Vdr mediates Wnt signaling pathway to regulate odontoblasts differentiation during dentin apposition

Area of Science:

• Biomineralization
• Molecular Biology
• Dental Research

Background:

• Dentin is a mineralized tissue produced by odontoblasts, essential for tooth health.
• The role of the vitamin D receptor (Vdr) in odontoblast function and dentin formation is not fully understood.
• Vdr's interaction with the Wnt signaling pathway during dentin apposition requires further investigation.

Purpose of the Study:

• To investigate the function of the vitamin D receptor (Vdr) in odontoblast mineralization and dentin homeostasis.
• To elucidate the role of Vdr in regulating the Wnt signaling pathway during dentin apposition.
• To explore potential therapeutic strategies for dental health based on Vdr function.

Main Methods:

• Utilized Vdr transgenic knockout mice (Vdr-/-) to assess dental phenotypes.
• Reduced Vdr expression in odontoblasts (Vdr-knockdown) to analyze mineralization and Wnt pathway changes.
• Treated Vdr-knockdown cells with lithium chloride (LiCl) to evaluate Wnt pathway activation and mineralization rescue.

Main Results:

• Vdr-/- mice exhibited enlarged pulp cavities, reduced dentin, and increased predentin.
• Vdr-knockdown odontoblasts showed decreased mineralization and reduced expression of key markers (Dspp, Alpl, Opn, Col-1, Bsp).
• Wnt signaling was downregulated in Vdr-knockdown cells, evidenced by altered levels of β-catenin, Lef1, Axin2, and Dkk1. LiCl treatment partially restored mineralization.

Conclusions:

• Vdr plays a critical role in regulating odontoblast differentiation and dentin mineralization.
• Vdr mediates the Wnt signaling pathway to control odontoblast function during dentin apposition.
• Targeting Vdr and Wnt signaling pathways may offer novel approaches for enhancing dental health and treating dentin defects.