HORMONAL CONTROL OF ADIPOSE GENE EXPRESSION

这项研究的长期目标是确定脂肪细胞如何 启动和传播差异化计划，特别是如何 关键基因(特别是C/EBApha基因)启动和 协调程序被转录激活或解除抑制。 这一信息可能导致新的预防和/或 逆转肥胖及其相关疾病，包括2型 糖尿病。这种方法应该会让我们找到转录因子 在脂肪发育途径的早期发挥作用。三种类型的 核反式作用因素已被确定，这些因素影响 C/EBPalpha启动子介导的转录：1.CUP(C/EBPalpha 未分化蛋白，明显抑制C/EBPalpha基因)。 我们已经对CUP进行了纯化和部分测序，从而鉴定了 AP-2Apha作为CUP复合体的一个组成部分；2.C/EBPalpha(它 自动激活自身基因的转录)和其他C/EBP家族 3.反式激活C/EBPalpha基因的PPARGamma。 我们的直接目标是确定这些因素是如何调节的 C/EBPalpha基因的转录及其本身是如何 受监管的。我们已经开发了一种新的方法，3T3-F442a 携带转基因的前脂肪细胞(例如，启动子-报告 构建物或调节基因)可以植入皮下 并发育成可用于分析的脂肪组织 转基因的表达及其功能。具体目标是 确定：CUP/AP-2Apha(和)的作用和机制(S) 可能是CUP抑制物复合体的其他组件)调节 C/EBPalpha基因的表达。角色(S)与作用机制 其他反式作用因子(PPARGamma)和顺式调节元件 (例如，Myc/ZIF和Sp1位点)调节C/EBPalpha基因。多么 C/EBPalpha(及其控制的脂肪细胞基因)受激素调控 分化的脂肪细胞，尤其是胰岛素和cAMP。

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.