MicroRNA biomarkers of Parkinson's disease in serum exosome-like microvesicles.

Parkinson's disease (PD) is a progressive age-related debilitating motor disorder and the second most common neurodegenerative disease after Alzheimer's disease. In this study, we aimed to investigate the expression of 24 candidate miRNAs in PD and to assess their diagnostic value in patients with PD. We collected serum samples from 109 patients with PD and 40 age- and sex-matched healthy volunteers (control group). RNAs encapsulated in exosome-like microvesicles in serum were extracted and reverse transcribed. Serum miRNAs were analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and the ability of the miRNAs to accurately discriminate PD was analyzed by receiver operating characteristic curves. Based on our analysis, we further validated the downregulation of miR-19b and the upregulation of miR-195 and miR-24 in patients with PD. When compared with the control group, the area under the curve (AUC) values for miR-19b, miR-24, and miR-195 were 0.753, 0.908, and 0.697, respectively. Therefore, analysis of the expression levels of miR-19b, miR-24, and miR-195 in serum may be useful for the diagnosis of PD.