Combined exposure to decabromodiphenyl ether and nano zero-valent iron aggravated oxidative stress and interfered with metabolism in earthworms.

Decabromodiphenyl ether (BDE-209) is a common brominated flame retardant in electronic waste, and nano zero-valent iron (nZVI) is a new material in the field of environmental remediation. Little is known about how BDE-209 and nZVI combined exposure influences soil organisms. During the 28 days study, we determined the effects of single and combined exposures to BDE-209 and nZVI on the oxidative stress and metabolic response of earthworms (Eisenia fetida). On day 7, compared to CK, malondialdehyde (MDA) content increased in most combined exposure groups. To remove MDA and reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities were induced in most combined exposure groups. On day 28, compared to CK, the activities of SOD and CAT were inhibited, while POD activity was significantly induced, indicating that POD plays an important role in scavenging ROS. Combined exposure to BDE-209 and nZVI significantly affected amino acid biosynthesis and metabolism, purine metabolism, and aminoacyl-tRNA biosynthesis pathways, interfered with energy metabolism, and aggravated oxidative stress in earthworms. These findings provide a basis for assessing the ecological impacts of using nZVI to remediate soils contaminated with BDE-209 from electronic waste.

Aspirin altered antibiotic resistance genes response to sulfonamide in the gut microbiome of zebrafish.

Pharmaceuticals are widespread in aquatic environments and might contribute to the prevalence of antibiotic resistance. However, the co-effect of antibiotics and non-antibiotic pharmaceuticals on the gut microbiome of fish is poorly understood. In this study, we characterized the variation of the zebrafish gut microbiome and resistome after exposure to sulfamethoxazole (SMX) and aspirin under different treatments. SMX contributed to the significant increase in the antibiotic resistance genes (ARGs) richness and abundance with 46 unique ARGs and five mobile genetic elements (MGEs) detected. Combined exposure to SMX and aspirin enriched total ARGs abundance and rearranged microbiota under short-term exposure. Exposure time was more responsible for resistome and the gut microbiome than exposure concentrations. Perturbation of the gut microbiome contributed to the functional variation related to RNA processing and modification, cell motility, signal transduction mechanisms, and defense mechanisms. A strong significant positive correlation (R = 0.8955, p < 0.001) was observed between total ARGs and MGEs regardless of different treatments revealing the key role of MGEs in ARGs transmission. Network analysis indicated most of the potential ARGs host bacteria belonged to Proteobacteria. Our study suggested that co-occurrence of non-antibiotics and antibiotics could accelerate the spread of ARGs in gut microbial communities and MGEs played a key role.

Insight into the differential toxicity of PFOA and PFBA based on a 3D-cultured MDA-MB-231 cell model.

Perfluoroalkyl substances (PFASs) are a category of high-concerned emerging contaminants which are suspected to correlate with various human adverse health outcomes including tumors. It is also a question whether short-chain PFASs are qualified alternatives under the regulation of long-chain PFASs. In this study, a three-dimensional (3D) culture system based on Gelatin methacrylate (GelMA) hydrogel matrix was used to investigate the impacts of 120-h perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) exposure of MDA-MB-231 cells. The results showed that PFOA exposure promoted the proliferation, migration, and invasion of MDA-MB-231 cells in an environmentally relevant concentration range (0.1 to 10 µM), exhibiting a clear malignant-promoting risk. In contrast, PFBA only showed a trend to induce non-invasive cell migration. Hippo/YAP signaling pathway was identified as the contributor to the differences between the two PFASs. PFOA but PFBA reduced YAP phosphorylation and increased the nuclear content of YAP, which further facilitated abundant key factors of epithelial-mesenchymal transition (EMT) process. Our results provided a new idea for the carcinogenicity of PFOA using a 3D-based paradigm. Although the effects by PFBA were much milder than PFOA in the current test duration, the cell model suitable for longer exposure is still necessary to better assess the safety of alternative short-chain PFASs.