DMP1-targeted Cre expression in odontoblasts and osteocytes

Area of Science:

• Cell Biology
• Biomineralization
• Genetics

Background:

• Odontoblasts in dentin and osteocytes in bone possess dendritic processes.
• Investigating common features of these cellular processes is crucial for understanding mineralized tissue biology.
• Dentin matrix protein 1 (DMP1) is highly expressed in both cell types.

Purpose of the Study:

• To compare the cellular morphology of odontoblasts and osteocytes.
• To develop and validate a transgenic mouse model for targeted gene manipulation in odontoblasts and osteocytes.

Main Methods:

• Scanning electron microscopy was used to visualize cellular morphology.
• A transgenic approach utilizing the Dmp1 promoter and intron was employed.
• Dmp1-Cre mice were crossed with ROSA26 reporter mice to assess Cre activity specificity and efficiency.

Main Results:

• Both odontoblasts and osteocytes exhibit an identical dendritic canalicular system.
• Extensive cellular processes form a complex network within the mineralized matrix of dentin and bone.
• The Dmp1 promoter-intron construct specifically targeted Cre cDNA expression/deletion in odontoblasts and osteocytes.
• Crossing Dmp1-Cre with ROSA26 reporter mice confirmed specific targeting of these cell types.

Conclusions:

• Odontoblasts and osteocytes share a common dendritic canalicular system.
• A novel Dmp1-Cre transgenic mouse model allows for specific gene function studies in both odontoblasts and osteocytes.
• This model provides a valuable tool for investigating the roles of specific genes in dentin and bone biology.