Long Non-coding RNA BACE1-AS May Serve as an Alzheimer's Disease Blood-Based Biomarker

Circulating long noncoding RNAs (lncRNAs) might serve as biomarkers for different pathological conditions. BACE1-AS lncRNA upregulates in the brain of people with Alzheimer's disease (AD) and might be detected in the bloodstream. To reveal if lncRNA BACE1-AS may serve as a blood-based biomarker for AD, we compared its levels in plasma and plasma-derived exosomes between AD (n = 45) and healthy people (n = 36). Exosomes were purified from plasma by Invitrogen (TM) Total Exosome Isolation Kit and characterized by scanning electron microscopy (SEM) and dynamic light scattering (DLS). Total RNA was extracted from whole plasma, and plasma-derived exosomes using TRIzol (R) LS or TRIzol (R) Reagents respectively were then reverse transcribed to the cDNA using PrimeScript II cDNA synthesis kit. The BACE1-AS levels were quantified by real-time PCR, and their biomarker potencies were evaluated using ROC curve analysis. Results obtained verified the presence of BACE1-AS in the plasma samples of both AD and healthy controls. We did not observe any significant differences between the levels of BACE1-AS in the plasma or plasma-derived exosomes of AD and control people. However, there were significant differences between AD subgroups and control in the whole plasma samples. The BACE1-AS level was low in pre-AD subgroup but it was high in full-AD people compared to the healthy controls. Moreover, ROC curve analysis revealed that lncRNA BACE1-AS may discriminate pre-AD and healthy control (75% sensitivity and 100% specificity), full-AD and healthy control (68% sensitivity and 100% specificity), and pre-AD and full-AD subgroups (78% sensitivity and 100% specificity), highlighting its potential as a biomarker for AD development. In conclusion, plasma BACE1-AS level may serve as a potent blood-based biomarker for Alzheimer's disease.