Ecotoxicology and Environmental Safety最新文献

Extreme temperature events (ETEs) and air pollutants are both linked to neurodegenerative diseases, yet their interactions remain underexplored. This case-crossover study examined the effects of ETEs and six ambient air pollutants (PM₁₀, PM_2.5, O₃, SO₂, NO₂, and CO) on mortality due to neurodegenerative diseases in a cold-winter, hot-summer region of China (2014-2021). Using a conditional logistic regression model combined with a distributed lag non-linear model, we found that heat wave and cold spell significantly increased overall neurodegenerative disease mortality, with peak effects at lag 0-14 days for heat wave (OR=1.77[95 %CI: 1.58, 1.98]) and lag 0-8 days for cold spell (OR=1.25[95 %CI: 1.10, 1.42]). All six air pollutants were significantly associated with mortality during the warm season, with PM_2.5 and SO₂ posing higher risks. Positive interactions were observed between heat wave and four air pollutants (PM₁₀, PM_2.5, SO₂, CO), particularly with SO₂ (interaction OR = 1.84[95 %CI: 1.68, 2.01]). The strongest interaction effects were found for Alzheimer's disease mortality across all subcategories. Vulnerable groups included females, individuals aged > 80 years, and those without a spouse. These findings highlight the compounded risks of ETEs and air pollution on neurodegenerative disease mortality, emphasizing the need for synergistic warning systems and targeted control measures. SYNOPSIS: This study provides evidence for the interaction between short-term exposure to extreme temperature events and air pollutants on neurodegenerative disease mortality.

Cadmium (Cd) contamination of agricultural lands jeopardizes soil quality and food safety. The field study evaluated the effect of pure vermicompost (VK), vermicompost amended with struvite (VS) and vermicompost amended with biochar (VB) applied to cadmium contaminated soil on celery (Apium graveolens L.) growth, soil to plant Cd migration, and soil properties. The results indicated that, compared to no amendment (CK) and VK, VS and VB enhanced celery growth and reduced Cd soil-to-plant migration by lowering Cd bioavailability and transport coefficients. Both VS and VB significantly increased soil properties including pH and organic matter (OM) that played a vital role in immobilizing Cd and preventing its transfer from soil to celery. Besides, amended vermicomposts increased soil bacterial diversity and enriched metal-resistant taxa (e.g., Firmicutes, Proteobacteria, Myxococcota, etc). Thus, VS and VB have strong potential for remediating Cd-contaminated soils.

Application of manganese (Mn) fertilizer is a promising strategy to reduce the accumulation of cadmium (Cd) and arsenic (As) in rice grains. However, the quantitative impact of Mn in co-contaminated soils on Cd and As accumulation at different growth stages remains unclear. This study employed controlled pot experiments to investigate the effect of Mn at varying dosages on As and Cd mobility in the soil-root-crop system during booting, heading, and maturity stages. The results revealed that Mn regulated heavy metal uptake in rice throughout its entire growth period, leading to significant reduction in grain Cd and As contents by 30-60 % and 20-25 %, respectively. The relative contribution of Mn to reducing grain Cd was 30.5, 33.9, and 35.6 % at the booting, heading, and maturity stages, respectively, while its contributions to reducing grain As were 37.7, 19.0, and 43.2 %. Mn influences grain total arsenic accumulation by promoting rice growth, enriching Mn in Fe-Mn plaques at the root surface, and reducing available As in soil. For Cd, Mn reduces grain Cd content by promoting growth, modulating root iron- manganese plaques, and adjusting gene expression at maturity. These findings offer new insights into the role of Mn in reducing grain Cd and As at different rice growth stages and aid in developing strategies for remediating As and Cd co-contaminated paddy soils and increasing crop yield.

Background: Cold exposure is a well-recognized environmental risk factor that contributes to coronary microvascular dysfunction. Adipsin, an adipokine with known cardioprotective properties, has not been fully explored in the context of cold exposure-induced cardiovascular injury. This study aimed to elucidate the role of Adipsin in modulating coronary microvascular function under cold stress and to investigate the underlying mechanisms.

Methods: Adipose tissue-specific Adipsin transgenic mice (Adipsin-Tg) and wild-type controls were exposed to cold conditions (4 °C) for four weeks. Cardiac function, perivascular fibrosis, and coronary microvascular function were assessed. Serum Adipsin levels were selectively reduced by injecting AAV9-shRab27a into inguinal white adipose tissue (ingWAT). Exosomes derived from the ingWAT of Adipsin-Tg mice were isolated and tested for their effects on endothelial barrier function under cold stress. Mechanistic studies focused on the RhoA/Rock1 signaling pathway, cytoskeletal remodeling, and adherens junctions (AJs) stability in cardiac microvascular endothelial cells (CMECs).

Results: Cold exposure significantly reduced Adipsin expression in ingWAT, accompanied by impaired cardiac diastolic function, increased perivascular fibrosis, and disrupted coronary microvasculature. Overexpression of Adipsin in adipose tissue alleviated these pathological changes, whereas knockdown of serum Adipsin via AAV9-shRab27a reversed the protective effects. Exosomes enriched with Adipsin restored endothelial barrier integrity and improved microvascular function under cold stress. Mechanistically, Adipsin-enriched exosomes inhibited the RhoA/Rock1 pathway and MLC phosphorylation, preserved cytoskeletal architecture, and stabilized AJs by preventing VE-cadherin phosphorylation and internalization. Gα13 was identified as a downstream mediator of Adipsin, and its deficiency abolished the inhibitory effects of Adipsin on RhoA/Rock1 signaling.

Conclusion: Adipsin plays a protective role against cold stress-induced coronary microvascular dysfunction and cardiac diastolic dysfunction by modulating Gα13-dependent inhibition of the RhoA/Rock1 pathway. These findings support the therapeutic potential of Adipsin in preventing cold exposure-related cardiovascular injury.

Tylosin (TYL), a widely used macrolide antibiotic in livestock and poultry production, has attracted considerable attention owing to its strong adsorption capacity, persistence, and ecological risks in aquatic and soil environments. Because of their high efficiency and substrate specificity, microbial degradation enzymes are among the most promising agents for removing TYL from the environment. In this study, α/β hydrolase (Rcmd-2829) was expressed and purified from Kurthia gibsonii TYL-A1. The results showed that the optimum reaction conditions for Rcmd-2829 were pH 9.0 and 30°C. Molecular docking analyses, molecular dynamics simulations, and site-directed mutagenesis confirmed the key role of the Ser-102 residue in the catalytic degradation of TYL by Rcmd-2829. Rcmd-2829 retained its high catalytic activity in aquaculture wastewater, removing 83 % of 150 mg/L of TYL within 5 d. This study is the first to elucidate the Ser-102-dependent molecular mechanism underlying TYL degradation by the α/β hydrolase Rcmd-2829, providing a foundation for the development of efficient enzymatic-remediation technologies.

Salinity stress can decline crop yield in agricultural systems. Beyond the environmental conditions that drive agricultural plant growth, the diverse roles of microbes represent a critical, often overlooked factor in shaping crop health and productivity. Salinization exerts a profound effect on soil microbial communities, with consequences for biogeochemical cycles. However, the salinity adaptation mechanisms of microorganisms participating in biogeochemical cycles remain incompletely understood, which hold considerable promise for microbial solutions in saline agriculture. In this study, metagenomics-based technology was employed to analyze agricultural soils within a region-scale irrigation area characterized by varying degrees of salinization. According to the results of generalized linear models, bell-shaped trends were observed for the diversity and abundance of biogeochemical cycling genes along the soil salinity gradient, all of which peaked at a salinity of approximately 7.5 ‰. Further comparisons indicated reduced total abundance of all biogeochemical cycling genes in high salinity soils (>7.5 ‰) compared to those in low salinity soils (<7.5 ‰). Furthermore, correlation analysis indicated the coupling of different biogeochemical cycling genes, which were observed to be possessed by similar functional microorganisms, with a predominance of Gammaproteobacteria and Alphaproteobacteria. The presence of elevated salt levels resulted in a decline in the abundance of various microorganisms that play roles in biogeochemical cycling, including members of the Alphaproteobacteria, Actinomycetia, Limnocylindira, and Gemmatimonadetes phyla. Concurrently, there was an enrichment of a limited number of salt-tolerant bacteria, predominantly classified under the Bacteroidia and Bacilli taxonomic groups. The coupling of different biogeochemical cycling genes in some metagenome-assembled genomes (MAGs) was confirmed through metagenomics binning. Three MAGs (strains of Methylophaga, Salinimicrobium, and Sediminibacterium, respectively) with diverse biogeochemical cycling functions were recognized as potential plant-growth-promoting bacteria under salinity stress. These findings contribute to the existing body of knowledge on the salinity adaptability of soil microbial communities and offer guidance for the management of saline agriculture.

Deoxynivalenol (DON) is primarily produced by Fusarium graminearum (F. graminearum) and widely contaminates cereal feedstuffs, posing a serious threat to livestock and poultry health. Given the difficulty of removing DON from feeds, the most fundamental approach to control DON contamination is to inhibit the mycelial growth and DON production of F. graminearum before harvest. Ergosterol biosynthesis inhibitors (EBIs) are widely used fungicides, but they can accelerate DON biosynthesis even while inhibiting mycelial growth. This may be related to the accumulation of farnesyl pyrophosphate (FPP), a shared precursor of ergosterol and DON biosynthesis. However, the role of FPP synthesis and metabolism in the mechanism by which EBIs promote DON biosynthesis remains poorly understood. In this study, four EBIs targeting different proteins involved in ergosterol synthesis pathway were selected for F. graminearum treatment. Phenotypic assays revealed that EBIs such as terbinafine hydrochloride, hexaconazole, and amorolfine hydrochloride significantly promote DON production. Metabolomic analysis confirmed that hexaconazole altered both FPP synthesis process and its metabolism through different branches. However, knocking out multiple significantly upregulated genes (Erg24, Erg6B, and Erg3) identified in the transcriptomic data did not affect the DON synthesis process. Furthermore, disrupting FPP synthesis or inhibiting the conversion of FPP to DON with exogenous substances inhibited both mycelial growth and DON production. Our study reveals the mechanism by which hexaconazole promotes DON synthesis, elucidates the effects of FPP synthesis and metabolism on DON biosynthesis, and explores the feasibility of targeting FPP synthesis and metabolic processes for new fungicide development.