Fig. 2
Supraphysiological E2 impairs endometrial receptivity. A Schematic illustration of experimental design where endometrial explants were treated with different concentrations of E2. B Heatmap showing the relative mRNA expression levels of genes associated with endometrial receptivity in endometrial explants treated with different concentrations of E2 or 24 h (n = 6) and 48 h (n = 5). Colored bars indicate relative mRNA expression levels detected by qPCR. C Immunohistochemical analysis of PCNA in endometrial explants treated with different concentrations of E2 for 24 h and 48 h. Scale bar: 20 μm. D Western blotting analysis of PCNA in endometrial explants treated with different concentrations of E2 for 24 h (n = 6) and 48 h (n = 5). The upper panel shows the quantification of PCNA level. E and F Relative mRNA levels of PGR (E) and ESR1 (F) in endometrial explants treated with or without the high level of E2 (n = 5). G Immunohistochemical analysis of PGR and ER in endometrial explants treated with or without E2. Scale bar: 20 μm. Data are presented as the mean ± SEM. *P < 0.05, **P < 0.01. ns, not significant. E2, estradiol; PCNA, proliferating cell nuclear antigen; PGR, progesterone receptor; ESR1, estrogen receptor 1