REGULATED ASSEMBLY OF THE EXTRACELLULAR MATRIX

描述(摘自申请者的摘要)：胶原蛋白稳定 大多数器官的结构。申请者已经证明了原纤维 最初组装成离散的原纤段。这些细分市场是 在发育中的细胞外结合成不连续的纤维 矩阵。随着发育的进行，节段的有规律的成熟 发生。这涉及到内部中间体(细分)的转换 未成熟的组织变成更长的，在大多数组织中，直径更大 纤维(肌腱)；形成较长的纤维，直径不变(角膜)； 或者可能与节段的持续(快速重塑)有关。相对于这一点 应用中，假设分段经历了沉积后 融合，随后是分子重排，导致更长的时间 成熟组织的纤维。这一假设预测了细分市场的变化 纤维形成过程中的结构从节段组装到原纤维 成长。申请人的原纤维生长模型预测了一种稳定和 在发展过程中的特定时间段的不稳定。他们 假设这一过程涉及时间和空间变化 与管段曲面关联的组件。他们建议他们的 数据显示与纤维相关的蛋白多糖和胶原蛋白有关。在这 应用，他们将研究预制纤维的生长 肌腱和角膜这两种截然不同的组织中的中间体。 具体地说，他们将表征和期间的分段结构 在纤维快速生长的时期之后。他们还将确定一个 候选大分子之间存在相关性 在纤维生长的特定阶段的表达/相互作用 形态、生化和分子遗传学方法。作为候选人 如果得到证实，它们在调节原纤维生长中的作用将是 检查过了。将研究通过核心蛋白聚糖和纤维调节蛋白进行的调节 最初，申请者的数据表明装饰素在 预测的失稳期，以及纤维调素在 矩阵稳定化的时期。它们在时间上的表达 候选分子将在发育过程中发生变化。逆转录病毒 构造体将准备减少(反义或显性否定)，或 延长可能的调控分子的表达。其影响将是 在体外使用胶原凝胶模型系统进行分析 被感染的细胞。对肌腱原位发育的影响也将是 分析过了。有人建议，对这些机制的理解 调控原纤维的形成、生长、基质组装和发育 特定于组织的体系结构将导致对发育的理解， 生长、修复和病理生物学，以及遗传的操作 精神错乱。

DESCRIPTION (Adapted from the Applicant's Abstract): Collagen stabilizes the structure of most organs. The applicants have demonstrated that fibrils are initially assembled as discrete fibril segments. These segments are incorporated into discontinuous fibers within developing extracellular matrices. As development proceeds, a regulated maturation of segments occurs. This involves the transformation of intermediates (segments) within the immature tissue into longer and, in most tissues, larger diameter fibrils (tendon); into longer fibrils with no change in diameter (cornea); or perhaps to persistence of segments (rapid remodeling). Relative to this application, it is hypothesized that segments undergo a post-depositional fusion, followed by molecular rearrangements that give rise to longer fibrils of the mature tissue. This hypothesis predicts changes in segment structure as fibrillogenesis proceeds from assembly of segments to fibril growth. The applicants' model of fibril growth predicts a stabilization and destabilization of segments at specific times in development. They hypothesize that this process involves temporal and spatial changes in components associated with the segment surface. They suggest that their data implicates the fibril-associated proteoglycans and collagens. In this application, they will study the growth of fibrils from preformed intermediates in two contrasting tissues, the tendon and cornea. Specifically, they will characterize the structure of segments during and after the period of rapid fibril growth. They also will determine whether a correlation exists between candidate macromolecules and expression/interaction at specific stages of fibril growth using morphological, biochemical and molecular genetic approaches. As candidates are substantiated, their roles in the regulation of fibril growth will be examined. Regulation via decorin and fibromodulin will be studied initially; the applicants' data indicating a decrease in decorin during the predicted period of destabilization, and an increase in fibromodulin during the period of matrix stabilization. The temporal expression of these candidate molecules will be altered during development. Retroviral constructs will be prepared to reduce (antisense or dominant-negative), or prolong expression of the putative regulatory molecules. The effects will be analyzed, in vitro, using a collagen gel model system populated by infected cells. The effects on tendon development in situ also will be analyzed. It is suggested that an understanding of the mechanisms regulating fibril formation, growth, matrix assembly and the development of tissue-specific architecture will lead to the understanding of development, growth, repair and pathobiology, as well as manipulations of inherited disorders.