Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, D-20246 Hamburg, Germany.
Nat Commun. 2013;4:1528. doi: 10.1038/ncomms2537.
Clinical interest in de novo lipogenesis has been sparked by recent studies in rodents demonstrating that de novo lipogenesis specifically in white adipose tissue produces the insulin-sensitizing fatty acid palmitoleate. By contrast, hepatic lipogenesis is thought to contribute to metabolic disease. How de novo lipogenesis in white adipose tissue versus liver is altered in human obesity and insulin resistance is poorly understood. Here we show that lipogenic enzymes and the glucose transporter-4 are markedly decreased in white adipose tissue of insulin-resistant obese individuals compared with non-obese controls. By contrast, lipogenic enzymes are substantially upregulated in the liver of obese subjects. Bariatric weight loss restored de novo lipogenesis and glucose transporter-4 gene expression in white adipose tissue. Notably, lipogenic gene expression in both white adipose tissue and liver was strongly linked to the expression of carbohydrate-responsive element-binding protein-β and to metabolic risk markers. Thus, de novo lipogenesis predicts metabolic health in humans in a tissue-specific manner and is likely regulated by glucose-dependent carbohydrate-responsive element-binding protein activation.
临床对从头合成脂肪生成的兴趣最近在啮齿动物研究中被激发,这些研究表明,白色脂肪组织中特有的从头合成脂肪生成产生了胰岛素增敏脂肪酸棕榈油酸。相比之下,肝脂肪生成被认为是代谢疾病的原因。人类肥胖和胰岛素抵抗中白色脂肪组织与肝脏的从头合成脂肪生成如何改变尚不清楚。在这里,我们发现与非肥胖对照组相比,胰岛素抵抗肥胖个体的白色脂肪组织中的脂肪生成酶和葡萄糖转运蛋白-4明显减少。相比之下,肥胖受试者的肝脏中的脂肪生成酶大量上调。减重手术可恢复白色脂肪组织中的从头合成脂肪生成和葡萄糖转运蛋白-4基因表达。值得注意的是,白色脂肪组织和肝脏中的脂肪生成基因表达与碳水化合物反应元件结合蛋白-β的表达和代谢风险标志物密切相关。因此,从头合成脂肪生成以组织特异性的方式预测人类的代谢健康,并且可能受葡萄糖依赖性碳水化合物反应元件结合蛋白激活的调节。