Molecular basis of mechanotransduction in bone cells

骨细胞力转导的分子基础

• 批准号: 7848952
• 负责人: JUN YOU
• 金额: $ 30.49万
• 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: 2009-06-22 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7848952
• 关键词: Affect; American; Attenuated; Behavior; Beta-Adrenergic Receptor Kinase 1; Biological Assay; Biological Process; Biology; Biomechanics; Bone Diseases; Bone Resorption; Calcium Signaling; Cells; Cyclic AMP-Dependent Protein Kinases; Data; Devices; Disease; Ensure; Exercise; Exhibits; G protein coupled receptor kinase; G-Protein-Coupled Receptors; Gene Deletion; Gene Expression; Gene Targeting; Goals; Health; Housing; In Vitro; Intervention; Knowledge; Lead; MAP Kinase Gene; Mechanics; Molecular; Mus; Nucleotides; Osteoblasts; Osteocytes; Osteogenesis; Osteoporosis; P2Y2 receptor; Parathyroid Hormone Receptor; Parathyroid Hormone Receptors; Parathyroid Hormones; Pharmaceutical Preparations; Phenotype; Phosphorylation; Play; Process; Property; Public Health; Purinergic P2 Receptors; Purinoceptor; Receptor Inhibition; Regimen; Regulation; Role; Series; Signal Pathway; Signal Transduction; Signaling Molecule; Small Interfering RNA; Solutions; Stimulus; Testing; Therapeutic Effect; Tissue Engineering; base; bone; bone cell; bone strength; cell behavior; cellular transduction; chromatin immunoprecipitation; cyclooxygenase 2; desensitization; design; extracellular; fluid flow; human PTH protein; improved; in vivo; indexing; insight; novel; osteogenic; osteopontin; overexpression; receptor; receptor expression; release of sequestered calcium ion into cytoplasm; research study; response; transcription factor; ulna

DESCRIPTION (provided by applicant): Osteoporosis, a significant health problem in US, is a disease with imbalance between the processes of bone formation and bone resorption. It is known that mechanical loading can influence these processes. Our long-term goal is to elucidate the molecular mechanisms of bone cell response to mechanical loading. Over the past several years, substantial evidence has indicated that extracellular nucleotides, such as ATP, signaling through P2 purinergic receptors, play an important role in the regulation of bone behavior. We and others demonstrated that mechanical loading induced fluid flow causes ATP release in bone cells, and ATP subsequently activates calcium signaling pathways via P2Y purinergic receptors. P2Y receptor is a G protein-coupled receptor (GPCR), which is universally critical in normal biological processes. However, the role of P2Y receptors in bone biology, particularly in bone mechanotransduction, is unknown. Our preliminary data suggest that P2Y2, one subtype of P2Y receptors, activated by ATP is involved in changes in gene expression in response to fluid flow. In addition, desensitization of a GPCR's has recently been shown to be an important component of the mechanosensing apparatus in bone. Our results suggest that G-protein coupled receptor kinase 2 (GRK2) is involved in the desensitization of P2Y activation in response to fluid flow. Interestingly, our preliminary results suggest that P2Y2 deficient mice exhibit moderate bone phenotype. More importantly, our data suggest that the osteogenic response to mechanical loading in P2Y2 deficient mice is suppressed. Thus, our central hypothesis is that biophysical signals, such as fluid flow, regulate bone cell behavior via a mechanism involving P2Y purinergic receptors which are desensitized by G-protein coupled receptor kinases. To test this hypothesis we will conduct a series of in vitro and in vivo experiments to examine the role of P2Y receptors in bone cell mechanotransduction (aim 1), the regulation of P2Y receptors by GRK (aim 2) and parathyroid hormone (PTH) (aim 3), and mechanical loading effects on intact bone from mice deficient in P2Y and GRK (aim 4). PUBLIC HEALTH RELVANCE. Osteoporosis is a significant health problem that affects over 44 million Americans. The proposed project is to determine the molecular mechanism responsible for mechanotransduction in bone via P2Y receptors. Completion of this project will ultimately lead to novel targets for pharmacological intervention in bone diseases that have a mechanical component, such as osteoporosis.

描述（由申请人提供）：骨质疏松症是美国的一个重要健康问题，是一种骨形成和骨吸收过程失衡的疾病。众所周知，机械载荷会影响这些过程。我们的长期目标是阐明骨细胞对机械负荷反应的分子机制。在过去的几年中，大量的证据表明，细胞外核苷酸，如ATP，通过P2嘌呤受体信号传导，在骨行为的调节中发挥重要作用。我们和其他人证明，机械负荷诱导的流体流动导致骨细胞中ATP的释放，ATP随后通过P2 Y嘌呤能受体激活钙信号通路。P2 Y受体是一种G蛋白偶联受体（GPCR），在正常的生物学过程中具有普遍的关键作用。然而，P2 Y受体在骨生物学中的作用，特别是在骨机械转导中，是未知的。我们的初步数据表明，P2 Y2，P2 Y受体的一个亚型，由ATP激活参与基因表达的变化，以响应流体流动。此外，GPCR的脱敏最近已被证明是骨中机械传感装置的重要组成部分。我们的研究结果表明，G-蛋白偶联受体激酶2（GRK 2）参与P2 Y激活的脱敏响应流体流动。有趣的是，我们的初步结果表明，P2 Y2缺陷小鼠表现出中度骨表型。更重要的是，我们的数据表明，在P2 Y2缺陷小鼠的成骨反应的机械负荷被抑制。因此，我们的中心假设是，生物物理信号，如流体流动，调节骨细胞的行为，通过涉及P2 Y嘌呤能受体的机制，这是脱敏的G蛋白偶联受体激酶。为了验证这一假设，我们将进行一系列体外和体内实验，以检查P2 Y受体在骨细胞机械转导中的作用（目的1），GRK（目的2）和甲状旁腺激素（PTH）（目的3）对P2 Y受体的调节，以及P2 Y和GRK缺陷小鼠完整骨的机械负荷效应（目的4）。公众健康的敬畏。骨质疏松症是一个严重的健康问题，影响超过4400万美国人。该项目旨在确定通过P2 Y受体在骨中进行机械传导的分子机制。该项目的完成将最终导致具有机械成分的骨疾病（如骨质疏松症）的药物干预的新靶点。