FLOW INDUCED MAPK AND CALCIUM SIGNALING IN CHONDROCYTES

软骨细胞中的血流诱导映射和钙信号传导

• 批准号: 6055712
• 负责人: WILMOT B VALHMU
• 金额: $ 2.03万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6055712
• 关键词: adenosine triphosphate; biological signal transduction; biomechanics; calcium flux; cell line; chondrocytes; collagen; electrochemistry; electrophysiology; enzyme activity; fluid flow; fluorescence microscopy; gene expression; human tissue; interleukin 1; mechanical stress; mechanoreceptors; mitogen activated protein kinase; platelet derived growth factor; polymerase chain reaction; proteoglycan; tissue /cell culture; transforming growth factors; tumor necrosis factor alpha

DESCRIPTION: (Taken from the application) Mechanical factors play significant and essential roles in modulating chondrocyte metabolic and biosynthetic activities. In articular cartilage, chondrocytes experience a variety of mechano-electrochemical stimuli to which they respond by altering their biosynthetic activities. The magnitude and frequencies of the applied mechanical forces are important factors which govern how the cells respond. Upon compression, the cells experience a combination of strains, pressures, fluid flow, and associated electrokinetic phenomena. Recent literature data suggest that electrokinetic forces may have greater roles in modulating chondrocyte biosynthetic activities in response to dynamic compression. Despite these and other insights gained from studies both in vitro and in vivo, relatively little is known about how chondrocytes sense and transduce extracellular mechanical signals into an ultimate physiologic or biosynthetic response. The primary goal of the current proposal is therefore to investigate the mechanisms through which fluid flow-associated mechano-electrochemical signals are transduced in articular chondrocytes. We hypothesize that: 1) Of the mechano-mechanoelectrical stimuli associated with fluid flow, shear stress rather than shear rate, flow velocity or electrokinetic phenomena, is the predominant modulator of chondrocyte activities; 2) chondrocytes sense and respond to transient flow initiation and steady-state flow conditions via independent mechanochemical transduction pathways; and 3) biochemical factors (e.g., growth factors, cytokines) modulate the response of chondrocytes to mechano-electrical stimuli. The specific aims designed to test these hypotheses are as follows: 1) Determine the effects of fluid-induced shear stress on activation of mitogen-activated protein kinases (MAPKs) and intracellular Ca2+ levels under conditions which delineate the roles of shear rate, flow velocity (e.g., convective transport) and electrokinetic phenomena (normal and altered concomitant streaming potential and streaming current); 2) Perform flow studies examining the effects of different flow onset rates on the Ca2+ and MAPK activation response in articular chondrocytes; 3) Determine the chondrocyte response to flow-induced stimuli in the presence of biochemical factors such as cytokines, serum growth factors, and flow-stimulated cell-conditioned media; and 4) Determine the chondrocyte biosynthetic activities in response to the fluid-induced stimuli quantified in Specific Aims 1 and 2. Successful completion of these studies will greatly enhance our knowledge of mechanotransduction in chondrocytes and contribute to the design of devices and procedures for the development of tissue-engineered cartilage substitutes.

描述：（取自应用程序） 机械因素在调节中起着重要和重要的作用 软骨细胞代谢和生物合成活性。 在关节软骨中， 软骨细胞经历各种机械 - 电化学刺激 他们通过改变其生物合成活动来做出回应。 大小 应用机械力的频率是重要因素 控制细胞的反应。 压缩后，细胞会经历 菌株，压力，流体流量和相关电动的组合 现象。 最近的文献数据表明，电动力可能 在调节软骨细胞生物合成活动中具有更大的作用 对动态压缩的响应。 尽管获得了这些和其他见解 从体外和体内的研究中，关于如何 软骨细胞感和细胞外机械信号纳入 最终的生理或生物合成反应。 主要目标 因此，当前的提议是为了调查该机制 流体流动相关的机械电气化学信号被转导 关节软骨细胞。 我们假设：1） 与流体流，剪切应力相关的机械力元电机刺激 而不是剪切速率，流速或电动现象是 软骨细胞活性的主要调节剂； 2）软骨细胞感和 通过响应瞬态流量引发和稳态流动条件 独立的机械化学转导途径； 3）生化 因素（例如生长因子，细胞因子）调节 软骨细胞到机械刺激。 旨在 测试这些假设如下：1）确定 流体诱导的剪切应力对有丝分裂原激活蛋白的激活 在条件下的激酶（MAPK）和细胞内Ca2+水平 描述剪切速率，流速的作用（例如对流 运输）和电动现象（正常和随之而改变 流势和流电流）； 2）进行流程研究 检查不同流动率对CA2+和MAPK的影响 关节软骨细胞的激活反应； 3）确定软骨细胞 在存在生化因素的情况下对流动诱导的刺激的反应 作为细胞因子，血清生长因子和流动刺激的细胞调节 媒体; 4）确定反应中的软骨细胞生物合成活性 在特定目的1和2中量化了流体诱导的刺激。 这些研究的成功完成将大大增强我们对 软骨细胞的机械转导并有助于设备的设计 和开发组织工程软骨的程序 替代品。