Promotes Odontoblast Differentiation in a Stage-Dependent Manner.

A comprehensive study of odontoblastic differentiation is essential to understand the process of tooth development and to achieve the ability of tooth regeneration in the future. Zinc finger E-box-binding homeobox 1 () is a transcription factor expressed in various neural crest-derived tissues, including the mesenchyme of the tooth germ. However, its role in odontoblastic differentiation remains unknown. In this study, we found the expression of gradually increased during odontoblast differentiation in vivo, as well as during induced differentiation of cultured primary murine dental papilla cells (mDPCs) in vitro. In addition, the differentiation of mDPCs was repressed in silenced cells. We used RNA sequencing (RNAseq) to identify the transcriptome-wide targets of and used assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) to explore the direct targets of in both the early stage (embryonic day 16.5; E16.5) and the late stage (postnatal day 0; PN0) of tooth development. We identified the motifs of transcription factors enriched in -dependent accessible chromatin regions and observed that only in the early stage of mDPCs could significantly change the accessibility of chromatin regions. In vivo and in vitro experiments confirmed that silencing of at E16.5 inhibited dentinogenesis. Analysis of RNA-seq and ATAC-seq resulted in the identification of , a gene directly regulated by during early odontoblast differentiation. enhances the expression of by binding to its -elements, and ZEB1 interacts with RUNX2. In the late stage of tooth development, we found that ZEB1 could directly bind to and increase the enhancer activity of an element upstream of and promote dentinogenesis. In this study, for the first time, we revealed that ZEB1 promoted odontoblast differentiation in the early stage by altering chromatin accessibility of -elements near genes such as , while in the late stage, it directly enhanced transcription, thereby performing a dual role.