Hepatic transcriptome of mice fed high fat diets containing palm or linseed oil

The beneficial effects of dietary long-chain (LC) n-3 polyunsaturated fatty acids (PUFA) in the prevention and/or treatment of some metabolic disorders result largely from their capacity to regulate the transcription level of many genes involved in metabolic and physiological homeostasis, especially in the liver. In this respect, they are known to bind and activate the Peroxisome Proliferator-Activated Receptor alpha (PPARalpha). The precursor of LC-PUFA, a-linoleic acid (ALA, C18:3 n-3) share some beneficial metabolic effects with its LC derivatives, however its role in gene regulation is poorly documented. Here, we analysed the hepatic transcriptome of mice fed for 5 weeks diets rich in either saturated FA from palm oil (PALM group) or ALA from linseed oil (LIN group). This modification of dietary fatty acid composition in a context of a high fat diet had a subtle but significant effect on the hepatic transcriptome. We identified mainly a group of genes that were upregulated in the LIN vs the PALM group and that include several well-known PPARalpha target genes involved in lipid and xenobiotic metabolism. Liver gene expression was measured in male C57BL/6J mice fed during 5 weeks a high fat diet (51% energy from fat) containing palm oil, rich in saturated fatty acids (n=10) or linseed oil, rich in 18:3 n-3 (n=8)

膳食长链（long-chain, LC）n-3多不饱和脂肪酸（polyunsaturated fatty acids, PUFA）在预防或治疗部分代谢紊乱中的有益作用，主要源于其可调控代谢与生理稳态相关众多基因的转录水平，该效应在肝脏组织中尤为显著。已知这类脂肪酸可结合并激活过氧化物酶体增殖物激活受体α（Peroxisome Proliferator-Activated Receptor alpha, PPARα）。长链PUFA的前体α-亚麻酸（α-linoleic acid, ALA, C18:3 n-3）与其长链衍生物共享部分有益代谢效应，但其在基因调控方面的作用却鲜有文献报道。本研究以雄性C57BL/6J小鼠为实验对象，将其分为两组，分别饲喂5周脂肪供能占比51%的高脂膳食：一组为富含棕榈油来源饱和脂肪酸的膳食（棕榈油组，PALM组，n=10），另一组为富含亚麻籽油来源α-亚麻酸的膳食（亚麻籽油组，LIN组，n=8）。该高脂膳食背景下的膳食脂肪酸组成改变，对小鼠肝脏转录组产生了细微但显著的影响。本研究主要鉴定到一组在亚麻籽油组相较于棕榈油组上调表达的基因，其中包含多个已知的、参与脂质与外源性物质代谢的PPARα靶基因。