I.A. Lea , D. Feifarek , A. Mihalchik , M. Heintz , L. Haws , H. Nyambego , K. Goyak , C. Palermo , S.J. Borghoff
{"title":"Evaluation of the endocrine disrupting potential of Di-isodecyl phthalate","authors":"I.A. Lea , D. Feifarek , A. Mihalchik , M. Heintz , L. Haws , H. Nyambego , K. Goyak , C. Palermo , S.J. Borghoff","doi":"10.1016/j.crtox.2025.100221","DOIUrl":"10.1016/j.crtox.2025.100221","url":null,"abstract":"<div><div>Low molecular weight <em>ortho</em>-phthalates have been implicated in perturbing androgen pathways when administered during the masculinization programming window. Di-isodecyl phthalate (DIDP) is a high molecular weight phthalate and as a high production volume chemical, its ability to disrupt endocrine pathways is important to understand its potential hazard. Both DIDP (and its metabolites) were evaluated to determine the potential to perturb endocrine pathways through a weight of evidence (WoE) assessment in accordance with the European Chemicals Agency (ECHA)/European Food Safety Authority (EFSA) Endocrine Disruptor Guidance (2018). A literature review was performed of toxicological data for DIDP related to estrogen, androgen, thyroid, or steroidogenesis pathways. Literature searches returned 41 relevant articles from which data were extracted and assessed in conjunction with data from 105 high-throughput assays. Because some of the <em>in vitro</em> assays lack metabolic capabilities, an <em>in silico</em> assessment of estrogen (E), androgen (A), thyroid (T) or steroidogenesis (S) activity was conducted. Based on the available evidence for the T pathway, DIDP did not elicit adverse thyroid outcomes <em>in vivo</em>. When considering the T mechanistic data, there was evidence that DIDP induced the liver pregnane X receptor (PXR) and some indication that DIDP increased iodide uptake in the thyroid. As there were no studies evaluating thyroid hormone levels <em>in vivo</em>, a data gap was identified because per the ECHA/EFSA guidance, the lack of this information prevents drawing a conclusion on the T pathway. However, the E, A and S pathways were sufficiently assessed to conclude a limited or lack of E, A or S related apical outcomes in <em>in vivo</em> studies; there was also a lack of endocrine activity in <em>in vitro</em> or <em>in vivo</em> mechanistic studies. These results suggest that DIDP does not meet the ECHA/EFSA criteria for an endocrine disruptor, therefore DIDP is unlikely to disrupt the androgen pathway during development.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"8 ","pages":"Article 100221"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluating fumonisin contamination in cattle feed: Impact on animal health, the agriculture industry and regulatory considerations","authors":"Ashli A. Brown , Tim Herrman","doi":"10.1016/j.crtox.2025.100235","DOIUrl":"10.1016/j.crtox.2025.100235","url":null,"abstract":"<div><div>In 2001, the US FDA released guidance levels (GLs) for fumonisin (FUM) in corn and corn by-products intended for human and animal consumption. Recent research challenges the conservatism of these GLs for ruminants, particularly for regions like the Texas High Plains, where blending permissions have been provoked, limiting the management of FUM contamination economically and maximization of corn availability for feedlots. This study evaluates whether scientific advancements since 2001 warrant a revision of these guidelines. Specifically, a 2020 study provides new data on cattle fed FUM concentrations up to 108.8 mg/kg, suggesting the current 60 mg/kg GL may be overly conservative. Using a combination of <em>meta</em>-analysis and the US EPA’s Benchmark Dose Software (BMDS), we assess the new scientific evidence. Our findings indicate that new data does not significantly refine the dose–response relationship for FUM in cattle, supporting the continued appropriateness of the current 60 mg/kg GL.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"8 ","pages":"Article 100235"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143911683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Prenatal linuron exposure disrupts adrenal steroidogenesis and induces adrenal insufficiency in male rat offspring","authors":"Duoduo Quan , Yang Cheng , Xinhe Zhou , Jiao Xu , Tingting Shangguan , Yibing Tang , Zhiguang Zhao , Qiang Xu","doi":"10.1016/j.crtox.2025.100254","DOIUrl":"10.1016/j.crtox.2025.100254","url":null,"abstract":"<div><div>Linuron, a commonly used agricultural herbicide in certain regions, has raised concerns due to its endocrine toxicity in humans and wildlife. While its gonadal toxicity is established, its direct impact on prenatal adrenal development remains unexplored. Pregnant Sprague-Dawley rats received linuron doses (0, 25, 50, 100 mg/kg/day) by oral gavage from gestational days 12–21. Linuron reduced serum CORT at 50 and 100 mg/kg and ALDO at 100 mg/kg but did not affect ACTH levels. At 100 mg/kg, linuron decreased cell density in the adrenal zona fasciculata without changing its thickness. It also altered the expression of key genes and proteins involved in adrenal function at 50 and/or 100 mg/kg. Additionally, linuron reduced the expression of key antioxidant enzymes (SOD2, GPX1, CAT) at 100 mg/kg. Linuron altered adrenal kinase signaling, activating AMPK but suppressing AKT, with no effect on ERK1/2 pathways. These findings reveal, for the first time, that linuron disrupts male fetal adrenal development and function likely through impaired steroidogenesis, oxidative stress, and dysregulated AKT/AMPK signaling, highlighting its role as a developmental adrenal disruptor.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"9 ","pages":"Article 100254"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144858294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacob W. Fleming , Molly C. McCloskey , Kevin Gray , David R. Nash , Vincent Leung , Christos Michas , Shawn M. Luttrell , Christopher Cavanaugh , Julie Mathieu , Shawn Mcquire , Mark Bothwell , David L. Mack , Nicholas A. Geisse , Alec S.T. Smith
{"title":"An automated platform for simultaneous, longitudinal analysis of engineered neuromuscular tissues for applications in neurotoxin potency testing","authors":"Jacob W. Fleming , Molly C. McCloskey , Kevin Gray , David R. Nash , Vincent Leung , Christos Michas , Shawn M. Luttrell , Christopher Cavanaugh , Julie Mathieu , Shawn Mcquire , Mark Bothwell , David L. Mack , Nicholas A. Geisse , Alec S.T. Smith","doi":"10.1016/j.crtox.2025.100218","DOIUrl":"10.1016/j.crtox.2025.100218","url":null,"abstract":"<div><div>Animal models of the neuromuscular junction (NMJ) have been widely studied but exhibit critical differences from human biology limiting utility in drug and disease modelling. Challenges with scarcity, scalability, throughput, and ethical considerations further limit the suitability of animal models for preclinical screening. Engineered models have emerged as alternatives for studying NMJ functionality in response to genetic and/or pharmacological challenge. However, these models have faced challenges associated with their poorly scalable creation, sourcing suitable cells, and the extraction of reliable, quantifiable metrics. We present a turnkey iPSC-based model of the NMJ employing channelrhodopsin-2 expression within the motor neuron (MN) population driving muscle contraction in response to blue light. MNs co-cultured with engineered skeletal muscle tissues produced twitch forces of 34.7 ± 22.7 µN in response to blue light, with a response fidelity > 92 %. Histological analysis revealed characteristic punctate acetylcholine receptor staining co-localized with the presynaptic marker synaptic vesicle protein-2. Dose-response studies using botulinum neurotoxin showed loss of function in a dose- and time-dependent manner (EC<sub>50</sub> − 0.11 ± 0.015 µg). Variability of the EC<sub>50</sub> values between 2 different iPSC differentiations of both cell types and 2 users was less than 2 %. Further testing with the acute neurotoxins acetylcholine mustard and d-tubocurarine validated the biological relevance of the postsynaptic machinery of the model. This model marks a meaningful progression of 3D engineered models of the NMJ, providing engineered tissues at a throughput relevant to potency and screening applications with an abundant iPSC cell source and standardized hardware-software ecosystem allowing technology transfer across laboratories.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"8 ","pages":"Article 100218"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143161444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S.J. Borghoff , B.N. Rivera , S. Fitch , A.N. Buerger , N.Y. Choksi , A. Franzen , M.J. Vincent , T. Covington , J. Bus , E. Rushton , I.A. Lea
{"title":"Systematic evaluation of the evidence base on methyl tert-butyl ether supporting a lack of concern for carcinogenic hazard in humans based on animal cancer studies and mechanistic data","authors":"S.J. Borghoff , B.N. Rivera , S. Fitch , A.N. Buerger , N.Y. Choksi , A. Franzen , M.J. Vincent , T. Covington , J. Bus , E. Rushton , I.A. Lea","doi":"10.1016/j.crtox.2025.100224","DOIUrl":"10.1016/j.crtox.2025.100224","url":null,"abstract":"<div><div>Methyl <em>tert</em>-butyl ether (MTBE) is a high-octane fuel component that helps gasoline burn cleaner and reduces automobile emissions. In 1999, the International Agency for Research on Cancer (IARC) categorized MTBE as “not classifiable” regarding human carcinogenicity. Since then, additional studies have been published that substantially added to the evidence base to examine the carcinogenic potential of MTBE in humans. A systematic literature search and review was conducted to identify mechanistic data, as well as studies investigating cancer in MTBE-exposed humans and experimental animals. Critical appraisal was performed for relevant studies with mechanistic data organized and evaluated within Key Characteristics of Carcinogens (KCCs). Three standard animal cancer bioassays showed a low incidence of hepatocellular adenomas in female mice (inhalation exposure), with renal adenomas/carcinoma (inhalation) and brain tumors (drinking water) in male rats exposed to high concentrations of MTBE. Evidence extracted from the literature demonstrate that the mechanism of male rat renal tumors does not operate in humans. Review of the strength of mechanistic data was based on activity, relevancy, and reliability, with information-dense KCC2—is genotoxic, and KCC10—alters cell proliferation, cell death, and nutrient supply, together supporting that MTBE is unlikely to be a carcinogenic hazard to humans.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"8 ","pages":"Article 100224"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aakash Patel , Suruchi Poddar , Daniel Nierenberg , Stephanie Lang , Hao Wang , Camilly Pestana Pires DeMello , Julio Gamarra , Alisha Colon , Paula Kennedy , Jeffry Roles , Jules Klion , Will Bogen , Christopher Long , Xiufang Guo , Patrick Tighe , Stephan Schmidt , Michael L. Shuler , James J. Hickman
{"title":"Microphysiological system to address the opioid crisis: A novel multi-organ model of acute opioid overdose and recovery","authors":"Aakash Patel , Suruchi Poddar , Daniel Nierenberg , Stephanie Lang , Hao Wang , Camilly Pestana Pires DeMello , Julio Gamarra , Alisha Colon , Paula Kennedy , Jeffry Roles , Jules Klion , Will Bogen , Christopher Long , Xiufang Guo , Patrick Tighe , Stephan Schmidt , Michael L. Shuler , James J. Hickman","doi":"10.1016/j.crtox.2024.100209","DOIUrl":"10.1016/j.crtox.2024.100209","url":null,"abstract":"<div><div>Opioids have been the primary method used to manage pain for hundreds of years, however the increasing prescription rate of these drugs in the modern world has led to a public health crisis of overdose related deaths. Naloxone is the current standard treatment for opioid overdose rescue, but it has not been fully investigated for potential off-target toxicity effects. The current methods for pharmaceutical development do not correlate well with pre-clinical animal studies compared to clinical results, creating a need for improved methods for therapeutic evaluation. Microphysiological systems (MPS) are a rapidly growing field, and the FDA has accepted this area of research to address this concern, offering a promising alternative to traditional animal models. This study establishes a novel multi-organ MPS model of acute opioid overdose and rescue to investigate the efficacy and off-target toxicity of naloxone in combination with opioids. By integrating primary human and human induced pluripotent stem cell (hiPSC)-derived cells, including preBötzinger complex neurons, liver, cardiac, and skeletal muscle components, this study establishes a novel functional multi-organ MPS model of acute opioid overdose and rescue to investigate the efficacy and off-target toxicity of naloxone in combination with opioids, with clinically relevant functional readouts of organ function. The system was able to successfully exhibit opioid overdose using methadone, as well as rescue using naloxone evidenced by the neuronal component activity. In addition to efficacy, the multi-organ platform was able to characterize potential off-target toxicity effects of naloxone, specifically in the cardiac component.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"8 ","pages":"Article 100209"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11745978/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143001854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nina Y. Yuan , William D. Richards , Kailyn T. Parham , Sophia G. Clark , Kaylie Greuel , Brandon Polzin , Steven W. Smith , Connie S. Lebakken
{"title":"Neural organoids incorporating microglia to assess neuroinflammation and toxicities induced by known developmental neurotoxins","authors":"Nina Y. Yuan , William D. Richards , Kailyn T. Parham , Sophia G. Clark , Kaylie Greuel , Brandon Polzin , Steven W. Smith , Connie S. Lebakken","doi":"10.1016/j.crtox.2025.100252","DOIUrl":"10.1016/j.crtox.2025.100252","url":null,"abstract":"<div><div>The use of iPSC-derived complex <em>in vitro</em> 3D cellular constructs is a promising avenue to more accurately predict human neural toxicities and reduce the use of animal models. We have generated a neural organoid model which incorporates iPSC-derived microglia and enables interrogation of neuroinflammation induced by pre-clinical drug candidates of varying modalities and chemical compounds in industrial use. Herein we describe the generation and characterization of this model system and its utility in assessing toxicity. We exposed the neuroimmune organoids to a variety of developmental neurotoxins and measured cellular damage by release of LDH, GFAP, and NF-L into the cell culture supernatants. Additionally, to determine whether the compounds led to activation of microglia-mediated inflammation, we measured IL-8 secretion and assessed microglia-specific gene transcriptional analysis using bulk RNA sequencing. Spearman correlation matrices using both differentially expressed genes in the RNA sequencing data and pathway analysis using Gene Ontology Enrichment revealed that microglia may play a role in the toxicity of these compounds which has been widely overlooked in standardized neurotoxicity tests. Treatment of the organoids with lead acetate demonstrates a dose–response curve of IL-8 secretion and alterations in the microglial morphology. Our findings suggest that both direct neurotoxicity and indirect neuroinflammatory mechanisms contribute to the potentially harmful effects of these compounds in the developing central nervous system.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"9 ","pages":"Article 100252"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Profiling assay performance in the DevTox germ layer reporter platform","authors":"John T. Gamble , Chad Deisenroth","doi":"10.1016/j.crtox.2025.100223","DOIUrl":"10.1016/j.crtox.2025.100223","url":null,"abstract":"<div><div>The U.S. Environmental Protection Agency (U.S. EPA) is mandated to develop new approach methods (NAMs) to detect chemicals risks to susceptible populations, including effects on pregnant women and their offspring. With limited hazard information available for current and new chemicals, NAMs can provide greater relevance to human biology, mechanistic insight, and higher testing capacity than traditional animal models. The DevTox Germ Layer Reporter (GLR) model platform was recently established for high-throughput screening and prioritization of potential developmental hazards. The model platform utilizes the RUES2-GLR pluripotent stem cell reporter line that expresses fluorescent fusion protein biomarkers SOX17 (endoderm), Brachyury (mesoderm), and SOX2 (ectoderm and pluripotency); enabling a multi-lineage readout of gastrulation lineages. The DevTox GLR-Endo assay used the model platform to evaluate chemical effects on differentiating endoderm, yielding a balanced accuracy (BA) of 72% against a training set of 43 developmental toxicants and 23 non-developmental toxicants. To assess the predictivity of additional early embryonic lineages, assays for pluripotency (DevTox GLR-Pluri), ectoderm (DevTox GLR-Ecto), and mesoderm (DevTox GLR-Meso) were developed. Chemical reference set (12 developmental toxicants and 4 non-developmental toxicants) activity for each assay revealed BAs of 92% for DevTox GLR-Endo and DevTox GLR-Pluri, 71% for DevTox GLR-Ecto, and 58% for DevTox GLR-Meso. Expanded testing of the DevTox GLR-Endo and DevTox GLR-Pluri with 63 developmental and non-developmental toxicants yielded BAs of 75% and 68%, respectively. Amongst the four DevTox GLR platform assays, the DevTox GLR-Endo assay maintained the highest degree of efficacy and overall predictive accuracy for the compound set evaluated in this study.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"8 ","pages":"Article 100223"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strategy for reproductive and developmental toxicity (DART) studies for marketing applications in pharmaceutical development","authors":"Yusuke Kagawa , Takuro Osawa , Naomi Koyama , Takashi Tanaharu , Daisuke Kigami","doi":"10.1016/j.crtox.2025.100258","DOIUrl":"10.1016/j.crtox.2025.100258","url":null,"abstract":"<div><div>Studies on reproductive toxicity are conducted to assess the effects of chemicals and pharmaceuticals on the reproductive function and fetal development. However, depending on the indication or modality, Fertility and Early Embryonic Development (FEED), Embryo-Fetal Development (EFD), and Pre/Postnatal Development (PPND) studies which evaluate all reproductive stages or EFD studies in a second species may not be necessary. Therefore, based on the Common Technical Document (CTD), PMDA review reports, and other documents of drugs with new active ingredients approved in Japan, we aimed to investigate the implementation status of DART studies by classifying the studies into FEED, EFD, and PPND types, and summarizing the reasons for not conducting the studies. This survey was conducted by the Reproductive and Developmental Toxicity Team of the Japan Pharmaceutical Manufacturers Association (JPMA) to address issues related to DART studies conducted as non-clinical studies for drug development. Of the three DART studies, 35% of drugs received marketing application without conducting EFD studies in at least one species. Among the three study types, PPND studies were the second most frequently waivered, with 36% not conducted. FEED studies had the lowest implementation rate among the three types of studies, with 40% not conducted. The primary reason for waiving at least one study was compliance with ICH S5, S6, S9, and M3 guidelines. In conclusion, the necessity of DART studies varied depending on the applicable ICH guideline and the characteristics of the drug, including therapeutic indication, target, endogenous substances, low exposure, and ADA formation. This suggests that the need for DART studies may be waived because of various reasons, each of which should be justified based on scientific rationale and risk analysis.</div></div>","PeriodicalId":11236,"journal":{"name":"Current Research in Toxicology","volume":"9 ","pages":"Article 100258"},"PeriodicalIF":2.9,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}