Versican/PG-M regulates chondrogenesis as an extracellular matrix molecule crucial for mesenchymal condensation
Versican/PG-M regulates chondrogenesis as an extracellular matrix molecule crucial for mesenchymal condensation
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DOI：
10.1074/jbc.m509341200
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发表时间：
2006-01-27
影响因子：
4.8
通讯作者：
Kimata, K
中科院分区：
文献类型：
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作者：
Kamiya, N;Watanabe, H;Kimata, K
间充质细胞凝聚是软骨发育的重要步骤。Versican/PG-M是一种大的硫酸软骨素蛋白聚糖，是在细胞外基质中在缩合过程中表达的主要分子之一。然而，它的作用，特别是作为细胞浓缩的环境，尚未阐明。在这里，我们使用新的软骨细胞系N1511显示了多功能蛋白聚糖/PG-M在软骨形成凝聚中的重要作用的几条证据.软骨形成刺激（甲状旁腺激素，地塞米松，10%血清治疗）诱导的多功能蛋白聚糖/PG-M的转录和蛋白质合成显着增加。多能蛋白聚糖/PG-M的稳定反义克隆取决于多能蛋白聚糖/PG-M表达的抑制，显示出不同的软骨形成能力，如聚集蛋白聚糖（一种主要的软骨细胞产物）的表达和沉积所示。在培养的早期阶段的细胞仅表达V0和V1形式，在多功能蛋白聚糖/PG-M的四种变体中具有更多的硫酸软骨素链，并且用软骨素酶ABC处理这些细胞抑制随后的软骨形成。此外，用β-木糖苷（硫酸软骨素合成的人工链引发剂）处理从而抑制核心蛋白的合成，抑制了软骨形成。此外，没有硫酸软骨素链的变体V3的强制表达破坏了天然多功能蛋白聚糖/PG-M（V0/V1）和已知在间充质凝聚期间表达的其他细胞外基质分子的沉积和组织，并导致随后的软骨形成的抑制。这些结果表明，多功能蛋白聚糖/PG-M参与正调控间充质基质的形成和软骨细胞分化的开始，通过连接的硫酸软骨素链。
Mesenchymal cell condensation is an essential step for cartilage development. Versican/PG-M, a large chondroitin sulfate proteoglycan, is one of the major molecules expressed in the extracellular matrix during condensation. However, its role, especially as an environment for cells being condensed, has not been elucidated. Here we showed several lines of evidence for essential roles of versican/PG- M in chondrogenic condensation using a new chondrocytic cell line, N1511. Chondrogenic stimuli (treatment with parathyroid hormone, dexamethasone, 10% serum) induced a marked increase in the transcription and protein synthesis of versican/PG-M. Stable antisense clones for versican/PG-M, depending on suppression of the expression of versican/PG- M, showed different capacities for chondrogenesis, as indicated by the expression and deposition of aggrecan, a major chondrocytic cell product. The cells in the early stages of the culture only expressed V0 and V1 forms, having more chondroitin sulfate chains among the four variants of versican/PG-M, and treatment of those cells with chondroitinase ABC suppressed subsequent chondrogenesis. Furthermore, treatment with beta-xyloside, an artificial chain initiator of chondroitin sulfate synthesis to consequently inhibit the synthesis on the core proteins, suppressed chondrogenesis. In addition, forced expression of the variant V3, which has no chondroitin sulfate chain, disrupted the deposition and organization of native versican/PG-M (V0/V1) and other extracellular matrix molecules known to be expressed during the mesenchymal condensation and resulted in the inhibition of subsequent chondrogenesis. These results suggest that versican/PG-M is involved in positively regulating the formation of the mesenchymal matrix and the onset of chondrocyte differentiation through the attached chondroitin sulfate chains.