Galectin 1 modulates attachment, spreading and migration of cultured vascular smooth muscle cells via interactions with cellular receptors and components of extracellular matrix

Galectin 1 (Gal-1), a lactose-binding lectin, is a component of vascular extracellular matrix and secreted by human vascular smooth muscle cells (SMCs). The purpose of this study was to investigate a possible role of Gal-1 in controlling adhesion and migration of cultured human vascular SMCs, Gal-1 co-localised with laminin and cellular fibronectin in extracellular matrix (ECM) secreted by cultured human vascular SMCs, Recombinant glutathione S-transferase (GST)-Gal-1 fusion protein bound to laminin and cellular fibronectin in ELISA, GST-Gal-1 inhibited SMC attachment to laminin via interactions with both SMCs and laminin, GST-Gal-1 inhibited SMC spreading on plastic or on laminin, but not on cellular fibronectin. GST-Gal-1 modulated SMC migration on laminin and inhibited migration on cellular fibronectin. GST-Gal-1 bound to several S-35-labelled proteins in SMC extracts including laminin and alpha 1 beta 1 integrin, identified by depletion of SMC protein extracts with respective antibodies. We conclude that Gal-1 is able to modulate SMC attachment, spreading and migration via interactions with ECM proteins and alpha 1 beta 1 integrin.