title: Microplastic Size-Dependent Toxicity, Oxidative Stress Induction, and p-JNK and p-p38 Activation in the Monogonont Rotifer (Brachionus koreanus).
abstract: In this study, we evaluated accumulation and adverse effects of ingestion of microplastics in the monogonont rotifer (Brachionus koreanus). The dependence of microplastic toxicity on particle size was investigated by measuring several in vivo end points and studying the ingestion and egestion using 0.05-, 0.5-, and 6-μm nonfunctionalized polystyrene microbeads. To identify the defense mechanisms activated in response to microplastic exposure, the activities of several antioxidant-related enzymes and the phosphorylation status of mitogen-activated protein kinases (MAPKs) were determined. Exposure to polystyrene microbeads of all sizes led to significant size-dependent effects, including reduced growth rate, reduced fecundity, decreased lifespan and longer reproduction time. Rotifers exposed to 6-μm fluorescently labeled microbeads exhibited almost no fluorescence after 24 h, while rotifers exposed to 0.05- and 0.5-μm fluorescently labeled microbeads displayed fluorescence until 48 h, suggesting that 6-μm microbeads are more effectively egested from B. koreanus than 0.05- or 0.5-μm microbeads. This observation provides a potential explanation for our findings that microbead toxicity was size-dependent and smaller microbeads were more toxic. In vitro tests revealed that antioxidant-related enzymes and MAPK signaling pathways were significantly activated in response to microplastic exposure in a size-dependent manner.
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University , Suwon 16419, South Korea.|Department of Chemistry, College of Natural Sciences, Hanyang University , Seoul 04763, South Korea.
authors.forename: Chang-Bum
authors.initials: CB
authors.lastname: Jeong
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University , Suwon 16419, South Korea.|Marine Chemistry and Geochemistry Research Center, Korea Institute of Ocean Science and Technology , Ansan 15627, South Korea.
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Won
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University , Suwon 16419, South Korea.
authors.forename: Hye-Min
authors.initials: HM
authors.lastname: Kang
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University , Suwon 16419, South Korea.
authors.forename: Min-Chul
authors.initials: MC
authors.lastname: Lee
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University , Suwon 16419, South Korea.
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Hwang
authors.affiliation: Marine Ecological Risk Assessment Center, West Sea Fisheries Research Institute, National Fisheries Research & Development Institute, Incheon 46083, South Korea.
authors.forename: Un-Ki
authors.initials: UK
authors.lastname: Hwang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan 430072, China.
authors.forename: Bingsheng
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Université de Lille, CNRS, Université Littoral Cote d'Opale , UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, F 62930 Wimereux, France.
authors.forename: Sami
authors.initials: S
authors.lastname: Souissi
authors.affiliation: Department of Life Sciences, College of Natural Sciences, Hanyang University , Seoul 04763, South Korea.
authors.forename: Su-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Biological Science, College of Science, Sungkyunkwan University , Suwon 16419, South Korea.
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018384:Oxidative Stress; D012403:Rotifera / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D020928:Mitogen-Activated Protein Kinases