Endometrial receptivity profile in patients with premature progesterone elevation on the day of HCG administration

Abstract

The impact of a premature elevation of serum progesterone level, the day of hCG administration in patients under controlled ovarian stimulation during IVF procedure, on human endometrial receptivity is still debated. In the present study, we investigated the endometrial gene expression profile shifts during the prereceptive and receptive secretory stage in patients with normal and elevated serum progesterone level on the day of hCG administration in fifteen patients under stimulated cycles. Then, specific biomarkers of endometrial receptivity in these two groups of patients were tested. Endometrial biopsies were performed on oocyte retrieval day and on day 3 of embryo transfer, respectively, for each patient. Samples were analysed using DNA microarrays and qRT-PCR. The endometrial gene expression shift from the prereceptive to the receptive stage was altered in patients with high serum progesterone level (>1.5 ng/mL) on hCG day, suggesting accelerated endometrial maturation during the periovulation period. This was confirmed by the functional annotation of the differentially expressed genes as it showed downregulation of cell cycle-related genes. Conversely, the profile of endometrial receptivity was comparable in both groups. Premature progesterone rise alters the endometrial gene expression shift between the prereceptive and the receptive stage but does not affect endometrial receptivity.

Figure 1

(a) Number of genes that were up- or downregulated in the normal and high [P] groups. (b) Venn diagram of the transcripts that were differentially expressed in the prereceptive and the receptive endometrial samples from patients with normal or high serum [P].

Figure 2

Signalling pathways that were altered in the high serum [P] group. The Ingenuity Pathway software was used to identify the functional pathways associated with genes that were differentially expressed between the prereceptive and receptive endometrial stages in the high [P] group. The majority of genes related to mitotic entry (a) and cell cycle (b) were downregulated. In this network, edge types are indicatives: a plain line indicates direct interactions, a dashed line indicates indirect interactions, a line without arrowhead indicates binding only, a line finishing with a vertical line indicates inhibition, and a line with an arrowhead indicates “acts on”. Green, downregulated; red, upregulated.

Figure 3

Validation by quantitative RT-PCR analysis of genes related to the cell cycle function modulated in the high [P] group. RNA isolated from hCG+2 and hCG+5 endometrial samples of normal and high serum [P] patients (n = 3/each group) was used. Data are the mean ± SEM. NS, nonsignificant.

Figure 4

Unsupervised hierarchical clustering of the prereceptive and receptive endometrium samples using the previously described [28] predictor list. Comparison of the gene expression profiles at hCG+2 and hCG+5 in the normal and high serum [P] groups revealed similar transcriptomic profiles. Green, downregulated; red, upregulated.

Figure 5

Validation by quantitative RT-PCR analysis of several biomarkers of endometrial receptivity using RNA isolated from hCG+5 endometrial samples of normal and high serum [P] patients (n = 3/each group). Data are the mean ± SEM. *P value < 0.05; NS, nonsignificant.