MT1-MMP, MMP-2, MMP-9, TIMP-1,-2,-3 e a proliferação celular da região odontogenica de dentes incisivos de ratos adultos

Abstract

Objectives: MT1-MMP and TIMP-2 are well known for their roles in the degradation of matrix components. However, new reports are emerging on the involvement of these molecules in cell kinetics. Doxycycline can inhibit metalloproteinase activity in different systems, but in tooth, under accelerated eruption and cell proliferation conditions, the effects of doxycycline have not been well explored. In this study, doxycycline and hypofunction were used to study the relationships between eruption rate, MT1-MMP and TIMP-2 protein expression as well as cell proliferation in the odontogenic region of the rat incisor tooth.Materials and methods: Male Wistar rats were treated with doxycycline for 14 days.Two days after the beginning the treatment, rats underwent tooth shortening to produce hypo-functional (HP) and doxycycline hypo-functional (DHP) groups. Rats with intact lower teeth maintained normal eruption and were called normofunctional (NF) or doxycycline normofunctional (DNF). In each group, eruption rates were measured, and the levels of MT1-34 MMP, TIMP-2 and Ki-67 were measured in different regions using immunostaining and western blotting. Results and conclusions:The increase of MT1-MMP and TIMP-2 expression allowed us to conclude that there is a relationship between cell proliferation and eruption rate in the HP and DHP groups, suggesting that MT1-MMP and TIMP-2 may have direct roles in increasing cell proliferation in the rat incisor tooth, as observed in other study models.