Immunohistochemical detection of the 1,25-dihydroxy vitamin D receptor in the human vagina

Background: Vitamin D plays a critical role in the regulation of growth and differentiation of squamous epithelium. The pleiotropic effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], include proliferative, pro-apoptotic, and pro-differentiation effects on numerous cell types. Although 1,25-dihydroxyvitamin D3 is involved in the regulation and differentiation of epithelium, there is no data in the aspect of the distribution of 1,25-(OH)2D3 receptor (VDR), estrogen receptor-B (ER-B) and ezrin, and how it changes according to the menstrual phases and serum vitamin D level in the human vagina. Objective: To detect of the 1,25-dihydroxyvitamin D3 receptor (VDR), estrogen receptor-B (ER-B), and ezrin in human vagina. Materials and Methods: This cross-sectional study enrolled 15 premenopausal women who had hysterectomies. Vaginal tissues were obtained from vaginal vaults of hysterectomized uterus and processed for immunohistochemical analysis. We recorded the localization, distribution, and expression of VDR, ER-B, and ezrin in the vaginal epithelium. Results: VDR was detected in all layers of vaginal epithelium regardless of the menstrual cycle stage and serum 25-hydroxyvitamin D levels. Conclusion: In this study, we have characterized the presence and distribution of VDR, ER-B, and ezrin in human vaginal epithelium, including menstrual cycle-related and vitamin D-related expression. However, the VDR-related mechanisms underlying vaginal epithelial proliferation and differentiation remain to be elucidated.