REGULATION OF CHOLESTEROL HOMEOSTASIS BY NONCODING RNAS

非编码 RNA 调节胆固醇稳态

基本信息

批准号：
8225176
负责人：
DANIEL S ORY
金额：
$ 45.22万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-01 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8225176
关键词：
Animal Model Atherosclerosis Cell Line Cells Chinese Hamster Ovary Cell Cholesterol Cholesterol Homeostasis Complement Computer Simulation Coupled Defect Disease Elements Endoplasmic Reticulum Equilibrium Event Exhibits Exons Fatty acid glycerol esters Feedback Functional RNA Gene Expression Gene Targeting Generations Genes Genetic Screening Genetic Translation Genomics Goals Hereditary Disease Human Human Genetics Inborn Errors of Metabolism Inborn Genetic Diseases Introns Knock-out Knockout Mice Laboratories Maintenance Mass Spectrum Analysis Measures Mediating Membrane Membrane Lipids Metabolic stress Metabolism MicroRNAs Modeling Molecular Molecular Target Nucleotides Oligonucleotides Open Reading Frames Orphan Pathway interactions Phenotype Physiological Predisposition Process Promoter Regions Proteomics RNA RNA Splicing Regulation Regulatory Pathway Role Small Nucleolar RNA Small RNA Sterols Time Translations Walking base cell growth regulation cell type cholesterol trafficking drug development embryonic stem cell feeding human DICER1 protein in vivo innovation lipoprotein cholesterol mRNA Precursor meetings mouse model mutant novel promoter public health relevance response trafficking uptake

项目摘要

DESCRIPTION (provided by applicant): Cellular cholesterol homeostasis is regulated at multiple cholesterol transfer steps and through a negative feedback loop that responds to elevations of membrane cholesterol in the endoplasmic reticulum (ER). Alterations in these sterol sensing and trafficking pathways in contribute to human inborn errors of metabolism and to acquired disease states. To elucidate mechanisms governing these critical cholesterol homeostatic pathways, we performed a functional genetic screen that led to isolation of cell lines with intracellular cholesterol trafficking defects that were enriched in mutants with disruption of long non-coding RNA (ncRNA) genes. These genes exhibit evolutionarily conserved exon/intron organization and core promoter regions, lack significant open reading-frames or nucleotide homology within exons, and contain short, highly conserved intronic regions that harbor small nucleolar RNA (snoRNA) species. This class of long ncRNAs appears principally to serve as host genes to facilitate expressing and processing of the orphan snoRNAs. We hypothesize that the processed snoRNAs modulate expression of genes involved in cholesterol homeostasis, possibly through control of splicing events or translation, and thus represent a previously unrecognized mode of regulation for cellular cholesterol homeostasis. The Specific Aims of this proposal are (1) To characterize ncRNA genes identified by our genetic screen that are critical for maintenance of cholesterol homeostasis, (2) To determine the role of the snoRNA host genes in regulation of intracellular cholesterol transfer and cellular cholesterol homeostasis, (3) To determine the molecular mechanism(s) through which the orphan snoRNA elements exert control over cholesterol regulatory pathways, and (4) To examine the physiological role of the orphan snoRNAs and gene pathways identified through the genetic screen by extending our cell-based studies to in vivo animal models. The proposed studies are innovative in that they explore a novel small RNA-dependent pathway not previously implicated in regulation of cellular cholesterol homeostasis. These studies are highly significant because elucidation of this RNA regulatory pathway has the potential to provide new molecular targets for manipulation of the cellular handling of cholesterol. This proposal is highly relevant to atherosclerosis, a common disease characterized by dysregulation of cholesterol homeostasis, as well as to rare, often fatal inborn errors of sterol metabolism. PUBLIC HEALTH RELEVANCE: Alterations in pathways that regulate cellular cholesterol balance contribute to human genetic diseases and to acquired disease states, such as atherosclerosis. Preliminary studies in our laboratory have identified a set of genes not previously implicated in these cholesterol regulatory pathways. The goal of this proposal is to study how these genes modulate the distribution and level of cholesterol in cells. The proposed studies may identify new targets for drug development for lowering cholesterol in disease states.

描述（由申请人提供）：细胞胆固醇稳态受到多个胆固醇转移步骤的调节，并通过负反馈回路对内质网（ER）中膜胆固醇升高做出反应。这些固醇传感和运输途径的改变导致了人类天生的代谢和获得性疾病状态的变化。为了阐明管理这些关键胆固醇稳态途径的机制，我们进行了一个功能性遗传筛选，该遗传筛选导致细胞系隔离细胞内胆固醇运输缺陷，这些缺陷富集在突变体中，这些突变体破坏了长期非编码RNA（NCRNA）基因。这些基因表现出进化保守的外显子/内含子组织和核心启动子区域，在外显子内缺乏明显的开放式阅读框架或核苷酸同源性，并且包含具有小核仁RNA（SNORNA）物种的短而高度保守的内含子区域。这类长NCRNA似乎主要充当宿主基因，以促进孤儿snornas的表达和处理。我们假设该加工的snoRAS调节胆固醇稳态涉及的基因的表达，可能是通过控制剪接事件或翻译的控制，因此代表了先前未识别的细胞胆固醇稳态调节模式。该提案的具体目的是（1）表征通过我们的遗传筛选确定的NCRNA基因，对于维持胆固醇稳态至关重要，（2）确定SNORNA宿主基因在调节细胞内胆固醇转移和细胞内胆固醇稳态（3）中的作用（3），（3）确定通过分子的控制（3），通过或渗透了（3）。调节途径和（4）通过将基于细胞的研究扩展到体内动物模型，以检查通过遗传筛查鉴定的孤儿snornas和基因途径的生理作用。拟议的研究具有创新性，因为它们探索了一种新型的小RNA依赖性途径，以前与细胞胆固醇稳态调节有关。这些研究非常重要，因为阐明这种RNA调节途径的潜力有可能为操纵胆固醇的细胞处理提供新的分子靶标。该提议与动脉粥样硬化高度相关，动脉粥样硬化是一种常见疾病，其特征是胆固醇稳态失调，以及稀有的，通常是致命的固醇代谢的稀有疾病。公共卫生相关性：调节细胞胆固醇平衡的途径改变有助于人类遗传疾病和获得的疾病状态，例如动脉粥样硬化。我们实验室的初步研究已经确定了一组以前与这些胆固醇调节途径有关的基因。该建议的目的是研究这些基因如何调节细胞中胆固醇的分布和水平。拟议的研究可能会确定用于降低疾病状态中胆固醇的药物开发的新靶标。