Expression of Matrix Metalloproteinase-11 Genes in Placentae and Uteri of Shiba Goats (Capra hircus)

Abstract

The matrix metalloproteinase-11 (MMP-11) is a member of the family of matrix metalloproteinases, and recently discovered by Bassett et al. (1990) in placentae and invasive mammary tumors of humans. Although propositions have been made suggesting that MMP-11 might play a crucial role in the metastatic invasion of cancer cells into the surrounding tissue, neither the enzymatic characteristics nor precise biological functions of MMP-11 have been clearly elucidated. Since trophoblast cells of mammalian embryos exhibit different degree of invasiveness during placentation in different groups of animals, it will be of interest to examine whether MMP-11 is present in animals which develop placentae of non-invasive type. We demonstrated that MMP-11 genes are present in the genome of the Shiba goat which develops placentae of non-invasive type (epitheliochorial or syndesmochorial), and determined a partial sequence of MMP-11 cDNA of the Shiba goat. MMP-11 genes are strongly expressed in the uterus of immature Shiba goats under the influence of ovarian estrogens (following PMSG and hCG treatments). In contrast to the human placenta where MMP-11 genes are abundantly expressed, the caprine placenta (Day 72 and Day 112 of gestation) contains MMP-11 mRNA, if at all, only at extremely low levels. The reason underlying the difference in the patterns of expression of MMP-11 genes in human and caprine placentae remains yet to be clarified. The zoo blot analysis of genomic DNA of different species of animals demonstrated that MMP-11 is distributed probably ubiquitously in mammals, although no solid biological functions have so far been assigned to the enzyme.