Overexpression of amyloid beta precursor protein enhances expression and secretion of ST6Gal1 in C2C12 myogenic cell line

Abstract

The Abeta (amyloid-beta) peptide is derived from the sequential cleavage of AbetaPP (amyloid-beta precursor protein) by two enzymes, the β- and γ-secretases. The major β-secretase, identified as the novel transmembrane aspartic protease BACE1 (beta site APP-cleaving enzyme 1), mediates the primary amyloidogenic cleavage of AbetaPP and initiates the production of Abeta. It has been implicated in the proteolytic processing of another substrate, namely ST6Gal1 (β galactoside α2,6-sialyltransferase 1), which is the major α2,6-sialyltransferase responsible for the broad synthesis of glycoproteins and glycolipids. The present study investigated the effect of overexpression of AbetaPP on expression and secretion of ST6Gal1 in skeletal muscle cells by inducing overexpression of wild-type full-length 751-AbetaPP in the mouse myogenic cell line C2C12. Expression and secretion of the ST6Gal1 enzyme were analysed by Western blot and/or immunofluorescence staining. The results of our study demonstrated that AbetaPP overexpression in C2C12 cells increased the expression and the secretion of ST6Gal1 enzyme in vitro.