Stimulation of CCL2 (MCP-1) and CCL2 mRNA by substance P in LAD2 human mast cells.

Chemokines are cytokines with chemotactic properties on inflammatory cells and other cell types. Chemokine (C-C motif) ligand 2 (CCL2), which is also called monocyte chemotactic protein 1 (MCP-1), is a potent chemotactic molecule that attracts lymphocytes, monocytes, mast cells, and memory T cells, but not neutrophils. CCL2/MCP-1 represents a link between the activation of monocytes, lymphocytes, basophils, mast cells, and eosinophils in inflammatory disorders, such as the late-phase allergic reaction. This C-C chemokine also plays a role in regulating Th-cell cytokine production and leukocyte trafficking. Laboratory of allergic diseases (LAD) cells is the first reported human mast cell line that closely resembles a primary culture of CD34+-derived human mast cells. These cells were cultured in vitro and treated with different concentrations of substance P (SP) for the production of CCL2/MCP-1. We used calcium ionophore as a positive control for stimulating transcription and translation of CCL2/MCP-1. The stimulation of SP on CCL2/MCP-1 was statistically significant (P < 0.05) compared with the control (untreated cells). In this study, we determined the expression and secretion of CCL2/MCP-1 from SP-activated LAD2 human mast cells in vitro. The levels of CCL2/MCP-1 from SP-activated LAD2 human mast cells were higher at 10 microM and at 18 h incubation compared with controls. This effect was also revealed on CCL2/MCP-1 messenger RNA (mRNA) expression, as determined by reverse transcriptase polymerase chain reaction (RT-PCR) analysis. Our data suggest that SP is an important neurotransmitter that can stimulate the chemokine CCL2, which plays a fundamental role in inflammation by recruiting inflammatory cells to specific cites.