title: Hemocyte responses of the thick shell mussel Mytilus coruscus exposed to nano-TiO2and seawater acidification.
abstract: With increasing production from nanotechnology industries, nanomaterials are inevitably released into the aquatic environment, thereby posing a potential risk to aquatic organisms. Thus, concerns have been raised on the potential ecotoxicological effect of nanoparticle. Furthermore, the ecotoxicological consequences caused by the interaction of nanoparticles with other environmental stresses, such as seawater acidification on marine animals, have not been evaluated. In particular, whether acidification enhances the susceptibility to nanoparticles in bivalves needs to be evaluated. In the present study, we investigated the combined effects of low pH and nanoscale titanium dioxide (nano-TiO2) on some immune parameters of hemocytes in the mussel Mytilus coruscus by flow cytometry under six combinations of two pH values (7.3 and 8.1) and three nano-TiO2concentrations (0, 2.5, and 10mgL-1) for 14 d. Afterward, the mussels were shifted to normal conditions without nano-TiO2at pH 8.1 for 7 d further to test their recovery from the multiple stresses. Total hemocyte count (THC), phagocytosis (Pha), esterase (Est), and lysosomal content (Lyso) decreased under low pH and high nano-TiO2concentration conditions, whereas hemocyte mortality (HM) and reactive oxygen species (ROS) increased with nano-TiO2concentrations under low pH conditions. The interactive effects between pH and nano-TiO2were observed at the latter part of the exposure experiment (7 and 14 d) in most hemocyte parameters. Nano-TiO2influenced the immune functions of mussel more severely than low pH. Slight recovery from the combined stresses was observed for HM, THC, Pha, and Lyso, but significant carry-over effects of nano-TiO2and low pH were still observed. This study demonstrated that both low pH and high concentration of nano-TiO2had negative effects on mussels, and these effects still acted for some time even though the mussels were already out of such stressors.
authors.affiliation: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China. Electronic address: 841685724@qq.com.
authors.forename: Xizhi
authors.initials: X
authors.lastname: Huang
authors.affiliation: Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China. Electronic address: lindaohui@zju.edu.cn.
authors.forename: Daohui
authors.initials: D
authors.lastname: Lin
authors.affiliation: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Ning
authors.affiliation: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Sui
authors.affiliation: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China; The Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China.
authors.forename: Menghong
authors.initials: M
authors.lastname: Hu
authors.affiliation: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China; The Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China.
authors.forename: Weiqun
authors.initials: W
authors.lastname: Lu
authors.affiliation: College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou 310058, China; The Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai 201306, China. Electronic address: yj_wang@shou.edu.cn.
authors.forename: Youji
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D006434:Hemocytes / Q000187:drug effects* / Q000276:immunology; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000633:toxicity*; D049878:Mytilus / Q000187:drug effects* / Q000276:immunology; D011897:Random Allocation; D012623:Seawater / Q000737:chemistry*; D013312:Stress, Physiological / Q000502:physiology; D014025:Titanium / Q000633:toxicity*; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium
keywords: Acidification; Flow cytometry; Hemocyte; Immune response; Mytilus coruscus; Nano-TiO(2)