title: MALDI imaging MS reveals candidate lipid markers of polycystic kidney disease.
abstract: Autosomal recessive polycystic kidney disease (ARPKD) is a severe, monogenetically inherited kidney and liver disease. PCK rats carrying the orthologous mutant gene serve as a model of human disease, and alterations in lipid profiles in PCK rats suggest that defined subsets of lipids may be useful as molecular disease markers. Whereas MALDI protein imaging mass spectrometry (IMS) has become a promising tool for disease classification, widely applicable workflows that link MALDI lipid imaging and identification as well as structural characterization of candidate disease-classifying marker lipids are lacking. Here, we combine selective MALDI imaging of sulfated kidney lipids and Fisher discriminant analysis (FDA) of imaging data sets for identification of candidate markers of progressive disease in PCK rats. Our study highlights strong increases in lower mass lipids as main classifiers of cystic disease. Structure determination by high-resolution mass spectrometry identifies these altered lipids as taurine-conjugated bile acids. These sulfated lipids are selectively elevated in the PCK rat model but not in models of related hepatorenal fibrocystic diseases, suggesting that they be molecular markers of the disease and that a combination of MALDI imaging with high-resolution MS methods and Fisher discriminant data analysis may be applicable for lipid marker discovery.
authors.affiliation: Institute of Instrumental Analytics and Bioanalytics, Mannheim University of Applied Sciences, 68163 Mannheim, Germany.
authors.forename: Hermelindis
authors.initials: H
authors.lastname: Ruh
authors.forename: Theresia
authors.initials: T
authors.lastname: Salonikios
authors.forename: Jens
authors.initials: J
authors.lastname: Fuchser
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwartz
authors.forename: Carsten
authors.initials: C
authors.lastname: Sticht
authors.forename: Christina
authors.initials: C
authors.lastname: Hochheim
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wirnitzer
authors.forename: Norbert
authors.initials: N
authors.lastname: Gretz
authors.forename: Carsten
authors.initials: C
authors.lastname: Hopf
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D016002:Discriminant Analysis; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008297:Male; D007690:Polycystic Kidney Diseases / Q000175:diagnosis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D055647:Rats, Transgenic; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D013433:Sulfoglycosphingolipids / Q000378:metabolism*; D013656:Taurocholic Acid / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D013433:Sulfoglycosphingolipids; D013656:Taurocholic Acid
keywords: Fisher discriminant analysis; Fourier transform ion cyclotron resonance mass spectrometry; Matrix-assisted laser desorption/ionization; autosomal recessive polycystic kidney disease; imaging mass spectrometry; taurocholic acid