Mechanosensing of osteoclasts in periodontitis.

项目总结/摘要 宿主对牙周病原体，特别是牙龈卟啉单胞菌（Pg）的免疫炎症反应， 在牙周炎中破坏牙齿支持组织。在产生的几种毒力因子中， 通过Pg，一种独特的致病脂质，磷酸甘油二氢神经酰胺（PGDHC），促进RANKL诱导的OC- 通过作用于非肌肉肌球蛋白II-A（Myh 9），同时抑制OB-生成因子IGF-的产生， 1、OCs。在我们的初步结果中，野生型Pg细胞和纯化的PGDHC，而不是丝氨酸棕榈酰 转移酶（SPT）KO Pg细胞（PGDHC产生缺陷），消除机械敏感性Piezo 1介导 OC发生的下调。这些数据表明PGDHC可能代表了一种独特的毒力因子， 导致破骨细胞中的压电机械系统失调，从而导致骨发育迟缓 再生根据这些证据和初步结果，可以假设， 机械敏感性Piezo 1 eleva细胞信号在OC中诱导IGF-1的产生并抑制OC-1。 而PGDHC通过与Myh 9结合，阻断了Piezo 1的机械传感功能，因此， 降低受牙周炎影响的牙槽骨的骨再生潜力。这一假设将是 通过以下两个具体目的进行测试：目的1）阐明PGDHC的分子机制- 介导的抑制Piezo 1通道在体外OC上的表达。目的2）确定PGDHC对大鼠脑缺血再灌注损伤的影响。 Piezo 1在小鼠结扎和Pg诱导的牙周炎模型中由OC表达。四大培训 候选人的目标包括：1）获得和提高与以下相关的先进科学方法的专业知识 骨免疫学和牙周病学，2）提高管理和分析复杂数据集的技能，3） 获得新的图像采集和分析技术，将细菌毒力因子与表达的Piezo 1联系起来 使用拉曼光谱学、体内成像、微CT和生物层干涉测量法，对破骨细胞进行研究，以及4） 培养领导研究项目所需的技能，包括撰写研究基金、管理实验室 人员、项目开发和执行。申办者Kawai博士和共同申办者Han博士， 在提出的牙周骨免疫学和免疫病理学研究中也有经验 作为博士后研究员在学术研究领域的职业发展的指导，将 承诺支持候选人的培训，沿着由5名专家组成的咨询委员会 脂质组学、骨生物学、机械感觉系统、微生物学和拉曼领域的研究人员 光谱，分别。所有所需的设备、装置、方案和材料均可在 赞助商和顾问的实验室。候选人将在中心获得一张办公桌和实验室空间， 协作研究（CCR）是南佛罗里达最大的生物医学研究大楼， 与各种尖端设备的核心设施，所有这些都可为候选人的 研究项目。

Project Summary/Abstract Host immune inflammatory response to periodontal pathogens, especially, Porphyromonas gingivalis (Pg), is engaged in the destruction of tooth-supporting tissues in periodontitis. Among several virulent factors produced by Pg, a unique pathogenic lipid, phosphoglycerol dihydroceramide (PGDHC), promotes RANKL-induced OC- genesis by acting on non-muscle myosin II-A (Myh9), while inhibiting the production of OB-genesis factor, IGF- 1, from OCs. In our preliminary results, wild-type Pg cells and purified PGDHC, but not serine palmitoyl transferase (SPT) KO Pg cells (deficient in PGDHC production), abrogated mechanosensitive Piezo1-mediated downregulation of OC-genesis. The data suggested that PGDHC may represent a unique virulence factor that causes dysregulation of Piezo1-mechanosnsing system in osteoclasts which leads to retarded bone regeneration. Based on these lines of evidence and preliminary results, it is hypothesized that mechanosensitive Piezo1 elicits a cell signal in OCs that induces the production of IGF-1 and suppress OC- genesis, while the PGDHC, by its binding to Myh9, blocks the mechanosensing function of Piezo1 and, hence, diminishing the bone regenerative potential of alveolar bone affected by periodontitis. This hypothesis will be tested by the following two Specific Aims: Aim 1) To elucidate the molecular mechanism underlying PGDHC- mediated inhibition of Piezo1 channel expressed on OCs in vitro. Aim 2) To determine the effect of PGDHC on the Piezo1 expressed by OCs in a mouse model of ligature and Pg-induced periodontitis. Major four training goals for the candidate include: 1) Gain and improve expertise in advanced science methods associated with osteoimmunology and periodontology, 2) Improve skills in management and analyses of complex datasets, 3) Acquire novel image acquisition and analysis techniques to link bacterial virulent factor and Piezo1 expressed on osteoclasts, using Raman spectroscopy, in vivo imaging, micro-CT and biolayer interferometry, and 4) Develop skills required to lead a research program, including grant writing, management of laboratory personnel, project development and execution. Sponsor, Dr. Kawai, and co-sponsor, Dr. Han, who are experienced in the proposed study addressing the periodontal osteoimmunology and immunopathology as well as mentoring of postdoctoral fellows for their career development in the academic research fields, will be committed to support the candidate’s training, along with consultation committees composed of 5 expert researchers in the fields of lipidomics, bone biology, mechanosensory system, microbiology, and Raman spectroscopy, respectively. All required equipment, devices, protocols and materials are available in the laboratories of sponsors and consultants. The candidate is given a desk and laboratory space in Center for Collaborative Research (CCR) which is the largest biomedical research building in South Florida, equipped with a variety of cutting-edge equipment in the core facilities, all of which are available for the candidate’s research project.