Toxicology Mechanisms and Methods最新文献

Dimethyl sulfoxide (DMSO) is a routinely used solvent in toxicology studies that are focused on toxicants with low natural solubility in water. However, prior research suggests that DMSO can alter neurological and behavioral outcomes under some circumstances, which could affect its suitability for neurotoxicology research. The current study evaluated the suitability of DMSO vehicles in an aquatic invertebrate model, Artemia nauplii. Subjects were exposed to solutions of 0.01-1% DMSO and assessed for mortality, motility, morphology, and recovery. In Experiment 1, 1-hr exposures significantly decreased swimming speed and increased rotation rates (0.01%, 1%) (slow, spiral swimming). In Experiment 2, 48-hr exposures suppressed swimming speed (0.1%, 1%), and path rotation (1%) (slower, non-spiral swimming), as well as body length (1%). In Experiment 3, following either 1-hr or 48-hr exposures to 1% DMSO, swimming speed and rotation rate persisted through 4-hr post-treatment, and recovered after a 24-hr washout period. Our results indicate that DMSO does affect motility and related behaviors in Artemia after 1- or 48-hr exposures, that these effects are reversible, and that progressive exposure to DMSO can alter the profile of effects. Consideration must be taken when determining what solvent to use when studying toxicants in aquatic species like Artemia.

The alterations in mitochondrial function are involved in various pathological conditions and hence the evaluation of such damage is crucial to determine the mitotoxic potential of different chemicals. Due to their 71% genetic similarity to humans, the similar mitochondrial functions, and metabolic processes of zebrafish (Danio rerio) have been used in analyses for this purpose. The aim of this study was to establish a standardized technique to assess mitochondrial dysfunction by analyzing oxygen consumption rate (OCR) in zebrafish embryos 24 h post-fertilization using the OROBOROS O2k Oxygraph. The technique involved the use of mitochondrial modulators and the OROBOROS O2k Oxygraph to directly assess mitochondrial and electron transport chain complex activity during embryonic development. Embryos were treated with a respiratory medium supplemented with malate, succinate, and pyruvate, and with digitonin to permeabilize the chorion and membranes for mitochondrial analysis. OCR measurements were performed in the presence of specific mitochondrial modulators: oligomycin, FCCP, rotenone and antimycin A. Optimized evaluation was achieved using 20 embryos per assay. Therefore, through the development of a protocol for synchronization analysis of OCR in zebrafish embryos, several parameters related to the effectiveness of the oxidative phosphorylation process could be rapidly determined. Since zebrafish are particularly useful to study mitochondrial dysfunction in toxicants, this protocol describes the procedure to quantitate the effect of toxicants on mitochondrial activity which turns out to be valuable to understanding the mechanism of xenobiotic toxicity.

Atrazine (ATZ), also known as 6-chloro-4-N-ethyl-2-N-propan-2-yl-1,3,5-triazine-2,4-diamine, is a common chlorinated triazine herbicide that has caused serious health and environmental concerns due to its persistence and classification as an endocrine-disrupting chemical. Atrazine (ATZ), a widely detected contaminant in drinking water, surface water, soil, and groundwater, has been associated with hormonal imbalances-particularly disrupting the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) axis, which is essential for ovarian function and follicular development. Emerging findings suggest that ATZ may contribute to ovarian dysfunction and potentially accelerate processes associated with premature ovarian insufficiency (POI), characterized by oocyte depletion, diminished ovarian reserve, and hormonal imbalance leading to early infertility. Mechanistically, ATZ disrupts several cellular signaling pathways, including MAPK, TGF-β/Smad, and Nrf2/Keap1, contributing to oxidative stress, apoptosis, granulosa cell dysfunction, and DNA damage. These molecular alterations culminate in impaired folliculogenesis and hormonal instability. Regulatory agencies worldwide, including the WHO, European Union, US EPA, and authorities in Brazil, India, and Argentina, are continually revising atrazine exposure limits in response to increasing evidence of its endocrine-disrupting potential and ecological hazards. This review highlights the known and plausible mechanisms by which ATZ disrupts ovarian function and follicular dynamics, which could be among the contributing factors potentially leading to POI. In light of emerging evidence and global regulatory disparities, it underscores the urgent need for stricter environmental policies, comprehensive toxicological assessments, and mechanistic studies to better evaluate ATZ's reproductive risks and inform future regulations.

Phthalate esters (PAEs) are ubiquitous environmental contaminants, with certain congeners potentially exhibiting breast cancer-promoting effects. However, their toxicological mechanisms remain poorly characterized. This study systematically investigates PAEs' direct interactions with breast cancer pathways using an integrated computational approach combining molecular docking-based inverse virtual screening with network toxicology. We computational screened 12 representative PAEs against 275 breast cancer-related proteins. Through rigorous network analysis using Cytoscape software with CytoNCA plugin, we identified six pivotal molecular targets: E1A binding protein p300 (EP300), somatic cytochrome c (CYCS), mechanistic target of rapamycin kinase (MTOR), prostaglandin-endoperoxide synthase 2 (PTGS2), peroxisome proliferator-activated receptor gamma (PPARγ), and progesterone receptor (PGR). KEGG pathway enrichment analysis revealed significant associations with two major oncogenic pathways: the cancer pathway and Kaposi's sarcoma-associated herpesvirus (KSHV) infection signaling pathway. Differential gene expression analysis and survival prognosis validation further substantiated these core targets' clinical relevance. Notably, this work identified six pivotal molecular targets (EP300, CYCS, MTOR, PTGS2, PPARγ, and PGR) and for the first time, linked PAEs to the KSHV infection pathway. Our findings establish a novel network toxicology framework for elucidating shared molecular mechanisms underlying PAEs-induced breast carcinogenesis, providing mechanistic insights to support environmental monitoring and preventive strategies against PAEs-associated breast cancer risks.

This paper studies the toxic effect of micron-sized quartz silica particles on primary human airway epithelial cells (AECs) and the molecular mechanism of its induction of apoptosis. Studies have found that micron-sized quartz silica particles cause AECs damage by activating cell apoptosis. By constructing a competitive endogenous RNA (ceRNA) network, it was identified that three circRNAs (hsa_circ_0052203, hsa_circ_0022429, hsa_circ_0052264) and four key miRNAs (hsa-miR-4646-5p, hsa-miR-150-3p, hsa-miR-6798-3p, hsa-miR-6756-5p) play key roles in regulating apoptosis. In addition, seven mRNAs (LMNB1, TP53AIP1, CASP10, BCL2, LMNB2, CFLAR and ITPR1) were significantly associated with the apoptosis. Functional enrichment analysis indicated that these genes were involved in biological processes such as nuclear lysis, hypoxia response and DNA damage. This study has for the first time revealed the role of the ceRNA network in the apoptosis of AECs induced by micron-sized quartz silica particles, providing new molecular targets and therapeutic ideas for the early pathogenesis of silicosis.

Crizotinib, a first-generation tyrosine kinase inhibitor, demonstrates excellent clinical efficacy in treating non-small cell lung cancer (NSCLC). However, its clinical application is often limited by severe hepatotoxicity, the underlying mechanisms of which remain poorly understood. This study aimed to investigate the molecular mechanisms of crizotinib-induced hepatotoxicity in mice using transcriptomic analysis. Male ICR mice were orally administered crizotinib at doses of 100, 200, and 300 mg/kg for 7 consecutive days. Hepatotoxicity was assessed by measuring serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, along with histopathological evaluation via hematoxylin and eosin (H&E) staining. Transcriptomic and bioinformatics analyses of liver tissues were conducted to identify potential toxicological pathways. Oxidative stress markers were quantified using biochemical assay kits. Hepatic macrophage activation was examined by F4/80 immunostaining, and protein expression levels were analyzed by western blotting. Crizotinib administration resulted in dose-dependent liver injury, as indicated by elevated serum ALT and AST levels, body weight loss, and histological abnormalities. Transcriptomic profiling revealed significant enrichment of oxidative stress-related pathways, with protein-protein interaction (PPI) analysis identifying Jun as a key hub gene. Crizotinib significantly increased hepatic reactive oxygen species (ROS), malondialdehyde (MDA), and oxidized glutathione (GSSG) levels, while reducing reduced glutathione (GSH) levels and the GSH/GSSG ratio. Additionally, crizotinib significantly upregulated Bax and downregulated Bcl-2 expression, promoted macrophage infiltration, and increased the expression of JNK and NLRP3 proteins. These findings suggest that crizotinib-induced hepatotoxicity may be mediated by ROS-induced activation of the JNK/NLRP3 signaling pathway, which subsequently promotes hepatic inflammation and apoptosis.

Previous studies have identified associations between lead (Pb) exposure and the incidence of Alzheimer's disease (AD), yet the underlying mechanisms are still missing. This investigation verified the association between Pb exposure burden and AD risk in a small case-control study. Using a nontargeted quantification lipidomic assay, the role of 3034 lipid metabolites in the associations between Pb exposure and AD risk was also explored. The results showed that serum Pb levels in AD patients were significantly higher than in control individuals. Meanwhile, serum Pb levels were positively associated with an increased risk of AD (OR = 1.10, 95% CI = 1.04-1.15). Lipidomic assay identified that four lipid metabolites, including phosphatidylcholine (PC) (33:2e), diacylglycerol (DG) (19:1e), sphingomyelins (SM) (d38:4), and phosphoserine (PS) (39:1), were significantly altered in the serum of AD patients. Among them, PC(33:2e) and SM(d38:4) were positively correlated with serum Pb levels. Moreover, PC(33:2e) and SM(d38:4) demonstrated mediation contributions of 60.49% and 20.38%, respectively, in the association between Pb exposure and AD incidence. Network toxicology suggests that Pb exposure may affect lipid metabolic processes in AD by modulating the activation of the MAPK, PI3K-Akt, AMPK, mTOR, and autophagy pathways. Our findings reveal novel insights into AD pathogenesis, suggesting that lipid metabolites may play a mediating role in the association between Pb exposure burden and AD risk.

Short-chain per- and polyfluoroalkyl substances (PFAS) are increasingly being used as substitutes for long-chain PFAS due to their lower bioaccumulation potential. However, their persistence and mobility can lead to toxicity and pose significant long-term health risks. Hence, the present study aims to investigate the toxicity and the molecular mechanisms associated with cancer and reproductive toxicity linked to short-chain PFAS based on network toxicology and molecular docking. The short-chain PFAS representatives used in this study include PFBA, PFBS, PFHxA, and PFHpA. The predicted biological targets for PFBA, PFBS, PFHxA, and PFHpA are 6, 2, 20, and 34, respectively. Potential targets from the disease library were identified and analyzed for protein-protein interactions and pathway enrichment. The top five targets were selected for molecular docking studies to examine interactions. Molecular docking indicated strong interactions between biological targets and pollutants, mainly through hydrogen bonds and salt bridges. Short-chain PFAS representatives have shown strong interaction with proteins such as HDAC3 (-6.133 kcal/mol), SHBG (-6.176 kcal/mol), PPARD (-6.355 kcal/mol and -6.205 kcal/mol), and FABP4 (-6.091 kcal/mol). This study also used molecular dynamics (MD) simulations to validate interactions, revealing significant dynamic behavior between proteins and ligands. Fourteen proteins linked to short-chain PFAS were associated with cancer and reproductive toxicity, with many targets common across diseases. Notably, PFHxA and PFHpA share several target proteins, suggesting similar effects in the body. Overall, the study provides an overview of the biological targets of short-chain PFAS and their potential health impacts.

Plastics are extensively used materials with a long environmental lifespan, posing significant risks to human health and the environment. Global plastic consumption has surged, with plastic waste expected to triple by 2060. The primary concern is the breakdown of plastics into nano and micro-sized particles, which can enter the body and have been detected in various organs and tissues. This review systematically examines the effects of micro and nanoplastics (MNPs) on the endocrine system using in vitro and in vivo experimental models. Following PRISMA guidelines, articles were sourced from databases like PubMed, Web of Science, and Scopus. After screening for relevance and removing duplicates and non-English articles, 103 articles focusing on the endocrine effects of MNPs were selected. MNPs can disrupt endocrine functions, altering reproductive hormones and gene expression patterns. In vivo exposure to MNPs increases inflammatory markers such as TNF-α, IL-6, IL-1β, and NF-κB, leading to apoptosis, inflammation, and oxidative stress. These disruptions impact the gonads, thyroid glands, and hormone secretion from the pituitary and hypothalamus. Most studies focus on terrestrial animals, with polystyrene being the most commonly used polymer. Future research should explore various plastic polymers, longer exposure durations, a broader range of concentrations, and human-level studies to better understand the toxicity of plastic particles. Reducing exposure to these pollutants requires legal changes, consumer behavior adjustments, and increased public awareness. Understanding the underlying processes can help propose methods to mitigate risks and protect human health.