miR-302a mediates IL-1β-induced COUP-TFII down-regulation and COX-2 up-regulation. A, Representative Western blot (left panel) and quantitative results (middle and right panels, n = 5) show levels of COUP-TFII and COX-2 proteins in normal endometrial stromal cells treated with miR-302a mimics (mimic) or scrambled miRNA (NC). *, Significant difference compared with control. B, Quantitative results show ratios of COX-2, COUP-TFII, and miR-302a in six pairs of endometrial stromal cells and endometriotic stromal cells from patients with endometriosis. Levels of COX-2, COUP-TFII, and miR-302a in eutopic endometrial stromal cells were set as 0.0 after logarithmic transformation. C, Representative Western blot (upper panel) and quantitative results (lower panels, n = 5) show levels of COUP-TFII and COX-2 proteins in normal endometrial stromal cells treated with IL-1β with or without pretreatment with recombinant IL-1β receptor antagonist (rIL-1ra). *, Significant difference from control; #, significant difference from PBS-treated cells. D, Representative Western blot (upper panel) and quantitative results (lower panels, n = 3) show levels of COUP-TFII and COX-2 proteins in normal endometrial stromal cells treated with IL-1β with or without pretreatment with miR-302a inhibitor (302a-Inh). *, Significant difference from control; #, significant difference from IL-1β-treated cells. E, Representative immunohistochemistry pictures show levels of COX-2 in donor endometrial tissues (donor) and endometriotic lesions (Endo) after injection of COUP-TFII-knockout or intact endometrial tissues into the peritoneal cavity of receipt mice for 4 weeks. COUP-TFII F/F, wild-type COUP-TFII; COUP-TFII −/−, uterine stroma-specific COUP-TFII knockout; E, epithelial cells; S, stromal cells.