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Hayashi M, Kudo C, Hanamoto H, Maegawa H, Usami N, Niwa H. Effects of hippocampal damage on pain perception in a rat model of Alzheimer's disease induced by amyloid-β and ibotenic acid injection into the hippocampus. Physiol Behav 2024; 285:114652. [PMID: 39096985 DOI: 10.1016/j.physbeh.2024.114652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 07/22/2024] [Accepted: 08/01/2024] [Indexed: 08/05/2024]
Abstract
Patients with Alzheimer's disease (AD) present with a variety of symptoms, including core symptoms as well as behavioral and psychological symptoms. Somatosensory neural systems are generally believed to be relatively unaffected by AD until late in the course of the disease; however, somatosensory perception in patients with AD is not yet well understood. One factor that may complicate the assessment of somatosensory perception in humans centers on individual variations in pathological and psychological backgrounds. It is therefore necessary to evaluate somatosensory perception using animal models with uniform status. In the current study, we focused on the hippocampus, the primary site of AD. We first constructed a rat model of AD model using bilateral hippocampal injections of amyloid-β peptide 1-40 and ibotenic acid; sham rats received saline injections. The Morris water maze test was used to evaluate memory impairment, and the formalin test (1 % or 4 % formalin) and upper lip von Frey test were performed to compare pain perception between AD model and sham rats. Finally, histological and immunohistochemical methods were used to evaluate tissue damage and neuronal activity, respectively, in the hippocampus. AD model rats showed bilateral hippocampal damage and had memory impairment in the Morris water maze test. Furthermore, AD model rats exhibited significantly less pain-related behavior in phase 2 (the last 50 min of the 60-minute observation) of the 4 % formalin test compared with the sham rats. However, no significant changes were observed in the von Frey test. Immunohistochemical observations of the trigeminal spinal subnucleus caudalis after 4 % formalin injection revealed significantly fewer c-Fos-immunoreactive cells in AD model rats than in sham rats, reflecting reduced neuronal activity. These results indicate that AD model rats with hippocampal damage have reduced responsiveness to persistent inflammatory chemical stimuli to the orofacial region.
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Affiliation(s)
- Masayoshi Hayashi
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-871, Japan.
| | - Chiho Kudo
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-871, Japan
| | - Hiroshi Hanamoto
- Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Hiroharu Maegawa
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-871, Japan
| | - Nayuka Usami
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-871, Japan
| | - Hitoshi Niwa
- Department of Dental Anesthesiology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-871, Japan
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2
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Schmidt FC, Fitz K, Feilen LP, Okochi M, Steiner H, Langosch D. Different transmembrane domains determine the specificity and efficiency of the cleavage activity of the γ-secretase subunit presenilin. J Biol Chem 2023; 299:104626. [PMID: 36944398 PMCID: PMC10164903 DOI: 10.1016/j.jbc.2023.104626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/07/2023] [Accepted: 03/11/2023] [Indexed: 03/23/2023] Open
Abstract
The γ-secretase complex catalyzes the intramembrane cleavage of C99, a carboxy-terminal fragment of the amyloid precursor protein. Two paralogs of its catalytic subunit presenilin (PS1 and PS2) are expressed which are autocatalytically cleaved into an N-terminal and a C-terminal fragment during maturation of γ-secretase. In this study, we compared the efficiency and specificity of C99 cleavage by PS1- and PS2-containing γ-secretases. Mass spectrometric analysis of cleavage products obtained in cell-free and cell-based assays revealed that the previously described lower amyloid-β (Aβ)38 generation by PS2 is accompanied by a reciprocal increase in Aβ37 production. We further found PS1 and PS2 to show different preferences in the choice of the initial cleavage site of C99. However, the differences in Aβ38 and Aβ37 generation appear to mainly result from altered subsequent stepwise cleavage of Aβ peptides. Apart from these differences in cleavage specificity, we confirmed a lower efficiency of initial C99 cleavage by PS2 using a detergent-solubilized γ-secretase system. By investigating chimeric PS1/2 molecules, we show that the membrane-embedded, nonconserved residues of the N-terminal fragment mainly account for the differential cleavage efficiency and specificity of both presenilins. At the level of individual transmembrane domains (TMDs), TMD3 was identified as a major modulator of initial cleavage site specificity. The efficiency of endoproteolysis strongly depends on nonconserved TMD6 residues at the interface to TMD2, i.e., at a putative gate of substrate entry. Taken together, our results highlight the role of individual presenilin TMDs in the cleavage of C99 and the generation of Aβ peptides.
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Affiliation(s)
- Fabian C Schmidt
- Biopolymer Chemistry, Technical University of Munich, Freising, Germany
| | - Katja Fitz
- Biopolymer Chemistry, Technical University of Munich, Freising, Germany
| | - Lukas P Feilen
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Masayasu Okochi
- Neuropsychiatry, Division of Internal Medicine, Department of Integrated Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Harald Steiner
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Division of Metabolic Biochemistry, Faculty of Medicine, Biomedical Center (BMC), Ludwig-Maximilians-University, Munich, Germany
| | - Dieter Langosch
- Biopolymer Chemistry, Technical University of Munich, Freising, Germany.
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Rhomboid protease RHBDL4 promotes retrotranslocation of aggregation-prone proteins for degradation. Cell Rep 2022; 40:111175. [PMID: 35947953 PMCID: PMC9437926 DOI: 10.1016/j.celrep.2022.111175] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/02/2022] [Accepted: 07/18/2022] [Indexed: 11/22/2022] Open
Abstract
Protein degradation is fundamentally important to ensure cell homeostasis. In the endoplasmic reticulum (ER), the ER-associated degradation (ERAD) pathway targets incorrectly folded and unassembled proteins for turnover by the cytoplasmic proteasome. Previously, we showed that the rhomboid protease RHBDL4, together with p97, mediates membrane protein degradation. However, whether RHBDL4 acts in concert with additional ERAD components is unclear, and its full substrate spectrum remains to be defined. Here, we show that, in addition to membrane proteins, RHBDL4 cleaves aggregation-prone luminal ERAD substrates. Since mutations of the RHBDL4 rhomboid domain led to stabilization of substrates at the cytoplasmic side, we hypothesize that, analogous to the homolog ERAD factor derlin, RHBDL4 is directly involved in substrate retrotranslocation. RHBDL4's interaction with the erlin ERAD complex and reciprocal interaction of rhomboid substrates with erlins suggest that RHBDL4 and erlins form a complex that clips substrates and thereby rescues aggregation-prone peptides in the ER from aggregation.
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PCSK9 acts as a key regulator of Aβ clearance across the blood-brain barrier. Cell Mol Life Sci 2022; 79:212. [PMID: 35344086 PMCID: PMC8960591 DOI: 10.1007/s00018-022-04237-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/25/2022] [Accepted: 03/08/2022] [Indexed: 12/18/2022]
Abstract
Despite the neurodegenerative disorder Alzheimer's disease (AD) is the most common form of dementia in late adult life, there is currently no therapy available to prevent the onset or slow down the progression of AD. The progressive cognitive decline in AD correlates with a successive accumulation of cerebral amyloid-β (Aβ) due to impaired clearance mechanisms. A significant percentage is removed by low-density lipoprotein receptor-related protein 1 (LRP1)-mediated transport across the blood-brain barrier (BBB) into the periphery. Circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to members of the low-density lipoprotein receptor protein family at the cell surface and targets them for lysosomal degradation, which reduces the number of functional receptors. However, the adverse impact of PCSK9 on LRP1-mediated brain Aβ clearance remains elusive. By using an established BBB model, we identified reduced LRP1-mediated brain-to-blood Aβ clearance due to PCSK9 across different endothelial monolayer in vitro. Consequently, the repetitive application of FDA-approved monoclonal anti-PCSK9 antibodies into 5xFAD mice decreased the cerebral Aβ burden across variants and aggregation state, which was not reproducible in brain endothelial-specific LRP1-/- 5xFAD mice. The peripheral PCSK9 inhibition reduced Aβ pathology in prefrontal cortex and hippocampus-brain areas critically involved in memory processing-and prevented disease-related impairment in hippocampus-dependent memory formation. Our data suggest that peripheral inhibition of PCSK9 by already available therapeutic antibodies may be a novel and easily applicable potential AD treatment.
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Spitzer P, Walter M, Göth C, Oberstein TJ, Linning P, Knölker HJ, Kornhuber J, Maler JM. Pharmacological Inhibition of Amyloidogenic APP Processing and Knock-Down of APP in Primary Human Macrophages Impairs the Secretion of Cytokines. Front Immunol 2020; 11:1967. [PMID: 33013850 PMCID: PMC7494750 DOI: 10.3389/fimmu.2020.01967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 07/21/2020] [Indexed: 12/18/2022] Open
Abstract
It has been previously shown that the amyloid precursor protein (APP) support the innate immune defense as an immune receptor. Amyloid β (Aβ) peptides seem to have properties of an antimicrobial peptide and can act as opsonines. In APP-deficient mouse models, a reduced secretion of cytokines has been observed. Still, it is unclear whether this can be attributed to the lack of APP or to the missing secretion of Aβ peptides. We inhibited the secretion of Aβ peptides in primary human monocyte derived macrophages with the γ-secretase inhibitor N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine-t-butyl-ester (DAPT) or the β-secretase inhibitor GL-189. Alternatively, we knocked down APP by transfection with siRNA. We measured tumor necrosis factor α (TNFα), interleukin 6 (IL-6) and interleukin (IL-10) by enzyme linked immunosorbent assay (ELISA) and evaluated the phagocytotic activity by flow cytometry. We observed reduced concentrations of TNFα and IL-6 in the media of APPk/d macrophages and after inhibition of the β-, or γ-secretase, especially after additional immunological activation with lipopolysaccharide (LPS). Secretion of IL-10 was increased after pharmacological inhibition of APP processing when the macrophages were not immunologically activated but was decreased during LPS-induced inflammation in APPk/d macrophages. No changes of the phagocytotic activity were observed. We conclude that macrophage APP and Aβ peptides support the initiation of an immune response and are involved in the regulation of TNFα, IL-6, and IL-10 secretion by human monocyte-derived macrophages.
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Affiliation(s)
- Philipp Spitzer
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Matthias Walter
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Caroline Göth
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Timo Jan Oberstein
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Philipp Linning
- Faculty of Chemistry, Technische Universität Dresden, Dresden, Germany
| | | | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Juan Manuel Maler
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
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6
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Development and Technical Validation of an Immunoassay for the Detection of APP 669-711 (Aβ -3-40) in Biological Samples. Int J Mol Sci 2020; 21:ijms21186564. [PMID: 32911706 PMCID: PMC7555726 DOI: 10.3390/ijms21186564] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 01/10/2023] Open
Abstract
The ratio of amyloid precursor protein (APP)669-711 (Aβ-3-40)/Aβ1-42 in blood plasma was reported to represent a novel Alzheimer's disease biomarker. Here, we describe the characterization of two antibodies against the N-terminus of Aβ-3-x and the development and "fit-for-purpose" technical validation of a sandwich immunoassay for the measurement of Aβ-3-40. Antibody selectivity was assessed by capillary isoelectric focusing immunoassay, Western blot analysis, and immunohistochemistry. The analytical validation addressed assay range, repeatability, specificity, between-run variability, impact of pre-analytical sample handling procedures, assay interference, and analytical spike recoveries. Blood plasma was analyzed after Aβ immunoprecipitation by a two-step immunoassay procedure. Both monoclonal antibodies detected Aβ-3-40 with no appreciable cross reactivity with Aβ1-40 or N-terminally truncated Aβ variants. However, the amyloid precursor protein was also recognized. The immunoassay showed high selectivity for Aβ-3-40 with a quantitative assay range of 22 pg/mL-7.5 ng/mL. Acceptable intermediate imprecision of the complete two-step immunoassay was reached after normalization. In a small clinical sample, the measured Aβ42/Aβ-3-40 and Aβ42/Aβ40 ratios were lower in patients with dementia of the Alzheimer's type than in other dementias. In summary, the methodological groundwork for further optimization and future studies addressing the Aβ42/Aβ-3-40 ratio as a novel biomarker candidate for Alzheimer's disease has been set.
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7
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Hornung K, Zampar S, Engel N, Klafki H, Liepold T, Bayer TA, Wiltfang J, Jahn O, Wirths O. N-Terminal Truncated Aβ4-42 Is a Substrate for Neprilysin Degradation in vitro and in vivo. J Alzheimers Dis 2020; 67:849-858. [PMID: 30664509 DOI: 10.3233/jad-181134] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In sporadic Alzheimer's disease (AD), an imbalance between production and clearance of amyloid-β (Aβ) peptides seems to account for enhanced Aβ accumulation. The metalloprotease neprilysin (NEP) is an important Aβ degrading enzyme as shown by a variety of in vitro and in vivo studies. While the degradation of full-length Aβ peptides such as Aβ1-40 and Aβ1-42 is well established, it is less clear whether NEP is also capable of degrading N-terminally truncated Aβ species such as the common variant Aβ4-42. In the present report, we confirmed the degradation of Aβ4-x species by neprilysin using in vitro digestion and subsequent analysis using gel-based assays and mass spectrometry. By crossing Tg4-42 mice expressing only Aβ4-42 peptides with homozygous NEP-knock-out mice (NEP-/-), we were able to demonstrate that NEP deficiency increased hippocampal intraneuronal Aβ levels and aggravated neuron loss in the Tg4-42 transgenic mouse model of AD.
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Affiliation(s)
- Karen Hornung
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany
| | - Silvia Zampar
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany
| | - Nadine Engel
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany
| | - Hans Klafki
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany
| | - Thomas Liepold
- Max Planck Institute of Experimental Medicine, Proteomics Group, Goettingen, Germany
| | - Thomas A Bayer
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany
| | - Jens Wiltfang
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Goettingen, Germany.,Department of iBiMED, Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Olaf Jahn
- Max Planck Institute of Experimental Medicine, Proteomics Group, Goettingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Goettingen, Germany
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Royea J, Lacalle-Aurioles M, Trigiani LJ, Fermigier A, Hamel E. AT2R's (Angiotensin II Type 2 Receptor's) Role in Cognitive and Cerebrovascular Deficits in a Mouse Model of Alzheimer Disease. Hypertension 2020; 75:1464-1474. [PMID: 32362228 DOI: 10.1161/hypertensionaha.119.14431] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Antihypertensive medications targeting the renin-angiotensin system have lowered the incidence and progression of Alzheimer disease. Understanding how these medications function could lead to novel therapeutic strategies. AT4Rs (angiotensin IV receptors) have been associated with angiotensin receptor blockers' cognitive, cerebrovascular, and neuroinflammatory rescue in Alzheimer disease models. Yet, whether AT4Rs act alone or with AT2Rs remains unknown. Here, we investigated whether AT2Rs contribute to losartan's benefits and whether chronic AT2R activation could mimic angiotensin receptor blocker benefits in transgenic mice overexpressing familial Alzheimer disease mutations of the human APP (amyloid precursor protein). Losartan-treated mice (10 mg/kg per day, drinking water, 7 months) received intracerebroventricular (1 month) administration of vehicle or AT2R antagonist PD123319 (1.6 nmol/day). PD123319 countered losartan's benefits on spatial learning and memory, neurovascular coupling, and hampered those on oxidative stress and nitric oxide bioavailability. PD123319 did not oppose losartan's benefits on short-term memory and vasodilatory function and had no benefit on neuroinflammation or Aβ (amyloid β) pathology. Mice receiving either vehicle or selective AT2R agonist compound 21 (intracerebroventricular: 1 nmol/day, 1 month or drinking water: 10 mg/kg per day, 7 months), showed no improvement in memory, vasodilatory function, or nitric oxide bioavailability. Compound 21 treatment normalized neurovascular coupling, reduced astrogliosis independent of persisting microgliosis, and exacerbated oxidative stress in APP mice. Compound 21 reduced dense core Aβ plaques, but not diffuse plaques or Aβ species. Our findings suggest that targeting AT2Rs is not an ideal strategy for restoring Aβ-related cognitive and cerebrovascular deficits.
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Affiliation(s)
- Jessika Royea
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Maria Lacalle-Aurioles
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Lianne J Trigiani
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Alice Fermigier
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
| | - Edith Hamel
- From the Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada H3A 2B4
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Trambauer J, Rodríguez Sarmiento RM, Fukumori A, Feederle R, Baumann K, Steiner H. Aβ43-producing PS1 FAD mutants cause altered substrate interactions and respond to γ-secretase modulation. EMBO Rep 2020; 21:e47996. [PMID: 31762188 PMCID: PMC6945062 DOI: 10.15252/embr.201947996] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/22/2022] Open
Abstract
Abnormal generation of neurotoxic amyloid-β peptide (Aβ) 42/43 species due to mutations in the catalytic presenilin 1 (PS1) subunit of γ-secretase is the major cause of familial Alzheimer's disease (FAD). Deeper mechanistic insight on the generation of Aβ43 is still lacking, and it is unclear whether γ-secretase modulators (GSMs) can reduce the levels of this Aβ species. By comparing several types of Aβ43-generating FAD mutants, we observe that very high levels of Aβ43 are often produced when presenilin function is severely impaired. Altered interactions of C99, the precursor of Aβ, are found for all mutants and are independent of their particular effect on Aβ production. Furthermore, unlike previously described GSMs, the novel compound RO7019009 can effectively lower Aβ43 production of all mutants. Finally, substrate-binding competition experiments suggest that RO7019009 acts mechanistically after initial C99 binding. We conclude that altered C99 interactions are a common feature of diverse types of PS1 FAD mutants and that also patients with Aβ43-generating FAD mutations could in principle be treated by GSMs.
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Affiliation(s)
- Johannes Trambauer
- Biomedical Center (BMC), Metabolic BiochemistryLudwig‐Maximilians‐UniversityMunichGermany
| | | | - Akio Fukumori
- Department of Aging NeurobiologyNational Center for Geriatrics and GerontologyObuJapan
- Department of Mental Health PromotionOsaka University Graduate School of MedicineToyonakaJapan
| | - Regina Feederle
- Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Helmholtz Center MunichGerman Research Center for Environmental HealthNeuherbergGermany
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
| | - Karlheinz Baumann
- Roche Pharma Research and Early DevelopmentRoche Innovation Center Basel, F. Hoffmann‐La Roche Ltd.BaselSwitzerland
| | - Harald Steiner
- Biomedical Center (BMC), Metabolic BiochemistryLudwig‐Maximilians‐UniversityMunichGermany
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
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10
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Ding S, Xu Y, Liu Q, Gu H, Zhu A, Shi G. Interface engineering of microelectrodes toward ultrasensitive monitoring of β-amyloid peptides in cerebrospinal fluid in Alzheimer's disease. Analyst 2020; 145:2331-2338. [DOI: 10.1039/c9an02285f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aβ monomers directed the assembly of Cu2+-PEI/AuNPs-hemin nanoprobes into network aggregates on a microelectrode interface for enhanced electrochemical analysis.
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Affiliation(s)
- Shushu Ding
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Yunxia Xu
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Qi Liu
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Hui Gu
- School of Chemistry and Chemical Engineering
- Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education
- Hunan University of Science and Technology
- Xiangtan
- People's Republic of China
| | - Anwei Zhu
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
| | - Guoyue Shi
- School of Chemistry and Molecular Engineering
- Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration
- East China Normal University
- Shanghai 200241
- People's Republic of China
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11
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Vöglein J, Willem M, Trambauer J, Schönecker S, Dieterich M, Biskup S, Giudici C, Utz K, Oberstein T, Brendel M, Rominger A, Danek A, Steiner H, Haass C, Levin J. Identification of a rare presenilin 1 single amino acid deletion mutation (F175del) with unusual amyloid-β processing effects. Neurobiol Aging 2019; 84:241.e5-241.e11. [DOI: 10.1016/j.neurobiolaging.2019.08.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/22/2019] [Accepted: 08/31/2019] [Indexed: 10/26/2022]
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12
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Solé M, Esteban-Lopez M, Taltavull B, Fábregas C, Fadó R, Casals N, Rodríguez-Álvarez J, Miñano-Molina AJ, Unzeta M. Blood-brain barrier dysfunction underlying Alzheimer's disease is induced by an SSAO/VAP-1-dependent cerebrovascular activation with enhanced Aβ deposition. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2189-2202. [PMID: 31047972 DOI: 10.1016/j.bbadis.2019.04.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/03/2019] [Accepted: 04/26/2019] [Indexed: 12/11/2022]
Abstract
Dysfunctions of the vascular system directly contribute to the onset and progression of Alzheimer's disease (AD). The blood-brain barrier (BBB) shows signs of malfunction at early stages of the disease. When Abeta peptide (Aβ) is deposited on brain vessels, it induces vascular degeneration by producing reactive oxygen species and promoting inflammation. These molecular processes are also related to an excessive SSAO/VAP-1 (semicarbazide-sensitive amine oxidase) enzymatic activity, observed in plasma and in cerebrovascular tissue of AD patients. We studied the contribution of vascular SSAO/VAP-1 to the BBB dysfunction in AD using in vitro BBB models. Our results show that SSAO/VAP-1 expression is associated to endothelial activation by altering the release of pro-inflammatory and pro-angiogenic angioneurins, most highly IL-6, IL-8 and VEGF. It is also related to a BBB structure alteration, with a decrease in tight-junction proteins such as zona occludens or claudin-5. Moreover, the BBB function reveals increased permeability and leukocyte adhesion in cells expressing SSAO/VAP-1, as well as an enhancement of the vascular Aβ deposition induced by mechanisms both dependent and independent of the enzymatic activity of SSAO/VAP-1. These results reveal an interesting role of vascular SSAO/VAP-1 in BBB dysfunction related to AD progression, opening a new window in the search of alternative therapeutic targets for fighting AD.
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Affiliation(s)
- Montse Solé
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
| | - María Esteban-Lopez
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Biel Taltavull
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Cristina Fábregas
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Rut Fadó
- Basic Sciences Department, Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Spain
| | - Núria Casals
- Basic Sciences Department, Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya (UIC), Sant Cugat del Vallès, Spain; Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Santiago de Compostela, Spain
| | - Jose Rodríguez-Álvarez
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Alfredo J Miñano-Molina
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Mercedes Unzeta
- Biochemistry and Molecular Biology Department, Institute of Neurosciences (INc), Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
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13
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Kronenberg-Versteeg D, Eichmann M, Russell MA, de Ru A, Hehn B, Yusuf N, van Veelen PA, Richardson SJ, Morgan NG, Lemberg MK, Peakman M. Molecular Pathways for Immune Recognition of Preproinsulin Signal Peptide in Type 1 Diabetes. Diabetes 2018; 67:687-696. [PMID: 29343547 DOI: 10.2337/db17-0021] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 01/10/2018] [Indexed: 11/13/2022]
Abstract
The signal peptide region of preproinsulin (PPI) contains epitopes targeted by HLA-A-restricted (HLA-A0201, A2402) cytotoxic T cells as part of the pathogenesis of β-cell destruction in type 1 diabetes. We extended the discovery of the PPI epitope to disease-associated HLA-B*1801 and HLA-B*3906 (risk) and HLA-A*1101 and HLA-B*3801 (protective) alleles, revealing that four of six alleles present epitopes derived from the signal peptide region. During cotranslational translocation of PPI, its signal peptide is cleaved and retained within the endoplasmic reticulum (ER) membrane, implying it is processed for immune recognition outside of the canonical proteasome-directed pathway. Using in vitro translocation assays with specific inhibitors and gene knockout in PPI-expressing target cells, we show that PPI signal peptide antigen processing requires signal peptide peptidase (SPP). The intramembrane protease SPP generates cytoplasm-proximal epitopes, which are transporter associated with antigen processing (TAP), ER-luminal epitopes, which are TAP independent, each presented by different HLA class I molecules and N-terminal trimmed by ER aminopeptidase 1 for optimal presentation. In vivo, TAP expression is significantly upregulated and correlated with HLA class I hyperexpression in insulin-containing islets of patients with type 1 diabetes. Thus, PPI signal peptide epitopes are processed by SPP and loaded for HLA-guided immune recognition via pathways that are enhanced during disease pathogenesis.
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Affiliation(s)
- Deborah Kronenberg-Versteeg
- Department of Immunobiology, Faculty of Life Sciences and Medicine, King's College London, London, U.K.
- National Institute for Health Research, Biomedical Research Centre at Guy's and St. Thomas' Hospital Foundation Trust and King's College London, London, U.K
| | - Martin Eichmann
- Department of Immunobiology, Faculty of Life Sciences and Medicine, King's College London, London, U.K
| | - Mark A Russell
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Arnoud de Ru
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Beate Hehn
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Norkhairin Yusuf
- Department of Immunobiology, Faculty of Life Sciences and Medicine, King's College London, London, U.K
| | - Peter A van Veelen
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, the Netherlands
| | - Sarah J Richardson
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Noel G Morgan
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, U.K
| | - Marius K Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Mark Peakman
- Department of Immunobiology, Faculty of Life Sciences and Medicine, King's College London, London, U.K
- National Institute for Health Research, Biomedical Research Centre at Guy's and St. Thomas' Hospital Foundation Trust and King's College London, London, U.K
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14
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Nyarko JN, Quartey MO, Pennington PR, Heistad RM, Dea D, Poirier J, Baker GB, Mousseau DD. Profiles of β-Amyloid Peptides and Key Secretases in Brain Autopsy Samples Differ with Sex and APOE ε4 Status: Impact for Risk and Progression of Alzheimer Disease. Neuroscience 2018; 373:20-36. [DOI: 10.1016/j.neuroscience.2018.01.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 12/21/2017] [Accepted: 01/03/2018] [Indexed: 11/25/2022]
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15
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Grigorenko AP, Moliaka YK, Plotnikova OV, Smirnov A, Nikishina VA, Goltsov AY, Gusev F, Andreeva TV, Nelson O, Bezprozvanny I, Rogaev EI. Mutational re-modeling of di-aspartyl intramembrane proteases: uncoupling physiologically-relevant activities from those associated with Alzheimer's disease. Oncotarget 2017; 8:82006-82026. [PMID: 29137240 PMCID: PMC5669866 DOI: 10.18632/oncotarget.18299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 04/28/2017] [Indexed: 12/18/2022] Open
Abstract
The intramembrane proteolytic activities of presenilins (PSEN1/PS1 and PSEN2/PS2) underlie production of β-amyloid, the key process in Alzheimer’s disease (AD). Dysregulation of presenilin-mediated signaling is linked to cancers. Inhibition of the γ-cleavage activities of PSENs that produce Aβ, but not the ε-like cleavage activity that release physiologically essential transcription activators, is a potential approach for the development of rational therapies for AD. In order to identify whether different activities of PSEN1 can be dissociated, we designed multiple mutations in the evolutionary conserved sites of PSEN1. We tested them in vitro and in vivo assays and compared their activities with mutant isoforms of presenilin-related intramembrane di-aspartyl protease (IMPAS1 (IMP1)/signal peptide peptidase (SPP)). PSEN1 auto-cleavage was more resistant to the mutation remodeling than the ε-like proteolysis. PSEN1 with a G382A or a P433A mutation in evolutionary invariant sites retains functionally important APP ε- and Notch S3- cleavage activities, but G382A inhibits APP γ-cleavage and Aβ production and a P433A elevates Aβ. The G382A variant cannot restore the normal cellular ER Ca2+ leak in PSEN1/PSEN2 double knockout cells, but efficiently rescues the loss-of-function (Egl) phenotype of presenilin in C. elegans. We found that, unlike in PSEN1 knockout cells, endoplasmic reticulum (ER) Ca2+ leak is not changed in the absence of IMP1/SPP. IMP1/SPP with the analogous mutations retained efficiency in cleavage of transmembrane substrates and rescued the lethality of Ce-imp-2 knockouts. In summary, our data show that mutations near the active catalytic sites of intramembrane di-aspartyl proteases have different consequences on proteolytic and signaling functions.
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Affiliation(s)
- Anastasia P Grigorenko
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA.,Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Youri K Moliaka
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Olga V Plotnikova
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Alexander Smirnov
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Vera A Nikishina
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA
| | - Andrey Y Goltsov
- Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Fedor Gusev
- Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Tatiana V Andreeva
- Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Omar Nelson
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9040, USA
| | - Ilya Bezprozvanny
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9040, USA
| | - Evgeny I Rogaev
- Department of Psychiatry, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA 01604, USA.,Department of Genomics and Human Genetics, Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991 Russia.,Center for Brain Neurobiology and Neurogenetics, Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.,Center for Genetics and Genetic Technologies, Faculty of Biology, Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119234, Russia
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16
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Angiotensin IV Receptors Mediate the Cognitive and Cerebrovascular Benefits of Losartan in a Mouse Model of Alzheimer's Disease. J Neurosci 2017; 37:5562-5573. [PMID: 28476949 DOI: 10.1523/jneurosci.0329-17.2017] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/30/2017] [Accepted: 04/22/2017] [Indexed: 12/21/2022] Open
Abstract
The use of angiotensin receptor blockers (ARBs) correlates with reduced onset and progression of Alzheimer's disease (AD). The mechanism depicting how ARBs such as losartan restore cerebrovascular and cognitive deficits in AD is unknown. Here, we propose a mechanism underlying losartan's benefits by selectively blocking the effects of angiotensin IV (AngIV) at its receptor (AT4R) with divalinal in mice overexpressing the AD-related Swedish and Indiana mutations of the human amyloid precursor protein (APP mice) and WT mice. Young (3-month-old) mice were treated with losartan (∼10 mg/kg/d, 4 months), followed by intracerebroventricular administration of vehicle or divalinal in the final month of treatment. Spatial learning and memory were assessed using Morris water mazes at 3 and 4 months of losartan treatment. Cerebrovascular reactivity and whisker-evoked neurovascular coupling responses were measured at end point (∼7 months of age), together with biomarkers related to neuronal and vascular oxidative stress (superoxide dismutase-2), neuroinflammation (astroglial and microglial activation), neurogenesis (BrdU-labeled newborn cells), and amyloidosis [soluble amyloid-β (Aβ) species and Aβ plaque load]. Divalinal countered losartan's capacity to rescue spatial learning and memory and blocked losartan's benefits on dilatory function and baseline nitric oxide bioavailability. Divalinal reverted losartan's anti-inflammatory effects, but failed to modify losartan-mediated reductions in oxidative stress. Neither losartan nor divalinal affected arterial blood pressure or significantly altered the amyloid pathology in APP mice. Our findings identify activation of the AngIV/AT4R cascade as the underlying mechanism in losartan's benefits and a target that could restore Aβ-related cognitive and cerebrovascular deficits in AD.SIGNIFICANCE STATEMENT Antihypertensive medications that target the renin angiotensin system, such as angiotensin receptor blockers (ARBs), have been associated with lower incidence and progression of Alzheimer's disease (AD) in cohort studies. However, the manner by which ARBs mediate their beneficial effects is unknown. Here, the angiotensin IV receptor (AT4R) was identified as mediating the cognitive and cerebrovascular rescue of losartan, a commonly prescribed ARB, in a mouse model of AD. The AT4R was further implicated in mediating anti-inflammatory benefits. AT4R-mediated effects were independent from changes in blood pressure, amyloidosis, and oxidative stress. Overall, our results implicate the angiotensin IV/AT4R cascade as a promising candidate for AD intervention.
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Ongali B, Nicolakakis N, Tong XK, Aboulkassim T, Imboden H, Hamel E. Enalapril Alone or Co-Administered with Losartan Rescues Cerebrovascular Dysfunction, but not Mnemonic Deficits or Amyloidosis in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2016; 51:1183-95. [PMID: 26923013 DOI: 10.3233/jad-150868] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The co-administration of angiotensin converting enzyme inhibitors (ACEi) and angiotensin II (AngII) receptor blockers (ARB) that bind angiotensin type 1 receptors (AT1R) may protect from Alzheimer's disease (AD) better than each treatment taken alone. We tested the curative potential of the non brain-penetrant ACEi enalapril (3 mg/kg/day) administered for 3 months either alone or in combination with the brain penetrant ARB losartan (10 mg/kg/day) in aged (∼15 months) transgenic mice overexpressing a mutated form of the human amyloid-β protein precursor (AβPP, thereafter APP mice). We studied cerebrovascular function, protein levels of oxidative stress markers (superoxide dismutases SOD1, SOD2 and the NADPH oxidase subunit p67phox), amyloid-β (Aβ) pathology, astrogliosis, cholinergic innervation, AT1R and angiotensin IV receptor (AT4R) levels, together with cognitive performance. Both treatments normalized cerebrovascular reactivity and p67phox protein levels, but they did not reduce the cerebrovascular levels of SOD1. Combined treatment normalized cerebrovascular SOD2 levels, significantly attenuated astrogliosis, but did not reduce the increased levels of cerebrovascular AT1R. Yet, combined therapy enhanced thioflavin-S labeled Aβ plaque burden, a tendency not significant when Aβ1 - 42 plaque load was considered. None of the treatments rescued cognitive deficits, cortical AT4R or cholinergic innervation. We conclude that both treatments normalized cerebrovascular function by inhibiting the AngII-induced oxidative stress cascade, and that the positive effects of the combined therapy on astrogliosis were likely due to the ability of losartan to enter brain parenchyma. However, enalapril did not potentiate, and may even dampen, the reported cognitive benefits of losartan, raising caution when selecting the most appropriate antihypertensive therapy in AD patients.
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Affiliation(s)
- Brice Ongali
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Nektaria Nicolakakis
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Xing-Kang Tong
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Tahar Aboulkassim
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Hans Imboden
- Institute of Cell Biology, University of Bern, Switzerland
| | - Edith Hamel
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
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18
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Kretner B, Trambauer J, Fukumori A, Mielke J, Kuhn PH, Kremmer E, Giese A, Lichtenthaler SF, Haass C, Arzberger T, Steiner H. Generation and deposition of Aβ43 by the virtually inactive presenilin-1 L435F mutant contradicts the presenilin loss-of-function hypothesis of Alzheimer's disease. EMBO Mol Med 2016; 8:458-65. [PMID: 26988102 PMCID: PMC5119496 DOI: 10.15252/emmm.201505952] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
As stated by the prevailing amyloid cascade hypothesis, Alzheimer's disease (AD) is caused by the aggregation and cerebral deposition of long amyloid‐β peptide (Aβ) species, which are released from a C‐terminal amyloid precursor protein fragment by γ‐secretase. Mutations in its catalytic subunit presenilin‐1 (PS1) increase the Aβ42 to Aβ40 ratio and are the major cause of familial AD (FAD). An opposing hypothesis states that loss of essential presenilin functions underlies the disease. A major argument for this hypothesis is the observation that the nearly inactive PS1 L435F mutant, paradoxically, causes FAD. We now show that the very little Aβ generated by PS1 L435F consists primarily of Aβ43, a highly amyloidogenic species which was overlooked in previous studies of this mutant. We further demonstrate that the generation of Aβ43 is not due to a trans‐dominant effect of this mutant on WT presenilin. Furthermore, we found Aβ43‐containing plaques in brains of patients with this mutation. The aberrant generation of Aβ43 by this particular mutant provides a direct objection against the presenilin hypothesis.
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Affiliation(s)
- Benedikt Kretner
- Biomedical Center, Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | - Johannes Trambauer
- Biomedical Center, Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Akio Fukumori
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
| | - Janina Mielke
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Peer-Hendrik Kuhn
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Neuroproteomics, Klinikum rechts der Isar and Institute for Advanced Study, Technische Universität München, Munich, Germany
| | - Elisabeth Kremmer
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany Institute of Molecular Immunology, Helmholtz Zentrum München, Munich, Germany
| | - Armin Giese
- Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Stefan F Lichtenthaler
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Neuroproteomics, Klinikum rechts der Isar and Institute for Advanced Study, Technische Universität München, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Haass
- Biomedical Center, Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Arzberger
- DZNE - German Center for Neurodegenerative Diseases, Munich, Germany Center for Neuropathology and Prion Research, Ludwig-Maximilians-University Munich, Munich, Germany Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Harald Steiner
- Biomedical Center, Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany DZNE - German Center for Neurodegenerative Diseases, Munich, Germany
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19
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Reinert J, Richard BC, Klafki HW, Friedrich B, Bayer TA, Wiltfang J, Kovacs GG, Ingelsson M, Lannfelt L, Paetau A, Bergquist J, Wirths O. Deposition of C-terminally truncated Aβ species Aβ37 and Aβ39 in Alzheimer's disease and transgenic mouse models. Acta Neuropathol Commun 2016; 4:24. [PMID: 26955942 PMCID: PMC4784385 DOI: 10.1186/s40478-016-0294-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 02/26/2016] [Indexed: 11/10/2022] Open
Abstract
In Alzheimer's disease (AD) a variety of amyloid β-peptides (Aβ) are deposited in the form of extracellular diffuse and neuritic plaques (NP), as well as within the vasculature. The generation of Aβ from its precursor, the amyloid precursor protein (APP), is a highly complex procedure that involves subsequent proteolysis of APP by β- and γ-secretases. Brain accumulation of Aβ due to impaired Aβ degradation and/or altered ratios between the different Aβ species produced is believed to play a pivotal role in AD pathogenesis. While the presence of Aβ40 and Aβ42 in vascular and parenchymal amyloid have been subject of extensive studies, the deposition of carboxyterminal truncated Aβ peptides in AD has not received comparable attention. In the current study, we for the first time demonstrate the immunohistochemical localization of Aβ37 and Aβ39 in human sporadic AD (SAD). Our study further included the analysis of familial AD (FAD) cases carrying the APP mutations KM670/671NL, E693G and I716F, as well as a case of the PSEN1 ΔExon9 mutation. Aβ37 and Aβ39 were found to be widely distributed within the vasculature in the brains of the majority of studied SAD and FAD cases, the latter also presenting considerable amounts of Aβ37 containing NPs. In addition, both peptides were found to be present in extracellular plaques but only scarce within the vasculature in brains of a variety of transgenic AD mouse models. Taken together, our study indicates the importance of C-terminally truncated Aβ in sporadic and familial AD and raises questions about how these species are generated and regulated.
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20
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Lei X, Yu J, Niu Q, Liu J, Fraering PC, Wu F. The FDA-approved natural product dihydroergocristine reduces the production of the Alzheimer's disease amyloid-β peptides. Sci Rep 2015; 5:16541. [PMID: 26567970 PMCID: PMC4644980 DOI: 10.1038/srep16541] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/15/2015] [Indexed: 02/05/2023] Open
Abstract
Known γ-secretase inhibitors or modulators display an undesirable pharmacokinetic profile and toxicity and have therefore not been successful in clinical trials for Alzheimer's disease (AD). So far, no compounds from natural products have been identified as direct inhibitors of γ-secretase. To search for bioactive molecules that can reduce the amount of amyloid-beta peptides (Aβ) and that have better pharmacokinetics and an improved safety profile, we completed a screen of ~400 natural products by using cell-based and cell-free γ-secretase activity assays. We identified dihydroergocristine (DHEC), a component of an FDA- (Food and Drug Administration)-approved drug, to be a direct inhibitor of γ-secretase. Micromolar concentrations of DHEC substantially reduced Aβ levels in different cell types, including a cell line derived from an AD patient. Structure-activity relationship studies implied that the key moiety for inhibiting γ-secretase is the cyclized tripeptide moiety of DHEC. A Surface Plasmon Resonance assay showed that DHEC binds directly to γ-secretase and Nicastrin, with equilibrium dissociation constants (Kd) of 25.7 nM and 9.8 μM, respectively. This study offers DHEC not only as a new chemical moiety for selectively modulating the activity of γ-secretase but also a candidate for drug repositioning in Alzheimer's disease.
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Affiliation(s)
- Xiling Lei
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jing Yu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Qi Niu
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jianhua Liu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Patrick C. Fraering
- Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland
| | - Fang Wu
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
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21
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Friedemann M, Helk E, Tiiman A, Zovo K, Palumaa P, Tõugu V. Effect of methionine-35 oxidation on the aggregation of amyloid-β peptide. Biochem Biophys Rep 2015; 3:94-99. [PMID: 29124171 PMCID: PMC5668694 DOI: 10.1016/j.bbrep.2015.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 07/22/2015] [Accepted: 07/28/2015] [Indexed: 01/12/2023] Open
Abstract
Aggregation of Aβ peptides into amyloid plaques is considered to trigger the Alzheimer’s disease (AD), however the mechanism behind the AD onset has remained elusive. It is assumed that the insoluble Aβ aggregates enhance oxidative stress (OS) by generating free radicals with the assistance of bound copper ions. The aim of our study was to establish the role of Met35 residue in the oxidation and peptide aggregation processes. Met35 can be readily oxidized by H2O2. The fibrillization of Aβ with Met35 oxidized to sulfoxide was three times slower compared to that of the regular peptide. The fibrils of regular and oxidized peptides looked similar under transmission electron microscopy. The relatively small inhibitory effect of methionine oxidation on the fibrillization suggests that the possible variation in the Met oxidation state should not affect the in vivo plaque formation. The peptide oxidation pattern was more complex when copper ions were present: addition of one oxygen atom was still the fastest process, however, it was accompanied by multiple unspecific modifications of peptide residues. Addition of copper ions to the Aβ with oxidized Met35 in the presence of H2O2, resulted a similar pattern of nonspecific modifications, suggesting that the one-electron oxidation processes in the peptide molecule do not depend on the oxidation state of Met35 residue. Thus, it can be concluded that Met35 residue is not a part of the radical generating mechanism of Aβ–Cu(II) complex. Aβ peptides with oxidized Met35 residue fibrillize three times slower than the reduced peptide. Met35 is the only residue in Aβ peptide that is oxidized by H2O2 in the absent of copper ions. In the presence of copper ions as catalyst multiple unspecific oxidative processes occur in Aβ. Previous oxidation of Met35 does not affect the unspecific oxidation in the presence of copper ions.
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Key Words
- AD, Alzheimer's disease
- Alzheimer's disease
- Aβ, Alzheimer's amyloid peptide
- Copper(II)ion
- HFIP, 1,1,1,3,3,3-hexafluoro-2-propanol
- Methionine oxidation
- OS, oxidative stress
- ROS, reactive oxygen species
- ThT, Thioflavin T
- β-amyloid
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Affiliation(s)
- Merlin Friedemann
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Eneken Helk
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Ann Tiiman
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Kairit Zovo
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Peep Palumaa
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Vello Tõugu
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
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22
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Liu T, Wu B, Wang Y, He H, Lin Z, Tan J, Yang L, Kamp DW, Zhou X, Tang J, Huang H, Zhang L, Bin L, Liu G. Particulate matter 2.5 induces autophagy via inhibition of the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin kinase signaling pathway in human bronchial epithelial cells. Mol Med Rep 2015; 12:1914-22. [PMID: 25845384 DOI: 10.3892/mmr.2015.3577] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 02/11/2015] [Indexed: 12/24/2022] Open
Abstract
Particulate matter 2.5 (PM2.5) is a significant risk factor for asthma. A recent study revealed that autophagy was associated with asthma pathogenesis. However, the specific mechanisms underlying PM2.5-induced autophagy in asthma have remained elusive. In the present study, PM2.5-induced autophagy was evaluated in Beas-2B human bronchial epithelial cells and the potential molecular mechanisms were investigated. Using electron microscopy, immunofluorescence staining and immunoblot studies, it was confirmed that PM2.5 induced autophagy in Beas-2B cells as a result of PM2.5-mediated inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway in Beas-2B cells. LY294002, a PI3K inhibitor, reduced the accumulation of microtubule-associated protein 1 light chain 3 II and attenuated the effect of PM2.5. Phosphorylated (p-)p38, p-extracellular signal-regulated kinase and p-c-Jun N-terminal kinase were dephosphorylated following exposure to PM2.5. The roles of p53, reactive oxygen species scavenger tetramethylthiourea and autophagy inhibitor 3-methyladenine in PM2.5-induced autophagy in Beas-2B cells were also investigated. The results suggested that the PI3K/Akt/mTOR signaling pathway may be a key contributor to PM2.5-induced autophagy in Beas-2B cells. The results of the present study therefore provided an a insight into potential future clinical applications targeting these signaling pathways, for the prevention and/or treatment of PM2.5-induced lung diseases.
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Affiliation(s)
- Tie Liu
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Bin Wu
- Department of Respiratory Medicine, Affiliated Hospital of Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Yahong Wang
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Huijuan He
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Ziying Lin
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Jianxin Tan
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Lawei Yang
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - David W Kamp
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine and Jesse Brown VA Medical Center, Chicago, IL 60611, USA
| | - Xu Zhou
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Jinfeng Tang
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Haili Huang
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Liangqing Zhang
- Department of Immunology and Tumor Research Institute, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shanxi 710061, P.R. China
| | - Liu Bin
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Gang Liu
- Clinical Research Center, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
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Solé M, Miñano-Molina AJ, Unzeta M. A cross-talk between Aβ and endothelial SSAO/VAP-1 accelerates vascular damage and Aβ aggregation related to CAA-AD. Neurobiol Aging 2015; 36:762-75. [DOI: 10.1016/j.neurobiolaging.2014.09.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 09/18/2014] [Accepted: 09/29/2014] [Indexed: 02/07/2023]
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Oberstein TJ, Spitzer P, Klafki HW, Linning P, Neff F, Knölker HJ, Lewczuk P, Wiltfang J, Kornhuber J, Maler JM. Astrocytes and microglia but not neurons preferentially generate N-terminally truncated Aβ peptides. Neurobiol Dis 2015; 73:24-35. [DOI: 10.1016/j.nbd.2014.08.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 08/05/2014] [Accepted: 08/31/2014] [Indexed: 12/30/2022] Open
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Tucci P, Mhillaj E, Morgese MG, Colaianna M, Zotti M, Schiavone S, Cicerale M, Trezza V, Campolongo P, Cuomo V, Trabace L. Memantine prevents memory consolidation failure induced by soluble beta amyloid in rats. Front Behav Neurosci 2014; 8:332. [PMID: 25285073 PMCID: PMC4168698 DOI: 10.3389/fnbeh.2014.00332] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 09/04/2014] [Indexed: 12/21/2022] Open
Abstract
It has been well documented that β-amyloid (Aβ) peptide accumulation and aggregation in the brain plays a crucial role in the pathophysiology of Alzheimer's disease (AD). However, a new orientation of the amyloid cascade hypothesis has evidenced that soluble forms of the peptide (sAβ) are involved in Aβ-induced cognitive impairment and cause rapid disruption of the synaptic mechanisms underlying memory. The primary aim of this study was to elucidate the effects of sAβ, acutely injected intracerebrally (i.c.v., 4 μM), on the short term and long term memory of young adult male rats, by using the novel object recognition task. Glutamatergic receptors have been proposed as mediating the effect of Aβ on synaptic plasticity and memory. Thus, we also investigated the effects of sAβ on prefrontal cortex (PFC) glutamate release and the specific contribution of N-methyl-D-aspartate (NMDA) receptor modulation to the effects of sAβ administration on the cognitive parameters evaluated. We found that a single i.c.v. injection of sAβ 2 h before testing did not alter the ability of rats to differentiate between a familiar and a novel object, in a short term memory test, while it was able to negatively affect consolidation/retrieval of long term memory. Moreover, a significant increase of glutamate levels was found in PFC of rats treated with the peptide 2 h earlier. Interestingly, memory deficit induced by sAβ was reversed by a NMDA-receptor antagonist, memantine (5 mg/kg i.p), administered immediately after the familiarization trial (T1). On the contrary, memantine administered 30 min before T1 trial, was not able to rescue long term memory impairment. Taken together, our results suggest that an acute i.c.v. injection of sAβ peptide interferes with the consolidation/retrieval of long term memory. Moreover, such sAβ-induced effect indicates the involvement of glutamatergic system, proposing that NMDA receptor inhibition might prevent or lead to the recovery of early cognitive impairment.
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Affiliation(s)
- Paolo Tucci
- Department of Experimental and Clinical Medicine, Faculty of Medicine, University of Foggia Foggia, Italy
| | - Emanuela Mhillaj
- Department of Experimental and Clinical Medicine, Faculty of Medicine, University of Foggia Foggia, Italy
| | - Maria Grazia Morgese
- Department of Experimental and Clinical Medicine, Faculty of Medicine, University of Foggia Foggia, Italy
| | - Marilena Colaianna
- Department of Pathology and Immunology, University of Geneva Geneva, Switzerland
| | - Margherita Zotti
- Department of Experimental and Clinical Medicine, Faculty of Medicine, University of Foggia Foggia, Italy
| | - Stefania Schiavone
- Department of Mental Health and Psychiatry, Geneva University Hospital and University of Geneva Geneva, Switzerland
| | - Maria Cicerale
- Department of Experimental and Clinical Medicine, Faculty of Medicine, University of Foggia Foggia, Italy
| | - Viviana Trezza
- Department of Sciences, University "Roma Tre" Rome, Italy
| | - Patrizia Campolongo
- Department of Physiology and Pharmacology, La Sapienza, University of Rome Rome, Italy
| | - Vincenzo Cuomo
- Department of Physiology and Pharmacology, La Sapienza, University of Rome Rome, Italy
| | - Luigia Trabace
- Department of Experimental and Clinical Medicine, Faculty of Medicine, University of Foggia Foggia, Italy
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26
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Mosser S, Alattia JR, Dimitrov M, Matz A, Pascual J, Schneider BL, Fraering PC. The adipocyte differentiation protein APMAP is an endogenous suppressor of Aβ production in the brain. Hum Mol Genet 2014; 24:371-82. [PMID: 25180020 PMCID: PMC4275069 DOI: 10.1093/hmg/ddu449] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The deposition of amyloid-beta (Aβ) aggregates in the brain is a major pathological hallmark of Alzheimer's disease (AD). Aβ is generated from the cleavage of C-terminal fragments of the amyloid precursor protein (APP-CTFs) by γ-secretase, an intramembrane-cleaving protease with multiple substrates, including the Notch receptors. Endogenous modulation of γ-secretase is pointed to be implicated in the sporadic, age-dependent form of AD. Moreover, specifically modulating Aβ production has become a priority for the safe treatment of AD because the inhibition of γ-secretase results in adverse effects that are related to impaired Notch cleavage. Here, we report the identification of the adipocyte differentiation protein APMAP as a novel endogenous suppressor of Aβ generation. We found that APMAP interacts physically with γ-secretase and its substrate APP. In cells, the partial depletion of APMAP drastically increased the levels of APP-CTFs, as well as uniquely affecting their stability, with the consequence being increased secretion of Aβ. In wild-type and APP/ presenilin 1 transgenic mice, partial adeno-associated virus-mediated APMAP knockdown in the hippocampus increased Aβ production by ∼20 and ∼55%, respectively. Together, our data demonstrate that APMAP is a negative regulator of Aβ production through its interaction with APP and γ-secretase. All observed APMAP phenotypes can be explained by an impaired degradation of APP-CTFs, likely caused by an altered substrate transport capacity to the lysosomal/autophagic system.
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Affiliation(s)
- Sebastien Mosser
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
| | - Jean-René Alattia
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
| | - Mitko Dimitrov
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
| | - Alexandre Matz
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
| | - Justine Pascual
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
| | - Bernard L Schneider
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
| | - Patrick C Fraering
- Brain Mind Institute and School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH1015, Switzerland
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Feneberg E, Steinacker P, Lehnert S, Schneider A, Walther P, Thal DR, Linsenmeier M, Ludolph AC, Otto M. Limited role of free TDP-43 as a diagnostic tool in neurodegenerative diseases. Amyotroph Lateral Scler Frontotemporal Degener 2014; 15:351-6. [PMID: 24834468 DOI: 10.3109/21678421.2014.905606] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
TAR DNA-binding protein 43 (TDP-43) is one of the neuropathological hallmarks in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). It is present in patients' blood and cerebrospinal fluid (CSF); however, the source and clinical relevance of TDP-43 measurements in body fluids is uncertain. We investigated paired CSF and serum samples, blood lymphocytes, brain urea fractions and purified exosomes from CSF for TDP-43 by one- (1D), and two-dimensional (2D) Western immunoblotting (WB) and quantitative mass spectrometry (MRM) in patients with ALS, FTLD and non-neurodegenerative diseases. By means of 2D-WB we were able to demonstrate a similar isoform pattern of TDP-43 in lymphocytes, serum and CSF in contrast to that of brain urea fractions with TDP-43 pathology. We found that the TDP-43 CSF to blood concentration ratio is about 1:200. As a possible brain specific fraction we found TDP-43 in exosome preparations from CSF by immunoblot and MRM. We conclude that TDP-43 in CSF originates mainly from blood. Measurements of TDP-43 in CSF and blood are of minor importance as a diagnostic tool, but may be important for monitoring therapy effects of TDP-43 modifying drugs.
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Ongali B, Nicolakakis N, Tong XK, Aboulkassim T, Papadopoulos P, Rosa-Neto P, Lecrux C, Imboden H, Hamel E. Angiotensin II type 1 receptor blocker losartan prevents and rescues cerebrovascular, neuropathological and cognitive deficits in an Alzheimer's disease model. Neurobiol Dis 2014; 68:126-36. [PMID: 24807206 DOI: 10.1016/j.nbd.2014.04.018] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 04/17/2014] [Accepted: 04/27/2014] [Indexed: 11/18/2022] Open
Abstract
Angiotensin II (AngII) receptor blockers that bind selectively AngII type 1 (AT1) receptors may protect from Alzheimer's disease (AD). We studied the ability of the AT1 receptor antagonist losartan to cure or prevent AD hallmarks in aged (~18months at endpoint, 3months treatment) or adult (~12months at endpoint, 10months treatment) human amyloid precursor protein (APP) transgenic mice. We tested learning and memory with the Morris water maze, and evaluated neurometabolic and neurovascular coupling using [(18)F]fluoro-2-deoxy-D-glucose-PET and laser Doppler flowmetry responses to whisker stimulation. Cerebrovascular reactivity was assessed with on-line videomicroscopy. We measured protein levels of oxidative stress enzymes (superoxide dismutases SOD1, SOD2 and NADPH oxidase subunit p67phox), and quantified soluble and deposited amyloid-β (Aβ) peptide, glial fibrillary acidic protein (GFAP), AngII receptors AT1 and AT2, angiotensin IV receptor AT4, and cortical cholinergic innervation. In aged APP mice, losartan did not improve learning but it consolidated memory acquisition and recall, and rescued neurovascular and neurometabolic coupling and cerebrovascular dilatory capacity. Losartan normalized cerebrovascular p67phox and SOD2 protein levels and up-regulated those of SOD1. Losartan attenuated astrogliosis, normalized AT1 and AT4 receptor levels, but failed to rescue the cholinergic deficit and the Aβ pathology. Given preventively, losartan protected cognitive function, cerebrovascular reactivity, and AT4 receptor levels. Like in aged APP mice, these benefits occurred without a decrease in soluble Aβ species or plaque load. We conclude that losartan exerts potent preventive and restorative effects on AD hallmarks, possibly by mitigating AT1-initiated oxidative stress and normalizing memory-related AT4 receptors.
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Affiliation(s)
- Brice Ongali
- Laboratory of Cerebrovascular Research, McGill University, Montréal, QC H3A 2B4, Canada
| | - Nektaria Nicolakakis
- Laboratory of Cerebrovascular Research, McGill University, Montréal, QC H3A 2B4, Canada
| | - Xin-Kang Tong
- Laboratory of Cerebrovascular Research, McGill University, Montréal, QC H3A 2B4, Canada
| | - Tahar Aboulkassim
- Laboratory of Cerebrovascular Research, McGill University, Montréal, QC H3A 2B4, Canada
| | | | - Pedro Rosa-Neto
- Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montréal, QC H3A 2B4, Canada; Douglas Hospital Research Centre, McGill University, Montréal, QC H3A 2B4, Canada
| | - Clotilde Lecrux
- Laboratory of Cerebrovascular Research, McGill University, Montréal, QC H3A 2B4, Canada
| | - Hans Imboden
- Institute of Cell Biology, University of Bern, Switzerland
| | - Edith Hamel
- Laboratory of Cerebrovascular Research, McGill University, Montréal, QC H3A 2B4, Canada.
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Development of a novel cellular model of Alzheimer's disease utilizing neurosphere cultures derived from B6C3-Tg(APPswe,PSEN1dE9)85Dbo/J embryonic mouse brain. SPRINGERPLUS 2014; 3:161. [PMID: 25140287 PMCID: PMC4137416 DOI: 10.1186/2193-1801-3-161] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 03/07/2014] [Indexed: 12/29/2022]
Abstract
Increased production, oligomerization and aggregation of amyloid-β (Aβ) peptides are hallmark pathologies of Alzheimer’s disease (AD). Expressing familial AD mutations (amyloid precursor protein and/or presenilins mutations), the Aβ-pathologies of AD has been recapitulated in animal models of AD. Very few primary cell culture-based models of AD are available and they exhibit very weak Aβ-pathologies compared to what is seen in AD patients and animal models of AD. CNS stem/progenitor cells are present in both embryonic and adult brains. They can be isolated, grown as neurospheres and differentiated into neurons, astrocytes and oligodendrocytes. It is not yet known whether CNS stem/progenitor cells can support the production of Aβ peptides in culture. In this report, we have established Aβ-pathologies such as production, secretion, oligomerization and aggregation of Aβ peptides utilizing neurosphere cultures to create a new cellular model of AD. These cultures were developed from E15 embryonic brains of transgenic mice carrying the Swedish mutations in humanized mouse APP cDNA and the exon-9 deleted human presenilin 1 cDNA both regulated by mouse prion protein gene (Prnp) promoter. Results demonstrated the expression of transgene transcripts, APPswe protein and its processed products only in transgene positive neurosphere cultures. These cultures generate and secrete both Aβ40 and Aβ42 peptides into culture medium at levels comparable to the Aβ load in the brain of AD patients and animal models of AD, and produce pathogenic oligomers of Aβ peptides. The Aβ42/Aβ40 ratio in the medium of transgene positive neurosphere cultures is higher than any known cellular models of AD. Conformation dependent immunocytochemistry demonstrated the possible presence of intracellular and extracellular aggregation of Aβ peptides in neurosphere cultures, which are also seen in AD brain and animal models of AD. Collectively, our neurosphere cultures provide robust Aβ-pathologies of AD better than existing cellular model of Alzheimer’s disease.
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Reorientation of the first signal-anchor sequence during potassium channel biogenesis at the Sec61 complex. Biochem J 2014; 456:297-309. [PMID: 24015703 PMCID: PMC3898203 DOI: 10.1042/bj20130100] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The majority of the polytopic proteins that are synthesized at the ER (endoplasmic reticulum) are integrated co-translationally via the Sec61 translocon, which provides lateral access for their hydrophobic TMs (transmembrane regions) to the phospholipid bilayer. A prolonged association between TMs of the potassium channel subunit, TASK-1 [TWIK (tandem-pore weak inwardly rectifying potassium channel)-related acid-sensitive potassium channel 1], and the Sec61 complex suggests that the ER translocon co-ordinates the folding/assembly of the TMs present in the nascent chain. The N-terminus of both TASK-1 and Kcv (potassium channel protein of chlorella virus), another potassium channel subunit of viral origin, has access to the N-glycosylation machinery located in the ER lumen, indicating that the Sec61 complex can accommodate multiple arrangements/orientations of TMs within the nascent chain, both in vitro and in vivo. Hence the ER translocon can provide the ribosome-bound nascent chain with a dynamic environment in which it can explore a range of different conformations en route to its correct transmembrane topology and final native structure. The Sec61 translocon provides an unexpectedly flexible and dynamic environment within which transmembrane regions of nascent polypeptides can be completely reoriented during the biosynthesis of multiple-spanning membrane proteins.
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31
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Proenca CC, Stoehr N, Bernhard M, Seger S, Genoud C, Roscic A, Paganetti P, Liu S, Murphy LO, Kuhn R, Bouwmeester T, Galimberti I. Atg4b-dependent autophagic flux alleviates Huntington's disease progression. PLoS One 2013; 8:e68357. [PMID: 23861892 PMCID: PMC3704647 DOI: 10.1371/journal.pone.0068357] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 05/29/2013] [Indexed: 01/24/2023] Open
Abstract
The accumulation of aggregated mutant huntingtin (mHtt) inclusion bodies is involved in Huntigton’s disease (HD) progression. Medium sized-spiny neurons (MSNs) in the corpus striatum are highly vulnerable to mHtt aggregate accumulation and degeneration, but the mechanisms and pathways involved remain elusive. Here we have developed a new model to study MSNs degeneration in the context of HD. We produced organotypic cortico-striatal slice cultures (CStS) from HD transgenic mice mimicking specific features of HD progression. We then show that induction of autophagy using catalytic inhibitors of mTOR prevents MSNs degeneration in HD CStS. Furthermore, disrupting autophagic flux by overexpressing Atg4b in neurons and slice cultures, accelerated mHtt aggregation and neuronal death, suggesting that Atg4b-dependent autophagic flux influences HD progression. Under these circumstances induction of autophagy using catalytic inhibitors of mTOR was inefficient and did not affect mHtt aggregate accumulation and toxicity, indicating that mTOR inhibition alleviates HD progression by inducing Atg4b-dependent autophagic flux. These results establish modulators of Atg4b-dependent autophagic flux as new potential targets in the treatment of HD.
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Affiliation(s)
- Catia C. Proenca
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Natacha Stoehr
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Mario Bernhard
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | | | | | | | - Shanming Liu
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Leon O. Murphy
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | | | - Tewis Bouwmeester
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Ivan Galimberti
- Developmental and Molecular Pathways, Novartis Institutes for Biomedical Research, Basel, Switzerland
- * E-mail:
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Tiiman A, Noormägi A, Friedemann M, Krishtal J, Palumaa P, Tõugu V. Effect of agitation on the peptide fibrillization: Alzheimer's amyloid-β peptide 1-42 but not amylin and insulin fibrils can grow under quiescent conditions. J Pept Sci 2013; 19:386-91. [PMID: 23609985 DOI: 10.1002/psc.2513] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 03/11/2013] [Indexed: 11/08/2022]
Abstract
Many peptides and proteins can form fibrillar aggregates in vitro, but only a limited number of them are forming pathological amyloid structures in vivo. We studied the fibrillization of four peptides--Alzheimer's amyloid-β (Aβ) 1-40 and 1-42, amylin and insulin. In all cases, intensive mechanical agitation of the solution initiated fast fibrillization. However, when the mixing was stopped during the fibril growth phase, the fibrillization of amylin and insulin was practically stopped, and the rate for Aβ40 substantially decreased, whereas the fibrillization of Aβ42 peptide continued to proceed with almost the same rate as in the agitated conditions. The reason for the different sensitivity of the in vitro fibrillization of these peptides towards agitation in the fibril growth phase remains elusive.
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Affiliation(s)
- Ann Tiiman
- Department of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, Tallinn, 12618, Estonia.
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Catricala S, Torti M, Ricevuti G. Alzheimer disease and platelets: how's that relevant. IMMUNITY & AGEING 2012; 9:20. [PMID: 22985434 PMCID: PMC3545835 DOI: 10.1186/1742-4933-9-20] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/01/2012] [Indexed: 02/06/2023]
Abstract
Alzheimer Disease (AD) is the most common neurodegenerative disorder worldwide, and account for 60% to 70% of all cases of progressive cognitive impairment in elderly patients. At the microscopic level distinctive features of AD are neurons and synapses degeneration, together with extensive amounts of senile plaques and neurofibrillars tangles. The degenerative process probably starts 20-30 years before the clinical onset of the disease. Senile plaques are composed of a central core of amyloid β peptide, Aβ, derived from the metabolism of the larger amyloid precursor protein, APP, which is expressed not only in the brain, but even in non neuronal tissues. More than 30 years ago, some studies reported that human platelets express APP and all the enzymatic activities necessary to process this protein through the same pathways described in the brain. Since then a large number of evidence has been accumulated to suggest that platelets may be a good peripheral model to study the metabolism of APP, and the pathophysiology of the onset of AD. In this review, we will summarize the current knowledge on the involvement of platelets in Alzheimer Disease. Although platelets are generally accepted as a suitable model for AD, the current scientific interest on this model is very high, because many concepts still remain debated and controversial. At the same time, however, these still unsolved divergences mirror a difficulty to establish constant parameters to better defined the role of platelets in AD.
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Affiliation(s)
- Silvia Catricala
- Department of Internal Medicine and Therapeutics, Section of Geriatrics, University of Pavia, ASP-IDR S,Margherita, Via Emilia 12, Pavia, 27100, Italy.
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Bibl M, Gallus M, Welge V, Lehmann S, Sparbier K, Esselmann H, Wiltfang J. Characterization of cerebrospinal fluid aminoterminally truncated and oxidized amyloid-β peptides. Proteomics Clin Appl 2012; 6:163-9. [PMID: 22532452 DOI: 10.1002/prca.201100082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE Carboxyterminally elongated and aminoterminally truncated Aβ peptides as well as their pyroglutamate and oxidized derivates are major constituents of human amyloid plaques. The objective of the present study was to characterize aminoterminally truncated or oxidized Aβ38, Aβ40, and Aβ42 peptide species in immunoprecipitated human cerebrospinal fluid (CSF). EXPERIMENTAL DESIGN We invented a novel sequential aminoterminally and carboxyterminally specific immunoprecipitation protocol and used the Aβ-SDS-PAGE/immunoblot for subsequent analysis of CSF Aβ peptide patterns. RESULTS In the present study, we identified the aminoterminally truncated Aβ peptides 2-40 and 2-42 as well as oxidized forms of Aβ1-38 and Aβ1-42 in CSF. Our protocol allowed the quantification of a pattern of Aβ peptides 1-38(ox), 2-40, and 2-42 in addition to the well known panel of Aβ 1-37, 1-38, 1-39, 1-40, 1-40(ox), and 1-42 in a group of seven patients with peripheral polyneuropathy. CONCLUSIONS AND CLINICAL RELEVANCE In the present approach, we could broaden the range of quantifiable Aβ peptides described in previous studies (i.e., 1-37, 1-38, 1-39, 1-40, 1-40(ox), and 1-42) by Aβ 1-38(ox), 2-40, and 2-42. An exact analysis of CSF Aβ peptides regarding their carboxy- and aminoterminus as well as posttranslational modification seems promising with respect to diagnostic and pathogenic aspects.
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Affiliation(s)
- Mirko Bibl
- Department of Psychiatry, Psychotherapy and Addiction Medicine, Kliniken Essen-Mitte, University of Duisburg-Essen, Essen, Germany.
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Winkler E, Kamp F, Scheuring J, Ebke A, Fukumori A, Steiner H. Generation of Alzheimer disease-associated amyloid β42/43 peptide by γ-secretase can be inhibited directly by modulation of membrane thickness. J Biol Chem 2012; 287:21326-34. [PMID: 22532566 DOI: 10.1074/jbc.m112.356659] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pathogenic generation of amyloid β-peptide (Aβ) by sequential cleavage of β-amyloid precursor protein (APP) by β- and γ-secretases is widely believed to causally underlie Alzheimer disease (AD). β-Secretase initially cleaves APP thereby generating a membrane-bound APP C-terminal fragment, from which γ-secretase subsequently liberates 37-43-amino acid long Aβ species. Although the latter cleavages are intramembranous and although lipid alterations have been implicated in AD, little is known of how the γ-secretase-mediated release of the various Aβ species, in particular that of the pathogenic longer variants Aβ(42) and Aβ(43), is affected by the lipid environment. Using a cell-free system, we have directly and systematically investigated the activity of γ-secretase reconstituted in defined model membranes of different thicknesses. We found that bilayer thickness is a critical parameter affecting both total activity as well as cleavage specificity of γ-secretase. Whereas the generation of the pathogenic Aβ(42/43) species was markedly attenuated in thick membranes, that of the major and rather benign Aβ(40) species was enhanced. Moreover, the increased production of Aβ(42/43) by familial AD mutants of presenilin 1, the catalytic subunit of γ-secretase, could be substantially lowered in thick membranes. Our data demonstrate an effective modulation of γ-secretase activity by membrane thickness, which may provide an approach to lower the generation of the pathogenic Aβ(42/43) species.
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Affiliation(s)
- Edith Winkler
- Adolf Butenandt Institute, Biochemistry, Ludwig Maximilians University Munich, Schillerstrasse 44, 80336 Munich, Germany
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Schieb H, Kratzin H, Jahn O, Möbius W, Rabe S, Staufenbiel M, Wiltfang J, Klafki HW. Beta-amyloid peptide variants in brains and cerebrospinal fluid from amyloid precursor protein (APP) transgenic mice: comparison with human Alzheimer amyloid. J Biol Chem 2011; 286:33747-58. [PMID: 21795681 DOI: 10.1074/jbc.m111.246561] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In this study, we report a detailed analysis of the different variants of amyloid-β (Aβ) peptides in the brains and the cerebrospinal fluid from APP23 transgenic mice, expressing amyloid precursor protein with the Swedish familial Alzheimer disease mutation, at different ages. Using one- and two-dimensional gel electrophoresis, immunoblotting, and mass spectrometry, we identified the Aβ peptides Aβ(1-40), -(1-42), -(1-39), -(1-38), -(1-37), -(2-40), and -(3-40) as well as minor amounts of pyroglutamate-modified Aβ (Aβ(N3pE)) and endogenous murine Aβ in brains from 24-month-old mice. Chemical modifications of the N-terminal amino group of Aβ were identified that had clearly been introduced during standard experimental procedures. To address this issue, we additionally applied amyloid extraction in ultrapure water. Clear differences between APP23 mice and Alzheimer disease (AD) brain samples were observed in terms of the relative abundance of specific variants of Aβ peptides, such as Aβ(N3pE), Aβ(1-42), and N-terminally truncated Aβ(2/3-42). These differences to human AD amyloid were also noticed in a related mouse line transgenic for human wild type amyloid precursor protein. Taken together, our findings suggest different underlying molecular mechanisms driving the amyloid deposition in transgenic mice and AD patients.
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Affiliation(s)
- Heinke Schieb
- Department of Psychiatry and Psychotherapy, LVR-Klinikum, Essen, University of Duisburg-Essen, D-45147 Essen, Germany
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37
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Schieb H, Weidlich S, Schlechtingen G, Linning P, Jennings G, Gruner M, Wiltfang J, Klafki HW, Knölker HJ. Structural design, solid-phase synthesis and activity of membrane-anchored β-secretase inhibitors on Aβ generation from wild-type and Swedish-mutant APP. Chemistry 2011; 16:14412-23. [PMID: 21132705 DOI: 10.1002/chem.201002878] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Covalent coupling of β-secretase inhibitors to a raftophilic lipid anchor via a suitable spacer by using solid-phase peptide synthesis leads to tripartite structures displaying substantially improved inhibition of cellular secretion of the β-amyloid peptide (Aβ). Herein, we describe a series of novel tripartite structures, their full characterization by NMR spectroscopy and mass spectrometry, and the analysis of their biological activity in cell-based assays. The tripartite structure concept is applicable to different pharmacophores, and the potency in terms of β-secretase inhibition can be optimized by adjusting the spacer length to achieve an optimal distance of the inhibitor from the lipid bilayer. A tripartite structure containing a transition-state mimic inhibitor was found to be less potent on Aβ generation from Swedish-mutant amyloid precursor protein (APP) than from the wild-type protein. Moreover, our observations suggest that specific variants of Aβ are generated from wild-type APP but not from Swedish-mutant APP and are resistant to β-secretase inhibition. Efficient inhibition of Aβ secretion by tripartite structures in the absence of appreciable neurotoxicity was confirmed in a primary neuronal cell culture, thus further supporting the concept.
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Affiliation(s)
- Heinke Schieb
- Department of Psychiatry and Psychotherapy, University of Duisburg-Essen, LVR-Klinikum, Essen, Germany
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Boumahrou N, Bevilacqua C, Beauvallet C, Miranda G, Andrei S, Rebours E, Panthier JJ, Bellier S, Martin P. Evolution of major milk proteins in Mus musculus and Mus spretus mouse species: a genoproteomic analysis. BMC Genomics 2011; 12:80. [PMID: 21276224 PMCID: PMC3048548 DOI: 10.1186/1471-2164-12-80] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 01/28/2011] [Indexed: 11/10/2022] Open
Abstract
Background Due to their high level of genotypic and phenotypic variability, Mus spretus strains were introduced in laboratories to investigate the genetic determinism of complex phenotypes including quantitative trait loci. Mus spretus diverged from Mus musculus around 2.5 million years ago and exhibits on average a single nucleotide polymorphism (SNP) in every 100 base pairs when compared with any of the classical laboratory strains. A genoproteomic approach was used to assess polymorphism of the major milk proteins between SEG/Pas and C57BL/6J, two inbred strains of mice representative of Mus spretus and Mus musculus species, respectively. Results The milk protein concentration was dramatically reduced in the SEG/Pas strain by comparison with the C57BL/6J strain (34 ± 9 g/L vs. 125 ± 12 g/L, respectively). Nine major proteins were identified in both milks using RP-HPLC, bi-dimensional electrophoresis and MALDI-Tof mass spectrometry. Two caseins (β and αs1) and the whey acidic protein (WAP), showed distinct chromatographic and electrophoresis behaviours. These differences were partly explained by the occurrence of amino acid substitutions and splicing variants revealed by cDNA sequencing. A total of 34 SNPs were identified in the coding and 3'untranslated regions of the SEG/Pas Csn1s1 (11), Csn2 (7) and Wap (8) genes. In addition, a 3 nucleotide deletion leading to the loss of a serine residue at position 93 was found in the SEG/Pas Wap gene. Conclusion SNP frequencies found in three milk protein-encoding genes between Mus spretus and Mus musculus is twice the values previously reported at the whole genome level. However, the protein structure and post-translational modifications seem not to be affected by SNPs characterized in our study. Splicing mechanisms (cryptic splice site usage, exon skipping, error-prone junction sequence), already identified in casein genes from other species, likely explain the existence of multiple αs1-casein isoforms both in SEG/Pas and C57BL/6J strains. Finally, we propose a possible mechanism by which the hallmark tandem duplication of a 18-nt exon (14 copies) may have occurred in the mouse genome.
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Affiliation(s)
- Nisrine Boumahrou
- INRA, UR1313 Génétique animale et Biologie intégrative UMR 1313, Equipe LGS, Jouy-en-Josas, France
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Schieb H, Spitzer P, Riess V, Wiltfang J, Klafki HW. A method to prevent cross contamination during 2-DE by β-amyloid peptides. Proteomics 2011; 10:3539-43. [PMID: 20827735 DOI: 10.1002/pmic.201000227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A method for the efficient decontamination of aluminium oxide ceramic 2-DE focusing trays from β-amyloid peptides (Aβ) is reported. As these contaminations were resistant to the standard cleaning procedures, additional harsh cleaning steps were necessary for their efficient removal. Our observations suggest that specific surface properties affect the degree of adsorption of the Aβ-peptides. "Surface catalysed amyloid aggregation" in the aluminium oxide ceramic trays is proposed as a possible underlying mechanism for the occurrence of proteinase K-resistant forms of Aβ.
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Affiliation(s)
- Heinke Schieb
- Department of Psychiatry and Psychotherapy, University of Duisburg-Essen, LVR-Klinikum, Essen, Germany
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40
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Bepridil and amiodarone simultaneously target the Alzheimer's disease beta- and gamma-secretase via distinct mechanisms. J Neurosci 2010; 30:8974-83. [PMID: 20592218 DOI: 10.1523/jneurosci.1199-10.2010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The two proteases beta-secretase and gamma-secretase generate the amyloid beta peptide and are drug targets for Alzheimer's disease. Here we tested the possibility of targeting the cellular environment of beta-secretase cleavage instead of the beta-secretase enzyme itself. beta-Secretase has an acidic pH optimum and cleaves the amyloid precursor protein in the acidic endosomes. We identified two drugs, bepridil and amiodarone, that are weak bases and are in clinical use as calcium antagonists. Independently of their calcium-blocking activity, both compounds mildly raised the membrane-proximal, endosomal pH and inhibited beta-secretase cleavage at therapeutically achievable concentrations in cultured cells, in primary neurons, and in vivo in guinea pigs. This shows that an alkalinization of the cellular environment could be a novel therapeutic strategy to inhibit beta-secretase. Surprisingly, bepridil and amiodarone also modulated gamma-secretase cleavage independently of endosomal alkalinization. Thus, both compounds act as dual modulators that simultaneously target beta- and gamma-secretase through distinct molecular mechanisms. In addition to Alzheimer's disease, compounds with dual properties may also be useful for drug development targeting other membrane proteins.
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A proteomic approach for the diagnosis of bacterial meningitis. PLoS One 2010; 5:e10079. [PMID: 20386697 PMCID: PMC2851643 DOI: 10.1371/journal.pone.0010079] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 03/16/2010] [Indexed: 11/19/2022] Open
Abstract
Background The discrimination of bacterial meningitis (BM) versus viral meningitis (VM) shapes up as a problem, when laboratory data are not equivocal, in particular, when Gram stain is negative. Methodology/Principal Findings With the aim to determine reliable marker for bacterial or viral meningitis, we subjected cerebrospinal fluid (CSF) to a quantitative proteomic screening. By using a recently established 2D-DIGE protocol which was adapted to the individual CSF flow, we compared a small set of patients with proven BM and VM. Thereby, we identified six potential biomarkers out of which Prostaglandin-H2 D-isomerase was already described in BM, showing proof of concept. In the subsequent validation phase on a more comprehensive collective of 80 patients, we could validate that in BM high levels of glial fibrillary acidic protein (GFAP) and low levels of soluble amyloid precursor protein alpha/beta (sAPPα/β) are present as possible binding partner of Fibulin-1. Conclusions/Significance We conclude that our CSF flow-adapted 2D-DIGE protocol is valid especially in comparing samples with high differences in total protein and suppose that GFAP and sAPPα/β have a high potential as additional diagnostic markers for differentiation of BM from VM. In the clinical setting, this might lead to an improved early diagnosis and to an individual therapy.
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42
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Page RM, Gutsmiedl A, Fukumori A, Winkler E, Haass C, Steiner H. Beta-amyloid precursor protein mutants respond to gamma-secretase modulators. J Biol Chem 2010; 285:17798-810. [PMID: 20348104 DOI: 10.1074/jbc.m110.103283] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pathogenic generation of the 42-amino acid variant of the amyloid beta-peptide (Abeta) by beta- and gamma-secretase cleavage of the beta-amyloid precursor protein (APP) is believed to be causative for Alzheimer disease (AD). Lowering of Abeta(42) production by gamma-secretase modulators (GSMs) is a hopeful approach toward AD treatment. The mechanism of GSM action is not fully understood. Moreover, whether GSMs target the Abeta domain is controversial. To further our understanding of the mode of action of GSMs and the cleavage mechanism of gamma-secretase, we analyzed mutations located at different positions of the APP transmembrane domain around or within the Abeta domain regarding their response to GSMs. We found that Abeta(42)-increasing familial AD mutations of the gamma-secretase cleavage site domain responded robustly to Abeta(42)-lowering GSMs, especially to the potent compound GSM-1, irrespective of the amount of Abeta(42) produced. We thus expect that familial AD patients carrying mutations at the gamma-secretase cleavage sites of APP should respond to GSM-based therapeutic approaches. Systematic phenylalanine-scanning mutagenesis of this region revealed a high permissiveness to GSM-1 and demonstrated a complex mechanism of GSM action as other Abeta species (Abeta(41), Abeta(39)) could also be lowered besides Abeta(42). Moreover, certain mutations simultaneously increased Abeta(42) and the shorter peptide Abeta(38), arguing that the proposed precursor-product relationship of these Abeta species is not general. Finally, mutations of residues in the proposed GSM-binding site implicated in Abeta(42) generation (Gly-29, Gly-33) and potentially in GSM-binding (Lys-28) were also responsive to GSMs, a finding that may question APP substrate targeting of GSMs.
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Affiliation(s)
- Richard M Page
- German Center for Neurodegenerative Diseases DZNE)and Adolf-Butenandt-Institute, Biochemistry, Ludwig-Maximilians-University, 80336 Munich, Germany
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Steinacker P, Hawlik A, Lehnert S, Jahn O, Meier S, Görz E, Braunstein KE, Krzovska M, Schwalenstöcker B, Jesse S, Pröpper C, Böckers T, Ludolph A, Otto M. Neuroprotective function of cellular prion protein in a mouse model of amyotrophic lateral sclerosis. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:1409-20. [PMID: 20075202 DOI: 10.2353/ajpath.2010.090355] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Transgenic mice expressing human mutated superoxide dismutase 1 (SOD1) linked to familial forms of amyotrophic lateral sclerosis are frequently used as a disease model. We used the SOD1G93A mouse in a cross-breeding strategy to study the function of physiological prion protein (Prp). SOD1G93APrp-/- mice exhibited a significantly reduced life span, and an earlier onset and accelerated progression of disease, as compared with SOD1G93APrp+/+ mice. Additionally, during disease progression, SOD1G93APrp-/- mice showed impaired rotarod performance, lower body weight, and reduced muscle strength. Histologically, SOD1G93APrp-/- mice showed reduced numbers of spinal cord motor neurons and extended areas occupied by large vacuoles early in the course of the disease. Analysis of spinal cord homogenates revealed no differences in SOD1 activity. Using an unbiased proteomic approach, a marked reduction of glial fibrillary acidic protein and enhanced levels of collapsing response mediator protein 2 and creatine kinase were detected in SOD1G93APrp-/- versus SOD1G93A mice. In the course of disease, Bcl-2 decreases, nuclear factor-kappaB increases, and Akt is activated, but these changes were largely unaffected by Prp expression. Exclusively in double-transgenic mice, we detected a significant increase in extracellular signal-regulated kinase 2 activation at clinical onset. We propose that Prp has a beneficial role in the SOD1G93A amyotrophic lateral sclerosis mouse model by influencing neuronal and/or glial factors involved in antioxidative defense, rather than anti-apoptotic signaling.
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Affiliation(s)
- Petra Steinacker
- Department of Neurology, University of Ulm, Steinhovelstr.1, 89075 Ulm, Germany
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Pérez-Revuelta BI, Fukumori A, Lammich S, Yamasaki A, Haass C, Steiner H. Requirement for small side chain residues within the GxGD-motif of presenilin for gamma-secretase substrate cleavage. J Neurochem 2009; 112:940-50. [PMID: 20021564 DOI: 10.1111/j.1471-4159.2009.06510.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
gamma-Secretase is a pivotal intramembrane-cleaving protease complex and important drug target for Alzheimer's disease. The protease not only releases small peptides, such as the amyloid-beta peptide, which drives Alzheimer's disease pathogenesis, but also intracellular domains, which can have critical functions in nuclear signaling. Unlike typical aspartyl proteases, gamma-secretase contains a non-classical GxGD active site motif in its catalytic subunit presenilin (PS) 1 or PS2. It is not known whether both glycines are of similar functional relevance and why the glycine residues are invariant elements of the motif. Here we identify the N-terminal glycine of the GxGD motif in PS1, G382, as a critical residue of the active site domain of gamma-secretase. Substitution of G382 by a number of different amino acids abrogated gamma-secretase activity. Only the smallest possible G382A substitution allowed substantial gamma-secretase activity. Depending on the substrate, however, the presence of G382 could become even an absolute functional requirement of gamma-secretase. Very similar results were obtained for the C-terminal glycine residue (G384) of the GxGD motif. Our data thus identify a requirement for small side chain residues in the active site domain of gamma-secretase and suggest that the glycines of the GxGD motif could be evolutionary conserved to allow cleavage of all possible gamma-secretase substrates, including those, which are highly sensitive to minimal alteration of the PS active site domain. These findings broaden our understanding of gamma-secretase substrate recognition and cleavage, which may prove crucial for therapeutic targeting of the enzyme.
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Affiliation(s)
- Blanca Isabel Pérez-Revuelta
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) and Adolf-Butenandt-Institute, Biochemistry, Ludwig-Maximilians-University, München, Germany
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Mollenhauer B, Trenkwalder C. Neurochemical biomarkers in the differential diagnosis of movement disorders. Mov Disord 2009; 24:1411-26. [PMID: 19412961 DOI: 10.1002/mds.22510] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In recent years, the neurochemical analysis of neuronal proteins in cerebrospinal fluid (CSF) has become increasingly accepted for the diagnosis of neurodegenerative dementia diseases such as Alzheimer's disease and Creutzfeldt-Jakob disease. CSF surrounds the central nervous system, and in the composition of CSF proteins one finds brain-specific proteins that are prioritized from blood-derived proteins. Levels of specific CSF proteins could be very promising biomarkers for central nervous system diseases. We need the development of more easily accessible biomarkers, in the blood. In neurodegenerative diseases with and without dementia, studies on CSF and blood proteins have investigated the usefulness of biomarkers in differential diagnosis. The clinical diagnoses of Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration still rely mainly on clinical symptoms as defined by international classification criteria. In this article, we review CSF biomarkers in these movement disorders and discuss recent published reports on the neurochemical intra vitam diagnosis of neurodegenerative disorders (including recent CSF alpha-synuclein findings).
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Smirnov A, Trupp A, Henkel A, Bloch E, Reulbach U, Lewczuk P, Riggert J, Kornhuber J, Wiltfang J. Differential processing and secretion of Aβ peptides and sAPPα in human platelets is regulated by thrombin and prostaglandine 2. Neurobiol Aging 2009; 30:1552-62. [DOI: 10.1016/j.neurobiolaging.2007.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 12/06/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
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Winkler E, Hobson S, Fukumori A, Dümpelfeld B, Luebbers T, Baumann K, Haass C, Hopf C, Steiner H. Purification, pharmacological modulation, and biochemical characterization of interactors of endogenous human gamma-secretase. Biochemistry 2009; 48:1183-97. [PMID: 19159235 DOI: 10.1021/bi801204g] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Gamma-secretase is a unique intramembrane-cleaving protease complex, which cleaves the Alzheimer's disease-associated beta-amyloid precursor protein (APP) and a number of other type I membrane proteins. Human gamma-secretase consists of the catalytic subunit presenilin (PS) (PS1 or PS2), the substrate receptor nicastrin, APH-1 (APH-1a or APH-1b), and PEN-2. To facilitate in-depth biochemical analysis of gamma-secretase, we developed a fast and convenient multistep purification procedure for the endogenous enzyme. The enzyme was purified from HEK293 cells in an active form and had a molecular mass of approximately 500 kDa. Purified gamma-secretase was capable of producing the major amyloid-beta peptide (Abeta) species, such as Abeta40 and Abeta42, from a recombinant APP substrate in physiological ratios. Abeta generation could be modulated by pharmacological gamma-secretase modulators. Moreover, the Abeta42/Abeta40 ratio was strongly increased by purified PS1 L166P, an aggressive familial Alzheimer's disease mutant. Tandem mass spectrometry analysis revealed the consistent coisolation of several proteins with the known gamma-secretase core subunits. Among these were the previously described gamma-secretase interactors CD147 and TMP21 as well as other known interactors of these. Interestingly, the Niemann-Pick type C1 protein, a cholesterol transporter previously implicated in gamma-secretase-mediated processing of APP, was identified as a major copurifying protein. Affinity capture experiments using a biotinylated transition-state analogue inhibitor of gamma-secretase showed that these proteins are absent from active gamma-secretase complexes. Taken together, we provide an effective procedure for isolating endogenous gamma-secretase in considerably high grade, thus aiding further characterization of this pivotal enzyme. In addition, we provide evidence that the copurifying proteins identified are unlikely to be part of the active gamma-secretase enzyme.
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Affiliation(s)
- Edith Winkler
- Center for Integrated Protein Science Munich and Adolf-Butenandt-Institute, Department of Biochemistry, Laboratory for Neurodegenerative Disease Research, Ludwig-Maximilians-University, 80336 Munich, Germany
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48
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Verwey NA, Veerhuis R, Twaalfhoven HAM, Wouters D, Hoozemans JJM, Bollen YJM, Killestein J, Bibl M, Wiltfang J, Hack CE, Scheltens P, Blankenstein MA. Quantification of amyloid-beta 40 in cerebrospinal fluid. J Immunol Methods 2009; 348:57-66. [PMID: 19576899 DOI: 10.1016/j.jim.2009.06.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 05/08/2009] [Accepted: 06/24/2009] [Indexed: 12/01/2022]
Abstract
BACKGROUND Truncated forms and full-length forms of the amyloid-beta 40 (Abeta40) are key molecules in the pathogenesis of dementia, and are detectable in CSF. Reliable methods to detect these biomarkers in CSF are of great importance for understanding the disease mechanisms and for diagnostic purposes. METHODS VU-alpha-Abeta40, a monoclonal antibody (mAb) specifically detecting Abeta40, was generated and characterized by solid and fluid phase ELISA, surface plasmon resonance spectroscopy (SPRS), immunoprecipitation (IP), immunohistochemical and Western blot (WB) analysis. In addition, an ELISA with VU-alpha-Abeta40 as catching and 6E10 as detecting mAbs was set up and validated. This ELISA was used to measure Abeta40 in CSF of controls (N=27), patients with Alzheimer's disease (AD; N=20), frontotemporal lobe dementia (FTLD; N=14), noninflammatory (N=15) and inflammatory (N=15) neurological conditions. RESULTS VU-alpha-Abeta40 specifically recognizes Abeta40 with high affinity (K(A)=1.3x10(9) M(-1)) and detects Abeta40 in AD brain specimens. The developed sandwich ELISA has a detection limit of 0.21 ng/mL, a mean recovery of 90%, and an intra- and inter-assay CV of 1.4% and 7.3%. FTLD patients had a lower mean level of Abeta40 (8.8 (1.9) ng/mL) than controls (12.0 (1.7) ng/mL); p<0.01). CONCLUSIONS VU-alpha-Abeta40 was successfully implemented in an ELISA which enables us to measure Abeta40 accurately in human CSF. Clinical validation revealed lower levels of Abeta40 in FTLD patients. This finding opens new possibilities for early and differential diagnosis of dementia.
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Affiliation(s)
- Nicolaas A Verwey
- Department of Neurology, VU University Medical Center, Alzheimer Center Amsterdam, P.O. Box 7057, 1007 MB Amsterdam, the Netherlands.
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Xu X. Gamma-secretase catalyzes sequential cleavages of the AbetaPP transmembrane domain. J Alzheimers Dis 2009; 16:211-24. [PMID: 19221413 DOI: 10.3233/jad-2009-0957] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The biogenesis of the amyloid-beta peptide (Abeta) is a central issue in Alzheimer's disease (AD) research. Abeta is produced by beta- and gamma-secretases from the amyloid-beta protein precursor (AbetaPP). These proteases are targets for the development of therapeutic compounds to downregulate Abeta production. gamma-secretase has received more attention 1) because it generates the C-terminus of Abeta, which is important in the pathogenesis of AD because the longer Abeta species are more amyloidogenic, and 2) because it cleaves AbetaPP within its transmembrane domain. In the understanding the mechanism of gamma-secretase cleavage, three major cleavage sites have been identified, namely, gamma-cleavage site at Abeta(40/42), zeta-cleavage site at Abeta(46), and epsilon-cleavage site at Abeta(49). Moreover, the novel finding that some of the known gamma-secretase inhibitors inhibit the formation of secreted Abeta(40) and Abeta(42), but cause an intracellular accumulation of long Abeta(46), provided information extremely important for the development of strategies aimed at the design of gamma-secretase inhibitors to prevent and treat AD. In addition, it has been established that the C-terminus of Abeta is generated by a series of sequential cleavages: first, epsilon-cleavage, followed by zeta-cleavage and finally by gamma-cleavage, commencing from the membrane boundary to the middle of the AbetaPP membrane domain.
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Affiliation(s)
- Xuemin Xu
- Department of Pathobiology, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA.
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Walsh DM, Thulin E, Minogue AM, Gustavsson N, Pang E, Teplow DB, Linse S. A facile method for expression and purification of the Alzheimer's disease-associated amyloid beta-peptide. FEBS J 2009; 276:1266-81. [PMID: 19175671 PMCID: PMC2702495 DOI: 10.1111/j.1742-4658.2008.06862.x] [Citation(s) in RCA: 218] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 12/10/2008] [Accepted: 12/17/2008] [Indexed: 11/28/2022]
Abstract
We report the development of a high-level bacterial expression system for the Alzheimer's disease-associated amyloid beta-peptide (Abeta), together with a scaleable and inexpensive purification procedure. Abeta(1-40) and Abeta(1-42) coding sequences together with added ATG codons were cloned directly into a Pet vector to facilitate production of Met-Abeta(1-40) and Met-Abeta(1-42), referred to as Abeta(M1-40) and Abeta(M1-42), respectively. The expression sequences were designed using codons preferred by Escherichia coli, and the two peptides were expressed in this host in inclusion bodies. Peptides were purified from inclusion bodies using a combination of anion-exchange chromatography and centrifugal filtration. The method described requires little specialized equipment and provides a facile and inexpensive procedure for production of large amounts of very pure Abeta peptides. Recombinant peptides generated using this protocol produced amyloid fibrils that were indistinguishable from those formed by chemically synthesized Abeta1-40 and Abeta1-42. Formation of fibrils by all peptides was concentration-dependent, and exhibited kinetics typical of a nucleation-dependent polymerization reaction. Recombinant and synthetic peptides exhibited a similar toxic effect on hippocampal neurons, with acute treatment causing inhibition of MTT reduction, and chronic treatment resulting in neuritic degeneration and cell loss.
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Affiliation(s)
- Dominic M Walsh
- Laboratory for Neurodegenerative Research, School of Biomolecular and Biomedical Science, Conway Institute, Belfield, University College Dublin, Republic of Ireland.
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