MOLECULAR DISSECTION OF REGIONAL ADIPOSITY

描述(申请人提供)：肥胖是一个日益增长的国家健康问题，它与心血管疾病和糖尿病的共病密切相关。基于人群的研究表明，过剩脂肪组织的区域位置与健康影响之间存在强烈的关联，腹内内脏肥胖会导致最有害的影响。对人类和啮齿动物的研究表明，每个白色脂肪组织(WAT)储存库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，还没有描述一个或另一个特定Wat储存库的脂肪细胞独有表达的基因。为了解决每个Wat仓库在转录上是不同的假设，我们准备并差异筛选了小鼠Wat仓库消减文库，并进行了初步的过滤器DNA阵列杂交研究。以小鼠为模型系统，R21提案中的研究进一步描绘了四个不同来源的脂肪细胞之间的基因表达差异-来自野生来源和肥胖来源的大网膜、皮下、附睾和腹膜后脂肪细胞。这些转录图谱将对不同水库中脂肪细胞基因表达的差异如何导致区域性肥胖症的病理生理提供关键的见解。具体目标有两个：1.利用DNA微阵列、消减克隆和差异显示，我们将鉴定白色脂肪细胞储存库特异性基因的表达谱。2.)将建立和验证用于高通量研究Wat Depot特异性基因表达的体外细胞培养模型。这项研究的长期目标是确定在水库规范和体内基因表达中起作用的DNA元件及其同源转录因子。这些知识将被用来确定导致区域性肥胖的病理生理学和共病的分子机制，并设计Wat Depot特异性启动子结构来进行有针对性的消融研究。只有这样，特定的水库对健康和疾病的贡献才能在体内得到评估和调节；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.