Apoptosis status and proliferative activity in mucopolysaccharidosis type I mice tongue mucosa cells

Abstract

Background: Mucopolysaccharidosis type I (MPS I) is caused by a deficiency of alfa‑iduronidase (IDUA), which leads to intralysosomal accumulation of glysosaminoglycans. Evidences point secondary events like oxidative stress on lysosomal storage diseases including MPS I. Patients with MPS I present a wide range of oral clinical manifestations, including tongue hypertrophy, hypertrophyc alveolar process, and carious teeth. However, the mechanisms by which these alterations occur are still not fully understood. The aim of this study was to analyze the proliferative activity as well as apoptosis in tongue mucosa cells from murine model of MPS I.

Materials and Methods: Protein expression of apoptotic markers such as p53, bcl‑2 and bax were evaluated in this setting. Ki‑67 was used as a proliferative marker. All analyses were made by immunohistochemistry in tongue cells. Statistical analysis was perfomed by Kruskal-Wallis nonparametric test followed by the Dunn’s test. P < 0.05 was considered for statistic significance.

Results: Histopathological analysis revealed no remarkable differences in tongue mucosa on MPS I mice when compared to control. By contrast, our results demonstrated that bcl‑2 immunoexpression was decreased in mice tongue mucosa cells of MPS I mice. p53, bax and ki‑67 immunoexpresssion did not show significant differences among controls and MPS I mice.

Conclusion: Taken together, our results suggest that IDUA deficiency, which characterizes MPS I, may induce apoptosis in mice tongue cells as a result of bcl‑2 down regulation.

Key Words: Apoptosis, bax, bcl‑2, ki‑67 mucopolysaccharidosis, p53, tongue mucosa cells