Transcriptional role of TLE3 in brown adipose tissue development and metabolism

TLE3在棕色脂肪组织发育和代谢中的转录作用

基本信息

批准号：
8628832
负责人：
Claudio J Villanueva
金额：
$ 16.02万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-03-01 至 2016-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8628832
关键词：
2,4-thiazolidinedione Address Adenoviruses Adipocytes Adipose tissue Adverse effects Affect Agonist Automobile Driving Brown Fat Cardiovascular Diseases Characteristics Chronic Disease Communication Data Development Diabetes Mellitus Dose Drosophila genus Endocrine Energy Intake Energy Metabolism Enhancers Environment Enzymes Epidemic Epigenetic Process Exhibits Fatty acid glycerol esters Gene Expression Genes Glucose High Prevalence Histones Homeostasis Homologous Gene In Vitro Individual Intervention K-Series Research Career Programs Knock-out Laboratories Lipids Maintenance Malignant Neoplasms Metabolic Metabolic Diseases Metabolic Pathway Metabolism Modeling Molecular Molecular Target Mus Non-Insulin-Dependent Diabetes Mellitus Obesity Overweight Pathogenesis Pathway interactions Peroxisome Proliferator-Activated Receptors Pharmacologic Substance Phenotype Play Population Positioning Attribute Publishing Radioisotopes Reporting Research Personnel Resistance Risk Role Signal Transduction Technology Testing Therapeutic Thermogenesis Thiazolidinediones Time Training Transgenic Animals Transgenic Mice Triglycerides Work Writing adipocyte biology adipocyte differentiation chromatin modification chromatin remodeling cofactor cost feeding follow-up gain of function gene function glucose metabolism glucose tolerance high throughput screening improved in vitro Model in vivo in vivo Model insight insulin sensitivity lipid biosynthesis lipid metabolism loss of function next generation sequencing novel overexpression programs promoter protein purification public health relevance response skills symposium transcription factor

项目摘要

DESCRIPTION (provided by applicant): Obesity increases the risk for chronic diseases such as type 2 diabetes, cardiovascular disease, and cancer. Obesity results from the imbalance between energy intake and energy expenditure, where excess energy is stored in adipocytes as triglycerides. PPAR? is a critical regulator of adipogenesis, regulating the expression of genes that are characteristic of the adipocyte lineage. The mechanisms that facilitate PPAR?- dependent gene expression during the course of adipogenesis are incompletely understood. Previously we reported that TLE3 is a transcriptional coregulator of PPAR? and is involved in a feed-forward transcriptional program to drive adipogenesis. In the proposed studies I will test the hypothesis that TLE3 is a key determinant in driving white versus brown fat selective gene expression. Preliminary data indicates that mice overexpressing TLE3 in brown adipose tissue (BAT) have a phenotypic switch from brown to white adipose tissue (WAT). As a result, TLE3 transgenic mice have an impaired thermogenic response when challenged with cold exposure. Mechanistic studies suggest that TLE3 counters Prdm16, a transcriptional coregulator of brown fat gene expression. In specific Aim 1 I will use in vitro models to investigate the function and mechanism of action of TLE3 in executing the WAT and BAT transcriptional programs. I will utilize in vitro gain and loss of function studies to determine whether TLE3 affects white versus brown fat gene expression. Gain of function approaches will include retroviral and adenoviral expression of TLE3 and/or Prdm16. Loss of function studies will utilize white and brown TLE3F/F preadipocytes infected with control or Cre-adenovirus to generate in vitro knockouts. I will explore the mechanism of action by examining the ability of TLE3 to direct chromatin remodeling and recruitment of histone modifying enzymes to adipocyte promoters. In specific Aim 2 I will use in vivo models to define the function of TLE3 in white and brown adipose tissue and systemic lipid metabolism. I have already generated transgenic animals expressing TLE3 in adipocytes, as well as mice with conditional deletion of TLE3 in adipocytes. I will use these models to examine the ability of TLE3 to affect adipocyte gene expression, thermogenesis and lipid and glucose metabolism. The proposed studies will be completed in the laboratory of Dr. Peter Tontonoz at UCLA, who has provided an enriching environment that will facilitate the transition to an independent investigator position. The career development award will provide protected time to develop critical skills in writing, networking, and communication. In addition to attending seminars at UCLA and attending conferences, I will take courses that will enhance technical training in the use of radioisotopes for the study of metabolic pathways, protein purification and characterization, and next generation sequencing technologies for the study of epigenetics. The proposed studies are a logical transition from my postdoctoral studies in adipogenesis to the burgeoning field of brown adipocyte biology.

描述（由申请人提供）：肥胖会增加患 2 型糖尿病、心血管疾病和癌症等慢性疾病的风险。肥胖是由于能量摄入和能量消耗之间的不平衡造成的，多余的能量以甘油三酯的形式储存在脂肪细胞中。过氧化物酶体活化受体？是脂肪生成的关键调节因子，调节脂肪细胞谱系特征基因的表达。在脂肪生成过程中促进 PPARβ 依赖性基因表达的机制尚不完全清楚。之前我们报道过TLE3是PPAR的转录共调节因子？并参与驱动脂肪生成的前馈转录程序。在拟议的研究中，我将检验以下假设：TLE3 是驱动白色脂肪与棕色脂肪选择性基因表达的关键决定因素。初步数据表明，在棕色脂肪组织（BAT）中过度表达 TLE3 的小鼠具有从棕色脂肪组织（WAT）到白色脂肪组织（WAT）的表型转变。因此，TLE3 转基因小鼠在受到冷暴露挑战时产热反应受损。机制研究表明，TLE3 可以对抗 Prdm16（棕色脂肪基因表达的转录共调节因子）。在具体目标 1 中，我将使用体外模型来研究 TLE3 在执行 WAT 和 BAT 转录程序中的功能和作用机制。我将利用体外功能获得和丧失研究来确定 TLE3 是否影响白色脂肪与棕色脂肪的基因表达。功能获得方法将包括 TLE3 和/或 Prdm16 的逆转录病毒和腺病毒表达。功能丧失研究将利用感染对照或 Cre 腺病毒的白色和棕色 TLE3F/F 前脂肪细胞来产生体外基因敲除。我将通过检查 TLE3 指导染色质重塑和向脂肪细胞启动子招募组蛋白修饰酶的能力来探索其作用机制。在具体目标 2 中，我将使用体内模型来定义 TLE3 在白色和棕色脂肪组织和全身脂质代谢中的功能。我已经培育出在脂肪细胞中表达 TLE3 的转基因动物，以及在脂肪细胞中条件性删除 TLE3 的小鼠。我将使用这些模型来检查 TLE3 影响脂肪细胞基因表达、产热以及脂质和葡萄糖代谢的能力。拟议的研究将在加州大学洛杉矶分校 Peter Tontonoz 博士的实验室中完成，他提供了一个丰富的环境，有利于向独立研究者职位的过渡。职业发展奖将提供受保护的时间来培养写作、网络和沟通方面的关键技能。此外通过参加加州大学洛杉矶分校的研讨会和会议，我将参加一些课程，以加强使用放射性同位素研究代谢途径、蛋白质纯化和表征以及用于表观遗传学研究的下一代测序技术的技术培训。拟议的研究是从我的脂肪生成博士后研究到棕色脂肪细胞生物学新兴领域的逻辑过渡。