Alterations of the microRNA network cause neurodegenerative disease.

Brain development crucially depends on the integrity of microRNA (miRNA) pathways, which function at the post-transcriptional level as a rheostat of the transcriptome and proteome of the cell. miRNAs are also involved in many other, more specific, aspects of neuronal function such as neurite outgrowth and synapse formation. Complete loss of miRNA expression in the brain leads to neurodegeneration in several animal models. Evidence from patient material is emerging that miRNA dysregulation could, indeed, contribute to neurodegenerative disorders. The translation of proteins previously implicated in familial forms of disease seems to be under control of miRNAs, and changes in miRNAs might explain how these proteins become affected in sporadic neurodegenerative disease. Thus, miRNAs are moving rapidly center stage as key regulators of neuronal development and function in addition to important contributors to neurodegenerative disorder.