EphrinB ligands are functional co-receptors for reelin to regulate neuronal migration [Elektronische Ressource] / von Aycan Senturk

Essmann

Sujets

• Biologie
• Gesundheit

Informations

• Publié par: goethe_universitat_frankfurt_am_main
• Publié le: 01 janvier 2010
• Nombre de lectures: 16
• Langue: English
• Poids de l'ouvrage: 6 Mo

Extrait

For my loving and supportive parents,
Nursen and Yilmaz Senturk
and for my dear grandfather Ramazan BIYIK who deeply wished but
could not join my graduations, sleep in peace...
















EphrinB ligands are functional
co-receptors for Reelin to regulate
neuronal migration


Dissertation zur Erlangung des Doktorgrades
der Naturwissenschaften

vorgelegt beim Fachbereich Biowissenschaften
der Johann Wolfgang Goethe-Universität
in Frankfurt am Main

von
Msc. Aycan Senturk
aus Olpe
Frankfurt am Main (2010)




Vom Fachbereich Biochemie, Chemie und Pharmazie der Johann Wolfgang Goethe-
Universität als Dissertation angenommen.

Dekanin: Prof. Dr. Anna Starzinski-Powitz
Gutachter: Prof. Dr. Amparo Acker-Palmer
Prof. Dr.Thomas Deller
Datum der Disputation: 14.02.2011








The part of the work presented in this thesis was performed in the laboratory of Prof. Dr. Amparo
Acker-Palmer, Junior Group – Signal transduction, at the Max-Planck-Institute of Neurobiology,
Martinsried, Germany and completed in the laboratory of Prof. Dr. Amparo Acker-Palmer, Institute
for Molecular Life Sciences (FMLS), Goethe University, Frankfurt.


1 Table of Contents

1 Table of Contents
1 Table of Contents ........................................................................ 5
2 Abbreviations .............. 9
3 Zusammenfasung ...... 13
4 Introduction .............................................................................. 19
4.1 Development of the cerebral cortex (corticogenesis) in mice ..................... 19
4.1.1 Development of the neocortex ................................. 19
4.1.2 Development of the hippocampus ........................................................... 21
4.1.3 Development of the cerebellum ............................... 22
4.2 Neuronal migration and layering in the cerebral cortex during embryonic
development and adulthood .............................................................................. 24
4.2.1 Role of Reelin in cortical neuronal migration ........... 25
4.2.2 Other functions of Reelin .......... 28
4.3 Defects in cortical layer formation of mice ................................................. 29
4.3.1 The reeler mice ......................................................... 30
4.3.1.1 Alterations in the cerebral cortex of the reeler mice ....................... 31
4.3.1.2 Alterations in the hippocampus of the reeler mice .......................................................... 33
4.3.1.3 Alterations in the cerebellum of the reeler mice ............................. 33
4.3.2 The Yotari and the Scrambler mice ........................................................... 34
4.3.3 The VLDLR and the ApoER2 knockout mice .............. 35
4.4 Reelin pathway ......................................................... 38
4.4.1 Reelin ........................................................................ 38
4.4.2 The lipoprotein receptors: VLDLR and ApoER2 ........ 39
4.4.3 Dab1 and signaling downstream of Dab1 ................................................. 41
4.4.3.1 Dab1 phosphorylation ...................................................................... 42
4.5 Eph receptors and their ephrin ligands ...................................................... 45
4.5.1 Structure of Eph receptors and ephrins ................... 46
4.5.1.1 Eph structure .................................................................................... 46
4.5.1.2 Ephrin structure ................................................ 47
5
Table of Contents 1
4.5.2 Bidirectional signaling mechanisms between Eph receptors and
ephrin ligands ........................................................................................................ 48
4.5.2.1 Mechanisms of Eph receptor “Forward” signaling ........................... 49
4.5.2.2 Mechanism of ephrin ligand “Reverse” signaling ............................. 50
4.5.3 Roles of Eph and ephrins in nervous system development ...................... 53
4.5.3.1 Axon guidance .................................................................................................................. 54
4.5.3.2 Synaptic Plasticity ............. 55
4.5.3.3 Segmentation ................... 55
4.5.3.4 Corticospinal tract formation ........................................................................................... 56
5 Results ...................................................... 59
5.1 Genetic interaction between Reelin and ephrinB pathways ....................... 60
5.1.1 Compound mice show reeler like phenotypes in the cerebral cortex. ..... 60
5.1.1.1 Cortical neurons invade the marginal zone in rl/+; b3-/- compound mutant mice. ........ 61
5.1.1.2 Cortical layering is altered in the rl/+; b3-/- compound mutant mice. ............................ 62
5.1.1.3 Interneuron distribution is altered in the compound mutant mice. ................................ 68
5.1.1.4 BrdU birth dating study reveals neuronal migration defect in rl/+; b3-/- compound
mutant mice. ................................................................................................... 70
5.1.1.5 Preplate splitting does not take place in the compound mutant embryos. ..................... 75
5.1.1.6 Radial glia scaffold is altered in the rl/+; b3-/- compound mutant mice. ........................ 76
5.1.2 rl/+; b3 -/- compound mice show reeler like phenotypes in the
hippocampus. ........................................................................................................ 78
5.1.2.1 CA1 shows layering defects in the hippocampus of rl/+; b3-/- compound mutant
mice. 79
5.1.2.2 The granular cell layer in the dentate gyrus of rl/+; b3-/- compound mice is less
compact. .......................................................................................................................................... 82
5.1.2.3 Mossy cells are dislocated in the rl/+; b3-/- compound mutant mice. ............................ 83
5.1.2.4 The radial glial scaffold of the dentate gyrus is altered in the rl/+; b3-/- compound
mutant mice. ................................................................................................................................... 84
5.1.2.5 The dendritic branching of hippocampal pyramidal neurons is increased in the rl/+;
b3-/- compound mutant mice. ........ 85
5.1.3 rl/+; b3-/- and rl/+; b2-/- compound mutant mice show reeler like
phenotypes in the cerebellum. ............................................................................. 88
5.1.3.1 Cerebellar Purkinje cell migration requires ephrinB ligands for proper migration .......... 88
5.2 Reelin, Dab1 and ephrinB ligands are in the same signaling complex. ......... 94
5.2.1 Reelin and Dab1 binds to ephrinB ligands. ............................................... 94
5.2.2 Reelin and ephrinB ligands functionally interact. ..... 95
5.2.3 Dab1 phosphorylation levels are reduced in ephrinB3 knockouts. .......... 96
6
1 Table of Contents
5.2.4 EphrinB ligands are in complex with Reelin receptors, ApoER2 and
VLDLR. 100
5.2.5 Dab1 phosphorylation is induced following ephrinB3 activation. ......... 101
5.3 EphrinB reverse signaling stimulation can rescue reeler phenotypes in the
cerebral cortex. ................................................................................................ 102
5.3.1 Activation of ephrinB ligands is sufficient to activate Reelin signaling
in cortical neuron cultures. ................................................. 102
5.3.2 Activation of ephrinBs rescues cortical migration defects in the reeler
mouse. 104
6 Discussion ............................................................................... 107
6.1 Concluding remarks ................. 116
7 Material and methods ............................................................. 119
7.1 Material .................................................................. 119
7.1.1.1 Antibodies ...................... 119
7.1.2 Chemicals, Reagents, Commercial Kits & Enzymes 120
7.1.3 Consumable Material .............................................................................. 122
7.1.4 Equipment ............................................................................................... 124
7.1.5 Oligonucleotides ..................... 126
7.1.6 Cell lines .................................. 127
7.1.7 Mice ........................................................................ 127
7.1.8 Primary cells and tissues ......... 127
7.2 Media and Standard Solutions ................................. 127
7.2.1 Media and Supplements for Cell Culture ................ 130
7.2.2 Media and Supplements for Primary Cell Culture .. 131
7.2.3 Media f