Plasma miR-153 and miR-223 Levels as Potential Biomarkers in Parkinson’s Disease

BACKGROUND: Small molecule RNAs (miRNAs) could induce downregulation of α-synuclein (SNCA) expression by binding the 3’ untranslated region of SNCA, thus playing an important role in the pathogenesis of Parkinson’s disease (PD). Recent studies suggest that SNCA-related miRNAs in saliva are promising PD biomarkers. Research on those miRNAs in plasma is rare in patients with PD. OBJECTIVE: To detect the plasma expression levels of three SNCA related miRNAs (miR-7, miR-153, and miR-223) in PD, and to explore their diagnostic value and associations with clinical phenotype. METHODS: MiR-7, miR-153, and miR-223 levels were detected in the plasma of 75 PD patients and 73 normal controls (NCs) via real-time quantitative polymerase chain reaction. The receiver operating characteristic (ROC) curves were delineated to evaluate their diagnostic value in PD. In addition, their associations with demographic, key motor, and non-motor symptoms were explored by serial scales. RESULTS: The expression levels of plasma miR-153 and miR-223 were significantly decreased in patients with PD relative to NCs. The area under the ROC curve separating PD from NCs was 63.1% for miR-153 and 86.2% for miR-223, respectively. The plasma miR-153 level in de novo PD was lower than that in treated patients (p = 0.006), its level increased gradually with disease duration (r = 0.358, p = 0.002) and Unified Parkinson’s Disease Rating Scale Part III score (r = 0.264, p = 0.022). Plasma miR-223 level was decreased in patients with clinical possible rapid eye movement sleep behavior disorder (cpRBD) compared with those without cpRBD (p < 0.001), and its level was negatively associated with RBDSQ score (r = -0.334, p = 0.003). Multiple linear regression analysis revealed that disease duration (p = 0.049) was the independently associated factor of miR-153 level; whereas, RBDSQ (p = 0.009) was related to miR-223 level in PD. CONCLUSION: Plasma miR-153 and miR-223 levels could be potential biomarkers of PD.