Combined effects of cartilage-derived factor with epidermal growth factor in bone and tooth developments

我们已成功地纯化了多种分子形式的软骨衍生因子，包括中性的11K、碱性的16K和26K的CDF。纯化的CDF可促进兔肋软骨细胞蛋白多糖的合成，但对DNA合成和细胞分裂的影响相对较小。相反，表皮生长因子(EGF)刺激软骨细胞的DNA合成和细胞分裂，但不刺激或抑制蛋白多糖的合成。CDF影响发生在软骨细胞周期G_1期早期的事件，以刺激DNA合成。CDF与EGF在刺激细胞DNA合成方面具有协同作用。我们发现，当培养的软骨细胞在G_1期的早期阶段暴露于生长抑素样生长因子时，它们会被激活，与EGF相互作用，致力于DNA合成。这意味着CDF在这个调节阶段激活细胞对非生长因子…的协同反应。更多的EGF。因此，软骨中的胞外分泌因子，如CDFS、成纤维细胞生长因子、转化生长因子等。我们发现磷酸酪氨酸磷酸酶抑制剂钒酸(0.6-6；MICRN&GT；M)能刺激兔肋软骨细胞合成软骨特异的蛋白多糖，并诱导形态分化。相反，钒酸盐(20-60；microrn&gt；M)减少了软骨细胞蛋白多糖的合成，并诱导了形态转化。因此，需要适度增加磷酸酪氨酸水平才能表达软骨细胞的光型，过高的水平会导致细胞表达转化的表型。兔软骨细胞在含有10%胎牛血清的Eagle‘s培养液中成功生长。细胞增殖形成软骨样结节，肥大的软骨细胞嵌入基质中，基质由软骨特有的蛋白多糖、II型和X型胶原组成。只有在该体系中碱性磷酸酶活性和1，25(OH)_2D_3受体水平显著增加后，才会发生钙化。因此，用这种高密度悬浮培养法模拟了活体兔肋骨生长板上发生的一系列事件。较少

We have succeeded in purifyin gvarious molecular species of cartilage-derived factor (CDF) including neutral 11k, basic 16k, and 26k CDFs. The purified CDF enhanced the synthesis of proteoglycans of rabbit costal chondrocytes in culture, but had relatively smaller effect on DNA synthesis and cell division. In contrast, epidermal growth factor (EGF) stimulated DNA synthesis and cell division of chondrocytes, but did not stimulate nor inhibit proteoglycan synthesis. CDF affected events occurring in the early stage of the G_1 phase of the cell cycle of chondrocytes to stimulate DNA synthesis. CDF had synergistic effects with EGF in stimulating DNA synthesis of the cells. We found that the culured chondrocytes become activated to interact with EGF for commitment to DNA synthesis when they are exposed to a somatomedin-like growth factor at an early stage of G_1 phase. This means that CDF activates cells at this regulatory stage to respond synergistically to the non-somatomedin growth factor … More EGF. Therefore, sutocrine factors in cartilage, such as CDFs, fibroblast growth factor, and transforming growth factor-<beta>, must We found that vanadate (0.6-6<micrn>M), an inibitor of phosphotyrosine phosphatase, stimulates the synthesis of cartilage-specific proteoglycans in rabbit costal chondrocytes and induced morphologic differentiation. In contrast, vanadate (20-60 <micrn>M) decreased cartilage proteoglycan synthesis by chondrocytes and induced morphologic transformation. Therefore, moderate increases in the level of phosphotyrosine are required for the expression of the chondrocyte phoenotype, excess increases cause cells to express the transformed phenotype.Rabbit chondrocytes were grown successfully in suspension in Eagle's medium supplemented with 10 % fetal calf serum. The cells proliferated and formed cartilage-like nodules, Where hypertrophic chondrocytes were embedded in matrix, composed of 'cartilage- specific' proteoglycans, type II and X-like collagens. The calcification occurred only after marked increases of alkaline phosphatase activity and 1,25(OH)_2D_3 receptor levels in this system. Therefore, sequential events occurring at the growth-plate of rabbit rib in vivo were simulated by this high-density suspension culture. Less