Howard Hughes Medical Institute, UCLA, Los Angeles, CA 90095, USA.
Cell Metab. 2013 Mar 5;17(3):423-35. doi: 10.1016/j.cmet.2013.01.016.
Transcriptional effectors of white adipocyte-selective gene expression have not been described. Here we show that TLE3 is a white-selective cofactor that acts reciprocally with the brown-selective cofactor Prdm16 to specify lipid storage and thermogenic gene programs. Occupancy of TLE3 and Prdm16 on certain promoters is mutually exclusive, due to the ability of TLE3 to disrupt the physical interaction between Prdm16 and PPARγ. When expressed at elevated levels in brown fat, TLE3 counters Prdm16, suppressing brown-selective genes and inducing white-selective genes, resulting in impaired fatty acid oxidation and thermogenesis. Conversely, mice lacking TLE3 in adipose tissue show enhanced thermogenesis in inguinal white adipose depots and are protected from age-dependent deterioration of brown adipose tissue function. Our results suggest that the establishment of distinct adipocyte phenotypes with different capacities for thermogenesis and lipid storage is accomplished in part through the cell-type-selective recruitment of TLE3 or Prdm16 to key adipocyte target genes.
尚未描述白色脂肪细胞选择性基因表达的转录效应因子。在这里,我们表明 TLE3 是一种白色选择性共激活因子,它与棕色选择性共激活因子 Prdm16 相互作用,以指定脂质储存和产热基因程序。由于 TLE3 能够破坏 Prdm16 与 PPARγ 之间的物理相互作用,因此 TLE3 和 Prdm16 在某些启动子上的占据是相互排斥的。当在棕色脂肪中高水平表达时,TLE3 对抗 Prdm16,抑制棕色选择性基因并诱导白色选择性基因,导致脂肪酸氧化和产热受损。相反,脂肪组织中缺乏 TLE3 的小鼠在腹股沟白色脂肪组织中表现出增强的产热作用,并免受年龄依赖性棕色脂肪组织功能恶化的影响。我们的结果表明,通过细胞类型选择性募集 TLE3 或 Prdm16 到关键脂肪细胞靶基因,部分完成了具有不同产热和脂质储存能力的不同脂肪细胞表型的建立。