Figure 3. The proposed mechanisms of induction of miR-124 expression in microglia and macrophages interacting with neuronal cells.
Increased expression of miR-124 in macrophages in the CNS is influenced by many factors of paracrine interactions between neuronal cells and microglia/macrophages: cell-cell contacts such as CD200-CD200R or CX3CR1-CX3CL, the presence of soluble factors secreted by neurons such as soluble form of CX3CL1 and TGF-β, and direct transfer of miR-124 from miR-124+ neuronal cells into macrophages through exosomal shuttle vesicles.