Immunolocalization and activity of the MMP-9 and MMP-2 in odontogenic region of the rat incisor tooth after post shortening procedure

Abstract

MMP-9 and MMP-2 are metalloproteinases which degrade the denatured collagen fibers. However, there is no report about roles of these MMPs in the odontogenic region of the adult rat incisor tooth under different eruption conditions. Male Wistar rats were divided in a normofunctional group (NF) in which their lower teeth remained in a normal eruption. In a hypofunctional group (HP) rats underwent shortening of their lower left incisor tooth every 2 days during 12 days. The eruption rate as well as the expression and activities of MMP-9 and MMP-2 were evaluated using imunohistochemistry and zymography. Although the shortening increased the eruption rate, no changes in the MMP-9 and MMP-2 were observed. We conclude that in adult rats, in opposite to development of tooth, the MMP-9 and MMP-2 present in the odontogenic region does not seem to play a direct role in the remodeling matrix, even after post-shortening procedures which to lead an acceleration of the eruption process in the incisor.

Relationship Between Cell Proliferation and Eruption Rate in the Rat Incisor

“…The effects of the shortening treatment in rat incisors are already well known (Ohshima and Chiba, ; Burn‐Murdoch, ; Ohshima et al, ; Novaes et al, ). In our recent studies, this procedure doubled the eruption rate and cell proliferation of the odontogenic region (Gomes et al, ). These results were also confirmed in the present investigation.…”

Doxycycline reduces the expression and activity of matrix metalloproteinase‐2 in the periodontal ligament of the rat incisor without altering the eruption process

“…Our previous hypothesis was that MMP‐2 and MMP‐9 were expressed in the odontogenic region after treatment of incisors with a shortening procedure. However, we demonstrated that only MMP‐2 was expressed , indicating that the expression of MMP‐2 in the odontogenic region may be important for the eruption process.…”

“…Thus, as our previous study demonstrated that only MMP‐2 is expressed in the dental follicles of incisors undergoing shortening treatment, this study aimed to investigate the effect of doxycycline on the expression and activity of MMP‐2 in the odontogenic region and in the periodontal ligament of the adult rat incisor during the processes of acceleration and continuous eruption (produced by a shortening treatment), in order to increase our knowledge of the role of MMP‐2 in the eruption process.…”

Immunohistochemical expression of matrix metalloproteinases in ameloblastomas and pericoronal follicles

“…MMP-1, MMP-2 and MMP-9 have also been found to regulate the developmental processes of tooth germs (10)(11)(12)(13)(14)(15)(16). However, the role of these proteins in pericoronal follicles (PF) has not been thoroughly evaluated, and few studies in the literature have compared the expression of metalloproteinases in follicles and AMs (4,8).…”