BACE1-AS prevents BACE1 mRNA degradation through the sequestration of BACE1-targeting miRNAs.

Abnormal long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) participate in the pathophysiology of Alzheimer's disease (AD). However, it remains unclear whether these two types of noncoding RNAs functionally interact and which factors mediate these interactions in AD. β-secretase 1 (BACE1) is the enzyme responsible for amyloid plaque formation, which is a central pathological feature of AD. The lncRNA BACE1-AS and some miRNAs have been implicated in the regulation of BACE1. In this study, we reveal that BACE1-AS shares many miRNA-response elements with BACE1. The overexpression of BACE1-AS results in the repression of miRNAs that target BACE1, thus preventing BACE1 mRNA from being degraded. The knockdown of BACE1-AS increases the levels of these miRNAs, thereby reducing the expression of BACE1. Thus, BACE1-AS functions as a competing endogenous RNA (ceRNA). Our results also deepen the understanding of the regulation of BACE1 by BACE1-AS. In addition to increasing the stability of BACE1 mRNA through the formation of RNA duplexes, BACE1-AS can regulate BACE1 indirectly by acting as a ceRNA. Therefore, we propose that BACE1 functions as a ceRNA and forms a network through its associations with protein-coding genes, lncRNAs and miRNAs in the pathophysiology of AD.