Role of GDNF and its Cross-Talk with Other Growth Factors in the Dopaminergic System

1. Review of the literature ..........................................................................................1 1.1. Brain dopaminergic system ..................................................................................... 1 1.1.1. Development of the midbrain dopaminergic system ............................ 2 1.2. Parkinson’s disease.................................................................................................... 3 1.2.1. Etiopathogenesis of Parkinson’s disease .................................................. 3 1.2.2. Diagnosis of Parkinson’s disease ............................................................... 5 1.2.3. Th erapeutic approaches to Parkinson’s disease ..................................... 5 1.2.4. Animal models of Parkinson’s disease ..................................................... 6 1.3. Neurotrophic factors .............................................................................................. 10 1.4. GDNF family ligands ............................................................................................. 13 1.4.1. Expression and functions ........................................................................ 13 1.4.2. Signalling ................................................................................................... 15 1.4.3. GFLs roles in the dopaminergic system ................................................ 16 1.4.4. Transgenic mouse models of GDNF and RET ..................................... 20 1.4.5. GDNF and NRTN in clinical studies ..................................................... 23 1.4.6. GDNF role in addiction ........................................................................... 24 1.5. VEGF family of growth factors ............................................................................. 26 1.6. Neurovascular crosstalk ......................................................................................... 27 2. Aims of the study ..................................................................................................30 3. Materials and methods .........................................................................................31 3.1. Microarray analysis ................................................................................................ 31 3.2. RNA and DNA methods ........................................................................................ 32 3.3. Cell culture methods .............................................................................................. 33 3.4. Immunological methods ....................................................................................... 33 3.5. In silico methods ..................................................................................................... 34 4. Results and discussion ..........................................................................................35 4.1. GDNF induced genes in cell culture .................................................................... 35 4.2. GDNF induced genes in animal models ............................................................. 37 4.3. Dopaminergic system of GDNF heterozygous mutant mice ............................ 40 4.4. Dopaminergic system of MEN2B knock-in mice .............................................. 41 4.5. A new method to assay the survival of dopaminergic neurons in vitro .......... 44 4.6. Neurotrophic eff ects of VEGF-C in the dopaminergic system ........................ 45 4.7. GDNF eff ects in the vascular system ................................................................... 48 4.8. Crosstalk of neuronal and vascular systems ....................................................... 49 5. Concluding remarks .............................................................................................51 6. Acknowledgements ...............................................................................................52 7. References .........................................................................................................54 Selected Abbrevia ons 6-OHDA 6-hydroxydopamine ARTN artemin BBB blood-brain barrier BDNF brain-derived neurotrophic factor CDNF cerebral dopamine neurotrophic factor CNS central nervous system CNTF ciliary neurotrophic factor CPu caudate putamen DA dopamine DAT dopamine transporter ERK extracellular signal-regulated kinase FGF fi broblast growth factor GDNF Hz glial cell line-derived neurotrophic factor heterozygous mouse GDNF glial cell line-derived neurotrophic factor GFAP glial fi brillary acidic protein GFL GDNF family ligand GFRα GDNF family receptor alpha ICV intracerebroventricular IGF-1 insulin-like growth factor 1 IL-6 interleukin 6 L-DOPA L-3,4-dihydroxyphenylalanine, levodopa LIF leukemia inhibitory factor M/+ heterozygous knock-in Ret-MEN2B mouse M/M homozygous knock-in Ret-MEN2B mouse MANF mesencephalic astrocyte-derived neurotrophic factor MEN2A multiple endocrine neoplasia type 2 A MEN2B multiple endocrine neoplasia type 2 B MPTP 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine NCAM neural cell adhesion molecule NGF nerve growth factor NRP neuropilin NRTN neurturin NT-3 neurotrophin-3 NT-4 neurotrophin-4 NTF neurotrophic factor PD Parkinson’s disease pERK phosphorylated extracellular signal-regulated kinase qRT-PCR quantitative reverse transcriptase polymerase chain reaction RECA-1 rat endothelial cell antibody-1 RET rearranged during transfection SN substantia nigra STR striatum TH tyrosine hydroxylase VEGF-A vascular endothelial growth factor A VEGF-C vascular endothelial growth factor C VEGFR vascular endothelial growth factor receptor Wt wild type littermates VTA ventral tegmental area List of original publica ons Th is thesis is based on the following publications, which are referred in the text by Roman numerals and on unpublished results presented in the text. I Airavaara M, Planken A, Gaddnäs H, Piepponen TP, Saarma M, Ahtee L (2004). Increased extracellular dopamine concentrations and FosB/DeltaFosB expression in striatal brain areas of heterozygous GDNF knockout mice. European Journal of Neuroscience 20(9):2336-2344. II Mijatovic J, Airavaara M, Planken A, Auvinen P, Raasmaja A, Piepponen TP, Costantini F, Ahtee L, Saarma M (2007). Constitutive Ret activity in knock-in Multiple Endocrine Neoplasia type B mice induces profound elevation of brain dopamine concentration via enhanced synthesis and increases the number of THpositive cells in the substantia nigra. Journal of Neuroscience 27:4799-4809. III Planken A, Porokuokka LL, Hänninen AL, Tuominen RK, Andressoo JO (2010). Medium-throughput computer aided micro-island method to assay embryonic dopaminergic neuron cultures in vitro. Journal of Neuroscience Methods 194(1):122-131. IV Piltonen M*, Planken A*, Leskelä O, Leppänen VM, Auvinen P, Andressoo JO. Alitalo K, Saarma M, and Männistö PT (2011). Vascular endothelial growth factor –C (VEGF-C) acts as a neurotrophic factor for dopamine neurons in vitro and in vivo. Neuroscience 192:550-563. *Equal contribution to the publication. Reprints made with pemission of the copyright holder.