Cell-type specific identification by different glycan features in neuroinflammation
The central nervous system (CNS) has specialised and diverse cell populations. Identifying cell-specific molecular signatures may reveal more comprehensive information about neurological pathways and CNS complexity. Glycosylation is the most common functional post-translation modification (PTM) in the brain and identifying cell-type dependent glycan features helps provide a better understanding of their role in brain cell intercellular interactions. In this study, we identified plasma membrane glycan features of three mammalian brain cell lines; BV2 (microglia), U87-MG (astrocytes) and differentiated SH-SY5Y (neurons) under lipopolysaccharide (LPS) stimulated inflammation. A panel of 9 lectins used here for histochemistry and fluorescence microscopy helps visually identify distinct cell-specific glycan features followed by quantification by FLD-HPLC and PGC-LC-MS/MS for released glycosaminoglycan disaccharides and N-glycans. Our results revealed cell type specific glycan expression, with cell selective binding of Sambucus nigra agglutinin (SNA) and Wisteria floribunda agglutinin (WFA) lectins. SNA lectin binding and LC-MS/MS revealed the absence of α-2,6 linked sialic acid glycans on U87-MG cells. BV2 microglia showed a significant decrease in the glycosaminoglycan, heparan sulphate over time under LPS inflammatory conditions. In summary, this study advances our knowledge of the complexity of brain cell glycan feature expression in a cell type specific and inflammation driven context.