Toxicol. Sci. [JOURNAL]
Sun
200 papers
Characterization of woodsmoke generated in the air pollution exposure lab and comparison to diesel exhaust.
Xi Y, Hardy K, Choudhary V … +5 more , Zaks J, Schwartz C, Rider CF, Bertram AK, Carlsten C
Toxicol Sci · 2026 Jan · PMID 41237059 · Full text
To address the increasing concern regarding woodsmoke (WS) exposure and better understand its effects on human health, a WS generation system was built in the Air Pollution Exposure Laboratory to facilitate future contro...
To address the increasing concern regarding woodsmoke (WS) exposure and better understand its effects on human health, a WS generation system was built in the Air Pollution Exposure Laboratory to facilitate future controlled human exposure studies. Ground lodgepole pine was burned to generate WS, with PM2.5 concentrations of approximately 500 µg/m3 obtained. The WS produced by this system was characterized and directly compared with diesel exhaust (DE) generated and collected at the same facility. For gases, WS showed slight increases in CO and CO2 compared with filtered air (FA), whereas DE had significantly higher levels of NOx, CO, CO2, and total volatile organic compounds than FA. The non-refractory composition of WS aerosols was approximately 98% organics, 0.2% ammonium, 1.3% nitrate, and 0.2% sulfate. Among the organic species, the fraction of oxygenated species was much higher in WS aerosols than in DE aerosols. Moreover, WS aerosols had higher concentrations of Cd compared with DE aerosols. Greater oxidative potential was also observed for WS compared with DE, with dithiothreitol consumption rates of 0.0090 nmol/min/µg. This study established a controlled human exposure platform for WS and described the methods used for analyzing and comparing the concentrations, particulate morphologies, chemical compositions, and oxidative potentials of different lab-generated pollutants. The observed differences between WS and DE in oxidative potential and amounts of gases, organic species, and metals provide a foundation for investigating how specific air pollution components differentially impact human health.
Dual use of combustible and electronic cigarettes progressively disrupts tight junctions and elevates oxidative stress, leading to compromised blood-brain barrier integrity.
Jadhav SR, Akter KA, Mara D … +1 more , Abbruscato TJ
Toxicol Sci · 2026 Jan · PMID 41223140 · Publisher ↗
Despite the adverse effects of combustible (C-cig) and electronic cigarettes (E-cig) being well studied, their combined impact as dual product use on the blood-brain barrier (BBB) remains underexplored. This study uses b...
Despite the adverse effects of combustible (C-cig) and electronic cigarettes (E-cig) being well studied, their combined impact as dual product use on the blood-brain barrier (BBB) remains underexplored. This study uses both in vitro and in vivo models to examine the effect of dual use of C-cig and E-cig products on BBB integrity. For short (24 h) and prolonged (5 d) duration, brain endothelial cell (bEnd.3) and primary astrocytes were exposed to C-cig, E-cig, and three dual combinations. Assessments included cell viability, sodium fluorescein (NaF) permeability assay across monolayer, astrocyte-conditioned media, and co-culture models, western-blot analysis of tight junction (TJ) proteins (zonula occludens-1 (ZO-1), occludin, and claudin-5), and antioxidative markers (NAD(P)H quinone dehydrogenase 1 (NQO1), heme oxygenase-1 (HO-1), and superoxide dismutase 2 (SOD2)). In vivo, male mice (C57BL/6) were acutely exposed (7 d), and outcomes included changes in body weight, plasma nicotine concentration using LCMS/MS, western-blot analysis of TJ proteins, and cytokine profiles. A significant increase in the NaF permeability was observed with Dual 1 exposure (1:1 C-cig:E-cig ratio), with significant downregulation of ZO-1 after short and claudin-5 expression after prolonged exposure duration. Dual exposure groups also elevated NQO1 and HO-1 levels, indicating a shift in oxidative stress, while SOD2 levels remained unchanged. In vivo, dual use resulted in weight loss, reduced ZO-1 expression, elevated plasma nicotine concentration, and an increase in proinflammatory cytokines (IL-13, KC). Dual use of C-cig and E-cig is often misinterpreted as a safer alternative due to perceived reduction in C-cig use. Our data indicate that this might not be the case, as dual use, particularly with a 1:1 ratio, significantly alters BBB integrity.
Correction to: Dermal absorption and metabolism of [14C]-C12 alkyl benzoate in Finsolv TN in human skin in vitro.
Toxicol Sci · 2025 Dec · PMID 41208183 · Publisher ↗
Abstract loading — click title to view on PubMed.
An in utero exposure to the synthetic estrogen diethylstilbestrol affects the fat pad composition in post-natal mammary glands.
Tovar-Parra D, McDermott A, Cardot J … +12 more , Juarez MN, Joao F, El Omri-Charai R, Berthiaume L, Dhawan B, Aghigh A, Breton Y, Légaré F, Delbès G, Pelletier M, Audet-Walsh É, Plante I
Toxicol Sci · 2026 Jan · PMID 41208031 · Full text
In utero exposure to the synthetic estrogen diethylstilbestrol (DES) has been linked to developmental abnormalities and elevated breast cancer risk in adulthood in human and rodent models. Although the impact of DES on t...
In utero exposure to the synthetic estrogen diethylstilbestrol (DES) has been linked to developmental abnormalities and elevated breast cancer risk in adulthood in human and rodent models. Although the impact of DES on the mammary epithelium has been thoroughly investigated, its effect on the other cell types of the mammary gland remains understudied. Here, given that the mammary gland development is strongly associated with its microenvironment, we aimed to investigate how in utero DES exposure alters the mammary gland's stromal and immune function across key developmental stages. To achieve this aim, timed-pregnant rats were gavaged daily with DES or vehicle from gestation days 16 to 21, and female offspring mammary glands were analyzed at pre-puberty (postnatal day 21 [PND21]), puberty (PND46), and adulthood (PND90). We assessed morphological and extracellular matrix changes, performed transcriptomic cell-type enrichment analysis, measured cytokine expression, and quantified immune cell populations. DES-exposed mammary glands exhibited pronounced stromal remodeling, including increased collagen deposition and orientation by adulthood. Gene expression profiling indicated DES-induced stage-specific immune alterations: Immune cell signatures were enriched at PND21 and PND90 but diminished at PND46. Correspondingly, DES increased macrophage populations at PND21 while reducing T-lymphocyte numbers at PND46 and PND90. DES exposure also dysregulated inflammatory cytokine/chemokine expression in adult glands, suggesting a persistent inflammatory environment. In conclusion, in utero exposure to an estrogenic compound can reprogram mammary development, inducing long-term changes in the extracellular matrix and immune landscape. These disruptions to stromal-immune homeostasis may impair normal mammary morphogenesis and increase susceptibility to breast pathologies later in life.
Maternal exposure to iopanoic acid disrupts thyroid hormone metabolism and impairs development of the rodent brain.
Thomas R, Ford J, Kuehn C … +3 more , Hawks MG, Wood C, Gilbert ME
Toxicol Sci · 2026 Jan · PMID 41206128 · Publisher ↗
Thyroid hormones (THs) regulate development, growth, and metabolism. Integral to the regulation of their action are the deiodinases (Dios), metabolizing enzymes that activate (Dio1 and Dio2) and deactivate (Dio3) THs, ex...
Thyroid hormones (THs) regulate development, growth, and metabolism. Integral to the regulation of their action are the deiodinases (Dios), metabolizing enzymes that activate (Dio1 and Dio2) and deactivate (Dio3) THs, exerting precise control over local TH action. We examined the effect of chemical interference with Dios on brain development in a rodent pregnancy model using iopanoic acid (IOP). Pregnant rat dams were exposed to 0, 5, or 10 mg/kg IOP daily by gavage from gestational day 6 to postnatal (PN) day 15. Pups were euthanized at PN0, 2, 6, and 14. Serum and brain TH and Dio activity in cortical microsomes were measured, and 2 neuroanatomical defects emblematic of TH insufficiency were examined in the brains of offspring. IOP increased serum total T4 and rT3 in dams and pups. IOP decreased Dio2 and Dio3 activity in the dam cortex and forebrain of PN0 and PN2 pups, with no effect seen on PN14. On PN2, brain T4 was increased, brain T3 was reduced, and TH-responsive genes were downregulated. A periventricular heterotopia was present in the brains of IOP-treated pups on PN14, whereas no change was seen in the numbers of parvalbumin-expressing neurons. The observation that IOP induced changes in serum THs that were not predictive of brain effects has profound implications for the interpretation of altered serum TH profiles in a chemical regulatory context as well as in a clinical setting.
Deoxynivalenol disrupts male mice reproduction through gut-testis axis dysregulation and metabolic alterations.
Dong PY, Chen Y, Li L … +9 more , Zhai CL, Yan YC, Bai Y, Li YY, Dong Y, Liu J, Zhang M, Liu YH, Zhang XF
Toxicol Sci · 2026 Jan · PMID 41206121 · Publisher ↗
The mycotoxin deoxynivalenol (DON) is a widespread contaminant that threatens male reproductive health, though the systemic mechanisms involving the gut-testis axis remain incompletely understood. We employed a multi-omi...
The mycotoxin deoxynivalenol (DON) is a widespread contaminant that threatens male reproductive health, though the systemic mechanisms involving the gut-testis axis remain incompletely understood. We employed a multi-omics approach-integrating transcriptomics, 16S rRNA sequencing, and serum metabolomics-in a mouse model to investigate these mechanisms. Oral exposure to DON (2 mg/kg/day for 2 weeks) induced testicular damage and disrupted the blood-testis barrier, marked by the downregulation of Occludin and GJA1, alongside the suppression of steroidogenesis-related genes and proteins, including StAR and CYP17A1. Concurrently, DON triggered gut microbiota dysbiosis, characterized by an increased abundance of Desulfovibrio and a decline in beneficial bacteria. Serum metabolomics further identified a significant depletion of key fatty acids and the cholesterol precursor 5-Alpha-Cholestanol. Crucially, fecal microbiota transplantation from DON-treated mice reproduced testicular damage and suppressed steroidogenesis in recipient animals, directly establishing the causal role of gut microbiota in DON-induced reproductive toxicity. These findings collectively demonstrate that DON impairs male reproductive function by inducing gut microbiota dysbiosis and associated metabolic alterations. This work advances our understanding of the gut-testis axis in toxicology and provides mechanistic insights for mitigating mycotoxin-induced reproductive dysfunction.
The PrecisionTox chemical library: creation of a chemical collection to discover evolutionary conserved biomolecular signatures of toxicity.
Martínez R, González-Sánchez JC, Sampani SI … +9 more , Scholz S, Escher BI, Henneberger L, Huchthausen J, Whelan M, Dickmeis T, Weiss C, Colbourne JK, Freedman JH
Toxicol Sci · 2025 Dec · PMID 41191910 · Full text
The large number and diversity of chemicals currently in use present significant challenges in assessing their human and environmental health risks due to a paucity of toxicological data. To address this shortage, high-t...
The large number and diversity of chemicals currently in use present significant challenges in assessing their human and environmental health risks due to a paucity of toxicological data. To address this shortage, high-throughput screening technologies are used to rapidly evaluate the toxicity of these chemicals. Suitable chemical libraries are crucial to evaluate the performance of these technologies and generate the cognate toxicity data. Unlike traditional chemical libraries designed for specific disease targets or receptor interactions, the PrecisionTox collection prioritizes diversity in targets and mechanisms of toxicity to ensure broad applicability in toxicity predictions to test the concept of phylotoxicology. Phylotoxicology proposes that mechanisms of toxicity are evolutionarily conserved among distantly related species. Furthermore, the application of phylotoxicology can contribute to the reduction of mammalian species in toxicity testing. Here, an approach for generating a chemical library based on chemical properties-physicochemical, biomolecular, and toxicological-as well as practical considerations, including compound availability, cost, purity, and shipping regulations, is reported. From an initial pool of over 1,500 nominees, a set of 200 chemicals was selected based on multiple criteria, including organ toxicity, environmental exposure, structure, modes of action, and toxicological relevance. Additionally, information on baseline toxicity, Absorption, Distribution, Metabolism, and Excretion properties and utility for in vitro testing was collected. This work underscores the necessity of thoughtful chemical selection to refine toxicological models, improve hazard identification, and support regulatory efforts to protect human and environmental health.
N6-methyladenosine reader YTHDF3-mediated Lcn2 mRNA stability promotes the hepatotoxicity of crizotinib.
Liu R, Liu H, Chen H … +6 more , An K, Wei J, Zhang J, Du Y, Wang Y, Tian X
Toxicol Sci · 2026 Jan · PMID 41183147 · Publisher ↗
Crizotinib, a multitarget tyrosine kinase inhibitor, is the standard first-line drug used for the clinical treatment of locally advanced or metastatic ALK-positive non-small cell lung cancer. However, the liver injury in...
Crizotinib, a multitarget tyrosine kinase inhibitor, is the standard first-line drug used for the clinical treatment of locally advanced or metastatic ALK-positive non-small cell lung cancer. However, the liver injury induced by crizotinib is a clinical problem that needs to be solved urgently. Therefore, the mechanism underlying crizotinib-induced liver injury must be elucidated to identify prevention and treatment methods. By establishing the mouse and cell models of crizotinib-induced liver injury, we found that crizotinib induced apoptosis in mouse liver tissue, L02 cells, and HepG2 cells. After treatment with crizotinib, the N6-methyladenosine (m6A) reading protein YTHDF3 was aberrantly downregulated in mouse liver tissue and L02 cells. RNA sequencing, m6A methylated RNA immunoprecipitation sequencing (MeRIP-seq), and MeRIP-qPCR were performed to identify the target gene of Lcn2. The upregulation of LCN2 was detected in both in vitro and in vivo models. Genetic inhibition of Lcn2 resulted in a reduction in the incidence of liver cell apoptosis induced by crizotinib. Additionally, knocking down YTHDF3 increased the mRNA stability and expression level of LCN2, whereas the overexpression of YTHDF3 inhibited the expression of LCN2 and apoptosis induced by crizotinib in L02 cells. Further mechanistic studies revealed a potential association between the YTHDF3 protein and Lcn2 mRNA and that YTHDF3 may affect the stability of Lcn2 mRNA in an m6A-dependent manner. Our findings revealed that the m6A reading protein YTHDF3-LCN2-apoptosis axis plays a critical role in mediating the hepatotoxicity of crizotinib, which provides potential intervention approaches for alleviating crizotinib-induced liver injury.
Hepatocyte-specific epidermal growth factor receptor (EGFR) deletion attenuates acetaminophen-induced liver injury in mice.
Jain S, Williams G, Mukherjee R … +5 more , Orr A, Liu JJ, Liu S, Locker J, Bhushan B
Toxicol Sci · 2026 Jan · PMID 41148051 · Full text
Epidermal growth factor receptor (EGFR) is mostly known for its proliferative role in the liver. Our earlier investigations indicated a paradoxical cell-death-promoting facet of EGFR in the acetaminophen (APAP)-induced l...
Epidermal growth factor receptor (EGFR) is mostly known for its proliferative role in the liver. Our earlier investigations indicated a paradoxical cell-death-promoting facet of EGFR in the acetaminophen (APAP)-induced liver injury (AILI) model. The current study investigates this unexpected role of EGFR in promoting AILI using a hepatocyte-specific EGFR deletion mouse model. Hepatocyte-specific EGFR-deficient mice were generated by administering AAV8.TBG.Cre in EGFRfl/fl mice and were subsequently treated with a severely toxic dose (500 mg/kg) of APAP. Liver injury, regeneration, and associated signaling pathways were assessed at different time intervals. EGFR deletion did not alter early liver injury at 6 h but significantly attenuated the progression of liver injury at 12 and 24 h following APAP overdose. Consistently, the key injury-initiating events, such as APAP-protein adducts formation and early JNK activation, remained unimpaired in EGFR-deficient mice. However, EGFR deletion restricted prolonged JNK activation and its mitochondrial translocation, resulting in reduced propagation of mitochondrial damage and release of cell death drivers. Further, the replenishment of antioxidant glutathione (GSH), which is known to limit the progression of liver injury, was strikingly faster in EGFR-deficient mice. RNA-seq analysis and consequent validation revealed marked upregulation of autophagy and its transcriptional regulator, transcription factor EB, a key response to remove damaged mitochondria, in EGFR-deficient mice. Paradoxically, EGFR deletion also promoted compensatory hepatocyte proliferation, possibly secondary to decreased severity of liver injury. Overall, hepatocyte-specific EGFR deletion halted the progression of AILI. Our study established an unexpected role of EGFR in promoting AILI progression, which has wide implications in liver biology.
In vivo exposure of mixed microplastic particles in mice and its impacts on the murine gut microbiome and metabolome.
Kim KJ, Garcia MM, Romero AS … +7 more , Jin Y, Chi J, Campen MJ, Gu H, Richardson JR, Castillo EF, Cui JY
Toxicol Sci · 2026 Jan · PMID 41143690 · Full text
Microplastics (MPs) are emerging environmental contaminants due to increasing global plastic production and waste. MPs, defined as plastic particles less than 5 mm in diameter, are formed through the degradation of large...
Microplastics (MPs) are emerging environmental contaminants due to increasing global plastic production and waste. MPs, defined as plastic particles less than 5 mm in diameter, are formed through the degradation of larger plastics via sunlight, weathering, and microbes. These plastic compounds are widely detected in water, soil, and food, as well as human stool and blood. The gut microbiome, often referred to as our second genome, is important in human health and is the primary point of contact for orally ingested MPs. To investigate the impact of ingested MPs on the gut microbiome and the metabolome, 8-week-old male and female C57BL/6 mice were orally gavaged with mixed plastic (5 µm) exposure consisting of polystyrene, polyethylene, and the biodegradable/biocompatible plastic, poly(lactic-co-glycolic acid), twice a week for 4 weeks at 0, 2, or 4 mg/week (n = 8/group). Fecal pellets were collected for bacterial DNA extraction and metagenomic shotgun sequencing, and serum was subjected to targeted and untargeted metabolomics. A total of 1,162 bacterial species and 1,437 metabolites were evaluated for downstream analysis. MPs' exposure resulted in significant sex-specific and dose-dependent changes to the gut microbiome composition, along with substantial regulation of predicted metabolic pathways. Untargeted metabolomics in serum showed that a low MPs dose displayed a more prominent effect on key metabolic pathways, such as amino acid metabolism, sugar metabolism, and inflammation. Additionally, short-chain fatty acid (SCFA)-targeted metabolomics showed significant changes in neuroprotective SCFA levels in both sexes. Our study demonstrates that MPs dysregulate the gut microbiome and serum metabolome, highlighting potential human disease risks.
Perinatal exposure to perfluoroalkyl substances impairs maternal care and induces depressive-like behavior in mice.
Rawtani H, Mellouk N, Jackson J … +4 more , Lee CY, Rodriguiz RM, Wetsel WC, Feng L
Toxicol Sci · 2026 Jan · PMID 41143687 · Publisher ↗
Postpartum mental health disorders are a critical yet understudied aspect of maternal health. Exposure to environmental toxicants such as per- and poly-fluoroalkyl substances (PFAS) has been associated with adverse healt...
Postpartum mental health disorders are a critical yet understudied aspect of maternal health. Exposure to environmental toxicants such as per- and poly-fluoroalkyl substances (PFAS) has been associated with adverse health outcomes, including reproductive and neurobehavioral dysfunction, whereas their specific effects on maternal behavior and mental health remain poorly characterized. This study investigated the effects of perinatal exposure to environmentally relevant concentrations of a PFAS mixture comprising 10 individual PFAS (PFHxA, PFPeA, PFHpA, PFBA, perfluorooctanoic acid [PFOA], PFOS, PFHxS, PFDA, and PFNA), as well as the alternative PFAS compound, perfluorobutane sulfonate (PFBS), on maternal caregiving behaviors and mental health. Female mice were exposed to the PFAS mixture (758.6 ng/l) or PFBS (7.9 ng/l) in reverse osmosis filtered water at levels detected in North Carolina drinking water, beginning before conception and continuing until the first day of birth. Maternal behaviors, including pup-directed care and nest construction, were assessed along with depressive- and anxiety-like behaviors using standardized behavioral tests. Fluoxetine was administered to a subset of animals to pharmacologically validate depressive-like outcomes. Both PFAS mixture and PFBS-exposed dams exhibited impaired maternal caregiving, including diminished nurturing behavior and poor nest building. Litters of PFBS-exposed dams emitted fewer ultrasonic vocalizations, suggesting altered maternal-offspring interaction. Dams exposed to the PFAS mixture also exhibited depressive-like behaviors that were reversed by fluoxetine treatment, whereas anxiety-like behavior was unaffected. These findings demonstrate that perinatal PFAS exposure disrupts maternal behavior and induces depressive-like phenotypes, reflecting the neurobehavioral risks of exposure during the perinatal period. This study emphasizes the potential for environmental contaminants to contribute to maternal mental health disorders and supports the need for further research on the effect of PFAS exposure in human populations.
Comparison of physiologically based pharmacokinetic modeling platforms for developmental neurotoxicity in vitro to in vivo extrapolation.
Kreutz A, Chang X, Lawless M … +4 more , Proença S, Schaller S, Kleinstreuer N, Hogberg HT
Toxicol Sci · 2026 Feb · PMID 41143686 · Publisher ↗
An extensive battery of 17 in vitro assays has been developed for assessing developmental neurotoxicity (DNT), with the aim of replacing or supplementing traditional in vivo guideline studies for risk assessment, as thes...
An extensive battery of 17 in vitro assays has been developed for assessing developmental neurotoxicity (DNT), with the aim of replacing or supplementing traditional in vivo guideline studies for risk assessment, as these mechanistic assays provide advantages over costly, lengthy in vivo studies. However, 1 major challenge in employing in vitro assays is the translation of in vitro bioactive concentrations into in vivo doses that can be compared with human exposures. This study describes an in vitro to in vivo extrapolation (IVIVE) approach to derive human-relevant administered equivalent doses based on chemical partitioning into DNT target organs during the critical period of brain development. We used data from chemicals previously found to elicit bioactivity in a subset (7 of 17) of the in vitro DNT battery assays conducted at the US Environmental Protection Agency. Three physiologically based pharmacokinetic modeling platforms were evaluated for their suitability for this DNT-IVIVE approach. Chemical predictions for administered equivalent doses were compared against in vivo effect levels, where available, and found to be within 3-fold for 78% of chemicals. To provide metrics for risk assessment considerations, administered equivalent doses were compared with predicted human exposures. Overall, this DNT-IVIVE approach was found to be relatively transferable among modeling platforms, albeit with varying limitations and considerations that should be taken into account for specific contexts of use.
Exploratory analysis of the impact of sex on sputum proteomic response to inhaled wood smoke in humans.
Nalesnik M, Hickman E, Almond M … +9 more , Herring L, Mordant AL, Mills AC, Payton A, Rager JE, Peden DB, Jaspers I, Alexis NE, Rebuli ME
Toxicol Sci · 2026 Jan · PMID 41134656 · Full text
Wildfires have surged in frequency and severity, and in 2022, they contributed to nearly 30% of the fine inhalable particulate matter (PM2.5) in the United States. Health effects from wildfire-induced wood smoke (WS) exp...
Wildfires have surged in frequency and severity, and in 2022, they contributed to nearly 30% of the fine inhalable particulate matter (PM2.5) in the United States. Health effects from wildfire-induced wood smoke (WS) exposure include worsened pre-existing lung diseases and lung function, increased emergency room visits, and increased risk of premature death. Evidence suggests that males and females have unique responses to air pollutants, but sex-specific responses to WS remain understudied. To evaluate whether males and females differentially respond to WS, we analyzed induced sputum samples in humans following a controlled chamber exposure to WS. A total of 79 participants were exposed to 500 µg/m3 of WS for 2 h with intermittent exercise, and a subset of participants' samples were analyzed for cellularity and cytokine concentrations, and protein expression in the sputum supernatants. Cell differentials were compared between pre-, 6 h, and 24 h post-exposure, and proteomic and cytokine signatures were compared between pre- and 24 h post-exposure. A total of 368 proteins were significantly different in females, and 27 were significantly different in males post-exposure. Pathway analysis revealed inhibition of leukocyte extravasation signaling, phagosome formation, and macrophage nitric oxide and reactive oxygen species pathways in females versus males. Females had a lower percentage of iNOS+ and a higher percentage of CD301+ sputum macrophages versus males. Overall, this exploratory analysis suggests that in response to acute WS exposure, different pathways are affected in females compared with males. Future studies are needed to determine whether this confers an immune advantage and to understand the mechanisms of sex-specific WS-induced respiratory effects.
Gossypol acetic acid affects locomotor activity by inducing mitophagy-related ferroptosis and apoptosis in zebrafish.
Wang Y, Li F, Xu L … +4 more , Zhao H, Sik A, Liu K, Wang R
Toxicol Sci · 2026 Jan · PMID 41134649 · Publisher ↗
Gossypol acetic acid (GAA), a medicinal form of gossypol, is a natural phenolic compound found in cottonseed, which possesses various biological activities, such as anti-fertility, antiviral, anti-inflammatory, antibacte...
Gossypol acetic acid (GAA), a medicinal form of gossypol, is a natural phenolic compound found in cottonseed, which possesses various biological activities, such as anti-fertility, antiviral, anti-inflammatory, antibacterial, and anticancer properties. However, its potential risks to aquatic organisms are poorly investigated. Here, the toxic effects on locomotor activity and the underlying mechanism were assessed in vitro and in vivo, using the zebrafish model and PC12 cells. The results showed that after treatment from 6 to 120 h post fertilization, 0.8 μM GAA significantly reduced the locomotor activity of zebrafish larvae. In addition, 0.6 and 0.8 μM GAA disrupted the dopamine neurons and the central nervous system, further inhibiting swimming activity. Furthermore, the muscle sarcomeres and hair cells of zebrafish larvae were affected after GAA exposure. Moreover, after GAA exposure, Fe2+ accumulated in the 0.6 and 0.8 μM GAA groups, and reactive oxygen species (ROS) increased, especially in the head region. In addition, apoptosis could be observed in both the head and tail muscle regions. RT-qPCR results showed that GAA dysregulated the mRNA expression of the genes correlated to mitophagy, oxidative stress, and ferroptosis pathways. The in vitro study using PC12 cells also showed that GAA could induce mitochondrial membrane potential rise, ROS generation, apoptosis, and ferroptosis. These results indicate that GAA affects locomotor activity by disrupting the nervous system and muscle in zebrafish, and its toxicity is closely related to mitochondrial dysfunction, oxidative stress, apoptosis, and ferroptosis.
Functional genomic analysis of non-canonical DNA regulatory elements of the aryl hydrocarbon receptor.
Shahriar S, Patel TD, Nakka M … +3 more , Grimm SL, Coarfa C, Gorelick DA
Toxicol Sci · 2026 Jan · PMID 41128614 · Full text
The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor activated by environmental toxicants like halogenated and polycyclic aromatic hydrocarbons, which then binds to DNA and regulates gene expres...
The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor activated by environmental toxicants like halogenated and polycyclic aromatic hydrocarbons, which then binds to DNA and regulates gene expression. AHR is implicated in numerous physiological processes, including liver and immune function, cell cycle control, oncogenesis, and metabolism. Traditionally, AHR binds a consensus DNA sequence (GCGTG), the xenobiotic response element (XRE), recruits coregulators, and modulates gene expression. Yet, recent evidence suggests AHR can also regulate gene expression via a non-consensus sequence (GGGA), termed the non-consensus XRE (NC-XRE). The prevalence and functional significance of NC-XRE motifs in the genome have remained unclear. Although chromatin immunoprecipitation (ChIP) and reporter studies hinted at AHR-NC-XRE interactions, direct evidence for transcriptional regulation in a native context was lacking. In this study, we analyzed AHR binding to NC-XRE sequences genome-wide in the mouse liver, integrating ChIP-seq and RNA-seq data to identify candidate AHR target genes containing NC-XRE motifs in their regulatory regions. We found NC-XRE motifs in 82% of AHR-bound DNA, significantly enriched compared with random regions, and present in promoters and enhancers of AHR targets. Functional genomics on the Serpine1 gene revealed that deleting NC-XRE motifs reduced TCDD-induced Serpine1 upregulation, demonstrating direct regulation. These findings provide the first direct evidence for AHR-mediated regulation via NC-XRE in a natural genomic context, advancing our understanding of AHR-bound DNA and its impact on gene expression and physiological relevance.
The endothelial growth factor angiopoietin-2 is an accurate prognostic biomarker in patients with acetaminophen-induced acute liver failure.
Umbaugh DS, Nguyen NT, Curry SC … +5 more , Rule JA, Lee WM, Ramachandran A, Jaeschke H, Acute Liver Failure Study Group
Toxicol Sci · 2025 Dec · PMID 41092397 · Full text
Acetaminophen (APAP) overdose is the leading cause of acute liver failure (ALF) in the United States, with many patients rapidly progressing to hyperacute liver failure. Although hepatocytes are the main target of APAP t...
Acetaminophen (APAP) overdose is the leading cause of acute liver failure (ALF) in the United States, with many patients rapidly progressing to hyperacute liver failure. Although hepatocytes are the main target of APAP toxicity, endothelial cells (ECs) are also affected. However, the efficacy of an endothelial-specific biomarker to predict patient outcomes remains unknown. This study aimed to evaluate angiopoietin-2 (ANGPT2) as a prognostic biomarker for poor outcomes in APAP-induced ALF. Using human and mouse single-cell RNA-sequencing data, we found that ANGPT2 expression was significantly elevated in ECs following APAP exposure. We measured circulating ANGPT2 levels in 2 independent APAP-ALF cohorts: A cohort from Phoenix (n = 43) and the ALF Study Group (n = 80). In the Phoenix cohort, ANGPT2 levels were significantly higher in nonsurvivors with an area under the receiver-operating characteristic curve of 0.938. In the ALF Study Group cohort, we stratified patients based on time of symptom onset, finding that ANGPT2 had improved prognostic value in early-presenting patients, with Day 1 and 3 AUC values of 0.825 and 0.918, respectively. Lastly, we combined the patient cohorts (n = 110), finding that ANGPT2 alone or in combination with Model for End-Stage Liver Disease (MELD) score outperformed MELD alone based on AUC (ANGPT2: 0.87, MELD: 0.83, ANGPT2+MELD: 0.90). Conclusions: ANGPT2 is a promising prognostic biomarker for APAP-induced ALF, reflecting endothelial stress and offering superior predictive value compared with MELD alone, especially in early-presenting patients. Its capacity for predicting poor outcomes underscores its value in improving patient prognosis and therapeutic intervention strategies in APAP overdose cases.
A cell-based Sonic Hedgehog signaling transduction system to identify additive and synergistic chemical interactions.
Beames TG, Everson JL, Desai DA … +4 more , Perez KY, Wu E, Eberhart JK, Lipinski RJ
Toxicol Sci · 2026 Jan · PMID 41092386 · Full text
Chemical co-exposures are important contributors to adverse biological responses yet remain poorly understood, especially in the context of prenatal development. Sonic Hedgehog (Shh) signaling is an essential development...
Chemical co-exposures are important contributors to adverse biological responses yet remain poorly understood, especially in the context of prenatal development. Sonic Hedgehog (Shh) signaling is an essential developmental pathway that is sensitive to small-molecule disruption and directly linked to common and etiologically complex human birth defects. Numerous mechanistically diverse small-molecule Shh pathway antagonists have been identified, but their interactions in pathway disruption have received minimal attention. We established a tractable co-culture model in which autonomous SHH ligand production initiates this complex inter- and intracellular signal transduction cascade and culminates in activation of a GLI-responsive luminescent reporter. Compounds reported to target SHH ligand processing (RU-SKI 43, AY 9944, U18666A), SMO-mediated signal transduction (cyclopamine, vismodegib, piperonyl butoxide, cannabidiol), and GLI transcription factors (GANT 61, arsenic trioxide) reduced Shh pathway-driven reporter activity with AC50 values in the low micromolar range or below. We then evaluated chemical interactions among Shh pathway inhibitors using isobolographic analysis. Co-exposure assays revealed additive interactions from combined SMO and GLI inhibition, whereas disruption of SMO and cholesterol dynamics synergistically decreased Shh pathway activity. Unexpectedly, piperonyl butoxide synergized with other SMO inhibitors, and further characterization of piperonyl butoxide's impacts on Shh signaling supported an additional mechanism of inhibition independent of SMO. In zebrafish embryos, combined exposure to piperonyl butoxide and cyclopamine also produced a synergistic increase in craniofacial dysmorphogenesis. These findings demonstrate the importance of tractable models that recapitulate complex signal transduction pathways to empirically test for additive and synergistic chemical interactions in risk assessment.
Cell painting in HepaRG cells: an interlaboratory reproducibility study.
Sherer E, Chen W, Aberasturi D … +7 more , Sagar K, Li Y, Sutake Z, Xu J, Harris FR, Harrill JA, LaRocca J
Toxicol Sci · 2025 Dec · PMID 41081626 · Publisher ↗
Traditional toxicological safety assessment relies heavily on the use of animals, and animal-free new approach methodologies (NAMs) are therefore critical for increasing the efficiency and human relevance of chemical haz...
Traditional toxicological safety assessment relies heavily on the use of animals, and animal-free new approach methodologies (NAMs) are therefore critical for increasing the efficiency and human relevance of chemical hazard screening. Cell Painting, a high-content imaging assay that quantifies phenotypic changes at the cellular level, is an approach that has been widely used for pharmacological discovery purposes. In the present study, Cell Painting methodologies were adapted to the human liver cell line, HepaRG, given that the liver is a common target organ in standard repeat-dose toxicological studies. The HepaRG cell line was selected for its expression of phase I and II enzymes and ability to metabolize xenobiotic chemicals, which are critical features for an in vitro toxicological assay to assess chemicals that could be extensively metabolized in vivo. An interlaboratory reproducibility assessment was conducted to optimize culture conditions, image acquisition, computational workflows for image segmentation and feature extraction, and derivation of phenotype-altering concentrations (PACs). Two laboratories, the US EPA Center for Computational Toxicology and Exposure (site 1) and Corteva Agriscience (site 2), tested a set of 20 phenotypic reference chemicals in the HepaRG Cell Painting assay for derivation of PACs. The results from site 1 and site 2 were highly concordant both in terms of PAC estimates and the profiles of phenotypic effects observed for the test chemicals. These results support the reproducibility and robustness of the Cell Painting assay in the metabolically competent HepaRG cell line, thereby providing a NAM with the potential to predict in vivo toxicity.
Toxicological profile of chemical interference of thyroid hormone metabolism via deiodinase enzymes in a rodent model.
Thomas R, Ford J, Kuehn C … +4 more , Wood C, Hawks M, Degitz S, Gilbert M
Toxicol Sci · 2025 Dec · PMID 41081624 · Publisher ↗
Thyroid hormones (THs) are highly iodinated molecules that regulate many aspects of mammalian physiology and are essential for normal growth and development. Deiodinases (Dio) are a family of metabolizing enzymes control...
Thyroid hormones (THs) are highly iodinated molecules that regulate many aspects of mammalian physiology and are essential for normal growth and development. Deiodinases (Dio) are a family of metabolizing enzymes controlling systemic and local availability of the major TH secreted from the thyroid gland. Despite their critical role in TH regulation, the toxicological characterization of the effects of chemical interference of Dios in mammalian models has remained relatively underexplored. Here, we investigated the effects of exposure to iopanoic acid (IOP), a potent in vitro inhibitor of Dio enzymes. Adult rats administered IOP (0, 1, 5, 10, and 50 mg/kg/day, oral gavage) for 14 days exhibited an increase in serum thyroxine (T4) and reverse T3 (rT3), consistent with an inhibition of deiodinase 1 (Dio1). To verify these serum TH effects were induced by IOP action on deiodination pathways, we examined Dio activity ex vivo in liver from exposed animals. TH metabolites quantified by liquid chromatography mass spectrometry (LC/MS/MS) were used as the readout of Dio activity. Dose-dependent reductions in Dio1 and Dio3 activity were confirmed in hepatic microsomes prepared from IOP-exposed animals. The findings provide a signature pattern for serum TH change to assist translation of in vitro assays for this mode of action of environmental contaminants and interpretation of regulatory reports of serum TH profiles. By elucidating the mechanistic underpinning of chemical-induced perturbations of this critical TH metabolic pathway, the findings may inform risk-based decision making and serve to help to refine regulatory strategies for TH system-disrupting compounds.
Contribution of particle-induced lysosome membrane permeabilization to NLRP3 inflammasome activation and mitochondrial ROS production.
Albright JM, Holian A
Toxicol Sci · 2025 Dec · PMID 41072925 · Full text
Nickel oxide nanoparticles (NiONPs) can trigger reactive oxygen species (ROS) production and NLRP3 inflammasome activation in macrophages as key steps in promoting lung inflammation. However, the impact of NiONP-induced...
Nickel oxide nanoparticles (NiONPs) can trigger reactive oxygen species (ROS) production and NLRP3 inflammasome activation in macrophages as key steps in promoting lung inflammation. However, the impact of NiONP-induced lysosome membrane permeabilization (LMP) on mitochondrial ROS (mtROS) production and NLRP3 inflammasome activation is unknown. Murine ex vivo alveolar macrophages (mexAM) were exposed to NiONPs or crystalline silica (cSiO2) as a positive control particle. Imipramine was used to inhibit LMP before measuring mtROS and NLRP3 inflammasome activation and MitoTEMPO was used to block mtROS before measuring LMP and NLRP3 inflammasome activation. The ability of phagocytosed NiONPs to leach Ni2+ and stimulate ROS production was also assessed. Exposure to either particle resulted in LMP, mtROS production, and NLRP3 inflammasome activation with cSiO2 causing greater effects than NiONPs. LMP was rate-limiting in cSiO2-induced NLRP3 inflammasome activation and mtROS production, which further activated the inflammasome. Similar to cSiO2, NiONP-induced LMP was rate-limiting in NLRP3 inflammasome activation. In contrast to cSiO2, NiONP-induced mtROS was detected whether or not LMP was inhibited. Furthermore, NiONP-derived Ni2+ ions were present in the cytosol whether or not LMP occurred, and Ni2+ release was proportional to measured mtROS production and hydroxyl radical formation. The inability of MitoTEMPO to block the effects of Ni2+ ions on mtROS production suggested an alternative unclear mechanism was involved. This study demonstrates that LMP serves as a pivotal upstream trigger of NLRP3 inflammasome activation and potentially ROS production in response to cSiO2 and NiONPs-underscoring the crucial role of lysosomes in particle-induced inflammation.
About
- Frequency
- Sun
- Papers found
- 200
- RSS feed
- Subscribe