Ulven Stine Marie, Dalen Knut Tomas, Gustafsson Jan-Ake, Nebb Hilde Irene
Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, P.O. Box 1046 Blindern, N-0316 Oslo, Norway.
Prostaglandins Leukot Essent Fatty Acids. 2005 Jul;73(1):59-63. doi: 10.1016/j.plefa.2005.04.009.
Liver X receptors (LXRalpha and LXRbeta) are members of the nuclear receptor superfamily and are activated by oxysterols and intermediates in the cholesterol synthetic pathway. The pivotal role of LXRs in the metabolic conversion of cholesterol to bile acids is well established. Analysis of gene expression in LXRalpha and LXRbeta deficient mice have confirmed that LXR regulates a number of target genes involved in both cholesterol and fatty acid metabolism in liver, macrophages and intestine. The observation that LXRalpha is responsive to fatty acids and is expressed in metabolic tissues suggests that it also plays a general role in lipid metabolism. Adipose tissue is the main storage site for fat in the body and plays a crucial role in overall lipid handling. Both LXRalpha and LXRbeta are expressed and activated by endogenous and synthetic ligands, which lead to lipid accumulation into adipocytes. This indicates an important regulatory role of LXR in several metabolic signaling pathways in the adipose tissue, such as glucose uptake and de novo fatty acid synthesis. Here, we review recent studies that provide new insights into the mechanisms by which LXRs act to influence fatty acid synthesis in liver and adipose tissue.
肝脏X受体（LXRα和LXRβ）是核受体超家族的成员，可被氧化甾醇和胆固醇合成途径中的中间体激活。LXRs在胆固醇向胆汁酸的代谢转化中起关键作用，这一点已得到充分证实。对LXRα和LXRβ基因敲除小鼠的基因表达分析证实，LXR调节肝脏、巨噬细胞和肠道中许多参与胆固醇和脂肪酸代谢的靶基因。LXRα对脂肪酸有反应并在代谢组织中表达，这一观察结果表明它在脂质代谢中也起普遍作用。脂肪组织是体内脂肪的主要储存部位，在整体脂质处理中起关键作用。LXRα和LXRβ均由内源性和合成配体表达并激活，这会导致脂质在脂肪细胞中积累。这表明LXR在脂肪组织的几种代谢信号通路中具有重要的调节作用，如葡萄糖摄取和脂肪酸从头合成。在此，我们综述了最近的研究，这些研究为LXRs影响肝脏和脂肪组织中脂肪酸合成的机制提供了新的见解。
