You are here:
Effects of micro- and nano-scale plastic exposures in blue mussels, Mytilus edulis
Citation:
Khan, B., M. Zahra, B. Holohan, E. Ward, A. Adeleye, T. Langknecht, R. Burgess, AND K. Ho. Effects of micro- and nano-scale plastic exposures in blue mussels, Mytilus edulis. SETAC North America, 43rd Annual Meeting, Pittsburgh, PA, November 13 - 17, 2022.
Impact/Purpose:
Plastic production, use and missue has soared in the last 40 years. Breakdown of plastic waste results in microplastic particles (<5mm). Small microplastics (< 10 um) and nanoplastics (< 1 um) are the most common, and understudied portions of microplastics. This presentation focuses on the effects of small microplastics and nanoplastics on an ecologically and economically important species, the blue mussel. Using cutting edge endpoints such as metabolomics and biomarkers, these results indicate that small micro and nanoplastics affect cellular antioxidant reactions, redox status and energy metabolism of mussels. Understanding these results can help us understand how changes in energy homeostais affect adverse outcomes at the organims level.
Description:
Plastic production and usage have increased dramatically over last several decades. Due to their durability, inadequate waste management and resistance to degradation, plastics tend to accumulate in landfills and aquatic habitats. Upon entering marine ecosystems, these contaminants can further break into micro- and nano-scale particles which can adversely affect resident biota. Due to their surface properties and small size, plastic particles can lead to cellular damage. Micro- and nano-scale plastics (MP and NP, respectively) can be internalized by suspension-feeding bivalves such as the blue mussel, Mytilus edulis. Here, we present results from a 14-day static renewal study with blue mussels exposed to micro- and nano-scale polystyrene (3 µm and 50 nm, respectively). Effects in gill and digestive gland tissues were evaluated using biochemical and metabolomic approaches. Biochemical assays included assessments of the ratio of oxidized and reduced glutathione, lipid peroxidation and total protein levels. Additionally, significant metabolites and affected pathways were identified using metabolomic analyses. Our results show the key effects of MP and NP exposures are on cellular antioxidant machinery and redox status. Energy metabolism was also impacted by exposures representing shifts in energy demands of detoxification processes. Metabolites related to immune function and inflammatory pathways were also affected likely due to particle-induced cellular injury. Overall, digestive gland tissues of NP-exposed mussels showed the most changes in cellular machinery. These results also indicate plastic particle exposures can result in the generation of reactive oxygen species (ROS) that are involved in several antioxidant and inflammatory signaling cascades. Further investigations are warranted into the effects of MP and NP exposures on the interactions between ROS, antioxidant responses and immune pathways. These molecular and cellular interactions between signaling cascades can also help us understand changes in energy homeostasis affecting adverse outcomes at individual levels.
