Environment International

BackgroundFine particulate matter (PM2.5), airborne particles with an aerodynamic diameter [&le;]2.5 m that can penetrate deep into the lungs and enter the circulation, is increasingly recognized as a risk factor for chronic kidney disease (CKD) with long-term exposure. We previously demonstrated that high-dose PM2.5 exposure prior to ischemia-reperfusion injury (IRI) aggravates acute kidney injury (AKI). Here, we investigated how prolonged, low-concentration urban PM2.5 exposure (<15 {micro}g/m3) affects kidney repair after AKI. MethodsSix-week-old mice underwent bilateral IRI or sham surgery, followed by six months of exposure to either filtered air or ambient PM2.5 exposure in a unique exposome chamber. Kidneys were analyzed using pathomics, electron and super-resolution microscopy, immunohistochemistry, transcriptomics, and LC-MS lipidomics/metabolomics. Complementary in vitro hypoxia-reoxygenation and PM2.5 exposure experiments were performed in proximal tubular epithelial cells. ResultsLong-term PM2.5 exposure had minimal effects in sham-operated mice, including no significant changes in body weight or kidney function. Despite preserved kidney function, IRI+PM2.5 mice exhibited reduced weight gain, a marked expansion of the interstitial area, attributable to enhanced fibrosis and inflammatory responses, microvascular rarefaction, and endothelial-to-mesenchymal transition, consistent with maladaptive repair features. Proximal tubules displayed mitochondrial injury, glycolytic reprogramming, lipid accumulation, and a senescent phenotype. Energy Dispersive X-ray (EDX) microscopy confirmed PM2.5-derived elements within proximal tubules lysosomes, accompanied by lysosomal stress. Transcriptional signature-based drug screening identified nicotinamide as a compound capable of reversing PM2.5-induced metabolic alterations; in vitro validation confirmed restoration of mitochondrial function. ConclusionsTogether, these findings show that chronic post-AKI exposure to PM2.5 at levels currently considered safe by regulatory bodies drives maladaptive repair and accelerates CKD progression through mitochondrial dysfunction, lysosomal stress senescence in proximal tubules, due to local PM2.5 element accumulation. Translational StatementAcute kidney injury frequently progresses to chronic kidney disease due to maladaptive repair, yet environmental drivers of this transition remain underrecognized. Using a controlled exposome chamber, we demonstrate that chronic exposure to low, real-world concentrations of urban PM2.5 during post-ischemic recovery results in the accumulation of PM2.5-derived elements within proximal tubular lysosomes, leading to organelle dysfunction, metabolic reprogramming, lipid accumulation, and a senescence-like phenotype. Importantly, transcriptomics-based drug repurposing identified nicotinamide as a candidate compound capable of reversing metabolic dysfunction in injured proximal tubular cells subjected to hypoxia-reoxygenation and PM2.5 exposure, an effect validated in vitro.

ObjectiveTo investigate associations between long-term environmental exposures, both external (ambient air pollution and built environment) and internal (circulating anthropogenic chemicals), and the human plasma metabolome, with the aim of generating biologically plausible hypotheses about affected metabolic pathways. MethodsWe analyzed plasma from 989 Estonian Biobank participants using untargeted LC-HRMS (Metabolon HD4). External exposures (PM2.5, PM10, NO2, ozone and built-environment metrics) were assigned using spatiotemporally resolved models developed in the EXPANSE project. Internal exposures were defined as ubiquitous anthropogenic compounds detected in the same metabolomics dataset. Associations between exposures and individual metabolites were quantified using left-censored regression models and then mapped to metabolite classes (Metabolon) and KEGG pathways. For enrichment analyses, one-sided Kolmogorov-Smirnov tests were applied to external exposures and Fishers exact tests to internal exposures. False discovery rate was controlled at 1% per exposure and database. ResultsExternal air pollutants exhibited distinct metabolic patterns: Higher NO2 exposure was associated with enrichment of metabolites involved in tyrosine metabolism; higher ozone with monohydroxy and dicarboxylate fatty acids (consistent with lipid peroxidation); and higher PM2.5 with acyl-carnitine subclasses and carbohydrate metabolism (glycolysis / gluconeogenesis / pyruvate). Built-environment associations were heterogeneous across metabolites and pathways. Internal anthropogenic chemicals showed broader metabolic associations than external exposures, involving a larger number of metabolites and metabolic classes. PFAS (PFOA, PFOS) were associated with long-chain polyunsaturated fatty acids (n3/n6) and lysophospho-lipids. Associations with 4-hydroxychlorothalonil, a fungicide, pointed to androgenic steroid metabolites and alpha-linolenic acid metabolism. The phenolic 2,4-di-tert-butylphenol, a plastic associated chemical, showed widespread associations with lipid classes, suggesting disruption of membrane remodeling and fatty acid handling. ConclusionLong-term environmental exposures, both external and internal, are measurably reflected in the human plasma metabolome. Across exposure domains, recurrent signals involved lipid metabolism, membrane composition, and oxidative stress-related pathways, highlighting these as common biological targets of environmental exposures. The findings generate testable hypotheses, including nitrosative stress-related alterations for NO2, lipid peroxidation for ozone, energy-metabolism perturbations for PM2.5, potential endocrine activity for chlorothalonil metabolites, and possible obesogenic effects of 2,4-di-tert-butylphenol.

The human toxicological risk assessment of per- and polyfluoroalkyl substances (PFAS) is challenging, due to their sheer number and structural diversity, but also the paucity of the toxicity data required to characterize them. The development of Next Generation Physiologically Based Kinetic (NG-PBK) models may assist in overcoming this challenge. The mechanistic nature of NG-PBK models allows for their extrapolation from data-rich PFAS, such as perfluorooctanoic acid (PFOA), to data-poor ones, facilitating their application in Next Generation Risk Assessment (NGRA). The present study proposes a NG-PBK model for PFOA in humans, parametrized exclusively using in vitro-, and in silico-derived data. The model describes the toxicokinetic processes of 1) partitioning to plasma and tissue proteins, 2) partitioning to cell membrane lipids, 3a) transporter-mediated entero-hepatic circulation and 3b) renal elimination and reabsorption, and 4) elimination via menstruation. Global sensitivity analysis indicated that the model was most sensitive to the fraction unbound in plasma, active-transport parameters, and tissue-plasma partition coefficients. The model was equivalent to already available validated human PFOA-PBK models, while compared to those, it is not calibrated to observed animal, nor human data, illustrating its strength in being mechanistic. The serum concentrations and half-lives predicted by the NG-PBK model were within the ranges of those reported in human volunteer and biomonitoring (HBM) studies, demonstrating the models capacity to accurately predict PFOA toxicokinetics on exposure estimates. Extrapolation of the NG-PBK model to other PFAS, in conjunction with its integration with HBM data, will facilitate the NGRA of PFAS. This is particularly relevant given the paucity of in vivo data for most PFAS, ensuring compliance with the 3R principles.

Per- and polyfluoroalkyl substances (PFAS) are manmade chemicals that are persistent in the environment and have been linked to various physiological and neurobehavioral outcomes, including anxiety disorders. Trifluoroacetic acid (TFA), a short chain PFAS and the most common PFAS degradation product, is increasingly detected in water, soil, and human blood, raising significant concerns about its developmental toxicity. However, the impact of early-life TFA exposure on neurodevelopment and behavior remain insufficiently characterized. In this study, we employed Zebrafish (Danio rerio) embryos as a New Approach Methodology (NAM), to evaluate the development, behavior, and protein expression changes in response to early-life TFA exposure. Embryos were exposed to environmentally relevant low and high concentrations of TFA beginning at one-cell stage. Early developmental physiology was assessed by measuring viability, tail twitch response, hatching rates, and chorion diameters during embryogenesis. Anxiety-like behaviors were evaluated at 5- and 6-days post-fertilization using validated behavioral assays such as the Light-Dark Test and Startle Response. Each test evaluates distinct anxiety-related behaviors by measuring locomotor activity, thigmotaxis (wall preference), and stimulus reactivity, with anxious zebrafish larvae showing increased movement in light and greater wall preference. Then to identify molecular pathways underlying observed developmental phenotypes with TFA exposure, proteomic analyses were performed on embryos at 24- and 48-hours post-fertilization. Our results indicate that TFA exposure altered developmental physiology, evidenced by reduced chorion diameters, and lead to increased anxiety-like behaviors with larvae exhibiting thigmotaxis. These phenotypic changes were accompanied by detectable alterations in the embryonic proteome. Collectively, our findings provide insight into how short-chain PFAS exposure during critical windows of development may contribute to neurobehavioral dysfunction, highlighting potential risks relevant to inform public health policies and environmental regulations.

Air pollution has been increasingly linked to adverse neurodevelopmental and neurodegenerative outcomes. While experimental and preclinical studies suggest that exposure to particulate matter (PM), particularly during gestation, may disrupt cognitive development, the impact of short-term PM exposure on cognitive and behavioral functioning in healthy young populations remains insufficiently explored in Spain. Moreover, few studies have incorporated individualized dosimetry models to estimate exposure more accurately. This study included 186 healthy young adults (mean age = 20.4 years) recruited from three Spanish cities (Teruel, Almeria, and Talavera) characterized by different pollution levels. Ambient fine and coarse PM concentrations were recorded 8, 15, and 30 days prior to psychological assessment. Instead of relying solely on raw in situ environmental measurements, individualized PM deposition was estimated using the Multiple-Path Particle Dosimetry Model (MPPD), allowing a more biologically meaningful exposure approximation. Psychological outcomes were assessed using validated questionnaires: DASS-21 (depression, anxiety, stress), BIS-11 (impulsivity), UCLA Loneliness Scale, and SWLS (life satisfaction). Behavioral performance was evaluated using computerized versions of the Attentional Network Task (ANT) and the Stroop Task. Blood NRF2 concentrations were analyzed as a biomarker potentially related to oxidative stress mechanisms. In situ data indicated that Talavera presented the highest pollution levels, followed by Almeria and Teruel. Linear regression analyses showed that coarse PM exposure across 8-, 15-, and 30-day windows significantly predicted poorer Executive Control Index performance in the ANT. Additionally, 15-day coarse PM and 30-day fine PM exposure were associated with greater cognitive interference. Oxidative stress markers were significantly associated with PM exposure levels. These findings support emerging evidence that short-term PM exposure may negatively affect executive and attentional processes even in healthy young adults. Further longitudinal research incorporating individualized exposure modeling is warranted to clarify causal pathways and underlying biological mechanisms. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/713644v1_ufig1.gif" ALT="Figure 1"> View larger version (79K): org.highwire.dtl.DTLVardef@1a0ac13org.highwire.dtl.DTLVardef@1812accorg.highwire.dtl.DTLVardef@120bf07org.highwire.dtl.DTLVardef@dd9a7c_HPS_FORMAT_FIGEXP M_FIG C_FIG

ObjectiveChronic obstructive pulmonary disease (COPD) is a leading cause of death in the industrialized world. Although smoking, air pollution, and occupational exposures are well established risk factors, the molecular pathways linking environmental exposures and biological susceptibility to COPD remain incompletely understood. Untargeted metabolomics offers a unique opportunity to simultaneously capture internalized environmental chemicals and endogenous metabolic perturbations. However, large prospective studies integrating broad exposomic and metabolic screening prior to COPD onset are lacking. MethodsWe conducted a nested case-control study within three European population-based cohorts (Doetinchem Cohort Study, KORA, SAPALDIA) and analyzed 1473 prospectively collected plasma samples. COPD was defined by a pre-bronchodilation FEV1/FVC ratio below 0.7 at follow-up (4-16 years after blood sample collection). We applied complementary untargeted liquid- and gas chromatography high-resolution mass spectrometry (LC- and GC-HRMS), enabling extensive coverage of endogenous metabolism and exogenous environmental contaminants, including pesticides, plastic-related chemicals, and polycyclic aromatic hydrocarbons. Controls maintained normal lung function and were matched to cases on age, sex, follow-up time, and sample collection round. We performed separate conditional logistic regression models for each metabolomic feature, and used Mummichog for prediction of biological pathways involved. The false discovery rate (FDR) was controlled using the Benjamini-Hochberg procedure. Long-term measurement reliability was evaluated using intraclass correlation coefficients (ICCs) from repeat samples in the Doetinchem Cohort Study. ResultsIn total, thousands of metabolomic features were screened, including 724 annotated exogenous compounds, 13 endogenous metabolites, and 197 features that could be derived as both. Nicotine and cotinine intensity levels were statistically significantly associated with COPD incidence at an FDR of 10%, validating the analytical and epidemiologic framework. Lower levels of butyrylcarnitine were related to COPD onset in never-smokers. Beyond smoking-related markers, lower levels of butyrylcarnitine were associated with increased COPD risk among never-smokers, implicating altered mitochondrial fatty-acid metabolism as a potential early pathway independent of tobacco exposure. Although most screened environmental contaminants, including PAHs and pesticides, were not associated with COPD at stringent significance thresholds, restricting analyses to temporally stable metabolites identified the insecticide metabolite phenyl N-methylcarbamate as a predictor. ConclusionThis large-scale, prospective untargeted metabolomics study represents one of the most comprehensive assessments to date of both environmental and endogenous metabolic predictors of COPD. Our findings demonstrate the feasibility of exposome-wide molecular screening years before disease onset, identify butyrylcarnitine as a novel metabolic predictor in never-smokers, and highlight the importance of accounting for temporal variability in metabolomic epidemiology.

Prenatal air pollution exposure is associated with childhood asthma, particularly among biological males. The mechanisms remain unclear, but may involve lasting epigenetic changes, such DNA methylation (DNAm), that occur during gestation in response to oxidative stress and inflammation. Higher maternal intake of "protective" micronutrients, like antioxidants, could buffer pollution-induced oxidative stress and inflammation to mitigate potentially adverse DNAm differences contributing to asthma. Using data from 515 CANDLE participants, we examined associations between prenatal NO2, PM2.5, and PM10 and cord blood DNAm, evaluated DNAm mediation of pollution associations with childhood wheeze phenotypes (transient, persistent, and late-onset), and assessed buffering of DNAm by maternal polyunsaturated fatty acid, vitamin C, or folate intake, and overall diet quality measured by the Alternative Healthy Eating Index-Pregnancy (AHEI-P). We identified 19, seven, and five regional DNAm differences associated NO2, PM2.5, and PM10. Mediation analyses suggested a role for HLA-DPA1/DPB1 DNAm in NO2 and PM2.5 associations with transient wheeze. To assess buffering, we fit pollutant-by-diet interaction models, defining buffering as an interaction opposite in sign to the main pollutant effect. One or more micronutrients or AHEI-P attenuated pollutant effects at 16 of 19 NO2-associated DMRs, including HLA-DPA1/DPB1, and all PM2.5- and PM10-associated DMRs. However, attenuation of HLA-DPA1/DPB1 DNAm did not significantly reduce the indirect effect of NO2 on transient wheeze. In sex-stratified analyses, biological males exhibited lower PM2.5-associated DNAm in SERPINB9, a gene linked to lung function. These findings suggest prenatal air pollution alters DNAm, which may contribute to transient wheeze, with some differences partially buffered by maternal diet. Significance StatementPrenatal air pollution exposure contributes to child wheeze and asthma, potentially through the oxidative stress response and subsequent changes to infant DNA methylomes. Here, we used data from the CANDLE cohort to identify cord blood DNAm differences associated with NO2, PM2.5, or PM10. We examined if any alterations mediated the relationship between prenatal air pollution exposures and transient, persistent, or late-onset wheeze at age 4 to 6 years. Some of these DNAm differences appeared to be at least partially buffered by maternal micronutrients and/or overall diet quality.

IntroductionAmbient air pollution, especially fine particulate matter 2.5 (PM2.5) has emerged as a critical environmental risk factor for cerebrovascular diseases, contributing to an estimated 7.9 million premature deaths annually. PM2.5 induces cellular toxicity and is hypothesized to disrupt the blood-brain barrier (BBB), a pathological hallmark in cerebrovascular diseases such as ischemic stroke. Despite epidemiological evidence linking PM2.5 to increased stroke incidence, its underlying cellular mechanism driving this association is poorly understood. It remains unclear how environmentally relevant pollution concentrations affects brain endothelial function or influence stroke-related biomarkers such as the lectin-like oxLDL receptor 1 (LOX-1). MethodPrimary adult male human brain microvascular endothelial cells (HBMEC) were exposed to PM2.5 (5, 15, 75, or 300 g/m3) collected from an urban environment in southern Sweden, or control. Thereafter, exposed to normoxia (21% O2) or hypoxia (1% O2) and glucose deprivation, followed by reperfusion as a model for ischemic stroke. Cell viability, oxidative stress, inflammation, BBB integrity (claudin-5, ZO-1) and LOX-1 protein expression were assessed. ResultsPM2.5 exposure induced cellular dysfunction, oxidative stress and inflammation starting at 75 g/m3 PM2.5. Notably, decreased claudin-5 and ZO-1 protein levels and increased LOX-1 expression at concentrations as low as 15 g/m3 PM2.5, levels commonly encountered in urban environments globally. The cellular effects of PM2.5 closely resembled those induced by ischemic-like injury. ConclusionThese findings demonstrate dose-dependent detrimental effects of PM2.5 on HBMEC. The results suggest that ambient urban PM2.5 may act as a predisposing factor for cerebrovascular disease onset, by causing endothelial and barrier dysregulation. HighlightsO_LIUrban PM2.5 dose-dependently disrupts BBB integrity in human brain endothelial cells C_LIO_LIPM2.5 induces endothelial dysfunction resembling ischemic-like injury C_LIO_LIUrban PM2.5 exposure upregulates cardiovascular disease biomarker LOX-1 C_LIO_LIA majority of the global population are exposed to BBB-disrupting PM2.5 levels C_LIO_LIVascular endothelial- and BBB dysfunction enhances risk for cerebrovascular disease C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=154 SRC="FIGDIR/small/702473v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@42cce6org.highwire.dtl.DTLVardef@19a2ff9org.highwire.dtl.DTLVardef@1c38e7corg.highwire.dtl.DTLVardef@1bfa837_HPS_FORMAT_FIGEXP M_FIG C_FIG

PFAS are ubiquitous endocrine-disrupting pollutants that cross the placenta and impact offspring health, but the extent and timing of their transfer to both placental and fetal compartments remain poorly understood. We aimed to characterize the relationship between trimester-specific maternal serum levels of prenatal PFAS and paired placental and cord levels at term. Data came from Glowing, a prospective birth cohort (n=151). Seventeen PFAS were measured in maternal serum, cord serum, and pulverized flash-frozen villous placenta with liquid chromatography-tandem mass spectrometry. Mixed effects models tested transplacental transfer efficiency (TTE) over pregnancy. Regularization models, stochastic intervention, and quantile g-computation models tested the association between maternal and placental or cord PFAS levels. TTE increased linearly across trimesters for all PFAS (p<0.001). Quartile increases in maternal PFAS were strongly associated with placental levels (0.018-0.24 ng/g, p<0.001). Stochastic intervention identified T1 PFNA and PFDA; T2 PFOS, PFOA, PFHxS, and PFNA; and T3 PFHxS as robust predictors (p<0.001) of placental levels, consistent with quantile-based contributions. Quartile increases in maternal and placental PFAS concentrations were associated with cord levels (0.08 ng/g-0.55 ng/g, p<0.001). Stochastic intervention identified T1 PFOS and PFHxS; T2 PFOS and PFNA; T3 PFOA; and placental PFOA as important predictors (p<0.05) of cord levels, consistent with quantile-based contributions. Early-to-mid gestation, especially 2nd trimester PFAS measures, were the strongest sentinels of placental and cord serum levels, apart from PFOA which was best reflected by 3rd trimester or placental levels. Placental PFOS and PFOA strongly influenced cord levels. Our findings underscore the heterogeneity in PFAS transfer or metabolism across pregnancy and the placenta.

Exposure of cells or tissues to chemical compounds can be analyzed through transcriptomic signatures, which can be used to classify chemical agents. This information can also enrich Adverse Outcome Pathways (AOP). Transcriptional signatures have generally been obtained using "bulk" analysis, by which the global gene expression pattern of an entire tissue is determined. Although this approach has been useful in toxicology, some information is lost, especially when tissues containing multiple cell types are considered. With the advent of single-cell transcriptomics (scRNA-seq), it is now possible to obtain higher resolution, cell type-specific responses in complex tissues. The aim of the present study was to evaluate the added value of scRNA-seq in analysis of the acute response of human bronchial epithelial cells grown at the air/liquid interface (ALI) to a known toxic compound, CdCl2, with well described transcriptional signatures of exposure. Fully differentiated mucocilliary epithelia obtained from three independent donors were exposed to 10 {micro}M CdCl2 and scRNA-seq analysis was performed on a total of 18255 cells to obtain cell type-specific signatures. Our results show that the contribution of each cell type to the overall transcriptomic bulk response varies. For example, the classical heavy metal detoxification response was only detected in multiciliated and secreting cells, while absent in basal cells. The data demonstrate that scRNA-seq provides high-resolution transcriptional signatures with unexpected features. This added information is likely to have implications for the refinement of AOPs and could serve as a basis for a new generation of tests in predictive toxicology.

Endocrine disrupting chemicals (EDCs) are of particular regulatory and research interest due to the increasing incidence of endocrine-related disorders, such as declining fertility rates and reproductive health problems. The Database of Endocrine Disrupting Chemicals and their Toxicity Profiles (DEDuCT) has gained importance in both academic and regulatory settings by systematically curating data from published literature to characterize these chemicals. Given the growing body of EDC literature, this study aimed to consolidate the latest research and update this critical database. First, more than 14000 research articles were screened through an extensive four-stage manual process, and integrated with the earlier version to create the updated DEDuCTv3.0, comprising 1043 unique EDCs and 796 unique endocrine-related endpoints curated from 3269 published articles. Thereafter, human- and rodent-specific biological endpoint data including interacting genes/proteins, phenotypes, diseases, and adverse outcome pathways (AOPs) were curated from toxicology-relevant databases and systematically integrated with DEDuCTv3.0 to construct a large-scale toxicology knowledge graph for EDCs, termed DEDuCT-KG. DEDuCT-KG was then hosted on a Neo4j database and made easily accessible through a novel interactive user interface. The utility of DEDuCT-KG was demonstrated by exploring potential mechanisms of action associated with obesogenic EDCs within DEDuCTv3.0. Furthermore, the constructed EDC-AOP network, linking 949 EDCs to 381 AOPs within AOP-Wiki, revealed diverse toxicity mechanisms associated with EDCs. Integration with consumer product database and regulatory chemical lists showed that some of these EDCs are present in food contact materials, personal care products, and daily use items, highlighting potential exposure pathways. Overall, all data compiled in this study have been integrated into the DEDuCT webserver, which has been further enhanced to align with FAIR principles. In sum, this study provides a much-needed update to DEDuCT and offers a single point of access to EDC-relevant data to accelerate research and regulation of EDCs.

Chronic exposure to pesticide mixtures through diet is common, yet their combined metabolic effects and interactions with dietary factors remain unclear. We identified four pesticides prevalent in human exposure (imazalil, thiabendazole, boscalid, lambda-cyhalothrin) and assessed their combined impacts on hepatic metabolism and metabolic homeostasis using human liver cells and male mice fed standard chow or western diets. We found that the pesticide mixture induced metabolic perturbations in human hepatocytes. In addition, the pesticide mixture altered hepatic gene expression in chow-fed mice and exacerbated western diet-induced glucose intolerance, fasting hyperglycemia, and insulin resistance without affecting body weight or liver steatosis. These findings reveal that dietary context influences the metabolic consequences of pesticide mixtures, highlighting the need to consider nutritional status when evaluating environmental contaminant risks. Our results suggest that pesticide mixtures at reference doses may contribute to metabolic dysregulation, particularly under obesogenic dietary conditions. Highlights- Four common pesticides in mixture disrupt metabolism in liver cells - Dietary exposure to this pesticide mixture alters hepatic gene expression in mice - The pesticide mixture exacerbates WD-induced disruptions in glucose homeostasis - Pesticides and diet interact in producing the metabolic effects of a pesticide mixture

1.IntroductionAir pollution (AirPoll) is a major environmental risk factor for age-related cognitive decline and dementia, yet we poorly understood the cellular and molecular mechanisms underlying its effects and their potential attenuation. MethodsWe combined single cell RNA sequencing with immunohistochemistry to determine transcriptional responses in microglia, astrocytes, neurons and neural stem cells in the hippocampus of mice following exposure to chronic diesel exhaust particle (DEP). Differential gene expression profiles were compared between filtered-air and DEP exposed animals. The gamma secretase modulator GSM-15606 (BPN) was used to probe selective rescue of inflammatory signatures across distinct cell populations. ResultsDEP exposure triggered robust inflammatory programs in microglia and astrocytes, including upregulation of cytokine signaling components, innate immune receptors, stress-responsive transcription factors, and markers of reactive glial phenotypes. In neural stem cells, DEP induced activation of gliosis-associated pathways, including Il6st, Stat3, and Txnip, consistent with a pro-inflammatory state that may bias lineage decisions. Immunostaining confirmed a significant reduction in immature neurons in the neurogenic niche after AirPoll exposure. GSM-15606 attenuated many DEP-induced transcriptional alterations in microglia and astrocytes, reducing expression of inflammatory mediators and reactive gliosis markers, but did not modulate the inflammatory profile of neural stem cells. ConclusionsAirPoll activates divergent inflammatory pathways across hippocampal cell populations and suppresses neurogenesis. Targeting inflammation with GSM-15606 selectively reverses glial but not neural stem cell responses, highlighting cell-type-specific mechanisms and potential therapeutic pathways to mitigate pollution-related cognitive vulnerability. These results support GSM-15606 as a protective agent against AirPoll-induced hippocampal dysfunction and amyloidogenic stress.

Managing post-weaning diarrhoea (PWD) in piglets is difficult due to limits on antibiotics and zinc. Chitosan is emerging as a potential feed additive. We analysed a chito-oligosaccharide hydrochloride (COS-HCl), a low molecular weight (LMW) chitosan, and a medium molecular weight (MMW) chitosan, and assessed their effects on growth, faecal consistency, microbiota, and potential interference with enterotoxigenic Escherichia coli (ETEC). The three chitosans were characterised using {superscript 1}H-NMR, SEC-RI-MS, and SEC-RI-MALLS. COS-HCl had an Mw of 0.824 kDa; LMW and MMW showed Mw ranges of 14.4 kDa (0.3-30 kDa) and 116 kDa (15-600 kDa). Degrees of acetylation were 9.5%, 6.5%, and 15%. Two 42-day field studies evaluated average daily gain (ADG), faecal consistency, and microbiota. In the first trial, COS-HCl at 0.025-0.1% did not significantly affect ADG (-33 to - 12 g/d). In the second, LMW and MMW at 0.01% did not significantly change ADG (-7 and +3 g/d). Faecal consistency, ETEC shedding, and microbiota composition were similar to controls. An enzymatic HPLC-MS method enabled quantification of MMW chitosan in premix. Our results highlight the importance of advanced chitosan characterisation for precision nutrition and suggest that a threshold dosemay be needed to benefit growth and gut health in PWD management. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/714014v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@19c9e23org.highwire.dtl.DTLVardef@152461aorg.highwire.dtl.DTLVardef@7886e0org.highwire.dtl.DTLVardef@df0d9b_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundChronic Kidney Disease of unknown etiology is a growing health concern in low-and middle-income countries. While occupational heat stress is recognized as a potential contributor to kidney dysfunction among agricultural workers, the causal relationship between heat stress, core body temperature (Tc), and kidney function remains unclear. MethodsWe conducted an observational study over two harvest seasons in Guatemala, following 148 male sugarcane workers across six months. Heat stress was measured using heat index (HI) and Tc with ingestible telemetric temperature pills. Particulate matter (PM) exposure was measured using personal breathing zone samplers worn during the work shift. We evaluated changes in kidney function using pre-and post-shift estimated glomerular filtration rate (eGFR). We applied G-computation to estimate causal effects and modeled hypothetical policy interventions reducing HI, Tc, and PM exposure, simulating occupational heat reduction strategies. ResultsThe average daily HI was 37.4 {degrees}C (SD: 2.0) with an average Tc increase of 1.16 {degrees}C (SD: 0.48) per shift. Both HI and Tc were associated with declines in eGFR across the work shift. At an HI of 34 {degrees}C, workers experienced an average eGFR decline of about 5 mL/min/1.73 m{superscript 2}, while at 40 {degrees}C the decline exceeded 16 mL/min/1.73 m{superscript 2}. High HI early in the season and elevated Tc later in the season contributed to kidney decline. A simulated intervention reducing HI exposure by 5% improved eGFR change by 1.46 mL/min/1.73 m{superscript 2}. PM exposure did not have a significant impact on eGFR decline. ConclusionReducing workday heat exposure may mitigate acute kidney function decline. These findings support the development of policy interventions aimed at reducing external heat exposure and internal heat strain to protect kidney health. More research is needed to investigate the potential contribution of other environmental factors, including PM exposure.

Phthalate plasticizers are contaminants of emerging concern that interfere with the synthesis, secretion, and transport of hormones and receptors, altering the immune response and energy balance. Phthalate metabolites have been detected in marine mammals globally, and while studies on phthalate toxicity in marine mammals are beginning to emerge, a comprehensive understanding of the cellular response to these compounds remains elusive. Here, we investigated the transcriptional and bioenergetic responses to mono-ethylhexyl phthalate (MEHP), the active metabolite of di(2-ethylhexyl) phthalate (DEHP), in primary dermal derived from northern elephant seals (Mirounga angustirostris), common dolphins (Delphinus delphis), and humans. MEHP exposure did not induce cytotoxicity in any species, but triggered distinct, species-specific changes in gene expression and mitochondrial metabolism. Human cells showed the greatest transcriptional response to MEHP, upregulating detoxification, antioxidant, and inflammatory genes, and downregulating lipid metabolism pathways. Although mitochondrial respiration declined only at the highest dose, sustained extracellular acidification rates and increased glycolytic gene expression indicate a metabolic shift toward glycolysis. In contrast, elephant seal cells upregulated antioxidant and immune genes while maintaining mitochondrial respiration until the highest MEHP dose, alongside increased expression of genes involved in oxidative phosphorylation, the TCA cycle, and mitochondrial dynamics, suggesting a delayed shift to glycolysis and a potential evolutionary adaptation to sustain mitochondrial function during energy-demanding conditions such as breath-hold diving. Dolphin cells exhibited fewer transcriptional changes, which were enriched for hormone signaling and mitotic pathways, and showed dose-dependent declines in both oxygen consumption and extracellular acidification rates, even at the lowest MEHP concentration, alongside upregulation of stress and hypoxia-related genes. Together, these findings highlight distinct cellular strategies for coping with phthalate exposure and likely species-specific susceptibility to toxicant-induced stress. This study provides new insights into how marine mammals respond to plastic-derived contaminants at the cellular level, reinforcing the need for species-specific ecotoxicological risk assessments.

Background/ObjectivesOccupational exposure to neurotoxicants such as pesticides, metals, and solvents has long been implicated in Parkinsons disease (PD) and Parkinsonism, yet the cumulative impact of multiple occupational exposure families over the working life remains insufficiently characterized. This study evaluated whether long-term cumulative occupational exposures, derived from the ALOHA+ Job-Exposure Matrix (ALOHA+-JEM), were associated with PD and Parkinsonism. MethodsA hospital-based matched case-control study was conducted in the province of Brescia, Italy, including 668 participants (334 PD/Parkinsonism cases and 334 matched controls). Cases and controls were 1:1 matched based on sex, age, and lifetime occupational duration. Lifetime occupational histories were coded using ISCO-08 and harmonized to ISCO-88 for linkage with ALOHA+-JEM. Conditional logistic regression estimated associations between cumulative exposures (none/low/high) and disease status, adjusting for smoking, parental history of PD/tremor, and SNCA rs356219 genotype. Multi-agent occupational exposure burden indexes were evaluated using positively constrained repeated-holdout Weighted Quantile Sum (WQS) regression (100 bootstraps, 100 holdouts) ResultsIn conditional logistic regression, parental history of PD or tremor (OR = 4.55, 95% CI: 2.44-8.48; q < 0.001) and the SNCA rs356219 CC genotype (OR = 2.17, 95% CI: 1.33-3.52; q = 0.013) were significantly associated with disease. High cumulative all pesticide exposure showed positive associations with combined PD + Parkinsonism (OR = 2.98, 95% CI: 1.23-7.25) and PD alone (OR = 3.56, 95% CI: 1.25-10.15). In WQS analyses, the composite occupational exposure burden index was positively associated with disease (combined PD + Parkinsonism: OR = 1.15, 95% CI: 1.00-1.30). All pesticides received the highest mean weight in all models (w = 0.434 for combined PD + Parkinsonism), followed by metals (w = 0.210), identifying them as contributing most strongly to the composite exposure index. ConclusionsLong-term cumulative occupational exposures were associated with increased odds of PD and Parkinsonism. All pesticides and metals were most strongly associated with PD and Parkinsonism, consistent with established neurotoxic mechanisms attributable to occupational environments. These findings underscore the importance of occupational exposure prevention and risk-reduction strategies in occupational settings and highlight workplace exposures as preventable contributors to Parkinsonian disorders.

As toxicology shifts towards non-animal testing, quantitative models are essential to predict adverse health effects from molecular or cellular perturbations. Quantitative Adverse Outcome Pathways (qAOPs) represent such models, building on mechanistic knowledge and quantifying the Key Event Relationships (KERs) described in AOPs. Despite the recognized need, the number of qAOPs remains limited. Bayesian-based approaches are often chosen for developing qAOP for their flexibility, but most use discretized variables, limiting their predictive power. In addition, these models are mainly built from newly generated data, underexploiting the large amount of information available. This study successfully leverages data from public literature and presents an innovative framework based on continuous variables to develop a Bayesian-based quantitative model for a central KER towards liver fibrosis. The model predicts the probability of the expression fold change for two key markers of hepatic stellate cell activation (aSMA and COL1A1), given the effects on tissue injury, using in vitro data from 9 chemicals. We propose a newly developed workflow to assist in knowledge identification, organization, and extraction from scientific literature and chemical databases. Based on in vitro data and in vivo information from the Open TG-GATEs (Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System) database, we estimate a biologically relevant range in COL1A1 fold change that indicates an activated state of stellate cells and high liver fibrosis odds ratios. Our study provides a case example of integrating published data and continuous variables to build a Bayesian-based model, which constitutes an essential step for predicting liver fibrosis from in vitro data.

Micro and nanoplastics are pollutants which concentration in different biotopes increases continuously over time, which poses the question of their potential effects on health. In animals, these micro and nanoplastics are recognized as particulate materials and thus handled by macrophages, which are therefore a key cell type to study. Most studies have used an experimental scheme in which the cells are exposed to a single dose of plastics, with a readout made immediately after exposure. However, this classical experimental scheme does not take into account the impact of biopersistence, nor the potential cellular adaptation that may take place when cells are exposed repeatedly to a low dose of plastics. We thus used a repeated exposure scheme, in order to better take into account these phenomena. Within this frame, we compared the macrophages responses to a persistent nanoplastic, i.e. polystyrene nanoparticles and to a biodegradable nanoplastic, i.e. polylactide, by a combination of proteomic and targeted experiments. Our results show that under this repeated exposure scheme, the proteome changes were of a lesser (for PS) or similar (for PLA) extent than under the acute exposure mode, indicating cell adaptation. However, PLA particles induced mitochondrial dysfunction and depression of response to bacterial molecules perceived as danger signals, such as lipopolysaccharide. Polystyrene nanoparticles also induced a slight alteration of the immune functions of macrophages. This indicates harmful effects even in the repeated exposure scheme.

BackgroundEvidence suggests maternal exposure to ambient air pollution increases the risk of stillbirth, but few studies conducted in the United States have evaluated temporally varying exposures or susceptibility across gestational windows. Moreover, the generalizability of existing findings is often limited by restricted geographic coverage or reliance on selected study populations. MethodsUsing Georgia vital records from 2005 to 2014, we conducted a matched case-control study including 8,384 stillbirths and 33,459 live birth controls matched on maternal county of residence and conception month. We used stratified Cox proportional hazards models with time-varying covariates to estimate hazard ratios (HRs) for ten air pollutants across five exposure windows (first month, weekly, and first, second, and third trimester). Our primary analysis included all stillbirths combined, with subgroup analyses separating second and third trimester losses. ResultsStillbirths had a median gestational age of 27 weeks (IQR: 6.67) compared with 38 weeks for live births (IQR: 2.13). Particulate matter showed strong associations in the second trimester exposure window for all stillbirths (PM10: HR = 1.07; 95% CI: 1.04, 1.11; PM2.5: HR = 1.05; 95% CI: 1.01, 1.09). This pattern was consistent for NO2 and NH4, which also exhibited positive associations across early and entire pregnancy exposure windows (first month, first trimester, weekly), with the strongest associations for the second trimester exposures. Associations were larger for second trimester stillbirths, whereas estimates for third trimester stillbirths were largely null or negative. ConclusionsIn this population-based study in Georgia, time-varying ambient air pollution exposures during pregnancy were associated with increased risk of stillbirth, particularly for second trimester exposures and for stillbirths occurring earlier in pregnancy. These findings highlight the importance of considering gestational timing when evaluating environmental risk factors for stillbirth. What this study addsThis study is the first to evaluate maternal ambient air pollution exposure and stillbirth using time-varying exposures on vital records in the state of Georgia. By examining ten air pollutants across multiple gestational windows and subset analyses by timing of stillbirth, we identified second trimester susceptibility to NO2, PM10, PM2.5, and NH4. These findings highlight periods of vulnerability to ambient air pollution during pregnancy.