Endocrine Aspects of Endometrial Stem Cell Function in Reproductive-Age Women

Besides the ovary, the endometrium is one of the most prominent fertility-determining tissues in women. Under the cyclic influence of gonadotropins and steroid hormones, the endometrium is characterized by an enormous regenerative capacity during the female reproductive period. Current evidence suggests that adult stem cells contribute to endometrial regeneration. These cells are characterized by defined stemness-associated marker gene expression patterns, high proliferative potential, long-term culturing properties, and multilineage differentiation potential. Whereas a dysregulated endometrial stem cell function has been linked to the pathogenesis of endometriosis, the therapeutic application of stem cells derived from menstrual blood or transcervical biopsies holds some promise for the therapy of fertility-associated conditions such as Asherman s syndrome. While the release of endothelial progenitor cells into the circulation is influenced by menstrual-cycle-dependent changes in steroid hormone levels, steroid-receptor negative tissue-resident endometrial stem cells appear to be indirectly stimulated by hormone-receptor positive cells within the endometrial stem cell niche.