Indoor dust contains various endocrine-disrupting contaminants, yet the effect drivers of observed glucocorticoid activity are completely unknown. This study conducted an effect-directed analysis using orthogonal fractionation to identify effect drivers of glucocorticoid activity in indoor dust. After the detection of bioactivity using a human cell line stably transfected with a reporter gene, the sample underwent parallel HPLC fractionations with octadecyl, pentafluorophenyl, and aminopropyl columns to obtain orthogonal fractions. The bioassays were utilized to screen the fractions and guide efforts towards prioritization of the bioactive chemicals using targeted and non-targeted analysis with LC-HRMS. The glucocorticoid activity of the identified potential candidates was confirmed by their testing in the same bioassay. To assess their contribution to the detected mixture effects, we calculated their relative potencies. This approach led to the identification of two pharmaceuticals, clobetasol propionate and mometasone furoate, at concentrations ranging from ng to μg per gram of dust, which together accounted for up to 77% of the observed glucocorticoid activity. This is the first report documenting the effect drivers of glucocorticoid receptor agonism in indoor dust; however, together with previous studies of various environmental samples, it documents that in cases when glucocorticoid receptor-agonistic activity is detected, drugs should be considered as likely relevant contaminants. The discovery of potent drugs in household dust highlights concerns for individuals exposed within domestic environments and emphasizes the need to consider pharmaceuticals as relevant contributors to indoor contamination.

• Klíčová slova
• Effect-directed analysis, Endocrine disrupting compounds, Glucocorticoid activity, In vitro, Indoor dust, Orthogonal fractionation,
• MeSH
• chemická frakcionace MeSH
• endokrinní disruptory analýza   MeSH
• glukokortikoidy * analýza   MeSH
• klobetasol MeSH
• látky znečišťující vzduch analýza   MeSH
• lidé MeSH
• mometason furoát MeSH
• monitorování životního prostředí metody   MeSH
• prach * analýza   MeSH
• receptory glukokortikoidů metabolismus   MeSH
• znečištění vzduchu ve vnitřním prostředí * analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• endokrinní disruptory MeSH
• glukokortikoidy * MeSH
• klobetasol MeSH
• látky znečišťující vzduch MeSH
• mometason furoát MeSH
• prach * MeSH
• receptory glukokortikoidů MeSH

Artificial conditions limit the ability of laboratory studies to describe the complex effects of polluted environments on aquatic life. This study aimed to evaluate the impacts of treated wastewater discharge on the survival, growth, and sex ratio balance of the population of brown trout (Salmo trutta m. fario) in situ. Five floating incubators with 1000 eggs each were placed in the upstream reference and treated wastewater-affected sites in the Czech Republic for approximately three months. The hatched fish were grown in a natural environment for nearly one year. Water quality, including nutrients, temperature, pharmaceutical and personal care products, biological effects by bioassays and fish mortality, metabolic rate, and growth, were measured regularly. Up to 72 pharmaceutical and personal care products (7400-23000 ng/sampler) were detected in the passive samplers deployed downstream of the sewage treatment plant effluent. In vitro bioassays of the sampler extracts indicated elevated oestrogenic effects, transthyretin binding inhibition, and aryl hydrocarbon-mediated and androgenic potencies, showing endocrine-disrupting potential at the polluted site. The cumulated mortality of brown trout in the exposed group (9.67%) was significantly higher (p < 0.05) than in the control group (5.16%). In addition, the body size, growth, and metabolic rate of exposed fish were significantly lower (p < 0.05). The sex ratio of brown trout in the effluent-affected stretch was imbalanced, and sterile individuals were detected after several months of natural development in the stream. The observed effects of treated wastewater on the early developmental stages of aquatic wildlife could be connected to the development and readiness of adult individuals and, consequently, to the sustainability of freshwater ecosystems. Applying the hatching apparatus used in fishery practices, followed by comparing mortality, development, and sex with reference localities, seems to be a promising biomonitoring approach that can indicate hotspots for in-depth investigation and risk assessment.

• Klíčová slova
• Growth change, In situ exposure, Pharmaceutical and personal care products, Population sex ratio, Real exposure scenario, Sewage treatment plant effluent,
• Publikační typ
• časopisecké články MeSH

Recent research efforts in endocrine disruption have focused on evaluating non-EATS (estrogen, androgen, thyroid, and steroidogenesis) pathways. Retinoid signaling disruption is noteworthy because of its teratogenic effects and environmental relevance. However, current environmental risk assessments are limited in their ability to evaluate impacts on individuals and populations. This study characterizes an Adverse Outcome Pathway (AOP) network linking retinoid signaling disruption to teratogenicity and survival in zebrafish. We identified Retinoic Acid Receptor (RAR) overactivation as the molecular initiating event leading to key events including craniofacial (CFM) and tail (TM) malformations, posterior swim bladder (SB) non-inflation, impaired swimming performance, and reduced feeding, ultimately resulting in decreased survival. Our study (1) determines critical sensitivity windows for CFM, posterior SB non-inflation, and TM, (2) provides quantitative measurements for CFM and TM, and (3) defines impacts on higher biological levels including food ingestion, swimming, and survival. Results show that all-trans retinoic acid (ATRA) induces strong teratogenic effects with sensitivity windows between 4 and 48 h post fertilization (hpf) for CFM, TM, and posterior SB non-inflation. TM is the most sensitive indicator, with EC50 of 0.2 - 0.26 µg/L across exposure windows 4-48, 4-72, 4-96, and 4-120 hpf. Besides inducing known malformations, ATRA impaired posterior SB inflation with EC50 of 1 - 1.21 µg/L across the same exposure windows. ATRA exposure (1 µg/L) resulted in 50 % food ingestion inhibition at 7 days post fertilization (dpf) and 10 % survival at 14 dpf. This study provides a regulatory-relevant framework linking developmental effects to population outcomes, highlighting ecological risks and needs for improved risk assessments.

• Klíčová slova
• Adverse outcome pathway, Behavior toxicity, Developmental toxicity, Endocrine disruption, Retinoic acid, Retinoids, Survival/mortality, Teratogenicity,
• MeSH
• chemické látky znečišťující vodu * toxicita   MeSH
• dánio pruhované * MeSH
• dráhy škodlivých účinků * MeSH
• embryo nesavčí * účinky léků   MeSH
• receptory kyseliny retinové metabolismus   genetika   MeSH
• retinoidy metabolismus   MeSH
• signální transdukce * účinky léků   MeSH
• teratogeny * toxicita   MeSH
• tretinoin * metabolismus   toxicita   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• receptory kyseliny retinové MeSH
• retinoidy MeSH
• teratogeny * MeSH
• tretinoin * MeSH

Thyroid hormone system disruption (THSD) is a growing concern in chemical hazard assessment due to its impact on human and environmental health and the scarce methods available for assessing the THSD potential of chemicals. In particular, the general lack of validated in silico and in vitro methods for assessing THS activity is of high concern. This manuscript provides an inventory of test methods relevant to THSD. Building on the Organisation for Economic Co-operation and Development (OECD) Guidance Document 150 and recent international developments, we highlight progress in in silico and in vitro methods, as well as in vivo assays. The provided inventory categorizes available methods according to the levels of the OECD Conceptual Framework, with an assessment of the validation status of each method. At Level 1, 12 in silico models that have been statistically validated and are directly related to THSD have been identified. At Level 2, 67 in vitro methods have been listed including those assessed in key initiatives such as the European Union Network of Laboratories for the Validation of Alternative Methods (EU-NETVAL) validation study to identify potential thyroid disruptors. At Levels 3-5, THSD-sensitive endpoints are being included in existing fish-based OECD Test Guidelines to complement amphibian assays. In total, the inventory counts 108 entries comprising established methods (e.g., OECD Test Guidelines) as well as citable methods that are under further development and in some cases are ready for validation or in the initial stages of validation. This work aims to support the ongoing development of strategies for regulatory hazard assessment, such as integrated approaches to testing and assessment (IATAs), for endocrine disruptors, addressing critical gaps in the current testing landscape for THSD in both human and environmental health contexts.

Endocrine disruption - the potential of chemicals, such as industrial chemicals or pesticides, to disrupt hormonal systems and cause adverse health effects - is of growing concern due to its impact on human and environmental health and the scarce methods available for assessing such hazards. In particular, the limited methods available for assessing disruption of the thyroid hormone system, is of high concern. This manuscript provides an inventory of test methods relevant for the assessment of thyroid hormone system disruption. We highlight progress in different types of methods such as computer simulations, cell-based methods, non-mammalian embryo-based methods and animal methods and include an assessment of the readiness of each method for implementation in chemical evaluations. In total, the inventory counts 108 entries comprising already established methods as well as recent developments. This work aims to support the ongoing development of strategies for evaluating endocrine disruption, addressing critical gaps in the current testing landscape for thyroid hormone system disruption in both human and environmental health contexts.

• Klíčová slova
• One Health, Thyroid hormone system disruption, endocrine disruption, new approach methods,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Environmental pollutants capable of interfering with the thyroid hormone (TH) system increasingly raise concern for both human and environmental health. Recently, resorcinol has received attention as a compound of concern due to its endocrine disrupting properties. It is a known inhibitor of thyroperoxidase (TPO), an enzyme required in TH synthesis, and therapeutic use of resorcinol exposure has led to hypothyroidism in humans. There is limited evidence concerning ecotoxicologically relevant effects of resorcinol in fish. A set of adverse outcome pathways (AOPs) has recently been developed linking thyroid hormone system disruption (THSD) to impaired swim bladder inflation and eye development in fish. In the present study, these AOPs were used to provide the background for testing potential THSD effects of resorcinol in zebrafish eleutheroembryos. We exposed zebrafish eleutheroembryos to resorcinol and assessed TH levels, swim bladder inflation and eye morphology. As a TPO inhibitor, resorcinol is expected to affect TH levels and eye morphology but not swim bladder inflation during embryonic development. Indeed, thyroxine (T4) levels were significantly decreased following resorcinol exposure. In contrast to our hypothesis, swim bladder inflation was impaired at 5 days post fertilization (dpf) and no effects on eye morphology were detected. Therefore, in vitro assays were performed to identify potential additional thyroid hormone system disruption-related mechanisms through which resorcinol may act. Two new mechanisms were identified: TH receptor (TR) antagonism and transthyretin (TTR) binding inhibition. Both of these mechanisms can plausibly be linked to impaired swim bladder inflation and could, therefore, explain the observed effect. Overall, our study contributes to the knowledge of the THSD potential of resorcinol both in vivo in the zebrafish model as well as in vitro.

• Klíčová slova
• Thyroid hormone system disruption, adverse outcome pathway, eye development, swim bladder inflation, thyroid hormone levels, zebrafish embryo,
• MeSH
• chemické látky znečišťující vodu toxicita   MeSH
• dánio pruhované * MeSH
• embryo nesavčí účinky léků   MeSH
• endokrinní disruptory * toxicita   MeSH
• hormony štítné žlázy * metabolismus   MeSH
• oči účinky léků   MeSH
• resorcinoly * toxicita   MeSH
• thyroxin MeSH
• vzdušné vaky účinky léků   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• endokrinní disruptory * MeSH
• hormony štítné žlázy * MeSH
• resorcinol MeSH Prohlížeč
• resorcinoly * MeSH
• thyroxin MeSH

Disruption of the thyroid hormone (TH) system is connected with diverse adverse health outcomes in wildlife and humans. It is crucial to develop and validate suitable in vitro assays capable of measuring the disruption of the thyroid hormone (TH) system. These assays are also essential to comply with the 3R principles, aiming to replace the ex vivo tests often utilised in the chemical assessment. We compared the two commonly used assays applicable for high throughput screening [Luminol and Amplex UltraRed (AUR)] for the assessment of inhibition of thyroid peroxidase (TPO, a crucial enzyme in TH synthesis) using several cell lines and 21 compounds from different use categories. As the investigated cell lines derived from human and rat thyroid showed low or undetectable TPO expression, we developed a series of novel cell lines overexpressing human TPO protein. The HEK-TPOA7 model was prioritised for further research based on the high and stable TPO gene and protein expression. Notably, the Luminol assay detected significant peroxidase activity and signal inhibition even in Nthy-ori 3-1 and HEK293T cell lines without TPO expression, revealing its lack of specificity. Conversely, the AUR assay was specific to TPO activity. Nevertheless, despite the different specificity, both assays identified similar peroxidation inhibitors. Over half of the tested chemicals with diverse structures and from different use groups caused TPO inhibition, including some widespread environmental contaminants suggesting a potential impact of environmental chemicals on TH synthesis. Furthermore, in silico SeqAPASS analysis confirmed the high similarity of human TPO across mammals and other vertebrate classes, suggesting the applicability of HEK-TPOA7 model findings to other vertebrates.

• Klíčová slova
• Amplex UltraRed, Cross-species, In vitro, Luminol, Peroxidation, Thyroid,
• MeSH
• autoantigeny metabolismus   MeSH
• buněčné linie MeSH
• endokrinní disruptory toxicita   MeSH
• HEK293 buňky MeSH
• jodidperoxidasa * antagonisté a inhibitory   metabolismus   genetika   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• luminol MeSH
• oxaziny MeSH
• proteiny vázající železo metabolismus   MeSH
• rychlé screeningové testy metody   MeSH
• štítná žláza účinky léků   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• Amplex Red MeSH Prohlížeč
• autoantigeny MeSH
• endokrinní disruptory MeSH
• jodidperoxidasa * MeSH
• luminol MeSH
• oxaziny MeSH
• proteiny vázající železo MeSH
• TPO protein, human MeSH Prohlížeč

Information on the indoor environment as a source of exposure with potential adverse health effects is mostly limited to a few pollutant groups and indoor types. This study provides a comprehensive toxicological profile of chemical mixtures associated with dust from various types of indoor environments, namely cars, houses, prefabricated apartments, kindergartens, offices, public spaces, and schools. Organic extracts of two different polarities and bioaccessible extracts mimicking the gastrointestinal conditions were prepared from two different particle size fractions of dust. These extracts were tested on a battery of human cell-based bioassays to assess endocrine disrupting potentials. Furthermore, 155 chemicals from different pollutant groups were measured and their relevance for the bioactivity was determined using concentration addition modelling. The exhaustive and bioaccessible extracts of dust from the different microenvironments interfered with aryl hydrocarbon receptor, estrogen, androgen, glucocorticoid, and thyroid hormone (TH) receptor signalling, and with TH transport. Noteably, bioaccessible extracts from offices and public spaces showed higher estrogenic effects than the organic solvent extracts. 114 of the 155 targeted chemicals were detectable, but the observed bioactivity could be only marginally explained by the detected chemicals. Diverse toxicity patterns across different microenvironments that people inhabit throughout their lifetime indicate potential health and developmental risks, especially for children. Limited data on the endocrine disrupting potency of relevant chemical classes, especially those deployed as replacements for legacy contaminants, requires further study.

• Klíčová slova
• Bioaccessibility, Endocrine disrupting chemicals, Human risk assessment, In vitro, Indoor dust,
• MeSH
• androgeny MeSH
• dítě MeSH
• endokrinní systém MeSH
• estrogeny MeSH
• látky znečišťující životní prostředí * MeSH
• lidé MeSH
• prach analýza   MeSH
• znečištění vzduchu ve vnitřním prostředí * analýza   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• androgeny MeSH
• estrogeny MeSH
• látky znečišťující životní prostředí * MeSH
• prach MeSH

Through investigating the combined impact of the environmental exposures experienced by an individual throughout their lifetime, exposome research provides opportunities to understand and mitigate negative health outcomes. While current exposome research is driven by epidemiological studies that identify associations between exposures and effects, new frameworks integrating more substantial population-level metadata, including electronic health and administrative records, will shed further light on characterizing environmental exposure risks. Molecular biology offers methods and concepts to study the biological and health impacts of exposomes in experimental and computational systems. Of particular importance is the growing use of omics readouts in epidemiological and clinical studies. This paper calls for the adoption of mechanistic molecular biology approaches in exposome research as an essential step in understanding the genotype and exposure interactions underlying human phenotypes. A series of recommendations are presented to make the necessary and appropriate steps to move from exposure association to causation, with a huge potential to inform precision medicine and population health. This includes establishing hypothesis-driven laboratory testing within the exposome field, supported by appropriate methods to read across from model systems research to human.

• Klíčová slova
• Environment, Exposome, Exposure, GxE, Human Health, Molecular Biology, Toxicology,
• MeSH
• expozom * MeSH
• lidé MeSH
• molekulární biologie MeSH
• vystavení vlivu životního prostředí * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Among endocrine disruption, interference with the thyroid hormone (TH) regulation is of increasing concern. Respective compounds encode through their structural features both the potential for TH disruption, and the bioavailability mitigating the toxicological effect. The aim of this study is to provide a substructure-based screening-level QSAR (quantitative structure-activity relationship) that discriminates bioavailable TH disruptors from not bioavailable counterparts, covering both direct and indirect (retinoid- and AhR-mediated) modes of action. The QSAR has been derived from literature data for 1642 compounds, and takes into account Lipinski's rule-of-five and the brain/blood partition coefficient Kbrain/blood. For its validation, an external test set of 145 substances has been used. For 1787 compounds meeting the model application domain, the model yields only one false negative. The discussion addresses the mechanistic meaning of the bioavailability triggers molecular weight, H-bond donor and acceptor, hydrophobicity (log Kow), and the physicochemical properties underlying log Kbrain/blood. The model may serve as bioavailability-screening step within a decision support system for the predictive assessment of chemicals regarding their potential to disrupt thyroid hormone function in a direct or indirect manner.

• Klíčová slova
• Absorption, Bioavailability, Blood/brain partitioning, In silico assessment, Penetration, Permeation, Retinoid, Thyroid hormone disruptors,
• MeSH
• biologická dostupnost MeSH
• endokrinní disruptory * toxicita   chemie   MeSH
• hormony štítné žlázy * MeSH
• kvantitativní vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• endokrinní disruptory * MeSH
• hormony štítné žlázy * MeSH

Cyanobacterial blooms are increasing in frequency and intensity globally, and impacting recreational waters as well as waters used for drinking water provisioning. They are sources of bioactive metabolites including retinoids and the neurotoxin anatoxin-a. Here, we investigated the effects of anatoxin-a on a differentiating in vitro human neural stem cell model previously characterised with retinoic acids. Effects on protein and gene expression upon exposure for 9 or 18 days to anatoxin-a alone or in co-exposure with all-trans retinoic acid were evaluated using a panel of neural and glial differentiation biomarkers. Anatoxin-a did not cause distinct developmental neurotoxicity alone, or in co-exposure with retinoic acid. However, in line with its excitotoxicity, in co-exposure with 200 nM all-trans retinoic acid it reduced the differentiation of acetylcholinergic neuron subtypes in the culture at 1000 nM (highest tested concentration). While this could have substantial functional implications for the developing nervous system, there is no indication for developmental neurotoxicity beyond its (excito-)toxicity to acetylcholinergic neurons, which only occurred in co-exposure to all-trans retinoic acid.

• Klíčová slova
• Anatoxin, Cyanotoxin, Developmental neurotoxicity, Differentiation, NSC, Retinoids,
• MeSH
• exprese genu MeSH
• lidé MeSH
• neurotoxické syndromy * etiologie   MeSH
• retinoidy metabolismus   MeSH
• sinice * MeSH
• toxiny kmene Cyanobacteria MeSH
• tretinoin toxicita   MeSH
• tropany * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anatoxin a MeSH Prohlížeč
• retinoidy MeSH
• toxiny kmene Cyanobacteria MeSH
• tretinoin MeSH
• tropany * MeSH