title: Switching of the core structures of glycosphingolipids from globo- and lacto- to ganglio-series upon human embryonic stem cell differentiation.
abstract: A systematic survey of expression profiles of glycosphingolipids (GSLs) in two hESC lines and their differentiated embryoid body (EB) outgrowth with three germ layers was carried out using immunofluorescence, flow cytometry, and MALDI-MS and MS/MS analyses. In addition to the well-known hESC-specific markers stage-specific embryonic antigen 3 (SSEA-3) and SSEA-4, we identified several globosides and lacto-series GSLs, previously unrevealed in hESCs, including Gb(4)Cer, Lc(4)Cer, fucosyl Lc(4)Cer, Globo H, and disialyl Gb(5)Cer. During hESC differentiation into EBs, MS analysis revealed a clear-cut switch in the core structures of GSLs from globo- and lacto- to ganglio-series, which was not as evident by immunostaining with antibodies against SSEA-3 and SSEA-4, owing to their cross-reactivities with various glycosphingolipids. Such a switch was attributable to altered expression of key glycosyltransferases (GTs) in the biosynthetic pathways by the up-regulation of ganglio-series-related GTs with simultaneous down-regulation of globo- and lacto-series-related GTs. Thus, these results provide insights into the unique stage-specific transition and mechanism for alterations of GSL core structures during hESC differentiation. In addition, unique glycan structures uncovered by MS analyses may serve as surface markers for further delineation of hESCs and help identify of their functional roles not only in hESCs but also in cancers.
authors.affiliation: Genomics Research Center, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Yuh-Jin
authors.initials: YJ
authors.lastname: Liang
authors.forename: Huan-Hsien
authors.initials: HH
authors.lastname: Kuo
authors.forename: Chi-Hung
authors.initials: CH
authors.lastname: Lin
authors.forename: Yen-Ying
authors.initials: YY
authors.lastname: Chen
authors.forename: Bei-Chia
authors.initials: BC
authors.lastname: Yang
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Cheng
authors.forename: Alice L
authors.initials: AL
authors.lastname: Yu
authors.forename: Kay-Hooi
authors.initials: KH
authors.lastname: Khoo
authors.forename: John
authors.initials: J
authors.lastname: Yu
mesh_terms: D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D015536:Down-Regulation; D058732:Embryoid Bodies / Q000166:cytology / Q000378:metabolism*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005732:Gangliosides / Q000378:metabolism; D005915:Globosides / Q000378:metabolism; D006028:Glycosphingolipids / Q000378:metabolism*; D006801:Humans; D007790:Lactosylceramides / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055746:Stage-Specific Embryonic Antigens / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D005732:Gangliosides; C472765:Globo-H; D005915:Globosides; D006028:Glycosphingolipids; D007790:Lactosylceramides; D055746:Stage-Specific Embryonic Antigens; C052924:stage-specific embryonic antigen-3; C066584:stage-specific embryonic antigen-4