Systematic Analysis of disease pathways in Congenital, Infantile and Juvenile Neuronal Ceroid Lipofuscinoses

Neuronal ceroid lipofuscinoses (NCL) are common inherited childhood brain disorders. Since 1995, 13 known NCL causative genes (CLN1-8, CLN10-14) have been identified. Despite progress in the NCL field, the primary function and physiological roles of most NCL proteins remain unresolved. In this thesis, we utilized various techniques, such as: functional proteomics, bioinformatics, and mouse disease models, in an effort to clarify disease pathways associated with congenital (CLN10), infantile, late-Infantile (CLN1, CLN5) and juvenile NCL (CLN3) in the human brain. Firstly, we examined the synaptic proteome in a cathepsin D (Ctsd / Cln10) knockout mouse model of congenital NCL, where the synaptic pathology resembles that of patients. Quantitative mass spectrometry analysis of mouse brain synaptosomes, showed that 43 proteins were differentially expressed in the Ctsd knockout mice brains. We used protein-protein interaction databases to generate a network of differentially expressed proteins and checked individual proteins for involvement in processes, pathways or disease phenotypes. This work highlighted defects in migratory functions of cathepsin D deficient cells that were attributed to downregulation of cytoskeletal proteins. We also aimed to map the CLN3-CLN5 protein interactome in the brain by identifying their associated proteins. Protein complexes from CLN3 or CLN5 expressing SH-SY5Y stable cells were analysed by mass spectrometry and processed by bioinformatics, to unravel molecular mechanisms underlying CLN3 and CLN5 diseases. Novel CLN3 and CLN5 interacting partners (42 and 31, respectively) were identified in this study. The extent of crosstalk amongst CLN3 and CLN5, suggests that the mechanisms leading to the functional deficits are shared between them. CLN3 was implicated in new roles of G-protein signalling and protein folding / sorting in the ER. Finally, we analysed protein complexes from human PPT1 (CLN1) expressing SH-SY5Y stable cells as described above. The goal of this study was to identify in vivo PPT1 substrates that could provide insight on the onset and progression of CLN1 disease. Our findings suggest putative new roles of PPT1 in neuronal migration and dopamine receptor mediated signalling pathway.

Grantor dc:publisher

Helsingin yliopisto

Year dc:date.issued

2014

Author dc:creator

• Scifo, Enzo

• biomedicine

Statement dc:rights

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Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/10138/136286

OAI record oai:identifier

https://helda.helsinki.fi/server/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Ahelda.helsinki.fi%3A10138%2F136286