Transcriptome Analysis of Dental Cells Using Single-cell RNA-sequence

Abstract

Dental anomalies such as enamel hypoplasia are associated to genetic disorder, however, only little is known about the responsible gene and molecular mechanism of dental anomalies. To date, non-ameloblast dental epithelial cell types; stratum intermedium, stellate reticulum, and outer enamel epithelium were not well characterized. Recently, the single-cell RNA-sequencing (scRNA-seq) technology was established as a novel transcriptome analysis. In this study, we performed scRNA-seq of dental cells from developing mouse incisor to characterize all stages- and all types-of dental cells. We found that secretory-stage of ameloblast were divided into two-subpopulations and showed distinct gene expression, indicating they have independent roles in tooth development. Furthermore, we identified Claudin-10 as a novel stratum intermedium marker gene from the scRNA-seq dataset. Interestingly, mutation of Claudin-10 causes Helix syndrome in human and the patients of Helix syndrome showed severe enamel attrition. By in vitro analyses, we found that Claudin-10 regulates the expression of alkaline phosphatase, which plays essential role in enamel mineralization. These findings contribute to identify marker genes of dental cell types and clarify the pathogenesis of dental anomalies.