The Key Laboratory of Aquaculture Nutrition and Feed (Ministry of Agriculture and Rural Affairs), The Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao 266237, China.
Biomolecules. 2022 Apr 30;12(5):659. doi: 10.3390/biom12050659.
Δ6 fatty acyl desaturase (Δ6Fads2) is regarded as the first rate-limiting desaturase that catalyzes the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA) from 18-carbon fatty acid in vertebrates, but the underlying regulatory mechanism of fads2 has not been comprehensively understood. This study aimed to investigate the regulation role of fads2 subjected to fatty acid in large yellow croaker and rainbow trout. In vivo, large yellow croaker and rainbow trout were fed a fish oil (FO) diet, a soybean oil (SO) diet or a linseed oil (LO) diet for 10 weeks. The results show that LO and SO can significantly increase fads2 expression (p < 0.05). In vitro experiments were conducted in HEK293T cells or primary hepatocytes to determine the transcriptional regulation of fads2. The results show that CCAAT/enhancer-binding protein α (C/EBPα) can up-regulate fads2 expression. GATA binding protein 3 (GATA3) can up-regulate fads2 expression in rainbow trout but showed opposite effect in large yellow croaker. Furthermore, C/EBPα protein levels were significantly increased by LO and SO (p < 0.05), gata3 expression was increased in rainbow trout by LO but decreased in large yellow croaker by LO and SO. In conclusion, we revealed that FO replaced by LO and SO increased fads2 expression through a C/EBPα and GATA3 dependent mechanism in large yellow croaker and rainbow trout. This study might provide critical insights into the regulatory mechanisms of fads2 expression and LC-PUFA biosynthesis.
Δ6 脂肪酸去饱和酶（Δ6Fads2）被认为是在脊椎动物中催化 18 碳脂肪酸生物合成长链多不饱和脂肪酸（LC-PUFA）的第一个限速去饱和酶，但 fad2 的潜在调控机制尚未得到全面理解。本研究旨在研究脂肪酸对大黄鱼和虹鳟中 fad2 的调控作用。在体内，大黄鱼和虹鳟分别用鱼油（FO）饲料、大豆油（SO）饲料或亚麻籽油（LO）饲料喂养 10 周。结果表明，LO 和 SO 可显著增加 fad2 表达（p＜0.05）。在 HEK293T 细胞或原代肝细胞中进行了体外实验，以确定 fad2 的转录调控。结果表明，CCAAT/增强子结合蛋白α（C/EBPα）可上调 fad2 表达。GATA 结合蛋白 3（GATA3）可上调虹鳟中 fad2 的表达，但在大黄鱼中则表现出相反的作用。此外，LO 和 SO 可显著增加 C/EBPα 蛋白水平（p＜0.05），LO 可增加虹鳟中 gata3 的表达，但 LO 和 SO 可降低大黄鱼中 gata3 的表达。总之，我们揭示了 FO 被 LO 和 SO 取代后，通过大黄鱼和虹鳟中 C/EBPα 和 GATA3 依赖的机制增加了 fad2 的表达。本研究可能为 fad2 表达和 LC-PUFA 生物合成的调控机制提供重要的见解。
