[MicroRNA in neurodegenerative disorders].

MicroRNAs (miRNAs) bind to the 3'-untranslated region of mRNA, and thereby suppress the gene expression. Recent studies suggest that miRNAs modify the pathogenesis of cancer and neurodegeneration. Our study demonstrated that the expression levels of miR-196a is increased in a mouse model of spinal and bulbar muscular atrophy (SBMA), a neurodegenerative disease caused by the expansion of polyglutamine in androgen receptor (AR). In cultured neuronal cells, miR-196a decayed the mutant AR mRNA via silencing CUG triplet repeat RNA binding protein 2, a potent miR-196a targeting mRNA, which contributed to stabilize the mutant AR mRNA. Adeno-associated virus vector-mediated delivery of this miRNA attenuates the expression of the mutant AR, resulting in the mitigation of motor neuron degeneration in the SBMA mice. Introduction of miRNA appears to be a novel therapeutic strategy for devastating neurodegenerative diseases.