ABCA1-Labeled Exosomes in Serum Contain Higher MicroRNA-193b Levels in Alzheimer’s Disease

Objective. We aimed to establish a method to determine whether microRNA-193b (miR-193b) levels in ABCA1-labeled serum exosomes might serve as a marker for the diagnosis of Alzheimer’s disease. Methods. We used immunocapture methods to determine the levels of ABCA1-labeled exosomal miR-193b in cultures of white blood cells (WBCs), red blood cells (RBCs), mouse hippocampal neuron HT-22 cells, and primary mouse neuronal cells. ABCA1-labeled exosomal miR-193b levels were also evaluated in the cerebrospinal fluid (CSF) and serum of APP/PS1 double-transgenic mice, as well as control subjects (n=60) and study participants with subjective cognitive decline (SCD, n=89), stage and mild cognitive impairment (MCI, n=92), and dementia of the Alzheimer type (DAT, n=92). Results. ABCA1 levels of exosomes harvested from the medium of HT-22 cells and neurons were significantly higher than those of RBCs and WBCs (P