Celluar Biological Analysis on the Mechanism of Mineralization of Human Bone Tissue and its Application for Reconstruction of Human Tissue in Vitro

将骨块包埋于胶原凝胶中，从人上颌骨分离成骨细胞。通过对分离细胞的培养和鉴定，细胞对甲状旁腺素和前列腺素E_2有反应，分泌骨钙素，并在单层培养中形成矿化区。当我们研究几种因素对细胞分化和增殖的影响时，骨基质中含有的血小板衍生生长因子往往会刺激细胞的增殖。据报道，骨髓组织中含有能够向成骨细胞和软骨母细胞分化的细胞。根据这些事实，我们培养了骨髓基质细胞，并阐明了组织中有成骨细胞，在体外形成矿化结节。对结节进行组织学和免疫组织化学分析。由于软骨细胞在骨形成过程中起着重要的作用，我们还对f…进行了研究更多平淡的研究。我们通过单层培养获得了终末分化的软骨细胞。维甲酸对细胞有促增殖作用。结果提示，维甲酸促软骨细胞增殖的机制不是由表皮生长因子介导，而是由蛋白激酶C介导。培养的软骨细胞胞浆和胞核均有维甲酸结合能力。这些结合能力可能参与了维甲酸的作用机制。此外，为了更深入地了解软骨内成骨的生理机制，我们观察了低钙饲料喂养的生长期大鼠下颌软骨的变化。结果表明，生长期大鼠缺钙后代谢紊乱，细胞外基质钙化不良，导致增殖细胞区细胞增殖受抑，软骨细胞成熟受抑，软骨吸收受抑，从而抑制和抑制了正常软骨内成骨的机制，抑制了下颌骨的软骨内生长。较少

Osteoblastic cells were isolated from human maxilla by embedding the bone pieces in collagen gel. As a result of the culture and characterization of the isolated cells, the cells responded to PTH and PGE_2, secreted osteocalcin and formed mineralized area in monolayer culture. When we investigated the effect of several factors on differentiation and proliferation of the cells, platelet-derived growth factor contained in the bone matrix tended to stimulate proliferation of the cells.Bone marrow tissue is reported to contain cells which can differentiate to osteoblast and chondroblast. From these facts, we cultured bone marrow stromal cells and elucidated that the tissue has osteogenic cells, which formed mineralized nodules in vitro. The nodules were analyzed histologically and immunohistochemically. Among the cells, it is confirmed to exist the cells which could mineralize without beta-glycerophosphate.As chondrocytes have an important role in bone formation, we have also studied the f … More ollowing research. We obtained terminally differentiated chondrocytes in monolayer culture. The cells tended to be stimulated proliferation by retinoic acid. The results suggested that the mechanism of proliferation by retinoic acid was not mediated by epidermal growth factor but by protein kinase C. The retinoic acid binding capacity was detected in both the cytosol and nuclear of the cultured chondrocytes. These binding capacity was supposed to be involved in the mechanism of retinoic acid.Furthermore, in order to obtain more insight into the physiologic mechanism of endochondral ossification, changes occurring in the mandibular cartilage of growing rats fed on a low-calcium diet were investigated. The results indicated that calcium-deficiency and subsequent metabolic disorder in growing rats induced inhibition of cell proliferation in the proliferative cell zone, inhibition of maturation of chondrocytes, and inhibition of cartilage resorption due to poor calcification of the extracellular matrix, so that the mechanism of normal endocondral ossification might be inhibited and enibited and endochondral growth of mandibular condyle by suppressed. Less