Endometriosis is a hormone-dependent inflammatory condition associated with pain and infertility. A growing body of evidence supports attenuated secretory-phase progesterone responsiveness in women with this disease. Herein, we compare the expression of progesterone receptor membrane components (PGRMC) 1 and 2 in eutopic endometrium from 11 women with laparoscopically and/or histologically proven stage III/IV endometriosis and 23 disease-free women. Menstrual cycle phase was determined using a combination of reported cycle day, serum hormone profile, and endometrial histologic dating. The PGRMC-1 (fold change -3.3; P < .05) and PGRMC-2 (fold-change -8.8; P < .05) gene expression were significantly downregulated in secretory phase, eutopic endometrium from women with endometriosis. Immunohistochemistry demonstrated decreased PGRMC-1 and PGRMC-2 protein expression in the secretory phase endometrial stroma cells of women with endometriosis. Consistent with the preclinical work of others, our results reflect downregulation of endometrial PGRMC-1 and PGRMC-2 expression in secretory phase endometrium from women with advanced stage endometriosis. Understanding the molecular mechanisms of attenuated progesterone action in endometriosis has important diagnostic and therapeutic implications.
Keywords: PGRMC-1; PGRMC-2; endometriosis; progesterone; progesterone receptor membrane component 1; progesterone receptor membrane component 2.