AbstractVascular smooth muscle cell (VSMC) migration play a key role in the development of intimal hyperplasia and atherosclerosis. Galectin-1 (Gal-1) is a redox-sensitive β-galactoside-binding lectin expressed in VSMCs with intracellular and extracellular localizations. Here we show that VSMCs deficient in Gal-1 (Gal-1-KO) exhibited greater motility than wild type (WT) cells. Likewise, Gal-1-KO-VSMC migration was inhibited by a redox-insensitive but activity-preserved Gal-1 (CSGal-1) in a glycan-dependent manner. Gal-1-KO-VSMCs adhered slower than WT cells on fibronectin. Cell spreading and focal adhesion (FA) formation examined by phalloidin and vinculin staining were less in Gal-1-KO-VSMCs. Concomitantly, FA kinase (FAK) phosphorylation was induced to a lower extent in Gal-1-KO cells. Analysis of FA dynamics by nocodazole washout assay demonstrated that FA disassembly, correlated with FAK de-phosphorylation, was faster in Gal-1-KO-VSMCs. Surface plasmon resonance assay demonstrated that CSGal-1 interacted with α5β1integrin and fibronectin in a glycan-dependent manner. Chemical crosslinking experiment and atomic force microscopy further revealed the involvement of extracellular Gal-1 in strengthening VSMC-fibronectin interaction. In vivo experiment showed that carotid ligation-induced neointimal hyperplasia was more severe in Gal-1-KO mice than WT counterparts. Collectively, these data disclose that Gal-1 restricts VSMC migration by modulating cell-matrix interaction and focal adhesion turnover, which limits neointimal formation post vascular injury.