Pro-inflammatory activities induced by CyPA–EMMPRIN interaction in monocytes

Excessive reactive oxygen species (ROS) is a critical driver of vascular inflammation in atherosclerosis. Cyclophilin A (CyPA) is the main ROS-induced factor that enhances the inflammatory activity of monocytes/macrophages in atherosclerotic plaque. However, the means by which CyPA interacts with monocytes/macrophages is unclear. Through Chemotaxis assay and ELISA test, we found CyPA strongly induced migration of monocytes and the expression of mmp-9, IL-6 and TNF-alpha. By Western blot, it demonstrated that CyPA activated NF-kappaB by ERK1/2 pathway. When blocking extracellular matrix metalloproteinase inducer (EMMPRIN) in monocytes, most of the CyPA effects including chemoattractant migration, activation of MAPK/NF-kappaB and cytokines releasing were significantly inhibited. Finally, CyPA simulation had no effect on EMMPRIN expression in monocytes. The current study shows that CyPA–EMMPRIN interaction is one of the key pro-inflammatory signaling pathways in monocytes, perhaps especially in response to ROS stimulation. This could be a potential target for atherosclerosis therapy.