Quantitative, Label-Free Proteomics in the Symptomatic Niemann-Pick, Type C1 Mouse Model Using Standard Flow Liquid Chromatography and Thermal Focusing Electrospray Ionization

Proteomics. 2019 May;19(9):e1800432. doi: 10.1002/pmic.201800432. Epub 2019 Apr 18.

Abstract

Niemann-Pick disease, type C1 (NPC1) is a fatal, autosomal recessive, neurodegenerative disorder caused by mutations in the NPC1 gene. As a result, there is accumulation of unesterified cholesterol and sphingolipids in the late endosomal/lysosomal system. This abnormal accumulation results in a cascade of pathophysiological events including progressive, cerebellar neurodegeneration, among others. While significant progress has been made to better understand NPC1, the downstream effects of cholesterol storage and the major mechanisms that drive neurodegeneration remain unclear. In the current study, a) the use of a commercial, highly efficient standard flow-ESI platform for protein biomarker identification is implemented and b) protein biomarkers are identified and evaluated at a terminal time point in the NPC1 null mouse model. In this study, alterations are observed in proteins related to fatty acid homeostasis, calcium binding and regulation, lysosomal regulation, and inositol biosynthesis and metabolism, as well as signaling by Rho family GTPases. New observations from this study include altered expression of Pcp2 and Limp2 in Npc1 mutant mice relative to control, with Pcp2 exhibiting multiple isoforms and specific to the cerebella. This study provides valuable insight into pathways altered in the late-stage pathophysiology of NPC1.

Keywords: AJS-ESI; Niemann Pick; cholesterol; lysosome; mass spectrometry; neurodegeneration; type C1.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD36 Antigens / genetics*
  • Cholesterol / genetics
  • Chromatography, Liquid
  • Disease Models, Animal
  • Guanine Nucleotide Exchange Factors / genetics*
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Liver / metabolism
  • Lysosomal Membrane Proteins / genetics*
  • Lysosomes / genetics
  • Mice
  • Mutation
  • Neuropeptides / genetics*
  • Niemann-Pick C1 Protein
  • Niemann-Pick Disease, Type C / genetics*
  • Proteomics / methods
  • Signal Transduction / genetics
  • Spectrometry, Mass, Electrospray Ionization

Substances

  • CD36 Antigens
  • Guanine Nucleotide Exchange Factors
  • Intracellular Signaling Peptides and Proteins
  • Lysosomal Membrane Proteins
  • Neuropeptides
  • Niemann-Pick C1 Protein
  • Npc1 protein, mouse
  • Pcp2 protein, mouse
  • Scarb2 protein, mouse
  • Cholesterol