Stem Cells in the Uterus Future Perspective of Treating Uterine Abnormalities

Stem cells are unique cells, which can replicate rapidly, and have the potential to become a wide variety of different cell types. In the early stage of embryonic development, our body contains a huge amount of stem cells which will later decide what exact cell types they want to form. Although their number is much less, but stem cells can be found in many adult tissues as well. The role of these adult stem cells is mainly hypothetical, but they seem to be important in maintaining tissue homeostasis through driving the regeneration or recovery of some organs – such as the skin, intestine or the bone marrow. The potential therapeutic roles of these cells have been implicated long ago, as they are supposed to take part in repairing injured tissues as well. The possible presence of stem cells in the uterus was raised more than a decade ago. The high regenerative capacity of the uterus after each menstrual cycle lead the scientist to examine whether adult stem cells are present in different layers of the uterus – especially in those which undergo cyclical regeneration. Indeed, it was shown that a small number of adult stem cells are present in the endometrium, and in the muscle layer (myometrium) of the uterus too. These cells undergo asymmetric cell divisions, to preserve their own population of non-differentiated cells, while also producing more differentiated cells that are capable of rapid proliferation and regenerate the damaged tissue. The physiological role of the endometrial stem cells is presumably their contribution to the cyclic endometrial regeneration during the reproductive years. However, they might also have some pathophysiological relevance in certain gynecological conditions as well; endometrial stem cells have been shown to take part in the development of endometriosis, while uterine fibroids are partly attributed to the malfunction of myometrial stem cells. The presence of these cells in the uterus opens up several future perspectives – first of all, because endometrial stem cells are very easily accessible, and second of all, because they were successfully differentiated into various cell types in vitro. Restoration of normal endometrium in Asherman-syndrome or even myocardium after ischemic injury were effectively achieved in animal models. These facts raised the possibility that endometrial stem cells may potentially be used in regenerative medicine in the near future. The most obvious option would be to treat uterine abnormalities with the aid of adult uterine stem cells. The transplantation of the uterus became possible after reporting the first successful live birth followed by the process recently. Even though this technique has several strains, the presence of stem cells in the uterus gives the basis of bioengineering artificial uterus, thus to overcome the most severe condition of uterine-related disorders, as the absolute lack of the organ.