Coelomic Metaplasia Theory of Endometriosis: Evidence from in vivo Studies and an in vitro Experimental Model

Abstract

Ultrastructure studies of pelvic peritoneal tissue from women undergoing laparotomy suggest that before endometriosis has become established in the peritoneum, there might be a metaplastic change by peritoneal mesothelial cells into endometrial glandular cells. A new in vitro experimental model of endometriosis using human ovarian surface epithelium cells has shown evidence that endometriotic lesions can arise by a process of metaplasia from the ovarian surface epithelium. In this model, when both ovarian surface epithelium and ovarian stromal cells were cocultured with 17β estradiol in a three-dimensional collagen gel lattice, the ovarian surface epithelium cells formed a lumen structure, surrounded by endometrial stromal cells with an epithelial mesenchymal structure. Immunoreactivity for epithelial membrane antigen and cytokeratin was shown in the glandular cells and cilia, as well as in the microvilli. Electron microscopy showed evidence of tight junctions on cell surfaces. These findings suggest that endometriosis may manifest as a serial change from the adjacent mesothelial cells.

MiR-199a attenuates endometrial stromal cell invasiveness through suppression of the IKK /NF- B pathway and reduced interleukin-8 expression

“…One of the currently accepted models of peritoneal endometriotic lesion development is that displaced endometrial tissue in retrograde menstrual fluid progresses through a process of adhesion, invasion, proliferation and neovascularization in order to become established at an ectopic site (Giudice and Kao, 2004;Hull et al, 2008). Also, altered immune surveillance, stem cells, genetic predisposition, environmental and hormonal factors could be involved in the pathogenesis (Koninckx et al, 1994;Matsuura et al, 1999;Gargett and Masuda, 2010;Giudice, 2010). A considerable body of evidence indicates that miR-199a may play a critical role in regulating cell adhesion, migration and invasion (Shen et al, 2010;Song et al, 2010;Cheung et al, 2011).…”

Immunohistochemical study of osteopontin and l-selectin in a rat endometriosis model and in human endometriosis

“…The pathogenesis of endometriosis is still poorly defined, although many hypotheses have been proposed (1,2). In our study published elsewhere, we induced a rat endometriosis model and subjected it to transcriptomics to examine the molecules that are related to endometriosis (unpublished data).…”

Identification of an Invasive, N-Cadherin-Expressing Epithelial Cell Type in Endometriosis Using a New Cell Culture Model

“…Furthermore, endometriosis may also arise via metaplasia in some cases. 2,3 Although it is well accepted that endometriotic lesions are composed of stroma and epithelial glandular cells, little is known about the development and characteristics of the cell types contributing to the pathogenesis of endometriosis.…”