Environmental Toxicology最新文献

Low expression of certain ribosomal proteins leads to the inactivation of p53, which is mediated mainly by RPL5 or RPL11 (ribosomal protein L11). It is also unknown what mechanisms drive aberrant ribosomal proteins expression in tumor. SRBD1 (S1 RNA-binding domain 1), as a highly conserved RNA-binding protein, is lowly expressed in glioma tissues and correlated with glioma prognosis. In this study, we observed that SRBD1 was closely related to p53 signaling. The upregulation of SRBD1 elevated p53 levels, thereby activating the p53 signaling pathway. As an RNA bind protein, SRBD1 could bind to the 5′-UTR of target genes and regulate RNA translation. We further conducted RNA immunoprecipitation using anti-SRDB1 antibody and noticed 29 hub RNA, including RPL11. RPL11 could inhibit MDM2-mediated p53 ubiquitination. SRBD1 upregulation promoted RPL11 binding to MDM2 via elevating RPL11 protein levels, which in turn activated the p53 signaling. Disrupting the p53 signaling blocked SRBD1-induced glioma suppression. In mouse xenograft model, SRBD1 ectopic expression was effective in reducing the total M2 tumor-associated macrophages (TAMs) density and suppressed glioma tumor growth. In summary, these data show that SRBD1 has a critical role in inhibition of glioma tumor growth and M2 macrophage polarization, and targeting RPL11-MDM2-p53 signaling may be an effective strategy to improve therapy and survival for glioma patients.

Microplastics are a growing concern as pollutants that impact both public health and the environment. However, the toxic effects of polypropylene microplastics (PP-MPs) are not well understood. This study aimed to investigate the effects of PP-MPs on cardiotoxicity and its underlying mechanisms. The cardiotoxicity of exposure to different amounts of PP-MPs were investigated in both ICR mice and H9C2 cells. Our results demonstrated that sub-chronic exposure to 5 and 50 mg/L PP-MPs led to myocardial structural damage, apoptosis, and fibrosis in mice cardiomyocytes. Flow cytometry analysis revealed that PP-MPs could decrease mitochondrial membrane potential and induce apoptosis in H9C2 cells. Western blotting revealed decreased expression of Bcl-2, poly(ADP-ribose) polymerase (PARP) and caspase 3 and increased expression of Bax, cleaved-PARP, and cleaved-caspase 3 in PP-MPs-treated cardiac tissue and H9C2 cells. These results confirmed the apoptotic effects induced by PP-MPs. Moreover, PP-MPs treatment triggered oxidative stress, as evidenced by the increased levels of malondialdehyde; reduction in glutathione peroxidase, superoxide dismutase, and catalase activities in mice cardiac tissues; and increased reactive oxygen species levels in H9C2 cells. Finally, western blotting demonstrated that exposure to PP-MPs significantly reduced the expression levels of Nrf2 and p-ERK proteins associated with MAPK-Nrf2 pathway in both cardiac tissue and H9C2 cells. Overall, our findings indicate that PP-MPs can induce cardiomyocyte apoptosis through MAPK-Nrf2 signaling pathway, which is triggered by oxidative stress. This study provides a foundation for determining the effects of PP-MPs on cardiotoxicity and their underlying mechanisms.

Several phthalates, mainly used as plasticizers, are known for their adverse effects on the male genital system. Previously, we demonstrated that an environmentally relevant mixture of six antiandrogenic phthalates (PMix), derived from a biomonitoring study in pregnant Brazilian women, was able to disrupt the reproductive development in male rats. Experimental groups (control, 0.1, 0.5, and 500 mg PMix/kg/day) were established starting from the extrapolated human dose (0.1 mg/kg/day), followed by doses 5 times and 5000 times higher. Pregnant rats received daily oral gavage administration of either vehicle (control) or PMix from gestational day 13 to postnatal day 10. Here, we examined male and female offspring regarding changes in gene expression of key reproductive factors in the hypothalamus and pituitary gland at adulthood and conducted a battery of behavioral tests in males, including partner preference, sexual behavior, and male attractiveness tests. PMix induced some changes in mating-related behavior in males, as demonstrated by the absence of preference for females against males and a higher number of penetrations up to ejaculation in the 0.5 dose group. PMix decreased Esr2 expression in the male hypothalamus across all three doses, and in females at mid and high doses in both the hypothalamus and pituitary. In male hypothalamus, we also observed decreased Kiss1 transcripts in these groups and a reduction in AR at the 0.5 dose group. In summary, our results provide further evidence that phthalates in a mixture, even at low doses, may exert cumulative effects on the structures underlying sexual behavior, which seems to be more sensitive than reproductive endpoints for the same experimental design.

Cigarette smoking causes multiple cancers by directly influencing mutation burden of driver mutations. However, the mechanism between somatic mutation caused by cigarette smoking and bladder tumorigenesis remains elusive. Smoking-related mutation profile of bladder cancer was characterized by The Cancer Genome Atlas cohort. Integraticve OncoGenomics database was utilized to detect the smoking-related driver genes, and its biological mechanism predictions were interpreted based on bulk transcriptome and single-cell transcriptome, as well as cell experiments. Cigarette smoking was associated with an increased tumor mutational burden under 65 years old (p = 0.031), and generated specific mutational signatures in smokers. RB1 was identified as a differentially mutated driver gene between smokers and nonsmokers, and the mutation rate of RB1 increased twofold after smoking (p = 0.008). RB1 mutations and the 4-aminobiphenyl interference could significantly decrease the RB1 expression level and thus promote the proliferation, invasion, and migration ability of bladder cancer cells. Enrichment analysis and real-time quantitative PCR (RT-qPCR) data showed that RB1 mutations inhibited cytochrome P450 pathway by reducing expression levels of UGT1A6 and AKR1C2. In addition, we also observed that the component of immunological cells was regulated by RB1 mutations through the stronger cell-to-cell interactions between epithelial scissor⁺ cells and immune cells in smokers. This study highlighted that RB1 mutations could drive smoking-related bladder tumorigenesis through inhibiting cytochrome P450 pathway and regulating tumor immune microenvironment.

Inflammation is an intrinsic protective mechanism against various forms of cellular injuries in humans; however, its undesired activation results in tissue damage and cell death. The onset of chronic inflammation and oxidative stress are the key characteristics of autoimmune inflammatory diseases such as rheumatoid arthritis (RA), for which an effective treatment is yet to be developed. Therefore, in this study, we investigated the protective effects and molecular mechanisms of a novel herbal preparation, Jing-Si herbal tea (JS), against H₂O₂-induced inflammation and cellular damage in HIG-82 synoviocytes. We found that JS did not show any significant alterations in cell viability at <188 μg/mL; however, a cytotoxic effect was observed at 188–1883 μg/mL concentrations tested. We found that expressions of inflammation associated extracellular matrix (ECM)-degrading proteases MMP-13, ADAMTS-2, -8, and -17 were abnormally enhanced under H₂O₂-induced pathological oxidative stress (ROS) in HIG-82 cells. Interestingly, JS treatment not only reduced the ROS levels but also significantly repressed the protein expressions of collagen degrading proteases in a dose-dependent manner. Treatment with JS showed enhanced cell viability against H₂O₂-induced toxic ROS levels. The expressions of cell protective aggrecan, Collagen II, and Bcl-2 were increased, whereas MMP-13, ADAMTS-2, Cytochrome C, and cleaved Caspase 3 were decreased by JS under inflammatory agents H₂O₂, MIA, LPS, and TNF-α treatment, respectively, in HIG-82 cells. Interestingly, the cytoprotective effect of JS treatment was attributed to a decreased mitochondrial localization of Bax and a reduction of Cytochrome C release into the cytoplasm of H₂O₂-treated HIG-82 cells. Collectively, our results suggest a novel protective mechanism of JS for RA treatment, which could be potentially applied as a complementary treatment or as an alternative therapeutic approach to mitigate inflammatory diseases.

Clear cell renal cell carcinoma (ccRCC) is characterized by its aggressive behavior and complex molecular heterogeneity, posing significant challenges for treatment and prognostication. This study offers a comprehensive analysis of ccRCC by leveraging both bulk and single-cell RNA sequencing data, with a specific aim to unravel the complexities of sphingolipid metabolism and the intricate dynamics within the tumor microenvironment (TME). By examining ccRCC samples sourced from public databases, our investigation delves deep into the genetic and transcriptomic landscape of this cancer type. Employing advanced analytical techniques, we have identified pivotal patterns in gene expression and cellular heterogeneity, with a special focus on the roles and interactions of various immune cells within the TME. Significantly, our research has unearthed insights into the dynamics of sphingolipid metabolism in ccRCC, shedding light on its potential implications for tumor progression and strategies for immune evasion. A novel aspect of this study is the development of a risk score model designed to enhance prognostic predictions for ccRCC patients, which is currently pending external validation to ascertain its clinical utility. Despite its contributions, the study is mindful of its limitations, including a reliance on observational data from public sources and a primary focus on RNA sequencing data, which may constrain the depth and generalizability of the findings. The study does not encompass critical aspects, such as protein expression, posttranslational modifications, and comprehensive metabolic profiles. Moreover, its retrospective design underscores the necessity for future prospective studies to solidify these preliminary conclusions. Our findings illuminate the intricate interplay between genetic alterations, sphingolipid metabolism, and immune responses in ccRCC. This research not only enhances our understanding of the molecular foundations of ccRCC but also paves the way for the development of targeted therapies and personalized treatment modalities. The study underlines the importance of cautious interpretation of results and champions ongoing research using diverse methodologies to thoroughly comprehend and effectively combat this formidable cancer type.

T-2 toxin is a trichothecene mycotoxin and is considered as an extremely inevitable pollutant with potent hepatotoxicity. However, the approach to alleviation of T-2 toxin-triggered hepatotoxicity has been recognized as a serious challenge. Resveratrol (Res) is a polyphenol natural product isolated from various plant species, but its protective effect against T-2 toxin hepatotoxicity and detailed mechanism remains obscure. In the present study, the effect of Res against the hepatotoxicity was evaluated, and the underlying mechanisms were further revealed in mice. Functionally, Res inhibited liver injury, oxidative damage, and mitochondrial dysfunction induced by T-2 toxin. Mechanistically, Res modulated Nrf2-mediated antioxidant pathway and glutathione synthesis inhibition. Collectively, our findings first showed beyond doubt that Res ameliorated T-2 toxin-triggered liver injury by regulating Nrf2 pathways in mice.