IL-6 induces CREB synthesis in vitro and in vivo. A) Western blot and quantification of CREB following 15 min treatment of DRG cultures with escalating concentrations of IL-6. N = 8 independent culture wells per condition. B) Western blot and quantification of CREB in the ipsilateral sciatic nerve following intraplantar (IPL) injection of IL-6 (0.1 ng) or vehicle. CREB protein is enhanced in the sciatic nerve 2 hrs post-injection but not at 15 min following treatment. N = 6 mice per condition. C) Western blot and quantification for nascently synthesized CREB retrogradely transported to the sciatic nerve. Retrograde axonal trafficking of nascently synthesized CREB was determined by co-injecting IL-6 (0.1 ng) or vehicle with the methionine analogue AHA into the paw and measuring, from the sciatic nerve, the amount of CREB with incorporated AHA, 2 hrs post injection. The input lane contains lysate from sciatic nerve that did not undergo immunoprecipitation and is labeled with biotin-avidin on incorporated AHA. N = 6 mice per condition. * = p < 0.05 and ** = p < 0.01.