School of Earth, Environmental, and Marine Sciences, University of Texas Rio Grande Valley, Brownsville, TX, USA.
School of Integrative Biological and Chemical Sciences, University of Texas Rio Grande Valley, 1 West University Blvd, TX, 78520, Brownsville, USA.
Environ Sci Pollut Res Int. 2023 Sep;30(41):94757-94778. doi: 10.1007/s11356-023-28862-6. Epub 2023 Aug 4.
Aquatic organisms are frequently exposed to various environmental stressors. Thus, the effects of high temperatures and herbicides on aquatic organisms are a major subject of interest. In this study, we studied the effects of short-term exposure (1 week) to Roundup®, a glyphosate-based herbicide (concentrations: 0.5 and 5 µg/L), on the morphology of gills, digestive glands, and connective tissues, and the expression of heat shock protein-70 (HSP70, a chaperone protein), cytochrome P450 (CYP450, a biomarker of environmental contaminants), dinitrophenyl protein (DNP, a biomarker of protein oxidation), nitrotyrosine protein (NTP, a biomarker of protein nitration), antioxidant enzymes such as superoxidase dismutase (SOD) and catalase (CAT) in tissues of American oyster, Crassostrea virginica (Gmelin, 1791) maintained at high temperature (30 °C). Histological analyses showed an increase in mucous production in the gills and digestive glands, and in hemocyte aggregation in the connective tissues as well as a structural change of lumen in the digestive glands of oysters exposed to Roundup. Immunohistochemical and quantitative RT-PCR analyses showed significant (P < 0.05) increases in HSP70, CYP450, DNP, NTP, CAT, and SOD mRNA and protein expressions in the tissues of oysters exposed to Roundup. Taken together, these results suggest that exposure to Roundup at high temperature induces overproduction of reactive oxygen species/reactive nitrogen species which in turn leads to altered prooxidant-antioxidant activity in oyster tissues. Moreover, our results provide new information on protein oxidation/nitration and antioxidant-dependent mechanisms for HSP70 and CYP450 regulations in oysters exposed to Roundup at high temperature.
水生生物经常暴露于各种环境胁迫因子中。因此，高温和除草剂对水生生物的影响是一个主要的研究课题。在本研究中，我们研究了暴露于农达（一种草甘膦为基础的除草剂，浓度：0.5 和 5μg/L）中 1 周对美洲牡蛎（Crassostrea virginica）鳃、消化腺和结缔组织形态以及热休克蛋白 70（HSP70，伴侣蛋白）、细胞色素 P450（CYP450，环境污染物生物标志物）、二硝基苯蛋白（DNP，蛋白质氧化的生物标志物）、硝基酪氨酸蛋白（NTP，蛋白质硝化的生物标志物）和抗氧化酶（超氧化物歧化酶 SOD 和过氧化氢酶 CAT）表达的影响，这些酶在高温（30°C）下的组织中。组织学分析显示，暴露于农达的牡蛎鳃和消化腺中粘液分泌增加，结缔组织中血细胞聚集，消化腺管腔结构发生变化。免疫组织化学和定量 RT-PCR 分析显示，暴露于农达的牡蛎组织中 HSP70、CYP450、DNP、NTP、CAT 和 SOD mRNA 和蛋白表达显著增加（P<0.05）。这些结果表明，高温下暴露于农达会导致活性氧/活性氮的过度产生，进而导致牡蛎组织中氧化应激和抗氧化活性的改变。此外，我们的结果为高温下暴露于农达的牡蛎中 HSP70 和 CYP450 调控的蛋白质氧化/硝化和抗氧化依赖机制提供了新的信息。
