The effects of progesterone on matrix mettalloproteinases in cultured human gingival fibroblasts

Abstract

During pregnancy many wo~en suffer from severe gingivitis, which almost never progresses to periodontitis, and resolves post-partum. Since progesterone is elevated during pregnancy and is known to influence MMPs in some reproductive tissues, we theorized that similar effects might be seen in oral tissue. The purpose of this research was to study gestational gingival changes in vitro, some of which may be due to progesterone modulation of certain MMPs. Primary cultures of non-pregnant female and male human gingival fibroblasts (HGF) cells were grown to confluence in 4% FBS in phenol red-free DMEM. The cells were then pre-treated for 72 hours in serum-free DMEM, without or with 10-6 M medroxyprogesterone acetate (MPA). IL-1 ~ (1 ng/ml) was added to initiate MMP production. After 24 hours, medium was removed and cells harvested for reverse·transcriptase - polymerase chain reaction (RT-PCR). Media samples were tested for collagenase production, utilizing zymograms (agarose gels containing gelatin). Cqmmercial ELISAs quantified production of total MMP-3 and pro-MMP-13. The mRNAs for MMPs-1, -2, -3, - 7, -9, -10, -13 and GAPDH (control) were amplified by RT-PCR in order to determine which were modulated by IL-1 ~ +/- MPA. MPA-treated and untreated cells were compared; cells from male and female sources behaved similarly. High levels_ of MMP activity were detected in untreated cells and control stimulated cells with zymogram gels, and levels decreased with MPA treatment. The RT-PCR showed that with the addition of MPA to HGF cultures, there was almost total cessation of specific MMP gene transcription for MMPs-1, -2, -3, -7, -10 and _-13 in response to IL-1 ~- The EL.ISAs confirmed significantly decreased MMP-3 and -13 protein levels (p<0.05). We conclude that MPA has the ability to significantly decrease production and activity of MMPs in response to IL-1 B, which could help to explain why pregnancy gingivitis usually doesn't lead to periodontitis.'