Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5510475 | Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology | 2017 | 11 Pages |
Abstract
Rabbitfish Siganus canaliculatus is the first marine teleost reported to have the ability of biosynthesizing C20-22 long-chain polyunsaturated fatty acids (LC-PUFA) from C18 precursors, and thus provides a model for studying the regulatory mechanisms of LC-PUFA biosynthesis in teleosts. To investigate the possible roles of peroxisome proliferator-activated receptors (PPARs), critical transcription factors involved in the regulation of lipid metabolism, in the regulation of LC-PUFA biosynthesis in rabbitfish, the PPAR genes were cloned and their expression characterization with PPAR agonists, dietary lipid resource, and ambient salinity were examined. Three cDNA sequences respectively encoding 477, 516 and 519 amino acids of PPARα, PPARβ, and PPARγ isoforms were obtained. PPARα exhibited a wide tissue expression with its highest levels in the heart and brain; PPARβ was predominantly expressed in the gills, while PPARγ was highly expressed in the intestine and gills. In rabbitfish primary hepatocytes, both the PPAR agonists 2-bromopalmitate (2-Bro) and fenofibrate (FF) increased the expression of PPARγ, SREBP1c and Elovl5, whereas FF depressed the expression of Î6/Î5 Fad. Moreover, a higher hepatic PPARβ expression was observed in fish fed diets with vegetable oils (VO) than that with fish oil (FO), in the former the expression of PPARα, PPARβ, and PPARγ were increased at the low ambient salinity (10 ppt), where an increasing expression of Î5/Î6 Fad, Î4 Fad and Elovl5 genes was previously reported. These results suggest that PPARs might be involved in the upregulation of LC-PUFA biosynthesis with dietary VO and low ambient salinity in rabbitfish.
Keywords
activation function 1SREBPRXRHNF4αLXRSREAF1Retinoid X receptorAF2LC-PUFAlinoleicALAELOVLSterol regulatory element binding proteinsORFEtOHPPAR response elementsEPADulbecco's Modified Eagle Medium: Nutrient Mixture F-12FBSEicosapentaenoic acid (20:5n-3)PPREsDBDLC-PUFA biosynthesisLBDarachidonic acid (20:4n-6)2-BromopalmitatecDNADMEM/F12DMSOPPARsAgonistEthanoldocosahexaenoic acid (22:6n-3)complementary deoxyribonucleic acidPolyunsaturated fatty acidsPUFALong-chain polyunsaturated fatty acidsFADactivation function 2DNA-Binding Domainligand binding domainARADHAdimethyl sulphoxideFish oilVegetable oilsfetal bovine serumsterol regulatory elementOpen reading framesFenofibratepolymerase chain reactionPCRliver X receptorPeroxisome proliferator-activated receptors
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Cuihong You, Danli Jiang, Qinghao Zhang, Dizhi Xie, Shuqi Wang, Yewei Dong, Yuanyou Li,