Glycomic Signature of Mouse Embryonic Stem Cells During Differentiation

Research Article

Rania Harfouche

Abstract

Background: The glycome has emerged as a key regulator of cell fate, partly through its ability to potentiate the action of numerous signaling pathways. We recently demonstrated that a sulfated component of the glycome plays a critical role in promoting the differentiation of embryonic stem cell (ESC)-derived embryoid bodies by modulating downstream growth factors, such as the insulin-like growth factor (IGF) signaling axis. However, the exact components of the glycome which promote ESC differentiation versus stemness remain uncharacterized, due to the lack of a rapid, simple and easily quantifiable methodology. As a proof-of-concept in this study, we utilized a custom-made glycoarray in combination with bioinformatics and molecular biology tools in order to uncover novel glyco-signatures underlying ESC differention in an embryoid body model. A better elucidation of the glycomic transcriptomal signature underlying ESC differentiation would allow us to better manipulate these cells towards a desired lineage. Method: We used a custom-designed Affymetrix microarray, the Glycogene-chip, to screen the transcriptome of differentiating embryoid bodies versus that of undifferentiated ESC. In conjunction with gene ontology, pathway analyses, real-time PCR and immunoblotting, we validated the involvement of the IGF family, and furthermore, uncovered novel differentially regulated genes belonging to the glycoprotein (Angiopoietin-1 and Angiopoietin-like members), sulfotransferase, sulfatase and glycosyltransferase families. Conclusion: These results suggest that the Glycogene-chip, in conjunction with the embryoid body model, provides a fast and reliable tool to uncover novel glycomic signatures that are critical to maitain ESC stemness versus differentiation. In turn, this will allow us to understand the mechanisms governing ESC fate, bringing us one step closer towards finding a new paradigm for the regenerative medicine field.

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