title: Copper-induced oxidative damage to the prophenoloxidase-activating system in the freshwater crayfish Procambarus clarkii.
abstract: Previous studies have demonstrated copper-induced proteins damage in gill and hepatopancreas of the freshwater crayfish Procambarus clarkii, but little information is available about its effects on key component of the innate defense in haemolymph. In the present study, we evaluated the relationship between oxidative carbonylation and prophenoloxidase-activating system (proPO-AS) activity, by exposing P. clarkii to sub-lethal concentrations (1/50, 1/12, 1/6 and 1/3 of the 96 h LC50) Cu(2+) up to 96 h. Six biomarkers of oxidative stress, i.e. reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), protein carbonyl (PC), malondialdehyde (MDA) and DNA-protein crosslinks (DPCs), and six indicators of immune status, i.e. total hemocyte counts (THCs), differential hemocyte counts (DHCs), hemocyanin (HC), prophenoloxidase (proPO), serine protease (SP) and phenoloxidase (PO), were determined in haemolymph. The results indicated that there was a significant increase (P < 0.05) in the levels of ROS, PC, MDA and DPCs accompanied by markedly decreased (P < 0.05) activities of proPO, SP, PO and HC in a dose and time dependent manner. The significant and positive correlations (P < 0.01) between ROS production and the formation of PC, MDA and DPCs were observed in crayfish at 96 h. There was a significant negative correlation (P < 0.01) between the levels of protein carbonyls and the activities of proPO and SP in hemocyte lysate supernatant and PO and HC in haemolymph. Carbonylated proteins may be recognized not merely as a specific signal in oxidative stress pathways but also as a "non-self" molecule in proPO-AS. In crayfish species, copper-catalyzed protein carbonylation may be one of the main mechanisms for immunity dysfunction in proPO-AS.
authors.affiliation: School of Life Science, Shanxi University, Taiyuan 030006, People's Republic of China. Electronic address: kqwei88@aliyun.com.
authors.forename: Keqiang
authors.initials: K
authors.lastname: Wei
authors.affiliation: School of Economics and Management, Shanxi University, Taiyuan 030006, People's Republic of China.
authors.forename: Junxian
authors.initials: J
authors.lastname: Yang
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics / Q000378:metabolism; D003400:Astacoidea / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D004156:Catechol Oxidase / Q000235:genetics / Q000378:metabolism*; D003300:Copper / Q000633:toxicity*; D004792:Enzyme Precursors / Q000235:genetics / Q000378:metabolism*; D006458:Hemolymph / Q000737:chemistry / Q000187:drug effects; D007113:Immunity, Innate / Q000187:drug effects*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D011897:Random Allocation
chemical_list: D060829:Arthropod Proteins; D015415:Biomarkers; D004792:Enzyme Precursors; D003300:Copper; C038451:pro-phenoloxidase; D004156:Catechol Oxidase
keywords: Copper; Haemolymph; Procambarus clarkii; Prophenoloxidase; Protein carbonylation