Shimobayashi, Etsuko. Mechanisms of PKC gamma-mediated inhibition of dendritic growth in cerebellar purkinje cells. 2016, PhD Thesis, University of Basel, Faculty of Science.
Official URL: http://edoc.unibas.ch/diss/DissB_11970
In this project, we took advantage of a mouse model for SCA14, which was developed in our lab. In S361G mutated PKC gamma (mPKCγ) transgenic mice carrying a PKCγ transgene with a mutation from a human SCA14 allele we have shown that PKC activity is increased and Purkinje cell dendritic growth is strongly inhibited in slice cultures. We then tested whether other SCA14 mutations, in particular located in the C1 domain, would show similar effects on Purkinje cell dendritic development as the S361G mutation. We constructed several PKCγ mutants carrying mutations from human SCA14 patients and transfected them to Purkinje cells. We found that mutations in the catalytic domain caused severe inhibition of Purkinje cell dendritic development. In contrast, mutations in the C1 domain didn’t show this effect. Our findings suggest that mutations in the PKCγ gene causing SCA14 can have different effects on PKC biological activity in Purkinje cells and that multiple mechanism may be involved in the pathogenesis of SCA14. In order to search for molecules involved in signal transduction of mPKCγ, we performed a gene chip microarray analysis using mPKCγ transgenic mice and identified Carbonic anhydrase 8 (Car8) and type 1 inositol 1, 4, 5-trisphosphate receptor (IP3R1) as mRNAs and proteins being upregulated in mPKCγ transgenic mice. Furthermore, Car8 over-expression in Purkinje cells resulted in the formation of small, stunted dendritic trees in Purkinje cell similar to those after PKCγ activation implying that Car8 negatively regulates dendritic development. On the other hand, Car8 knocked down failed to rescue the morphology of the dendritic tree in Purkinje cells from mPKCγ transgenic mice or after pharmacological PKC activation. This indicates that Car8 is not directly downstream of mPKCγ signalling for Purkinje cell dendritic development but is likely to be part of a larger signalling network including PKCγ and IP3R1 which controls dendritic growth of Purkinje cells.
|Advisors:||Kapfhammer, Josef and Rüegg, Markus and Schaeren-Wiemers, Nicole|
|Faculties and Departments:||03 Faculty of Medicine > Departement Biomedizin > Division of Anatomy > Developmental Neurobiology and Regeneration (Kapfhammer)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||1 Online-Ressource (151 Seiten)|
|Last Modified:||22 Dec 2016 10:49|
|Deposited On:||22 Dec 2016 10:49|
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