Expression of matrix metalloproteinase-2, tissue inhibitors of metalloproteinase-1,-3 at the implantation site of rhesus monkey during the early stage of pregnancy

We have examined the expression of MMP-2, TIMP-1, and TIMP-3 mRNA at the implantation site of rhesus monkeys during early stage of pregnancy using in situ hybridization and Northern blot analysis. The results indicate that MMP-2 mRNA was mainly localized in the chorinoic villi and epithelial plaque, suggesting that MMP-2 may be involved in the process of epithelial plaque and trophoblast invasion. TIMP-3 was specifically expressed in the cells around the spiral arteries and maternal-fetal interface. Therefore, TIMP-3 may be the main inhibitor that restricts the trophoblast invasion. The TIMP-1 mRNA was detected in trophoblast villi and maternal decidua; however, its distribution was not cell-specific, suggesting a general role in the protection of trophoblast villi and maternal decidua from proteolysis by the MMPs secreted by themselves.