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

• 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
• 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

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）：肥胖增加了慢性疾病的风险，例如2型糖尿病，心血管疾病和癌症。肥胖是由于能量摄入和能量消耗之间的不平衡引起的，在脂肪细胞中，多余的能量作为甘油三酸酯。 ppar？是脂肪形成的关键调节剂，它调节脂肪细胞谱系特征的基因表达。促进pPAR的机制？ - 在脂肪形成过程中依赖基因表达是不完全理解的。以前，我们报道TLE3是PPAR的转录核心测量仪？并参与了馈送转录程序以驱动脂肪形成。在拟议的研究中，我将检验以下假设：TLE3是驱动白色和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）中过表达TLE3的小鼠具有从棕色到白色脂肪组织（WAT）的表型转换。结果，当受到冷暴露挑战时，TLE3转基因小鼠的热反应受损。机械研究表明，TLE3反理PRDM16，这是棕色脂肪基因表达的转录核心调节剂。在特定目标1中，我将使用体外模型来研究TLE3在执行WAT和BAT转录程序中的作用和机理。我将利用体外增益和功能研究的丧失来确定TLE3是否影响白色脂肪基因表达。功能方法的增益将包括TLE3和/或PRDM16的逆转录病毒和腺病毒表达。功能研究的丧失将利用感染对照或CRE-腺病毒感染的白色和棕色TLE3F/F前脂肪细胞来产生体外敲除。我将通过检查TLE3指导染色质重塑和募集组蛋白修饰酶为脂肪细胞启动子的能力来探索作用机理。在特定目标2中，我将使用体内模型来定义TLE3在白色和棕色脂肪组织以及全身脂质代谢中的功能。我已经产生了在脂肪细胞中表达TLE3的转基因动物，以及在脂肪细胞中有条件缺失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，热生成以及脂质和葡萄糖代谢的能力。拟议的研究将在UCLA的Peter Tontonoz博士的实验室完成，后者提供了一个丰富的环境，将促进过渡到独立研究者职位。职业发展奖将提供受保护的时间，以发展写作，网络和沟通方面的关键技能。此外 参加加州大学洛杉矶分校的研讨会并参加会议，我将参加课程，以增强放射性同位素的技术培训，用于研究代谢途径，蛋白质纯化和表征以及下一代测序技术，以研究表观遗传学。拟议的研究是从我在掺杂的博士后研究到棕色脂肪细胞生物学的新兴领域的逻辑过渡。