Abnormal Galectin Signaling in the Pathomechanisms of Placental Dysfunction in Gestational Diabetes Mellitus

Recognition and binding to β-galactose-containing carbohydrates and lipids are crucial for several fundamental biological processes that are mediated primarily by a family of proteins known as galectins (S-type lectins). Galectins in the human placenta regulate critical processes such as maternal–fetal immune tolerance, trophoblast invasion, vascular remodeling and angiogenesis, ensuring proper fetal development and preventing pregnancy complications such as preeclampsia and miscarriage. Gestational diabetes mellitus (GDM) is a widespread complication of pregnancy, affecting approximately 1 in 7 pregnancies, and its incidence is increasing globally, indicating a particularly strong association with the obesity pandemic. Profiles of placental expression and distribution of individual galectins significantly change during the course of GDM. This is accompanied by placental dysfunction, which is especially severe with poor glycemic control. The aim of this review is to present the current state of knowledge on the involvement of abnormal galectin signaling in the pathomechanisms of GDM-associated placental dysfunction. Further research is needed to determine whether changes in placental galectins occur secondary to metabolic abnormalities in GDM or are involved as a primary cause. Galectins present in placental tissue and serum should be validated as potential biomarkers of GDM.