Toxicology Mechanisms and Methods最新文献

Background: Benzo(a)pyrene (BaP) is an environmental pollutant linked to several cancers, including esophageal cancer (ESCA). Understanding its impact on gene expression and associated molecular pathways in ESCA is crucial for developing targeted therapies.

Methods: Using the TCGA-ESCA dataset, we identified differentially expressed genes (DEGs) related to BaP exposure. Enrichment analyses and protein-protein interaction (PPI) network construction were performed to explore the biological significance of these DEGs. Molecular docking studies assessed the interactions between BaP and core subnetwork genes. Survival analysis and immune cell infiltration analysis were conducted to evaluate the prognostic value of TGFBR2. Chemotherapy drug sensitivity was analyzed based on TGFBR2 expression levels.

Results: We identified 5757 DEGs in ESCA, with 33 genes linked to both BaP exposure and ESCA. Enrichment analyses revealed significant pathways, including p53 signaling and apoptosis. Key genes (ACTB, CDKN2A, TGFBR2) were verified for their differential expression. Molecular docking demonstrated strong BaP binding to several core proteins. High TGFBR2 expression correlated with better survival, enhanced immune infiltration, and altered sensitivity to chemotherapeutic agents.

Conclusion: Our study highlights the molecular mechanisms by which BaP influences ESCA, with TGFBR2 emerging as a potential prognostic marker and therapeutic target. These insights pave the way for personalized treatments in BaP-induced esophageal carcinogenesis.

This study investigates the protective effects of diacerein (DCN) against amiodarone (AMIO)-induced hepatotoxicity in a rat model. AMIO administration resulted in significant elevations of liver enzymes, ALT and AST, indicating hepatocellular membrane disruption and oxidative stress, as demonstrated by elevated levels of malondialdehyde (MDA) and decreased glutathione (GSH). Additionally, pro-inflammatory cytokines including TNF-α and IL-1β were expressed more when AMIO triggered the Toll-like receptor 4/nuclear factor kappa B/inflammasome 3 (TLR4/NF-κB/NLRP3) inflammatory pathway, along with elevated caspase-1 (CASP1) levels, which promoted apoptosis. In contrast, oral administration of DCN for two weeks effectively mitigated these effects by reducing liver enzyme levels and improving histopathological alterations. DCN also demonstrated anti-oxidant properties by decreasing MDA levels and increasing nuclear factor erythroid 2-related factor 2 (Nrf2) and GSH content. Furthermore, DCN downregulated the hepatic content of TLR4, NF-κB p65, NLRP3, CASP1, and pro-inflammatory cytokines, thereby inhibiting the activation of the inflammatory cascade. Moreover, DCN reduced protein expression of caspase 3. Those findings suggest that DCN exerts its hepatoprotective effects through its anti-oxidant activity, modulation of TLR4/NF-κB/NLRP3 inflammatory pathways, and reduction of apoptosis. These results provide new insights into potential therapeutic strategies for managing AMIO-induced hepatotoxicity, warranting further investigation into the underlying molecular mechanisms of DCN's protective effects.

Gliotoxin (GTX) is a potent mycotoxin that has been shown to induce neurotoxicity through the generation of oxidative stress and disruption of cellular signaling, leading to neuronal cell damage. The neurotoxic effects of GTX have been implicated in various neurodegenerative conditions, making the search for protective agents crucial. This study investigates the chemoprotective effects of acorn flour extract (ACFE) at different temperatures (20 °C, 60 °C, 80 °C, and 100 °C) on SH-SY5Y cells exposed to GTX using both pretreatment and simultaneous treatment strategies (direct treatment, pretreatment and simultaneous treatment). Cell viability was assessed using the MTT assay after 24 and 48 h of exposure. ACFE exhibited varying cytoprotective effects depending on the temperature and exposure conditions. Pre- treatment with 100 °C significantly increased cell viability by up to 51.6% at low GTX concentrations after 48 h; however, ACFE at 60 °C and 80 °C also demonstrated notable protective effects in pretreatment, suggesting a broader range of effective temperatures. Similarly, simultaneous treatment with ACFE (20 °C and 60 °C) enhanced cell viability by up to 124.7% at specific GTX concentrations. In general, higher extraction temperatures (80 °C and 100 °C) were associated with greater chemoprotective potential. These findings support the potential therapeutic application of ACFE in protecting against oxidative stress and neuronal damage, emphasizing the influence of extraction temperature and treatment timing on its efficacy. Further investigations are needed to explore the underlying molecular mechanisms involved in ACFE's protective effects.

3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGR) inhibitors, commonly known as statins, are drugs frequently used in the treatment of hypercholesterolemia and hyperlipidemia. However, the current study has demonstrated that simvastatin induces neurotoxicity and is associated with cellular coenzyme Q₁₀ (CoQ₁₀) depletion. CoQ₁₀ has a significant role in the mitochondrial electron transport chain (ETC), in addition to being a fundamental lipid-soluble antioxidant. Depletion of CoQ₁₀ is frequently associated with impaired mitochondrial function and increased oxidative stress. The aim of this study was to investigate the potential mechanisms of simvastatin-induced neurotoxicity assessing mitochondrial function and evidence of oxidative stress in an in vitro SH-SY5Y human neuronal cell line. Fluorescence studies assessed via flow cytometry determined significant increases in intracellular and mitochondrial reactive oxygen species production following SH-SY5Y treatment with simvastatin compared to control cells. Additionally, spectrophotometric enzyme studies determined a significant (p < 0.0001) inhibition of ETC complex I and II-III activities which accompanied a significant decrease in neuronal CoQ₁₀ content (p < 0.005) and cell viability (p < 0.0001). The results of the present study have indicated evidence of mitochondrial dysfunction and increased oxidative stress, resulting in increased loss of neuronal viability following simvastatin treatment. Thus, these results demonstrate evidence of neurotoxicity associated with statin therapy.

In recent years, researchers have focused on using new materials for screws in bone jaw tissue replacement. However, concerns regarding the cytotoxicity and biocompatibility of these materials for cells remain a subject of ongoing discussion. In this study, a novel implant for bone jaw tissue regeneration was fabricated by depositing the titanium carbo-nitride (TiCN) film on NiTi shape memory alloy substrate using the Cathodic Arc Physical Vapor Deposition (CAPVD) technique. Our study emphasized positive cellular responses of TiCN-coated NiTi substrate on diabetic rat tooth gum cells for 1, 15, and 30 days. Initially, the evaluation focused on the characterization and distribution of NiTi alloy in tissues. Then, the levels of factors such as components of White Blood Cells (WBC), ATP, oxidative stress parameters, cytochrome c release and damage to the lysosomal membrane were evaluated in all groups. The results indicated that in the group of diabetic rats with TiCN-coated NiTi substrate, the level of oxidative stress parameters decreased. In addition, the cell viability, glutathione (GSH) intracellular and ATP increased and the rate of cytochrome c release, and damage to the lysosome membrane decreased. It can be concluded that the TiCN-coated NiTi screw is a promising material for bone jaw tissue replacement in diabetic patients due to its low cytotoxicity.

Pre-clinical toxicological investigations are pivotal in the development of safer and more efficacious chemotherapeutic agents. Oleanolic acid (OA), a naturally occurring pentacyclic triterpenoid, has demonstrated anticancer potential but is often limited by the toxic side effects of its derivatives. In the current study, we carried out the facile synthesis of a modified OA analogue, OD2, and studied its cytotoxicity and efficacy analysis across several cell lines. Mechanistic toxicology was explored through fluorescence-based assays. Annexin-V/Propidium Iodide (A-V/PI) staining and TUNEL assays were used to confirm apoptosis. OD2 exhibited dose-dependent cytotoxicity, with a pronounced effect on A549 lung cancer cells compared to other cancerous and non-cancerous cell lines. Apoptosis was found to be the predominant mode of cell death, evidenced by Fluorescence imaging analysis of chromatin condensation and mitochondrial dysfunction. This was further validated by an increase in Annexin-V-positive and TUNEL-positive cells in treated groups. OD2 activated the intrinsic mitochondrial apoptotic pathway as evidenced by increased Bax and decreased Bcl-2 protein abundance levels. While the current study showcases the therapeutic potential of the selective toxicological activity of OD2, future studies will focus on the deconvolution of its potential polypharmacological mode of action and decoding the basis of its selective action, so as to glean important lessons that can be applied in the development of chemotherapeutic agents with favorable toxicological profiles.

There is mounting evidence about the connection between particulate matter (PM) and neuroinflammation. This study aimed to evaluate the toxicological effects of PM_2.5 associated with inflammatory factors in a mouse's multiple sclerosis (MS) model. Thirty C57BL/6 male mice were categorized into five groups: a group of healthy mice, a control cuprizone-induced MS group, and three MS-induced groups, intranasally exposed to three concentrations of ambient air PM_2.5 (5, 10, and 20 mg/mL) from Tehran in a phosphate-buffered saline (PBS) solution. All mice were investigated by motor function, molecular, and histopathological assays. Moreover, the chemical content of the collected PM_2.5 was assessed and reported. The cumulative exposure doses were equal to 0.025, 0.05, and 0.1 mg per gram of body weight of mice, which were approximately 3.52, 7.04, and 14.08 times higher than the human daily dose in Tehran. The PM_2.5-exposed groups showed a high inflammatory response characterized by a significant increase in the mRNA expression of tumor necrosis alpha (TNF-α), NLRP3, and interleukin 18 (IL-18). In addition, the PM_2.5-exposed groups exhibited a notably lower velocity level, total traveled distance (TD), and duration traveled in the central zone (DC) than the control group. The histopathological assays revealed significant pathological alterations and demyelination in the PM2.5-exposed groups compared to the control group. Identifying the risks and reducing the likelihood of exposure through preventive measures and regulations can result in financial savings and improve the quality of life for MS patients.

The androgen receptor (AR) activation by androgens is vital for tissue development, sexual differentiation, and reproductive attributes in zebrafish (Danio rerio). However, our understanding of the molecular mechanisms behind their activation remains limited. In this study, we employed both ab initio (AlphaFold) and homology (SWISS-MODEL) structure models of zebrafish androgen receptor ligand-binding domain (zAR-LBD) to explore the binding specificity, binding affinity, and molecular interactions of endogenous hormones (testosterone (T), 11-ketotestosterone (11-KT), and dihydrotestosterone (DHT)) in a computational simulation. Molecular docking analysis showed that both structures formed the same interactions and similar patterns of binding energy with androgens. Molecular Dynamics (MD) simulation analysis revealed that hydrogen bond occupancy aligned with in vitro findings related to androgenic effect. When comparing complexes modeled by SWISS-MODEL and AlphaFold, significant differences were observed in root mean square deviation (RMSD) and root mean square fluctuations (RMSF). The AlphaFold structures also exhibited a clear separation between ligands in principal component analysis. Further correlation analysis between in silico features and in vitro EC50 values identified MMPBSA energies as the most significant contributors to ligand-specific variance in the in silico complexes (p < 0.05). Overall, this integrative approach offers significant insights into the molecular mechanisms underlying zebrafish AR activity.

Research on chlorinated paraffins (CPs) is growing, with accumulating evidence of CPs being present in biological matrices and animal tissues. However, their cellular-level impacts remain underexplored. This study investigates the effects of medium-chain CPs on adipose and liver cell models. The results show that CPs are more toxic at lower concentrations in 3T3-L1 preadipocytes than in adipocytes, suggesting that intracellular lipids may offer protection against these contaminants. However, neither simulated lipolysis in adipocytes nor lipogenesis in HepG2 hepatocytes revealed any lipid-dependent effects of CPs. CP exposure reduced heme oxygenase 1 expression, indicating a biological response to these contaminants. In a coculture model of adipocytes and macrophages, CP exposure influenced cell signaling, with lipid-rich adipocytes modulating macrophage immune responses. Our results demonstrate that medium-chain CPs accumulation in lipid-rich tissues does not significantly affect their toxic effects. However, it may influence cell signaling within adipose tissue.

This research explored the effects of dalapon exposure on the expression of various genes, including cat, sod1, sod2, sod3a, sod3b, gpx1a, gpx3, gpx4a, gpx4b, gpx7, gpx8, gpx9, gstr, g6pd, and gsr, along with the activities of related antioxidant enzymes (AEs), such as CAT, SOD, GPX, G6PD, GST, and GR in zebrafish. Kidney and liver tissues were analyzed to assess oxidative stress levels. Results indicated that both the concentration of dalapon (25 and 50 ppm) and the duration of exposure had a significant effect on AE activities and gene expression. RT-PCR analysis suggested that changes in gene expression among dalapon-exposed zebrafish might indicate a rapid response to pesticide-induced stress. Moreover, the activities of CAT, G6PD, and GST increased in response to dalapon exposure at the specified concentrations. In contrast, prolonged exposure exceeding 72 h led to significantly higher malondialdehyde levels in liver and kidney tissues compared to the control group. These findings enhance our understanding of the role of antioxidant enzymes in oxidative stress and provide important insights for developing aquaculture breeding programs focused on improving fish stress tolerance. Furthermore, phylogenetic analysis and conserved gene synteny analysis confirmed that the antioxidant enzyme genes in zebrafish are orthologous to those found in other model organisms, such as medaka and stickleback. Consequently, these results could be beneficial for other vertebrate species.