A Role of Osteoimmunology in Leptin-Regulated Bone Metabolism

骨免疫学在瘦素调节骨代谢中的作用

基本信息

批准号：
7687920
负责人：
Erica Lynn Scheller
金额：
$ 4.2万
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：
2008
资助国家：
美国
起止时间：
2008-09-01 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7687920
关键词：
Absorbable Gelatin Sponge Affect Age Alkaline Phosphatase Arthritis Binding Bone Density Bone Diseases Bone Marrow CCL2 gene Cell Differentiation process Cell Line Cells Coculture Techniques Conditioned Culture Media Data Environment Enzyme-Linked Immunosorbent Assay Eotaxin Equilibrium Fatty acid glycerol esters Granulocyte-Macrophage Colony-Stimulating Factor Harvest Hormones Hour Hypothalamic structure Immune Immune system Implant In Vitro Individual Inflammation Interferon Type II Interleukin-10 Interleukin-13 Interleukin-17 Interleukin-6 Interleukin-9 Investigation Leptin Leptin resistance Link Maintenance Marketing Marrow Measurement Measures Mediating Metastatic Neoplasm to the Bone Microarray Analysis Molecular Profiling Monitor Mus Neoplasm Metastasis Obesity Osteoblasts Osteocalcin Osteoclasts Osteogenesis Osteomyelitis Osteoporosis Periodontal Diseases Peripheral Phenotype Phosphorylation Play Population Porifera Postmenopausal Osteoporosis Production Proliferating Proteins Recombinants Regulation Reporter Role Signal Transduction Small Inducible Cytokine A3 Staining method Stains Stress Stromal Cells Surgical Replantation Suspension substance Suspensions Sympathetic Nervous System System Techniques Time Transgenic Organisms United States National Institutes of Health Woman base bone bone loss bone mass bone metabolism bone sialoprotein cytokine db/db mouse direct application in vivo leptin receptor lipid metabolism long bone macrophage mineralization monocyte monolayer mouse model novel oncostatin M osteoblast differentiation osteogenic receptor scaffold subcutaneous synthetic polymer Bioplex uptake vertebra body

项目摘要

DESCRIPTION (provided by applicant): Osteoimmunology is defined as the interplay between the immune system and bone metabolism. This field has developed from the realization that during times of inflammation and stress, immune cells generated in the bone secrete factors that can profoundly affect bone regulation. Leptin is a 16 kDa adipocytokine produced by fat-containing cells. Binding of leptin to central long-form receptors in the hypothalamus stimulates bone loss by decreasing osteoblast function. It has also been demonstrated in vitro that direct binding of leptin to bone marrow stromal cells (BMSCs) can promote their differentiation toward an osteogenic lineage. We hypothesize and have generated preliminary data to suggest that a novel third mechanism of leptin-mediated bone regulation exists. It is hypothesized that leptin acts peripherally in the bone marrow by binding to immune cells such as macrophages to indirectly regulate bone mass through secondary changes in BMSC differentiation and osteoblast function. We will explore these osteoimmunologic interactions to better define the niche of the BMSC and to determine the role our immune system may play in post-natal bone maintenance. To explore our hypothesis in the context of leptin we will employ both in vitro and in vivo techniques. Leptin and leptin-receptor deficient mouse models will be utilized for harvest of primary macrophages and BMSCs. Macrophage cells will be analyzed for their ability to secrete mineralization and differentiation-regulating cytokines through the use of bead-based multichannel ELISA, marketed as BioPlex by Bio-Rad. Differentiation of BMSCs will also be monitored in the presence of control or stimulated macrophages and their products. Finally, local leptin regulation of in vivo bone formation will be explored by re-implanting harvested BMSCs subcutaneously in gelfoam scaffolds. The resulting ossicles will be qualitatively analyzed using micro-CT and immunohistological techniques. This concept of osteoimmunology implies a circle of creation and influence in the marrow cavity and has important implications for the study of inflammation-linked bone disorders including osteoporosis, cancer metastasis to the bone, arthritis, osteomyelitis and periodontal disease.

描述（由申请人提供）：骨免疫学被定义为免疫系统和骨代谢之间的相互作用。这一领域的发展源于这样一种认识：在炎症和压力时期，骨骼中产生的免疫细胞会分泌能够深刻影响骨骼调节的因子。瘦素是一种由含脂肪细胞产生的 16 kDa 脂肪细胞因子。瘦素与下丘脑中央长型受体的结合通过降低成骨细胞功能来刺激骨质流失。体外实验还证明，瘦素与骨髓基质细胞（BMSC）直接结合可以促进它们向成骨谱系分化。我们假设并生成了初步数据，表明瘦素介导的骨调节存在第三种新机制。据推测，瘦素通过与巨噬细胞等免疫细胞结合，在骨髓外周发挥作用，通过骨髓间充质干细胞分化和成骨细胞功能的二次变化来间接调节骨量。我们将探索这些骨免疫相互作用，以更好地定义 BMSC 的生态位，并确定我们的免疫系统在产后骨维持中可能发挥的作用。为了在瘦素的背景下探索我们的假设，我们将采用体外和体内技术。瘦素和瘦素受体缺陷型小鼠模型将用于收获原代巨噬细胞和骨髓间充质干细胞。通过使用基于微珠的多通道 ELISA（由 Bio-Rad 以 BioPlex 名义销售），将分析巨噬细胞分泌矿化和分化调节细胞因子的能力。还将在对照或刺激巨噬细胞及其产物存在的情况下监测 BMSC 的分化。最后，通过将收获的骨髓间充质干细胞皮下重新植入明胶海绵支架中，探索体内骨形成的局部瘦素调节。将使用显微 CT 和免疫组织学技术对所得小骨进行定性分析。骨免疫学的这一概念意味着骨髓腔中的创造和影响循环，对于炎症相关的骨疾病（包括骨质疏松症、癌症骨转移、关节炎、骨髓炎和牙周病）的研究具有重要意义。