Figure 4.

IL-6 and NGF induce cap-dependent translation of nascent proteins in primary sensory neurons by activating ERK and mTOR pathways. A, A schematic diagram illustrating the experimental procedure. B, DRG neurons pretreated with rapamycin (500 nm, Rap), U0126 (10 μm), and anisomycin (50 μm, Anis) for 30 min followed by treatment with vehicle, IL-6 (50 ng/ml), and/or NGF (10 ng/ml) with and without inhibitors for 30 min. Fluorescence units were reported as percentage of vehicle. Treatment with IL-6 and/or NGF increases the incorporation of AHA, indicative of increased nascent protein synthesis, and this effect was inhibited by mTOR (rapamycin), MEK (U0126), and general protein synthesis (anisomycin) inhibitors. C, Western blot and quantification of primary sensory neurons in culture pretreated with vehicle or the inhibitor of eIF4F complex formation, 4EGI1 (20 μm), for 30 min followed by treatment with vehicle or IL-6 (50 ng/ml) and NGF (10 ng/ml) in AHA-containing media 30 min. *p < 0.05, ***p < 0.001.