Methylation and Exposure Biomarkers of the Hebei Spirit Oil Spill Cohort in Taean, Korea*
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Environmental Pollution 263 (2020) 114607 Contents lists available at ScienceDirect Environmental Pollution journal homepage: www.elsevier.com/locate/envpol Cross-sectional and longitudinal associations between global DNA (hydroxy) methylation and exposure biomarkers of the Hebei Spirit oil spill cohort in Taean, Korea* Nivedita Chatterjee a, Jaeseong Jeong a, Myung-Sook Park b, Mina Ha c, * Hae-Kwan Cheong d, Jinhee Choi a, a School of Environmental Engineering, University of Seoul, 163 Seoulsiripdae-ro, Dongdaemun-gu, Seoul, 02504, South Korea b Taean Environmental Health Center, Taean, Chungnam, 32148, South Korea c Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Chungnam, 31116, South Korea d Department of Social and Preventive Medicine, Sungkyunkwan University School of Medicine, Suwon, Gyeonggi, 16419, South Korea article info abstract Article history: The Hebei Spirit oil spill (HSOS) occurred on the west coast of South Korea (Taean county) on December Received 8 October 2019 7, 2007, and studies revealed that exposure to the oil spill was associated with various adverse health Received in revised form issues in the inhabiting population. However, no studies evaluated the association between crude-oil 25 March 2020 exposure and epigenetic changes. This study aimed to investigate the HSOS exposure-associated longi- Accepted 14 April 2020 tudinal and cross-sectional variations in global DNA methylation (5-mc) and/or hydroxymethylation (5- Available online 18 April 2020 hmc) and expression profiles of related genes in Taean cohort participants from 2009 (AH-baseline) and 2014 (AH-follow-up) relative to the reference group (AL). We measured global DNA 5-mc and 5-hmc Keywords: fi fi Hebei Spirit oil spill adult cohort levels and related gene expression levels in whole blood. We identi ed signi cant associations be- DNA methylation (5-mc) tween HSOS exposure and AH-baseline-5-mc, AH-baseline-5-hmc, and AH-follow-up-5-hmc. HSOS DNA hydroxymethylation (5-hmc) exposure was associated with lower %5-mc content and higher %5-hmc content in the same individuals DNMT3B from both the cross-sectional and longitudinal studies. In addition, we found a strong correlation be- TET1 tween 5-mc and DNMT3B expression, and between 5-hmc and TET1 expression. Our findings suggested that epigenetic changes are important biomarkers for HSOS exposure and that 5-hmc is likely to be more sensitive for environmental epidemiological studies. © 2020 Elsevier Ltd. All rights reserved. 1. Introduction City. Shortly after the accident, many volunteers, most of which were local residents with military personnel, participated in longer The Hebei Spirit oil spill (HSOS) occurred on the west coast of cleanup activities for periods ranging from days to several months South Korea (Taean county) on December 7, 2007 and was (Ha et al., 2012). During the early clean-up work, some of the par- considered not only one of the worst oil spills in Korea, but also one ticipants lacked protective equipment and were exposed to oil- of the most serious oil spills in the history of East Asia (Yim et al., related chemicals. Previous studies on the Taean cohort suggested 2012). The spill size was relatively small (estimated 10,900 tons adverse health effects, such as the increased levels of oxidative of crude oil) compared to those of other major oil spill accidents stress biomarkers (MDA and 8-OHdG) and PAH metabolites (1-OHP worldwide (e.g., the Exxon Valdez spilled 37,000 tons of crude oil) and 2-NAPH) in clean-up participants, which were found to be (Kim et al., 2017). However, the main concern regarding the HSOS correlated with the duration of clean-up work in a cross-sectional was that the accident occurred near a heavily populated area, only study (Eom et al., 2011; Ha et al., 2012; Kim et al., 2017; Noh about 10 km away from the beach and the residential area of Taean et al., 2015). In general, crude oil contains various substances, including volatile organic compounds (VOCs), polycyclic aromatic hydrocar- bons (PAHs), and heavy metals. The majority of the components * This paper has been recommended for acceptance by Christian Sonne. present in crude oil are classified under group 1 (carcinogenic), * Corresponding author. E-mail address: [email protected] (J. Choi). group 2A (probably carcinogenic), and group 2B (possibly https://doi.org/10.1016/j.envpol.2020.114607 0269-7491/© 2020 Elsevier Ltd. All rights reserved. 2 N. Chatterjee et al. / Environmental Pollution 263 (2020) 114607 carcinogenic) chemicals in International Agency for Research on participate clean-up work for AL group. Finally, 30 persons for AL Cancer (IARC) monograms (Choi et al., 2018; Park et al., 2017; Yang (AL-follow-up group) and 32 for AH (AH-baseline as well as AH- et al., 2017). follow-up groups) were included in the present study. The study The ‘induction of epigenetic alterations’ is one of ten key char- protocol was approved by the Institutional Review Board of Dan- acteristics of carcinogens described in IARC monographs 112 and kook University Hospital, and informed consent was obtained from 113 (Smith et al., 2016). An increasing number of studies reported a all subjects (IRB no. 0904-027, 2014-06-013). significant association between epigenetic biomarkers and disease. Alterations in epigenetic biomarkers, particularly global DNA 2.2. Questionnaire methylation levels, including 5-methylcytosine (5-mc) and 5- hydroxymethylcytosine (5-hmc) levels, and the expression levels Demographic information was obtained through self-reported of their regulatory genes are associated the incidence of various questionnaire each surveys. Socio-demographic factors, i.e., age at types of cancer (Fouad et al., 2018; Joyce et al., 2016; Li et al., 2017; the oil spill accident (<60, 60), gender (male, female), healthy Lian et al., 2012; Sarabi and Naghibalhossaini, 2015; Tucker et al., behavior, i.e., smoking status (never smoker, current smoker, ex- 2018; Wilson et al., 2007). smoker) were considered. Participants were asked about duration On the other hand, the epigenetic alterations showed a relation of participated cleanup-works. The distance from the oil spill site with various environmental and occupational exposure (Cardenas was calculated using the ArcGIS Desktop ver.9.3 geographic infor- et al., 2017, 2015; Martin and Fry, 2018; Sanchez-Guerra et al., mation system (ESRI, Redlands, CA, USA), based on the latitude and 2015; Tellez-Plaza et al., 2014) and the incidence of various types longitude of the residential address, and considered when selecting of cancer (Fouad et al., 2018; Joyce et al., 2016; Li et al., 2017; Lian the group. et al., 2012; Sarabi and Naghibalhossaini, 2015; Tucker et al., 2018; Wilson et al., 2007). Nonetheless, the association of 5-mc 2.3. Global DNA methylation (5-mc) and global DNA and 5-hmc levels with specific biological changes caused by envi- hydroxymethylation (5-hmc) measurements ronmental exposure has not been well explored in epidemiological studies, except for a few recent studies (Cardenas et al., 2017; Total DNA from whole blood samples were extracted using a Sanchez-Guerra et al., 2015; Tellez-Plaza et al., 2014). DNA extraction kit (NucleoSpin, Macherey-Nagel). DNA quality and No studies have investigated epigenetic changes, such as global quantity were evaluated using a micro-volume spectrophotometer DNA methylation levels following crude oil spill exposure, and their (ASP-2680, ACTGene, Piscataway, NJ, USA). Next, global DNA associations with biomarkers for exposure or health effects. methylation [MethylFlash Global DNA Methylation (5-mc) ELISA In the present study, we analyzed the associations and corre- Easy Kit (Colorimetric)] and global DNA hydroxymethylation lations among global DNA methylation (5-mc) and DNA hydrox- [MethylFlash Global DNA Hydroxymethylation (5-hmc) ELISA Easy ymethylation (5-hmc) markers, expression levels of associated Kit (Colorimetric)] assays were carried out according to the man- genes (DNMTs, TETs, and MBDs), oxidative stress biomarkers (8- ufacturer’s instructions using an ELISA kit (Epigentek Group Inc., OHdG and MDA), and DNA repair genes (OGG1, MHT1, ERCC1, NY, USA). Briefly, 1e8 mL (100 ng) of DNA was added to the wells. XPA, and XPC) in subsamples of longitudinal studies (sampling and The samples were incubated at 37 C for 90 min, followed by the assessment for two time points) of the HSOS in Taean, Korea. addition of capture and detection antibodies. The absorbance was read at 450 nm. A standard curve was generated from the plot of OD 2. Materials and methods values relative to those of the positive controls. 2.1. Study population and sample (urine and blood) collection 2.4. Measurement of MDA and 8-OHdG levels The number of adults (aged 18 years or older) who agreed to We used the existing results of MDA and 8-OHdG levels participate in the survey of the cohort study were 9585 from 2009 measured in the previous study of the cohort (Noh et al., 2015). to 2017. From the high exposed area (AH), the number of partici- Briefly, urinary MDA levels were determined by measuring the pants in 2009 (the baseline survey) was 1741 whereas in 2014 (the levels of thiobarbituric acid reactive substances using a high- follow-up survey) only 615 adults were participated (Fig. 1). The performance liquid chromatography instrument equipped with a references of this cohort study was from the low exposed area of fluorescence detector (Agarwal and Chase, 2002). Urinary 8-OHdG same county with that of high exposed area but distant from the levels were determined using an 8-OHdG competitive enzyme- oil-spill accident site. The adult participants (AL) from low-exposed linked immunosorbent assay (ELISA) kit (Japan Institute for the group were 7505 at baseline survey in 2009 while only 187 adults Control of Aging, Kyoto, Japan) (Noh et al., 2015). were participated in follow-up survey in 2014 (Fig. 1).