Skip to main content

Mass and relative elution time profiling: Two-dimensional analysis of sphingolipids in Alzheimer's disease brains

Journal Article


Download full-text (Open Access)

Abstract


  • Current lipidomic profiling methods rely mainly on MS to identify unknown lipids within a complex sample. We describe a new approach, involving LCxMS/MS (liquid chromatographyxtandem MS) analysis of sphingolipids based on both mass and hydrophobicity, and use this method to characterize the SM (sphingomyelin), ceramide and GalCer (galactosylceramide) content of hippocampus from AD (Alzheimer's disease) and control subjects. Using a mathematical relationship we exclude the influence of sphingolipid mass on retention time, and generate two-dimensional plots that facilitate accurate visualization and characterization of the different ceramide moieties within a given sphingolipid class, because related molecules align horizontally or vertically on the plots. Major brain GalCer species that differ in mass by only 0.04 Da were easily differentiated on the basis of their hydrophobicity. The importance of our method's capacity to define all of the major GalCer species in the brain samples is illustrated by the novel observation that the proportion of GalCer with hydroxylated fatty acids increased approximately 2-fold in the hippocampus of AD patients, compared with age- and gender-matched controls. This suggests activation of fatty acid hydroxylase in AD. Our method greatly improves the clarity of data obtained in a lipid profiling experiment and can be expanded to other lipid classes. © The Authors Journal compilation © 2011 Biochemical Society.

Authors


  •   Hejazi, Leila (external author)
  •   Wong, Jason W. H. (external author)
  •   Cheng, D (external author)
  •   Proschogo, Nicholas W. (external author)
  •   Ebrahimi, D (external author)
  •   Garner, Brett
  •   Don, Anthony (external author)

Publication Date


  • 2011

Citation


  • Hejazi, L., Wong, J. W. H., Cheng, D., Proschogo, N., Ebrahimi, D., Garner, B. & Don, A. S. (2011). Mass and relative elution time profiling: Two-dimensional analysis of sphingolipids in Alzheimer's disease brains. Biochemical Journal, 438 (1), 165-175.

Scopus Eid


  • 2-s2.0-79960798079

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1222&context=ihmri

Ro Metadata Url


  • http://ro.uow.edu.au/ihmri/207

Number Of Pages


  • 10

Start Page


  • 165

End Page


  • 175

Volume


  • 438

Issue


  • 1

Abstract


  • Current lipidomic profiling methods rely mainly on MS to identify unknown lipids within a complex sample. We describe a new approach, involving LCxMS/MS (liquid chromatographyxtandem MS) analysis of sphingolipids based on both mass and hydrophobicity, and use this method to characterize the SM (sphingomyelin), ceramide and GalCer (galactosylceramide) content of hippocampus from AD (Alzheimer's disease) and control subjects. Using a mathematical relationship we exclude the influence of sphingolipid mass on retention time, and generate two-dimensional plots that facilitate accurate visualization and characterization of the different ceramide moieties within a given sphingolipid class, because related molecules align horizontally or vertically on the plots. Major brain GalCer species that differ in mass by only 0.04 Da were easily differentiated on the basis of their hydrophobicity. The importance of our method's capacity to define all of the major GalCer species in the brain samples is illustrated by the novel observation that the proportion of GalCer with hydroxylated fatty acids increased approximately 2-fold in the hippocampus of AD patients, compared with age- and gender-matched controls. This suggests activation of fatty acid hydroxylase in AD. Our method greatly improves the clarity of data obtained in a lipid profiling experiment and can be expanded to other lipid classes. © The Authors Journal compilation © 2011 Biochemical Society.

Authors


  •   Hejazi, Leila (external author)
  •   Wong, Jason W. H. (external author)
  •   Cheng, D (external author)
  •   Proschogo, Nicholas W. (external author)
  •   Ebrahimi, D (external author)
  •   Garner, Brett
  •   Don, Anthony (external author)

Publication Date


  • 2011

Citation


  • Hejazi, L., Wong, J. W. H., Cheng, D., Proschogo, N., Ebrahimi, D., Garner, B. & Don, A. S. (2011). Mass and relative elution time profiling: Two-dimensional analysis of sphingolipids in Alzheimer's disease brains. Biochemical Journal, 438 (1), 165-175.

Scopus Eid


  • 2-s2.0-79960798079

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=1222&context=ihmri

Ro Metadata Url


  • http://ro.uow.edu.au/ihmri/207

Number Of Pages


  • 10

Start Page


  • 165

End Page


  • 175

Volume


  • 438

Issue


  • 1