The investigation of the presence of telocyte cells in the human ovarian stroma

Telocytes have been identified as a relatively new and fascinating type of interstitial cells. These cells, previously known as interstitial Cajal-like cells (ICLCs), can now be distinguished in the literature by their extremely long and thin telopods. Telocytes are present in various organs, including the female reproductive system in human and other living species but no literature exists yet explaining their presence, localization, roles, or morphological characterization in human ovaries. Telocytes have been shown to play important roles in cell-to-cell signaling, immune surveillance, regulation of tissue morphogenesis and homeostasis, as well as in various pathologies and even tumorigenesis. Telocytes can express or co-express different markers, but in general, CD34, vimentin and PDGRF-β, c-kit and α-SMA have been considered reliable telocyte markers. Studies have confirmed the existence of multiple stromal cell clusters in the human ovary, but comprehensive demonstrations of cell types and characters remain insufficient. Therefore, assessing whether telocytes are present in the human ovarian stroma is critical for understanding the as-yet-undefined stromal cells in the ovaries. This study investigates tissues from women who underwent Total Hysterectomy and Bilateral Salpingo-Oophorectomy (THBSO) surgery, aged 18-65, who were admitted to the hospital due to various uterine diseases and had not received chemotherapy. Ovarian tissues were marked with CD34/c-kit, CD34/vimentin, CD34/PDGFR-β and CD34/α-SMA by immunohistochemical and immunofluorescence analyses, and telocytes were distinguished from fibroblasts and pericytes and identified as completely different cells. In addition, the ultrastructure of these cells labelled with CD34 was examined by transmission electron microscopy and the immunogold method, and their presence in the human ovary was confirmed, considering their typical morphology. In this context, we believe that the results of our study will shed light on future studies on ovarian morphology and provide guidance for a better understanding of the mechanisms of ovarian pathologies.