Affiliations: Department of Anatomy, Key Lab for Biomechanics of Chongqing, Third Military Medical University, Chongqing, China | Department of Otolaryngology, Southwest Hospital, Third Military Medical University, Chongqing, China
Note: [] These authors contributed equally to this work.
Note: [] Addresses for correspondence: Drs. Chuhong Zhu or Can Wen, Department of Anatomy, Key Lab for Biomechanics of Chongqing, Third Military Medical University, Chongqing 400038, China. E-mails: [email protected], [email protected].
Abstract: Objective: To determine if A20, a zinc finger protein that mediates the inflammatory response, affects monocyte-endothelial cell–cell interactions induced by low shear flow. Methods: Primary cultured endothelial cells (EC) were transfected with an A20 expression vector, and the VCAM-1, ICAM-1 and IL-8 mRNA, and protein expression levels in A20-transfected EC lysates were checked by PCR array and ELISA, respectively. CD14-positive monocyte migration toward and adhesion to EC were measured using a parallel plate flow chamber. Results: Low shear stress, defined as 0.2 Pa for 6 h, normally increases VCAM-1, ICAM-1 and IL-8 expression in EC and allows for binding of monocytes to EC. We found that overexpression of A20 in EC inhibits their normal expression of VCAM-1, ICAM-1 and IL-8 under low shear stress conditions. We also found that A20 inhibits IκBα degradation in EC following low shear stress exposure and that it attenuates the rolling and EC adhesive properties of shear-induced monocytes as compared with untransfected control EC. The results demonstrate that A20 overexpression in EC inhibits low shear flow-induced monocyte–EC interactions. These findings may be useful in the development of therapeutic agents aimed at treating chronic inflammatory diseases like atherosclerosis.
