Galectin-3 Contributes to Luteolysis by Binding to Beta 1 Integrin in the Bovine Corpus Luteum1

Abstract

Luteolysis is characterized by a reduction in progesterone (P4) production and tissue degeneration in the corpus luteum (CL). One of major events during luteolysis is luteal cell death. Galectin-3, a ubiquitously expressed protein involved in many cellular processes, serves as an antiapoptotic and/or proapoptotic factor in various cell types. Although galectin-3 is detected in the bovine CL, its role remains unclear. The expression of galectin-3 in the bovine CL was higher at the regressed stage than at the other luteal stages. Galectin-3 was localized on luteal steroidogenic cells (LSCs). When cultured LSCs were exposed to prostaglandin F2alpha (PGF) for 48 h, the expression and secretion of galectin-3 increased. When the cultured LSCs were treated with galectin-3 for 24 h, cleaved caspase-3 expression was increased, and the cell viability was decreased, whereas P4 production did not change. Beta 1 integrin, a target protein of galectin-3, was expressed in bovine CL and possessed glycans, which galectin-3 binds. Furthermore, galectin-3 bound to glycans of luteal beta 1 integrin. The decreased cell viability of cultured LSCs by galectin-3 was suppressed by beta 1 integrin antibody. The overall findings suggest that the secreted galectin-3 stimulated by PGF plays a role in structural luteolysis by binding to beta 1 integrin.

Modified citrus pectin inhibits galectin-3 function to reduce atherosclerotic lesions in apoE-deficient mice

“…Galectin-3 participates in the ECM-cell adhesion process, and the association between galectin-3 and ECM proteins, particularly laminin and fibronectin, is essential for leucocyte movement. Furthermore, the interaction of galectin-3 with fibronectin is unique for the macrophage migratory process (23), indicating that galectin-3 may guide monocyte-derived macrophages to transmigrate across the endothelium and reach the arterial media, via its ECM binding ability. Previous studies have demonstrated that galectin-3 has no impact on the expression of adhesion molecules, such as selectin, ICAM, VCAM and very late antigen-4, indicating that galectin-3 is not an inflammatory modulator.…”

“…VCAM-1 may mediate rolling-type adhesion and firm adhesion, depending on the avidity status of α4β1-integrin (25). It has been demonstrated that galectin-3 is capable of associating with β1 integrin, via its carbohydrate recognition domain, in a lactose-dependent manner (23). The binding of galectin-3 with α4β1 integrin may further modulate its receptor state and alter its affinity to VCAM-1; therefore, galectin-3 may be indirectly involved in α4β1-integrin-VCAM-1 dependent rolling and adhesion.…”

Investigation of bovine conceptus galectins and the effect of bovine conceptus secretory proteins on the endometrial epithelial transcriptome

“…The stromal cells exhibited a significant 177-fold increase of SLC15A3 while glandular epithelial cells had a 36-fold increase [181]. Data from the current study show the up-regulation of SLC15A3 in the epithelial and fibroblast cells due to IFNT (logFC 6.29 and 7.06, respectively; protein from humans and an unidentified mammal in vitro to elicit a response on cultured bovine luteal cells [118]. However, we conclude that recombinant mouse LGALS3 protein did not elicit a cellular response in the bovine cells.…”

“…Specifically, in the nonpregnant bovine uterus, LGALS3 has been localized via IHC in epithelial cells as well as macrophages located in the submucosa but absent in endometrial glands [117]. In the bovine CL, LGALS3 expression was elevated at the regressed state in comparison to all other luteal stages and was localized on steroidogenic cells in the CL [118].…”

“…Bovine luteal cells express β-1 integrin and contain glycans to which LGALS3 will bind. Hashiba et al (2014) found that PGF stimulated secreted LGALS3 from cultured luteal steroidogenic cells and LGALS3 plays a structural luteolytic role through binding to β-1 integrin [118]. Induced by LGALS3, a form of programmed cell death, termed anoikis, occurs in the bovine luteal steroidogenic cells due to inhibition of β-1 integrin-extracellular matrix binding [118,124,125].…”