Galectin-1 Overexpression in Endometriosis and Its Regulation by Neuropeptides (CRH, UCN) Indicating Its Important Role in Reproduction and Inflammation

Endometriosis is an inflammatory disease of women of reproductive age featured by the presence of ectopic endometrium and is strongly related to infertility. Galectins, carbonhydrate-binding proteins, have been found to have pro- or anti-inflammatory roles in the reproductive tract and in pathological conditions concerning infertility. Galectin-1, which is expressed at endometrium and decidua, plays a major role in implantation and trophoblast invasion. Also, the neuropeptides, corticotropin releasing hormone (CRH) and urocortin (UCN) and their receptors are expressed in eutopic and ectopic endometrium showing a differential expression pattern in endometriotic women compared to healthy ones. The aim of this study was to examine the galectin-1 expression in endometriotic lesions and compare its expression in eutopic endometrium of endometriotic and healthy women. Furthermore, we examined the effect of CRH and UCN in galectin-1 expression in Ishikawa cell line and macrophages and investigated the implication of CRHR1 in these responses. Eutopic and ectopic endometrium specimens, Ishikawa cell line and mice macrophages were used. Immunohistochemistry and western blot analysis were performed in order to identify galectin-1 expression in ectopic and eutopic endometrium of women with and without endometriosis and the regulatory effect of CRH and UCN on galectin-1 expression. This study presents for the first time that galectin-1 is overexpressed in endometriotic lesions compared to eutopic endometrium of endometriotic women and is more abundantly expressed in eutopic endometrium of disease women compared to healthy ones. Furthermore, it is shown that CRH and UCN upregulate galectin-1 expression in Ishikawa cell line and macrophages and this effect is mediated through CRHR1. These results suggest that galectin-1 might play an important role in endometriosis pathology and infertility profile of women suffering from endometriosis by being at the same time regulated by CRH and UCN interfering in the immune disequilibrium which characterizes this pathological condition.