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，并已成为一种流行病。虽然Wat主要是一个能量储存器官，但棕色脂肪组织(BAT)通过UCP1释放能量产生热量，以维持体温。随着人类成年人对蝙蝠/蝙蝠样组织的认识，增加蝙蝠或蝙蝠的活动可能会对抗肥胖。通过筛选能够激活UCP1启动子的已知和可能的转录因子文库，我们最近发现了一个属于C3H锌指家族的蛋白质，它可以强健地激活UCP1和其他产热基因。这种转录因子在BAT和WAT中富含，在冷暴露时被诱导。我们用EMSA和SELEX以及芯片检测了该C3H因子与UCP1和其他BAT基因启动子区域的结合。用CRISPR-Cas9系统在培养的BAT细胞中进行消融，可以抑制UCP1和其他靶基因，从而减少解偶联呼吸。此外，小鼠脂肪组织中的过度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则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-MS分析，我们确定了一个组蛋白甲基转移酶，我们发现它相互作用并协同发挥作用。在小鼠中，脂肪特异性地去除这种表观遗传因子也减少了促进肥胖的能量消耗。我们的目标是了解这种新的C3H型转录因子及其相互作用蛋白在生热基因程序和生热过程中的分子机制和生理意义：目的1研究这种C3H型转录因子在激活UCP1启动子中的功能，并研究其全基因组靶点。目的2是研究其相互作用的辅因子在产热基因程序的表观遗传调控中的关系和功能。最后，目标3是通过小鼠的功能得失研究这种C3H因子及其辅助因子在体内的作用以及它们在产热和肥胖中的关系。我们的研究将有助于更好地理解生热计划，并可能为未来开发有效的肥胖治疗方法提供靶点。

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.