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RESEARCH PRODUCT

Architecture of cell differentiation, stress-mediated protein expression and transport in iPSC-derived Motor Neurons bearing a pG376D TDP-43 mutation

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description

BACKGROUND AND RATIONALE. ALS is a fatal neurodegenerative disease caused by loss of motoneurons (MNs). Growingevidence suggests that the disease has a strong genetic basis. Up to now, more than 50 ALS-related genes have beenfound. Among these, TARDBP plays a critical role in ALS. Pathogenic mutations in TARDBP gene are found in 1–3% offamilial ALS cases. A few years ago, a novel G376D TARDBP mutation associated to ALS was reported (Conforti et al, 2011). Recently, a verylarge genealogic tree from this G376D family was made (2HE Association, personal communication) leading to a largecollection of DNA, plasma and fibroblasts (FBs) from several family members, both affected and not clinically affected.The pattern of transmission appears dominant, though the penetrance is incomplete. The availability of such amplebiological material prompted us to study the role of this G376D mutation on the pathophysiology of the disease, with afocus on stress.BROAD OBJECTIVES. This project aims to dissect the molecular mechanisms leading to MN degeneration due to thepG376D TDP-43 mutation. To this objective we will use MNs from G376D FBs-derived iPSCs. We will study the growth anddifferentiation of the mutant MNs as compared to wild-type cells, and the role of cellular stress on cell degeneration.PROJECT DESIGN AND METHODS. FBs from pG376D TDP-43 mutation carriers will be deprogrammed to iPSCs. This part ofthe project will be carried out by an external partner. We will then differentiate the iPSC into MNs, and we will study themorphology, the pattern of cellular differentiation and neurite growth both in mutant and wild-type cells. Furthermore, theexpression and subcellular localization of the mutant TDP-43 will be studied in the iPSC-derived MNs. Then we will assessthe effects of acute and chronic stress on the subcellular distribution of TDP-43 in MNs from both asymptomatic andsymptomatic mutation carriers, and healthy controls (HCs). EXPECTED RESULTS. This pilot project will offer an initialvaluable, translational, approach to investigate the role of an aggressive TDP-43 mutation in differentiated iPSC-derivedMNs and the effect of cellular stress as a cell-autonomous factor involved in the neurodegenerative process. Amechanistic understanding of what occurs in preclinical models represents the basis for developing new therapies toprevent the development of this devastating MND.