Obesity and diabetes genetics and therapeutics in Caenorhabditis elegans.

描述（由申请人提供）：本博士后申请概述了利用秀丽隐杆线虫生物识别肥胖和糖尿病发病机制相关基因的计划。肥胖和2型糖尿病是非常普遍的，高度相关的疾病，在2002年给美国造成了超过1320亿美元的损失，并且在生命年损失方面给社会造成了更大的损失。具体目标是利用基因组学（RNA干扰）和正向遗传学以及新获得的高通量技术对新基因进行饱和筛选，这些新基因在失活时，会导致身体脂肪含量或线粒体生物发生的神经内分泌调节缺陷。由于脂肪代谢失调和线粒体功能障碍都与II型糖尿病的发病机制有明确的关系，因此从筛选中发现的与人类同源的基因将成为进一步研究的主题。由于许多已知的在人类糖尿病中起重要作用的基因在秀丽隐杆线虫中发生突变时也会导致衰老、抗逆性或生殖缺陷，因此将对每一个被确定影响脂肪或线粒体的新基因进行这些多性状分析。在这些测试中获得优先分数的突变体将有能量稳态缺陷，通过定量分析脂质含量、食物消耗和能量消耗来详细表征。遗传上位将确定哪些基因在已知途径或调节能量稳态的新途径中运作。通过转基因报告基因和组织特异性拯救构建，建立感兴趣基因的表达组织和作用细胞类型。对于最有希望的脂肪和线粒体突变体，将使用串联质谱和微阵列mRNA谱分析进行代谢组学分析，以进一步探索代谢缺陷的分子性质。最后，为了确定可能的肥胖或糖尿病治疗方法，一个小分子文库将筛选逆转突变表型的化合物，即肥胖或线粒体缺陷。这项工作的最终目标是确定和表征肥胖和糖尿病发病机制的核心基因，确定可能的治疗分子，并为未来扩大这些努力创造一个平台。

DESCRIPTION (provided by applicant): This postdoctoral fellowship proposal outlines plans to use the organism Caenorhabditis elegans to identify genes involved in the pathogenesis of obesity and diabetes. Obesity and type 2 diabetes are extremely prevalent, highly associated diseases that cost the US more than $132 billion in 2002, and produce an even greater cost on society in terms of life-years lost. Specific aims are to use genomics (RNA interference) and forward genetics together with newly-available, high-throughput technology to perform saturating screens for novel genes which, when inactivated, cause defects in neuroendocrine regulation of body fat content or mitochondrial biogenesis. Genes emerging from the screens with close human homologues will be the subject of further study, since both dysregulated fat metabolism and mitochondrial dysfunction have been clearly implicated in the pathogenesis of type II diabetes. As many known genes important in human diabetes also cause aging, stress resistance or reproductive defects when mutated in C. elegans, assays for these pleiotropies will be conducted for each novel gene identified to affect fat or mitochondria. Mutants receiving priority scores in these assays will have energy homeostasis defects characterized in detail by quantitative assays for lipid content, food consumption, and energy expenditure. Genetic epistasis will identify which genes operate within known pathways or novel pathways regulating energy homeostasis. The tissue of expression and cell type of action will be established for interesting genes by transgenic reporter and tissue-specific rescue constructs. For the most promising fat and mitochondrial mutants, metabolomic profiling using tandem mass spectrometry and microarray mRNA profiling analysis will be conducted to further explore the molecular nature of metabolic defects. Finally, in order to identify possible obesity or diabetes therapeutics, a small-molecule library will be screened for compounds that reverse mutant phenotypes, i.e. obesity or mitochondrial defects. The ultimate goals of this work are to identify and characterize genes central to the pathogenesis of obesity and diabetes, to identify possible therapeutic molecules, and to create a platform to expand these efforts in the future. PUBLIC HEALTH RELEVANCE: Obesity and type 2 diabetes are tightly linked diseases well recognized to be among the leading causes of premature illness and death. Over one billion people are overweight and more than 200 million have diabetes worldwide. The proposed research fellowship aims to identify novel genes involved in the development of obesity and diabetes and possible drugs to fight these devastating diseases, using new technology and a genetic system in which the role of every single gene can be studied systematically.