From cohorts to molecules: adverse impacts of endocrine disrupting mixtures. Transcriptomics Analysis
Ontology highlight
ABSTRACT: Convergent evidence associates exposure to endocrine disrupting chemicals (EDCs) with major human diseases, even at regulation-compliant concentrations. This might be because humans are exposed to EDC mixtures, whereas chemical regulation is based on a risk assessment of individual compounds. Here, we developed a mixture-centered risk assessment strategy that integrates epidemiological and experimental evidence. We identified that exposure to an EDC mixture in early pregnancy is associated with language delay in offspring. At human-relevant concentrations, this mixture disrupted hormone-regulated and disease-relevant regulatory networks in human brain organoids and in the model organisms Xenopus leavis and Danio rerio, as well as behavioral responses. Reinterrogating epidemiological data, we found that up to 54% of the children had prenatal exposures above experimentally derived levels of concern, reaching, for the upper decile compared with the lowest decile of exposure, a 3.3 times higher risk of language delay.
Project description:Endocrine disrupting chemicals (EDCs) are man-made compounds that alter functions of the endocrine system. Environmental mixtures of EDCs might have adverse effects on human health, even though their individual concentrations are below regulatory levels of concerns. However, studies identifying and experimentally testing adverse effects of real-life mixtures are scarce. In this study, we aimed at evaluating an epidemiologically identified EDC mixture in an experi-mental setting to delineate its cellular and epigenetic effects. The mixture was established using data from Swedish Environmental Longitudinal Mother and child Asthma and allergy (SELMA) study where it was associated with lower birth weight, an early marker for prenatal metabolic programming. This mixture was then tested for its ability to change metabolic programming of human mesenchymal stem cells. In these cells, we assessed if the mixture induced adipogenesis and genome-wide DNA methylation changes. The mixture increased lipid droplet accumulation already at concentrations corresponding to levels measured in the pregnant women of the SELMA study. Furthermore, we identified differentially methylated regions in genes important for adipogenesis and thermogenesis. This study shows that a mixture reflecting human real-life exposure can induce molecular and cellular changes during development that could underlie adverse outcomes.
Project description:Chemical health risk assessment is based on single chemicals, but humans and wildlife are exposed to extensive mixtures of industrial substances and pharmaceuticals. Such exposures are life-long and correlate with multiple morbidities, including infertility. How combinatorial effects of chemicals should be handled in hazard characterization and risk assessment are open questions. Further, test systems are missing for several relevant health outcomes including reproductive health and fertility in women. Here, our aim was to screen multiple ovarian cell models for phthalate induced effects to identify biomarkers of exposure. We used an epidemiological cohort study to define different phthalate mixtures for in vitro testing. The mixtures were then tested in five cell models representing ovarian granulosa or stromal cells, namely COV434, KGN, primary human granulosa cells, primary mouse granulosa cells, and primary human ovarian stromal cells. Exposures at epidemiologically relevant exposure level did not markedly elicit cytotoxicity or affect steroidogenesis in short 24-hour exposure. However, significant effects on gene expression were discovered by RNA-sequencing. Altogether, the exposures changed the average expression of 124 genes (9-479 genes per exposure) in human cell models, without obvious concentration or mixture-dependent effects on gene numbers. The mixtures stimulated distinct changes in different cell models. Despite differences, our analyses suggest commonalities in responses towards phthalates, which forms a starting point for follow-up studies on identification and validation of candidate biomarkers that could be developed to novel assays for regulatory testing or even into clinical tests.
Project description:<div>BACKGROUND: Epidemiological evidence suggests a link between pesticide exposure and the development of metabolic diseases. However, most experimental studies have evaluated the metabolic effects of pesticides using individual molecules, often at non relevant doses or in combination with other risk factors such as high fat diets.<br></div><div>OBJECTIVES: We aimed to evaluate, in mice, the metabolic consequences of chronic dietary exposure to a pesticide mixture at non-toxic doses, relevant to consumers’ risk assessment.<br></div> METHODS: A mixture of six pesticides commonly used in France i.e. boscalid, captan, chlorpyrifos, thiofanate, thiacloprid, and ziram was incorporated in a standard chow diet, at doses exposing mice to the acceptable daily intake (ADI) of each pesticide. Wild-type (WT) and Constitutive Androstane Receptor knock-out (CAR-/-) C57Bl6/J male and female mice were exposed for 52 weeks. We assessed metabolic parameters (body-weight, food and water consumption, glucose tolerance, urinary metabolome) throughout the experiment. At the end of the experiment, we evaluated liver metabolism (histology, transcriptomics, metabolomics) and pesticide detoxification using LC/MS.<br>RESULTS: In males, pesticide exposure increased body weight and adiposity and induced hepatic steatosis and glucose intolerance. Exposed females exhibited fasted hyperglycaemia, hepatic oxidative stress and perturbations of gut microbiota-related urinary metabolites. The Constitutive Androstane Receptor is involved in the sexually dimorphic response to pesticide exposure.<br><div> CONCLUSIONS: We show for the first time the sexually dimorphic obesogen and diabetogen effects of a chronic dietary exposure to a realistic mixture of pesticides, which are partially mediated through CAR. This raises questions about the relevance of ADI for individual pesticides when present in a mixture.</div><div><br></div><div><b>Untargeted urine UPLC-MS assay</b> protocols and data are reported in the current study <b>MTBLS596</b>.</div><div><br><b>Untargeted urine, plasma and liver NMR assay</b> protocols and data associated to this study are reported in <a href=https://www.ebi.ac.uk/metabolights/mtbls602><b>MTBLS602</b></a>.<br></div>
Project description:<div>BACKGROUND: Epidemiological evidence suggests a link between pesticide exposure and the development of metabolic diseases. However, most experimental studies have evaluated the metabolic effects of pesticides using individual molecules, often at non-relevant doses or in combination with other risk factors such as high fat diets.<br></div><div>OBJECTIVES: We aimed to evaluate, in mice, the metabolic consequences of chronic dietary exposure to a pesticide mixture at non-toxic doses, relevant to consumers’ risk assessment.<br></div>METHODS: A mixture of six pesticides commonly used in France i.e. boscalid, captan, chlorpyrifos, thiofanate, thiacloprid, and ziram was incorporated in a standard chow diet, at doses exposing mice to the acceptable daily intake (ADI) of each pesticide. Wild-type (WT) and Constitutive Androstane Receptor knock-out (CAR-/-) C57Bl6/J male and female mice were exposed for 52 weeks. We assessed metabolic parameters (body-weight, food and water consumption, glucose tolerance, urinary metabolome) throughout the experiment. At the end of the experiment, we evaluated liver metabolism (histology, transcriptomics, metabolomics) and pesticide detoxification using LC/MS.<br>RESULTS: In males, pesticide exposure increased body weight and adiposity and induced hepatic steatosis and glucose intolerance. Exposed females exhibited fasted hyperglycaemia, hepatic oxidative stress and perturbations of gut microbiota-related urinary metabolites. The Constitutive Androstane Receptor is involved in the sexually dimorphic response to pesticide exposure.<br><div> CONCLUSIONS: We show for the first time the sexually dimorphic obesogen and diabetogen effects of a chronic dietary exposure <br>to a realistic mixture of pesticides, which are partially mediated through CAR. This raises questions about the relevance of ADI for <br>individual pesticides when present in a mixture.</div><div><br></div><div><b>Untargeted urine, plasma and liver NMR assay</b> protocols and data are reported in the current study <b>MTBLS602</b>.<br><br><b>Untargeted urine UPLC-MS assay</b> protocols and data associated to this study are reported in <a href="https://www.ebi.ac.uk/metabolights/MTBLS596"><b>MTBLS596</b></a>.<br></div><div><br></div>
Project description:For the purpose of mechanism-based risk assessment, we investigated temporal concentration-dependent responses in cultures of PHH and HepaRG cells exposed to three cosmetics ingredients, 2,7-naphthalenediol (NPT), triclosan (TCS) and butylated hydroxytoluene (BHT), that are suspected to have liver injury liability. To facilitate the identification of early KEs and visualisation of their development over time, samples were collected at 4 time points, namely 8 and 24 hours (single exposure), 48 and 72 hours (daily repeated exposure), after exposure to a broad concentration range. Concentrations were selected based on the estimated Cmax of the cosmetic ingredients. The selected maximum concentration was set at approximately 100x Cmax, whilst the minimum tested concentration was approximately 0.2x Cmax. The large concentration range allowed to apply benchmark concentration (BMC) modelling on individual genes as well as gene co-expression networks to derive in vitro transcriptomics benchmark concentrations (BMCs) and assess their suitability to be used as PoD in chemical risk assessment.
Project description:For the purpose of mechanism-based risk assessment, we investigated temporal concentration-dependent responses in cultures of PHH and HepaRG cells exposed to three drugs, acetaminophen (APAP), cyclosporine A (CSA) and valproic acid (VPA), that have a high liability for drug-induced liver injury. To facilitate the identification of early KEs and visualisation of their development over time, samples were collected at 4 time points, namely 8 and 24 hours (single exposure), 48 and 72 hours (daily repeated exposure), after exposure to a broad concentration range. Concentrations were selected based on the reported total Cmax of each drug. As these are approved drugs currently on the market, they are not expected to induce overt adverse effects around Cmax. Therefore, the selected maximum concentration was set at approximately 30x Cmax, whilst the minimum tested concentration was approximately 0.1x Cmax. The large concentration range allowed to apply benchmark concentration (BMC) modelling on individual genes as well as gene co-expression networks to derive in vitro transcriptomics benchmark concentrations (BMCs) and assess their suitability to be used as PoD in chemical risk assessment.
Project description:Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of concern due to their persistence and potential adverse health effects. Epidemiological studies have linked PFAS with an increased risk of uterine diseases including fibroids however, the mechanisms involved remain to be elucidated. This study investigated the effects of individual PFAS, including long-chain “legacy” PFAS [perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS)] and short-chain “alternative” PFAS compounds [undecafluoro-2-methyl-3-oxahexanoic acid (GENX/HFPO-DA), perfluorobutanesulfonic acid (PFBS)], as well as a mixture of these chemicals on the function and transcriptome of an immortalized human myometrial cell line (UT-TERT). UT-TERT cells exposed to individual PFAS displayed increased cell viability and proliferation. Flow cytometry analysis revealed that PFOS and the PFAS mixture altered cell cycle progression. Migration assays demonstrated that PFOS and the PFAS mixture significantly enhanced UT-TERT cell migration. Gap junction intercellular communication (GJIC) was impaired following PFOA, PFBS, and PFAS mixture exposure, indicating potential disruptions in cell-to-cell communication within the uterine environment. Transcriptomic analysis using RNA-seq identified substantial changes in gene expression after exposure to environmentally relevant levels of individual PFAS and PFAS mixture. Pathway analysis revealed common molecular pathways associated with PFAS exposure, including Cell-to-Cell Signaling, Lipid Metabolism, and Cell Death and Survival, while other pathways were unique to specific PFAS. These findings highlight the multifaceted effects of PFAS on myometrial cells, providing insights into the potential mechanisms underlying PFAS-associated health risks. Further research is necessary to elucidate the long-term implications of PFAS exposure on uterine function and overall reproductive health.
Project description:This study reports a comparative assessment of the biological impact of a heated tobacco aerosol from the tobacco heating system (THS) 2.2 and smoke from a combustible 3R4F cigarette. Human organotypic bronchial epithelial cultures were exposed to an aerosol from THS2.2 (a candidate modified-risk tobacco product) or 3R4F smoke at similar nicotine concentrations. A systems toxicology approach was applied to enable a comprehensive exposure impact assessment. Culture histology, cytotoxicity, secreted pro-inflammatory mediators, ciliary beating, and genome-wide mRNA/miRNA profiles were assessed at various time points post-exposure. Series of experimental repetitions were conducted to increase the robustness of the assessment. At similar nicotine concentrations, THS2.2 aerosol elicited lower cytotoxicity compared with 3R4F smoke. No morphological change was observed following exposure to THS2.2 aerosol, even at nicotine concentration three times that of 3R4F smoke. Lower levels of secreted mediators and fewer miRNA alterations were observed following exposure to THS2.2 aerosol than following 3R4F smoke. Based on the computational analysis of the gene expression changes, 3R4F (0.13 mg nicotine/L) elicited the highest biological impact (100%) in the context of Cell Fate, Cell Proliferation, Cell Stress, and Inflammatory Network Models at 4 h post-exposure. Whereas, the corresponding impact of THS2.2 (0.14 mg nicotine/L) was 7.6%.
Project description:Animal and epidemiological studies suggest that lycopene and fish oil may modify the risk or delay progression of prostate cancer, however, the molecular mechanisms involved are poorly understood. We examined the effects of these micronutrients on prostate gene expression in a double-blind placebo-controlled randomized clinical trial (Molecular Effects of Nutritional Supplements, MENS).