title: UV-B radiation-induced oxidative stress and p38 signaling pathway involvement in the benthic copepod Tigriopus japonicus.
abstract: Ultraviolet B (UV-B) radiation presents an environmental hazard to aquatic organisms. To understand the molecular responses of the intertidal copepod Tigriopus japonicus to UV-B radiation, we measured the acute toxicity response to 96 h of UV-B radiation, and we also assessed the intracellular reactive oxygen species (ROS) levels, glutathione (GSH) content, and antioxidant enzyme (GST, GR, GPx, and SOD) activities after 24 h of exposure to UV-B with LD50 and half LD50 values. Also, expression patterns of p53 and hsp gene families with phosphorylation of p38 MAPK were investigated in UV-B-exposed copepods. We found that the ROS level, GSH content, and antioxidant enzyme activity levels were increased with the transcriptional upregulation of antioxidant-related genes, indicating that UV-B induces oxidative stress by generating ROS and stimulating antioxidant enzymatic activity as a defense mechanism. Additionally, we found that p53 expression was significantly increased after UV-B irradiation due to increases in the phosphorylation of the stress-responsive p38 MAPK, indicating that UV-B may be responsible for inducing DNA damage in T. japonicus. Of the hsp family genes, transcriptional levels of hsp20, hsp20.7, hsp70, and hsp90 were elevated in response to a low dose of UV-B radiation (9 kJ m(-2)), suggesting that these hsp genes may be involved in cellular protection against UV-B radiation. In this paper, we performed a pathway-oriented mechanistic analysis in response to UV-B radiation, and this analysis provides a better understanding of the effects of UV-B in the intertidal benthic copepod T. japonicus.
authors.affiliation: Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Bo-Mi
authors.initials: BM
authors.lastname: Kim
authors.affiliation: Department of Marine Science, College of Natural Sciences, Incheon National University, Incheon 406-772, South Korea.
authors.forename: Jae-Sung
authors.initials: JS
authors.lastname: Rhee
authors.affiliation: Pacific Ocean Research Center, Korea Institute of Ocean Science and Technology, Ansan 426-744, South Korea.
authors.forename: Kyun-Woo
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Marine Sciences and Convergent Technology, College of Science and Technology, Hanyang University, Ansan 426-791, South Korea.
authors.forename: Kyung-Hoon
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Su-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 110-743, South Korea. Electronic address: ymlee70@smu.ac.kr.
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Lee
authors.affiliation: Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea. Electronic address: jslee2@skku.edu.
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000818:Animals; D033342:Copepoda / Q000378:metabolism* / Q000528:radiation effects*; D005786:Gene Expression Regulation / Q000528:radiation effects; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D007928:Lethal Dose 50; D020935:MAP Kinase Signaling System / Q000502:physiology / Q000528:radiation effects*; D018384:Oxidative Stress / Q000528:radiation effects*; D040081:Protein Array Analysis; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome; D014466:Ultraviolet Rays
chemical_list: D017382:Reactive Oxygen Species; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D005978:Glutathione
keywords: Copepod; Heat shock protein; Oxidative stress; Tigriopus japonicus; UV-B; p38 MAPK; p53