Differential Gene Expression of Matrix Metalloproteinase-3 and -13 during Mineralization of MC3T3-E1 Cells Cultured on Titanium Implant Material

Abstract

Successful dental implant requires optimal tissue repair after implant insertion, which involves formation of new bone directly bonded to the device. The objective of this study was to use real-time PCR to investigate the temporal mRNA expression patterns of matrix metalloproteinases (MMP-2, -3, -9, -13, and -14) and tissue inhibitors of metalloproteinases (TIMP-1, -2, and -3) that contribute to tissue repair, during mineralization of MC3T3-E1 cells cultured on titanium (Ti). Lysates of the cells cultured on Ti and plastic wells (Pl) for 10 to 50 days were used for calcium and mRNA quantification. Although the onset of calcium accumulation in the cultures on Ti (30-40 days) was slower than cultures on Pl (20-30 days), the gene expression patterns during mineralization were similar in both cultures. The mRNA expression patterns of MMP-3 and -13 were distinctly different during the period from just before mineralization onset to mineralization development. The level of MMP-13 was substantial until just before the onset of mineralization but declined as mineralization developed, while MMP-3 level increased once mineralization proceeded. MMP-2, -9, and -14 and TIMP-1, -2, and -3 showed constant levels throughout. This report presents the gene expression of MMP-2, -3, -9, -13, and -14 and TIMP-1, -2, and -3 during mineralization by MC3T3-E1 cells cultured on titanium implant material, and suggest temporally distinct roles of MMP-3 and -13 in new bone formation around the implant.