miRNA expression profile from Adipocyte-derived Small Extracellular Vesicles from the Serum and cerebrospinal fluid of Alzheimer Disease Patients and Controls

Midlife obesity increases the risk of developing AD. Adipocyte-derived small extracellular vesicles (ad-sEVs) have been implicated as a mecha-nism in several obesity-related diseases. We hypothesized that ad-sEVs from patients with AD would contain miRNAs predicted to downregulate pathways involved in synaptic plasticity and memory formation. We isolated ad-sEVs from the serum and cerebrospinal fluid (CSF) of patients with AD and controls and compared miRNA expression profiles Ad-sEV miRNA was isolated from the serum (n=12 controls, n=17 AD) and cerebrospinal fluid (n=10 controls, n=14 AD). Total RNA was extracted using mirVana microRNA Isolation kits (Life Technologies). Total RNA was amplified with the Complete Seramir Exosome RNA Amplification Kit (System Biosciences, Mountainview, CA). RNA quality was assessed on a subset of these samples using the Agilent 2100 Bioanalyzer and nanodrop. RNA concentration was measured using a Qubit RNA Broad Range Assay Kit (Thermo Fisher Scientific, Waltham, MA). 1,000 ng of RNA was labeled with Affymetrix FlashTag Biotin HSR RNA Labeling Kit (Affymetrix, Santa Clara, CA) per the manufacturer’s instructions. Labeled RNA was hybridized to Affymetrix GeneChip microRNA 4.0 arrays. Chips were run using a Fluidics Station 450 Protocol (Affymetrix, Santa Clara, CA). The results were exported to Partek Genomics Suite for analysis.