To investigate the use of microRNA-7-5p (miR-7-5p) as a potential biomarker for Parkinson's disease (PD) progression.
Data was obtained at two longitudinal points (Baseline and 36 months) from 315 (208 male/107 female) drug-naïve PD patients and 160 (108 male /52 female) age- and sex-matched healthy controls (HC) from the Parkinson's Progression Marker Initiative (PPMI). Whole blood miR-7-5p was longitudinally correlated with a) clinical assessment tools (MDS-UPDRS motor and total scores), b) markers of inflammation (NLRP3 mRNA, IL-1β mRNA, and NfL), and c) α-syn expression (α-syn mRNA, CSF α-syn). Analyses were done using rmcorr in R.
MiR-7-5p levels decreased by 17% in PD patients over 36 months. Longitudinal, Ln miR-7-5p had a strong negative correlation with MDS-UPDRS-motor and total scores in men with PD and with NfL for all PD subjects. There was no correlation between miR-7-5p and CSF α-syn protein in either group.
Our data demonstrate the importance of gender differences in biomarker discovery and suggest a robust association between lower levels of miR-7-5p and markers of clinical progression in men with PD. These findings support the use of miR-7-5p as a progression biomarker, which could lead to a quantifiable tool for disease-modifying therapies.