Figure 2.

a, Conditioned media from human brain endothelial cells (Endo-CM) increased phospho-Akt levels in recipient OPCs. b, Blockade of Akt signaling with the PI3-kinase inhibitor LY294002 prevented Akt from being phosphorylated in OPCs exposed to endothelial-conditioned media (Endo-CM). c, LY294002 blocked the ability of Endo-CM to amplify OPC proliferation. d, e, The Src tyrosine kinase inhibitor PP2 reduces Akt phosphorylation in OPCs exposed to cerebral endothelial-conditioned media. No effects were seen with the inactive drug PP3. f, Correspondingly, PP2 decreases the OPC-proliferative properties of endothelial-conditioned media, and the inactive drug PP3 had no effect. *p < 0.05.