Triglyceride (TG) down-regulates expression of MCP-1 and CCR2 in PMA-derived THP-1 macrophages

Triglycerides (TGs) are implicated in the development of atherosclerosis. A key contributing factor for atherosclerosis is the migration of macrophages to atherosclerotic lesions. MCP-1 is a major chemoattractant for macrophages to atherosclerotic lesions. We examined the expression profile of MCP-1 and CCR2 in THP-1 macrophages in response to TG treatment by RT-PCR analysis. Chemical inhibitors were used to identify cell signaling pathway(s) involved in regulation of MCP-1 and CCR2 expression. We found that treatment of THP-1 macrophages with TG down-regulated MCP-1 expression in a time and dose-dependent manner. PMA treatment alone did not affect MCP-1 expression. Using chemical inhibitors of cell signaling pathways, we found that the NF-κB inhibitor inhibited TG-induced down-regulation of MCP-1. CCR2 expression decreased after TG treatment in THP-1 macrophages and the PKC inhibitor alleviated TG-induced down-regulation of CCR2. Our results provide further insights into the role of TG on macrophages during atherosclerosis.