Department of Oral and Maxillofacial Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian, China.
Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, Fujian, China.
J Anat. 2022 Feb;240(2):385-397. doi: 10.1111/joa.13545. Epub 2021 Sep 26.
Hard palate consists anteriorly of the palatal process of the maxilla (ppmx) and posteriorly of the palatal process of the palatine (ppp). Currently, palatal osteogenesis is receiving increasing attention. This is the first study to provide an overview of the osteogenesis process of the mouse hard palate. We found that the period in which avascular mesenchymal condensation becomes a vascularized bone structure corresponds to embryonic day (E) 14.5 to E16.5 in the hard palate. The ppmx and ppp differ remarkably in morphology and molecular respects during osteogenesis. Osteoclasts in the ppmx and ppp are heterogeneous. There was a multinucleated giant osteoclast on the bone surface at the lateral-nasal side of the ppmx, while osteoclasts in the ppp were more abundant and adjacent to blood vessels but were smaller and had fewer nuclei. In addition, bone remodeling in the hard palate was asymmetric and exclusively occurred on the nasal side of the hard palate at E18.5. During angiogenesis, CD31-positive endothelial cells were initially localized in the surrounding of palatal mesenchymal condensation and then invaded the condensation in a sprouting fashion. At the transcriptome level, we found 78 differentially expressed genes related to osteogenesis and angiogenesis between the ppmx and ppp. Fifty-five related genes were up/downregulated from E14.5 to E16.5. Here, we described the morphogenesis and the heterogeneity in the osteogenic and angiogenic genes profiles of the ppmx and ppp, which are significant for subsequent studies of normal and abnormal subjects.
硬腭前部由上颌的腭突（ppmx）构成，后部由腭骨的腭突（ppp）构成。目前，腭骨发生受到越来越多的关注。这是首次对小鼠硬腭骨发生过程进行综述的研究。我们发现，无血管间质凝聚形成血管化骨结构的时期对应硬腭的胚胎第 14.5 天至第 16.5 天。在硬腭骨发生过程中，ppmx 和 ppp 在形态和分子上有显著差异。ppmx 和 ppp 中的破骨细胞是异质的。在 ppmx 的鼻侧，骨表面有一个多核巨细胞破骨细胞，而 ppp 中的破骨细胞更为丰富，且与血管相邻，但较小且核较少。此外，硬腭的骨重建是不对称的，仅在 E18.5 时发生在硬腭的鼻侧。在血管生成过程中，CD31 阳性的内皮细胞最初定位于腭间充质凝聚物的周围，然后以出芽的方式侵入凝聚物。在转录组水平上，我们发现 78 个与成骨和血管生成相关的差异表达基因存在于 ppmx 和 ppp 之间。从 E14.5 到 E16.5，有 55 个相关基因上调/下调。在此，我们描述了 ppmx 和 ppp 的成骨和血管生成基因谱的形态发生和异质性，这对后续研究正常和异常对象具有重要意义。
