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Pedriali G, Ramaccini D, Bouhamida E, Branchini A, Turrin G, Tonet E, Scala A, Patergnani S, Pinotti M, Trapella C, Giorgi C, Tremoli E, Campo G, Morciano G, Pinton P. 1,3,8-Triazaspiro[4.5]decane Derivatives Inhibit Permeability Transition Pores through a FO-ATP Synthase c Subunit Glu119-Independent Mechanism That Prevents Oligomycin A-Related Side Effects. Int J Mol Sci 2023; 24:ijms24076191. [PMID: 37047160 PMCID: PMC10094280 DOI: 10.3390/ijms24076191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/17/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Permeability transition pore (PTP) molecular composition and activity modulation have been a matter of research for several years, especially due to their importance in ischemia reperfusion injury (IRI). Notably, c subunit of ATP synthase (Csub) has been identified as one of the PTP-forming proteins and as a target for cardioprotection. Oligomycin A is a well-known Csub interactor that has been chemically modified in-depth for proposed new pharmacological approaches against cardiac reperfusion injury. Indeed, by taking advantage of its scaffold and through focused chemical improvements, innovative Csub-dependent PTP inhibitors (1,3,8-Triazaspiro[4.5]decane) have been synthetized in the past. Interestingly, four critical amino acids have been found to be involved in Oligomycin A-Csub binding in yeast. However, their position on the human sequence is unknown, as is their function in PTP inhibition. The aims of this study are to (i) identify for the first time the topologically equivalent residues in the human Csub sequence; (ii) provide their in vitro validation in Oligomycin A-mediated PTP inhibition and (iii) understand their relevance in the binding of 1,3,8-Triazaspiro[4.5]decane small molecules, as Oligomycin A derivatives, in order to provide insights into Csub interactions. Notably, in this study we demonstrated that 1,3,8-Triazaspiro[4.5]decane derivatives inhibit permeability transition pores through a FO-ATP synthase c subunit Glu119-independent mechanism that prevents Oligomycin A-related side effects.
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Carrer A, Laquatra C, Tommasin L, Carraro M. Modulation and Pharmacology of the Mitochondrial Permeability Transition: A Journey from F-ATP Synthase to ANT. Molecules 2021; 26:molecules26216463. [PMID: 34770872 PMCID: PMC8587538 DOI: 10.3390/molecules26216463] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/21/2021] [Accepted: 10/23/2021] [Indexed: 12/22/2022] Open
Abstract
The permeability transition (PT) is an increased permeation of the inner mitochondrial membrane due to the opening of the PT pore (PTP), a Ca2+-activated high conductance channel involved in Ca2+ homeostasis and cell death. Alterations of the PTP have been associated with many pathological conditions and its targeting represents an incessant challenge in the field. Although the modulation of the PTP has been extensively explored, the lack of a clear picture of its molecular nature increases the degree of complexity for any target-based approach. Recent advances suggest the existence of at least two mitochondrial permeability pathways mediated by the F-ATP synthase and the ANT, although the exact molecular mechanism leading to channel formation remains elusive for both. A full comprehension of this to-pore conversion will help to assist in drug design and to develop pharmacological treatments for a fine-tuned PT regulation. Here, we will focus on regulatory mechanisms that impinge on the PTP and discuss the relevant literature of PTP targeting compounds with particular attention to F-ATP synthase and ANT.
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Investigating the Potential of Conjugated Selenium Redox Folic Acid as a Treatment for Triple Negative Breast Cancer. Antioxidants (Basel) 2020; 9:antiox9020138. [PMID: 32033374 PMCID: PMC7071027 DOI: 10.3390/antiox9020138] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/24/2020] [Accepted: 02/03/2020] [Indexed: 02/07/2023] Open
Abstract
Previous studies have demonstrated that redox selenium compounds arrest cancer cell viability in vitro through their pro-oxidative activity by generating superoxide (O2•−). Currently, there are no efficacious treatment options for women with Triple Negative Breast Cancer (TNBC). However, the association between the over-expression of the Folate Receptor Alpha (FRA) in TNBC and other cancer cells, has led to the possibility that TNBCs might be treated by targeting the FRA with redox selenium covalent Folic Acid conjugates. The present study reports the synthesis of the redox active vitamer, Selenofolate, generating superoxide. Superoxide (O2•−) catalytic generation by Selenofolate was assessed by an in vitro chemiluminescence (CL) assay and by a Dihydroethidium (DHE) in vivo assay. Cytotoxicity of Selenofolate was assessed against the TNBC cell line MDA-MB-468 and an immortalized, mammary epithelial cell line, HME50-5E. Cytotoxicity of Selenofolate was compared to Folic Acid and sodium selenite, in a time and dose dependent manner. Selenofolate and selenite treatments resulted in greater inhibition of MDA-MB-468 cell proliferation than HME50-5E as evaluated by Trypan Blue exclusion, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) metabolic assay and Annexin V apoptosis assays. Folate receptor alpha (FRA) protein expression was assessed by Western blotting, with the experimental results showing that redox active Selenofolate and selenite, but not Folic Acid, was cytotoxic to MDA-MB-468 cells in vitro, suggesting a possible clinical option for treating TNBC and other cancers over-expressing FRA.
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Soukupová K, Rudolf E. Suppression of proliferation and activation of cell death by sodium selenite involves mitochondria and lysosomes in chemoresistant bladder cancer cells. J Trace Elem Med Biol 2019; 52:58-67. [PMID: 30732900 DOI: 10.1016/j.jtemb.2018.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/30/2018] [Accepted: 11/26/2018] [Indexed: 01/13/2023]
Abstract
The specific effects of sodium selenite (selenite) on a chemoresistant human bladder cancer cell line RT-112/D21 were investigated during 72 h. Selenite at low concentration of 2.5 μmol (otherwise tolerated in normal urothelial cells UROtsa) suppressed growth and proliferation of the tested cancer cells via induced oxidative stress. Selenite further altered mitochondrial functions (i.e. decreased mitochondrial membrane potential, increased production of superoxide and reduced ATP synthesis), disrupted lysosomal membranes and activated autophagy. These changes in selenite-exposed cells ultimately resulted in their demise via necrosis and other cell death modality displaying heterotypic apoptotic and autophagic features.
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Affiliation(s)
- K Soukupová
- Department of Medical Biology and Genetics Charles University, Faculty of Medicine in Hradec Králové, Zborovská 2089, 500 03 Hradec Králové, Czech Republic
| | - E Rudolf
- Department of Medical Biology and Genetics Charles University, Faculty of Medicine in Hradec Králové, Zborovská 2089, 500 03 Hradec Králové, Czech Republic.
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Yu B, Ma L, Jin J, Jiang F, Zhou G, Yan K, Liu Y. Mitochondrial toxicity induced by a thiourea gold(i) complex: mitochondrial permeability transition and respiratory deficit. Toxicol Res (Camb) 2018; 7:1081-1090. [PMID: 30542602 PMCID: PMC6240812 DOI: 10.1039/c8tx00169c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 08/29/2018] [Indexed: 12/20/2022] Open
Abstract
Gold(i) complexes have been widely used as antibacterial and antitumor agents because of their excellent biological activities. However, there are few reports on the study of gold(i) complexes at the subcellular level. Herein, we investigated the toxicity of a gold(i) complex (N,N'-disubstituted cyclic thiourea ligand) - AuTuCl - to isolated mitochondria via various methods. The results showed that AuTuCl induced mitochondrial swelling, elevated ROS generation and triggered collapse of the membrane potential, which indicated the induction of mitochondrial permeability transition (MPT). It also enhanced the permeability of H+ and K+ of the inner membrane and declined membrane fluidity, which might be the result of MPT. Moreover, AuTuCl impaired the mitochondrial respiratory chain and suppressed the activities of complexes II and IV in the respiratory chain. It also triggered the deficiency of ATP and the effusion of Cyt c, which were strictly related to respiration and apoptosis. These results indicated that AuTuCl severely affected the structure and function of mitochondria. It was proposed that MPT and impairment of the respiratory chain were responsible for the mitotoxicity of AuTuCl, thus causing energy deficiency and even apoptosis. This conceivable mechanism can serve as a clue for better understanding of the toxicology of AuTuCl.
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Affiliation(s)
- Bingqiong Yu
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
| | - Long Ma
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
| | - Jiancheng Jin
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
| | - Fenglei Jiang
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
| | - Gangcheng Zhou
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
| | - Kun Yan
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
| | - Yi Liu
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE) College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China . ; ; Tel: +8627-68753465
- College of Chemistry and Material Sciences , Guangxi Teachers Education University , Nanning 530001 , P. R. China
- Key Laboratory of Coal Conversion and New Carbon Materials of Hubei Province , College of Chemistry and Chemical Engineering , Wuhan University of Science and Technology , Wuhan 430081 , P. R. China
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6
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Morciano G, Preti D, Pedriali G, Aquila G, Missiroli S, Fantinati A, Caroccia N, Pacifico S, Bonora M, Talarico A, Morganti C, Rizzo P, Ferrari R, Wieckowski MR, Campo G, Giorgi C, Trapella C, Pinton P. Discovery of Novel 1,3,8-Triazaspiro[4.5]decane Derivatives That Target the c Subunit of F1/FO-Adenosine Triphosphate (ATP) Synthase for the Treatment of Reperfusion Damage in Myocardial Infarction. J Med Chem 2018; 61:7131-7143. [DOI: 10.1021/acs.jmedchem.8b00278] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Giampaolo Morciano
- Maria Pia Hospital, GVM Care & Research, 10132, Torino, Italy
- Maria Cecilia Hospital, GVM Care & Research, 48033, Cotignola, Ravenna, Italy
| | | | - Gaia Pedriali
- Maria Cecilia Hospital, GVM Care & Research, 48033, Cotignola, Ravenna, Italy
| | | | | | | | | | | | | | | | | | - Paola Rizzo
- Maria Cecilia Hospital, GVM Care & Research, 48033, Cotignola, Ravenna, Italy
| | - Roberto Ferrari
- Maria Cecilia Hospital, GVM Care & Research, 48033, Cotignola, Ravenna, Italy
- Cardiovascular Institute, Azienda Ospedaliera-Universitaria S. Anna, Cona, Ferrara 44121, Italy
| | - Mariusz R. Wieckowski
- Department of Biochemistry, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw 02-093, Poland
| | - Gianluca Campo
- Maria Cecilia Hospital, GVM Care & Research, 48033, Cotignola, Ravenna, Italy
- Cardiovascular Institute, Azienda Ospedaliera-Universitaria S. Anna, Cona, Ferrara 44121, Italy
| | | | | | - Paolo Pinton
- Maria Cecilia Hospital, GVM Care & Research, 48033, Cotignola, Ravenna, Italy
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He H, Huang W, Oo TL, Gu M, Zhan J, Wang A, He LF. Nitric oxide suppresses aluminum-induced programmed cell death in peanut ( Arachis hypoganea L.) root tips by improving mitochondrial physiological properties. Nitric Oxide 2018; 74:47-55. [DOI: 10.1016/j.niox.2018.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 01/08/2018] [Accepted: 01/14/2018] [Indexed: 10/18/2022]
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8
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Hosnedlova B, Kepinska M, Skalickova S, Fernandez C, Ruttkay-Nedecky B, Malevu TD, Sochor J, Baron M, Melcova M, Zidkova J, Kizek R. A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species-A Critical Review. Int J Mol Sci 2017; 18:E2209. [PMID: 29065468 PMCID: PMC5666889 DOI: 10.3390/ijms18102209] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/10/2017] [Accepted: 10/11/2017] [Indexed: 12/18/2022] Open
Abstract
Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.
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Affiliation(s)
- Bozena Hosnedlova
- Department of Viticulture and Enology, Faculty of Horticulture, Mendel University in Brno, Valtická 337, CZ-691 44 Lednice, Czech Republic.
| | - Marta Kepinska
- Department of Biomedical and Environmental Analyses, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland.
| | - Sylvie Skalickova
- Central Laboratory, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1946/1, 612 42 Brno, Czech Republic.
| | - Carlos Fernandez
- School of Pharmacy and Life Sciences, Robert Gordon University, Garthdee Road, Aberdeen AB107GJ, UK.
| | - Branislav Ruttkay-Nedecky
- Central Laboratory, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1946/1, 612 42 Brno, Czech Republic.
| | | | - Jiri Sochor
- Department of Viticulture and Enology, Faculty of Horticulture, Mendel University in Brno, Valtická 337, CZ-691 44 Lednice, Czech Republic.
| | - Mojmir Baron
- Department of Viticulture and Enology, Faculty of Horticulture, Mendel University in Brno, Valtická 337, CZ-691 44 Lednice, Czech Republic.
| | - Magdalena Melcova
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 166 28 Prague, Czech Republic.
| | - Jarmila Zidkova
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 166 28 Prague, Czech Republic.
| | - Rene Kizek
- Department of Biomedical and Environmental Analyses, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland.
- Central Laboratory, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences Brno, Palackeho 1946/1, 612 42 Brno, Czech Republic.
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Herrero E, Wellinger RE. Yeast as a model system to study metabolic impact of selenium compounds. MICROBIAL CELL 2015; 2:139-149. [PMID: 28357286 PMCID: PMC5349236 DOI: 10.15698/mic2015.05.200] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Inorganic Se forms such as selenate or selenite (the two more abundant forms in nature) can be toxic in Saccharomyces cerevisiae cells, which constitute an adequate model to study such toxicity at the molecular level and the functions participating in protection against Se compounds. Those Se forms enter the yeast cell through other oxyanion transporters. Once inside the cell, inorganic Se forms may be converted into selenide through a reductive pathway that in physiological conditions involves reduced glutathione with its consequent oxidation into diglutathione and alteration of the cellular redox buffering capacity. Selenide can subsequently be converted by molecular oxygen into elemental Se, with production of superoxide anions and other reactive oxygen species. Overall, these events result in DNA damage and dose-dependent reversible or irreversible protein oxidation, although additional oxidation of other cellular macromolecules cannot be discarded. Stress-adaptation pathways are essential for efficient Se detoxification, while activation of DNA damage checkpoint and repair pathways protects against Se-mediated genotoxicity. We propose that yeast may be used to improve our knowledge on the impact of Se on metal homeostasis, the identification of Se-targets at the DNA and protein levels, and to gain more insights into the mechanism of Se-mediated apoptosis.
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Affiliation(s)
- Enrique Herrero
- Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, IRBLleida, Rovira Roure 80, 25198 Lleida, Spain
| | - Ralf E Wellinger
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Universidad de Sevilla, 41092 Sevilla, Spain
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Xia CF, Lv L, Chen XY, Fu BQ, Lei KL, Qin CQ, Liu Y. Nd(III)-induced rice mitochondrial dysfunction investigated by spectroscopic and microscopic methods. J Membr Biol 2015; 248:319-26. [PMID: 25650179 PMCID: PMC4381042 DOI: 10.1007/s00232-015-9773-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 01/14/2015] [Indexed: 11/30/2022]
Abstract
The production capacity and yield of neodymium (Nd) in China have ranked the first in the world. Because of its unique biophysical and biochemical properties, Nd compounds have entered into the agricultural environment greatly to promote plant growth. Mitochondria play a crucial role in respiration and metabolism during the growth of plants. However, little is known about the mechanism by which Nd act at the mitochondrial level in plant cells. In this study, rice mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were examined to be important factors for mitochondria permeability transition pore (mPTP) opening induced by Nd(III). The protection of cyclosporin A (CsA) and dithiothreitol (DTT) could confirm that Nd(III) could trigger mPTP opening. Additionally, mitochondrial membrane breakdown observed by TEM and the release of cytochrome c (Cyt c) could also elucidate the mPTP opening from another point of view. At last, the study showed that Nd(III) could restrain the mitochondrial membrane lipid peroxide, so it might interact with anionic lipid too. This detection will be conductive to the safe application of Nd compounds in agriculture and food industry.
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Affiliation(s)
- Cai-Fen Xia
- School of Chemistry and Materials Science, Hubei Engineering University, Xiaogan, 432000, People's Republic of China
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Gao JL, Wu M, Wang X, Zhang YZ, Jiang FL, Liu Y, Dai J. Membrane permeability transition and dysfunction of rice mitochondria effected by Er(III). J Membr Biol 2014; 248:39-46. [PMID: 25249020 DOI: 10.1007/s00232-014-9730-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 09/11/2014] [Indexed: 11/27/2022]
Abstract
Herein, the biological effects of heavy rare earth ion Er(III) on rice mitochondria were comprehensively investigated mainly by spectroscopic methods. The experimental results demonstrated that Er(III) could lead to the swelling of rice mitochondria, collapse of mitochondrial transmembrane potential, decrease of membrane fluidity, promotion of H(+) permeability and suppression of K(+) permeability. These further indicated that Er(III) could induce the mitochondrial permeability transition (MPT) and the dysfunction of rice mitochondria. The ultra-structure change of mitochondria observed by transmission electron microscopy (TEM) also proved that Er(III) induced MPT. Moreover, the testing results of the protective effect of four different agents on mitochondrial swelling implied that the thiol chelation on the mitochondrial inner membrane was the main reason that caused the MPT.
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Affiliation(s)
- Jia-ling Gao
- Department of Chemistry, College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, Hubei, People's Republic of China,
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Selenite-mediated production of superoxide radical anions in A549 cancer cells is accompanied by a selective increase in SOD1 concentration, enhanced apoptosis and Se-Cu bonding. J Biol Inorg Chem 2014; 19:813-28. [PMID: 24535002 DOI: 10.1007/s00775-014-1113-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 01/23/2014] [Indexed: 12/29/2022]
Abstract
Selenite may exert its cytotoxic effects against cancer cells via the generation of reactive oxygen species (ROS). We investigated sources of, and the cellular response to, superoxide radical anion (O2 (·-)) generated in human A549 lung cancer cells after treatment with selenite. A temporal delay was observed between selenite treatment and increases in O2 (·-) production and biomarkers of apoptosis/necrosis, indicating that the reduction of selenite by the glutathione reductase/NADPH system (yielding O2 (·-)) is a minor contributor to ROS production under these conditions. By contrast, mitochondrial and NADPH oxidase O2 (·-) generation were the major contributors. Treatment with a ROS scavenger [poly(ethylene glycol)-conjugated superoxide dismutase (SOD) or sodium 4,5-dihydroxybenzene-1,3-disulfonate] 20 h after the initial selenite treatment inhibited both ROS generation and apoptosis determined at 24 h. In addition, SOD1 was selectively upregulated and its perinuclear cytoplasmic distribution was colocalised with the cellular distribution of selenium. Interestingly, messenger RNA for manganese superoxide dismutase, catalase, inducible haem oxygenase 1 and glutathione peroxidase either remained unchanged or showed a delayed response to selenite treatment. Colocalisation of Cu and Se in these cells (Weekley et al. in J. Am. Chem. Soc. 133:18272-18279, 2011) potentially results from the formation of a Cu-Se species, as indicated by Cu K-edge extended X-ray absorption fine structure spectra. Overall, SOD1 is upregulated in response to selenite-mediated ROS generation, and this likely leads to an accumulation of toxic hydrogen peroxide that is temporally related to decreased cancer cell viability. Increased expression of SOD1 gene/protein coupled with formation of a Cu-Se species may explain the colocalisation of Cu and Se observed in these cells.
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Xia CF, Zhao J, Jin JC, Yuan L, Chen XY, Peng W, Jiang FL, Qin CQ, Dai J, Liu Y. Ce(III)-induced rice mitochondrial permeability transition investigated by spectroscopic and microscopic studies. Biol Trace Elem Res 2013; 152:284-91. [PMID: 23417494 DOI: 10.1007/s12011-013-9621-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 01/24/2013] [Indexed: 10/27/2022]
Abstract
Cerium has been widely used as fertilizer and feed additives in agriculture, but it might finally impair human health by food chain accumulation with its dosage increased in environmental and crops samples. To resolve the conflict, we investigated the effects of Ce(III) on isolated rice mitochondrial permeability transition (MPT) by examining mitochondrial swelling, transmembrane potential, membrane fluidity with spectroscopy, and observing the mitochondrial ultrastructure, meanwhile, the interaction site(s) and mechanism between Ce(III) and mitochondria were also studied. The results showed that the low level of Ce(III) had little effect on rice MPT, however, the higher level of Ce(III) could induce rice MPT, and the thiol (-SH) groups of membrane proteins (defined as "S" site) matched by Ce(III)-triggered rice MPT pore opening.
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Affiliation(s)
- Cai-Fen Xia
- State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People's Republic of China
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Exploiting the Role of Resveratrol in Rat Mitochondrial Permeability Transition. J Membr Biol 2013; 246:365-73. [DOI: 10.1007/s00232-013-9540-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 03/22/2013] [Indexed: 01/03/2023]
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15
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Mitochondrial response in the apical and lateral flower buds of the Hanfu apple to cold stress during the dormancy stage. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.chnaes.2012.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Weekley CM, Harris HH. Which form is that? The importance of selenium speciation and metabolism in the prevention and treatment of disease. Chem Soc Rev 2013; 42:8870-94. [DOI: 10.1039/c3cs60272a] [Citation(s) in RCA: 371] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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17
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Mechanism(s) of Toxic Action of Zn and Selenite: A Study on AS-30D Hepatoma Cells and Isolated Mitochondria. Biochem Res Int 2011; 2011:387297. [PMID: 21860797 PMCID: PMC3154521 DOI: 10.1155/2011/387297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 06/06/2011] [Indexed: 02/05/2023] Open
Abstract
Mitochondria of AS-30D rat ascites hepatoma cells are found to be the main target for Zn2+ and sodium selenite (Na2SeO3). High [mu]M concentrations of Zn2+ or selenite were strongly cytotoxic, killing the AS-30D cells by both apoptotic and necrotic ways. Both Zn2+ and selenite produced strong changes in intracellular generation of reactive oxygen species (ROS) and the mitochondrial dysfunction via the mitochondrial electron transport chain (mtETC) disturbance, the membrane potential dissipation, and the mitochondrial permeability transition pore opening. The significant distinctions in toxic action of Zn2+ and selenite on AS-30D cells were found. Selenite induced a much higher intracellular ROS level (the early event) compared to Zn2+ but a lower membrane potential loss and a lower decrease of the uncoupled respiration rate of the cells, whereas the mtETC disturbance was the early and critical event in the mechanism of Zn2+ cytotoxicity. Sequences of events manifested in the mitochondrial dysfunction produced by the metal/metalloid under test are compared with those obtained earlier for Cd2+, Hg2+, and Cu2+ on the same model system.
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S-15176 and its methylated derivative suppress the CsA-insensitive mitochondrial permeability transition and subsequent cytochrome c release induced by silver ion, and show weak protonophoric activity. Mol Cell Biochem 2011; 358:45-51. [DOI: 10.1007/s11010-011-0919-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 06/07/2011] [Indexed: 10/18/2022]
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19
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Rigobello MP, Folda A, Citta A, Scutari G, Gandin V, Fernandes AP, Rundlöf AK, Marzano C, Björnstedt M, Bindoli A. Interaction of selenite and tellurite with thiol-dependent redox enzymes: Kinetics and mitochondrial implications. Free Radic Biol Med 2011; 50:1620-9. [PMID: 21397686 DOI: 10.1016/j.freeradbiomed.2011.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2010] [Revised: 02/17/2011] [Accepted: 03/04/2011] [Indexed: 12/13/2022]
Abstract
The interactions of selenite and tellurite with cytosolic and mitochondrial thioredoxin reductases (TrxR1 and TrxR2) and glutathione reductases (GR) from yeast and mammalian sources were explored. Both TrxR1 and TrxR2 act as selenite and tellurite reductases. Kinetic treatment shows that selenite has a greater affinity than tellurite with both TrxR1 and TrxR2. Considering both k(cat) and K(m), selenite shows a better catalytic efficiency than tellurite with TrxR1, whereas with TrxR2, the catalytic efficiency is similar for both chalcogens. Tellurite is a good substrate for GR, whereas selenite is almost completely ineffective. Selenite or tellurite determine a large mitochondrial permeability transition associated with thiol group oxidation. However, with increasing concentrations of both chalcogens, only about 25% of total thiols are oxidized. In isolated mitochondria, selenite or tellurite per se does not stimulate H₂O₂ production, which, however, is increased by the presence of auranofin. They also determine a large oxidation of mitochondrial pyridine nucleotides. In ovarian cancer cells both chalcogens decrease the mitochondrial membrane potential. These results indicate that selenite and tellurite, interacting with the thiol-dependent enzymes, alter the balance connecting pyridine nucleotides and thiol redox state, consequently leading to mitochondrial and cellular alterations essentially referable to a disulfide stress.
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Spectroscopic and Microscopic Studies on the Mechanisms of Mitochondrial Toxicity Induced by Different Concentrations of Cadmium. J Membr Biol 2011; 241:39-49. [DOI: 10.1007/s00232-011-9361-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 03/04/2011] [Indexed: 01/26/2023]
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21
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Isaev NK, Stelmashook EV, Dirnagl U, Plotnikov EY, Kuvshinova EA, Zorov DB. Mitochondrial free radical production induced by glucose deprivation in cerebellar granule neurons. BIOCHEMISTRY (MOSCOW) 2011; 73:149-55. [DOI: 10.1134/s0006297908020053] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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22
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ZHAN J, KOU RJ, LI CZ, HE HY, HE LF. Effects of Aluminum on Physiological Characteristics of Mitochondrial Membrane in Peanut Root Tips. ZUOWU XUEBAO 2009. [DOI: 10.3724/sp.j.1006.2009.01059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Yamada A, Yamamoto T, Yamazaki N, Yamashita K, Kataoka M, Nagata T, Terada H, Shinohara Y. Differential permeabilization effects of Ca2+ and valinomycin on the inner and outer mitochondrial membranes as revealed by proteomics analysis of proteins released from mitochondria. Mol Cell Proteomics 2009; 8:1265-77. [PMID: 19218587 DOI: 10.1074/mcp.m800377-mcp200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It is well established that cytochrome c is released from mitochondria when the permeability transition (PT) of this organelle is induced by Ca2+. Our previous study showed that valinomycin also caused the release of cytochrome c from mitochondria but without inducing this PT (Shinohara, Y., Almofti, M. R., Yamamoto, T., Ishida, T., Kita, F., Kanzaki, H., Ohnishi, M., Yamashita, K., Shimizu, S., and Terada, H. (2002) Permeability transition-independent release of mitochondrial cytochrome c induced by valinomycin. Eur. J. Biochem. 269, 5224-5230). These results indicate that cytochrome c may be released from mitochondria with or without the induction of PT. In the present study, we examined the protein species released from valinomycin- and Ca2+-treated mitochondria by LC-MS/MS analysis. As a result, the proteins located in the intermembrane space were found to be specifically released from valinomycin-treated mitochondria, whereas those in the intermembrane space and in the matrix were released from Ca2+-treated mitochondria. These results were confirmed by Western analysis. Furthermore to examine how the protein release occurred, we examined the correlation between the species of released proteins and those of the abundant proteins in mitochondria. Consequently most of the proteins released from mitochondria treated with either agent were highly expressed proteins in mitochondria, indicating that the release occurred not selectively but in a manner dependent on the concentration of the proteins. Based on these results, the permeabilization effects of Ca2+ and valinomycin on the inner and outer mitochondrial membranes are discussed.
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Affiliation(s)
- Akiko Yamada
- double daggerSchool of Dentistry, University of Tokushima, Kuramotocho-3, Tokushima 770-8504, Japan
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Skommer J, Wlodkowic D, Deptala A. Larger than life: Mitochondria and the Bcl-2 family. Leuk Res 2007; 31:277-86. [PMID: 16911824 DOI: 10.1016/j.leukres.2006.06.027] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2006] [Revised: 06/04/2006] [Accepted: 06/16/2006] [Indexed: 01/09/2023]
Abstract
The intrinsic pathway of apoptosis relies on mitochondrial membrane permeabilization, with Bcl-2 proteins serving as its master regulators. They form a complex network of interactions both within the family and with multiple cellular factors outside the family. The understanding of the processes that regulate mitochondrial breach, and mechanisms that direct the pro- and anti-apoptotic functions of Bcl-2 proteins, should assist the development of novel anticancer therapies. Thus, it is of no surprise that research in the field is gaining momentum. In this review we outline the current concepts on regulatory circuits governing mitochondrial rupture and action of Bcl-2 proteins during cell death, and how this burgeoning knowledge is being translated into the clinics with the hope to combat cancer.
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Affiliation(s)
- Joanna Skommer
- Department of Clinical Sciences, University of Kuopio, Harjulantie 1 C, 70211 Kuopio, Finland.
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25
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Tang R, Liu H, Wang T, Huang K. Mechanisms of selenium inhibition of cell apoptosis induced by oxysterols in rat vascular smooth muscle cells. Arch Biochem Biophys 2005; 441:16-24. [PMID: 16039982 DOI: 10.1016/j.abb.2005.06.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2005] [Revised: 05/18/2005] [Accepted: 06/13/2005] [Indexed: 10/25/2022]
Abstract
Our previous study reported that oxysterol cholestane-3beta,5 alpha, 6 beta-triol (Triol) induced vascular smooth muscle cells (VSMCs) apoptosis, which was inhibited by selenium pretreatment. To further investigate the mechanisms of the inhibition, the glutathione peroxidase (GPx) activity, the total antioxidant capacity (T-AOC), the total superoxide dismutase (SOD) activity, and the level of lipid peroxidation (the content of malondialdehyde, MDA) of VSMCs were measured, and fluidity of cell membrane, reactive oxygen species (ROS) level, the reduction of mitochondrial membrane potential (Delta psi(m)), and the intracellular Ca(2+) in single cell were detected using several fluorescence indicators. Meanwhile, the mRNA levels of c-myc, bcl-2, GPx, and thioredoxin reductase (TR) were measured by reverse transcriptase polymerase chain reaction (RT-PCR) analysis. The results showed that the decrease of GPx activity, T-AOC, SOD activity, the fluidity of cell membrane, the Delta psi(m), and the mRNA expression of c-myc, bcl-2, GPx, and TR of VSMCs and the increase of MDA, ROS generation, and intracellular Ca(2+), significantly induced by Triol (10 microM, 24h) were inhibited to a different extent, respectively, when cells were pretreated with sodium selenite (50 nM, 12 or 24h) before exposure to Triol. These effects were time dependent and enhanced with prolongation of the time of pretreatment. In conclusion, the results in the present work showed that the mechanism of selenium inhibition of cell apoptosis induced by oxysterols in rat VSMCs was related with the antioxidation of selenoproteins.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Cells, Cultured
- Cholestanols/pharmacology
- Drug Combinations
- Male
- Membrane Fluidity/drug effects
- Mitochondria/drug effects
- Mitochondria/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Rats
- Rats, Wistar
- Reactive Oxygen Species/metabolism
- Selenium/pharmacology
- Sterols/pharmacology
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Affiliation(s)
- Rong Tang
- Department of Chemistry, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
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26
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Wang H, Yang X, Zhang Z, Xu H. Both calcium and ROS as common signals mediate Na(2)SeO(3)-induced apoptosis in SW480 human colonic carcinoma cells. J Inorg Biochem 2004; 97:221-30. [PMID: 14512201 DOI: 10.1016/s0162-0134(03)00284-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recent studies have shown that reactive oxygen species (ROS) play a crucial role in Se-induced cell apoptosis. A number of studies have demonstrated that perturbed cellular calcium homeostasis has been implicated in apoptosis. The main objective of this study was to evaluate the role of Ca(2+) in Na(2)SeO(3)-induced apoptosis and the relationship between Ca(2+) and ROS in human colonic carcinoma cells SW480. When SW480 cells were exposed to 25-100 microM Na(2)SeO(3), both cell apoptosis and growth inhibition were observed by flow cytometric analysis and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Na(2)SeO(3) was able to induce increase of [Ca(2+)](i) and ROS production and disrupt mitochondrial membrane potential (Delta Psi m) in SW480 cells monitored by using a confocal laser scanning microscope. Ca(2+) channel inhibitor CoCl(2) and an intracellular Ca(2+) chelator o-phtalaldehyde, 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid acetoxymethyl ester (BAPTA) completely inhibited [Ca(2+)](i) increase, but catalase had no effect on Na(2)SeO(3)-induced increase of [Ca(2+)](i). BAPTA-AM, CoCl(2), and mitochondrial Ca(2+) uptake inhibitor ruthenium red blocked Delta Psi m dissipation. The increase of ROS was also suppressed by CoCl(2), BAPTA, ruthenium red, N-acetylcysteine and catalase, respectively. The mitochondrial uncoupler carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP) completely inhibited Na(2)SeO(3)-induced ROS increase. This showed that ROS increase is due to mitochondrial Ca(2+) overload. The Na(2)SeO(3)-induced apoptosis of SW480 cells was also inhibited by CoCl(2), BAPTA, ruthenium red, N-acetylcysteine, and catalase, respectively. The results mentioned above imply that both calcium and Ca(2+)-dependent ROS as a signal molecule mediate apoptosis induced by Na(2)SeO(3) in SW480 cells.
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Affiliation(s)
- Haitao Wang
- College of Pharmacy, Wuhan University, Wuhan 430072, China.
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27
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Belusko PB, Nakajima T, Azuma M, Shearer TR. Expression changes in mRNAs and mitochondrial damage in lens epithelial cells with selenite. Biochim Biophys Acta Gen Subj 2003; 1623:135-42. [PMID: 14572911 DOI: 10.1016/j.bbagen.2003.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An overdose of sodium selenite induces cataracts in young rats. The mid-stage events producing the cataract include calpain-induced hydrolysis and precipitation of lens proteins. Apoptosis in lens epithelial cells has been suggested as an initial event in selenite cataracts. Expression levels of two genes associated with apoptosis were altered in lens epithelial cells from selenite-injected rats. The purpose of the present experiment was to perform a more comprehensive search for changes in expression of mRNAs in lens epithelial cells in order to more fully delineate the early events in selenite-induced cataracts. Lens epithelial cells were harvested at 1 and 2 days after a single subcutaneous injection of sodium selenite (30 mumol/kg body weight) into 12-day-old rats. Gene expression was analyzed using a commercial DNA array (Rat Genome U34A GeneChip array, Affymetrix). Of approximately 8000 genes assayed by hybridization, 13 genes were decreased and 27 genes were increased in the rat lens epithelial cells after injection of selenite. Some of the up-regulated genes included apoptosis-related genes, and a majority of the down-regulated genes were mitochondrial genes. Previously observed changes in expression of EGR-1 mRNA were also confirmed. Changes in the expression patterns of mRNAs were also confirmed by RT-PCR. To determine the mechanism for damage of lens epithelial cells (alpha TN4 cell) by culture in selenite, leakage of cytochrome c from mitochondria was measured. Selenite caused significant leakage of cytochrome c into the cytosol of alpha TN4 cells. Our data suggested that the loss of integrity of lens epithelial cells by selenite might be caused by preferential down-regulation of mitochondrial RNAs, release of cytochrome c, and impaired mitochondrial function. Up-regulation of mRNAs involved in maintenance of DNA, regulation of metabolism, and induction of apoptosis may also play roles.
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Affiliation(s)
- P B Belusko
- Senju Laboratory of Ocular Sciences, Senju Pharmaceutical Co. Ltd., Beaverton, OR 97006, USA
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Liu H, Yuan L, Yang X, Wang K. La(3+), Gd(3+) and Yb(3+) induced changes in mitochondrial structure, membrane permeability, cytochrome c release and intracellular ROS level. Chem Biol Interact 2003; 146:27-37. [PMID: 12902150 DOI: 10.1016/s0009-2797(03)00072-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Lanthanides (Ln) were known to induce cell apoptosis, which might be the results of their effects on mitochondria (MT). This study was trying to clarify the role of MT and reactive oxygen species (ROS) in Ln-induced apoptosis. We found that micromolar or lower concentration of La(3+), Gd(3+) and Yb(3+) bound to MT and induced swelling of isolated MT; EGTA treatment can inhibit the process. In addition, La(3+), Gd(3+) and Yb(3+) increased the MT membrane fluidity and decreased the MT membrane potential (DeltaPsi(m)). All these were inferred to the results of MT permeability transition pore opening. Release of cytochrome c (Cyt-c) from the MT upon incubation with Ln ions was monitored by immunocytochemistry, however, Cyt-c release was observed only in the cytosol of cells. In parallel with these events, there was a higher level of ROS found in the cells exposed to Ln. It was proposed that Ln-induced apoptosis via the MT pathways and it was highly possible that ROS were involved in the mechanism.
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Affiliation(s)
- Huixue Liu
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China
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29
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Suzuki H, Yanaka A, Shibahara T, Matsui H, Nakahara A, Tanaka N, Muto H, Momoi T, Uchiyama Y. Ammonia-induced apoptosis is accelerated at higher pH in gastric surface mucous cells. Am J Physiol Gastrointest Liver Physiol 2002; 283:G986-95. [PMID: 12223359 DOI: 10.1152/ajpgi.00482.2001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastric luminal ammonia produced by Helicobacter pylori has been shown to cause gastric mucosal injury. This study was conducted to examine the mechanisms by which gastric luminal ammonia causes apoptosis of gastric epithelial cells. Monolayers of GSM06 cells, developed from murine gastric surface mucous cells, were cultured in the absence or presence of 10-30 mM NH(4)Cl at ambient pH of 5.0, 6.0, and 7.0. In the presence of luminal NH(4)Cl, GSM06 cells showed 1) cell shrinkage and nuclear chromatin condensation, 2) DNA fragmentation into oligonucleosomes, 3) leakage of cytochrome c into cytosolic fraction without affecting bax expression, and 4) increases in activity of caspases-3 and -9. These changes were accentuated when the cells were cultured at pH 7.0. In the absence of NH(4)Cl, none of these changes was detected at any pH examined. These results suggest that gastric luminal ammonia, at concentrations detected in H. pylori-infected subjects, induces apoptosis of gastric epithelial cells by release of cytochrome c from mitochondria, followed by activation of caspases-9 and -3, especially at higher ambient pH.
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Affiliation(s)
- Hideo Suzuki
- Department of Gastroenterology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki 305-8575, Japan
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