Role of mechanical strain in GAP junctions in osteocytes

机械应变在骨细胞间隙连接中的作用

• 批准号: 6583191
• 负责人: Jean X Jiang
• 金额: $ 21.52万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6583191
• 关键词: biological signal transduction; cell cell interaction; cell communication molecule; cell component structure /function; cytology; fluid flow; gap junctions; mechanical stress; membrane channels; osteoblasts; osteocytes; prostaglandin E; tissue /cell culture

Osteocytes embedded in the matrix of bone are thought to be mechanosensory cells involved in the regulation of both the mass and structure of bone formation. The osteocyte is thought to signal the osteoclast to induce bone resorption and the osteoblast to begin bone formation. Coordination of these remodeling processes is mediated, in part, by cell-to-cell gap junction-mediated intercellular communication in transmitting mechanical signals to the other bone cells essential for bone formation and remodeling. The objective of this application is to understand the role that gap junction channels play in regulating the signals stimulated by mechanical stress in osteocytes. The central hypothesis of the project is that gap junction-mediated intercellular communication is one of the major pathways that mediate and coordinate the signals generated by mechanical loading. This hypothesis has been formulated on the basis of strong preliminary findings, which suggest that gap junctions are essential for mediating the osteocyte cell responses to mechanical stress, and that intercellular communication mediated by gap junctions between osteocytes is stimulated in the presence of the applied strain. The central hypothesis to be tested and the objective of the application will be accomplished by pursuing four specific aims: 1). Confirm the essential role that gap junctions play in osteocyte responses to mechanical stress induced by fluid flow; 2). Identify and characterize the connexin(s) responsible for formation of functional gap junction channels in osteocytes; 3). Determine if fluid flow is more effective than mechanical stretch in regulating gap junction function in osteocytes, and 4). Determine if prostaglandin E2 regulates osteocyte gap function response to shear stress induced by fluid flow. The proposed research is innovative, because osteocyte-like cell lines will be employed as the principal model system with complementary experiments using primary osteocyte cultures. Moreover, this study combines comprehensive biochemical, molecular, genetic and functional approaches with unique mechanical engineering applications. It is our expectation that our experimental findings will have a major impact on our understanding on how signals generated by mechanical strain are coordinated between the osteocytes and other cellular elements of the bone micro-environment. The outcomes will be significant because this new knowledge will contribute to broaden our understanding of how mechanical signals are transduced and modulated in osteocytes. Furthermore, this research activity should make a contribution to the general strategies for the prevention/treatment of bone diseases such as osteoporosis and to new ideas and potential molecular targets for drug development and discovery.

嵌入骨基质中的骨细胞被认为是参与调节骨骼形成的质量和结构的机械感觉细胞。骨细胞被认为可以向破骨细胞诱发骨吸收，并诱导成骨细胞开始骨形成。这些重塑过程的配位是通过细胞间隙连接介导的细胞间介导的细胞间通信在将机械信号传输到其他对于骨形成和重塑必不可少的骨细胞时介导的。该应用的目的是了解间隙连接通道在调节骨细胞中机械应力刺激的信号中所起的作用。该项目的中心假设是间隙连接介导的细胞间通信是介导和协调机械负载产生的信号的主要途径之一。该假设是基于强烈的初步发现提出的，该发现表明，间隙连接对于介导骨细胞对机械应力的反应至关重要，并且在施加应变的情况下刺激了由骨细胞之间的间隙连接介导的细胞间通信。要测试的中心假设和应用的目标将通过追求四个具体目标来实现：1）。确认间隙连接在骨细胞对流体流动引起的机械应力反应中起作用的基本作用； 2）。识别并表征负责骨细胞中功能间隙连接通道形成的连接蛋白； 3）。确定流体流量在调节骨细胞中的间隙连接功能和4）方面是否比机械拉伸更有效，而4）。确定前列腺素E2是否调节骨细胞间隙功能对流体流动引起的剪切应力的响应。拟议的研究具有创新性，因为使用原发性骨细胞培养物进行了互补实验，将骨细胞样细胞系用作主要模型系统。此外，这项研究将综合的生化，分子，遗传和功能方法与独特的机械工程应用结合在一起。我们期望我们的实验发现将对我们对机械应变产生的信号的理解产生重大影响。结果将是重要的，因为这种新知识将有助于扩大我们对骨细胞中机械信号的转导和调节的理解。 此外，这项研究活动应为预防/治疗骨骼疾病的一般策略做出贡献，例如骨质疏松症以及新思想以及药物开发和发现的潜在分子靶标。