Benítez-Dorta Vanessa, Caballero María J, Betancor Mónica B, Manchado Manuel, Tort Lluis, Torrecillas Silvia, Zamorano María J, Izquierdo Marisol, Montero Daniel
Grupo de Investigación en Acuicultura (GIA), Instituto Ecoaqua, Universidad de Las Palmas de Gran Canaria, Parque científico Tecnológico Marino, Carretera de Taliarte s/n. Telde, Las Palmas, Canary Islands, Spain.
Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
Gen Comp Endocrinol. 2017 Oct 1;252:173-185. doi: 10.1016/j.ygcen.2017.06.022. Epub 2017 Jun 23.
The present study examined the short and mid-term effects of a rise in temperature from 18°C to 24°C on the expression of genes related to the stress response regulation in juveniles of Senegalese sole, Solea senegalensis. The animals were exposed to a temperature increase of 6°C, after 1month of acclimation at 18°C. After this process, samples of different tissues were collected from a total of 96 fish at four sampling points: 1h, 24h, 3days and 1week. The transcript levels of a set of genes involved in the stress response such as glucocorticoid receptors 1 and 2, corticotrophin-releasing factor, corticotrophin-releasing factor binding proteins, proopiomelanocortin A and B, and cellular stress defense (heat shock protein 70, 90AA and 90AB) were quantified at these sampling points. Additionally, blood samples were also taken to measure the circulating plasma cortisol concentration. Thermal stress induced by increasing temperature prompted an elevation of plasma cortisol levels in juvenile Senegalese sole after 1h as a short-term response, and a consecutive increase after one week, as a mid-term response. Senegalese sole seemed to respond positively in terms of adaptive mechanisms, with a rapid over-expression of grs and hsps in liver and brain, significantly higher after one hour post stress, denoting the fast and acute response of those tissues to a rapid change on temperature. The ratio hsp90/gr also increased 24h after thermal shock, ratio proposed to be an adaptive mechanism to prevent proteosomal degradation of GR. As a mid-term response, the elevation of brain crfbp gene expression one week after thermal shock could be an adaptive mechanism of negative feedback on HPI axis. Taken together, these data suggested an initial up-regulation of the glucocorticoid receptor complex linked genes in response to a temperature increase in Senegalese sole, with heat shock protein 90 potentially being a regulatory factor for the glucocorticoid receptor in the presence of cortisol.
本研究考察了温度从18°C升高到24°C对塞内加尔鳎（Solea senegalensis）幼鱼应激反应调节相关基因表达的短期和中期影响。在18°C下适应1个月后，使动物暴露于6°C的温度升高环境中。在此过程之后，在四个采样点从总共96条鱼中收集不同组织的样本：1小时、24小时、3天和1周。在这些采样点对一组参与应激反应的基因的转录水平进行了定量，这些基因包括糖皮质激素受体1和2、促肾上腺皮质激素释放因子、促肾上腺皮质激素释放因子结合蛋白、阿黑皮素原A和B，以及细胞应激防御（热休克蛋白70、90AA和90AB）。此外，还采集了血样以测量循环血浆皮质醇浓度。温度升高引起的热应激促使塞内加尔鳎幼鱼在1小时后血浆皮质醇水平升高作为短期反应，并在1周后持续增加作为中期反应。塞内加尔鳎在适应机制方面似乎有积极反应，肝脏和大脑中的糖皮质激素受体和热休克蛋白迅速过度表达，在应激后1小时显著更高，表明这些组织对温度快速变化的快速和急性反应。热休克后24小时热休克蛋白90/糖皮质激素受体的比率也增加，该比率被认为是防止糖皮质激素受体蛋白体降解的一种适应机制。作为中期反应，热休克1周后大脑促肾上腺皮质激素释放因子结合蛋白基因表达的升高可能是下丘脑-垂体-肾上腺轴负反馈的一种适应机制。综上所述，这些数据表明，塞内加尔鳎在温度升高时，糖皮质激素受体复合物相关基因最初会上调，在存在皮质醇的情况下，热休克蛋白90可能是糖皮质激素受体的调节因子。
