Toole B P, Linsenmayer T F
Clin Orthop Relat Res. 1977 Nov-Dec(129):258-78.
Morphogenesis of skeletal tissues is accompanied by dramatic changes in the types and amounts of extracellular macromolecules synthesized. These changes correlate with the morphological and structural characteristics of each tissue type involved in skeletogenesis, viz. mesenchyme, cartilage and bone. At the beginning of skeletogenesis, a hyaluronate-rich extracellular matrix may provide a beneficial milieu for mesenchymal cell migration and proliferation, and prevent precocious differentiation. This matrix also contains type I collagen and possibly a unique sulfated proteoglycan. Cartilage differentiation, during endochondral osteogenesis, involves the removal of hyaluronate and the production of large amounts of type II collagen and a characteristic chondroitin sulfate-proteoglycan. Further complex transitions in arrangement and concentration of proteoglycan occur in the epiphyseal growth plate followed by sudden depletion at the site of initiation of bone formation. In addition, at this site, the type of collagen synthesized reverts from type II back to type I. Bone formation at periosteal sites also involves removal of proteoglycan. The collagen component of both osteoid and bone matrix is type I but the level of hydroxylation of lysine moieties may be significantly higher in osteoid. It is proposed that changes in extracellular matrix composition are important factors in the control of morphogenesis as well as in providing suitable structural properties to the developing skeletal tissues.
骨骼组织的形态发生伴随着合成的细胞外大分子的类型和数量的显著变化。这些变化与骨骼发生过程中涉及的每种组织类型的形态和结构特征相关，即间充质、软骨和骨。在骨骼发生开始时，富含透明质酸的细胞外基质可能为间充质细胞的迁移和增殖提供有利环境，并防止过早分化。这种基质还含有I型胶原，可能还有一种独特的硫酸化蛋白聚糖。在软骨内成骨过程中，软骨分化涉及透明质酸的去除以及大量II型胶原和一种特征性硫酸软骨素蛋白聚糖的产生。在骨骺生长板中，蛋白聚糖的排列和浓度会发生进一步复杂的转变，随后在骨形成起始部位突然减少。此外，在这个部位，合成的胶原类型从II型恢复为I型。骨膜部位的骨形成也涉及蛋白聚糖的去除。类骨质和骨基质的胶原成分都是I型，但类骨质中赖氨酸残基的羟化水平可能明显更高。有人提出，细胞外基质组成的变化是控制形态发生以及为发育中的骨骼组织提供合适结构特性的重要因素。
