent that is clinically approved to fight both carcinomas and sarcomas. It has relatively high efficiency in treating ovarian cancers and metastatic testicular cancers. It is generally accepted that the major mechanism of cisplatin anti-cancer action is DNA damage. However, cisplatin is also effective in metastatic cancers and should, therefore, affect slow-cycling cancer stem cells in some way. In this review, we focused on the alternative effects of cisplatin that can support a good therapeutic response. First, attention was paid to the effects of cisplatin at the cellular level such as changes in intracellular pH and cellular mechanical properties. Alternative cellular targets of cisplatin, and the effects of cisplatin on cancer cell metabolism and ER stress were also discussed. Furthermore, the impacts of cisplatin on the tumor microenvironment and in the whole organism context were reviewed. In this review, we try to reveal possible causes of the unexpected effectiveness of this anti-cancer drug.
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Affiliation(s)
- Martina Raudenska
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | - Jan Balvan
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic. and Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic and Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, CZ-612 00 Brno, Czech Republic
| | - Michaela Fojtu
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
| | - Jaromir Gumulec
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic. and Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic and Central European Institute of Technology, Brno University of Technology, Purkynova 656/123, CZ-612 00 Brno, Czech Republic
| | - Michal Masarik
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic. and Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic and BIOCEV, First Faculty of Medicine, Charles University, Průmyslová 595, CZ-252 50 Vestec, Czech Republic
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3
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Hosoda E, Hiraoka D, Hirohashi N, Omi S, Kishimoto T, Chiba K. SGK regulates pH increase and cyclin B-Cdk1 activation to resume meiosis in starfish ovarian oocytes. J Cell Biol 2019; 218:3612-3629. [PMID: 31537709 PMCID: PMC6829648 DOI: 10.1083/jcb.201812133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 07/19/2019] [Accepted: 08/15/2019] [Indexed: 12/31/2022] Open
Abstract
Tight regulation of intracellular pH (pHi) is essential for biological processes. Fully grown oocytes, having a large nucleus called the germinal vesicle, arrest at meiotic prophase I. Upon hormonal stimulus, oocytes resume meiosis to become fertilizable. At this time, the pHi increases via Na+/H+ exchanger activity, although the regulation and function of this change remain obscure. Here, we show that in starfish oocytes, serum- and glucocorticoid-regulated kinase (SGK) is activated via PI3K/TORC2/PDK1 signaling after hormonal stimulus and that SGK is required for this pHi increase and cyclin B-Cdk1 activation. When we clamped the pHi at 6.7, corresponding to the pHi of unstimulated ovarian oocytes, hormonal stimulation induced cyclin B-Cdk1 activation; thereafter, oocytes failed in actin-dependent chromosome transport and spindle assembly after germinal vesicle breakdown. Thus, this SGK-dependent pHi increase is likely a prerequisite for these events in ovarian oocytes. We propose a model that SGK drives meiotic resumption via concomitant regulation of the pHi and cell cycle machinery.
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Affiliation(s)
- Enako Hosoda
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Daisaku Hiraoka
- Science and Education Center, Ochanomizu University, Tokyo, Japan
| | | | - Saki Omi
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Takeo Kishimoto
- Science and Education Center, Ochanomizu University, Tokyo, Japan
| | - Kazuyoshi Chiba
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
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Slaby S, Hanotel J, Marchand G, Lescuyer A, Bodart JF, Leprêtre A, Lemière S, Marin M. Maturation of Xenopus laevis oocytes under cadmium and lead exposures: Cell biology investigations. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 193:105-110. [PMID: 29053961 DOI: 10.1016/j.aquatox.2017.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 09/25/2017] [Accepted: 10/14/2017] [Indexed: 06/07/2023]
Abstract
Since amphibians are recognised as good models to assess the quality of environments, only few studies have dealt with the impacts of chemical contaminants on their gametes, while toxic effects at this stage will alter all the next steps of their life cycle. Therefore, we propose to investigate the oocyte maturation of Xenopus laevis in cadmium- and lead-contaminated conditions. The impacts of cadmium and lead ions were explored on events involved in the hormone-dependent process of maturation. In time-course experiments, cadmium, at the highest concentration, delayed and prevented the germinal vesicle breakdown. Even in the absence of progesterone this ion could also induce it. No such spontaneous maturation was observed after lead exposures. An acceleration of the process at the highest tested concentration of lead (90μM), in presence of progesterone, was recorded. Cytological observations highlighted that cadmium exposures drove severe disturbances of meiotic spindle morphogenesis. At last, cadmium exposures altered the MAPK pathway, regarding the activation of ERK2 and RSK, but also the activation and the activity of the MPF, by disturbing the state of phosphorylation of Cdc2 and histone H3. Xenopus laevis oocytes were affected by these metal ion exposures, notably by Cd2+. Signatures of these metal exposures on the oocyte maturation were detected. This germ cell appeared to be a relevant model to assess the effects of environmental contaminants such as metals.
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Affiliation(s)
- Sylvain Slaby
- Univ. Lille, CNRS, INRA, UMR 8576-UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France; Univ. Lille, EA 4515-LGCgE - Laboratoire Génie Civil et géo-Environnement, Cité scientifique, SN3, F-59655 Villeneuve d'Ascq, France
| | - Julie Hanotel
- Univ. Lille, CNRS, INRA, UMR 8576-UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
| | - Guillaume Marchand
- Univ. Lille, CNRS, INRA, UMR 8576-UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
| | - Arlette Lescuyer
- Univ. Lille, CNRS, INRA, UMR 8576-UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
| | - Jean-François Bodart
- Univ. Lille, CNRS, INRA, UMR 8576-UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
| | - Alain Leprêtre
- Univ. Lille, EA 4515-LGCgE - Laboratoire Génie Civil et géo-Environnement, Cité scientifique, SN3, F-59655 Villeneuve d'Ascq, France
| | - Sébastien Lemière
- Univ. Lille, EA 4515-LGCgE - Laboratoire Génie Civil et géo-Environnement, Cité scientifique, SN3, F-59655 Villeneuve d'Ascq, France
| | - Matthieu Marin
- Univ. Lille, CNRS, INRA, UMR 8576-UGSF - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France.
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5
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Pal DS, Abbasi M, Mondal DK, Varghese BA, Paul R, Singh S, Datta R. Interplay between a cytosolic and a cell surface carbonic anhydrase in pH homeostasis and acid tolerance of Leishmania. J Cell Sci 2017; 130:754-766. [PMID: 28062849 DOI: 10.1242/jcs.199422] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/23/2016] [Indexed: 12/11/2022] Open
Abstract
Leishmania parasites have evolved to endure the acidic phagolysosomal environment within host macrophages. How Leishmania cells maintain near-neutral intracellular pH and proliferate in such a proton-rich mileu remains poorly understood. We report here that, in order to thrive in acidic conditions, Leishmania major relies on a cytosolic and a cell surface carbonic anhydrase, LmCA1 and LmCA2, respectively. Upon exposure to acidic medium, the intracellular pH of the LmCA1+/-, LmCA2+/- and LmCA1+/-:LmCA2+/- mutant strains dropped by varying extents that led to cell cycle delay, growth retardation and morphological abnormalities. Intracellular acidosis and growth defects of the mutant strains could be reverted by genetic complementation or supplementation with bicarbonate. When J774A.1 macrophages were infected with the mutant strains, they exhibited much lower intracellular parasite burdens than their wild-type counterparts. However, these differences in intracellular parasite burden between the wild-type and mutant strains were abrogated if, before infection, the macrophages were treated with chloroquine to alkalize their phagolysosomes. Taken together, our results demonstrate that haploinsufficiency of LmCA1 and/or LmCA2 renders the parasite acid-susceptible, thereby unravelling a carbonic anhydrase-mediated pH homeostatic circuit in Leishmania cells.
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Affiliation(s)
- Dhiman Sankar Pal
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
| | - Mazharul Abbasi
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
| | - Dipon Kumar Mondal
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
| | - Binitha Anu Varghese
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
| | - Ritama Paul
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
| | - Shalini Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
| | - Rupak Datta
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur-741246, West Bengal, India
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Gelaude A, Marin M, Cailliau K, Jeseta M, Lescuyer‐Rousseau A, Vandame P, Nevoral J, Sedmikova M, Martoriati A, Bodart J. Nitric Oxide Donor
s
‐Nitroso‐
n
‐Acetyl Penicillamine (SNAP) Alters Meiotic Spindle Morphogenesis in
Xenopus
Oocytes. J Cell Biochem 2015; 116:2445-54. [DOI: 10.1002/jcb.25211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/22/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Armance Gelaude
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
| | - Matthieu Marin
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
| | - Katia Cailliau
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
| | - Michal Jeseta
- Veterinary Research InstituteBrno ‐ Genetics and ReproductionBrnoCzech Republic
| | - Arlette Lescuyer‐Rousseau
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
| | - Pauline Vandame
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
| | - Jan Nevoral
- Czech University of Life Sciences in PragueFaculty of AgrobiologyFood and Natural Resources, Department of Veterinary SciencesPragueCzech Republic
| | - Marketa Sedmikova
- Czech University of Life Sciences in PragueFaculty of AgrobiologyFood and Natural Resources, Department of Veterinary SciencesPragueCzech Republic
| | - Alain Martoriati
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
| | - Jean‐François Bodart
- Université Lillel, Sciences et TechnologiesRégulation des Signaux de Division Team, UMR 8576 CNRS, FR3688 CNRSVilleneuve dAscqFrance
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7
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Molin M, Demir AB. Linking Peroxiredoxin and Vacuolar-ATPase Functions in Calorie Restriction-Mediated Life Span Extension. Int J Cell Biol 2014; 2014:913071. [PMID: 24639875 PMCID: PMC3930189 DOI: 10.1155/2014/913071] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 11/11/2013] [Accepted: 12/15/2013] [Indexed: 01/09/2023] Open
Abstract
Calorie restriction (CR) is an intervention extending the life spans of many organisms. The mechanisms underlying CR-dependent retardation of aging are still poorly understood. Despite mechanisms involving conserved nutrient signaling pathways proposed, few target processes that can account for CR-mediated longevity have so far been identified. Recently, both peroxiredoxins and vacuolar-ATPases were reported to control CR-mediated retardation of aging downstream of conserved nutrient signaling pathways. In this review, we focus on peroxiredoxin-mediated stress-defence and vacuolar-ATPase regulated acidification and pinpoint common denominators between the two mechanisms proposed for how CR extends life span. Both the activities of peroxiredoxins and vacuolar-ATPases are stimulated upon CR through reduced activities in conserved nutrient signaling pathways and both seem to stimulate cellular resistance to peroxide-stress. However, whereas vacuolar-ATPases have recently been suggested to control both Ras-cAMP-PKA- and TORC1-mediated nutrient signaling, neither the physiological benefits of a proposed role for peroxiredoxins in H2O2-signaling nor downstream targets regulated are known. Both peroxiredoxins and vacuolar-ATPases do, however, impinge on mitochondrial iron-metabolism and further characterization of their impact on iron homeostasis and peroxide-resistance might therefore increase our understanding of the beneficial effects of CR on aging and age-related diseases.
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Affiliation(s)
- Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, 413 90 Gothenburg, Sweden
| | - Ayse Banu Demir
- Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, 413 90 Gothenburg, Sweden
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Urla, Izmir, Turkey
- Department of Oncology, Institute of Oncology, Dokuz Eylul University, 35340 Inciralti, Izmir, Turkey
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8
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Orij R, Urbanus ML, Vizeacoumar FJ, Giaever G, Boone C, Nislow C, Brul S, Smits GJ. Genome-wide analysis of intracellular pH reveals quantitative control of cell division rate by pH(c) in Saccharomyces cerevisiae. Genome Biol 2012; 13:R80. [PMID: 23021432 PMCID: PMC3506951 DOI: 10.1186/gb-2012-13-9-r80] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 09/10/2012] [Accepted: 09/26/2012] [Indexed: 01/20/2023] Open
Abstract
Background Because protonation affects the properties of almost all molecules in cells, cytosolic pH (pHc) is usually assumed to be constant. In the model organism yeast, however, pHc changes in response to the presence of nutrients and varies during growth. Since small changes in pHc can lead to major changes in metabolism, signal transduction, and phenotype, we decided to analyze pHc control. Results Introducing a pH-sensitive reporter protein into the yeast deletion collection allowed quantitative genome-wide analysis of pHc in live, growing yeast cultures. pHc is robust towards gene deletion; no single gene mutation led to a pHc of more than 0.3 units lower than that of wild type. Correct pHc control required not only vacuolar proton pumps, but also strongly relied on mitochondrial function. Additionally, we identified a striking relationship between pHc and growth rate. Careful dissection of cause and consequence revealed that pHc quantitatively controls growth rate. Detailed analysis of the genetic basis of this control revealed that the adequate signaling of pHc depended on inositol polyphosphates, a set of relatively unknown signaling molecules with exquisitely pH sensitive properties. Conclusions While pHc is a very dynamic parameter in the normal life of yeast, genetically it is a tightly controlled cellular parameter. The coupling of pHc to growth rate is even more robust to genetic alteration. Changes in pHc control cell division rate in yeast, possibly as a signal. Such a signaling role of pHc is probable, and may be central in development and tumorigenesis.
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Affiliation(s)
- Rick Orij
- Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands
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Participation of IP3R, RyR and L-type Ca2+ channel in the nuclear maturation of Rhinella arenarum oocytes. ZYGOTE 2012; 22:110-23. [DOI: 10.1017/s0967199412000287] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SummaryDuring meiosis resumption, oocytes undergo a series of nuclear and cytosolic changes that prepare them for fertilization and that are referred to as oocyte maturation. These events are characterized by germinal vesicle breakdown (GVBD), chromatin condensation and spindle formation and, among cytosolic changes, organelle redistribution and maturation of Ca2+-release mechanisms. The progression of the meiotic cell cycle is regulated by M phase/maturation-promoting factor (MPF) and mitogen-activated protein kinase (MAPK). Changes in the levels of intracellular free Ca2+ ion have also been implicated strongly in the triggering of the initiation of the M phase. Ca2+ signals can be generated by Ca2+ release from intracellular Ca2+ stores (endoplasmic reticulum; ER) or by Ca2+ influx from the extracellular space. In this sense, the L-type Ca2+ channel plays an important role in the incorporation of Ca2+ from the extracellular space. Two types of intracellular Ca2+ receptor/channels are known to mediate the intracellular Ca2+ release from the ER lumen. The most abundant, the inositol 1,4,5-trisphosphate receptor (IP3R), and the other Ca2+ channel, the ryanodine receptor (RyR), have also been reported to mediate Ca2+ release in several oocytes. In amphibians, MPF and MAPK play a central role during oocyte maturation, controlling several events. However, no definitive relationships have been identified between Ca2+ and MPF or MAPK. We investigated the participation of Ca2+ in the spontaneous and progesterone-induced nuclear maturation in Rhinella arenarum oocytes and the effect of different pharmacological agents known to produce modifications in the Ca2+ channels. We demonstrated that loading competent and incompetent oocytes with the intracellular calcium chelator BAPTA/AM produced suppression of spontaneous and progesterone-induced GVBD. In our results, the capacity of progesterone to trigger meiosis reinitiation in Rhinella in the presence of L-type Ca2+ channel blockers (nifedipine and lanthane) indicated that spontaneous and progesterone-induced maturation would be independent of extracellular calcium influx, but would be sensitive to intracellular Ca2+ deprivation. As demonstrated by the effect of thimerosal and heparin in Rhinella arenarum, the intracellular increase in Ca2+ during maturation is also mediated mainly by IP3R. In addition, our results using caffeine, an agonist of the RyR, could suggest that Ca2+ release from ryanodine-sensitive stores is not essential for oocyte maturation in Rhinella. The decrease in MPF activity with NaVO3 negatively affected the percentage of thimerosal-induced GVBD. This finding suggests that Ca2+ release through the IP3R could be involved in the signalling pathway that induces MPF activation. However, the inhibition of MAP/ERK kinase (MEK) by PD98128 or P90 by geldanamycin produced a significant decrease in the percentages of GVBD induced by thimerosal. This finding suggests that Ca2+ release per se cannot bypass the inhibition of the MAPK activity.
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Marin M. Calcium Signaling in Xenopus oocyte. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:1073-94. [DOI: 10.1007/978-94-007-2888-2_49] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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11
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Abstract
Although cancer is a diverse set of diseases, cancer cells share a number of adaptive hallmarks. Dysregulated pH is emerging as a hallmark of cancer because cancers show a 'reversed' pH gradient with a constitutively increased intracellular pH that is higher than the extracellular pH. This gradient enables cancer progression by promoting proliferation, the evasion of apoptosis, metabolic adaptation, migration and invasion. Several new advances, including an increased understanding of pH sensors, have provided insight into the molecular basis for pH-dependent cell behaviours that are relevant to cancer cell biology. We highlight the central role of pH sensors in cancer cell adaptations and suggest how dysregulated pH could be exploited to develop cancer-specific therapeutics.
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Affiliation(s)
- Bradley A Webb
- Department of Cell and Tissue Biology, University of California, San Francisco, California 94143, USA
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12
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Calcium dynamics during physiological acidification in Xenopus oocyte. J Membr Biol 2010; 236:233-45. [PMID: 20717657 DOI: 10.1007/s00232-010-9290-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 07/19/2010] [Indexed: 10/19/2022]
Abstract
Interplays between intracellular pH (pHi) and calcium ([Ca(2+)](i)) variations remain unclear, though both proton and calcium homeostasis changes accompany physiological events such as Xenopus laevis oocyte maturation. In this report, we used NH(4)Cl and changes of extracellular pH (pHe) to acidify the cytosol in a physiological range. In oocytes voltage-clamped at -80 mV, NH(4)Cl triggered an inward current, the main component of which is a Ca(2+)-dependent chloride current. Calcium imaging confirmed that NH(4)Cl provoked a [Ca(2+)](i) increase. The mobilized sources of calcium were discriminated using the triple-step protocol as a means to follow both the calcium-activated chloride currents (ICl-Ca) and the hyperpolarization- and acid-activated nonselective cation current (I(In)). These currents were stimulated during external addition of NH(4)Cl. This upregulation was abolished by BAPTA-AM, caffeine and heparin. By both buffering pHi changes with MOPS and by inhibiting calcium influx with lanthanum, intracellular acidification, initiated by NH(4)Cl and extracellular acidic medium, was shown to trigger a [Ca(2+)](i) increase through both calcium release and calcium influx. The calcium pathways triggered by pHe changes are similar to those activated by NH(4)Cl, thus suggesting that there is a robust signaling mechanism allowing the cell to adjust to variable environmental conditions.
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13
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Alterations in mouse embryo intracellular pH by DMO during culture impair implantation and fetal growth. Reprod Biomed Online 2010; 21:219-29. [PMID: 20615756 DOI: 10.1016/j.rbmo.2010.05.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 07/02/2009] [Accepted: 04/16/2010] [Indexed: 02/08/2023]
Abstract
The preimplantation embryo is highly susceptible to in-vitro stress, and although this does not necessarily perturb blastocyst development, it can significantly affect embryo physiology and the ability to form a viable pregnancy. This study determined that the preimplantation mouse embryo is highly sensitive to a small decrease in intracellular pH (<0.2 pH units). Embryos cultured in media containing a weak acid (5,5-dimethyl-2,4-oxazolidinedione; DMO) formed blastocysts with decreased cell number and inner cell mass number, as well as increased apoptosis, even though blastocyst development and morphology were unchanged. Interestingly, the effects were similar regardless of whether the pH stress was present for a short-term 'acute' exposure (during the zygote to 2-cell, or 2-cell to 8-cell division) or an extended 'chronic' period of time (continually from the zygote to the blastocyst stage). Exposure to DMO during the first cleavage division did not alter implantation; however, fetal weight and crown-rump length were significantly decreased (P<0.05). In contrast, continuous exposure to DMO throughout preimplantation development reduced not only implantation but also fetal weight and crown-rump length. This study highlights the importance of correct intracellular pH and demonstrates that slight deviations can significantly impact embryo development and viability.
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Saitoh T, Tsuchiya Y, Kinoshita T, Itoh M, Yamashita S. Inhibition of apoptosis by ascorbic and dehydroascorbic acids in Xenopus egg extracts. Reprod Med Biol 2008; 8:3-9. [PMID: 29699301 DOI: 10.1007/s12522-008-0001-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 09/16/2008] [Indexed: 11/30/2022] Open
Abstract
Purpose The viability of mammalian eggs after ovulation is reported to be improved by the presence of ascorbic acid in the culture medium. However, the pro-survival mechanisms of ascorbic acid are poorly understood. The molecular pathways of apoptosis are evolutionarily conserved among animal species, and Xenopus eggs are technically and ethically more suitable for biochemical analyses than mammalian eggs. We used Xenopus egg cytoplasmic extracts to examine the direct intracellular effects of ascorbic acid. Methods Incubation of egg extracts for more than 4 h induces the spontaneous release of cytochrome c from mitochondria. This event triggers the activation of caspases, cleavage of substrate proteins, and execution of apoptosis. Multiple signal transduction pathways including proteolysis and protein phosphorylation are also involved in this process. We examined whether any of these events might be inhibited by the addition of ascorbic acid. Results Ascorbic acid showed no effect against cytochrome c release, but prevented caspase activation and substrate cleavage. Ascorbic acid also blocked the proteolysis of apoptosis inhibitor proteins and the dephosphorylation of p42 MAP kinase. However, dehydroascorbic acid (oxidized form of ascorbic acid) and acetate (unrelated acid) were equally effective, indicating that these effects were primarily due to their acidity. In addition, dehydroascorbic acid inhibited caspase activities directly in vitro. Conclusions The anti-apoptotic effect of ascorbic acid in Xenopus egg extracts is mainly due to cytoplasmic acidification rather than its intracellular antioxidant activity. Instead, oxidative conversion of ascorbic acid into dehydroascorbic acid may inhibit apoptosis through the inhibition of caspases.
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Affiliation(s)
- Tomohiro Saitoh
- Department of Obstetrics and Gynecology Toho University Medical Center Sakura Hospital 564-1 Shimoshizu Sakura-shi 285-8741 Chiba Japan
| | - Yuichi Tsuchiya
- Department of Biochemistry Toho University School of Medicine 5-21-16 Omori-nishi Ota-ku 143-8540 Tokyo Japan
| | - Toshihiko Kinoshita
- Department of Obstetrics and Gynecology Toho University Medical Center Sakura Hospital 564-1 Shimoshizu Sakura-shi 285-8741 Chiba Japan
| | - Motohiro Itoh
- Department of Obstetrics and Gynecology Toho University Medical Center Sakura Hospital 564-1 Shimoshizu Sakura-shi 285-8741 Chiba Japan
| | - Shigeru Yamashita
- Department of Biochemistry Toho University School of Medicine 5-21-16 Omori-nishi Ota-ku 143-8540 Tokyo Japan
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Chien EJ, Liao CF, Chang CP, Pu HF, Lu LM, Shie MC, Hsieh DJY, Hsu MT. The non-genomic effects on Na+/H+-exchange 1 by progesterone and 20α-hydroxyprogesterone in human T cells. J Cell Physiol 2007; 211:544-50. [PMID: 17323380 DOI: 10.1002/jcp.20962] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Progesterone is an endogenous immunomodulator and can suppress T-cell activation during pregnancy. We have previously shown that the non-genomic effects of progesterone, especially acidification, are exerted via plasma membrane sites and suppress cellular genomic responses to mitogens. This study aimed to show that acidification is due to a non-genomic inhibition of Na(+)/H(+)-exchange 1 (NHE1) by progesterone and correlate this with immunosuppressive phytohemagglutinin (PHA)-induced T-cell proliferation. The presence of amiloride-sensitive NHE 1 was identified in T cells. The activity of NHE1 was inhibited by progesterone but not by 20alpha-hydroxyprogesterone (20alpha-OHP). Furthermore, 20alpha-OHP was able to compete with progesterone and release the inhibitory effect on the NHE1. The inhibition of NHE1 activity by progesterone-BSA demonstrated non-genomic action via plasma membrane sites. Finally, co-stimulation with PHA and progesterone or amiloride, (5-(N, N-dimethyl)-amiloride, DMA), inhibited PHA-induced T-cell proliferation, but this inhibition did not occur with 20alpha-OHP and PHA co-stimulation. However, when DMA was applied 72 h after PHA stimulation, it was able to suppress PHA-induced T-cell proliferation. This is the first study to show that progesterone causes a rapid non-genomic inhibition of plasma membrane NHE1 activity in T cells within minutes which is released by 20alpha-OHP. The inhibition of NHE1 leads to immunosuppressive T-cell proliferation and suggests that progesterone might exert a major rapid non-genomic suppressive effect on NHE1 activity at the maternal-fetal interface in vivo and that 20alpha-OHP may possibly be able to quickly release the suppression when T cells circulated away from the interface.
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Affiliation(s)
- Eileen Jea Chien
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China.
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