title: Matrix-assisted laser desorption/ionization tissue profiling of secretoneurin in the nucleus accumbens shell from cocaine-sensitized rats.
abstract: Proteins in the nucleus accumbens mediate many cocaine-induced behaviors. In an effort to measure changes in nucleus accumbens protein expression as potential biomarkers for addiction, coronal tissue sections were obtained from rats that developed behavioral sensitization after daily administration of cocaine, or from daily saline-treated controls. The tissue sections were subjected to matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) profiling and tissue imaging. For profiling experiments, brain sections were manually spotted with matrix over the nucleus accumbens, a brain region known to regulate cocaine sensitization. Summed mass spectra (10,000 laser shots, grid) were acquired and spectra were aligned to reference peaks. Using bioinformatics tools, eight spectral features were found to be altered by cocaine treatment. Based on additional sequencing experiments with MALDI tandem MS and database searches of measured masses, secretoneurin (m/z 3653) was identified as having an increased expression. In addition, the distribution of m/z 3653 in the nucleus accumbens was determined by MALDI tissue imaging, and the increased expression of its precursor protein, secretogranin II, was verified by immunoblotting.
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA. uys@musc.edu
authors.forename: Joachim D
authors.initials: JD
authors.lastname: Uys
authors.forename: Angus C
authors.initials: AC
authors.lastname: Grey
authors.forename: Armina
authors.initials: A
authors.lastname: Wiggins
authors.forename: John H
authors.initials: JH
authors.lastname: Schwacke
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Schey
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kalivas
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001923:Brain Chemistry; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000378:metabolism*; D019295:Computational Biology / Q000379:methods; D030562:Databases, Protein; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D053381:Secretogranin II / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D046888:Tissue Array Analysis / Q000379:methods*
chemical_list: D009479:Neuropeptides; D053381:Secretogranin II; C081159:secretoneurin; D003042:Cocaine