Nonrequirement of continuous stimulation with MCP-1 for cell migration and determination of directional migration by initial stimulation with chemokine

Monocyte chemoattractant protein-1 (MCP-1) induces monocyte migration through interaction with the MCP-1 receptor CCR2. In this report we have examined the length of chemokine stimulation necessary for induction of cell migration and whether continuous stimulation is required for active migration. Monocytic THP-1 cells prestimulated with MCP-1 for 15 to 30 min exhibited a migration response after the chemokine was removed from the culture medium, indicating that a short exposure to chemokine stimulation is sufficient for migration of THP-1 cells and continuous stimulation is not required for active migration. A reverse gradient of MCP-1 had no effect on migration after prestimulation with MCP-1. This implies that cells are determined to directionally migrate by initial stimulation with MCP-1. Furthermore, cell migration after prestimulation with MCP-1 was inhibited by a p38 inhibitor, but not by a phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, indicating that p38, but not PI3-kinase, is involved in the migration response after the determination of direction by initial chemokine stimulation.