High-fat-diet-induced inflammation depresses the appetite of blunt snout bream (Megalobrama amblycephala) through the transcriptional regulation of leptin/mammalian target of rapamycin.
The aim of this article was to investigate the mechanism of appetite suppression induced by high-fat diets (HFD) in blunt snout bream (Megalobrama amblycephala). Fish (average initial weight 40·0 (sem 0·35) g) were fed diets with two fat levels (6 and 11 %) with four replicates. HFD feeding for 30 d could significantly increase the weight gain rate, but feeding for 60 d cannot. Food intake of M. amblycephala began to decline significantly in fish fed the HFD for 48 d. HFD feeding for 60 d significantly reduced the expression of neuropeptide Y and elevated the expression of cocaine- and amphetamine-regulated transcript (CART), actions both in favour of suppression of appetite. The activation of fatty acid sensing was partly responsible for the weakened appetite. In addition, inflammatory factors induced by the HFD may be involved in the regulation of appetite by increasing the secretion of leptin and then activating the mammalian target of rapamycin (mTOR). Lipopolysaccharide (LPS, 2·0 mg/kg of fish weight) was administered to induce inflammation, and sampling was performed after 3, 6, 9, 12, 18, 24 and 48 h of LPS injection. Within 6-24 h of LPS injection, the food intake and appetite of M. amblycephala decreased significantly, whereas the mRNA expression of leptin and mTOR increased significantly. Our results indicate that inflammatory cytokines may be the cause of appetite suppression in M. amblycephala fed a HFD.
['Dai|Yong-Jun|YJ|', 'Jiang|Guang-Zhen|GZ|', 'Yuan|Xiang-Yang|XY|', 'Liu|Wen-Bin|WB|']
D000821:Animal Feed D000818:Animals D001066:Appetite D003530:Cyprinidae D059305:Diet, High-Fat D004435:Eating D005227:Fatty Acids D005399:Fishes D005786:Gene Expression Regulation D007249:Inflammation D020738:Leptin D050356:Lipid Metabolism D008070:Lipopolysaccharides D008099:Liver D009419:Nerve Tissue Proteins D012333:RNA, Messenger D058570:TOR Serine-Threonine Kinases
Appetite Megalobrama amblycephala High-fat diets Food intake Inflammatory factors AKT protein kinase B CART cocaine- and amphetamine-regulated transcript CPT1 carnitine palmitoyltransferase 1 FA fatty acid FAT fatty acid translocase HFD high-fat diet IκB inhibitor of κB LPS lipopolysaccharide NFD normal-fat diet NPY neuropeptide Y SREBP1c sterol regulatory element-binding protein type 1c mTOR mammalian target of rapamycin