DFF45 expression in human endometrium is associated with menstrual cycle phases and decreases after menopause.

Human endometrium undergoes cyclic structural and functional modifications, and if no conception occurs menstruation is observed as the result of endometrial cell apoptosis via DFF40/DFF45 complex activation. In postmenopausal endometrium, the proliferative potential of endometrial cells is decreased, while their susceptibility to apoptosis increases. The study group comprised 104 nonpregnant adult women (78 of reproductive age and 36 after menopause) with no neoplasm or hormonal treatment during the past 6 months. Immunohistochemistry and Western blot methods were used for DFF45 identification and semiquantitative assessment of its amount. Significantly more DFF45-positive cells were detected in the endometrial glands compared to stroma, and this pattern was constant throughout the whole menstrual cycle and also present in postmenopausal endometrial species. The lowest mean relative amount of DFF45 was detected in postmenopausal endometrial samples. In women of reproductive age, the highest mean relative amount of DFF45 was identified in an early secretory phase of the menstrual cycle, the lowest median value of the relative amount of DFF45 was observed in the late proliferative phase, and the difference was significant. The DFF45 level in human endometrium corresponds to the respective phase of the menstrual cycle and decreases significantly after menopause.