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Watamura N, Kakiya N, Fujioka R, Kamano N, Takahashi M, Nilsson P, Saito T, Iwata N, Fujisawa S, Saido TC. The dopaminergic system promotes neprilysin-mediated degradation of amyloid-β in the brain. Sci Signal 2024; 17:eadk1822. [PMID: 39106321 DOI: 10.1126/scisignal.adk1822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 04/21/2024] [Accepted: 07/01/2024] [Indexed: 08/09/2024]
Abstract
Deposition of amyloid-β (Aβ) in the brain can impair neuronal function and contribute to cognitive decline in Alzheimer's disease (AD). Here, we found that dopamine and the dopamine precursor levodopa (also called l-DOPA) induced Aβ degradation in the brain. Chemogenetic approaches in mice revealed that the activation of dopamine release from ventral tegmental area (VTA) neurons increased the abundance and activity of the Aβ-degrading enzyme neprilysin and reduced the amount of Aβ deposits in the prefrontal cortex in a neprilysin-dependent manner. Aged mice had less dopamine and neprilysin in the anterior cortex, a decrease that was accentuated in AD model mice. Treating AD model mice with levodopa reduced Aβ deposition and improved cognitive function. These observations demonstrate that dopamine promotes brain region-specific, neprilysin-dependent degradation of Aβ, suggesting that dopamine-associated strategies have the potential to treat this aspect of AD pathology.
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Affiliation(s)
- Naoto Watamura
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Naomasa Kakiya
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Ryo Fujioka
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Naoko Kamano
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Mika Takahashi
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Per Nilsson
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, 171 64, Solna, Sweden
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi 467-8601, Japan
- Department of Neuroscience and Pathobiology, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Nobuhisa Iwata
- Department of Genome-based Drug Discovery & Leading Medical Research Core Unit, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Shigeyoshi Fujisawa
- Laboratory for Systems Neurophysiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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2
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Azargoonjahromi A. Immunotherapy in Alzheimer's disease: focusing on the efficacy of gantenerumab on amyloid-β clearance and cognitive decline. J Pharm Pharmacol 2024:rgae066. [PMID: 38767981 DOI: 10.1093/jpp/rgae066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/08/2024] [Indexed: 05/22/2024]
Abstract
Gantenerumab, a human monoclonal antibody (mAb), has been thought of as a potential agent to treat Alzheimer's disease (AD) by specifically targeting regions of the amyloid-β (Aβ) peptide sequence. Aβ protein accumulation in the brain leads to amyloid plaques, causing neuroinflammation, oxidative stress, neuronal damage, and neurotransmitter dysfunction, thereby causing cognitive decline in AD. Gantenerumab involves disrupting Aβ aggregation and promoting the breakdown of larger Aβ aggregates into smaller fragments, which facilitates the action of Aβ-degrading enzymes in the brain, thus slowing down the progression of AD. Moreover, Gantenerumab acts as an opsonin, coating Aβ plaques and enhancing their recognition by immune cells, which, combined with its ability to improve the activity of microglia, makes it an intriguing candidate for promoting Aβ plaque clearance. Indeed, the multifaceted effects of Gantenerumab, including Aβ disaggregation, enhanced immune recognition, and improved microglia activity, may position it as a promising therapeutic approach for AD. Of note, reports suggest that Gantenerumab, albeit its capacity to reduce or eliminate Aβ, has not demonstrated effectiveness in reducing cognitive decline. This review, after providing an overview of immunotherapy approaches that target Aβ in AD, explores the efficacy of Gantenerumab in reducing Aβ levels and cognitive decline.
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3
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Gutierrez-Merino C. Brain Hydrophobic Peptides Antagonists of Neurotoxic Amyloid β Peptide Monomers/Oligomers-Protein Interactions. Int J Mol Sci 2023; 24:13846. [PMID: 37762148 PMCID: PMC10531495 DOI: 10.3390/ijms241813846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/02/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Amyloid β (Aβ) oligomers have been linked to Alzheimer's disease (AD) pathogenesis and are the main neurotoxic forms of Aβ. This review focuses on the following: (i) the Aβ(1-42):calmodulin interface as a model for the design of antagonist Aβ peptides and its limitations; (ii) proteolytic degradation as the major source of highly hydrophobic peptides in brain cells; and (iii) brain peptides that have been experimentally demonstrated to bind to Aβ monomers or oligomers, Aβ fibrils, or Aβ plaques. It is highlighted that the hydrophobic amino acid residues of the COOH-terminal segment of Aβ(1-42) play a key role in its interaction with intracellular protein partners linked to its neurotoxicity. The major source of highly hydrophobic endogenous peptides of 8-10 amino acids in neurons is the proteasome activity. Many canonical antigen peptides bound to the major histocompatibility complex class 1 are of this type. These highly hydrophobic peptides bind to Aβ and are likely to be efficient antagonists of the binding of Aβ monomers/oligomers concentrations in the nanomolar range with intracellular proteins. Also, their complexation with Aβ will protect them against endopeptidases, suggesting a putative chaperon-like physiological function for Aβ that has been overlooked until now. Remarkably, the hydrophobic amino acid residues of Aβ responsible for the binding of several neuropeptides partially overlap with those playing a key role in its interaction with intracellular protein partners that mediates its neurotoxicity. Therefore, these latter neuropeptides are also potential candidates to antagonize Aβ peptides binding to target proteins. In conclusion, the analysis performed in this review points out that hydrophobic endogenous brain neuropeptides could be valuable biomarkers to evaluate the risk of the onset of sporadic AD, as well as for the prognosis of AD.
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Affiliation(s)
- Carlos Gutierrez-Merino
- Instituto de Biomarcadores de Patologías Moleculares, Universidad de Extremadura, 06006 Badajoz, Spain
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4
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Buhr A, Schiemann R, Meyer H. Neprilysin 4: an essential peptidase with multifaceted physiological relevance. Biol Chem 2023; 404:513-520. [PMID: 36653344 DOI: 10.1515/hsz-2022-0286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023]
Abstract
Neprilysins are highly conserved ectoenzymes that hydrolyze and thus inactivate signaling peptides in the extracellular space. Herein, we focus on Neprilysin 4 from Drosophila melanogaster and evaluate the existing knowledge on the physiological relevance of the peptidase. Particular attention is paid to the role of the neprilysin in regulating feeding behavior and the expression of insulin-like peptides in the central nervous system. In addition, we assess the function of the peptidase in controlling the activity of the sarcoplasmic and endoplasmic reticulum Ca2+ ATPase in myocytes, as well as the underlying molecular mechanism in detail.
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Affiliation(s)
- Annika Buhr
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Ronja Schiemann
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany
| | - Heiko Meyer
- Department of Biology/Chemistry, Zoology and Developmental Biology Section, Osnabruck University, Barbarastrasse 11, D-49076 Osnabruck, Germany.,Center for Cellular Nanoanalytics (CellNanOs), Barbarastrasse 11, D-49076 Osnabruck, Germany
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5
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Rofo F, Metzendorf NG, Saubi C, Suominen L, Godec A, Sehlin D, Syvänen S, Hultqvist G. Blood-brain barrier penetrating neprilysin degrades monomeric amyloid-beta in a mouse model of Alzheimer's disease. Alzheimers Res Ther 2022; 14:180. [PMID: 36471433 PMCID: PMC9720954 DOI: 10.1186/s13195-022-01132-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 11/25/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Aggregation of the amyloid-β (Aβ) peptide in the brain is one of the key pathological events in Alzheimer's disease (AD). Reducing Aβ levels in the brain by enhancing its degradation is one possible strategy to develop new therapies for AD. Neprilysin (NEP) is a membrane-bound metallopeptidase and one of the major Aβ-degrading enzymes. The secreted soluble form of NEP (sNEP) has been previously suggested as a potential protein-therapy degrading Aβ in AD. However, similar to other large molecules, peripherally administered sNEP is unable to reach the brain due to the presence of the blood-brain barrier (BBB). METHODS To provide transcytosis across the BBB, we recombinantly fused the TfR binding moiety (scFv8D3) to either sNEP or a previously described variant of NEP (muNEP) suggested to have higher degradation efficiency of Aβ compared to other NEP substrates, but not per se to degrade Aβ more efficiently. To provide long blood half-life, an Fc-based antibody fragment (scFc) was added to the designs, forming sNEP-scFc-scFv8D3 and muNEP-scFc-scFv8D3. The ability of the mentioned recombinant proteins to degrade Aβ was first evaluated in vitro using synthetic Aβ peptides followed by sandwich ELISA. For the in vivo studies, a single injection of 125-iodine-labelled sNEP-scFc-scFv8D3 and muNEP-scFc-scFv8D3 was intravenously administered to a tg-ArcSwe mouse model of AD, using scFc-scFv8D3 protein that lacks NEP as a negative control. Different ELISA setups were applied to quantify Aβ concentration of different conformations, both in brain tissues and blood samples. RESULTS When tested in vitro, sNEP-scFc-scFv8D3 retained sNEP enzymatic activity in degrading Aβ and both constructs efficiently degraded arctic Aβ. When intravenously injected, sNEP-scFc-scFv8D3 demonstrated 20 times higher brain uptake compared to sNEP. Both scFv8D3-fused NEP proteins significantly reduced aggregated Aβ levels in the blood of tg-ArcSwe mice, a transgenic mouse model of AD, following a single intravenous injection. In the brain, monomeric and oligomeric Aβ were significantly reduced. Both scFv8D3-fused NEP proteins displayed a fast clearance from the brain. CONCLUSION A one-time injection of a BBB-penetrating NEP shows the potential to reduce, the likely most toxic, Aβ oligomers in the brain in addition to monomers. Also, Aβ aggregates in the blood were reduced.
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Affiliation(s)
- Fadi Rofo
- grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Biomedicinskt Centrum BMC, Husargatan 3, 751 24 Uppsala, Sweden
| | - Nicole G. Metzendorf
- grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Biomedicinskt Centrum BMC, Husargatan 3, 751 24 Uppsala, Sweden
| | - Cristina Saubi
- grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Biomedicinskt Centrum BMC, Husargatan 3, 751 24 Uppsala, Sweden
| | - Laura Suominen
- grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Biomedicinskt Centrum BMC, Husargatan 3, 751 24 Uppsala, Sweden
| | - Ana Godec
- grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Biomedicinskt Centrum BMC, Husargatan 3, 751 24 Uppsala, Sweden
| | - Dag Sehlin
- grid.8993.b0000 0004 1936 9457Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Stina Syvänen
- grid.8993.b0000 0004 1936 9457Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Greta Hultqvist
- grid.8993.b0000 0004 1936 9457Department of Pharmacy, Uppsala University, Biomedicinskt Centrum BMC, Husargatan 3, 751 24 Uppsala, Sweden
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6
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Lennon MJ, Rigney G, Raymont V, Sachdev P. Genetic Therapies for Alzheimer's Disease: A Scoping Review. J Alzheimers Dis 2021; 84:491-504. [PMID: 34569966 DOI: 10.3233/jad-215145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Effective, disease modifying therapies for Alzheimer's disease (AD) remain a quandary, following a panoply of expensive failures in human clinical trials. Given the stagnation in therapeutics, alternative approaches are needed. Recent successes of genetic therapies in other neurodegenerative diseases may highlight the way forward. This scoping review explores suggested targets of genetic therapy in AD, with a focus on vector-based approaches in pre-clinical and clinical trials. Putative targets of genetic therapies tested in pre-clinical trials include amyloid pathway intermediates and enzymes modulation, tau protein downregulation, APOE4 downregulation and APOE2 upregulation, neurotrophin expression (nerve growth factor (NGF) and brain-derived neurotrophic factor), and inflammatory cytokine alteration, among several other approaches. There have been three completed human clinical trials for genetic therapy in AD patients, all of which upregulated NGF in AD patients, showing some mixed evidence of benefit. Several impediments remain to be surpassed before genetic therapies can be successfully applied to AD, including the challenge of delivering monogenic genetic therapies for complex polygenic disorders, risks in the dominant delivery method (intracranial injection), stability of genetic therapies in vivo, poor translatability of pre-clinical AD models, and the expense of genetic therapy production. Genetic therapies represent an exciting opportunity within the world of AD therapeutics, but clinical applications likely remain a long term, rather than short term, possibility.
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Affiliation(s)
- Matthew J Lennon
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK.,Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Grant Rigney
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Perminder Sachdev
- Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia
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7
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Owens LV, Benedetto A, Dawson N, Gaffney CJ, Parkin ET. Gene therapy-mediated enhancement of protective protein expression for the treatment of Alzheimer's disease. Brain Res 2021; 1753:147264. [PMID: 33422539 DOI: 10.1016/j.brainres.2020.147264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/22/2020] [Accepted: 12/20/2020] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is the leading form of dementia but lacks curative treatments. Current understanding of AD aetiology attributes the development of the disease to the misfolding of two proteins; amyloid-β (Aβ) and hyperphosphorylated tau, with their pathological accumulation leading to concomitant oxidative stress, neuroinflammation, and neuronal death. These processes are regulated at multiple levels to maintain homeostasis and avert disease. However, many of the relevant regulatory proteins appear to be downregulated in the AD-afflicted brain. Enhancement/restoration of these 'protective' proteins, therefore, represents an attractive therapeutic avenue. Gene therapy is a desirable means of achieving this because it is not associated with the side-effects linked to systemic protein administration, and sustained protein expression virtually eliminates compliance issues. The current article represents a focused and succinct review of the better established 'protective' protein targets for gene therapy enhancement/restoration rather than being designed as an exhaustive review incorporating less validated protein subjects. In addition, we will discuss how the risks associated with uncontrolled or irreversible gene expression might be mitigated through combining neuronal-specific promoters, inducible expression systems and localised injections. Whilst many of the gene therapy targets reviewed herein are yet to enter clinical trials, preclinical testing has thus far demonstrated encouraging potential for the gene therapy-based treatment of AD.
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Affiliation(s)
- Lauren V Owens
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Alexandre Benedetto
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Christopher J Gaffney
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK
| | - Edward T Parkin
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YG, UK.
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8
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Rofo F, Ugur Yilmaz C, Metzendorf N, Gustavsson T, Beretta C, Erlandsson A, Sehlin D, Syvänen S, Nilsson P, Hultqvist G. Enhanced neprilysin-mediated degradation of hippocampal Aβ42 with a somatostatin peptide that enters the brain. Am J Cancer Res 2021; 11:789-804. [PMID: 33391505 PMCID: PMC7738863 DOI: 10.7150/thno.50263] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022] Open
Abstract
Background: Aggregation of the amyloid-beta (Aβ) peptide is one of the main neuropathological events in Alzheimer's disease (AD). Neprilysin is the major enzyme degrading Aβ, with its activity enhanced by the neuropeptide somatostatin (SST). SST levels are decreased in the brains of AD patients. The poor delivery of SST over the blood-brain barrier (BBB) and its extremely short half-life of only 3 min limit its therapeutic significance. Methods: We recombinantly fused SST to a BBB transporter binding to the transferrin receptor. Using primary neuronal cultures and neuroblastoma cell lines, the ability of the formed fusion protein to activate neprilysin was studied. SST-scFv8D3 was administered to mice overexpressing the Aβ-precursor protein (AβPP) with the Swedish mutation (APPswe) as a single injection or as a course of three injections over a 72 h period. Levels of neprilysin and Aβ were quantified using an Enzyme-linked immunosorbent assay (ELISA). Distribution of SST-scFv8D3 in the brain, blood and peripheral organs was studied by radiolabeling with iodine-125. Results: The construct, SST-scFv8D3, exhibited 120 times longer half-life than SST alone, reached the brain in high amounts when injected intravenously and significantly increased the brain concentration of neprilysin in APPswe mice. A significant decrease in the levels of membrane-bound Aβ42 was detected in the hippocampus and the adjacent cortical area after only three injections. Conclusion: With intravenous injections of our BBB permeable SST peptide, we were able to significantly increase the levels neprilysin, an effect that was followed by a significant and selective degradation of membrane-bound Aβ42 in the hippocampus. Being that membrane-bound Aβ triggers neuronal toxicity and the hippocampus is the central brain area in the progression of AD, the study has illuminated a new potential treatment paradigm with a promising safety profile targeting only the disease affected areas.
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9
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Leontsinis I, Mantzouranis M, Tsioufis P, Andrikou I, Tsioufis C. Recent advances in managing primary hypertension. Fac Rev 2020; 9:4. [PMID: 33659936 PMCID: PMC7894269 DOI: 10.12703/b/9-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Hypertension remains a leading risk factor for cardiovascular mortality and morbidity globally despite the availability of effective and well-tolerated antihypertensive medications. Accumulating evidence suggests a more aggressive blood pressure regulation aimed at lower targets, particularly for selected patient groups. Our concepts of the optimal method for blood pressure measurement have radically changed, maintaining appropriate standard office measurements for initial assessment but relying on out-of-office measurement to better guide our decisions. Thorough risk stratification provides guidance in decision making; however, an individualized approach is highly recommended to prevent overtreatment. Undertreatment, on the other hand, remains a major concern and is mainly attributed to poor adherence and resistant or difficult-to-control forms of the disease. This review aims to present modern perspectives, novel treatment options, including innovative technological applications and developing interventional and pharmaceutical therapies, and the major concerns emerging from several years of research and epidemiological observations related to hypertension management.
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Affiliation(s)
- Ioannis Leontsinis
- First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, 108 Vas. Sofias Ave, 11527, Athens, Greece
| | - Manos Mantzouranis
- First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, 108 Vas. Sofias Ave, 11527, Athens, Greece
| | - Panagiotis Tsioufis
- First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, 108 Vas. Sofias Ave, 11527, Athens, Greece
| | - Ioannis Andrikou
- First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, 108 Vas. Sofias Ave, 11527, Athens, Greece
| | - Costas Tsioufis
- First Cardiology Clinic, Medical School, National and Kapodistrian University of Athens, Hippokration Hospital, 108 Vas. Sofias Ave, 11527, Athens, Greece
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10
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Palazzi L, Pasquato A, Vicario M, Roulin A, Polverino de Laureto P, Cendron L. C‐terminal tails mimicking bioactive intermediates cause different plasma degradation patterns and kinetics in neuropeptides γ‐MSH, α‐MSH, and neurotensin. J Pept Sci 2020; 26:e3279. [DOI: 10.1002/psc.3279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 06/29/2020] [Accepted: 07/17/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Luana Palazzi
- Department of Pharmaceutical and Pharmacological Sciences and CRIBI University of Padova Padova Italy
| | - Antonella Pasquato
- Institute of Microbiology University Hospital Center and University of Lausanne Lausanne Switzerland
| | | | - Alexandre Roulin
- Department of Ecology and Evolution, Faculty of Biology and Medicine University of Lausanne Lausanne Switzerland
| | | | - Laura Cendron
- Department of Biology University of Padova Padova Italy
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11
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Kanuka M, Ouchi F, Kato N, Katsuki R, Ito S, Miura K, Hikida M, Tamura T. Endoplasmic Reticulum Associated Degradation of Spinocerebellar Ataxia-Related CD10 Cysteine Mutant. Int J Mol Sci 2020; 21:ijms21124237. [PMID: 32545905 PMCID: PMC7352294 DOI: 10.3390/ijms21124237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/12/2020] [Accepted: 06/12/2020] [Indexed: 12/31/2022] Open
Abstract
Spinocerebellar ataxia (SCA) is one of the most severe neurodegenerative diseases and is often associated with misfolded protein aggregates derived from the genetic mutation of related genes. Recently, mutations in CD10 such as C143Y have been identified as SCA type 43. CD10, also known as neprilysin or neuroendopeptidase, digests functional neuropeptides, such as amyloid beta, in the extracellular region. In this study, we explored the cellular behavior of CD10 C143Y to gain an insight into the functional relationship of the mutation and SCA pathology. We found that wild-type CD10 is expressed on the plasma membrane and exhibits endopeptidase activity in a cultured cell line. CD10 C143Y, however, forms a disulfide bond-mediated oligomer that does not appear by the wild-type CD10. Furthermore, the CD10 C143Y mutant was retained in the endoplasmic reticulum (ER) by the molecular chaperone BiP and was degraded through the ER-associated degradation (ERAD) process, in which representative ERAD factors including EDEM1, SEL1L, and Hrd1 participate in the degradation. Suppression of CD10 C143Y ERAD recovers intracellular transport but not enzymatic activity. Our results indicate that the C143Y mutation in CD10 negatively affects protein maturation and results in ER retention and following ERAD. These findings provide beneficial insight into SCA type 43 pathology.
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Affiliation(s)
- Mai Kanuka
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
| | - Fuka Ouchi
- Department of Life Science, Faculty of Engineering Science, Akita University, Akita 010-8502, Japan;
| | - Nagisa Kato
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
| | - Riko Katsuki
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
| | - Saori Ito
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
| | - Kohta Miura
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
| | - Masaki Hikida
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
- Department of Life Science, Faculty of Engineering Science, Akita University, Akita 010-8502, Japan;
| | - Taku Tamura
- Department of Life Science, Graduate school of Engineering and Resource, Akita University, Akita 010-8502, Japan; (M.K.); (N.K.); (R.K.); (S.I.); (K.M.); (M.H.)
- Department of Life Science, Faculty of Engineering Science, Akita University, Akita 010-8502, Japan;
- Correspondence: ; Tel.: +81-18-889-2377
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12
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Frost GR, Jonas LA, Li YM. Friend, Foe or Both? Immune Activity in Alzheimer's Disease. Front Aging Neurosci 2019; 11:337. [PMID: 31920620 PMCID: PMC6916654 DOI: 10.3389/fnagi.2019.00337] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 11/21/2019] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is marked by the presence of amyloid beta (Aβ) plaques, neurofibrillary tangles (NFT), neuronal death and synaptic loss, and inflammation in the brain. AD research has, in large part, been dedicated to the understanding of Aβ and NFT deposition as well as to the pharmacological reduction of these hallmarks. However, recent GWAS data indicates neuroinflammation plays a critical role in AD development, thereby redirecting research efforts toward unveiling the complexities of AD-associated neuroinflammation. It is clear that the innate immune system is intimately associated with AD progression, however, the specific roles of glia and neuroinflammation in AD pathology remain to be described. Moreover, inflammatory processes have largely been painted as detrimental to AD pathology, when in fact, many immune mechanisms such as phagocytosis aid in the reduction of AD pathologies. In this review, we aim to outline the delicate balance between the beneficial and detrimental aspects of immune activation in AD as a more thorough understanding of these processes is critical to development of effective therapeutics for AD.
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Affiliation(s)
- Georgia R. Frost
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
| | - Lauren A. Jonas
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
| | - Yue-Ming Li
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, Manhattan, NY, United States
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, Ithaca, NY, United States
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13
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Feygina EE, Katrukha AG, Semenov AG. Neutral Endopeptidase (Neprilysin) in Therapy and Diagnostics: Yin and Yang. BIOCHEMISTRY (MOSCOW) 2019; 84:1346-1358. [PMID: 31760922 DOI: 10.1134/s0006297919110105] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Neprilysin (NEP) is a zinc-dependent metalloproteinase that exists in organisms in both transmembrane and soluble forms. NEP substrates are involved in regulating the cardiovascular and nervous systems. In this review, we discuss some of the biochemical characteristics and physiological functions of this enzyme with special emphasis on the use of NEP as a therapeutic target. The history and various physiological aspects of applying NEP inhibitors for treating heart failure and attempts to increase NEP activity when treating Alzheimer's disease using gene and cell therapies are described. Another important issue discussed is the role of NEP as a potential marker for predicting the risk of cardiovascular disease complications. The diagnostic and prognostic performance of soluble NEP in various types of heart failure is analyzed and presented. We also discuss the methods and approaches for measuring NEP activity for prognosis and diagnosis, as well as a possible new role of natriuretic peptides (NEP substrates) in cardiovascular diagnostics.
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Affiliation(s)
- E E Feygina
- HyTest Ltd., Turku, 20520, Finland. .,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A G Katrukha
- HyTest Ltd., Turku, 20520, Finland.,Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
| | - A G Semenov
- HyTest Ltd., Turku, 20520, Finland.,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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14
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Sandoval K, Umbaugh D, House A, Crider A, Witt K. Somatostatin Receptor Subtype-4 Regulates mRNA Expression of Amyloid-Beta Degrading Enzymes and Microglia Mediators of Phagocytosis in Brains of 3xTg-AD Mice. Neurochem Res 2019; 44:2670-2680. [PMID: 31630317 DOI: 10.1007/s11064-019-02890-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 09/06/2019] [Accepted: 10/03/2019] [Indexed: 02/06/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder resulting in memory and cognitive impairment. The use of somatostatin receptor subtype-4 (SSTR4) agonists have been proposed for AD treatment. This study investigated the effects of selective SSTR4 agonist NNC 26-9100 on mRNA expression of key genes associated with AD pathology (microglia mediators of Aβ phagocytosis, amyloid-beta (Aβ)-degrading enzymes, anti-oxidant enzymes and pro-inflammatory cytokines) in 3xTg-AD mice. Mice were administered NNC 26-9100 (0.2 µg, i.c.v.) or vehicle control, with cortical and subcortical brain tissue collected at 6 h and 24 h post-treatment. At 6 h, NNC 26-9100 treatment decreased cortical expression of cluster of differentiation-33 (Cd33) by 25%, while increasing cortical and subcortical macrophage scavenger receptor-1 (Msr1) by 1.8 and 2.0-fold, respectively. The Cd33 downregulation and Msr1 upregulation support a state of microglia associated Aβ phagocytosis. At 24 h, NNC 26-9100 treatment increased the cortical expression of Sstr4 (4.9-fold), Aβ-degrading enzymes neprilysin (9.3-fold) and insulin degrading enzyme (14.8-fold), and the antioxidant catalase (3.6-fold). Similar effects at 24 h were found in subcortical tissue with NNC 26-9100 treatment, but did not reach statistical significance. No changes in pro-inflammatory cytokine expression were found. These data demonstrated NNC 26-9100 facilitates transcriptional changes in brain tissue identified with Aβ phagocytosis and clearance, further supporting SSTR4 as a treatment target for AD.
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Affiliation(s)
- Karin Sandoval
- Department of Pharmaceutical Sciences Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, 200 University Park Drive., Building 220, Edwardsville, IL, 62025, USA
| | - David Umbaugh
- Department of Pharmaceutical Sciences Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, 200 University Park Drive., Building 220, Edwardsville, IL, 62025, USA
| | - Austin House
- Department of Pharmaceutical Sciences Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, 200 University Park Drive., Building 220, Edwardsville, IL, 62025, USA
| | - Albert Crider
- Department of Pharmaceutical Sciences Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, 200 University Park Drive., Building 220, Edwardsville, IL, 62025, USA
| | - Ken Witt
- Department of Pharmaceutical Sciences Pharmaceutical Sciences, School of Pharmacy, Southern Illinois University Edwardsville, 200 University Park Drive., Building 220, Edwardsville, IL, 62025, USA.
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15
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Loera-Valencia R, Piras A, Ismail MAM, Manchanda S, Eyjolfsdottir H, Saido TC, Johansson J, Eriksdotter M, Winblad B, Nilsson P. Targeting Alzheimer's disease with gene and cell therapies. J Intern Med 2018; 284:2-36. [PMID: 29582495 DOI: 10.1111/joim.12759] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) causes dementia in both young and old people affecting more than 40 million people worldwide. The two neuropathological hallmarks of the disease, amyloid beta (Aβ) plaques and neurofibrillary tangles consisting of protein tau are considered the major contributors to the disease. However, a more complete picture reveals significant neurodegeneration and decreased cell survival, neuroinflammation, changes in protein and energy homeostasis and alterations in lipid and cholesterol metabolism. In addition, gene and cell therapies for severe neurodegenerative disorders have recently improved technically in terms of safety and efficiency and have translated to the clinic showing encouraging results. Here, we review broadly current data within the field for potential targets that could modify AD through gene and cell therapy strategies. We envision that not only Aβ will be targeted in a disease-modifying treatment strategy but rather that a combination of treatments, possibly at different intervention times may prove beneficial in curing this devastating disease. These include decreased tau pathology, neuronal growth factors to support neurons and modulation of neuroinflammation for an appropriate immune response. Furthermore, cell based therapies may represent potential strategies in the future.
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Affiliation(s)
- R Loera-Valencia
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - A Piras
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - M A M Ismail
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden.,Theme Neuro, Diseases of the Nervous System Patient Flow, Karolinska University Hospital, Huddinge, Sweden
| | - S Manchanda
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - H Eyjolfsdottir
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden.,Theme Aging, Karolinska University Hospital, Huddinge, Sweden
| | - T C Saido
- RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - J Johansson
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
| | - M Eriksdotter
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden.,Theme Aging, Karolinska University Hospital, Huddinge, Sweden
| | - B Winblad
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden.,Theme Aging, Karolinska University Hospital, Huddinge, Sweden
| | - P Nilsson
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, Solna, Sweden
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16
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Li H, Sun X, Yu F, Xu L, Miu J, Xiao P. In Silico Investigation of the Pharmacological Mechanisms of Beneficial Effects of Ginkgo biloba L. on Alzheimer's Disease. Nutrients 2018; 10:nu10050589. [PMID: 29747475 PMCID: PMC5986469 DOI: 10.3390/nu10050589] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 05/01/2018] [Accepted: 05/08/2018] [Indexed: 11/21/2022] Open
Abstract
Based on compelling experimental and clinical evidence, Ginkgo biloba L. exerts a beneficial effect in ameliorating mild to moderate dementia in patients with Alzheimer’s disease (AD) and other neurological disorders, although the pharmacological mechanisms remain unknown. In the present study, compounds, their putative target proteins identified using an inverse docking approach, and clinically tested AD-related target proteins were systematically integrated together with applicable bioinformatics methods in silico. The results suggested that the beneficial effects of G. biloba on AD may be contributed by the regulation of hormone sensitivity, improvements in endocrine homeostasis, maintenance of endothelial microvascular integrity, and proteolysis of tau proteins, particularly prior to amyloid β-protein (Aβ) plaque formation. Moreover, we identified six putative protein targets that are significantly related to AD, but have not been researched or have had only preliminary studies conducted on the anti-AD effects of G. biloba. These mechanisms and protein targets are very significant for future scientific research. In addition, the existing mechanisms were also verified, such as the reduction of oxidative stress, anti-apoptotic effects, and protective effects against amyloidogenesis and Aβ aggregation. The discoveries summarized here may provide a macroscopic perspective that will improve our understanding of the molecular mechanism of medicinal plants or dietary supplements, as well as new clues for the future development of therapeutic strategies for AD.
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Affiliation(s)
- Hongxiang Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, 151 Malianwa North Road, Beijing 100193, China.
| | - Xiaoyuan Sun
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, 151 Malianwa North Road, Beijing 100193, China.
| | - Fan Yu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, 151 Malianwa North Road, Beijing 100193, China.
| | - Lijia Xu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, 151 Malianwa North Road, Beijing 100193, China.
| | - Jianhua Miu
- Guangxi Institute of Medicinal Plant Development, Nanning, 189 Changgang Road, Nanning 520023, China.
| | - Peigen Xiao
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Beijing 100193, China.
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, 151 Malianwa North Road, Beijing 100193, China.
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17
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Sadri A. Excess amyloid beta can be degraded in healthy humans. Ann Neurol 2018; 83:650. [DOI: 10.1002/ana.25186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 01/08/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Arash Sadri
- Department of Toxicology and Pharmacology, Faculty of Pharmacy; Tehran University of Medical Sciences, P.O. Box 14155-6451; Tehran Iran
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18
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Lucey BP, Hicks TJ, Elbert DL, Ovod V, Mawuenyega KG, Morris JC, Bateman RJ. Reply to "Excess amyloid beta can be degraded in healthy humans". Ann Neurol 2018; 83:650-651. [PMID: 29457845 DOI: 10.1002/ana.25185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 02/15/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Brendan P Lucey
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO
| | - Terry J Hicks
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO
| | - Donald L Elbert
- Department of Neurology, Dell Medical School, University of Texas, Austin, TX
| | - Vitaliy Ovod
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO
| | - Kwasi G Mawuenyega
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO
| | - John C Morris
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO.,Knight Alzheimer's Disease Research Center, Washington University, Saint Louis, MO
| | - Randall J Bateman
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO.,Knight Alzheimer's Disease Research Center, Washington University, Saint Louis, MO
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19
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Chen GF, Xu TH, Yan Y, Zhou YR, Jiang Y, Melcher K, Xu HE. Amyloid beta: structure, biology and structure-based therapeutic development. Acta Pharmacol Sin 2017; 38:1205-1235. [PMID: 28713158 PMCID: PMC5589967 DOI: 10.1038/aps.2017.28] [Citation(s) in RCA: 976] [Impact Index Per Article: 139.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 03/02/2017] [Indexed: 12/12/2022] Open
Abstract
Amyloid beta peptide (Aβ) is produced through the proteolytic processing of a transmembrane protein, amyloid precursor protein (APP), by β- and γ-secretases. Aβ accumulation in the brain is proposed to be an early toxic event in the pathogenesis of Alzheimer's disease, which is the most common form of dementia associated with plaques and tangles in the brain. Currently, it is unclear what the physiological and pathological forms of Aβ are and by what mechanism Aβ causes dementia. Moreover, there are no efficient drugs to stop or reverse the progression of Alzheimer's disease. In this paper, we review the structures, biological functions, and neurotoxicity role of Aβ. We also discuss the potential receptors that interact with Aβ and mediate Aβ intake, clearance, and metabolism. Additionally, we summarize the therapeutic developments and recent advances of different strategies for treating Alzheimer's disease. Finally, we will report on the progress in searching for novel, potentially effective agents as well as selected promising strategies for the treatment of Alzheimer's disease. These prospects include agents acting on Aβ, its receptors and tau protein, such as small molecules, vaccines and antibodies against Aβ; inhibitors or modulators of β- and γ-secretase; Aβ-degrading proteases; tau protein inhibitors and vaccines; amyloid dyes and microRNAs.
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Affiliation(s)
- Guo-Fang Chen
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Ting-Hai Xu
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yan Yan
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yu-Ren Zhou
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yi Jiang
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Karsten Melcher
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - H Eric Xu
- VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, MI 49503, USA
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20
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The effect of angiotensin receptor neprilysin inhibitor, sacubitril/valsartan, on central nervous system amyloid-β concentrations and clearance in the cynomolgus monkey. Toxicol Appl Pharmacol 2017; 323:53-65. [DOI: 10.1016/j.taap.2017.03.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 01/11/2023]
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21
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Kaplinsky E. Changing the treatment of heart failure with reduced ejection fraction: clinical use of sacubitril-valsartan combination. J Geriatr Cardiol 2016; 13:914-923. [PMID: 28133468 PMCID: PMC5253408 DOI: 10.11909/j.issn.1671-5411.2016.11.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 11/13/2016] [Accepted: 11/21/2016] [Indexed: 12/11/2022] Open
Abstract
Despite significant therapeutic advances, patients with chronic heart failure (HF) remain at high risk of morbidity and mortality. Sacubitril valsartan (previously known as LCZ696) is a new oral agent approved for the treatment of symptomatic chronic heart failure in adults with reduced ejection fraction. It is described as the first in class angiotensin receptor neprilysin inhibitor (ARNI) since it incorporates the neprilysin inhibitor, sacubitril and the angiotensin II receptor antagonist, valsartan. Neprilysin is an endopeptidase that breaks down several vasoactive peptides including natriuretic peptides (NPs), bradykinin, endothelin and angiotensin II (Ang-II). Therefore, a natural consequence of its inhibition is an increase of plasmatic levels of both, NPs and Ang-II (with opposite biological actions). So, a combined inhibition of these both systems (Sacubitril / valsartan) may enhance the benefits of NPs effects in HF (natriuresis, diuresis, etc) while Ang-II receptor is inhibited (reducing vasoconstriction and aldosterone release). In a large clinical trial (PARADIGM-HF with 8442 patients), this new agent was found to significantly reduce cardiovascular and all cause mortality as well as hospitalizations due to HF (compared to enalapril). This manuscript reviews clinical evidence for sacubitril valsartan, dosing and cautions, future directions and its considered place in the therapy of HF with reduced ejection fraction.
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Affiliation(s)
- Edgardo Kaplinsky
- Cardiology Unit, Medicine Department, Hospital Municipal de Badalona.Via Augusta Av. 9-13 (08911), Badalona, Spain
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22
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Grimm MOW, Regner L, Mett J, Stahlmann CP, Schorr P, Nelke C, Streidenberger O, Stoetzel H, Winkler J, Zaidan SR, Thiel A, Endres K, Grimm HS, Volmer DA, Hartmann T. Tocotrienol Affects Oxidative Stress, Cholesterol Homeostasis and the Amyloidogenic Pathway in Neuroblastoma Cells: Consequences for Alzheimer's Disease. Int J Mol Sci 2016; 17:ijms17111809. [PMID: 27801864 PMCID: PMC5133810 DOI: 10.3390/ijms17111809] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/18/2016] [Accepted: 10/21/2016] [Indexed: 12/14/2022] Open
Abstract
One of the characteristics of Alzheimer´s disease (AD) is an increased amyloid load and an enhanced level of reactive oxidative species (ROS). Vitamin E has known beneficial neuroprotective effects, and previously, some studies suggested that vitamin E is associated with a reduced risk of AD due to its antioxidative properties. However, epidemiological studies and nutritional approaches of vitamin E treatment are controversial. Here, we investigate the effect of α-tocotrienol, which belongs to the group of vitamin E, on AD-relevant processes in neuronal cell lines. In line with the literature, α-tocotrienol reduced the ROS level in SH-SY5Y cells. In the presence of tocotrienols, cholesterol and cholesterol esters, which have been shown to be risk factors in AD, were decreased. Besides the unambiguous positive effects of tocotrienol, amyloid-β (Aβ) levels were increased accompanied by an increase in the activity of enzymes responsible for Aβ production. Proteins and gene expression of the secretases and their components remained unchanged, whereas tocotrienol accelerates enzyme activity in cell-free assays. Besides enhanced Aβ production, tocotrienols inhibited Aβ degradation in neuro 2a (N2a)-cells. Our results might help to understand the controversial findings of vitamin E studies and demonstrate that besides the known positive neuroprotective properties, tocotrienols also have negative characteristics with respect to AD.
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Affiliation(s)
- Marcus O W Grimm
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
- Neurodegeneration and Neurobiology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
- Deutsches Institut für DemenzPrävention (DIDP), Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Liesa Regner
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Janine Mett
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Christoph P Stahlmann
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Pascal Schorr
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
- Institute of Bioanalytical Chemistry, Saarland University, 66123 Saarbrücken, Germany.
| | - Christopher Nelke
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Olga Streidenberger
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Hannah Stoetzel
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Jakob Winkler
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Shatha R Zaidan
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Andrea Thiel
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Kristina Endres
- Department of Psychiatry and Psychotherapy, Clinical Research Group, University Medical Centre Johannes Gutenberg-University Mainz, Untere Zahlbacher Straße 8, 55131 Mainz, Germany.
| | - Heike S Grimm
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
| | - Dietrich A Volmer
- Institute of Bioanalytical Chemistry, Saarland University, 66123 Saarbrücken, Germany.
| | - Tobias Hartmann
- Experimental Neurology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
- Neurodegeneration and Neurobiology, Saarland University, Kirrberger Straße 1, 66421 Homburg/Saar, Germany.
- Department of Psychiatry and Psychotherapy, Clinical Research Group, University Medical Centre Johannes Gutenberg-University Mainz, Untere Zahlbacher Straße 8, 55131 Mainz, Germany.
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23
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Burrell M, Henderson SJ, Ravnefjord A, Schweikart F, Fowler SB, Witt S, Hansson KM, Webster CI. Neprilysin Inhibits Coagulation through Proteolytic Inactivation of Fibrinogen. PLoS One 2016; 11:e0158114. [PMID: 27437944 PMCID: PMC4954676 DOI: 10.1371/journal.pone.0158114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/12/2016] [Indexed: 12/11/2022] Open
Abstract
Neprilysin (NEP) is an endogenous protease that degrades a wide range of peptides including amyloid beta (Aβ), the main pathological component of Alzheimer's disease (AD). We have engineered NEP as a potential therapeutic for AD but found in pre-clinical safety testing that this variant increased prothrombin time (PT) and activated partial thromboplastin time (APTT). The objective of the current study was to investigate the effect of wild type NEP and the engineered variant on coagulation and define the mechanism by which this effect is mediated. PT and APTT were measured in cynomolgus monkeys and rats dosed with a human serum albumin fusion with an engineered variant of NEP (HSA-NEPv) as well as in control plasma spiked with wild type or variant enzyme. The coagulation factor targeted by NEP was determined using in vitro prothrombinase, calibrated automated thrombogram (CAT) and fibrin formation assays as well as N-terminal sequencing of fibrinogen treated with the enzyme. We demonstrate that HSA-NEP wild type and HSA-NEPv unexpectedly impaired coagulation, increasing PT and APTT in plasma samples and abolishing fibrin formation from fibrinogen. This effect was mediated through cleavage of the N-termini of the Aα- and Bβ-chains of fibrinogen thereby significantly impairing initiation of fibrin formation by thrombin. Fibrinogen has therefore been identified for the first time as a substrate for NEP wild type suggesting that the enzyme may have a role in regulating fibrin formation. Reductions in NEP levels observed in AD and cerebral amyloid angiopathy may contribute to neurovascular degeneration observed in these conditions.
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Affiliation(s)
- Matthew Burrell
- Antibody Discovery and Protein Engineering, MedImmune, Milstein Building, Granta Park, Cambridge, United Kingdom
| | - Simon J. Henderson
- Biologics Safety Assessment, MedImmune, Aaron Klug Building, Granta Park, Cambridge, United Kingdom
| | - Anna Ravnefjord
- Cardiovascular and Metabolic Disease iMed, AstraZeneca R&D, SE-431 83 Mölndal, Sweden
| | - Fritz Schweikart
- Pharmaceutical Development, AstraZeneca R&D, SE-431 83 Mölndal, Sweden
| | - Susan B. Fowler
- Antibody Discovery and Protein Engineering, MedImmune, Milstein Building, Granta Park, Cambridge, United Kingdom
| | - Susanne Witt
- Antibody Discovery and Protein Engineering, MedImmune, Milstein Building, Granta Park, Cambridge, United Kingdom
| | - Kenny M. Hansson
- Cardiovascular and Metabolic Disease iMed, AstraZeneca R&D, SE-431 83 Mölndal, Sweden
| | - Carl I. Webster
- Antibody Discovery and Protein Engineering, MedImmune, Milstein Building, Granta Park, Cambridge, United Kingdom
- * E-mail:
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24
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Langenickel TH, Tsubouchi C, Ayalasomayajula S, Pal P, Valentin M, Hinder M, Jhee S, Gevorkyan H, Rajman I. The effect of LCZ696 (sacubitril/valsartan) on amyloid-β concentrations in cerebrospinal fluid in healthy subjects. Br J Clin Pharmacol 2016; 81:878-90. [PMID: 26663387 PMCID: PMC4834603 DOI: 10.1111/bcp.12861] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/16/2015] [Accepted: 12/08/2015] [Indexed: 12/11/2022] Open
Abstract
AIMS LCZ696 (angiotensin receptor neprilysin inhibitor) is a novel drug developed for the treatment of heart failure with reduced ejection fraction. Neprilysin is one of multiple enzymes degrading amyloid-β (Aβ). Its inhibition may increase Aβ levels. The potential exists that treatment of LCZ696, through the inhibition of neprilysin by LBQ657 (an LCZ696 metabolite), may result in accumulation of Aβ. The aim of this study was to assess the blood-brain-barrier penetration of LBQ657 and the potential effects of LCZ696 on cerebrospinal fluid (CSF) concentrations of Aβ isoforms in healthy human volunteers. METHODS In a double-blind, randomized, parallel group, placebo-controlled study, healthy subjects received once daily LCZ696 (400 mg, n = 21) or placebo (n = 22) for 14 days. RESULTS LCZ696 had no significant effect on CSF AUEC(0,36 h) of the aggregable Aβ species 1-42 or 1-40 compared with placebo (estimated treatment ratios 0.98 [95% CI 0.73, 1.34; P = 0.919] and 1.05 [95% CI 0.82, 1.34; P = 0.702], respectively). A 42% increase in CSF AUEC(0,36 h) of soluble Aβ 1-38 was observed (estimated treatment ratio 1.42 [95% CI 1.05, 1.91; P = 0.023]). CSF levels of LBQ657 and CSF Aβ 1-42, 1-40, and 1-38 concentrations were not related (r(2) values 0.022, 0.010, and 0.008, respectively). CONCLUSIONS LCZ696 did not cause changes in CSF levels of aggregable Aβ isoforms (1-42 and 1-40) compared with placebo, despite achieving CSF concentrations of LBQ657 sufficient to inhibit neprilysin. The clinical relevance of the increase in soluble CSF Aβ 1-38 is currently unknown.
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Affiliation(s)
- Thomas H. Langenickel
- Translational Medicine, Novartis Institutes for Biomedical ResearchNovartis Pharma AGBaselSwitzerland
| | - Chiaki Tsubouchi
- Translational Medicine, Novartis Institutes for Biomedical ResearchNovartis Pharma AGBaselSwitzerland
| | - Surya Ayalasomayajula
- Drug Metabolism and PharmacokineticsNovartis Institutes for Biomedical ResearchEast HanoverNew JerseyUSA
| | - Parasar Pal
- Biostatistical Sciences, Integrated Development Functions and RegionsNovartis Healthcare Pvt LtdHyderabadIndia
| | - Marie‐Anne Valentin
- Translational Medicine, Novartis Institutes for Biomedical ResearchNovartis Pharma AGBaselSwitzerland
| | - Markus Hinder
- Translational Medicine, Novartis Institutes for Biomedical ResearchNovartis Pharma AGBaselSwitzerland
| | | | - Hakop Gevorkyan
- California Clinical Trials Medical Group in Affiliation with PAREXEL InternationalGlendaleCaliforniaUSA
| | - Iris Rajman
- Translational Medicine, Novartis Institutes for Biomedical ResearchNovartis Pharma AGBaselSwitzerland
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Murakami K, Watanabe T, Koike T, Kamata M, Igari T, Kondo S. Pharmacological properties of a novel and potent γ-secretase modulator as a therapeutic option for the treatment of Alzheimer's disease. Brain Res 2015; 1633:73-86. [PMID: 26707977 DOI: 10.1016/j.brainres.2015.12.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/03/2015] [Accepted: 12/11/2015] [Indexed: 11/17/2022]
Abstract
Previous studies of γ-secretase inhibitors (GSIs) and Notch-sparing GSIs have shown reduced amyloid-β (Aβ) peptide levels but increased Notch-related and -unrelated adverse effects. In this study, we examined the effects of compound-1 on Aβ processing and cognitive function and assessed Notch-related and -unrelated adverse effects. Compound-1 reduced Aβ40 and Aβ42 levels but inversely increased Aβ37 in Neuro2a cells, leading to no net changes in total Aβ levels, indicating that compound-1 is a γ-secretase modulator (GSM). In time-course experiments, compound-1 reduced Aβ40 and Aβ42 levels in tris-soluble fractions, with peak reduction at approximately 3h after oral administration in C57BL mice. Moreover, at >1mg/kg, compound-1 dose dependently reduced Aβ40 and Aβ42 levels in Tg2576 mice. Chronic treatment with compound-1 in Tg2576 mice for 4 months significantly reduced both soluble and insoluble Aβ42 levels and ameliorated cognitive impairments, even after drug withdrawal for 10 days following oral administration for 2 months. In contrast with compound-1, at 100-fold higher doses (100mg/kg), the GSI LY450139 decreased HES1 mRNA expression in thymus tissues and increased the intensity of periodic acid-Schiff (PAS)-positive areas in the intestine. Moreover, the Notch-sparing GSI BMS708163 led to amyloid precursor protein (APP)-β-C-terminal fragment accumulation in mouse primary neurons. BMS708163 significantly hampered cognitive function in normal mice 1 month after administration, whereas compound-1 significantly improved cognitive function. Taken together, the present novel and orally active GSM is a promising molecule for the treatment of pathologies associated with Aβ42 and Aβ40.
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Affiliation(s)
- Koji Murakami
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan
| | - Tomomichi Watanabe
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan
| | - Tatsuki Koike
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan
| | - Makoto Kamata
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan
| | - Tomoko Igari
- Drug Metabolism and Pharmacokinetics Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan
| | - Shinichi Kondo
- CNS Drug Discovery Unit, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa 251-8555, Japan.
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Jha NK, Jha SK, Kumar D, Kejriwal N, Sharma R, Ambasta RK, Kumar P. Impact of Insulin Degrading Enzyme and Neprilysin in Alzheimer’s Disease Biology: Characterization of Putative Cognates for Therapeutic Applications. J Alzheimers Dis 2015; 48:891-917. [DOI: 10.3233/jad-150379] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Niraj Kumar Jha
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Saurabh Kumar Jha
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Dhiraj Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Noopur Kejriwal
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Renu Sharma
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Rashmi K. Ambasta
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University (Formerly DCE), Shahbad Daulatpur, Delhi, India
- Department of Neurology, Tufts University School of Medicine, Boston, MA, USA
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Webster CI, Burrell M, Olsson LL, Fowler SB, Digby S, Sandercock A, Snijder A, Tebbe J, Haupts U, Grudzinska J, Jermutus L, Andersson C. Engineering neprilysin activity and specificity to create a novel therapeutic for Alzheimer's disease. PLoS One 2014; 9:e104001. [PMID: 25089527 PMCID: PMC4121237 DOI: 10.1371/journal.pone.0104001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/05/2014] [Indexed: 02/07/2023] Open
Abstract
Neprilysin is a transmembrane zinc metallopeptidase that degrades a wide range of peptide substrates. It has received attention as a potential therapy for Alzheimer’s disease due to its ability to degrade the peptide amyloid beta. However, its broad range of peptide substrates has the potential to limit its therapeutic use due to degradation of additional peptides substrates that tightly regulate many physiological processes. We sought to generate a soluble version of the ectodomain of neprilysin with improved activity and specificity towards amyloid beta as a potential therapeutic for Alzheimer’s disease. Extensive amino acid substitutions were performed at positions surrounding the active site and inner surface of the enzyme and variants screened for activity on amyloid beta 1–40, 1–42 and a variety of other physiologically relevant peptides. We identified several mutations that modulated and improved both enzyme selectivity and intrinsic activity. Neprilysin variant G399V/G714K displayed an approximately 20-fold improved activity on amyloid beta 1–40 and up to a 3,200-fold reduction in activity on other peptides. Along with the altered peptide substrate specificity, the mutant enzyme produced a markedly altered series of amyloid beta cleavage products compared to the wild-type enzyme. Crystallisation of the mutant enzyme revealed that the amino acid substitutions result in alteration of the shape and size of the pocket containing the active site compared to the wild-type enzyme. The mutant enzyme offers the potential for the more efficient degradation of amyloid beta in vivo as a therapeutic for the treatment of Alzheimer’s disease.
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Affiliation(s)
- Carl I. Webster
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, United Kingdom
- * E-mail:
| | - Matthew Burrell
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, United Kingdom
| | | | - Susan B. Fowler
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, United Kingdom
| | - Sarah Digby
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, United Kingdom
| | - Alan Sandercock
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, United Kingdom
| | - Arjan Snijder
- Discovery Sciences, AstraZeneca R & D, Mölndal, Sweden
| | - Jan Tebbe
- Global Drug Discovery, Global Biologics, Bayer HealthCare AG, Cologne, Germany
| | - Ulrich Haupts
- Global Drug Discovery, Global Biologics, Bayer HealthCare AG, Cologne, Germany
| | - Joanna Grudzinska
- Global Drug Discovery, Global Biologics, Bayer HealthCare AG, Cologne, Germany
| | - Lutz Jermutus
- Antibody Discovery and Protein Engineering, MedImmune, Cambridge, United Kingdom
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Ohkushi G, Suzuki N, Kobayashi S, Chikuma T. Axonal transport of neprilysin in rat sciatic nerves. J Mol Neurosci 2013; 53:96-102. [PMID: 24362764 DOI: 10.1007/s12031-013-0202-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/02/2013] [Indexed: 12/24/2022]
Abstract
Axonal transport of neprilysin, a putative neuropeptide degrading-enzyme, was examined in the proximal, middle, and distal segments of rat sciatic nerves using a double ligation technique. Neprilysin activity was significantly increased not only in the proximal segment but also in the distal segment 12-120 h after ligation, and the maximal neprilysin activity was found in the proximal and distal segments at 96 and 72 h, respectively. Western blot analysis of neprilysin showed that its immunoreactivities in the proximal and distal segments were 2.8- and 2.4-fold higher than that in the middle segment, indicating that neprilysin is transported by anterograde and retrograde axonal flow. These observations suggest that neprilysin may be involved in the metabolism of neuropeptides in nerve terminals or synaptic clefts.
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Affiliation(s)
- Genki Ohkushi
- Department of Analytical Chemistry of Medicines, Showa Pharmaceutical University, 3-3165 Higashi-tamagawagakuen, Machida, Tokyo, 194-8543, Japan
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29
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Henderson SJ, Andersson C, Narwal R, Janson J, Goldschmidt TJ, Appelkvist P, Bogstedt A, Steffen AC, Haupts U, Tebbe J, Freskgård PO, Jermutus L, Burrell M, Fowler SB, Webster CI. Sustained peripheral depletion of amyloid-β with a novel form of neprilysin does not affect central levels of amyloid-β. ACTA ACUST UNITED AC 2013; 137:553-64. [PMID: 24259408 PMCID: PMC3914468 DOI: 10.1093/brain/awt308] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lowering levels of peripheral amyloid-β has been proposed as a strategy to reduce plaques in patients with Alzheimer’s disease. Henderson et al. test a modified version of the amyloid-degrading enzyme neprilysin in rats, monkeys and Tg2576 mice. Levels of amyloid-β were reduced in the bloodstream, but not in the CNS. Alzheimer’s disease is characterized by the accumulation of amyloid deposits in the brain and the progressive loss of cognitive functions. Although the precise role of amyloid-β in disease progression remains somewhat controversial, many efforts to halt or reverse disease progression have focussed on reducing its synthesis or enhancing its removal. It is believed that brain and peripheral soluble amyloid-β are in equilibrium and it has previously been hypothesized that a reduction in peripheral amyloid-β can lower brain amyloid-β, thereby reducing formation of plaques predominantly composed of insoluble amyloid-β; the so-called peripheral sink hypothesis. Here we describe the use of an amyloid-β degrading enzyme, the endogenous metallopeptidase neprilysin, which is fused to albumin to extend plasma half-life and has been engineered to confer increased amyloid-β degradation activity. We used this molecule to investigate the effect of degradation of peripheral amyloid-β on amyloid-β levels in the brain and cerebrospinal fluid after repeated intravenous dosing for up to 4 months in Tg2576 transgenic mice, and 1 month in rats and monkeys. This molecule proved highly effective at degradation of amyloid-β in the periphery but did not alter brain or cerebrospinal fluid amyloid-β levels, suggesting that the peripheral sink hypothesis is not valid and is the first time that this has been demonstrated in non-human primates.
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Affiliation(s)
- Simon J Henderson
- 1 MedImmune, Milstein Building, Granta Park, Cambridge, CB21 6GH, UK
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31
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Nalivaeva NN, Belyaev ND, Zhuravin IA, Turner AJ. The Alzheimer's amyloid-degrading peptidase, neprilysin: can we control it? Int J Alzheimers Dis 2012; 2012:383796. [PMID: 22900228 PMCID: PMC3412116 DOI: 10.1155/2012/383796] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 06/01/2012] [Indexed: 02/07/2023] Open
Abstract
The amyloid cascade hypothesis of Alzheimer's disease (AD) postulates that accumulation in the brain of amyloid β-peptide (Aβ) is the primary trigger for neuronal loss specific to this pathology. In healthy brain, Aβ levels are regulated by a dynamic equilibrium between Aβ release from the amyloid precursor protein (APP) and its removal by perivascular drainage or by amyloid-degrading enzymes (ADEs). During the last decade, the ADE family was fast growing, and currently it embraces more than 20 members. There are solid data supporting involvement of each of them in Aβ clearance but a zinc metallopeptidase neprilysin (NEP) is considered as a major ADE. NEP plays an important role in brain function due to its role in terminating neuropeptide signalling and its decrease during ageing or after such pathologies as hypoxia or ischemia contribute significantly to the development of AD pathology. The recently discovered mechanism of epigenetic regulation of NEP by the APP intracellular domain (AICD) opens new avenues for its therapeutic manipulation and raises hope for developing preventive strategies in AD. However, consideration needs to be given to the diverse physiological roles of NEP. This paper critically evaluates general biochemical and physiological functions of NEP and their therapeutic relevance.
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Affiliation(s)
- N. N. Nalivaeva
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, RAS, 44 Thorez Avenue, Saint Petersburg 194223, Russia
| | - N. D. Belyaev
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - I. A. Zhuravin
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, RAS, 44 Thorez Avenue, Saint Petersburg 194223, Russia
| | - A. J. Turner
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
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32
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Kakiya N, Saito T, Nilsson P, Matsuba Y, Tsubuki S, Takei N, Nawa H, Saido TC. Cell surface expression of the major amyloid-β peptide (Aβ)-degrading enzyme, neprilysin, depends on phosphorylation by mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) and dephosphorylation by protein phosphatase 1a. J Biol Chem 2012; 287:29362-72. [PMID: 22767595 PMCID: PMC3436156 DOI: 10.1074/jbc.m112.340372] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neprilysin is one of the major amyloid-β peptide (Aβ)-degrading enzymes, the expression of which declines in the brain during aging. The decrease in neprilysin leads to a metabolic Aβ imbalance, which can induce the amyloidosis underlying Alzheimer disease. Pharmacological activation of neprilysin during aging therefore represents a potential strategy to prevent the development of Alzheimer disease. However, the regulatory mechanisms mediating neprilysin activity in the brain remain unclear. To address this issue, we screened for pharmacological regulators of neprilysin activity and found that the neurotrophic factors brain-derived neurotrophic factor, nerve growth factor, and neurotrophins 3 and 4 reduce cell surface neprilysin activity. This decrease was mediated by MEK/ERK signaling, which enhanced phosphorylation at serine 6 in the neprilysin intracellular domain (S6-NEP-ICD). Increased phosphorylation of S6-NEP-ICD in primary neurons reduced the levels of cell surface neprilysin and led to a subsequent increase in extracellular Aβ levels. Furthermore, a specific inhibitor of protein phosphatase-1a, tautomycetin, induced extensive phosphorylation of the S6-NEP-ICD, resulting in reduced cell surface neprilysin activity. In contrast, activation of protein phosphatase-1a increased cell surface neprilysin activity and lowered Aβ levels. Taken together, these results indicate that the phosphorylation status of S6-NEP-ICD influences the localization of neprilysin and affects extracellular Aβ levels. Therefore, maintaining S6-NEP-ICD in a dephosphorylated state, either by inhibition of protein kinases involved in its phosphorylation or by activation of phosphatases catalyzing its dephosphorylation, may represent a new approach to prevent reduction of cell surface neprilysin activity during aging and to maintain physiological levels of Aβ in the brain.
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Affiliation(s)
- Naomasa Kakiya
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
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The human CD10 lacking an N-glycan at Asn(628) is deficient in surface expression and neutral endopeptidase activity. Biochim Biophys Acta Gen Subj 2012; 1820:1715-23. [PMID: 22766194 DOI: 10.1016/j.bbagen.2012.06.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 06/22/2012] [Accepted: 06/25/2012] [Indexed: 11/22/2022]
Abstract
BACKGROUND CD10, also known as neprilysin or enkephalinase exhibiting neutral endopeptidase (NEP) activity, is expressed by B-lineage hematopoietic cells as well as a variety of cells from normal tissues. It cleaves peptides such as cytokines to act for terminating inflammatory responses. Although CD10 molecules of the human pre-B-cell line NALM-6 have 6 consensus N-glycosylation sites, three of them are known to be N-glycosylated by X-ray crystallography. METHODS In order to investigate the role of N-glycans in the full expression of NEP activity, we modified N-glycans by treatment of NALM6 cells with various glycosidases or alter each of the consensus N-glycosylation sites by generating site-directed mutagenesis and compared the NEP activities of the sugar-altered CD10 with those of intact CD10. RESULTS CD10 of the human B-cell line NALM-6 was dominantly localized in raft microdomains and heterogeneously N-glycosylated. Although neither desialylation nor further degalactosylation caused defective NEP activity, removal of only a small part of N-glycans by treatment with glycopeptidase F under non-denaturing conditions decreased NEP activity completely. All of the three consensus sites of CD10 in HEK293 cells introduced with wild type-CD10 were confirmed to be N-glycosylated. Surface expression of N-glycan at Asn(628)-deleted CD10 by HEK293 cells was greatly decreased as well as it lost entire NEP activities. CONCLUSIONS N-glycosylation at Asn(628) is essential not only for NEP activities, but also for surface expression. GENERAL SIGNIFICANCE Quality control system does not allow dysfunctional ecto-type proteases to express on plasma membrane.
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Scheffler K, Stenzel J, Krohn M, Lange C, Hofrichter J, Schumacher T, Brüning T, Plath AS, Walker L, Pahnke J. Determination of spatial and temporal distribution of microglia by 230nm-high-resolution, high-throughput automated analysis reveals different amyloid plaque populations in an APP/PS1 mouse model of Alzheimer's disease. Curr Alzheimer Res 2012; 8:781-8. [PMID: 21244350 DOI: 10.2174/156720511797633179] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Revised: 10/24/2010] [Accepted: 11/10/2010] [Indexed: 12/17/2022]
Abstract
One early and prominent pathologic feature of Alzheimer's disease (AD) is the appearance of activated microglia in the vicinity of developing β-amyloid deposits. However, the precise role of microglia during the course of AD is still under discussion. Microglia have been reported to degrade and clear β-amyloid, but they also can exert deleterious effects due to overwhelming inflammatory reactions. Here, we demonstrate the occurrence of developing plaque populations with distinct amounts of associated microglia using time-dependent analyses of plaque morphology and the spatial distribution of microglia in an APP/PS1 mouse model. In addition to a population of larger plaques (>700µm(2)) that are occupied by a moderate contingent of microglial cells across the course of aging, a second type of small β-amyloid deposits develops (≤400µm(2)) in which the plaque core is enveloped by a relatively large number of microglia. Our analyses indicate that microglia are strongly activated early in the emergence of senile plaques, but that activation is diminished in the later stages of plaque evolution (>150 days). These findings support the view that microglia serve to restrict the growth of senile plaques, and do so in a way that minimizes local inflammatory damage to other components of the brain.
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Affiliation(s)
- Katja Scheffler
- University of Rostock, Department of Neurology, Neurodegeneration Research Laboratory, Gehlsheimer Str. 20, 18147 Rostock, Germany
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Wang S, Wang R, Chen L, Bennett DA, Dickson DW, Wang DS. Expression and functional profiling of neprilysin, insulin-degrading enzyme, and endothelin-converting enzyme in prospectively studied elderly and Alzheimer's brain. J Neurochem 2010; 115:47-57. [PMID: 20663017 DOI: 10.1111/j.1471-4159.2010.06899.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The brain steady state level of β-amyloid (Aβ) is determined by the balance between its production and removal, the latter through egress across blood and CSF barriers as well as Aβ degradation. The major Aβ-degrading enzymes are neprilysin (NEP), insulin-degrading enzyme (IDE), and endothelin-converting enzyme (ECE-1). Although evidence suggests that NEP is down-regulated in Alzheimer's disease (AD), the role of IDE and ECE in the Aβ accumulation in aging and dementia remains less certain. In this study, we examined mRNA and protein expression, as well as biological activity of NEP, IDE, and ECE-1 in human frontal cortex by real-time RT-PCR for mRNA, immunoblotting for protein, and highly sensitive and specific fluorescence assays for activity. The relationships between Aβ-degrading enzymes and pathologic measures and clinical features were also assessed. The results showed that NEP mRNA, protein level, and activity were decreased in AD compared with normal controls with no cognitive impairment (NCI). In contrast, IDE activity was unchanged, but there was higher expression of IDE mRNA, indicating a possible compensatory reaction because of deficits in activity. ECE-1 expression in AD brain showed no significant difference compared with age-matched controls. Correlation analyses suggested that NEP expression was correlated with Aβ accumulation and clinical diagnosis, being lower in AD than in no cognitive impairment. In contrast, neither IDE nor ECE-1 correlated with Aβ or clinical diagnosis. These findings provide additional support for NEP as the major protease involved in Aβ degradation and suggest its possible therapeutic targeting in AD.
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Affiliation(s)
- Suqing Wang
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53705, USA
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Abstract
Extensive β-amyloid (Aβ) deposits in brain parenchyma
in the form of senile plaques and in blood vessels in the form of
amyloid angiopathy are pathological hallmarks of Alzheimer's
disease (AD). The mechanisms underlying Aβ deposition
remain unclear. Major efforts have focused on Aβ production,
but there is little to suggest that increased production of
Aβ plays a role in Aβ deposition, except for rare
familial forms of AD. Thus, other mechanisms must be involved in
the accumulation of Aβ in AD. Recent data shows that
impaired clearance may play an important role in Aβ
accumulation in the pathogenesis of AD. This review focuses on our
current knowledge of Aβ-degrading enzymes, including
neprilysin (NEP), endothelin-converting enzyme (ECE),
insulin-degrading enzyme (IDE), angiotensin-converting enzyme
(ACE), and the plasmin/uPA/tPA system as they relate to amyloid
deposition in AD.
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Affiliation(s)
- Deng-Shun Wang
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Wisconsin, Madison, WI 53705, USA
- *Deng-Shun Wang:
| | - Dennis W. Dickson
- Departments of Pathology (Neuropathology) and Neuroscience, Mayo Clinic College of Medicine, Jacksonville, FL 32224, USA
| | - James S. Malter
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Wisconsin, Madison, WI 53705, USA
- Waisman Center for Developmental Disabilities, School of Medicine, University of Wisconsin, Madison, WI 53705, USA
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Nilsson P, Iwata N, Muramatsu SI, Tjernberg LO, Winblad B, Saido TC. Gene therapy in Alzheimer's disease - potential for disease modification. J Cell Mol Med 2010; 14:741-57. [PMID: 20158567 PMCID: PMC3823109 DOI: 10.1111/j.1582-4934.2010.01038.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 02/09/2010] [Indexed: 01/12/2023] Open
Abstract
Alzheimer's disease (AD) is the major cause of dementia in the elderly, leading to memory loss and cognitive decline. The mechanism underlying onset of the disease has not been fully elucidated. However, characteristic pathological manifestations include extracellular accumulation and aggregation of the amyloid beta-peptide (Abeta) into plaques and intracellular accumulation and aggregation of hyperphosphorylated tau, forming neurofibrillary tangles. Despite extensive research worldwide, no disease modifying treatment is yet available. In this review, we focus on gene therapy as a potential treatment for AD, and summarize recent work in the field, ranging from proof-of-concept studies in animal models to clinical trials. The multifactorial causes of AD offer a variety of possible targets for gene therapy, including two neurotrophic growth factors, nerve growth factor and brain-derived neurotrophic factor, Abeta-degrading enzymes, such as neprilysin, endothelin-converting enzyme and cathepsin B, and AD associated apolipoprotein E. This review also discusses advantages and drawbacks of various rapidly developing virus-mediated gene delivery techniques for gene therapy. Finally, approaches aiming at down-regulating amyloid precursor protein (APP) and beta-site APP cleaving enzyme 1 levels by means of siRNA-mediated knockdown are briefly summarized. Overall, the prospects appear hopeful that gene therapy has the potential to be a disease modifying treatment for AD.
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Affiliation(s)
- Per Nilsson
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science InstituteWako-shi, Saitama, Japan
- KI-Alzheimer’s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska InstitutetNovum, Huddinge, Sweden
| | - Nobuhisa Iwata
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science InstituteWako-shi, Saitama, Japan
| | - Shin-ichi Muramatsu
- Division of Neurology, Department of Medicine, Jichi Medical SchoolShimotsuke, Tochigi, Japan
| | - Lars O Tjernberg
- KI-Alzheimer’s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska InstitutetNovum, Huddinge, Sweden
| | - Bengt Winblad
- KI-Alzheimer’s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska InstitutetNovum, Huddinge, Sweden
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science InstituteWako-shi, Saitama, Japan
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Frånberg J, Karlström H, Winblad B, Tjernberg LO, Frykman S. gamma-Secretase dependent production of intracellular domains is reduced in adult compared to embryonic rat brain membranes. PLoS One 2010; 5:e9772. [PMID: 20333303 PMCID: PMC2841641 DOI: 10.1371/journal.pone.0009772] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 02/25/2010] [Indexed: 12/20/2022] Open
Abstract
Background γ-Secretase is an intramembrane aspartyl protease whose cleavage of the amyloid precursor protein (APP) generates the amyloid β-peptide (Aβ) and the APP intracellular domain. Aβ is widely believed to have a causative role in Alzheimer's disease pathogenesis, and therefore modulation of γ-secretase activity has become a therapeutic goal. Besides APP, more than 50 substrates of γ-secretase with different cellular functions during embryogenesis as well as adulthood have been revealed. Prior to γ-secretase cleavage, substrates are ectodomain shedded, producing membrane bound C-terminal fragments (CTFs). Principal Findings Here, we investigated γ-secretase cleavage of five substrates; APP, Notch1, N-cadherin, ephrinB and p75 neurotrophin receptor (p75-NTR) in membranes isolated from embryonic, young or old adult rat brain by analyzing the release of the corresponding intracellular domains (ICDs) or Aβ40 by western blot analysis and ELISA respectively. The highest levels of all ICDs and Aβ were produced by embryonic membranes. In adult rat brain only cleavage of APP and Notch1 could be detected and the Aβ40 and ICD production from these substrates was similar in young and old adult rat brain. The CTF levels of Notch1, N-cadherin, ephrinB and p75-NTR were also clearly decreased in the adult brain compared to embryonic brain, whereas the APP CTF levels were only slightly decreased. Conclusions In summary our data suggests that γ-secretase dependent ICD production is down-regulated in the adult brain compared to embryonic brain. In addition, the present approach may be useful for evaluating the specificity of γ-secretase inhibitors.
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Affiliation(s)
- Jenny Frånberg
- Karolinska Institutet Alzheimer's Disease Research Center (KI-ADRC), Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden.
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Duclot F, Meffre J, Jacquet C, Gongora C, Maurice T. Mice knock out for the histone acetyltransferase p300/CREB binding protein-associated factor develop a resistance to amyloid toxicity. Neuroscience 2010; 167:850-63. [PMID: 20219649 DOI: 10.1016/j.neuroscience.2010.02.055] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 02/11/2010] [Accepted: 02/20/2010] [Indexed: 10/19/2022]
Abstract
p300/CREB binding protein-associated factor (PCAF) regulates gene expression by acting through histone acetylation and as a transcription coactivator. Although histone acetyltransferases were involved in the toxicity induced by amyloid-beta (Abeta) peptides, nothing is known about PCAF. We here analyzed the sensitivity of PCAF knockout (KO) mice to the toxic effects induced by i.c.v. injection of Abeta(25-35) peptide, a nontransgenic model of Alzheimer's disease. PCAF wild-type (WT) and KO mice received Abeta(25-35) (1, 3 or 9 nmol) or scrambled Abeta(25-35) (9 nmol) as control. After 7 days, Abeta(25-35) toxicity was measured in the hippocampus of WT mice by a decrease in CA1 pyramidal cells and increases in oxidative stress, endoplasmic reticulum stress and induction of apoptosis. Memory deficits were observed using spontaneous alternation, water-maze learning and passive avoidance. Non-treated PCAF KO mice showed a decrease in CA1 cells and learning alterations. However, Abeta(25-35) injection failed to induce toxicity or worsen the deficits. This resistance to Abeta(25-35) toxicity did not involve changes in glutamate or acetylcholine systems. Examination of enzymes involved in Abeta generation or degradation revealed changes in transcription of presenilins, activity of neprilysin (NEP) and an absence of Abeta(25-35)-induced regulation of NEP activity in PCAF KO mice, partly due to an altered expression of somatostatin (SRIH). We conclude that PCAF regulates the expression of proteins involved in Abeta generation and degradation, thus rendering PCAF KO insensitive to amyloid toxicity. Modulating acetyltransferase activity may offer a new way to develop anti-amyloid therapies.
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Affiliation(s)
- F Duclot
- INSERM U 710, Montpellier, France
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40
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Vázquez MC, Vargas LM, Inestrosa NC, Alvarez AR. c-Abl modulates AICD dependent cellular responses: transcriptional induction and apoptosis. J Cell Physiol 2009; 220:136-43. [PMID: 19306298 DOI: 10.1002/jcp.21743] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
APP intracellular domain (AICD) has been proposed as a transcriptional inductor that moves to the nucleus with the adaptor protein Fe65 and regulates transcription. The two proteins, APP and Fe65, can be phosphorylated by c-Abl kinase. Neprilysin has been proposed as a target gene for AICD. We found that AICD expression is decreased by treatment with STI-571, a c-Abl inhibitor, suggesting a modulation of AICD transcription by c-Abl kinase. We observed interaction between c-Abl kinase, the AICD fragment and the Fe65 adaptor protein. In addition, STI-571 reduces apoptosis in APPSw, and the apoptotic response induced by Fe65 over-expression was inhibited by with the expression of a kinase dead (KD) c-Abl and enhanced by over-expression of WT-c-Abl. However, in the APPSw cells, the ability of the KD-c-Abl to protect against Fe65 was reduced. Finally, in APPSw clone, we detected higher trans-activation of the pro-apoptotic p73 isoform, TAp73 promoter. Our results show that c-Abl modulates AICD dependent cellular responses, transcriptional induction as well as the apoptotic response, which could participate in the onset and progression of the neurodegenerative pathology, observed in Alzheimer's disease (AD).
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Affiliation(s)
- Mary C Vázquez
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontifical Catholic University of Chile, Santiago, Chile
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41
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Minocycline prevents Aβ(25–35)-induced reduction of somatostatin and neprilysin content in rat temporal cortex. Life Sci 2009; 84:205-10. [DOI: 10.1016/j.lfs.2008.11.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 11/18/2008] [Accepted: 11/26/2008] [Indexed: 11/20/2022]
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42
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Xiao ZM, Sun L, Liu YM, Zhang JJ, Huang J. Estrogen regulation of the neprilysin gene through a hormone-responsive element. J Mol Neurosci 2009; 39:22-6. [PMID: 19127446 DOI: 10.1007/s12031-008-9168-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 12/10/2008] [Indexed: 02/05/2023]
Abstract
Our previous data showed that neprilysin (NEP), a zinc metalloendopeptidase, which can degrade amyloid-beta peptide (Abeta) whose central nerve system accumulation is the primary cause of Alzheimer's disease (AD), responds to estrogen in the brain. Recently, it has been shown that the transcription of the neprilysin gene can be up regulated by progesterone, androgens, and glucocorticoids through two androgen response elements within the NEP gene--an androgen response region (ARR) and an androgen response element (ARE). Through a yeast report gene system, we now find that the ARR but not the ARE respond to estrogen. However, androgen could efficiently enhance the expression of the report gene mainly through ARE. Our results indicate that the decrease of NEP, caused by the decline of estrogen or androgen with aging, may be an important factor leading to Abeta accumulation and AD.
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Affiliation(s)
- Zhi-Min Xiao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072, China
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43
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Miners JS, Verbeek MM, Rikkert MO, Kehoe PG, Love S. Immunocapture-based fluorometric assay for the measurement of neprilysin-specific enzyme activity in brain tissue homogenates and cerebrospinal fluid. J Neurosci Methods 2007; 167:229-36. [PMID: 17904641 DOI: 10.1016/j.jneumeth.2007.08.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 08/20/2007] [Accepted: 08/20/2007] [Indexed: 11/27/2022]
Abstract
Neprilysin, a zinc-metalloendopeptidase, has important roles in the physiology and pathology of many diseases such as hypertension, cancer and Alzheimer's disease. We have developed an immunocapture assay to measure the specific enzyme activity of neprilysin in brain tissue homogenates and cerebrospinal fluid (CSF). The assay uses a neprilysin-specific antibody, previously used in a commercially available ELISA kit, to isolate and immobilise NEP from brain homogenates and CSF, prior to the addition of a fluorogenic peptide substrate (Mca-RPPGFSAFK(Dnp)). This fluorogenic substrate is ordinarily cleaved by multiple enzymes. We have shown that without the immunocapture phase, even under reaction conditions reported to be specific for neprilysin - i.e. in the presence of thiorphan, at pH above 7 - the fluorogenic peptide substrate does not allow neprilysin activity in brain homogenates and CSF to be discriminated from that of other closely related enzymes. The specificity of the immunocapture enzyme activity assay was confirmed by >80% inhibition of substrate cleavage in brain homogenates and CSF in the presence of thiorphan. The assay allows high-throughput analysis and, critically, also ensures a high level of enzyme specificity even when assaying crude tissue homogenates or CSF.
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Affiliation(s)
- James Scott Miners
- Dementia Research Group, Institute of Clinical Neurosciences, Clinical Science at North Bristol, University of Bristol, Frenchay Hospital, Frenchay, Bristol BS16 1LE, UK.
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Abstract
Alzheimer's disease (AD) is the most common form of dementia in industrialized nations. If more effective therapies are not developed that either prevent AD or block progression of the disease in its very early stages, the economic and societal cost of caring for AD patients will be devastating. Only two types of drugs are currently approved for the treatment of AD: inhibitors of acetyl cholinesterase, which symptomatically enhance cognitive state to some degree but are not disease modifying; and the adamantane derivative, memantine. Memantine preferentially blocks excessive NMDA receptor activity without disrupting normal receptor activity and is thought to be a neuroprotective agent that blocks excitotoxicty. Memantine therefore may have a potentially disease modifying effect in multiple neurodegenerative conditions. An improved understanding of the pathogeneses of AD has now led to the identification of numerous therapeutic targets designed to alter amyloid beta protein (Abeta) or tau accumulation. Therapies that alter Abeta and tau through these various targets are likely to have significant disease modifying effects. Many of these targets have been validated in proof of concept studies in preclinical animal models, and some potentially disease modifying therapies targeting Abeta or tau are being tested in the clinic. This review will highlight both the promise of and the obstacles to developing such disease modifying AD therapies.
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Affiliation(s)
- Todd E Golde
- Mayo Clinic College of Medicine, Department of Neuroscience, Mayo Clinic Jacksonville 4500 San Pablo Road., Jacksonville, Florida 32224, USA.
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45
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Sakamoto T, Saito H, Ishii K, Takahashi H, Tanabe S, Ogasawara Y. Aluminum inhibits proteolytic degradation of amyloid beta peptide by cathepsin D: a potential link between aluminum accumulation and neuritic plaque deposition. FEBS Lett 2006; 580:6543-9. [PMID: 17112520 DOI: 10.1016/j.febslet.2006.10.075] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Revised: 10/20/2006] [Accepted: 10/31/2006] [Indexed: 10/23/2022]
Abstract
Neuritic plaques are the key pathological feature of Alzheimer's disease, and amyloid beta (Abeta) peptides are major component of these plaques. In this study, we demonstrated the influence of aluminum (Al) on the Abeta peptide degradation by cathepsin D. Al did not directly affect the cathepsin D activity using small synthetic substrate. However, when Abeta peptides were used as substrate, the apparent inhibitory effect of Al on cathepsin D activity was observed. This inhibitory effect disappeared by treatment of desferrioxamine. These results indicate that Al has the potential to interact and disrupt Abeta peptide catabolism via the inhibition of proteolytic degradation.
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Affiliation(s)
- Takashi Sakamoto
- Department of Environmental Biology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan
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Miners JS, Van Helmond Z, Chalmers K, Wilcock G, Love S, Kehoe PG. Decreased Expression and Activity of Neprilysin in Alzheimer Disease Are Associated With Cerebral Amyloid Angiopathy. J Neuropathol Exp Neurol 2006; 65:1012-21. [PMID: 17021406 DOI: 10.1097/01.jnen.0000240463.87886.9a] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Neprilysin (NEP) degrades amyloid-beta (Abeta) and is thought to contribute to its clearance from the brain. In Alzheimer disease (AD), downregulation of NEP has been suggested to contribute to the development of cerebral amyloid angiopathy (CAA). We examined the relationship among NEP, CAA, and APOE status in AD and elderly control cases. NEP was most abundant in the tunica media of cerebrocortical blood vessels and in pyramidal neurons. In homogenates of the frontal cortex, NEP protein levels were reduced in AD but not significantly; NEP enzymatic activity was significantly reduced in AD. Immunohistochemistry revealed a reduction of both vascular and parenchymal NEP. The loss of vessel-associated NEP in AD was inversely related to the severity of CAA, and analysis of cases with severe CAA showed that levels of vascular NEP were reduced to the same extent in Abeta-free and Abeta-laden vessels, strongly suggesting that the reduction in NEP is not simply secondary to CAA. Possession of APOE epsilon4 was associated with significantly lower levels of both parenchymal and vascular NEP. Colinearity of epsilon4 with the presence of moderate to severe CAA precluded assessment of the independence of this association from NEP levels. However, logistic regression analysis showed low NEP levels to be a significant independent predictor of moderate to severe CAA.
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Affiliation(s)
- James Scott Miners
- Dementia Research Group, Institute of Clinical Neurosciences, Clinical Science at North Bristol, University of Bristol, Frenchay Hospital, Frenchay, Bristol, United Kingdom.
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Herzig MC, Van Nostrand WE, Jucker M. Mechanism of cerebral beta-amyloid angiopathy: murine and cellular models. Brain Pathol 2006; 16:40-54. [PMID: 16612981 PMCID: PMC8095938 DOI: 10.1111/j.1750-3639.2006.tb00560.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cerebral amyloid angiopathy of the beta-amyloid type (Abeta-CAA) is a risk factor for hemorrhagic stroke and independently is believed to contribute to dementia. Naturally occurring animal models of Abeta-CAA are scarce and not well suited for the laboratory. To this end, a variety of transgenic mouse models have been developed that, similar to cerebral Abeta-amyloidosis in humans, develop either Abeta-CAA only or both Abeta-CAA and parenchymal amyloid, or primarily parenchymal amyloid with only scarce Abeta-CAA. The lessons learned from these mouse models are: i) Abeta-CAA alone is sufficient to induce cerebral hemorrhage and associate pathologies including neuroinflammation, ii) the origin of vascular amyloid is mainly neuronal, iii) Abeta-CAA results largely from impaired Abeta clearance, iv) a high ratio Abeta40:42 favors vascular over parenchymal amyloidosis, and v) genetic risk factors such as ApoE modulate Abeta-CAA and CAA-induced hemorrhages. Therapeutic strategies to inhibit Abeta-CAA are poor at the present time. Once Abeta-CAA is present current Abeta immunotherapy strategies have failed to clear vascular amyloid and even run the risk of serious side effects. Despite this progress in deciphering the pathomechanism of Abeta-CAA, with these first generation mouse models of Abeta-CAA, refining these models is needed and will help to understand the emerging importance of Abeta-CAA for dementia and to develop biomarkers and therapeutic strategies.
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Affiliation(s)
- Martin C. Herzig
- Department of Cellular Neurology, Hertie‐Institute for Clinical Brain Research, University of Tübingen, Germany
- Department of Neuropathology, Institute of Pathology, University of Basel, Switzerland
| | | | - Mathias Jucker
- Department of Cellular Neurology, Hertie‐Institute for Clinical Brain Research, University of Tübingen, Germany
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Saido TC, Iwata N. Metabolism of amyloid beta peptide and pathogenesis of Alzheimer's disease. Towards presymptomatic diagnosis, prevention and therapy. Neurosci Res 2006; 54:235-53. [PMID: 16457902 DOI: 10.1016/j.neures.2005.12.015] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 12/19/2005] [Accepted: 12/27/2005] [Indexed: 12/29/2022]
Abstract
The conversion of what has been interpreted as "normal brain aging" to Alzheimer's disease (AD) via a transition state, i.e. mild cognitive impairment, appears to be a continuous process caused primarily by aging-dependent accumulation of amyloid beta peptide (Abeta) in the brain. This notion give us a hope that, by manipulating the Abeta levels in the brain, we may be able not only to prevent and cure the disease but also to partially control some very significant aspects of brain aging. Abeta is constantly produced from its precursor and immediately catabolized under normal conditions, whereas dysmetabolism of Abeta seems to lead to pathological deposition upon aging. We have focused our attention on elucidation of the unresolved mechanism of Abeta catabolism in the brain. In this review, we describe a new approach to prevent AD development by reducing Abeta burdens in aging brains through up-regulation the catabolic mechanism involving neprilysin that can degrade both monomeric and oligomeric forms of Abeta. The strategy of combining presymptomatic diagnosis with preventive medicine seems to be the most pragmatic in both medical and socio-economical terms. We also introduce a novel non-invasive amyloid imaging approach using a high-power magnetic resonance imaging (MRI) for the presymptomatic diagnosis of AD.
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Affiliation(s)
- Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama, Japan.
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49
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Iwata N, Higuchi M, Saido TC. Metabolism of amyloid-beta peptide and Alzheimer's disease. Pharmacol Ther 2005; 108:129-48. [PMID: 16112736 DOI: 10.1016/j.pharmthera.2005.03.010] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2005] [Indexed: 12/17/2022]
Abstract
The accumulation of amyloid-beta peptide (Abeta), a physiological peptide, in the brain is a triggering event leading to the pathological cascade of Alzheimer's disease (AD) and appears to be caused by an increase in the anabolic activity, as seen in familial AD cases or by a decrease in catabolic activity. Neprilysin is a rate-limiting peptidase involved in the physiological degradation of Abeta in the brain. As demonstrated by reverse genetics studies, disruption of the neprilysin gene causes elevation of endogenous Abeta levels in mouse brain in a gene-dose-dependent manner. Thus, the reduction of neprilysin activity will contribute to Abeta accumulation and consequently to AD development. Evidence that neprilysin in the hippocampus and cerebral cortex is down-regulated with aging and from an early stage of AD development supports a close association of neprilysin with the etiology and pathogenesis of AD. Therefore, the up-regulation of neprilysin represents a promising strategy for therapy and prevention. Recently, somatostatin, which acts via a G-protein-coupled receptor (GPCR), has been identified as a modulator that increases brain neprilysin activity, resulting in a decrease of Abeta levels. Thus, it may be possible to pharmacologically control brain Abeta levels with somatostatin receptor agonists.
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Affiliation(s)
- Nobuhisa Iwata
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Wako-shi, Saitama 351-0198, Japan.
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50
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Piccini A, Russo C, Gliozzi A, Relini A, Vitali A, Borghi R, Giliberto L, Armirotti A, D'Arrigo C, Bachi A, Cattaneo A, Canale C, Torrassa S, Saido TC, Markesbery W, Gambetti P, Tabaton M. beta-amyloid is different in normal aging and in Alzheimer disease. J Biol Chem 2005; 280:34186-92. [PMID: 16103127 DOI: 10.1074/jbc.m501694200] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The mechanism of neurodegeneration caused by beta-amyloid in Alzheimer disease is controversial. Neuronal toxicity is exerted mostly by various species of soluble beta-amyloid oligomers that differ in their N- and C-terminal domains. However, abundant accumulation of beta-amyloid also occurs in the brains of cognitively normal elderly people, in the absence of obvious neuronal dysfunction. We postulated that neuronal toxicity depends on the molecular composition, rather than the amount, of the soluble beta-amyloid oligomers. Here we show that soluble beta-amyloid aggregates that accumulate in Alzheimer disease are different from those of normal aging in regard to the composition as well as the aggregation and toxicity properties.
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Affiliation(s)
- Alessandra Piccini
- Department of Neurosciences, Ophthalmology, and Genetics, University of Genoa, Genoa, Italy
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