MicroRNA machinery in Parkinson's disease: a platform for neurodegenerative diseases

MicroRNAs (miRNAs) are noncoding RNAs that recognize their protein-coding target genes and whereby subjugate them after transcription. Despite the infancy of this field of science, the role of miRNAs in neurodegeneration is well-acknowledged. This review was conducted to indicate that Parkinson's disease (PD) is not excluded from this rule. To this end, we evaluated the existing literature and arranged PD-associated miRNAs according to their mechanism of action, particularly apoptosis, autophagy, inflammation, mitochondrial dysfunction and oxidative stress. According to this arrangement, a majority of PD-associated miRNAs were indicated to influence autophagic/apoptotic pathways. We also categorized PD-associated miRNAs according to that they could exert detrimental or beneficial or both into three sets, activator, inhibitor, and double-edged, correspondingly. Considering this criterion, a majority of PD-associated miRNAs were included in the activator category. In addition, evidences from genetic association studies investigating genetic variants of or related to miRNAs in PD patients are presented. Finally, possible applications of the miRNA machinery in PD, including mechanistic networks, diagnostic, prognostic and therapeutic potentials, are discussed. But there may be additional miRNAs involved in the pathogenesis of PD which have hitherto remained unknown and thus further studies are needed to explore the issue and to extend this platform.