PROTEOGLYCAN STRUCTURE, METABOLISM AND ROLE IN TENDON

对于蛋白聚糖的结构和作用知之甚少， 纤维性细胞外基质 提出了实验来研究 正常致密组织细胞外基质中的蛋白多糖成分 结缔组织，肌腱，和调制的数量和类型， 当肌腱受到改变的机械作用时， 力. 将使用牛深屈肌腱的不同区域。 近端部分仅承受纵向张力， 主要是小的硫酸皮肤素蛋白聚糖（MW相当于100 千）。 远侧部分也受到压缩， 部队有较高的蛋白多糖含量，其中大部分是作为一个较大的 分子量（MW相当于1百万）。 肌腱的外植体在培养中将 可用于确定新的合成和周转特性 在肌腱的每个区域合成蛋白多糖。 细胞培养物进行 从每个区域和数量和化学特性， 将测定各自合成的蛋白聚糖和胶原。 这些 研究将确定基质大分子的细胞代谢， 系统 此外，蛋白聚糖在决定细胞凋亡中的作用， 钢筋束结构和材料特性将通过1） 肌腱成纤维细胞培养基质的超微结构研究 已知在体外抑制原纤维形成的蛋白聚糖 增加，2）蛋白聚糖与胶原蛋白结合的体外分析，以及3） 肌腱材料特性的变化与移除 通过酶消化从组织中提取蛋白聚糖。 最后 周围基质的化学和物理性质的影响 对肌腱成纤维细胞蛋白多糖合成的影响将通过以下方法确定： 使细胞在悬浮液中、胶原凝胶中以及在非细胞上生长， 冻干肌腱基质。 蛋白多糖合成的表达， 胎儿和成人细胞将通过使培养物中的细胞经受 不同的机械应力。 恢复受损肌腱的功能是一个困难的医疗问题。 问题. 研究肌腱成纤维细胞的能力， 产生蛋白聚糖和这些大分子的功能作用， 因此基质性质与基本细胞和组织生物学相关， 以及在外科手术和组织再生中的应用。

Little is known about either the structure or the role of proteoglycans in fibrous extracellular matrices. Experiments are proposed to study the proteoglycan constituents in the extracellular matrix of a normal dense connective tissue, tendon, and the modulation in both amounts and types of proteoglycan that occurs when tendon is subjected to altered mechanical forces. Distinct regions of the bovine deep flexor tendon will be used. The proximal portion is subjected to only longitudinal tension and contains predominantly a small dermatan sulfate proteoglycan (MW equivalent to 100 thousand). The distal portion which is aldo subject to compressional forces has a higher proteoglycan content and much of this is as a larger molecular (MW equivalent to 1 million). Explants of tendon in culture will be used to determine the synthetic and turnover characteristics of newly synthesized proteoglycans in each region of tendon. Cell cultures will be initiated from each region and the amounts and chemical characteristics of proteoglycans and collagen synthesized by each will be determined. These studies will define the cellular metabolism of matrix macromolecules in the system. In addition, the role of proteoglycans in determining the structural and material properties of tendon will be investigated by 1) ultrastructural study of the matrix produced by tendon fibroblast cultures to which proteoglycans known to inhibit fibrillogenesis in vitro have been added, 2) in vitro analysis of proteoglycan binding to collagen, and 3) changes in the material properties of tendon related to removal of proteoglycans from the tissue by enzymatic digestion. Finally, the influence of the chemical and physical properties of a surrounding matrix on proteoglycan synthesis by tendon fibroblasts will be determined by growing the cells in suspension, in collagen gels, and on acellular, freeze-dried tendon matrices. The expression of proteoglycan synthesis by fetal and adult cells will be modulated by subjecting cells in culture to different mechanical stresses. Restoration of function to a damaged tendon is a difficult medical problem. Investigation of the capabilities of tendon fibroblasts to produce proteoglycans and the functional role of these macromolecules for matrix properties is thus relevant both to basic cell and tissue biology as well as to application in surgical procedures and tissue regeneration.