Introduction:Immune checkpoint inhibitors (ICIs) enhance antitumor responses by blocking inhibitory receptors, including PD-1 and CTLA-4. Overactivation can trigger systemic toxicity akin to autoimmune diseases, including kidney manifestations. We sought to 1) profile immune signaling and 2) interrogate potential mechanisms of ICI-related kidney injury in a Human Immune System (HIS) tumor-bearing mouse model treated with nivolumab and ipilimumab. Methods:Immunodeficient BRGS (BALB/c-Rag2 null Il2rγ null Sirpα NOD) neonates were engrafted with human CD34+ cells to generate HIS-BRGS mice. Human MDA-MB-231 tumor cells were implanted subcutaneously; once tumors reached ~150 mm3, mice received weekly intraperitoneal vehicle (PBS) or ICI (nivolumab 20 mg/kg + ipilimumab 10 mg/kg) for 4 weeks (Veh BRGS n=4; ICI BRGS n=6; Veh HIS-BRGS n=7; ICI HIS-BRGS n=7). Kidneys were evaluated by histopathology (H&E, TEM), flow cytometry for human immune phenotypes, multiplex ELISA (80 human proteins; 10 injury biomarkers), bulk RNA sequencing, and targeted qPCR. Pearson correlations identified predictors of histopathological injury. Results:Renal vasculitis and interstitial nephritis were observed only in ICI-treated HIS-BRGS mice. These kidneys showed a shift toward CD4+ T-cell enrichment with an increased TNF-α production capacity compared to CD8+ counterparts. Toxicity was accompanied by increased renal concentrations of human cytokines, chemokines, and soluble receptors. ICI treatment significantly elevated serine proteases (Granzyme A/B) and NGF-β, while decreasing IL-4. Interstitial nephritis correlated with renal PD-1 and MIF. Renal vasculitis correlated with kidney PD-1, CCL1, MIF, Granzyme A, IL-15, and BAFF. Traditional injury biomarkers (KIM-1, NGAL) remained unchanged; however, a trending decrease in EGF was observed. Conclusions:Our study suggests that shifts in human T-cell populations and specific immune proteins could serve as promising biomarkers and mechanistic targets for ICI nephrotoxicity. The tumor-bearing HIS-BRGS mouse model reproducibly recapitulates the histopathological and immunological features of human ICI-induced nephrotoxicity and represents a validated preclinical platform for testing novel therapeutic interventions to preserve kidney function during cancer immunotherapy.

Zearalenone (ZEN) is a mycotoxin that widely contaminates human food supplies. In animal models, exposure to ZEN has extensive impacts on reproduction and pregnancy including contributing to early parturition. Here, we translate that research to humans by examining gestational exposure to ZEN in relation to the timing of birth and placental corticotropin releasing hormone (pCRH), a hormone that regulates the timing of parturition. Utilizing data from a pregnancy cohort (UPSIDE; Rochester, NY; n = 299), we investigated exposure to ZEN and its metabolites in relation to: 1) gestational age at birth; and 2) pCRH across pregnancy. Adjusted linear regression models were fitted to examine gestational age at birth and pCRH in relation to three maternal urinary mycoestrogen measures in each trimester: (1) ZEN; (2) its metabolite, α-zearalenol (aZOL); and (3) the sum of ZEN and its five metabolites (∑mycoestrogens). For models examining pCRH, we additionally fitted linear mixed effects models to account for repeated measures. All models were refitted stratified by fetal sex. Mycoestrogens were detected in over 90% of samples in each trimester. Sex-stratified analyses showed distinct sex differences in trimester 2 in relation to exposure, with higher gestational age at birth in males (β:2.35 days, 95%CI:0.14, 4.56) and lower gestational age at birth in females (β:-1.70 days, 95%CI:-3.35, -0.07). In linear mixed effects models examining pCRH, ZEN was positively associated with pCRH concentrations: ZEN (%Δ:5.17, 95%CI:1.09, 9.36). Mycoestrogen exposure may be associated with sex-specific changes in gestational age at birth and higher pCRH, a risk factor for preterm birth.

BACKGROUND:Zearalenone (ZEN) is a grain-contaminating mycotoxin and potent estrogen receptor agonist linked to reproductive and perinatal disruption in animal models, with emerging epidemiologic evidence in humans. Despite widespread U.S. exposure, dietary sources remain unclear. OBJECTIVE:This pilot study assessed prenatal mycoestrogen exposure and related dietary sources in a U.S. pregnant cohort. METHODS:Pregnant women (n = 33) recruited in New Brunswick, NJ provided urine samples and completed time-matched 24-h dietary recalls at three points across pregnancy (Visit 1: 18-20 weeks; Visit 2: 24-26 weeks and Visit 3: 28-32 weeks gestation). Urinary mycoestrogens were quantified using LC/MSMS and corrected for specific gravity. RESULTS:At least one ZEN metabolite was detected in every sample (Visit, median: 1: 0.058 ng/mg; 2: 0.042 ng/mg; 3: 0.055 ng/mg), and intraclass correlation coefficients among detected metabolites ranged from 0.62 to 0.95. Across visits, Hispanic participants (39%) had 52-109% higher mycoestrogen concentrations compared to non-Hispanic participants (p < 0.05). Consumption of corn and other grain products within the past 24 h was strongly correlated with urinary concentrations of ZEN and its metabolites (r: 0.30-0.92; p < 0.05), with weaker positive correlations observed for oils and popcorn. SIGNIFICANCE:Given robust toxicologic evidence and emerging epidemiologic findings suggesting adverse maternal and child health impacts, identifying key exposure pathways is critical. IMPACT:This pilot study identifies corn and cereal-based foods as key contributors to ZEN prenatal exposure and highlights higher concentrations among Hispanic participants. By clarifying exposure pathways, these findings support improved food-safety monitoring and targeted strategies to reduce endocrine-disrupting chemical exposures during pregnancy.

Hepatotoxicity remains a leading cause of drug attrition and post-marketing withdrawal, resulting from diverse and complex toxicity mechanisms. Traditional in vitro models can only capture a limited subset of toxicity pathways, and animal studies face translational and ethical limitations. Regulatory agencies have therefore promoted new approach methodologies, including human-relevant assays, omics technologies, and computational models to improve predictive toxicology and support evidence-based decision-making. However, most machine learning models for hepatotoxicity either rely solely on chemical structure or operate as black boxes, limiting mechanistic interpretability and broader applicability. Here, we introduce the virtual toxicity network (vToxiNet), a biologically constrained deep learning framework that embeds systems toxicology knowledge directly into neural network architecture for interpretable hepatotoxicity prediction. vToxiNet integrates chemical descriptors, high-throughput assay responses, transcriptomic signatures, and Reactome pathway hierarchy to construct a virtual adverse outcome pathway network. Across cross-validation and multiple external validation datasets, vToxiNet demonstrates robust predictive performance and generalizes to previously unseen chemicals. Importantly, interpretation of vToxiNet enables gene and pathway-level attribution, supporting mechanism-informed hazard characterization and chemical prioritization. These results demonstrate that encoding biological hierarchy as architectural constraints enables both predictive accuracy and mechanistic insight, establishing a generalizable framework for modeling complex biological outcomes.

Background:Rising global temperatures and eutrophication are increasing the intensity and frequency of cyanobacterial harmful algal blooms that release toxins including microcystin-LR (MC-LR). MC-LR inhibits protein phosphatases in the human liver and brain, but its accumulation in the placenta is unclear. Placental transporter expression varies across pregnancy and is influenced by physiological cues, such as low oxygen concentrations which activate HIF1A, and trophoblast cell fusion forming syncytiotrophoblasts that engage CREB-driven transcription. This study examined whether MC-LR accumulates in placental cells, which transporters mediate uptake, and how these transporters are regulated by HIF1A and CREB. Methods:Intracellular accumulation of MC-LR (0.1-10 μM, 3 hour) was measured in human cytotrophoblasts (JAR, BeWo) and extravillous trophoblasts (HTR-8/SVneo) by western blotting for MC-LR-adducted proteins. Organic anion transporting polypeptide (OATP) involvement was tested using cyclosporin A (10 μM), an OATP inhibitor, before exposure to the OATP substrate or MC-LR. Cells were also cultured under 3%, 8%, or 20% O2 to induce hypoxic responses or treated with forskolin (a potent intracellular cAMP inducer) to stimulate cell fusion before MC-LR exposure. Results:MC-LR accumulated in all three placenta cell lines in a concentration-dependent manner. Cyclosporin A reduced MC-LR uptake by 57% in JAR cells, confirming OATP-mediated transport. Low O2 increased OATP4A1 expression and function but reduced protein phosphatase expression, decreasing MC-LR-bound proteins by 52-72%. Forskolin increased OATP4A1 expression and enhanced MC-LR uptake >2.5-fold. Conclusion:MC-LR enters placental trophoblasts via active OATP transport, likely OATP4A1, and uptake increases under hypoxia and trophoblast fusion.

Micro and nanoplastics (MNPs) are a ubiquitous environmental contaminant that humans are exposed through multiple routes. Multiple studies have demonstrated that MNPs deposit in human placental tissues and can translocate across the placental barrier. Maternal blood enters the placenta through uterine spiral arteries. During development of the placenta, trophoblasts enter the arteriolar lumen and invade the endothelial layer. This remodeling reduces vascular contractility and maintains maternal blood flow into the placenta. Simultaneously, the placenta increases surface area through angiogenic branching, facilitating the indirect contact of maternal and fetal blood spaces and promoting maternal-fetal exchange. To date, no groups have investigated how maternal MNP exposure affects these key steps of placentation. Therefore, in this study, pregnant Sprague Dawley rats were exposed to air containing polyamide-12 MNP throughout gestation. Placental morphology, invasion of spiral arteries, and angiogenic signaling were evaluated in male and female placentas at GD16 and GD20. Maternal MNP inhalation significantly reduced the relative distance of trophoblast invasion into the placental region that houses maternal spiral arteries. Additionally, MNP exposure increased staining of smooth muscle actin around maternal spiral arteries, indicating poor remodeling and likely reducing uteroplacental blood flow. Likewise, inhalation of MNPs altered the size and number of maternal and fetal blood spaces, favoring less surface area for maternal-fetal exchange. Lastly, significant changes in the expression and spatial distribution of angiogenic and antiangiogenic mRNAs that regulate vascular branching and surface area were observed. Future studies are needed to characterize the mechanisms by which polyamide-12 MNP influences placental hemodynamics.

Regulatory agencies require comprehensive toxicity testing for prenatal drug exposure, including new drugs in development, to reduce concerns about developmental toxicity, that is, drug-induced toxicity and adverse effects in pregnant women and fetuses. However, defining developmental toxicity endpoints and optimal analysis of associated public big data remain challenging. Recently, artificial intelligence (AI) approaches have had a critical role in analyzing complex, high-dimensional data, uncovering subtle relationships between chemical exposures and associated developmental risks. Here, we present an overview of major big data resources and data-driven models that focus on predicting various toxicity endpoints. We also highlight emerging, interpretable AI models that integrate multimodal data and domain knowledge to reveal toxic mechanisms underlying complex endpoints, and outline a potential framework that leverages multiple interpretable models to comprehensively evaluate chemical-induced developmental toxicity.

The pregnane X receptor (PXR), a ligand-activated transcription factor, regulates the expression of genes involved in endobiotic and xenobiotic metabolism, inflammation, and fibrosis. Disruption of PXR functions can affect processes critical to metabolic dysfunction-associated steatohepatitis (MASH) progression. Although ligand-dependent PXR functions are well studied, its regulation by post-translational modification, particularly phosphorylation, remains unclear. PXR has a conserved phosphorylation motif within its ligand binding domain (Ser347 in mice; Ser350 in humans). In vitro studies showed that this site mutation impairs human PXR transcriptional activity; however, the mechanism remains elusive. To investigate this phosphorylation site role in MASH development, wild-type and PXR Ser347Ala knock-in mutation (PXR-KI) mice were fed either a high-fat diet or a control chow diet for 16 weeks. On control chow diet, PXR-KI mice exhibited decreased expression of alternative bile acid (BA) synthesis genes compared with wild-type mice. On a high-fat diet, PXR-KI mice manifested more severe hepatic steatosis, revealed by elevated serum total cholesterol, and increased expression of genes involved in lipid metabolism. In addition, changes in BA metabolism and transporter genes suggested a cholestatic pattern in this group of mice. BA profiling showed higher levels of conjugated, hydrophilic, primary BA in the serum and liver, and increased unconjugated BA in the intestine. The data suggest that PXR Ser347 phosphorylation motif is essential for regulating PXR functions to maintain endobiotic metabolism and alleviate hepatotoxicity during MASH progression. SIGNIFICANT STATEMENT: The ligand-independent role of pregnane X receptor (PXR) is unclear. In phosphodeficient PXR knock-in mice, loss of Ser347 phosphorylation worsened hepatic steatosis and altered bile acid homeostasis under high-fat diet feeding, uncovering a novel role and therapeutic potential of PXR phosphorylation in fatty liver diseases.

In recent years, multiple computational studies have used machine learning models to predict substrate binding and inhibition of ATP-binding cassette (ABC) transporters. However, many of these studies relied on relatively small training sets with limited applicability. In this study, we manually curated over 24,000 bioactivity records (i.e., inhibition, binding affinity, permeability) for the ABC transporters P-gp, BCRP, MRP1, and MRP2 from more than 900 literature sources in ChEMBL, with additional data from PubChem and Metrabase. This effort yielded eight data sets, comprising around 8800 unique chemicals with one or more substrate binding or inhibition activities for these four efflux transporters. Quantitative structure-activity relationship (QSAR) models were developed for each of the eight data sets using combinations of four machine learning algorithms and three sets of chemical descriptors. The resulting models demonstrated excellent performance by 5-fold cross-validation, achieving an average correct classification rate (CCR) of 0.764 for the substrate binding models and 0.839 for the inhibition models. Models were validated with additional compounds from DrugBank that were known substrates or inhibitors. We further analyzed how model predictions for efflux transporter activity could estimate exposure of the brain to xenobiotics. Notably, compounds predicted as P-gp and BCRP substrates were twice or more likely to have low brain exposure compared to compounds with high brain exposure. This study provides a large and curated drug transporter binding and inhibition database for computational modeling. Applicable models based on this large database for predicting transporter substrate binding and inhibition can be used to evaluate more complex drug bioactivities, such as exposure of protected tissues to chemicals.

BACKGROUND:Zearalenone (ZEN) is an estrogenic mycotoxin ("mycoestrogen") that contaminates global grain crops leading to detectable concentrations of ZEN and its metabolites, including the synthetic version α-zearalanol (also called zeranol; ZER), in human populations. Despite in vitro and in vivo animal evidence of endocrine disruption by ZEN, there has been limited investigation in humans. OBJECTIVES:To examine markers of fetal growth following prenatal exposure to ZEN and evaluate the role of the placental efflux transporter BCRP/ABCG2 in protecting against ZEN's potential fetoplacental toxicity. METHODS:Placentas were collected from participants (n=271) in the Understanding Pregnancy Signals and Development cohort (Rochester, New York, USA). Placental ZEN and its metabolites were analyzed from tissue samples using HPLC-MS. Birth weights and placental weights were obtained from medical records and direct measurement, respectively; fetoplacental weight ratio (FPR) was calculated by dividing birth weight by placental weight. Covariate-adjusted generalized linear regression models were used to examine ZEN, ZER, and total mycoestrogens (sum of ZEN, ZER, and their metabolites) in relation to birth length, birth weight, placental weight and FPR. We additionally stratified models by infant sex and ABCG2 C421A (Q141K) genotype. RESULTS:Mycoestrogens were detected in 84% of placentas (median ZEN: 0.010 ng/g) and total mycoestrogens were associated with lower FPR [-0.20; 95% confidence interval (CI): -0.32, -0.08], particularly in female infants (-0.31; 95% CI: -0.52, -0.09). Associations with birth weight were inverse and overall nonsignificant. Among the 17% of participants with the reduced function 421A ABCG2 variant (AA or AC), total mycoestrogens were associated with lower birth weight (-113.5g; 95% CI: -226.5, -0.50), whereas in wild-type individuals, total mycoestrogens were associated with higher placental weight (9.9; 95% CI: 0.57, 19.2) and reduced FPR (-0.19; 95% CI: -0.33, -0.05). DISCUSSION:Results from this epidemiological study of prenatal mycoestrogen exposure and perinatal health suggest that mycoestrogens may reduce placental efficiency, resulting in lower birth weight, particularly in female and ABCG2 421A infants. https://doi.org/10.1289/EHP14478.

Exposure to organophosphate pesticides (OPPs) has been linked to adverse birth outcomes, including low birthweight. Maternal biomarkers are commonly used as proxies for fetal exposure, but fetal exposure also depends on placental transport mechanisms. In 240 mother-newborn pairs, we explored how genetic variation in membrane transporters influences the association between maternal OPP concentrations and birthweight. Single nucleotide polymorphisms (SNPs) in the OAT4/SLC22A11 and OATP2B1/SLCO2B1 membrane transporters modified the relationship between OPP exposure and birthweight-for-gestational age, with significant inverse associations observed only among individuals with variant transporter genotypes. In this small study, we found that transporter genotype may influence the placental disposition of environmental chemicals and perinatal susceptibility to toxicity.

Despite the crucial role of the placenta in supporting pregnancy and fetal development, research into its susceptibility to environmental exposures has been limited by methodological challenges. We review diverse approaches to studying placental biology and responses to chemical exposures, and provide a comprehensive assessment of traditional and emerging methodologies. Beginning with an overview of placental biology and species differences, we evaluate in vivo and in vitro models, and discuss their strengths and limitations. We examine advances, including placental transfer models, toxicokinetic frameworks, and 3D microphysiological systems, for their potential to address current gaps. Last, we consider molecular epidemiology and high-throughput analyses as complementary strategies. Together, these tools support better experimental design and enhance our understanding of placental vulnerability to chemical exposures.

The maternal–fetal environment is influenced by multiple factors, including nutrition and environmental contaminants, which can impact long-term development. Perinatal exposure to organophosphate flame retardants (OPFRs) disrupts energy homeostasis and causes maladaptive behaviors in mice. Maternal obesity affects development by impairing blood–brain barrier (BBB) formation, influencing brain regions involved in energy regulation and behavior. This study examined the combined effects of maternal obesity and perinatal OPFR treatment on offspring development. Female mice were fed either a low-fat (LFD) or a high-fat diet (HFD) for 8 weeks, mated, and treated with either sesame oil or an OPFR mixture (tris(1,3-dichloro-2-propyl)phosphate, tricresyl phosphate, and triphenyl phosphate, 1 mg/kg each) from gestational day 7 to postnatal day 14. Results showed that both maternal diet and OPFR treatment disrupted blood–brain barrier integrity, energy balance, and reproductive gene expression in the hypothalamus of neonates. The expression of hepatic genes related to lipid and xenobiotic metabolism was also altered. In adulthood, LFD OPFR-treated female offspring exhibited increased avoidance behavior, while HFD OPFR-treated females demonstrated memory impairments. Metabolic assessments revealed decreased energy expenditure and nighttime activity in LFD OPFR-treated females. These findings suggest that maternal diet and OPFR treatment alter hypothalamic and liver gene expression in neonates, potentially leading to long-term metabolic and behavioral changes.

While immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, they can elicit organ-related immune-related adverse events (irAEs) such as kidney injury. Here, our study evaluated the ability of a humanized immune system (HIS) tumor-bearing mouse model to investigate ICI-mediated kidney injury. Non-humanized (BRGS) and humanized (HIS-BRGS) mice were implanted with human breast cancer cells and treated with either nivolumab (anti-PD-1) or a combination of nivolumab and ipilimumab (anti-CTLA-4) for four weeks. Histopathological analysis revealed that HIS-BRGS mice treated with ICIs exhibited significant interstitial nephritis and vasculitis/periarteritis, consistent with kidney phenotypes observed in patients. Combination therapy resulted in more extensive kidney pathology than nivolumab alone and exhibited an accumulation of T helper cells in the affected areas. Importantly, our results suggest that HIS-BRGS mice can effectively recapitulate features of ICI-induced kidney injury observed in patients and can be used to study mechanisms and prevention strategies to limit irAEs.

BACKGROUND:The farnesoid X receptor (FXR) has been identified as a therapeutic target for metabolic dysfunction-associated steatohepatitis (MASH). FXR is the major homeostatic regulator of bile acids (BAs) with dysregulation of BAs and/or FXR implicated in the pathogenesis of MASH. Synthetic whole-body FXR agonists have been developed to treat MASH. Although beneficial for MASH treatment, these whole-body modulators contribute to unfavorable side effects such as pruritus and an elevation in low-density liporoteins, thereby highlighting the importance of tissue and cell-restricted modulation of FXR in the development of novel therapeutics for MASH to negate potential harmful off-target effects. METHODS:The objective of this study was to determine the tissue-specific role of FXR in MASH development using male and female wild-type (WT), liver FXR KO (FXRhep-/-), intestinal FXR KO (FXRint-/-), and whole body FXR KO (FXR KO) mice fed either a low-fat control diet (CTL) or a MASH "Fast Food" (FF) diet. RESULTS:The results showed, in females, hepatic, but not intestinal, deficiency of FXR was associated with severe liver injury, through increased ALT, ALP, and genes indicative of inflammation and fibrosis when comparing FXRhep-/- versus FXRint-/-. Regardless of sex, hepatic FXR deficiency triggered the activation of neuroinflammation and neurodegenerative canonical pathways. CONCLUSIONS:These data suggest that hepatic FXR is more critical in suppressing liver injury during MASH development in female mice. However, this same trend was not clear in the male cohorts, highlighting sex differences and potential roles for sexual dimorphism in MASH development.

Acute kidney injury (AKI) occurs in approximately one-third of patients treated with cisplatin and there is an outstanding need for mitigation strategies to decrease the frequency and severity of cisplatin-induced AKI. This study evaluated bardoxolone methyl (BARD) as a nephroprotectant in a multidose, tumor-bearing mouse model of cisplatin-induced AKI. BARD is an attractive therapeutic intervention due to its ability to protect against cisplatin-induced nephrotoxicity by activating Nrf2 and previous reports suggesting anti-tumorigenic effects. In this study, CMT167 tumor-bearing mice were treated with four weekly doses of cisplatin with or without BARD and evaluated for survival, tumor growth, and clinical and histological measures of AKI. Kidney injury and/or function were evaluated by quantification of urinary kidney injury molecule-1 (KIM-1) and serum creatinine (SCr) levels as well as histopathology. Compared to mice receiving cisplatin alone, co-treatment with BARD significantly enhanced survival (p = 0.01). Moreover, BARD prevented elevation of urinary KIM-1 concentrations as early as one week after cisplatin treatment (p < 0.01) – a response that was observed throughout the 4-week study period. Cisplatin increased SCr concentrations by four weeks, which was prevented by BARD co-administration (p < 0.01). Cisplatin treatment significantly decreased tumor burden compared to vehicle-treated mice (p < 0.05 after two cisplatin doses) – a response that was not altered by BARD co-treatment. Overall, the results of this study demonstrate that BARD has the potential to improve survival and reduce clinical measures of kidney injury in tumor-bearing mice treated with cisplatin, suggesting it could be used as a nephroprotectant to mitigate cisplatin-induced AKI.

The environmental toxicant cadmium (Cd) impairs the growth of rodents and humans in utero which in turn heightens susceptibility to diseases later in life. We previously demonstrated that the maternal-facing efflux transporter, breast cancer resistance protein (human BCRP/ABCG2, mouse Bcrp/Abcg2) confers resistance against Cd toxicity in human trophoblasts. In the current study, we sought to determine whether the absence of Bcrp alters the fetoplacental disposition and toxicity of Cd in mice. Pregnant female wild-type (WT) and Bcrp-null mice (n = 9-10/group) were administered a single injection of saline (5 ml/kg) or CdCl2 (5 mg/kg) on gestational day (GD) 9. Following Cd treatment, Bcrp-null offspring were shorter and accumulated more Cd in their placentas on GD 17 compared to WT mice. Because Cd can adversely impact placentation and transplacental nutrient delivery in mice, multiple pathways were assessed using morphometrics and immunohistochemistry including placenta zonation, vasculature development, and nutrient transporter expression. Most notably, the placentas of Bcrp-null mice had reduced immunostaining of the cell adhesion marker, β-catenin, and the trophoblast marker, cytokeratin, as well as decreased expression of divalent metal nutrient transporters (Dmt1, Zip14, and ZnT1) following Cd treatment. In summary, the absence of Bcrp expression increased placental concentrations of Cd which was associated with shorter fetal size that may be related to differential changes in molecular patterns of placental development and nutrition.