Decorin mimic promotes endothelial cell health in endothelial monolayers and endothelial–smooth muscle co‐cultures

Non‐specific cytotoxins, including paclitaxel and sirolimus analogues, currently utilized as anti‐restenotic therapeutics, affect not only smooth muscle cells (SMCs) but also neighbouring vascular endothelial cells (ECs). These drugs inhibit the formation of an intact endothelium following vessel injury, thus emphasizing the critical need for new candidate therapeutics. Utilizing our in vitro models, including EC monolayers and both hyperplastic and quiescent EC–SMC co‐cultures, we investigated the ability of DS–SILY₂₀, a decorin mimic, to promote EC health. DS–SILY₂₀ increased EC proliferation and migration by 1.5‐ and 2‐fold, respectively, which corresponded to increased phosphorylation of ERK‐1/2. Interestingly, IL‐6 secretion and the production of both E‐selectin and P‐selectin were reduced in the presence of 10 μm DS–SILY₂₀, even in the presence of the potent pro‐inflammatory cytokine platelet‐derived growth factor (PDGF). In hyperplastic and quiescent EC–SMC co‐cultures, DS–SILY₂₀ treatment reduced the secretion of IFNγ, IL‐1β, IL‐6 and TNFα, corresponding to a 23% decrease in p38 phosphorylation. E‐selectin and P‐selectin expression was further reduced following DS–SILY₂₀ treatment in both co‐culture models. These results indicate that DS–SILY₂₀ promotes EC health and that this decorin mimic could serve as a potential therapeutic to promote vessel healing following percutaneous coronary intervention (PCI). Copyright © 2015 John Wiley & Sons, Ltd.