Diagnostic Performance of miR-485-3p in Patients with Parkinson's Disease and its Relationship with Neuroinflammation.

Parkinson's disease (PD) is one of the most common progressive neurodegenerative diseases. Some microRNAs (miRNAs) play critical roles in the development of many neurological diseases. This study aims to evaluate the clinical significance and biological function of miR-485-3p in the development and progression of PD. The expression of miR-485-3p in serum of PD patients was analyzed by quantitative real-time PCR (qRT-PCR). LPS-treated microglia BV2 cells were used to mimic neuroinflammation in the pathogenesis of PD. The levels of inflammatory cytokines, including IL-1β, IL-6 and TNF-α, were detected by enzyme-linked immunosorbent assay (ELISA). The diagnosis value of miR-485-3p was evaluated by plotting receiver operating characteristic (ROC) curves. A luciferase reporter assay was performed to demonstrate the interaction between miR-485-3p and FBXO45. The results showed that miR-485-3p was significantly up-regulated in serum of PD patients compared with that in both Alzheimer's disease (AD) and healthy cases, and had diagnostic accuracy for PD screening. The activated microglia BV2 cells induced by LPS also had elevated miR-485-3p, and the knockdown of miR-485-3p inhibited the release of pro-inflammatory cytokines. FBXO protein 45 (FBXO45) served as a potential target of miR-485-3p, which was speculated to mediate the function of miR-485-3p. Our results suggest that the up-regulated expression of miR-485-3p in PD may be a novel diagnostic biomarker for PD. Reducing the expression level of miR-485-3p can inhibit the inflammatory responses of BV2 cells, which indicated that miR-485-3p, as a regulator of neuroinflammation, may have the potential as a therapeutic target in PD.