title: The key enzyme of the sialic acid metabolism is involved in embryoid body formation and expression of marker genes of germ layer formation.
abstract: The bi-functional enzyme UDP-N-acetyl-2-epimerase/N-acetylmannosamine kinase (GNE) is the key enzyme of the sialic acid biosynthesis. Sialic acids are negatively charged nine carbon amino sugars and are found on most glycoproteins and many glycolipids in terminal positions, where they are involved in a variety of biological important molecular interactions. Inactivation of the GNE by homologous recombination results in early embryonic lethality in mice. Here, we report that GNE-deficient embryonic stem cells express less differentiation markers compared to wild-type embryonic stem cells. As a result, GNE-deficient embryonic stem cells fail to form proper embryoid bodies (EB) within the first day of culture. However, when culturing these cells in the presence of sialic acids for three days, also GNE-deficient embryonic stem cells form normal EBs. In contrast, when culturing these cells in sialic acid reduced medium, GNE-deficient embryonic stem cells proliferate faster and form larger EBs without any change in the expression of markers of the germ layers.
authors.affiliation: Institut für Physiologische Chemie, Martin-Luther-Universität Halle-Wittenberg, Hollystr.1, Halle D-06114, Germany. ruediger.horstkorte@medizin.uni-halle.de.
authors.forename: Wenke
authors.initials: W
authors.lastname: Weidemann
authors.forename: Jessica
authors.initials: J
authors.lastname: Hering
authors.forename: Dorit
authors.initials: D
authors.lastname: Bennmann
authors.forename: Annett
authors.initials: A
authors.lastname: Thate
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Horstkorte
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D002478:Cells, Cultured; D058732:Embryoid Bodies / Q000378:metabolism*; D053595:Embryonic Stem Cells / Q000378:metabolism; D005855:Germ Layers / Q000378:metabolism*; D051379:Mice; D009097:Multienzyme Complexes / Q000172:deficiency / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D009097:Multienzyme Complexes; C482901:UDP-N-acetylglucosamine 2-epimerase - N-acetylmannosamine kinase; D019158:N-Acetylneuraminic Acid