The role of exosomes derived from endothelial cells (ECs) in the progression of atherosclerosis (AS) and inflammation remains largely unexplored. We aimed to investigate whether exosome derived from CD137-modified ECs (CD137-Exo) played a major role in AS and to elucidate the potential mechanism underlying the inflammatory effect. Exosomes derived from mouse brain microvascular ECs treated with agonist anti-CD137 antibody were used to explore the effect of CD137 signalling in AS and inflammation in vitro and vivo. CD137-Exo efficiently induced the progression of AS in ApoE mice. CD137-Exo increased the proportion of Th17 cells both in vitro and vivo. The IL-6 contained in CD137-Exo which is regulated by Akt and NF-КB pathway was verified to activate Th17 cell differentiation. IL-17 increased apoptosis, inhibited cell viability and improved lactate dehydrogenase (LDH) release in ECs subjected to inflammation induced by lipopolysaccharide (LPS). The expression of soluble intercellular adhesion molecule1 (sICAM-1), monocyte chemoattractant protein-1 (MCP-1) and E-selectin in the supernatants of ECs after IL-17 treatment was dramatically increased. CD137-Exo promoted the progression of AS and Th17 cell differentiation via NF-КB pathway mediated IL-6 expression. This finding provided a potential method to prevent local and peripheral inflammation in AS.
