Tissue Localization of Glycosphingolipid Accumulation in a Gaucher Disease Mouse Brain by LC-ESI-MS/MS and High-Resolution MALDI Imaging Mass Spectrometry

Abstract

To better understand regional brain glycosphingolipid (GSL) accumulation in Gaucher disease (GD) and its relationship to neuropathology, a feasibility study using mass spectrometry and immunohistochemistry was conducted using brains derived from a GD mouse model (4L/PS/NA) homozygous for a mutant GCase (V394L [4L]) and expressing a prosaposin hypomorphic (PS-NA) transgene. Whole brains from GD and control animals were collected using one hemisphere for MALDI FTICR IMS analysis and the other for quantitation by LC-ESI-MS/MS. MALDI IMS detected several HexCers across the brains. Comparison with the brain hematoxylin and eosin (H&E) revealed differential signal distributions in the midbrain, brain stem, and CB of the GD brain versus the control. Quantitation of serial brain sections with LC-ESI-MS/MS supported the imaging results, finding the overall HexCer levels in the 4L/PS-NA brains to be four times higher than the control. LC-ESI-MS/MS also confirmed that the elevated hexosyl isomers were glucosylceramides rather than galactosylceramides. MALDI imaging also detected differential analyte distributions of lactosylceramide species and gangliosides in the 4L/PS-NA brain, which was validated by LC-ESI-MS/MS. Immunohistochemistry revealed regional inflammation, altered autophagy, and defective protein degradation correlating with regions of GSL accumulation, suggesting that specific GSLs may have distinct neuropathological effects.

Recent advances in mass spectrometry imaging for multiomics application in neurology

“…An interesting shift toward proinflammatory molecules (uric acid) in the purinergic pathway was observed, which associated with a decrease in antioxidant level (ascorbic acid). Together, these observations fit well with the increased oxidative stress and neuroinflammation commonly observed in AD (Esteve, Jones et al, ). The ability of MALDI imaging to provide a greater understanding of drug and metabolite tissue distribution is very exciting and at the heart of the widespread interest in this technique.…”

“…MSI has been widely used in mapping lipids in mouse brain tissues, including fatty acids (Hirahara et al, ; Ibrahim et al, ; Lerner et al, ; Wu, Comi, Li, Rubakhin, & Sweedler, ; Zhou et al, ), ceramides (Barbacci et al, ; Muller et al, ; Nielsen et al, ; Woods et al, ), cardiolipins (Amoscato et al, ; Sparvero et al, ), phospholipids (Angel, Spraggins, Baldwin, & Caprioli, ; Guo et al, ; Hama et al, ; Hankin et al, ; Jadoul et al, ; Janfelt et al, ; Koizumi et al, ; Landgraf et al, ; Matsumoto et al, , ; Miyawaki et al, ; Shanta et al, ; Smith et al, ; Sparvero et al, ; Sugiura et al, ; Wang et al, ; Wang, Wang, & Han, ; Whitehead et al, ; Zaima et al, ), and sphingolipids (Caughlin et al, , ; Caughlin, Park, Yeung, Cechetto, & Whitehead, ; Chan et al, ; Dufresne et al, ; Ermini et al, ; Goto‐Inoue et al, ; Jackson et al, , ; Jones et al, ; Meriaux, Franck, Wisztorski, Salzet, & Fournier, ; Sugiura, Shimma, Konishi, Yamada, & Setou, ; Weishaupt, Caughlin, Yeung, & Whitehead, ; Whitehead et al, ). Gangliosides, amphipathic molecules composed of a ceramide lipid anchor linked to an oligosaccharide, are sialic acid‐containing glycosphingolipids and play numerous important roles in neuronal functions.…”

Characterization of the visceral and neuronal phenotype of 4L/PS-NA mice modeling Gaucher disease

“…Thus, GlcCer concentrations increased about 18 times in the cerebellum of 18 week old 4L/PS-NA mice as compared to controls at the same age, which is comparable to the reported 23 times increase in 20 week old 4L/PS-NA mice [30]. Even a higher, 32.6-fold increase in the levels of GlcCer d18:1/18:0 in the cerebellum of 18 week old 4L/PS-NA mice was reported [31]. A possible reason for the difference in the estimated GlcCer ratio between the 4L/PS-NA and control mice could be a lower estimated level of GlcCer in 4L/PS-NA mice, since the mean cerebellar GlcCer levels in the 4L/PS-NA mice reported by [31] were about 145 μg/g, which is similar to the levels of 180 μg/g wet weight measured in our study.…”

“…Even a higher, 32.6-fold increase in the levels of GlcCer d18:1/18:0 in the cerebellum of 18 week old 4L/PS-NA mice was reported [31]. A possible reason for the difference in the estimated GlcCer ratio between the 4L/PS-NA and control mice could be a lower estimated level of GlcCer in 4L/PS-NA mice, since the mean cerebellar GlcCer levels in the 4L/PS-NA mice reported by [31] were about 145 μg/g, which is similar to the levels of 180 μg/g wet weight measured in our study. The highest levels of GlcSph in the cerebellum of 18 week old 4L/PS-NA mice was in average 8.4 times higher as compared to control mice, which is well in agreement to the reported 9 times higher GlcSph in the 4L/ PS-NA of 20 week old mice [30].…”

Mass spectrometry imaging of lipids: untargeted consensus spectra reveal spatial distributions in Niemann-Pick disease type C1

“…A method for enhancing neutral lipid mapping was shown in a mouse model of Fabry disease (35). Other lysosomal disorders with imaging studies include Farber (36), Gaucher (37,38), and Sandhoff disease (39,40). Recently, the I1061T NPC1 point mutant model was used to develop an infrared spectroscopy-MALDI imaging workflow.…”