title: TransOmic analysis of forebrain sections in Sp2 conditional knockout embryonic mice using IR-MALDESI imaging of lipids and LC-MS/MS label-free proteomics.
abstract: Quantitative methods for detection of biological molecules are needed more than ever before in the emerging age of "omics" and "big data." Here, we provide an integrated approach for systematic analysis of the "lipidome" in tissue. To test our approach in a biological context, we utilized brain tissue selectively deficient for the transcription factor Specificity Protein 2 (Sp2). Conditional deletion of Sp2 in the mouse cerebral cortex results in developmental deficiencies including disruption of lipid metabolism. Silver (Ag) cationization was implemented for infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) to enhance the ion abundances for olefinic lipids, as these have been linked to regulation by Sp2. Combining Ag-doped and conventional IR-MALDESI imaging, this approach was extended to IR-MALDESI imaging of embryonic mouse brains. Further, our imaging technique was combined with bottom-up shotgun proteomic LC-MS/MS analysis and western blot for comparing Sp2 conditional knockout (Sp2-cKO) and wild-type (WT) cortices of tissue sections. This provided an integrated omics dataset which revealed many specific changes to fundamental cellular processes and biosynthetic pathways. In particular, step-specific altered abundances of nucleotides, lipids, and associated proteins were observed in the cerebral cortices of Sp2-cKO embryos.
authors.affiliation: W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Philip
authors.initials: P
authors.lastname: Loziuk
authors.affiliation: W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.|Department of Chemistry, Saarland University, 66123, Saarbruecken, Germany.|Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152, Martinsried, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Meier
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA.
authors.forename: Caroline
authors.initials: C
authors.lastname: Johnson
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27607, USA. Troy_Ghashghaei@ncsu.edu.
authors.forename: H Troy
authors.initials: HT
authors.lastname: Ghashghaei
authors.affiliation: W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA. dcmuddim@ncsu.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Muddiman
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D008055:Lipids / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D018345:Mice, Knockout; D016548:Prosencephalon / Q000196:embryology / Q000378:metabolism*; D051704:Sp2 Transcription Factor / Q000235:genetics; D013055:Spectrophotometry, Infrared / Q000379:methods*; D059467:Transcriptome
chemical_list: D008055:Lipids; D051704:Sp2 Transcription Factor
keywords: Embryonic brain; IR-MALDESI; Lipidomics; Mass spectrometry imaging; Proteomics