bluuebunny/crossref_metadata_2025_split huggingface dataset:
OR06-06 Association Between Mixed Dioxin Exposure And Thyroid Functions In U.S. Adults: A Comparison Of Three Statistical Models
Authors: Han Cheng , Lee Sun , Pearce Elizabeth N 
Published: October 2023

Abstract
Disclosure: C. Han: None. S. Lee: None. E.N. Pearce: None.
Background: Previous studies of the relationship between dioxin exposure and thyroid function have usually been based on multi-chemical linear models and results have been inconsistent. However, complex nonlinear relationships and interactions between mixed dioxin exposures and thyroid function have not been studied. We applied three different statistical models to assess the joint effect of 20 dioxins on thyroid function. Methods: A total of 6 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 4 dioxin-like polychlorinated biphenyls (DL-PCBs) and serum TSH were measured in the serum of U.S. adults by the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2010. We fitted multivariable logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models to estimate the association of individual and mixed dioxin exposures with high TSH. Results: Among the 2818 individuals included in our analysis, 1.99% had TSH &gt;5.6 uIU/mL. In the multivariable logistic regression established for each single dioxin, 1,2,3,7,8-pncdd, 1,2,3,4,7,8-hxcdd, 1,2,3,6,7,8-hxcdd, 1,2,3,7,8,9-hxcdd, 1,2,3,4,7,8-Hexachlorofuran, 1,2,3,6,7,8-Hexachlorofuran, 3,3',4,4',5,5'-hexachlorobiphenyl, 3,3',4,4',5-Pentachlorobiphenyl, and 2,3,7,8-Tetrachloro-p-dioxin were positively associated with high TSH, and 3,4,4',5-Tetrachlorobiphenyl was negatively associated with high TSH. In the WQS regression model, the WQS index was significantly associated (OR (95% CI): 2.03 (1.06, 3.88)) with high TSH, and 1,2,3,7,8-pncdd (weighted at 0.24) made the largest contribution. In the BKMR analysis, a significant positive association was found between mixed dioxin exposure and high TSH when all dioxins were at their 55 to 70th percentile, compared to their 50th percentile. TSH was lower when all dioxins were at their 30th to 45th percentile, compared to their 50th percentile. Conclusion: By comparing the three statistical models, we concluded that the whole-body burden of 20 dioxins was significantly positively associated with high TSH. 1,2,3,7,8-pncdd played the most important roles in hypothyroidism.
Presentation: Thursday, June 15, 2023
SAT424 Neuroendocrine And Developmental Impacts Of Early Exposure To Estrogenic Endocrine Disruptors
Authors: Streifer Madeline , Mendez Skylar , Raval Raj , Thompson Lindsay , Gore Andrea C 
Published: October 2023

Abstract
Disclosure: M. Streifer: None. S. Mendez: None. R. Raval: None. L. Thompson: None. A.C. Gore: None.
Polychlorinated biphenyls (PCBs) are a class of endocrine disrupting chemical (EDC), exposure to which during early development can result in a variety of neuroendocrine and reproductive abnormalities. Hypothalamic kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) and KNDy (Kisspeptin-Neurokinin B-Dynorphin expressing) neurons in the arcuate nucleus (ARC) are involved in reproductive development, maturation, and success; dysfunctions in kisspeptin signaling can lead to hypogonadotropic hypogonadism and sub- or infertility. KNDy and kisspeptin neurons develop under the influence of gonadal hormones, notably estradiol, and are vulnerable to early exposure to estrogenic EDCs. In this experiment male and female rats were perinatally exposed to the weakly estrogenic PCB mixture Aroclor 1221 (A1221) to determine if and how altered kisspeptin signaling in the ARC and AVPV affects reproductive development. Using RNAscope, a novel in situ hybridization technique, we are exploring if changes in the number of KNDy and kisspeptin neurons or RNA expression of kisspeptin and regulatory peptides neurokinin B and dynorphin are potential mechanisms of the increased incidence of reproductive disorders associated with estrogenic PCB exposure. A1221 exposure did not alter the number of kisspeptin-expressing neurons in the AVPV, though quantification of RNA expression and analysis in the ARC are still ongoing. Serum LH, FSH, estradiol, and testosterone were measured as they are involved in the kisspeptin signaling pathway. In A1221 exposed females, serum LH and FSH were decreased, and estradiol was increased in early life (postnatal day 8). A1221 exposed males had decreased serum LH at a prepubertal time point (postnatal day 30), but FSH and testosterone were unaffected by treatment. Developmental markers that could be indicative of dysfunctions in kisspeptin and KNDy neuron function were monitored. A1221 exposure did not cause any obvious abnormal developmental delays in males or females. Moving forward, we plan on further exploring the effects of developmental A1221 exposure in the AVPV and ARC through gene expression profiling.
Presentation: Saturday, June 17, 2023
SAT427 Effects Of Polychlorinated Biphenyls (PCBs) On Transcription Factor NFκB Activation In Neonatal Rat Microglia Primary Culture
Authors: Dressel Carissa E , Valdez Gia M , Bell Margaret R 
Published: October 2023

Abstract
Disclosure: C.E. Dressel: None. G.M. Valdez: None. M.R. Bell: None.
Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are lipophilic and accumulate in the food chain. Despite bans on PCB production, human exposure continues and can cause disruptions in endocrine, nervous, and immune system functions. As such, PCBs may interfere with the actions of microglia, the innate immune cells of the central nervous system. Healthy microglia are critical for neural development, maintenance of neural functions, and responses to stress, injury, or infection. Initial studies of primary neonatal rat microglial cultures indicate that PCBs alter gene expression of proinflammatory cytokine TNF-α and IL-1β in response to a secondary inflammatory lipopolysaccharide (LPS) challenge. Production of these cytokines is, in part, regulated by transcription factor NFκB. This experiment tests the hypothesis that PCBs alter NFκB activation in neonatal microglia. The forebrains of male and female neonatal Sprague-Dawley rats were dissected to remove meninges, homogenized with collagenase and gentle trituration, and plated on coverslips in DMEM FBS+ media to establish a primary mixed glial culture. After one week, microglia were subcultured using mild trypsin treatment and maintained in conditioned media for 24 hours. The microglia were then exposed to either PCB 153 (0.1 µM) or DMSO vehicle control (0.036%) for 18 hours. After 18 hours, the cells were treated with either LPS (0.5 µg/mL) or PBS vehicle control for 4 hours and then fixed. Immunocytochemistry was used to visualize NFκB and identify microglia, with anti-p65 and Ox42 antibodies, respectively. Coverslips were mounted with DAPI-containing media and the cells were imaged via confocal microscopy. In response to immune activation, NFκB typically translocates from the cytosol to the nucleus. Therefore, we assessed NFκB activation by quantifying p65 fluorescent pixel intensity and percentage of area covered in nuclear or cytoplasmic regions according to DAPI and Ox42 channel masks using ImageJ. A two-way ANOVA was used to identify the effects of PCB vs. DMSO exposure and LPS vs. PBS challenge. Preliminary data indicated that LPS increased the ratio of nuclear to cytosolic NFκB, as expected. PCB exposed cells tended to have lower NFκB presence in the nucleus and cell as a whole, but a greater proportion of NFκB staining localized within the nucleus relative to the rest of the cell. With the current sample (n=4-6 per group, 2-3 males and females each), no interactions between PCBs and LPS were observed. Continued work will increase sample size to explore sex differences and the time course of NFκB response to PCBs, which may help broaden our understanding of the mechanisms by which PCBs affect normal brain activity and disrupt healthy endocrine, immune, and neural development.
Presentation: Saturday, June 17, 2023
SAT431 In-vitro Effects Of Benzophenones 2 And 3 On Cell Proliferation And Autophagy Factors Gene Expression In Lβt2 Cells
Authors: Riaño Gómez Juan Manuel , Sorianello Eleonora , Lux-Lantos Victoria Adela , Webster Nicholas Julian , Fernandez Marina Olga 
Published: October 2023

Abstract
Disclosure: J.M. Riaño Gómez: None. E. Sorianello: None. V.A. Lux-Lantos: None. N.J. Webster: None. M.O. Fernandez: None.
Introduction: Humans and wildlife are exposed to Endocrine Disrupting Chemicals (EDC). Previously, we showed that the in-vitro exposure to Benzophenones 2 and 3 (BP2 and BP3, UV filters) increase cell proliferation in GN11 cells (Susan Wray, USA), and that BP2 and BP3 increase p62 gene expression after 12-h exposure in GT1-7 cells (Pam Mellon, UCSD, USA). In this study, we evaluated the in-vitro effects of BP2 and BP3 on cell proliferation and autophagy factors expression in LβT2 cells (pituitary gonadotropes, Pam Mellon). Materials and Methods: LβT2 cells were plated in 96-well plates (Proliferation Assay) or in 12-well plates (gene expression studies) in DMEM high glucose, with 10% FBS, sodium pyruvate and Penicillin/Streptomicin (complete medium). Before adding the stimuli, media were changed to DMEM without phenol red, with charcoal-stripped FBS (2% for proliferation and 10% for gene expression studies). Proliferation was evaluated using MTS (Promega, WI, USA), in response to BP2 and BP3 (1x10-7 y 1x10-9 M) after 12 or 24-h exposure. Ulk1, Lamp2 and p62 expression was evaluated after 6 or 24-h exposure to BP2 or BP3. RNA was extracted, reverse transcribed and gene expression analyzed by qPCR, using Ppib as control gene. Results were presented as Media±SE and analyzed by ANOVA (Statistica, StatSoft Inc, USA). Results: After 12 or 24-h exposure, BP2 as well as BP3 increased cell proliferation in LβT2 cells [Control-12h:100.0±23.0; BP2-7-12h:201.6±64.0; BP2-9-12h:308.2±80.7; BP3-7-12h:325.2±98.1, BP3-9-12h:339.5±90.4; Control-24h:100.0±24.5; BP2-7-24h: 201.4±45.9; BP2-9-24h:318.2±97.1; BP3-7-24h:289.6±59.9, BP3-9-24h:272.3±99.0; ANOVA: Interaction ns, Main Effect Treatment: BP2-9, BP3-7, BP3-9 different from Control p&lt;0.05, n=5]. After 6 or 24-h exposure, BP3 1x10-9 M increased p62 gene expression, whereas neither BP2 nor BP3 1x10-7 M had an effect on p62 expression [ANOVA: Interaction ns, Main Effect Treatment: BP3-9 different from Control, p&lt;0.05, n=3]. There was no difference in Ulk1 and Lamp2 expression. Conclusions: BP2 and BP3, the EDC evaluated, increased cell proliferation in pituitary gonadotropes, LβT2 cells. Furthermore, BP3 increased expression of p62 at the lower dose used, but not at the higher dose. These results indicate that exposure to these chemicals alter normal physiology in the pituitary, what could promote pituitary pathologies. More results are underway to understand the mechanisms involved. Supported by CONICET, ANPCYT, VA SD Healthcare System, NIH, Fund. Williams, Fund. R. Barón.
Presentation: Saturday, June 17, 2023
SAT432 Interactions Of Endocrine-disrupting Chemical (EDC) Exposure And Fear Recall On Small Noncoding RNA (sncRNA) Contents Of Rat Caput Extracellular Vesicles
Authors: Gillette Ross , Aguirre Meagan , Bell Kiersten , Nadeem Yusra , Thompson Lindsay , Gore Andrea C 
Published: October 2023

Abstract
Disclosure: R. Gillette: None. M. Aguirre: None. K. Bell: None. Y. Nadeem: None. L. Thompson: None. A.C. Gore: None.
Extracellular vesicles (EVs) transfer a complex repertoire of small non-coding RNAs (sncRNA) to sperm as they transit the caput of the epididymis. These molecules are essential for the functional competence of sperm and are directly influenced by environmental factors such as stress, diet, and drug use. We hypothesized that prenatal exposure to EDCs would alter the sncRNA contents of caput extracellular vesicles, and that an exposure to a previously established contextual fear cue would exacerbate this effect. Pregnant dams were fed Nilla Wafers with either 3% DMSO (vehicle control) or Aroclor 1221 (1 mg/kg; a weakly estrogenic EDC) from embryonic day (E)8 until E18 and post-natal day (PND)1 to P21. In adulthood male rat offspring were subjected to a contextual fear conditioning paradigm in which each rat was exposed to an odorant paired with a shock (four 500 ms shocks at 0.7 mA) for three consecutive days. Two weeks later, all rats were returned to the conditioning chambers and exposed to the odorant for 5 minutes (no shocks). The next day, male rats were euthanized and the epididymis was dissected. EVs and total RNA isolated from the caput portion were sequenced on a NovaSeq 6000 SP in a single-end 75 bp format. Reads were checked for quality, trimmed for adapter sequences, aligned to the rat genome, and assigned an annotation designation across 10 different categories of sncRNA. We found that the majority of caput EV sncRNA were either tRNA fragments or piRNA and that unlike mice, miRNA accounted for a small portion of the total reads. The third largest category of aligned reads was in intergenic space and not associated with canonical small non-coding (snc) RNA loci. In-depth investigation determined these reads (∼19 nt) aligned strictly within the boundaries of known CpG islands (CpGi), which have not previously been reported to express any form of sncRNA. Re-exposure to a fear-associated scent 24 hours prior to sample collection substantially reduced the proportion tRNAs in EVs, which were supplanted by an increase in piRNA, CpGi sRNA, and lncRNA. This effect was exacerbated by prenatal EDC exposure and was particularly prevalent in the lncRNA and CpGi sRNA categories. Taken together our data show that the small RNA contents of caput epididymosomes of male rats is substantially different from previous observations reported in mice. We demonstrate that exposure to a contextual fear cue is a powerful influence on sncRNA composition of caput extracellular vesicles and that it is uniquely altered by prenatal EDC exposure. Finally, we provide evidence for what we believe may be a novel category of sncRNA.
Presentation: Saturday, June 17, 2023
SAT433 Improving The Risk Assessment Procedures For Endocrine Disrupting Chemicals Affecting Thyroid Homeostasis: A Scoping Study
Authors: La Motta Concettina 
Published: October 2023

Abstract
Disclosure: C. La Motta: None.
This project aims at improving the risk assessment procedure currently adopted for the endocrine disrupting chemicals (EDCs), focusing in particular on those contained in food contact materials and articles and affecting thyroid homeostasis. EDCs generally display a complex toxicity profile, thus making toxicological evaluation and health risk assessment difficult to achieve. The current standardized methods are rather insufficient to identify and test their complex toxicity, and the application of traditional risk assessment principles may be problematic for this kind of substances. This issue is even more crucial when ECDs are part of food contact materials and articles, which are commonly used by the whole population. The increasingly wider distribution of these products on the global market raised the exposure of consumers to chemical agents on constant and cumulative basis, even for persistent compounds, highlighting the urgency of governing the matter. A number of lists including chemicals exploited for the manufacture of food contact materials and articles have been drawn up by international regulators and public and private bodies. However, besides far from being harmonized, they do not provide systematic information regarding thyroid disrupting properties. Actually, the awareness of science on the thyroid safety profile of compounds intentionally used in the food planet is still limited and fragmented, thus requiring an intensive research activity to fill the existing knowledge gap. We carried out a thoroughly survey of the available databases of chemicals for food contact materials and articles, selecting sixteen EDCs characterized by a high level of uncertainty concerning the toxicological profile and/or dearth of information on human exposure data. The selected compounds should be now investigated by making use of both computational tools and in vitro and in vivo studies, to ascertain their adverse thyroid effects. The resulting outcomes will allow to achieve a reliable risk assessment for the benefit of entire population.
Presentation: Saturday, June 17, 2023
OR01-04 The Growth Hormone Receptor Interacts With Transcriptional Regulator, HMGN1, Upon GH-induced Nuclear Translocation
Authors: Jain Lekha , Vickers Mark H , Jacob Bincy , Middleditch Martin J , Chudakova Daria A , Ganley Austen R D , O'Sullivan Justin M , Perry Jo K 
Published: October 2023

Abstract
Disclosure: L. Jain: None. M.H. Vickers: None. B. Jacob: None. M.J. Middleditch: None. D.A. Chudakova: None. A.R. Ganley: None. J.M. O’Sullivan: None. J.K. Perry: None.
Numerous classical cell-surface receptors that were previously thought to signal exclusively at the cell-surface can also translocate to the nucleus upon ligand binding, with increasing evidence supporting a transcriptional role for examples such as the epidermal growth factor receptor. In addition to classic cell-surface growth hormone receptor (GHR)-mediated signaling, the GHR is rapidly imported into the nucleus of cells upon stimulation with growth hormone (GH). Nuclear GHR localization has been associated with increased cancer cell proliferation. However, whether there are transcriptional changes associated with nuclear GHR import remains to be determined. To investigate whether the GHR interacts with transcription regulators in the nucleus following nuclear translocation we used immunoprecipitation combined with mass spectrometry. GH-dependent phosphorylation of STAT5 was confirmed by western blotting in the human cell-lines RL95-2 (endometrial cancer cell-line), and MCF-10A (mammary epithelial cell-line). The GHR was found to rapidly translocate to the nucleus in both cell lines following GH treatment by immunofluorescence staining, with maximal localisation at 5-10 minutes (p&lt;0.001; RL95-2). Combined immunoprecipitation-mass spectrometry analysis of RL95-2 whole cell lysates following GH stimulation (500 ng/mL, 10 mins) identified 40 novel GHR binding partners, including 3 transcriptional regulators (HMGN1, SUMO1 and DDX21). Gene expression analysis identified 416 genes that were differentially expressed following GH treatment (500 ng/mL, 90 mins). Intersection of differentially expressed genes with known gene targets of HMGN1 (ChIP-Atlas) identified an enrichment of HMGN1 target genes (p&lt;0.001). Co-immunoprecipitation combined with western blot analysis confirmed that HMGN1 associated with the GHR in nuclear extracts. Our results suggest that GHR nuclear translocation might mediate GH actions via interaction with chromatin factors that then drive changes in specific downstream transcriptional programs.
Presentation: Thursday, June 15, 2023
SAT662 Bone Morphogenetic Protein 7 Induces Transdifferentiation Of Human White Preadipocytes Into Thermogenic Beige Adipocytes
Authors: Ali Sahara Leena , Cero Cheryl , Katz Jacqueline , Zhu Alexander , Cypess Aaron Martin 
Published: October 2023

Abstract
Disclosure: S.L. Ali: None. J. Katz: None. A.M. Cypess: None.
Chronic treatment of women with mirabegron, which activates the β3-adrenergic receptor, increases the mass and energy expenditure of thermogenic adipocytes and leads to metabolic benefits including improvement of glucose and lipid homeostasis. In humans, thermogenic adipose tissue is composed of brown and beige/brite (from “brown-in-white”) cells that have different lineages and potentially different functions. Beige cells are of therapeutic interest because they are derived from white adipose tissue, which is present at a considerably higher volume compared to brown adipose tissue. Identifying processes that can transdifferentiate white into beige cells could lead to treatments for obesity-related metabolic disease. We hypothesized that short-term treatment with bone morphogenetic protein 7 (BMP7), a member of the transforming growth factor-β (TGF-β) family of cell regulatory proteins, prior to differentiation could be sufficient to induce white to beige transition in human white preadipocytes. We established paired clonal immortalized human white and brown preadipocyte lines and differentiated the white adipocytes ± BMP7 (3.3 nM) for 7 days prior to differentiation. Cells were collected at d0 (undifferentiated) and d30 (fully mature adipocytes) for gene expression analyses. Short-term exposure to BMP7 in white preadipocytes significantly decreased the expression of white-specific markers TCF21 and HOXC8. The beige-specific markers TBX1 and TMEM26, and the thermogenic marker UCP1 were significantly higher in BMP7-treated white adipocytes. However, long term, 30-day exposure to BMP7 treatment reversed the thermogenic transdifferentiation both human white and brown adipocytes. Basal and drug-induced maximal respiration measured via Seahorse XFe96 Analyzer were significantly higher in short-term BMP7-treated white adipocytes. Our data indicate that BMP7 is capable of transdifferentiating human white preadipocytes into thermogenic beige adipocytes. Given that extended treatment reduced the impact of BMP7 indicates that precise timing of interventions will be needed to utilize white-to-beige transdifferentiation to treat obesity-associated metabolic disease.
Presentation: Saturday, June 17, 2023