| Leukocyte infiltration in the CNS following trauma or inflammation is triggered in part through the action of the chemokine, Monocyte Chemoattractant Protein-1 (MCP-1), in astrocytes. In response to many situations, including trauma, the extracellular concentration of ATP increases. We have discovered that ATP receptor activation in astrocytes plays a central role in MCP-1 upregulation. In cultured astrocytes, activation of purinergic P2X7 receptors leads to the activation of the MAP kinases ERK1, ERK2, and p38. P2X7 receptor engagement also leads to an increase in the expression of the chemokine MCP-1, an effect mediated by MAP kinase cascades. These data show that transmitter receptors in astrocytes may mediate communication with hematopoietic inflammatory cells. |
