Genetics of IGF1 and Bone Density: The Role of Nocturnin

IGF1 和骨密度的遗传学：Nocturnin 的作用

基本信息

批准号：
8101832
负责人：
CLIFFORD JAMES ROSEN
金额：
$ 31.98万
依托单位：
MAINEHEALTH
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-07-22 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8101832
关键词：
3&apos Untranslated Regions 3T3-L1 Cells Adipocytes Adipose tissue Affect Age Age Reporting Age-Related Bone Loss Aging Bone Density Calvaria Candidate Disease Gene Cell Differentiation process Cells Chromosome inversion Chromosomes, Human, Pair 11 Chromosomes, Human, Pair 3 Chromosomes, Human, Pair 6 Circadian Rhythms Computer Simulation Congenic Mice Databases Development Diet Epidemiologic Studies Fatty acid glycerol esters Female Gene Expression Gene Expression Profiling Genes Genetic Genetic Determinism Genetic Polymorphism Genotype Goals Half-Life Health Hepatic Histology Homologous Gene IGF1 gene In Vitro Inbred Strains Mice Insulin-Like Growth Factor I Intra-abdominal Knockout Mice Light Liver Longevity Magnetic Resonance Imaging Maintenance Maps Marrow Mediator of activation protein Messenger RNA Metabolic Molecular Molecular Profiling Mouse Strains Mus Nature Neonatal Obesity Osteoblasts Osteoporosis Pathway interactions Pattern Phenotype Play Production Quantitative Genetics Quantitative Trait Loci Regulation Relative (related person)Role Serum Site Small Interfering RNA Stromal Cells Testing Therapeutic Intervention Time Tissues Transcript Translations Untranslated Regions Up-Regulation Variant abdominal fat bone bone cell bone mass bone turnover cancer risk gain of function in vivo insight insulin sensitivity lipid biosynthesis mRNA Stability male nocturnin novel osteoblast differentiation osteogenic overexpression prevent programs rosiglitazone skeletal substantia spongiosa tool

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of AR45433 had been to define the genetic determinants of IGF-I using two inbred strains of mice, B6 and C3H. We were successful in identifying the strongest QTL for IGF-I and bone density on mouse Chr6, and made a congenic mouse (6T) that carried this locus from C3H, on a B6 background. 6T mice had low bone mass, reduced IGF-I, and enhanced marrow adiposity, but increased insulin sensitivity. Using in silico data bases, expression profiling and sequencing, we excluded one candidate gene, and ascertained that Pparg polymorphisms were a major contributor to the 6T metabolic and skeletal phenotypes. In 6T mice we noted marked up regulation of a Ppar3 -inducible gene, Nocturnin (Noc), which is a circadian deadenylase that targets long 3'UTRs and causes destabilization of mRNA transcripts. In contrast we found that Noc null mice had high bone mass and reduced marrow fat. In vitro silencing of the Noc gene in adipocytes caused an increase in Igf1 transcripts and a reduction in downstream adipogenic markers. Hence, in this proposal we postulate that Pparg regulates IGF-I through activation of Noc, leading to enhanced adipogenesis but destabilization of Igf1mRNA and impaired MSC allocation into bone. To test that hypothesis, we propose 2 specific aims: Specific Aim 1: Determine the role of Noc in skeletal acquisition and maintenance. We will comprehensively define the skeletal and metabolic phenotypes of three mouse strains on a regular and high fat diet and after rosiglitazone treatment: a- Noc null mice, b-:conditional adipose specific Pparg deleted (FKO 3) mice.,and c- B6 littermate controls. Specific Aim 2: Interrogate the molecular mechanisms that define Noc actions on IGF-I and MSC allocation. We will determine Igf1 mRNA stability in B6, 6T and Noc-/- mice,and examine the deadenylating activity of NOC in B6 and 6T. We will also assess the time course of Noc expression in adipocytes and MSCs, and determine how silencing of Noc affects Igf1 and downstream adipogenic and osteogenic targets. Delineating the effects of Noc on skeletal acquisition and maintenance will provide a clearer perspective about age-relate bone loss, and the fate of marrow stromal cells relative to bone and fat. Moreover, identification of a non-transcriptional pathway that regulates IGF-I would have major implications for epidemiologic studies of circulating IGF-I and its relationship to longevity, cancer risk, and osteoporosis. It could also reveal new targets for therapeutic intervention to blunt or enhance IGF-I actions in tissue specific sites. PUBLIC HEALTH RELEVANCE: Our studies will provide valuable insight into the significance of one gene, Nocturnin, that is important in the origin of both fat and bone cells. The exploration of its nature as a light-dark cycle gene regulating the production of insulin-like growth factor 1 should clarify the importance of this pathway in normal bone maintenance, as well as age- related osteoporosis.

描述（由申请人提供）：AR45433的长期目标是使用两种小鼠B6和C3H的近交菌株定义IGF-I的遗传决定因素。我们成功地识别了小鼠ChR6上IGF-I和骨密度的最强QTL，并在B6背景下制造了一种从C3H传递该基因座的优质小鼠（6T）。 6T小鼠的骨骼质量低，IGF-I降低，骨髓肥胖增强，但胰岛素敏感性提高。在使用硅数据库，表达分析和测序中，我们排除了一个候选基因，并确定PPARG多态性是6T代谢和骨骼表型的主要贡献者。在6T小鼠中，我们注意到标记了PPAR3诱导基因的调节，夜曲蛋白（NOC），这是一种昼夜节律降解酶，靶向长3'UTR，并导致mRNA转录物的不稳定。相比之下，我们发现NOC零小鼠的骨骼质量很高，骨髓脂肪减少。 NOC基因在脂肪细胞中的体外沉默导致IGF1转录本的增加和下游脂肪形成标记的降低。因此，在此提案中，我们假定PPARG通过激活NOC来调节IGF-I，从而导致脂肪生成增强，但IGF1MRNA的稳定性不稳定并损害了MSC分配到骨骼中。为了检验该假设，我们提出了2个特定目的：具体目的1：确定NOC在骨骼采集和维持中的作用。我们将全面定义三种小鼠菌株的骨骼和代谢表型，在定期且高脂肪饮食中，以及罗格列酮治疗后：A- NOC NULL小鼠，B-：有条件的脂肪特异性PPARG删除（FKO 3）小鼠。具体目标2：询问定义对IGF-I和MSC分配的NOC作用的分子机制。我们将确定B6、6T和NOC - / - 小鼠中的IGF1 mRNA稳定性，并检查B6和6T中NOC的致命活性。我们还将评估脂肪细胞和MSC中NOC表达的时间过程，并确定NOC的沉默如何影响IGF1和下游脂肪生成和成骨靶标。描述NOC对骨骼采集和维持的影响将提供有关年龄相关的骨质流失以及骨髓基质细胞相对于骨骼和脂肪的命运的更清晰的观点。此外，对调节IGF-I的非转录途径的鉴定将对循环IGF-I及其与寿命，癌症风险和骨质疏松症的关系的流行病学研究产生重大影响。它还可以揭示用于治疗干预的新靶标，以钝性或增强组织特定部位的IGF-I作用。公共卫生相关性：我们的研究将为一种在脂肪和骨细胞的起源中很重要的基因，夜曲蛋白的意义提供宝贵的见解。探索其性质作为调节胰岛素样生长因子1产生的轻便循环基因，应阐明该途径在正常骨骼维持中的重要性以及与年龄相关的骨质疏松症。