HORMONAL CONTROL OF ADIPOSE GENE EXPRESSION

这项研究的长期目标是确定脂肪细胞 差异化计划的启动和传播，特别是，如何 关键基因（特别是C/EBAalpha基因）启动和 协调程序被转录激活或去抑制。 这些信息可能会导致新的方法来预防和/或 逆转肥胖及其相关疾病，包括2型 糖尿病 这种方法应该会引导我们找到转录因子， 在脂肪发育途径中发挥作用。 三种类型的 核反式作用因子已被确定， 由C/EBPalpha启动子介导的转录：1. CUP（C/EB Palpha 未分化蛋白，C/EBPalpha基因的表观阻遏物）。 我们对CUP进行了纯化和部分测序， AP-2A α作为CUP复合物的组分; 2. C/EBPalpha（ 自激活自身基因的转录）和其他C/EBP家族 成员; 3。PPARgamma，其反式激活C/EBPalpha基因。 我们的近期目标是确定这些因素如何调节 C/EBPalpha基因的转录以及它们本身是如何 监管. 我们开发了一种新的方法， 携带转基因的前脂肪细胞（例如，启动子-报告子 构建体或调节基因）可以皮下植入 无胸腺小鼠，并发育成脂肪组织，可以分析其 转基因的表达及其功能。 具体目标是 确定：CUP/AP-2A α（和 可能是CUP阻遏物复合物的其他成分）调节 C/EBPalpha基因的表达。作用和作用机制 其他反式作用因子（PPARgamma）和顺式调节元件 (e.g., Myc/Zif和Sp1位点），其调节C/EBPalpha基因。如何 C/EBPalpha（和它控制的脂肪细胞基因）在细胞内受到神经调节， 胰岛素和cAMP水平显著升高。

The long-term goal of this research is to determine how the adipocyte differentiation program is initiated and propagated, in particular, how key genes (specifically, the C/EBAalpha gene) that initiate and coordinate the program are transcriptionally activated or derepressed. This information may lead to new approaches for the prevention and/or reversal of obesity and its associated diseases including Type 2 diabetes. This approach should lead us to transcription factors that function earlier in the adipose developmental pathway. Three types of nuclear trans-acting factors have been identified which affect transcription mediated by the C/EBPalpha promoter: 1. CUP (C/EBPalpha Undifferentiated Protein, an apparent repressor of the C/EBPalpha gene). We have purified and partially sequenced CUP, and thereby identified AP-2Aalpha as a component of the CUP complex; 2. C/EBPalpha (which autoactivates transcription of its own gene) and other C/EBP family members; and 3. PPARgamma, which transactivates the C/EBPalpha gene. Our immediate goal is to determine how these factors regulate transcription of the C/EBPalpha gene and how they themselves are regulated. We have developed a new methodology whereby 3T3-F442A preadipocytes that harbor a transgene (e.g., promoter-reporter constructs or regulatory genes) can be implanted subcutaneously into athymic mice and develop into adipose tissue that can be analyzed for expression of the transgene and its function. The SPECIFIC AIMS are to determine: the role and mechanism(s) by which CUP/AP-2Aalpha (and possibly other components of the CUP repressor complex) regulates expression of the C/EBPalpha gene. the role(s) and mechanisms of action of other trans-acting factors (PPARgamma) and cis-regulatory elements (e.g., the Myc/Zif and Sp1 sites) that regulate the C/EBPalpha gene. how C/EBPalpha (and adipocyte genes it controls) is hormonally regulated in the differentiated adipocyte notably in insulin and cAMP.