Osteoblastic lineage cells regulate osteoclastogenesis via Cx43 and gap junctions

成骨细胞谱系细胞通过 Cx43 和间隙连接调节破骨细胞生成

• 批准号: 7715025
• 负责人: Yue Zhang
• 金额: $ 7.76万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-07 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7715025
• 关键词: Address; Affect; Albers-Schonberg disease; Bone Density; Bone Diseases; Bone Resorption; Cell Count; Cell Lineage; Cell Membrane Proteins; Cells; Complementary DNA; Connexin 43; Connexins; Connexon; Data; Distal; Femur; Gap Junctions; In Vitro; Innate Bone Remodeling; Ion Channel; Ions; Knock-out; Knockout Mice; Label; Lead; Mammalian Cell; Mediating; Membrane; Messenger RNA; Metabolic Bone Diseases; Mus; Osteoblasts; Osteoclasts; Osteocytes; Osteopenia; Osteoporosis; Phenotype; Population; Porosity; Proteins; Regulation; Relative (related person); Role; Serum Markers; Signaling Molecule; Small Interfering RNA; System; TNFSF11 gene; Thick; Tumor necrosis factor receptor 11b; Wild Type Mouse; Work; abstracting; attenuation; bone; bone cell; in vivo; intercellular communication; loss of function; new therapeutic target; novel; osteoclastogenesis; public health relevance; vector

DESCRIPTION (provided by applicant): Project Summary/Abstract The normal remodeling of bone requires synchronized activity between bone resorbing osteoclastic and bone forming osteoblastic cells. This synchronization includes the recruitment of osteoblasts and osteoclasts, and the stimulation of osteoclast and osteoblast proliferation and differentiation. Imbalances between bone resorption and formation may lead to bone disorders, such as osteoporosis and osteopetrosis. Gap junctions (GJ) are membrane-spanning channels that allow passage of ions and signaling molecules, less than 1KD in size, between two adjacent cells. Each gap junction is composed of two hemichannels or connexons and each connexon is comprised of 6 connexins. The predominant form of connexin in bone cells is Cx43. Previous In vitro studies demonstrated that Cx43, hemichannel and GJ regulate osteoblast, osteocyte and osteoclast differentiation and function. However, little is known about the in vivo function of Cx43 and GJIC in bone. To address this deficit, we specifically deleted Cx43 in mouse osteoblasts and osteocytes. The knockout mice displayed osteopenic phenotypes with increased osteoclast number. Therefore, in this application, we hypothesize that osteoblastic lineage cells, including osteoblasts and osteocytes, communicate with osteoclastic cells and inhibit osteoclastogenesis via Cx43 and GJIC. Our hypothesis predicts that reducing Cx43 levels and heterotypic GJIC between osteoblastic lineage cells and osteoclastic lineage cells leads to increased osteoclastic activity. We will examine whether osteoblastic lineage cells regulate osteoclastogenesis via Cx43 and GJIC by completing three aims over a 3 year period: Aim 1, demonstrate Cx43-mediated GJIC between osteoblastic or osteocytic and osteoclastic cells; Aim 2, quantify osteoclast cell number and activity, both in vivo and in vitro, induced by osteoblasts and osteocytes with different Cx43 levels; and aim 3, investigate the mechanism of Cx43 and GJIC mediated osteoblastic and osteocytic cell regulated osteoclastogenesis. By completing these aims we will not only identify new functions of Cx43 and GJIC in bone, but will also identify novel mechanisms contributing to osteopenia. PUBLIC HEALTH RELEVANCE: Project Narrative We will examine whether osteoclasts communicate with osteocblastic lineage cells via Cx43 mediated gap junctional intercellular communication (GJIC). Furthermore, We will also investigate the role and mechanism of Cx43 and GJIC in osteoclastogenesis regulated by osteoblastic lineage cells. The completion of the proposed aims will greatly help to develop novel therapeutic targets for disorders of bone metabolism including osteopenias and osteopetrosis.

描述（由申请人提供）： 项目摘要/摘要 骨的正常重塑需要骨吸收破骨细胞和骨形成成骨细胞之间的同步活动。这种同步包括成骨细胞和破骨细胞的募集，以及破骨细胞和成骨细胞增殖和分化的刺激。骨吸收和形成之间的不平衡可能导致骨疾病，例如骨质疏松症和骨石症。间隙连接 (GJ) 是跨膜通道，允许尺寸小于 1KD 的离子和信号分子在两个相邻细胞之间通过。每个间隙连接由两个半通道或连接子组成，每个连接子由 6 个连接蛋白组成。骨细胞中连接蛋白的主要形式是 Cx43。先前的体外研究表明，Cx43、半通道和 GJ 调节成骨细胞、骨细胞和破骨细胞的分化和功能。然而，对于 Cx43 和 GJIC 在骨中的体内功能知之甚少。为了解决这一缺陷，我们特意删除了小鼠成骨细胞和骨细胞中的 Cx43。基因敲除小鼠表现出骨质减少表型，破骨细胞数量增加。因此，在本申请中，我们假设成骨细胞谱系细胞（包括成骨细胞和骨细胞）与破骨细胞通讯，并通过 Cx43 和 GJIC 抑制破骨细胞生成。我们的假设预测，降低成骨细胞谱系细胞和破骨细胞谱系细胞之间的 Cx43 水平和异型 GJIC 会导致破骨细胞活性增加。我们将通过在 3 年时间内完成三个目标来检查成骨细胞谱系细胞是否通过 Cx43 和 GJIC 调节破骨细胞生成：目标 1，证明成骨细胞或骨细胞与破骨细胞之间的 Cx43 介导的 GJIC；目标 2，量化由不同 Cx43 水平的成骨细胞和骨细胞诱导的体内和体外破骨细胞数量和活性；目标3，研究Cx43和GJIC介导的成骨细胞和骨细胞调节破骨细胞生成的机制。通过完成这些目标，我们不仅将确定 Cx43 和 GJIC 在骨骼中的新功能，还将确定导致骨质减少的新机制。 公共卫生相关性： 项目叙述 我们将检查破骨细胞是否通过 Cx43 介导的间隙连接细胞间通讯 (GJIC) 与破骨细胞谱系细胞进行通讯。此外，我们还将研究Cx43和GJIC在成骨细胞谱系细胞调控的破骨细胞生成中的作用和机制。所提出的目标的完成将极大地有助于开发骨代谢紊乱（包括骨质减少症和骨石化症）的新治疗靶点。