EXTRACELLULAR COMPARTMENTS--MATRIX DEVELOPMENT & REPAIR

胶原蛋白组装成细胞外基质的研究将在 形态发生、生长和修复。肌腱、角膜和真皮成纤维细胞 建立与纤维相关的细胞外空间的层次结构， 束，以及发育过程中的组织特定聚集体。独一无二的 结构域为成纤维细胞提供了一种影响 基质组装中的细胞外步骤。一种不连续的纤维基质 被组装起来，大约10微米长的纤维片段被沉积到 由14日龄鸡胚腱成纤维细胞捆绑而成。我们建议， 原纤段是正常的组装中间体，允许有序 线性的、横向的和中间的发育以及生长。大小， 纤维节段在不同发育阶段的结构和命运 将使用电子显微镜、连续切片和 三维重建技术。原纤段在不同的 发育阶段也将从形态上提取出来 进行了表征和化学分析，这些数据与 就地获取。在开发的早期阶段，分段是可提取的 作为离散的单位，而在以后的阶段，情况可能并非如此。我们 假设节段的线性和/或横向融合可以是 负责形成更长、更厚、更成熟的纤维。的变化 纤维表面可能介导这些融合和化学作用的能力 分析段将允许识别与以下内容相关的差异 发育或组织来源。节段的组装，后跟一根柱子- 沉积成熟度可能是一种重要的一般机制。为了测试 这一点，将在雏鸡的形态发生过程中进行研究。 角膜和真皮，以及在修复过程中。该委员会的组成人员 细胞外的隔室将用免疫化学方法定位。中的更改 片段和/或纤维间基质的表面属性可以 与隔间中的成分差异有关，导致 添加或移除特定的蛋白多糖、胶原蛋白类型、 前肽或其他大分子。了解所涉及的机制 在胶原原纤维的形成、沉积和结缔组织的发育过程中 原位组织构筑将有助于我们理解 发育、生长、损伤和修复以及遗传性疾病。

Collagen assembly into extracellular matrices will be studied during morphogenesis, growth, and repair. Tendon, cornea and dermal fibroblasts establish a hierarchy of extracellular spaces associated with fibrils, bundles, and tissue specific aggregates during development. The distinct domains provide a mechanism for the fibroblast to influence the extracellular steps in matrix assembly. A discontinuous fibrillar matrix is assembled, and fibril segments, about 10 microm long, are deposited into bundles by the 14-day chick embryo tendon fibroblast. We propose that the fibril segment is a normal assembly intermediate, permitting orderly linear, lateral, and intercalary development as well as growth. The size, structure, and fate of fibril segments during different stages of development will be defined using electron microscopy, serial sections, and three dimensional reconstruction techniques. Fibril segments at different stages of development also will be extracted, morphologically characterized, analyzed chemically, and these data correlated with those obtained in situ. In early stages of development, segments are extractable as discrete units while at later stages this may not be the case. We hypothesize that a linear and/or lateral fusion of segments may be responsible for longer, thicker, more mature fibrils. Changes in the fibril surface may mediate these fusions and the ability to chemically analyze segments will permit the identifi- cation of differences related to development or tissue source. The assembly of segments followed by a post- depositional maturation may be an important general mechanism. To test this, fibril segments will be studied during morphogenesis of the chick cornea and dermis, as well as during repair. Constituents of the extracellular compartments will be localized immunochemically. Changes in the surface properties of the segments and/or the interfibrillar matrix may be related to compositional differences in the compartments resulting in the addition or removal of specific proteoglycans, collagen types, propeptides or other macromolecules. Understanding the mechanisms involved in collagen fibril formation, deposition, and the development of connective tissue architecture in situ will contribute to our understanding of development, growth, injury and repair as well as inherited disorders.