title: The enzymatic activity of sialidase Neu2 is inversely regulated during in vitro myoblast hypertrophy and atrophy.
abstract: Sialidase Neu2 is an exoglycosidase that removes terminal sialic acids from glycolipids and glycoproteins. In this study, we investigated Neu2 expression during muscle hypertrophy and atrophy. Neu2 mRNA and enzymatic activity were significantly increased in hypertrophic myofibers. A rise in Neu2 activity was observed after constitutive activation of AKT or Igf-1 treatment as well as in myoblasts treated with vasopressin or trichostatin, an inhibitor of histone deacetylases. In contrast, myofiber atrophy obtained by dexamethasone treatment or starvation triggered a significant loss of Neu2 activity and was paralleled by downregulation of Neu2 transcript levels. Overall, we may conclude that Neu2 enzymatic activity is causally linked to proper muscle differentiation and growth.
authors.affiliation: Department of Biomedical Sciences and Biotechnology, Unit of Biochemistry, University of Brescia, Viale Europa 11, 25123 Brescia, Italy. fanzani@med.unibs.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fanzani
authors.forename: Roberta
authors.initials: R
authors.lastname: Giuliani
authors.forename: Francesca
authors.initials: F
authors.lastname: Colombo
authors.forename: Stefania
authors.initials: S
authors.lastname: Rossi
authors.forename: Elena
authors.initials: E
authors.lastname: Stoppani
authors.forename: Wim
authors.initials: W
authors.lastname: Martinet
authors.forename: Augusto
authors.initials: A
authors.lastname: Preti
authors.forename: Sergio
authors.initials: S
authors.lastname: Marchesini
mesh_terms: D000818:Animals; D001284:Atrophy / Q000139:chemically induced; D002454:Cell Differentiation / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D006984:Hypertrophy; D024510:Muscle Development / Q000235:genetics; D018485:Muscle Fibers, Skeletal / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D032446:Myoblasts / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology*; D009439:Neuraminidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051381:Rats
chemical_list: D003907:Dexamethasone; C528920:Neu2 protein, rat; D009439:Neuraminidase