Bone and Cartilage Regenerative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Sensory and Motor System Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Cell Mol Life Sci. 2019 Oct;76(20):3939-3952. doi: 10.1007/s00018-019-03191-5. Epub 2019 Jun 14.
Articular cartilage is formed at the end of epiphyses in the synovial joint cavity and permanently contributes to the smooth movement of synovial joints. Most skeletal elements develop from transient cartilage by a biological process known as endochondral ossification. Accumulating evidence indicates that articular and growth plate cartilage are derived from different cell sources and that different molecules and signaling pathways regulate these two kinds of cartilage. As the first sign of joint development, the interzone emerges at the presumptive joint site within a pre-cartilage tissue. After that, joint cavitation occurs in the center of the interzone, and the cells in the interzone and its surroundings gradually form articular cartilage and the synovial joint. During joint development, the interzone cells continuously migrate out to the epiphyseal cartilage and the surrounding cells influx into the joint region. These complicated phenomena are regulated by various molecules and signaling pathways, including GDF5, Wnt, IHH, PTHrP, BMP, TGF-β, and FGF. Here, we summarize current literature and discuss the molecular mechanisms underlying joint formation and articular development.
关节软骨形成于滑膜关节腔的骨骺末端，为滑膜关节的平滑运动提供永久性贡献。大多数骨骼元素通过一种称为软骨内骨化的生物学过程从短暂的软骨发育而来。越来越多的证据表明，关节软骨和生长板软骨来自不同的细胞来源，不同的分子和信号通路调节这两种软骨。作为关节发育的第一个标志，在软骨前组织内的假定关节部位出现过渡区。之后，关节在过渡区的中心发生空化，过渡区及其周围的细胞逐渐形成关节软骨和滑膜关节。在关节发育过程中，过渡区细胞不断向外迁移到骺软骨，周围的细胞向内流入关节区域。这些复杂的现象受到各种分子和信号通路的调节，包括 GDF5、Wnt、IHH、PTHrP、BMP、TGF-β 和 FGF。在这里，我们总结了目前的文献，并讨论了关节形成和关节发育的分子机制。
