Imaging of complex sulfatides SM3 and SB1a in mouse kidney using MALDI-TOF/TOF mass spectrometry
Imaging of complex sulfatides SM3 and SB1a in mouse kidney using MALDI-TOF/TOF mass spectrometry
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DOI：
10.1007/s00216-011-4802-0
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发表时间：
2011-07-01
影响因子：
4.3
通讯作者：
Hopf, Carsten
中科院分区：
文献类型：
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作者：
Marsching, Christian;Eckhardt, Matthias;Hopf, Carsten
硫脂脂是一类酸性鞘糖脂，在哺乳动物髓磷脂和肾脏中高度表达，它们被认为分别稳定神经元结构和信号传导，并影响肾细胞的渗透稳定性。最近，9-氨基吖啶（9-AA）作为一种负离子基质被引入，它对低复杂度的半乳糖神经酰胺- i -3-硫酸盐硫脂具有高选择性，适合于基质辅助解吸/电离（MALDI）质谱（MS）的定量分析。通过分析野生型小鼠和ASA -/-型小鼠肾脏的脂质提取物和低温标本的酸性组分，我们发现9-AA也能通过MALDI-TOF/TOF MS对复杂的乳酸神经酰胺- ii3 -硫酸盐和神经节四氢神经酰胺- ii3， IV3双硫酸盐硫fatides进行敏感的靶分析和成像。利用MALDI成像质谱技术，我们发现(1)具有相同神经酰胺锚点的硫fatides在小鼠肾脏中的不同定位。但是不同的聚糖-硫酸盐头基团和(2)磺胺脂具有相同的头基团但具有不同的酰基或鞘基基团。对照和磺胺脂储存arylsulfatase A-缺陷（ASA -/-）小鼠肾硫脂的MALDI图像比较显示出相对表达差异，很可能反映了不同肾细胞类型硫脂转换的差异。这些结果建立了使用9-AA基质的MALDI成像质谱作为一种无标记的方法，用于研究人鞘糖脂储存病动物模型中硫脂质的相对转化。
Sulfatides, a class of acidic glycosphingolipids, are highly expressed in mammalian myelin and in kidney, where they are thought to stabilize neuronal structures and signaling and to influence osmotic stability of renal cells, respectively. Recently, 9-aminoacridine (9-AA) has been introduced as a negative ion matrix that displays high selectivity for low complexity galactosylceramid-I-3-sulfate sulfatides and that is suitable for quantitative analysis by matrix-assisted desorption/ionization (MALDI) mass spectrometry (MS). Analyzing acidic fractions of lipid extracts and cryosections from kidneys of wild type and arylsulfatase A-deficient (ASA -/-) mice, we demonstrate that 9-AA also enables sensitive on-target analysis as well as imaging of complex lactosylceramide-II3-sulfate and gangliotetraosylceramide-II3, IV3 bis-sulfate sulfatides by MALDI-TOF/TOF MS. Utilizing the MALDI imaging MS technique, we show differential localization in mouse kidney of (1) sulfatides with identical ceramide anchors, but different glycan-sulfate head groups but also of (2) sulfatides with identical head groups but with different acyl- or sphingoid base moieties. A comparison of MALDI images of renal sulfatides from control and sulfatide storing arylsulfatase A-deficient (ASA -/-) mice revealed relative expression differences, very likely reflecting differences in sulfatide turnover of the various renal cell types. These results establish MALDI imaging MS with 9-AA matrix as a label-free method for spatially resolved ex vivo investigation of the relative turnover of sulfatides in animal models of human glycosphingolipid storage disease.