Reddi A H
Department of Orthopaedic Surgery, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
Clin Orthop Relat Res. 1995 Apr(313):115-9.
In postnatal mammals, there are persistent molecular signals and responding cells in bone to initiate osteogenesis and repair in response to trauma. The responding osteogenic precursor cells are of 2 categories: determined and inducible. The latter can be induced by demineralized bone matrix to form bone. Demineralized bone matrix consists of extracellular matrix and tightly associated bone morphogenetic proteins. The genes for bone morphogenetic proteins have been cloned, the recombinant proteins have been expressed, and currently their mechanism of action is being explored. Bone morphogenetic proteins are pleiotropic initiators of inducible osteogenic precursor cells. Bone morphogenetic proteins govern the 3 key steps in the osteogenic cascade: chemotaxis, mitosis, and differentiation. The receptors for bone morphogenetic proteins have been cloned and expressed and consist of 2 classes, Types I and II, that are membrane bound serine/threonine protein kinases. Bone morphogenetic proteins bind to extracellular matrix and their collaborative action on osteogenic cells culminates in the terminal differentiation of the osteoblast-osteocyte continuum. Bone morphogenetic proteins are currently on the threshold for clinical applications.
在出生后的哺乳动物中，骨骼中存在持续的分子信号和响应细胞，以在创伤后启动骨生成和修复。响应性成骨前体细胞有两类：确定性的和可诱导性的。后者可被脱矿骨基质诱导形成骨。脱矿骨基质由细胞外基质和紧密相关的骨形态发生蛋白组成。骨形态发生蛋白的基因已被克隆，重组蛋白已被表达，目前其作用机制正在被探索。骨形态发生蛋白是可诱导性成骨前体细胞的多效性启动因子。骨形态发生蛋白控制成骨级联反应中的三个关键步骤：趋化性、有丝分裂和分化。骨形态发生蛋白的受体已被克隆和表达，由两类组成，即I型和II型，它们是膜结合的丝氨酸/苏氨酸蛋白激酶。骨形态发生蛋白与细胞外基质结合，它们对成骨细胞的协同作用最终导致成骨细胞 - 骨细胞连续体的终末分化。骨形态发生蛋白目前正处于临床应用的门槛上。
