Evaluation of nanoplastics toxicity in the soil nematode Caenorhabditis elegans by iTRAQ-based quantitative proteomics

Plastic pollution is recognized as a major threat to ecosystems in the 21st century. Large plastic objects undergo biotic and abiotic degradation to generate micro- and nano-sized plastic pieces. Despite tremendous efforts to evaluate the adverse effects of microplastics, a comprehensive understanding of the toxicity of nanoplastics remains elusive, especially at the protein level. To this end, we used isobaric-tag-for-relative-and-absolute-quantitation-based quantitative proteomics to investigate the proteome dynamics of the soil nematode Caenorhabditis elegans in response to exposure to 100 nm polystyrene nanoplastics (PS-NPs). After 48 h of exposure to 0.1, 1, or 10 mg/L PS-NPs, 136 out of 1684 proteins were differentially expressed and 108 of these proteins were upregulated. These proteins were related to ribosome biogenesis, translation, proteolysis, kinases, protein processing in the endoplasmic reticulum, and energy metabolism. Remarkably, changes in proteome dynamics in response to exposure to PS-NPs were consistent with the phenotypic defects of C. elegans. Collectively, our findings demonstrate that disruption of proteome homeostasis is a biological consequence of PS-NPs accumulation in C. elegans, which provides insights into the molecular mechanisms underlying the toxicology of nanoplastics.