MiR-16 attenuates β-amyloid-induced neurotoxicity through targeting β-site amyloid precursor protein-cleaving enzyme 1 in an Alzheimer’s disease cell model

Abstract

The aberrant deposition of β-amyloid (Aβ) is closely linked to the pathogenesis and development of Alzheimer's disease (AD). MiR-16 was abnormally downregulated and may be related to the development of AD. However, the functional role and molecular mechanism of miR-16 in AD pathogenesis are still not well elucidated. The expressions of miR-16 and β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) mRNA and protein levels in AD brain tissues and Aβ-treated PC12 cellular AD model were examined by qRT-PCR and western blot analyses. Luciferase reporter assay was used to verify the potential target of miR-16. The cell viability, apoptosis, and caspase-3 activity in PC12 cells were determined by the MTT assay, flow cytometry analysis, and caspase-3 activity assay, respectively. Downregulation of miR-16 and upregulation of BACE1 existed in AD tissues and the cellular AD model of PC12. In addition, miR-16 directly suppressed BACE1 expression. Moreover, miR-16 overexpression and BACE1 knockdown facilitated Aβ-induced cell toxicity, apoptosis, and caspase-3 activity in N2a cells, which was partially eliminated by overexpression of BACE1. In contrast, BACE1 knockdown reversed the miR-16 inhibition-mediated inhibitory effect on Aβ-induced cell toxicity, apoptosis, and caspase-3 activity in PC12 cells. Collectively, miR-16 attenuated Aβ-induced neurotoxicity through targeting BACE1 in an Aβ insult cellular AD model, providing a potential therapeutic target for AD treatment.