Chang et al. reported that microglial inactivation by ketamine is at least partially due to the inhibition of ERK12 phosphorylation. Ryu et al. reported that thrombin induces NO release from cultured rat microglia via selleck chem Cabozantinib protein kinase C, mitogen activated protein kinase, and NF kappa B. Thus, we speculate that EMF exposure activates microglia through other signaling pathways. It has been demonstrated that activated microglia secrete a diverse range of pro inflammatory and neuro toxic factors such as superoxide, TNF a, interleukin 1b, IL 6 and NO. The cytokines IL 1b and TNF a, as mentioned above, may stimulate microglia to produce monocyte chemoattractant protein 1, macrophage in?ammatory protein 1a, and MIP 1b, which also may contribute to neuroinflammation.

After becoming activated by cytokines, microglia also release more cytokines into the extracellular space, thus forming an autocrine loop with positive feedback between microglial activation and cytokine production. This loop could explain the maintenance of microglial activation and the enhancement of pro inflammatory responses for 24 h after EMF exposure. Inhibitors,Modulators,Libraries Several reports have reported that STAT3 acts as a transcription factor in modulating cytokine induced pro and anti inflamma tory responses. Recently, Tanabe et al. reported that TNF a induces IL 6 synthesis through the JAKSTAT3 pathway in rat C6 glioma cells. Mir et al. indicated that the enhancing effect of TNF a Inhibitors,Modulators,Libraries on IFN g induced iNOSNO generation is dependent on the JAK STAT signaling pathway.

In this study, P6 was found to reduce CD11b expression, decrease the expres Inhibitors,Modulators,Libraries sion of TNF a and iNOS, and relieve the release of TNF a and NO at 12 h in EMF activated microglia. Our data suggest that a feedback loop may be formed to maintain the activation of microglia and extend the pro inflammatory responses through the JAK2 STAT3 path way. Based on these data, we hypothesize that after EMF exposure there might be some other signaling pathway that rapidly activates microglia. pro inflam matory factors secreted by activated microglia may activate the JAK Inhibitors,Modulators,Libraries STAT pathway. and the Inhibitors,Modulators,Libraries activated JAK STAT signaling pathway may further induce release of pro inflammatory factors and maintain the activation of microglia. We studied the effects of EMF exposure on cultured N9 microglial cells and demonstrate that an initial acti vation of microglia is induced by EMF exposure.

In addition, many other physical factors such as infrasound exposure, irradiation, heat shock treatment and hyperthermia, can stimulate activation and pro inflam matory reactions of microglia. The transmem brane signal transduction mechanisms of microglial activation in these physical environments this explanation remain poorly understood. Further investigations into these transmem brane signal transduction mechanisms may help to pro tect humans against electromagnetic radiation, ionizing radiation and other hazardous physical factors.