Role of Osteoactivin in Osteoclasts

骨激活素在破骨细胞中的作用

基本信息

批准号：
7591159
负责人：
Matilda Han-Chin Sheng
金额：
$ 0.07万
依托单位：
LOMA LINDA VETERANS ASSN RESEARCH & EDUC
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：
2008-04-01 至 2009-10-24
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7591159
关键词：
Address Bone Resorption Cell Adhesion Cell Nucleus Cells Development Disease Endothelial Cells Functional disorder Genes Growth In Vitro Integrins Measures Mediating Molecular Mus Mutate Osteoblasts Osteoclasts Osteoporosis Pathway interactions Pharmaceutical Preparations Physiology Play RGD (sequence)Regulation Role Signal Transduction Small Interfering RNA Testing Tissues Transgenic Mice Variant Wasting Syndrome Work bone effective therapy in vivo insight migration mutant novel osteoactivin osteoblast differentiation overexpression promoter repaired tartrate-resistant acid phosphatase

Address Bone Resorption Cell Adhesion Cell Nucleus Cells Development Disease Endothelial Cells Functional disorder Genes Growth In Vitro Integrins Measures Mediating Molecular Mus Mutate Osteoblasts Osteoclasts Osteoporosis Pathway interactions Pharmaceutical Preparations Physiology Play RGD (sequence)Regulation Role Signal Transduction Small Interfering RNA Testing Tissues Transgenic Mice Variant Wasting Syndrome Work bone effective therapy in vivo insight migration mutant novel osteoactivin osteoblast differentiation overexpression promoter repaired tartrate-resistant acid phosphatase

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项目摘要

DESCRIPTION (provided by applicant): Bone resorption is essential for all aspects of bone physiology: growth, remodeling, and repair. The most prevalent disease associated with an abnormality in bone resorption is osteoporosis, which is frequently a result of an excess bone resorption. The osteoclast is the primary bone-resorbing cells. Understanding the molecular mechanisms that regulate osteoclast formation and activity could provide insights into the pathophysiology of osteoporosis, and also better use of the currently available anti-resorptive drugs for bone wasting diseases. This project seeks to define the functional role of a new osteoclastic gene, osteoactivin (OA), in osteoclast formation and function and its potential molecular mechanism. OA is expressed in a wide variety of tissues and has been suggested to play a regulatory role in osteoblast differentiation and in endothelial cell adhesion. This proposal presented evidence that 1) OA is highly expressed in mature osteoclasts and its expression is upregulated during the differentiation of osteoclasts, 2) OA has a regulatory role in osteoclast formation, spreading, and activity, and 3) its molecular mechanism involves an interaction with integrin ¿3 and/or ¿1, presumably through its RGD motifs. Accordingly, this revised proposal tests two specific hypotheses: 1) OA has an important regulatory role in osteoclast formation and bone resorption activity in vivo and in vitro; and 2) OA regulates osteoclast formation and/or bone resorption activity in an integrin-dependent manner through its RGD motifs. The first hypothesis is addressed by two approaches: In the in vitro approach, primary murine osteoclast precursors will be used to determine if siRNA-mediated OA gene knockdown interferes with the RANKL-induced differentiation of osteoclasts as measured by osteoclast size, number of nuclei per osteoclast, migration, and bone resorption. The second in vivo approach is to generate transgenic mice with targeted overexpression of OA in cells of osteoclast lineage using the tartrate-resistant acid phosphatase C promoter. The in vivo function of OA on osteoclast formation and resorption will be determined by assessing the effects of targeted overexpression of OA on osteoclast formation and functions in the transgenic mice in vivo. The second hypothesis is tested by two strategies: the first strategy is to, with the use of preosteoclasts of OA transgenic mice, determine if siRNA-mediated knockdown of integrin ¿3 and/or ¿1 expression blocks the OA-induced increase in osteoclast formation and/or functions. The second strategy is to determine the effects of forced overexpression of RGD-mutated OA variants in murine osteoclast precursors on osteoclast formation, migration, and resorption, and compare the effects of forced overexpression of RGD- mutants in osteoblasts on osteoblast differentiation. If the hypotheses are correct, this work will provide insights into the functional role of this novel osteoclastic gene and define the interaction between OA and the integrin signaling in the regulation of osteoclast formation and activity. It may also provide a novel gene or pathway target for development of novel and effective treatment of osteoporosis and related bone-wasting diseases.

描述（由适用提供）：骨骼分辨对于骨骼生理的各个方面至关重要：生长，改造和修复。与骨治疗异常相关的最普遍的疾病是骨质疏松症，这通常是过量骨治疗的结果。破骨细胞是主要的骨质细胞。了解调节破骨细胞形成和活性的分子机制可以提供对骨质疏松症的病理生理学的见解，并更好地利用当前可用的抗抑郁药来浪费骨骼疾病。该项目旨在定义新的骨碎裂基因骨活蛋白（OA）在破骨细胞形成和功能及其潜在分子机制中的功能作用。 OA在多种组织中表达，并被认为在成骨细胞分化和内皮细胞粘合剂中起着调节作用。该提案提供了证据，表明1）OA在成熟的破骨细胞中高度表达，其表达在破骨细胞的分化过程中进行了更新，2）OA在破骨细胞形成，扩散和活动中具有调节作用，其分子机制涉及与整合蛋白»3和/或/或/或/或或或eS pers的相互作用。根据此，该修订的建议检验了两个特定的假设：1）OA在体内和体外的破骨细胞形成和骨骼分辨活性中具有重要的调节作用； 2）OA通过其RGD基序以整合素依赖性方式调节破骨细胞的形成和/或骨骼分辨活性。第一个假设通过两种方法来解决：在体外方法中，将使用原发性鼠类破骨细胞前体来确定siRNA介导的OA基因敲低干扰是否会与RANKL诱导的破骨细胞分化的分化，这些分化是由破骨细胞大小的大小，每个骨化核酸菌的核量，迁移，迁移，迁移和骨骼的核能的数量。第二种体内方法是使用耐锈蚀酸磷酸酶C启动子在破骨细胞谱系细胞中具有靶向OA靶向过表达的转基因小鼠。 OA对破骨细胞形成和分辨率的体内功能将通过评估OA的靶向过表达对体内转基因小鼠的破骨细胞形成和功能的影响来确定。第二个假设通过两种策略进行了检验：第一种策略是使用OA转基因小鼠的前细胞前，确定siRNA介导的整联蛋白3和/或»1表达是否会阻止OA诱导的骨质细胞形成和/或功能。第二种策略是确定鼠骨骨细胞前体中RGD突变的OA变体强制过表达对破骨细胞形成，迁移和分辨率的影响，并比较成质细胞差异中RGD突变物强制过表达的影响。如果假设是正确的，则这项工作将提供有关该新成骨细胞基因的功能作用的见解，并定义OA与整联蛋白信号之间的相互作用在调节骨细胞形成和活性的调节中。它还可能为开发新颖有效治疗骨质疏松症和相关造成骨浪费疾病的新基因或途径靶标提供了新的基因或途径。