Chemical Research in Toxicology最新文献

The usage of cobalt (Co) and nickel (Ni) in numerous commercial, industrial, and military applications causes widespread exposure nowadays, and concerns are rising about adverse impacts on human health. Emphasis is on the respiratory system, with both metals classified as (possibly) carcinogenic upon inhalation by the International Agency for Research on Cancer (IARC), but limited data are available upon oral exposure. Therefore, this study aims to evaluate the in vitro genotoxicity of Co(II) and Ni(II) and their combination in HepG2 cells, since exposure of those environmental pollutants occurs realistically in concert. Here, Co(II) exposure led to the induction of single-strand breaks and oxidative DNA damage detected by the Comet assay as FPG-sensitive sites, while Ni(II) increased the abundance of γ-H2AX, an indicator for double-strand breaks. Notably, combined exposure to Co(II) and Ni(II) resulted in enhanced DNA damage, especially at the chromosomal level, with increased formation of micronuclei as well as polynucleated cells, indicating a stronger effect compared to single exposure. Furthermore, both metals induced the DNA damage response pathway PARylation. As this process involves the consumption of large amounts of cellular NAD⁺ after DNA damage, the energy state was assessed upon exposure with Co(II) and Ni(II). Current data indicate that especially Co(II) altered the cellular energy state. This study reveals distinct mechanisms of DNA damage exhibited by Co(II) and Ni(II), which were enhanced after a combined treatment. This highlights the need for further research to estimate the genotoxic potential of targeting cells upon oral intake with increasing environmental entry.

The usage of cobalt (Co) and nickel (Ni) in numerous commercial, industrial, and military applications causes widespread exposure nowadays, and concerns are rising about adverse impacts on human health. Emphasis is on the respiratory system, with both metals classified as (possibly) carcinogenic upon inhalation by the International Agency for Research on Cancer (IARC), but limited data are available upon oral exposure. Therefore, this study aims to evaluate the in vitro genotoxicity of Co(II) and Ni(II) and their combination in HepG2 cells, since exposure of those environmental pollutants occurs realistically in concert. Here, Co(II) exposure led to the induction of single-strand breaks and oxidative DNA damage detected by the Comet assay as FPG-sensitive sites, while Ni(II) increased the abundance of γ-H2AX, an indicator for double-strand breaks. Notably, combined exposure to Co(II) and Ni(II) resulted in enhanced DNA damage, especially at the chromosomal level, with increased formation of micronuclei as well as polynucleated cells, indicating a stronger effect compared to single exposure. Furthermore, both metals induced the DNA damage response pathway PARylation. As this process involves the consumption of large amounts of cellular NAD⁺ after DNA damage, the energy state was assessed upon exposure with Co(II) and Ni(II). Current data indicate that especially Co(II) altered the cellular energy state. This study reveals distinct mechanisms of DNA damage exhibited by Co(II) and Ni(II), which were enhanced after a combined treatment. This highlights the need for further research to estimate the genotoxic potential of targeting cells upon oral intake with increasing environmental entry.

Malondialdehyde (MDA), a major reactive byproduct of lipid peroxidation, has been implicated in numerous pathological conditions as a result of altering the structure and function of crucial proteins. One such protein is α-synuclein (α-Syn), which plays a vital role in the pathogenesis of Parkinson’s disease (PD). This study investigates the hypothesis that MDA causes structural alterations in α-Syn, promoting its aggregation and exacerbating its toxicological effects. In vivo experiments were conducted where MDA and MDA-modified α-Syn were injected to the brain of mice. Behavioral assessments were performed to evaluate motor function changes, while immunohistochemistry was employed to examine the extent of α-Syn aggregation in brain tissues. An extraction protocol was also developed exquisitely, enabling quantification of modified α-Syn from brain tissue. Moreover, ¹⁵Nitrogen-labeled α-Syn was employed to establish an absolute quantification method on nLC-HRMS/MS. Our findings demonstrate that MDA-induced modifications in α-Syn alter its structural properties and also significantly enhance its aggregation propensity, potentially contributing to the neurodegenerative processes observed in PD. The developed model displayed a nonreversible decline in motor function, neurodegeneration, and aggregation of proteins in the brain mimicking the PD conditions. This research provides valuable insights into the molecular mechanisms of PD, emphasizing the role of MDA-modified proteins in the etiology of PD.

Malondialdehyde (MDA), a major reactive byproduct of lipid peroxidation, has been implicated in numerous pathological conditions as a result of altering the structure and function of crucial proteins. One such protein is α-synuclein (α-Syn), which plays a vital role in the pathogenesis of Parkinson's disease (PD). This study investigates the hypothesis that MDA causes structural alterations in α-Syn, promoting its aggregation and exacerbating its toxicological effects. In vivo experiments were conducted where MDA and MDA-modified α-Syn were injected to the brain of mice. Behavioral assessments were performed to evaluate motor function changes, while immunohistochemistry was employed to examine the extent of α-Syn aggregation in brain tissues. An extraction protocol was also developed exquisitely, enabling quantification of modified α-Syn from brain tissue. Moreover, ¹⁵Nitrogen-labeled α-Syn was employed to establish an absolute quantification method on nLC-HRMS/MS. Our findings demonstrate that MDA-induced modifications in α-Syn alter its structural properties and also significantly enhance its aggregation propensity, potentially contributing to the neurodegenerative processes observed in PD. The developed model displayed a nonreversible decline in motor function, neurodegeneration, and aggregation of proteins in the brain mimicking the PD conditions. This research provides valuable insights into the molecular mechanisms of PD, emphasizing the role of MDA-modified proteins in the etiology of PD.

The ever-increasing use of chemicals and the rising incidence of adverse reproductive effects in the modern environment have become an emerging concern. Several studies have shown that environmental contaminants, such as organophosphate flame retardants (OPFRs), negatively impact reproductive health. To evaluate the potential endocrine-related adverse reproductive effects of widely used and priority-listed compound 2-Ethylhexyl diphenyl phosphate (EHDPP), we characterized its effects on adrenal steroidogenesis in human adrenocortical (H295R) cells. The cells were exposed to EHDPP (1 and 5 μM) for 48 h, and the production of hormones, including progesterone, androstenedione, testosterone, estradiol, cortisol, and aldosterone, was measured. In addition, LC-MS/MS-based lipidomics analysis was done to quantify intracellular lipid profiles, and transcriptional assays were performed to examine the expression of genes related to corticosteroidogenesis, lipid metabolism, and mitochondrial dynamics. Our findings indicate that EHDPP disrupts hormone regulation in vitro, as evidenced by increased estradiol, cortisol, and aldosterone secretion. The expression of key corticosteroidogenic genes (CYP11B2, CYP21A1, 3β-HSD2, and 17β-HSD1) was upregulated significantly upon EHDPP exposure. Intracellular lipidomics revealed EHDPP-mediated disruption, including reduced total cholesterol ester, sphingolipids, and increased phospholipids, triglyceride species, and saturated-monounsaturated lipids subspecies. These alterations were accompanied by decreased ACAT2 and SCD1 gene expression. Moreover, a shift in mitochondrial dynamics was indicated by increased MF1 expression and decreased FIS1 expression. These data suggest that EHDPP disrupts adrenal steroidogenesis and lipid homeostasis, emphasizing its potential endocrine-disrupting effects.

Nuclear receptors form a family of proteins capable of accommodating a wide variety of small molecules in their ligand binding domain, ranging from therapeutic compounds to endocrine-disrupting chemicals. The rapid identification of these compounds, especially within the latter category, is of paramount importance. Using data extracted from the CompTox Dashboard, an Environmental Protection Agency initiative, we assessed the effectiveness of a combination of molecular docking and pharmacophore models in identifying ligands binding to six nuclear receptors: androgen receptor, estrogen receptor alpha, estrogen receptor beta, glucocorticoid receptor, peroxisome proliferator-activated receptor gamma, and thyroid hormone receptor alpha. For each nuclear receptor, we selected a specifically designed and optimized in silico protocol that, in conjunction with experimental assays, can prioritize compounds for further evaluation to detect any potential toxicological concerns.

The ever-increasing use of chemicals and the rising incidence of adverse reproductive effects in the modern environment have become an emerging concern. Several studies have shown that environmental contaminants, such as organophosphate flame retardants (OPFRs), negatively impact reproductive health. To evaluate the potential endocrine-related adverse reproductive effects of widely used and priority-listed compound 2-Ethylhexyl diphenyl phosphate (EHDPP), we characterized its effects on adrenal steroidogenesis in human adrenocortical (H295R) cells. The cells were exposed to EHDPP (1 and 5 μM) for 48 h, and the production of hormones, including progesterone, androstenedione, testosterone, estradiol, cortisol, and aldosterone, was measured. In addition, LC-MS/MS-based lipidomics analysis was done to quantify intracellular lipid profiles, and transcriptional assays were performed to examine the expression of genes related to corticosteroidogenesis, lipid metabolism, and mitochondrial dynamics. Our findings indicate that EHDPP disrupts hormone regulation in vitro, as evidenced by increased estradiol, cortisol, and aldosterone secretion. The expression of key corticosteroidogenic genes (CYP11B2, CYP21A1, 3β-HSD2, and 17β-HSD1) was upregulated significantly upon EHDPP exposure. Intracellular lipidomics revealed EHDPP-mediated disruption, including reduced total cholesterol ester, sphingolipids, and increased phospholipids, triglyceride species, and saturated-monounsaturated lipids subspecies. These alterations were accompanied by decreased ACAT2 and SCD1 gene expression. Moreover, a shift in mitochondrial dynamics was indicated by increased MF1 expression and decreased FIS1 expression. These data suggest that EHDPP disrupts adrenal steroidogenesis and lipid homeostasis, emphasizing its potential endocrine-disrupting effects.

Nuclear receptors form a family of proteins capable of accommodating a wide variety of small molecules in their ligand binding domain, ranging from therapeutic compounds to endocrine-disrupting chemicals. The rapid identification of these compounds, especially within the latter category, is of paramount importance. Using data extracted from the CompTox Dashboard, an Environmental Protection Agency initiative, we assessed the effectiveness of a combination of molecular docking and pharmacophore models in identifying ligands binding to six nuclear receptors: androgen receptor, estrogen receptor alpha, estrogen receptor beta, glucocorticoid receptor, peroxisome proliferator-activated receptor gamma, and thyroid hormone receptor alpha. For each nuclear receptor, we selected a specifically designed and optimized in silico protocol that, in conjunction with experimental assays, can prioritize compounds for further evaluation to detect any potential toxicological concerns.

Gallbladder cancer (GBC) is an aggressive malignancy, with gallstone disease (GSD) recognized as the primary risk factor. Although the precise mechanism linking GSD to GBC remains unclear, evidence suggests that gallstone characteristics play a significant role. This study investigates the physicochemical characteristics of gallstones critical for GBC development. We analyzed 40 gallstone samples from 30 GSD and 10 GBC with GSD (GBCGS) patients using advanced spectroscopic and imaging techniques such as fourier transform infrared (FTIR), powder X-ray diffraction (PXRD), nuclear magnetic resonance (NMR), and scanning electron microscopy energy-dispersive X-ray (SEM-EDX)). Subsequently, elemental analysis of 10 gallstones each from GBCGS and GSD was conducted via inductively coupled plasma-mass spectrometry (ICP-MS). Gallstones from the GSD group were identified as cholesterol (70%), mixed (13.3%), pigment (6.7%), and calcium carbonate (10%), while the GBCGS group included only cholesterol (70%) and mixed (30%) types. Cholesterol was the dominant organic component in most gallstones, with the cholesterol and mixed types exhibiting highly crystalline phases characterized by a stacked plate-like microstructure, particularly prominent in the GBCGS group. Additionally, the GBCGS group revealed significantly higher concentrations of carcinogenic elements such as arsenic, chromium, mercury, iron, and lead (p < 0.05), suggesting their accumulation in the gallbladder and gallstones. Consequently, our findings highlight that the physicochemical properties of cholesterol-rich gallstones and exposure to carcinogenic elements play a key role in the pathogenesis of GBC in Assam. These results emphasize the need for further research into cholesterol dysregulation and its link to elemental toxicity.

Gallbladder cancer (GBC) is an aggressive malignancy, with gallstone disease (GSD) recognized as the primary risk factor. Although the precise mechanism linking GSD to GBC remains unclear, evidence suggests that gallstone characteristics play a significant role. This study investigates the physicochemical characteristics of gallstones critical for GBC development. We analyzed 40 gallstone samples from 30 GSD and 10 GBC with GSD (GBCGS) patients using advanced spectroscopic and imaging techniques such as fourier transform infrared (FTIR), powder X-ray diffraction (PXRD), nuclear magnetic resonance (NMR), and scanning electron microscopy energy-dispersive X-ray (SEM-EDX)). Subsequently, elemental analysis of 10 gallstones each from GBCGS and GSD was conducted via inductively coupled plasma-mass spectrometry (ICP-MS). Gallstones from the GSD group were identified as cholesterol (70%), mixed (13.3%), pigment (6.7%), and calcium carbonate (10%), while the GBCGS group included only cholesterol (70%) and mixed (30%) types. Cholesterol was the dominant organic component in most gallstones, with the cholesterol and mixed types exhibiting highly crystalline phases characterized by a stacked plate-like microstructure, particularly prominent in the GBCGS group. Additionally, the GBCGS group revealed significantly higher concentrations of carcinogenic elements such as arsenic, chromium, mercury, iron, and lead (p < 0.05), suggesting their accumulation in the gallbladder and gallstones. Consequently, our findings highlight that the physicochemical properties of cholesterol-rich gallstones and exposure to carcinogenic elements play a key role in the pathogenesis of GBC in Assam. These results emphasize the need for further research into cholesterol dysregulation and its link to elemental toxicity.