Caracterização de vias partilhadas por genes associados a doenças degenerativas de neurónios motores: da Drosophila a modelos celulares humanos de doença

Identifying shared pathways across MNDs and robust biomarkers for early detection and disease progression are core research challenges that so far have not been successfully met. The aim of the ComPASS project is to contribute to novel developments on both aspects by translating our team’s innovative discoveries in Drosophila models to relevant human systems. Our previous studies, focused on a systems-level, cross-disease characterization of common gene regulatory programs in pre-symptomatic Drosophila models of MND, established two important paradigms. The first is that distinct MND-associated genetic backgrounds converge onto specific protein functional consortia involved in critical neuronal functions. Although this signature was captured using transcriptomics and integrative data analysis approaches, the common functional impact will only become relevant and directly observable at the level of protein molecular machines, which must be characterized by biochemical methods. The second paradigm is that although displaying tissue-specific functions, justifying the predominantly neuronal disease phenotype, these molecular machines are composed of a very high number of ubiquitous elements, which are predicted to establish paralogous associations in other cell types. This observation implies that changes in the composition of these consortia should be detectable in non-neuronal cell types, with the potential to act as early dysfunction biomarkers. The fact that we were able to detect these disturbances in models that did not display any evidence of neurodegenerative phenotypes further supports this concept. The clear functional conservation of pathways leading to MND between Drosophila and human disease models implies the transferable nature of core principles across species. However, it is well known that the identification of gene orthologues offers several challenges, and the molecular networks established in each system have significant differences. Therefore, to achieve the aim outlined above, the project will involve the following specific objectives: 1) Computational cross-species and cross-tissue mapping of candidate functional protein consortia. 2) Functional analysis of neuromuscular junction dysfunction phenotypes linked to the disruption of identified NMD functional units in fly models. 3) Development of highly comparable, inducible SMN, FUS and TDP-43 RNAi neuroblastoma cell lines as novel models for the study of loss-of-function of MND disease genes. 4) Quantitative and functional characterization of candidate protein consortia in differentiated and undifferentiated model cell lines. 5) Validation of robust biomarkers in disease-relevant genetic backgrounds using patient-derived iPSCs. Bridging the current trend of large-scale, multi-omic approaches for unbiased discovery and the robustness of biochemical studies, this proposal sets objective standards for pursuing knowledge translation between complex, data-driven hypothesis derived from animal disease models, into a much-needed identification of actionable targets and biomarkers that can be used to benefit patients. The deep insights that will be gained from the highly detailed analysis of molecular machines acting across species and cell types will push our understanding of the molecular processes underlying MND diseases beyond the current state-of-the-art, generating invaluable insights for the biomedical research community.