Novel transcriptional regulators for thermogenic program

肥胖，即多余的白色脂肪组织（WAT）的积累，与2型糖尿病和其他慢性疾病有关，并且已经成为流行病。虽然WAT主要是一个能量储存器官，但棕色脂肪组织（BAT）通过UCP 1消耗能量以产生热量，以维持体温。随着人类成年人中BAT/BAT样组织的识别，增加BAT或BAT活性可以对抗肥胖。通过筛选已知的和推测的能激活UCP 1启动子的转录因子库，我们最近发现了一个属于C3 H锌指家族的蛋白，该蛋白能强烈激活UCP 1和其他产热基因。这种转录因子富含BAT而不是WAT，并且在冷暴露时被诱导。我们通过EMSA和SELEX以及ChIP检测到这种C3 H因子在UCP 1和其他BAT基因的启动子区域的结合。通过CRISPR-Cas9系统在培养的BAT细胞中的消融抑制了UCP 1和其他靶基因，以减少解偶联呼吸。此外，小鼠脂肪组织中的过表达增加了能量消耗，伴随着对饮食诱导的肥胖的抵抗，而脂肪组织中的消融促进了肥胖和胰岛素抵抗。为了进一步研究该因子的功能，通过TAP-质谱分析，我们鉴定了组蛋白甲基转移酶，我们发现其相互作用并协同发挥作用。在小鼠中，这种表观遗传因子的脂肪特异性消融也降低了促进肥胖的能量消耗。我们的目标是了解这种新的C3 H转录因子及其相互作用蛋白在产热基因程序和产热中的分子机制和生理意义：目的1是研究这种C3 H因子在激活UCP 1启动子中的功能，并研究其全基因组靶点。目的二是研究其相互作用辅因子在产热基因程序表观遗传调控中的关系和功能。最后，目的3是研究在体内的作用，这种C3 H因子，其辅因子和它们之间的关系，在产热和肥胖症的获得和丧失功能的研究小鼠。我们的研究将有助于更好地了解产热程序，并可能为未来开发有效的肥胖治疗提供目标。

Obesity, the accumulation of excess white adipose tissue (WAT), is associated with type 2 diabetes and other chronic diseases and has become an epidemic. While WAT is primarily an energy storage organ, brown adipose tissue (BAT) dissipates energy for heat generation via UCP1 to maintain body temperature. With the recognition of BAT/BAT-like tissues in human adults, increasing BAT or BAT activity may combat obesity. By screening a library of known and putative transcription factors that can activate UCP1 promoter, we recently have identified a largely uncharacterized a protein belonging to C3H zinc finger family, that can robustly activate UCP1 and other thermogenic genes. This transcription factor is enriched in BAT versus WAT and is induced upon cold-exposure. We detected binding of this C3H factor at the promoter regions of UCP1 and other BAT genes by EMSA and SELEX as well as by ChIP. Ablation by CRISPR-Cas9 system in BAT cells in culture suppressed UCP1 and other target genes to reduce uncoupled respiration. Moreover, overexpression in adipose tissue in mice increased energy expenditure to accompany resistance to diet- induced obesity, whereas ablation in adipose tissue promoted obesity and insulin resistance. To further examine the function of this factor, by TAP-Mass spec analysis, we identified a histone methyltransferase, which we found to interact and function synergistically. Adipose specific ablation of this epigenetic factor in mice also decreased energy expenditure promoting obesity. Our goal is to understand the molecular mechanisms and physiological significance of this new C3H transcription factor and its interacting protein for the thermogenic gene program and thermogenesis: Aim 1 is to investigate the function of this C3H factor in activating UCP1 promoter and study its genome-wide targets. Aim 2 is to examine the relationship and function of its interacting cofactor in epigenetic regulation of the thermogenic gene program. Finally, Aim 3 is to study the in vivo role of this C3H factor, its cofactor and their relationship in thermogenesis and adiposity by gain- and loss-of function studies in mice. Our research will help better understand the thermogenic program and may provide targets for developing effective obesity therapeutics in the future.