Fish Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain.
Fish Shellfish Immunol. 2013 Mar;34(3):843-8. doi: 10.1016/j.fsi.2012.12.026. Epub 2013 Jan 11.
The present work describes effects of dietary inulin, two microalgae (Tetraselmis chuii and Phaeodactylum tricornutum) and Bacillus subtilis (solely or combined with inulin or microalgae) on the expression of different genes in the intestine of the gilthead seabream (Sparus aurata L.) following four weeks of a feeding trial. Selected genes were grouped into five categories: genes involved in inflammation (genes encoding proinflammatory proteins), genes related to the cytoskeleton, genes encoding proteins of junction complexes, genes implicated in digestion processes and genes related to transport proteins. Regarding proinflammatory genes, interleukin-8 (IL-8) expression showed a significant increase in the fish fed all the assayed diets, except the B. subtilis + inulin diet, whereas the expression of caspase-1 (CASP-1) was also increased by the B. subtilis and B. subtilis + T. chuii diets. Cyclooxygenase-2 (COX-2) gene expression only increased in fish fed the B. subtilis diet. Among cytoskeletal and junctional genes, only β-actin and occludin were significantly affected by the assayed diets. β-actin expression was up-regulated by the inulin-containing diets (inulin and B. subtilis + inulin diets), whereas occludin expression increased in the fish fed all the assayed diets, except the P. tricornutum diet. Finally, the expression of transport protein genes demonstrated that the inulin diet and all the experimental diets containing B. subtilis significantly increased transferrin expression, whereas digestive enzymes were not affected by the experimental diets. In conclusion, our results demonstrated that inulin, B. subtilis and microalgae can modulate intestinal gene expression in the gilthead seabream. To our knowledge, this is the first study of the effects of some food additives on the intestinal expression of different genes in this species. More studies are needed to understand the role of these genes in maintaining the integrity and functionality of the intestine.
本研究描述了在为期四周的饲养试验后，菊粉、两种微藻（钝顶螺旋藻和三角褐指藻）和枯草芽孢杆菌（单独或与菊粉或微藻联合）对金头鲷肠道中不同基因表达的影响。所选基因分为五类：参与炎症的基因（编码促炎蛋白的基因）、与细胞骨架相关的基因、编码连接复合体蛋白的基因、参与消化过程的基因和与转运蛋白相关的基因。关于促炎基因，除了枯草芽孢杆菌+菊粉组外，所有试验组均显著增加了白细胞介素-8（IL-8）的表达，而枯草芽孢杆菌和枯草芽孢杆菌+钝顶螺旋藻组还增加了半胱天冬酶-1（CASP-1）的表达。环氧化酶-2（COX-2）基因的表达仅在枯草芽孢杆菌组中增加。在细胞骨架和连接基因中，只有β-肌动蛋白和紧密连接蛋白受到试验组的显著影响。β-肌动蛋白的表达在含有菊粉的饮食（菊粉和枯草芽孢杆菌+菊粉饮食）中上调，而紧密连接蛋白的表达在所有试验组中都增加，除了三角褐指藻饮食组。最后，转运蛋白基因的表达表明，菊粉饮食和所有含有枯草芽孢杆菌的试验饮食均显著增加了转铁蛋白的表达，而消化酶不受试验饮食的影响。总之，我们的研究结果表明，菊粉、枯草芽孢杆菌和微藻可以调节金头鲷肠道基因的表达。据我们所知，这是首次研究一些食品添加剂对该物种肠道中不同基因表达的影响。需要更多的研究来了解这些基因在维持肠道完整性和功能中的作用。
