MOLECULAR DISSECTION OF REGIONAL ADIPOSITY

描述（由申请人提供）：肥胖是一个日益严重的国家健康问题，它与心血管疾病和糖尿病的合并症密切相关。基于人群的研究表明，过量脂肪组织的区域位置与健康影响之间存在很强的关联，腹部内内脏脂肪导致的有害影响最大。对人类和啮齿动物的研究表明，每一种白色脂肪组织（WAT）都有独特的生理和代谢特征。然而，这些表型差异背后的基因表达模式得到的研究非常有限，并且没有来自一个或另一个特定WAT储库的脂肪细胞专有表达的基因被描述。为了解决每个WAT库在转录上不同的假设，我们准备了一个小鼠WAT库减去文库并进行了差异筛选，并进行了先导过滤DNA阵列杂交研究。利用小鼠作为模型系统，本R21提案的研究进一步描述了野生型和肥胖来源的四种不同WAT储存库（网膜、皮下、附睾和腹膜后）中脂肪细胞的基因表达差异。这些转录谱将对不同WAT仓库中脂肪细胞基因表达的差异如何导致区域肥胖的病理生理产生重要的见解。将进行两个具体目标：1.)利用DNA微阵列，减法克隆和差异显示，我们将描述白色脂肪细胞库特异性基因表达的特征。2)。用于高通量研究WAT库特异性基因表达的体外细胞培养模型将被生成并验证。本研究的长期目标是鉴定在体内WAT库规范和基因表达中起作用的DNA元件及其同源转录因子。这些知识将用于定义导致局部肥胖的病理生理和合并症的分子机制，并设计WAT仓库特异性启动子结构以进行靶向消融研究。只有这样，才能在体内评估和调节特定WAT库对健康和疾病的贡献；这样的实验用目前的分子工具是不可行的。R21提案中研究计划的完成将是实现这些长期目标的关键一步。

DESCRIPTION (provided by applicant): Obesity is a growing national health concern and it is closely linked to comorbidities of cardiovascular disease and diabetes. Population-based studies have indicated a strong association between regional location of excess adipose tissue and health impact, with intra-abdominal visceral adiposity resulting in the most deleterious effects. Studies in humans and rodents indicate that each white adipose tissue (WAT) depot has unique physiological and metabolic profiles. However, the gene expression patterns underlying these phenotypic distinctions have received very limited study and no gene with expression exclusive to adipocytes from one or another particular WAT depot has been described. To address the hypothesis that each WAT depot is transcriptionally distinct, we have prepared and differentially screened a murine WAT depot subtracted library and conducted pilot filter DNA array hybridization studies. Using the mouse as a model system, studies in this R21 proposal further delineate the gene expression differences between adipocytes found in each of four distinct WAT depots - omental, subcutaneous, epididymal and retroperitoneal from wild type and obese sources. These transcriptional profiles will yield critical insights into how differences in gene expression of adipocytes in various WAT depots lead to pathophysiology of regional adiposity. Two specific aims will be conducted: 1.) Utilizing DNA microarray, subtracted cloning, and differential display, we will characterize profiles of white adipocyte depot-specific gene expression. 2.) In vitro cell culture models for the high throughput study of WAT depot specific gene expression will be generated and validated. The long-term goal of this research is to identify DNA elements and their cognate transcription factors that function in WAT depot specification and gene expression in vivo. This knowledge will be used to define the molecular mechanisms that result in pathophysiology and co-morbidities of regional obesity and to design WAT depot-specific promoter constructs to conduct targeted ablation studies. Only in this way can the contribution of a particular WAT depot to health and disease be assessed and modulated in vivo; such experiments are not feasible with current molecular tools. The completion of the research plan in this R21 proposal will be a critical step in achieving these long-term goals.