Abstract:
Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases
capable of degrading the different components of the extracellular matrix, and are
involved in different physiological processes such as cell proliferation, differentiation,
angiogenesis, apoptosis and cell migration. Dysregulation of MMPs has been reported
in a number of cancers. Consequently, we postulate that this might be replicated in the
pathogenesis of endometriosis, since the two conditions share similar developmental
stages. We invested in the expression pattern of MT2-MMP and MT3-MMP in ectopic
endometrium of persons with and without endometriosis as well as their possible role
in the pathogenesis of endometriosis. Tissue samples were obtained after surgery from
healthy endometrium, endometrium with endometriosis and adenomyosis, deep
infiltrating endometriosis (DIE), peritoneal endometriosis (PE) and ovarian
endometriosis (Ov). Expression of the MT-MMPs was determined using
immunohistochemistry. Both proteins were expressed in the glandular and luminal
epithelial cells of endometrium of persons with and without endometriosis. There was
no cycle-dependent differences in the endometrium of persons with and without
endometriosis. Interestingly, there was enhanced expression of both MT2-MMP and
MT3-MMP in adenomyosis. In contrast, MT2-MMP there was decreased in ovarian,
peritoneal and DIE, decreased MT3-MMP in peritoneal and DIE compared to eutopic
endometrium and adenomyosis. The equal expression of MT-MMPs in endometrium of
persons with and those without endometriosis in contrast to the impaired expression in
adenomyosis and ectopic lesions suggest that the changes occurred after and not before
implantation. The altered expression of MT2-MMP and MT3-MMP in adenomyosis and
ectopic endometrium suggest distinct interactions in the different environments.
