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Babayan N, Tadevosyan G, Khondkaryan L, Grigoryan R, Sarkisyan N, Haroutiounian R, Stopper H. Ochratoxin A induces global DNA hypomethylation and oxidative stress in neuronal cells in vitro. Mycotoxin Res 2019; 36:73-81. [PMID: 31441013 DOI: 10.1007/s12550-019-00370-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 08/07/2019] [Accepted: 08/13/2019] [Indexed: 12/24/2022]
Abstract
Recently, it was reported that ochratoxin A (OTA) mycotoxin, produced by a number of Aspergillus and Penicillium fungal species, may cause neuropsychological impairment or mental and emotional disorders but the mechanism of neurotoxicity remains unknown. Adverse effects of OTA in human (SHSY5Y) and mouse (HT22) neuronal cell lines were studied in vitro. OTA was found to be non-cytotoxic in both cell lines at concentrations 2.5-30 μmol/l, which are above the levels reported for human and animal plasma. OTA led to slightly elevated chromosomal instability in HT22 cells at concentrations of 15-30 μmol/l after 48 h, while in SHSY5Y cells, no evidence for genotoxic effects was observed at concentrations of 2.5-30 μmol/l. OTA treatment at 10 μmol/l resulted in elevated levels of unmethylated cytosines in CpG dinucleotides (up to 1.4-fold), elevated levels of intracellular reactive oxygen species (up to 1.6-fold), and in elevated levels of oxidized DNA purines (up to 2.2-fold) in both cell lines. Detected global DNA hypomethylation and oxidative stress were found to be reversible in 96 h and 24-72 h, respectively. In general, the observed pattern of OTA-induced effects in both cell lines was similar, but HT22 cells exhibited higher sensitivity, as well as better repair capacity in response to OTA toxicity. In conclusion, the results suggest that oxidative stress and epigenetic changes are directly involved in OTA-induced neurotoxicity, while cytotoxicity and genotoxicity cannot be considered as primary cause of toxicity in neuronal cells in vitro.
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Affiliation(s)
- Nelly Babayan
- Institute of Molecular Biology, National Academy of Sciences of Armenia, Hasratyan 7, 0014, Yerevan, Armenia. .,Yerevan State University, A. Manoogian 1, 0025, Yerevan, Armenia.
| | - Gohar Tadevosyan
- Institute of Molecular Biology, National Academy of Sciences of Armenia, Hasratyan 7, 0014, Yerevan, Armenia
| | - Lusine Khondkaryan
- Institute of Molecular Biology, National Academy of Sciences of Armenia, Hasratyan 7, 0014, Yerevan, Armenia
| | - Ruzanna Grigoryan
- Institute of Molecular Biology, National Academy of Sciences of Armenia, Hasratyan 7, 0014, Yerevan, Armenia
| | - Natalya Sarkisyan
- Institute of Molecular Biology, National Academy of Sciences of Armenia, Hasratyan 7, 0014, Yerevan, Armenia
| | | | - Helga Stopper
- Institute of Pharmacology and Toxicology, University of Wuerzburg, Versbacher 9, 997078, Wuerzburg, Germany
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Wang F, Yang QW, Zhao WJ, Du QY, Chang ZJ. Effects of short-time exposure to atrazine on miRNA expression profiles in the gonad of common carp (Cyprinus carpio). BMC Genomics 2019; 20:587. [PMID: 31315571 PMCID: PMC6636164 DOI: 10.1186/s12864-019-5896-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 06/11/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Atrazine is widely used in agriculture and is a known endocrine disrupting chemical. Atrazine can seep into the water body through surface, posing a potential threat to the aquatic ecological environment and human drinking water source. In vertebrate, studies have shown that it can affect reproduction and development seriously, but its molecular mechanism for aquatic animals is unknown. Aquaculture is very common in China, especially common carp, whose females grow faster than males. However, the effects of atrazine on the reproduction of carp, especially miRNA, have not been investigated. RESULTS In this study, common carp (Cyprinus carpio) at two key developmental stages were exposed to atrazine in vitro. Sex ratio was observed to analyze the effect of atrazine on the sex. MiRNA expression profiles were analysed to identify miRNAs related to gonad development and to reveal the atrazine mechanisms interfering with gonad differentiation. The results showed that the sex ratio was biased towards females. Atrazine exposure caused significant alteration of multiple miRNAs. Predicted targets of differently-expressed miRNAs were involved in many reproductive biology signalling pathways. CONCLUSIONS Our results indicate that atrazine promoted the expression of female-biased genes by decreasing miRNAs in primordial gonad. In addition, our results indicate that atrazine can up-regulate aromatase expression through miRNAs, which supports the hypothesis that atrazine has endocrine-disrupting activity by altering the gene expression profile of the Hypothalamus-Pituitary-Gonad axis through its corresponding miRNAs.
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Affiliation(s)
- Fang Wang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Qian-Wen Yang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Wen-Jie Zhao
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Qi-Yan Du
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Zhong-Jie Chang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China.
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53
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Turner A. Heavy Metals in the Glass and Enamels of Consumer Container Bottles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8398-8404. [PMID: 31185163 DOI: 10.1021/acs.est.9b01726] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The glass and enameled decorations of bottles of alcoholic beverages sourced from retailers in the U.K. were analyzed by X-ray fluorescence spectrometry for various heavy metals. In the glass substrate, lead, cadmium, and chromium were present at concentrations up to about 1100, 1100, and 3000 μg g-1, respectively, but their environmental and health risks are deemed to be low significance. Of more concern from an environmental and, potentially, occupational exposure perspective are the concentrations and mobilities of Pb and Cd in the enamels of many bottles. Thus, Pb concentrations up to about 100000 μg g-1 were found on the décor of various wine bottles and a beer bottle, and Cd concentrations of up to 20000 μg g-1 were measured in the decorated regions on a range of spirits, beer, and wine bottles. Moreover, maximum concentrations that leached from enameled glass fragments according to a standard test that simulates water and other liquids percolating through a landfill were about 1200 and 3200 μg L-1 for Pb and Cd, respectively, with several fragments exceeding the U.S. Model Toxins in Packaging Legislation and, therefore, defined as "hazardous". Given that safer decorative alternatives are available and that a precautionary principle should be adopted for toxic heavy metals, the pervasive use of Pb and Cd in the enamels of consumer bottles is brought into question.
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Affiliation(s)
- Andrew Turner
- School of Geography, Earth and Environmental Sciences , University of Plymouth , Drake Circus , Plymouth PL4 8AA U.K
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Xiong J, Yuan BF, Feng YQ. Mass Spectrometry for Investigating the Effects of Toxic Metals on Nucleic Acid Modifications. Chem Res Toxicol 2019; 32:808-819. [PMID: 30920205 DOI: 10.1021/acs.chemrestox.9b00042] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The extensive use of toxic metals in industry and agriculture leads to their wide distribution in the environment, which raises critical concerns over their toxic effects on human health. Many toxic metals are reported to be mildly mutagenic or non-mutagenic, indicating that genetic-based mechanisms may not be primarily responsible for toxic metal-induced carcinogenesis. Increasing evidence has demonstrated that exposure to toxic metals can alter epigenetic modifications, which may lead to the dysregulation of gene expression and disease susceptibility. It is now becoming clear that a full understanding of the effects of toxic metals on cellular toxicity and carcinogenesis will need to consider both genetic- and epigenetic-based mechanisms. Uncovering the effects of toxic metals on epigenetic modifications in nucleic acids relies on the detection and quantification of these modifications. Mass spectrometry (MS)-based methods for deciphering epigenetic modifications have substantially advanced over the past decade, and they are now becoming widely used and essential tools for evaluating the effects of toxic metals on nucleic acid modifications. This Review provides an overview of MS-based methods for analysis of nucleic acid modifications. In addition, we also review recent advances in understanding the effects of exposure to toxic metals on nucleic acid modifications.
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Affiliation(s)
- Jun Xiong
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry , Wuhan University , Wuhan 430072 , P.R. China
| | - Bi-Feng Yuan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry , Wuhan University , Wuhan 430072 , P.R. China
| | - Yu-Qi Feng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry , Wuhan University , Wuhan 430072 , P.R. China
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Khan F, Momtaz S, Abdollahi M. The relationship between mercury exposure and epigenetic alterations regarding human health, risk assessment and diagnostic strategies. J Trace Elem Med Biol 2019; 52:37-47. [PMID: 30732897 DOI: 10.1016/j.jtemb.2018.11.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 11/08/2018] [Accepted: 11/11/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Exposure to the environmental toxicants poses a serious threat to human health. The extent of exposure and the development of diseases are interrelated with each other. Chronic exposure to mercury (Hg) increases the risk of developing serious human disorders from embryo to adulthood. OBJECTIVES The purpose of this review is to highlight the most common human disorders induced by Hg exposure on the basis of epigenetic mechanisms. A growing body of evidence shows that Hg exposure leads to alterations in the epigenetic markers. METHODS We performed an organized search of the available literature using PubMed, Google Scholar, Medline, Reaxys, EMBASE and Scopus databases. All the relevant citations, including research and review articles in English were evaluated. The search terms included mercury, Hg, epigenetics, epigenetic alterations, DNA methylation, histone modifications, microRNAs (miRNAs), and risk assessment. RESULTS Data on human toxicity due to Hg exposure shows broad variations in terms of chemical nature, doses, and the rate of exposure. Hg consumption either via foods or environmental sources may create deleterious health effects on various physiological systems at least partially through an epigenetic mechanism. CONCLUSION Hg exposure could trigger epigenetic alterations, hence leading to various human disorders including reduced newborn cerebellum size, adverse behavioral outcomes, atherosclerosis and myocardial infarction. Similarly, in adults, occupational Hg exposure has been associated with an increased risk of autoimmunity. It has been revealed that miRNAs in the woman's cervix are a novel responder to maternal Hg exposure during pregnancy. Hg-induced epigenetic alterations analysis of kidney tissues showed a significant interruption in renal function. DNA methylation and histone post-translation modifications are predominant types of Hg epigenetic alterations.
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Affiliation(s)
- Fazlullah Khan
- Toxicology and Diseases Group, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences (TUMS), Tehran, Iran; Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeideh Momtaz
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, Karaj, Iran; Toxicology and Diseases Group, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Mohammad Abdollahi
- Toxicology and Diseases Group, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences (TUMS), Tehran, Iran; Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
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56
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Roy Choudhury S. Genome-wide alterations of epigenomic landscape in plants by engineered nanomaterial toxicants. COMPREHENSIVE ANALYTICAL CHEMISTRY 2019. [DOI: 10.1016/bs.coac.2019.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Rathod J, Tu HP, Chang YI, Chu YH, Tseng YY, Jean JS, Wu WS. YARG: A repository for arsenic-related genes in yeast. PLoS One 2018; 13:e0201204. [PMID: 30048518 PMCID: PMC6062094 DOI: 10.1371/journal.pone.0201204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 07/10/2018] [Indexed: 11/30/2022] Open
Abstract
Arsenic is a toxic metalloid. Moderate levels of arsenic exposure from drinking water can cause various human health problems such as skin lesions, circulatory disorders and cancers. Thus, arsenic toxicity is a key focus area for environmental and toxicological investigations. Many arsenic-related genes in yeast have been identified by experimental strategies such as phenotypic screening and transcriptional profiling. These identified arsenic-related genes are valuable information for studying arsenic toxicity. However, the literature about these identified arsenic-related genes is widely dispersed and cannot be easily acquired by researchers. This prompts us to develop YARG (Yeast Arsenic-Related Genes) database, which comprehensively collects 3396 arsenic-related genes in the literature. For each arsenic-related gene, the number and types of experimental evidence (phenotypic screening and/or transcriptional profiling) are provided. Users can use both search and browse modes to query arsenic-related genes in YARG. We used two case studies to show that YARG can return biologically meaningful arsenic-related information for the query gene(s). We believe that YARG is a useful resource for arsenic toxicity research. YARG is available at http://cosbi4.ee.ncku.edu.tw/YARG/.
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Affiliation(s)
- Jagat Rathod
- Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Hao-Ping Tu
- Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Yung-I Chang
- Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Han Chu
- Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Yan-Yuan Tseng
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Jiin-Shuh Jean
- Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Sheng Wu
- Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan
- * E-mail:
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58
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Pamphlett R, Kum Jew S. Inorganic mercury in human astrocytes, oligodendrocytes, corticomotoneurons and the locus ceruleus: implications for multiple sclerosis, neurodegenerative disorders and gliomas. Biometals 2018; 31:807-819. [PMID: 29959651 PMCID: PMC6133182 DOI: 10.1007/s10534-018-0124-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/21/2018] [Indexed: 12/11/2022]
Abstract
Neurotoxic metals have been implicated in the pathogenesis of multiple sclerosis, neurodegenerative disorders and brain tumours but studies of the location of heavy metals in human brains are rare. In a man who injected himself with metallic mercury the cellular location of mercury in his brain was studied after 5 months of continuous exposure to inorganic mercury arising from metallic mercury deposits in his organs. Paraffin sections from the primary motor and sensory cortices and the locus ceruleus in the pons were stained with autometallography to detect inorganic mercury and combined with glial fibrillary acidic protein immunohistochemistry to identify astrocytes. Inorganic mercury was found in grey matter subpial, interlaminar, protoplasmic and varicose astrocytes, white matter fibrous astrocytes, grey but not white matter oligodendrocytes, corticomotoneurons and some locus ceruleus neurons. In summary, inorganic mercury is taken up by five types of human brain astrocytes, as well as by cortical oligodendrocytes, corticomotoneurons and locus ceruleus neurons. Mercury can induce oxidative stress, stimulate autoimmunity and damage DNA, mitochondria and lipid membranes, so its location in these CNS cells suggests it could play a role in the pathogenesis of multiple sclerosis, neurodegenerative conditions such as Alzheimer's disease and amyotrophic lateral sclerosis, and glial tumours.
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Affiliation(s)
- Roger Pamphlett
- Discipline of Pathology, The University of Sydney, Camperdown, Australia. .,Discipline of Pathology, Brain and Mind Centre, The University of Sydney and Department of Neuropathology, Royal Prince Alfred Hospital, 94 Mallett St, Camperdown, NSW, 2050, Australia.
| | - Stephen Kum Jew
- Discipline of Pathology, The University of Sydney, Camperdown, Australia
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59
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Maheshwari N, Khan FH, Mahmood R. 3,4-Dihydroxybenzaldehyde lowers ROS generation and protects human red blood cells from arsenic(III) induced oxidative damage. ENVIRONMENTAL TOXICOLOGY 2018; 33:861-875. [PMID: 29732668 DOI: 10.1002/tox.22572] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 04/16/2018] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Arsenic (As) is a potent environmental toxicant and chronic exposure to it results in various malignancies in humans. Oxidative stress has been implicated in the etiopathogenesis of As-induced toxicity. This investigated the protective effect of plant antioxidant 3,4-dihydroxybenzaldehyde (DHB) on sodium meta-arsenite (SA), an As-(III) compound, induced oxidative damage in human red blood cells (RBC). The RBC were first incubated with different concentrations of DHB and then treated with SA at 37°C. Hemolysates were prepared and assayed for various biochemical parameters. Treatment of RBC with SA alone enhanced the generation of reactive oxygen species and increased lipid and protein oxidation. Reduced glutathione levels, total sulfhydryl content and cellular antioxidant power were significantly decreased in SA alone treated RBC, compared to the untreated control cells. This was accompanied by membrane damage, alterations in activities of antioxidant enzymes and deranged glucose metabolism. Incubation of RBC with DHB, prior to treatment with SA, significantly and dose-dependently attenuated the SA-induced changes in all these parameters. Scanning electron microscopy of RBC confirmed these biochemical results. Treatment of RBC with SA alone converted the biconcave discoids to echinocytes but the presence of DHB inhibited this conversion and the RBC retained their normal shape. These results show that DHB protects human RBC from SA-induced oxidative damage, most probably due to its antioxidant character.
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Affiliation(s)
- Nikhil Maheshwari
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
| | - Fahim Halim Khan
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
| | - Riaz Mahmood
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
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60
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Khan S, Malik A. Toxicity evaluation of textile effluents and role of native soil bacterium in biodegradation of a textile dye. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:4446-4458. [PMID: 29185221 DOI: 10.1007/s11356-017-0783-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/16/2017] [Indexed: 06/07/2023]
Abstract
Water pollution caused by the discharge of hazardous textile effluents is a serious environmental problem worldwide. In order to assess the pollution level of the textile effluents, various physico-chemical parameters were analyzed in the textile wastewater and agricultural soil irrigated with the wastewater (contaminated soil) using atomic absorption spectrophotometer and gas chromatography-mass spectrometry (GC-MS) analysis that demonstrated the presence of several toxic heavy metals (Ni, Cu, Cr, Pb, Cd, and Zn) and a large number of organic compounds. Further, in order to get a comprehensive idea about the toxicity exerted by the textile effluent, mung bean seed germination test was performed that indicated the reduction in percent seed germination and radicle-plumule growth. The culturable microbial populations were also enumerated and found to be significantly lower in the wastewater and contaminated soil than the ground water irrigated soil, thus indicating the biotic homogenization of indigenous microflora. Therefore, the study was aimed to develop a cost effective and ecofriendly method of textile waste treatment using native soil bacterium, identified as Arthrobacter soli BS5 by 16S rDNA sequencing that showed remarkable ability to degrade a textile dye reactive black 5 with maximum degradation of 98% at 37 °C and pH in the range of 5-9 after 120 h of incubation.
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Affiliation(s)
- Sana Khan
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
| | - Abdul Malik
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India.
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Mitra P, Sharma S, Purohit P, Sharma P. Clinical and molecular aspects of lead toxicity: An update. Crit Rev Clin Lab Sci 2017; 54:506-528. [DOI: 10.1080/10408363.2017.1408562] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Prasenjit Mitra
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
| | - Shailja Sharma
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
| | - Purvi Purohit
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
| | - Praveen Sharma
- Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, India
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Cote IL, McCullough SD, Hines RN, Vandenberg JJ. Application of epigenetic data in human health risk assessment. CURRENT OPINION IN TOXICOLOGY 2017; 6:71-78. [PMID: 29333520 DOI: 10.1016/j.cotox.2017.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Despite the many recent advances in the field of epigenetics, application of this knowledge in environmental health risk assessment has been limited. In this paper, we identify opportunities for application of epigenetic data to support health risk assessment. We consider current applications and present a vision for the future.
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Affiliation(s)
- Ila L Cote
- National Center for Environmental Assessment, Office of Research and Development, United States Environmental Protection Agency, Washington DC 22202, USA
| | - Shaun D McCullough
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Ronald N Hines
- National Health and Environmental Effects Research Laboratory, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - John J Vandenberg
- National Center for Environmental Assessment, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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64
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LaRocca J, Johnson KJ, LeBaron MJ, Rasoulpour RJ. The interface of epigenetics and toxicology in product safety assessment. CURRENT OPINION IN TOXICOLOGY 2017. [DOI: 10.1016/j.cotox.2017.11.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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65
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Rager JE, Auerbach SS, Chappell GA, Martin E, Thompson CM, Fry RC. Benchmark Dose Modeling Estimates of the Concentrations of Inorganic Arsenic That Induce Changes to the Neonatal Transcriptome, Proteome, and Epigenome in a Pregnancy Cohort. Chem Res Toxicol 2017; 30:1911-1920. [PMID: 28927277 DOI: 10.1021/acs.chemrestox.7b00221] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Prenatal inorganic arsenic (iAs) exposure influences the expression of critical genes and proteins associated with adverse outcomes in newborns, in part through epigenetic mediators. The doses at which these genomic and epigenomic changes occur have yet to be evaluated in the context of dose-response modeling. The goal of the present study was to estimate iAs doses that correspond to changes in transcriptomic, proteomic, epigenomic, and integrated multi-omic signatures in human cord blood through benchmark dose (BMD) modeling. Genome-wide DNA methylation, microRNA expression, mRNA expression, and protein expression levels in cord blood were modeled against total urinary arsenic (U-tAs) levels from pregnant women exposed to varying levels of iAs. Dose-response relationships were modeled in BMDExpress, and BMDs representing 10% response levels were estimated. Overall, DNA methylation changes were estimated to occur at lower exposure concentrations in comparison to other molecular endpoints. Multi-omic module eigengenes were derived through weighted gene co-expression network analysis, representing co-modulated signatures across transcriptomic, proteomic, and epigenomic profiles. One module eigengene was associated with decreased gestational age occurring alongside increased iAs exposure. Genes/proteins within this module eigengene showed enrichment for organismal development, including potassium voltage-gated channel subfamily Q member 1 (KCNQ1), an imprinted gene showing differential methylation and expression in response to iAs. Modeling of this prioritized multi-omic module eigengene resulted in a BMD(BMDL) of 58(45) μg/L U-tAs, which was estimated to correspond to drinking water arsenic concentrations of 51(40) μg/L. Results are in line with epidemiological evidence supporting effects of prenatal iAs occurring at levels <100 μg As/L urine. Together, findings present a variety of BMD measures to estimate doses at which prenatal iAs exposure influences neonatal outcome-relevant transcriptomic, proteomic, and epigenomic profiles.
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Affiliation(s)
- Julia E Rager
- ToxStrategies, Inc. , Austin, Texas 78759, United States
| | - Scott S Auerbach
- National Toxicology Program, National Institutes of Health , Research Triangle Park, North Carolina 27709, United States
| | | | - Elizabeth Martin
- Department of Environmental Sciences and Engineering, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27516, United States
| | | | - Rebecca C Fry
- Department of Environmental Sciences and Engineering, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27516, United States
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Shaw JLA, Judy JD, Kumar A, Bertsch P, Wang MB, Kirby JK. Incorporating Transgenerational Epigenetic Inheritance into Ecological Risk Assessment Frameworks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9433-9445. [PMID: 28745897 DOI: 10.1021/acs.est.7b01094] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Chronic exposure to environmental contaminants can induce heritable "transgenerational" modifications to organisms, potentially affecting future ecosystem health and functionality. Incorporating transgenerational epigenetic heritability into risk assessment procedures has been previously suggested. However, a critical review of existing literature yielded numerous studies claiming transgenerational impacts, with little compelling evidence. Therefore, contaminant-induced epigenetic inheritance may be less common than is reported in the literature. We identified a need for multigeneration epigenetic studies that extend beyond what could be deemed "direct exposure" to F1 and F2 gametes and also include subsequent multiple nonexposed generations to adequately evaluate transgenerational recovery times. Also, increased experimental replication is required to account for the highly variable nature of epigenetic responses and apparent irreproducibility of current studies. Further, epigenetic end points need to be correlated with observable detrimental organism changes before a need for risk management can be properly determined. We suggest that epigenetic-based contaminant studies include concentrations lower than current "EC10-20" or "Lowest Observable Effect Concentrations" for the organism's most sensitive phenotypic end point, as higher concentrations are likely already regulated. Finally, we propose a regulatory framework and optimal experimental design that enables transgenerational epigenetic effects to be assessed and incorporated into conventional ecotoxicological testing.
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Affiliation(s)
- Jennifer L A Shaw
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
| | - Jonathan D Judy
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
- University of Florida , Soil and Water Sciences Department, 1692 McCarthy Drive, Gainesville, Florida 32611, United States
| | - Anupama Kumar
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
| | - Paul Bertsch
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Land and Water , Brisbane, Queensland Australia , 4001
| | - Ming-Bo Wang
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Agriculture and Food Unit, Black Mountain, Canberra, Australian Capital Territory, Australia , 2601
| | - Jason K Kirby
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
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de Angelis C, Galdiero M, Pivonello C, Salzano C, Gianfrilli D, Piscitelli P, Lenzi A, Colao A, Pivonello R. The environment and male reproduction: The effect of cadmium exposure on reproductive function and its implication in fertility. Reprod Toxicol 2017; 73:105-127. [PMID: 28774687 DOI: 10.1016/j.reprotox.2017.07.021] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 07/11/2017] [Accepted: 07/26/2017] [Indexed: 12/22/2022]
Abstract
Cadmium is an environmental pollutant known as endocrine disruptor. Testis is particularly susceptible to cadmium, and testis injury occurs at high but even low levels of exposure. Cadmium reproductive toxicity is mediated by multiple mechanisms, including structural damage to testis vasculature and blood-testis barrier, inflammation, cytotoxicity on Sertoli and Leydig cells, oxidative stress mainly by means of mimicry and interference with essential ions, apoptosis, interference with selected signaling pathways and epigenetic regulation of genes involved in the regulation of reproductive function, and disturbance of the hypothalamus-pituitary-gonadal axis. The current review outlines epidemiological observational findings from environmental and occupational exposure in humans, and reports experimental studies in humans and animals. Lastly, a focus on the pathogenetic mechanisms of cadmium toxicity and on the specific mechanisms of cadmium sensitivity and resistance, particularly assessed in animal models, is included. Despite convincing experimental findings in animals and supporting evidences in humans identifying cadmium as reproductive toxicant, observational findings are controversial, suffering from heterogeneity of study design and pattern of exposure, and from co-exposure to multiple pollutants.
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Affiliation(s)
| | | | - Claudia Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università "Federico II" di Napoli, Naples, Italy.
| | - Ciro Salzano
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università "Federico II" di Napoli, Naples, Italy.
| | - Daniele Gianfrilli
- Dipartimento di Medicina Sperimentale, Università di Roma "La Sapienza", Rome, Italy.
| | | | - Andrea Lenzi
- Dipartimento di Medicina Sperimentale, Università di Roma "La Sapienza", Rome, Italy.
| | - Annamaria Colao
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università "Federico II" di Napoli, Naples, Italy.
| | - Rosario Pivonello
- Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Università "Federico II" di Napoli, Naples, Italy.
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Gomes LEDO, Correa LB, Sá F, Neto RR, Bernardino AF. The impacts of the Samarco mine tailing spill on the Rio Doce estuary, Eastern Brazil. MARINE POLLUTION BULLETIN 2017; 120:28-36. [PMID: 28477986 DOI: 10.1016/j.marpolbul.2017.04.056] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/17/2017] [Accepted: 04/26/2017] [Indexed: 05/21/2023]
Abstract
Over 50 million cubic meters of mining tailings were released in the Rio Doce basin after the collapse of the Fundão dam (Samarco) in November 2015. Predicting significant impacts on the Rio Doce estuary, we sampled sediments to investigate short-term impacts on the benthic assemblages and trace metal accumulation on estuarine sediments. With the arrival of the tailing plumes in the estuary, we detected a predominance of clay particles and increased trace metal concentrations of up to 5 times in some areas. The rapid sedimentation after the impact also impacted estuarine macrofaunal assemblages through loss surface-dwelling taxa. As expected, the impacts on benthic assemblages observed up to 3days after the arrival of tailings were not clearly associated with trace metal concentrations, but long-term effects need to be studied. We recommend that the high spatial variability within the estuary be considered in future impact assessment studies.
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Affiliation(s)
- Luiz Eduardo de Oliveira Gomes
- Grupo de Ecologia Bêntica, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29055-460, Brazil
| | - Lucas Barreto Correa
- BIOENV Meio Ambiente, Av. das Acácias, 456, Coqueiral, Aracruz, ES 29199-156, Brazil
| | - Fabian Sá
- BIOENV Meio Ambiente, Av. das Acácias, 456, Coqueiral, Aracruz, ES 29199-156, Brazil
| | - Renato Rodrigues Neto
- Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29055-460, Brazil
| | - Angelo Fraga Bernardino
- Grupo de Ecologia Bêntica, Departamento de Oceanografia e Ecologia, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, Vitória, ES 29055-460, Brazil.
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Jablonska E, Socha K, Reszka E, Wieczorek E, Skokowski J, Kalinowski L, Fendler W, Seroczynska B, Wozniak M, Borawska MH, Wasowicz W. Cadmium, arsenic, selenium and iron- Implications for tumor progression in breast cancer. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 53:151-157. [PMID: 28586725 DOI: 10.1016/j.etap.2017.05.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
The aim of this study was to determine Cd (cadmium) and As (arsenic) contents in human breast cancer tissues, investigate their interactions with Se (selenium) and Fe (iron), and assess their further implications for tumor progression. Metal contents were determined in 42 tissue sets (tumor and adjacent tissue) collected from 42 women diagnosed with primary breast cancer. Analytical methods included AAS and ICP-MS techniques. Significantly higher contents of Cd (p=0.0003), Se (p<0.0001) and Fe (p=0.0441) whereas significantly lower content of As (p<0.0001) were observed in tumors as compared to adjacent tissues. There was a significant positive correlation between Cd and As contents in tumor tissue. However, only Cd was significantly associated with histological type of tumor, its size, grading and progesterone receptor status. This study support the role of Cd in breast cancer risk and progression. The possible link between As exposure and breast cancer is still not clear.
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Affiliation(s)
- E Jablonska
- Nofer Institute of Occupational Medicine, Department of Molecular Genetics and Epigenetics, Teresy 8 Str, 91-348 Lodz, Poland.
| | - K Socha
- Medical University of Bialystok, Department of Bromatology, A. Mickiewicza 2D Str, 15-222 Bialystok, Poland
| | - E Reszka
- Nofer Institute of Occupational Medicine, Department of Molecular Genetics and Epigenetics, Teresy 8 Str, 91-348 Lodz, Poland
| | - E Wieczorek
- Nofer Institute of Occupational Medicine, Department of Molecular Genetics and Epigenetics, Teresy 8 Str, 91-348 Lodz, Poland
| | - J Skokowski
- Medical University of Gdansk, Department of Surgical Oncology, M. Smoluchowskiego 17 Str, 80-952 Gdansk, Department of Medical Laboratory Diagnostics and Bank of Frozen Tissues and Genetic Specimens, Debinki 7, 80-211 Gdansk, Poland
| | - L Kalinowski
- Medical University of Gdansk, Department of Surgical Oncology, M. Smoluchowskiego 17 Str, 80-952 Gdansk, Department of Medical Laboratory Diagnostics and Bank of Frozen Tissues and Genetic Specimens, Debinki 7, 80-211 Gdansk, Poland
| | - W Fendler
- Medical University of Lodz, Department of Pediatrics, Oncology, Hematology and Diabetology, Sporna 35/50 Str, 91-738 Lodz, Poland
| | - B Seroczynska
- Medical University of Gdansk, Department of Surgical Oncology, M. Smoluchowskiego 17 Str, 80-952 Gdansk, Department of Medical Laboratory Diagnostics and Bank of Frozen Tissues and Genetic Specimens, Debinki 7, 80-211 Gdansk, Poland
| | - M Wozniak
- Medical University of Gdansk, Department of Surgical Oncology, M. Smoluchowskiego 17 Str, 80-952 Gdansk, Department of Medical Laboratory Diagnostics and Bank of Frozen Tissues and Genetic Specimens, Debinki 7, 80-211 Gdansk, Poland
| | - M H Borawska
- Medical University of Bialystok, Department of Bromatology, A. Mickiewicza 2D Str, 15-222 Bialystok, Poland
| | - W Wasowicz
- Nofer Institute of Occupational Medicine, Department of Biological and Environmental Monitoring, Teresy 8 Str, 91-348 Lodz, Poland
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A Tox21 Approach to Altered Epigenetic Landscapes: Assessing Epigenetic Toxicity Pathways Leading to Altered Gene Expression and Oncogenic Transformation In Vitro. Int J Mol Sci 2017; 18:ijms18061179. [PMID: 28587163 PMCID: PMC5486002 DOI: 10.3390/ijms18061179] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 05/19/2017] [Accepted: 05/22/2017] [Indexed: 02/07/2023] Open
Abstract
An emerging vision for toxicity testing in the 21st century foresees in vitro assays assuming the leading role in testing for chemical hazards, including testing for carcinogenicity. Toxicity will be determined by monitoring key steps in functionally validated molecular pathways, using tests designed to reveal chemically-induced perturbations that lead to adverse phenotypic endpoints in cultured human cells. Risk assessments would subsequently be derived from the causal in vitro endpoints and concentration vs. effect data extrapolated to human in vivo concentrations. Much direct experimental evidence now shows that disruption of epigenetic processes by chemicals is a carcinogenic mode of action that leads to altered gene functions playing causal roles in cancer initiation and progression. In assessing chemical safety, it would therefore be advantageous to consider an emerging class of carcinogens, the epigenotoxicants, with the ability to change chromatin and/or DNA marks by direct or indirect effects on the activities of enzymes (writers, erasers/editors, remodelers and readers) that convey the epigenetic information. Evidence is reviewed supporting a strategy for in vitro hazard identification of carcinogens that induce toxicity through disturbance of functional epigenetic pathways in human somatic cells, leading to inactivated tumour suppressor genes and carcinogenesis. In the context of human cell transformation models, these in vitro pathway measurements ensure high biological relevance to the apical endpoint of cancer. Four causal mechanisms participating in pathways to persistent epigenetic gene silencing were considered: covalent histone modification, nucleosome remodeling, non-coding RNA interaction and DNA methylation. Within these four interacting mechanisms, 25 epigenetic toxicity pathway components (SET1, MLL1, KDM5, G9A, SUV39H1, SETDB1, EZH2, JMJD3, CBX7, CBX8, BMI, SUZ12, HP1, MPP8, DNMT1, DNMT3A, DNMT3B, TET1, MeCP2, SETDB2, BAZ2A, UHRF1, CTCF, HOTAIR and ANRIL) were found to have experimental evidence showing that functional perturbations played “driver” roles in human cellular transformation. Measurement of epigenotoxicants presents challenges for short-term carcinogenicity testing, especially in the high-throughput modes emphasized in the Tox21 chemicals testing approach. There is need to develop and validate in vitro tests to detect both, locus-specific, and genome-wide, epigenetic alterations with causal links to oncogenic cellular phenotypes. Some recent examples of cell-based high throughput chemical screening assays are presented that have been applied or have shown potential for application to epigenetic endpoints.
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Appleton AA, Jackson BP, Karagas M, Marsit CJ. Prenatal exposure to neurotoxic metals is associated with increased placental glucocorticoid receptor DNA methylation. Epigenetics 2017; 12:607-615. [PMID: 28548590 DOI: 10.1080/15592294.2017.1320637] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Epigenetic alterations related to prenatal neurotoxic metals exposure may be key in understanding the origins of cognitive and neurobehavioral problems in children. Placental glucocorticoid receptor (NR3C1) methylation has been linked to neurobehavioral risk in early life, but has not been examined in response to neurotoxic metals exposure despite parallel lines of research showing metals exposure and NR3C1 methylation each contribute to a similar set of neurobehavioral phenotypes. Thus, we conducted a study of prenatal neurotoxic metals exposure and placental NR3C1 methylation in a cohort of healthy term singleton pregnancies from Rhode Island, USA (n = 222). Concentrations of arsenic (As; median 0.02 ug/g), cadmium (Cd; median 0.03 μg/g), lead (Pb; median 0.40 μg/g), manganese (Mn; median 0.56 μg/g), mercury (Hg; median 0.02 μg/g), and zinc (Zn; 145.18 μg/g) measured in infant toenails were categorized as tertiles. Multivariable linear regression models tested the independent associations for each metal with NR3C1 methylation, as well as the cumulative risk of exposure to multiple metals simultaneously. Compared to the lowest exposure tertiles, higher levels of As, Cd, Pb, Mn, and Hg were each associated with increased placental NR3C1 methylation (all P<0.02). Coefficients for these associations corresponded with a 0.71-1.41 percent increase in NR3C1 methylation per tertile increase in metals concentrations. For Zn, the lowest exposure tertile compared with the highest tertile was associated with 1.26 percent increase in NR3C1 methylation (P=0.01). Higher cumulative metal risk scores were marginally associated with greater NR3C1 methylation. Taken together, these results indicate that prenatal exposure to neurotoxic metals may affect the offspring's NR3C1 activity, which may help explain cognitive and neurodevelopmental risk later in life.
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Affiliation(s)
- Allison A Appleton
- a Department of Epidemiology and Biostatistics , University at Albany School of Public Health , Rensselaer , NY , USA
| | - Brian P Jackson
- b Department of Earth Sciences, Dartmouth College , Hanover , NH , USA
| | - Margaret Karagas
- c Department of Epidemiology , Geisel School of Medicine at Dartmouth , One Medical Center Drive, Lebanon , NH , USA
| | - Carmen J Marsit
- d Department of Environmental Health, Rollins School of Public Health , Emory University , Atlanta , GA , USA
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Šrut M, Drechsel V, Höckner M. Low levels of Cd induce persisting epigenetic modifications and acclimation mechanisms in the earthworm Lumbricus terrestris. PLoS One 2017; 12:e0176047. [PMID: 28426746 PMCID: PMC5398608 DOI: 10.1371/journal.pone.0176047] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/04/2017] [Indexed: 12/17/2022] Open
Abstract
Toxic effects of cadmium (Cd), a common soil pollutant, are still not very well understood, particularly in regard to its epigenetic impact. Therefore, the aim of this study was to assess DNA methylation changes and their persistence in the earthworm Lumbricus terrestris upon chronic low dose Cd exposure using methylation sensitive amplification polymorphism (MSAP). Moreover, the biomarker response and fitness of the earthworms, as well as the expression of detoxification-related genes (metallothionein (MT) and phytochelatin synthase (PCS)) was evaluated. Low levels of Cd caused an increase in genome-wide DNA methylation, which remained partly modified, even after several months of recovery in unpolluted soil. Increased cellular stress seemed to decrease after two weeks of exposure whereas fitness parameters remained unaffected by Cd, probably as a result from the activation of detoxification mechanisms like the expression of MTs. Interestingly, even though the level of Cd exposure was very low, MT expression levels indicate the development of acclimation mechanisms. Taken together, this study demonstrates that acclimation, as well as epigenetic modifications can occur already in moderately polluted environments. In addition, these effects can have long-lasting impacts on key species of soil invertebrates and might persist long after the actual heavy metal challenge has passed.
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Affiliation(s)
- Maja Šrut
- Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, Zagreb, Croatia
| | - Victoria Drechsel
- Department of Ecophysiology, Institute of Zoology, University of Innsbruck, Center for Molecular Biosciences, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Martina Höckner
- Department of Ecophysiology, Institute of Zoology, University of Innsbruck, Center for Molecular Biosciences, Technikerstr. 25, A-6020 Innsbruck, Austria
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73
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Bommarito PA, Martin E, Fry RC. Effects of prenatal exposure to endocrine disruptors and toxic metals on the fetal epigenome. Epigenomics 2017. [PMID: 28234024 DOI: 10.2217/epi-20160112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Exposure to environmental contaminants during pregnancy has been linked to adverse outcomes at birth and later in life. The link between prenatal exposures and latent health outcomes suggests that these exposures may result in long-term epigenetic reprogramming. Toxic metals and endocrine disruptors are two major classes of contaminants that are ubiquitously present in the environment and represent threats to human health. In this review, we present evidence that prenatal exposures to these contaminants result in fetal epigenomic changes, including altered global DNA methylation, gene-specific CpG methylation and microRNA expression. Importantly, these changes may have functional cellular consequences, impacting health outcomes later in life. Therefore, these epigenetic changes represent a critical mechanism that warrants further study.
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Affiliation(s)
- Paige A Bommarito
- Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Elizabeth Martin
- Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rebecca C Fry
- Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Curriculum in Toxicology, University of North Carolina School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27516, USA
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74
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Bommarito PA, Martin E, Fry RC. Effects of prenatal exposure to endocrine disruptors and toxic metals on the fetal epigenome. Epigenomics 2017; 9:333-350. [PMID: 28234024 DOI: 10.2217/epi-2016-0112] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Exposure to environmental contaminants during pregnancy has been linked to adverse outcomes at birth and later in life. The link between prenatal exposures and latent health outcomes suggests that these exposures may result in long-term epigenetic reprogramming. Toxic metals and endocrine disruptors are two major classes of contaminants that are ubiquitously present in the environment and represent threats to human health. In this review, we present evidence that prenatal exposures to these contaminants result in fetal epigenomic changes, including altered global DNA methylation, gene-specific CpG methylation and microRNA expression. Importantly, these changes may have functional cellular consequences, impacting health outcomes later in life. Therefore, these epigenetic changes represent a critical mechanism that warrants further study.
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Affiliation(s)
- Paige A Bommarito
- Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Elizabeth Martin
- Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rebecca C Fry
- Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Curriculum in Toxicology, University of North Carolina School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27516, USA
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Bowers EC, McCullough SD. Linking the Epigenome with Exposure Effects and Susceptibility: The Epigenetic Seed and Soil Model. Toxicol Sci 2017; 155:302-314. [PMID: 28049737 PMCID: PMC5291212 DOI: 10.1093/toxsci/kfw215] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The epigenome is a dynamic mediator of gene expression that shapes the way that cells, tissues, and organisms respond to their environment. Initial studies in the emerging field of "toxicoepigenetics" have described either the impact of an environmental exposure on the epigenome or the association of epigenetic signatures with the onset or progression of disease; however, the majority of these pioneering studies examined the relationship between discrete epigenetic modifications and the effects of a single environmental factor. Although these data provide critical blocks with which we construct our understanding of the role of the epigenome in susceptibility and disease, they are akin to individual letters in a complex alphabet that is used to compose the language of the epigenome. Advancing the use of epigenetic data to gain a more comprehensive understanding of the mechanisms underlying exposure effects, identify susceptible populations, and inform the next generation risk assessment depends on our ability to integrate these data in a way that accounts for their cumulative impact on gene regulation. Here we will review current examples demonstrating associations between the epigenetic impacts of intrinsic factors, such as such as age, genetics, and sex, and environmental exposures shape the epigenome and susceptibility to exposure effects and disease. We will also demonstrate how the "epigenetic seed and soil" model can be used as a conceptual framework to explain how epigenetic states are shaped by the cumulative impacts of intrinsic and extrinsic factors and how these in turn determine how an individual responds to subsequent exposure to environmental stressors.
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Affiliation(s)
- Emma C Bowers
- Curriculum in Toxicology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Shaun D McCullough
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711
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Soria EA, Pérez RD, Queralt I, Pérez CA, Bongiovanni GA. Immunotoxicological effects of arsenic bioaccumulation on spatial metallomics and cellular enzyme response in the spleen of male Wistar rats after oral intake. Toxicol Lett 2017; 266:65-73. [DOI: 10.1016/j.toxlet.2016.12.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 12/15/2016] [Accepted: 12/18/2016] [Indexed: 12/29/2022]
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Devóz PP, Gomes WR, De Araújo ML, Ribeiro DL, Pedron T, Greggi Antunes LM, Batista BL, Barbosa F, Barcelos GRM. Lead (Pb) exposure induces disturbances in epigenetic status in workers exposed to this metal. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2017; 80:1098-1105. [PMID: 28862539 DOI: 10.1080/15287394.2017.1357364] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Previous studies showed that lead (Pb) exposure may modulate gene expression by changes in the epigenetic status. However, little is known about the impact of Pb exposure and alterations on DNA methylation patterns in humans exposed to this metal. The aim of this study was to assess the consequences of exposure to Pb on DNA global methylation, in order to gain a better understanding of the interactions between Pb exposure and epigenetic effects. The study included 100 male workers employed in automotive battery factories from Paraná State, Brazil. Concentrations of Pb in blood (B-Pb) and plasma (P-Pb) were determined by ICP-MS, the percentage (%) of global DNA methylation was determined by quantification of 5-methylcytosine using indirect ELISA, and sociodemographic data collected by questionnaire by trained interviewers. The mean age was 37 ± 10 (18-67 years); 18% of participants were smokers, while 32% reported consumption of alcoholic beverages. The B-Pb and P-Pb levels were 20 ± 11 and 0.56 ± 0.64 µg/dl, respectively; % global DNA methylation was 2.8 ± 1.1% (ranging from 1.1 to 6.5%). B-Pb and P-Pb concentrations were significantly correlated. Furthermore, a marked association was noted between Pb biomarkers and DNA global methylation. Taken together, our data demonstrated that Pb exposure induced alterations on DNA global methylation in workers who were exposed to the metal and consequently may result in disturbances in the regulation of gene expression, leading to potentially several health adverse effect outcomes.
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Affiliation(s)
- Paula Pícoli Devóz
- a Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , Ribeirão Preto , Brazil
| | - Willian Robert Gomes
- a Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , Ribeirão Preto , Brazil
| | - Marília Ladeira De Araújo
- b Department of Biosciences , Institute of Health and Society, Federal University of São Paulo , Santos , Brazil
| | - Diego Luis Ribeiro
- c Departament of Genetics, School of Medicine of Ribeirão Preto, Ribeirão Preto , University of São Paulo , Ribeirão Preto , Brazil
| | - Tatiana Pedron
- d Center of Natural and Human Sciences , Federal University of ABC , Santo André , Brazil
| | - Lusânia Maria Greggi Antunes
- a Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , Ribeirão Preto , Brazil
| | - Bruno Lemos Batista
- d Center of Natural and Human Sciences , Federal University of ABC , Santo André , Brazil
| | - Fernando Barbosa
- a Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto , University of São Paulo , Ribeirão Preto , Brazil
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Dioni L, Sucato S, Motta V, Iodice S, Angelici L, Favero C, Cavalleri T, Vigna L, Albetti B, Fustinoni S, Bertazzi P, Pesatori A, Bollati V. Urinary chromium is associated with changes in leukocyte miRNA expression in obese subjects. Eur J Clin Nutr 2017; 71:142-148. [PMID: 27731332 PMCID: PMC5222989 DOI: 10.1038/ejcn.2016.197] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 08/09/2016] [Accepted: 08/20/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND/OBJECTIVES Epidemiological studies suggest a link between chromium (Cr) status and cardiovascular disease. Increased urinary excretion of Cr was reported in subjects with diabetes compared with non-diabetic controls and those with non-diabetic insulin resistance. Epigenetic alterations have been linked to the presence of Cr, and microRNA (miRNA) expression has been implicated in the pathogenesis of metabolic diseases and cardiovascular diseases (CVDs). We investigated the association between Cr excretion and miRNA expression in leukocytes from obese subjects. We also examined the relationship between altered miRNA expression and selected clinical parameters to further investigate mechanisms linking Cr to metabolic diseases and CVDs. SUBJECTS/METHODS We analyzed urinary Cr in 90 Italian subjects using inductively coupled plasma-mass spectrometry. Peripheral blood miRNA levels were screened with TaqMan Low-Density Array Human MicroRNA A. Cr level-associated expression of miRNAs was detected with multivariate regression analyses, and the top 10 candidate miRNAs were selected for validation. We also used multivariate regression analyses to assess possible associations between validated miRNAs and glycated hemoglobin (A1c) and blood pressure (BP). The validated miRNAs were further investigated by functional analysis with Ingenuity Pathway Analysis software. RESULTS Urinary Cr levels (mean: 0.35 μg/l; s.d.=0.24) ranged from 0.05 to 1.27 μg/l. In the screening phase, 43 miRNAs were negatively associated with Cr. Of the top 10 miRNAs selected for validation, nine (miR-451, miR-301, miR-15b, miR-21, miR-26a, miR-362-3p, miR-182, miR-183 and miR-486-3p) were downregulated in association with Cr (P-false discovery rate (FDR)<0.10). miR-451 expression was associated with A1c (β=-0.06; P=0.0416), whereas miR-486-3p expression was associated both with diastolic (β=2.1; P=0.004) and systolic BP (β=3.3; P=0.003). CONCLUSIONS These results indicate that miR-451 and miR-486-3p are involved in the link between Cr levels and metabolic diseases and CVDs.
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Affiliation(s)
- L Dioni
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - S Sucato
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - V Motta
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - S Iodice
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - L Angelici
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - C Favero
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - T Cavalleri
- Laboratory of Molecular Gastroenterology, Department of Gastroenterology, Humanitas Clinical and Research Center, Rozzano, Italy
| | - L Vigna
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Preventive Medicine, Milan, Italy
| | - B Albetti
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
| | - S Fustinoni
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Preventive Medicine, Milan, Italy
| | - P Bertazzi
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Preventive Medicine, Milan, Italy
| | - A Pesatori
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Preventive Medicine, Milan, Italy
| | - V Bollati
- EPIGET—Epidemiology, Epigenetics and Toxicology Lab—Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Milan, Italy
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Department of Preventive Medicine, Milan, Italy
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Abstract
Obesity is a complex and multifactorial disease, which likely comprises multiple subtypes. Emerging data have linked chemical exposures to obesity. As organismal response to environmental exposures includes altered gene expression, identifying the regulatory epigenetic changes involved would be key to understanding the path from exposure to phenotype and provide new tools for exposure detection and risk assessment. In this report, we summarize published data linking early-life exposure to the heavy metals, cadmium and lead, to obesity. We also discuss potential mechanisms, as well as the need for complete coverage in epigenetic screening to fully identify alterations. The keys to understanding how metal exposure contributes to obesity are improved assessment of exposure and comprehensive establishment of epigenetic profiles that may serve as markers for exposures.
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Affiliation(s)
- Sarah S Park
- Department of Biological Sciences, Center for Human Health & the Environment, North Carolina State University, Raleigh, NC 27695 USA
| | - David A Skaar
- Department of Biological Sciences, Center for Human Health & the Environment, North Carolina State University, Raleigh, NC 27695 USA
| | - Randy L Jirtle
- Department of Biological Sciences, Center for Human Health & the Environment, North Carolina State University, Raleigh, NC 27695 USA.,Department of Oncology, McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53705, USA.,Department of Sport & Exercise Sciences, Institute of Sport & Physical Activity Research, University of Bedfordshire, Bedford, Bedfordshire, UK
| | - Cathrine Hoyo
- Department of Biological Sciences, Center for Human Health & the Environment, North Carolina State University, Raleigh, NC 27695 USA
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80
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Cord Blood DNA Methylation Biomarkers for Predicting Neurodevelopmental Outcomes. Genes (Basel) 2016; 7:genes7120117. [PMID: 27918480 PMCID: PMC5192493 DOI: 10.3390/genes7120117] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 11/19/2016] [Accepted: 11/29/2016] [Indexed: 01/15/2023] Open
Abstract
Adverse environmental exposures in pregnancy can significantly alter the development of the fetus resulting in impaired child neurodevelopment. Such exposures can lead to epigenetic alterations like DNA methylation, which may be a marker of poor cognitive, motor and behavioral outcomes in the infant. Here we review studies that have assessed DNA methylation in cord blood following maternal exposures that may impact neurodevelopment of the child. We also highlight some key studies to illustrate the potential for DNA methylation to successfully identify infants at risk for poor outcomes. While the current evidence is limited, in that observations to date are largely correlational, in time and with larger cohorts analyzed and longer term follow-up completed, we may be able to develop epigenetic biomarkers that not only indicate adverse early life exposures but can also be used to identify individuals likely to be at an increased risk of impaired neurodevelopment even in the absence of detailed information regarding prenatal environment.
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81
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Alegría-Torres JA, Carrizales-Yánez L, Díaz-Barriga F, Rosso-Camacho F, Motta V, Tarantini L, Bollati V. DNA methylation changes in Mexican children exposed to arsenic from two historic mining areas in San Luis potosí. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:717-723. [PMID: 27862296 DOI: 10.1002/em.22062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/24/2016] [Indexed: 05/24/2023]
Abstract
Arsenic is a carcinogen and epimutagen that threatens the health of exposed populations worldwide. In this study, we examined the methylation status of Alu and long interspersed nucleotide elements (LINE-1) and their association with levels of urinary arsenic in 84 Mexican children between 6 and 12 years old from two historic mining areas in the State of San Luis Potosí, Mexico. Urinary arsenic levels were determined by atomic absorption spectrophotometry and DNA methylation analysis was performed in peripheral blood leukocytes by bisulfite-pyrosequencing. The geometric mean of urinary arsenic was 26.44 µg/g Cr (range 1.93-139.35). No significant differences in urinary arsenic or methylation patterns due to gender were observed. A positive correlation was found between urinary arsenic and the mean percentage of methylated cytosines in Alu sequences (Spearman correlation coefficient r = 0.532, P < 0.001), and a trend of LINE-1 hypomethylation was also observed (Spearman correlation coefficient r = -0.232, P = 0.038) after adjustment for sex and age. A linear regression model showed an association with log-normalized urinary arsenic for Alu (β = 1.05, 95% CI: 0.67; 1.43, P < 0.001) and LINE-1 (β = -0.703, 95% CI: -1.36; -0.38, P = 0.038). Despite the low-level arsenic exposure, a subtle epigenetic imbalance measured as DNA methylation was detected in the leukocytes of Mexican children living in two historic mining areas. Environ. Mol. Mutagen. 57:717-723, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jorge Alejandro Alegría-Torres
- Departamento de Farmacia, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, México
- Laboratorio de Investigación Molecular en Nutrición (LIMON), Universidad del Centro de México UCEM, San Luis Potosí, México
| | - Leticia Carrizales-Yánez
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología (CIACYT), Universidad Autónoma de San Luis Potosí, México
| | - Fernando Díaz-Barriga
- Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología (CIACYT), Universidad Autónoma de San Luis Potosí, México
| | - Fernando Rosso-Camacho
- Laboratorio de Investigación Molecular en Nutrición (LIMON), Universidad del Centro de México UCEM, San Luis Potosí, México
| | - Valeria Motta
- Department of Clinical Sciences and Community Health, EPIGET - Epidemiology, Epigenetics and Toxicology Laboratory, University of Milano, Milan, Italy
- Epidemiology Unit, Fondazione Ca' Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Letizia Tarantini
- Department of Clinical Sciences and Community Health, EPIGET - Epidemiology, Epigenetics and Toxicology Laboratory, University of Milano, Milan, Italy
- Epidemiology Unit, Fondazione Ca' Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
| | - Valentina Bollati
- Department of Clinical Sciences and Community Health, EPIGET - Epidemiology, Epigenetics and Toxicology Laboratory, University of Milano, Milan, Italy
- Epidemiology Unit, Fondazione Ca' Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy
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82
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Cho Y, Song MK, Jeong SC, Lee K, Heo Y, Kim TS, Ryu JC. MicroRNA response of inhalation exposure to hexanal in lung tissues from Fischer 344 rats. ENVIRONMENTAL TOXICOLOGY 2016; 31:1909-1921. [PMID: 26403475 DOI: 10.1002/tox.22192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 08/24/2015] [Accepted: 08/29/2015] [Indexed: 06/05/2023]
Abstract
In previous studies, we have investigated the relationships between environmental chemicals and health risk based on omics analysis and identified significant biomarkers. Our current findings indicate that hexanal may be an important toxicant of the pulmonary system in epigenetic insights. MicroRNA (miRNA) is an important indicator of biomedical risk assessment and target identification. Hexanal is highly detectable in the exhaled breath of patients with chronic obstructive pulmonary disease (COPD) and chronic inflammatory lung disease. In this study, we aimed to identify hexanal-characterized miRNA-mRNA correlations involved in lung toxicity. Microarray analysis identified 56 miRNAs that commonly changed their expression more than 1.3-fold in three doses (600, 1000, and 1500 ppm) within hexanal-exposed Fischer 344 rats by inhalation, and 226 genes were predicted to be target genes of miRNAs through TargetScan analysis. By integrating analyses of miRNA and mRNA expression profiles, we identified one anti-correlated target gene (Chga; chromogranin A; parathyroid secretory protein 1). Comparative toxicogenomics database (CTD) analysis of this gene showed that Chga is involved with several disease categories such as cancer, respiratory tract disease, nervous system disease, and cardiovascular disease. Further research is necessary to elucidate the mechanisms of hexanal-responsive toxicologic pathways at the molecular level. This study concludes that our integrated approach to miRNA and mRNA enables us to identify molecular events in disease development induced by hexanal in an in vivo rat model. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1909-1921, 2016.
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Affiliation(s)
- Yoon Cho
- Center for Environment, Health and Welfare Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongryang, Seoul, 130-650, Korea
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Seoungbuk-Gu, Seoul, 136-701, Korea
| | - Mi-Kyung Song
- Center for Environment, Health and Welfare Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongryang, Seoul, 130-650, Korea
| | - Seung-Chan Jeong
- Center for Environment, Health and Welfare Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongryang, Seoul, 130-650, Korea
| | - Kyuhong Lee
- Human and Environmental Toxicology, University of Science and Technology, Gajeong-Ro 217, Yuseong-Gu, Daejeon, 305-350, Korea
- Inhalation Toxicology Research Center, Korea Institute of Toxicology, 30, Baekhak 1-Gil, Jeongeup-Si, Jeollabuk-Do, 580-185, Korea
| | - Yongju Heo
- Human and Environmental Toxicology, University of Science and Technology, Gajeong-Ro 217, Yuseong-Gu, Daejeon, 305-350, Korea
- Inhalation Toxicology Research Center, Korea Institute of Toxicology, 30, Baekhak 1-Gil, Jeongeup-Si, Jeollabuk-Do, 580-185, Korea
| | - Tae Sung Kim
- Division of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Anam-Dong, Seoungbuk-Gu, Seoul, 136-701, Korea
| | - Jae-Chun Ryu
- Center for Environment, Health and Welfare Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology (KIST), P.O. Box 131, Cheongryang, Seoul, 130-650, Korea
- Human and Environmental Toxicology, University of Science and Technology, Gajeong-Ro 217, Yuseong-Gu, Daejeon, 305-350, Korea
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83
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Ruiter S, Sippel J, Bouwmeester MC, Lommelaars T, Beekhof P, Hodemaekers HM, Bakker F, van den Brandhof EJ, Pennings JLA, van der Ven LTM. Programmed Effects in Neurobehavior and Antioxidative Physiology in Zebrafish Embryonically Exposed to Cadmium: Observations and Hypothesized Adverse Outcome Pathway Framework. Int J Mol Sci 2016; 17:ijms17111830. [PMID: 27827847 PMCID: PMC5133831 DOI: 10.3390/ijms17111830] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/14/2016] [Accepted: 10/24/2016] [Indexed: 02/02/2023] Open
Abstract
Non-communicable diseases (NCDs) are a major cause of premature mortality. Recent studies show that predispositions for NCDs may arise from early-life exposure to low concentrations of environmental contaminants. This developmental origins of health and disease (DOHaD) paradigm suggests that programming of an embryo can be disrupted, changing the homeostatic set point of biological functions. Epigenetic alterations are a possible underlying mechanism. Here, we investigated the DOHaD paradigm by exposing zebrafish to subtoxic concentrations of the ubiquitous contaminant cadmium during embryogenesis, followed by growth under normal conditions. Prolonged behavioral responses to physical stress and altered antioxidative physiology were observed approximately ten weeks after termination of embryonal exposure, at concentrations that were 50–3200-fold below the direct embryotoxic concentration, and interpreted as altered developmental programming. Literature was explored for possible mechanistic pathways that link embryonic subtoxic cadmium to the observed apical phenotypes, more specifically, the probability of molecular mechanisms induced by cadmium exposure leading to altered DNA methylation and subsequently to the observed apical phenotypes. This was done using the adverse outcome pathway model framework, and assessing key event relationship plausibility by tailored Bradford-Hill analysis. Thus, cadmium interaction with thiols appeared to be the major contributor to late-life effects. Cadmium-thiol interactions may lead to depletion of the methyl donor S-adenosyl-methionine, resulting in methylome alterations, and may, additionally, result in oxidative stress, which may lead to DNA oxidation, and subsequently altered DNA methyltransferase activity. In this way, DNA methylation may be affected at a critical developmental stage, causing the observed apical phenotypes.
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Affiliation(s)
- Sander Ruiter
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Josefine Sippel
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Manon C. Bouwmeester
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Tobias Lommelaars
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Piet Beekhof
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Hennie M. Hodemaekers
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Frank Bakker
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Evert-Jan van den Brandhof
- Centre for Environmental Quality, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands;
| | - Jeroen L. A. Pennings
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
| | - Leo T. M. van der Ven
- Centre for Health Protection, National Institute for Public Health and the Environment (RIVM), Bilthoven 3720BA-1, The Netherlands; (P.B.); (H.M.H.); (F.B.); (J.L.A.P.)
- Correspondence: ; Tel.: +31-30-2742681
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84
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Yu CW, Liao VHC. Transgenerational Reproductive Effects of Arsenite Are Associated with H3K4 Dimethylation and SPR-5 Downregulation in Caenorhabditis elegans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10673-10681. [PMID: 27579588 DOI: 10.1021/acs.est.6b02173] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Arsenic is a prevalent environmental toxin. Arsenic is associated with a wide variety of adverse effects; however, studies on whether As-induced toxicities can be transferred from parents to offspring have received little attention. Caenorhabditis elegans has become an important animal model in biomedical and environmental toxicology research. In this study, transgenerational reproductive toxicity by arsenite exposure and the underlying mechanisms in C. elegans were investigated over six generations (F0-F5). Following arsenite maternal exposure of the F0 generation, subsequent generations (F1-F5) were cultured under arsenite-free conditions. We found that the brood size of C. elegans was significantly reduced by arsenite exposure in F0 and that this reduction in brood size was also observed in the offspring generations (F1-F5), after the toxicant had been removed from the diet. In addition, adult worms from F0 and F1 generations accumulated arsenite and arsenate when F0 L4 larvae were exposed to arsenite for 24 h. We found that the mRNA level of H3K4me2 demethylase LSD/KDM1, spr-5, was significantly reduced in the F0 exposed generation and subsequent unexposed generations (F1-F3). Likewise, the mRNA levels of spr-5 were also significantly decreased in the F1-F3 generations. Moreover, dimethylation of global H3K4 was increased in the F0-F3 generations. Our study demonstrates that maternal arsenite exposure causes transgenerational reproductive effects in C. elegans, which might be associated with H3K4 dimethylation and SPR-5 downregulation.
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Affiliation(s)
- Chan-Wei Yu
- Department of Bioenvironmental Systems Engineering, National Taiwan University , No. 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Vivian Hsiu-Chuan Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University , No. 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan
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85
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Li M, Pi H, Yang Z, Reiter RJ, Xu S, Chen X, Chen C, Zhang L, Yang M, Li Y, Guo P, Li G, Tu M, Tian L, Xie J, He M, Lu Y, Zhong M, Zhang Y, Yu Z, Zhou Z. Melatonin antagonizes cadmium-induced neurotoxicity by activating the transcription factor EB-dependent autophagy-lysosome machinery in mouse neuroblastoma cells. J Pineal Res 2016; 61:353-69. [PMID: 27396692 DOI: 10.1111/jpi.12353] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/07/2016] [Indexed: 12/20/2022]
Abstract
Cadmium (Cd), a highly ubiquitous heavy metal, induces neurotoxicity. Melatonin, a major secretory product of the pineal gland, protects against Cd-induced neurotoxicity. However, the mechanism that accounts for this protection remains to be elucidated. Herein, we exposed mouse neuroblastoma cells (Neuro-2a cells) to different concentrations of cadmium chloride (CdCl2 ) (12.5, 25, and 50 μ mol L(-1) ) for 24 hours. We showed that Cd inhibits autophagosome-lysosome fusion and impairs lysosomal function, subsequently leading to nerve cell death. In addition, Cd decreases the level of transcription factor EB (TFEB) but induces the nuclear translocation of TFEB, associated with compromised lysosomal function or a compensatory effect after the impairment of the autophagic flux. Moreover, compared to the 50-μ mol L(-1) Cd group, administration of 1 μ mol L(-1) melatonin increased "TFEB-responsive genes" (P<.05) and the levels of lysosomal-associated membrane protein (0.57±0.06 vs 1.00±0.11, P<.05), preserved lysosomal protease activity (0.52±0.01 vs 0.90±0.02, P<.05), maintained the lysosomal pH level (0.50±0.01 vs 0.87±0.05, P<.01), and enhanced autophagosome-lysosome fusion (0.05±0.00 vs 0.21±0.01, P<.01). Notably, melatonin enhanced TFEB expression (0.37±0.04 vs 0.72±0.07, P<.05) and nuclear translocation (2.81±0.08 vs 3.82±0.05, P<.05). Tfeb siRNA blocked the melatonin-mediated elevation in autophagy-lysosome machinery in Cd-induced neurotoxicity (P<.01). Taken together, these results uncover a potent role for TFEB-mediated autophagy in the pathogenesis of Cd-induced neurotoxicity, suggesting that control of the autophagic pathway by melatonin might provide an important clue for exploring potential targets for novel therapeutics of Cd-induced neurotoxicity.
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Affiliation(s)
- Min Li
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Huifeng Pi
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Zhiqi Yang
- Brain Research Center, Third Military Medical University, Chongqing, China
- Department of Neurology, Army General Hospital in Lanzhou, Lanzhou, China
| | - Russel J Reiter
- Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Shangcheng Xu
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Xiaowei Chen
- Department of Neurology, Army General Hospital in Lanzhou, Lanzhou, China
| | - Chunhai Chen
- Department of Occupational Health, Third Military Medical University, Chongqing, China
- Department of Molecular Biology, University of Texas Southwestern Medical Center, San Antonio, TX, USA
| | - Lei Zhang
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Min Yang
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Yuming Li
- Institute of Hepatobiliary Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Pan Guo
- Department of Occupational Health, Third Military Medical University, Chongqing, China
- Department of Neurology, Wuhan General Hospital, Wuhan, China
| | - Gaoming Li
- Department of Health Statistics, Third Military Medical University, Chongqing, China
| | - Manyu Tu
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Li Tian
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Jia Xie
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Mindi He
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Yonghui Lu
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Min Zhong
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Yanwen Zhang
- Department of Occupational Health, Third Military Medical University, Chongqing, China
| | - Zhengping Yu
- Department of Occupational Health, Third Military Medical University, Chongqing, China.
| | - Zhou Zhou
- Department of Occupational Health, Third Military Medical University, Chongqing, China.
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86
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Genetics of the human placenta: implications for toxicokinetics. Arch Toxicol 2016; 90:2563-2581. [DOI: 10.1007/s00204-016-1816-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/04/2016] [Indexed: 10/21/2022]
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87
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Kim HY, Wegner SH, Van Ness KP, Park JJ, Pacheco SE, Workman T, Hong S, Griffith W, Faustman EM. Differential epigenetic effects of chlorpyrifos and arsenic in proliferating and differentiating human neural progenitor cells. Reprod Toxicol 2016; 65:212-223. [PMID: 27523287 DOI: 10.1016/j.reprotox.2016.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 07/21/2016] [Accepted: 08/10/2016] [Indexed: 12/16/2022]
Abstract
Understanding the underlying temporal and mechanistic responses to neurotoxicant exposures during sensitive periods of neuronal development are critical for assessing the impact of these exposures on developmental processes. To investigate the importance of timing of neurotoxicant exposure for perturbation of epigenetic regulation, we exposed human neuronal progenitor cells (hNPCs) to chlorpyrifos (CP) and sodium arsenite (As; positive control) during proliferation and differentiation. CP or As treatment effects on hNPCs morphology, cell viability, and changes in protein expression levels of neural differentiation and cell stress markers, and histone H3 modifications were examined. Cell viability, proliferation/differentiation status, and epigenetic results suggest that hNPCs cultures respond to CP and As treatment with different degrees of sensitivity. Histone modifications, as measured by changes in histone H3 phosphorylation, acetylation and methylation, varied for each toxicant and growth condition, suggesting that differentiation status can influence the epigenetic effects of CP and As exposures.
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Affiliation(s)
- Hee Yeon Kim
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Susanna H Wegner
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Kirk P Van Ness
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Julie Juyoung Park
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Sara E Pacheco
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Tomomi Workman
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Sungwoo Hong
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - William Griffith
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States
| | - Elaine M Faustman
- Department of Environmental and Occupational Health, Institute of Risk Analysis and Risk Communication, University of Washington, 4225 Roosevelt Way NE, Seattle, WA, United States.
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88
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Research directives toward deciphering adverse outcome pathways induced by environmental metallotoxins. Curr Opin Chem Eng 2016. [DOI: 10.1016/j.coche.2016.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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89
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Chappell G, Pogribny IP, Guyton KZ, Rusyn I. Epigenetic alterations induced by genotoxic occupational and environmental human chemical carcinogens: A systematic literature review. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2016; 768:27-45. [PMID: 27234561 PMCID: PMC4884606 DOI: 10.1016/j.mrrev.2016.03.004] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 01/30/2023]
Abstract
Accumulating evidence suggests that epigenetic alterations play an important role in chemically-induced carcinogenesis. Although the epigenome and genome may be equally important in carcinogenicity, the genotoxicity of chemical agents and exposure-related transcriptomic responses have been more thoroughly studied and characterized. To better understand the evidence for epigenetic alterations of human carcinogens, and the potential association with genotoxic endpoints, we conducted a systematic review of published studies of genotoxic carcinogens that reported epigenetic endpoints. Specifically, we searched for publications reporting epigenetic effects for the 28 agents and occupations included in Monograph Volume 100F of the International Agency for the Research on Cancer (IARC) that were classified as "carcinogenic to humans" (Group 1) with strong evidence of genotoxic mechanisms of carcinogenesis. We identified a total of 158 studies that evaluated epigenetic alterations for 12 of these 28 carcinogenic agents and occupations (1,3-butadiene, 4-aminobiphenyl, aflatoxins, benzene, benzidine, benzo[a]pyrene, coke production, formaldehyde, occupational exposure as a painter, sulfur mustard, and vinyl chloride). Aberrant DNA methylation was most commonly studied, followed by altered expression of non-coding RNAs and histone changes (totaling 85, 59 and 25 studies, respectively). For 3 carcinogens (aflatoxins, benzene and benzo[a]pyrene), 10 or more studies reported epigenetic effects. However, epigenetic studies were sparse for the remaining 9 carcinogens; for 4 agents, only 1 or 2 published reports were identified. While further research is needed to better identify carcinogenesis-associated epigenetic perturbations for many potential carcinogens, published reports on specific epigenetic endpoints can be systematically identified and increasingly incorporated in cancer hazard assessments.
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Affiliation(s)
- Grace Chappell
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Igor P Pogribny
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR, USA
| | | | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA.
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90
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Tang SC, Yeh JI, Hung SJ, Hsiao YP, Liu FT, Yang JH. Glycolic Acid Silences Inflammasome Complex Genes, NLRC4 and ASC, by Inducing DNA Methylation in HaCaT Cells. DNA Cell Biol 2016; 35:124-34. [PMID: 26784358 DOI: 10.1089/dna.2015.2993] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AHAs (α-hydroxy acids), including glycolic acid (GA), have been widely used in cosmetic products and superficial chemical peels. Inflammasome complex has been shown to play critical roles in inflammatory pathways in human keratinocytes. However, the anti-inflammatory mechanism of GA is still unknown. The aim of this study is to investigate the relationship between the expression of the inflammasome complex and epigenetic modification to elucidate the molecular mechanism of the anti-inflammatory effect of GA in HaCaT cells. We evaluated NLRP3, NLRC4, AIM2, and ASC inflammasome complex gene expression on real-time polymerase chain reaction (PCR). Methylation changes were detected in these genes following treatment with DNA methyltransferase (DNMT) inhibitor 5-aza-2'-deoxycytidine (5-Aza) with or without the addition of GA using methylation-specific PCR (MSP). GA inhibited the expressions of these inflammasome complex genes, and the decreases in the expressions of mRNA were reversed by 5-Aza treatment. Methylation was detected in NLRC4 and ASC on MSP, but not in NLRP3 or AIM2. GA decreased NLRC4 and ASC gene expression by increasing not only DNA methyltransferase 3B (DNMT-3B) protein level, but also total DNMT activity. Furthermore, silencing of DNMT-3B (shDNMT-3B) increased the expressions of NLRC4 and ASC. Our data demonstrated that GA treatment induces hypermethylation of promoters of NLRC4 and ASC genes, which may subsequently lead to the hindering of the assembly of the inflammasome complex in HaCaT cells. These results highlight the anti-inflammatory potential of GA-containing cosmetic agents in human skin cells and demonstrate for the first time the role of aberrant hypermethylation in this process.
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Affiliation(s)
- Sheau-Chung Tang
- 1 Department of Biochemistry, School of Medicine, Tzu Chi University , Hualien, Taiwan
- 2 Institute of Biomedical Sciences , Academia Sinica, Taipei, Taiwan
| | - Jih-I Yeh
- 3 Institute of Medicine, College of Medicine, Tzu Chi University , Hualien, Taiwan
- 4 Department of Family Medicine, Buddhist Tzu Chi General Hospital , Hualien, Taiwan
| | - Sung-Jen Hung
- 3 Institute of Medicine, College of Medicine, Tzu Chi University , Hualien, Taiwan
- 5 Department of Dermatology, Buddhist Tzu Chi General Hospital , Hualien, Taiwan
| | - Yu-Ping Hsiao
- 6 Institute of Medicine, College of Medicine, Chung Shan Medical University , Taichung, Taiwan
- 7 Department of Dermatology, Chung Shan Medical University Hospital , Taichung, Taiwan
| | - Fu-Tong Liu
- 2 Institute of Biomedical Sciences , Academia Sinica, Taipei, Taiwan
- 8 Department of Dermatology, University of California Davis School of Medicine , Sacramento, California
| | - Jen-Hung Yang
- 1 Department of Biochemistry, School of Medicine, Tzu Chi University , Hualien, Taiwan
- 3 Institute of Medicine, College of Medicine, Tzu Chi University , Hualien, Taiwan
- 5 Department of Dermatology, Buddhist Tzu Chi General Hospital , Hualien, Taiwan
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91
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Metzger DCH, Schulte PM. Epigenomics in marine fishes. Mar Genomics 2016; 30:43-54. [PMID: 26833273 DOI: 10.1016/j.margen.2016.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 12/31/2022]
Abstract
Epigenetic mechanisms are an underappreciated and often ignored component of an organism's response to environmental change and may underlie many types of phenotypic plasticity. Recent technological advances in methods for detecting epigenetic marks at a whole-genome scale have launched new opportunities for studying epigenomics in ecologically relevant non-model systems. The study of ecological epigenomics holds great promise to better understand the linkages between genotype, phenotype, and the environment and to explore mechanisms of phenotypic plasticity. The many attributes of marine fish species, including their high diversity, variable life histories, high fecundity, impressive plasticity, and economic value provide unique opportunities for studying epigenetic mechanisms in an environmental context. To provide a primer on epigenomic research for fish biologists, we start by describing fundamental aspects of epigenetics, focusing on the most widely studied and most well understood of the epigenetic marks: DNA methylation. We then describe the techniques that have been used to investigate DNA methylation in marine fishes to date and highlight some new techniques that hold great promise for future studies. Epigenomic research in marine fishes is in its early stages, so we first briefly discuss what has been learned about the establishment, maintenance, and function of DNA methylation in fishes from studies in zebrafish and then summarize the studies demonstrating the pervasive effects of the environment on the epigenomes of marine fishes. We conclude by highlighting the potential for ongoing research on the epigenomics of marine fishes to reveal critical aspects of the interaction between organisms and their environments.
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Affiliation(s)
- David C H Metzger
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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92
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Vilahur N, Vahter M, Broberg K. The Epigenetic Effects of Prenatal Cadmium Exposure. Curr Environ Health Rep 2016; 2:195-203. [PMID: 25960943 PMCID: PMC4417128 DOI: 10.1007/s40572-015-0049-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Prenatal exposure to the highly toxic and common pollutant cadmium has been associated with adverse effects on child health and development. However, the underlying biological mechanisms of cadmium toxicity remain partially unsolved. Epigenetic disruption due to early cadmium exposure has gained attention as a plausible mode of action, since epigenetic signatures respond to environmental stimuli and the fetus undergoes drastic epigenomic rearrangements during embryogenesis. In the current review, we provide a critical examination of the literature addressing prenatal cadmium exposure and epigenetic effects in human, animal, and in vitro studies. We conducted a PubMed search and obtained eight recent studies addressing this topic, focusing almost exclusively on DNA methylation. These studies provide evidence that cadmium alters epigenetic signatures in the DNA of the placenta and of the newborns, and some studies indicated marked sexual differences for cadmium-related DNA methylation changes. Associations between early cadmium exposure and DNA methylation might reflect interference with de novo DNA methyltransferases. More studies, especially those including environmentally relevant doses, are needed to confirm the toxicoepigenomic effects of prenatal cadmium exposure and how that relates to the observed health effects of cadmium in childhood and later life.
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Affiliation(s)
- Nadia Vilahur
- Institute of Environmental Medicine, Unit of Metals and Health, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77 Stockholm, Sweden
| | - Marie Vahter
- Institute of Environmental Medicine, Unit of Metals and Health, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77 Stockholm, Sweden
| | - Karin Broberg
- Institute of Environmental Medicine, Unit of Metals and Health, Karolinska Institutet, Nobels väg 13, Box 210, SE-171 77 Stockholm, Sweden
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93
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Tao S, Rojo de la Vega M, Quijada H, Wondrak GT, Wang T, Garcia JGN, Zhang DD. Bixin protects mice against ventilation-induced lung injury in an NRF2-dependent manner. Sci Rep 2016; 6:18760. [PMID: 26729554 PMCID: PMC4700431 DOI: 10.1038/srep18760] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 08/26/2015] [Indexed: 12/19/2022] Open
Abstract
Mechanical ventilation (MV) is a therapeutic intervention widely used in the clinic to assist patients that have difficulty breathing due to lung edema, trauma, or general anesthesia. However, MV causes ventilator-induced lung injury (VILI), a condition characterized by increased permeability of the alveolar-capillary barrier that results in edema, hemorrhage, and neutrophil infiltration, leading to exacerbated lung inflammation and oxidative stress. This study explored the feasibility of using bixin, a canonical NRF2 inducer identified during the current study, to ameliorate lung damage in a murine VILI model. In vitro, bixin was found to activate the NRF2 signaling pathway through blockage of ubiquitylation and degradation of NRF2 in a KEAP1-C151 dependent manner; intraperitoneal (IP) injection of bixin led to pulmonary upregulation of the NRF2 response in vivo. Remarkably, IP administration of bixin restored normal lung morphology and attenuated inflammatory response and oxidative DNA damage following MV. This observed beneficial effect of bixin derived from induction of the NRF2 cytoprotective response since it was only observed in Nrf2+/+ but not in Nrf2−/− mice. This is the first study providing proof-of-concept that NRF2 activators can be developed into pharmacological agents for clinical use to prevent patients from lung injury during MV treatment.
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Affiliation(s)
- Shasha Tao
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
| | | | - Hector Quijada
- Arizona Respiratory Center and Department of Medicine, University of Arizona, Tucson, AZ 85721
| | - Georg T Wondrak
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA.,Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
| | - Ting Wang
- Arizona Respiratory Center and Department of Medicine, University of Arizona, Tucson, AZ 85721
| | - Joe G N Garcia
- Arizona Respiratory Center and Department of Medicine, University of Arizona, Tucson, AZ 85721
| | - Donna D Zhang
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA.,Arizona Cancer Center, University of Arizona, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
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94
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Jiang T, Harder B, Rojo de la Vega M, Wong PK, Chapman E, Zhang DD. p62 links autophagy and Nrf2 signaling. Free Radic Biol Med 2015; 88:199-204. [PMID: 26117325 PMCID: PMC4628872 DOI: 10.1016/j.freeradbiomed.2015.06.014] [Citation(s) in RCA: 430] [Impact Index Per Article: 47.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 12/15/2022]
Abstract
The Nrf2-Keap1-ARE pathway is a redox and xenobiotic sensitive signaling axis that functions to protect cells against oxidative stress, environmental toxicants, and harmful chemicals through the induction of cytoprotective genes. To enforce strict regulation, cells invest a great deal of energy into the maintenance of the Nrf2 pathway to ensure rapid induction upon cellular insult and rapid return to basal levels once the insult is mitigated. Because of the protective role of Nrf2 transcriptional programs, controlled activation of the pathway has been recognized as a means for chemoprevention. On the other hand, constitutive activation of Nrf2, due to somatic mutations of genes that control Nrf2 degradation, promotes carcinogenesis and imparts chemoresistance to cancer cells. Autophagy, a bulk protein degradation process, is another tightly regulated complex cellular process that functions as a cellular quality control system to remove damaged proteins or organelles. Low cellular nutrient levels can also activate autophagy, which acts to restore metabolic homeostasis through the degradation of macromolecules to provide nutrients. Recently, these two cellular pathways were shown to intersect through the direct interaction between p62 (an autophagy adaptor protein) and Keap1 (the Nrf2 substrate adaptor for the Cul3 E3 ubiquitin ligase). Dysregulation of autophagy was shown to result in prolonged Nrf2 activation in a p62-dependent manner. In this review, we will discuss the progress that has been made in dissecting the intersection of these two pathways and the potential tumor-promoting role of prolonged Nrf2 activation.
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Affiliation(s)
- Tao Jiang
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
| | - Bryan Harder
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
| | | | - Pak K Wong
- Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, AZ 85721, USA
| | - Eli Chapman
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
| | - Donna D Zhang
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA; Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA.
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95
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Liu S, Jiang J, Li L, Amato NJ, Wang Z, Wang Y. Arsenite Targets the Zinc Finger Domains of Tet Proteins and Inhibits Tet-Mediated Oxidation of 5-Methylcytosine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11923-31. [PMID: 26355596 PMCID: PMC4784102 DOI: 10.1021/acs.est.5b03386] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Arsenic toxicity is a serious public health problem worldwide that brings more than 100 million people into the risk of arsenic exposure from groundwater and food contamination. Although there is accumulating evidence linking arsenic exposure with aberrant cytosine methylation in the global genome or at specific genomic loci, very few have investigated the impact of arsenic on the oxidation of 5-methylcytosine (5-mC) mediated by the Ten-eleven translocation (Tet) family of proteins. Owing to the high binding affinity of As(III) toward cysteine residues, we reasoned that the highly conserved C3H-type zinc fingers situated in Tet proteins may constitute potential targets for arsenic binding. Herein, we found that arsenite could bind directly to the zinc fingers of Tet proteins in vitro and in cells, and this interaction substantially impaired the catalytic efficiency of Tet proteins in oxidizing 5-mC to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and 5-carboxylcytosine (5-caC). Treatments with arsenite also led to a dose-dependent decrease in the level of 5-hmC, but not 5-mC, in DNA isolated from HEK293T cells overexpressing the catalytic domain of any of the three Tet proteins and from mouse embryonic stem cells. Together, our study unveiled, for the first time, that arsenite could alter epigenetic signaling by targeting the zinc fingers of Tet proteins and perturbing the Tet-mediated oxidation of 5-mC in vitro and in cells. Our results offer important mechanistic understanding of arsenic epigenotoxicity and carcinogenesis in mammalian systems and may lead to novel approaches for the chemoprevention of arsenic toxicity.
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Affiliation(s)
- Shuo Liu
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
| | - Ji Jiang
- Cell, Molecular and Developmental Biology Graduate Program, University of California, Riverside, California 92521, United States
| | - Lin Li
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Nicholas J. Amato
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
| | - Zi Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California 92521, United States
- Cell, Molecular and Developmental Biology Graduate Program, University of California, Riverside, California 92521, United States
- Department of Chemistry, University of California, Riverside, California 92521, United States
- Corresponding Author. Phone: 951-827-2700; fax: 951-827-4713;
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96
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Sanders AP, Burris HH, Just AC, Motta V, Amarasiriwardena C, Svensson K, Oken E, Solano-Gonzalez M, Mercado-Garcia A, Pantic I, Schwartz J, Tellez-Rojo MM, Baccarelli AA, Wright RO. Altered miRNA expression in the cervix during pregnancy associated with lead and mercury exposure. Epigenomics 2015; 7:885-96. [PMID: 26418635 DOI: 10.2217/epi.15.54] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AIM Toxic metals including lead and mercury are associated with adverse pregnancy outcomes. This study aimed to assess the association between miRNA expression in the cervix during pregnancy with lead and mercury levels. MATERIALS & METHODS We obtained cervical swabs from pregnant women (n = 60) and quantified cervical miRNA expression. Women's blood lead, bone lead and toenail mercury levels were analyzed. We performed linear regression to examine the association between metal levels and expression of 74 miRNAs adjusting for covariates. RESULTS Seventeen miRNAs were negatively associated with toenail mercury levels, and tibial bone lead levels were associated with decreased expression of miR-575 and miR-4286. CONCLUSION The findings highlight miRNAs in the human cervix as novel responders to maternal chemical exposure during pregnancy.
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Affiliation(s)
- Alison P Sanders
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Heather H Burris
- Department of Neonatology, Beth Israel Deaconess Medical Center & Division of Newborn Medicine, Boston Children's Hospital & Harvard Medical School, 330 Brookline Ave, RO 318, Boston, MA 02215, USA
| | - Allan C Just
- Department of Environmental Health, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Valeria Motta
- Laboratory of Environmental Epigenetics, Exposure Epidemiology & Risk Program, Harvard TH Chan School of Public Health, Boston, MA 02115, USA.,Department of Clinical Sciences & Community Health University of Milan - Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Chitra Amarasiriwardena
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Laboratory of Environmental Epigenetics, Exposure Epidemiology & Risk Program, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Katherine Svensson
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Emily Oken
- Department of Population Medicine, Harvard Medical School & Harvard Pilgrim Health Care Institute, Boston, MA 02215, USA
| | - Maritsa Solano-Gonzalez
- Center for Nutrition & Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Adriana Mercado-Garcia
- Center for Nutrition & Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Ivan Pantic
- Laboratory of Environmental Epigenetics, Exposure Epidemiology & Risk Program, Harvard TH Chan School of Public Health, Boston, MA 02115, USA.,Division of Research in Public Health, National Institute of Perinatology, Mexico City, Mexico
| | - Joel Schwartz
- Department of Environmental Health, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Martha M Tellez-Rojo
- Center for Nutrition & Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Andrea A Baccarelli
- Department of Environmental Health, Harvard TH Chan School of Public Health, Boston, MA 02115, USA.,Laboratory of Environmental Epigenetics, Exposure Epidemiology & Risk Program, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Robert O Wright
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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97
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Niedzwiecki MM, Liu X, Hall MN, Thomas T, Slavkovich V, Ilievski V, Levy D, Alam S, Siddique AB, Parvez F, Graziano JH, Gamble MV. Sex-specific associations of arsenic exposure with global DNA methylation and hydroxymethylation in leukocytes: results from two studies in Bangladesh. Cancer Epidemiol Biomarkers Prev 2015; 24:1748-57. [PMID: 26364164 DOI: 10.1158/1055-9965.epi-15-0432] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 08/20/2015] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Depletion of global 5-hydroxymethylcytosine (5-hmC) is observed in human cancers and is strongly implicated in skin cancer development. Although arsenic (As)-a class I human carcinogen linked to skin lesion and cancer risk-is known to be associated with changes in global %5-methylcytosine (%5-mC), its influence on 5-hmC has not been widely studied. METHODS We evaluated associations of As in drinking water, urine, and blood with global %5-mC and %5-hmC in two studies of Bangladeshi adults: (i) leukocyte DNA in the Nutritional Influences on Arsenic Toxicity study (n = 196; 49% male, 19-66 years); and (ii) peripheral blood mononuclear cell DNA in the Folate and Oxidative Stress study (n = 375; 49% male, 30-63 years). RESULTS Overall, As was not associated with global %5-mC or %5-hmC. Sex-specific analyses showed that associations of As exposure with global %5-hmC were positive in males and negative in females (P for interaction < 0.01). Analyses examining interactions by elevated plasma total homocysteine (tHcys), an indicator of B-vitamin deficiency, found that tHcys also modified the association between As and global %5-hmC (P for interaction < 0.10). CONCLUSION In two samples, we observed associations between As exposure and global %5-hmC in blood DNA that were modified by sex and tHcys. IMPACT Our findings suggest that As induces sex-specific changes in 5-hmC, an epigenetic mark that has been associated with cancer. Future research should explore whether altered %5-hmC is a mechanism underlying the sex-specific influences of As on skin lesion and cancer outcomes.
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Affiliation(s)
- Megan M Niedzwiecki
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Xinhua Liu
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, New York
| | - Megan N Hall
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York
| | - Tiffany Thomas
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Vesna Slavkovich
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Vesna Ilievski
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Diane Levy
- Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, New York
| | - Shafiul Alam
- Columbia University Arsenic Project in Bangladesh, Dhaka, Bangladesh
| | - Abu B Siddique
- Columbia University Arsenic Project in Bangladesh, Dhaka, Bangladesh
| | - Faruque Parvez
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Joseph H Graziano
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York
| | - Mary V Gamble
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York.
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98
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Environmental Impact on DNA Methylation in the Germline: State of the Art and Gaps of Knowledge. BIOMED RESEARCH INTERNATIONAL 2015; 2015:123484. [PMID: 26339587 PMCID: PMC4538313 DOI: 10.1155/2015/123484] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/03/2015] [Indexed: 12/19/2022]
Abstract
The epigenome consists of chemical changes in DNA and chromatin that without modifying the DNA sequence modulate gene expression and cellular phenotype. The epigenome is highly plastic and reacts to changing external conditions with modifications that can be inherited to daughter cells and across generations. Whereas this innate plasticity allows for adaptation to a changing environment, it also implies the potential of epigenetic derailment leading to so-called epimutations. DNA methylation is the most studied epigenetic mark. DNA methylation changes have been associated with cancer, infertility, cardiovascular, respiratory, metabolic, immunologic, and neurodegenerative pathologies. Experiments in rodents demonstrate that exposure to a variety of chemical stressors, occurring during the prenatal or the adult life, may induce DNA methylation changes in germ cells, which may be transmitted across generations with phenotypic consequences. An increasing number of human biomonitoring studies show environmentally related DNA methylation changes mainly in blood leukocytes, whereas very few data have been so far collected on possible epigenetic changes induced in the germline, even by the analysis of easily accessible sperm. In this paper, we review the state of the art on factors impinging on DNA methylation in the germline, highlight gaps of knowledge, and propose priorities for future studies.
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99
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Tyler CR, Hafez AK, Solomon ER, Allan AM. Developmental exposure to 50 parts-per-billion arsenic influences histone modifications and associated epigenetic machinery in a region- and sex-specific manner in the adult mouse brain. Toxicol Appl Pharmacol 2015; 288:40-51. [PMID: 26193056 DOI: 10.1016/j.taap.2015.07.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/13/2015] [Accepted: 07/16/2015] [Indexed: 01/07/2023]
Abstract
Epidemiological studies report that arsenic exposure via drinking water adversely impacts cognitive development in children and, in adults, can lead to greater psychiatric disease susceptibility, among other conditions. While it is known that arsenic toxicity has a profound effect on the epigenetic landscape, very few studies have investigated its effects on chromatin architecture in the brain. We have previously demonstrated that exposure to a low level of arsenic (50ppb) during all three trimesters of fetal/neonatal development induces deficits in adult hippocampal neurogenesis in the dentate gyrus (DG), depressive-like symptoms, and alterations in gene expression in the adult mouse brain. As epigenetic processes control these outcomes, here we assess the impact of our developmental arsenic exposure (DAE) paradigm on global histone posttranslational modifications and associated chromatin-modifying proteins in the dentate gyrus and frontal cortex (FC) of adult male and female mice. DAE influenced histone 3K4 trimethylation with increased levels in the male DG and FC and decreased levels in the female DG (no change in female FC). The histone methyltransferase MLL exhibited a similar sex- and region-specific expression profile as H3K4me3 levels, while histone demethylase KDM5B expression trended in the opposite direction. DAE increased histone 3K9 acetylation levels in the male DG along with histone acetyltransferase (HAT) expression of GCN5 and decreased H3K9ac levels in the male FC along with decreased HAT expression of GCN5 and PCAF. DAE decreased expression of histone deacetylase enzymes HDAC1 and HDAC2, which were concurrent with increased H3K9ac levels but only in the female DG. Levels of H3 and H3K9me3 were not influenced by DAE in either brain region of either sex. These findings suggest that exposure to a low, environmentally relevant level of arsenic during development leads to long-lasting changes in histone methylation and acetylation in the adult brain due to aberrant expression of epigenetic machinery based on region and sex.
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Affiliation(s)
- Christina R Tyler
- Department of Neurosciences, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Alexander K Hafez
- Department of Neurosciences, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Elizabeth R Solomon
- Department of Neurosciences, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Andrea M Allan
- Department of Neurosciences, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.
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Miousse IR, Chalbot MCG, Lumen A, Ferguson A, Kavouras IG, Koturbash I. Response of transposable elements to environmental stressors. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2015; 765:19-39. [PMID: 26281766 PMCID: PMC4544780 DOI: 10.1016/j.mrrev.2015.05.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 12/21/2022]
Abstract
Transposable elements (TEs) comprise a group of repetitive sequences that bring positive, negative, as well as neutral effects to the host organism. Earlier considered as "junk DNA," TEs are now well-accepted driving forces of evolution and critical regulators of the expression of genetic information. Their activity is regulated by epigenetic mechanisms, including methylation of DNA and histone modifications. The loss of epigenetic control over TEs, exhibited as loss of DNA methylation and decondensation of the chromatin structure, may result in TEs reactivation, initiation of their insertional mutagenesis (retrotransposition) and has been reported in numerous human diseases, including cancer. Accumulating evidence suggests that these alterations are not the simple consequences of the disease, but often may drive the pathogenesis, as they can be detected early during disease development. Knowledge derived from the in vitro, in vivo, and epidemiological studies, clearly demonstrates that exposure to ubiquitous environmental stressors, many of which are carcinogens or suspected carcinogens, are capable of causing alterations in methylation and expression of TEs and initiate retrotransposition events. Evidence summarized in this review suggests that TEs are the sensitive endpoints for detection of effects caused by such environmental stressors, as ionizing radiation (terrestrial, space, and UV-radiation), air pollution (including particulate matter [PM]-derived and gaseous), persistent organic pollutants, and metals. Furthermore, the significance of these effects is characterized by their early appearance, persistence and presence in both, target organs and peripheral blood. Altogether, these findings suggest that TEs may potentially be introduced into safety and risk assessment and serve as biomarkers of exposure to environmental stressors. Furthermore, TEs also show significant potential to become invaluable surrogate biomarkers in clinic and possible targets for therapeutic modalities for disease treatment and prevention.
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Affiliation(s)
- Isabelle R Miousse
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Marie-Cecile G Chalbot
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Annie Lumen
- Division of Biochemical Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Alesia Ferguson
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Ilias G Kavouras
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Igor Koturbash
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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