1
|
Tao L, Chiarelli MP, Pavlova S, Kolokythas A, Schwartz J, DeFrancesco J, Salameh B, Green SJ, Adami G. Enrichment of polycyclic aromatic hydrocarbon metabolizing microorganisms on the oral mucosa of tobacco users. PeerJ 2024; 12:e16626. [PMID: 38188172 PMCID: PMC10771095 DOI: 10.7717/peerj.16626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 11/16/2023] [Indexed: 01/09/2024] Open
Abstract
Certain soil microbes resist and metabolize polycyclic aromatic hydrocarbons (PAHs). The same is true for a subset of skin microbes. In the human mouth, oral microbes have the potential to oxidize tobacco PAHs, thereby increasing these chemicals' ability to cause cancer of adjacent epithelium. We hypothesized that we could identify, in smokers, the oral mucosal microbes that can metabolize PAH. We isolated bacteria and fungi that survived long-term in minimal media with PAHs as the sole carbon source, under aerobic conditions, from the oral mucosa in 17 of 26 smokers and two of 14 nonsmokers. Of bacteria genera that survived harsh PAH exposure in vitro, most were found at trace levels, except for Staphylococcus, Actinomyces, and Kingella, which were more abundant. Two PAH-resistant strains of Candida albicans (C. albicans) were isolated from smokers. C. albicans was a prime candidate to contribute to carcinogenesis in tobacco users as it is found orally at high levels in tobacco users on the mucosa, and some Candida species can metabolize PAHs. However, when C. albicans isolates were tested for metabolism of two model PAH substrates, pyrene and phenanthrene, they were not capable, suggesting they cannot metabolize PAH under the conditions used. In conclusion, evidence for large scale microbial degradation of tobacco PAHs under aerobic conditions on the oral mucosa remains lacking, though nonabundant PAH metabolizers are certainly present.
Collapse
Affiliation(s)
- Lin Tao
- Department of Oral Biology, College of Dentistry, University of Illinois Chicago, Chicago, IL, United States of America
| | - M Paul Chiarelli
- Department of Chemistry and Biochemistry, Loyola University of Chicago, Chicago, IL, United States of America
| | - Sylvia Pavlova
- Department of Oral Biology, College of Dentistry, University of Illinois Chicago, Chicago, IL, United States of America
| | - Antonia Kolokythas
- Department of Oral and Maxillofacial Surgery, Eastman Institute for Oral Health, University of Rochester, Rochester, NY, United States of America
| | - Joel Schwartz
- Oral Medicine and Diagnostic Sciences, University of Illinois Chicago, Chicago, IL, United States of America
| | - James DeFrancesco
- Forensic Science Program — Department of Criminal Justice, Loyola University of Chicago, Chicago, IL, United States of America
| | - Benjamin Salameh
- Oral Medicine and Diagnostic Sciences, University of Illinois Chicago, Chicago, IL, United States of America
| | - Stefan J. Green
- DNA Sequencing Core, Research Resources Center, University of Illinois Chicago, Chicago, IL, United States of America
| | - Guy Adami
- Oral Medicine and Diagnostic Sciences, University of Illinois Chicago, Chicago, IL, United States of America
| |
Collapse
|
2
|
Dephosphorylation of the pre-initiation complex is critical for origin firing. Mol Cell 2023; 83:12-25.e10. [PMID: 36543171 DOI: 10.1016/j.molcel.2022.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 08/13/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022]
Abstract
In eukaryotes, cyclin-dependent kinase (CDK) ensures that the genome is duplicated exactly once by inhibiting helicase loading factors before activating origin firing. CDK activates origin firing by phosphorylating two substrates, Sld2 and Sld3, forming a transient and limiting intermediate-the pre-initiation complex (pre-IC). Here, we show in the budding yeast Saccharomyces cerevisiae that the CDK phosphorylations of Sld3 and Sld2 are rapidly turned over during S phase by the PP2A and PP4 phosphatases. PP2ARts1 targets Sld3 specifically through an Rts1-interaction motif, and this targeted dephosphorylation is important for origin firing genome-wide, for formation of the pre-IC at origins and for ensuring that Sld3 is dephosphorylated in G1 phase. PP2ARts1 promotes replication in vitro, and we show that targeted Sld3 dephosphorylation is critical for viability. Together, these studies demonstrate that phosphatases enforce the correct ordering of replication factor phosphorylation and in addition to kinases are also key drivers of replication initiation.
Collapse
|
3
|
Ma X, Wu S. Oxygenated polycyclic aromatic hydrocarbons in food: toxicity, occurrence and potential sources. Crit Rev Food Sci Nutr 2022; 64:4882-4903. [PMID: 36384378 DOI: 10.1080/10408398.2022.2146652] [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] [Indexed: 11/18/2022]
Abstract
Oxygenated polycyclic aromatic hydrocarbons (OPAHs) are polycyclic aromatic hydrocarbons (PAHs) functionalized with at least one carbonyl group and are generally thought to be more toxic than PAHs. In this review, the physical-chemical properties, toxicity, occurrence, and potential sources of OPAHs in food were comprehensively discussed. The toxicities of 1,2-naphthoquinone, 1,4-naphthoquinone, 6H-benzo[cd]pyren-6-one, benzo[a]anthracene-7,12-quinone and 9,10-phenanthrenequinone were prominent among the OPAHs. Both 1,4-naphthoquinone and 1,2-naphthoquinone exhibited strong genotoxicity, cytotoxicity, and developmental toxicity. 6H-benzo[cd]pyren-6-one and benzo[a]anthracene-7,12-quinone showed high genotoxicity and cardiovascular toxicity. Although 9,10-phenanthrenequinone showed no genotoxicity, it exhibited almost the strongest cytotoxicity. For the majority of foods, the concentrations of OPAHs and PAHs were on the same order of magnitude. OPAHs tend to be positively correlated with the corresponding PAH concentrations in oil and fried food, while for barbequed food and seafood, no obvious correlation was found. In addition, 9-fluorenone, 9,10-anthraquinone, benzanthrone and 1,2-acenaphthenequinone had high abundance in food. Environmental pollution, food composition, storage conditions, heating methods, and other treatments influence the accumulation of OPAHs in food. Furthermore, oxygen and water played an important role in the transformation from PAHs to OPAHs. In short, this review guides the evaluation and further reduction of OPAH-related health risks in food.
Collapse
Affiliation(s)
- Xin Ma
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Shimin Wu
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
4
|
Baker's Yeast-Based Microbial Fuel Cell Mediated by 2-Methyl-1,4-Naphthoquinone. MEMBRANES 2021; 11:membranes11030182. [PMID: 33800926 PMCID: PMC8001437 DOI: 10.3390/membranes11030182] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 11/16/2022]
Abstract
Microbial fuel cell (MFC) efficiency depends on charge transfer capability from microbe to anode, and the application of suitable redox mediators is important in this area. In this study, yeast viability experiments were performed to determine the 2-methyl-1,4-naphthoquinone (menadione (MD)) influence on different yeast cell species (baker's yeast and Saccharomyces cerevisiae yeast cells). In addition, electrochemical measurements to investigate MFC performance and efficiency were carried out. This research revealed that baker's yeast cells were more resistant to dissolved MD, but the current density decreased when yeast solution concentration was incrementally increased in the same cell. The maximal calculated power of a designed baker's yeast-based MFC cell anode was 0.408 mW/m2 and this power output was registered at 24 mV. Simultaneously, the cell generated a 62-mV open circuit potential in the presence of 23 mM potassium ferricyanide and the absence of glucose and immobilized MD. The results only confirm that MD has strong potential to be applied to microbial fuel cells and that a two-redox-mediator-based system is suitable for application in microbial fuel cells.
Collapse
|
5
|
Rozene J, Morkvenaite-Vilkonciene I, Bruzaite I, Dzedzickis A, Ramanavicius A. Yeast-based microbial biofuel cell mediated by 9,10-phenantrenequinone. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.137918] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
6
|
Raj A, Nachiappan V. Hydroquinone exposure accumulates neutral lipid by the activation of CDP-DAG pathway in Saccharomyces cerevisiae. Toxicol Res (Camb) 2021; 10:354-367. [PMID: 33884185 DOI: 10.1093/toxres/tfab005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 01/09/2021] [Accepted: 01/17/2021] [Indexed: 11/13/2022] Open
Abstract
Benzene metabolites (HQ and BQ) are toxic compounds and their presence in human cause alteration in cellular respiration and kidney damage. In the current study, Saccharomyces cerevisiae has been used as a model organism and acute exposure of hydroquinone (HQ) decreased cell growth and increased reactive oxygen species (ROS). The expression of apoptosis regulatory genes (YCA1, NUC1, YSP1 and AIF1) were increased with HQ exposure in the wild-type cells. HQ exposure in the wild-type cells altered both the phospholipid and neutral lipid levels. Phosphatidylcholine is a vital membrane lipid that has a vital role in membrane biogenesis and was increased significantly with HQ. The neutral lipid results were supported with lipid droplets data and mRNA expression study. The phospholipid knockouts (Kennedy pathway) accumulated neutral lipids via the CDP-DAG (cytidine-diphosphate-diacylglycerol) pathway genes both in the presence and absence of HQ.
Collapse
Affiliation(s)
- Abhishek Raj
- Biomembrane Lab, Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| | - Vasanthi Nachiappan
- Biomembrane Lab, Department of Biochemistry, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu, India
| |
Collapse
|
7
|
Tikhomirova AA, Tcyrulnikov NA, Wilson RM. Synthesis, characterization, DNA binding and cleaving properties of photochemically activated phenanthrene dihydrodioxin. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.04.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
8
|
Cytotoxicity of Air Pollutant 9,10-Phenanthrenequinone: Role of Reactive Oxygen Species and Redox Signaling. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9523968. [PMID: 29984252 PMCID: PMC6015725 DOI: 10.1155/2018/9523968] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 04/30/2018] [Indexed: 01/22/2023]
Abstract
Atmospheric pollution has been a principal topic recently in the scientific and political community due to its role and impact on human and ecological health. 9,10-phenanthrenequinone (9,10-PQ) is a quinone molecule found in air pollution abundantly in the diesel exhaust particles (DEP). This compound has studied extensively and has been shown to develop cytotoxic effects both in vitro and in vivo. 9, 10-PQ has been proposed to play a critical role in the development of cytotoxicity via generation of reactive oxygen species (ROS) through redox cycling. This compound also reduces expression of glutathione (GSH), which is critical in Phase II detoxification reactions. Understanding the underlying cellular mechanisms involved in cytotoxicity can allow for the development of therapeutics designed to target specific molecules significantly involved in the 9,10-PQ-induced ROS toxicity. This review highlights the developments in the understanding of the cytotoxic effects of 9, 10-PQ with special emphasis on the possible mechanisms involved.
Collapse
|
9
|
Scanning electrochemical microscopy based evaluation of influence of pH on bioelectrochemical activity of yeast cells − Saccharomyces cerevisiae. Colloids Surf B Biointerfaces 2017; 149:1-6. [DOI: 10.1016/j.colsurfb.2016.09.039] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 09/23/2016] [Accepted: 09/26/2016] [Indexed: 11/19/2022]
|
10
|
Shang Y, Zhang L, Jiang Y, Li Y, Lu P. Airborne quinones induce cytotoxicity and DNA damage in human lung epithelial A549 cells: the role of reactive oxygen species. CHEMOSPHERE 2014; 100:42-49. [PMID: 24480427 DOI: 10.1016/j.chemosphere.2013.12.079] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/13/2013] [Accepted: 12/20/2013] [Indexed: 06/03/2023]
Abstract
Ambient particulate matter (PM) is associated with adverse health effects. Quinones present in PM are hypothesized to contribute to these harmful effects through the generation of reactive oxygen species (ROS). However, whether the ROS induced by quinones is involved in mediating DNA damage as well as other biological responses in pulmonary cells is less well known. In this study, the toxic effects of five typical airborne quinones, including 1,2-naphthoquinone, 2-methylanthraquinone, 9,10-phenanthrenequinone, 2-methyl-1,4-naphthoquinone, and acenaphthenequinone, on cytotoxicity, DNA damage, intracellular calcium homeostasis, and ROS generation, were studied in human lung epithelial A549 cells. An antioxidant N-acetylcysteine (NAC) was used to examine the involvement of ROS in adverse biological responses induced by quinones. The quinones caused a concentration-dependent viability decrease, cellular LDH release, DNA damage, and ROS production in A549 cells. 1,2-Naphthoquinone, but not the other four quinones, increased intracellular calcium (Ca(2+)) levels in a dose-dependent manner. These toxic effects were abolished by administration of NAC, suggesting that ROS played a key role in the observed toxic effects of quinones in A549 cells. These results emphasize the importance of quinones in PM on the adverse health effects of PMs, which has been underestimated in the past few years, and highlight the need, when evaluating the effects on health and exposure management, to always consider their qualitative chemical compositions in addition to the size and concentration of PMs.
Collapse
Affiliation(s)
- Yu Shang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Ling Zhang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yuting Jiang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yi Li
- Chinese Academy of Meteorological Sciences, Beijing 100081, China.
| | - Ping Lu
- Center for Spatial Information Science and Sustainable Development Applications, College of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, China
| |
Collapse
|
11
|
Huang M, Zhang L, Mesaros C, Zhang S, Blaha MA, Blair IA, Penning TM. Metabolism of a representative oxygenated polycyclic aromatic hydrocarbon (PAH) phenanthrene-9,10-quinone in human hepatoma (HepG2) cells. Chem Res Toxicol 2014; 27:852-63. [PMID: 24646012 PMCID: PMC4028327 DOI: 10.1021/tx500031p] [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] [Indexed: 11/28/2022]
Abstract
![]()
Exposure
to polycyclic aromatic hydrocarbons (PAHs) in the food
chain is the major human health hazard associated with the Deepwater
Horizon oil spill. Phenanthrene is a representative PAH present in
crude oil, and it undergoes biological transformation, photooxidation,
and chemical oxidation to produce its signature oxygenated derivative,
phenanthrene-9,10-quinone. We report the downstream metabolic fate
of phenanthrene-9,10-quinone in HepG2 cells. The structures of the
metabolites were identified by HPLC–UV–fluorescence
detection and LC–MS/MS. O-mono-Glucuronosyl-phenanthrene-9,10-catechol
was identified, as reported previously. A novel bis-conjugate, O-mono-methyl-O-mono-sulfonated-phenanthrene-9,10-catechol,
was discovered for the first time, and evidence for both of its precursor
mono conjugates was obtained. The identities of these four metabolites
were unequivocally validated by comparison to authentic enzymatically
synthesized standards. Evidence was also obtained for a minor metabolic
pathway of phenanthrene-9,10-quinone involving bis-hydroxylation followed
by O-mono-sulfonation. The identification of 9,10-catechol
conjugates supports metabolic detoxification of phenanthrene-9,10-quinone
through interception of redox cycling by UGT, COMT, and SULT isozymes
and indicates the possible use of phenanthrene-9,10-catechol conjugates
as biomarkers of human exposure to oxygenated PAH.
Collapse
Affiliation(s)
- Meng Huang
- Center of Excellence in Environmental Toxicology and ‡Center for Cancer Pharmacology, Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6160, United States
| | | | | | | | | | | | | |
Collapse
|
12
|
Kanaly RA, Hamamura N. 9,10-Phenanthrenedione biodegradation by a soil bacterium and identification of transformation products by LC/ESI-MS/MS. CHEMOSPHERE 2013; 92:1442-1449. [PMID: 23611246 DOI: 10.1016/j.chemosphere.2013.03.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/18/2013] [Accepted: 03/19/2013] [Indexed: 06/02/2023]
Abstract
Transformation of 9,10-phenanthrenedione, a cytotoxic derivative of phenanthrene, was shown to occur by a soil bacterium belonging to the genus Sphingobium. Phenanthrene-grown cells of this strain were exposed to 50mgL(-1) 9,10-phenanthrenedione in liquid cultures, extracted, and extracts were analyzed by liquid chromatography electrospray ionization mass spectrometry in negative ionization mode. Full scan analyses of exposed cells over the range from m/z 50 to m/z 500 were compared to abiotic and biotic controls. Product and precursor ion scan mode analyses indicated that at least three aromatic ring-cleavage transformation products of 9,10-phenanthrenedione were present and structures for these products, corresponding to [M-H](-)=271, [M-H](-)=241, and [M-H](-)=339 were proposed to be 4-(1-hydroxy-3,4-dioxo-2-naphthyl)-2-oxo-but-3-enoic acid, 2,2'-diphenic acid and 2-[(6-carboxy-2,3-dihydroxy-phenyl)-hydroxy-methyl]-5-oxo-hex-3-enedioic acid. The identity of 2,2'-diphenic acid was confirmed by comparison to an authentic standard and when the strain was exposed to 50mgL(-1) 2,2'-diphenic acid in separate assays, a transformation product with a similar mass spectrum as 9,10-phenanthrenedione-derived [M-H](-)=339 was revealed. Based upon these results, pathways for the transformation of 9,10-phenanthrenedione by strain KK22 were proposed. Strain KK22 appeared unable to use 9,10-phenanthrenedione as a growth substrate under these conditions. This is the first report of potential biotransformation pathways of 9,10-phenanthrenedione by a bacterium.
Collapse
Affiliation(s)
- Robert A Kanaly
- Department of Genome System Science, Faculty of Bionanosciences, Yokohama City University, Yokohama 236-0027, Japan.
| | | |
Collapse
|
13
|
Toyooka T, Shinmen T, Aarts JMMJG, Ibuki Y. Dual effects of N-acetyl-L-cysteine dependent on NQO1 activity: suppressive or promotive of 9,10-phenanthrenequinone-induced toxicity. Toxicol Appl Pharmacol 2012; 264:404-12. [PMID: 22925602 DOI: 10.1016/j.taap.2012.08.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 08/13/2012] [Accepted: 08/18/2012] [Indexed: 01/10/2023]
Abstract
A typical antioxidant, N-acetyl-L-cysteine (NAC) generally protects cells from oxidative damage induced by reactive oxygen species (ROS). 9,10-Phenanthrenequinone (9,10-PQ), a major quinone in diesel exhaust particles, produces ROS in redox cycling following two-electron reduction by NAD(P)H:quinone oxidoreductase 1 (NQO1), which has been considered as a cause of its cyto- and genotoxicity. In this study, we show that NAC unexpectedly augments the toxicity of 9,10-PQ in cells with low NQO1 activity. In four human skin cell lines, the expression and the activity of NQO1 were lower than in human adenocarcinoma cell lines, A549 and MCF7. In the skin cells, the cytotoxicity of 9,10-PQ was significantly enhanced by addition of NAC. The formation of DNA double strand breaks accompanying phosphorylation of histone H2AX, was also remarkably augmented. On the other hand, the cyto- and genotoxicity were suppressed by addition of NAC in the adenocarcinoma cells. Two contrasting experiments: overexpression of NQO1 in CHO-K1 cells which originally expressed low NQO1 levels, and knock-down of NQO1 in the adenocarcinoma cell line A549 by transfection of RNAi, also showed that NAC suppressed 9,10-PQ-induced toxicity in cell lines expressing high NQO1 activity and enhanced it in cell lines with low NQO1 activity. The results suggested that dual effects of NAC on the cyto- and genotoxicity of 9,10-PQ were dependent on tissue-specific NQO1 activity.
Collapse
Affiliation(s)
- Tatsushi Toyooka
- Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan
| | | | | | | |
Collapse
|
14
|
Gurbani D, Kukshal V, Laubenthal J, Kumar A, Pandey A, Tripathi S, Arora A, Jain SK, Ramachandran R, Anderson D, Dhawan A. Mechanism of inhibition of the ATPase domain of human topoisomerase IIα by 1,4-benzoquinone, 1,2-naphthoquinone, 1,4-naphthoquinone, and 9,10-phenanthroquinone. Toxicol Sci 2012; 126:372-90. [PMID: 22218491 DOI: 10.1093/toxsci/kfr345] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The inhibition of human topoisomerase IIα (Hu-TopoIIα), a major enzyme involved in maintaining DNA topology, repair, and chromosome condensation/decondensation results in loss of genomic integrity. In the present study, the inhibition of ATPase domain of Hu-TopoIIα as a possible mechanism of genotoxicity of 1,4-benzoquinone (BQ), hydroquinone (HQ), naphthoquinone (1,2-NQ and 1,4-NQ), and 9,10-phenanthroquinone (9,10-PQ) was investigated. In silico modeling predicted that 1,4-BQ, 1,2-NQ, 1,4-NQ, and 9,10-PQ could interact with Ser-148, Ser-149, Asn-150, and Asn-91 residues of the ATPase domain of Hu-TopoIIα. Biochemical inhibition assays with the purified ATPase domain of Hu-TopoIIα revealed that 1,4-BQ is the most potent inhibitor followed by 1,4-NQ > 1,2-NQ > 9,10-PQ > HQ. Ligand-binding studies using isothermal titration calorimetry revealed that 1,4-BQ, HQ, 1,4-NQ, 1,2-NQ, and 9,10-PQ enter into four sequentially binding site models inside the domain. 1,4-BQ exhibited the strongest binding, followed by 1,4-NQ > 1,2-NQ > 9,10-PQ > HQ, as revealed by their average K(d) values. The cellular fate of such inhibition was further evidenced by an increase in the number of Hu-TopoIIα-DNA cleavage complexes in the human lung epithelial cells (BEAS-2B) using trapped in agarose DNA immunostaining (TARDIS) assay, which utilizes antibody specific for Hu-TopoIIα. Furthermore, the increase in γ-H2A.X levels quantitated by flow cytometry and visualized by immunofluorescence microscopy illustrated that accumulation of DNA double-strand breaks inside the cells can be attributed to the inhibition of Hu-TopoIIα. These findings collectively suggest that 1,4-BQ, 1,2-NQ, 1,4-NQ, and 9,10-PQ inhibit the ATPase domain and potentially result in Hu-TopoIIα-mediated clastogenic and leukemogenic events.
Collapse
Affiliation(s)
- Deepak Gurbani
- Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Lucknow-226001, Uttar Pradesh, India
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Xu C, Wang J, Gao Y, Lin H, Du L, Yang S, Long S, She Z, Cai X, Zhou S, Lu Y. The anthracenedione compound bostrycin induces mitochondria-mediated apoptosis in the yeast Saccharomyces cerevisiae. FEMS Yeast Res 2010; 10:297-308. [PMID: 20345898 DOI: 10.1111/j.1567-1364.2010.00615.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Bostrycin is an anthracenedione with phytotoxic and antibacterial activity that belongs to the large family of quinones. We have isolated bostrycin from the secondary metabolites of a mangrove endophytic fungus, no. 1403, collected from the South China Sea. Using the yeast Saccharomyces cerevisiae as a model, we show that bostrycin inhibits cell proliferation by blocking the cell cycle at G1 phase and ultimately leads to cell death in a time- and dose-dependent manner. Bostrycin-induced lethal cytotoxicity is accompanied with increased levels of intracellular reactive oxygen species and hallmarks of apoptosis such as chromatin condensation, DNA fragmentation and externalization of phosphatidylserine. We further show that bostrycin decreases mitochondrial membrane electric potential and causes mitochondrial destruction during the progression of cell death. Bostrycin-induced cell death was promoted in YCA1 null yeast strain but was partially rescued in AIF1 null mutant both in fermentative and respiratory media, strongly indicating that bostrycin induces apoptosis in yeast cells through a mitochondria-mediated but caspase-independent pathway.
Collapse
Affiliation(s)
- Chunling Xu
- State Key Laboratory of Biocontrol, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Current awareness on yeast. Yeast 2008. [DOI: 10.1002/yea.1559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|