RT Journal Article SR Electronic T1 A Cytokine-like Protein DKK3 Is Atheroprotective JF Circulation JO Circulation FD Lippincott Williams & Wilkins DO 10.1161/CIRCULATIONAHA.117.027690 A1 Yu, Baoqi A1 Kiechl, Stefan A1 Qi, Dan A1 Wang, Xiaochong A1 Song, Yanting A1 Weger, Siegfried A1 Mayr, Agnes A1 Le Bras, Alexandra A1 Karamariti, Eirini A1 Zhang, Zhongyi A1 del Barco Barrantes, Ivan A1 Niehrs, Christof A1 Schett, Georg A1 Hu, Yanhua A1 Wang, Wen A1 Willeit, Johann A1 Qu, Aijuan A1 Xu, Qingbo YR 2017 UL http://circ.ahajournals.org/content/early/2017/07/03/CIRCULATIONAHA.117.027690.abstract AB Background—Dickkopf-related protein (DKK) 3 is a secreted protein that is involved in the regulation of cardiac remodeling and vascular smooth muscle cell differentiation, but little is known about its role in atherosclerosis.Methods—We tested the hypothesis that DKK3 is atheroprotective using both epidemiological and experimental approaches. Blood DKK3 levels were measured in the Bruneck Study in 2000 (n=684) and then in 2005 (n=574). DKK3-deficient mice were crossed to ApoE-/- mice to evaluate atherosclerosis development and vessel injury-induced neointimal formation. Endothelial cell migration and the underlying mechanisms were studied using in vitro cell culture models. Results—In the prospective population-based Bruneck Study, the level of plasma DKK3 was inversely related to carotid artery intima-media thickness and five-year progression of carotid atherosclerosis, independently from standard risk factors for atherosclerosis. Experimentally, we analyzed the area of atherosclerotic lesions, femoral artery injury-induced re-endothelialization and neointima formation in both DKK3-/-/ApoE-/- and DKK3+/+/ApoE-/- mice. It was demonstrated that DKK3 deficiency accelerated atherosclerosis and delayed re-endothelialization with consequently exacerbated neointima formation. To explore the underlying mechanisms, we performed transwell and scratch migration assays using cultured human endothelial cells, which exhibited a significant induction in cell migration in response to DKK3 stimulation. This DKK3-induced migration was associated with activation of ROR2 and DVL1, activated Rac1 GTPases and upregulated JNK and c-jun phosphorylation in endothelial cells. Knockdown of ROR2 receptor using specific siRNA or transfection of a dominant negative form of Rac1 in endothelial cells markedly inhibited cell migration and downstream JNK and c-jun phosphorylation. Conclusions—This study provides the evidence for a role of DKK3 in the protection against atherosclerosis involving endothelial migration and repair, with great therapeutic potential implications against atherosclerosis.