Objective: To investigate endometrium receptivity in patients with luteinized unruptured follicle (LUF) by measuring the expression of estrogen receptor (ER), progesterone receptor (PR) and integrin alphaVbeta3 in the endometrium.
Methods: From May 2007 to Nov. 2007, 17 infertile women with LUF were selected as LUF group matched with 13 infertile cases with normal ovulation as control group. They all underwent frozen-thawed embryo transfer in Reproductive Medicine Center, Renmin Hospital of Wuhan University. Endometrial tissue in anterior and posterior wall of uterus of LUF group and control group were biopsied by a small curettage between 7 and 11 days after luteinizing hormone (LH) surge. The expression of ER, PR and integrin alphaVbeta3 in endometrium were detected by immunohistochemistry staining. The level of estrogen and progesterone were measured by chemiluminescence assay. Then, the relationship between alphaVbeta3 expression in endometrium and the level of estrogen/progesterone were analyzed in LUF patients.
Results: (1) There was no remarkable difference in the level of estrogen between LUF [(656 +/- 299) pmol/L] and control group [(727 +/- 275) pmol/L, P > 0.05]. However, the level of progesterone were (23 +/- 8) nmol/L in LUF group and (35 +/- 10) nmol/L in control group, which reached statistical difference (P < 0.01). (2) The expression of ER, PR in endometrium of LUF patients were 183.9 +/- 2.4 and 168 +/- 3, which were significantly higher than 109.4 +/- 6.3 and 106 +/- 4 in control group (P < 0.01). The expression of integrin alphaVbeta3 in endometrium of 115 +/- 11 in LUF group were significantly lower than 191 +/- 9 in control group (P < 0.01). (4) In LUF group, the expression of alphaVbeta3 in endometrium was correlated positively with the level of progesterone (r = 0.77, P < 0.01) and irrelevant with the level of estrogen (r = 0.01, P > 0.05).
Conclusion: The higher expression of estrogen and progesterone and lower expression of integrin alphaVbeta3 might confer impaired receptivity of endometrium and interfere with embryo implantation.