Synapse‐enriched miRNA expression in Alzheimer’s disease cortex tissue

Background Synapse degeneration is one of the earliest changes in Alzheimer’s disease (AD) and is the major neuropathologic correlate of cognitive impairment. The aim of this study was to characterize microRNA (miRNA) dysregulation at AD synapses post‐mortem brain tissue and explore the specificity for AD. Method We prepared synaptosomes (SYN) by serial ultracentrifugation of 10 AD (mean age = 77.4±13.3) and 10 control (CN; mean age = 72.3±18.8) temporal cortex samples over a sucrose gradient and saved the homogenates (H). We extracted and quantified miRNA from SYN and H fractions by TaqMan Advanced miRNA Assay‐Openarray system. We calculated deltaCt and performed linear regression to identify differentially expressed (DE) miRNA across AD and CN SYN, adjusting for multiple testing using Benjamini‐Hochberg method (α