title: The role of Cu/Zn-SOD and Mn-SOD in the immune response to oxidative stress and pathogen challenge in the clam Meretrix meretrix.
abstract: The copper/zinc superoxide dismutase (Cu/Zn-SOD) and manganese superoxide dismutase (Mn-SOD) could effectively eliminate reactive oxygen species (ROS) and maintain the redox balance of immune system. In the present study, the potential synergy of Cu/Zn-SOD and Mn-SOD in immune system was investigated in the clam Meretrix meretrix. The expression of Cu/Zn-SOD mainly distributed in hepatopancreas and that of Mn-SOD was higher in gill of M. meretrix, and their mRNA and protein activity paralleled with each other. In response to H2O2 challenge, Cu/Zn-SOD mRNA showed significantly higher level at 24 h post-challenge and Mn-SOD mRNA was significantly higher at 12 and 24 h post-challenge in the experimental clams than in the control clams (P<0.05). After injection with Vibrio-parahaemolyticus-related bacterium (MM21), the Cu/Zn-SOD mRNA was significantly up-regulated at 24 h and 48 h post-injection and Mn-SOD mRNA was significantly higher at 24 h post-injection in MM21-injected clams than in control clams (P<0.05), suggesting that both of them might involve in the immune defense to Vibrio challenge. The mRNA expression of Cu/Zn-SOD and Mn-SOD was examined in a Vibrio-resistant population and a control population after MM21 immersion challenge. The increased transcription of Cu/Zn-SOD and Mn-SOD in the resistant population suggested both of them could benefit the immune system to defend against pathogen infection. As expression of Mn-SOD mRNA depended on stimuli and was more easily inducible, its response to H2O2 and Vibrio challenge was earlier than Cu/Zn-SOD. Our study suggested the redox balance might play an important role in M. meretrix to resist pathogen infection.
authors.affiliation: Key Laboratory of Sustainable Utilization of Marine Fisheries Resources, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Lu
authors.affiliation: Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: bzliu@qdio.ac.cn.
authors.forename: Baozhong
authors.initials: B
authors.lastname: Liu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D049872:Bivalvia / Q000201:enzymology* / Q000276:immunology / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D020869:Gene Expression Profiling; D043143:Hepatopancreas / Q000378:metabolism; D006861:Hydrogen Peroxide; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000276:immunology*; D013482:Superoxide Dismutase / Q000276:immunology* / Q000378:metabolism; D014736:Vibrio parahaemolyticus / Q000276:immunology*
chemical_list: D017931:DNA Primers; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase
keywords: Cu/Zn-SOD; Meretrix meretrix; Mn-SOD; Oxidative stress; Vibrio