Folic Acid Is Able to Polarize the Inflammatory Response in LPS Activated Microglia by Regulating Multiple Signaling Pathways

Figure 7

Schematic representation of a probable signaling pathway of folic acid mediated modulation of inflammatory response in microglia cells. (a) LPS activated BV-2 cells increases the expression of proinflammatory cytokines by MAPK phosphorylation and NF-κB activation. The phosphorylation of IKK induces proteasomal degradation of IκB-α, enabling the active form of NF-κB to translocate into the nucleus and induce IL-1β, TNF-α, and iNOS expression. Alternatively, NF-κB is also activated by MAPK phosphorylation triggered by LPS treatment. (b) The folic acid pretreatment of LPS stimulated cells induces p38 MAPK phosphorylation leading to the upregulation of IL-10 production, selectively reduced in presence of p38 pharmacological inhibitor SB203580. IL-10 overproduction increases SOCS expression. Finally, SOCS proteins bind NF-κB and suppress its activation.

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