Search

Hexavalent chromium [Cr(VI)] is a widely distributed carcinogen in industrial contexts and general environmental contexts. Emerging research highlights the central role of ribosomal DNA (rDNA) in DNA Damage Responses (DDRs). However, there remains a lack of investigation into the potential dose-dependent relationship between exposure to Cr(VI) and alterations in rDNA copy number (CN), as well as the related mechanisms underlying these effects. A molecular epidemiological investigation involving 67 workers exposed to Cr(VI) and 75 unexposed controls was conducted. There was a notable increase in ZNF385A expression, variations in rDNA CN, and elevated γH2AX levels in the peripheral blood of Cr(VI)-exposed workers. Restricted cubic spline (RCS) models showed that blood Cr levels in the exposed population exhibited non-linear dose-dependent relationships with γH2AX, rDNA CN, and ZNF385A. Of considerable interest, there were robust and positive associations between ZNF385A and both γH2AX and rDNA CN. Further in vitro experiments provided concrete evidence that Cr(VI) simultaneously caused an increase in ZNF385A expression and variations in rDNA CN. ZNF385A-depleted cells showed increased sensitivity to Cr(VI)-mediated DDRs and alterations in rDNA CN. This study indicated that ZNF385A played a highly significant role in the rDNA CN variation in response to Cr(VI)-induced DNA damage.

Objectives: This study aimed to analyze the possible role of rDNA copy number variation in the association between hexavalent chromium [Cr (VI)] exposure and semen quality in semen donors and further confirm this association in mice. Methods: In this cross-sectional study, whole blood and semen samples were collected from 155 semen donors in the Zhejiang Human Sperm Bank from January 1st to April 31st, 2021. Adult C57BL/6 J male mice were treated with different doses of Cr (VI) (0, 10, or 15 mg/kg b.w./day). Semen quality, including semen volume, total spermatozoa count, sperm concentration, progressive motility, and total motility, were analyzed according to the WHO laboratory manual. Cr concentration was detected using inductively coupled plasma mass spectrometry. The rDNA copy number was measured using qPCR. Results: In semen donors, whole blood Cr concentration was negatively associated with semen concentration and total sperm counts. Semen 5 S and 45 S rDNA copy numbers were negatively associated with whole blood Cr concentration and whole blood 5.8 S rDNA copy number was negatively associated with semen Cr concentration. In mice, Cr (VI) damaged testicular tissue, decreased semen quality, and caused rDNA copy number variation. Semen quality was related to the rDNA copy number in whole blood, testicular tissue, and semen samples in mice. Conclusion: Cr (VI) was associated with decreased semen quality in semen donors and mice. Our findings suggest an in-depth analysis of the role of the rDNA copy number variation in the Cr (VI)-induced impairment of semen quality.

Dextrans (DXs) are a group of natural polysaccharides with different branching patterns. Previous studies examining the effects of DXs on plant protein gels have only focused on α-(1 → 3)-branched DXs. Here, we compared the effects of α-(1 → 3)-branched DX L12 with those of two α-(1 → 2)-branched DXs on the properties of glucono-δ-lactone-induced faba bean protein isolate (FPI) gels. DX L12 showed stronger effects in decreasing gel hardness and enhancing gel viscoelasticity than the other two DXs. Moreover, DX L12 decreased the water-holding capacity of FPI gels, whereas the other DXs enhanced it. Microstructural analysis revealed that DX addition promoted phase separation during gel formation. However, FPI/L12 gels exhibited greater phase separation than the other two gels and contained larger void spaces. These differences could be attributed to the varying water adsorption and self-association properties of the DXs. These findings could guide the application of DX in the tailored preparation of plant protein gels.

Short-chain fatty acids (SCFAs) exhibit anticancer activity in cellular and animal models of colon cancer. Acetate, propionate, and butyrate are the three major SCFAs produced from dietary fiber by gut microbiota fermentation and have beneficial effects on human health. Most previous studies on the antitumor mechanisms of SCFAs have focused on specific metabolites or genes involved in antitumor pathways, such as reactive oxygen species (ROS) biosynthesis. In this study, we performed a systematic and unbiased analysis of the effects of acetate, propionate, and butyrate on ROS levels and metabolic and transcriptomic signatures at physiological concentrations in human colorectal adenocarcinoma cells. We observed significantly elevated levels of ROS in the treated cells. Furthermore, significantly regulated signatures were involved in overlapping pathways at metabolic and transcriptomic levels, including ROS response and metabolism, fatty acid transport and metabolism, glucose response and metabolism, mitochondrial transport and respiratory chain complex, one-carbon metabolism, amino acid transport and metabolism, and glutaminolysis, which are directly or indirectly linked to ROS production. Additionally, metabolic and transcriptomic regulation occurred in a SCFAs types-dependent manner, with an increasing degree from acetate to propionate and then to butyrate. This study provides a comprehensive analysis of how SCFAs induce ROS production and modulate metabolic and transcriptomic levels in colon cancer cells, which is vital for understanding the mechanisms of the effects of SCFAs on antitumor activity in colon cancer.

A post-synthetic modification strategy for anchoring PdO nanoparticles on the Beta zeolite surface and obtaining stable and highly dispersed PdO sites with abundant active Pdn+ (0 ) 99% methane conversion at 375 °C with a space velocity of 30,000 mL h−1 g−1 and a satisfied long-term (>30 h) CH4 oxidation stability at 340 °C. Such a post-synthetic strategy provides a new way to disperse and stabilize noble metal particles on zeolite support for harsh catalytic process.

Intestinal barrier function and intestinal flora imbalance lead to neonatal necrotizing enterocolitis (NEC). Lactobacillus rhamnosus GG (LGG) has been used to prevent or treat NEC in many animal models and clinical trials; however, its underlying action mechanism remains elucidated. Here, we observed intestinal stem cell (ISC) and intestinal barrier disruption in an NEC mouse model, characterized by reduced number of tight junctions (TJs) and expression of Lgr5, inhibition of ISC differentiation and the Wnt/β-catenin signaling pathway, and disturbance of the intestinal microbiota microenvironment. LGG oral administration in these mice re-established the intestinal flora, increased Wnt3a and Wnt7b levels in the small intestinal tissue, activated the Wnt/β-catenin signaling pathway, promoted ISC regeneration, reduced intestinal tumor necrosis factor-α and interleukin-6 levels, increased the number of TJs, and improved intestinal barrier function; NEC-induced intestinal injury was also reduced. Therefore, LGG administration can alleviate intestinal lesions by enhancing mucosal barrier function in NEC.

Understanding the coordinative relationship between urbanization and ecosystem services (ESs) has a great significance in sustainable development in urban agglomeration. In this paper, InVEST model was firstly used to assess the spatio-temporal evaluation of four types of ESs (water yield, carbon storage, soil retention and nitrogen export) in the Yangtze River Delta Urban Agglomerations (YRDUA) of China from 2000 to 2020. Then comprehensive evaluation index system of urbanization was established from the multi-dimensions of economy, population and land to analyze the urbanization level during the study period. Finally, a comprehensive ecosystem service (CES) index was developed to explore the coordinative relationship between ESs and urbanization by using coupling coordinating degree model (CCDM). The results revealed that: 1) Urbanization has led to greatly land use/ land cover change, which caused the degradation of carbon storage and water purification, and the improvement of water yield and soil retention. The higher water yield and nitrogen export mainly clustered around urban areas, while higher carbon storage and soil retention were distributed in forest-rich cities in the Zhejiang and the southern of Anhui. There were positive correlations between different ESs. And the CES of cities in the YRDUA had deteriorated during the study period. 2) The urbanization levels of almost all cities showed an overall upward trend, with Shanghai the highest urbanization, followed by Nanjing and Hangzhou, and rapid urban expansion mainly occurred in developed urban areas. 3) The coordinative relationship between CES and urbanization in the YRDUA was always in mild incoordination, showing an obvious spatial distribution pattern of “higher in the south, but lower in the north”. The coordinative relationship between CES and urbanization in most cities in the north of YRDUA has not achieved coordination development, with the state of moderate or mild incoordination, while the cities in the south has attained coordination development, with the state of primary or even superior coordination. Therefore, our study suggested that differentiated urban space management and control policies should be made for the YRDUA to improve the overall coordinative relationship between CES and urbanization.