Chemerin promotes proliferation and migration of vascular smooth muscle and increases 2 mouse blood pressure 3 4

21 Blood chemerin concentration shows positive correlation not only with body mass index and 22 serum triglyceride level but also with systolic blood pressure. While it seems likely that chemerin 23 influences vascular smooth muscle cells (SMCs) proliferation and migration which are crucial to the 24 development of hypertension, it remains to be clarified. Here, we investigated whether chemerin 25 controls SMCs proliferation and migration in vitro and also affects blood pressure in vivo. In vitro, 26 chemerin significantly stimulated rat mesenteric arterial SMCs proliferation and migration as 27 determined by cell counting assay and Boyden chamber assay, respectively. The migratory effect of 28 chemerin was confirmed in human aortic SMCs. Chemerin significantly increased reactive oxygen 29 species (ROS) production in SMCs and phosphorylation of Akt (Ser473) and extracellular 30 signal-regulated kinase (ERK) as measured by fluorescent staining and Western blotting, respectively. 31 Various inhibitors (ROS inhibitor: N-acetyl-l-cysteine, PI3K inhibitor: LY294002, mitogen-activated 32 protein kinase kinase inhibitor: PD98059, NADPH oxidase inhibitor: gp-91 ds-tat and xanthine 33 oxidase inhibitor: allopurinol) as well as chemokine-like receptor (CMKLR)1 small interfering RNA 34 significantly inhibited chemerin-induced SMCs proliferation and migration. Furthermore, chemerin 35 neutralizing antibody prevented carotid neointimal hyperplasia in mouse ligation model. In vivo, 36 chronic chemerin treatment (6 μg/kg, 6 weeks) increased systolic blood pressure as well as 37 phosphorylation of Akt and ERK in mouse isolated aorta. In summary, we for the first time 38 demonstrate that chemerin/CMKLR1 stimulates SMCs proliferation and migration via 39