Figure 7.

miR-124 mediates the cholinergic anti-inflammatory action through targeting STAT3 and TACE. Nicotine upregulates miR-124 expression through activating α7nAChR in LPS-stimulated macrophages. STAT3 is critical for IL-6 production in response to LPS. Its activation leads to increased transcription and production of IL-6, which in turn induces STAT3 phosphorylation via IL-6 receptor and further increases IL-6 transcription, forming a positive feedback loop. miR-124 targets STAT3, and decreases STAT3 and its phosphorylation, resulting in the reduction of IL-6 at the transcription level. In addition, miR-124 targets TACE to modulate TNF-α maturation.