A critical role for PLD1 in osteoclast fusion

PLD1 在破骨细胞融合中的关键作用

基本信息

批准号：
9803233
负责人：
GUANGWEI DU
金额：
$ 34.62万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9803233
关键词：
Actins Address Aging Binding Proteins Biology Bone Diseases Bone Resorption Bone remodeling Cell fusion Cells Cellular biology Communication Cytoskeletal Modeling Cytoskeleton Data Developmental Process Differentiation Antigens Disease Equilibrium Estrogens Event Foundations Generations Genes Genetic Goals Health Homeostasis In Vitro Inflammatory Knock-out Knockout Mice Knowledge Lipids Malignant Neoplasms Membrane Methods Molecular Mus Myelogenous Myosin ATPase Osteoblasts Osteoclasts Osteoporosis Ovariectomy Pathologic Pathway interactions Phosphatidic Acid Phospholipase D Phospholipids Physiological Physiological Processes Play Positioning Attribute Production Regulation Research Personnel Role Signal Pathway Signal Transduction Synapses Testing Therapeutic Treatment Efficacy X-Ray Computed Tomography base bone bone loss bone resorbing activity bone strength experience experimental study in vivo knock-down mouse model new therapeutic target novel novel therapeutics osteoclastogenesis phospholipase D1 polymerization public health relevance response side effect small hairpin RNA spatiotemporal synaptic inhibition therapeutic target transcriptome sequencing

项目摘要

Abstract Cell-cell fusion is a cellular event that is critical to several developmental and physiological processes including bone homeostasis. Bone homeostasis is maintained by bone-forming osteoblasts and bone-resorbing osteoclasts. The fusion of osteoclasts is critical for osteoclast activation and function. Elevated osteoclastogenesis and bone resorption leads to osteoporosis that is a severe health problem characterized by imbalanced bone remodeling in aging and pathological conditions. Current anti-resorptive treatments for bone loss, which target early osteoclast differentiation and/or viability, have been limited by low response rates or side effects. Recent studies suggest that targeting molecules controling osteoclast fusion may be a better anti- resorptive therapeutic strategy for bone loss. However, very little is known about the molecular mechanisms underlying osteoclast fusion. We recently found that phospholipase D1 (PLD1), through generating the signaling phospholipid phosphatidic acid (PA), plays a critical role in osteoclast fusion. Our In vitro experiments show that PLD1 activity is activated during osteoclastogenesis. Inhibition or genetic deletion of PLD1 inhibit the fusion of mononucleated osteoclasts to multinucleated osteoclasts. PLD1 promotes osteoclast fusion through regulating the formation of the protrusive membrane structure at fusogenic synapses. Through both a PA- binding protein screen and RNA-Seq, we have identified a potential mechanism through which PLD1 regulates osteoclast fusion. Finally, global deletion of Pld1, the gene encoding PLD1, protects mice from bone loss. Based on these data, we hypothesize PLD1-generated PA plays a critical role in osteoclast fusion through regulating the formation of the protrusive fusogenic synapse. We will test our hypothesis with the following specific aims. In Aim 1, we will demonstrate that the spatiotemporal production of PLD1-genereated PA is critical for osteoclast fusion. In Aim 2, we will elucidate the mechanisms through which PLD1 coordinates actin cytoskeletal reorganization and membrane remodeling during osteoclast fusion. In Aim 3, we will define the role of osteoclast PLD1 in bone homeostasis in both physiological and pathological conditions using knockout mouse models. The goals of this project are to elucidate the role of PLD1 in osteoclast fusion and bone homeostasis and identify new and more effective therapeutic targets for osteoporosis and other bone diseases.

抽象的细胞与细胞融合是一种对多种发育和生理过程至关重要的细胞事件包括骨稳态。骨稳态由骨形成成骨细胞和骨吸收维持破骨细胞。破骨细胞的融合对于破骨细胞的激活和功能至关重要。高架破骨细胞生成和骨吸收导致骨质疏松症，这是一种严重的健康问题，其特征是衰老和病理条件下骨重塑不平衡。目前骨的抗再吸收治疗针对早期破骨细胞分化和/或活力的损失受到低反应率或副作用。最近的研究表明，控制破骨细胞融合的靶向分子可能是更好的抗破骨细胞药物。骨质流失的再吸收治疗策略。然而，人们对其分子机制知之甚少潜在的破骨细胞融合。我们最近发现磷脂酶 D1 (PLD1)，通过生成信号磷脂磷脂酸（PA）在破骨细胞融合中发挥着关键作用。我们的体外实验表明 PLD1 活性在破骨细胞生成过程中被激活。 PLD1 的抑制或基因缺失会抑制单核破骨细胞与多核破骨细胞融合。 PLD1通过促进破骨细胞融合调节融合突触突出膜结构的形成。通过 PA- 结合蛋白筛选和RNA-Seq，我们已经确定了PLD1调节的潜在机制破骨细胞融合。最后，Pld1（编码 PLD1 的基因）的整体缺失可以保护小鼠免受骨质流失。基于这些数据，我们假设 PLD1 生成的 PA 通过以下方式在破骨细胞融合中发挥关键作用：调节突出融合突触的形成。我们将用以下方法检验我们的假设具体目标。在目标 1 中，我们将证明 PLD1 生成的 PA 的时空生产是对于破骨细胞融合至关重要。在目标 2 中，我们将阐明 PLD1 协调肌动蛋白的机制破骨细胞融合过程中的细胞骨架重组和膜重塑。在目标 3 中，我们将定义使用敲除破骨细胞 PLD1 在生理和病理条件下骨稳态中的作用鼠标模型。该项目的目标是阐明 PLD1 在破骨细胞融合和骨形成中的作用体内平衡并确定骨质疏松症和其他骨疾病的新的、更有效的治疗靶点。