Female infertility is an increasing global public health concern. Growing evidence suggests that exposure to organophosphate flame retardants (OPFRs) may contribute to reproductive dysfunction. However, the OPFRs most strongly associated with female infertility and the potential molecular pathways underlying these associations remain unclear. This study employed an integrated framework combining epidemiological analysis, network toxicology, molecular docking, and adverse outcome pathway (AOP) construction to investigate the association between OPFR exposure and female infertility and to explore plausible underlying mechanisms. Cross-sectional data from 1044 women in the National Health and Nutrition Examination Survey (NHANES) 2013-2018 cycles were analyzed using multivariable logistic regression, restricted cubic spline (RCS), Quantile g-computation (Qgcomp), weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR). Diphenyl phosphate (DPhP) was consistently identified as the OPFR metabolite most strongly positively associated with female infertility and showed the greatest relative influence across the mixture models. Network toxicology prioritized six steroidogenic enzymes (CYP11A1, CYP17A1, CYP19A1, HSD3B1, HSD17B1, and HSD17B2) as candidate molecular targets, and molecular docking predicted favorable interactions of DPhP and its parent compound triphenyl phosphate (TPhP) with these proteins. Integration of these computational findings with existing AOPs suggested a plausible mechanistic framework involving perturbation of steroidogenesis, altered estradiol biosynthesis, and disruption of androgen-estrogen homeostasis, which may contribute to impaired female reproductive function. These findings provide cross-sectional evidence for an association between DPhP exposure and female infertility and generate mechanistic hypotheses regarding TPhP/DPhP-associated reproductive effects that warrant further experimental and prospective validation.
This study aimed to investigate the association between multiple metals exposure and mild cognitive impairment (MCI) among adults residing along the Yangtze River in Anhui Province, China. We integrated network toxicology, epidemiological cohort studies and in vitro experiments under human-realistic doses to elucidate the potential biological mechanisms of MCI induced by multiple metals exposure. Among the 1337 participants, cadmium (Cd) was positively associated with incident MCI (OR = 1.13, 95% CI: 1.01-1.26) and exhibited the strongest positive weight in the multiple-mixture models. Network toxicology analysis and molecular docking simulations evaluated the binding affinity of Cd to the targets related to cognitive function, and identified NFKB1 as the core key target. Cell experiments based on the actual Cd exposure concentrations of study population indicate that Cd can promote the activation of NF-κB in SH-SY5Y cells, and upregulate the expression of inflammatory factors. Population validation experiment showed that TNF-α and IL-6 partially mediated the association between Cd and MCI. Collectively, this study clarifies the potential biological mechanisms of MCI induced by multiple metals exposure, providing novel exposure biomarkers and therapeutic targets for the comprehensive prevention and treatment of MCI.
Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a frequently encountered and distressing disorder of the urinary system, yet the contribution of ubiquitous environmental contaminants such as bisphenol A (BPA) remains poorly understood. In this study, we integrated network toxicology, molecular docking and molecular dynamics simulations, and experimental validation to investigate this association. In RWPE-1 cells, BPA pretreatment markedly enhanced subsequent lipopolysaccharide (LPS)-induced inflammatory responses, indicating that BPA acts not as a potent direct pro-inflammatory stimulus, but rather as a sensitizer that lowers the threshold for inflammatory activation. Network toxicology, followed by molecular docking and molecular dynamics simulations, identified the PI3K/AKT signaling pathway as a potential target of BPA, with AKT1 emerging as a key candidate that exhibited stable binding in silico. This mechanism was further validated both in vitro and in vivo, where BPA exposure was associated with suppression of PI3K/AKT signaling, exacerbation of mitochondrial oxidative stress, accumulation of oxidized mitochondrial DNA, and enhanced activation of the NLRP3 inflammasome, as evidenced by increased levels of NLRP3, ASC, cleaved caspase-1, and mature IL-1β. Functionally, activation of PI3K/AKT by SC79 significantly attenuated BPA-induced oxidative stress, mitochondrial dysfunction, and inflammasome activation, whereas the mitochondrial reactive oxygen species scavenger Mito-TEMPO primarily inhibited downstream inflammasome activation. In an experimental autoimmune prostatitis model, BPA exposure exacerbated prostatic inflammation and inflammatory cytokine production, effects that were markedly reversed by SC79 and Mito-TEMPO. Collectively, our study provides integrative evidence that environmental BPA exposure may contribute to increased susceptibility to prostatic inflammation under pathological conditions and identifies impaired PI3K/AKT signaling, mitochondrial oxidative stress, and NLRP3 inflammasome activation as key underlying mechanisms, thereby providing a mechanistic basis for future preventive and therapeutic strategies.
Background Lead (Pb) and cadmium (Cd) remain widespread environmental toxicants, and the kidney is a major target organ. However, reliance on a single biomarker matrix or renal endpoint may incompletely characterize Pb–Cd-associated renal abnormalities. Whether blood- and urine-based Pb/Cd biomarkers exhibit differential association profiles across renal outcomes, and whether outcome-oriented networks converge on shared candidate pathways, remains unclear. Methods We analyzed NHANES 2011–2018 data from 5049 adults. Blood and urinary Pb and Cd biomarkers were evaluated in relation to estimated glomerular filtration rate (eGFR), albuminuria [log(UACR)], and a CKD-compatible phenotype using survey-weighted regression, whereas Pb–Cd mixtures were examined using case-weighted quantile g-computation and generalized weighted quantile sum regression. Effect modification by age, sex, BMI, diabetes, and hypertension was evaluated using formal interaction tests with false-discovery-rate correction. An outcome-oriented network toxicology framework was constructed using CKD-, albuminuria-, and broad renal injury-oriented disease modules. HEK293T cells were used for targeted cellular assessment of cytotoxicity, intracellular metal accumulation, redox and inflammatory responses, and transcriptional changes in genes prioritized by network analysis following Pb, Cd, or combined exposure. Exploratory molecular docking was performed to examine potential metal–protein interaction sites. Results Individual-biomarker and mixture analyses showed that the observed associations varied across biomarker matrices and renal outcomes. Urinary Pb was positively associated with eGFR; urinary Cd and blood Pb were associated with higher log(UACR); and blood Pb and blood Cd were associated with higher odds of the CKD-compatible phenotype. The urinary Pb–Cd mixture was positively associated with eGFR and log(UACR), whereas the blood mixture was associated with higher log(UACR) and higher odds of the CKD-compatible phenotype. Formal interaction analyses identified age-related heterogeneity in selected blood-based associations, while inverse associations of blood Pb, blood Cd, and urinary Cd with eGFR were stronger among participants with diabetes. Outcome-oriented network analysis consistently prioritized IL1B and IL6 as shared inflammatory hubs, while peripheral network architecture differed across renal modules. In HEK293T cells, combined Pb–Cd exposure increased intracellular metal burden and cytotoxicity, reduced antioxidant capacity, and altered the expression of IL1B, IL6, and selected stress-response genes. Conclusion Blood- and urine-based Pb and Cd biomarkers exhibited distinct association profiles across renal outcomes, indicating that a single biomarker matrix or endpoint may incompletely characterize Pb–Cd-associated renal abnormalities. Outcome-oriented networks converged on IL1B and IL6 as shared inflammatory hubs within distinct peripheral architectures, with targeted cellular evidence supporting the responsiveness of prioritized targets. These findings establish an integrative, multi-matrix and multi-outcome framework for the mechanistic interpretation and risk assessment of Pb–Cd co-exposure.
The application of sludge compost to saline-alkali soil is a key strategy for sustainable sludge management and degraded land improvement. Sewage sludge is rich in soil-enhancing nutrients but contains high levels of mercury. However, the environmental behavior of mercury during sludge compost-mediated saline-alkali soil amelioration, remain poorly understood. Therefore, this study selected the saline-alkali soil of Yellow River Delta as the test soils, and prepared co-compost from sewage sludge and corn straw as the soil amendment, to explore the variations of total mercury (THg), mercury speciation, and atmosphere release of Hg0 during the improvement of saline-alkali soil. The results showed a decrease in THg content. After improving saline-alkali soil with sludge compost, the proportion of labile Hg species and humic complexes increased. Sludge compost increased the net methylation rate in the soil near the water level under non-flooded conditions and in the surface soil under flooded conditions. The application of sludge compost under flooded conditions increased the relative abundance of mercury-methylating microorganisms in the soil. Sludge compost increased the concentration of the dissolved total mercury (DTHg) in soil pore water, thereby enhancing mercury mobility. Under non-flooded conditions, sludge compost promoted the release of Hg0 in soil. Flooded conditions are not conducive to the release of Hg0 in soil. Flooded conditions elevated the risk of methylmercury (MeHg) formation, while non-flooded conditions promoted the release of soil mercury into the atmosphere. The study revealed the pollution risk of mercury in saline-alkali soil improved by sludge under different scenarios.
E-cigarette aerosols cause increased oxidative stress in vitro, in animal models, and in users, a condition linked to disease progression, including cancer. This study investigates how prolonged exposure to e-cigarette aerosols affects key cellular pathways involved in antioxidant defense and stemness. Human oral and lung epithelial cells were exposed for two weeks to e-cigarette aerosol extracts delivering 30 ng/mL nicotine, a concentration that mimics users’ plasma levels. Gene and protein expression were assessed using real-time RT-PCR and western blotting analyses, respectively, while the spheroid formation assay was performed to evaluate stemness. E-cigarette exposure significantly upregulated the antioxidant regulator NRF2 and its downstream targets (e.g., SOD2, CAT, and HMOX1), while decreasing its negative regulator KEAP1. Unexpectedly, TGF-β1 protein and its downstream signaling, ERK1/2 proteins, were also elevated. Chronic exposure of cell lines to e-cigarette aerosols resulted in increased spheroid formation and elevated expression of stem cell markers (BMI1, OCT4, SNAIL, and SLUG), indicating enhanced stem-like features. Collectively, these findings demonstrate that chronic e-cigarette aerosol exposure induces concurrent activation of NRF2 and TGF-β signaling and enhances stem-like features in human oral and lung epithelial cells. These molecular and phenotypic alterations may contribute to early cellular events associated with oral and lung carcinogenesis, highlighting the need for further investigation into the long-term health consequences of sustained e-cigarette use.
This study employed C57BL/6 male mice to examine the effects of PM2.5 exposure on male reproductive function and early embryonic development. Single-cell transcriptomic analysis revealed significant DNA damage and metabolic dysregulation in the testicular tissues of PM2.5-exposed mice, starting at the undifferentiated spermatogonia stage. Untargeted metabolomics further identified metabolic disturbances in sperm, with notable alterations in key pathways, including galactose metabolism, glycine, serine, and threonine metabolism, and nucleotide metabolism. PM2.5 exposure significantly impaired sperm motility, thereby reducing its fertilizing capacity. Although the blastocyst formation rate in the PM2.5-exposed group did not differ significantly from that of the Control group, clear developmental delays were observed in peri-implantation embryos, accompanied by substantial transcriptomic abnormalities. Notably, pronounced dysregulation in differentially expressed genes was already evident at the 2-cell and blastocyst stages, suggesting that PM2.5 exposure may disrupt subsequent developmental processes by altering gene expression patterns in pre-implantation embryos.
Ethanol-induced pericardial edema is a common morphological manifestation of developmental cardiotoxicity in zebrafish. However, there is currently a lack of methods that can provide objective and reproducible quantitative measurements of pericardial edema severity. Here, we established a non-invasive, three-dimensional (3D) quantitative framework using Spectral Domain Optical Coherence Tomography (SD-OCT) to resolve this limitation. Validation using a lipid-filled scattering phantom yielded measured and theoretical values with a relative error below 1%. No significant difference existed between these two values (P > 0.05). In the in vivo experiments, zebrafish embryos were exposed to 0%, 0.5%, 1.0%, or 2.0% ethanol. At 72 hpf, pericardial edema volume (PEV) was quantified from consecutive OCT cross-sectional images, while lateral-view bright-field images were used for qualitative morphological assessment. Notably, OCT-based three-dimensional volumetric analysis revealed an increase in PEV at 0.5% ethanol. Visual inspection of stereomicroscope images did not reveal obvious morphological changes. Heart rate decreased and malondialdehyde (MDA) levels increased in the ethanol-exposed groups, providing complementary functional and biochemical evidence of ethanol toxicity. These findings support OCT-derived PEV as a complementary quantitative structural endpoint for characterizing ethanol-induced pericardial alterations in zebrafish.
Per- and polyfluoroalkyl substances (PFAS) have been frequently detected in polar environments despite the absence of substantial local emissions, raising concerns about long-range atmospheric transport (LRAT) and precursor-driven inputs to remote regions. This study characterized the occurrence and distribution of neutral (nPFAS) and ionic PFAS (iPFAS) in air, soil, and moss collected near King Sejong Station, Antarctica. Year-long passive air samples revealed the predominance of volatile fluorotelomer alcohols (FTOHs) in atmosphere, accompanied by short-chain perfluorobutanoic acid (PFBA) and perfluorobutanesulfonate (PFBS). Spatial variations in FTOH composition showed modest site-specific differences potentially associated with air-mass transport and mixing, while strong correlations between FTOHs and their transformation products indicated active atmospheric oxidation. PFBA was the most consistently observed PFAS in air, soil, and moss, reflecting its high mobility and ubiquity in Antarctica. Field-derived soil-air partitioning coefficients (KSA) further suggested that short-chain PFAS may be introduced through multiple pathways, including direct atmospheric transport and soil-associated precursor degradation. These findings situate Antarctic PFAS occurrence within wider global emission and transport dynamics. Sustained atmospheric monitoring will be critical for assessing how evolving PFAS usage influences long-range transport to the Antarctic environment.
This study developed an OECD-aligned QSAR model with an explicit applicability domain to predict the adsorption of Sulfonylurea (SUs) herbicides and methabenzthiazuron in agricultural volcanic ash-derived soils (VADS), a variable-charge system poorly represented in current pesticide adsorption QSAR models. Twenty-four SUs and methabenzthiazuron were evaluated in ten VADS, generating 250 compound-VADS systems from batch adsorption-desorption experiments. The dataset was complemented by soil physicochemical characterization, adsorption kinetics, and adsorption-desorption analysis, and descriptor-based QSAR modelling using a Lamarckian Genetic Algorithm for variable selection and Ridge regression across interaction, soil-specific, and herbicide-specific edaphic scenarios, with external validation and domain of applicability (DA). Adsorption was consistently nonlinear, and the Freundlich model best described equilibrium behavior. Across the 250 systems, Kfads ranged from 0.04 to 519.50, Kfdes from 0.24 to 229.91, and the hysteresis coefficient (H) from 0.00 to 0.94, indicating strong variability in retention and reversibility. The interaction scenario provided the main predictive result: with 210 training and 40 external observations [Formula: see text] = 0.438, [Formula: see text] = 0.347, RMSEtest = 0.492, and 30/40 (75%) DAcoverage). The final QSAR interaction retained 24 descriptors, indicating that adsorption in VADS is governed by the interplay between herbicide ionisation/polarity and 3D electronic features as well as soil organo-mineral reactive domains (OM, C/N, Fe, Cu, S, and P-Olsen). Accordingly, the predictive signal arose from herbicide-soil coupling rather than from molecular or edaphic properties alone. Within its calibrated chemical and edaphic space, the QSAR model provides a mechanistically interpretable, exploratory screening tool for identifying higher-mobility SUs-VADS combinations.
Holistic protection goals in environmental hazard and risk assessment, complex pollutant mixtures, and limitations in targeted chemical analysis highlight the need for robust, mechanistically informative bioanalytics to support water quality monitoring. Given the scarcity of high-throughput, non-mammalian in vitro effect-based methods, this study evaluates the suitability of mammalian models as surrogates for aquatic species by investigating interspecies differences in the activation of oxidative stress (Nrf2/Keap1/ARE) and xenobiotic metabolism (AhR/ARNT/XRE) pathways quantified with cellular reporter gene assays. Wastewater treatment plant influent and effluent samples, alongside reference compounds, were analysed in human, mouse, and zebrafish reporter assays. Bioanalytics were complemented by in silico-mediated effect-directed analysis, iceberg-, molecular docking-, and chemical bioavailability-modelling. For Nrf2/Keap1/ARE, high concordance in reporter activity across species was observed in response to environmental samples, whereas the reference compound tert-butylhydroquinone elicited species-/assay-specific differences due to varying ligand affinities for the Keap1 redox sensor. In contrast, metazachlor exposure resulted in conserved activation patterns across species. For AhR/ARNT/XRE, interspecies variability in bioactivity was observed across environmental samples and the reference compound 2,3,7,8-tetrachlorodibenzodioxin, yielding divergent bioequivalent concentration estimates. In silico-mediated effect-directed analysis identified climbazole, daidzein, and thiabendazole as principal aryl hydrocarbon receptor activators, which also displayed species-/assay-specific activity under isolated exposure. Molecular docking confirmed species-dependent receptor-ligand affinities, while bioavailability modelling excluded differential cellular uptake, supporting receptor-mediated mechanisms as key drivers. Collectively, mammalian reporter assays can approximate oxidative stress responses in aquatic species, but limitations remain for xenobiotic metabolism, highlighting the need for species-representative assays and caution when contextually interpreting data from mammalian systems.
Per- and polyfluoroalkyl substances (PFAS) are a class of neurotoxic persistent organic pollutants that may increase the risk of cognitive impairment and dementia, yet their association with schizophrenia (SCZ) remains unclear. This study aimed to investigate the relationship between plasma PFAS levels and the risk of schizophrenia. The concentrations of PFAS in plasma were measured using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS). To evaluate the single and combined effects of PFAS exposure on the risk of schizophrenia, we employed multivariable logistic regression, restricted cubic splines (RCS), Bayesian kernel machine regression (BKMR), and generalized weighted quantile sum (gWQS) models. Logistic regression analysis revealed that, compared with the lowest quartile (Q1), the odds ratios (ORs) for PFOS and PFHxS in the highest quartile (Q4) were 0.17 (95% CI:0.09∼0.36) and 0.39 (95% CI:0.21∼0.71), respectively. RCS analysis suggested nonlinear relationships between PFUnDA, PFOS, PFOA, and PFHxS and schizophrenia. In the assessment of mixture exposure effects, the BKMR model indicated an overall negative association between PFAS mixtures and schizophrenia risk, and gWQS analysis further identified PFHxS as the component with the highest weight contribution. Additionally, correlations were observed between the levels of PFUnDA, PFOS, and PFHxS and inflammatory indices in patients with schizophrenia. Future large-scale prospective studies combined with toxicological mechanism research are needed to further validate these findings.
Per- and polyfluoroalkyl substances (PFAS), widely used as durable additives in various consumer products for their water- and oil-repellent properties, persist environmentally and bioaccumulate, raising substantial health concerns. The primary route of human exposure towards PFAS is via contaminated food and drinking water, however, mounting evidence highlights inhalation as additional, critical route of exposure. In particular, inhalation of perfluorooctane sulfonate (PFOS) adversely affects respiratory health through immune disruption, oxidative stress, and impaired barrier function, particularly evident during prenatal exposure. Recent evidence reveals that emerging, anthropogenic PFOS exposure activates innate immune pathways conserved over millions of years of evolution leading to inflammation and tissue injury. PFOS has been shown to trigger the AIM2 inflammasome via mitochondrial damage and DNA release, inducing pyroptosis and IL-1β secretion leading to prolonged inflammation and tissue injury. Beyond inflammasomes, the cGAS/STING axis, which is closely co-regulated with the inflammasome, recognizes ectopic DNA and contributes to PFOS-induced inflammatory responses. Co-exposures to airborne pollutants or infections might additionally amplify these effects, as demonstrated by increased expression of AIM2, cGAS, and STING in lung cells following bacterial or particulate challenges. This commentary highlights the critical need for mechanistic research on PFOS-triggered innate immune signalling and potential harmful co-exposure interactions particularly in the lung to better assess health risks and inform regulatory policies for these persistent environmental contaminants.
The aim of this study was to explore the DNA methylation mechanisms by which maternal betaine (BET) supplementation during pregnancy alleviates fluoride-induced learning and memory impairments in offspring rats. Female and male rats were mated 2:1 in cage. After pregnancy, they were divided into control group, sodium fluoride (NaF) group, low BET group, and high BET group. The neurobehavioral test showed that slower swimming speed, longer escape latency and fewer platform shuttles were observed in NaF groups, but these were reversed by BET intervention. Furthermore, Hematoxylin and Eosin (H&E) staining revealed disrupted structures of hippocampal neurons in the NaF group, a reduction in intracellular Nissl bodies was evidenced by Nissl staining as well. However, BET treatment could improve the above changes. Targeted Bisulfite Sequencing (TBS) analysis showed that DNA methylation levels in the promoter regions of Guanine nucleotide-binding protein Gs subunit alpha (GNAS) was lower in the NaF group compared to controls, and increased after BET intervention. Furthermore, the NaF group showed significantly increased protein and mRNA expression levels of both GNAS, while it was reduced after low-dose BET intervention. Additionally, the protein and mRNA expression of DNA methyltransferases (DNMTs) were significantly reduced in NaF group, whereas a higher expression levels of these protein and mRNA were observed in the low-dose BET group. Maternal BET supplementation attenuates fluoride-induced learning and memory impairments in rats, potentially by elevating DNA methylation levels in the promoter regions of the GNAS genes.
Phthalic acid esters (PAEs) are produced in large quantities by industry because they are suitable constituents of plastics, thanks to their chemical properties. Considering the great risks for human health due to exposure to PAEs, the problem related to the effects of these plasticizers on food-producing animals should not be put on the back burner because foods represent one of the first pathways of their absorption for humans. Recent studies suggest that phthalate contamination in the rumen can affect its function and alter the microbial balance. Hence, understanding what happens after ingestion is crucial. This study assessed the impact of dimethyl-, diethyl-, and di-n-octyl- phthalate (DMP, DEP, and DOP, respectively) on rumen fermentation and microbial communities, by means of an in vitro approach. Phthalates significantly altered the fatty acid profile. Saturated fatty acids decreased, while monounsaturated and polyunsaturated ones increased under DEP treatment. The DOP reduced C20:4 n-6 and C22:6 n-3. Stearic acid (C18:0) remained dominant but decreased in DEP and DOP conditions. Several C18:1 isomers and omega-3 were affected, particularly by DOP. The highest abatement of phthalates was observed for DOP (63.062%), while DEP and DMP (5.159 and 4.838%) had a similar low decrease compared to the initial concentration. Microbial community analysis revealed shifts in beta diversity, with DEP causing the most distinct changes. Bacterial genera such as Rhodococcus and Streptococcus increased in DEP, while other genera like Aliarcobacter and Parabacteroides declined. DEP, DMP, and DOP induced genus-specific responses, highlighting PAE-selective impact on rumen ecology.
Continuous use of organophosphate for dengue vector management has increased the risk of resistance development in Aedes aegypti, threatening the effectiveness of current control programmes. This study evaluated susceptibility and mechanisms associated with organophosphate resistance in Ae. aegypti populations from five dengue-endemic districts of sub-Himalayan West Bengal, India. Larvae and adults were subjected to insecticide bioassays, synergist assays, biochemical assays, gene expression analysis, partial sequencing of the acetylcholinesterase gene (ace-1), and molecular docking. Bioassays confirmed malathion resistance (mortality<90%) in DAR, JAL and ALI populations, whereas UTT and COO exhibited possible resistance (mortality=90-98%). High temephos resistance (RR50>10) was detected in DAR, JAL and ALI, while UTT showed moderate resistance (RR50=7.31) and COO remained susceptible (RR50=2.52). Pre-exposure to triphenyl phosphate restored susceptibility in most populations, indicating possible carboxylesterase-mediated metabolic resistance. Resistant populations exhibited significantly elevated alpha and beta carboxylesterase activity. Stage-specific overexpression was observed, with CCEae3a (13.68-39.21-fold) overexpressed in resistant larvae, whereas CCEae6a (12.25-33.99-fold) was overexpressed in resistant adults and both positively correlating with resistance phenotypes. Enzyme activity and gene expression were significantly correlated with reduced malathion mortality and increased temephos LC50. Most individuals from JAL, COO and UTT did not exhibit altered AChE activity, while altered activity was detected in < 25% of individuals from DAR and ALI. Partial ace-1 sequence analysis identified no organophosphate resistance-associated polymorphisms within analysed region, suggesting limited role of target-site insensitivity. Molecular docking suggested possible interactions of malathion and temephos with carboxylesterase. These findings provide biochemical and molecular markers for resistance surveillance and support integrated vector management.
Anthropogenic activities are driving an increasing flux of rare earth elements (REE) into environmental compartments, raising concerns about their biological impact, particularly on microorganisms that sustain ecosystem functioning. Here, we provide a systematic assessment of the toxicity of all 16 REE toward Pseudomonas putida KT2440, a soil bacterium that can use these metals as enzyme cofactors. Dose-response growth inhibition assays revealed high sensitivity to light REE. Toxicity correlated strongly with ionic radius, with IC50 values ranging from 0.3 µM for lanthanum to 10 µM for scandium. Serial propagation of P. putida under gradually increasing REE stress yielded resistant populations, from which two stably resistant strains were isolated. Genome resequencing showed that both strains carried a single mutation in uxpB, encoding an alkaline phosphatase. Gene deletion and overexpression experiments, together with phosphatase activity measurements, confirmed the involvement of uxpB in REE resistance. Our findings reveal a previously unrecognized mechanism of tolerance to REE, suggesting that mutations enhancing phosphatase activity promote phosphate release from organic phosphorus compounds, thereby reducing REE bioavailability through phosphate-mediated complexation and/or immobilization.
Nitrate is the predominant groundwater pollutant within the European union (EU), despite comprehensive legislation. In this study, acute (up to 96 h) and time-independent toxicity of nitrate (NO3-) were investigated for two groundwater amphipod species, Niphargus inopinatus and N. grandii. Nitrate concentrations applied ranged from 10 to 5000 mg/L NO3-. Bulk stable nitrogen isotope analysis was used to assess the potential uptake and exchange of nitrate derived nitrogen into biomass. Furthermore, we challenged the hypothesis that amphipods via their gut microbiome contribute to nitrate removal from contaminated groundwater. Acute sublethal effects occurred after 24 h of exposure only at 5000 mg/L, the highest nitrate concentration tested. Mortality remained at 0% for both species after 96 h. The 96-h EC50 values were 397 mg/L for N. inopinatus and 1298 mg/L for N. grandii, whereas the time-independent ultimate EC50 were calculated with 127 mg/L and 164 mg/L NO3-, respectively, matching nitrate concentrations frequently found in contaminated groundwaters. These values were reached already after 6 and 10 days, respectively. A time-independent LC50 of 386 mg/L NO3- could be estimated for only N. inopinatus. The NOEC of NO3- after 4 weeks of exposure was 100 mg/L for both species. Chronic nitrate exposure, did not change the δ¹ ⁵N signature of test animals’ bulk biomass. No evidence was collected for a nitrate reduction in groundwater mediated by the invertebrates. The present study underlines the need for further studies with stygobiont organisms, but also emphasizes its limitations.
Arsenic, a widely distributed environmental contaminant, poses a significant global public health challenge, affecting hundreds of millions of individuals worldwide. Chronic arsenic exposure is a well-established risk factor for bladder cancer, however, the fundamental underlying molecular processes mechanisms remain incompletely understood. In this study, C57BL/6 mice were exposed to sodium arsenite (NaAsO₂; 0, 8, 20, and 50 mg/L) through drinking water for 20 weeks, and human normal bladder epithelial cells (SV-HUC-1) were chronically treated with 0.5 μM NaAsO2 for 40 weeks. The results demonstrate that long-term arsenic exposure induces aberrant growth of bladder epithelial cells both in vitro and in vivo. Mechanistically, arsenic increased intracellular Ca2 + levels, which were played a role in promoting pre-malignant phenotypes. This study identified calcium-dependent calcineurin (CaN) as a key downstream effector of Ca2+signaling, with its activity enhanced by arsenic-induced Ca2+elevation. Long-term arsenic exposure promoted pre-malignant cellular behavior through CaN activation. Furthermore, CaN enhanced the activity of nuclear factor kappa B (NF-κB) and nuclear factor of activated T cells (NFAT) pathways, both of which are closely associated with tumorigenesis in arsenic-exposed bladder epithelial cells. Pharmacological inhibition of CaN effectively suppressed arsenic-induced activation of both NF-κB and NFAT pathways. Finally, this study demonstrated that store-operated calcium entry (SOCE) serves as the source of elevated intracellular Ca²⁺ levels, and that arsenic activates NF-κB and NFAT signaling pathways through SOCE-mediated Ca²⁺ influx. These findings reveal a mechanistic link whereby chronic arsenic exposure induces SOCE-mediated Ca2+ elevation, activates CaN, and subsequently promotes NF-κB and NFAT pathway activation, ultimately driving pre-malignant behavior of bladder epithelial cells.
The widespread use of Wi-Fi-derived radiofrequency electromagnetic radiation (RF-EMR) has raised concerns regarding male reproductive health; however, whether paternal exposure exerts transgenerational effects on offspring development remains unclear. This study investigated the effects of chronic paternal 2.4 GHz Wi-Fi RF-EMR exposure (whole-body SAR 0.125-0.5 W/kg, 4 h/day, 6 days/week for 20 weeks) on sperm quality in F0 male mice and placental development in F1 offspring, with a focus on epigenetic regulation. Paternal RF-EMR exposure significantly reduced sperm concentration and increased the sperm abnormality rate in F0 males. F1 offspring exhibited reduced fetal weight and placental efficiency, with more pronounced impairments in male offspring. Mechanistically, paternal exposure reduced the proportion of placental labyrinth layer and downregulated multiple nutrient transporters in a male-biased manner. Epigenetic analysis revealed sex-dependent histone modifications in placentas following paternal RF-EMR exposure: male placentas exhibited increased H3K9me2/3, H3K27me3, H3K27ac, and H3K4me2, whereas female placentas exhibited decreased H3K4me2. ChIP-qPCR targeting transporter promoters revealed sex-specific enrichment of repressive histone marks in placentas from exposed fathers. In male placentas, H3K27me3 was increased at the Atp1a1 and Slc22a3 promoters, and H3K9me3 was increased at the Atp1a1 and Slc2a1 promoters. In female placentas, H3K27me3 at the Slc3a2 promoter was significantly decreased. Collectively, chronic paternal Wi-Fi RF-EMR exposure impairs fetal growth and placental efficiency, with male offspring being more susceptible, and is associated with disrupted placental structure, impaired nutrient transport, and sex-dependent histone modifications in the offspring placenta. These findings underscore the importance of considering paternal RF-EMR exposure in reproductive risk assessment.
