Spatiotemporal interplay between epithelial and mesenchymal cells drives human dentinogenesis

Area of Science:

• Developmental Biology
• Regenerative Medicine
• Genomics

Background:

• Tooth dentin is crucial for tooth structure and function, but defects are often irreparable.
• Human dentin development involves complex interactions between dental papilla (DP) cells and dental epithelium (DE).

Purpose of the Study:

• To create a comprehensive human tooth development atlas using single-cell RNA sequencing and spatial transcriptomics.
• To elucidate the epithelial-mesenchymal interactions guiding tooth development.
• To identify key signaling pathways and cell populations involved in dentin formation.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics were employed.
• Analysis focused on epithelial-mesenchymal interactions during tooth development from initiation to eruption.
• Identification and isolation of specific cell populations, including DLX6-AS1+ DP cells.

Main Results:

• A detailed human tooth development atlas was generated, revealing DE's role in orchestrating DP differentiation via WNT-NOTCH signaling.
• Key signaling molecules and pathways governing tooth development were identified.
• DLX6-AS1+ DP cells, isolated from adult dental pulp stem cells (DPSCs), demonstrated the ability to generate tubular dentin in vivo.

Conclusions:

• The study provides novel insights into human tooth development mechanisms.
• DLX6-AS1+ DPSCs represent a promising cell source for regenerative dental therapies.
• This research lays the foundation for developing new treatments for dentin defects.