Dragos Steven M, Bergeron Karl F, Desmarais Frédérik, Suitor Katherine, Wright David C, Mounier Catherine, Mutch David M
Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada; and.
Département des sciences biologiques et centre de recherche BioMed, Université du Québec à Montréal, Montreal, Quebec, Canada.
Am J Physiol Cell Physiol. 2017 Sep 1;313(3):C295-C304. doi: 10.1152/ajpcell.00097.2017. Epub 2017 Jun 28.
White adipose tissue (WAT) has a critical role in lipid handling. Previous work demonstrated that SCD1 is an important regulator of WAT fatty acid (FA) composition; however, its influence on the various interconnected pathways influencing WAT lipid handling remains unclear. Our objective was to investigate the role of SCD1 on WAT lipid handling using knockout (KO) mice and SCD1-inhibited 3T3-L1 adipocytes by measuring gene, protein, and metabolite markers related to FA reesterification, glyceroneogenesis, and lipolysis. Triacylglycerol (TAG) content was higher in inguinal WAT (iWAT) from KO mice compared with wild-type, but significantly lower in epididymal WAT (eWAT). The SCD1 desaturation index was decreased in both WAT depots in KO mice. FA reesterification, as measured with a NEFA:glycerol ratio, was reduced in both WAT depots in KO mice, as well as SCD1-inhibited 3T3-L1 adipocytes. , , and gene expression was reduced in both WAT depots of KO mice, while and gene expression showed depot-specific regulation. , , and gene expression was reduced, and phosphoenolpyruvate carboxykinase protein content was ablated, in SCD1-inhibited adipocytes. Our data provide evidence that SCD1 has a broad impact on WAT lipid handling by altering TAG composition in a depot-specific manner, reducing FA reesterification, and regulating markers of lipolysis and glyceroneogenesis.
白色脂肪组织(WAT)在脂质处理中起关键作用。先前的研究表明,硬脂酰辅酶A去饱和酶1(SCD1)是WAT脂肪酸(FA)组成的重要调节因子;然而,其对影响WAT脂质处理的各种相互关联途径的影响仍不清楚。我们的目标是通过测量与FA再酯化、甘油生成和脂肪分解相关的基因、蛋白质和代谢物标志物,研究SCD1基因敲除(KO)小鼠和SCD1抑制的3T3-L1脂肪细胞中SCD1对WAT脂质处理的作用。与野生型相比,KO小鼠腹股沟白色脂肪组织(iWAT)中的三酰甘油(TAG)含量更高,但附睾白色脂肪组织(eWAT)中的TAG含量显著更低。KO小鼠两个脂肪库中的SCD1去饱和指数均降低。用非酯化脂肪酸与甘油的比率衡量,KO小鼠的两个脂肪库以及SCD1抑制的3T3-L1脂肪细胞中的FA再酯化均减少。KO小鼠两个脂肪库中的 、 和 基因表达均降低,而 和 基因表达表现出脂肪库特异性调节。在SCD1抑制的脂肪细胞中, 、 和 基因表达降低,磷酸烯醇式丙酮酸羧激酶蛋白含量缺失。我们的数据表明,SCD1通过以脂肪库特异性方式改变TAG组成、减少FA再酯化以及调节脂肪分解和甘油生成的标志物,对WAT脂质处理产生广泛影响。