2D-DiGE Analysis of the Human Endometrial Secretome Reveals Differences between Receptive and Nonreceptive States in Fertile and Infertile Women

Abstract

Endometrial secretions in the uterine cavity contain mediators important for endometrial receptivity and embryo implantation. Unbiased analysis of uterine fluid from a receptive versus nonreceptive time of the menstrual cycle and in fertile and infertile women will provide new insights into uterine receptivity. We hypothesized that proteomic analysis of human uterine lavages would identify proteins important for the establishment of pregnancy in humans. Lavages collected from fertile (n = 7) and infertile (n = 8) women during the midsecretory (MS) phase, and from fertile women during the midproliferative (MP) (n = 7) phase, were assessed using 2D-differential in gel electrophoresis (2D-DiGE) over a pI 4-7 range. Statistical analysis revealed 7 spots that were significantly decreased in the MP compared to the MS phase, while 18 spots showed differential expression between fertile and infertile women. A number of proteins were identified by mass spectrometry, including antithrombin III and alpha-2-macroglobulin, whose production was confirmed in endometrial epithelium. Their staining pattern suggests roles during embryo implantation. Assessment of the human endometrial secretome has identified differences in the protein content of uterine fluid with respect to receptivity and fertility.

Comparison of endometrial biopsies of fertile women and womenwith repeated implantation failure at the ultrastructural level

“…A comparison of protein abundances between the fertile and infer tile women revealed that several proteins were present at altered levels depending on cycle stage or fertility status (21). Nevertheless, most of the microvilli remained comparable in terms of size and number in both groups despite an irregular appearance in the RIF group (Figure 2a).…”

Hsa-miR-30d, secreted by the human endometrium, is taken up by the pre-implantation embryo and might modify its transcriptome

“…Accumulated evidence suggests that the EF serves as the 'uterine milk' (Burton et al, 2007;Khalil et al, 2009) that nurtures the embryo not only during implantation but beyond (Godfrey and Barker, 2001;Kennedy et al, 2007). The EF contains a variety of molecules, including glycodelin (van der Gaast et al, 2009), cytokines (Boomsma et al, 2009;Simón et al, 1996), lipids and proteins (Domínguez et al, 2009;Hannan et al, 2010), but their impacts on embryo physiology and the putative developmental origins of adult diseases are unknown (Barker, 1990).…”

The Use of Proteomics in Assisted Reproduction

“…Hannan et al studied the endometrial secretome of seven fertile women during both the mid-proliferative and mid-secretory phase and compared it with that of eight infertile women only during the mid-secretory phase. The comparison identified seven proteins that were significantly more highly expressed during the mid-secretory phase in the first group, whereas 18 spots showed differential expression (12 were increased and six were reduced) between the two groups of patients that subsequently needed to be further investigated concerning their functionality (120). Similarly, Scotchie et al identified 42 differentially expressed proteins in the uterine fluid in the pre-receptive and receptive state of the endometrium.…”