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）：肥胖增加慢性疾病的风险，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，其中多余的能量以甘油三酯的形式储存在脂肪细胞中。PPAR？是脂肪形成的关键调节因子，调节脂肪细胞谱系特征性基因的表达。促进PPAR的机制？在脂肪形成过程中的依赖性基因表达尚不完全清楚。以前我们报道TLE 3是一个转录共调节因子的过氧化物酶体增殖物激活受体？并参与前馈转录程序以驱动脂肪生成。在拟议的研究中，我将测试TLE 3是驱动白色与棕色脂肪选择性基因表达的关键决定因素的假设。初步数据表明，在棕色脂肪组织（BAT）中过表达TLE 3的小鼠具有从棕色脂肪组织（WAT）到白色脂肪组织（WAT）的表型转换。因此，TLE 3转基因小鼠在受到冷暴露攻击时具有受损的产热反应。机制研究表明，TLE 3计数器Prdm 16，棕色脂肪基因表达的转录辅助调节因子。在具体的目标1中，我将使用体外模型来研究TLE 3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TLE 3是否影响白色与棕色脂肪基因表达。功能获得方法将包括TLE 3和/或Prdm 16的逆转录病毒和腺病毒表达。功能丧失研究将利用用对照或Cre-腺病毒感染的白色和棕色TLE 3 F/F前脂肪细胞来产生体外敲除。我将通过检测TLE 3指导染色质重塑和组蛋白修饰酶向脂肪细胞启动子的募集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TLE 3在白色和棕色脂肪组织和全身脂质代谢中的功能。我已经产生了在脂肪细胞中表达TLE 3的转基因动物，以及脂肪细胞中TLE 3有条件缺失的小鼠。我将使用这些模型来研究TLE 3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的Peter Tontonoz博士的实验室完成，他提供了一个丰富的环境，这将有助于过渡到独立的研究者职位。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。除了 通过参加加州大学洛杉矶分校的研讨会和会议，我将学习一些课程，这些课程将加强在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方面的技术培训。这些建议的研究是从我的博士后研究脂肪形成到新兴的棕色脂肪细胞生物学领域的逻辑过渡。