The Mechanisms of Bone Mass Regulation by FIP200

FIP200 调节骨量的机制

基本信息

批准号：
8531862
负责人：
Fei Liu
金额：
$ 33.24万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8531862
关键词：
Adult Autophagocytosis Biological Blood Bone Density Bone Development Bone Diseases Calvaria Cell Lineage Cell physiology Cells Complex Defect Degradation Pathway Development Disease Disease model Embryo Embryonic Development Excision Family Future Genes Genetic Glucocorticoids Goals Growth Health Homeostasis Human Interruption Knock-out Knockout Mice Knowledge Lesion Malignant Neoplasms Mammalian Cell Measures Membrane Metabolic Mitochondria Molecular Mus Neonatal Nutrient Nutritional Organelles Osteoblasts Osteoporosis PTK2 gene Pathogenesis Pathway interactions Patients Perinatal Phenotype Play Population Proteins Public Health Reactive Oxygen Species Regulation Role Signal Pathway Signal Transduction Signaling Molecule Sirolimus Skeletal Development Staging Starvation Tissues Transgenic Mice Ubiquitin Vascular blood supply Woman age group aged base bone bone cell bone health bone loss bone mass bone metabolism cell type improved in vivo inhibitor/antagonist men mouse model mutant novel novel therapeutics osteoblast differentiation postnatal prevent research study response skeletal treatment planning

项目摘要

DESCRIPTION (provided by applicant): The long term goal of the proposed studies is to understand the mechanisms of cell signaling in the regulation of key cellular functions in skeletal development/disease. In this proposal, we focus on the role of FIP200 (FAK-family Interacting Protein of 200 kDa) in the regulation of osteoblast differentiation. FIP200 was initially identifie as a novel FAK and Pyk2 inhibitor. Recently, FIP200 was identified as an essential component of mammalian autophagy. Despite our knowledge about FIP200 as a key signaling node in both embryogenesis and cancer development, it is unknown to what extent FIP200 regulates bone metabolism. In our preliminary studies, we found: 1. FIP200 conditional knockout in osteoblasts led to a severe osteopenic phenotype; 2. Osteoblast differentiation was greatly impaired in FIP200-null primary osteoblast cultures; 3. Primary calvarial osteoblasts have active basal and high inductive autophagy activity. However, FIP200 null primary calvarial osteoblasts expressing GFP-LC3 failed to form punctuate membrane structures in response to starvation and rapamycin treatment, indicating that FIP200 null osteoblasts had autophagy deficiency; 4. FIP200-null osteoblasts had large ubiquitin-positive aggregates, another indication of defective autophagy in these cells; and 5. Early neonatal FIP200 Osx-CKO mice had significant growth retardation in response to naturally occurring starvation as a result of sudden loss of maternal blood supply. Therefore, we hypothesize that FIP200 regulates bone mass through its regulation on osteoblast autophagy. The overall objective of the proposed project is to determine the molecular mechanisms and signaling pathways by which FIP200 regulates osteoblast function and bone mass using a combination of molecular, cell biological and mouse genetic approaches. The specific aims of this proposal are: Aim 1. To determine to what extent FIP200 regulates osteoblast function through its autophagic role. Aim 2. To elucidate the mechanism by which FIP200 regulates early postnatal bone development. Aim 3. To determine the role of FIP200 in bone homeostasis in adult mice. Health relevence: As a major public health threat, osteoporosis is present in an estimated 44 million men and women aged 50 and older, which represents 55 percent of the population in that age group in the USA. The proposed study with unique mouse disease model is highly valuable for determining the molecular and cellular mechanisms of pathogenesis of osteoporosis. It will allow us to define a novel bone mass regulation mechanism by autophagy, which is fundamentally important for the development of new therapeutics to treat bone diseases including osteoporosis. 1

描述（由申请人提供）：拟议研究的长期目标是了解骨骼关键细胞功能调节细胞信号的机制发育/疾病。在此提案中，我们关注FIP200（FAK-family相互作用的200 kDa）在成骨细胞分化的调节中的作用。 FIP200最初被识别为一种新型的FAK和PYK2抑制剂。最近，FIP200被确定为哺乳动物自噬的重要组成部分。尽管我们对FIP200作为胚胎发生和癌症发育的关键信号节点的了解，但未知FIP200在多大程度上调节骨代谢。在我们的初步研究中，我们发现：1。FIP200成骨细胞中有条件敲除导致严重的骨质减少表型。 2。成骨细胞的分化在FIP200-NULL原发性成骨细胞培养物中受到了极大的损害。 3。原发性钙细胞成骨细胞具有活性的基础和高电感自噬活性。然而，表达GFP-LC3的FIP200无效的原发性成骨细胞未能响应饥饿和雷帕霉素治疗而形成膜结构，表明FIP200 NULL成骨细胞具有自噬缺陷； 4。FIP200-NULL成骨细胞具有较大的泛素阳性聚集体，这是这些细胞中自噬有缺陷的另一种迹象。和5。新生儿FIP200早期OSX-CKO小鼠由于孕产妇供应的突然丧失而自然发生饥饿，因此具有显着的生长迟缓。因此，我们假设FIP200通过其对成骨细胞自噬的调节来调节骨量。拟议项目的总体目标是确定FIP200使用分子，细胞生物学和小鼠遗传方法的组合来调节成骨细胞功能和骨骼质量的分子机制和信号通路。该提案的具体目的是：目标1。确定FIP200在多大程度上通过其自噬作用调节成骨细胞的功能。目的2。阐明FIP200调节早期产后骨发育的机制。目标3。确定FIP200在成年小鼠中骨稳态中的作用。健康相关性：作为一个主要的公共卫生威胁，据估计，骨质疏松症估计有4,400万名50岁及50岁以上的男女，占美国该年龄段的人口的55％。提出的具有独特小鼠疾病模型的研究对于确定骨质疏松症发病机理的分子和细胞机制非常有价值。它将使我们能够通过自噬来定义一种新型的骨质量调节机制，这对于开发新疗法以治疗包括骨质疏松在内的骨骼疾病至关重要。 1