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The search for antiprion compounds has been encouraged by the fact that transmissible spongiform encephalopathies (TSEs) share molecular mechanisms with more prevalent neurodegenerative pathologies, such as Parkinson's and Alzheimer's diseases. Cellular prion protein (PrP) conversion into protease-resistant forms (protease-resistant PrP [PrP] or the scrapie form of PrP [PrP]) is a critical step in the development of TSEs and is thus one of the main targets in the screening for antiprion compounds. In this work, three trimethoxychalcones (compounds J1, J8, and J20) and one oxadiazole (compound Y17), previously identified to be potential antiprion compounds, were evaluated through different approaches in order to gain inferences about their mechanisms of action. None of them changed PrP mRNA levels in N2a cells, as shown by reverse transcription-quantitative real-time PCR. Among them, J8 and Y17 were effective in real-time quaking-induced conversion reactions using rodent recombinant PrP (rPrP) from residues 23 to 231 (rPrP) as the substrate and PrP seeds from hamster and human brain. However, when rPrP from residues 90 to 231 (rPrP), which lacks the N-terminal domain, was used as the substrate, only J8 remained effective, indicating that this region is important for Y17 activity, while J8 seems to interact with the PrP globular domain. J8 also reduced the fibrillation of mouse rPrP seeded with -produced fibrils. Furthermore, most of the compounds decreased the amount of PrP on the N2a cell surface by trapping this protein in the endoplasmic reticulum. On the basis of these results, we hypothesize that J8, a nontoxic compound previously shown to be a promising antiprion agent, may act by different mechanisms, since its efficacy is attributable not only to PrP conversion inhibition but also to a reduction of the PrP content on the cell surface.

Este artigo apresenta uma ferramenta para modelagem de características para linhas de produtos de software sensíveis ao contexto. UbiFEX utiliza como base a notação de mesmo nome, que permite a representação de forma explícita das entidades e informações de contexto relevantes para o domínio e a influência desse tipo de informação na variabilidade dos produtos. Além disso, uma ferramenta para simulação de contextos foi desenvolvida com o objetivo de verificar em tempo de desenvolvimento a consistência da reconfiguração dinâmica dos produtos.

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