Uptake of Polystyrene Nanoplastic and its Impacts on the Proteome of Salmonid cells

Abstract

Micro- and nanoplastic particles, produced from the breakdown of larger plastic debris, represent a whole new field of hazardous pollution with the potential to cause great damage on a range of marine species. This escalating concern of plastic pollution in marine environments and its consequential impacts on marine species, has emphasized the urgency for an in-depth understanding of the uptake and resultant impacts of plastic particles at both cellular and tissue levels, in aquaculture species such as Atlantic salmon (Salmo salar L.). To date, there is limited information regarding the uptake and subsequent effects of nanoplastics in salmon species, especially at cellular level. This study aimed to provide insight on the uptake of polystyrene nanoplastics (PS-NPs) and the potential responses that are activated in salmonids cells by the ingestion of these external stressors. The immortalized cell lines Atlantic Salmon Kidney cells and Salmon Head Kidney cells (ASK-1 and SHK-1), as well as Chinook Salmon (Oncorhynchus tshawytscha) Embryonic cells (CHSE-214) were exposed to nanoplastic (NP) particles embedded with fluorescent dye. The presence of the NPs within the cells was confirmed through fluorescent microscopy and DeltaVision™ deconvolution imaging, as well as a fluorescence-based flow cytometry, demonstrating their internalization by the cells. A comprehensive proteomic analysis utilizing liquid chromatography-mass spectrometry (LC-MS), revealed a diverse set of differentially expressed proteins. These proteins play crucial roles in essential cellular biological functions, including oxidative stress, apoptosis, endocytosis and immune responses, suggesting a perturbation of these biological processes by NPs in the salmonid cells. The findings from this study provided new information on the uptake and potential impact of polystyrene nanoplastic exposure on the proteomes of ASK-1, SHK-1 and CHSE-214 cells. These results will contribute to our understanding of the effects of nanoplastic exposure on fish health, and broadly provide valuable insights into the implications of nanoplastic pollution in the aquatic ecosystems.