Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois.
Department of Implant Dentistry, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatlogy, Xi'an, Shaanxi, China.
J Cell Physiol. 2019 May;234(5):6679-6687. doi: 10.1002/jcp.27410. Epub 2018 Oct 20.
Runx2 plays an essential role in embryonic disc tissue development in mice. However, the role of runt-related transcription factor 2 (Runx2) in postnatal disc tissue growth and development has not been defined. In the present studies, we generated Runx2 conditional knockout (KO) mice (Runx2 ), in which Runx2 was deleted in Aggrecan-expressing cells in disc tissue at postnatal 2-weeks of age. We then analyzed changes in disc tissue growth and development using histology and immunohistochemical methods in 3-month-old mice. We found that large vacuolated notochordal cells were accumulated in the nucleus pulposus (NP) in Runx2 KO mice. The growth plate cartilage tissue in the disc was thicker in Runx2 KO mice. We also found a significant upregulation of Indian hedgehog (Ihh) expression in the cells in NP cells and in annulus fibrosus cells of Runx2 KO mice. These results demonstrated that Runx2 may play an important role in postnatal disc tissue development through interacting with Ihh signaling.
Runx2 在小鼠胚胎椎间盘组织发育中发挥重要作用。然而，runt 相关转录因子 2（Runx2）在出生后椎间盘组织生长和发育中的作用尚未确定。在本研究中，我们生成了 Runx2 条件性敲除（KO）小鼠（Runx2 KO），在该小鼠中，Runx2 在出生后 2 周时椎间盘组织中表达 Aggrecan 的细胞中被删除。然后，我们使用组织学和免疫组织化学方法在 3 月龄小鼠中分析椎间盘组织生长和发育的变化。我们发现，Runx2 KO 小鼠的髓核中积累了大量空泡状的脊索细胞。Runx2 KO 小鼠的椎间盘生长板软骨组织更厚。我们还发现 Runx2 KO 小鼠的 NP 细胞和纤维环细胞中 Indian hedgehog（Ihh）表达显著上调。这些结果表明，Runx2 可能通过与 Ihh 信号相互作用在出生后椎间盘组织发育中发挥重要作用。
