[Expression of ß-catenin in the apical papilla and dental pulp tissues of human permanent teeth].

PURPOSE: The expression of ß-catenin at the level of mRNA and protein in the apical papilla and dental pulp tissues of human permanent teeth were compared to explore the possible relationship between ß-catenin and the development of pulp-dentin complex. METHODS: Forty-eight healthy permanent teeth in need of extraction for orthodontic treatment were obtained. The apical papilla and dental pulp tissues were isolated immediately when the teeth were extracted. All the samples were divided into 3 groups: group1, apical papilla of immature permanent teeth; group 2, dental pulp tissues of immature permanent teeth; group 3, dental pulp tissues of mature permanent teeth. RT-PCR and Western blot techniques were used to examine the expression of ß-catenin at the level of mRNA and protein respectively. Meta Morph software was used to measure the gray value of the positively expressed bands. Two-sample t test was performed to analyze the expression intensity (gray value) of ß-catenin by use of SPSS 11.0 software package. RESULTS: ß-catenin was positively expressed at both mRNA level and protein level in all the samples investigated. The expression intensity of ß-catenin in the dental pulp tissues of human immature permanent teeth was higher than that in the apical papillary tissues and that in the dental pulp tissues of human mature permanent teeth as well. The differences were statistically significant (P<0.05). CONCLUSIONS: ß-catenin was expressed in both the apical papilla and dental pulp tissues of immature and mature permanent teeth, but the expression intensity was different. It indicated that ß-catenin may play an important role in the development of pulp-dentin complex and in the reparative process after the dental pulp injury.