Investigating ApoE4‐mediated metabolic alteration of H4 neuroglioma cells of Alzheimer’s disease

Abstract

AbstractBackgroundMetabolites and proteins in ApoE4‐carried H4 neuroglioma cells were analyzed to investigate the potential mechanism of the risk gene ApoE4 involved in Alzheimer’s disease (AD).MethodMetabolomics of ApoE4‐carried and wild‐type H4 cells was performed by applying a novel workflow composed of Orbital trapping secondary ion mass spectrometry (OrbiSIMS) as a screening tool, followed by LC‐MS/MS targeted metabolomics for further confirming polar molecules. Proteins affected by ApoE4 were identified by performing LC‐MS‐based proteomics, followed by investigating the protein network and functional enrichment analysis using the STRING database.ResultThe initial OrbiSIMS approach has shown the advantages of detecting large numbers of metabolites with minimal sample preparation, small sample size and a relatively rapid analysis time, allowing 192 putatively annotated metabolites detected in our study. We found glycerophospholipid metabolism, aspartate, glutamate and alanine are the most affected pathways by ApoE4. Polar‐targeted metabolomics of LC‐MS/MS further revealed that the metabolism of taurine and hypotaurine is also affected by ApoE4. Besides, proteomics results suggest an overall metabolic process, RNA splicing process, and translation associated with ApoE4‐related AD development.ConclusionOur results have elucidated the metabolic alteration of H4 neuroglioma cells in the presence of ApoE4, supporting the hypothesis of the low ability of ApoE4 in transporting lipids and discovering two new potential pathways that may be involved in AD. In addition, proteomics analysis by LC‐MS further proved the ApoE4‐mediated dysfunction of nitrogen compound metabolism and RNA splicing process.