Huntington's disease: from experimental results to interaction networks, patho-pathway construction and disease hypothesis
© Gonzalez-Couto et al; licensee BioMed Central Ltd. 2007
Published: 8 May 2007
Protein-protein interaction networks and mechanistic pathway models are excellent tools in the drug discovery process. They can be used to identify and select targets for a given disease hypothesis. Combining information from diverse sources, like in house experiments as well as literature, allows further development of interaction networks into detailed descriptions of cellular pathways. Computerized pathway diagrams allow integrating all relevant data regarding a project into one framework by linking the different data sources. Interaction networks analysis and pathway design tools are used to support target identification and validation activities. Experimental results are incorporated in protein interaction networks, analyzed and further developed into biomolecular pathopathways including literature findings to understand the underlying modulation mechanisms. The pathway diagrams are also used as communication tools, particularly for interdisciplinary project teams, thus ensuring a common understanding and facilitating critical interrogations about disease hypotheses. The analyses of experimental results, the initial construction of an HD pathopathway are presented and two mechanistic disease hypotheses are discussed.
Materials and methods
Differential proteomics experiments (DPEs) were performed on rat PC12 cells containing either wild-type or mutant full-length (PolyQ) Huntingtin (Htt) under control of a doxycycline-inducible promoter . Cell extracts were prepared at 0, 12, and 48 hours post-induction to identify proteins involved in pre-apoptotic intracellular events. Protein expression modulation was measured using DIGE technology  followed by statistical analysis for spot selection and automated spot picking. The protein content of each picked spot was analyzed by mass spectrometry (MS).
DPE results were used to develop an HD pathopathway including proteins modulated by PolyQ Htt expression. In this experimental result set, the proteins from the Ubiquitin-Proteasome pathway were chosen for in depth analysis, and UCHL1 was identified as a component potentially playing opposite roles in HD.
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