Project description:Nanoplastics pollution is a rising environmental concern whose impacts on biodiversity and human health are far from being understood. This is particularly salient in aquatic ecosystems, where the majority of species depend on external fertilization for reproduction. Here we evaluated the effects of a short-term exposure to engineered polystyrene nanoplastics (NPs) in the zebrafish germ line to further explore their impact on reproduction. To this end, zebrafish (Danio rerio) were exposed to 5 mg/L of 45 nm polystyrene (PS)-NPs via water for 96h. We show that, in males, nanoplastics induced testicular histological alterations with abnormal sperm clustering and chromatin compaction, resulting in viable spermatozoa but with reduced motility. Moreover, in females we observed an alteration in oocyte stages frequencies during oogenesis, possibly reflecting alterations in oocyte growth. RNA-sequencing analysis in male testis links nanoplastic induced alterations in the expression of genes involved in chromatin structure, meiosis and DNA double-strand break formation and repair progression, and gametes recognition. Flow cytometry analysis revealed that the observed effects in males were directly due to nanoplastics penetrating the testicular barrier and being internalized within germline cells. Overall, our results demonstrate that acute exposure to NPs can compromise reproductive fitness, underscoring the environmental and health impacts of NPs pollution.
Project description:Reactive aldehydes such as 4-HNE, MDA and acrolein are implicated in the pathological development of diabetes as their widespread and universally exposed characteristics. Trans, trans-2,4-decadienal (tt-DDE) come from lipid peroxidation of omega-6 and is most abundant aldehyde in cooking oil fumes, while, its role in diabetes remained unknown. Aldh9a1 is a cytosolic enzyme that catalyze the NAD+-dependent oxidation of a variety of aldehydes and has its homology aldh9a1b in zebrafish. To investigate the function of endogenous and exogenous tt-DDE, aldh9a1b knockout zebrafish are established using CRISPR/Cas9 technology. TT-DDE was confirmed to act as substrate for aldh9a1b and a series of experiments are performed on a histological, metabolomic and transcriptomic level in aldh9a1b-/- zebrafish. Both aldh9a1b-/- larvae and adult fish displayed abnormal retinal vasculature and impaired glucose homeostasis, which are caused by tt-DDE induced downregulated insulin signaling pathway. Furthermore, the abnormal hyaloid vasculature in the fish can be reversed by insulin receptor sensitizer and metformin exhibited strongest effects among them. Altogether, these results identified tt-DDE as the preferred substrate for aldh9a1b, which subsequently causes microvascular damage and impaired glucose metabolism by insulin resistance.
Project description:Plastic particles in water environment can adsorb heavy metals, leading to combined toxicity to aquatic organisms. However, current conclusions are mostly obtained based on cell population-average responses. Heterogeneity effects among cell populations in aquatic organisms remain unclear. This study analyzed the heterogeneity effects of 200 μg/L 100 nm polystyrene nanoplastics (PS-NPs), 50 μg/L lead (Pb), and their combined exposures on zebrafish intestine cells by single-cell RNA sequencing.A total of 38640 cells in the zebrafish intestine was obtained and identified as seven cell populations, including enterocytes, macrophages, neutrophils, B cells, T cells, enteroendocrine cells, and goblet cells.Co-exposure of PS-NPs and Pb caused similar transcriptome profiles with PS-NPs exposure in macrophages, which changed immunological recognition processes. The Pb exposure influenced the macrophages by direct cytotoxicity. However, the Pb alone and combined exposures induced similar modes of action in the enterocytes, including the generation of oxidative stress and abnormal lipid metabolism.
2022-02-25 | GSE165888 | GEO
Project description:Mixture toxicity of 6PPD-quinone and polystyrene nanoplastics in zebrafish
Project description:Nanoplastics with small particle size and high surface area/volume ratio make them easy to absorb environmental pollutants and affect their bioavailability. In this study, polystyrene nanoplastic beads (PS-NPBs) with a particle size of 100nm and sunscreen butyl methoxydibenzoylmethane (BMDBM) contained in personal care products were chosen as target pollutants to study their developmental toxicity and interactive effects on zebrafish embryo. The exposure period was 2-12 hours post fertilization (hpf). The BMDBM and PS-NPBs significantly upregulated the genes related to antioxidant enzymes and downregulated the gene expression of aromatase and DNA methyltransferases, but the influenced genes were not exactly the same, and the combined exposure reduced the adverse effects on the expression of all genes. With the help of single-cell RNA sequencing technology, the neural mid cells were identified as the target cells of both pollutants, and brain development, head development and notch signaling pathway were the functions they commonly altered. The key genes and functions that are specifically affected by BMDBM and/or PS-NPBs were identified. The BMDBM mainly affect the differentiation and fate of neurons in central nervous system through the regulation of her5, her6, her11, lfng, pax2a and fgfr4. The PS-NPBs regulated the expression of olig2, foxg1a, fzd8b, six3a, rx1, lhx2b, nkx2.1a and sfrp5 to alter nervous system development, retinal development, and stem cell differentiation. The phenotypic responses of zebrafish larvae at 120 hpf were tested, and significant inhibition of locomotor activity was found, indicating that early disrupting effect on central nervous system would have a sustained impact on the behavior of zebrafish.
Project description:Nanoplastics, as an emerging persistent pollutant of global concern in recent years, have posed a potential threat to human health. However, there is little known about the adverse effects of nanoplastics on the female reproductive system. Here, polystyrene nanoplastics (PS-NPs) with a diameter of 50 nm were selected as representative nanosized plastic particles to investigate the potential effects of subchronic exposure on placenta development in mice.
Project description:Nanoplastics are produced by breakdown of plastics in environmental contamination or commercial use for cosmetics or daily expenses. Emerging evidence indicate that ingested nanoplastics with a size smaller than 100 nm have the potential to reach the brain and induces neurotoxicity. However, the potential toxicity of nanoplastics on brain are limited because of difficulties in synthesize of nanoplastics. In present study, we synthesized the fluorescent polystyrene nanoplastics (PSNPs) and examined the toxicity of PSNPs in brain in vivo and in vitro analyses by comparison to IR-813 fluorophore. Synthesized PSNPs were characterized by fluorescence imaging system, scanning electron microscopy, and Fourier-transform infrared spectroscopy. PSNPs were detected in adult mice brain by oral ingestion. In addition, a series of behavioral analyses showed that oral ingestion of PSNPs induced memory impairments. Among brain cells, PSNPs were predominantly internalized in microglia, and uptake of PSNPs induced microglial activation. In addition, the conditioned medium derived from microglia exposed to PSNPs repressed hippocampal neuronal activity. Furthermore, transcriptome analysis showed that PSNPs changed gene expressions in microglia, elevation of neuroinflammation in contrast to suppression of neurotrophic factors. These results indicated that predominant uptake of PSNPs in microglia induced elevation of neuroninflammatory responses whereas suppression of neurotrophic factors that may contribute to the cognitive impairment. Our findings indicate the toxic mechanism and potential detrimental effect of nanoplastic in brain and suggest a potential risk of cognitive impairment by exposure to nanoplastics.
Project description:Acute exposure to acrylamide (ACR), a type-2 alkene, may lead to a ataxia, skeletal muscles weakness and numbness of the extremities in exposed human and laboratory animals. Recently, a zebrafish model for ACR neurotoxicity mimicking most of the pathophysiological processes described in mammalian models, was generated in 8 days post-fertilization larvae. In order to better understand the predictive value of the zebrafish larvae model of acute ACR neurotoxicity, in the present manuscript the ACR acute neurotoxicity has been characterized in the brain of adult zebrafish, and the results compared with those obtained with the whole-larvae. Although qualitative and quantitative analysis of the data shows important differences in the ACR effects between the adult brain and the whole-larvae, the overall effects of ACR in adult zebrafish, including a significant decrease in locomotor activity, altered expression of transcriptional markers of proteins involved in synaptic vesicle cycle, presence of ACR-adducts on cysteine residues of some synaptic proteins, and changes in the profile of some neurotransmitter systems, are similar to those described in the larvae. Thus, these results support the suitability of the zebrafish ACR acute neurotoxicity recently developed in larvae for screening of molecules with therapeutic value to treat this toxic neuropathy.
Project description:We use the zebrafish embryo model to study the innate immune response against polystyrene particles. Therefore, we injected 700nm polystyrene into the yolk at 2 dpf and took samples at 1 and 3 days post injection.