Direct profiling of the phospholipid composition of adult Caenorhabditis elegans using whole-body imaging mass spectrometry

• Published in: Analytical and bioanalytical chemistry 2015, Vol.407 (25), p.7589-7602
• Main Authors: Hameed, Saira, Ikegami, Koji, Sugiyama, Eiji, Matsushita, Shoko, Kimura, Yoshishige, Hayasaka, Takahiro, Sugiura, Yuki, Masaki, Noritaka, Waki, Michihiko, Ohta, Isao, Hossen, Md Amir, Setou, Mitsutoshi
• Format: Article
• Language: English
• Subjects: Adults; Analytical Chemistry; Animals; Biochemistry; Biomolecules; Caenorhabditis elegans; Caenorhabditis elegans - chemistry; Caenorhabditis elegans - genetics; Caenorhabditis elegans - ultrastructure; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; Encoding; fatty acid composition; Fatty acids; Fatty Acids - analysis; Fatty Acids - genetics; Food Science; Freezing; genes; Genetics; Identification and classification; image analysis; Ionization; Laboratory Medicine; Lasers; Mass spectrometry; Methods; Monitoring/Environmental Analysis; mutants; Mycotoxins; Nematodes; New Applications of Mass Spectrometry in Biomedicine; omega-3 fatty acids; Peptides; phosphatidylcholines; Phospholipids; Phospholipids - analysis; Phospholipids - genetics; Physiological aspects; Profiling; Research Paper; Scientific imaging; soil nematodes; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; Stable isotopes; stearoyl-CoA desaturase; Sublimation; Whole Body Imaging - methods
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-015-8932-7

A protocol for the direct analysis of the phospholipid composition in the whole body of adult soil nematode, Caenorhabditis elegans (C. elegans), was developed, which combined freeze-cracking of the exoskeletal cuticle and matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). Biomolecules in the m/z range from 700 to 900 were more effectively detected in the freeze-cracked than from simple frozen adult nematode bodies. Different distribution of biomolecules was observed in a nematode body when the matrix was applied with a sublimation deposition method. The whole-body IMS technique was applied on genetically deficient mutant C. elegans to combine whole-body lipidomics and genetics, by comparing the fatty acid compositions, especially of the phosphatidylcholine (PC) species, between the wild-type and fat-1 mutants, which lack the gene encoding an n-3 fatty acid desaturase. A significant reduction of PC(20:5/20:5) and PC(20:4/20:5) and a marked increase of PC(20:4/20:4), PC(20:3/20:4), and PC(20:3/20:3) were detected in the fat-1 mutants in positive ion mode. In addition, phospholipid compositions other than PCs were analyzed in negative ion mode. A loss of a possible phosphatidylinositol (PI) with 18:0/20:5 and a compensative accumulation of putative PI(18:0/20:4) were detected in the fat-1 mutants. In conclusion, the whole-body MALDI-IMS technique is useful for the profiling of multiple biomolecules in C. elegans in both intra- and inter-individual levels.