Reproductive toxicity of UV-photodegraded polystyrene microplastics induced by DNA damage-dependent cell apoptosis in Caenorhabditis elegans

• Published in: The Science of the total environment Vol. 811; p. 152350
• Main Authors: Chen, Haibo, Yang, Yue, Wang, Chen, Hua, Xin, Li, Hui, Xie, Dongli, Xiang, Mingdeng, Yu, Yunjiang
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.03.2022
• Subjects: Aged microplastics; Animals; Apoptosis; Caenorhabditis elegans; Caenorhabditis elegans - genetics; Cell apoptosis; DNA Damage; Microplastics; Plastics; Polystyrenes; Reproductive toxicity; Caenorhabditis elegans; Reproductive toxicity; DNA damage; Aged microplastics; Cell apoptosis
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.152350

Although many studies have investigated the toxic effects of polystyrene microplastics (PS-MPs), toxicity of natural aged of PS-MPs to soil organisms remains unclear. The photodegradation of virgin PS-MPs under UV irradiation was investigated, and reproductive toxicity of pristine and UV-photodegraded PS-MPs at environmental concentrations (0.1–100 μg/L) was examined to Caenorhabditis elegans. Using brood size and egg ejection rate as endpoints, acute exposure to aged PS-MPs resulted in more severe reproductive toxicity than pristine PS-MPs. Exposure to 100 μg/L aged PS-MPs significantly increased the number of HUS-1::GFP foci and the expression of genes required for DNA damage, such as clk-2, cep-1, and egl-1, suggesting induction of DNA damage. Additionally, the number of cell corpses and apoptosis-related gene expression (e.g., ced-3, ced-4, and ced-9) were significantly altered, indicating induction of apoptosis. Germline apoptosis induced by aged PS-MPs was altered in egl-1, hus-1, cep-1, ced-3, ced-4, and ced-9 mutants. Thus, the reproductive toxicity of aged PS-MPs may be due to DNA damage-induced cell apoptosis, and the HUS-1-CEP-1-EGL-1-CED-9-CED-4-CED-3 signalling pathway is involved in regulating cell apoptosis in nematodes. [Display omitted] •Aged PS-MPs exposure caused more severe reproductive toxicity than virgin PS-MPs.•Reproductive toxicity may be due to cell apoptosis activated by DNA damage.•HUS-1-CEP-1-EGL-1-CED-9-CED-4-CED-3 pathway may be involved in regulating apoptosis.