LC-PUFA对草鱼脂肪细胞活性氧(ROS)平衡的影响及机制研究

ROS is not only a cytotoxin but also a key signal molecules in animal cells, it plays crucial roles in the development, differentiation, pathogenesis and apoptosis of adipocytes. In the basis of the reduction of the body's lipid accumulation which induced by the Long-chain unsaturated fatty acid (LC-PUFA), we will use the grass carp （Ctenopharyngodon idellus）,an important commercial species of cyprinid, as the animal model in this project. Cell culture, RNA interference, Real-time PCR, Western blot, as well as some traditional nutrition methods will be applied in virto and in vivo. The aim of this project is investigating the effects of different types and contents of LC-PUFA (EPA & DHA) on the ROS balance of adipocytes. The genes and proteins which relate to ROS production and elimination will be examined. They include NADPH oxidase, UCPs, Nrf2/ARE, and the families of antioxidases. Through those indicators examined, we may be able to define the specific pathways affecting ROS balance under the exposure of different types and concentration of LC-PUFA and integrate the results into a systemic theory. The results obtained from the project may provide new thoughts and foundation for the principle and technique of lipid metabolism controlling in freshwater fish, and thus has great significance in the theory and application.

活性氧既有细胞毒效应又是重要的信号分子，在脂肪细胞的发育、分化、病变和凋亡过程中均发挥重要作用。基于长链多不饱和脂肪酸(LC-PUFA)可降低动物机体脂质蓄积的现象，本项目拟以我国重要淡水经济鱼类草鱼(Ctenopharyngodon idellus)为试验材料，采用离体细胞培养与在体饲喂、RNA干扰、流式细胞术、实时定量PCR和Western blot等细胞和分子生物学技术，研究LC-PUFA对草鱼脂肪细胞活性氧平衡的影响，并通过检测NADPH氧化酶、线粒体呼吸相关蛋白、Nrf2/ARE相关蛋白以及抗氧化酶等相关指标的变化情况，明确LC-PUFA影响ROS平衡的具体途径，深入探讨ROS平衡变化过程中ROS产生和清除通路上发生的分子事件，系统分析其作用机制。研究结果将为淡水鱼脂质代谢调控原理及技术研究提供新的思路和研究依据，具有较大的理论和应用价值。

活性氧既有细胞毒效应又是重要的信号分子，在脂肪细胞的发育、分化、病变和凋亡过程中均发挥重要作用。基于长链多不饱和脂肪酸(LC-PUFA)可降低动物机体脂质蓄积的现象，本项目以我国重要淡水经济鱼类草鱼(Ctenopharyngodon idellus)为试验材料，采用离体细胞培养、流式细胞术、实时定量PCR和ROS荧光探针检测等细胞和分子生物学技术，研究了DHA对草鱼脂肪细胞活性氧平衡的影响，结果发现DHA能够以剂量依赖的方式影响草鱼脂肪细胞ROS，当DHA浓度超过200 μM会显著提高草鱼脂肪细胞ROS的含量，这些ROS部分来自于NADPH氧化酶，但是随着DHA浓度的升高，线粒体产生的ROS逐渐占据了更大比例；DHA诱导产生的ROS大部分是超氧阴离子。在DHA诱导活性氧产生的过程中，抗氧化系统调控的核心基因Nrf2的表达也随之上调。研究结果将为淡水鱼脂质代谢调控原理及技术研究提供新的思路和研究依据，具有较大的理论和应用价值。