Pub Date : 2025-12-12DOI: 10.1016/j.tox.2025.154371
Chong Liu , Yan Zhao , Ji-ji Dao , Yu-ke Ma , Jie Liu , Chen-meng Qiao , Chun Cui , Yan-qin Shen , Shuang-xi Chen , Li Yu , Wei-jiang Zhao
The impact of polystyrene microplastics (PS-MPs) on the nervous system has been documented, yet the potential role of PS-MPs exposure in exacerbating neuronal damage and neuroinflammation in Alzheimer's disease (AD) remains unclear. Our research demonstrated that oral exposure to PS-MPs caused hippocampal mitochondrial damage in APP/PS1 mice, reduced expression of hippocampal mitochondrial and synapse-associated proteins, inhibited ErbB4 signaling pathway, and damaged hippocampal neurons. Additionally, PS-MPs exposure induced overactivation of astrocytes and microglia with NLRP3 pathway activation, increased β-amyloid (Aβ) deposition, and ultimately worsened cognitive dysfunction in APP/PS1 mice. Subsequent in vitro findings showed that PS-MPs exacerbated hippocampal neuronal damage under Aβ pathology, suppressed ErbB4 signaling pathway, and disrupted mitochondrial and synaptic function. The compromised hippocampal neurons enhanced microglial NLRP3 pathway activation. These results suggest that exposure to PS-MPs induces hippocampal neuronal damage, impairs mitochondrial and synaptic function, and exacerbates neuroinflammation and cognitive deficits, ultimately contributing to AD progression. Collectively, these findings enhance our understanding of the mechanisms by which MPs expedite the progression and influence management of AD.
{"title":"Food-borne polystyrene microplastic exposure exacerbates cognitive deficiency via enhanced neuronal synaptic damage and neuroinflammation in Alzheimer's disease","authors":"Chong Liu , Yan Zhao , Ji-ji Dao , Yu-ke Ma , Jie Liu , Chen-meng Qiao , Chun Cui , Yan-qin Shen , Shuang-xi Chen , Li Yu , Wei-jiang Zhao","doi":"10.1016/j.tox.2025.154371","DOIUrl":"10.1016/j.tox.2025.154371","url":null,"abstract":"<div><div>The impact of polystyrene microplastics (PS-MPs) on the nervous system has been documented, yet the potential role of PS-MPs exposure in exacerbating neuronal damage and neuroinflammation in Alzheimer's disease (AD) remains unclear. Our research demonstrated that oral exposure to PS-MPs caused hippocampal mitochondrial damage in APP/PS1 mice, reduced expression of hippocampal mitochondrial and synapse-associated proteins, inhibited ErbB4 signaling pathway, and damaged hippocampal neurons. Additionally, PS-MPs exposure induced overactivation of astrocytes and microglia with NLRP3 pathway activation, increased β-amyloid (Aβ) deposition, and ultimately worsened cognitive dysfunction in APP/PS1 mice. Subsequent in vitro findings showed that PS-MPs exacerbated hippocampal neuronal damage under Aβ pathology, suppressed ErbB4 signaling pathway, and disrupted mitochondrial and synaptic function. The compromised hippocampal neurons enhanced microglial NLRP3 pathway activation. These results suggest that exposure to PS-MPs induces hippocampal neuronal damage, impairs mitochondrial and synaptic function, and exacerbates neuroinflammation and cognitive deficits, ultimately contributing to AD progression. Collectively, these findings enhance our understanding of the mechanisms by which MPs expedite the progression and influence management of AD.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154371"},"PeriodicalIF":4.6,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145757679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.tox.2025.154370
Ute Haßmann , Lisa Gölz , René Geci , Konstantinos Stefanidis , Justin Lucky Brandt , Eleanor North , Katreece Feiertag , Christel Renate Schopfer , Sigrid Amann , Stephanie Melching-Kollmuss , Robert Landsiedel
Endocrine-disrupting chemicals (EDCs) are a growing focus in human and environmental risk assessment, as reflected by the new EU CLP hazard classes for endocrine disruptors. Within this context, the symposium “Cross-Species Extrapolation in Endocrine Disruption Assessments” was held at the 10th German Pharm-Tox Summit (GPTS) 2025 in Hannover (March 11–13), which formed part of the 91st annual meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT). The symposium assembled diverse lines of research addressing endocrine disruption from complementary angles. Contributions ranged from advanced experimental model systems, such as refined zebrafish embryo assays for thyroid hormone disruption, to high-throughput in silico and in vitro–based kinetic modelling frameworks that support quantitative in vitro to in vivo extrapolation and AOP-informed risk assessment. Clinical and translational perspectives were added by targeted LC–MS/MS profiling of steroid conjugates as biomarkers for adrenal tumours. Further talks expanded the mechanistic toolbox for thyroid disruption, including enzyme- and protein-binding–based in vitro assays, and highlighted metabolic endocrine disruptors that act beyond the EATS (estrogen, androgen, thyroid and steroidogenesis) pathways. A regulatory-oriented analysis of thyroid-related modes of action across vertebrate taxa underscored the importance of clearly defining domains of applicability for cross-species extrapolation. At the same time, the discussions revealed critical gaps, including still limited taxonomic applicability domains, incomplete regulatory coverage beyond established endocrine pathways and limited transparency in predictive tools. Together, these contributions illustrate how integrated experimental, computational and regulatory science can advance mechanism-based, animal-reduced assessment of endocrine disruptors.
{"title":"Integrative assessment of endocrine disruption: From in vitro mechanisms to species extrapolation – Highlights of the German Pharma-Tox Summit 2025","authors":"Ute Haßmann , Lisa Gölz , René Geci , Konstantinos Stefanidis , Justin Lucky Brandt , Eleanor North , Katreece Feiertag , Christel Renate Schopfer , Sigrid Amann , Stephanie Melching-Kollmuss , Robert Landsiedel","doi":"10.1016/j.tox.2025.154370","DOIUrl":"10.1016/j.tox.2025.154370","url":null,"abstract":"<div><div>Endocrine-disrupting chemicals (EDCs) are a growing focus in human and environmental risk assessment, as reflected by the new EU CLP hazard classes for endocrine disruptors. Within this context, the symposium “Cross-Species Extrapolation in Endocrine Disruption Assessments” was held at the 10th German Pharm-Tox Summit (GPTS) 2025 in Hannover (March 11–13), which formed part of the 91st annual meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology (DGPT). The symposium assembled diverse lines of research addressing endocrine disruption from complementary angles. Contributions ranged from advanced experimental model systems, such as refined zebrafish embryo assays for thyroid hormone disruption, to high-throughput in silico and in vitro–based kinetic modelling frameworks that support quantitative in vitro to in vivo extrapolation and AOP-informed risk assessment. Clinical and translational perspectives were added by targeted LC–MS/MS profiling of steroid conjugates as biomarkers for adrenal tumours. Further talks expanded the mechanistic toolbox for thyroid disruption, including enzyme- and protein-binding–based in vitro assays, and highlighted metabolic endocrine disruptors that act beyond the EATS (estrogen, androgen, thyroid and steroidogenesis) pathways. A regulatory-oriented analysis of thyroid-related modes of action across vertebrate taxa underscored the importance of clearly defining domains of applicability for cross-species extrapolation. At the same time, the discussions revealed critical gaps, including still limited taxonomic applicability domains, incomplete regulatory coverage beyond established endocrine pathways and limited transparency in predictive tools. Together, these contributions illustrate how integrated experimental, computational and regulatory science can advance mechanism-based, animal-reduced assessment of endocrine disruptors.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154370"},"PeriodicalIF":4.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145752286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.tox.2025.154369
Carine El Hajjar , Ivannah Pottier , Marie Lelong , Valérie Lecureur , Véronique André
The PM10 fraction of representative indoor pollution (SRM® 2585) was repeatedly nebulized (1 and 6 μg/cm2/day) on functional mucociliary pseudo-epithelia (NHBE cells differentiated at the Air Liquide Interface, ALI). Four consecutive daily exposures have been performed and the biomarkers were analyzed on day 4, 8 and 11. Exposures at the lower dose induced at day 4 a significant increase in cellular ROS and modulations of the expression of few genes associated with genotoxicity and oxidative stress. IL-6 expression was strongly upregulated accompanied by a delayed increased secretion in the basal medium, whereas IL-8 expression was downregulated. At the highest dose, a weak and transient decrease in epithelial cohesion was observed, as well as a potential alteration of the cilia. The mucus secretion tended to increase whereas expression of MUC5AC and MUC5B was downregulated. Co-exposure to macrophage mediators (produced by pre-exposure of human macrophages to the PM2.5 fraction of SRM® 2585) induced significant overexpression of MUC5AC, IL-6 and IL-8 in the pseudo-epithelium. Three genes involved in oxidative processes, distinct from those highlighted with PM10 alone, were modulated. Despite repeated exposures, the magnitude of the mucociliary pseudo-epithelial responses remained low overall. Trapping of PM10 in the mucus associated with efficient ciliary beating contributed to limit cellular responses. Thus, this physiological process must be considered for realistic in vitro toxicity assessments. Co-exposure protocol allowed to integrate the role of the innate immune system into the overall response of the lung tissue.
{"title":"Biological responses of human tracheobronchial mucociliary pseudo-epithelium repeatedly exposed at the air-liquid interface to PM10 indoor particles","authors":"Carine El Hajjar , Ivannah Pottier , Marie Lelong , Valérie Lecureur , Véronique André","doi":"10.1016/j.tox.2025.154369","DOIUrl":"10.1016/j.tox.2025.154369","url":null,"abstract":"<div><div>The PM<sub>10</sub> fraction of representative indoor pollution (SRM® 2585) was repeatedly nebulized (1 and 6 μg/cm<sup>2</sup>/day) on functional mucociliary pseudo-epithelia (NHBE cells differentiated at the Air Liquide Interface, ALI). Four consecutive daily exposures have been performed and the biomarkers were analyzed on day 4, 8 and 11. Exposures at the lower dose induced at day 4 a significant increase in cellular ROS and modulations of the expression of few genes associated with genotoxicity and oxidative stress. IL-6 expression was strongly upregulated accompanied by a delayed increased secretion in the basal medium, whereas IL-8 expression was downregulated. At the highest dose, a weak and transient decrease in epithelial cohesion was observed, as well as a potential alteration of the cilia. The mucus secretion tended to increase whereas expression of MUC5AC and MUC5B was downregulated. Co-exposure to macrophage mediators (produced by pre-exposure of human macrophages to the PM<sub>2.5</sub> fraction of SRM® 2585) induced significant overexpression of MUC5AC, IL-6 and IL-8 in the pseudo-epithelium. Three genes involved in oxidative processes, distinct from those highlighted with PM<sub>10</sub> alone, were modulated. Despite repeated exposures, the magnitude of the mucociliary pseudo-epithelial responses remained low overall. Trapping of PM<sub>10</sub> in the mucus associated with efficient ciliary beating contributed to limit cellular responses. Thus, this physiological process must be considered for realistic <em>in vitro</em> toxicity assessments. Co-exposure protocol allowed to integrate the role of the innate immune system into the overall response of the lung tissue.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154369"},"PeriodicalIF":4.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.tox.2025.154368
Li Li , Meng Dan , Shengnan Li, Xiaojing Cui, Shibo Bao, Shengxiang Luo, Jun Cao
High mobility group A2 (HMGA2) overexpression is often observed in cancers. Previously, we found that HMGA2 contributed to hexavalent chromium [Cr (VI)]-mediated autophagy. In this study, interestingly, Cr (VI) treatment triggered both autophagy and the mammalian target of rapamycin (mTOR) in vivo ( BALB/c mice, 0.5 and 1.5 mg/kg, p.o.) and in vitro (0.1, 0.2 and 0.4 μM in A549 and HELF cells), and both autophagy and mTOR were implicated in Cr (VI)-initiated cell growth. Autophagy and mTOR were both significantly induced by HMGA2 overexpression in vivo (BALB/c mice were intratracheal injected with 10 μg and 20 μg pcDNA3.1-HMGA2 plasmid complexes) and in vitro (A549 and HELF cells). Using the autophagy suppressor, 3-methyladenine (3MA, 2 mM), chloroquine (CQ, 10 μM), and knockdown of autophagy-related protein 4 homolog B (ATG4B) gene by siRNA, it was shown that Cr (VI)-provoked mTOR was reliant on autophagy. Furthermore, the results of the scratch assay indicated that HMGA2-mediated cell migration depends on autophagy, mTOR, and glycolysis. Chromatin immunoprecipitation assay elucidated elective binding of HMGA2 protein to the ATG4B promoter region, but not AKT1 and mTOR. Altogether, our findings demonstrated that both autophagy and mTOR could be induced by Cr (VI) and they were involved in Cr (VI)-caused cell growth and migration. HMGA2 mediated this effect by transcription regulation of ATG4B. These suggested that blocking the HMGA2-autophagy-mTOR axis could serve as an effective strategy to inhibit Cr (VI)-induced cell viability.
{"title":"Hexavalent chromium induced autophagy-dependent mTOR expression mediated by upregulation of HMGA2","authors":"Li Li , Meng Dan , Shengnan Li, Xiaojing Cui, Shibo Bao, Shengxiang Luo, Jun Cao","doi":"10.1016/j.tox.2025.154368","DOIUrl":"10.1016/j.tox.2025.154368","url":null,"abstract":"<div><div>High mobility group A2 (HMGA2) overexpression is often observed in cancers. Previously, we found that HMGA2 contributed to hexavalent chromium [Cr (VI)]-mediated autophagy. In this study, interestingly, Cr (VI) treatment triggered both autophagy and the mammalian target of rapamycin (mTOR) <em>in vivo</em> ( BALB/c mice, 0.5 and 1.5 mg/kg, p.o.) and <em>in vitro</em> (0.1, 0.2 and 0.4 μM in A549 and HELF cells), and both autophagy and mTOR were implicated in Cr (VI)-initiated cell growth. Autophagy and mTOR were both significantly induced by HMGA2 overexpression <em>in vivo</em> (BALB/c mice were intratracheal injected with 10 μg and 20 μg pcDNA3.1-HMGA2 plasmid complexes) and <em>in vitro</em> (A549 and HELF cells). Using the autophagy suppressor, 3-methyladenine (3MA, 2 mM), chloroquine (CQ, 10 μM), and knockdown of autophagy-related protein 4 homolog B (<em>ATG4B</em>) gene by siRNA, it was shown that Cr (VI)-provoked mTOR was reliant on autophagy. Furthermore, the results of the scratch assay indicated that HMGA2-mediated cell migration depends on autophagy, mTOR, and glycolysis. Chromatin immunoprecipitation assay elucidated elective binding of HMGA2 protein to the <em>ATG4B</em> promoter region, but not <em>AKT1</em> and <em>mTOR</em>. Altogether, our findings demonstrated that both autophagy and mTOR could be induced by Cr (VI) and they were involved in Cr (VI)-caused cell growth and migration. HMGA2 mediated this effect by transcription regulation of <em>ATG4B</em>. These suggested that blocking the HMGA2-autophagy-mTOR axis could serve as an effective strategy to inhibit Cr (VI)-induced cell viability.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154368"},"PeriodicalIF":4.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145744605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-09DOI: 10.1016/j.tox.2025.154367
Haoran Zhang , Yijia Li , Xiaoxia Wang , Chenping Kang , Qiong Zhang , Defeng Liu , Jiaming Mao , Qianqian Xiao , Weidong Hao
Chlorocholine chloride (CCC) is a commonly used plant growth regulator. It was shown that CCC exposure could lead to decreased testosterone biosynthesis, delayed puberty onset, and damaged spermatogenesis in pubertal rodents, but the underlying mechanism is still not well understood. The testosterone level is determined not only by the functional activity of Leydig cell but also by its number and maturational status. To identify the critical developmental stage at which CCC impairs Leydig cell maturation and elucidate its underlying mechanisms, pubertal rats were exposed to 0, 75, 137.5, and 200 mg/kg bw/day CCC from PND14 (progenitor Leydig cells, PLCs) to PND28 (immature Leydig cells, ILCs) and from PND28 to PND56 (adult Leydig cells, ALCs) respectively. The results showed that, for exposure from PLCs stage, CCC exposure at 137.5 and 200 mg/kg bw/day led to histopathological changes of rat testes and impaired Leydig cell lineage specification in rats. CCC exposure at 200 mg/kg bw/day significantly decreased the mRNA expression of Star, Lhcgr, Cyp17a1, and Hsd17b3. Hormonal measurement and proteomic analysis revealed that both the disruption of the hypothalamic-pituitary-testis axis and the aberrant activation of the PI3K/AKT signaling pathway contribute to the impairment of Leydig cell lineage specification. For exposure from ILCs stage, Leydig cell development was not affected, but serum and testicular testosterone levels decreased resulting from the down-regulation of StAR, CYP11A1, and HSD3B1. In conclusion, our study found that CCC exposure could delay the development process of rat Leydig cells by disruption of Leydig cell differentiation during early developmental stage, which might lead to decreased testosterone level.
{"title":"Chlorocholine chloride delays progenitor Leydig cell differentiation via PI3K/AKT pathway activation in rats","authors":"Haoran Zhang , Yijia Li , Xiaoxia Wang , Chenping Kang , Qiong Zhang , Defeng Liu , Jiaming Mao , Qianqian Xiao , Weidong Hao","doi":"10.1016/j.tox.2025.154367","DOIUrl":"10.1016/j.tox.2025.154367","url":null,"abstract":"<div><div>Chlorocholine chloride (CCC) is a commonly used plant growth regulator. It was shown that CCC exposure could lead to decreased testosterone biosynthesis, delayed puberty onset, and damaged spermatogenesis in pubertal rodents, but the underlying mechanism is still not well understood. The testosterone level is determined not only by the functional activity of Leydig cell but also by its number and maturational status. To identify the critical developmental stage at which CCC impairs Leydig cell maturation and elucidate its underlying mechanisms, pubertal rats were exposed to 0, 75, 137.5, and 200 mg/kg bw/day CCC from PND14 (progenitor Leydig cells, PLCs) to PND28 (immature Leydig cells, ILCs) and from PND28 to PND56 (adult Leydig cells, ALCs) respectively. The results showed that, for exposure from PLCs stage, CCC exposure at 137.5 and 200 mg/kg bw/day led to histopathological changes of rat testes and impaired Leydig cell lineage specification in rats. CCC exposure at 200 mg/kg bw/day significantly decreased the mRNA expression of <em>Star</em>, <em>Lhcgr</em>, <em>Cyp17a1</em>, and <em>Hsd17b3</em>. Hormonal measurement and proteomic analysis revealed that both the disruption of the hypothalamic-pituitary-testis axis and the aberrant activation of the PI3K/AKT signaling pathway contribute to the impairment of Leydig cell lineage specification. For exposure from ILCs stage, Leydig cell development was not affected, but serum and testicular testosterone levels decreased resulting from the down-regulation of StAR, CYP11A1, and HSD3B1. In conclusion, our study found that CCC exposure could delay the development process of rat Leydig cells by disruption of Leydig cell differentiation during early developmental stage, which might lead to decreased testosterone level.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154367"},"PeriodicalIF":4.6,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145744633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-09DOI: 10.1016/j.tox.2025.154366
Jiajia Yang , Kai Yan , Xiaofang Li , Wenjing Deng , Meian He , Hao Zhu , Xiliang Yan , Bing Yan
Chemical-induced neurotoxicity poses a challenge for safety assessment due to the complexity of central nervous system responses and the limitations of conventional assays. We developed an adverse outcome pathway (AOP)-guided machine-learning framework that links molecular initiating events, using the activation of the aryl hydrocarbon receptor (AhR) and Nrf2-mediated oxidative stress responses as examples, to neurotoxicity. A curated dataset was assembled from public sources and the literature, key molecular features such as nitrogen-containing groups were identified as structural alerts associated with neurotoxicity. Within this framework, AhR and Nrf2 activity information (measured or predicted) was integrated with structural fingerprints to enhance biological interpretability while maintaining robust predictive performance (e.g., AUC value > 0.80) in both cross-validation and external validation. The AOP-based model was further applied to virtual screening of 7576 compounds, with blood–brain barrier (BBB) permeability and applicability domain (AD) constraints ensuring reliable predictions. Molecular docking of 12 prioritized persistent organic pollutants (POPs) further supported these predictions, revealing strong binding affinities with AhR (up to –10.2 kcal/mol) and Nrf2 (up to –7.9 kcal/mol) through interactions such as hydrogen bonding and π–π stacking. Overall, this strategy highlights AOP-based machine learning as a powerful approach to connect structure, mechanism, and outcomes, thereby improving chemical risk assessment and prioritization.
{"title":"Linking AhR and Nrf2 activation to neurotoxicity through adverse outcome pathway-based machine learning","authors":"Jiajia Yang , Kai Yan , Xiaofang Li , Wenjing Deng , Meian He , Hao Zhu , Xiliang Yan , Bing Yan","doi":"10.1016/j.tox.2025.154366","DOIUrl":"10.1016/j.tox.2025.154366","url":null,"abstract":"<div><div>Chemical-induced neurotoxicity poses a challenge for safety assessment due to the complexity of central nervous system responses and the limitations of conventional assays. We developed an adverse outcome pathway (AOP)-guided machine-learning framework that links molecular initiating events, using the activation of the aryl hydrocarbon receptor (AhR) and Nrf2-mediated oxidative stress responses as examples, to neurotoxicity. A curated dataset was assembled from public sources and the literature, key molecular features such as nitrogen-containing groups were identified as structural alerts associated with neurotoxicity. Within this framework, AhR and Nrf2 activity information (measured or predicted) was integrated with structural fingerprints to enhance biological interpretability while maintaining robust predictive performance (e.g., AUC value > 0.80) in both cross-validation and external validation. The AOP-based model was further applied to virtual screening of 7576 compounds, with blood–brain barrier (BBB) permeability and applicability domain (AD) constraints ensuring reliable predictions. Molecular docking of 12 prioritized persistent organic pollutants (POPs) further supported these predictions, revealing strong binding affinities with AhR (up to –10.2 kcal/mol) and Nrf2 (up to –7.9 kcal/mol) through interactions such as hydrogen bonding and π–π stacking. Overall, this strategy highlights AOP-based machine learning as a powerful approach to connect structure, mechanism, and outcomes, thereby improving chemical risk assessment and prioritization.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154366"},"PeriodicalIF":4.6,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145726133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.tox.2025.154365
Rebecca L. Jensen , Robyn T. Kiy , Carol E. Jolly , Dominic P. Williams , Amy E. Chadwick
AZD1979 is a melanin-concentrating hormone receptor 1 (MCHr1) antagonist, which was developed for obesity treatment, but clinical development was halted due to unanticipated liver toxicity. Mitochondrial DNA (mtDNA) variation influences hepatic energy metabolism and may underlie individual susceptibility to drug-induced mitotoxicity. Transmitochondrial cybrids offer a model to assess the impact of mtDNA variation on drug response against a constant nuclear background. This study assessed the mitotoxic potential of AZD1979 in HepG2 wild-type (WT) cells and HepG2 transmitochondrial cybrids representing distinct mtDNA haplogroups from the H and J haplogroup lineages. A 2-hour acute metabolic switch assay was performed in HepG2 WT cells and transmitochondrial cybrids to identify mitochondrial toxicity, with confirmatory Seahorse extracellular flux analysis. AZD1979 was identified as a potent mitotoxicant in HepG2 WT cells, inducing mitochondrial dysfunction prior to cell death. AZD1979 caused reductions in basal respiration, ATP-linked respiration, and spare respiratory capacity, and inhibited complex I-driven respiration. Cybrids displayed haplogroup-specific differences in susceptibility. Haplogroup J2b1g showed the highest sensitivity, while J1c1e, despite lacking spare respiratory capacity, was less susceptible. These findings highlight the role of mtDNA in shaping individual responses to mitochondrial toxicants and that transmitochondrial cybrid models could support early assessment of mitochondrial liability.
{"title":"Mitotoxic effects of the melanin-concentrating hormone receptor 1 (MCHr1) antagonist AZD1979 are influenced by mitochondrial DNA variation in HepG2 cybrids","authors":"Rebecca L. Jensen , Robyn T. Kiy , Carol E. Jolly , Dominic P. Williams , Amy E. Chadwick","doi":"10.1016/j.tox.2025.154365","DOIUrl":"10.1016/j.tox.2025.154365","url":null,"abstract":"<div><div>AZD1979 is a melanin-concentrating hormone receptor 1 (MCHr1) antagonist, which was developed for obesity treatment, but clinical development was halted due to unanticipated liver toxicity. Mitochondrial DNA (mtDNA) variation influences hepatic energy metabolism and may underlie individual susceptibility to drug-induced mitotoxicity. Transmitochondrial cybrids offer a model to assess the impact of mtDNA variation on drug response against a constant nuclear background. This study assessed the mitotoxic potential of AZD1979 in HepG2 wild-type (WT) cells and HepG2 transmitochondrial cybrids representing distinct mtDNA haplogroups from the H and J haplogroup lineages. A 2-hour acute metabolic switch assay was performed in HepG2 WT cells and transmitochondrial cybrids to identify mitochondrial toxicity, with confirmatory Seahorse extracellular flux analysis. AZD1979 was identified as a potent mitotoxicant in HepG2 WT cells, inducing mitochondrial dysfunction prior to cell death. AZD1979 caused reductions in basal respiration, ATP-linked respiration, and spare respiratory capacity, and inhibited complex I-driven respiration. Cybrids displayed haplogroup-specific differences in susceptibility. Haplogroup J2b1g showed the highest sensitivity, while J1c1e, despite lacking spare respiratory capacity, was less susceptible. These findings highlight the role of mtDNA in shaping individual responses to mitochondrial toxicants and that transmitochondrial cybrid models could support early assessment of mitochondrial liability.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154365"},"PeriodicalIF":4.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-03DOI: 10.1016/j.tox.2025.154364
Katharina S. Nitsche , Paul L. Carmichael , Wouter Bakker , Hans Bouwmeester , Iris Müller
Liver microphysiological systems (MPS) have gained increasing attention as human-relevant models for chemical safety assessments, particularly for studies with defined endpoints, such as cholestatic injury. In this study, we built upon a previously established HepaRG-based liver MPS model using the OrganoPlate® 3-lane system. Our aim in this proof-of-concept study was to characterise the synthetic capacity and metabolic function, focusing on the bile acid secretion, under both basal and chemically treated conditions at three independent time points. Undifferentiated HepaRG cells were seeded into the perfusion channels coated with Matrigel and cultured under flow condition without the addition of dimethyl sulfoxide (DMSO). We monitored cell self-organisation, health, and maturation using microscopy, viability assays, albumin and individual bile acid secretion profiling, and gene expression analysis. To assess the metabolic competence and treatment responses regarding the bile acid secretion, the cells were exposed to rifampicin and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 48 h. Despite the absence of DMSO supplementation, HepaRG cells self-organised into maturing aggregates and demonstrated inducible CYP1A2 and CYP3A4 activity by day 3. Although the synthetic capacity was generally low, the model secreted all primary (conjugated) bile acids and exhibited clear time-dependent changes in the bile acid composition under treatment. These proof-of-concept findings highlight the potential of flow conditions to enable in situ HepaRG maturation and represent a promising step toward defining a potential context of use as a tool for cholestatic injury.
{"title":"Characterising a HepaRG liver microphysiological system for individual bile acid secretion and chemical induced disruptions","authors":"Katharina S. Nitsche , Paul L. Carmichael , Wouter Bakker , Hans Bouwmeester , Iris Müller","doi":"10.1016/j.tox.2025.154364","DOIUrl":"10.1016/j.tox.2025.154364","url":null,"abstract":"<div><div>Liver microphysiological systems (MPS) have gained increasing attention as human-relevant models for chemical safety assessments, particularly for studies with defined endpoints, such as cholestatic injury. In this study, we built upon a previously established HepaRG-based liver MPS model using the OrganoPlate® 3-lane system. Our aim in this proof-of-concept study was to characterise the synthetic capacity and metabolic function, focusing on the bile acid secretion, under both basal and chemically treated conditions at three independent time points. Undifferentiated HepaRG cells were seeded into the perfusion channels coated with Matrigel and cultured under flow condition without the addition of dimethyl sulfoxide (DMSO). We monitored cell self-organisation, health, and maturation using microscopy, viability assays, albumin and individual bile acid secretion profiling, and gene expression analysis. To assess the metabolic competence and treatment responses regarding the bile acid secretion, the cells were exposed to rifampicin and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 48 h. Despite the absence of DMSO supplementation, HepaRG cells self-organised into maturing aggregates and demonstrated inducible CYP1A2 and CYP3A4 activity by day 3. Although the synthetic capacity was generally low, the model secreted all primary (conjugated) bile acids and exhibited clear time-dependent changes in the bile acid composition under treatment. These proof-of-concept findings highlight the potential of flow conditions to enable <em>in situ</em> HepaRG maturation and represent a promising step toward defining a potential context of use as a tool for cholestatic injury.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154364"},"PeriodicalIF":4.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-02DOI: 10.1016/j.tox.2025.154363
Kang Wang , Huixian Chen , Pinyi Chen , Lei Wu , Yan Jiang , Tao Chen
Perfluorooctane sulfonamide (PFOSA), an immediate precursor of perfluorooctane sulfonate (PFOS), is widely detected in the environment. Recent studies have indicated that the aryl hydrocarbon receptor (AhR) mediates PFOSA-induced cardiac defects; however, the precise mechanisms remain unclear. Given that genes involved in endoplasmic reticulum stress (ERS) are enriched in zebrafish larvae following PFOSA exposure, we hypothesized that AhR mediates PFOSA-induced cardiac defects through ERS. In this study, we observed a dose-dependent increase in the ERS markers Grp78 and Chop in the hearts of zebrafish larvae exposed to PFOSA. Furthermore, PFOSA-induced ERS activated the PERK branch of the unfolded protein response (UPR), while inhibition of either AhR or reactive oxygen species (ROS) significantly attenuated PFOSA-triggered ERS and PERK branch activation. The results further demonstrated that PFOSA-induced ERS and PERK activation led to 1) mitochondrial calcium overload through the Ip3r/Grp75/Vdac1 complex, and 2) downregulation of PGC-1α resulting from CHOP overexpression. Collectively, these events resulted in apoptosis in the zebrafish embryonic heart. AhR/ROS-dependent ERS, PERK branch activation, and mitochondrial damage were also observed in rat embryonic cardiomyocytes exposed to PFOSA. In conclusion, our findings indicate that PFOSA induces ERS and activates the PERK branch through the AhR/ROS axis, leading to mitochondrial damage via calcium overload and PGC-1α suppression, ultimately resulting in apoptosis and cardiac defects. Overall, these results highlight the fundamental role of ERS in the cardiac developmental toxicity of PFOSA.
{"title":"AhR/ROS-mediated endoplasmic reticulum stress contributes to PFOSA-induced cardiac defects","authors":"Kang Wang , Huixian Chen , Pinyi Chen , Lei Wu , Yan Jiang , Tao Chen","doi":"10.1016/j.tox.2025.154363","DOIUrl":"10.1016/j.tox.2025.154363","url":null,"abstract":"<div><div>Perfluorooctane sulfonamide (PFOSA), an immediate precursor of perfluorooctane sulfonate (PFOS), is widely detected in the environment. Recent studies have indicated that the aryl hydrocarbon receptor (AhR) mediates PFOSA-induced cardiac defects; however, the precise mechanisms remain unclear. Given that genes involved in endoplasmic reticulum stress (ERS) are enriched in zebrafish larvae following PFOSA exposure, we hypothesized that AhR mediates PFOSA-induced cardiac defects through ERS. In this study, we observed a dose-dependent increase in the ERS markers Grp78 and Chop in the hearts of zebrafish larvae exposed to PFOSA. Furthermore, PFOSA-induced ERS activated the PERK branch of the unfolded protein response (UPR), while inhibition of either AhR or reactive oxygen species (ROS) significantly attenuated PFOSA-triggered ERS and PERK branch activation. The results further demonstrated that PFOSA-induced ERS and PERK activation led to 1) mitochondrial calcium overload through the Ip3r/Grp75/Vdac1 complex, and 2) downregulation of PGC-1α resulting from CHOP overexpression. Collectively, these events resulted in apoptosis in the zebrafish embryonic heart. AhR/ROS-dependent ERS, PERK branch activation, and mitochondrial damage were also observed in rat embryonic cardiomyocytes exposed to PFOSA. In conclusion, our findings indicate that PFOSA induces ERS and activates the PERK branch through the AhR/ROS axis, leading to mitochondrial damage via calcium overload and PGC-1α suppression, ultimately resulting in apoptosis and cardiac defects. Overall, these results highlight the fundamental role of ERS in the cardiac developmental toxicity of PFOSA.</div></div>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":"520 ","pages":"Article 154363"},"PeriodicalIF":4.6,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145669377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zinc oxide nanoparticles (ZNPs) are extensively used in cosmetics and topical medications and are considered safe for normal skin. However, patients with inflammatory dermatoses, who have an impaired skin barrier, may be at increased risk of percutaneous exposure to ZNPs. Limited research currently exists on the percutaneous toxicity of ZNPs in such conditions. Therefore, this study aimed to evaluate the safety of ZNPs in inflammatory dermatoses. ZNP treatment increased inflammatory human immortalised keratinocyte (HaCaT) cell death and significantly elevated phosphorylated mixed lineage kinase domain-like protein (p-MLKL) protein expression in a concentration-dependent manner, showing that ZNPs trigger necroptosis in HaCaT cells. Further exploration revealed that ZNPs induced mitochondrial swelling and rupture and abnormal opening of the mitochondrial permeability transition pore (mPTP) in inflammatory HaCaT cells as well as decreased the expression of spastic paraplegia 7 (SPG7), a critical protein of the mPTP. Furthermore, phosphatidylserine decarboxylase (PISD) expression in the inner mitochondrial membrane (IMM) was significantly reduced. SPG7 overexpression reversed mPTP opening and necroptosis, whereas PISD overexpression directly upregulated SPG7 expression, inhibited mPTP opening, and reversed necroptosis. Our results indicate that ZNPs contribute to mPTP opening and mitochondrial swelling and rupture via the PISD/SPG7 pathway, an important mechanism leading to necroptosis in inflammatory HaCaT cells. Overall, this study highlights the potential hazards of ZNP exposure in patients with inflammatory dermatoses, reveals the mechanism of injury by which ZNPs induce skin toxicity, and provides data for future dermatotoxicological studies on ZNPs.
{"title":"Mechanism of PISD/SPG7-mediated mPTP opening in necroptosis of inflammatory HaCaT cells induced by nano-zinc oxide.","authors":"Menglei Wang, Qianwen Yang, Wantong Xiao, Yawen Luo, Jiawen Chen, Ziyi Tang, Yu Wei, Haiqing Li, Wanchun You, Yue Zheng, Li Li","doi":"10.1016/j.tox.2025.154258","DOIUrl":"10.1016/j.tox.2025.154258","url":null,"abstract":"<p><p>Zinc oxide nanoparticles (ZNPs) are extensively used in cosmetics and topical medications and are considered safe for normal skin. However, patients with inflammatory dermatoses, who have an impaired skin barrier, may be at increased risk of percutaneous exposure to ZNPs. Limited research currently exists on the percutaneous toxicity of ZNPs in such conditions. Therefore, this study aimed to evaluate the safety of ZNPs in inflammatory dermatoses. ZNP treatment increased inflammatory human immortalised keratinocyte (HaCaT) cell death and significantly elevated phosphorylated mixed lineage kinase domain-like protein (p-MLKL) protein expression in a concentration-dependent manner, showing that ZNPs trigger necroptosis in HaCaT cells. Further exploration revealed that ZNPs induced mitochondrial swelling and rupture and abnormal opening of the mitochondrial permeability transition pore (mPTP) in inflammatory HaCaT cells as well as decreased the expression of spastic paraplegia 7 (SPG7), a critical protein of the mPTP. Furthermore, phosphatidylserine decarboxylase (PISD) expression in the inner mitochondrial membrane (IMM) was significantly reduced. SPG7 overexpression reversed mPTP opening and necroptosis, whereas PISD overexpression directly upregulated SPG7 expression, inhibited mPTP opening, and reversed necroptosis. Our results indicate that ZNPs contribute to mPTP opening and mitochondrial swelling and rupture via the PISD/SPG7 pathway, an important mechanism leading to necroptosis in inflammatory HaCaT cells. Overall, this study highlights the potential hazards of ZNP exposure in patients with inflammatory dermatoses, reveals the mechanism of injury by which ZNPs induce skin toxicity, and provides data for future dermatotoxicological studies on ZNPs.</p>","PeriodicalId":23159,"journal":{"name":"Toxicology","volume":" ","pages":"154258"},"PeriodicalIF":4.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144804916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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