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和 在软组织中成骨，这些软组织通常不形成软骨或 骨头。Urist将这种因子称为BMP，即骨形态发生 蛋白。从骨骼中鉴定这种蛋白质的努力还没有 因为金额小而高度成功 BMP的交互性质以及BMP的复杂组成 骨头。此外，涉及活体的检测系统 植入，需要大量的蛋白质。我们有 从两个新的角度来看待这个问题：1)在 建立了体外细胞培养方法；2)进行了应用 牙本质基质的BMP活性高于 骨基质。在我们的初步研究中，我们已经证明了 在大鼠牙本质基质中存在一种因子，它是 体外成软骨和体内成骨，提取物和 分离非胶原蛋白，定位该组分 与分离的非胶原蛋白一起，位于 含有分离的非胶原蛋白的组份，位于 含有分离的非胶原蛋白的部分， 定位具有体外成软骨活性的组分，以及 显示非肌源性新生大鼠肌肉成纤维细胞有 摄取它的受体。我们现在提议：1)净化中央情报局 同源性，并获得其氨基辅助序列；2)测定其 体内活性；3)制备免疫和核苷酸探针 其鉴定；4)定量受体结合部位和 确定受体的性质和摄取过程；5) 研究生长因子和其他调节剂在 其体外活性；6)探索CIA在体内的骨应用 缺陷修复。我们相信，这些研究可以是巨大的。 进一步密切软骨化组织工程应用的重要性 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.