Toxicology Mechanisms and Methods最新文献

Objectives: This study, aimed to determine and compare DNA damage in e-cigarette and HTP (IQOS) users by assessing DNA-adducts, which are biomarkers of various DNA alkylation and oxidation.

Methods: For the evaluation of DNA alkylation, N³-Ethyladenine (N³-EtA) and N³-Methyladenine (N³-MeA) adducts were used. DNA oxidation was assessed using, 8-hydroxy-2'-deoxyguanosine(8-OHdG). The urinary cotinine, N³-MeA, N³-EtA, and 8-OHdG concentrations of the cigarette smokers (n:39), e-cigarette users (n:28), IQOS users (n:20), passive smokers (n:32), and nonsmokers(n:41) who lived Ankara, Turkiye were determined using, liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results: In light of the detected 8-OHdG levels, e-cigarette (3.19 ng/g creatinine) and IQOS (4.38 ng/g creatinine) users had higher oxidative DNA damage than healthy nonsmokers (2.51 ng/g creatinine). Alkylated DNA-adducts were identified in the urine of e-cigarette (N³-MeA: 3.92 ng/g creatinine; N³-EtA: 0.23 ng/g creatinine) and IQOS (N³-MeA: 7.54 ng/g creatinine; N³-EtA: 0.29 ng/g creatinine) users. In the generation of N³-MeA adducts, a significant difference was found between IQOS users and e-cigarette users (p < 0.05). Also, DNA alkylation in flavored e-cigarette users (N³-MeA: 4.51 ng/g creatinine; N³-EtA: 0.27 ng/g creatinine) was higher than in non-flavored e-cigarette users (N³-MeA: 2.27 ng/g creatinine; N³-EtA: 0.06 ng/g creatinine). The highest cotinine levels were found in cigarette smokers (16.1316 ng/g creatinine). No significant difference was found when e-cigarette (1163.02 ng/g creatinine) and IQOS smokers were compared (1088.3 ng/g creatinine).

Conclusion: People who use e-cigarettes and IQOS may be at higher risk of genotoxicity than those who do not use and are not exposed to any tobacco products. Furthermore, the usage of flavoring additives in e-cigarettes contributed to additional genotoxic damage risks.

Aims: Excessive alcohol consumption is associated with cardiac dysfunction and the development of myocardial fibrosis. In this study, we aimed to investigate the direct impacts of ethanol on myocardial fibroblasts and elucidate the underlying mechanism responsible for chronic ethanol-induced myocardial fibrosis.

Methods: Rat primary cardiac fibroblasts exposed to ethanol for 24 h and C57BL/6J mice fed on Lieber-DeCarli diet to establish an ethanol intoxication model in vitro and in vivo, respectively. Histological analyses, molecular biology techniques, and analytical chemistry methods were then conducted.

Results and conclusion: In vivo and vitro experiments revealed that chronic ethanol exposure induced increased myocardial fibrosis and augmented the transdifferentiation of myocardial fibroblasts. Simultaneously, it elicited an upregulation in the production of long-chain and very-long-chain ceramides in cardiac fibroblasts. The excessive accumulation of ceramide leads to elevated levels of intracellular oxidative stress, culminating in the activation of TGF-β-SMAD3 signaling and the development of fibrosis. Intervention of these pathways with pharmacological inhibitors in vitro or in vivo inhibited fibrosis. In conclusion, ethanol increased ceramides and reactive oxygen species (ROS) in cardiac fibroblasts, resulting in the activation of TGF-β-SMAD3 signaling, transdifferentiation of fibroblasts, and myocardial fibrosis.

Objectives: Five solvent extracts (n-hexane, ethyl acetate, ethanol, ethanol/water (70%), and water) of Gladiolus italicus Mill. from Turkey were evaluated for chemical and biological properties.

Methods: Antioxidant activities, inhibitory properties against key enzymes involved in the etiology of chronic diseases were tested, as well as cytotoxic effects on different cell lines. Chemical characterization was also carried out to determine the most abundant compounds of each extract.

Results: The highest total phenolic content (TPC) was observed in the water extract while highest TFC in ethanol/water extract. The most abundant compounds in the extracts were hyperoside (69041.06 mg kg^-1), isoquercitrin (46239.49 mg kg^-1), delphindin-3,5-diglucoside (42043.81 mg kg^-1), myricetin (21486.61 mg kg^-1), and kaempferol-3-glucoside (21199.76 mg kg^-1). Molecular dynamic (MD) simulations confirmed the structural stability and dynamic conformational integrity of these complexes over a period of 100 ns. In network pharmacology, A total of 657 unique target genes were screened: 52 associated with programmed cell death-1 (PD-1), 85 with vascular endothelial growth factor receptor-2 (VEGFR2), and 130 with fibroblast growth factor receptor-2 (FGFR2), identifying crucial gene interactions for these proteins. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, revealing significant interactions and pathways such as the advanced glycation end products (AGE) and their receptors (RAGE) signaling pathway in diabetic complications and T- helper 17 (Th17) cell differentiation, among others. This elucidation of complex networks involving key genes like AKT Serine/Threonine Kinase 1 (AKT1), MYC proto-oncogene (MYC), tumor protein 53 (TP53), Interleukin 6 (IL6), and tumor necrosis factor (TNF) provides a promising foundation for the development of targeted therapies in the treatment of non-communicable diseases.

Conclusion: These results show that G. italicus could be a natural source of potent antioxidants and enzyme inhibitors which need to be further explored for the development of biopharmaceuticals.

Alveolar macrophages (AMs), the first line against the invasion of foreign invaders, play a predominant role in the pathogenesis of silicosis. Studies have shown that inhaled silica dust is recognized and engulfed by AMs, resulting in the production of large amounts of silica-induced reactive oxygen species (ROS), including particle-derived ROS and macrophage-derived ROS. These ROS change the microenvironment of the AMs where the macrophage phenotype is stimulated to swift from M0 to M1 and/or M2, and ultimately emerge as the M2 phenotype to trigger silicosis. This is a complex process accompanied by various molecular biological events. Unfortunately, the detailed processes and mechanisms have not been systematically described. In this review, we first systematically introduce the process of ROS induced by silica in AMs. Then, describe the role and molecular mechanism of M2-type macrophage polarization caused by silica-induced ROS. Finally, we review the mechanism of pulmonary fibrosis induced by M2 polarized AMs. We conclude that silica-induced ROS initiate the fibrotic process of silicosis by inducing macrophage into M2 phenotype, and that targeted intervention of silica-induced ROS in AMs can reprogram the macrophage polarization and ameliorate the pathogenesis of silicosis.

Benzene exposure is known to cause serious damage to the human hematopoietic system. However, recent studies have found that chronic benzene exposure may also cause neurological damage, but there were few studies in this issue. The aim of this study was to investigate the mechanism of damage to the central nervous system (CNS) by chronic benzene exposure with a multi-omics analysis. We established a chronic benzene exposure model in C57BL/6J mice by gavage of benzene-corn oil suspension, identified the differentially expressed proteins (DEPs) and differentially expressed genes (DEGs) in mice brain using 4D Label-free proteomic and RNA-seq transcriptomic. We observed that the benzene exposure mice had a significant loss of body weight, reduction in complete blood counts, abnormally high MRI signals in brain white matter, as well as extensive brain edema and neural demyelination. 162 DEPs were identified by the proteome, including 98 up-regulated and 64 down-regulated proteins. KEGG pathway analysis of DEPs showed that they were mainly involved in the neuro-related signaling pathways such as metabolic pathways, pathways of neurodegeneration, chemical carcinogenesis, Alzheimer disease, and autophagy. EPHX1, GSTM1, and LIMK1 were identified as important candidate DEGs/DEPs by integrated proteomic and transcriptomic analyses. We further performed multiple validation of the above DEGs/DEPs using fluorescence quantitative PCR (qPCR), parallel reaction monitoring (PRM), immunohistochemistry, and immunoblotting to confirm the reliability of the multi-omics study. The functions of these DEGs/DEPs were further explored and analyzed, providing a theoretical basis for the mechanism of nerve damage caused by benzene exposure.

Doxorubicin (Dox) is an effective and commonly used anticancer drug; however, it leads to several side effects including cardiotoxicity which contributes to poor quality of life for cancer patients. Creatine (Cr) is a promising intervention to alleviate Dox-induced cardiotoxicity. This study aimed to examine the effects of Cr beforeDox on cardiac mitochondrial creatine kinase (MtCK). Male rats were randomly assigned to one of two 4-week Cr feeding interventions (standard Cr diet or Cr loading diet) or a control diet (Con, n = 20). Rats in the standard Cr diet (Cr1, n = 20) were fed 2% Cr for 4-weeks. Rats in the Cr loading diet (Cr2, n = 20) were fed 4% Cr for 1-week followed by 2% Cr for 3-weeks. After 4-weeks, rats received either a bolus injection of 15 mg/kg Dox or a placebo saline injection (Sal). Five days post-injections left ventricle (LV) was excised and analyzed for MtCK expression using Western blot and ELISA. A significant drug effect was observed for LV mass (p < 0.05), post hoc testing revealed LV mass of Con + Dox and Cr2 + Dox was significantly lower than Con + Sal (p < 0.05). A significant drug effect was observed for MtCK (p = 0.03) through Western blot. A significant drug effect (p = 0.03) and interaction (p = 0.02) was observed for MtCK using ELISA. Post hoc testing revealed that Cr2 + Dox had significantly higher MtCK than Cr1 + Sal and Cr2 + Sal. Data suggest that a reduction in LV mass and MtCK may contribute to Dox-induced cardiotoxicity, and Cr supplementation may play a potential role in mitigating cardiotoxicity by preserving mitochondrial CK.

New approach methodologies (NAMs) offer information tailored to the intended application while reducing the use of animals. NAMs aim to develop quantitative structure-activity relationship (QSAR) and quantitive-Read-Across structure-activity relationship (q-RASAR) models to predict and categorize the acute toxicity of known and unknown endocrine-disrupting chemicals (EDCs) against zebrafish. EDCs are a diverse group of toxic substances that disrupt the endocrine system of humans and animals. The q-RASAR model was constructed and verified using validation metrics (R² = 0.886 and Q² = 0.814) which found to be more reliable model compare to QSAR model. The substructure fingerprint was well-fitted for the classification model and it was validated using 10-fold average accuracy (Q = 86.88%), specificity (Sp = 88.89%), Matthew's correlation curve (MCC = 0.621) and receiver operating characteristics (ROC = 0.828). The dataset of unknown substances revealed that phenolphthalein (Php) exhibited a significant level of toxicity based on q-RASAR model. The docking and simulation study indicated that the computationally derived important features successfully bound to the target zebrafish sex hormone binding globulin (zfSHBG). The experimental LC50 value of 0.790 mg L^-1 was very close to the predicted value of 0.763 mg L^-1, which provides high confidence to the developed model.

The endocannabinoid (eCB) system comprises endogenous ligands, cannabinoid receptors (CBRs), and their regulatory proteins; its alteration leads to many diseases including cancer. Thus, becomes a therapeutic target for synthetic cannabinoids aimed to control cancer cell proliferation, migration, adhesion, and invasion. However, little is known about adhesion molecules regulation through CBRs activation. The aim of this study was to evaluate the effects of a CB1/CB2 agonist, WIN-55, 212-2 (WIN), on the regulation of adhesion molecules platelet endothelial cell adhesion molecule-1 (PECAM-1) and vascular endothelial cadherin (VE-cadherin) in HeLa cells. CBRs expression was evaluated by immunofluorescence staining in HeLa cells and cell viability (thiazolyl blue tetrazolium bromide), cell adhesion (crystal violet), adhesion molecules expression and location (Western blot and immunofluorescence staining assays) were all assessed on cells treated with different WIN concentrations. Receptors CB1, CB2, and G-protein-coupled receptor 55 were expressed in HeLa cells. Additionally, biphasic effects were observed in their metabolic activity and adhesive properties: low WIN concentrations resulted in significant increases whereas, high ones decreased them compared to controls (p < 0.0001), demonstrating that WIN elicits opposite effects depending on the concentration and exposure time. PECAM-1 was detected in HeLa cell's cytoplasm, membrane, and perinuclear region, whereas VE-cadherin had a nuclear distribution. There were no significant differences in PECAM-1 and VE-cadherin expression and location, suggesting that WIN does not modulate these proteins. These findings support the potential use of WIN due to its anticancer properties without dysregulating adhesion molecules. WIN possible contribution to inhibit cancer progression should be further investigated.

The study aimed to assess the toxic effect of cadmium (Cd) on the exocrine and endocrine functions of pancreas, the changes in pancreatic tissue after Cd withdrawal, and the protective effects of vitamin C (VC) and Nigella sativa (NS) against Cd-induced damage. Rats were assigned to: control, Cd-treated (0.5 mg/kg/d intraperitoneal [IP] injection), VC and Cd-treated (receiving 100 mg/kg/d VC orally and Cd concomitantly), NS and Cd-treated (receiving 20 mg/kg/d NS and Cd, simultaneously), and Cd withdrawal (receiving Cd for 30 d then living free for recovery for other 30 d). Blood samples were collected and post-sacrifice pancreatic specimens were processed for light and electron microscope study. Quantitative analyses of pancreatic collagen area%, pancreatic islet parameters, β cell density, and insulin immunoexpression were done. Fasting blood glucose was significantly increased in Cd-treated and Cd-withdrawal groups, while co-treatment with VC and NS caused significant reductions (p < 0.05). Cd-induced extensive degenerative changes in pancreatic acini and islets at light and ultrastructure levels. Obvious fibrosis and congestion of blood vessels were noticed. Significant reductions in pancreatic islet number, volume, and surface area and diminished beta cell count and insulin immunoexpression were observed. After withdrawal of Cd, the whole pancreatic tissue still showed a serious impact. Concomitant treatment with VC or NS obviously reduced these degenerative changes and significantly improved pancreatic islet parameters and insulin immunoexpression. VC showed a better amendment than NS, but this difference was statistically insignificant. Therefore, VC and NS could be used as prophylactic agents that lessen Cd consequences on the pancreas.