Signalling pathways involved in the chemotactic activity of CXCL12 in cultured rat cerebellar neurons and CHP100 neuroepithelioma cells

We compared the signal transduction pathways activated by stromal cell-derived factor-1 (CXCL12) chemokine in two different cell systems: primary cultures of rat cerebellar granule neurons (CGN) and human neuroepithelioma CHP100 cells. Both cell types express functional CXC chemokine receptor 4 (CXCR4), which is coupled both to extracellular signal-regulated kinase (ERK) and Akt phosphorylation pathways. The activation of ERK shows different dependency on the phosphatidylinositol 3-kinase (PI3-K) pathway and different sensitivity to pertussis toxin (PTX) treatment, indicative of coupling to different G proteins in the two cell systems considered. We demonstrate that the inhibition of either the ERK kinase or the PI3-K pathways blocks the CXCL12 induced-chemotaxis in CHP100 cells; while only PI3-K activity is stringently necessary for CGN migration.