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Sanders OD. Virus-Like Cytosolic and Cell-Free Oxidatively Damaged Nucleic Acids Likely Drive Inflammation, Synapse Degeneration, and Neuron Death in Alzheimer's Disease. J Alzheimers Dis Rep 2023; 7:1-19. [PMID: 36761106 PMCID: PMC9881037 DOI: 10.3233/adr-220047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/21/2022] [Indexed: 12/13/2022] Open
Abstract
Oxidative stress, inflammation, and amyloid-β are Alzheimer's disease (AD) hallmarks that cause each other and other AD hallmarks. Most amyloid-β-lowering, antioxidant, anti-inflammatory, and antimicrobial AD clinical trials failed; none stopped or reversed AD. Although signs suggest an infectious etiology, no pathogen accumulated consistently in AD patients. Neuropathology, neuronal cell culture, rodent, genome-wide association, epidemiological, biomarker, and clinical studies, plus analysis using Hill causality criteria and revised Koch's postulates, indicate that the virus-like oxidative damage-associated molecular-pattern (DAMP) cytosolic and cell-free nucleic acids accumulated in AD patients' brains likely drive neuroinflammation, synaptotoxicity, and neurotoxicity. Cytosolic oxidatively-damaged mitochondrial DNA accumulated outside mitochondria dose-dependently in preclinical AD and AD patients' hippocampal neurons, and in AD patients' neocortical neurons but not cerebellar neurons or glia. In oxidatively-stressed neural cells and rodents' brains, cytosolic oxidatively-damaged mitochondrial DNA accumulated and increased antiviral and inflammatory proteins, including cleaved caspase-1, interleukin-1β, and interferon-β. Cytosolic double-stranded RNA and DNA are DAMPs that induce antiviral interferons and/or inflammatory proteins by oligomerizing with various innate-immune pattern-recognition receptors, e.g., cyclic GMP-AMP synthase and the nucleotide-binding-oligomerization-domain-like-receptor-pyrin-domain-containing-3 inflammasome. In oxidatively-stressed neural cells, cytosolic oxidatively-damaged mitochondrial DNA caused synaptotoxicity and neurotoxicity. Depleting mitochondrial DNA prevented these effects. Additionally, cell-free nucleic acids accumulated in AD patients' blood, extracellular vesicles, and senile plaques. Injecting cell-free nucleic acids bound to albumin oligomers into wild-type mice's hippocampi triggered antiviral interferon-β secretion; interferon-β injection caused synapse degeneration. Deoxyribonuclease-I treatment appeared to improve a severe-AD patient's Mini-Mental Status Exam by 15 points. Preclinical and clinical studies of deoxyribonuclease-I and a ribonuclease for AD should be prioritized.
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Affiliation(s)
- Owen Davis Sanders
- Nebraska Medical Center, Omaha, NE, USA,Correspondence to: Owen Davis Sanders, 210 S 16th St. Apt. 215, Omaha, NE 68102, USA. E-mails: and
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2
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Noor A, Zafar S, Shafiq M, Younas N, Siegert A, Mann FA, Kruss S, Schmitz M, Dihazi H, Ferrer I, Zerr I. Molecular Profiles of Amyloid-β Proteoforms in Typical and Rapidly Progressive Alzheimer's Disease. Mol Neurobiol 2021; 59:17-34. [PMID: 34618331 PMCID: PMC8786784 DOI: 10.1007/s12035-021-02566-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/13/2021] [Indexed: 11/02/2022]
Abstract
The molecular determinants of atypical clinical variants of Alzheimer's disease, including the recently discovered rapidly progressive Alzheimer's disease (rpAD), are unknown to date. Fibrilization of the amyloid-β (Aβ) peptide is the most frequently studied candidate in this context. The Aβ peptide can exist as multiple proteoforms that vary in their post-translational processing, amyloidogenesis, and toxicity. The current study was designed to identify these variations in Alzheimer's disease patients exhibiting classical (sAD) and rapid progression, with the primary aim of establishing if these variants may constitute strains that underlie the phenotypic variability of Alzheimer's disease. We employed two-dimensional polyacrylamide gel electrophoresis and MALDI-ToF mass spectrometry to validate and identify the Aβ proteoforms extracted from targeted brain tissues. The biophysical analysis was conducted using RT-QuIC assay, confocal microscopy, and atomic force microscopy. Interactome analysis was performed by co-immunoprecipitation. We present a signature of 33 distinct pathophysiological proteoforms, including the commonly targeted Aβ40, Aβ42, Aβ4-42, Aβ11-42, and provide insight into their synthesis and quantities. Furthermore, we have validated the presence of highly hydrophobic Aβ seeds in rpAD brains that seeded reactions at a slower pace in comparison to typical Alzheimer's disease. In vitro and in vivo analyses also verified variations in the molecular pathways modulated by brain-derived Aβ. These variations in the presence, synthesis, folding, and interactions of Aβ among sAD and rpAD brains constitute important points of intervention. Further validation of reported targets and mechanisms will aid in the diagnosis of and therapy for Alzheimer's disease.
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Affiliation(s)
- Aneeqa Noor
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Saima Zafar
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany. .,Biomedical Engineering and Sciences Department, School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Bolan Road, Islamabad, H-12, 44000, Pakistan.
| | - Mohsin Shafiq
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany.,Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Neelam Younas
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Anna Siegert
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Florian A Mann
- Institute of Physical Chemistry, Georg-August University, Tammannstraße 6, 37077, Göttingen, Germany
| | - Sebastian Kruss
- Institute of Physical Chemistry, Georg-August University, Tammannstraße 6, 37077, Göttingen, Germany
| | - Matthias Schmitz
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Hassan Dihazi
- Department of Nephrology and Rheumatology, Georg-August University, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Isidre Ferrer
- Department of Pathology and Experimental Therapeutics, University of BarcelonaCIBERNEDBellvitge University Hospital (IDIBELL), Carrer de la Feixa Llarga, 08907, Hospitalet de Llobregat, Spain
| | - Inga Zerr
- Clinical Department of Neurology, University Medical Center Göttingen and the German Center for Neurodegenerative Diseases (DZNE), Robert-Koch-Straße 40, 37075, Göttingen, Germany
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3
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Sanchez-Mico MV, Jimenez S, Gomez-Arboledas A, Muñoz-Castro C, Romero-Molina C, Navarro V, Sanchez-Mejias E, Nuñez-Diaz C, Sanchez-Varo R, Galea E, Davila JC, Vizuete M, Gutierrez A, Vitorica J. Amyloid-β impairs the phagocytosis of dystrophic synapses by astrocytes in Alzheimer's disease. Glia 2020; 69:997-1011. [PMID: 33283891 DOI: 10.1002/glia.23943] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 12/27/2022]
Abstract
Reactive astrocytes and dystrophic neurites, most aberrant presynaptic elements, are found surrounding amyloid-β plaques in Alzheimer's disease (AD). We have previously shown that reactive astrocytes enwrap, phagocytose, and degrade dystrophic synapses in the hippocampus of APP mice and AD patients, but affecting less than 7% of dystrophic neurites, suggesting reduced phagocytic capacity of astrocytes in AD. Here, we aimed to gain insight into the underlying mechanisms by analyzing the capacity of primary astrocyte cultures to phagocytose and degrade isolated synapses (synaptoneurosomes, SNs) from APP (containing dystrophic synapses and amyloid-β peptides), Tau (containing AT8- and AT100-positive phosphorylated Tau) and WT (controls) mice. We found highly reduced phagocytic and degradative capacity of SNs-APP, but not AT8/AT100-positive SNs-Tau, as compared with SNs-WT. The reduced astrocyte phagocytic capacity was verified in hippocampus from 12-month-old APP mice, since only 1.60 ± 3.81% of peri-plaque astrocytes presented phagocytic structures. This low phagocytic capacity did not depend on microglia-mediated astrocyte reactivity, because removal of microglia from the primary astrocyte cultures abrogated the expression of microglia-dependent genes in astrocytes, but did not affect the phagocytic impairment induced by oligomeric amyloid-β alone. Taken together, our data suggest that amyloid-β, but not hyperphosphorylated Tau, directly impairs the capacity of astrocytes to clear the pathological accumulation of oligomeric amyloid-β, as well as of peri-plaque dystrophic synapses containing amyloid-β, perhaps by reducing the expression of phagocytosis receptors such as Mertk and Megf10, thus increasing neuronal damage in AD. Therefore, the potentiation or recovery of astrocytic phagocytosis may be a novel therapeutic avenue in AD.
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Affiliation(s)
- Maria V Sanchez-Mico
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, USA
| | - Sebastian Jimenez
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Angela Gomez-Arboledas
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Biologia Celular, Genetica y Fisiologia, Instituto de Investigación Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - Clara Muñoz-Castro
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Carmen Romero-Molina
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Victoria Navarro
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Elisabeth Sanchez-Mejias
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Biologia Celular, Genetica y Fisiologia, Instituto de Investigación Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - Cristina Nuñez-Diaz
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Biologia Celular, Genetica y Fisiologia, Instituto de Investigación Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - Raquel Sanchez-Varo
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Biologia Celular, Genetica y Fisiologia, Instituto de Investigación Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - Elena Galea
- Institut de Neurociències and Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,ICREA, Barcelona, Spain
| | - José C Davila
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Dpto. Biologia Celular, Genetica y Fisiologia, Instituto de Investigación Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - Marisa Vizuete
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, 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.,Dpto. Biologia Celular, Genetica y Fisiologia, Instituto de Investigación Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - Javier Vitorica
- Dpto. Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.,Instituto de Biomedicina de Sevilla (IBiS)-Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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4
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Pedrero-Prieto CM, Flores-Cuadrado A, Saiz-Sánchez D, Úbeda-Bañón I, Frontiñán-Rubio J, Alcaín FJ, Mateos-Hernández L, de la Fuente J, Durán-Prado M, Villar M, Martínez-Marcos A, Peinado JR. Human amyloid-β enriched extracts: evaluation of in vitro and in vivo internalization and molecular characterization. Alzheimers Res Ther 2019; 11:56. [PMID: 31253170 PMCID: PMC6599264 DOI: 10.1186/s13195-019-0513-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/12/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Intracerebral inoculation of extracts from post-mortem human Alzheimer's disease brains into mice produces a prion-like spreading effect of amyloid-β. The differences observed between these extracts and the synthetic peptide, in terms of amyloid-β internalization and seed and cell-to-cell transmission of cytosolic protein aggregates, suggest that brain extracts contain key contributors that enhance the prion-like effect of amyloid-β. Nevertheless, these potential partners are still unknown due to the complexity of whole brain extracts. METHODS Herein, we established a method based on sequential detergent solubilization of post-mortem samples of human brains affected by Alzheimer's disease that strongly enrich amyloid-β aggregates by eliminating 92% of the remaining proteins. Internalization of Aβ1-42 from the enriched AD extracts was evaluated in vitro, and internalization of fluorescent-labeled AD extracts was also investigated in vivo. Furthermore, we carried out a molecular characterization of the Aβ-enriched fraction using label-free proteomics, studying the distribution of representative components in the amygdala and the olfactory cortex of additional human AD brain samples by immunohistochemistry. RESULTS Aβ1-42 from the enriched AD extracts are internalized into endothelial cells in vitro after 48 h. Furthermore, accumulation of fluorescent-labeled Aβ-enriched extracts into mouse microglia was observed in vivo after 4 months of intracerebral inoculation. Label-free proteomics (FDR < 0.01) characterization of the amyloid-β-enriched fraction from different post-mortem samples allowed for the identification of more than 130 proteins, several of which were significantly overrepresented (i.e., ANXA5 and HIST1H2BK; p < 0.05) and underrepresented (i.e., COL6A or FN1; p < 0.05) in the samples with Alzheimer's disease. We were also able to identify proteins exclusively observed in Alzheimer's disease (i.e., RNF213) or only detected in samples not affected by the disease (i.e., CNTN1) after the enrichment process. Immunohistochemistry against these proteins in additional tissues revealed their particular distribution in the amygdala and the olfactory cortex in relation to the amyloid-β plaque. CONCLUSIONS Identification and characterization of the unique features of these extracts, in terms of amyloid-β enrichment, identification of the components, in vitro and in vivo cell internalization, and tissue distribution, constitute the best initial tool to further investigate the seeding and transmissibility proposed in the prion-like hypothesis of Alzheimer's disease.
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Affiliation(s)
- Cristina M. Pedrero-Prieto
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Alicia Flores-Cuadrado
- Department of Medical Sciences, Ciudad Real Medical School; Neuroplasticity and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Daniel Saiz-Sánchez
- Department of Medical Sciences, Ciudad Real Medical School; Neuroplasticity and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Isabel Úbeda-Bañón
- Department of Medical Sciences, Ciudad Real Medical School; Neuroplasticity and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Javier Frontiñán-Rubio
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Francisco J. Alcaín
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Lourdes Mateos-Hernández
- SaBio. Instituto de Investigación en Recursos Cinegéticos IREC, CSIC-UCLM-JCCM, Ciudad Real, Spain
- UMR BIPAR, INRA, ANSES, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94700 Maisons-Alfort, France
| | - José de la Fuente
- SaBio. Instituto de Investigación en Recursos Cinegéticos IREC, CSIC-UCLM-JCCM, Ciudad Real, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK USA
| | - Mario Durán-Prado
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Margarita Villar
- SaBio. Instituto de Investigación en Recursos Cinegéticos IREC, CSIC-UCLM-JCCM, Ciudad Real, Spain
| | - Alino Martínez-Marcos
- Department of Medical Sciences, Ciudad Real Medical School; Neuroplasticity and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Juan R. Peinado
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
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5
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Marciani DJ. Promising Results from Alzheimer's Disease Passive Immunotherapy Support the Development of a Preventive Vaccine. RESEARCH 2019; 2019:5341375. [PMID: 31549066 PMCID: PMC6750119 DOI: 10.34133/2019/5341375] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 04/18/2019] [Indexed: 12/23/2022]
Abstract
The apparently near-term effects of the monoclonal antibody BAN2401 in slowing the progression of prodromal Alzheimer's disease (AD) has created cautious optimism about the therapeutic use of antibodies that neutralize cytotoxic soluble amyloid-β aggregates, rather than removing plaque. Plaque being protective, as it immobilizes cytotoxic amyloid-β, rather than AD's causative agent. The presence of natural antibodies against cytotoxic amyloid-β implies the existence of a protective anti-AD immunity. Hence, for vaccines to induce a similar immunoresponse that prevents and/or delays the onset of AD, they must have adjuvants that stimulate a sole anti-inflammatory Th2 immunity, plus immunogens that induce a protective immunoresponse against diverse cytotoxic amyloid-β conformers. Indeed, amyloid-β pleomorphism may explain the lack of long-term protection by monoclonal antibodies that neutralize single conformers, like aducanumab. A situation that would allow new cytotoxic conformers to escape neutralization by previously effective monoclonal antibodies. Stimulation of a vaccine's effective immunoresponse would require the concurrent delivery of immunogen to dendritic cells and their priming, to induce a polarized Th2 immunity. An immunoresponse that would produce besides neutralizing antibodies against neurotoxic amyloid-β oligomers, anti-inflammatory cytokines; preventing inflammation that aggravates AD. Because of age-linked immune decline, vaccines would be significantly more effective in preventing, rather than treating AD. Considering the amyloid-β's role in tau's pathological hyperphosphorylation and their synergism in AD, the development of preventive vaccines against both amyloid-β and tau should be considered. Due to convenience and cost, vaccines may be the only option available to many countries to forestall the impending AD epidemic.
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Affiliation(s)
- D J Marciani
- Qantu Therapeutics, Inc., 612 E. Main Street, Lewisville, TX 75057, USA
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6
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Santiago-Mujica E, Flunkert S, Rabl R, Neddens J, Loeffler T, Hutter-Paier B. Hepatic and neuronal phenotype of NPC1 -/- mice. Heliyon 2019; 5:e01293. [PMID: 30923761 PMCID: PMC6423819 DOI: 10.1016/j.heliyon.2019.e01293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 01/15/2019] [Accepted: 02/26/2019] [Indexed: 12/14/2022] Open
Abstract
Niemann-Pick type C disease (NPC) is a fatal autosomal recessive disorder characterized by a defect in the intracellular transport of lipoproteins leading to the accumulation of lipids in diverse tissues. A visceral and neuronal phenotype mimicking human NPC1 disease has been described in NPC1 mutant mice. These mice are by now the most widely used NPC1 rodent model to study NPC and developmental compounds against this devastating disease. Here we characterized NPC1-/- mice for their hepatic and neuronal phenotype to confirm the stability of the phenotype, provide a characterization of disease progression and pinpoint the age of robust phenotype onset. Animals of 4-10 weeks of age were analyzed for general health, motor deficits as well as hepatic and neuronal alterations with a special focus on cerebellar pathology. Our results show that NPC1-/- mice have a reduced general health at the age of 9-10 weeks. Robust motor deficits can be observed even earlier at 8 weeks of age. Hepatic changes included increased organ weight and cholesterol levels at 6 weeks of age accompanied by severely increased liver enzyme levels. Analysis of NPC1-/- brain pathology showed decreased cholesterol and increased Aβ levels in the hippocampus at the age of 6 weeks. Further analysis revealed a decrease of the cytokine IL-12p70 in the cerebellum along with a very early increase of astrocytosis. Hippocampal IL-12p70 levels were increased at the age of 6 weeks followed by increased activated microglia levels. By the age of 10 weeks, also cerebellar Aβ levels were increased along with strongly reduced Calbindin D-28k levels. Our results validate and summarize the progressive development of the hepatic and neuronal phenotype of NPC1-/- mice that starts with cerebellar astrocytosis, making this mouse model a valuable tool for the development of new compounds against NPC.
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Key Words
- AAALAC, Association for Assessment and Accreditation of Laboratory Animal Care
- ALT, alanine aminotransferase
- ANOVA, Analysis of variance
- AOI, Area of interest
- AP, alkaline phosphatase
- APP, Amyloid Precursor Protein
- AST, aspartate aminotransferase
- CD45, cluster of differentiation 45
- CNS, central nervous system
- Cell biology
- DAPI, 4′,6-Diamidin-2-phenylindol
- GFAP, Glial fibrillary acidic protein
- IFN-γ, Interferon-gamma
- IL-10/12, Interleukin-10/12
- KC, keratinocyte chemoattractant
- MAP2, microtubuli-associated protein 2
- Molecular biology
- NPC, Niemann-Pick type C
- Neuroscience
- Physiology
- TNF-α, tumor necrosis factor-alpha
- WT, wildtype
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7
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Romero-Molina C, Navarro V, Sanchez-Varo R, Jimenez S, Fernandez-Valenzuela JJ, Sanchez-Mico MV, Muñoz-Castro C, Gutierrez A, Vitorica J, Vizuete M. Distinct Microglial Responses in Two Transgenic Murine Models of TAU Pathology. Front Cell Neurosci 2018; 12:421. [PMID: 30487735 PMCID: PMC6246744 DOI: 10.3389/fncel.2018.00421] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/26/2018] [Indexed: 11/18/2022] Open
Abstract
Microglial cells are crucial players in the pathological process of neurodegenerative diseases, such as Alzheimer’s disease (AD). Microglial response in AD has been principally studied in relation to amyloid-beta pathology but, comparatively, little is known about inflammatory processes associated to tau pathology. In the hippocampus of AD patients, where tau pathology is more prominent than amyloid-beta pathology, a microglial degenerative process has been reported. In this work, we have directly compared the microglial response in two different transgenic tau mouse models: ThyTau22 and P301S. Surprisingly, these two models showed important differences in the microglial profile and tau pathology. Where ThyTau22 hippocampus manifested mild microglial activation, P301S mice exhibited a strong microglial response in parallel with high phospho-tau accumulation. This differential phospho-tau expression could account for the different microglial response in these two tau strains. However, soluble (S1) fractions from ThyTau22 hippocampus presented relatively high content of soluble phospho-tau (AT8-positive) and were highly toxic for microglial cells in vitro, whereas the correspondent S1 fractions from P301S mice displayed low soluble phospho-tau levels and were not toxic for microglial cells. Therefore, not only the expression levels but the aggregation of phospho-tau should differ between both models. In fact, most of tau forms in the P301S mice were aggregated and, in consequence, forming insoluble tau species. We conclude that different factors as tau mutations, accumulation, phosphorylation, and/or aggregation could account for the distinct microglial responses observed in these two tau models. For this reason, deciphering the molecular nature of toxic tau species for microglial cells might be a promising therapeutic approach in order to restore the deficient immunological protection observed in AD hippocampus.
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Affiliation(s)
- Carmen Romero-Molina
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Victoria Navarro
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Raquel Sanchez-Varo
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Sebastian Jimenez
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Juan J Fernandez-Valenzuela
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Maria V Sanchez-Mico
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Clara Muñoz-Castro
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Antonia Gutierrez
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Javier Vitorica
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Marisa Vizuete
- Departamento Bioquimica y Biologia Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
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8
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Milanovic D, Petrovic S, Brkic M, Avramovic V, Perovic M, Ivkovic S, Glibetic M, Kanazir S. Short-Term Fish Oil Treatment Changes the Composition of Phospholipids While Not Affecting the Expression of Mfsd2a Omega-3 Transporter in the Brain and Liver of the 5xFAD Mouse Model of Alzheimer's Disease. Nutrients 2018; 10:nu10091250. [PMID: 30200627 PMCID: PMC6165196 DOI: 10.3390/nu10091250] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/25/2018] [Accepted: 08/28/2018] [Indexed: 01/22/2023] Open
Abstract
Long-term fish oil (FO) supplementation is able to improve Alzheimer’s disease (AD) pathology. We aimed to determine the impact of short-term fish oil (FO) intake on phospholipids composition and plaque pathology in 5xFAD mice, a widely used animal model of AD. A 3-week-long FO supplementation administered at 3 months of age decreased the number of dense core plaques in the 5xFAD cortex and changed phospholipids in the livers and brains of wild-type (Wt) and 5xFAD mice. Livers of both genotypes responded by increase of n-3 and reciprocal decrease of n-6 fatty acids. In Wt brains, FO supplementation induced elevation of n-3 fatty acids and subsequent enhancement of n-6/n-3 ratio. However, in 5xFAD brains the improved n-6/n-3 ratio was mainly due to FO-induced decrease in arachidonic and adrenic n-6 fatty acids. Also, brain and liver abundance of n-3 fatty acids were strongly correlated in Wts, oppositely to 5xFADs where significant brain-liver correlation exists only for n-6 fatty acids. Expression of omega-3 transporter Mfs2a remained unchanged after FO supplementation. We have demonstrated that even a short-term FO intake improves the phospholipid composition and has a significant effect on plaque burden in 5xFAD brains when applied in early stages of AD pathology.
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Affiliation(s)
- Desanka Milanovic
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Snjezana Petrovic
- Center of Excellence in Nutrition and Metabolism Research, CENM, Tadeusa Koscuska 1, 11000 Belgrade, Serbia.
| | - Marjana Brkic
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Vladimir Avramovic
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Milka Perovic
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Sanja Ivkovic
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Marija Glibetic
- Center of Excellence in Nutrition and Metabolism Research, CENM, Tadeusa Koscuska 1, 11000 Belgrade, Serbia.
| | - Selma Kanazir
- Department of Neurobiology, Institute for Biological Research, University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
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9
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Chatterjee S, Mudher A. Alzheimer's Disease and Type 2 Diabetes: A Critical Assessment of the Shared Pathological Traits. Front Neurosci 2018; 12:383. [PMID: 29950970 PMCID: PMC6008657 DOI: 10.3389/fnins.2018.00383] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/22/2018] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) and Type 2 Diabetes Mellitus (T2DM) are two of the most prevalent diseases in the elderly population worldwide. A growing body of epidemiological studies suggest that people with T2DM are at a higher risk of developing AD. Likewise, AD brains are less capable of glucose uptake from the surroundings resembling a condition of brain insulin resistance. Pathologically AD is characterized by extracellular plaques of Aβ and intracellular neurofibrillary tangles of hyperphosphorylated tau. T2DM, on the other hand is a metabolic disorder characterized by hyperglycemia and insulin resistance. In this review we have discussed how Insulin resistance in T2DM directly exacerbates Aβ and tau pathologies and elucidated the pathophysiological traits of synaptic dysfunction, inflammation, and autophagic impairments that are common to both diseases and indirectly impact Aβ and tau functions in the neurons. Elucidation of the underlying pathways that connect these two diseases will be immensely valuable for designing novel drug targets for Alzheimer's disease.
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Affiliation(s)
- Shreyasi Chatterjee
- Centre of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Amritpal Mudher
- Centre of Biological Sciences, University of Southampton, Southampton, United Kingdom
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10
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Navarro V, Sanchez-Mejias E, Jimenez S, Muñoz-Castro C, Sanchez-Varo R, Davila JC, Vizuete M, Gutierrez A, Vitorica J. Microglia in Alzheimer's Disease: Activated, Dysfunctional or Degenerative. Front Aging Neurosci 2018; 10:140. [PMID: 29867449 PMCID: PMC5958192 DOI: 10.3389/fnagi.2018.00140] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/25/2018] [Indexed: 12/11/2022] Open
Abstract
Microglial activation has been considered a crucial player in the pathological process of multiple human neurodegenerative diseases. In some of these pathologies, such as Amyotrophic Lateral Sclerosis or Multiple Sclerosis, the immune system and microglial cells (as part of the cerebral immunity) play a central role. In other degenerative processes, such as Alzheimer’s disease (AD), the role of microglia is far to be elucidated. In this “mini-review” article, we briefly highlight our recent data comparing the microglial response between amyloidogenic transgenic models, such as APP/PS1 and AD patients. Since the AD pathology could display regional heterogeneity, we focus our work at the hippocampal formation. In APP based models a prominent microglial response is triggered around amyloid-beta (Aβ) plaques. These strongly activated microglial cells could drive the AD pathology and, in consequence, could be implicated in the neurodegenerative process observed in models. On the contrary, the microglial response in human samples is, at least, partial or attenuated. This patent difference could simply reflect the lower and probably slower Aβ production observed in human hippocampal samples, in comparison with models, or could reflect the consequence of a chronic long-standing microglial activation. Beside this differential response, we also observed microglial degeneration in Braak V–VI individuals that, indeed, could compromise their normal role of surveying the brain environment and respond to the damage. This microglial degeneration, particularly relevant at the dentate gyrus, might be mediated by the accumulation of toxic soluble phospho-tau species. The consequences of this probably deficient immunological protection, observed in AD patients, are unknown.
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Affiliation(s)
- Victoria Navarro
- Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Elisabeth Sanchez-Mejias
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Biomedicina de Malaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Sebastian Jimenez
- Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Clara Muñoz-Castro
- Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Seville, 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.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Biomedicina de Malaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Jose C Davila
- Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Biomedicina de Malaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Marisa Vizuete
- Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Seville, 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.,Departamento Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Instituto de Biomedicina de Malaga (IBIMA), Universidad de Málaga, Málaga, Spain
| | - Javier Vitorica
- Departamento Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.,Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Seville, Spain.,Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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11
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Di Fede G, Catania M, Maderna E, Ghidoni R, Benussi L, Tonoli E, Giaccone G, Moda F, Paterlini A, Campagnani I, Sorrentino S, Colombo L, Kubis A, Bistaffa E, Ghetti B, Tagliavini F. Molecular subtypes of Alzheimer's disease. Sci Rep 2018; 8:3269. [PMID: 29459625 PMCID: PMC5818536 DOI: 10.1038/s41598-018-21641-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 02/07/2018] [Indexed: 12/21/2022] Open
Abstract
Protein misfolding and aggregation is a central feature of several neurodegenerative disorders including Alzheimer's disease (AD), in which assemblies of amyloid β (Aβ) peptides accumulate in the brain in the form of parenchymal and/or vascular amyloid. A widely accepted concept is that AD is characterized by distinct clinical and neuropathological phenotypes. Recent studies revealed that Aβ assemblies might have structural differences among AD brains and that such pleomorphic assemblies can correlate with distinct disease phenotypes. We found that in both sporadic and inherited forms of AD, amyloid aggregates differ in the biochemical composition of Aβ species. These differences affect the physicochemical properties of Aβ assemblies including aggregation kinetics, resistance to degradation by proteases and seeding ability. Aβ-amyloidosis can be induced and propagated in animal models by inoculation of brain extracts containing aggregated Aβ. We found that brain homogenates from AD patients with different molecular profiles of Aβ are able to induce distinct patterns of Aβ-amyloidosis when injected into mice. Overall these data suggest that the assembly of mixtures of Aβ peptides into different Aβ seeds leads to the formation of distinct subtypes of amyloid having distinctive physicochemical and biological properties which result in the generation of distinct AD molecular subgroups.
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Affiliation(s)
- Giuseppe Di Fede
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Marcella Catania
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Emanuela Maderna
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Roberta Ghidoni
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | - Luisa Benussi
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | - Elisa Tonoli
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | - Giorgio Giaccone
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Fabio Moda
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Anna Paterlini
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
| | | | | | - Laura Colombo
- Department of Molecular Biochemistry and Pharmacology, IRCCS Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy
| | - Adriana Kubis
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy.,Department of Toxicology, Wroclaw Medical University, Wrocław, Poland
| | - Edoardo Bistaffa
- IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University, Indianapolis, Indiana, USA
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12
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Dual roles of Aβ in proliferative processes in an amyloidogenic model of Alzheimer's disease. Sci Rep 2017; 7:10085. [PMID: 28855626 PMCID: PMC5577311 DOI: 10.1038/s41598-017-10353-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/08/2017] [Indexed: 12/20/2022] Open
Abstract
Alzheimer’s disease is a major neurodegenerative disorder that leads to severe cognitive deficits in the elderly population. Over the past two decades, multiple studies have focused on elucidating the causative factors underlying memory defects in Alzheimer’s patients. In this regard, new evidence linking Alzheimer’s disease-related pathology and neuronal stem cells suggests that hippocampal neurogenesis impairment is an important factor underlying these cognitive deficits. However, because of conflicting results, the impact of Aβ pathology on neurogenesis/gliogenesis remains unclear. Here, we investigated the effect of Aβ on neuronal and glial proliferation by using an APP/PS1 transgenic model and in vitro assays. Specifically, we showed that neurogenesis is affected early in the APP/PS1 hippocampus, as evidenced by a significant decrease in the proliferative activity due to a reduced number of both radial glia-like neural stem cells (type-1 cells) and intermediate progenitor cells (type-2 cells). Moreover, we demonstrated that soluble Aβ from APP/PS1 mice impairs neuronal cell proliferation using neurosphere cultures. On the other hand, we showed that oligomeric Aβ stimulates microglial proliferation, whereas no effect was observed on astrocytes. These findings indicate that Aβ has a differential effect on hippocampal proliferative cells by inhibiting neuronal proliferation and triggering the formation of microglial cells.
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13
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α-Synuclein Aggregates with β-Amyloid or Tau in Human Red Blood Cells: Correlation with Antioxidant Capability and Physical Exercise in Human Healthy Subjects. Mol Neurobiol 2017; 55:2653-2675. [PMID: 28421539 DOI: 10.1007/s12035-017-0523-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/06/2017] [Indexed: 10/19/2022]
Abstract
Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), β-amyloid1-42 (Aβ), and tau, in both brain and peripheral tissue. In addition to homo-oligomers, the role of α-syn interactions with Aβ or tau has gradually emerged. The altered protein accumulation has been related to both oxidative stress and physical activity; nevertheless, no correlation among the presence of peripheral α-syn hetero-aggregates, antioxidant capacity, and physical exercise has been discovered as of yet. Herein, the content of α-syn, Aβ, tau, and of their heterocomplexes was determined in red blood cells (RBCs) of healthy subjects (sedentary and athletes). Such parameters were related to the extent of the antioxidant capability (AOC), a key marker of oxidative stress in aging-related pathologies, and to physical exercise, which is known to play an important preventive role in NDs and to modulate oxidative stress. Tau content and plasma AOC toward hydroxyl radicals were both reduced in older or sedentary subjects; in contrast, α-syn and Aβ accumulated in elderly subjects and showed an inverse correlation with both hydroxyl AOC and the level of physical activity. For the first time, α-syn heterocomplexes with Aβ or tau were quantified and demonstrated to be inversely related to hydroxyl AOC. Furthermore, α-syn/Aβ aggregates were significantly reduced in athletes and inversely correlated with physical activity level, independent of age. The positive correlation between antioxidant capability/physical activity and reduced protein accumulation was confirmed by these data and suggested that peripheral α-syn heterocomplexes may represent new indicators of ND-related protein misfolding.
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14
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Soluble phospho-tau from Alzheimer's disease hippocampus drives microglial degeneration. Acta Neuropathol 2016; 132:897-916. [PMID: 27743026 PMCID: PMC5106501 DOI: 10.1007/s00401-016-1630-5] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/05/2016] [Accepted: 10/05/2016] [Indexed: 01/22/2023]
Abstract
The role of microglial cells in the development and progression of Alzheimer's disease (AD) has not been elucidated. Here, we demonstrated the existence of a weak microglial response in human AD hippocampus which is in contrast to the massive microglial activation observed in APP-based models. Most importantly, microglial cells displayed a prominent degenerative profile (dentate gyrus > CA3 > CA1 > parahippocampal gyrus), including fragmented and dystrophic processes with spheroids, a reduced numerical density, and a significant decrease in the area of surveillance ("microglial domain"). Consequently, there was a substantial decline in the area covered by microglia which may compromise immune protection and, therefore, neuronal survival. In vitro experiments demonstrated that soluble fractions (extracellular/cytosolic) from AD hippocampi were toxic for microglial cells. This toxicity was abolished by AT8 and/or AT100 immunodepletion, validating that soluble phospho-tau was the toxic agent. These results were reproduced using soluble fractions from phospho-tau-positive Thy-tau22 hippocampi. Cultured microglial cells were not viable following phagocytosis of SH-SY5Y cells expressing soluble intracellular phospho-tau. Because the phagocytic capacity of microglial cells is highly induced by apoptotic signals in the affected neurons, we postulate that accumulation of intraneuronal soluble phospho-tau might trigger microglial degeneration in the AD hippocampus. This microglial vulnerability in AD pathology provides new insights into the immunological mechanisms underlying the disease progression and highlights the need to improve or develop new animal models, as the current models do not mimic the microglial pathology observed in the hippocampus of AD patients.
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15
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Koss DJ, Jones G, Cranston A, Gardner H, Kanaan NM, Platt B. Soluble pre-fibrillar tau and β-amyloid species emerge in early human Alzheimer's disease and track disease progression and cognitive decline. Acta Neuropathol 2016; 132:875-895. [PMID: 27770234 PMCID: PMC5106509 DOI: 10.1007/s00401-016-1632-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 10/07/2016] [Accepted: 10/08/2016] [Indexed: 12/17/2022]
Abstract
Post-mortem investigations of human Alzheimer’s disease (AD) have largely failed to provide unequivocal evidence in support of the original amyloid cascade hypothesis, which postulated deposition of β-amyloid (Aβ) aggregates to be the cause of a demented state as well as inductive to tau neurofibrillary tangles (NFTs). Conflicting evidence suggests, however, that Aβ plaques and NFTs, albeit to a lesser extent, are present in a substantial subset of non-demented individuals. Hence, a range of soluble tau and Aβ species has more recently been implicated as the disease-relevant toxic entities. Despite the incorporation of soluble proteins into a revised amyloid cascade hypothesis, a detailed characterization of these species in the context of human AD onset, progression and cognitive decline has been lacking. Here, lateral temporal lobe samples (Brodmann area 21) of 46 human cases were profiled via tau and Aβ Western blot and native state dot blot protocols. Elevations in phospho-tau (antibodies: CP13, AT8 and PHF-1), pathological tau conformations (MC-1) and oligomeric tau (TOC1) agreed with medical diagnosis (non-AD cf. AD) and Braak stage classification (low, intermediate and high), alongside elevations in soluble Aβ species (MOAB-2 and pyro-glu Aβ) and a decline in levels of the amyloid precursor protein. Strong correlations were observed between individual Braak stages and multiple cognitive measures with all tau markers as well as total soluble Aβ. In contrast to previous reports, SDS-stable Aβ oligomers (*56) were not found to be reliable for all classifications and appeared likely to be a technical artefact. Critically, the robust predictive value of total soluble Aβ was dependent on native state quantification. Elevations in tau and Aβ within soluble fractions (Braak stage 2–3 cf. 0) were evident earlier than previously established in fibril-focused disease progression scales. Together, these data provide strong evidence that soluble forms of tau and Aβ co-localise early in AD and are closely linked to disease progression and cognitive decline.
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16
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Dorostkar MM, Zou C, Blazquez-Llorca L, Herms J. Analyzing dendritic spine pathology in Alzheimer's disease: problems and opportunities. Acta Neuropathol 2015; 130:1-19. [PMID: 26063233 PMCID: PMC4469300 DOI: 10.1007/s00401-015-1449-5] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 06/02/2015] [Accepted: 06/02/2015] [Indexed: 12/22/2022]
Abstract
Synaptic failure is an immediate cause of cognitive decline and memory dysfunction in Alzheimer’s disease. Dendritic spines are specialized structures on neuronal processes, on which excitatory synaptic contacts take place and the loss of dendritic spines directly correlates with the loss of synaptic function. Dendritic spines are readily accessible for both in vitro and in vivo experiments and have, therefore, been studied in great detail in Alzheimer’s disease mouse models. To date, a large number of different mechanisms have been proposed to cause dendritic spine dysfunction and loss in Alzheimer’s disease. For instance, amyloid beta fibrils, diffusible oligomers or the intracellular accumulation of amyloid beta have been found to alter the function and structure of dendritic spines by distinct mechanisms. Furthermore, tau hyperphosphorylation and microglia activation, which are thought to be consequences of amyloidosis in Alzheimer’s disease, may also contribute to spine loss. Lastly, genetic and therapeutic interventions employed to model the disease and elucidate its pathogenetic mechanisms in experimental animals may cause alterations of dendritic spines on their own. However, to date none of these mechanisms have been translated into successful therapeutic approaches for the human disease. Here, we critically review the most intensely studied mechanisms of spine loss in Alzheimer’s disease as well as the possible pitfalls inherent in the animal models of such a complex neurodegenerative disorder.
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Affiliation(s)
- Mario M. Dorostkar
- />Ludwig-Maximilians University Munich, Center for Neuropathology and Prion Research, Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Chengyu Zou
- />Ludwig-Maximilians University Munich, Center for Neuropathology and Prion Research, Feodor-Lynen-Str. 23, 81377 Munich, Germany
- />Graduate School of Systemic Neuroscience, Ludwig-Maximilians-University Munich, Munich, Germany
- />German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Lidia Blazquez-Llorca
- />Ludwig-Maximilians University Munich, Center for Neuropathology and Prion Research, Feodor-Lynen-Str. 23, 81377 Munich, Germany
- />German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Jochen Herms
- />German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Str. 23, 81377 Munich, Germany
- />Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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