Top-down proteomics with mass spectrometry imaging: a pilot study towards discovery of biomarkers for neurodevelopmental disorders

• Published in: PloS one 2014-04, Vol.9 (4), p.e92831
• Main Authors: Ye, Hui, Mandal, Rakesh, Catherman, Adam, Thomas, Paul M, Kelleher, Neil L, Ikonomidou, Chrysanthy, Li, Lingjun
• Format: Article
• Language: English
• Subjects: Alzheimer's disease; Animals; Animals, Newborn; Apoptosis; Autism; Biological markers; Biology and Life Sciences; Biomarkers; Brain; Brain - metabolism; Brain - pathology; Brain Chemistry - drug effects; Brain Diseases - metabolism; Brain Diseases - pathology; Calcium-binding protein; Calcium-binding proteins; Calmodulin; Chemical agents; Cytochrome; Cytochrome oxidase; Cytochrome-c oxidase; Dizocilpine; Dizocilpine Maleate - pharmacology; Excitatory Amino Acid Antagonists - pharmacology; Exposure; Fractionation; Gene Expression Regulation - drug effects; Glutamic acid receptors (ionotropic); Health aspects; High-performance liquid chromatography; Homeostasis; Learning; Liquid chromatography; Mass Spectrometry; Mass spectroscopy; Medicine and Health Sciences; Memory; Methyl aspartate; N-Methyl-D-aspartic acid receptors; Neonates; Nerve Tissue Proteins - antagonists & inhibitors; Nerve Tissue Proteins - metabolism; Neurodevelopmental disorders; Neurogenesis; Neuroimaging; Neurology; Neuropeptides; Parkinson's disease; Peptides; Pharmaceuticals; Pharmacology; Pharmacy; Physical Sciences; Prostate cancer; Proteins; Proteomics; Rats; Rats, Wistar; Research and Analysis Methods; Scientific imaging; Ubiquitin
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0092831

In the developing mammalian brain, inhibition of NMDA receptor can induce widespread neuroapoptosis, inhibit neurogenesis and cause impairment of learning and memory. Although some mechanistic insights into adverse neurological actions of these NMDA receptor antagonists exist, our understanding of the full spectrum of developmental events affected by early exposure to these chemical agents in the brain is still limited. Here we attempt to gain insights into the impact of pharmacologically induced excitatory/inhibitory imbalance in infancy on the brain proteome using mass spectrometric imaging (MSI). Our goal was to study changes in protein expression in postnatal day 10 (P10) rat brains following neonatal exposure to the NMDA receptor antagonist dizocilpine (MK801). Analysis of rat brains exposed to vehicle or MK801 and comparison of their MALDI MS images revealed differential relative abundances of several proteins. We then identified these markers such as ubiquitin, purkinje cell protein 4 (PEP-19), cytochrome c oxidase subunits and calmodulin, by a combination of reversed-phase (RP) HPLC fractionation and top-down tandem MS platform. More in-depth large scale study along with validation experiments will be carried out in the future. Overall, our findings indicate that a brief neonatal exposure to a compound that alters excitatory/inhibitory balance in the brain has a long term effect on protein expression patterns during subsequent development, highlighting the utility of MALDI-MSI as a discovery tool for potential biomarkers.