OSTEOCLAST MEDIATED BONE REMODELING

破骨细胞介导的骨重塑

• 批准号: 6338643
• 负责人: Philip A Osdoby
• 金额: $ 24.58万
• 依托单位: BARNES-JEWISH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6338643
• 关键词: RNase protection assay; biological signal transduction; cell cell interaction; cell differentiation; chemokine; chickens; cytokine; cytokine receptors; enzyme linked immunosorbent assay; hormone regulation /control mechanism; human tissue; immunocytochemistry; in situ hybridization; integrins; laboratory mouse; osteoblasts; osteoclasts; osteogenesis; physiologic bone resorption; polymerase chain reaction; tissue /cell culture

Bone development and remodeling are dependent on a complex interactive network of humoral and local factors produced by bone cells, bone marrow cells, immunocompetent cells, vascular cells, and precursors for these cell populations. Insights obtained as to which osteoblast factors influence osteoclast (Oc) development and how they have helped define the cellular and molecular processes involved in bone development and remodeling and provide potential new therapeutic strategies to overcome endocrine or local disorders in bone formation and resorption becomes uncoupled. The converse of this avenue of research has to date received only limited attention, namely, how Ocs might regulate osteoblast development, activity, and senescence. There is now a growing awareness based on experimental evidence demonstrating that Ocs synthesize and release cytokines, growth factors, matrix molecules, arachidonic acid metabolites, and other reactive species such as superoxide and nitric oxide. These may influence osteoblast differentiation and action. The objectives outlined in this project re designed to build on our observations that Ocs and Oc-like cells can modulate osteoblast development and activity. During the last period of support we showed that Ocs produce small pro-inflammatory peptides know as chemokines, such as IL-8 and GROalpha, in a regulated fashion and that these chemokines influenced osteoblast development and function. To further define the role of Oc-derived chemokines in normal and pathological bone remodeling we propose: 1) to expand our analysis of chemokines proposed by Ocs and their modulation by hormonal cytokine and matrix-dependent signals, 2) to examine the effects of Oc-derived chemokines, such as IL-8 and GROalpha, on osteoblast development and function, including their influence on osteoblast migration, integrin expression, matrix synthesis or degradation, and 3) to identify and characterize osteoblast chemokine receptors has a function of osteoblast development, physiology, and pathophysiology. Recent signal transduction mechanisms involved in Oc- derived chemokine mediated modulation of osteoblastogenesis and activity will be examined. All of the above studies will use a combination of in vivo and in vitro approaches, and model systems including the rat calvarial injection model for histomorphometric studies, human tissue sections for in situ hybridization and immunohistochemical analysis, isolated human and avian Ocs human Oc-like cells, the mouse Oc-like cell developmental, and cells obtained from an IL-8 receptor knockout mouse. Oc chemokine production, mRNA steady state levels and regulation will be assessed by RT=PCR, RNAse protection assay, chemokine ELISA, and in situ hybridization techniques. Osteoblast development and activity will be evaluated based on multiple biochemical and molecular markers of the osteoblast phenotype, including integrins, matrix proteins, and metalloproteinases. Such studies are anticipated to reveal new aspects of normal bone remodeling mechanisms and have potential to lend insight into skeletal pathologies such as osteoporosis, osteoarthritis and other inflammatory bone disorders.

骨骼的发育和重塑依赖于复杂的相互作用 由骨细胞、骨髓产生的体液和局部因子网络 细胞、免疫活性细胞、血管细胞及其前体细胞 细胞群。关于哪些成骨细胞因子的见解 影响破骨细胞（Oc）的发育以及它们如何帮助定义 参与骨骼发育和发育的细胞和分子过程 重塑并提供潜在的新治疗策略来克服 内分泌或骨形成和吸收的局部紊乱变得 脱钩。迄今为止，这一研究途径的反面已经收到 仅有限关注，即 Ocs 如何调节成骨细胞 发育、活动和衰老。现在人们的意识越来越强 基于证明 Ocs 合成和 释放细胞因子、生长因子、基质分子、花生四烯酸 代谢物和其他活性物质，例如超氧化物和硝酸 氧化物。这些可能影响成骨细胞的分化和作用。这 该项目中概述的目标经过重新设计，以我们的 观察到 Ocs 和 Oc 样细胞可以调节成骨细胞 发展和活动。在上一次支持期间，我们表明 Ocs 产生小的促炎肽，称为趋化因子，例如 IL-8 和 GROalpha，以受调节的方式，并且这些趋化因子 影响成骨细胞的发育和功能。进一步明确角色 Oc 衍生趋化因子在正常和病理性骨重塑中的作用 建议：1）扩大我们对 Ocs 提出的趋化因子的分析及其 通过激素细胞因子和基质依赖性信号进行调节，2) 检查 Oc 衍生趋化因子的影响，例如 IL-8 和 GROalpha， 成骨细胞的发育和功能，包括它们对 成骨细胞迁移、整合素表达、基质合成或 降解，3) 鉴定和表征成骨细胞趋化因子 受体具有成骨细胞发育、生理和功能的功能 病理生理学。最近的信号转导机制涉及 Oc- 衍生趋化因子介导的成骨细胞生成和活性调节 将接受检查。所有上述研究都将结合使用 体内和体外方法以及包括大鼠在内的模型系统 用于组织形态计量学研究的颅骨注射模型，人体组织 原位杂交和免疫组织化学分析切片， 分离的人类和鸟类 Ocs 人类 Oc 样细胞、小鼠 Oc 样细胞 发育细胞和从 IL-8 受体敲除小鼠获得的细胞。奥克 趋化因子的产生、mRNA稳态水平和调节将 通过 RT=PCR、RNAse 保护测定、趋化因子 ELISA 和原位评估 杂交技术。成骨细胞的发育和活性将 根据多种生化和分子标记进行评估 成骨细胞表型，包括整合素、基质蛋白和 金属蛋白酶。预计此类研究将揭示新的方面 正常的骨重塑机制，并有可能深入了解 骨骼疾病，如骨质疏松症、骨关节炎和其他 炎症性骨疾病。