The Soluble Interleukin-6 Receptor Governs IL-6 Signaling In Rat Hippocampal Neuron

We focused our research on the roles of interlerkin-6 membrance-bond form and soluble form receptors in the IL-6 signaling of newborn rat hippocampal neuron.Firstly, we cultured the rat hippocampal neurons in Neurobasal serum-free medium containing 2% B27 supplement. The neurons showed good growth in Neurobasal + B27 medium. Neurons are then identified with the fluorescently labeled antibody raised againstβ-tubulin, and astrocytes with the fluorenscently tagged antibody against the astrocyte-specific protein GFAP.Secondly, using the Confocal Scanning Microscope, we found that the neurons cultured in Neurobasal medium are full of the membrance-bound IL-6 receptor. Our result conflict with the hypothesis that the reason of neurons could not response to IL-6 simulation is lacking of membrance-bound IL-6 receptors. In order to find out which form of IL-6 receptor determines neural IL-6 signaling, we treated the cultured neurons with medium starvation.Based on Western Blotting, we found that the neurons treated with starvation could not response to IL-6 efficiently. Compared with starved neurons, the neurons cultured with full culture medium could be strongly stimulated by cytokine IL-6. Integrated the experimental data, we concluded that it is the soluble form of IL-6 receptor, but not membrance-bound form of IL-6 receptor, that mediates the IL-6 signaling in newborn rat hippocampal neuron. The function of membrance-bound IL-6 receptor in neuron is unknown.