Adiponectin deficit during the precarious glucose economy of early lactation in dairy cows.

Giesy, Sarah L,Yoon, Bohyung,Currie, W Bruce,Kim, Jin Wook,Boisclair, Yves R Association for the Study of Internal Secretions 2012 Endocrinology Vol.153 No.12

<P>In rodents and primates, insulin resistance develops during pregnancy and fades after parturition. In contrast, dairy cows and other ruminants maintain insulin resistance in early lactation (EL). This adaptation favors mammary glucose uptake, an insulin-independent process, at a time when the glucose supply is scarce. Reduction in circulating levels of the insulin-sensitizing hormone adiponectin promotes insulin resistance in other species, but whether it contributes to insulin resistance in EL dairy cows is unknown. To address this question, plasma adiponectin was measured in high-yielding dairy cows during the transition from late pregnancy (LP) to EL. Plasma adiponectin varied in quadratic fashion with the highest levels in LP, a maximal reduction of 45% on the day after parturition and a progressive return to LP values over the next 8 wk. Adiponectin circulated nearly exclusively in high molecular weight complexes in LP, and this distribution remained unaffected in EL. The reduction of plasma adiponectin in EL occurred without changes in adiponectin mRNA in adipose tissue but was associated with repression of the expression of proteins associated with the endoplasmic reticulum and involved in assembly of adiponectin oligomers. Finally, EL increased the expression of the adiponectin receptor 1 in muscle and adiponectin receptor 2 in liver but had no effect on the expression of these receptors in adipose tissue and in the mammary gland. These data suggest that reduced plasma adiponectin belongs to the subset of hormonal adaptations in EL dairy cows facilitating mammary glucose uptake via promotion of insulin resistance.</P>

Genotoxicity of Several Polybrominated Diphenyl Ethers (PBDEs) and Hydroxylated PBDEs, and Their Mechanisms of Toxicity

Ji, Kyunghee,Choi, Kyungho,Giesy, John P.,Musarrat, Javed,Takeda, Shunichi American Chemical Society 2011 Environmental science & technology Vol.45 No.11

<P>Polybrominated diphenyl ethers (PBDEs) have been extensively utilized as flame retardants, and recently there has been concern about potential adverse effects in humans and wildlife. Their hydroxylated analogs (OH-BDEs) have received increasing attention due to their potential for endocrine and neurological toxicities. However, the potentials and mechanisms of genotoxicity of these brominated compounds have scarcely been investigated. In the present study, genotoxicity of tetra-BDEs, penta BDE, octa-BDE, deca-BDE, and tetra-OH-BDEs were investigated by use of chicken DT40 cell lines including wild-type cells and a panel of mutant cell lines deficient in DNA repair pathways. Tetra-BDEs have greater genotoxic potential than do the other BDEs tested. OH-tetra-BDEs were more genotoxic than tetra-BDEs. DT40 cells, deficient in base excision repair (<I>Pol</I>β<SUP>–/–</SUP>) and translesion DNA synthesis (<I>REV3</I><SUP>–/–</SUP>) pathways, were hypersensitive to the genotoxic effects of tetra-BDEs and OH-tetra-BDEs. The observation of chromosomal aberrations and gamma-H2AX assay confirmed that the studied brominated compounds caused double strand breaks. Pretreatment with <I>N</I>-acetyl-<SMALL>l</SMALL>-cysteine (NAC) significantly rescued the <I>Pol</I>β<SUP>–/–</SUP> and <I>REV3</I><SUP>–/–</SUP> mutants, which is consistent with the hypothesis that PBDEs and OH-BDEs cause DNA damage mediated through reactive oxygen species (ROS). Some tetra-BDEs and OH-tetra-BDEs caused base damage through ROS leading to replication blockage and subsequent chromosomal breaks.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es104344e'>ACS Electronic Supporting Info</A></P>

Effect-Directed Analysis: Current Status and Future Challenges

홍성진,John P. Giesy,이정숙,이종현,김종성 한국해양과학기술원 2016 Ocean science journal Vol.51 No.3

Effect-directed analysis (EDA) has become useful for identification of toxicant(s) that occur in mixtures in the environment, especially those that are causative agents of specific adverse effects. Here, we summarize and review EDA methodology including preparation of samples, biological analyses, fractionations, and instrumental analyses, highlighting key scientific advancements. A total of 63 documents since 1999 (Scopus search) including 46 research articles, 13 review papers, and 4 project descriptions, have been collected and reviewed in this study. At the early stage (1999– 2010), most studies that applied EDA focused on organic extracts of freshwater and coastal contaminated sediments and wastewater. Toxic effects were often measured using cell-based bioassays (in vitro) and the causative chemicals were identified by use of low resolution gas chromatography with mass selective detector (GCMSD). More recently (2010–present), EDA has been extended to various matrices such as biota, soil, crude oil, and suspended solids and techniques have been improved to include determination of bioavailability in vivo. In particular, methods for non-target screenings of organic chemicals in environmental samples using cutting-edge instrumentation such as time of flight-mass spectrometry (ToF-MS), Fourier transform-ion cyclotron resonance (FT-ICR), and Orbitrap mass spectrometer have been developed. This overview provides descriptions of recent improvements of EDA and suggests future research directions based on current understandings and limitations.

Assessment of potential biological activities and distributions of endocrine-disrupting chemicals in sediments of the west coast of South Korea

Jeon, Seungyeon,Hong, Seongjin,Kwon, Bong-Oh,Park, Jinsoon,Song, Sung Joon,Giesy, John P.,Khim, Jong Seong Pergamon Press 2017 Chemosphere Vol.168 No.-

<P><B>Abstract</B></P> <P>The west coast of Korea has experienced environmental deterioration for more than half a century. In the present study, we specifically aimed to: i) evaluate potential toxicities of contaminants in sediments that cause effects mediated through the aryl hydrocarbon receptor (AhR) and estrogen receptor (ER); ii) determine spatio-temporal distributions of polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APs); and iii) identify causes of greater potencies of samples. From 2010 to 2014, sediments were collected from 12 major estuarine and coastal regions along the west coast of South Korea. <I>In vitro</I> cell bioassays were performed to determine AhR- and ER-mediated potencies using H4IIE-<I>luc</I> and MVLN cells, respectively. Fifteen PAHs and six APs in sediments were identified by GC/MSD. Results of bioassays generally showed a low-to-moderate degree of contamination, however, greater AhR- and ER-mediated potencies were measured at some locations. Concentrations of PAHs and APs varied among locations, which indicated that sources were independently affected by the surrounding environment (e.g., industrial complex and cities). Results of bioassays were generally well correlated with concentrations of putative causative chemicals. Benzo[<I>k</I>]fluoranthene, dibenz[<I>a</I>,<I>h</I>]anthracene, and benzo[<I>b</I>]fluoranthene were the major AhR agonists, explaining approximately 30% of the bioassay-derived benzo[<I>a</I>]pyrene equivalent concentration (BaP-EQ). Unknown AhR and ER agonists and potential mixture effects remain in question. Overall, the present study provides baseline information on chemical contaminations and potential toxicity of sediments in a fairly wide geographical region of the west coast of South Korea.</P> <P><B>Highlights</B></P> <P> <UL> <LI> AhR and ER potencies in sediments from the west coast of Korea were characterized. </LI> <LI> Bioassay results generally showed a low-to-moderate contamination of sediments. </LI> <LI> Distributions of PAHs and APs were generally affected by human activities. </LI> <LI> Five- and six-ring PAHs were the major AhR-active compounds in sediments. </LI> <LI> Known and unknown aromatics with log K<SUB>ow</SUB> 5–8 are likely major AhR agonists. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A comprehensive model for chemical bioavailability and toxicity of organic chemicals based on first principles

Forrest, Jay,Bazylewski, Paul,Bauer, Robert,Hong, Seongjin,Kim, Chang Yong,Giesy, John P.,Khim, Jong Seong,Chang, Gap Soo Frontiers Media SA 2014 Frontiers in marine science Vol.1 No.-

Long-term changes in distributions of dioxin-like and estrogenic compounds in sediments of Lake Sihwa, Korea: Revisited mass balance

Lee, Junghyun,Hong, Seongjin,Yoon, Seo Joon,Kwon, Bong-Oh,Ryu, Jongseong,Giesy, John P.,Allam, Ahmed A.,Al-khedhairy, Abdulaziz A.,Khim, Jong Seong Elsevier 2017 CHEMOSPHERE - Vol.181 No.-

<P><B>Abstract</B></P> <P>In the late 1990s, severe pollution by persistent organic contaminants (POCs) was observed in Lake Sihwa by use of a combination of instrumental analyses and <I>in vitro</I> bioassays. To determine long-term changes (>15-year gaps) in distributions of POCs and their potential toxic potencies in the given region, sediment assessments were reconducted. Target chemicals include polycyclic aromatic hydrocarbons (PAHs), alkylphenols (APs), and recently reported emerging chemicals, styrene oligomers (SOs). We employed <I>in vitro</I> bioassays (such as H4IIE-<I>luc</I> and MVLN) to determine potential sediment toxicities. The reduction rates of mean concentrations of APs and SOs in sediments between the two sampling years (1998 vs. 2015) were estimated to be 99% and 67%, respectively. Although APs and SOs significantly declined over the 15-year period, concentrations of PAHs were consistent. Results of the bioassays were consistent with the instrumental data, with relatively great concentrations of all target compounds being detected, particularly in inland creeks. Compositions of all target compounds exhibited changes in homologue patterns over the 15 years considered. This result indicated varying and/or continuing sources in this region. In particular, PAHs were dominated by higher-molecular-weight PAHs (e.g., benzo[<I>g,h,i</I>]perylene and benzo[<I>b</I>]fluoranthene) in recent years. This result might indicate consumption of oil-related fuels. Quantitative potency balance analysis revealed that concentrations of instrumentally-derived equivalents accounted for as little as 18.5% of bioassay-derived equivalents, which indicated significant amounts of unknown and/or unmeasured compounds were present. The present study documented the continuing severe pollution by selected POCs in the Lake Sihwa region over the last 15 years, indicating a lack of management in the area studied.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Long term changes in concentrations of POCs in sediments of Lake Sihwa, Korea were characterized. </LI> <LI> After 15 years, relatively great concentrations of PAHs were still found in sediments of inland creeks. </LI> <LI> Concentrations of APs and SOs decreased over the past 15 years but hotspots were still found. </LI> <LI> Potencies of specific endpoints determined <I>in vitro</I> were still great after 15 years, which indicated continuing inputs of POCs. </LI> <LI> SOs are emerging pollutants that have been present in sediments for 17 years. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Ecogenomic responses of benthic communities under multiple stressors along the marine and adjacent riverine areas of northern Bohai Sea, China

Xie, Yuwei,Hong, Seongjin,Kim, Seonjin,Zhang, Xiaowei,Yang, Jianghua,Giesy, John P.,Wang, Tieyu,Lu, Yonglong,Yu, Hongxia,Khim, Jong Seong Elsevier 2017 CHEMOSPHERE - Vol.172 No.-

<P><B>Abstract</B></P> <P>Benthic communities in the aquatic ecosystem are influenced by both natural and anthropogenic stressors. To understand the ecogenomic responses of sediment communities to the multiple stressors of polluted environments, the bacteria, protistan and metazoan communities in sediments from marine and adjacent riverine areas of North Bohai Sea were characterized by environmental DNA meta-systematics, and their associations with environmental variables were assessed by multiple statistical approaches. The bacterial communities were dominated by <I>Firmicutes</I> (mean 22.4%), <I>Proteobacteria</I> (mean 21.6%) and <I>Actinobacteria</I> (mean 21.5%). The protistan communities were dominated by <I>Ochrophyta</I> (33.7%), <I>Cercozoa</I> (18.9%) and <I>Ciliophora</I> (17.9%). <I>Arthropoda</I> (71.1%) dominated the metazoan communities in sediments. The structures of communities in sediments were shaped by both natural variables (spatial variability and/or salinity (presented as Na and Ca)) and anthropogenic contaminants, including DDTs, PAHs or metals (Cu, Al, Co, Cr, Cu, Fe, K, Mg, Mn, Ni and Zn). Particularly, the correlation network of multiple communities was modulated by the concentrations of Na and DDTs at the family level. Overall, environmental DNA meta-systematics can provide a powerful tool for biomonitoring, sediment quality assessment, and key stressors identification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bacterial, protistan and metazoan communities were characterized with ecogenomics. </LI> <LI> The influences of salinity on benthic communities overwhelmed these of pollutants. </LI> <LI> Variations of community structures also associated with DDTs, PAHs or metals. </LI> </UL> </P>

eDNA-based bioassessment of coastal sediments impacted by an oil spill

Xie, Yuwei,Zhang, Xiaowei,Yang, Jianghua,Kim, Seonjin,Hong, Seongjin,Giesy, John P.,Yim, Un Hyuk,Shim, Won Joon,Yu, Hongxia,Khim, Jong Seong Elsevier 2018 Environmental pollution Vol.238 No.-

<P><B>Abstract</B></P> <P>Oil spills offshore can cause long-term ecological effects on coastal marine ecosystems. Despite their important ecological roles in the cycling of energy and nutrients in food webs, effects on bacteria, protists or arthropods are often neglected. Environmental DNA (eDNA) metabarcoding was applied to characterize changes in the structure of micro- and macro-biota communities of surface sediments over a 7-year period since the occurrence of <I>Hebei Spirit</I> oil <I>spil</I>l on December 7, 2007. Alterations in diversities and structures of micro- and macro-biota were observed in the contaminated area where concentrations of polycyclic aromatic hydrocarbons were greater. Successions of bacterial, protists and metazoan communities revealed long-term ecological effects of residual oil. Residual oil dominated the largest cluster of the community-environment association network. Presence of bacterial families (<I>Aerococcaceae</I> and <I>Carnobacteriaceae</I>) and the protozoan family (<I>Platyophryidae</I>) might have conferred sensitivity of communities to oil pollution. Hydrocarbon-degrading bacterial families (<I>Anaerolinaceae</I>, <I>Desulfobacteraceae</I>, <I>Helicobacteraceae</I> and <I>Piscirickettsiaceae</I>) and algal family (<I>Araphid pennate</I>) were resistant to adverse effects of spilt oil. The protistan family (<I>Subulatomonas</I>) and arthropod families (<I>Folsomia</I>, <I>Sarcophagidae Opomyzoidea,</I> and <I>Anomura</I>) appeared to be positively associated with residual oil pollution. eDNA metabarcoding can provide a powerful tool for assessing effects of anthropogenic pollution, such as oil spills on sediment communities and its long-term trends in coastal marine environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Long-term ecological impact on coastal sediment community by an oil spill were accessed by eDNA metabarcoding. </LI> <LI> Residual oils altered the alpha-diversity, beta-diversity and compositions of multiple sedimentary communities. </LI> <LI> The largest cluster of the sedimentary community-environment association network was dominated by residual oils. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Reconnaissance of dioxin-like and estrogen-like toxicities in sediments of Taean, Korea-seven years after the <i>Hebei Spirit</i> oil spill

Kim, Cheolmin,Lee, Inae,Jung, Dawoon,Hong, Seongjin,Khim, Jong Seong,Giesy, John P.,Yim, Un Hyuk,Shim, Won Joon,Choi, Kyungho Elsevier 2017 CHEMOSPHERE - Vol.168 No.-

<P><B>Abstract</B></P> <P>Oil spills near the coastlines may damage marine and intertidal ecosystem. Constituents of the oil have been reported to cause toxic consequences mediated by aryl hydrocarbon receptor (AhR), and estrogen receptor (ER). In the present study, AhR– and ER–mediated toxicities of coastal sediments of Taean were investigated seven years after <I>Hebei Spirit</I> oil spill (HSOS). Sediment samples were collected on June and October 2014 from seven locations along the Taean coastline, where signs of oil spill were detected. Sediment samples were extracted in Soxhlet extractors and further processed through activated silica gels to separate into four fractions; F1 (saturate hydrocarbons), F2 (aromatic hydrocarbons), F3 (resins and polar compounds), and F4 (residues). ER–mediated and AhR–mediated potencies (% E2<SUB>max</SUB> and % TCDD<SUB>max</SUB>) of each fraction were determined using MVLN cells and H4IIE-<I>luc</I> cells, respectively. F2 and F3 fractions of Sinduri 1, Sinduri 2, and Sogeunri 1 samples showed greater AhR–mediated potencies (up to 107% TCDD<SUB>max</SUB>). Chemical analysis revealed that PAH components are correlated with AhR–binding activities. The % E2<SUB>max</SUB> results varied by sample: While there was no noticeable induction of ER–dependent responses (<45%), some aromatics fractions (F2) exhibited the highest ER–mediated responses. Compared with previous reports from the same sites, both AhR–mediated and ER–mediated potencies have decreased over time. Nevertheless, AhR–mediated potencies could be identified in the environmental samples even after 7 years of the incident. Therefore, possible ecosystem implications of these findings should be further investigated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dioxin-like toxicities were found in sediments affected by <I>Hebei Spirit</I> oil spill. </LI> <LI> Fractionized samples could not explain toxicities observed in whole extracts. </LI> <LI> Toxicity interactions of oil components are suspected in sediment samples of HSOS. </LI> <LI> Follow-up of mechanism-based bioassays combined with chemical analyses is required. </LI> </UL> </P>

Distribution and bioaccumulation of lead in the coastal watersheds of the Northern Bohai and Yellow Seas in China

Kong, Peiru,Luo, Wei,Lu, Yonglong,Wang, Tieyu,Jiao, Wentao,Hu, Wenyou,Naile, Jonathan E.,Khim, Jong Seong,Giesy, John P. Springer-Verlag 2015 Environmental geochemistry and health Vol.37 No.3