Abstract:
Small plastic debris (0.1 μm-5 mm) or microplastics (MPs) have become major pollutants of aquatic ecosystems worldwide and studies suggest that MPs exposure can pose serious threats to human and wildlife health. However, to date the potential biological impacts of MPs accumulating in low amount in tissues during early life remains unclear. Here, for a more realistic assessment, we have used environmentally representative, mildly weathered, polyethylene terephthalate microplastics (PET MPs), cryomilled (1-100 μm) and fluorescently labelled. We leveraged the amphibian Xenopus laevis tadpoles as an animal model to define the biodistribution of PET MPs and determine whether exposure to PET MPs induce perturbations of antiviral immunity. Exposure to PET MPs for 1-14 days resulted in detectable PET MPs biodistribution in intestine, gills, liver, and kidney as determined by fluorescence microscopy on whole mount tissues. PET MPs accumulation rate in tissues was further evaluated via a novel in situ enzymatic digestion and subsequent filtration using silicon nanomembranes, which shows that PET MPs rapidly accumulate in tadpole intestine, liver and kidneys and persist over a week. Longer exposure (1 month) of tadpoles to relatively low concentration of PET MPs (25 μg/ml) significantly increased susceptibility to viral infection and altered innate antiviral immunity without inducing overt inflammation. This study provides evidence that exposure to MPs negatively impact immune defenses of aquatic vertebrates.
摘要:
小塑料碎片(0.1μm至5mm)或微塑料(MPs)已成为全球水生生态系统的主要污染物,研究表明,MPs暴露可能对人类和野生动植物的健康构成严重威胁。然而,迄今为止,在生命早期组织中少量积累的MPs的潜在生物学影响尚不清楚.这里,为了更现实的评估,我们使用了环保代表,轻度风化,聚对苯二甲酸乙二醇酯微塑料(PETMPs),冷冻(2-100μm)并荧光标记。我们利用两栖动物Xenopusand作为动物模型来定义PETMPs的生物分布,并确定暴露于PETMPs是否会引起抗病毒免疫的干扰。暴露于PETMPs1至14天导致可检测的PETMPs在肠道中的生物分布,ill,肝脏,和肾脏,通过荧光显微镜在整个坐骑组织上确定。PETMPs在组织中的积累速率通过新的原位酶消化和随后的过滤使用硅纳米膜进一步评估。这表明PETMPs在t肠迅速积累,肝脏和肾脏,持续一周以上。长期(1个月)的t暴露于相对低浓度的PETMPs(25μg/ml)显着增加了对病毒感染的易感性,并改变了先天抗病毒免疫,而不会引起明显的炎症。这项研究提供了证据,表明暴露于MP会对水生脊椎动物的免疫防御产生负面影响。