Osteoblast stimulation effects on osteoclast activity

描述（由申请人提供）：本研究的长期目标是阐明植入物诱导的骨溶解的机制以及机械载荷对该过程的影响。本申请中提出的生物训练与申请人的工程背景相结合，将使申请人能够完成本文提出的研究，并开展针对骨溶解的未来研究。当前应用的目标是确定底物在增强成骨细胞机械反应性中的作用以及受刺激的可溶性因子对破骨细胞的影响。具体来说，我们将通过分析人工基质和天然基质上具有交流能力和缺乏的成骨细胞系的这些因素，来确定基质是否有助于细胞扁平、细胞网络和细胞间的交流。然后，我们将通过定量测定流体诱导的细胞分泌的骨保护素（OPG）及其配体（RANKL）水平来确定这些因素是否有助于成骨细胞的机械反应性。最后，我们将确定增强的成骨细胞反应性是否与破骨细胞生成和功能性破骨细胞活性的抑制相结合，方法是通过量化OPG、RANKL和破骨细胞在成骨细胞流体流动研究中存在和不存在刺激介质时的骨吸收。我们认为，相对于人工基质，天然基质通过促进细胞扁平化、细胞网络和细胞间通讯来促进成骨细胞的机械反应性。此外，我们提出成骨细胞和破骨细胞之间存在耦合机制，它们能够协调骨形成和骨吸收，并且成骨细胞活性的刺激导致可溶性因子的上调，从而促进破骨细胞生成和破骨细胞活性的抑制。未来的工作将集中在结合骨基质的原位机械传导模型的发展上。这一领域的研究将阐明正常细胞感知和响应机械负荷的机制，以及在这一过程中环境的影响。这是理解与疾病和负荷环境改变相关的这些机制的分解的第一步。这项工作有几个临床相关的应用，包括种植体和转移性骨溶解，骨质疏松症，骨质疏松症，骨折愈合和功能性组织工程。

DESCRIPTION (provided by applicant): The long-term goal of this research is to elucidate the mechanisms involved in implant-induced osteolysis and the effect(s) of mechanical loading on this process. Biological training proposed in this application augmented with the applicant's engineering background, would enable the applicant to complete the research proposed herein and develop future research aimed at osteolysis. The goal of the current application is to determine the role of the substrate in enhancing the mechanoresponsiveness of osteoblastic cells and the effects of stimulated soluble factors on osteoclastic cells. Specifically, we will determine if substrate contributes to cell flattening, cell networking and cell-cell communication by analyzing these factors in communication-competent and -deficient osteoblastic cell lines on artificial and native substrates. We will then determine if these factors contribute to the mechanoresponsiveness of osteoblastic cells by quantifying fluid flow-induced cell secreted levels of osteoprotegerin (OPG) and its ligand (RANKL). Finally, we will determine if enhanced osteoblastic responsiveness is coupled to an inhibition of osteoclastogenesis and functional osteoclastic activity by quantifying OPG, RANKL and bone resorption by osteoclasts in the presence and absence of stimulated media from the osteoblastic fluid flow studies. We propose that a native substrate, relative to an artificial substrate, contributes to the mechanoresponsiveness of osteoblastic cells by promoting cell flattening, cell networking and cell-cell communication. Furthermore, we propose that coupling mechanisms exist between osteoblastic and osteoclastic cells which enable the orchestration of bone formation and resorption and that stimulation of osteoblastic activity results in an upregulation of soluble factors promoting inhibition of osteoclastogenesis and osteoclastic activity. Future work will focus on the development of in situ mechanotransduction models incorporating bone substrates. Research in this area will illuminate the mechanisms by which normal cells sense and respond to mechanical loading and the effects of the milieu in this process. This is the first step in understanding the breakdown of these mechanisms associated with disease and altered loading environments. This work has several clinically relevant applications including implant- and metastatic-induced osteolysis, osteoporosis, osteopetrosis, fracture healing and functional tissue engineering.