Localization of interferon regulatory factor-1 in human endometrium throughout the menstrual cycle

Objective: To determine the expression and localization of IRF-1 in human e ndometrium throughout the menstrual cycle. Design: A comparative study. Setting: Department of Obstetrics and Gynecology, Kyoto Prefectural Univers ity of Medicine. Patients: Thirty-eight women aged 33 to 46 years, with regular menstrual cy cles and nonpathological endometrium, undergoing hysterectomy. Intervention(s): Endometrial tissues were obtained from operative samples. Main Outcome Measure(s): Expression of IRF-1 mRNA throughout the menstrual cycle was investigated using semiquantitative reverse transcription-polymer ase chain reaction. Localization of IRF-1 protein was determined using immu nohistochemistry. Result(s): IRF-1 mRNA was expressed in the human endometrium at each phase of the menstrual cycle. The immunoreactivity for IRF-1 was observed in the extranuclear compartment of the surface and glandular epithelial cells, bot h during the proliferative and secretory phases, as well as in the gland se cretion during the secretory phase. In contrast, stromal cells were nearly unstained. Conclusion(s): IRF-1 was localized in the human endometrium, implying that this nuclear, protein plays some role other than as a transcription factor. (Fertil Steril(R) 2001;75:992-6. (C) 2001 by American Society for Reproduc tive Medicine.).