Chemical Research in Toxicology最新文献

{"title":"Interview with Professor Amanda Bryant-Friedrich, 2024 Founders Award Winner, American Chemical Society Division of Chemical Toxicology.","authors":"Andrea Andress Huacachino","doi":"10.1021/acs.chemrestox.4c00360","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00360","url":null,"abstract":"","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142386384","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":"Using 2-(2-Chlorophenyl)thiazolidine-4-carboxylic Acid as a Novel Biomarker for 2-Chlorobenzalmalononitrile Exposure.","authors":"Guanrui Pan, Hei-Tak Tse, Ho-Wai Chan, Wan Chan","doi":"10.1021/acs.chemrestox.4c00304","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00304","url":null,"abstract":"<p><p>This study addressed the development of a novel biomarker for 2-chlorobenzalmalononitrile (CS) gas exposure. Using liquid chromatographic and mass spectrometric techniques, we found that CS underwent rapid hydrolysis into 2-chlorobenzaldehyde (2-CBA), a highly reactive intermediate that reacted swiftly with endogenous cysteine (Cys) and Cys residues in proteins, producing a stable 2-(2-chlorophenyl)thiazolidine-4-carboxylic acid adduct (ClPh-SPro) in high yield, which may be used as a CS exposure dosimeter. In particular, it was found that most CS was rapidly hydrolyzed under physiologically relevant conditions, with over 90% of CS being converted into 2-CBA in as short as 20 min. The resultant 2-CBA then reacted swiftly with Cys (<i>k</i> = 0.086 M^-1 s^-1), forming the stable thiazolidine-4-carboxylic acid adduct, which was detected both in the intracellular fluid and in the cell-isolated proteins of CS-exposed lung cells, as well as in purified human serum albumin. It is expected that the results of this study will facilitate exposure assessment for bystanders who may have been exposed to high levels of CS gas unwillingly.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142378779","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 Interaction of Myeloperoxidase with the Industrial Contaminant 6-PPD: A Potential Pathway for Reactive Metabolites.","authors":"Steven Lockhart, Dinesh Babu, Newton H Tran, Béla Reiz, Lusine Tonoyan, Arno G Siraki","doi":"10.1021/acs.chemrestox.4c00265","DOIUrl":"10.1021/acs.chemrestox.4c00265","url":null,"abstract":"<p><p>6-PPD (<i>N</i>-[1,3-dimethylbutyl]-<i>N</i>'-phenyl-<i>p</i>-phenylenediamine) is an industrial antioxidant reported to be an environmental contaminant. It was found to be highly toxic to coho salmon and potentially other aquatic organisms. The toxicity of 6-PPD in humans, however, remains unknown. The neutrophil enzyme myeloperoxidase (MPO) is known to catalyze xenobiotic metabolism; therefore, its role in 6-PPD cytotoxicity was investigated using the MPO-rich HL-60 cell line. UV-visible spectroscopy and liquid chromatography-mass spectrometry (LC/MS) were performed to investigate the MPO-mediated oxidation of 6-PPD and identify possible metabolites in the absence and presence of glutathione (GSH). 6-PPD's cytotoxicity, effect on mitochondrial membrane potential (MMP), and GSH-depleting ability in HL-60 cells were assessed. Electron paramagnetic resonance (EPR) was used to determine GSH radical formation using DMPO, and mitochondrial-derived superoxide was assessed with the mito-TEMPO-H probe. Evaluation of the 6-PPD-induced cellular injury pathways was performed by preincubating an antioxidant and an MPO inhibitor with HL-60 cells. UV-vis analysis of MPO-catalyzed oxidation of 6-PPD demonstrated changes in the 6-PPD spectrum, whereas the addition of GSH altered the spectrum, indicating possible GSH conjugate formation. LC/MS showed the formation of multiple products, including GSH-6-PPD conjugates and a GSH conjugate to a 4-hydroxydiphenylamine (a known 6-PPD degradant), which could potentially induce cytotoxicity. 6-PPD demonstrated concentration-dependent cytotoxicity, and cellular GSH levels were decreased by 6-PPD. Similarly, the level of MMP decreased, suggesting mitochondrial depolarization. Furthermore, the EPR spin probe for mitochondrial superoxide showed a positive relationship with 6-PPD concentration, and EPR spin-trapping demonstrated 6-PPD concentration-dependent GSH radical signal intensity using MPO/H₂O₂. The GSH precursor, NAC, demonstrated partial cytoprotection against 6-PPD; however, the MPO inhibitor PF-1355 surprisingly showed no significant cytoprotective effect. Our results suggest that MPO could be a potential catalyst for 6-PPD toxicity in humans. However, MPO inhibition did not significantly affect cellular viability, suggesting an MPO-independent toxicity pathway. These findings warrant a deeper investigation to determine 6-PPD mammalian toxicity pathways.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363352","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":"Correction to \"Use of Structural Alerts for Reactive Metabolites in the Application SpotRM\".","authors":"Alf Claesson","doi":"10.1021/acs.chemrestox.4c00391","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00391","url":null,"abstract":"","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363351","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":"Selective HLA Class II Allele-Restricted Activation of Atabecestat Metabolite-Specific Human T-Cells.","authors":"Megan Ford, Paul J Thomson, Jan Snoeys, Xiaoli Meng, Dean J Naisbitt","doi":"10.1021/acs.chemrestox.4c00262","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00262","url":null,"abstract":"<p><p>Elevations in hepatic enzymes were detected in several trial patients exposed to the Alzheimer's drug atabecestat, which resulted in termination of the drug development program. Characterization of hepatic T-lymphocyte infiltrates and diaminothiazine (DIAT) metabolite-responsive, human leukocyte antigen (HLA)-DR-restricted, CD4+ T-lymphocytes in the blood of patients confirmed an immune pathogenesis. Patients with immune-mediated liver injury expressed a restricted panel of HLA-DRB1 alleles including HLA-DRB1*12:01, HLA-DRB1*13:02, and HLA-DRB1*15:01. Thus, the objectives of this study were to (i) generate DIAT-responsive T-cell clones from HLA-genotyped drug-naive donors, (ii) characterize pathways of DIAT-specific T-cell activation, and (iii) assess HLA allele restriction of the DIAT-specific T-cell response. Sixteen drug-naive donors expressing the HLA-DR molecules outlined above were recruited, and T-cell clones were generated. Cellular phenotype, function, and HLA-allele restriction were assessed using culture assays. Peptides displayed by HLA class II molecules in the presence and absence of atabecestat were analyzed by mass spectrometry. Several DIAT-responsive CD4+ clones, displaying no reactivity toward the parent drug, were successfully generated from donors expressing HLA-DRB1*12:01, HLA-DRB1*13:02, and HLA-DRB1*15:01 but not from other donors expressing other HLA-DRB1 alleles. T-cell clones were activated following direct binding of DIAT to HLA-DR proteins expressed on the surface of antigen presenting cells. DIAT binding did not alter the HLA-DRB1 peptide binding repertoire, indicative of a binding interaction with the HLA-associated peptide rather than with the HLA protein itself. DIAT-specific T-cell responses displayed HLA-DRB1*12:01, HLA-DRB1*13:02, and HLA-DRB1*15:01 restriction. These data demonstrate that DIAT displays a degree of selectivity toward HLA protein and associated peptides, with expression of certain alleles increasing and that of others decreasing, the likelihood that a drug-specific T-cell response develops.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142337331","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":"Mechanistic Insights into Toxicity of Titanium Dioxide Nanoparticles at the Micro- and Macro-levels.","authors":"Sharmistha Chatterjee, Parames C Sil","doi":"10.1021/acs.chemrestox.4c00235","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00235","url":null,"abstract":"<p><p>Titanium oxide nanoparticles (TiO₂ NPs) have been regarded as a legacy nanomaterial due to their widespread usage across multiple fields. The TiO₂ NPs have been and are still extensively used as a food and cosmetic additive and in wastewater and sewage treatment, paints, and industrial catalysis as ultrafine TiO₂. Recent developments in nanotechnology have catapulted it into a potent antibacterial and anticancer agent due to its excellent photocatalytic potential that generates substantial amounts of highly reactive oxygen radicals. The method of production, surface modifications, and especially size impact its toxicity in biological systems. The anatase form of TiO₂ (<30 nm) has been found to exert better and more potent cytotoxicity in bacteria as well as cancer cells than other forms. However, owing to the very small size, anatase particles are able to penetrate deep tissue easily; hence, they have also been implicated in inflammatory reactions and even as a potent oncogenic substance. Additionally, TiO₂ NPs have been investigated to assess their toxicity to large-scale ecosystems owing to their excellent reactive oxygen species (ROS)-generating potential compounded with widespread usage over decades. This review discusses in detail the mechanisms by which TiO₂ NPs induce toxic effects on microorganisms, including bacteria and fungi, as well as in cancer cells. It also attempts to shed light on how and why it is so prevalent in our lives and by what mechanisms it could potentially affect the environment on a larger scale.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142337328","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":"Derisking Future Agrochemicals before They Are Made: Large-Scale In Vitro Screening for In Silico Modeling of Thyroid Peroxidase Inhibition.","authors":"Martin Adamczewski, Britta Nisius, Nina Kausch-Busies","doi":"10.1021/acs.chemrestox.4c00248","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00248","url":null,"abstract":"<p><p>Inhibition of thyroid peroxidase (TPO) is a known molecular initiating event for thyroid hormone dysregulation and thyroid toxicity. Consequently, TPO is a critical off-target for the design of safer agrochemicals. To date, fewer than 500 structurally characterized TPO inhibitors are known, and the most comprehensive result set generated under identical conditions encompasses approximately 1000 compounds from a subset of the ToxCast compound collection. Here we describe a collaboration between wet lab and data scientists combining a large in vitro screen and the subsequent development of an in silico model for predicting TPO inhibition. The screen encompassed more than 100,000 diverse drug-like agrochemical compounds and yielded more than 6000 structurally novel TPO inhibitors. On this foundation, we applied different machine learning techniques and compared their performance. We discuss use cases for in silico TPO models in agrochemical research and explain that model recall is of particular importance when selecting compounds from large virtual compound collections. Furthermore, we show that due to the higher structural diversity of our training data, our final model allowed better generalization than models trained on the ToxCast data set. We now have a tool to predict TPO inhibition even for molecules that are only available virtually, such as hits from virtual screenings, or compounds under consideration for inclusion in our screening collection. Structures and activity data for 34,524 compounds are provided. This data set includes almost all inhibitors, including more than 3000 proprietary structures, and a large proportion of the inactives.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142277306","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":"Near-Infrared Fluorescent Turn-On Probe for Selective Detection of Hypochlorite in Aqueous Medium and Live Cell Imaging","authors":"Anwesha Maiti, Saikat Kumar Manna, Satyajit Halder, Rajdeep Ganguly, Anirban Karak, Pintu Ghosh, Kuladip Jana, Ajit Kumar Mahapatra","doi":"10.1021/acs.chemrestox.4c00222","DOIUrl":"https://doi.org/10.1021/acs.chemrestox.4c00222","url":null,"abstract":"Hypochlorite, as an important reactive oxygen species (ROS), plays a vital role in many physiological and pathological processes, but an excess concentration of hypochlorite (ClO^–) may become toxic to humans and cause disease. Hence, the selective and rapid detection of hypochlorite (ClO^–) is necessary for human safety. Here, we report a novel near-infrared (NIR) fluorescence “turn-on” and highly selective benzophenoxazinium chloride-based fluorescent probe, <b>BPH</b> (benzophenoxazinium dihydroxy benzaldehyde), for hypochlorite detection. Due to hypochlorite-induced vicinal diol oxidation to the corresponding ortho benzoquinone derivative, the photoinduced electron transfer (PET) process, which was operating from vicinal diol to the benzophenoxazinium chloride receptor moiety, was suddenly inhibited, as a result of which strong NIR fluorescence “turn-on” emission was observed. The detection limit of <b>BPH</b> was found to be 2.39 × 10^–10 M, or 0.23 nM. <b>BPH</b> was successfully applied for exogenous and endogenous hypochlorite detection in live MDA-MB 231 cells.","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260484","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":"Sensitive Detection of Histones and γ-H2AX by Immunoblotting: Problems and Solutions.","authors":"Casey Krawic, Michal W Luczak, Anatoly Zhitkovich","doi":"10.1021/acs.chemrestox.4c00307","DOIUrl":"10.1021/acs.chemrestox.4c00307","url":null,"abstract":"<p><p>Histones and their posttranslational modifications (PTMs) are critical regulators of gene expression. Differentiation, environmental stressors, xenobiotics, and major human diseases cause significant changes in histone variants and PTMs. Western blotting is the mainstay methodology for detection of histones and their PTMs in the majority of studies. Surprisingly, despite their high abundance in cells, immunoblotting of histones typically involves loading of large protein amounts that are normally used for detection of sparse cellular proteins. We systematically examined technical factors in the Western-blotting-based detection of human histones with >30 antibodies. We found that under multiple protein transfer conditions, many histone epitopes on polyvinylidene fluoride (PVDF) membranes had a very low antibody accessibility, which was dramatically increased by the addition of a simple denaturation step. Denaturation of membrane-bound proteins also enhanced the specificity of some histone antibodies. In comparison to standard PVDF membranes, the sensitivity of histone detection on standard nitrocellulose membranes was typically much higher, which was further increased by the inclusion of the same denaturation step. Optimized protocols increased by >100-times detection sensitivity for the genotoxic marker γ-H2AX with two monoclonal antibodies. The impact of denaturation and nitrocellulose use varied for different histones, but for each histone, it was generally similar for antibodies targeting N-terminal and C-terminal regions. In summary, denaturation of membrane-bound histones strongly improves their detection by Westerns, resulting in more accurate measurements and permitting analyses with small biological samples.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11409373/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142138561","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":"Effect of Butyrate on Food-Grade Titanium Dioxide Toxicity in Different Intestinal In Vitro Models.","authors":"Janine M Becht, Hendrik Kohlleppel, Roel P F Schins, Angela A M Kämpfer","doi":"10.1021/acs.chemrestox.4c00086","DOIUrl":"10.1021/acs.chemrestox.4c00086","url":null,"abstract":"<p><p>Short-chain fatty acids (SCFA) are an important energy source for colonocytes and crucial messenger molecules both locally in the intestine and systemically. Butyrate, one of the most prominent and best-studied SCFA, was demonstrated to exert anti-inflammatory effects, improve barrier integrity, enhance mucus synthesis in the intestine, and promote cell differentiation of intestinal epithelial cells in vitro. While the physiological relevance is undisputed, it remains unclear if and to what extent butyrate can influence the effects of xenobiotics, such as food-grade titanium dioxide (E171, _fgTiO₂), in the intestine. TiO₂ has been controversially discussed for its DNA-damaging potential and banned as a food additive within the European Union (EU) since 2022. First, we used enterocyte Caco-2 monocultures to test if butyrate affects the cytotoxicity and inflammatory potential of _fgTiO₂ in a pristine state or following pretreatment under simulated gastric and intestinal pH conditions. We then investigated pretreated _fgTiO₂ in intestinal triple cultures of Caco-2, HT29-MTX-E12, and THP-1 cells in homeostatic and inflamed-like state for cytotoxicity, barrier integrity, cytokine release as well as gene expression of mucins, oxidative stress markers, and DNA repair. In Caco-2 monocultures, butyrate had an ambivalent role: pretreated but not pristine _fgTiO₂ induced cytotoxicity in Caco-2 cells, which was not observed in the presence of butyrate. Conversely, _fgTiO₂ induced the release of interleukin 8 in the presence but not in the absence of butyrate. In the advanced in vitro models, butyrate did not affect the characteristics of the healthy or inflamed states and caused negligible effects in the investigated end points following _fgTiO₂ exposure. Taken together, the effects of _fgTiO₂ strongly depend on the applied testing approach. Our findings underline the importance of the experimental setup, including the choice of in vitro model and the physiological relevance of the exposure scenario, for the hazard testing of food-grade pigments like TiO₂.</p>","PeriodicalId":31,"journal":{"name":"Chemical Research in Toxicology","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11409378/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142102163","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}