Chen Hongli, Ding Yunpeng, Wang Yu, Sun Yao
Department of Oral Implantology, Stomatological Hospital and Dental School of Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai, China.
J Histochem Cytochem. 2024 Jun 5;72(6):221554241259059. doi: 10.1369/00221554241259059.
Jawbones and long bones, despite their shared skeletal lineage, frequently exhibit distinct origins and developmental pathways. Identifying specific progenitor subsets for mandibular osteogenesis remains challenging. Type II collagen is conventionally associated with cartilaginous structures, yet our investigation has identified the presence of type II collagen positive (Col2) cells within the jawbone development and regeneration. The role of Col2 cells in jawbone morphogenesis and repair has remained enigmatic. In this study, we analyze single-cell RNA sequencing data from mice jawbone at embryonic day 10.5. Through fate-mapping experiments, we have elucidated that Col2 cells and their progeny are instrumental in mandibular osteogenesis across both fetal and postnatal stages. Furthermore, lineage tracing with a tamoxifen-inducible CreER system has established the pivotal role of Col2 cells, marked by Col2-CreER and originating from the primordial Meckel's cartilage, in jawbone formation. Moreover, our research explored models simulating jawbone defects and tooth extraction, which underscored the osteogenic differentiation capabilities of postnatal Col2 cells during repair. This finding not only highlights the regenerative potential of Col2 cells but also suggests their versatility in contributing to skeletal healing and regeneration. In conclusion, our findings position Col2 cells as essential in orchestrating osteogenesis throughout the continuum of mandibular development and repair.
颌骨和长骨尽管有着共同的骨骼谱系,但它们的起源和发育途径常常截然不同。确定下颌骨成骨的特定祖细胞亚群仍然具有挑战性。传统上,II型胶原蛋白与软骨结构相关联,但我们的研究发现在颌骨发育和再生过程中存在II型胶原蛋白阳性(Col2)细胞。Col2细胞在颌骨形态发生和修复中的作用一直不明确。在本研究中,我们分析了胚胎第10.5天小鼠颌骨的单细胞RNA测序数据。通过命运图谱实验,我们阐明了Col2细胞及其后代在胎儿期和出生后阶段的下颌骨成骨过程中都发挥着重要作用。此外,利用他莫昔芬诱导的CreER系统进行谱系追踪,确定了以Col2-CreER标记、起源于原始梅克尔软骨的Col2细胞在颌骨形成中的关键作用。而且,我们的研究探索了模拟颌骨缺损和拔牙的模型,这突出了出生后Col2细胞在修复过程中的成骨分化能力。这一发现不仅凸显了Col2细胞的再生潜力,还表明它们在促进骨骼愈合和再生方面具有多功能性。总之,我们的研究结果表明Col2细胞在协调下颌骨发育和修复的整个连续过程中的成骨作用至关重要。