Toxicological Sciences最新文献

{"title":"Late gestational exposure to flutamide alters stromal composition and immune landscape in the rat mammary gland during pre-puberty, peri-puberty, and adulthood.","authors":"David Tovar Parra, Alec McDermott, Jysiane Cardot, Melany Nicole Juarez, Fabien Joao, Rhizlane El Omri-Charai, Line Berthiaume, Bhawna Dhawan, Arash Aghigh, Yann Breton, François Légaré, Géraldine Delbès, Martin Pelletier, Étienne Audet-Walsh, Isabelle Plante","doi":"10.1093/toxsci/kfag053","DOIUrl":"10.1093/toxsci/kfag053","url":null,"abstract":"<p><p>Perinatal development of the mammary gland is regulated by hormonal signals that influence cell proliferation, extracellular matrix remodeling, immune cell recruitment, and intracellular signaling. Although the role of estrogen in mammary gland development is well established, the impact of androgens remains less understood. To address this gap, we inhibited androgen signaling in utero using the anti-androgen flutamide (FLU) and investigated the effects on mammary gland development in rats. Using an integrative strategy combining histology, transcriptomics, lipidomics, cytokine profiling, and high-resolution imaging, mammary tissue were analyzed at pre-puberty (postnatal days [PND] 21), peri-puberty (PND46), and adulthood (PND90). FLU exposure induced subtle, yet significant, alterations in mammary morphology and molecular signatures. At PND21, the FLU-exposed group exhibited an increased number of adipocytes with reduced size. Transcriptomic analysis revealed differentially expressed genes at PND21 and enrichment in pathways related to androgen response and immune signaling, but minimal changes at later developmental stages. Lipidomic profiling showed transient disruption in long-chain fatty acid composition at early developmental stages. Cytokine profiling revealed a reduced adaptive immune response at PND46 and PND90, and second-harmonic generation imaging demonstrated changes in collagen fiber orientation and density across all developmental stages. These data indicate that prenatal androgen signaling is essential for proper stromal development and the establishment of early transcriptional networks in the mammary gland, with only minor long-term effects on glandular architecture in adult nulliparous females.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13220753/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147975743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-concentration MEHP triggers mtDNA depletion in undifferentiated HepaRG and C2C12 cultures and disrupts mitochondrial homeostasis in both HepaRG culture states.","authors":"Md Mostafijur Rahman, Pabitra Khadka, Carolyn K J Young, Jing Wang, Elizabeth M McCormick, Marni J Falk, Matthew J Young","doi":"10.1093/toxsci/kfag049","DOIUrl":"10.1093/toxsci/kfag049","url":null,"abstract":"<p><p>Phthalates are often called \"everywhere chemicals\" because they are widely used in consumer products and are detectable in the environment and humans. One of the most studied phthalates, di-2-ethylhexyl phthalate (DEHP), is metabolized to mono-(2-ethylhexyl) phthalate (MEHP), which is known to disrupt metabolic processes through peroxisome proliferator-activated receptor (PPAR) signaling. However, accumulating evidence suggests that lipophilic phthalates also affect mitochondria, key regulators of oxidative metabolism, autophagy, and apoptosis. Based on previous observations that undifferentiated cells are more sensitive to a mitotoxic agent, we hypothesized that MEHP differentially affects mitochondrial function and mitochondrial DNA (mtDNA) maintenance across hepatic cell states. To test this, we used the human HepaRG hepatoma-derived cell line, which can be cultured in undifferentiated and differentiated states, and assessed viability and mitochondrial function following prolonged 6- and 12-d high-concentration MEHP treatments. Prolonged treatments reduced viability and altered bioenergetics in both states. Short treatments (1 to 3 d) reduced viability only in differentiated cultures and were associated with mtDNA depletion in undifferentiated cultures. In both states, MEHP increased the expression of the low-molecular-weight mitochondrial genome maintenance exonuclease (MGME1) isoform, altered the levels of autophagy-related factors, and induced apoptosis. In another mitochondrial-competent myoblast model (C2C12 cells), a high concentration of MEHP was associated with mtDNA depletion, whereas lower concentrations were associated with modest reductions in cell density without detectable mtDNA loss. These results demonstrate state-dependent mitochondrial responses to MEHP and indicate that a reduced endpoint cell density is a sensitive outcome occurring independently of, and at lower concentrations than, mtDNA depletion in undifferentiated cells.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13195206/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147782029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RNAseq analysis demonstrates polarization state-dependent responses to ambient particulate matter in a particle composition-specific manner.","authors":"Timothy R Smyth, Stephanie Brocke, Weidong Wu, Zhen An, Ilona Jaspers","doi":"10.1093/toxsci/kfag050","DOIUrl":"10.1093/toxsci/kfag050","url":null,"abstract":"<p><p>Macrophages are key innate immune cells which exist on a spectrum between pro-inflammatory (M1) and pro-resolutory (M2) states while retaining the ability to reprogram following exposure to new stimuli. Particulate matter (PM) exposure significantly alters macrophage function, leading to increasing respiratory infection morbidity and mortality. However, the influence of macrophage polarization on PM responses remains poorly understood. We hypothesized that human macrophages would demonstrate polarization state- and seasonality-specific responses to airborne PM collected from Xinxiang, China. CD14+CD16- monocytes were differentiated into macrophages and polarized using established methods with or without PM co-exposure followed by RNA sequencing (RNAseq). Macrophage expression profiles were primarily determined by inflammatory (M1) versus naive (M0) and alternative activation (M2), regardless of PM exposure. However, differential expression analysis using polarization state-specific reference groups uncovered distinct gene and pathway expression patterns. Directly polarized M0- > M1 macrophages exhibited the fewest unique differentially expressed genes (DEGs) but displayed similar pathway level activity to reprogrammed M2- > M1 cells. M2 macrophages showed the highest number of unique DEGs suggesting increased chemotactic pathway activity. Conversely, M0 cells exhibited greater expression of major inflammatory cytokines and chemokines. Although polarization state was the primary driver of gene and pathway responses, expression levels varied depending on PM collection dates and correlated strongly with individual PM components in M0 and M2 cells. These findings highlight the need to consider both particle seasonality and macrophage polarization state when studying PM's impact on macrophages as these factors may contribute to the negative health outcomes associated with PM exposure during respiratory infections.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13189859/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147821123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An environmentally relevant mixture of organophosphate esters induces cholesterol biosynthesis in THP-1 macrophages.","authors":"Braeden H Giles, Bernard Robaire, Koren K Mann","doi":"10.1093/toxsci/kfag048","DOIUrl":"10.1093/toxsci/kfag048","url":null,"abstract":"<p><p>Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, are environmental toxicants known to disrupt lipid metabolism. Although most studies have focused on individual OPEs, environmental exposures typically involve complex mixtures. Our previous studies demonstrated that a representative OPE mixture from Canadian household dust promotes cholesterol and lipid droplet accumulation in THP-1 macrophages. However, the molecular mechanisms underlying this lipid dysregulation remain unclear. Here, we employed tandem mass tag (TMT)-based quantitative proteomics to investigate how OPE mixtures alter protein expression and lipid regulation in macrophages. THP-1 macrophages were exposed to vehicle or environmentally relevant dilutions of the OPE mixture for 48 h. Lysates were subjected to TMT labeling and mass spectrometry. Bioinformatic analyses using STRING and Ingenuity Pathway Analysis identified 162 differentially expressed proteins, with unsupervised clustering highlighting cholesterol biosynthesis as a key pathway. Further validation via qPCR and upstream analysis implicated the sterol regulatory element-binding protein 2 (SREBP2) signaling axis in OPE-induced cholesterol biosynthesis. Functional assays revealed that atorvastatin-mediated HMG-CoA reductase inhibition, the rate limiting enzyme in cholesterol biosynthesis, prevents cholesterol buildup and lipid droplet formation in macrophages. These findings provide the first evidence that an environmentally relevant OPE mixture can induce cholesterol biosynthesis in human macrophages. These studies provide mechanistic evidence that an environmentally relevant mixture of organophosphate esters induces cholesterol biosynthesis in macrophages. These findings link real-world exposure to lipid pathways implicated in metabolic disease and support the need for updated regulatory standards that protect human health.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13189854/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147782032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating experimental data and mechanistic modeling to assess potential lead exposure from tampon use.","authors":"Corie A Ellison, Patrick R Doyle, Christina A Haven, Denise M McClenathan, Cindy M Obringer, Kara E Woeller","doi":"10.1093/toxsci/kfag052","DOIUrl":"10.1093/toxsci/kfag052","url":null,"abstract":"<p><p>Trace levels of lead (Pb) have been reported in tampons, prompting concerns about potential exposure during menstrual product use. However, the presence of a chemical in a product does not necessarily translate to biologically relevant exposure. In this study, we characterized the distribution and binding of Pb in menstrual fluid and developed a deterministic, compartmental mass-balance model to evaluate the release and fate of Pb that may be present as an inadvertent trace impurity in tampons. Our experimental measurements demonstrated that Pb preferentially partitions to the red blood cell (RBC) fraction of menstrual fluid. The remaining Pb was distributed in the plasma fraction, where the majority was protein-bound. These distribution and binding characteristics were broadly comparable to those reported for systemic blood. Utilizing these data, a mechanistic model was parameterized to describe the release of Pb from a tampon into menstrual fluid, partitioning between menstrual fluid compartments, reabsorption into the tampon during fluid uptake, and potential permeation across vaginal tissue. Under the conservative assumptions evaluated here, model simulations for a 4-h tampon wear scenario predicted that the majority of theoretically released Pb is reabsorbed into the tampon, with only a very small fraction (<1 ng; <0.3%) available for potential absorption into vaginal tissue. Sensitivity and alternative release scenario analyses demonstrated that predicted tissue uptake remained minimal across various plausible conditions. Collectively, these findings underscore the importance of integrating chemical presence data with physiological context and mechanistic modeling to inform exposure assessment and support science-based evaluation of product safety.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13215380/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147843165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benzene-induced pulmonary dysfunction in diabetic mice.","authors":"Ahtesham Hussain, Sanjay Srivastava, Igor N Zelko","doi":"10.1093/toxsci/kfag054","DOIUrl":"10.1093/toxsci/kfag054","url":null,"abstract":"<p><p>Benzene is among the most produced chemicals in the United States, and epidemiological evidence links benzene exposure to impaired pulmonary function; yet, the influence of pre-existing metabolic disease on susceptibility remains poorly defined. We investigated the effects of inhaled benzene on pulmonary mechanics and surfactant homeostasis in diabetic mice with varying glycemic severity. Mildly hyperglycemic KK and severely hyperglycemic, insulin-resistant KK-Ay mice were exposed to filtered air or 50 ppm benzene (6 h/d, 5 d/wk) for 2 wk. Pulmonary function was assessed by the forced-oscillation technique, and bronchoalveolar lavage fluid was analyzed for surfactant proteins and lipid composition by lipidomics; whole-lung transcriptomes were profiled by RNA sequencing. Benzene increased respiratory system resistance and Newtonian resistance in KK-Ay mice without altering tissue elastance or compliance in either strain. Methacholine challenge revealed exaggerated bronchoconstriction in benzene-exposed KK-Ay mice, with significant increases in Rn and tissue damping absent in benzene-exposed KK controls. Surfactant protein B was reduced by benzene in both strains, whereas SP-C was diminished in benzene-exposed KK-Ay mice compared with benzene-exposed KK controls. Lipidomic profiling demonstrated benzene-induced surfactant lipid remodeling characterized by elevated triradylglycerols, increased phosphatidylcholine-to-phosphatidylethanolamine ratio, and reduced phosphatidylserine, with specific lipid classes correlating with airway resistance. Transcriptomic analysis identified enrichment of neurotransmitter transport, ion-channel, and calcium-regulated exocytosis pathways, alongside upregulation of phase II detoxification enzymes. These findings demonstrate that in severe hyperglycemic KK-Ay mice, benzene induced airway hyperresponsiveness through convergent disruption of surfactant protein/lipid homeostasis, identifying poorly controlled diabetes as a risk factor for benzene-related respiratory toxicity.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13220762/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147975789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling toxicological adverse outcomes: toward construction and simulation of large-scale networks.","authors":"Nensi Ikonomi, Natalie Ketter, Mario A A Pepe","doi":"10.1093/toxsci/kfag043","DOIUrl":"10.1093/toxsci/kfag043","url":null,"abstract":"<p><p>Predicting toxicological adverse outcomes is crucial for advancing in silico toxicology strategies. Modern toxicology increasingly relies on systems biology approaches to model and interpret these outcomes. Adverse outcome pathways (AOPs) focus on systems-level descriptions and causal linear relations among initiating, key, and adverse outcome events. Key characteristics (KC)-based topologies capture mechanistic breadth via interconnected property-based modules without assuming linear causality. From another perspective, emerging physiological maps dive deeper into toxicological mechanisms by mapping them at the detailed molecular level. To capture the dynamic nature of toxicological responses, especially their time- and dose-dependent behaviors, there is growing interest in integrating systems biology and mathematical modeling strategies. Although dynamic models have been applied to small-scale AOPs, larger regulatory networks remain largely unexplored from a dynamic perspective. In this review, we highlight recent efforts to combine systems and network biology approaches for predicting toxicological adverse outcomes, covering network construction, analysis, and dynamic predictions. We also explore the aspect of dynamically simulating large-scale molecular networks and its potential contribution to systems toxicology. Specifically, we charter the use of logic-based models (Boolean networks) as an integrative approach to understand molecular crosstalk and cellular phenotypes, highlighting the potential repurpose of existing models. To this end, we show 2 use cases on toxicological applications of Boolean network models. Finally, we prospectively discuss the importance and need of bridging molecular and systemic scales and integrating these modeling strategies with high-dimensional data sources, including omics and multi-omics datasets.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13120877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147676967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal variation in markers of immune signaling and wound repair in primary human airway epithelial cells following acute versus repeated woodsmoke condensate exposure.","authors":"Elise Hickman, Chloe K Chou, Cole Seifert, Jessie Chappel, Yong Ho Kim, Elizabeth Corteselli, Julia E Rager","doi":"10.1093/toxsci/kfag035","DOIUrl":"10.1093/toxsci/kfag035","url":null,"abstract":"<p><p>Wildfire smoke (WFS) exposures are becoming more common, and firefighters and community members are often exposed to WFS for days to weeks. Controlled studies assessing the effects of repeated exposure to WFS and woodsmoke (WS; as a surrogate for WFS) or compared acute versus repeated exposure have evaluated a limited number of timepoints and endpoints using rodent models. Here, we leveraged differentiated primary human bronchial epithelial cells (HBECs) to test the hypothesis that different molecular responses occur upon acute versus repeat exposures to WS. HBECs (n = 4 donors) were exposed to 22 µg/cm2 red oak WS condensate for an acute, 4-h exposure, or repeat exposures of 4 h/d, 3 d/wk, across 2 wk. Membrane permeability, cell viability, and transcriptional responses were measured at the end of each exposure paradigm, and secreted proteins were measured throughout the repeat exposure. Acute exposure significantly increased expression of genes involved in fibrosis and immune response, whereas repeated exposure significantly decreased expression of genes involved in tissue repair and remodeling. Secreted protein responses were similar to transcriptomic responses and demonstrated temporal variation in response to exposure. This study supports the feasibility of using HBECs to evaluate acute and repeat WS exposures and indicates differential responses from these exposures with direct relevance to pulmonary disease processes, including those involved in fibrosis, asthma, and chronic obstructive pulmonary disease. These findings highlight the need for future studies to better understand molecular responses to repeated smoke exposures.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13120886/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147494467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergent latent neurotoxic effects of manganese following nominal chronic exposures in human stem cell and Caenorhabditis elegans models.","authors":"Xueqi Tang, Airton C Martins, Anke M Tukker, Hyunjin Kim, Michael Aschner, Aaron B Bowman","doi":"10.1093/toxsci/kfag040","DOIUrl":"10.1093/toxsci/kfag040","url":null,"abstract":"<p><p>Behavioral deficits can emerge after the removal of manganese (Mn) exposures in humans and other mammals. Although epidemiological studies provide substantial evidence supporting latency, challenges reproducing such effects in alternative models have slowed mechanistic understanding. Here, we report in 2 systems, human-induced pluripotent stem cell (hiPSC)-derived and Caenorhabditis elegans, that prior chronic exposure elicits clear latent neurotoxic effects in gene expression and functional outcomes. To identify these effects and investigate underlying mechanisms, single-cell RNA sequencing was employed in hiPSC-derived cortical culture to provide comparisons of transcriptomic changes immediately following versus after cessation of chronic Mn exposures. Transcriptomic alterations revealed latent effects after cessation of elevated Mn that were not detected immediately following 40-day exposures. To confirm the reproducibility of the observed latent magnification of chronic Mn-induced neurotoxicity, behavioral endpoints were evaluated in C. elegans. We detected a significant amplification of 2 motor phenotypes after a period of exposure cessation. These data demonstrate, in 2 genetic and mechanistically tractable systems, the detection of novel latent neurotoxic effects not detected until the cessation of a chronic exposure at a magnitude well beyond the effects of the chronic Mn exposure itself. Identified alterations support a linkage between the latent effects following chronic Mn exposure and a broad range of neurodegenerative etiologies and provide insight into the cellular pathways involved. Using both in vitro and in vivo experimental models provides complementary evidence that substantially strengthens the robustness and translational relevance of these novel findings.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":"209 4","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13127424/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147781101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative estimates of inter-individual variability for new approach methodologies-based systemic safety toolbox using a population-based human in vitro model.","authors":"Ibrahim Alshammari, Lucie C Ford, Han-Hsuan D Tsai, Hsing-Chieh Lin, Chander K Negi, Allison N Dickey, Fred A Wright, Alistair M Middleton, Maria T Baltazar, Joe Reynolds, Sophie Cable, Ans Punt, Weihsueh A Chiu, Ivan Rusyn","doi":"10.1093/toxsci/kfag038","DOIUrl":"10.1093/toxsci/kfag038","url":null,"abstract":"<p><p>Next-generation risk assessment (NGRA) frameworks use new approach methodologies (NAMs) to support regulatory decisions without animal testing. Although NAM-based approaches are well established for hazard and dose-response assessment, inter-individual variability is still typically addressed using default uncertainty factors for inter-individual variability. This study evaluated an NAM-based strategy to quantify chemical-specific variability using a human cell model. We hypothesized that integrating chemical-specific variability data into NGRA would yield more protective risk estimates. Using 131 human lymphoblastoid cell lines (LCLs) from four European and African subpopulations, we assessed differences in cytotoxic responses to 53 substances, including industrial chemicals, pharmaceuticals, pesticides, and consumer-use compounds. Concentration-response testing (0.3 nM to 300 μM) data were analyzed using Bayesian modeling to calculate points of departure per cell line. Of the substances tested, 18 exhibited cytotoxic effects, enabling the derivation of chemical-specific variability factors. These factors were designated as toxicodynamic variability factors at the 5th percentile (TDVF05) because of the limited metabolic capacity of lymphoblast cell lines. The median TDVF05 was 3.8 (range 1 to 46), largely consistent with default assumptions. A genome-wide association study (GWAS) identified genomic loci, primarily containing transporter and metabolism genes, associated with variability in cytotoxicity, suggesting mechanistic bases for inter-individual differences. Overall, this study shows that human LCLs are a practical high-throughput in vitro model for quantifying inter-individual variability, strengthening confidence in NGRA risk predictions and supporting hypothesis generation on chemical-specific genetic and mechanistic drivers of human variability. However, cell-based systems have limited coverage of adverse effects and require careful alignment with in vivo dosimetry.</p>","PeriodicalId":23178,"journal":{"name":"Toxicological Sciences","volume":" ","pages":""},"PeriodicalIF":5.2,"publicationDate":"2026-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13099385/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147514903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}