Increase of MT1-MMP, TIMP-2 and Ki-67 proteins in the odontogenic region of the rat incisor post-shortening procedure

Abstract

MT1-MMP and TIMP-2 are well known for their roles in remodelling of extracellular matrix components. However, reports are emerging on the involvement of these molecules in cell kinetics. In the rat incisor tooth, a shortening treatment increases the eruption and cell proliferation rates. However, the role of MT1-MMP and TIMP-2 proteins in these processes is still to be evaluated. Male Wistar rats were divided in two groups. In the normofunctional group (NF) the lower teeth of the rats remained in a normal eruption process. In the hypofunctional group (HP) rats their lower left incisor tooth was shortened every 2days during 12days. The eruption rate was estimated during the shortening period and MT1-MMP, TIMP-2 and Ki-67 protein expression from the odontogenic region was measured after the treatment. In HP groups an increase in eruption rate, and in MT1-MMP/TIMP-2 and Ki-67 expression were observed. We conclude that there is a relationship between the increase in eruption rate, and in levels of MT1-MMP, TIMP-2 and Ki-67 in the HP group. This suggests that MT1-MMP and TIMP-2 may have some role in cell proliferation during the eruption of the rat incisor tooth.