Toxicology最新文献

Perfluorooctane sulfonate (PFOS) and its alternatives are widely utilized in industrial and commercial applications. However, their environmental persistence and widespread detection in diverse matrices in recent years have raised significant public health concerns. Studies reported that exposure to PFOS in cerebrospinal fluid will increase the risk of cognitive decline in humans. However, the underlying toxicological mechanism is still unclear. The aim of this study was to elucidate the possible toxic targets and potential molecular mechanisms of Alzheimer's disease (AD) induced by PFOS exposure through network toxicology, molecular docking and in vitro verification. Firstly, the results of network toxicology suggested that the mechanisms of PFOS-induced AD were mainly associated with the PI3K-AKT, neurodegeneration, apoptosis and NOD-like receptor signaling pathways. Subsequently, molecular docking simulations confirmed a strong binding interaction between PFOS and the key targets including SRC, ESR1, CASP3, BCL2, ERBB2, and TNF. Finally, we used HT22 and SH-SY5Y cell lines to validate the toxic effects of PFOS and found that PFOS aggravated neuronal cell apoptosis and AKT/GSK3β/NF-κB/NLRP3 pathway mediated inflammatory damages. Briefly, these findings indicated that PFOS exposure could contribute to the initiation and progression of AD by activating apoptosis and inflammatory related signaling pathways, thus affecting proliferation of neuronal cells. This study provides a theoretical basis for understanding the molecular mechanisms involved in PFOS-induced neurotoxicity.

Chlorinated paraffins (CPs) are complex mixture of chlorinated straight-chain hydrocarbons, including short-, medium-, and long-chain CPs (SCCPs, MCCPs, and LCCPs), to which humans are exposed environmentally. Although PM_2.5-bound CPs were positively associated with asthma and related symptoms, the toxicological effects of CPs on the respiratory system remain limitedly understood. CPs were extracted from PM_2.5 samples collected in three cities in southern China, representing distinct SCCPs, MCCPs, and LCCPs profiles. The A549/THP-1 co-culture cells, an in vitro respiratory model, were exposed to PM_2.5-derived extracts containing CPs (CP extract). The gradient was established according to the extract dosage calibrated based on its quantified SCCP content with environmentally relevant concentrations. Cell viability, oxidative stress, inflammatory factors, cell cycle distribution, and genotoxicity were assessed. CP extracts reduced cell viability, increased pro-inflammatory factors concentrations, induced cell cycle arrest and DNA damage. Furthermore, CP mixtures were prepared using standards to simulate PM_2.5-relevant compositions. But the results showed weak toxicological effects of CP mixtures, suggesting CPs play a relatively weak role or CPs exhibit toxicological effects through alternative pathways. Interesting, varying compositional ratios of SCCPs, MCCPs, and LCCPs may induce different cytotoxic effects. These findings provide in vitro evidence for explaining adverse effects of PM_2.5-bound CPs on A549/THP-1 cells. More research is needed to clarify the respiratory toxicological effects of CPs.

Perfluorooctanoic acid (PFOA), a persistent organic pollutant and prominent member of the per- and polyfluoroalkyl substances (PFAS) family, continues to raise global concern due to its bioaccumulation and potential for chronic human exposure. While hepatic and systemic toxicities of PFOA are well documented, its effects on lung epithelial integrity, particularly at environmentally relevant concentrations, remain incompletely understood. In this study, we investigated the cellular and molecular responses to PFOA in human alveolar lung epithelial cells (A549) cultured under both 2D submerged monolayer and 3D air-liquid interface (ALI) conditions, representing systemic and barrier-relevant exposure models. Cells were exposed to 10-1000nM PFOA for 24h to assess changes in pro-inflammatory mediators, including transcription factors-NF-κB and STAT3, pattern recognition receptors (TLR4 and RAGE), cytokine/chemokine production (IL-6, IL-8, CCL2, CCL5), and damage-associated molecular patterns (HSP70, HMGB1). PFOA also appeared to trigger translational stress responses, including stress granule and P-body formation, along with alterations in Hippo signaling via YAP/TAZ overactivation. PFOA-challenged cells exhibited activation of Polycomb Repressive Complexes and associated silencing histone marks (H3K27me3, H2AK119Ub), along with HDACs and SIRT family members, indicative of a redox-driven Polycomb-mediated gene silencing program. Oxidative stress was identified as the central driver of epigenetic and Hippo pathway disruptions, as observed in cells pre-exposed to 1 mM N-acetylcysteine (NAC). Despite these molecular alterations, epithelial cell migration capacity remains unaffected under acute exposure. Our results provide key mechanistic insights into PFOA-mediated disruption of redox homeostasis, immune signaling, and epigenetic plasticity in A549 cells, as well as identifying biomarkers for future biomonitoring efforts and studying regulatory frameworks.

CRISPR-based approaches can complement other genomics-based toxicology studies by enabling causal interrogation of gene function modulating chemical-induced toxicity. Moreover, CRISPR screens enable scalable and systematic identification of functional pathways involved in cellular response to chemical exposure. Cell-based functional toxicogenomics approaches using CRISPR provide a potential powerful tool for the development of mechanism-driven new approach methodologies (NAMs) for toxicodynamic and toxicokinetic hazard screening to enable more effective risk assessment. To improve the physiological relevance of in vitro functional toxicogenomics, we developed a three-dimensional (3D) CRISPR screening platform using HepG2/C3A spheroids cultured in a continuously rotating bioreactor (ClinoStar). We evaluated the potential utility of a 3D CRISPR screen as compared to conventional 2D screen using a custom CRISPR sgRNA library representing common loss-of-function genetic variants in the human population and exposure to the well characterized DNA damaging toxicant, doxorubicin. The 3D platform identified more genes and pathways in which variants have previously been associated with doxorubicin toxicity in clinical studies than the 2D system. These results support the utility of 3D CRISPR screening to identify physiologically relevant genetic determinants underlying chemical toxicity.

Under the U.S. Tobacco Regulatory Act of 2020, all novel nicotine-containing products require a Premarket Tobacco Product Application (PMTA) and FDA authorization before they can be marketed. However, lengthy PMTA review timelines have prompted some manufacturers to replace traditional nicotine with 6-methyl-nicotine (6-MN), a non-tobacco-derived analog that delivers comparable psychoactive effects while evading existing regulatory pathways. Despite its growing market presence as a purportedly "safer" alternative, the toxico-pharmacokinetic profile of 6-MN remains poorly characterized. This study assessed the toxicity after exposure to nicotine or 6-MN-containing e-liquid aerosols using a 3D EpiAirway tissue model. RT-qPCR analyses revealed differential effects on transcripts associated with DNA damage (53BP1, ATR), inflammation (NF-κB1), and cancer (MYCBP). Morphological evaluation of the airway tissues exposed to either aerosol showed an increase in epithelial thickness, a decrease in E-cadherin protein levels, increased goblet cell hypertrophy, evidenced by positive PAS staining and elevated mucus (MUC5AC protein) production, and a reduction in Occludin protein (part of the tight junction complex), which is suggestive of epithelial remodeling. Exposure to PG/VG aerosols alone significantly increased the release of MIP-1α, IFN-γ, and IL-4. Conversely, spearmint-flavored aerosols containing 6-MN or nicotine decreased several pro-inflammatory cytokines, significantly reducing TNF-α, Eotaxin, MCP-1, RANTES, and G-CSF levels, potentially via NF-κB and ERK1/2 pathways. Our findings reveal differential toxicological and chemical profiles for nicotine and 6-MN aerosols; however, flavorings may confer similar cytotoxicity, as measured by LDH and metabolic activity, in 6-MN formulations as they do in those with nicotine. Thus, 6-MN is not a "safer" nicotine alternative.

With the pervasive environmental distribution of plastics, their fragmentation into nanoplastics (NPs) has raised growing concerns regarding potential biological toxicity, particularly in neuronal cells. This study investigated the toxic effects and underlying mechanisms of NPs on SH-SY5Y cells. Five types of NPs were first systematically characterized using scanning electron microscopy (SEM), hydrodynamic diameter measurement, and Zeta potential analysis. Cell internalisation of fluorescently labelled NPs was observed using confocal microscopy. Cell viability was assessed across different NP concentrations to determine the optimal exposure dose. In vitro exposure to the five types of nanoplastics (PE-NPs, PET-NPs, PMMA-NPs, PP-NPs, and PS-NPs) resulted in differential reductions in SH-SY5Y cell viability. Notably, the PE-NPs and PP-NPs treatment groups exhibited a more significant decrease in cell viability, whereas the PET-NPs and PMMA-NPs treatment groups showed a relatively mild reduction in cell viability. Oxidative stress indicators (ROS, MMP, LDH, MDA, GSH, and SOD) were measured, and apoptosis was evaluated by TUNEL and EdU assays. Transcriptome sequencing was performed on PE- and PP-exposed cells, followed by GO/KEGG enrichment analyses; differentially expressed genes were validated via RT-qPCR, Western blotting, and amino acid content detection. Characterisation results showed that NPs were uniformly spherical particles (∼200 nm) with high aqueous stability (zeta potential: -30 to -20 mV) and could be internalized by SH-SY5Y cells. NPs reduced cell viability in a concentration-dependent manner, with 400 μg/mL selected for subsequent experiments. NP exposure increased reactive oxygen species (ROS) levels, impaired mitochondrial function, induced apoptosis, and disrupted cell proliferation in SH-SY5Y cells. Transcriptomic and validation results revealed that NPs disrupted amino acid and one-carbon unit metabolism. Collectively, NPs induce SH-SY5Y cell damage through oxidative stress, apoptosis, and amino acid metabolism disorder. These findings provide insights into NP-induced neuronal toxicity, laying the groundwork for further studies on the health risks of NPs and the development of targeted protective strategies.

Maintaining normal testicular structure and function is closely related to the blood-testis barrier (BTB). Meanwhile, cigarette smoke extract (CSE) affects testicular function. However, whether CSE mediates BTB damage and the underlying mechanism(s) are unclear. This study investigates the effects of CSE on the BTB in mice by focusing on changes in hormone levels. CSE was prepared and administered intranasally at different concentrations to 6-8-week-old male Balb/c mice for five weeks. After cigarette smoke components successfully entered and accumulated in the mice, the seminiferous tubules of the testes were atrophied, spermatogenic cell arrangement became disordered, sperm quality declined, and spermatogenesis was impaired. Furthermore, CSE exposure disrupted the hypothalamic-pituitary-gonadal axis. CSE also damaged the ultrastructure of the BTB, leading to impaired integrity and increased permeability. The associated disruption of BTB function was caused by inhibiting key proteins, including occludin, Zonula occludens-1(ZO-1), N-cadherin, β-catenin, and connexin-43, correlated with hormonal changes. Collectively, these findings suggest that cigarette smoke exposure disrupts BTB structure and function by altering hormone levels and suppressing the expression of BTB-related proteins, affecting spermatogenesis and male reproductive capacity.