Activation of matrix metalloproteinase-2 at the interface between epithelial cells and fibroblasts from human periodontal ligament

Abstract

Matrix metalloproteinase (MMP)-2 can degrade type IV collagen, and MMP-14 can activate pro-MMP-2. Bone sialoprotein (BSP) specifically binds pro-MMP-2 and active MMP-2. The expression of MMP-2, MMP-14, and BSP were analyzed by immunohistochemistry, in situ hybridization, and RT-PCR at the interface between cells of the epithelial rests of Malassez (ERM) and fibroblasts from human periodontal ligament (HPDL). ERM cells at the interface strongly expressed MMP-2 and MMP-14 proteins. In situ hybridization analysis showed that HPDL fibroblasts expressed MMP-2 mRNA, and ERM cells expressed MMP-14 mRNA at the interface strongly. BSP and its mRNA were expressed strongly in HPDL fibroblasts at the interface. RT-PCR analysis demonstrated that the expressions of MMP-2 mRNA and BSP mRNA were significantly high. These findings indicate that upregulated MMP-2 activated by MMP-14 in ERM cells and BSP in HPDL fibroblasts could degrade matrix molecules.