An Approach to Glycobiology from Glycolipidomics: Ganglioside Molecular Scanning in the Brains of Patients with Alzheimer's Disease by TLC-Blot/Matrix Assisted Laser Desorption/Ionization-Time of Flight MS

We have established a new approach to glyco- and lipidomics using a thin layer chromatography (TLC)-Blot/matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MS) system. This new approach consists of a combination of a method for transferring lipids separated on a TLC-plate to a poly-vinylidene difluoride (PVDF) membrane and direct mass spectrometric analysis of the individual lipids on the membrane by ion trap-type MALDI-TOF MS. This technology was applied to the analysis of individual lipids from the human brain. Then, based on the results of this analysis, ganglioside molecular species in neural diseases were analyzed. The levels of gangliosides GD1b and GT1b were lower in the hippocampal gray matter of patients with Alzheimer's disease than in the hippocampal gray matter of patients with Parkinson's disease or the control patients. The molecular scanning of individual ganglioside molecular species showed a significant reduction of d20:1/C18:0 ceramide-containing gangliosides in patients with Alzheimer's disease. These findings suggest that Alzheimer's disease is a kind of ganglioside metabolic disease affecting the hippocampal area. A new approach to glycobiology by the TLC-Blot/MALDI-TOF MS system is proposed.