title: Quantitative imaging mass spectrometry of renal sulfatides: validation by classical mass spectrometric methods.
abstract: Owing to its capability of discriminating subtle mass-altering structural differences such as double bonds or elongated acyl chains, MALDI-based imaging MS (IMS) has emerged as a powerful technique for analysis of lipid distribution in tissue at moderate spatial resolution of about 50 μm. However, it is still unknown if MS(1)-signals and ion intensity images correlate with the corresponding apparent lipid concentrations. Analyzing renal sulfated glycosphingolipids, sulfatides, we validate for the first time IMS-signal identities using corresponding sulfatide-deficient kidneys. To evaluate the extent of signal quenching effects interfering with lipid quantification, we surgically dissected the three major renal regions (papillae, medulla, and cortex) and systematically compared MALDI IMS of renal sulfatides with quantitative analyses of corresponding lipid extracts by on-target MALDI TOF-MS and by ultra-performance LC-ESI-(triple-quadrupole)tandem MS. Our results demonstrate a generally strong correlation (R(2) > 0.9) between the local relative sulfatide signal intensity in MALDI IMS and absolute sulfatide quantities determined by the other two methods. However, high concentrations of sulfatides in the papillae and medulla result in an up to 4-fold signal suppression. In conclusion, our study suggests that MALDI IMS is useful for semi-quantitative dissection of relative local changes of sulfatides and possibly other lipids in tissue.
authors.affiliation: Center for Applied Research "Applied Biomedical Mass Spectrometry" (ABIMAS), Mannheim, Germany Lipid Pathobiochemistry Group within German Cancer Research Center (DKFZ), Heidelberg, Germany Department of Cellular and Molecular Pathology, German Cancer Research Center (DKFZ), Heidelberg, Germany Institute of Medical Technology, University of Heidelberg and Mannheim University of Applied Sciences, Mannheim, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Marsching
authors.affiliation: Department of Cellular and Molecular Pathology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Jennemann
authors.affiliation: Lipid Pathobiochemistry Group within German Cancer Research Center (DKFZ), Heidelberg, Germany Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Mannheim, Germany.
authors.forename: Raphael
authors.initials: R
authors.lastname: Heilig
authors.affiliation: Center for Applied Research "Applied Biomedical Mass Spectrometry" (ABIMAS), Mannheim, Germany Department of Cellular and Molecular Pathology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Hermann-Josef
authors.initials: HJ
authors.lastname: Gröne
authors.affiliation: Center for Applied Research "Applied Biomedical Mass Spectrometry" (ABIMAS), Mannheim, Germany Institute of Medical Technology, University of Heidelberg and Mannheim University of Applied Sciences, Mannheim, Germany Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Mannheim, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Hopf
authors.affiliation: Center for Applied Research "Applied Biomedical Mass Spectrometry" (ABIMAS), Mannheim, Germany Lipid Pathobiochemistry Group within German Cancer Research Center (DKFZ), Heidelberg, Germany Department of Cellular and Molecular Pathology, German Cancer Research Center (DKFZ), Heidelberg, Germany Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, Mannheim, Germany.
authors.forename: Roger
authors.initials: R
authors.lastname: Sandhoff
mesh_terms: D000818:Animals; D005260:Female; D007668:Kidney / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D057054:Molecular Imaging / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013433:Sulfoglycosphingolipids / Q000737:chemistry / Q000378:metabolism*
chemical_list: D013433:Sulfoglycosphingolipids
keywords: cortex; electrospray ionization-mass spectrometry; galactosylceramide I3-sulfate; lactosylceramide II3-sulfate; liquid chromatography; matrix-assisted laser desorption/ionization-time-of-flight; medulla; papillae; tandem mass spectrometry