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.
MATERIALS 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-mannose type N-glycans and terminal alpha2,3-sialylation was increased in CD133+ cells. Elevated alpha2,3-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.