Dicer and miRNA in adipocyte differentiation and fat metabolism

Dicer 和 miRNA 在脂肪细胞分化和脂肪代谢中的作用

• 批准号: 7140621
• 负责人: STEPHEN JONES
• 金额: $ 19.84万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-20 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140621
• 关键词: RNA interference; adipocytes; cell differentiation; enzyme activity; exoribonucleases; gene targeting; genetically modified animals; glucose tolerance test; insulin; laboratory mouse; lipid metabolism; microRNAs; northern blottings; pancreatic islet function; polymerase chain reaction; southern blotting; tissue /cell culture

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the role(s) of the miRNA processing enzyme Dicer and of microRNA (miRNA) molecules in the regulation of mammalian adipocyte differentiation and fat metabolism. miRNAs are small ~22 nucleotide non-coding ribonucleic acids that regulate gene expression by interacting with target mRNA transcripts. Little is known about the precise biological roles of most mammalian miRNAs, but the abundance of different miRNA molecules encoded in mammalian genomes and their specific spatial and temporal patterns of expression suggest that these molecules may regulate a broad array of functions, including development, cell growth, and cell differentiation. Several recent publications indicate potential roles for miRNA molecules in adipogenesis in Drosophila, and in adipocyte differentiation and in glucose-dependent insulin exocytosis in mammalian cultured cells. These findings suggest that miRNA molecules regulate mammalian fat metabolism in vivo and may be therapeutic targets for treatment of diabetes mellitus. Dicer is a key enzyme in the processing of miRNA molecules. Our lab has recently utilized gene targeting in ES cells to create a Dicer-conditional allele in mice. The use of this new model circumvents the early embryonic lethal phenotype of Dicer-null mice, permitting analysis of the roles of Dicer and, by extension, miRNA in a wide variety of biological events. We have used viral-mediated transduction of Cre recombinase into mouse embryonic fibroblasts derived from these Dicer conditional mice to generate primary fibroblasts lacking Dicer activity. We propose to utilize these viable, Dicer-null, primary cells to study the effects of miRNA on adipocyte differentiation in vitro. Furthermore, we propose to cross the Dicer conditional mice with Ins2-Cre transgenic mice in order to analyze insulin secretion and adipogenesis in mice that lack Dicer in pancreatic beta cells. These experiments should provide definitive in vivo evidence for RNAi - mediated regulation of insulin production and mammalian fat metabolism. Relevance to Public Health: Diabetes and other obesity-related diseases affect a significant percentage of the population. By identifying the role of Dicer and of miRNA molecules in fat metabolism, these experiments will determine if these molecules are attractive targets for therapeutic intervention in diabetes and obesity.

描述（由申请人提供）：该项目的长期目标是了解miRNA加工酶dicer和microRNA（miRNA）分子在调节哺乳动物脂肪细胞分化和脂肪代谢中的作用。 miRNA是小〜22个核苷酸非编码核糖核酸，通过与靶mRNA转录物相互作用来调节基因表达。关于大多数哺乳动物miRNA的精确生物学作用知之甚少，但是在哺乳动物基因组中编码的不同miRNA分子及其表达的特定空间和时间模式表明，这些分子可能调节广泛的功能，包括发育，细胞生长和细胞分化。最近的一些出版物表明，miRNA分子在果蝇中的脂肪形成以及脂肪细胞分化以及葡萄糖依赖性胰岛素胞吐作用中的潜在作用。这些发现表明，miRNA分子在体内调节哺乳动物脂肪代谢，并且可能是治疗糖尿病的治疗靶标。 DICER是miRNA分子加工中的关键酶。我们的实验室最近在ES细胞中利用了基因靶向，在小鼠中创建了迪切尔 - 条件等位基因。这种新模型的使用避免了dicer-null小鼠的早期胚胎致命表型，从而允许分析dicer的作用，并扩展在各种生物学事件中miRNA。我们已经使用了病毒介导的CRE重组酶转导源自这些dicer条件小鼠的小鼠胚胎成纤维细胞，以产生缺乏丁香活性的原发性成纤维细胞。我们建议利用这些可行的，dicer-null的原代细胞研究miRNA对体外脂肪细胞分化的影响。此外，我们建议用INS2-CRE转基因小鼠穿越DICER条件小鼠，以分析在胰腺β细胞中缺乏dicer的小鼠中的胰岛素分泌和脂肪形成。这些实验应为RNAi介导的胰岛素产生和哺乳动物脂肪代谢的调节提供明确的体内证据。 与公共卫生有关：糖尿病和其他与肥胖有关的疾病会影响很大一部分人口。通过鉴定迪切尔和miRNA分子在脂肪代谢中的作用，这些实验将确定这些分子是否是糖尿病和肥胖症治疗干预的有吸引力的靶标。