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: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: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.
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. This deep sequence study was designed to determine the gene expression profile by polystyrene particle toxicity. RNA was isolated from embryos at 1 and 3 days post injection. Wildtypes zebrafish embryos were micro-injected into the yolk (2dpf) with 1nl of 5mg/ml of 700nm red fluorescent polystyrene particles suspended in PVP (Polyvinylpyrrolidone) (n=3), mock injected with pvp (n=2), or Non-injected as a control (n=3). After injections embryos were transferred into fresh egg water and incubated at 28°C. At 1 and 3 days post injection 10 embryos per group were snap-frozen in liquid nitrogen, and total RNA was isolated using TRIZOL reagent.
Project description:Nanoplastics (NPs) and Microcystins (MCs) are widely distributed in the aquatic environment, and ultraviolet (UV)-aging can change the surface properties of NPs, thereby influence the adsorption behavior of NPs to the co-existing pollutants. In the present study, we investigated the influence of UV aging on the adsorption of MCs by polystyrene nanoplastics (PSNPs) and explored toxicity variations among pristine, aged, and MCs-loaded PSNPs to human HepG2 cells.
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: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.