Enhancement of matrix metalloproteinase (MMP)-2 activity in gingival tissue and cultured fibroblasts from Down's syndrome patients

OBJECTIVES: To identify one of the possible factors responsible for periodo ntal disease in Down's syndrome (trisomy 21) patients, we studied the enzym e activity and the mRNA expression pattern of matrix metalloproteinases (MM Ps) of cultured gingival fibroblasts (GF) and fresh gingival tissues. MATERIALS AND METHODS: Gingival tissue was used as the cell source and was biopsied at the time of dental treatment from nine patients with Down's syn drome and nine non-Down's controls. GF were cultivated in serum-free media for analyses of their MMP activities at the transcription or the protein le vel. The MMP activities in the supernates were measured by gelatin impregna ted zymography. Relative levels of MMP mRNA from the cultured GF or freshly isolated gingival tissues were determined using the reverse transcription polymerase chain reaction (RT-PCR). RESULT AND CONCLUSIONS: The production of the active type of MMP-2 in GF fr om Down's syndrome patients (D-GF) was found to be significantly higher (P < 0.05) than that of the control GF (C-GF) at the protein level. The mRNA e xpressions of membrane-typeI MMP (MTI-MMP) and MMP-2 in D-GF were constitut ively augmented when compared with those of C-GF. These findings suggest th at specific increase of the active form of MMP-2 in D-GF may possibly be du e to the concomitant expression of MTI-MMP in the cultured cells, and this could be related to the pathogenesis of gingivitis/periodontitis associated with Down's syndrome patients.