Glycomics of Proteoglycan Biosynthesis in Murine Embryonic Stem Cell Differentiation
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- 作者：Alison V. Nairn ; Akiko Kinoshita-Toyoda ; Hidenao Toyoda ; Jin Xie ; Kyle Harris ; Stephen Dalton ; Michael Kulik ; J. Michael Pierce ; Toshihiko Toida ; Kelley W. Moremen ; Robert J. Linhardt
- 刊名：Journal of Proteome Research
- 出版年：2007
- 出版时间：November 2007
- 年：2007
- 卷：6
- 期：11
- 页码：4374 - 4387
- 全文大小：722K
- 年卷期：v.6,no.11(November 2007)
- ISSN：1535-3907
文摘
Glycosaminoglycans (GAGs) play a critical role in binding and activation of growth factors involved incell signaling critical for developmental biology. The biosynthetic pathways for GAGs have beenelucidated over the past decade and now analytical methodology makes it possible to determine GAGcomposition in as few as 10 million cells. A glycomics approach was used to examine GAG content,composition, and the level of transcripts encoding for GAG biosynthetic enzymes as murine embryonicstem cells (mESCs) differentiate to embryoid bodies (EBs) and to extraembryonic endodermal cells(ExE) to better understand the role of GAGs in stem cell differentiation. Hyaluronan synthesis wasenhanced by 13- and 24-fold, most likely due to increased expression of hyaluronan synthase-2.Chondroitin sulfate (CS)/dermatan sulfate (DS) synthesis was enhanced by 4- and 6-fold, and heparansulfate (HS) synthesis was enhanced by 5- and 8-fold following the transition from mESC to EB andExE. Transcripts associated with the synthesis of the early precursors were largely unaltered, suggestingother factors account for enhanced GAG synthesis. The composition of both CS/DS and HS also changedupon differentiation. Interestingly, CS type E and highly sulfated HS both increase as mESCs differentiateto EBs and ExE. Differentiation was also accompanied by enhanced 2-sulfation in both CS/DS and HSfamilies. Transcript levels for core proteins generally showed increases or remained constant uponmESC differentiation. Finally, transcripts encoding selected enzymes and isoforms, including GlcNAc-4,6-O-sulfotransferase, C5-epimerases, and 3-O-sulfotransferases involved in late GAG biosynthesis,were also enriched. These biosynthetic enzymes are particularly important in introducing GAG finestructure, essential for intercellular communication, cell adhesion, and outside-in signaling. Knowingthe changes in GAG fine structure should improve our understanding the biological properties ofdifferentiated stem cells.