Dipartimento di Scienze della Vita e dell'Ambiente (DiSVA), Università Politecnica delle Marche, Ancona, Italy.
Dipartimento di Scienze della Vita e dell'Ambiente (DiSVA), Università Politecnica delle Marche, Ancona, Italy; CoNISMa, Consorzio Interuniversitario per le Scienze del Mare, Roma, Italy.
Chemosphere. 2017 Feb;169:493-502. doi: 10.1016/j.chemosphere.2016.11.093. Epub 2016 Nov 25.
Despite the great interest in the consequences of climate change on the physiological functioning of marine organisms, indirect and interactive effects of rising temperature and pCO on bioaccumulation and responsiveness to environmental pollutants are still poorly explored, particularly in terms of cellular mechanisms. According to future projections of temperature and pH/pCO, this study investigated the main cellular pathways involved in metal detoxification and oxidative homeostasis in Mediterranean mussels, Mytilus galloprovincialis, exposed for 4 weeks to various combinations of two levels of pH/pCO (8.2/∼400 μatm and 7.4/∼3000 μatm), temperature (20 and 25 °C), and cadmium addition (0 and 20 μg/L). Bioaccumulation was increased in metal exposed organisms but it was not further modulated by different temperature and pH/pCO combinations. However, interactions between temperature, pH and cadmium had significant effects on induction of metallothioneins, responses of the antioxidant system and the onset of oxidative damages, which was tissue dependent. Multiple stressors increased metallothioneins concentrations in the digestive gland revealing different oxidative effects: while temperature and cadmium enhanced glutathione-dependent antioxidant protection and capability to neutralize peroxyl radicals, the metal increased the accumulation of lipid peroxidation products under acidified conditions. Gills did not reveal specific effects for different combinations of factors, but a general stress condition was observed in this tissue after various treatments. Significant variations of immune system were mainly caused by increased temperature and low pH, while co-exposure to acidification and cadmium enhanced metal genotoxicity and the onset of permanent DNA damage in haemocytes. Elaboration of the whole biomarker data in a cellular hazard index, corroborated the synergistic effects of temperature and acidification which increased the toxicological effects of cadmium. The overall results confirmed that climate change could influence ecotoxicological effects of environmental contaminants, highlighting the importance of a better knowledge of cellular mechanisms to understand and predict responsiveness of marine organisms to such multiple stressors.
尽管人们对气候变化对海洋生物生理功能的影响非常感兴趣，但对于温度和 pCO2 升高对生物蓄积和对环境污染物响应的间接和交互影响，特别是在细胞机制方面，仍研究甚少。根据对温度和 pH 值/pCO2 的未来预测，本研究调查了地中海贻贝（Mytilus galloprovincialis）中参与金属解毒和氧化平衡的主要细胞途径，该贻贝在 4 周内暴露于两种 pH 值/pCO2（8.2/∼400 μatm 和 7.4/∼3000 μatm）、温度（20 和 25°C）和镉添加（0 和 20 μg/L）的不同组合中。暴露于金属的生物体内的生物蓄积增加，但不同的温度和 pH 值/pCO2 组合并未进一步调节生物蓄积。然而，温度、pH 值和镉之间的相互作用对金属硫蛋白的诱导、抗氧化系统的响应和氧化损伤的发生有显著影响，这与组织有关。多胁迫因素增加了消化腺中金属硫蛋白的浓度，揭示了不同的氧化效应：虽然温度和镉增强了谷胱甘肽依赖的抗氧化保护和中和过氧自由基的能力，但在酸化条件下，金属增加了脂质过氧化产物的积累。鳃在不同因素组合下没有表现出特定的效应，但在各种处理后，该组织表现出一般的应激状态。免疫系统的显著变化主要是由温度升高和 pH 值降低引起的，而酸化和镉的共同暴露则增强了血细胞的金属遗传毒性和永久性 DNA 损伤的发生。在细胞危害指数中对整个生物标志物数据的详细分析，证实了温度和酸化的协同作用增加了镉的毒性效应。总体结果证实，气候变化可能会影响环境污染物的生态毒理学效应，强调了更好地了解细胞机制对于理解和预测海洋生物对这些多种胁迫因素的响应的重要性。
