Imaging of lipids of whole-body specimens
in two-dimensional (2D)
analysis provides a global picture of the lipid changes in lipid-disturbed
diseases, enabling a better understanding of lipid functions and lipid-modulation
processes in different organs. However, 2D imaging of a single cross
section can hardly characterize the whole-body lipid alterations.
In this work, a three-dimensional matrix-assisted laser desorption/ionization
mass spectrometry imaging (3D MALDI-MSI) approach was developed for
analysis of whole-body zebrafish, for the first time, and applied
to identify altered lipids and map their spatial distributions by
using a zebrafish model of Niemann–Pick disease type C1 (NPC1),
a neurovisceral lipid storage disorder causing both neurodegenerative
disorder and visceral organ damage. The constructed 3D fish model
provided comprehensive information on the 3D distribution of lipids
of interest and allowed direct correlations between these lipids and
organs of the fish. Obtained results revealed that several sphingolipids
and phospholipids showed significant alterations and exhibited different
localization patterns in various organs such as the brain, spinal
cord, intestines, and liver–spleen region in the npc1 gene mutant fish compared to those of the wild type. The whole-body
3D MALDI-MSI approach revealed unique lipid signatures for different
NPC1-affected organs, which might offer insights into the link between
the impaired lipid storage and subsequent clinical symptoms, such
as neurodegeneration and hepatosplenomegaly.