The organ-specific toxicity resulting from microplastic (MP) exposure has been extensively explored, particularly concerning the gut, liver, testis, and lung. However, under natural conditions, these effects are not restricted to specific organs or tissues. Investigating whether MP exposure presents a systemic threat to an entire organism, impacting factors such as lifespan, sleep, and fecundity, is essential. In this study, we investigated the effects of dietary exposure to two different doses of MPs (1-5 μm) using the terrestrial model organism Drosophila melanogaster. Results indicated that the particles caused gut damage and remained within the digestive system. Continuous MP exposure significantly shortened the lifespan of adult flies. Even short-term exposure disrupted sleep patterns, increasing the length of daytime sleep episodes. Additionally, one week of MP exposure reduced ovary size, with a trend towards decreased egg-laying in mated females. Although MPs did not penetrate the brain or ovaries, transcriptome analysis revealed altered gene expression in these tissues. In the ovary, Gene Ontology (GO) analysis indicated genotoxic effects impacting inflammation, circadian regulation, and metabolic processes, with significant impacts on extracellular structure-related pathways. In the brain, GO analysis identified changes in pathways associated with proteolysis and carbohydrate metabolism. Overall, this study provides compelling evidence of the systemic negative effects of MP exposure, highlighting the urgent need to address and mitigate environmental MP pollution.
微塑料暴露导致的特定器官毒性包括肠道、肝脏、睾丸和肺毒性等已得到了广泛的研究。然而，微塑料暴露对整个生物体的系统性影响，包括寿命长短、睡眠质量和繁殖能力等尚不明晰。在该研究中，我们利用陆生动物模型黑腹果蝇（ Drosophila melanogaster），研究饮食摄入1-5微米微塑料暴露的系统性影响及其分子机制。结果发现，微塑料的摄入可导致肠道损伤。终生暴露于微塑料会导致果蝇的寿命显著缩短。短期微塑料暴露已足以导致白天睡眠片段时长增加，睡眠结构受到干扰；卵巢体积缩小，且交配后雌蝇产卵率呈下降趋势。尽管暴露后的大脑及卵巢内并未观察到微塑料的存在，但脑组织及卵巢组织转录组分析表明其基因表达受到干扰。具体包括，在卵巢中，微塑料暴露诱导了与炎性反应、昼夜节律调节及代谢过程相关的基因毒性效应。在大脑中，微塑料暴露引起蛋白水解和碳水化合物代谢过程相关基因通路的改变。我们的研究表明微塑料暴露的影响不仅仅局限于特定器官组织，而是系统性的影响了生物体的健康。如何采取有效策略以减轻微塑料这一环境污染的健康危害应受到更多关注。.
Keywords: Drosophila melanogaster; Lifespan; Microplastics; Reproduction; Risk assessment; Sleep.