Unique Transcriptome, Pathways, and Networks in the Human Endometrial Fibroblast Response to Progesterone in Endometriosis1

Eutopic endometrium in endometriosis has molecular evidence of resistance to progesterone (P4) and activation of the PKA pathway in the stromal compartment. To investigate global and temporal responses of eutopic endometrium to P4, we compared early (6-h), intermediate (48-h), and late (14-Day) transcriptomes, signaling pathways, and networks of human endometrial stromal fibroblasts (hESF) from women with endometriosis (hESFendo) with hESF from women without endometriosis (hESFnonendo). Endometrial biopsy samples were obtained from subjects with and without mild peritoneal endometriosis (n = 4 per group), and hESF were isolated and treated with P4 (1 μM) plus estradiol (E2) (10 nM), E2 alone (10 nM), or vehicle for up to 14 days. Total RNA was subjected to microarray analysis using a Gene 1.0 ST (Affymetrix) platform and analyzed by using bioinformatic algorithms, and data were validated by quantitative real-time PCR and ELISA. Results revealed unique kinetic expression of specific genes and unique pathways, distinct biological and molecular processes, and signaling pathways and networks during the early, intermediate, and late responses to P4 in both hESFnonendo and hESFendo, although a blunted response to P4 was observed in the latter. The normal response of hESF to P4 involves a tightly regulated kinetic cascade involving key components in the P4 receptor and MAPK signaling pathways that results in inhibition of E2-mediated proliferation and eventual differentiation to the decidual phenotype, but this was not established in the hESFendo early response to P4. The abnormal response of this cell type to P4 may contribute to compromised embryonic implantation and infertility in women with endometriosis.