Aberrant Expression of Transforming Growth Factor-beta1 in Endometrium of Infertile Women During the Window of Implantation

Song, In Ok; Kim, Jin Young; Yang, Kwang Moon; Yoo, Keun Jai; Koong, Mi Kyoung; Kang, Inn Soo; Kim, Kye Hyun; Huh, Young Buhm

Abstract

OBJECTIVE
TGF-beta1 is a polypeptide which stimulates the growth of some mesenchymal cell types and inhibits the growth of epithelial cell types. Several studies have reported that TGF-beta1 is present in the endometrial tissue and it is also involved in a variety of physiological processes such as the implantation of the embryo into the endometrium. However, the expression of endometrial TGF-beta1 have not been well established in infertile women with endometriosis or hydrosalpinx having impaired endometrial receptivity. Therefore, the aim of this study was to determine the expression of endometrial TGF-beta1 in infertile women and to compare it with that of fertile women during the window of implantation.
MATERIALS AND METHODS
Endometrial biopsies were performed during the window of implantation from 10 normal fertile women and 15 infertile women (5 unexplained infertility, 5 endometriosis and 5 tubal disease with hydrosalpinx). We performed immunohistochemistry using paraffin-embedded endometrial tissues. The staining intensity of TGF-beta1-immunostained section was assessed by semi-quantitative histologic score (H-score=Sum[Pi x (i +1)]; i: intensity 0-3, Pi: %cells for each given intensity) of 100 cells.
RESULTS
In normal fertile women, the staining intensity of TGF-beta1 in the glandular epithelium was higher than that of stromal cells. But the stromal cells showed an irregularly distributed positivity. In infertile women, their expression patterns were similar to those in fertile women. There was no statistically significant difference in the staining intensity of TGF-beta1 between the glandular epithelium and stromal cell of women with unexplained infertility and that of fertile women. However, the staining intensity of TGF-beta1 in the glandular epithelium and stromal cell of women with endometriosis or hydrosalpinx were significantly higher (p<0.01) than those in fertile women.
CONCLUSION
This study demonstrated that increased expression of endometrial TGF-beta1 in women with endometriosis or hydrosalpinx during the window of implantation may cause endometrial dysfunction during the implantation process such as endometrial-embryonic interactions and endometrial proteolytic activity.