Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background aims. Dermatan sulfate (DS), an anticoagulant and antithrombotic glycosaminoglycan, also has anti-inflammatory activity. In this study, we investigated the effect of DS treatment in the presence or absence of bone marrow mononuclear cells (MNCs) or endothelial progenitor cells (EPCs) in the vascular response to carotid artery lesion in C57BL6 mice. Methods. Thrombus formation, the expression of adhesion molecules and factors involved in vascular remodeling, inflammation or vascular tone were analyzed by histologic examination, Western blotting and enzyme-linked immunoassay 1 and 3 days after vascular injury. Results. DS injections prevented thrombus formation and decreased P-selectin expression after 3 days of the injury. DS treatment also increased plasma SDF-1 levels but failed to rescue endothelial nitric oxide synthase (eNOS) expression, which is responsible for vascular tone. Treatment with MNCs alone failed to prevent thrombus formation 1 day after injury and increased intercellular adhesion molecule-1 expression, likely because of the inflammatory nature of these cells. Treatment with EPCs with DS was the most efficient among all therapies studied. Dual administration of EPCs and DS promoted an increase in the expression of adhesion molecules and, at the same time, induced a higher expression of eNOS at the injury site. Furthermore, it stimulated an elevated number of EPCs to migrate and adhere to the vascular wall. Discussion. Simultaneous treatment with EPCs and DS increased the expression of adhesion molecules, prevented thrombosis, rescued the expression of eNOS and increased migration of EPCs to the site of injury, thereby affecting thrombus remodeling and inflammation and can be involved in vessel hemostasis.1710 14471464Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2010/01119-3, 2012/23640-2, CNPq 307784/2013-4]