A novel brain-derived neurotrophic factor-modulating peptide attenuates Aβ1-42-induced neurotoxicity in vitro

Abstract

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, which plays important roles in learning and memory formation and in protecting neurons from diverse neurotoxic insults, such as amyloid-beta (Aβ). Since BDNF expression is decreased in patients with Alzheimer’s disease, various strategies have attempted to increase BDNF levels. In a previous study, we screened and identified a novel BDNF-modulating peptide (consisting of methionine–valine–glycine, named Neuropep-1) by a positional scanning–synthetic peptide combinatorial library (PS–SPCL). Neuropep-1 exhibited neuroprotective effects against in vitro and in vivo Alzheimer’s disease models. Based on the previous PS–SPCL data, we modified the amino acid sequence of Neuropep-1 in this study to identify a more potent novel BDNF-modulating peptide. By replacing the valine in the second position with aspartic acid, the resulting Neuropep-4 was found to be highly effective in inducing BDNF expression even at concentrations of 1pM in the SH–SY5Y cell line and rat primary cortical neurons. In addition, among the tested peptides, Neuropep-4 provided neurons with the strongest protection against oligomeric and/or fibrillar Aβ1-42-induced cell death through BDNF upregulation. These results suggest the potential of Neuropep-4 as a therapeutic candidate for treating neurodegenerative diseases, such as AD.