The universe of galectin-binding partners and their functions in health and disease

Galectins, a family of evolutionarily conserved glycan-binding proteins, play key roles in diverse biological processes including tissue repair, adipogenesis, immune cell homeostasis, angiogenesis and pathogen recognition. Dysregulation of galectins and their ligands has been observed in a wide range of pathologic conditions including cancer, autoimmune inflammation, infection, fibrosis and metabolic disorders. Through protein-glycan or protein-protein interactions, these endogenous lectins can shape initiation, perpetuation and resolution of these processes, suggesting their potential roles in disease monitoring and treatment. However, in spite of considerable progress, a full understanding of the biology and therapeutic potential of galectins has not been reached due to their diversity, multiplicity of cell targets, and receptor promiscuity. In this article we discuss the multiple galectin-binding partners present in different cell types, focusing on their contributions to selected physiologic and pathologic settings. Understanding the molecular bases of galectin-ligand interactions, particularly their glycan-dependency, biochemical nature of selected receptors and underlying signaling events, might contribute to design rational therapeutic strategies to control a broad range of pathologic conditions.