Meta-microRNAs as potential noninvasive markers for early diagnosis of Alzheimer’s disease

Introduction The aim of this study was to investigate the potential role of a microRNA panel as early diagnostic markers for Alzheimer’s disease (AD). Methods The differentially expressed serum microRNAs were screened with microarray among cognitively normal controls (CNC), mild cognitive impairment (MCI), and AD. QRT-PCR assay was applied to evaluate differentially expressed microRNAs with two independent cohorts including 202 participants. Logistic regression model based on microRNA panel was constructed using a training cohort and then validated using an independent cohort. Results First, four differentially expressed serum microRNAs (let-7g, miR-197, miR-126 and miR-29a) were found, which expressions were positively correlated with mini mental state examination (MMSE) score. Second, a microRNA panel with the four microRNAs demonstrated good diagnostic performance for MCI and AD with 84% and 92% accuracy. Third, when combined with MMSE score, the diagnostic performance of the microRNA panel was further improved. Discussion Blood microRNAs are potential AD biomarkers that may lead to new diagnostic strategies.