Effects of Dietary Selenium and Oxidized Fish Oils on Intestinal Lipid Metabolism and Antioxidant Responses of Yellow Catfish Pelteobagrus fulvidraco

Abstract

Currently, the effect of selenium and oxidized fish oil interactions on the intestinal lipid metabolism and antioxidant responses of fish remains unknown. Herein, yellow catfish Pelteobagrus fulvidraco (weight: 3.99 ± 0.01 g) were used as experimental animals and were fed four diets: an adequate amount of selenium (0.25 mg kg−1) with fresh fish oil (A-Se+FFO), an adequate amount of selenium with oxidized fish oil (A-Se+OFO), a high amount of selenium (0.50 mg kg−1) with fresh fish oil (H-Se+FFO), and a high amount of selenium with oxidized fish oil (H-Se+OFO). The feeding experiment was conducted for 10 weeks. The results showed that selenium supplementation alleviated the intestinal tissue damage and reduced the lipid accumulation that was induced by oxidized fish oils. Meanwhile, we also found that 0.50 mg kg−1 selenium reduced the oxidative stress that is caused by oxidized fish oils through increasing the GSH and the activity and mRNA expression of antioxidant enzymes. Dietary selenium and oxidized fish oils also affected the mRNA expression of intestinal selenoproteins including selenow2a, selenop2, and selenot2. Mechanistically, Se and oxidized eicosapentaenoic acid (oxEPA) influenced the GSH content by affecting the DNA binding ability of activating transcription factor (ATF) 3 to the slc7a11 promoter. For the first time, our results suggested that selenium alleviated the oxidized fish oil-induced intestinal lipid deposition and the oxidative stress of the fish. We also elucidated the novel mechanism of selenium increasing the GSH content by affecting the interaction of ATF3 and the slc7a11 promoter.

Molecular Identification and Expression Analysis of an Intelectin Gene in the Yellow Catfish Pelteobagrus fulvidraco (Siluriformes: Bagridae)

“…Expressed sequence tags (EST) encoding an ITLN homolog were isolated from P. fulvidraco by random sequencing and transcriptome analysis [34][35][36][37]. Oligonucleotide primers were designed using the Primer 5.0 software (www.premierbiosoft.com/primerdesign/ (accessed on 15 October 2020)) (Table 1).…”

“…The yellow catfish Pelteobagrus fulvidraco is an important commercial freshwater aquaculture species in Asian countries, with a high market value in China. Recently, yellow catfish have been used as an experimental model for fish breeding [32], development [33], lipid metabolism [34], genomics [35], and toxicology [36]. Although infectious disease outbreaks associated with pathogenic microorganisms have caused high mortality rates and led to catastrophic economic losses in farmed P. fulvidraco, little is known about the immune system of this species.…”

Transcriptome Analysis Revealed Potential Immune-Related Genes of Head Kidney in the Yellow Catfish (Pelteobagrus fulvidraco) Challenged with Aeromonas hydrophila

“…One of the most destructive pathogens, causing significant losses, is Aeromonas hydrophila, a Gram-negative bacterium, which is an oxidase-positive and facultative anaerobic. This is an opportunistic aquatic pathogen that produces various virulence factors, including hemolysins, aerolysins, adhesins, enterotoxins, phospholipase, and lipase [4], P. fulvidraco has become increasingly popular as a model fish for studying breeding technology, toxicology, immune response, and lipid metabolism in recent years [5][6][7][8][9]. However, the effect of A. hydrophila on P. fulvidraco has not been reported.…”