Differential Expression of Two β-Galactoside-Binding Lectins in the Reproductive Tracts of Pregnant Mice1

Abstract

Two beta-galactoside-binding proteins were isolated from uteroplacental complexes of pregnant mice and identified as the S-Lac lectins galectin-1 and galectin-3. The spatiotemporal pattern of appearance of those proteins was determined by immunocytochemistry. Galectin-1 was present in all tissue compartments of the uterus except the luminal and glandular epithelium. It was found in the uteri of animals from all preimplantation stages of pregnancy, as well as in those from nonpregnant, ovariectomized, or sexually immature animals. After implantation of the embryo, cells of the decidua basalis were labeled, as were granular metrial gland cells, all trophoblastic elements of the placenta, the myometrium, and nondecidualized endometrium. By contrast, there was little evidence of galectin-3 in the uteri of nonpregnant animals or during the preimplantation stages of pregnancy. However, immunoreactive material was observed in endometrial cells of the primary decidual zone immediately after implantation and at later stages of pregnancy in the decidua basalis, metrial gland, and all trophoblastic elements of the placenta. There was no evidence of galectin-3 in the myometrium or nondecidualized endometrium. After parturition, amounts of galectin-3 in the endometrium and metrial triangle appeared to decrease as the implantation sites were resorbed. These data suggested that the function of galectin-1 is one of tissue maintenance, whereas the function of galectin-3 is related specifically to pregnancy.

Histological Mapping and Subtype-Specific Functions of Galectins in Health and Disease

“…Changes in galectin expression during the estrous cycle are also observed in other parts of the female reproductive tract, including the oviduct, uterus, and vagina, indicating that ovarian steroids regulate galectin expression in these organs (6). The expression of galectin-1 and -3 in the implantation site in the mouse uterus and placenta was previously reported by Phillips et al (18). Other galectins including galectin-9, -11/15, -13, -14, and -16 are known to be expressed in the placenta of women and domestic animals (5,(19)(20)(21)(22), suggesting an important role for galectins in the establishment and maintenance of pregnancy.…”

T cell apoptosis at the maternal–fetal interface in early human pregnancy, involvement of galectin-1

“…This redundancy may be important only in genetic backgrounds that pose an increased immunological stress. As multiple galectins are present in the human decidua (28)(29)(30)(31), multiple galectins present in the murine placenta (39) could, conceivably, compensate for each other.…”

Interfering with Gal-1–mediated angiogenesis contributes to the pathogenesis of preeclampsia

“…Galectin-1 (Gal-1), an evolutionarily conserved glycan-binding protein, is abundant in the female reproductive tract, where it displays an increased expression during pregnancy in mammals (8,9). Circulating Gal-1 levels increase during the first trimester compared with nonpregnant women and reach a maximum in the second trimester, which is maintained until term (10).…”