Piazza Rômi S, Trevisan Rafael, Flores-Nunes Fabrício, Toledo-Silva Guilherme, Wendt Nestor, Mattos Jacó J, Lima Daína, Taniguchi Satie, Sasaki Silvio Tarou, Mello Álvaro C P, Zacchi Flávia L, Serrano Miguel A S, Gomes Carlos H A M, Bícego Márcia C, Almeida Eduardo A de, Bainy Afonso C D
Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry, Department of Biochemistry, Federal University of Santa Catarina, UFSC, Florianópolis, SC, Brazil.
Aquaculture Pathology Research Center - NEPAQ, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
Aquat Toxicol. 2016 Aug;177:146-55. doi: 10.1016/j.aquatox.2016.05.025. Epub 2016 May 26.
Understanding the mechanism of phenanthrene (PHE) biotransformation and related cellular responses in bivalves can be an important tool to elucidate the risks of polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms. In the present study it was analyzed the transcriptional levels of 13 biotransformation genes related to cytochrome P450 (CYP), glutathione S-transferase (GST), sulfotransferase (SULT), flavin-containing monooxygenase and fatty acid-binding proteins by qPCR in gill of scallops Nodipecten nodosus exposed for 24 or 96h to 50 or 200μgL(-1) PHE (equivalent to 0.28 and 1.12μM, respectively), followed by depuration in clean water for 96h (DEP). Likewise, it was quantified the activity of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione reductase (GR), glucose 6-phosphate dehydrogenase (G6PDH), GST and levels of lipid peroxidation. Increased transcriptional levels of CYP2UI-like, CYP2D20-like, CYP3A11-like, GSTomega-like, SULT1B1-like genes were detected in organisms exposed to PHE for 24 or 96h. In parallel, GR and GPX activities increased after 96h exposure to 200μgL(-1) PHE and G6PDH activity increased after 24h exposure to 50μgL(-1) PHE. This enhancement of antioxidant and phase I and II biotransformation systems may be related to the 2.7 and 12.5 fold increases in PHE bioaccumulation after 96h exposure to 50 and 200μgL(-1) PHE, respectively. Interestingly, DEP caused reestablishment of GPX and GR activity, as well as to the transcript levels of all upregulated biotransformation genes (except for SULT1B1-like). Bioaccumulated PHE levels decreased 2.5-2.9 fold after depuration, although some biochemical and molecular modifications were still present. Lipid peroxidation levels remained lower in animals exposed to 200μgL(-1) PHE for 24h and DEP. These data indicate that N. nodosus is able to induce an antioxidant and biotransformation-related response to PHE exposure, counteracting its toxicity, and DEP can be an effective protocol for bivalve depuration after PHE exposure.
了解菲（PHE）在双壳贝类中的生物转化机制及相关细胞反应，可能是阐明多环芳烃（PAHs）对水生生物风险的重要工具。在本研究中，通过qPCR分析了栉孔扇贝（Nodipecten nodosus）鳃中13个与细胞色素P450（CYP）、谷胱甘肽S-转移酶（GST）、磺基转移酶（SULT）、含黄素单加氧酶和脂肪酸结合蛋白相关的生物转化基因的转录水平，这些扇贝暴露于50或200μg L⁻¹的PHE（分别相当于0.28和1.12μM）中24或96小时，然后在清洁水中净化96小时（DEP）。同样，对过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）、超氧化物歧化酶（SOD）、谷胱甘肽还原酶（GR）、葡萄糖6-磷酸脱氢酶（G6PDH）、GST的活性以及脂质过氧化水平进行了定量分析。在暴露于PHE 24或96小时的生物体中，检测到CYP2UI样、CYP2D20样、CYP3A11样、GSTomega样、SULT1B1样基因的转录水平升高。同时，在暴露于200μg L⁻¹的PHE 96小时后，GR和GPX活性增加，在暴露于50μg L⁻¹的PHE 24小时后，G6PDH活性增加。抗氧化以及I相和II相生物转化系统的这种增强，可能分别与暴露于50和200μg L⁻¹的PHE 96小时后PHE生物积累增加2.7倍和12.5倍有关。有趣的是，DEP导致GPX和GR活性恢复，以及所有上调的生物转化基因（除SULT1B1样外）的转录水平恢复。净化后，生物积累的PHE水平下降了2.5 - 2.9倍，尽管仍存在一些生化和分子修饰。在暴露于200μg L⁻¹的PHE 24小时及DEP后的动物中，脂质过氧化水平仍然较低。这些数据表明，栉孔扇贝能够对PHE暴露诱导抗氧化和生物转化相关反应，抵消其毒性，并且DEP可能是PHE暴露后双壳贝类净化的有效方案。
