Blood RNAs predictive of molecular changes in the brain and clinical outcome in Parkinson’s disease

The ability to use blood to predict the outcomes of Parkinson’s disease (PD), including disease progression and development of cognitive and motor complications, would be of enormous clinical value. We undertook deep RNA sequencing from the caudate and putamen of postmortem PD (n=35) and control (n=40) striatum, and compared molecular profiles with clinical features, and samples obtained from antemortem peripheral blood from an independent cohort. Cognitive and motor complications of PD were associated with molecular changes in the caudate (e.g., stress response) and putamen (endothelial pathways) respectively. Later and earlier-onset PD were molecularly distinct, and disease duration was associated with changes in caudate (oligodendrocyte development) and putamen (cellular senescence) respectively. Molecular signatures in the postmortem PD brain were also evident in antemortem peripheral blood, and correlated with clinical disease features. Together, these findings identify molecular signatures in PD patients' brain and blood of potential pathophysiologic and prognostic importance