Runx2-deficient mice lack mandibular condylar cartilage and have deformed Meckel's cartilage
Runx2-deficient mice lack mandibular condylar cartilage and have deformed Meckel's cartilage
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DOI：
10.1007/s00429-004-0393-2
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发表时间：
2004-07-01
期刊：
影响因子：
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通讯作者：
Komori, T
中科院分区：
文献类型：
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作者：
Shibata, S;Suda, N;Komori, T
Runx2（runt相关转录因子2）缺陷小鼠缺乏下颌髁突软骨和下颌骨。髁突原基由间充质凝聚组成，表达I型胶原mRNA和碱性磷酸酶活性，但不表达II型胶原和聚集蛋白聚糖mRNA。因此，下颌髁突软骨的分化停止在前成骨细胞（成骨细胞）阶段。翼外肌附着于此原基上，在附着部位，如下颌体原基、角突和冠突，也形成了相对丰富的间充质致密物。三维重建模型显示，各间充质凝聚体相互连接，大致勾勒出下颌骨的形态。Runx2缺陷小鼠的Meckel软骨有两个异位软骨突起，二腹肌和肌舌骨肌附着于其上。这些发现表明Runx2对于下颌髁突软骨的形成以及Meckel软骨的正常发育是必不可少的，并且肌肉组织影响下颌骨形态。
Runx2 (runt-related transcription factor 2) deficient mice lacked the mandibular condylar cartilage and the mandibular bone. The anlage of the condylar process consisted of mesenchymal condensation, which expressed Type I collagen mRNA and alkaline phosphatase activity, but not Type II collagen and aggrecan mRNAs. Therefore, the differentiation of the mandibular condylar cartilage stopped at the preosteoblast (skeletoblast) stage. The lateral pterygoid muscle was attached to this anlage, and relatively abundant mesenchymal condensations were also formed at the muscle-attaching sites, e.g. the anlage of the mandibular body, the angular and coronoid processes. Three-dimensional reconstruction models showed that each mesenchymal condensation was connected to one another, and roughly outlined the shape of the mandible. Meckel's cartilage in the Runx2-deficient mice had two ectopic cartilaginous processes to which the digastric and myohyoid muscles were attached. These findings indicate that Runx2 is essential for the formation of the mandibular condylar cartilage, as well as for normal development of Meckel's cartilage and that muscle tissues influence mandible morphology.