The pro-alpha2(XI) collagen gene is expressed in odontoblasts

Area of Science:

• Biochemistry
• Developmental Biology
• Oral Biology

Background:

• Dentine extracellular matrix shares similarities with bone, primarily composed of type I collagen.
• Minor fibrillar collagens, like types V and XI, are co-expressed but their roles in dentine are less understood.

Purpose of the Study:

• To investigate the gene and protein expression of type V and XI collagens in mouse incisor teeth.
• To determine the specific collagen chains involved in dentine formation and their localization.

Main Methods:

• Reverse transcription-polymerase chain reaction (RT-PCR) for gene expression analysis.
• In situ hybridization and immunohistochemistry for spatial localization of transcripts and proteins.
• Western blot analysis using specific antibodies.

Main Results:

• Transcripts for pro-alpha1(XI), pro-alpha2(XI), pro-alpha1(V), and pro-alpha2(V) chains were detected in mouse incisors.
• Pro-alpha2(XI) protein, typically found in cartilage, was identified in odontoblasts.
• Real-time RT-PCR indicated predominant expression of pro-alpha2(XI), pro-alpha1(V), and pro-alpha2(V) in the crown and pro-alpha1(XI) in the root.
• Expression of pro-alpha2(XI) was confirmed in an odontoblastic cell line (hTERT-immortalized).

Conclusions:

• The findings suggest a novel subtype of type V/XI collagen molecule containing the alpha2(XI) chain in dentine.
• This subtype may play a role in collagen fibril formation and skeletal morphogenesis within the tooth structure.