Abstract：
Multiple genetic and environmental etiologies contribute to the pathogenesis of cleft palate, which is the most common of the inherited disorders of the craniofacial complex. Insights into the molecular mechanisms regulating osteogenic differentiation and patterning in the palate during embryogenesis are limited and needed for the development of innovative diagnostics and cures. This study used the Pax9-/- mouse model with a consistent phenotype of cleft secondary palate to investigate the role of Pax9 in the process of palatal osteogenesis. Although prior research has identified the upregulation of Wnt pathway modulators Dkk1 and Dkk2 in Pax9-/- palate mesenchyme, limitations of spatial resolution and technology restricted a more robust analysis. Here, data from single-nucleus transcriptomics and chromatin accessibility assays validated by in situ highly multiplex targeted single-cell spatial profiling technology suggest a distinct relationship between Pax9+ and osteogenic populations. Loss of Pax9 results in spatially restricted osteogenic domains bounded by Dkk2, which normally interfaces with Pax9 in the mesenchyme. Moreover, the loss of Pax9 leads to a disruption in the normal osteodifferentiaion of palatal osteogenic mesenchymal cells. These results suggest that Pax9-dependent Wnt signaling modulators influence osteogenic programming during palate formation, potentially contributing to the observed cleft palate phenotype.
摘要：
多种遗传和环境病因有助于腭裂的发病机理，这是最常见的颅面复合体遗传性疾病。对在胚胎发生过程中调节上颚成骨分化和模式的分子机制的见解是有限的，并且是开发创新诊断和治疗方法所必需的。本研究使用具有一致表型的次生腭裂的Pax9-/-小鼠模型来研究Pax9在腭成骨过程中的作用。尽管先前的研究已经确定了Pax9-/-腭部间充质中Wnt通路调节剂Dkk1和Dkk2的上调，空间分辨率和技术的限制限制了更稳健的分析。这里,通过原位高度多重靶向单细胞空间谱分析技术验证的单核转录组学和染色质可及性测定的数据表明,Pax9+与成骨群体之间存在明显的关系.Pax9的丢失导致由Dkk2界定的空间受限的成骨结构域，Dkk2通常与间充质中的Pax9接口。此外，Pax9的缺失导致腭成骨间充质细胞正常骨分化的破坏。这些结果表明Pax9依赖性Wnt信号调节剂在腭形成过程中影响成骨编程，可能有助于观察到的腭裂表型。
