TY  - THES
AU  - Hebestreit, Alina
TI  - A Cell Panel to Characterise Tau Aggregation
PB  - Rheinische Friedrich-Wilhelms-Universität Bonn
VL  - Dissertation
M1  - DZNE-2025-00136
SP  - 125 p.
PY  - 2025
N1  - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn, 2024
AB  - Tauopathies are neurodegenerative diseases characterised by the pathological folding of Tau into highly ordered, !3-sheet rich fibrils (so-called amyloid), which progressively spreadthrough the central nervous system in a prion-like manner. Despite extensive research, interand intracellular prion-like Tau aggregate formation and transmission mechanisms remainunresolved. Tauopathies can be classified based on the aggregating Tau isoforms, which differ in the number of amino-terminal inserts (1 N, 2N) and the number of repeats (3R or 4R).Cryogenic electron microscopy (cryoEM) revealed distinct Tau amyloid core structures associated with different Tauopathies. The clinical presentation and progression of these diseases are highly variable, potentially related to the accumulation of disease-specific Tau aggregates with amyloid cores that comprise shorter or longer stretches of the repeat region.However, the impact of these distinct amyloid folds on the prion-like spreading of Tau aggregates remains to be fully understood. This project had two aims. First, we used a semiautomatedhigh-throughput screen to identify Tau aggregation inhibitors. A previously established HEK cell line expressing the P301 LJV337M Tau 4R repeat domain was used for the screen. Two hits were identified in a library of 144 compounds that effectively inhibited Tau aggregation. Second, a cell panel expressing different Tau fragments based on the cryoEM Tau amyloid cores was established. The commonly used Tau repeat domain fragments might not represent the most suitable model to study Tau aggregation as the length of the Tau variants might affect its fibril conformation. The exact regions that form the core of the amyloid fibril might allow only selective intramolecular interactions, potentially enabling disease-specific seeding. Therefore, we established cell lines expressing the short cryoEM Tau core fragments associated with different Tauopathies (AD, CBD, PSP and PiD). Our data showed that highly expressed cryoEM Tau core fragments spontaneously aggregate. Cells with weak stable expression and no spontaneous aggregation were generated to investigate fibril-induced seeding. We demonstrated that the length and number of repeats of our Tau fragments influence the efficiency by which they are misfolded by exogenous Tau 3R or 4R fibrils. Tau fragments were seeded best by patient-derived Tau fibrils with an amyloid core of identical length and repeat number. The length of the expressed cryoEM Tau core fragments likely allows only the assembly of specific core conformations due to possibly fewer and more selective intramolecular interactions. In summary, our cell panel can discriminate between 3R, 4R and mixed 3R/4R Tauopathies. The inter- and intracellular mechanisms involved in Tau aggregation and propagation can be investigated using our cell panel assay. Our data can help to develop new therapeutic strategies to inhibit or reduce the aggregation of Tau by compounds.
LB  - PUB:(DE-HGF)11
UR  - https://pub.dzne.de/record/275903
ER  -