Discoordinate Regulation of Expression of Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases-3 in Bovine Endometrial Stromal Cells on Type-I Collagen Gel

To clarify the mechanism of extracellular matrix (ECM) remodeling in bovine endometrium, we investigated the regulation of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-3 (TIMP-3) in bovine endometrial stromal cells (BESCs) on type-I collagen gel. When BESCs were seeded onto the center of collagen gel placed in culture dishes, the cells proliferated and formed multiple cell layers after 2 weeks. Under this culture condition, the production of progelatinase B/promatrix metalloproteinase (proMMP)-9 was augmented, which was not occurred with monolayered BESCs on plastic dishes. The mRNA expression of progelatinase A/proMMP-2 was not changed, but proMMP-2 activation was augmented. Furthermore, the level of prostromelysin-1/proMMP-3 mRNA was decreased, whereas the gene expression of TIMP-3 tended to increase in BESCs cultured on collagen gel. When BESCs cultured on collagen gel were treated with transforming growth factor-beta1 (TGF-beta1), the levels of proMMP-9 in the medium and TIMP-3 mRNA were augmented, but the mRNA expression of proMMP-3 was further suppressed. However, the expression and activation of proMMP-2 were not changed by TGF-beta1 in BESCs cultured on either plastic or collagen-gel dishes. These results suggest that the expression of MMPs-2, 3 and 9 and TIMP-3 is likely to be discoordinately regulated due to interaction with collagen and/or TGF-beta1 in bovine endometrium, and thereby different sets of MMPs may be associated with ECM remodeling during implantation and placentation in vivo.