Galectin 1 in dermatology: current knowledge and perspectives

Galectins are a family of soluble proteins that are widely distributed in nature and bind to a variety of glycoproteins and glycolipids bearing β-galactoside residues. They are involved in highly important processes at the molecular and cellular level in human cutaneous and extracutaneous tissues, and they exert biological effects of paramount importance through their interaction with cytoplasmic and nuclear proteins and the components of the cell surface and extracellular matrix. Galectin 1 (Gal 1), the first galectin isolated, is a noncovalent homodimeric protein with a 14 kDa monomer that contains one carbohydrate-recognition domain (CRD) and preferentially recognizes galactose-β1-4-N-acetyl-glucosamine sequences on N- or O-linked glycans. Gal 1 occurs intracellularly, extracellularly, and on the cell surface. In the last few years Gal 1 has emerged as a multifaceted protein that exerts a wide spectrum of regulatory effects in diverse normal and abnormal tissues and conditions, indicating a tremendous therapeutic potential. This review summarizes current knowledge on the expression of Gal 1 in normal and diseased human skin, its implications in the pathogenesis, diagnosis, and prognosis of cutaneous disorders, and the novel approach to the treatment of these disorders offered by the use of Gal 1 or its inhibitors/antagonists.