n-3 PUFA reduction caused by fabp2 deletion interferes with triacylglycerol metabolism and cholesterolhomeostasis in fish
Fatty acid-binding protein 2 (Fabp2), which is involved in the transport of long-chain fatty acids, is widely studied in mammals. Nevertheless, the role of this protein in teleost fish is mostly unknown. Here, we produced a fabp2−/− zebrafish (KO) animal model. Compared with wild-type zebrafish (WT), KO had a markedly decreased content of intestinal n-3 poly-unsaturated fatty acids (n-3 PUFAs) and increased levels of intestinal, hepatic, and serum triacylglycerols (TAG). The intestinal transcriptome analysis of KO and WT revealed an obviously disrupted TAG metabolism and up-regulated bile secretion in KO. Expression levels of the genes related to fatty acid transport and cholesterol (CL) absorption in the intestine of KO were significantly lower than those of WT, while the expression levels of genes related to intestinal TAG synthesis and hepatic CL synthesis were in the opposite direction. To confirm these findings, we further established fabp2 transgenic zebrafish (TG). Compared with WT, TG had a markedly increased content of intestinal n-3 PUFAs, a significantly decreased level of hepatic TAG, and significantly higher expression of genes related to fatty acid transport and CL absorption in the intestine. In conclusion, this study suggests that teleost fish fabp2 could promote intestinal n-3 PUFA absorption to mediate TAG synthesis and CL homeostasis, by regulating the genes involved in lipid metabolism.
Keywordsfabp2 Zebrafish Gene knockout and overexpressed Triacylglycerol metabolism Cholesterol homeostasis
This study was supported by the National Natural Science Foundation of China (31672660 and 31872579), State Key Laboratory of Freshwater Ecology and Biotechnology (Y119011F01), and Fundamental Research Funds for the Central Universities (2662018PY034).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
All zebrafish procedures in this study were in accordance with the recommendations in the Guide for the Institutional Animal Ethics Committee and the use of Laboratory Animals of Huazhong Agricultural University.
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