Systemic adaptation of lipid metabolism in response to low‐ and high‐fat diet in Nile tilapia (Oreochromis niloticus)

• Published in: Physiological reports Vol. 3; no. 8; pp. e12485 - n/a
• Main Authors: He, An‐Yuan, Ning, Li‐Jun, Chen, Li‐Qiao, Chen, Ya‐Li, Xing, Qi, Li, Jia‐Min, Qiao, Fang, Li, Dong‐Liang, Zhang, Mei‐Ling, Du, Zhen‐Yu
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.08.2015; John Wiley & Sons, Ltd
• Subjects: Adaptation; Adipocytes; Adipose tissue; Biosynthesis; Carbohydrates; Diet; Dietary lipid level; Energy; Fatty acids; Feeding; Fish; Food; Glycolysis; Growth rate; High fat diet; Homeostasis; lipid homeostasis; Lipid metabolism; Lipids; Liver; Low fat diet; Mammals; Metabolic syndrome; Metabolites; Natural selection; Nile tilapia; Nutrient deficiency; Nutrition research; Oreochromis niloticus; Original Research; Physiology; Proteins; Studies; Tilapia; triglyceride; Western blotting; triglyceride; lipid homeostasis; Nile tilapia; Dietary lipid level; lipid metabolism
• ISSN: 2051-817X; 2051-817X
• DOI: 10.14814/phy2.12485

Natural selection endows animals with the abilities to store lipid when food is abundant and to synthesize lipid when it is limited. However, the relevant adaptive strategy of lipid metabolism has not been clearly elucidated in fish. This study examined the systemic metabolic strategies of Nile tilapia to maintain lipid homeostasis when fed with low‐ or high‐fat diets. Three diets with different lipid contents (1%, 7%, and 13%) were formulated and fed to tilapias for 10 weeks. At the end of the feeding trial, the growth rate, hepatic somatic index, and the triglyceride (TG) contents of serum, liver, muscle, and adipose tissue were comparable among three groups, whereas the total body lipid contents and the mass of adipose tissue increased with the increased dietary lipid levels. Overall quantitative PCR, western blotting and transcriptomic assays indicated that the liver was the primary responding organ to low‐fat (LF) diet feeding, and the elevated glycolysis and accelerated biosynthesis of fatty acids (FA) in the liver is likely to be the main strategies of tilapia toward LF intake. In contrast, excess ingested lipid was preferentially stored in adipose tissue through increasing the capability of FA uptake and TG synthesis. Increasing numbers, but not enlarging size, of adipocytes may be the main strategy of Nile tilapia responding to continuous high‐fat (HF) diet feeding. This is the first study illuminating the systemic adaptation of lipid metabolism responding to LF or HF diet in fish, and our results shed new light on fish physiology. We illustrated the adaptive strategy of lipid metabolism responding to low or high fat diets in Nile tilapia. Briefly, the elevated glycolysis and accelerated biosynthesis of fatty acids in the liver were the main strategies of tilapia towards low fat intake. Increasing numbers, but not enlarging size, of adipocytes was the main strategy of Nile tilapia responding to continuous high‐fat diet feeding.