Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL 61801, USA.
Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 South Goodwin Avenue, Urbana, IL 61801, USA.
Prog Lipid Res. 2014 Jan;53:124-44. doi: 10.1016/j.plipres.2013.12.001. Epub 2013 Dec 18.
In mammals, excess energy is stored primarily as triglycerides, which are mobilized when energy demands arise. This review mainly focuses on the role of long chain fatty acids (LCFAs) in regulating energy metabolism as ligands of peroxisome proliferator-activated receptors (PPARs). PPAR-alpha expressed primarily in liver is essential for metabolic adaptation to starvation by inducing genes for beta-oxidation and ketogenesis and by downregulating energy expenditure through fibroblast growth factor 21. PPAR-delta is highly expressed in skeletal muscle and induces genes for LCFA oxidation during fasting and endurance exercise. PPAR-delta also regulates glucose metabolism and mitochondrial biogenesis by inducing FOXO1 and PGC1-alpha. Genes targeted by PPAR-gamma in adipocytes suggest that PPAR-gamma senses incoming non-esterified LCFAs and induces the pathways to store LCFAs as triglycerides. Adiponectin, another important target of PPAR-gamma may act as a spacer between adipocytes to maintain their metabolic activity and insulin sensitivity. Another topic of this review is effects of skin LCFAs on energy metabolism. Specific LCFAs are required for the synthesis of skin lipids, which are essential for water barrier and thermal insulation functions of the skin. Disturbance of skin lipid metabolism often causes apparent resistance to developing obesity at the expense of normal skin function.
在哺乳动物中，多余的能量主要以甘油三酯的形式储存，当能量需求出现时，甘油三酯就会被动员起来。这篇综述主要关注长链脂肪酸（LCFAs）作为过氧化物酶体增殖物激活受体（PPARs）的配体，在调节能量代谢中的作用。主要在肝脏中表达的 PPAR-α 对于通过诱导β氧化和酮体生成来适应饥饿，以及通过下调成纤维细胞生长因子 21 来降低能量消耗，是至关重要的。PPAR-δ在骨骼肌中高度表达，在禁食和耐力运动期间诱导 LCFA 氧化的基因。PPAR-δ还通过诱导 FOXO1 和 PGC1-α 来调节葡萄糖代谢和线粒体生物发生。脂肪细胞中 PPAR-γ靶向的基因表明，PPAR-γ感知到进入的非酯化 LCFA，并诱导将 LCFA 储存为甘油三酯的途径。脂联素，PPAR-γ的另一个重要靶点，可能作为脂肪细胞之间的间隔物，以维持其代谢活性和胰岛素敏感性。这篇综述的另一个主题是皮肤 LCFAs 对能量代谢的影响。特定的 LCFAs 是皮肤脂质合成所必需的，皮肤脂质对于皮肤的水屏障和热绝缘功能至关重要。皮肤脂质代谢的紊乱常常导致明显的肥胖抵抗，以牺牲正常的皮肤功能为代价。
