A critical role for PLD1 in osteoclast fusion

PLD1 在破骨细胞融合中的关键作用

• 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
• 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

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.

摘要 细胞-细胞融合是一种细胞事件，对多种发育和生理过程至关重要 包括骨平衡骨稳态是由成骨细胞和骨吸收维持的 破骨细胞破骨细胞的融合对于破骨细胞的活化和功能至关重要。升高 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，其特征在于 在衰老和病理条件下不平衡的骨重建。目前的骨抗吸收治疗 靶向早期破骨细胞分化和/或活力的骨丢失受到低应答率的限制， 副作用.最近的研究表明，靶向控制破骨细胞融合的分子可能是一种更好的抗- 骨吸收治疗策略。然而，关于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（PLD 1），通过产生 信号磷脂磷脂酸（PA）在破骨细胞融合中起关键作用。我们的体外实验 显示PLD 1活性在破骨细胞生成期间被激活。PLD 1的抑制或基因缺失抑制 单核破骨细胞融合为多核破骨细胞。PLD 1通过促进破骨细胞融合 调节融合性突触的膨胀膜结构的形成。通过一个PA- 结合蛋白筛选和RNA-Seq，我们已经确定了一个潜在的机制，通过PLD 1调节 破骨细胞融合最后，编码PLD 1的基因Pld 1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PLD 1产生的PA在破骨细胞融合中起关键作用， 调节突出融合突触的形成。我们将用以下内容来检验我们的假设 明确的目标。在目的1中，我们将证明PLD 1产生的PA的时空产生是 对破骨细胞融合至关重要。在目标2中，我们将阐明PLD 1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 利用基因敲除在生理和病理条件下破骨细胞PLD 1在骨稳态中的作用 小鼠模型。本研究的目的是阐明PLD 1在破骨细胞融合和骨形成中的作用。 体内平衡和确定新的和更有效的治疗骨质疏松症和其他骨疾病的目标。