title: Extracellular o-linked N-acetylglucosamine is enriched in stem cells derived from human umbilical cord blood.
abstract: Stem cells have a unique ability to self-renew and differentiate into diverse cell types. Currently, stem cells from various sources are being explored as a promising new treatment for a variety of human diseases. A diverse set of functional and phenotypical markers are used in the characterization of specific therapeutic stem cell populations. The glycans on the stem cell surface respond rapidly to alterations in cellular state and signaling and are therefore ideal for identifying even minor changes in cell populations. Many stem cell markers are based on cell surface glycan epitopes including the widely used markers SSEA-3, SSEA-4, Tra 1-60, and Tra 1-81. We have now discovered by mRNA analysis that a novel glycosyltranferase, epidermal growth factor (EGF) domain-specific O-linked GlcNAc transferase (EOGT), is highly expressed in stem cells. EOGT is responsible for adding O-linked N-acetylglucosamine (O-GlcNAc) to folded EGF domains on extracellular proteins, such as those on the Notch receptors. We were able to show by immunological assays that human umbilical cord blood-derived mesenchymal stromal cells display O-GlcNAc, the product of EOGT, and that O-GlcNAc is further elongated with galactose to form O-linked N-acetyllactosamine. We suggest that these novel glycans are involved in the fine tuning of Notch receptor signaling pathways in stem cells.
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Heli
authors.initials: H
authors.lastname: Suila
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Tia
authors.initials: T
authors.lastname: Hirvonen
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Ilja
authors.initials: I
authors.lastname: Ritamo
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Suvi
authors.initials: S
authors.lastname: Natunen
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Jarno
authors.initials: J
authors.lastname: Tuimala
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Saara
authors.initials: S
authors.lastname: Laitinen
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Heidi
authors.initials: H
authors.lastname: Anderson
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Johanna
authors.initials: J
authors.lastname: Nystedt
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Jarkko
authors.initials: J
authors.lastname: Räbinä
authors.affiliation: Finnish Red Cross Blood Service , Helsinki, Finland .
authors.forename: Leena
authors.initials: L
authors.lastname: Valmu
keywords: biomarkers; cellular biology; stem cells