Chemokines have been reported to play important roles in atherosclerotic development. Recently, we found C-C motif
ligand 8 (CCL8), a rarely studied
chemokine in
atherosclerosis, was highly expressed in the endothelium of advanced human carotid plaques. We hypothesized whether CCL8 promotes
atherosclerosis through endothelial dysfunction.
Apolipoprotein E-deficient mice under the Western diet were used to construct
atherosclerosis models. Adeno-associated viruses (AAV) with CCL8 and the CCL8-antibody were injected into mice respectively to conduct CCL8 overexpression and suppression. The results showed that atherosclerotic lesions were significantly increased in the AAV-CCL8 group, while, lesions in the aortic sinus were reduced in the CCL8-antibody group. With CCL8 treatment (200 ng/ml, 24 h) in vitro, the permeability of human aortic endothelial cells (HAECs) increased and the expression of junctional
proteins Zonula occluden-1, and
Vascular endothelial cadherin were decreased. This effect was dependent on
reactive oxygen species (ROS) generation, which could be blocked by
l-Ascorbic acid and
Apocynin. Results showed that
NADPH oxidase 2 (NOX2) expression also increased with CCL8 stimulation and the ROS, and permeability increase of HAECs could be inhibited when NOX2 interfered with the specific
siRNA. Additionally, we further found ERK1/2, PI3K-AKT, and NF-κB pathways were involved in the activation of CCL8. Our results indicated that CCL8 might also play important roles in
atherosclerosis and this effect, at least in part, was caused by NOX2/ROS-induced endothelial permeability increase. This study might contribute to a deeper understanding of the connection between
chemokines and
atherosclerosis.