Figure 4.

Effects of ManNAc and its derivatives on the metabolome. (A-C) Metabolome analyses of hiPSCs, non-orexigenic cells, and hiONs. Undifferentiated hiPSCs, intermediate neural cells (on day 14), and neural cells (on day 20) treated with or without ManNAc or potent (ManNFAc) or less-potent (Me-α-ManNAc) derivatives were subjected to a metabolome analysis by LC-MS. The values of the metabolites are presented in a heatmap showing hiPSCs, non-orexin neural cells (days 14 and 20), and ManNAc-, ManNFAc-, and Me-α-ManNAc-treated cells (A). The metabolites, which are significantly changed in ManNAc-, ManNFAc- and Me-α-ManNAc-treated cells compared with in non-treated cells, are listed in the right of heatmap (Welch's t-test). Levels of metabolites related to the nicotinamide pathway and the hexosamine synthetic pathway (HBP) (B). *, P<0.05 (Welch's t-test) compared with non-treated neural cells at day 20 (Non, green bar). NAD+/NADH ratio calculated from the metabolome data in hiPSCs and neural differentiated cells (C). (D) Metabolism of ManNAc and its derivatives through the sialic acid synthetic pathway. COS-7 cells were incubated with Lac-Sph-BODIPY (fluorescent glycolipid substrate)-BSA complex and ManNAc, ManNFAc, or 5S-ManNAc. Total lipid extraction was analyzed using Nano LC-MS. Formation of Neu5AcF-Gal-Glc-R was detected by MS. In contrast, the glycolipid containing 5S-Neu5Ac was not detectable.