Placental Galectin-2 Expression in Gestational Diabetes: A Systematic, Histological Analysis

Abstract

Gestational diabetes mellitus (GDM) is the most common pregnancy-associated metabolic disorder that negatively impacts on the health of both mothers and their offspring in the long-term. The molecular mechanisms involved are not fully understood. As in other states of insulin resistance, a disproportionate immune response in GDM leads to a state of chronic low-grade inflammation. Galectin-2 exerts regulatory effects on different immune cells. This study investigated galectin-2 expression in the placenta of 40 GDM patients and 40 controls, in a sex-specific manner. Immunohistochemistry was used for semi-quantitative analysis of expression strength. The phenotypes of galectin-2 expressing cells were characterized through double immunofluorescence. We found a significant up-regulation of galectin-2 in the fetal syncytiotrophoblast, as well as in the maternal decidua of GDM placentas. Double staining showed a strong galectin-2 expression in extra villous trophoblast cells and fetal endothelial cells in GDM. These findings present the first systematic investigation of galectin-2 in GDM. The findings contribute to the emerging understanding of the role of immunomodulation and inflammation in GDM and of galectin-2 itself. This might also have implications for the long-term cardiovascular health of the offspring.

Novel Biomolecules in the Pathogenesis of Gestational Diabetes Mellitus

“…Galectins are a large family belonging to the lectins with relatively broad specificity [ 31 ]. They have diverse functions, including mediating cell-cell interactions, cell-matrix adhesion, and trans-membrane signaling.…”

Galectins in Cancer and the Microenvironment: Functional Roles, Therapeutic Developments, and Perspectives

“…Glucocorticoid treatment can reverse diabetic retinopathy-induced Gal-1 expression in hypoxia [ 13 ]. During pregnancy, Gal-2 was observed in a metabolic disorder that caused gestational diabetes mellitus [ 28 ]. Increased serum Gal-3 and Gal-4 expression was observed in diabetes patients [ 29 , 30 ], and levels of Gal-3 were correlated with cardiovascular events in type 2 diabetes mellitus patients [ 31 , 32 , 33 ].…”

Galectins in Endothelial Cell Biology and Angiogenesis: The Basics

“…The findings of this extensive galectin profiling study corroborated previous observations [ 15 , 16 , 17 , 18 ] and were later confirmed by different research groups in endothelial cells from variable origins [ 19 , 20 , 21 , 22 , 23 , 24 ]. Only recently, it was reported that galectin-2 protein expression was also detectable in endothelial cells, albeit in a specific context, i.e., in fetal endothelial cells in the placenta of women with gestational diabetes mellitus [ 25 ]. While this needs further confirmation, it indicates that the cellular context can control specific endothelial galectin expression.…”