MicroRNA: novel modulators of the cholinergic anti-inflammatory pathway.

MicroRNAs (miRNAs) have emerged as key gene regulators controlling the expression of many target mRNAs. The nervous system harbors highest number of miRNAs expressed in a spatially and temporally controlled manner. Neural miRNAs have been accredited with diverse roles like regulation of neural differentiation, synaptogenesis, inflammation, memory and cognition. Their aberrant expression and/or function has been linked to various neurodegenerative, neuroinflammatory and stress related disorders. Recent evidence indicates that miRNAs are essential to the fine tuning of the immune responses. Besides controlling the maturation, proliferation and differentiation of myeloid and lymphoid lineages they participate directly by modulating the signaling pathways through the Toll-like receptors and thus the cytokine response. The miRNAs commuting between the nervous and immune systems and affecting the neuro-immune dialogue are emerging.