Mechanisms of IGF-I gene transcriptional activation by growth hormone signaling

描述（由申请人提供）： 项目摘要： 这个应用程序代表了一个年轻的医生，科学家继续他的科学发展的目标，成为一个独立的研究者的承诺的努力。凭借儿科内分泌学的临床背景，他在健康相关研究领域的职业生涯的广泛目标集中在了解激素对细胞内信号传导途径和基因调控的整合。这里描述的5年路径包括在Peter Rotwein博士指导下的研究培训和课程，以提高他的科学背景。这些活动将在俄勒冈州健康与科学大学进行。该研究计划的重点是表征转录因子Stat 5 b在生长激素刺激下介导IGF-I基因表达的机制，这是一个具有重要临床意义的主题，因为IGF-I在管理许多基本生理过程（包括出生后生长）中起着关键作用。具体而言，目标包括Stat 5 b结合的IGF-I基因位点和与Stat 5 b相互作用以促进转录起始的蛋白质的表征。染色质免疫沉淀试验在急性生长激素给药垂体切除大鼠的生理模型的背景下，将评估在增强子和两个IGF-I启动子的转录因子和转录共激活因子的结合的时间和空间动力学，而捕获染色体构象（3C）测定将用于直接连接在两个位点的分子事件。功能评估将包括报告基因活性、限制性内切酶可及性、组蛋白修饰和基因转录的测定。总之，这些研究将提供一个全面的模型，在生长激素刺激后的IGF基因位点的分子事件。 项目相关性： 胰岛素样生长因子-1是人类健康和疾病状态中的关键蛋白质，其作用从儿童生长的基本过程延伸到促进癌症进展。该项目旨在确定胰岛素样生长因子-l生产受生长激素控制的过程。

DESCRIPTION (provided by applicant): Project Summary: This application represents a committed effort of a young physician-scientist to continue his scientific development towards a goal of becoming an independent investigator. With a clinical background in pediatric endocrinology, the broad objectives of his career in health-related research are centered on understanding the integration of hormones on intracellular signaling pathways and gene regulation. The 5-year path described here includes a combination of research training under the mentorship of Dr. Peter Rotwein and coursework to enhance his scientific background. These activities will be conducted at Oregon Health & Science University. The focus of the research proposal is on characterization of the mechanisms by which the transcription factor Stat5b mediates IGF-l gene expression upon growth hormone stimulation, a topic of significant clinical relevance given the critical role of IGF-I in governing many fundamental physiologic processes, including postnatal growth. Specifically, the aims include characterization of sites of the IGF-I gene to which Stat5b binds and proteins that interact with Stat5b to facilitate initiation of transcription. Chromatin immunoprecipitation assays in the context of a physiologic model of acute growth hormone administration to hypophysectomized rats will assess the temporal and spatial kinetics of binding of transcription factors and transcriptional co-activators at enhancers and the two IGF-I promoters, while capturing chromosome conformation (3C) assays will serve to directly link molecular events at two loci. Functional assessments will include assays for reporter gene activity, restriction enzyme accessibility, histone modifications, and gene transcription. Taken together, these studies will provide a comprehensive model of molecular events at the IGF-gene locus upon growth hormone stimulation. Project relevance: Insulin-like growth factor-l is a critical protein in human health and disease states, with roles extending from fundamental processes of childhood growth to contributing to cancer progression. This project seeks to identify the processes by which insulin-like growth factor-l production is controlled by growth hormone.