Recently discovered interstitial cells "telocytes" as players in the pathogenesis of uterine leiomyomas.

Uterine telocytes are interstitial cells characterized by a very long cytoplasmic prolongations, which form a 3D network, functionally integrating a wide variety of different cells. Leiomyomas (uterine fibroids) are benign tumors, which pose a huge threat concerning various health problems in women affected by this condition. The exact cause of leiomyomas development is, however, still largely unknown. Therefore, in an attempt to clarify their etiology, we performed an immunohistochemical characterization of telocytes in leiomyomas as well as in normal myometrium. Tissue samples of intramural leiomyomas from 26 women (age 46.26 ±â€¯11.07) were immunohistochemically stained for the expression of c-kit (CD117) antigen, one of the markers of telocytes. C-kit (CD117) antigen is useful for a routine immunohistochemical identification of uterine telocytes in histological sections of myometrium. In normal, healthy myometrium the c-kit positive telocytes occupy approximately 2.2% of the area of a tissue slide, contrasting with no detectable c-kit positive cells within leiomyomas. As telocytes are thought to be key players in the regulation of tissue homoeostasis, our data suggest that uterine telocyte loss may have important implications in the pathogenesis of leiomyomas. In addition, we supposed to summarize three hypotheses on the association of the cells telocytes loss within the myometrium and formation of leiomyomas. These hypotheses include the loss of telocytes' functions as "sex hormone sensors" and regulators of smooth muscle cells cycle; the role of telocytes as progenitor cells for the development of leiomyomas; and the hypothesis of decreased angiogenesis after telocytes' loss with subsequent hypoxia (as a key factor for leiomyomas development).

Functional histology and possible clinical significance of recently discovered telocytes inside the female reproductive system.

PURPOSE: Key discoveries of recent years comprise detection of telocytes. These cells of connective tissue have extremely long cytoplasmic processes through which they form functionally connected spatial networks. Through their processes they mutually contact and functionally connect also cells of the immune system, nerve fibres and smooth muscle cells. They are located in various parts of the female reproductive system where they can perform specifically significant functions, which are summarized in our literature review. METHODS: Literature regarding "telocytes" and "interstitial Cajal-like cells" was reviewed using scientific databases PubMed/Medline, SCOPUS, and Web of Knowledge. RESULTS: Among other things telocytes regulate peristaltic muscle movements in the uterine tubes. Their decreased activity, e.g., in inflammatory diseases or endometriosis, causes disorders of a transport function through the uterine tubes resulting in infertility or tubal pregnancy. In the uterine myometrium they are, first, responsible for regulation of muscle contraction (in expelling menstrual blood or in childbirth) and, second, they participate also in immune surveillance during embryo implantation. They likely control also uterine involution post partum. Their function in the vagina has not been elucidated yet, but probably they participate in production of slow contraction waves during sexual intercourse. In the mammary gland their function may be to regulate cellular proliferation and apoptosis, thus they may play a role also in the development and growth of tumours. In the placenta, they may monitor and regulate blood flow through chorionic villi and they participate in aetiopathogenesis of preeclampsia. CONCLUSION: However, all above-mentioned functions of telocytes are purely hypothetic and have been published only recently. Therefore, only further research will demonstrate whether this recently discovered cell population will really play a key role in all processes mentioned, or whether it is just an effort of scientists to clarify unknown cause of some diseases in gynaecology and obstetrics. Our literature review is completed by our own original photomicrographs documenting telocytes in various organs of the female reproductive system.