A role for lysyl oxidase regulation in the control of normal collagen deposition in differentiating osteoblast cultures
A role for lysyl oxidase regulation in the control of normal collagen deposition in differentiating osteoblast cultures
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DOI：
10.1002/jcp.10476
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发表时间：
2004-07-01
影响因子：
5.6
通讯作者：
Trackman, PC
中科院分区：
文献类型：
--
作者：
Hong, HH;Pischon, N;Trackman, PC
表型正常的成骨细胞培养物的分化导致体外骨样细胞外基质的形成。最大的胶原蛋白合成发生在这些培养物的生命早期，而不溶性胶原蛋白沉积发生较晚，并伴随着胶原蛋白合成速率的降低。控制胶原沉积的机制似乎可能包括细胞外胶原生物合成酶的调节，但这些酶在分化成骨细胞中的表达模式很少受到关注。本研究确定赖氨酰氧化酶的调节作为表型正常小鼠MC 3 T3-E1细胞在RNA和蛋白质表达和酶活性水平上分化的函数。此外，检测编码前胶原C蛋白酶的BMP-1/mRNA水平的调节。赖氨酰氧化酶在控制不溶性胶原积累中的作用在抑制研究中进一步研究，使用对氨基丙腈，赖氨酰氧化酶酶活性的特异性抑制剂。结果表明，赖氨酰氧化酶的调节作为分化的MC 3 T3-E1细胞的功能，赖氨酰氧化酶活性的最大增加之前的最有效的阶段不溶性胶原蛋白的积累。相比之下，BMP-1/MMP的组成型表达更强。抑制赖氨酰氧化酶在这些文化中增加异常胶原纤维的积累，通过溶解度研究和电子显微镜测定。总之，这些数据支持赖氨酰氧化酶活性的调节在成骨细胞培养控制胶原沉积中起关键作用。(C)2004 Wiley-Liss，Inc.
Differentiation of phenotypically normal osteoblast cultures leads to fori nation of a bone-like extracellular matrix in vitro. Maximum collagen synthesis occurs early in the life of these Cultures, whereas insoluble collagen deposition occurs later and is accompanied by a diminished rate of collagen synthesis. The mechanisms that control collagen deposition seem likely to include regulation of extracellular collagen biosynthetic enzymes, but expression patterns of these enzymes in differentiating osteoblasts has received little attention. The present study determined the regulation of lysyl oxidase as a function of differentiation of phenotypically normal murine MC3T3-E1 cells at the level of RNA and protein expression and enzyme activity. In addition, the regulation of BMP-1/mTLD mRNA levels that encodes procollagen C-proteinases was assayed. The role of lysyl oxidase in controlling insoluble collagen accumulation was further investigated in inhibition studies utilizing P-aminopropionitrile, a specific inhibitor of lysyl oxidase enzyme activity. Results indicate that lysyl oxidase is regulated as a function of differentiation of MC3T3-E1 cells, and that the maximum increase in lysyl oxidase activity precedes the most efficient phase of insoluble collagen accumulation. By contrast BMP-1/mTLD is more constitutively expressed. Inhibition of lysyl oxidase in these cultures increases the accumulation of abnormal collagen fibrils, as determined by solubility studies and by electron microscopy. Taken together, these data support that regulation of lysyl oxidase activity plays a key role in the control of collagen deposition by osteoblast cultures. (C) 2004 Wiley-Liss, Inc.