The fumarprotocetraric acid inhibits tau covalently, avoiding cytotoxicity of aggregates in cells

• Published in: Molecules
• Main Authors: González, Camila, Cartagena, Constanza, Caballero, Leonardo, Melo, Francisco, Areche Medina, Carlos Alberto, Cornejo, Alberto
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI 2021
• Subjects: Lichens; Tauopathies; Alpha,beta carbonyl group; Inhibitors; Aggregates; Cytotoxicity; Antarctic; Inach; Antarc*; antartic*; Instituto Antartico Chileno
• Online Access: https://doi.org/10.3390/molecules26123760; https://repositorio.uchile.cl/handle/2250/182873

Neurodegenerative disorders, including Tauopathies that involve tau protein, base their pathological mechanism on forming proteinaceous aggregates, which has a deleterious effect on cells triggering an inflammatory response. Moreover, tau inhibitors can exert their mechanism of action through noncovalent and covalent interactions. Thus, Michael’s addition appears as a feasible type of interaction involving an , unsaturated carbonyl moiety to avoid pathological confirmation and further cytotoxicity. Moreover, we isolated three compounds from Antarctic lichens Cladonia cariosa and Himantormia lugubris: protolichesterinic acid (1), fumarprotocetraric acid (2), and lichesterinic acid (3). The maleimide cysteine labeling assay showed that compounds 1, 2, and 3 inhibit at 50 M, but compounds 2 and 3 are statistically significant. Based on its inhibition capacity, we decided to test compound 2 further. Thus, our results suggest that compound 2 remodel soluble oligomers and diminish sheet content, as demonstrated through ThT experiments. Hence, we added externally treated oligomers with compound 2 to demonstrate that they are harmless in cell culture. First, the morphology of cells in the presence of aggregates does not suffer evident changes compared to the control. Additionally, the externally added aggregates do not provoke a substantial LDH release compared to the control, indicating that treated oligomers do not provoke membrane damage in cell culture compared with aggregates alone. Thus, in the present work, we demonstrated that Michael’s acceptors found in lichens could serve as a scaffold to explore different mechanisms of action to turn tau aggregates into harmless species. Instituto Antartico Chileno (INACH) RT_18-19 ANID-Chile Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1201013 Fondequip EQM 130149 EQM 170111 Dicyt-Usach 041831MH Versión publicada - versión final del editor