Growth Factors

Galectins are involved in various physiological functions, such as inflammation, immune responses, cell migration, autophagy, and signaling . They are expressed in numerous cell types and tissues, including hepatocytes, activated macrophages, dendritic cells, bone marrow, and epithelial cells in the intestines and lungs . The expression pattern of galectins varies between cell types and tissues, and they can be found in the cytosol, nucleus, extracellular matrix, or in circulation .

Galectins play a crucial role in mediating cell-cell interactions, cell-matrix adhesion, and transmembrane signaling . They are involved in immune responses by modulating inflammation, cell migration, and pathogen recognition . Galectins can bind to both carbohydrate and non-carbohydrate ligands, serving as adaptors within the cell to recruit enzymes and regulate pre-mRNA splicing, mRNA stability, autophagy, and apoptosis .

Galectins function through carbohydrate-dependent and carbohydrate-independent interactions. They bind to glycosylated proteins and lipids on the surface of host cells and pathogens, forming signaling and adhesion networks . Intracellularly, galectins can tune kinase and G-protein-coupled signaling cascades important for nutrient sensing, cell cycle progression, and transformation . They also participate in pre-mRNA splicing in the nucleus and recruit components of autophagosomes during intracellular infection .

The expression and activity of galectins are regulated through transcriptional regulation and post-translational modifications. Glycosylation is a common post-translational modification process that affects galectin function . Galectins can regulate cell death both intracellularly and extracellularly by cross-linking glycans on the outside of cells and transducing signals across the membrane to trigger apoptosis . They also play a role in autophagy regulation and inflammasome-dependent cell death programs .

Galectins have significant applications in biomedical research, diagnostic tools, and therapeutic strategies. They are involved in immune and inflammatory responses, tumor development and progression, neural degeneration, atherosclerosis, diabetes, and wound repair . Galectin-3, in particular, has been studied for its role in cancer immunotherapy and overcoming tumor immune escape . Inhibition of galectins is being explored as a potential therapeutic approach in cancer treatment .

Galectins play a vital role throughout the life cycle, from development to aging and disease. They are involved in cell growth, differentiation, apoptosis, cell adhesion, chemoattraction, and cell migration . Galectins also participate in immune regulation, pattern recognition, and pathogenesis of autoimmune diseases and cancer . Their functions are essential for maintaining cellular homeostasis and responding to physiological and pathological conditions.