文章基本信息

标题：Quantitative imaging mass spectrometry of renal sulfatides: validation by classical mass spectrometric methods
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作者：Christian Marsching ; Richard Jennemann ; Raphael Heilig 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2014
卷号：55
期号：11
页码：2343-2353
DOI：10.1194/jlr.M051821
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：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 MS¹-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 (R² > 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.
关键词：liquid chromatography ; matrix-assisted laser desorption/ionization-time-of-flight ; electrospray ionization-mass spectrometry ; tandem mass spectrometry ; galactosylceramide I³-sulfate ; lactosylceramide II³-sulfate ; cortex ; medulla ; papillae