Oxidative stress contributes to the pathogenesis of
neurodegenerative diseases. With the aim to find
reagents that reduce oxidative stress, a phage display library was screened for
peptides mimicking α2,6-sialyllactose (6'-SL), which is known to beneficially influence neural functions. Using Sambucus nigra
lectin, which specifically binds to 6'-SL, we screened a phage display library and found a
peptide comprising identical sequences of 12
amino acids. Mimetic
peptide, reverse
peptide and scrambled
peptide were tested for inhibition of 6'-SL binding to the
lectin. Indeed,
lectin binding to 6'-SL was inhibited by the most frequently identified mimetic
peptide, but not by the reverse or scrambled
peptides, showing that this
peptide mimics 6'-SL. Functionally, mimetic
peptide, but not the reverse or scrambled
peptides, increased viability and expression of
neural cell adhesion molecule L1 in SK-N-SH human
neuroblastoma cells, and promoted survival and neurite outgrowth of cultured mouse cerebellar granule neurons challenged by H2O2-induced oxidative stress. The combined results indicate that the 6'-SL mimetic
peptide promotes neuronal survival and neuritogenesis, thus raising hopes for the treatment of
neurodegenerative diseases. This study was approved by the Medical Ethics Committee of Shantou University Medical College, China (approval No. SUMC 2014-004) on February 20, 2014.