Elucidating the Transcriptional Brakes on Adipocyte Thermogenesis

项目摘要/总结 棕色脂肪组织（BAT）通过一种称为适应性的过程消耗能量的能力 产热使其成为肥胖干预的有吸引力的目标;然而，观察到BAT质量 在人类肥胖中的减少引起了对其在完全激活时临床上影响体重的能力的关注。 能量储存白色脂肪组织（WAT）也可以采用“棕色样”产热表型;然而， 是白色脂肪细胞中生热基因程序的有效分子制动器，有助于维持其能量- 存储表型。由于WAT比BAT的质量大得多， 在白色脂肪细胞中的程序可能是干预肥胖的更可行的策略;然而， 控制能量燃烧与能量储存脂肪细胞谱系的建立和维持 仍然未定义。 ZFP 423是锌指蛋白C2 H2家族的成员，是一种生理调节的转录因子， 通过抑制产热来维持储能白色脂肪细胞表型的因子 棕色/米色脂肪细胞的基因程序特征。ZFP 423与棕色脂肪细胞物理相互作用 在白色脂肪细胞中抑制EBF 2决定因子EBF 2，以防止EBF 2依赖性染色质重塑和PPARg 关键产热基因的占有率。 我打算在杜克大学医学院进行的博士培训中进行的实验 科学家培训计划将利用生物化学，分子生物学和小鼠 遗传学这项工作是在杜克大学分子生理学系的拉纳·古普塔博士的指导下进行的。 研究所，旨在1）解决ZFP 423直接募集NuRD复合物的能力的假设 对EBF 2抑制白色脂肪细胞（Aim 1）产热的能力是必需的，和2）测试EBF 2对EBF 2的抑制作用。 假设小鼠中ZFP 423-EBF复合物的遗传破坏足以允许产热WAT 重塑和预防肥胖和代谢功能障碍的发展。我提出的总体目标是 研究的目的是进一步确定导致产热抑制的关键蛋白质-蛋白质相互作用。 ZFP 423在白色脂肪细胞中的基因程序。这项工作的顺利完成将突出 转录“刹车”对脂肪细胞中产热基因表达的影响，并可能提出一种策略， WAT促进体重减轻和/或改善营养平衡的产热能力。

PROJECT ABSTRACT/SUMMARY The ability of brown adipose tissue (BAT) to expend energy through a process called adaptive thermogenesis makes it an attractive target for intervention in obesity; however, the observation that BAT mass diminishes in human obesity raises concerns about its ability to clinically impact body weight when fully activated. Energy-storing white adipose tissue (WAT) can also adopt a “brown-like” thermogenic phenotype; however, there are potent molecular brakes on thermogenic gene program in white adipocytes that help maintain its energy- storing phenotype. Since WAT is present in far greater mass than BAT, activation of the thermogenic gene program in white adipocytes may be a more viable strategy for intervention in obesity; however, the mechanisms controlling the establishment and maintenance of the energy-burning vs. energy-storing adipocyte lineages remain undefined. ZFP423, a member of the C2H2 family of zinc finger proteins, is a physiologically regulated transcription factor that functions to maintain the energy-storing white adipocyte phenotype by suppressing the thermogenic gene program characteristic of brown/beige fat cells. ZFP423 physically interacts with the brown adipocyte determination factor, EBF2, in white adipocytes to prevent EBF2-dependent chromatin remodeling and PPARg occupancy at key thermogenic genes. The experiments that I propose to conduct as part of my PhD training in the Duke University Medical Scientist Training Program will utilize advanced approaches in biochemistry, molecular biology, and mouse genetics. This work, conducted under the mentorship of Dr. Rana Gupta at the Duke Molecular Physiology Institute, is designed to 1) address the hypothesis that the ability of ZFP423 to directly recruit the NuRD complex to EBF2 is essential for its ability to suppress thermogenesis in white adipocytes (Aim1), and 2) test the hypothesis that genetic disruption of the ZFP423-EBF complex in mice is sufficient to permit thermogenic WAT remodeling and prevent the development of obesity and metabolic dysfunction. The overall goal of my proposed research is to further define the critical protein-protein interactions leading to the suppression of the thermogenic gene program by ZFP423 in white adipocytes. Successful completion of this work will highlight the importance of transcriptional “brakes” on thermogenic gene expression in adipocytes and may suggest a strategy to unlock the thermogenic capacity of WAT to promote weight loss and/or improve nutrient homeostasis.