Biomarker discovery for psychiatric disorders [Elektronische Ressource] : insights from quantitative proteomics studies in animal models / vorgelegt von Michaela Filiou

Michaela Filiou

Sujets

• Biologie

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2010
• Nombre de lectures: 10
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Biomarker discovery for psychiatric disorders:
Insights from quantitative proteomics studies
in animal models







Dissertation
der Fakultät für Biologie
der Ludwig-Maximilians-Universität München


vorgelegt von
Michaela Filiou



München, Juli 2010







..

,

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To my beloved parents

























Erstgutachter: Prof. Dr. Rainer Landgraf
Zweitgutachter: Prof. Dr. George Boyan

Tag der mündlichen Prüfung: 15 Dezember 2010

Abstract
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Abstract

Although psychiatric disorders are among the leading causes of disability in modern societies, no
molecular biomarkers exist for their accurate diagnosis, classification and treatment efficacy
assessment. Proteomics technologies provide useful tools for identifying protein markers related
to disease pathophysiology. To unravel the neurobiological underpinnings and identify candidate
biomarkers for anxiety disorders, we interrogated the mouse model of high (HAB), normal (NAB)
and low (LAB) anxiety-related behavior by a combined quantitative proteomics and metabolomics
approach. The cingulate cortex synaptosome proteomes of HAB and LAB mice were compared
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by in vivo N metabolic labeling and quantitative proteomics. In addition, the cingulate cortex
metabolomes of HAB/NAB/LAB mice were quantified, and altered protein and metabolite
networks were identified by in silico pathway analysis. Differential expression of sideroflexin-5
(Sfxn5), carbonic anhydrase 2 (Car2), myosin, heavy polypeptide 10 (Myh10) and succinate
dehydrogenase, subunit b (Sdhb) in HAB and LAB mice was validated by Western blot in an
independent HAB/NAB/LAB population, providing a set of candidate biomarkers for anxiety-
related behavior. Proteomics, metabolomics and in silico analyses revealed pronounced
mitochondrial pathway alterations, suggesting previously not highlighted roles of the organelle in
modulating anxiety-related behavior by affecting energy metabolism, oxidative stress and
neurotransmission processes.
To allow an accurate characterization of the HAB/NAB/LAB mouse model, proteomics tools were
established and optimized. Mouse synaptosome proteome profiling was carried out to create a
reference map for quantitative proteomics experiments. Furthermore, the quantitative proteomics
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platform based on metabolic labeling of the HAB/NAB/LAB mouse model with the N heavy
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isotope was established, and the N isotope effect on the proteome during metabolic labeling
was investigated.
To elucidate the role of the G72 protein in schizophrenia, the G72/G30 transgenic mouse model
of schizophrenia-like symptoms was studied with traditional, gel-based proteomics approaches.
The cerebellar proteomes of G72/G30 transgenic mice were compared with wild type (WT)
i Abstract
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controls, revealing differential expression of proteins involved in mitochondrial function and
oxidative stress.
Taken together, quantitative proteomics approaches were applied to identify disease-specific
differences in animal models of psychiatric disorders. Our data provide the basis for the
establishment of a biomarker panel for anxiety disorders and schizophrenia and offer insights
toward a systemic understanding of mental disease and discovery of novel therapeutic targets.





















ii Table of contents
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Table of contents

Abstract i
Table of contents iii
Abbreviations viii
Protein names x
1 Introduction 1
1.1 Psychiatric disorders 1
1.1.1 Anxiety and depression 1
1.1.2 Schizophrenia 2
1.2 Biomarkers for psychiatric disorders 3
1.2.1 What is a biomarker? 3
1.2.2 The quest for biomarkers in psychiatric research 3
1.3 Mouse models for psychiatric disorders 4
1.3.1 Advantages of mouse models in psychiatric research 4
1.3.2 The HAB/NAB/LAB mouse model of trait anxiety 4
1.3.2.1 Bidirectional selective breeding 4
1.3.2.2 Behavioral and molecular characteristics 5
1.3.3 The G72/G30 transgenic mouse model of schizophrenia-like symptoms 6
1.4 Biomarker discovery platforms 7
1.4.1 Quantitative proteomics 7
1.4.1.1 Advantages of studying the proteome 7
1.4.1.2 Mass spectrometry 7
1.4.1.3 Mass spectrometry instrumentation 9
1.4.1.4 Mass spectrometry-based proteomics 10
1.4.1.5 Quantitative proteomics methodologies 10
1.4.2 Quantitative metabolomics 12
1.5 Biomarker discovery in the HAB/NAB/LAB mouse model of trait anxiety 13
2 Aim of the thesis 15
iii