Chemokines direct neural progenitor cell migration following striatal cell loss

In this study we demonstrate the chemokines MCP-1, MIP-1alpha and GRO-alpha play a role in directing adult subventricular zone (SVZ)-derived progenitor cell migration following striatal cell death. MCP-1, MIP-1alpha and GRO-alpha were significantly upregulated in the striatum 2-3 days following QA-induced lesioning, correlating with maximum SVZ-derived progenitor cell recruitment into the lesioned striatum. We established that SVZ-derived progenitor cells express receptors for each chemokine, and demonstrated MCP-1, MIP-1alpha and GRO-alpha to be potent chemoattractants for SVZ-derived progenitor cells in vitro. Immunofluorescence revealed MCP-1, MIP-1alpha and GRO-alpha are predominantly expressed in the striatum by NG2-positive cells that appear to infiltrate from the bloodstream 6 h following QA lesioning. These results indicate that upregulation of MCP-1, MIP-1alpha and GRO-alpha following striatal cell death leads to chemoattraction of SVZ-derived progenitor cells into the damaged striatum and raises a potential role for blood-derived cells in directing the recruitment of SVZ-derived progenitors following brain injury.