THE INFLUENCE OF TYPE-I COLLAGEN ON THE DEVELOPMENT AND MAINTENANCE OF THE OSTEOBLAST PHENOTYPE IN PRIMARY AND PASSAGED RAT CALVARIAL OSTEOBLASTS - MODIFICATION OF EXPRESSION OF GENES SUPPORTING CELL-GROWTH, ADHESION, AND EXTRACELLULAR-MATRIX MINERALIZATION
THE INFLUENCE OF TYPE-I COLLAGEN ON THE DEVELOPMENT AND MAINTENANCE OF THE OSTEOBLAST PHENOTYPE IN PRIMARY AND PASSAGED RAT CALVARIAL OSTEOBLASTS - MODIFICATION OF EXPRESSION OF GENES SUPPORTING CELL-GROWTH, ADHESION, AND EXTRACELLULAR-MATRIX MINERALIZATION
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DOI：
10.1006/excr.1995.1005
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发表时间：
1995-01-01
影响因子：
3.7
通讯作者：
LIAN, JB
中科院分区：
文献类型：
--
作者：
LYNCH, MP;STEIN, JL;LIAN, JB
与在塑料上培养的细胞相比，在I型胶原膜上生长的来自第21天胎鼠颅骨的成骨细胞表现出分化表型的更早和增强的表达。表征生长和分化的三个不同时期的基因的时间表达被显著地修改。在最初的增殖期，在塑料（纤连蛋白，β 1整联蛋白，肌动蛋白）正常表达的基因的表达从50%下降到70%，在胶原蛋白上生长的细胞。通常在增殖后期表达最高水平的基因（骨连接素，骨钙素和骨桥蛋白）在很早的时候就上调了几倍。碱性磷酸酶活性升高2至3倍，在增殖期间，而mRNA水平保持较低，这表明转录后修饰。在胶原蛋白上培养细胞的最显著结果是基质的加速和均匀矿化，而在塑料上培养仅限于骨结节的局灶性矿化。I型胶原蛋白支持在没有糖皮质激素补充的情况下维持传代细胞的成骨细胞表型特性，所述糖皮质激素补充是在塑料上传代培养的成骨细胞分化所需的。用1，25（OH）（2）D-3处理塑料上增殖的大鼠成骨细胞阻断成骨细胞分化和基质矿化。虽然分化相关基因（碱性磷酸酶和骨钙素）上调维生素D，胶原基质上的文化不能克服矿化的抑制。总之，这些研究确定了I型胶原蛋白在介导成熟成骨细胞表型表达的信号级联和以生理方式矿化细胞外基质中的关键作用。(C)出版社：Academic Press
Osteoblasts derived from Day 21 fetal rat calvaria grown on films of collagen type I exhibit an earlier and enhanced expression of the differentiated phenotype, compared to cells cultured on plastic. The temporal expression of genes characterizing three distinct periods of growth and differentiation are dramatically modified. During the initial proliferation period, expression of genes normally expressed at high levels on plastic (fibronectin, beta 1 integrin, and actin) was decreased from 50 to 70% in cells grown on collagen. Genes normally expressed at maximal levels in the postproliferative period (osteonectin, osteocalcin, and osteopontin) were up-regulated severalfold very early. Alkaline phosphatase enzyme activity was elevated 2- to 3-fold during the proliferation period, while mRNA levels remained low, suggesting post-transcriptional modifications. The most dramatic consequence of culture of cells on collagen is the accelerated and uniform mineralization of the matrix in contrast to the focal mineralization confined to bone nodules in cultures on plastic. Type I collagen supports maintenance of osteoblast phenotypic properties of passaged cells in the absence of glucocorticoid supplementation required for differentiation of osteoblasts subcultivated on plastic. Treatment of proliferating rat osteoblasts on plastic with 1,25(OH)(2)D-3 blocks osteoblast differentiation and matrix mineralization. Although differentiation-related genes (alkaline phosphatase and osteocalcin) were up-regulated by vitamin D, culture on the collagen matrix could not overcome the inhibition of mineralization. Taken together, these studies define the critical role of type I collagen in mediating the signaling cascade for expression of a mature osteoblast phenotype and mineralization of the extracellular matrix in a physiological manner. (C) 1995 Academic Press, Inc.