Effect of compressive loading on chondrocyte differentiation in agarose cultures of chick limb-bud cells
Effect of compressive loading on chondrocyte differentiation in agarose cultures of chick limb-bud cells
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DOI：
10.1002/jor.1100180112
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发表时间：
2000-01-01
影响因子：
2.8
通讯作者：
Goldstein, SA
中科院分区：
文献类型：
--
作者：
Elder, SH;Kimura, JH;Goldstein, SA
众所周知，机械负荷对软骨组织的体内平衡很重要，并且越来越多的证据表明它也会影响软骨分化。尽管已经大力研究了机械力对软骨细胞生物合成和基因表达的影响，但机械环境对软骨细胞分化的影响很少受到关注。这项研究的长期目的是研究机械负荷在细胞分化中的调节作用。这项研究的目的是确定机械压缩是否可以在体外调节软骨细胞分化。 23/24阶段，嵌入琼脂糖凝胶中的鸡肢体细胞受到静态（恒定4.5 kPa应力）或在未限制压缩期间的静态（9.0-kPa峰值应力下的9.0-kPa峰值应力）。表型谱系。与未加载的对照相比，环状压缩负荷大约增加了软骨结节的数量和第8天的硫酸盐掺入量，而静态压缩对这两种措施的影响很小。压缩方案均未显着影响整体细胞活力或结节内细胞的增殖。由于将肢体bud间充质细胞直接接种到琼脂糖中，因此对琼脂糖中软骨结节的评估反映了产生软骨细胞的原始细胞的比例。因此，结果表明，通过环状机械压缩诱导许多间充质细胞进入软骨途径的大约两倍。硫酸盐掺入和结节密度增加的一致性表明，机械压缩对间充质细胞的主要作用是对细胞分化的，而不是随后的代谢。需要进一步的研究来确定与循环压缩负荷相关的主要软骨基因信号，并确定其影响或通过软骨谱系进展的机制，或两者兼有。
It is well established that mechanical loading is important to homeostasis of cartilage tissue, and growing evidence suggests that it influences cartilage differentiation as well. Whereas the effect of mechanical forces on chondrocyte biosynthesis and gene expression has been vigorously investigated, the effect of the mechanical environment on chondrocyte differentiation has received little attention. The long-term objective of this research is to investigate the regulatory role of mechanical loading in cell differentiation. The goal of this study was to determine if mechanical compression could modulate chondrocyte differentiation in vitro. Stage 23/24, chick limb-bud cells, embedded in agarose gel, were subjected to either static (constant 4.5-kPa stress) or cyclic (9.0-kPa peak stress at 0.33 Hz) loading in unconfined compression during the initial phase of commitment to a phenotypic lineage. Compared with nonloaded controls, cyclic compressive loading roughly doubled the number of cartilage nodules and the amount of sulfate incorporation on day 8, whereas static compression had little effect on these two measures. Neither compression protocol significantly affected overall cell viability or the proliferation of cells within nodules. Since limb-bud mesenchymal cells were seeded directly into agarose, an assessment of cartilage nodules in the agarose reflects the proportion of the original cells that had given rise to chondrocytes. Thus, the results indicate that about twice as many mesenchymal cells were induced to enter the chondrogenic pathway by cyclic mechanical compression. The coincidence of the increase in sulfate incorporation and nodule density indicates that the primary effect of mechanical compression on mesenchymal cells was on cellular differentiation and not on their subsequent metabolism. Further studies are needed to identify the primary chondrogenic signal associated with cyclic compressive loading and to determine the mechanism by which it influences commitment to or progression through the chondrogenic lineage, or both.