Mundy G R
Division of Endocrinology and Metabolism, University of Texas Health Center at San Antonio 78284-7877, USA.
Clin Orthop Relat Res. 1995 Apr(313):19-26.
Although bone formation traditionally has been difficult to study in vitro, recent improvements in cell culture techniques have made it possible to study primary cultures of fetal rat calvarial osteoblasts, and to examine specific gene events associated with osteoblast proliferation, differentiation, and mineralization of extracellular matrix to form bone nodules. Results of studies show that extracellular matrix proteins such as Type I collagen and osteocalcin are expressed. Also expressed are growth regulatory factors such as the bone morphogenetic proteins, which are presumably secreted and stored in the bone matrix or involved in additional osteoblast differentiation in an autocrine/paracrine role. The bone matrix is 1 source of these growth regulatory factors for bone formation; another is those animal and human tumors associated with osteoblastic metastases. In some of these tumors, an extended form of basic fibroblast growth factor has been identified, and various bone morphogenetic proteins have been found in others.
虽然传统上骨形成很难在体外进行研究，但细胞培养技术最近的进展使得研究胎鼠颅骨成骨细胞的原代培养成为可能，并且能够检测与成骨细胞增殖、分化以及细胞外基质矿化形成骨结节相关的特定基因事件。研究结果表明，诸如I型胶原蛋白和骨钙素等细胞外基质蛋白会表达。同样会表达的还有生长调节因子，例如骨形态发生蛋白，它们可能会被分泌并存储在骨基质中，或者以自分泌/旁分泌的作用参与额外的成骨细胞分化。骨基质是这些用于骨形成的生长调节因子的一个来源；另一个来源是那些与成骨细胞转移相关的动物和人类肿瘤。在其中一些肿瘤中，已鉴定出一种延长形式的碱性成纤维细胞生长因子，而在其他肿瘤中则发现了各种骨形态发生蛋白。
