Immunohistochemical assessment of galectin-3 during pre-implantation in\nmouse endometrium

Background: Galectin-3 (Gal-3), a β-galactoside-binding lectin, is\na multifunctional lectin that involves in a number of critical\nbiological processes. Objective: The purpose of this study was to\ninvestigate the expression pattern of Gal-3 in mouse endometrium during\nestrus phase of estrous cycle and pre-implantation. Materials and\nMethods: In this experimental study 42 NMRI female mice were divided in\nseven different groups. Ovulation in NMRI female mice was stimulated by\ninjecting hMG and hCG. Estrus phase was considered as stimulated and\nun-stimulated groups. The other groups of mice were mated, and the day\nof vaginal plug formation was considered as the day 1 of pregnancy. The\nmice of all groups were sacrificed on different days of\npre-implantation period and their uterine horns were fixed and avidin-\nbiotin complex method of immunohistochemistry (IHC) was applied.\nResults: In estrus group, Gal-3 immunoreactivity in luminal epithelium\nwas strong, in stromal cells very strong, in glandular epithelium very\nweak and endothelial cells very strong. No identifiable difference was\nobserved in un-stimulated and stimulated estrus phase. In test groups,\ndays 1-2, insignificant difference of Gal-3 expression was observed. On\nday 3, luminal epithelium and stromal cells showed significant decrease\nin comparison to estrus and day 1 (p=0.001). On the 4th and 5th days,\nluminal epithelium and stromal cells showed significant decrease in\ncomparison to estrus phase and days 1-3 (p=0.0001). Conclusion: The\ndata suggested that successful implantation is probably associated with\nthe downregulation of Gal-3 in the mouse endometrium at the beginning\nof pregnancy.