MINERAL MATRIX RELATIONS IN CALCIFYING TISSUES

钙化组织中矿物质基质的关系

• 批准号: 2080716
• 负责人: WILLIAM J LANDIS
• 金额: $ 29.15万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1996-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2080716
• 关键词: calcification; cartilage development; chickens; collagen; computer graphics /printing; electron probe spectrometry; extracellular matrix; growth /development; high voltage electron microscopy; laboratory mouse; laboratory rat; normal ossification; phosphoproteins; stereochemistry; tendons; tissue /cell culture; turkeys

The long term objective of this application is to obtain new information of the organization and chemistry of vertebrate skeletal tissues: bone, cartilage, and tendon. Investigation of calcification in normal and abnormal samples will examine interaction between mineral crystals and extracellular matrix and the precise role of collagen, vesicles, and certain phosphorylated proteins in mineral nucleation, growth and development. Mineralization will be studied initially in normal chicks, rats, mice, and turkeys as vertebrate model systems and later in examples of abnormal calcification including rickets, osteoporosis, calcergy, calciphylaxis, and osteopetrosis. Ultrastructural, biochemical, immunocytochemical, and biophysical methods will be applied to determine the presence, nature, location, and relation of mineral and organic matrix components in the respective tissues. Specifically, the hypothesis to be tested is: Certain phosphoproteins located in extracellular organic matrices of vertebrate tissues are required for the deposition of mineral in calcification. These phosphoproteins are associated with collagen and/or extracellular vesicles to provide critical nucleation sites for mineral formation. Growth and development of mineral subsequent to nucleation is under strict control of stereochemical and physicochemical constraints. The precise aims for examining this hypothesis are to 1) characterize in the calcifying systems the macromolecular stereochemistry of collagen fibrils and their spatial and structural relationship with phosphoproteins or extracellular vesicles using conventional and high voltage electron microscopy, three-dimensional computer image reconstruction, microscopic tomography, and simulated video techniques; 2) identify microscopic sites of mineral deposition through electron diffraction-dark field imaging, high resolution electron probe microanalysis, and topographic imaging in conjunction with conventional and anhydrous sample preparation and 3) determine the spatial and temporal interaction between mineral and phosphoproteins, collagen, and other organic matrix constituents through correlation of the above imaging methods. The data will contribute to knowledge of normal structure, organization, and physiological functions of cells and extracellular matrices of mineralizing tissues and fundamental events of vertebrate calcification.

该应用程序的长期目标是获取新的信息 脊椎动物骨骼组织的组织和化学：骨， 软骨和肌腱。 正常和钙化的调查 异常样品将检查矿物晶体和 细胞外基质以及胶原蛋白、囊泡和 某些磷酸化蛋白质参与矿物质成核、生长和 发展。 矿化作用将首先在正常雏鸡中进行研究， 大鼠、小鼠和火鸡作为脊椎动物模型系统，稍后在示例中 异常钙化，包括佝偻病、骨质疏松症、钙过敏症、 钙化防御和骨硬化症。 超微结构、生化、 将应用免疫细胞化学和生物物理方法来确定 矿物和有机基质的存在、性质、位置和关系 各组织中的成分。 具体而言，假设为 测试的是：位于细胞外有机物中的某些磷蛋白 脊椎动物组织基质是矿物质沉积所必需的 钙化中。 这些磷蛋白与胶原蛋白相关 和/或细胞外囊泡提供关键的成核位点 矿物形成。 矿物的生长和发育 成核过程受到立体化学和物理化学的严格控制 限制。 检验该假设的确切目标是 1) 表征钙化系统中的大分子立体化学 胶原纤维的分布及其空间和结构关系 磷蛋白或细胞外囊泡使用常规和高 电压电子显微镜、三维计算机图像 重建、显微断层扫描和模拟视频技术； 2） 通过电子识别矿物沉积的微观部位 衍射暗场成像、高分辨率电子探针 微量分析和形貌成像与传统和 无水样品制备和 3) 确定空间和时间 矿物质与磷蛋白、胶原蛋白和其他物质之间的相互作用 通过上述成像的相关性来确定有机基质成分 方法。 这些数据将有助于了解正常结构， 细胞和细胞外的组织和生理功能 矿化组织基质和脊椎动物的基本事件 钙化。