Chemically modified tetracyclines stimulate matrix metalloproteinase-s production by periodontal ligament cells

Background and Objective: The purpose of this study was to investigate the effects of chemically modified tetracyclines (CMTs) on the production of gelatinases [matrix metalloproteinase (MMP)-2 and -9] by human periodontal ligament (PDL) cells, and on the activity of recombinant gelatinases. Material and Methods: Human PDL cells were cultured with CMT-1, -3, -5, -7 or -8 in concentrations of 0, 1, 5, 10, 20, 50, 100, 200 and 500 μm. Gelatin zymography was used to determine MMP-2 and -9 production of the cells. The amount of DNA present in the cultures was analyzed using a fluorescent assay. The cytotoxicity of the CMTs was also determined. Recombinant human MMP-2 and -9 were incubated with the CMTs (0-500 μm) and their activity was analyzed using an internally quenched fluorogenic substrate. Results: MMP-2 production was stimulated up to sevenfold by CMT-1, -3, -7 and -8 at low concentrations (10-200 μm). No significant amounts of MMP-9 were produced. In contrast, MMP-2 and -9 activity was reduced by ≈ 10-40-fold at higher concentrations (200-500 μm). CMT-5 had no effect on the production or on the activity of MMP-2 and -9. Only CMT-3 and -8 had cytotoxic effects on the PDL cells at the highest concentrations. Conclusion: Surprisingly, CMTs are able to stimulate MMP-2 production at relatively low concentrations. However, at higher concentrations they exert a much stronger inhibitory effect on gelatinase activity. A possible stimulatory effect of CMTs on MMP production should be considered in their clinical use. © 2006 The Authors. Chemicals / CAS: DNA, 9007-49-2; gelatin, 9000-70-8; gelatinase A, 146480-35-5; gelatinase B, 146480-36-6; DNA, 9007-49-2; Enzyme Inhibitors; Gelatin, 9000-70-8; Matrix Metalloproteinase 2, EC 3.4.24.24; Matrix Metalloproteinase 9, EC 3.4.24.35; Recombinant Proteins; Tetracycline