Osteocytes and Mechano-Transduction

骨细胞和机械传导

• 批准号: 8731056
• 负责人: PAOLA DIVIETI PAJEVIC
• 金额: $ 35.28万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-03-01
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8731056
• 关键词: American; Antigens; Biology; Bioreactors; CD44 gene; Calvaria; Caring; Cell Line; Cells; Characteristics; Complement; Development; Disease; Environment; Esthesia; Fibroblast Growth Factor; Force of Gravity; Foundations; Gene Expression Profiling; Green Fluorescent Proteins; Growth Factor; Homeostasis; Hormonal; Hormones; Immobilization; In Vitro; International; Ions; Knowledge; Life; Liquid substance; Measures; Mechanical Stimulation; Mechanics; Microgravity; Minerals; Mission; Modeling; Molecular; Mus; Nervous System Trauma; Osteocytes; Paralysed; Parathyroid Hormone Receptor; Parathyroid gland; Pathway interactions; Phenotype; Play; Regulation; Role; Signal Transduction; Simian virus 40; Simulate; Small Interfering RNA; Spinal cord injury; Technology; Temperature; Testing; Transcript; Transgenes; Transgenic Mice; United States National Aeronautics and Space Administration; Viral Tumor Antigens; bone; bone cell; calcium phosphate; cost effective; dentin matrix protein 1; established cell line; fluid flow; in vitro Model; in vivo; inorganic phosphate; insight; long bone; patient population; promoter; public health relevance; response; scaffold; sensor; skeletal; skeletal disorder; skeletal disorder therapy; therapeutic development; tissue support frame

DESCRIPTION (provided by applicant): Osteocytes, the most abundant cells in bone, are believed to play a key role in skeletal mechanosensing whereby they modulate bone modeling and remodeling in response to changes in shear or strain forces. Although it is well-established that bone responds to its mechanical environment, the mechanisms underlying the mechano- transduction pathway are poorly understood. Moreover, recent findings have documented a role of osteocytes in the regulation of phosphate homeostasis. Using a mechanically active or static culture condition to culture osteocytes, we will test the hypothesis that SOST and FGF-23 are important regulators of mechano-sensation. Initial studies will be devoted to establish conditionally immortalized osteocytic cell lines derived from transgenic mice expressing the fluorescent green protein (GFP) under the control of DMP-1 (known to be expressed exclusively in osteocytes) and carrying the temperature-sensitive immortalizing SV40 antigen. Cells will be grown on 3D scaffold and subjected to 1g, microgravity (NASA horizontal bioreactor) or increase mechanical stimulation (NASA vertical Bioreactor). We will then investigate the role of SOST and FGF23 signaling in osteocytes (under static and dynamic condition) by selectively silencing these transcripts using small interfering RNAs (siRNA). Analysis of gene expression patterns under these conditions and measuring secretion of sclerostin and FGF23 will provide insights into mechano-transduction pathways and mineral ion regulation (UH2). Lastly utilizing the microgravity environment and minimal fluid shear culture conditions available only onboard of the International Space Station (ISS) we propose to investigate osteocytes responses to unloading conditions (UH3). The eOSTEO flight hardware will be modified accordingly to the aims of this ISS mission. Implementation Partner for this proposal are Calm Technologies and the Canadian Space Agency (CSA). Results derived from the studies proposed could have significant implications for therapy of bone disorders related to disuse or immobilization.

描述（由申请人提供）：骨细胞是骨骼中最丰富的细胞，被认为在骨骼机械传感中发挥关键作用，从而响应剪切力或应变力的变化来调节骨骼建模和重塑。尽管骨骼对其机械环境作出反应这一点已得到充分证实，但人们对机械传导途径的机制知之甚少。此外，最近的研究结果证明了骨细胞在调节磷酸盐稳态中的作用。使用机械活动或静态培养条件来培养骨细胞，我们将检验 SOST 和 FGF-23 是机械感觉重要调节剂的假设。初步研究将致力于建立源自转基因小鼠的条件永生化骨细胞系，该细胞系在 DMP-1（已知仅在骨细胞中表达）的控制下表达荧光绿色蛋白（GFP）并携带温度敏感的永生化 SV40 抗原。细胞将在 3D 支架上生长并受到 1g 微重力（NASA 水平生物反应器）或增加机械刺激（NASA 垂直生物反应器）。然后，我们将通过使用小干扰 RNA (siRNA) 选择性沉默这些转录本来研究 SOST 和 FGF23 信号在骨细胞中（静态和动态条件下）的作用。在这些条件下分析基因表达模式并测量硬化素和 FGF23 的分泌将有助于深入了解机械传导途径和矿物质离子调节 (UH2)。最后，我们建议利用仅在国际空间站（ISS）上可用的微重力环境和最小流体剪切培养条件来研究骨细胞对卸载条件（UH3）的反应。 eOSTEO 飞行硬件将根据本次国际空间站任务的目标进行相应修改。该提案的实施合作伙伴是 Calm Technologies 和加拿大航天局 (CSA)。所提出的研究结果可能对与废用或固定相关的骨疾病的治疗产生重大影响。