Publicação
Investigations of S100 proteins and their role in huntingtin aggregation
| datacite.subject.fos | Departamento de Química e Bioquímica | pt_PT |
| dc.contributor.advisor | Gomes, Cláudio M. | |
| dc.contributor.advisor | Wanker, Erich E. | |
| dc.contributor.author | Botelho, Marta Sofia Silva da Cruz | |
| dc.date.accessioned | 2024-02-15T17:35:09Z | |
| dc.date.embargo | 2025-10-21 | |
| dc.date.issued | 2023 | |
| dc.date.submitted | 2023 | |
| dc.description | Tese de mestrado, Bioquímica e Biomedicina , 2023, Universidade de Lisboa, Faculdade de Ciências | pt_PT |
| dc.description.abstract | Huntington's disease (HD) is a progressive neurodegenerative disorder characterized by an autosomal dominant inheritance, leading to a triad of motor, cognitive, and behavioural symptoms. HD is an incurable disease caused by a CAG trinucleotide repeat expansion in the HTT gene, which translates into an expanded polyglutamine tract (polyQ) in the huntingtin (Htt) protein, leading to the formation of mutant huntingtin (mHtt). The expanded polyQ tract destabilizes the conformation of huntingtin, and promotes the assembly of amyloidogenic protein aggregates, primarily composed of N-terminal Htt fragments. This accumulation disrupts various essential brain functions, ultimately leading to neuronal degeneration. S100B is a calcium-binding alarmin that is predominantly synthesized by astrocytes in the nervous system. Depending on the concentration, S100B operates as an aggravating proinflammatory cytokine or as a protective anti-aggregation chaperone, inhibiting amyloid aggregation and mitigating toxicity in the presence of Ca2+ . Considering S100B's significance in other neurodegenerative conditions and its chaperone role, this work aims to explore its potential involvement in huntingtin aggregation and in HD pathology. To address this, both cellular assays and in vitro assays were performed. First, interactions between S100B and huntingtin were investigated using a dual luminescence-based co-immunoprecipitation assay (LuTHy), for detection of protein-protein interactions in mammalian cells. Secondly, the effects of endogenous and exogenous S100B on live cells expressing wild-type and mutant huntingtin were studied through bimolecular fluorescence complementation (BiFC) assays, to evaluate potential changes in the amounts and dynamics of Htt inclusions. Furthermore, in vitro assays explored how the S100B protein influences Htt aggregation, employing a FRET-based Htt aggregate seeding (FRASE) approach, which revealed that S100B significantly delays and inhibits Htt aggregation, while operating at suprastoichiometric concentrations. With this work, it is expected to unravel the relationship between HD and the S100B protein, which might constitute a foundation for the development of novel therapeutic approaches. | pt_PT |
| dc.identifier.tid | 203489578 | |
| dc.identifier.uri | http://hdl.handle.net/10451/62657 | |
| dc.language.iso | eng | pt_PT |
| dc.subject | Doença de Huntington | pt_PT |
| dc.subject | huntingtina | pt_PT |
| dc.subject | agregação proteica | pt_PT |
| dc.subject | S100B | pt_PT |
| dc.subject | Teses de mestrado - 2023 | pt_PT |
| dc.title | Investigations of S100 proteins and their role in huntingtin aggregation | pt_PT |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | embargoedAccess | pt_PT |
| rcaap.type | masterThesis | pt_PT |
| thesis.degree.name | Tese de mestrado em Bioquímica e Biomedicina | pt_PT |