title: Sialylation and muscle performance: sialic acid is a marker of muscle ageing.
abstract: Sialic acids (Sia) are widely expressed as terminal monosaccharides on eukaryotic glycoconjugates. They are involved in many cellular functions, such as cell-cell interaction and signal recognition. The key enzyme of sialic acid biosynthesis is the bifunctional UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE), which catalyses the first two steps of Sia biosynthesis in the cytosol. In this study we analysed sialylation of muscles in wild type (C57Bl/6 GNE (+/+)) and heterozygous GNE-deficient (C57Bl/6 GNE (+/-)) mice. We measured a significantly lower performance in the initial weeks of a treadmill exercise in C57Bl/6 GNE (+/-) mice compared to wild type C57Bl/6 GNE (+/+) animals. Membrane bound Sia of C57Bl/6 GNE (+/-) mice were reduced by 33-53% at week 24 and by 12-15% at week 80 in comparison to C57Bl/6 GNE (+/+) mice. Interestingly, membrane bound Sia concentration increased with age of the mice by 16-46% in C57Bl/6 GNE (+/+), but by 87-207% in C57Bl/6 GNE (+/-). Furthermore we could identify specific morphological changes in aged muscles. Here we propose that increased Sia concentrations in muscles are a characteristic feature of ageing and could be used as a marker for age-related changes in muscle.
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Hanisch
authors.affiliation: Institute of Physiological Chemistry, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Wenke
authors.initials: W
authors.lastname: Weidemann
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Mona
authors.initials: M
authors.lastname: Großmann
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Pushpa Raj
authors.initials: PR
authors.lastname: Joshi
authors.affiliation: Institute of Pathology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Holzhausen
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany ; Institute of Cell and Neurobiology, Charité, Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Gisela
authors.initials: G
authors.lastname: Stoltenburg
authors.affiliation: Institute of Neuropathology, RWTH Aachen University and JARA Brain Translational Medicine, Aachen, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Weis
authors.affiliation: Department of Neurology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Zierz
authors.affiliation: Institute of Physiological Chemistry, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Horstkorte
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*
chemical_list: D019158:N-Acetylneuraminic Acid