Defining Preadipocyte Signature Genes

描述(申请人提供)：肥胖症在美国处于流行状态，它会导致包括心脏病和2型糖尿病在内的危及生命的疾病的发展。最近的研究表明，成人脂肪组织中脂肪细胞的周转程度很高，这表明前体前脂肪细胞正在不断产生成熟的脂肪细胞。针对脂肪形成分子机制的治疗方法有可能在治疗和预防肥胖症方面有效。脂肪组织中存在的前体脂肪细胞的发育还不是很清楚，这一领域的研究由于我们无法准确识别这种细胞类型而受到限制。此外，将细胞定义为功能性前脂肪细胞的独特基因队列尚未确定。因此，迫切需要开发新的分子工具来研究脂肪细胞前体，识别和表征脂肪形成的新途径和分子程序。到目前为止，对前体脂肪细胞表达的脂肪生成抑制物的研究表明，该基因群可能是脂肪生成过程调节因子的特别丰富的来源。这项研究项目旨在通过全面的方法来识别和研究定义功能性前脂肪细胞的基因，以解决我们对脂肪细胞谱系和前脂肪细胞/脂肪细胞生物学知识的空白。为了解决这一问题，我们开发并验证了一种新的白色前脂肪细胞培养模型(SCAP-23)，该模型来源于小鼠的白色脂肪组织。我们将利用这一模型和高度特征化的3T3-L1白色前脂肪细胞模型和其他细胞系，并分析WAT的前脂肪细胞群体。我们的方法将整合以生物信息学为基础的方法分析的转录图谱数据，并对前脂肪细胞和脂肪细胞中已识别的候选基因和分子途径进行功能测试。在目标1中，我们将利用前脂肪细胞在培养和体内移植中进行的功能研究，鉴定新的前脂肪细胞表达的脂肪生成抑制物和成熟脂肪细胞的表型。在目标2中，我们将进行全基因组转录分析，以确定在承诺的前脂肪细胞中高度丰富和选择性表达的基因。候选的前脂肪细胞承诺/能力基因将通过功能研究来测试间充质前体对前脂肪细胞谱系的承诺的作用。它们的基因敲除对前脂肪细胞承诺和分化的影响也将被确定。我们预测，这些研究将发现脂肪细胞谱系的新分子途径。此外，我们的工作将产生对研究界非常有用的新的基因表达数据集，并将为开发新的分子工具来研究前脂肪细胞奠定重要基础。 与公共健康相关：通过确定脂肪组织形成和功能的潜在分子过程，我们可以更好地定义肥胖的治疗方法和治疗方法。虽然关于脂肪细胞的功能基因有相当多的信息，但那些对成熟脂肪细胞产生的细胞类型至关重要的基因，被称为前脂肪细胞，在很大程度上仍未被探索。通过更好地定义这些基因及其功能，我们的目标是揭示研究脂肪组织发育和控制前脂肪细胞向脂肪细胞转化的过程的独特方法，这最终将导致对肥胖的更好理解和治疗。

DESCRIPTION (provided by applicant): Obesity is at epidemic proportions in the United States and it contributes to the development of life-threatening illnesses including heart disease and type 2 diabetes. Recent studies have demonstrated a significant degree of adipocyte turnover in adult human adipose tissue, indicative of ongoing production of mature adipocytes from precursor preadipocytes. Therapies that target molecular mechanisms of adipogenesis have the potential to be effective in the treatment and prevention of obesity. The development of adipocytes from precursors present in adipose tissue is not well understood and research in this area has been limited by our inability to precisely identify this cell type. Moreover, the unique cohort of genes that define a cell as a functional preadipocyte has not been determined. As such, there remains a pressing need to develop new molecular tools to study the fat cell precursor and to identify and characterize novel pathways and molecular programs of adipogenesis. Studies with preadipocyte-expressed inhibitors of adipogenesis conducted to date indicate that this gene cohort may be a particularly rich source of regulators of the adipogenic process. This research project is designed to address gaps in our knowledge of the adipocyte lineage and preadipocyte/adipocyte biology via comprehensive approaches to identify and study genes that define functional preadipocytes. To address this we have a developed and validated a new white preadipocyte cell culture model (ScAP-23) derived from murine white adipose tissue. We will utilize this model and the highly characterized 3T3-L1 white preadipocyte model and other cell lines and analysis of preadipocyte-containing populations of WAT. Our approaches will integrate transcriptional profiling data analyzed with bioinformatics-based methodologies and functional testing of identified candidate genes and molecular pathways in preadipocytes and adipocytes. In Aim 1 we will identify novel preadipocyte-expressed inhibitors of adipogenesis and the mature adipocyte phenotype using gain of function studies conducted in preadipocytes in culture and with in vivo transplantation. In Aim 2 we will conduct genome-wide transcriptional analysis to identify genes highly enriched and selectively expressed in committed preadipocytes. Candidate preadipocyte commitment/competence genes will be tested for roles in commitment of mesenchymal precursors to the preadipocyte lineage by gain of function studies. The effect of their knockdown on preadipocyte commitment and differentiation will also be determined. We predict these studies will uncover new molecular pathways for the adipocyte lineage. In addition, our work will generate new gene expression datasets highly useful to the research community and will form an important foundation for the development of new molecular tools to study preadipocytes. PUBLIC HEALTH RELEVANCE: By determining the molecular processes underlying the formation and function of adipose tissue we can better define therapies and treatments for obesity. While there is considerable information on the genes which function in adipocytes, those which that are important for the cell type from which mature adipocytes arise, termed preadipocytes, remain largely unexplored. By better defining these genes and their functions we aim to uncover unique ways to study the development of adipose tissue and control the process of conversion of preadipocytes to adipocytes that will ultimately lead to better understanding and treatment of obesity.