Immunohistochemistry and in situ hybridization investigation of transforming growth factor-beta: during odontoblast and ameloblast differentiation.

OBJECTIVE: The purpose of this study was to investigate the expression of transforming growth factor-beta, TGF-beta 1 during odontoblast and ameloblast differentiation. METHODS: The analysis was made on 5-micron serial sections of the glutaraldehyde-fixed and paraffin-embedded mandibular first and second molars of a neonatal mouse. A specific and affinity-purified antibody to TGF-beta 1 and a digoxigenin-labeled cRNA probe were used. RESULTS: The results showed that the TGF-beta 1 was expressed in a spatial and temporal pattern in dental tissues. The immunoreactivity of dental tissues for TGF-beta 1 was consistent with the expression of TGF-beta 1 mRNA revealed by in situ hybridization before dentin matrix formation. The TGF-beta 1 was evenly expressed in dental papilla and inner enamel epithelium. The expression of TGF-beta 1 was increased in the layer of odontoblasts and ameloblasts and in the stratum intermedium with the formation of dentin matrix, where the staining was also observed. CONCLUSIONS: These findings suggest that TGF-beta 1 may have an important role in extracellular matrix formation and cytodifferentation.