β‐catenin, a key mediator of Wnt signaling, plays multiple roles in tooth development. However, the role of β‐catenin in Hertwig's epithelial root sheath (HERS) during root formation remains unclear. In this study, we generated inducible tissue‐specific β‐catenin conditional knockout mice (Ctnnb1^i∆shh) to investigate how β‐catenin in HERS affects tooth root development. The inactivation of β‐catenin in HERS led to interrupted root elongation due to premature disruption of HERS. This phenotype was accompanied by reduced cell‐cell adhesion and decreased expression of junctional proteins, as well as increased epithelial‐to‐mesenchymal transition of HERS cells upon β‐catenin depletion. Accordingly, stabilization of β‐catenin in HERS (Catnb^i∆shh) led to the formation of unfragmented HERS and resulted in the failure of HERS dissociation, with increased expression of junctional proteins. Our results suggest that fine control of β‐catenin is important for HERS to guide root formation through regulating its structural integrity.

中文翻译：

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Hertwig 上皮根鞘中的细胞动力学受牙根发育过程中 β-catenin 活性的调节

β-catenin 是 Wnt 信号传导的关键介质，在牙齿发育中发挥多种作用。然而，β-连环蛋白在根形成过程中在赫特维希上皮根鞘（HERS）中的作用仍不清楚。在这项研究中，我们生成了诱导型组织特异性β-catenin条件敲除小鼠 ( Ctnnb1 ^i∆shh )，以研究 HERS 中的 β-catenin 如何影响牙根发育。由于HERS的过早破坏，HERS中β-连环蛋白的失活导致根伸长中断。这种表型伴随着细胞间粘附减少和连接蛋白表达减少，以及在 β-连环蛋白耗竭时 HERS 细胞上皮间质转化增加。因此，β-连环蛋白的稳定在 HERS ( Catnb ^iΔshh ) 导致未片段化 HERS 的形成并导致 HERS 解离失败，连接蛋白的表达增加。我们的研究结果表明，β-catenin 的精细控制对于 HERS 通过调节其结构完整性来指导根形成很重要。