Figure 5.

SDF-1 induces phosphorylation and translocation of CREB into the nucleus. E6 retinal neurons were cultured in defined minimal medium for 24 hr (A1–A3) and then exposed to 100 ng/ml SDF-1 (B1–B3), SDF-1 plus a 20 μm concentration of the CXCR4 antagonist AMD3100 (C1–C3), SDF-1 plus 100 ng/ml PTX (D1–D3), SDF-1 plus a 200 nm concentration of the PKA inhibitor PKI (E1–E3), or SDF-1 plus a 20 μm concentration of MAP kinase inhibitor PD98059 (F1–F3). After 30 min, the cultures were fixed and stained for islet-1 (A1–F1) (green) and phosphorylated CREB (A2–F2) (red). Merged images are shown in A3–F3. SDF-1 induces translocation of phosphorylated CREB into the nuclei of retinal neurons that is blocked by all three pharmacological agents.