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Trambauer J, Fukumori A, Steiner H. Pathogenic Aβ generation in familial Alzheimer’s disease: novel mechanistic insights and therapeutic implications. Curr Opin Neurobiol 2020; 61:73-81. [DOI: 10.1016/j.conb.2020.01.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/16/2020] [Accepted: 01/23/2020] [Indexed: 01/06/2023]
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Wuli W, Tsai ST, Chiou TW, Harn HJ. Human-Induced Pluripotent Stem Cells and Herbal Small-Molecule Drugs for Treatment of Alzheimer's Disease. Int J Mol Sci 2020; 21:E1327. [PMID: 32079110 DOI: 10.3390/ijms21041327] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 12/28/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by extracellular amyloid plaques composed of the β-amyloid peptides and intracellular neurofibrillary tangles and associates with progressive declines in memory and cognition. Several genes play important roles and regulate enzymes that produce a pathological accumulation of β-amyloid in the brain, such as gamma secretase (γ-secretase). Induced pluripotent stem cells from patients with Alzheimer’s disease with different underlying genetic mechanisms may help model different phenotypes of Alzheimer’s disease and facilitate personalized drug screening platforms for the identification of small molecules. We also discuss recent developments by γ-secretase inhibitors and modulators in the treatment of AD. In addition, small-molecule drugs isolated from Chinese herbal medicines have been shown effective in treating Alzheimer’s disease. We propose a mechanism of small-molecule drugs in treating Alzheimer’s disease. Combining therapy with different small-molecule drugs may increase the chance of symptomatic treatment. A customized strategy tailored to individuals and in combination with therapy may be a more suitable treatment option for Alzheimer’s disease in the future.
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Trambauer J, Rodríguez Sarmiento RM, Fukumori A, Feederle R, Baumann K, Steiner H. Aβ43-producing PS1 FAD mutants cause altered substrate interactions and respond to γ-secretase modulation. EMBO Rep 2020; 21:e47996. [PMID: 31762188 PMCID: PMC6945062 DOI: 10.15252/embr.201947996] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/22/2022] Open
Abstract
Abnormal generation of neurotoxic amyloid-β peptide (Aβ) 42/43 species due to mutations in the catalytic presenilin 1 (PS1) subunit of γ-secretase is the major cause of familial Alzheimer's disease (FAD). Deeper mechanistic insight on the generation of Aβ43 is still lacking, and it is unclear whether γ-secretase modulators (GSMs) can reduce the levels of this Aβ species. By comparing several types of Aβ43-generating FAD mutants, we observe that very high levels of Aβ43 are often produced when presenilin function is severely impaired. Altered interactions of C99, the precursor of Aβ, are found for all mutants and are independent of their particular effect on Aβ production. Furthermore, unlike previously described GSMs, the novel compound RO7019009 can effectively lower Aβ43 production of all mutants. Finally, substrate-binding competition experiments suggest that RO7019009 acts mechanistically after initial C99 binding. We conclude that altered C99 interactions are a common feature of diverse types of PS1 FAD mutants and that also patients with Aβ43-generating FAD mutations could in principle be treated by GSMs.
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Affiliation(s)
- Johannes Trambauer
- Biomedical Center (BMC), Metabolic BiochemistryLudwig‐Maximilians‐UniversityMunichGermany
| | | | - Akio Fukumori
- Department of Aging NeurobiologyNational Center for Geriatrics and GerontologyObuJapan
- Department of Mental Health PromotionOsaka University Graduate School of MedicineToyonakaJapan
| | - Regina Feederle
- Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Helmholtz Center MunichGerman Research Center for Environmental HealthNeuherbergGermany
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
| | - Karlheinz Baumann
- Roche Pharma Research and Early DevelopmentRoche Innovation Center Basel, F. Hoffmann‐La Roche Ltd.BaselSwitzerland
| | - Harald Steiner
- Biomedical Center (BMC), Metabolic BiochemistryLudwig‐Maximilians‐UniversityMunichGermany
- German Center for Neurodegenerative Diseases (DZNE)MunichGermany
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Walter S, Jumpertz T, Hüttenrauch M, Ogorek I, Gerber H, Storck SE, Zampar S, Dimitrov M, Lehmann S, Lepka K, Berndt C, Wiltfang J, Becker-Pauly C, Beher D, Pietrzik CU, Fraering PC, Wirths O, Weggen S. The metalloprotease ADAMTS4 generates N-truncated Aβ4-x species and marks oligodendrocytes as a source of amyloidogenic peptides in Alzheimer's disease. Acta Neuropathol 2019; 137:239-257. [PMID: 30426203 DOI: 10.1007/s00401-018-1929-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 10/17/2018] [Accepted: 11/04/2018] [Indexed: 02/06/2023]
Abstract
Brain accumulation and aggregation of amyloid-β (Aβ) peptides is a critical step in the pathogenesis of Alzheimer's disease (AD). Full-length Aβ peptides (mainly Aβ1-40 and Aβ1-42) are produced through sequential proteolytic cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. However, studies of autopsy brain samples from AD patients have demonstrated that a large fraction of insoluble Aβ peptides are truncated at the N-terminus, with Aβ4-x peptides being particularly abundant. Aβ4-x peptides are highly aggregation prone, but their origin and any proteases involved in their generation are unknown. We have identified a recognition site for the secreted metalloprotease ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4) in the Aβ peptide sequence, which facilitates Aβ4-x peptide generation. Inducible overexpression of ADAMTS4 in HEK293 cells resulted in the secretion of Aβ4-40 but unchanged levels of Aβ1-x peptides. In the 5xFAD mouse model of amyloidosis, Aβ4-x peptides were present not only in amyloid plaque cores and vessel walls, but also in white matter structures co-localized with axonal APP. In the ADAMTS4-/- knockout background, Aβ4-40 levels were reduced confirming a pivotal role of ADAMTS4 in vivo. Surprisingly, in the adult murine brain, ADAMTS4 was exclusively expressed in oligodendrocytes. Cultured oligodendrocytes secreted a variety of Aβ species, but Aβ4-40 peptides were absent in cultures derived from ADAMTS4-/- mice indicating that the enzyme was essential for Aβ4-x production in this cell type. These findings establish an enzymatic mechanism for the generation of Aβ4-x peptides. They further identify oligodendrocytes as a source of these highly amyloidogenic Aβ peptides.
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Eimer WA, Vijaya Kumar DK, Navalpur Shanmugam NK, Rodriguez AS, Mitchell T, Washicosky KJ, György B, Breakefield XO, Tanzi RE, Moir RD. Alzheimer's Disease-Associated β-Amyloid Is Rapidly Seeded by Herpesviridae to Protect against Brain Infection. Neuron 2018; 99:56-63.e3. [PMID: 30001512 PMCID: PMC6075814 DOI: 10.1016/j.neuron.2018.06.030] [Citation(s) in RCA: 368] [Impact Index Per Article: 61.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 12/13/2022]
Abstract
Amyloid-β peptide (Aβ) fibrilization and deposition as β-amyloid are hallmarks of Alzheimer's disease (AD) pathology. We recently reported Aβ is an innate immune protein that protects against fungal and bacterial infections. Fibrilization pathways mediate Aβ antimicrobial activities. Thus, infection can seed and dramatically accelerate β-amyloid deposition. Here, we show Aβ oligomers bind herpesvirus surface glycoproteins, accelerating β-amyloid deposition and leading to protective viral entrapment activity in 5XFAD mouse and 3D human neural cell culture infection models against neurotropic herpes simplex virus 1 (HSV1) and human herpesvirus 6A and B. Herpesviridae are linked to AD, but it has been unclear how viruses may induce β-amyloidosis in brain. These data support the notion that Aβ might play a protective role in CNS innate immunity, and suggest an AD etiological mechanism in which herpesviridae infection may directly promote Aβ amyloidosis.
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MESH Headings
- Alzheimer Disease/metabolism
- Alzheimer Disease/virology
- Amyloid beta-Peptides/metabolism
- Amyloidosis/metabolism
- Amyloidosis/virology
- Animals
- Brain/metabolism
- Brain/virology
- Cells, Cultured
- Disease Models, Animal
- Encephalitis, Herpes Simplex/metabolism
- Encephalitis, Herpes Simplex/virology
- Encephalitis, Viral/metabolism
- Encephalitis, Viral/virology
- Herpesviridae
- Herpesvirus 1, Human
- Herpesvirus 6, Human
- Humans
- Mice
- Mice, Transgenic
- Neurofibrillary Tangles/metabolism
- Neurons
- Plaque, Amyloid/metabolism
- Roseolovirus Infections/metabolism
- Roseolovirus Infections/virology
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Affiliation(s)
- William A Eimer
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Deepak Kumar Vijaya Kumar
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Nanda Kumar Navalpur Shanmugam
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Alex S Rodriguez
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Teryn Mitchell
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Kevin J Washicosky
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Bence György
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Xandra O Breakefield
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
| | - Robert D Moir
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
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Kara E, Marks JD, Roe AD, Commins C, Fan Z, Calvo-Rodriguez M, Wegmann S, Hudry E, Hyman BT. A flow cytometry-based in vitro assay reveals that formation of apolipoprotein E (ApoE)-amyloid beta complexes depends on ApoE isoform and cell type. J Biol Chem 2018; 293:13247-13256. [PMID: 29950521 DOI: 10.1074/jbc.ra117.001388] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 05/21/2018] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein E (ApoE) is a secreted apolipoprotein with three isoforms, E2, E3, and E4, that binds to lipids and facilitates their transport in the extracellular environment of the brain and the periphery. The E4 allele is a major genetic risk factor for the sporadic form of Alzheimer's disease (AD), and studies of human brain and mouse models have revealed that E4 significantly exacerbates the deposition of amyloid beta (Aβ). It has been suggested that this deposition could be attributed to the formation of soluble ApoE isoform-specific ApoE-Aβ complexes. However, previous studies have reported conflicting results regarding the directionality and strength of those interactions. In this study, using a series of flow cytometry assays that maintain the physiological integrity of ApoE-Aβ complexes, we systematically assessed the association of Aβ with ApoE2, E3, or E4. We used ApoE secreted from HEK cells or astrocytes overexpressing ApoE fused with a GFP tag. As a source of soluble Aβ peptide, we used synthetic Aβ40 or Aβ42 or physiological Aβ secreted from CHO cell lines overexpressing WT or V717F variant amyloid precursor protein (APP). We observed significant interactions between the different ApoE isoforms and Aβ, with E4 interacting with Aβ more strongly than the E2 and E3 isoforms. We also found subtle differences depending on the Aβ type and the ApoE-producing cell type. In conclusion, these results indicate that the strength of the ApoE-Aβ association depends on the source of Aβ or ApoE.
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Affiliation(s)
- Eleanna Kara
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Jordan D Marks
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Allyson D Roe
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Caitlin Commins
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Zhanyun Fan
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Maria Calvo-Rodriguez
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Susanne Wegmann
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Eloise Hudry
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
| | - Bradley T Hyman
- From the Alzheimer's Disease Research Laboratory, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129
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Ramesh S, Govindarajulu M, Lynd T, Briggs G, Adamek D, Jones E, Heiner J, Majrashi M, Moore T, Amin R, Suppiramaniam V, Dhanasekaran M. SIRT3 activator Honokiol attenuates β-Amyloid by modulating amyloidogenic pathway. PLoS One 2018; 13:e0190350. [PMID: 29324783 PMCID: PMC5764272 DOI: 10.1371/journal.pone.0190350] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/13/2017] [Indexed: 01/06/2023] Open
Abstract
Honokiol (poly-phenolic lignan from Magnolia grandiflora) is a Sirtuin-3 (SIRT3) activator which exhibit antioxidant activity and augment mitochondrial functions in several experimental models. Modern evidence suggests the critical role of SIRT3 in the progression of several metabolic and neurodegenerative diseases. Amyloid beta (Aβ), the precursor to extracellular senile plaques, accumulates in the brains of patients with Alzheimer's disease (AD) and is related to the development of cognitive impairment and neuronal cell death. Aβ is generated from amyloid-β precursor protein (APP) through sequential cleavages, first by β-secretase and then by γ-secretase. Drugs modulating this pathway are believed to be one of the most promising strategies for AD treatment. In the present study, we found that Honokiol significantly enhanced SIRT3 expression, reduced reactive oxygen species generation and lipid peroxidation, enhanced antioxidant activities, and mitochondrial function thereby reducing Aβ and sAPPβ levels in Chinese Hamster Ovarian (CHO) cells (carrying the amyloid precursor protein-APP and Presenilin PS1 mutation). Mechanistic studies revealed that Honokiol affects neither protein levels of APP nor α-secretase activity. In contrast, Honokiol increased the expression of AMPK, CREB, and PGC-1α, thereby inhibiting β-secretase activity leading to reduced Aβ levels. These results suggest that Honokiol is an activator of SIRT3 capable of improving antioxidant activity, mitochondrial energy regulation, while decreasing Aβ, thereby indicating it to be a lead compound for AD drug development.
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Affiliation(s)
- Sindhu Ramesh
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Manoj Govindarajulu
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Tyler Lynd
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Gwyneth Briggs
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Danielle Adamek
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Ellery Jones
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Jake Heiner
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Mohammed Majrashi
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Timothy Moore
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Rajesh Amin
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Vishnu Suppiramaniam
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
| | - Muralikrishnan Dhanasekaran
- Department of Drug Discovery and Development, Harrison School of Pharmacy, Auburn University, Auburn, AL, United States of America
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Kumar DKV, Choi SH, Washicosky KJ, Eimer WA, Tucker S, Ghofrani J, Lefkowitz A, McColl G, Goldstein LE, Tanzi RE, Moir RD. Amyloid-β peptide protects against microbial infection in mouse and worm models of Alzheimer's disease. Sci Transl Med 2017; 8:340ra72. [PMID: 27225182 DOI: 10.1126/scitranslmed.aaf1059] [Citation(s) in RCA: 651] [Impact Index Per Article: 93.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/10/2016] [Indexed: 12/19/2022]
Abstract
The amyloid-β peptide (Aβ) is a key protein in Alzheimer's disease (AD) pathology. We previously reported in vitro evidence suggesting that Aβ is an antimicrobial peptide. We present in vivo data showing that Aβ expression protects against fungal and bacterial infections in mouse, nematode, and cell culture models of AD. We show that Aβ oligomerization, a behavior traditionally viewed as intrinsically pathological, may be necessary for the antimicrobial activities of the peptide. Collectively, our data are consistent with a model in which soluble Aβ oligomers first bind to microbial cell wall carbohydrates via a heparin-binding domain. Developing protofibrils inhibited pathogen adhesion to host cells. Propagating β-amyloid fibrils mediate agglutination and eventual entrapment of unatttached microbes. Consistent with our model, Salmonella Typhimurium bacterial infection of the brains of transgenic 5XFAD mice resulted in rapid seeding and accelerated β-amyloid deposition, which closely colocalized with the invading bacteria. Our findings raise the intriguing possibility that β-amyloid may play a protective role in innate immunity and infectious or sterile inflammatory stimuli may drive amyloidosis. These data suggest a dual protective/damaging role for Aβ, as has been described for other antimicrobial peptides.
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Affiliation(s)
- Deepak Kumar Vijaya Kumar
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Se Hoon Choi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Kevin J Washicosky
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - William A Eimer
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Stephanie Tucker
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Jessica Ghofrani
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Aaron Lefkowitz
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Gawain McColl
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Lee E Goldstein
- Department of Psychiatry, Boston University, Boston, MA 02215, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
| | - Robert D Moir
- Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
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9
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Wirths O, Walter S, Kraus I, Klafki HW, Stazi M, Oberstein TJ, Ghiso J, Wiltfang J, Bayer TA, Weggen S. N-truncated Aβ 4-x peptides in sporadic Alzheimer's disease cases and transgenic Alzheimer mouse models. Alzheimers Res Ther 2017; 9:80. [PMID: 28978359 PMCID: PMC5628465 DOI: 10.1186/s13195-017-0309-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/11/2017] [Indexed: 01/03/2023]
Abstract
Background The deposition of neurotoxic amyloid-β (Aβ) peptides in plaques in the brain parenchyma and in cerebral blood vessels is considered to be a key event in Alzheimer’s disease (AD) pathogenesis. Although the presence and impact of full-length Aβ peptides such as Aβ1–40 and Aβ1–42 have been analyzed extensively, the deposition of N-terminally truncated Aβ peptide species has received much less attention, largely because of the lack of specific antibodies. Methods This paper describes the generation and characterization of novel antibodies selective for Aβ4–x peptides and provides immunohistochemical evidence of Aβ4–x in the human brain and its distribution in the APP/PS1KI and 5XFAD transgenic mouse models. Results The Aβ4–x staining pattern was restricted mainly to amyloid plaque cores and cerebral amyloid angiopathy in AD and Down syndrome cases and in both AD mouse models. In contrast, diffuse amyloid deposits were largely negative for Aβ4–x immunoreactivity. No overt intraneuronal staining was observed. Conclusions The findings of this study are consistent with previous reports demonstrating a high aggregation propensity of Aβ4–x peptides and suggest an important role of these N-truncated Aβ species in the process of amyloidogenesis and plaque core formation. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0309-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Oliver Wirths
- Division of Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany. .,Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany.
| | - Susanne Walter
- Department of Neuropathology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Inga Kraus
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany
| | - Hans W Klafki
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany
| | - Martina Stazi
- Division of Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany
| | - Timo J Oberstein
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen, Germany
| | - Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, NY, USA.,Departments of Psychiatry, New York University School of Medicine, New York, NY, USA
| | - Jens Wiltfang
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.,Institute for Research in Biomedicine (iBiMED), Medical Sciences Department, University of Aveiro, Aveiro, Portugal
| | - Thomas A Bayer
- Division of Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany.,Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, von-Siebold-Strasse 5, 37075, Goettingen, Germany
| | - Sascha Weggen
- Department of Neuropathology, Heinrich-Heine-University, Düsseldorf, Germany
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10
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Czirr E, Castello NA, Mosher KI, Castellano JM, Hinkson IV, Lucin KM, Baeza-Raja B, Ryu JK, Li L, Farina SN, Belichenko NP, Longo FM, Akassoglou K, Britschgi M, Cirrito JR, Wyss-Coray T. Microglial complement receptor 3 regulates brain Aβ levels through secreted proteolytic activity. J Exp Med 2017; 214:1081-1092. [PMID: 28298456 PMCID: PMC5379986 DOI: 10.1084/jem.20162011] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 12/20/2022] Open
Abstract
Czirr et al. report that microglia lacking complement receptor 3 display increased extracellular Aβ degrading activity and that targeting the receptor with a small molecule increases Aβ clearance in vivo, thus identifying a microglial receptor as a novel therapeutic target. Recent genetic evidence supports a link between microglia and the complement system in Alzheimer’s disease (AD). In this study, we uncovered a novel role for the microglial complement receptor 3 (CR3) in the regulation of soluble β-amyloid (Aβ) clearance independent of phagocytosis. Unexpectedly, ablation of CR3 in human amyloid precursor protein–transgenic mice results in decreased, rather than increased, Aβ accumulation. In line with these findings, cultured microglia lacking CR3 are more efficient than wild-type cells at degrading extracellular Aβ by secreting enzymatic factors, including tissue plasminogen activator. Furthermore, a small molecule modulator of CR3 reduces soluble Aβ levels and Aβ half-life in brain interstitial fluid (ISF), as measured by in vivo microdialysis. These results suggest that CR3 limits Aβ clearance from the ISF, illustrating a novel role for CR3 and microglia in brain Aβ metabolism and defining a potential new therapeutic target in AD.
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Affiliation(s)
- Eva Czirr
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Nicholas A Castello
- Gladstone Institute of Neurological Disease, University of California, San Francisco, San Francisco, CA 94158
| | - Kira I Mosher
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Joseph M Castellano
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, CA 94305
| | - Izumi V Hinkson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, CA 94305.,Center for Tissue Regeneration, Repair, and Restoration, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | - Kurt M Lucin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Bernat Baeza-Raja
- Gladstone Institute of Neurological Disease, University of California, San Francisco, San Francisco, CA 94158
| | - Jae Kyu Ryu
- Gladstone Institute of Neurological Disease, University of California, San Francisco, San Francisco, CA 94158
| | - Lulin Li
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, CA 94305.,Center for Tissue Regeneration, Repair, and Restoration, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | - Sasha N Farina
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305.,Center for Tissue Regeneration, Repair, and Restoration, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | - Nadia P Belichenko
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - Katerina Akassoglou
- Gladstone Institute of Neurological Disease, University of California, San Francisco, San Francisco, CA 94158.,Department of Neurology, University of California, San Francisco, San Francisco, CA 94158
| | - Markus Britschgi
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305
| | - John R Cirrito
- Department of Neurology, Washington University, St. Louis, MO 63110.,Knight Alzheimer's Disease Research Center, Washington University Medical Center, St. Louis, MO 63110.,Hope Center for Neurological Disorders, Washington University, St. Louis, MO 63110
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305 .,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, CA 94305.,Center for Tissue Regeneration, Repair, and Restoration, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
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11
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Hüttenrauch M, Walter S, Kaufmann M, Weggen S, Wirths O. Limited Effects of Prolonged Environmental Enrichment on the Pathology of 5XFAD Mice. Mol Neurobiol 2016; 54:6542-6555. [DOI: 10.1007/s12035-016-0167-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/27/2016] [Indexed: 10/20/2022]
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12
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Saul A, Wirths O. Endogenous Apolipoprotein E (ApoE) Fragmentation Is Linked to Amyloid Pathology in Transgenic Mouse Models of Alzheimer’s Disease. Mol Neurobiol 2017; 54:319-27. [DOI: 10.1007/s12035-015-9674-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/18/2015] [Indexed: 01/03/2023]
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13
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Lessard CB, Cottrell BA, Maruyama H, Suresh S, Golde TE, Koo EH. γ-Secretase Modulators and APH1 Isoforms Modulate γ-Secretase Cleavage but Not Position of ε-Cleavage of the Amyloid Precursor Protein (APP). PLoS One 2015; 10:e0144758. [PMID: 26678856 PMCID: PMC4683055 DOI: 10.1371/journal.pone.0144758] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/23/2015] [Indexed: 12/30/2022] Open
Abstract
The relative increase in Aβ42 peptides from familial Alzheimer disease (FAD) linked APP and PSEN mutations can be related to changes in both ε-cleavage site utilization and subsequent step-wise cleavage. Cleavage at the ε-site releases the amyloid precursor protein (APP) intracellular domain (AICD), and perturbations in the position of ε-cleavage are closely associated with changes in the profile of amyloid β-protein (Aβ) species that are produced and secreted. The mechanisms by which γ-secretase modulators (GSMs) or FAD mutations affect the various γ-secretase cleavages to alter the generation of Aβ peptides have not been fully elucidated. Recent studies suggested that GSMs do not modulate ε-cleavage of APP, but the data were derived principally from recombinant truncated epitope tagged APP substrate. Here, using full length APP from transfected cells, we investigated whether GSMs modify the ε-cleavage of APP under more native conditions. Our results confirmed the previous findings that ε-cleavage is insensitive to GSMs. In addition, fenofibrate, an inverse GSM (iGSM), did not alter the position or kinetics of ε-cleavage position in vitro. APH1A and APH1B, a subunit of the γ-secretase complex, also modulated Aβ42/Aβ40 ratio without any alterations in ε-cleavage, a result in contrast to what has been observed with PS1 and APP FAD mutations. Consequently, GSMs and APH1 appear to modulate γ-secretase activity and Aβ42 generation by altering processivity but not ε-cleavage site utilization.
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Affiliation(s)
- Christian B. Lessard
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - Barbara A. Cottrell
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - Hiroko Maruyama
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - Suraj Suresh
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - Todd E. Golde
- Center for Translational Research in Neurodegenerative Disease, Department of Neuroscience, College of Medicine, University of Florida, Florida, United States of America
| | - Edward H. Koo
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
- Departments of Medicine and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- * E-mail:
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14
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Antonios G, Borgers H, Richard BC, Brauß A, Meißner J, Weggen S, Pena V, Pillot T, Davies SL, Bakrania P, Matthews D, Brownlees J, Bouter Y, Bayer TA. Alzheimer therapy with an antibody against N-terminal Abeta 4-X and pyroglutamate Abeta 3-X. Sci Rep 2015; 5:17338. [PMID: 26626428 DOI: 10.1038/srep17338] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/28/2015] [Indexed: 11/28/2022] Open
Abstract
Full-length Aβ1-42 and Aβ1-40, N-truncated pyroglutamate Aβ3-42 and Aβ4-42 are major variants in the Alzheimer brain. Aβ4-42 has not been considered as a therapeutic target yet. We demonstrate that the antibody NT4X and its Fab fragment reacting with both the free N-terminus of Aβ4-x and pyroglutamate Aβ3-X mitigated neuron loss in Tg4-42 mice expressing Aβ4-42 and completely rescued spatial reference memory deficits after passive immunization. NT4X and its Fab fragment also rescued working memory deficits in wild type mice induced by intraventricular injection of Aβ4-42. NT4X reduced pyroglutamate Aβ3-x, Aβx-40 and Thioflavin-S positive plaque load after passive immunization of 5XFAD mice. Aβ1-x and Aβx-42 plaque deposits were unchanged. Importantly, for the first time, we demonstrate that passive immunization using the antibody NT4X is therapeutically beneficial in Alzheimer mouse models showing that N-truncated Aβ starting with position four in addition to pyroglutamate Aβ3-x is a relevant target to fight Alzheimer’s disease.
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15
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Storck SE, Meister S, Nahrath J, Meißner JN, Schubert N, Di Spiezio A, Baches S, Vandenbroucke RE, Bouter Y, Prikulis I, Korth C, Weggen S, Heimann A, Schwaninger M, Bayer TA, Pietrzik CU. Endothelial LRP1 transports amyloid-β(1-42) across the blood-brain barrier. J Clin Invest 2015; 126:123-36. [PMID: 26619118 DOI: 10.1172/jci81108] [Citation(s) in RCA: 268] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 10/22/2015] [Indexed: 12/20/2022] Open
Abstract
According to the neurovascular hypothesis, impairment of low-density lipoprotein receptor-related protein-1 (LRP1) in brain capillaries of the blood-brain barrier (BBB) contributes to neurotoxic amyloid-β (Aβ) brain accumulation and drives Alzheimer's disease (AD) pathology. However, due to conflicting reports on the involvement of LRP1 in Aβ transport and the expression of LRP1 in brain endothelium, the role of LRP1 at the BBB is uncertain. As global Lrp1 deletion in mice is lethal, appropriate models to study the function of LRP1 are lacking. Moreover, the relevance of systemic Aβ clearance to AD pathology remains unclear, as no BBB-specific knockout models have been available. Here, we developed transgenic mouse strains that allow for tamoxifen-inducible deletion of Lrp1 specifically within brain endothelial cells (Slco1c1-CreER(T2) Lrp1(fl/fl) mice) and used these mice to accurately evaluate LRP1-mediated Aβ BBB clearance in vivo. Selective deletion of Lrp1 in the brain endothelium of C57BL/6 mice strongly reduced brain efflux of injected [125I] Aβ(1-42). Additionally, in the 5xFAD mouse model of AD, brain endothelial-specific Lrp1 deletion reduced plasma Aβ levels and elevated soluble brain Aβ, leading to aggravated spatial learning and memory deficits, thus emphasizing the importance of systemic Aβ elimination via the BBB. Together, our results suggest that receptor-mediated Aβ BBB clearance may be a potential target for treatment and prevention of Aβ brain accumulation in AD.
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16
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Brendel M, Jaworska A, Herms J, Trambauer J, Rötzer C, Gildehaus FJ, Carlsen J, Cumming P, Bylund J, Luebbers T, Bartenstein P, Steiner H, Haass C, Baumann K, Rominger A. Amyloid-PET predicts inhibition of de novo plaque formation upon chronic γ-secretase modulator treatment. Mol Psychiatry 2015; 20:1179-87. [PMID: 26055427 PMCID: PMC4759098 DOI: 10.1038/mp.2015.74] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/31/2015] [Accepted: 04/13/2015] [Indexed: 01/18/2023]
Abstract
In a positron-emission tomography (PET) study with the β-amyloid (Aβ) tracer [(18)F]-florbetaben, we previously showed that Aβ deposition in transgenic mice expressing Swedish mutant APP (APP-Swe) mice can be tracked in vivo. γ-Secretase modulators (GSMs) are promising therapeutic agents by reducing generation of the aggregation prone Aβ42 species without blocking general γ-secretase activity. We now aimed to investigate the effects of a novel GSM [8-(4-Fluoro-phenyl)-[1,2,4]triazolo[1,5-a]pyridin-2-yl]-[1-(3-methyl-[1,2,4]thiadiazol-5-yl)-piperidin-4-yl]-amine (RO5506284) displaying high potency in vitro and in vivo on amyloid plaque burden and used longitudinal Aβ-microPET to trace individual animals. Female transgenic (TG) APP-Swe mice aged 12 months (m) were assigned to vehicle (TG-VEH, n=12) and treatment groups (TG-GSM, n=12), which received daily RO5506284 (30 mg kg(-1)) treatment for 6 months. A total of 131 Aβ-PET recordings were acquired at baseline (12 months), follow-up 1 (16 months) and follow-up 2 (18 months, termination scan), whereupon histological and biochemical analyses of Aβ were performed. We analyzed the PET data as VOI-based cortical standard-uptake-value ratios (SUVR), using cerebellum as reference region. Individual plaque load assessed by PET remained nearly constant in the TG-GSM group during 6 months of RO5506284 treatment, whereas it increased progressively in the TG-VEH group. Baseline SUVR in TG-GSM mice correlated with Δ%-SUVR, indicating individual response prediction. Insoluble Aβ42 was reduced by 56% in the TG-GSM versus the TG-VEH group relative to the individual baseline plaque load estimates. Furthermore, plaque size histograms showed differing distribution between groups of TG mice, with fewer small plaques in TG-GSM animals. Taken together, in the first Aβ-PET study monitoring prolonged treatment with a potent GSM in an AD mouse model, we found clear attenuation of de novo amyloidogenesis. Moreover, longitudinal PET allows non-invasive assessment of individual plaque-load kinetics, thereby accommodating inter-animal variations.
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Affiliation(s)
- M Brendel
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - A Jaworska
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - J Herms
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - J Trambauer
- Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - C Rötzer
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - F-J Gildehaus
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - J Carlsen
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - P Cumming
- Department of Psychiatry, University of Oslo, Oslo, Norway
| | - J Bylund
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - T Luebbers
- Roche Pharma Research and Early Development, Small Molecule Research, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - P Bartenstein
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - H Steiner
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - C Haass
- DZNE—German Center for Neurodegenerative Diseases, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany,Biomedical Center (BMC), Ludwig-Maximilians-University of Munich, Munich, Germany
| | - K Baumann
- Roche Pharma Research and Early Development, Neuroscience Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - A Rominger
- Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany,Department of Nuclear Medicine, Ludwig-Maximilians-University of Munich, Marchioninistr. 15, Munich 81377, Germany. E-mail:
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Mori T, Koyama N, Segawa T, Maeda M, Maruyama N, Kinoshita N, Hou H, Tan J, Town T. Methylene blue modulates β-secretase, reverses cerebral amyloidosis, and improves cognition in transgenic mice. J Biol Chem 2014; 289:30303-30317. [PMID: 25157105 DOI: 10.1074/jbc.m114.568212] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Amyloid precursor protein (APP) proteolysis is required for production of amyloid-β (Aβ) peptides that comprise β-amyloid plaques in the brains of patients with Alzheimer disease (AD). Here, we tested whether the experimental agent methylene blue (MB), used for treatment of methemoglobinemia, might improve AD-like pathology and behavioral deficits. We orally administered MB to the aged transgenic PSAPP mouse model of cerebral amyloidosis and evaluated cognitive function and cerebral amyloid pathology. Beginning at 15 months of age, animals were gavaged with MB (3 mg/kg) or vehicle once daily for 3 months. MB treatment significantly prevented transgene-associated behavioral impairment, including hyperactivity, decreased object recognition, and defective spatial working and reference memory, but it did not alter nontransgenic mouse behavior. Moreover, brain parenchymal and cerebral vascular β-amyloid deposits as well as levels of various Aβ species, including oligomers, were mitigated in MB-treated PSAPP mice. These effects occurred with inhibition of amyloidogenic APP proteolysis. Specifically, β-carboxyl-terminal APP fragment and β-site APP cleaving enzyme 1 protein expression and activity were attenuated. Additionally, treatment of Chinese hamster ovary cells overexpressing human wild-type APP with MB significantly decreased Aβ production and amyloidogenic APP proteolysis. These results underscore the potential for oral MB treatment against AD-related cerebral amyloidosis by modulating the amyloidogenic pathway.
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Affiliation(s)
- Takashi Mori
- Departments of Biomedical Sciences and Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan; Departments of Pathology, Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan,.
| | - Naoki Koyama
- Departments of Biomedical Sciences and Saitama Medical Center and University, Kawagoe, Saitama 350-8550, Japan
| | - Tatsuya Segawa
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Masahiro Maeda
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Nobuhiro Maruyama
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Noriaki Kinoshita
- Immuno-Biological Laboratories Co., Ltd., Fujioka, Gunma 375-0005, Japan
| | - Huayan Hou
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and University of South Florida, Tampa, Florida 33613
| | - Jun Tan
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center and University of South Florida, Tampa, Florida 33613; Neuroimmunology Laboratory, Department of Psychiatry and Behavioral Neurosciences, Morsoni College of Medicine, University of South Florida, Tampa, Florida 33613, and
| | - Terrence Town
- Zilkha Neurogenetic Institute, Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California 90089-2821.
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18
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Li S, Deng J, Hou H, Tian J, Giunta B, Wang Y, Sawmiller D, Smith A, Sanberg PR, Obregon D, Mori T, Tan J. Specific antibody binding to the APP672-699 region shifts APP processing from α- to β-cleavage. Cell Death Dis 2014; 5:e1374. [PMID: 25118934 DOI: 10.1038/cddis.2014.336] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/02/2014] [Accepted: 07/09/2014] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD), a progressive neurodegenerative disorder that is the most common cause of dementia in the elderly, is characterized by the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles, as well as a progressive loss of synapses and neurons in the brain. The major pertinacious component of amyloid plaques is Aβ, a variably sized peptide derived from the integral membrane protein amyloid precursor protein (APP). The Aβ region of APP locates partly within its ecto- and trans-membrane domains. APP is cleaved by three proteases, designated as α-, β-, and γ-secretases. Processing by β- and γ-secretase cleaves the N- and C-terminal ends of the Aβ region, respectively, releasing Aβ, whereas α-secretase cleaves within the Aβ sequence, releasing soluble APPα (sAPPα). The γ-secretase cleaves at several adjacent sites to yield Aβ species containing 39-43 amino acid residues. Both α- and β-cleavage sites of human wild-type APP are located in APP672-699 region (ectodomain of β-C-terminal fragment, ED-β-CTF or ED-C99). Therefore, the amino acid residues within or near this region are definitely pivotal for human wild-type APP function and processing. Here, we report that one ED-C99-specific monoclonal antibody (mAbED-C99) blocks human wild-type APP endocytosis and shifts its processing from α- to β-cleavage, as evidenced by elevated accumulation of cell surface full-length APP and β-CTF together with reduced sAPPα and α-CTF levels. Moreover, mAbED-C99 enhances the interactions of APP with cholesterol. Consistently, intracerebroventricular injection of mAbED-C99 to human wild-type APP transgenic mice markedly increases membrane-associated β-CTF. All these findings suggest that APP672-699 region is critical for human wild-type APP processing and may provide new clues for the pathogenesis of sporadic AD.
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Groot AJ, Habets R, Yahyanejad S, Hodin CM, Reiss K, Saftig P, Theys J, Vooijs M. Regulated proteolysis of NOTCH2 and NOTCH3 receptors by ADAM10 and presenilins. Mol Cell Biol 2014; 34:2822-32. [PMID: 24842903 DOI: 10.1128/MCB.00206-14] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In mammals, there are four NOTCH receptors and five Delta-Jagged-type ligands regulating many aspects of embryonic development and adult tissue homeostasis. NOTCH proteins are type I transmembrane receptors that interact with ligands on adjacent cells and are activated by regulated intramembrane proteolysis (RIP). The activation mechanism of NOTCH1 receptors upon ligand binding is well understood and requires cleavage by ADAM10 metalloproteases prior to intramembranous cleavage by γ-secretase. How the other human NOTCH receptor homologues are activated upon ligand binding is not known. Here, we dissect the proteolytic activation mechanism of the NOTCH2 and NOTCH3 receptors. We show that NOTCH2 and NOTCH3 signaling can be triggered by both Delta-Jagged-type ligands and requires ADAM10 and presenilin-1 or -2. Importantly, we did not find any role for the highly related ADAM17/TACE (tumor necrosis factor alpha-converting enzyme) protease in ligand-induced NOTCH2 or NOTCH3 signaling. These results demonstrate that canonical ligand-induced proteolysis of the NOTCH1, -2, and -3 receptors strictly depends on consecutive cleavage of these receptors by ADAM10 and the presenilin-containing γ-secretase complex, leading to transcriptional activation.
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Härtig W, Saul A, Kacza J, Grosche J, Goldhammer S, Michalski D, Wirths O. Immunolesion-induced loss of cholinergic projection neurones promotes β-amyloidosis and tau hyperphosphorylation in the hippocampus of triple-transgenic mice. Neuropathol Appl Neurobiol 2014; 40:106-20. [DOI: 10.1111/nan.12050] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 03/28/2013] [Indexed: 01/13/2023]
Affiliation(s)
- W. Härtig
- Paul Flechsig Institute for Brain Research; University of Leipzig; Leipzig Germany
| | - A. Saul
- Division of Molecular Psychiatry; Department of Psychiatry; University of Göttingen; Göttingen Germany
| | - J. Kacza
- Institute of Anatomy, Histology and Embryology; Faculty of Veterinary Medicine; University of Leipzig; Leipzig Germany
| | - J. Grosche
- Paul Flechsig Institute for Brain Research; University of Leipzig; Leipzig Germany
| | - S. Goldhammer
- Paul Flechsig Institute for Brain Research; University of Leipzig; Leipzig Germany
| | - D. Michalski
- Department of Neurology; University of Leipzig; Leipzig Germany
| | - O. Wirths
- Division of Molecular Psychiatry; Department of Psychiatry; University of Göttingen; Göttingen Germany
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21
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Meister S, Zlatev I, Stab J, Docter D, Baches S, Stauber RH, Deutsch M, Schmidt R, Ropele S, Windisch M, Langer K, Wagner S, von Briesen H, Weggen S, Pietrzik CU. Nanoparticulate flurbiprofen reduces amyloid-β42 generation in an in vitro blood-brain barrier model. Alzheimers Res Ther 2013; 5:51. [PMID: 24280275 PMCID: PMC3978673 DOI: 10.1186/alzrt225] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 10/16/2013] [Indexed: 12/16/2022]
Abstract
INTRODUCTION The amyloid-β42 (Aβ42) peptide plays a crucial role in the pathogenesis of Alzheimer's disease (AD), the most common neurodegenerative disorder affecting the elderly. Over the past years, several approaches and compounds developed for the treatment of AD have failed in clinical studies, likely in part due to their low penetration of the blood-brain barrier (BBB). Since nanotechnology-based strategies offer new possibilities for the delivery of drugs to the brain, this technique is studied intensively for the treatment of AD and other neurological disorders. METHODS The Aβ42 lowering drug flurbiprofen was embedded in polylactide (PLA) nanoparticles by emulsification-diffusion technique and their potential as drug carriers in an in vitro BBB model was examined. First, the cytotoxic potential of the PLA-flurbiprofen nanoparticles on endothelial cells and the cellular binding and uptake by endothelial cells was studied. Furthermore, the biological activity of the nanoparticulate flurbiprofen on γ-secretase modulation as well as its in vitro release was examined. Furthermore, the protein corona of the nanoparticles was studied as well as their ability to transport flurbiprofen across an in vitro BBB model. RESULTS PLA-flurbiprofen nanoparticles were endocytosed by endothelial cells and neither affected the vitality nor barrier function of the endothelial cell monolayer. The exposure of the PLA-flurbiprofen nanoparticles to human plasma occurred in a rapid protein corona formation, resulting in their decoration with bioactive proteins, including apolipoprotein E. Furthermore, luminally administered PLA-flurbiprofen nanoparticles in contrast to free flurbiprofen were able to modulate γ-secretase activity by selectively decreasing Aβ42 levels in the abluminal compartment of the BBB model. CONCLUSIONS In this study, we were able to show that flurbiprofen can be transported by PLA nanoparticles across an in vitro BBB model and most importantly, the transported flurbiprofen modulated γ-secretase activity by selectively decreasing Aβ42 levels. These results demonstrate that the modification of drugs via embedding in nanoparticles is a promising tool to facilitate drug delivery to the brain, which enables future development for the treatment of neurodegenerative disorders like AD.
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Affiliation(s)
- Sabrina Meister
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Iavor Zlatev
- Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, Muenster, Germany
| | - Julia Stab
- Department of Cell Biology and Applied Virology, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany
| | - Dominic Docter
- Molecular and Cellular Oncology/Mainz Screening Center (MSC), ENT-Department, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sandra Baches
- Department of Neuropathology, Heinrich Heine University, Duesseldorf, Germany
| | - Roland H Stauber
- Molecular and Cellular Oncology/Mainz Screening Center (MSC), ENT-Department, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Mordechai Deutsch
- The Biophysical Interdisciplinary Schottenstein Center for the Research and Technology of the Cellome, Bar Ilan University, Ramat gan, Israel
| | - Reinhold Schmidt
- Department of Neurology, Medical University of Graz, Graz, Austria
| | - Stefan Ropele
- Department of Neurology, Medical University of Graz, Graz, Austria
| | | | - Klaus Langer
- Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, Muenster, Germany
| | - Sylvia Wagner
- Department of Cell Biology and Applied Virology, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany
| | - Hagen von Briesen
- Department of Cell Biology and Applied Virology, Fraunhofer Institute for Biomedical Engineering, St. Ingbert, Germany
| | - Sascha Weggen
- Department of Neuropathology, Heinrich Heine University, Duesseldorf, Germany
| | - Claus U Pietrzik
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Saul A, Sprenger F, Bayer TA, Wirths O. Accelerated tau pathology with synaptic and neuronal loss in a novel triple transgenic mouse model of Alzheimer's disease. Neurobiol Aging 2013; 34:2564-73. [DOI: 10.1016/j.neurobiolaging.2013.05.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 04/11/2013] [Accepted: 05/04/2013] [Indexed: 01/16/2023]
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Carreras I, McKee AC, Choi JK, Aytan N, Kowall NW, Jenkins BG, Dedeoglu A. R-flurbiprofen improves tau, but not Aß pathology in a triple transgenic model of Alzheimer's disease. Brain Res 2013; 1541:115-27. [PMID: 24161403 DOI: 10.1016/j.brainres.2013.10.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 10/10/2013] [Accepted: 10/15/2013] [Indexed: 11/24/2022]
Abstract
We have previously reported that chronic ibuprofen treatment improves cognition and decreases intracellular Aß and phosphorylated-tau levels in 3xTg-AD mice. Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) that independently of its anti-inflammatory effects has anti-amyloidogenic activity as a gamma-secretase modulator (GSM) and both activities have the potential to decrease Aß pathology. To further understand the effects of NSAIDs in 3xTg-AD mice, we treated 3xTg-AD mice with R-flurbiprofen, an enantiomer of the NSAID flurbiprofen that maintains the GSM activity but has greatly reduced anti-inflammatory activity, and analyzed its effect on cognition, Aß, tau, and the neurochemical profile of the hippocampus. Treatment with R-flurbiprofen from 5 to 7 months of age resulted in improved cognition on the radial arm water maze (RAWM) test and decreased the level of hyperphosphorylated tau immunostained with AT8 and PHF-1 antibodies. No significant changes in the level of Aß (using 6E10 and NU-1 antibodies) were detected. Using magnetic resonance spectroscopy (MRS) we found that R-flurbiprofen treatment decreased the elevated level of glutamine in 3xTg-AD mice down to the level detected in non-transgenic mice. Glutamine levels correlated with PHF-1 immunostained hyperphosphorylated tau. We also found an inverse correlation between the concentration of glutamate and learning across all the mice in the study. Glutamine and glutamate, neurochemicals that shuttles between neurons and astrocytes to maintain glutamate homeostasis in the synapses, deserve further attention as MR markers of cognitive function.
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Antonios G, Saiepour N, Bouter Y, Richard BC, Paetau A, Verkkoniemi-Ahola A, Lannfelt L, Ingelsson M, Kovacs GG, Pillot T, Wirths O, Bayer TA. N-truncated Abeta starting with position four: early intraneuronal accumulation and rescue of toxicity using NT4X-167, a novel monoclonal antibody. Acta Neuropathol Commun 2013; 1:56. [PMID: 24252153 DOI: 10.1186/2051-5960-1-56] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 08/10/2013] [Indexed: 12/27/2022] Open
Abstract
Background The amyloid hypothesis in Alzheimer disease (AD) considers amyloid β peptide (Aβ) deposition causative in triggering down-stream events like neurofibrillary tangles, cell loss, vascular damage and memory decline. In the past years N-truncated Aβ peptides especially N-truncated pyroglutamate AβpE3-42 have been extensively studied. Together with full-length Aβ1–42 and Aβ1–40, N-truncated AβpE3-42 and Aβ4–42 are major variants in AD brain. Although Aβ4–42 has been known for a much longer time, there is a lack of studies addressing the question whether AβpE3-42 or Aβ4–42 may precede the other in Alzheimer’s disease pathology. Results Using different Aβ antibodies specific for the different N-termini of N-truncated Aβ, we discovered that Aβ4-x preceded AβpE3-x intraneuronal accumulation in a transgenic mouse model for AD prior to plaque formation. The novel Aβ4-x immunoreactive antibody NT4X-167 detected high molecular weight aggregates derived from N-truncated Aβ species. While NT4X-167 significantly rescued Aβ4–42 toxicity in vitro no beneficial effect was observed against Aβ1–42 or AβpE3-42 toxicity. Phenylalanine at position four of Aβ was imperative for antibody binding, because its replacement with alanine or proline completely prevented binding. Although amyloid plaques were observed using NT4X-167 in 5XFAD transgenic mice, it barely reacted with plaques in the brain of sporadic AD patients and familial cases with the Arctic, Swedish and the presenilin-1 PS1Δ9 mutation. A consistent staining was observed in blood vessels in all AD cases with cerebral amyloid angiopathy. There was no cross-reactivity with other aggregates typical for other common neurodegenerative diseases showing that NT4X-167 staining is specific for AD. Conclusions Aβ4-x precedes AβpE3-x in the well accepted 5XFAD AD mouse model underlining the significance of N-truncated species in AD pathology. NT4X-167 therefore is the first antibody reacting with Aβ4-x and represents a novel tool in Alzheimer research.
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Zhang SQ, Obregon D, Ehrhart J, Deng J, Tian J, Hou H, Giunta B, Sawmiller D, Tan J. Baicalein reduces β-amyloid and promotes nonamyloidogenic amyloid precursor protein processing in an Alzheimer's disease transgenic mouse model. J Neurosci Res 2013; 91:1239-46. [PMID: 23686791 PMCID: PMC3810722 DOI: 10.1002/jnr.23244] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 02/08/2013] [Accepted: 03/22/2013] [Indexed: 12/20/2022]
Abstract
Baicalein, a flavonoid isolated from the roots of Scutellaria baicalensis, is known to modulate γ-aminobutyric acid (GABA) type A receptors. Given prior reports demonstrating benefits of GABAA modulation for Alzheimer’s disease (AD) treatment, we wished to determine whether this agent might be beneficial for AD. CHO cells engineered to overexpress wild-type amyloid precursor protein (APP), primary culture neuronal cells from AD mice (Tg2576) and AD mice were treated with baicalein. In the cell cultures, baicalein significantly reduced the production of β-amyloid (Aβ) by increasing APP α-processing. These effects were blocked by the GABAA antagonist bicuculline. Likewise, AD mice treated daily with i.p. baicalein for 8 weeks showed enhanced APP α-secretase processing, reduced Aβ production, and reduced AD-like pathology together with improved cognitive performance. Our findings suggest that baicalein promotes nonamyloidogenic processing of APP, thereby reducing Aβ production and improving cognitive performance, by activating GABAA receptors. © 2013 Wiley Periodicals, Inc.
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Affiliation(s)
- She-Qing Zhang
- Department of Neurology, Shanghai Changhai Hospital, Shanghai, China.
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26
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Abstract
γ-Secretase is an aspartyl intramembranal protease composed of presenilin, Nicastrin, Aph1, and Pen2 with 19 transmembrane domains. γ-Secretase cleaves the amyloid precursor proteins (APP) to release Aβ peptides that likely play a causative role in the pathogenesis of Alzheimer's disease (AD). In addition, γ-secretase cleaves Notch and other type I membrane proteins. γ-Secretase inhibitors (GSIs) have been developed and used for clinical studies. However, clinical trials have shown adverse effects of GSIs that are potentially linked with nondiscriminatory inhibition of Notch signaling, overall APP processing, and other substrate cleavages. Therefore, these findings call for the development of disease-modifying agents that target γ-secretase activity to lower levels of Aβ42 production without blocking the overall processing of γ-secretase substrates. γ-Secretase modulators (GSMs) originally derived from nonsteroidal anti-inflammatory drugs (NSAIDs) display such characteristics and are the focus of this review. However, first-generation GSMs have limited potential because of the low potency and undesired neuropharmacokinetic properties. This generation of GSMs has been suggested to interact with the APP substrate, γ-secretase, or both. To improve the potency and brain availability, second-generation GSMs, including NSAID-derived carboxylic acid and non-NSAID-derived heterocyclic chemotypes, as well as natural product-derived GSMs have been developed. Animal studies of this generation of GSMs have shown encouraging preclinical profiles. Moreover, using potent GSM photoaffinity probes, multiple studies unambiguously have showed that both carboxylic acid and heterocyclic GSMs specifically target presenilin, the catalytic subunit of γ-secretase. In addition, two types of GSMs have distinct binding sites within the γ-secretase complex and exhibit different Aβ profiles. GSMs induce a conformational change of γ-secretase to achieve modulation. Various models are proposed and discussed. Despite the progress of GSM research, many outstanding issues remain to be investigated to achieve the ultimate goal of developing GSMs as effective AD therapies.
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Affiliation(s)
- Christina J Crump
- Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center , 1275 York Avenue, New York, New York 10065, United States
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27
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Kretner B, Fukumori A, Kuhn PH, Pérez-Revuelta BI, Lichtenthaler SF, Haass C, Steiner H. Important functional role of residue x of the presenilin GxGD protease active site motif for APP substrate cleavage specificity and substrate selectivity of γ-secretase. J Neurochem 2013; 125:144-56. [PMID: 23237322 DOI: 10.1111/jnc.12124] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 12/10/2012] [Accepted: 12/10/2012] [Indexed: 11/30/2022]
Abstract
γ-Secretase plays a central role in the generation of the Alzheimer disease-causing amyloid β-peptide (Aβ) from the β-amyloid precursor protein (APP) and is thus a major Alzheimer's disease drug target. As several other γ-secretase substrates including Notch1 and CD44 have crucial signaling functions, an understanding of the mechanism of substrate recognition and cleavage is key for the development of APP selective γ-secretase-targeting drugs. The γ-secretase active site domain in its catalytic subunit presenilin (PS) 1 has been implicated in substrate recognition/docking and cleavage. Highly critical in this process is its GxGD active site motif, whose invariant glycine residues cannot be replaced without causing severe functional losses in substrate selection and/or cleavage efficiency. Here, we have investigated the contribution of the less well characterized residue x of the motif (L383 in PS1) to this function. Extensive mutational analysis showed that processing of APP was overall well-tolerated over a wide range of hydrophobic and hydrophilic mutations. Interestingly, however, most L383 mutants gave rise to reduced levels of Aβ37-39 species, and several increased the pathogenic Aβ42/43 species. Several of the Aβ42/43 -increasing mutants severely impaired the cleavages of Notch1 and CD44 substrates, which were not affected by any other L383 mutation. Our data thus establish an important, but compared with the glycine residues of the motif, overall less critical functional role for L383. We suggest that L383 and the flanking glycine residues form a spatial arrangement in PS1 that is critical for docking and/or cleavage of different γ-secretase substrates.
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Affiliation(s)
- Benedikt Kretner
- Adolf-Butenandt-Institute, Biochemistry, Ludwig-Maximilians-University, Munich, Germany
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Zettl H, Ness J, Hähnke V, Beher D, Jumpertz T, Saric A, Baumann K, Pietrzik CU, Bulic B, Schneider G, Weggen S. Discovery of γ-secretase modulators with a novel activity profile by text-based virtual screening. ACS Chem Biol 2012; 7:1488-95. [PMID: 22725102 DOI: 10.1021/cb3001952] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We present an integrated approach to identify and optimize a novel class of γ-secretase modulators (GSMs) with a unique pharmacological profile. Our strategy included (i) virtual screening through application of a recently developed protocol (PhAST), (ii) synthetic chemistry to discover structure-activity relationships, and (iii) detailed in vitro pharmacological characterization. GSMs are promising agents for treatment or prevention of Alzheimer's disease. They modulate the γ-secretase product spectrum (i.e., amyloid-β (Aβ) peptides of different length) and induce a shift from toxic Aβ42 to shorter Aβ species such as Aβ38 with no or minimal effect on the overall rate of γ-secretase cleavage. We describe the identification of a series of 4-hydroxypyridin-2-one derivatives, which display a novel type of γ-secretase modulation with equipotent inhibition of Aβ42 and Aβ38 peptide species.
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Affiliation(s)
- Heiko Zettl
- Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Julia Ness
- Department of Neuropathology, Heinrich-Heine-University, D-40225 Duesseldorf, Germany
| | - Volker Hähnke
- Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Dirk Beher
- Global Research & Early Development, Merck Serono S. A., CH-1202 Geneva, Switzerland
| | - Thorsten Jumpertz
- Department of Neuropathology, Heinrich-Heine-University, D-40225 Duesseldorf, Germany
| | - Arman Saric
- Global Research & Early Development, Merck Serono S. A., CH-1202 Geneva, Switzerland
| | - Karlheinz Baumann
- F. Hoffmann-La Roche AG, pRED, Pharma Research & Early Development, DTA CNS, CH-4070 Basel, Switzerland
| | - Claus U. Pietrzik
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University, D-55128 Mainz, Germany
| | - Bruno Bulic
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, D-53175 Bonn, Germany
| | - Gisbert Schneider
- Institute of Pharmaceutical Sciences, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Sascha Weggen
- Department of Neuropathology, Heinrich-Heine-University, D-40225 Duesseldorf, Germany
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Rennhack A, Jumpertz T, Ness J, Baches S, Pietrzik CU, Weggen S, Bulic B. Synthesis of a potent photoreactive acidic γ-secretase modulator for target identification in cells. Bioorg Med Chem 2012; 20:6523-32. [PMID: 23000293 DOI: 10.1016/j.bmc.2012.08.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 07/23/2012] [Accepted: 08/08/2012] [Indexed: 11/24/2022]
Abstract
Supramolecular self-assembly of amyloidogenic peptides is closely associated with numerous pathological conditions. For instance, Alzheimer´s disease (AD) is characterized by abundant amyloid plaques originating from the proteolytic cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. Compounds named γ-secretase modulators (GSMs) can shift the substrate cleavage specificity of γ-secretase toward the production of non-amyloidogenic, shorter Aβ fragments. Herein, we describe the synthesis of highly potent acidic GSMs, equipped with a photoreactive diazirine moiety for photoaffinity labeling. The probes labeled the N-terminal fragment of presenilin (the catalytic subunit of γ-secretase), supporting a mode of action involving binding to γ-secretase. This fundamental step toward the elucidation of the molecular mechanism governing the GSM-induced shift in γ-secretase proteolytic specificity should pave the way for the development of improved drugs against AD.
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Bulic B, Ness J, Hahn S, Rennhack A, Jumpertz T, Weggen S. Chemical Biology, Molecular Mechanism and Clinical Perspective of γ-Secretase Modulators in Alzheimer's Disease. Curr Neuropharmacol 2012; 9:598-622. [PMID: 22798753 PMCID: PMC3391656 DOI: 10.2174/157015911798376352] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 10/25/2010] [Accepted: 11/01/2010] [Indexed: 12/25/2022] Open
Abstract
Comprehensive evidence supports that oligomerization and accumulation of amyloidogenic Aβ42 peptides in brain is crucial in the pathogenesis of both familial and sporadic forms of Alzheimer's disease. Imaging studies indicate that the buildup of Aβ begins many years before the onset of clinical symptoms, and that subsequent neurodegeneration and cognitive decline may proceed independently of Aβ. This implies the necessity for early intervention in cognitively normal individuals with therapeutic strategies that prioritize safety. The aspartyl protease γ-secretase catalyses the last step in the cellular generation of Aβ42 peptides, and is a principal target for anti-amyloidogenic intervention strategies. Due to the essential role of γ-secretase in the NOTCH signaling pathway, overt mechanism-based toxicity has been observed with the first generation of γ-secretase inhibitors, and safety of this approach has been questioned. However, two new classes of small molecules, γ-secretase modulators (GSMs) and NOTCH-sparing γ-secretase inhibitors, have revitalized γ-secretase as a drug target in AD. GSMs are small molecules that cause a product shift from Aβ42 towards shorter and less toxic Ab peptides. Importantly, GSMs spare other physiologically important substrates of the γ-secretase complex like NOTCH. Recently, GSMs with nanomolar potency and favorable in vivo properties have been described. In this review, we summarize the knowledge about the unusual proteolytic activity of γ-secretase, and the chemical biology, molecular mechanisms and clinical perspective of compounds that target the γ-secretase complex, with a particular focus on GSMs.
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Affiliation(s)
- Bruno Bulic
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, D-53175 Bonn, Germany
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31
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Wang H, Megill A, He K, Kirkwood A, Lee HK. Consequences of inhibiting amyloid precursor protein processing enzymes on synaptic function and plasticity. Neural Plast 2012; 2012:272374. [PMID: 22792491 DOI: 10.1155/2012/272374] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 04/22/2012] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease, one of whose major pathological hallmarks is the accumulation of amyloid plaques comprised of aggregated β-amyloid (Aβ) peptides. It is now recognized that soluble Aβ oligomers may lead to synaptic dysfunctions early in AD pathology preceding plaque deposition. Aβ is produced by a sequential cleavage of amyloid precursor protein (APP) by the activity of β- and γ-secretases, which have been identified as major candidate therapeutic targets of AD. This paper focuses on how Aβ alters synaptic function and the functional consequences of inhibiting the activity of the two secretases responsible for Aβ generation. Abnormalities in synaptic function resulting from the absence or inhibition of the Aβ-producing enzymes suggest that Aβ itself may have normal physiological functions which are disrupted by abnormal accumulation of Aβ during AD pathology. This interpretation suggests that AD therapeutics targeting the β- and γ-secretases should be developed to restore normal levels of Aβ or combined with measures to circumvent the associated synaptic dysfunction(s) in order to have minimal impact on normal synaptic function.
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Obregon D, Hou H, Deng J, Giunta B, Tian J, Darlington D, Shahaduzzaman M, Zhu Y, Mori T, Mattson MP, Tan J. Soluble amyloid precursor protein-α modulates β-secretase activity and amyloid-β generation. Nat Commun 2012; 3:777. [PMID: 22491325 DOI: 10.1038/ncomms1781] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 03/08/2012] [Indexed: 01/02/2023] Open
Abstract
In sporadic age-related forms of Alzheimer's disease (AD), it is unclear why amyloid-β (Aβ) peptides accumulate. Here we show that soluble amyloid precursor protein-α (sAPP-α) decreases Aβ generation by directly associating with β-site APP-converting enzyme (BACE)1, thereby modulating APP processing. Whereas specifically targeting sAPP-α using antibodies enhances Aβ production; in transgenic mice with AD-like pathology, sAPP-α overexpression decreases β-amyloid plaques and soluble Aβ. In support, immunoneutralization of sAPP-α increases APP amyloidogenic processing in these mice. Given our current findings, and because a number of risk factors for sporadic AD serve to lower levels of sAPP-α in brains of AD patients, inadequate sAPP-α levels may be sufficient to polarize APP processing towards the amyloidogenic, Aβ-producing route. Therefore, restoration of sAPP-α or enhancement of its association with BACE may be viable strategies to ameliorate imbalances in APP processing that can lead to AD pathogenesis.
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Weggen S, Beher D. Molecular consequences of amyloid precursor protein and presenilin mutations causing autosomal-dominant Alzheimer's disease. Alzheimers Res Ther 2012; 4:9. [PMID: 22494386 PMCID: PMC3334542 DOI: 10.1186/alzrt107] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Mutations in both the amyloid precursor protein (APP) and the presenilin (PSEN) genes cause familial Alzheimer's disease (FAD) with autosomal dominant inheritance and early onset of disease. The clinical course and neuropathology of FAD and sporadic Alzheimer's disease are highly similar, and patients with FAD constitute a unique population in which to conduct treatment and, in particular, prevention trials with novel pharmaceutical entities. It is critical, therefore, to exactly defi ne the molecular consequences of APP and PSEN FAD mutations. Both APP and PSEN mutations drive amyloidosis in FAD patients through changes in the brain metabolism of amyloid-β (Aβ) peptides that promote the formation of pathogenic aggregates. APP mutations do not seem to impair the physiological functions of APP. In contrast, it has been proposed that PSEN mutations compromise γ-secretase-dependent and -independent functions of PSEN. However, PSEN mutations have mostly been studied in model systems that do not accurately refl ect the genetic background in FAD patients. In this review, we discuss the reported cellular phenotypes of APP and PSEN mutations, the current understanding of their molecular mechanisms, the need to generate faithful models of PSEN mutations, and the potential bias of APP and PSEN mutations on therapeutic strategies that target Aβ.
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Affiliation(s)
- Sascha Weggen
- Department of Neuropathology, Heinrich-Heine-University, Moorenstrasse 5, D-40225 Düsseldorf, Germany.
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34
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Deng J, Hou H, Giunta B, Mori T, Wang YJ, Fernandez F, Weggen S, Araki W, Obregon D, Tan J. Autoreactive-Aβ antibodies promote APP β-secretase processing. J Neurochem 2012; 120:732-40. [PMID: 22188568 DOI: 10.1111/j.1471-4159.2011.07629.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Several prior investigations of Alzheimer's disease (AD) patients have indicated naturally occurring autoantibodies against amyloid-β (Aβ) species are produced. Although many studies have focused on the relative concentrations or binding affinities of autoantibodies against Aβ-related proteins in AD and aging, data regarding their functional properties are limited. It is generally believed that these antibodies act to aid in clearance of Aβ. However, as antibodies which bind to Aβ also typically bind to the parent amyloid precursor protein (APP), we reasoned that certain Aβ-targeting autoantibodies may bind to APP thereby altering its conformation and processing. Here we show for the first time, that naturally occurring Aβ-reactive autoantibodies isolated from AD patients, but not from healthy controls, promote β-secretase activity in cultured cells. Furthermore, using monoclonal antibodies to various regions of Aβ, we found that antibodies generated against the N-terminal region, especially Aβ(1-17) , dose dependently promoted amyloidogenic processing of APP viaβ-secretase activation. Thus, this property of certain autoantibodies in driving Aβ generation could be of etiological importance in the development of sporadic forms of AD. Furthermore, future passive or active anti-Aβ immunotherapies must consider potential off-target effects resulting from antibodies targeting the N-terminus of Aβ, as co-binding to the corresponding region of APP may actually enhance Aβ generation.
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Affiliation(s)
- Juan Deng
- Rashid Laboratory for Developmental Neurobiology, Department of Psychiatry and Neurosciences, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
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Jumpertz T, Rennhack A, Ness J, Baches S, Pietrzik CU, Bulic B, Weggen S. Presenilin is the molecular target of acidic γ-secretase modulators in living cells. PLoS One 2012; 7:e30484. [PMID: 22238696 PMCID: PMC3253113 DOI: 10.1371/journal.pone.0030484] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 12/16/2011] [Indexed: 01/19/2023] Open
Abstract
The intramembrane-cleaving protease γ-secretase catalyzes the last step in the generation of toxic amyloid-β (Aβ) peptides and is a principal therapeutic target in Alzheimer's disease. Both preclinical and clinical studies have demonstrated that inhibition of γ-secretase is associated with prohibitive side effects due to suppression of Notch processing and signaling. Potentially safer are γ-secretase modulators (GSMs), which are small molecules that selectively lower generation of the highly amyloidogenic Aβ42 peptides but spare Notch processing. GSMs with nanomolar potency and favorable pharmacological properties have been described, but the molecular mechanism of GSMs remains uncertain and both the substrate amyloid precursor protein (APP) and subunits of the γ-secretase complex have been proposed as the molecular target of GSMs. We have generated a potent photo-probe based on an acidic GSM that lowers Aβ42 generation with an IC50 of 290 nM in cellular assays. By combining in vivo photo-crosslinking with affinity purification, we demonstrated that this probe binds the N-terminal fragment of presenilin (PSEN), the catalytic subunit of the γ-secretase complex, in living cells. Labeling was not observed for APP or any of the other γ-secretase subunits. Binding was readily competed by structurally divergent acidic and non-acidic GSMs suggesting a shared mode of action. These findings indicate that potent acidic GSMs target presenilin to modulate the enzymatic activity of the γ-secretase complex.
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Affiliation(s)
- Thorsten Jumpertz
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
| | - Andreas Rennhack
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, Bonn, Germany
| | - Julia Ness
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
| | - Sandra Baches
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
| | - Claus U. Pietrzik
- Molecular Neurodegeneration Group, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Bruno Bulic
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, Bonn, Germany
- * E-mail: (BB); (SW)
| | - Sascha Weggen
- Department of Neuropathology, Heinrich-Heine-University, Duesseldorf, Germany
- * E-mail: (BB); (SW)
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Hillmann A, Hahn S, Schilling S, Hoffmann T, Demuth HU, Bulic B, Schneider-Axmann T, Bayer TA, Weggen S, Wirths O. No improvement after chronic ibuprofen treatment in the 5XFAD mouse model of Alzheimer's disease. Neurobiol Aging 2011; 33:833.e39-50. [PMID: 21943956 DOI: 10.1016/j.neurobiolaging.2011.08.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 08/08/2011] [Accepted: 08/16/2011] [Indexed: 12/24/2022]
Abstract
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that has been reported to reduce the risk of developing Alzheimer's disease (AD). Its preventive effects in AD are likely pleiotropic as ibuprofen displays both anti-inflammatory activity by inhibition of cyclooxygenases and anti-amyloidogenic activity by modulation of γ-secretase. In order to study the anti-inflammatory properties of ibuprofen independent of its anti-amyloidogenic activity, we performed a long-term treatment study with ibuprofen in 5XFAD mice expressing a presenilin-1 mutation that renders this AD model resistant to γ-secretase modulation. As expected, ibuprofen treatment for 3 months resulted in a reduction of the inflammatory reaction in the 5XFAD mouse model. Importantly, an unchanged amyloid beta (Aβ) plaque load, an increase in soluble Aβ42 levels, and an aggravation of some behavioral parameters were noted, raising the question whether suppression of inflammation by nonsteroidal anti-inflammatory drug is beneficial in AD.
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Affiliation(s)
- Antje Hillmann
- Division of Molecular Psychiatry and Alzheimer Ph.D. Graduate School, Department of Psychiatry, University Medicine Goettingen, Goettingen, Germany
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Sagi SA, Lessard CB, Winden KD, Maruyama H, Koo JC, Weggen S, Kukar TL, Golde TE, Koo EH. Substrate sequence influences γ-secretase modulator activity, role of the transmembrane domain of the amyloid precursor protein. J Biol Chem 2011; 286:39794-803. [PMID: 21868380 DOI: 10.1074/jbc.m111.277228] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A subset of non-steroidal anti-inflammatory drugs modulates the γ cleavage site in the amyloid precursor protein (APP) to selectively reduce production of Aβ42. It is unclear precisely how these γ-secretase modulators (GSMs) act to preferentially spare Aβ40 production as well as Notch processing and signaling. In an effort to determine the substrate requirements in NSAID/GSM activity, we determined the effects of sulindac sulfide and flurbiprofen on γ-cleavage of artificial constructs containing several γ-secretase substrates. Using FLAG-tagged constructs that expressed extracellularly truncated APP, Notch-1, or CD44, we found that these substrates have different sensitivities to sulindac sulfide. γ-Secretase cleavage of APP was altered by sulindac sulfide, but CD44 and Notch-1 were either insensitive or only minimally altered by this compound. Using chimeric APP constructs, we observed that the transmembrane domain (TMD) of APP played a pivotal role in determining drug sensitivity. Substituting the APP TMD with that of APLP2 retained the sensitivity to γ-cleavage modulation, but replacing TMDs from Notch-1 or ErbB4 rendered the resultant molecules insensitive to drug treatment. Specifically, the GXXXG motif within APP appeared to be critical to GSM activity. Consequently, the modulatory effects on γ-cleavage appears to be substrate-dependent. We hypothesize that the substrate present in the γ-secretase complex influences the conformation of the complex so that the binding site of GSMs is either stabilized or less favorable to influence the cleavage of the respective substrates.
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Affiliation(s)
- Sarah A Sagi
- Department of Neurosciences, University of California San Diego, La Jolla, California 92093, USA
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Zall A, Kieser D, Höttecke N, Naumann EC, Thomaszewski B, Schneider K, Steinbacher DT, Schubenel R, Masur S, Baumann K, Schmidt B. NSAID-derived γ-secretase modulation requires an acidic moiety on the carbazole scaffold. Bioorg Med Chem 2011; 19:4903-9. [PMID: 21763147 DOI: 10.1016/j.bmc.2011.06.062] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 06/21/2011] [Accepted: 06/22/2011] [Indexed: 01/04/2023]
Abstract
Modulation of γ-secretase activity holds potential for the treatment of Alzheimer's disease. Most NSAID-derived γ-secretase modulators feature a carboxylic acid, which may impair blood-brain barrier permeation. The structure activity relationship of 33 carbazoles featuring diverse carboxylic acid isosteres or metabolic precursors thereof was established in a cellular amyloid secretion assay. The modulatory activity was observed for acidic moieties and metabolically labile esters only, which supports our hypothesis of an acid-lysine interaction to be relevant for this type of γ-secretase modulators.
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Affiliation(s)
- Andrea Zall
- Clemens Schöpf-Institute of Chemistry and Biochemistry, Technische Universität Darmstadt, Petersenstr. 22, Darmstadt D-64287, Germany
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Affiliation(s)
- Joshua D Grill
- Department of Neurology, Mary S, Easton Center for Alzheimer's Disease Research, David Geffen School of Medicine at UCLA, 10911 Weyburn Avenue, Suite 200, Los Angeles, CA 90095-07226, USA.
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