Discrimination of cellular developmental states focusing on glycan transformation and membrane dynamics by using BODIPY-tagged lactosyl ceramide

Glycosphingolipid (GSL) is a group of molecules composed of hydrophilic glycan part and hydophobic ceramide creating diverse family. GSLs are de novo synthesised from ceramide at endoplasmic reticulum and Golgi apparatus, and transported to outer surface of plasma membrane. It has been known that the glycan structures of GSLs changes reflecting disease states. We envisioned that analysing the glycan pattern of GSLs enables distinguishing diseases. For this purpose, we utilised a fluorescently tagged compound, LacCerBODIPY (1). At first, compound 1 was taken up by a cultured PC12D cells and transformed into various GSLs. As a result, change in the GSL patterns of differentiation states of the cells was successfully observed by using an analysis platform, nano liquid chromatography (LC)-fluorescence detected (FLD)-electrospray ionisation (ESI)-mass spectrometry (MS), which could quantitate and provide molecular ion simultaneously. We found that the compound 1 remained for about 10 min on the plasma membrane before it is converted into other GSLs. We therefore investigated more rapid way of discriminating different cellular states by fluorescence recovery after photobleaching, which revealed that it is possible to distinguish the differentiation states as well.