Studies of Osteoclast Lineage in Health and Disease

健康和疾病中破骨细胞谱系的研究

• 批准号: 10005546
• 负责人: Joseph A Lorenzo
• 金额: $ 41.17万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-12 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10005546
• 关键词: Age; Blood; Blood Circulation; Bone Diseases; Bone Marrow; Bone callus; CXCR4 gene; Calvaria; Cells; Development; Disease; Disease model; Drug Targeting; Engraftment; Femoral Fractures; Fracture; Gene Deletion; Goals; Health; Home environment; Homeostasis; Homing; Inflammation; Inflammatory; Kinetics; Label; Marrow; Measures; Modeling; Molecular; Monitor; Mus; Myelogenous; Osteitis; Osteoclasts; Osteolysis; Osteolytic; Parabiosis; Phenotype; Population; Process; Receptor Cell; Role; Signal Transduction; Site; Source; Spleen; TNF gene; Testing; Time; Vascular blood supply; bone; bone turnover; chemokine receptor; defined contribution; experimental study; in vivo; migration; progenitor; recruit; repaired; therapy design; therapy development; trafficking

Although, we know much about the molecular signals that regulate OC function, we know relatively little about the lineage development and mechanisms that OC use to develop from progenitors. The goal of this application is to better define OC progenitor (OCP) development and trafficking and the mechanisms regulating this process in health and disease so that we can identify potential drug targets to develop superior therapies for bone diseases. The central hypotheses are: 1) During homeostasis marrow-resident cells are the principal OCP source, while during inflammation or fracture repair, circulating cells become a significant source of OCP. 2) The mechanisms regulating OCP migration, engraftment and maturation to OC in bone differ between healthy and disease states. To test these hypotheses, we propose the following aims: 1. Define the role that CX3CR1+ OCP have in OC development during homeostasis and identify mechanisms regulating their homing and engraftment. 1A) Perform time course studies in CX3CR1-CreERT2-Ai14 mice at various ages to examine the kinetics of labeled OC. We will also monitor the kinetics of labeled OCP in the bone marrow, blood and spleen. 1B) The cell receptors EBI2 and CX3CR1 are expressed on OCP and have previously been implicated to influence OCP homing, engraftment and maturation. We will determine their role in OCP lineage development and trafficking in vivo under homeostatic conditions using CX3CR1-CreERT2-Ai14 mice and gene deletion. 2. Examine OCP homing from the circulation during bone inflammation and fracture repair. These studies will examine two disease models in which we previously demonstrated that circulating OCP are recruited to engraft in bone: TNFa-induced bone inflammation and a repairing fracture. 2A) Study a TNFa-induced inflammatory bone model (a WT parabiont has TNFα injected over its calvaria; the other parabiont is a CX3CR1-EGFP; TRAP-tdTomato mouse) and determine the rate that circulating labeled cells home to the inflammatory site, form OC and disappear. OCP kinetics will be measured as in 1A. 2B) Study a parabiosis fracture model (a WT parabiont receives a femur fracture; the other parabiont is a CX3CR1-EGFP; TRAP-tdTomato mouse) and determine the rate that circulating labeled cells home to the repairing callus, form OC and disappear. OCP kinetics will be measured as in 1A. 2C) Determine the phenotype and kinetics of circulating OCP that home to bone with TNFa-induced inflammation or fracture repair by injecting various populations of OCP from CX3CR1-EGFP; TRAP-tdTomato mice and monitoring the rates that labeled OC appear and disappear in bone. 2D) Determine if gene deletion of EBI2 or CX3CR1 CXCR4 alters the ability of circulating OCP to home and mature into OC in the models of TNFa-induced bone inflammation and fracture repair studied in aim 2C.

虽然，我们对调节OC功能的分子信号了解很多，但我们对 OC用来从祖细胞发展的谱系发展和机制。该应用程序的目标 是更好地定义OC祖细胞（OCP）的发展和贩运以及调节此过程的机制 在健康和疾病中，我们可以确定潜在的药物靶标，以开发出骨骼的优质疗法 疾病。中央假设是：1）在稳态期间，骨髓居住的细胞是主要的OCP 来源，在炎症或断裂修复期间，循环细胞成为重要的来源 OCP。 2）调查OCP迁移，植入和成熟到OC的机制不同 在健康状态和疾病状态之间。为了检验这些假设，我们提出以下目的： 1。定义CX3CR1+ OCP在稳态期间OC发育中的作用并确定 调节其归宿和植入的机制。 1A）在CX3CR1-CREERT2-AI14小鼠的各个年龄进行时间课程研究以检查的动力学 标记为OC。我们还将监测骨髓，血液和索伦中标记的OCP的动力学。 1b）单元接收器EBI2和CX3CR1在OCP上表示，以前已与 影响OCP归宿，参与和成熟。我们将确定它们在OCP谱系开发中的作用 使用CX3CR1-CREERT2-AI14小鼠和基因缺失在体内贩运体内。 2。检查骨骼注射和断裂修复过程中循环中的OCP归巢。 这些研究将研究两个疾病模型，我们以前证明了循环OCP是 招募以植入骨头：TNFA诱导的骨注射和修复骨折。 2A）研究TNFA诱导的炎症骨模型（WT副抗合体在其钙质上注射了TNFα； 其他抛物线是CX3CR1-EGFP；陷阱-TDTOMATO小鼠）并确定循环标记细胞的速率 炎症部位的故乡，形成OC并消失。 OCP动力学将以1A的形式进行测量。 2b）研究抛物线抗体骨折模型（WT parabiont接受了股骨骨折；另一个副骨是一个 CX3CR1-EGFP;陷阱-TDTOMATO小鼠），并确定循环标记的细胞回家的速率 修复愈伤组织，形成OC并消失。 OCP动力学将以1A的形式进行测量。 2C）确定带有TNFA诱发的炎症的循环OCP的表型和动力学 或通过从CX3CR1-EGFP注入各种OCP来修复裂缝；陷阱-TDTOMATO小鼠和 监视标记OC外观并消失在骨骼中的速率。 2d）确定EBI2或CX3CR1 CXCR4的基因缺失是否改变了循环OCP在家的能力和 在AIM 2C中，在TNFA诱导的骨注射和断裂修复的模型中，成熟到OC中。