SKF83959 Inhibits Microglia Mediated Inflammation Via Allosterically Modulating Sigma-1 Receptors

Object: To investigate the effects of sigma-1 receptor allosteric modulator SKF83959 on microglia-mediated inflammatory response and its mechanism.Methods: We employed LPS-stimulated BV2 microglia to explore anti-inflammatory effect of SKF83959. Cell viability was measured by a colorimetric assay with MTT assay. The levels of NO and TNF-α in culture medium supernatants were measured by Griess and ELISA assay, respectively. Flow cytometry was used to detect the generation of intracellular ROS. TNF-α, IL-1β and iNOS mRNA levels were quantified by Quantitative real-time PCR(Q-PCR). i NOS, phosphorylation of mitogen-activated protein kinases(MAPKs)and IκB kinase/inhibitor of nuclear factor-κBα(IKK/ IκBα)protein expression levels were examined by Western Blot. SKF83959 impact on the binding activity of DHEA and sigma-1 receptor was evaluated by radioligand binding assay. Intracellular DHEA was quantified by ELISA assay. A microglia-conditioned media system was performed to study the neuroprotective effect of SKF83959.Results: SKF83959 displayed the anti-inflammatory effect in the LPS-activated BV2 microglia. BD1047 or BD1063 blocked the anti-inflammatory effects of SKF83959. SKF83959 promoted the binding of sigma-1 receptor with DHEA and ketoconazole abolished the anti-inflammatory effect of SKF83959. SKF83959 enha nced the anti-inflammatory effect of exogenous DHEA in a synergic manner. SKF83959 can ameliorate the microglial neurotoxicity to HT-22 neuroblastoma cells in a microglia-conditioned media system. We found that the MAPK/ERK or NFκB signaling pathways and D1 receptor activation is not involved in the anti-inflammatory effects of SKF83959.Conclusion: SKF83959 can inhibit the activation of BV2 microglia to ameliorate the inflammatory response and neurotoxicity via the modulation of sigma-1 receptor in an allosteric manner.