Chemical Research in Toxicology最新文献

{"title":"Refining the Amino Reactivity-Based Identification of Respiratory Sensitizers","authors":"Martin Simoneit,&nbsp;Helene Langer,&nbsp;Nadin Ulrich and Alexander Böhme*,&nbsp;","doi":"10.1021/acs.chemrestox.4c0054510.1021/acs.chemrestox.4c00545","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00545https://doi.org/10.1021/acs.chemrestox.4c00545","url":null,"abstract":"<p >The sensitization of the respiratory tract may lead to various pulmonary diseases such as asthma. It can be triggered by the chemical reaction of organic electrophiles with nucleophiles of lung proteins with amino groups being of particular interest in this case. For assessing the dermal sensitization potential of chemicals, the direct peptide reactivity assay (DPRA) has become an OECD-accepted nonanimal test system. However, issues with the identification of known respiratory sensitizers such as isocyanates and anhydrides based on their amino reactivity in the DPRA have been reported. Hence, in this study the chemoassay employing glycine-<i>para</i>-nitroanilide (Gly-pNA) as model nucleophile is applied to eight iso(thio)cyanates, seven anhydrides, four dinitrobenzenes, one triazine, five acrylates, glutaraldehyde, and chloramine T to quantify their amino reactivity in terms of the second order rate constant <i>k</i>_Gly and the DPRA-like 24 h percent depletion <i>D</i>_Gly. A comparison of <i>D</i>_Gly with respective DPRA amino reactivity data (<i>D</i>_DPRA) showed that in particular iso(thio)cyanates and anhydrides are substantially more reactive toward Gly-pNA. This can be rationalized by the unintentional and so far not considered reaction of the test compounds with the ammonium acetate buffer used for DPRA testing. A detailed analysis of this reaction includes half-lives and analytically determined adduct patterns and indicates that it can hamper the envisaged depletion of the DPRA amino nucleophile. Finally, the obtained log <i>k</i>_Gly values range from −3.73 to ≥ 4.52 and allow for an improved identification of respiratory sensitizers. Hence, the Gly-pNA chemoassay may serve as a nonanimal screening method as one part of a mechanism-informed integrated testing and assessment strategy for respiratory sensitizers.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":"38 6","pages":"1046–1060 1046–1060"},"PeriodicalIF":3.7,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.chemrestox.4c00545","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catalytic-Dependent Role of DNA Polymerase κ in Nucleotide Excision Repair","authors":"Abbey Rebok,&nbsp;Mariela C. Torres,&nbsp;Julia R. Ambrose and Thomas E. Spratt*,&nbsp;","doi":"10.1021/acs.chemrestox.5c0008510.1021/acs.chemrestox.5c00085","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.5c00085https://doi.org/10.1021/acs.chemrestox.5c00085","url":null,"abstract":"<p >DNA polymerase kappa (pol κ) is an error-prone Y-family polymerase primarily associated with translesion DNA synthesis (TLS), a DNA damage tolerance mechanism that prevents replication fork stalling. Pol κ has been implicated in other DNA repair and tolerance pathways such as nucleotide excision repair (NER). However, the role of error-prone pol κ in the NER pathway remains unclear. We sought to investigate if pol κ had a catalytic role in NER by using the pol κ selective nucleoside analogue, <i>N</i>²-(4-ethynylbenzyl)-2′-deoxyguanosine (EBndG). Here, we identified robust, cell cycle-independent catalytic activity of pol κ in cells not treated with DNA-damaging agents. We identified approximately 40% of pol κ catalytic activity was reduced with loss of either XPC or XPA, but not CSB, indicating pol κ has a role in global genome-NER. We monitored pol κ catalytic activity after treatment with benzo(<i>a</i>)pyrene diol epoxide and UVB radiation, and we observed that pol κ catalytic activity increased in an NER-dependent manner. Our study highlights that pol κ is consistently active in cells and possesses a key catalytic role in NER.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":"38 6","pages":"1103–1112 1103–1112"},"PeriodicalIF":3.7,"publicationDate":"2025-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The DNA Repair Protein MGMT Protects against the Genotoxicity of N-Nitrosodimethylamine, but Not N-Nitrosodiethanolamine and N-Nitrosomethylaniline, in Human HepG2 Liver Cells with CYP2E1 Expression","authors":"Max J. Carlsson,&nbsp;Natalie Herzog,&nbsp;Christina Felske,&nbsp;Gabriel Ackermann,&nbsp;Alexander Regier,&nbsp;Simon Wittmann,&nbsp;Raúl Fernández Cereijo,&nbsp;Shana J. Sturla,&nbsp;Jan-Heiner Küpper and Jörg Fahrer*,&nbsp;","doi":"10.1021/acs.chemrestox.5c0013310.1021/acs.chemrestox.5c00133","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.5c00133https://doi.org/10.1021/acs.chemrestox.5c00133","url":null,"abstract":"<p ><i>N</i>-nitrosamines are genotoxic contaminants that occur in the diet, consumer products, and the environment. More recently, <i>N</i>-nitrosamines were also detected as drug impurities. After uptake, <i>N</i>-nitrosamines undergo metabolic activation by cytochrome P450 monooxygenases (CYPs), resulting in DNA damage and tumor formation. In this study, the genotoxicity and cytotoxicity of three <i>N</i>-nitrosamines with structurally distinct substituents, <i>N</i>-nitrosodimethylamine (NDMA), <i>N</i>-nitrosodiethanolamine (NDELA) and <i>N</i>-nitrosomethylaniline (NMA), were analyzed in human HepG2 liver cell models proficient or deficient in CYP2E1 biotransformation. Furthermore, the impact of the DNA repair protein <i>O</i>⁶-methylguanine-DNA methyltransferase (MGMT) was investigated. The novel genetically engineered HepG2-CYP2E1 cell line strongly expressed CYP2E1, which was not detectable in wildtype (WT) HepG2 cells. We then confirmed that the CYP2E1 substrate NDMA caused <i>O</i>⁶-methyldesoxyguanosine adducts and DNA strand breaks in a CYP2E1-dependent manner, leading to cytotoxicity. By the same approach, we demonstrated that NDELA induced DNA strand breaks in HepG2-CYP2E1 cells, whereas no effect was observed for NMA. However, NMA was revealed to cause DNA cross-links. Furthermore, both NDELA and NMA were cytotoxic in HepG2-CYP2E1 cells, but not in WT cells. Subsequently, the pharmacological MGMT inhibitor <i>O</i>⁶-benzylguanine was used to deplete MGMT in both HepG2 cell models. MGMT inhibition clearly increased DNA strand break levels due to NDMA exposure, whereas DNA strand break formation by NDELA and NMA were not affected by inhibiting MGMT. In line with these findings, the clastogenic effects of NDMA were potentiated in the absence of MGMT. In contrast to that, NDELA- and NMA-induced clastogenicity was not influenced by MGMT inhibition. Taken together, our study revealed that all three structurally diverse <i>N</i>-nitrosamines are cytotoxic and clastogenic in a CYP2E1-dependent manner, while only NDMA and NDELA caused DNA strand breaks. Furthermore, we demonstrated for the first time that DNA repair by MGMT does not confer protection against NDELA and NMA-triggered DNA strand break induction and clastogenicity.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":"38 6","pages":"1134–1146 1134–1146"},"PeriodicalIF":3.7,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of Trace Skin Sensitizers Using Novel Nucleophiles with Quaternary Ammonium by Liquid Chromatography-Mass Spectrometry.","authors":"Masataka Kitadani, Yohei Shimizu, Akihiro Moriuchi, Ryo Koike","doi":"10.1021/acs.chemrestox.4c00497","DOIUrl":"10.1021/acs.chemrestox.4c00497","url":null,"abstract":"<p><p>Various methods for assessing the risk of skin sensitization have been developed to reduce the number of animal tests. Although sensitization can be induced by trace amounts of impurities in the raw materials, current test methods have limitations in detecting sensitization from impurities and in not identifying the cause. In this study, novel nucleophiles, <i>N</i>-(4-trimethylammoniobenzoyl)-2-sulfanylethylamine (TMAS) and <i>N</i>-(4-trimethylammoniobenzoyl)-6-aminohexylamine (TMAA), were synthesized for the highly sensitive detection of trace skin sensitizers using mass spectrometry. The reactivities of TMAS and TMAA were verified using several sensitizers. TMAS and TMAA were selectively reactive with sensitizers, and adducts were detected with a sensitivity of 10 μg/L in solution. Because a specific product ion (<i>m</i>/<i>z</i> 148.08) was detected in all adducts, selective detection by various tandem mass spectrometric analyses, such as selective reaction monitoring, is feasible. This method is effective for the detection and structural analysis of skin sensitizers present in raw materials.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":" ","pages":"849-857"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Toxicity of Terpene- and Amino Acid-Based Natural Deep Eutectic Solvents.","authors":"Madushmita Hatimuria, Sweety Basumatary, Amit Kumar Trivedi, Vinod Kumar, Satish Kumar Pandey, Ashok Pabbathi","doi":"10.1021/acs.chemrestox.5c00026","DOIUrl":"10.1021/acs.chemrestox.5c00026","url":null,"abstract":"<p><p>Over the past decade, there has been a significant increase in the discovery of greener solvents for industrial applications. In this context, deep eutectic solvents (DESs) have emerged as promising candidates across various sectors, including biomass conversion, paper and pulp, pharmaceuticals, and textiles. A new class of DESs, known as natural deep eutectic solvents (NADESs), is derived from natural chemicals and is expected to be more environmentally friendly. However, research into the environmental impact and toxicity of NADESs is still limited. Given the broad applications of DESs and the urgent need for sustainable alternatives, studying their toxicity is crucial. In our current study, we focused on NADESs formulated from menthol, thymol, and amino acid. We assessed their toxicity on different cell lines using standard biochemical assays. Remarkably, our findings also indicate that these NADESs exhibit low toxicity in the HaCaT cell line and a mice blood sample. We also found that all of the tested NADESs have shown better antimicrobial property values compared to the individual components of NADESs, indicating the importance of NADES formulation for applications. Among the tested NADESs, menthol:thymol (1:1) showed the best antibacterial properties. These results hold significant implications for the development of NADESs in industrial applications, suggesting a path forward for the adoption of greener and safer solvents.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":" ","pages":"923-929"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143955907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data Exploration for Target Predictions Using Proprietary and Publicly Available Data Sets.","authors":"Aljoša Smajić, Thomas Steger-Hartmann, Gerhard F Ecker, Anke Hackl","doi":"10.1021/acs.chemrestox.4c00347","DOIUrl":"10.1021/acs.chemrestox.4c00347","url":null,"abstract":"<p><p>When applying machine learning (ML) approaches for the prediction of bioactivity, it is common to collect data from different assays or sources and combine them into single data sets. However, depending on the data domains and sources from which these data are retrieved, bioactivity data for the same macromolecular target may show a high variance of values (looking at a single compound) and cover very different parts of the chemical space as well as the bioactivity range (looking at the whole data set). The effectiveness and applicability domain of the resulting prediction models may be strongly influenced by the sources from which their training data were retrieved. Therefore, we investigated the chemical space and active/inactive distribution of proprietary pharmaceutical data from Bayer AG and the publicly available ChEMBL database, and their impact when applied as training data for classification models. For this end, we applied two different sets of descriptors in combination with different ML algorithms. The results show substantial differences in chemical space between the two different data sources, leading to suboptimal prediction performance when models are applied to domains other than their training data. MCC values between -0.34 and 0.37 among all targets were retrieved, indicating suboptimal model performance when models trained on Bayer AG data were tested on ChEMBL data and vice versa. The mean Tanimoto similarity of the nearest neighbors between these two data sources indicated similarities for 31 targets equal to or less than 0.3. Interestingly, all applied methods to assess overlap of chemical space of the two data sources to predict the applicability of models beyond their training data sets did not correlate with observed performances. Finally, we applied different strategies for creating mixed training data sets based on both public and proprietary sources, using assay format (cell-based and cell-free) information and Tanimoto similarities.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":" ","pages":"820-833"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12093362/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143954633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imidazole-Based ALK5 Inhibitor Attenuates TGF-β/Smad-Mediated Hepatic Stellate Cell Activation and Hepatic Fibrogenesis.","authors":"Si-Qi Wang, Yu-Qing Meng, Yan-Ling Wu, Ji-Xing Nan, Cheng-Hua Jin, Li-Hua Lian","doi":"10.1021/acs.chemrestox.5c00036","DOIUrl":"10.1021/acs.chemrestox.5c00036","url":null,"abstract":"<p><p>Liver fibrosis resulting from severe liver damage is a major clinical problem for which effective pharmacological drugs and treatment strategies are lacking. TGF-β, a hallmark of liver fibrosis, has been shown to promote ALK5 phosphorylation in an activated state. Hence, the suppression of ALK5 signal transduction has emerged as a promising therapeutic strategy for the treatment of liver fibrosis. In this study, the imidazole derivative J-1149, which exhibited inhibitory activity against ALK5, was synthesized to exert antifibrotic effects, and the inhibition mechanisms were uncovered. Our findings suggested that J-1149 significantly attenuated HSC activation and liver fibrogenesis by acting on the TGF-β/Smad signaling pathway. Concurrently, the potential of J-1149 to impede the P2X7R/NLRP3 axis, curtail the infiltration of macrophages and neutrophils, and reduce liver fibrogenesis was also highlighted. These results demonstrated that J-1149 is a promising candidate for the treatment of liver fibrosis.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":" ","pages":"930-941"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143952368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tale of Three <i>N</i>-Nitrosamines and the Variables Needed to Assess Their Carcinogenicity In Silico Incorporated into a Single Workflow.","authors":"Jakub Kostal, Adelina Voutchkova-Kostal","doi":"10.1021/acs.chemrestox.4c00482","DOIUrl":"10.1021/acs.chemrestox.4c00482","url":null,"abstract":"<p><p><i>N</i>-Nitrosamine impurities in pharmaceuticals present a considerable challenge for regulators and industry alike, where the absence of carcinogenic-potency studies has left a gap that must be adequately filled to protect public health. In the interim, this means balancing risk assessment with the necessity to continue research, development, and supply of pharmaceuticals. In the long term, we need a cost-effective solution that optimizes both. As if beholden to Newton's Third Law, every crisis breeds an opportunity of equal magnitude. Consequently, cross-industry consortia have been racing to find a solution by advancing our current science. Recent spotlight has been on in silico tools, as a fast and increasingly reliable alternative to in vivo and in vitro testing. Because <i>N</i>-nitrosamine bioactivation lends itself uniquely to quantum mechanics (QM) approaches, the integration of electronic-structure considerations has emerged as the dominant in silico approach. This signifies a considerable leap in predictive toxicology, which has, for much of its existence, relied on atomistic (quantitative) structure-activity relationships, i.e., (Q)SARs. Here we present a validation of an integrated docking-QM approach within the CADRE program and demonstrate its utility on three different impurities, <i>N</i>-nitroso-7-monomethylamino-6-deoxytetracycline, <i>N</i>-nitroso-dabigatran etexilate, and 1-methyl-4-nitrosopiperazine. We show that a combined in silico strategy, which considers bioavailability, transport, cytochrome P450 binding, and reactivity, can be leveraged to supplement the overly conservative Carcinogenic Potency Categorization Approach (CPCA) in setting the daily acceptable intake (AI) using defensible, highly mechanistic, and quantitative drivers of <i>N</i>-nitrosamine metabolism. To that end, we argue that while <i>N</i>-nitroso-7-monomethylamino-6-deoxytetracycline and 1-methyl-4-nitrosopiperazine are cohort-of-concern impurities, <i>N</i>-nitroso-dabigatran etexilate is not a potent carcinogen (TD₅₀ > 1.5 mg/kg/day), contrasting the CPCA-derived AI. Lastly, we discuss how the CADRE tool can be integrated with the broader landscape of QM methods and the CPCA into a single harmonized in silico strategy for carcinogenicity assessment of <i>N</i>-nitrosamine impurities.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":" ","pages":"834-848"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143951560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Obituary for Robert P. Hanzlik (1943–2025)","authors":"John R. Cashman*,&nbsp; and ,&nbsp;Matthew A. Cerny,&nbsp;","doi":"10.1021/acs.chemrestox.5c0016810.1021/acs.chemrestox.5c00168","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.5c00168https://doi.org/10.1021/acs.chemrestox.5c00168","url":null,"abstract":"","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":"38 5","pages":"745–746 745–746"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144083564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"Sara Casati,&nbsp;Roberta F. Bergamaschi,&nbsp;Riccardo Primavera,&nbsp;Alessandro Ravelli,&nbsp;Ivana Lavota,&nbsp;Alessio Battistini,&nbsp;Gabriella Roda,&nbsp;Chiara Ciccarelli,&nbsp;Claudio Guidotti and Paola Rota*,&nbsp;","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":"38 5","pages":"XXX-XXX XXX-XXX"},"PeriodicalIF":3.7,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.chemrestox.5c00068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144450247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}