In this proposal, we examined samples from living neurologically normal individuals (n=72), cognitively normal Parkinson's disease (PD; n=21), PD with mild cognitive impairment (PD-MCI; n=18), PD with dementia (PDD; n=23), and dementia with Lewy-bodies (DLB; n=18), Alzheimer’s disease (AD; n=33) and mild cognitive impairment (MCI, n=38). The main goal for this study was to assess the diagnostic utility of small RNA contents from extracellular vesicles (EVs) for the prediction of cognitive decline. Plasma samples were collected and the RNA from extracellular vesicles (EVs) was isolated using the Qiagen exoRNeasy kit, and the small RNA contents were sequenced using the PerkinElmer NextFlex kit (v2). While PD is typically thought of as a motor disorder, there are significant non-motor symptoms that can be devastating. One of the most common non-motor symptoms of PD is dementia (PDD). While PD subjects that develop dementia all have Lewy bodies, there is often co-pathology with tau and β-amyloid found at autopsy or by PET amyloid imaging; thus, subjects diagnosed with AD were also included in the study. The development of the category, mild cognitive impairment (MCI) in AD, and in PD, provides an opportunity to identify and examine a transitional state between normal aging and dementia; this is a patient population ideally suited for therapeutic intervention. Progress in the detection, validation, and standardization of molecular biomarkers from biofluids, such as extracellular RNAs (exRNAs), would be efficient and cost-effective aids in the assessment of disease progression, cognitive decline, and response to therapeutics. We have provided the raw fastq files for the sequencing data from each sample. We are also providing demographic information, as complete as we have for each person; including age, diagnosis, sex, and cognitive assessments.

Small RNA Contents of Extracellular Vesicles from Patients with Cognitive    Decline

Neurodegenerative Diseases study with RNA-Seq data on dbGaP (223 participants)