The Role and Mechanism of RGS12 in Bone Resorption

RGS12在骨吸收中的作用和机制

• 批准号: 7078561
• 负责人: SHUYING YANG
• 金额: $ 8.78万
• 依托单位: ADA FORSYTH INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7078561
• 关键词: G protein; RNA interference; biological signal transduction; calcium channel; calcium flux; cell differentiation; gene expression; genetic regulation; genetically modified animals; histology; immunofluorescence technique; in situ hybridization; laboratory mouse; newborn animals; osteoclasts; osteoporosis; pathologic bone resorption; physiologic bone resorption; protein protein interaction; tibia; transcription factor

DESCRIPTION (provided by applicant): Osteoclasts are the principal bone-resorbing cells, and their activity has a profound impact on skeletal health. Disorders of skeletal insufficiency, such as osteoporosis, are typically characterized by enhanced osteoclastic bone resorption relative to bone formation. A more complete understanding of the mechanisms by which osteoclasts differentiate from their precursors and degrade the skeleton is therefore critical to developing therapies for these often-debilitating diseases. Recent evidence showed that Regulator of G-protein signaling (RGS) proteins, play an important part in the regulation of Ca 2+ oscillations. RGS12 gene is a large regulator of G protein, having multiple functional modules, such as PDZ, PTB (phosphor-tyrosine binding), Rap binding domains and GoLoCo domain. RGS12 is capable of direct interactions through its PTB domain with the tyrosine-phosphorylated calcium channel in culture of primary dorsal root ganglion neurons. We have found that mouse RGS12 gene was predominately expressed in RANKL-induced osteoclast like cells (OLCs). Knockdown of RGS12 expression using RNA interference (RNAi) inhibited Ca 2+ oscillations and osteoclast terminal differentiation induced by RANKL in vitro. Nevertheless, there is no in vivo evidence for a general requirement for RGS12 signaling in osteoclast differentiation and bone resorption. Based on our preliminary data and the nature of RGS12, we hypothesized that RGS12 plays an essential role in osteoclast gene expression, osteoclast differentiation and activation through the regulation of Ca2+ oscillations and interaction with calcium channel. To test this hypothesis, we propose two specific aims. In aim 1, to generate RGS12 null allele to study the role of RGS12 in bone resorption using knockout technology. In aim 2, using RGS12 knockout model to define the function of RGS12 in regulating Ca2+ signal in osteoclast, in osteoclast gene expression regulation, and in osteoclast differentiation and activation so as to apply this knowledge to develop new diagnostics and therapeutics for human diseases of bone, especially for osteoporosis

描述（由申请人提供）：破骨细胞是主要的骨呈现细胞，其活性对骨骼健康产生了深远的影响。骨骼功能不全（例如骨质疏松症）的疾病通常以相对于骨形成的骨质碎片性骨吸收增强。因此，更完整地了解破骨细胞与其前体区分开并降解骨骼的机制对于为这些经常连续的疾病开发疗法至关重要。最近的证据表明，G蛋白信号传导（RGS）蛋白的调节剂在调节Ca 2+振荡中起重要作用。 RGS12基因是G蛋白的大调节剂，具有多个功能模块，例如PDZ，PTB（磷 - 酪氨酸结合），RAP结合结构域和Goloco结构域。 RGS12能够通过其PTB结构域与酪氨酸磷酸化的钙通道进行直接相互作用，而原发性背根神经元培养物。我们发现小鼠RGS12基因主要在RANKL诱导的破骨细胞（OLC）中表达。使用RNA干扰（RNAI）敲低RGS12表达抑制了Ca 2+的振荡和rankl在体外诱导的破骨细胞末端分化。然而，在破骨细胞分化和骨吸收中的RGS12信号传导的一般要求没有体内证据。根据我们的初步数据和RGS12的性质，我们假设RGS12通过调节CA2+振荡以及与钙通道的相互作用在破骨细胞基因表达，破骨细胞分化和激活中起着至关重要的作用。为了检验这一假设，我们提出了两个具体目标。在AIM 1中，生成RGS12无效等位基因以研究RGS12在使用基因敲除技术中的作用。在AIM 2中，使用RGS12基因敲除模型来定义RGS12在整骨细胞中调节Ca2+信号的功能