OSTEOGENIC FACTOR FROM DENTIN MATRIX

矿化组织的细胞外基质中含有一种蛋白质 具有诱导软骨形成能力的因子， 通常不形成软骨的软组织中的骨生成， 骨头 乌里斯特称这种因子为BMP，即骨形态发生因子。 蛋白 对这种来自骨骼的蛋白质进行表征的努力还没有 成功的原因是数量少， BMP的相互作用性质，以及BMP的复杂组成， 骨头 此外，涉及体内的测定系统 移植需要大量的蛋白质。 我们有 从两个新的角度探讨了这一问题：1）在 已经开发了体外细胞培养试验; 2）已经使用 事实上，牙本质基质具有比牙本质基质更高的BMP活性， 骨基质 在我们最初的研究中，我们已经证明了 大鼠牙本质基质中存在一种因子， 体外成软骨和体内成骨，提取和 对非胶原蛋白进行分级， 用分级分离的非胶原蛋白， 具有分级分离的非胶原蛋白的级分，位于 具有分级分离的非胶原蛋白的级分， 定位具有体外软骨形成活性的级分，并且 显示非肌源性新生大鼠肌肉成纤维细胞 受体对其进行摄取。 我们现在建议：1）净化中情局， 同源性并获得其氨基酸序列; 2）测定其 体内活性; 3）制备免疫和核苷酸探针， 其鉴定; 4）定量受体结合位点， 确定受体的性质和摄取过程; 5） 研究生长因子和其他调节因子对 其体外活性;和6）探索CIA在骨中的体内使用 缺陷修复 我们相信，这些研究可以是巨大的， 重要的是使软骨形成和 成骨剂用于骨缺损的修复。

Mineralized tissues contain in their extracellular matrix a protein factor which has the capacity to induce chondrogenesis and osteogenesis in soft tissues that normally do not form cartilage or bone. Urist has called this factor BMP, the bone morphogenetic protein. Efforts to characterize this protein from bone have not been successful because of the small amount and highly interactive nature of BMP, and the complex composition of the bone. Moreover, the assay systems, involving in vivo implantation, have required large amounts of protein. We have approached this problem from two fresh perspectives: 1) an in vitro cell culture assay has been developed; 2) use has been made of the fact that dentin matrix has a higher BMP activity than bone matrix. In our initial studies we have demonstrated the presence of a factor in the rat dentin matrix which is chondrogenic in vitro and osteogenic in vivo, extracted and fractionated the noncollagenous proteins, located the fraction with fractionated the noncollagenous proteins, located the fraction with fractionated the noncollagenous proteins, located the fraction with fractionated the noncollagenous proteins, located the fraction with in vitro chondrogenic activity, and shown that nonmyogenic nionatal rat muscle fibroblasts have receptors for its uptake. We now propose to: 1) purify the CIA to homogeneity and obtain its amino aid sequence; 2) determine its in vivo activity; 3) prepare immunologic and nucleotide probes for its identification; 4) quantitate the receptor binding site and determine the nature of the receptor and the uptake process; 5) examine the role of growth factors and other regulatory agents on its activity in vitro; and 6) explore the use of CIA in vivo in bone defect repair. We believe that these studies can be of immense importance in bringing closer the application of chondrogenic and osteogenic agents to the repair of bone defects.