N-glycan structures and associated gene expression reflect the characteristic N-glycosylation pattern of human hematopoietic stem and progenitor cells

Objective. Cell surface glycans contribute to the adhesion capacity of cells and are essential in cellular signal transduction. Yet, the glycosylation of hematopoietic stem and progenitor cells (HSPC), such as CD133(+) cells, is poorly explored. Matetials and Methods. N-glycan structures of cord blood-derived CD133(+) and CD133(-) cells were analyzed with mass spectrometric profiling and exoglycosidase digestion, cell surface glycan epitopes with lectin binding assay, and expression of N-glycan biosynthesis-related genes with microarray analysis. Results. Over 10% difference was demonstrated in the N-glycan profiles of CD133(+) and CD133(-) cells. Biantennary complex-type N-glycans were enriched in CD133(+) cells. Of the genes regulating the synthesis of these structures, CD133(+) cells overexpressed MGAT2 and underexpressed MGAT4. Moreover, the amount of high-marmose type N-glycans and terminal oE2,3-sialylation was increased in CD133(+) cells. Elevated alpha 2,3-sialylation was supported by the overexpression of ST3GAL6. Conclusion. Our work presents new information on the characters of HSPCs. The new knowledge of HSPC-specific N-glycosylation advances their identification and provides tools to promote HSPC homing and mobilization or targeting to specific tissues. (c) 2007 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.