TYPE X COLLAGEN IN LIMB DEVELOPMENT

X 型胶原蛋白在四肢发育中的作用

• 批准号: 3448261
• 负责人: THOMAS M SCHMID
• 金额: $ 5.18万
• 依托单位: RUSH UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-01 至 1988-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3448261
• 关键词: bone development; bone metabolism; cartilage development; cartilage metabolism; chondrocytes; collagenase; early embryonic stage; extracellular matrix; gel electrophoresis; histochemistry /cytochemistry; histogenesis; hydroxyapatites; hypertrophy; immunochemistry; immunofluorescence technique; limbs; mammalian embryology; microscopy; normal ossification; osteogenesis; tissue /cell culture

Long bones form the major supportive structures of limbs. The ossified tissue first develops around and finally within a cartilage primordium. The maturation of embryonic long bones is dependent on the synchronous transition from cartilage to bone. The long term goal of this project is to understand the cellular regulation of endochondral bone formation. The process may be conveniently studied in the epiphyseal growth plate where the cellular changes occur as a linear continuum. The chondrocytes pass through several stages typified by high mitotic activity or high levels of macromolecular synthesis. Finally, the cells hypertrophy and are replaced by osteogenic cells. Recently, a short collagen molecule, termed type X collagen, has been shown to be a specific product of the hypertrophic chondrocytes. The aims of this study will be to examine the structural function of type X collagen during the formation of endochondral bone. The temporal and spatial distribution of the molecule have been determined by immunohistochemical methods and suggest type X collagen may be involved in the turnover or calcification of the hypertrophic cartilage matrix. The possible role of the molecule in the turnover of the matrix will be assessed by first quantitating the ratio of type X to type II collagen in the matrix. Second, the rates of a mammalian collagenase degradation of types X and II will be compared. Third, hypertrophic cartilage will be analyzed for the presence of enzymes capable of degrading type X collagen. The potential function of the molecule in the calcification of tissue will also be examined. First, the histological distribution of hydroxyapatite will be compared with the location of type X by immunohistochemistry. Second, intramembranous bone will be analyzed biochemically for the presence of type X collagen which has been detected in the tissue by indirect immonufluoresence.

长骨形成四肢的主要支撑结构。 僵化的 组织首先在软骨原基周围发育，最后在软骨原基内发育。 胚胎长骨的成熟取决于同步 从软骨到骨的过渡。 该项目的长期目标是 了解软骨内骨形成的细胞调节。 这 过程可以在骨骺生长板中方便地研究，其中 细胞变化以线性连续体的形式发生。 软骨细胞通过 通过以高有丝分裂活性或高水平的有丝分裂为代表的几个阶段 高分子合成。 最后，细胞肥大并被替换 由成骨细胞。 最近，一种短的胶原蛋白分子，称为 X 型 胶原蛋白，已被证明是肥大肌的特定产物 软骨细胞。 本研究的目的是检验结构 X 型胶原蛋白在软骨内骨形成过程中的功能。 这 分子的时间和空间分布由下式确定 免疫组织化学方法表明 X 型胶原蛋白可能参与 肥大软骨基质的更新或钙化。 这 分子在基质周转中的可能作用是 通过首先定量 X 型与 II 型胶原蛋白的比率来评估 矩阵。 其次，哺乳动物胶原酶的降解速率 将比较 X 型和 II 型。 三、软骨肥大 分析是否存在能够降解 X 型胶原蛋白的酶。 该分子在组织钙化中的潜在功能将 也予以检查。 一、羟基磷灰石的组织学分布 将通过免疫组织化学与X型的位置进行比较。 其次，将对膜内骨进行生化分析，以了解 组织中检测到 X 型胶原蛋白的存在 间接免疫荧光。