Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis

Oculoleptomeningeal amyloidosis (OA) is a fatal and untreatable hereditary disease characterized by the accumulation of transthyretin (TTR) amyloid within the central nervous system. The mechanisms underlying the pathogenesis of OA, and in particular how amyloid triggers neuronal damage, are still u...

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Autores principales: Azevedo, E P, Ledo, J H, Barbosa, G, Sobrinho, M, Diniz, L, Fonseca, A C C, Gomes, F, Romão, L, Lima, F R S, Palhano, F L, Ferreira, S T, Foguel, D
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3789183/
https://www.ncbi.nlm.nih.gov/pubmed/24008733
http://dx.doi.org/10.1038/cddis.2013.325
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author Azevedo, E P
Ledo, J H
Barbosa, G
Sobrinho, M
Diniz, L
Fonseca, A C C
Gomes, F
Romão, L
Lima, F R S
Palhano, F L
Ferreira, S T
Foguel, D
author_facet Azevedo, E P
Ledo, J H
Barbosa, G
Sobrinho, M
Diniz, L
Fonseca, A C C
Gomes, F
Romão, L
Lima, F R S
Palhano, F L
Ferreira, S T
Foguel, D
author_sort Azevedo, E P
collection PubMed
description Oculoleptomeningeal amyloidosis (OA) is a fatal and untreatable hereditary disease characterized by the accumulation of transthyretin (TTR) amyloid within the central nervous system. The mechanisms underlying the pathogenesis of OA, and in particular how amyloid triggers neuronal damage, are still unknown. Here, we show that amyloid fibrils formed by a mutant form of TTR, A25T, activate microglia, leading to the secretion of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nitric oxide. Further, we found that A25T amyloid fibrils induce the activation of Akt, culminating in the translocation of NFκB to the nucleus of microglia. While A25T fibrils were not directly toxic to neurons, the exposure of neuronal cultures to media conditioned by fibril-activated microglia caused synapse loss that culminated in extensive neuronal death via apoptosis. Finally, intracerebroventricular (i.c.v.) injection of A25T fibrils caused microgliosis, increased brain TNF-α and IL-6 levels and cognitive deficits in mice, which could be prevented by minocycline treatment. These results indicate that A25T fibrils act as pro-inflammatory agents in OA, activating microglia and causing neuronal damage.
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spelling pubmed-37891832013-10-18 Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis Azevedo, E P Ledo, J H Barbosa, G Sobrinho, M Diniz, L Fonseca, A C C Gomes, F Romão, L Lima, F R S Palhano, F L Ferreira, S T Foguel, D Cell Death Dis Original Article Oculoleptomeningeal amyloidosis (OA) is a fatal and untreatable hereditary disease characterized by the accumulation of transthyretin (TTR) amyloid within the central nervous system. The mechanisms underlying the pathogenesis of OA, and in particular how amyloid triggers neuronal damage, are still unknown. Here, we show that amyloid fibrils formed by a mutant form of TTR, A25T, activate microglia, leading to the secretion of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and nitric oxide. Further, we found that A25T amyloid fibrils induce the activation of Akt, culminating in the translocation of NFκB to the nucleus of microglia. While A25T fibrils were not directly toxic to neurons, the exposure of neuronal cultures to media conditioned by fibril-activated microglia caused synapse loss that culminated in extensive neuronal death via apoptosis. Finally, intracerebroventricular (i.c.v.) injection of A25T fibrils caused microgliosis, increased brain TNF-α and IL-6 levels and cognitive deficits in mice, which could be prevented by minocycline treatment. These results indicate that A25T fibrils act as pro-inflammatory agents in OA, activating microglia and causing neuronal damage. Nature Publishing Group 2013-09 2013-09-05 /pmc/articles/PMC3789183/ /pubmed/24008733 http://dx.doi.org/10.1038/cddis.2013.325 Text en Copyright © 2013 Macmillan Publishers Limited http://creativecommons.org/licenses/by-nc-sa/3.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/
spellingShingle Original Article
Azevedo, E P
Ledo, J H
Barbosa, G
Sobrinho, M
Diniz, L
Fonseca, A C C
Gomes, F
Romão, L
Lima, F R S
Palhano, F L
Ferreira, S T
Foguel, D
Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
title Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
title_full Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
title_fullStr Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
title_full_unstemmed Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
title_short Activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
title_sort activated microglia mediate synapse loss and short-term memory deficits in a mouse model of transthyretin-related oculoleptomeningeal amyloidosis
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3789183/
https://www.ncbi.nlm.nih.gov/pubmed/24008733
http://dx.doi.org/10.1038/cddis.2013.325
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