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Sanchez-Varo R, Sanchez-Mejias E, Fernandez-Valenzuela JJ, De Castro V, Mejias-Ortega M, Gomez-Arboledas A, Jimenez S, Sanchez-Mico MV, Trujillo-Estrada L, Moreno-Gonzalez I, Baglietto-Vargas D, Vizuete M, Davila JC, Vitorica J, Gutierrez A. Plaque-Associated Oligomeric Amyloid-Beta Drives Early Synaptotoxicity in APP/PS1 Mice Hippocampus: Ultrastructural Pathology Analysis. Front Neurosci 2021; 15:752594. [PMID: 34803589 PMCID: PMC8600261 DOI: 10.3389/fnins.2021.752594] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/04/2021] [Indexed: 01/14/2023] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disorder characterized by initial memory impairments that progress to dementia. In this sense, synaptic dysfunction and loss have been established as the pathological features that best correlate with the typical early cognitive decline in this disease. At the histopathological level, post mortem AD brains typically exhibit intraneuronal neurofibrillary tangles (NFTs) along with the accumulation of amyloid-beta (Abeta) peptides in the form of extracellular deposits. Specifically, the oligomeric soluble forms of Abeta are considered the most synaptotoxic species. In addition, neuritic plaques are Abeta deposits surrounded by activated microglia and astroglia cells together with abnormal swellings of neuronal processes named dystrophic neurites. These periplaque aberrant neurites are mostly presynaptic elements and represent the first pathological indicator of synaptic dysfunction. In terms of losing synaptic proteins, the hippocampus is one of the brain regions most affected in AD patients. In this work, we report an early decline in spatial memory, along with hippocampal synaptic changes, in an amyloidogenic APP/PS1 transgenic model. Quantitative electron microscopy revealed a spatial synaptotoxic pattern around neuritic plaques with significant loss of periplaque synaptic terminals, showing rising synapse loss close to the border, especially in larger plaques. Moreover, dystrophic presynapses were filled with autophagic vesicles in detriment of the presynaptic vesicular density, probably interfering with synaptic function at very early synaptopathological disease stages. Electron immunogold labeling showed that the periphery of amyloid plaques, and the associated dystrophic neurites, was enriched in Abeta oligomers supporting an extracellular location of the synaptotoxins. Finally, the incubation of primary neurons with soluble fractions derived from 6-month-old APP/PS1 hippocampus induced significant loss of synaptic proteins, but not neuronal death. Indeed, this preclinical transgenic model could serve to investigate therapies targeted at initial stages of synaptic dysfunction relevant to the prodromal and early AD.
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Affiliation(s)
- Raquel Sanchez-Varo
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Fisiologia Humana, Histologia Humana, Anatomia Patologica y Educacion Fisica y Deportiva, Facultad de Medicina, Universidad de Málaga, Málaga, Spain
| | - Elisabeth Sanchez-Mejias
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Juan Jose Fernandez-Valenzuela
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Vanessa De Castro
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Marina Mejias-Ortega
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Angela Gomez-Arboledas
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Sebastian Jimenez
- Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio CSIC/Universidad de Sevilla, Seville, Spain
| | - Maria Virtudes Sanchez-Mico
- Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio CSIC/Universidad de Sevilla, Seville, Spain
| | - Laura Trujillo-Estrada
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Ines Moreno-Gonzalez
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Department of Neurology, McGovern Medical School, UTHealth Science Center at Houston, Houston, TX, United States
| | - David Baglietto-Vargas
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Marisa Vizuete
- Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio CSIC/Universidad de Sevilla, Seville, Spain
| | - Jose Carlos Davila
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Javier Vitorica
- Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio CSIC/Universidad de Sevilla, Seville, Spain
| | - Antonia Gutierrez
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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2
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Fernandez-Valenzuela JJ, Sanchez-Varo R, Muñoz-Castro C, De Castro V, Sanchez-Mejias E, Navarro V, Jimenez S, Nuñez-Diaz C, Gomez-Arboledas A, Moreno-Gonzalez I, Vizuete M, Davila JC, Vitorica J, Gutierrez A. Enhancing microtubule stabilization rescues cognitive deficits and ameliorates pathological phenotype in an amyloidogenic Alzheimer's disease model. Sci Rep 2020; 10:14776. [PMID: 32901091 PMCID: PMC7479116 DOI: 10.1038/s41598-020-71767-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 08/18/2020] [Indexed: 01/10/2023] Open
Abstract
In Alzheimer's disease (AD), and other tauopathies, microtubule destabilization compromises axonal and synaptic integrity contributing to neurodegeneration. These diseases are characterized by the intracellular accumulation of hyperphosphorylated tau leading to neurofibrillary pathology. AD brains also accumulate amyloid-beta (Aβ) deposits. However, the effect of microtubule stabilizing agents on Aβ pathology has not been assessed so far. Here we have evaluated the impact of the brain-penetrant microtubule-stabilizing agent Epothilone D (EpoD) in an amyloidogenic model of AD. Three-month-old APP/PS1 mice, before the pathology onset, were weekly injected with EpoD for 3 months. Treated mice showed significant decrease in the phospho-tau levels and, more interesting, in the intracellular and extracellular hippocampal Aβ accumulation, including the soluble oligomeric forms. Moreover, a significant cognitive improvement and amelioration of the synaptic and neuritic pathology was found. Remarkably, EpoD exerted a neuroprotective effect on SOM-interneurons, a highly AD-vulnerable GABAergic subpopulation. Therefore, our results suggested that EpoD improved microtubule dynamics and axonal transport in an AD-like context, reducing tau and Aβ levels and promoting neuronal and cognitive protection. These results underline the existence of a crosstalk between cytoskeleton pathology and the two major AD protein lesions. Therefore, microtubule stabilizers could be considered therapeutic agents to slow the progression of both tau and Aβ pathology.
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Affiliation(s)
- Juan Jose Fernandez-Valenzuela
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Raquel Sanchez-Varo
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Clara Muñoz-Castro
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, C/Prof. Garcia Gonzalez 2, 41012, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC, Universidad de Sevilla, Sevilla, Spain
| | - Vanessa De Castro
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain
| | - Elisabeth Sanchez-Mejias
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Victoria Navarro
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, C/Prof. Garcia Gonzalez 2, 41012, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC, Universidad de Sevilla, Sevilla, Spain
| | - Sebastian Jimenez
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, C/Prof. Garcia Gonzalez 2, 41012, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC, Universidad de Sevilla, Sevilla, Spain
| | - Cristina Nuñez-Diaz
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Angela Gomez-Arboledas
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Ines Moreno-Gonzalez
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Marisa Vizuete
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, C/Prof. Garcia Gonzalez 2, 41012, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC, Universidad de Sevilla, Sevilla, Spain
| | - Jose Carlos Davila
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Javier Vitorica
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain. .,Dpto. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, C/Prof. Garcia Gonzalez 2, 41012, Sevilla, Spain. .,Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio/CSIC, Universidad de Sevilla, Sevilla, Spain.
| | - Antonia Gutierrez
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
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Sanchez-Mejias E, Nuñez-Diaz C, Sanchez-Varo R, Gomez-Arboledas A, Garcia-Leon JA, Fernandez-Valenzuela JJ, Mejias-Ortega M, Trujillo-Estrada L, Baglietto-Vargas D, Moreno-Gonzalez I, Davila JC, Vitorica J, Gutierrez A. Distinct disease-sensitive GABAergic neurons in the perirhinal cortex of Alzheimer's mice and patients. Brain Pathol 2019; 30:345-363. [PMID: 31491047 PMCID: PMC7064898 DOI: 10.1111/bpa.12785] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 09/02/2019] [Indexed: 12/29/2022] Open
Abstract
Neuronal loss is the best neuropathological substrate that correlates with cortical atrophy and dementia in Alzheimer's disease (AD). Defective GABAergic neuronal functions may lead to cortical network hyperactivity and aberrant neuronal oscillations and in consequence, generate a detrimental alteration in memory processes. In this study, using immunohistochemical and stereological approaches, we report that the two major and non-overlapping groups of inhibitory interneurons (SOM-cells and PV-cells) displayed distinct vulnerability in the perirhinal cortex of APP/PS1 mice and AD patients. SOM-positive neurons were notably sensitive and exhibited a dramatic decrease in the perirhinal cortex of 6-month-old transgenic mice (57% and 61% in areas 36 and 35, respectively) and, most importantly, in AD patients (91% in Braak V-VI cases). In addition, this interneuron degenerative process seems to occur in parallel, and closely related, with the progression of the amyloid pathology. However, the population expressing PV was unaffected in APP/PS1 mice while in AD brains suffered a pronounced and significant loss (69%). As a key component of cortico-hippocampal networks, the perirhinal cortex plays an important role in memory processes, especially in familiarity-based memory recognition. Therefore, disrupted functional connectivity of this cortical region, as a result of the early SOM and PV neurodegeneration, might contribute to the altered brain rhythms and cognitive failures observed in the initial clinical phase of AD patients. Finally, these findings highlight the failure of amyloidogenic AD models to fully recapitulate the selective neuronal degeneration occurring in humans.
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Affiliation(s)
- Elisabeth Sanchez-Mejias
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Cristina Nuñez-Diaz
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Raquel Sanchez-Varo
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Angela Gomez-Arboledas
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Juan Antonio Garcia-Leon
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Juan Jose Fernandez-Valenzuela
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Marina Mejias-Ortega
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Laura Trujillo-Estrada
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - David Baglietto-Vargas
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Ines Moreno-Gonzalez
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Jose Carlos Davila
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Javier Vitorica
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBIS)-Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Antonia Gutierrez
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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Torres M, Jimenez S, Sanchez-Varo R, Navarro V, Trujillo-Estrada L, Sanchez-Mejias E, Carmona I, Davila JC, Vizuete M, Gutierrez A, Vitorica J. Defective lysosomal proteolysis and axonal transport are early pathogenic events that worsen with age leading to increased APP metabolism and synaptic Abeta in transgenic APP/PS1 hippocampus. Mol Neurodegener 2012; 7:59. [PMID: 23173743 PMCID: PMC3575255 DOI: 10.1186/1750-1326-7-59] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 11/04/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Axonal pathology might constitute one of the earliest manifestations of Alzheimer disease. Axonal dystrophies were observed in Alzheimer's patients and transgenic models at early ages. These axonal dystrophies could reflect the disruption of axonal transport and the accumulation of multiple vesicles at local points. It has been also proposed that dystrophies might interfere with normal intracellular proteolysis. In this work, we have investigated the progression of the hippocampal pathology and the possible implication in Abeta production in young (6 months) and aged (18 months) PS1(M146L)/APP(751sl) transgenic mice. RESULTS Our data demonstrated the existence of a progressive, age-dependent, formation of axonal dystrophies, mainly located in contact with congophilic Abeta deposition, which exhibited tau and neurofilament hyperphosphorylation. This progressive pathology was paralleled with decreased expression of the motor proteins kinesin and dynein. Furthermore, we also observed an early decrease in the activity of cathepsins B and D, progressing to a deep inhibition of these lysosomal proteases at late ages. This lysosomal impairment could be responsible for the accumulation of LC3-II and ubiquitinated proteins within axonal dystrophies. We have also investigated the repercussion of these deficiencies on the APP metabolism. Our data demonstrated the existence of an increase in the amyloidogenic pathway, which was reflected by the accumulation of hAPPfl, C99 fragment, intracellular Abeta in parallel with an increase in BACE and gamma-secretase activities. In vitro experiments, using APPswe transfected N2a cells, demonstrated that any imbalance on the proteolytic systems reproduced the in vivo alterations in APP metabolism. Finally, our data also demonstrated that Abeta peptides were preferentially accumulated in isolated synaptosomes. CONCLUSION A progressive age-dependent cytoskeletal pathology along with a reduction of lysosomal and, in minor extent, proteasomal activity could be directly implicated in the progressive accumulation of APP derived fragments (and Abeta peptides) in parallel with the increase of BACE-1 and gamma-secretase activities. This retard in the APP metabolism seemed to be directly implicated in the synaptic Abeta accumulation and, in consequence, in the pathology progression between synaptically connected regions.
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Affiliation(s)
- Manuel Torres
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Cientificas Universidad de Sevilla, c/ Manuel Siurot s/n, 41013, Sevilla, Spain
- Department Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, 41012, Spain
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Sebastian Jimenez
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Cientificas Universidad de Sevilla, c/ Manuel Siurot s/n, 41013, Sevilla, Spain
- Department Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, 41012, Spain
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Raquel Sanchez-Varo
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Department Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Universidad de Malaga, Malaga, 29071, Spain
| | - Victoria Navarro
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Cientificas Universidad de Sevilla, c/ Manuel Siurot s/n, 41013, Sevilla, Spain
- Department Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, 41012, Spain
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Laura Trujillo-Estrada
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Department Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Universidad de Malaga, Malaga, 29071, Spain
| | - Elisabeth Sanchez-Mejias
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Department Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Universidad de Malaga, Malaga, 29071, Spain
| | - Irene Carmona
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Cientificas Universidad de Sevilla, c/ Manuel Siurot s/n, 41013, Sevilla, Spain
- Department Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, 41012, Spain
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Jose Carlos Davila
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Department Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Universidad de Malaga, Malaga, 29071, Spain
| | - Marisa Vizuete
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Cientificas Universidad de Sevilla, c/ Manuel Siurot s/n, 41013, Sevilla, Spain
- Department Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, 41012, Spain
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Antonia Gutierrez
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Department Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Universidad de Malaga, Malaga, 29071, Spain
| | - Javier Vitorica
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocio, Consejo Superior de Investigaciones Cientificas Universidad de Sevilla, c/ Manuel Siurot s/n, 41013, Sevilla, Spain
- Department Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, 41012, Spain
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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Sanchez-Varo R, Trujillo-Estrada L, Sanchez-Mejias E, Torres M, Baglietto-Vargas D, Moreno-Gonzalez I, De Castro V, Jimenez S, Ruano D, Vizuete M, Davila JC, Garcia-Verdugo JM, Jimenez AJ, Vitorica J, Gutierrez A. Abnormal accumulation of autophagic vesicles correlates with axonal and synaptic pathology in young Alzheimer's mice hippocampus. Acta Neuropathol 2012; 123:53-70. [PMID: 22020633 PMCID: PMC3249205 DOI: 10.1007/s00401-011-0896-x] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/27/2011] [Accepted: 10/13/2011] [Indexed: 12/25/2022]
Abstract
Dystrophic neurites associated with amyloid plaques precede neuronal death and manifest early in Alzheimer's disease (AD). In this work we have characterized the plaque-associated neuritic pathology in the hippocampus of young (4- to 6-month-old) PS1(M146L)/APP(751SL) mice model, as the initial degenerative process underlying functional disturbance prior to neuronal loss. Neuritic plaques accounted for almost all fibrillar deposits and an axonal origin of the dystrophies was demonstrated. The early induction of autophagy pathology was evidenced by increased protein levels of the autophagosome marker LC3 that was localized in the axonal dystrophies, and by electron microscopic identification of numerous autophagic vesicles filling and causing the axonal swellings. Early neuritic cytoskeletal defects determined by the presence of phosphorylated tau (AT8-positive) and actin-cofilin rods along with decreased levels of kinesin-1 and dynein motor proteins could be responsible for this extensive vesicle accumulation within dystrophic neurites. Although microsomal Aβ oligomers were identified, the presence of A11-immunopositive Aβ plaques also suggested a direct role of plaque-associated Aβ oligomers in defective axonal transport and disease progression. Most importantly, presynaptic terminals morphologically disrupted by abnormal autophagic vesicle buildup were identified ultrastructurally and further supported by synaptosome isolation. Finally, these early abnormalities in axonal and presynaptic structures might represent the morphological substrate of hippocampal dysfunction preceding synaptic and neuronal loss and could significantly contribute to AD pathology in the preclinical stages.
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Jimenez S, Torres M, Vizuete M, Sanchez-Varo R, Sanchez-Mejias E, Trujillo-Estrada L, Carmona-Cuenca I, Caballero C, Ruano D, Gutierrez A, Vitorica J. Age-dependent accumulation of soluble amyloid beta (Abeta) oligomers reverses the neuroprotective effect of soluble amyloid precursor protein-alpha (sAPP(alpha)) by modulating phosphatidylinositol 3-kinase (PI3K)/Akt-GSK-3beta pathway in Alzheimer mouse model. J Biol Chem 2011; 286:18414-25. [PMID: 21460223 PMCID: PMC3099658 DOI: 10.1074/jbc.m110.209718] [Citation(s) in RCA: 145] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 03/04/2011] [Indexed: 01/04/2023] Open
Abstract
Neurotrophins, activating the PI3K/Akt signaling pathway, control neuronal survival and plasticity. Alterations in NGF, BDNF, IGF-1, or insulin signaling are implicated in the pathogenesis of Alzheimer disease. We have previously characterized a bigenic PS1×APP transgenic mouse displaying early hippocampal Aβ deposition (3 to 4 months) but late (17 to 18 months) neurodegeneration of pyramidal cells, paralleled to the accumulation of soluble Aβ oligomers. We hypothesized that PI3K/Akt/GSK-3β signaling pathway could be involved in this apparent age-dependent neuroprotective/neurodegenerative status. In fact, our data demonstrated that, as compared with age-matched nontransgenic controls, the Ser-9 phosphorylation of GSK-3β was increased in the 6-month PS1×APP hippocampus, whereas in aged PS1×APP animals (18 months), GSK-3β phosphorylation levels displayed a marked decrease. Using N2a and primary neuronal cell cultures, we demonstrated that soluble amyloid precursor protein-α (sAPPα), the predominant APP-derived fragment in young PS1×APP mice, acting through IGF-1 and/or insulin receptors, activated the PI3K/Akt pathway, phosphorylated the GSK-3β activity, and in consequence, exerted a neuroprotective action. On the contrary, several oligomeric Aβ forms, present in the soluble fractions of aged PS1×APP mice, inhibited the induced phosphorylation of Akt/GSK-3β and decreased the neuronal survival. Furthermore, synthetic Aβ oligomers blocked the effect mediated by different neurotrophins (NGF, BDNF, insulin, and IGF-1) and sAPPα, displaying high selectivity for NGF. In conclusion, the age-dependent appearance of APP-derived soluble factors modulated the PI3K/Akt/GSK-3β signaling pathway through the major neurotrophin receptors. sAPPα stimulated and Aβ oligomers blocked the prosurvival signaling. Our data might provide insights into the selective vulnerability of specific neuronal groups in Alzheimer disease.
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Affiliation(s)
- Sebastian Jimenez
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Manuel Torres
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Marisa Vizuete
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Raquel Sanchez-Varo
- the Departamento Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
| | - Elisabeth Sanchez-Mejias
- the Departamento Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
| | - Laura Trujillo-Estrada
- the Departamento Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
| | - Irene Carmona-Cuenca
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Cristina Caballero
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Diego Ruano
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Antonia Gutierrez
- the Departamento Biología Celular, Genética y Fisiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
| | - Javier Vitorica
- From the Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla
- the Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, 41013 Sevilla, and
- the Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
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Inflammatory response in the hippocampus of PS1M146L/APP751SL mouse model of Alzheimer's disease: age-dependent switch in the microglial phenotype from alternative to classic. J Neurosci 2008; 28:11650-61. [PMID: 18987201 DOI: 10.1523/jneurosci.3024-08.2008] [Citation(s) in RCA: 291] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Although the microglial activation is concomitant to the Alzheimer's disease, its precise role (neuroprotection vs neurodegeneration) has not yet been resolved. Here, we show the existence of an age-dependent phenotypic change of microglial activation in the hippocampus of PS1xAPP model, from an alternative activation state with Abeta phagocytic capabilities (at 6 months) to a classic cytotoxic phenotype (expressing TNF-alpha and related factors) at 18 months of age. This switch was coincident with high levels of soluble Abeta oligomers and a significant pyramidal neurodegeneration. In vitro assays, using astromicroglial cultures, demonstrated that oligomeric Abeta42 and soluble extracts from 18-month-old PS1xAPP hippocampus produced a potent TNF-alpha induction whereas monomeric Abeta42 and soluble extract from 6- or 18-month-old control and 6-month-old PS1xAPP hippocampi produced no stimulation. This stimulatory effect was avoided by immunodepletion using 6E10 or A11. In conclusion, our results show evidence of a switch in the activated microglia phenotype from alternative, at the beginning of Abeta pathology, to a classical at advanced stage of the disease in this model. This change was induced, at least in part, by the age-dependent accumulation of extracellular soluble Abeta oligomers. Finally, these cytotoxic activated microglial cells could participate in the neuronal lost observed in AD.
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