Endometriosis is characterized by the formation and development of endometrial tissues outside the uterus, based on an imbalance between proliferation and cell death, leading to the uncontrolled growth of ectopic foci. The potential target for the regulation of these processes is the endocannabinoid system, which was found to be involved in the migration, proliferation, and survival of tumor cells. In this paper, we investigated the effect of endocannabinoid-like compounds from the N-acyl dopamine (NADA) family on the viability of stromal cells from ectopic and eutopic endometrium of patients with ovarian endometriosis. N-arachidonoyldopamine, N-docosahexaenoyldopamine, and N-oleoyldopamine have been shown to have a five-times-more-selective cytotoxic effect on endometrioid stromal cells. To study the mechanisms of the toxic effect, inhibitory analysis, measurements of caspase-3/9 activity, reactive oxygen species, and the mitochondrial membrane potential were performed. It was found that NADA induced apoptosis via an intrinsic pathway through the CB1 receptor and downstream serine palmitoyltransferase, NO synthase activation, increased ROS production, and mitochondrial dysfunction. The higher selectivity of NADA for endometriotic stromal cells and the current lack of effective drug treatment can be considered positive factors for further research of these compounds as possible therapeutic agents against endometriosis.

Cell cultures isolated from endometriosis lesions by enzymatic dissociation consisted of fibroblast-like cells expressing CD90, CD73, and CD105; cell viability in these cultures was >90%, but this parameter decreased by passage 3. Zero passage cultures contained 10-25% epithelial cells expressing cytokeratin-7, but by passage 2, the cultures became more homogeneous and epithelial cells disappeared. The proportion of proliferating cells and population doubling level increased from passage 1 to passage 3. The cultures from the endometrium were induced to adipogenic and osteogenic differentiation in vitro. The cultures derived from ectopic endometrium have properties of multipotent mesenchymal stromal cells that exhibited in vitro similarities and differences from cell cultures from eutopic endometrium, which allows using this cell model for the search and testing of new drugs and technologies aimed at suppression of the growth and spread of endometriosis lesions.

We isolated and characterized cell cultures from eutopic endometrium and endometriotic lesions of women with malformations of the internal reproductive organs. The cells had fibroblast-like shape and intensively expressed CD90, CD73, CD105, CD44, CD146, and CD117 and were capable of induced adipogenic and osteogenic differentiation in vitro. The obtained cultures exhibited properties of multipotent mesenchymal stromal cells; at the same time, they demonstrated in vitro immunophenotypic differences from cell cultures of eutopic and ectopic endometrium of women without developmental abnormalities, which suggests their functional difference. The cells from eutopic endometrium and from ectopic endometriotic lesions can be used as the model for studying of the etiology and pathogenesis of endometriosis and for testing new drugs for this specific group of patients. Markers CD90 and CD117 were identified as promising molecules for the development of minimally invasive diagnostics of endometriosis based on cell cultures from eutopic endometrium.

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Cell cultures isolated from human endometrium by enzyme digestion consisted of highly viable fibroblast-like mesenchymal cells expressing CD90, CD73, and CD105. During passage 1, the cultures contained a small fraction of cytokeratin-7(+) epithelial cells that disappeared by passage 2. The cultures from the endometrium could be induced to adipogenic, osteogenic and chondrogenic differentiation in vitro. These findings suggest that human endometrium is a convenient source of biomaterial for minimally invasive isolation of cultures that exhibit typical morphology and immunophenotypic profile of resident multipotent mesenchymal stromal cells retain high viability in vitro.