151
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Al-Atrache Z, Lopez DB, Hingley ST, Appelt DM. Astrocytes infected with Chlamydia pneumoniae demonstrate altered expression and activity of secretases involved in the generation of β-amyloid found in Alzheimer disease. BMC Neurosci 2019; 20:6. [PMID: 30786875 PMCID: PMC6383264 DOI: 10.1186/s12868-019-0489-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/12/2019] [Indexed: 12/12/2022] Open
Abstract
Background Epidemiologic studies strongly suggest that the pathophysiology of late-onset Alzheimer disease (AD) versus early-onset AD has environmental rather than genetic causes, thus revealing potentially novel therapeutic targets to limit disease progression. Several studies supporting the “pathogen hypothesis” of AD demonstrate a strong association between pathogens and the production of β-amyloid, the pathologic hallmark of AD. Although the mechanism of pathogen-induced neurodegeneration of AD remains unclear, astrocytes, a key player of the CNS innate immune response and producer/metabolizer of β-amyloid, have been implicated. We hypothesized that Chlamydia pneumoniae infection of human astrocytes alters the expression of the amyloid precursor protein (APP)-processing secretases, ADAM10, BACE1, and PSEN1, to promote β-amyloid formation. Utilizing immunofluorescent microscopy, molecular, and biochemical approaches, these studies explore the role of an intracellular respiratory pathogen, Chlamydia pneumoniae, as an environmental trigger for AD pathology. Human astrocytoma cells in vitro were infected with Chlamydia pneumoniae over the course of 6–72 h. The gene and protein expression, as well as the enzymatic activity of non-amyloidogenic (ADAM10), and pro-amyloidogenic (BACE1 and PSEN1) secretases were qualitatively and quantitatively assessed. In addition, the formation of toxic amyloid products as an outcome of pro-amyloidogenic APP processing was evaluated through various modalities. Results Chlamydia pneumoniae infection of human astrocytoma cells promoted the transcriptional upregulation of numerous genes implicated in host neuroinflammation, lipid homeostasis, microtubule function, and APP processing. Relative to that of uninfected astrocytes, BACE1 and PSEN1 protein levels were enhanced by nearly twofold at 48–72 h post-Chlamydia pneumoniae infection. The processing of APP in Chlamydia pneumoniae-infected astrocytes favors the pro-amyloidogenic pathway, as demonstrated by an increase in enzymatic activity of BACE1, while that of ADAM10 was decreased. Fluorescence intensity of β-amyloid and ELISA-quantified levels of soluble-APP by products revealed temporally similar increases, confirming a BACE1/PSEN1-mediated processing of APP. Conclusions Our findings suggest that Chlamydia pneumoniae infection of human astrocytes promotes the pro-amyloidogenic pathway of APP processing through the upregulation of expression and activity of β-secretase, upregulated expression of γ-secretase, and decreased activity of α-secretase. These effects of astrocyte infection provide evidence for a direct link between Chlamydia pneumoniae and AD pathology. Electronic supplementary material The online version of this article (10.1186/s12868-019-0489-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zein Al-Atrache
- Department of Bio-Medical Sciences, Center for Chronic Disorders of Aging, Philadelphia College of Osteopathic Medicine, 4170 City Avenue, Philadelphia, PA, 19131, USA
| | - Danielle B Lopez
- Department of Bio-Medical Sciences, Center for Chronic Disorders of Aging, Philadelphia College of Osteopathic Medicine, 4170 City Avenue, Philadelphia, PA, 19131, USA
| | - Susan T Hingley
- Department of Bio-Medical Sciences, Center for Chronic Disorders of Aging, Philadelphia College of Osteopathic Medicine, 4170 City Avenue, Philadelphia, PA, 19131, USA
| | - Denah M Appelt
- Department of Bio-Medical Sciences, Center for Chronic Disorders of Aging, Philadelphia College of Osteopathic Medicine, 4170 City Avenue, Philadelphia, PA, 19131, USA.
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152
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Alves da Costa C, Duplan E, Rouland L, Checler F. The Transcription Factor Function of Parkin: Breaking the Dogma. Front Neurosci 2019; 12:965. [PMID: 30697141 PMCID: PMC6341214 DOI: 10.3389/fnins.2018.00965] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 12/03/2018] [Indexed: 01/19/2023] Open
Abstract
PRKN (PARK2) is a key gene involved in both familial and sporadic Parkinson’s disease that encodes parkin (PK). Since its discovery by the end of the 90s, both functional and more recently, structural studies led to a consensual view of PK as an E3 ligase only. It is generally considered that this function conditions the cellular load of a subset of cytosolic proteins prone to proteasomal degradation and that a loss of E3 ligase function triggers an accumulation of potentially toxic substrates and, consequently, a neuronal loss. Furthermore, PK molecular interplay with PTEN-induced kinase 1 (PINK1), a serine threonine kinase also involved in recessive cases of Parkinson’s disease, is considered to underlie the mitophagy process. Thus, since mitochondrial homeostasis significantly governs cell health, there is a huge interest of the scientific community centered on PK function. In 2009, we have demonstrated that PK could also act as a transcription factor (TF) and induces neuroprotection via the downregulation of the pro-apoptotic and tumor suppressor factor, p53. Importantly, the DNA-binding properties of PK and its nuclear localization suggested an important role in the control of several genes. The duality of PK subcellular localization and of its associated ubiquitin ligase and TF functions suggests that PK could behave as a key molecular modulator of various physiological cellular signaling pathways that could be disrupted in pathological contexts. Here, we update the current knowledge on PK direct and indirect TF-mediated control of gene expression.
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Affiliation(s)
- Cristine Alves da Costa
- Université Côte d'Azur, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, IPMC, Team Labeled "Laboratory of Excellence (LABEX) DistAlz", Valbonne, France
| | - Eric Duplan
- Université Côte d'Azur, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, IPMC, Team Labeled "Laboratory of Excellence (LABEX) DistAlz", Valbonne, France
| | - Lila Rouland
- Université Côte d'Azur, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, IPMC, Team Labeled "Laboratory of Excellence (LABEX) DistAlz", Valbonne, France
| | - Frédéric Checler
- Université Côte d'Azur, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, IPMC, Team Labeled "Laboratory of Excellence (LABEX) DistAlz", Valbonne, France
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153
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Mueed Z, Tandon P, Maurya SK, Deval R, Kamal MA, Poddar NK. Tau and mTOR: The Hotspots for Multifarious Diseases in Alzheimer's Development. Front Neurosci 2019; 12:1017. [PMID: 30686983 PMCID: PMC6335350 DOI: 10.3389/fnins.2018.01017] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 12/17/2018] [Indexed: 12/14/2022] Open
Abstract
The hyperphosphorylation of tau protein and the overexpression of mTOR are considered to be the driving force behind Aβ plaques and Neurofibrillay Tangles (NFT's), hallmarks of Alzheimer's disease (AD). It is now evident that miscellaneous diseases such as Diabetes, Autoimmune diseases, Cancer, etc. are correlated with AD. Therefore, we reviewed the literature on the causes of AD and investigated the association of tau and mTOR with other diseases. We have discussed the role of insulin deficiency in diabetes, activated microglial cells, and dysfunction of blood-brain barrier (BBB) in Autoimmune diseases, Presenilin 1 in skin cancer, increased reactive species in mitochondrial dysfunction and deregulated Cyclins/CDKs in promoting AD pathogenesis. We have also discussed the possible therapeutics for AD such as GSK3 inactivation therapy, Rechaperoning therapy, Immunotherapy, Hormonal therapy, Metal chelators, Cell cycle therapy, γ-secretase modulators, and Cholinesterase and BACE 1-inhibitors which are thought to serve a major role in combating pathological changes coupled with AD. Recent research about the relationship between mTOR and aging and hepatic Aβ degradation offers possible targets to effectively target AD. Future prospects of AD aims at developing novel drugs and modulators that can potentially improve cell to cell signaling, prevent Aβ plaques formation, promote better release of neurotransmitters and prevent hyperphosphorylation of tau.
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Affiliation(s)
- Zeba Mueed
- Department of Biotechnology, Invertis University, Bareilly, India
| | - Pallavi Tandon
- Department of Biotechnology, Invertis University, Bareilly, India
| | | | - Ravi Deval
- Department of Biotechnology, Invertis University, Bareilly, India
| | - Mohammad A Kamal
- King Fahad Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.,Enzymoics, Hebersham, NSW, Australia.,Novel Global Community Educational Foundation, Hebersham, NSW, Australia
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154
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Li CD, Junaid M, Chen H, Ali A, Wei DQ. Helix-Switch Enables C99 Dimer Transition between the Multiple Conformations. J Chem Inf Model 2019; 59:339-350. [PMID: 30570254 DOI: 10.1021/acs.jcim.8b00559] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
C99 is the immediate precursor of amyloid-β (Aβ) and therefore is a central intermediate in the pathway that is believed to result in Alzheimer's disease (AD). Recent studies have shown that C99 dimerization changes the Aβ ratio, but the mechanism remains unclear. Previous studies of the C99 dimer have produced controversial structure models. To address these questions, we investigated C99 dimerization using molecular dynamics (MD) simulations. A helix-switch model was revealed in the formation and transition of the C99 dimer, and six types of conformations were identified. The different conformations show differential exposures of γ-cleavage sites and insertion depths in the bilayer, which may modulate γ-cleavage of C99 and lead to different Aβ levels. Our results redefine C99 dimerization, provide a framework to mediate the current controversial results, and give insights into the understanding of the relationship between C99 dimerization and Aβ formation.
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Affiliation(s)
- Cheng-Dong Li
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China.,Department of Mechanical Engineering and Material Science , Yale University , New Haven , Connecticut 06520-8286 , United States
| | - Muhammad Junaid
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
| | - Hui Chen
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
| | - Arif Ali
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
| | - Dong-Qing Wei
- State Key Laboratory of Microbial Metabolism and College of Life Sciences and Biotechnology , Shanghai Jiao Tong University , Minhang District, Shanghai 200240 , China
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155
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Hitzenberger M, Zacharias M. γ-Secretase Studied by Atomistic Molecular Dynamics Simulations: Global Dynamics, Enzyme Activation, Water Distribution and Lipid Binding. Front Chem 2019; 6:640. [PMID: 30662893 PMCID: PMC6328467 DOI: 10.3389/fchem.2018.00640] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/07/2018] [Indexed: 11/14/2022] Open
Abstract
γ-secretase, an intramembrane-cleaving aspartyl protease is involved in the cleavage of a large number of intramembrane proteins. The most prominent substrate is the amyloid precursor protein, whose proteolytic processing leads to the production of different amyloid Aβ peptides. These peptides are known to form toxic aggregates and may play a key role in Alzheimer's disease (AD). Recently, the three-dimensional structure of γ-secretase has been determined via Cryo-EM, elucidating the spatial geometry of this enzyme complex in different functional states. We have used molecular dynamics (MD) simulations to study the global dynamics and conformational transitions of γ-secretase, as well as the water and lipid distributions in and around the transmembrane domains in atomic detail. Simulations were performed on the full enzyme complex and on the membrane embedded parts alone. The simulations revealed global motions compatible with the experimental enzyme structures and indicated little dependence of the dynamics of the transmembrane domains on the soluble extracellular subunits. During the simulation on the membrane spanning part a transition between an inactive conformation (with catalytic residues far apart) toward a putatively active form (with catalytic residues in close proximity) has been observed. This conformational change is associated with a distinct rearrangement of transmembrane helices, a global compaction of the catalytically active presenilin subunit a change in the water structure near the active site and a rigidification of the protein fold. The observed conformational rearrangement allows the interpretation of the effect of several mutations on the activity of γ-secretase. A number of long-lived lipid binding sites could be identified on the membrane spanning surface of γ-secretase which may coincide with association regions of hydrophobic membrane helices to form putative substrate binding exosites.
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Affiliation(s)
| | - Martin Zacharias
- Physics Department T38, Technical University of Munich, Garching, Germany
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156
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Futai E. Advanced Yeast Models of Familial Alzheimer Disease Expressing FAD-Linked Presenilin to Screen Mutations and γ-Secretase Modulators. Methods Mol Biol 2019; 2049:403-417. [PMID: 31602624 DOI: 10.1007/978-1-4939-9736-7_23] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
γ-Secretase is a multisubunit membrane protein complex containing catalytic presenilin (PS1 or PS2) and cofactors such as nicastrin, Aph-1, and Pen2. γ-Secretase hydrolyzes the transmembrane domains of type-I membrane proteins, which include the amyloid precursor protein (APP). APP is cleaved by γ-secretase to produce amyloid β peptide (Aβ), which is deposited in the brains of Alzheimer disease patients. However, the mechanism of this unusual proteolytic process within the lipid bilayer remains unknown. We have established a yeast transcriptional activator Gal4p system with artificial γ-secretase substrates containing APP or Notch fragments to examine the enzymatic properties of γ-secretase. The γ-secretase activities were evaluated by transcriptional activation of reporter genes upon Gal4 release from the membrane bound substrates as assessed by growth of yeast or β-galactosidase assay. We also established an in vitro yeast microsome assay system which identified different Aβ species produced by trimming. The yeast system allows for the screening of mutations and chemicals that inhibit or modulate γ-secretase activity. Herein we describe the genetic and biochemical methods used to analyze γ-secretase activity using the yeast reconstitution system. By studying the loss-of-function properties of PS1 mutants, it is possible to successfully screen FAD suppressor mutations and identify γ-secretase modulators (GSMs), which are promising Alzheimer disease therapeutic agents.
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Affiliation(s)
- Eugene Futai
- Department of Molecular and Cell Biology, Graduate School of Agricultural Sciences, Tohoku University, Sendai, Miyagi, Japan.
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157
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Stoychev KR, Stoimenova-Popova M, Chumpalova P, Ilieva L, Swamad M, Kamburova-Martinova Z. A Clinical Case of Patient Carrying Rare Pathological PSEN1 Gene Mutation (L424V) Demonstrates the Phenotypic Heterogenity of Early Onset Familial AD. Front Psychiatry 2019; 10:857. [PMID: 31920735 PMCID: PMC6918796 DOI: 10.3389/fpsyt.2019.00857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 10/31/2019] [Indexed: 12/22/2022] Open
Abstract
Dementia comprises several neurodegenerative disorders with similar neuropsychiatric features and Alzheimer's disease (AD) is the most common of them. Genetic factors are strongly implicated into its etiology especially for early-onset cases (EOAD) occuring before the age of 65. About 10% of these are inherited in autosomal dominant fashion via pathogenic polymorphisms in three genes- APP, PSEN-1, and PSEN-2. Despite genotypic clarity, however, phenotypic variability exists with different symptom constellations observed in patients with identical mutations. Below, we present a case of a 39-year-old male with a family history for early onset dementia who was referred to our department with anamnesis for abrupt behavioral change 7 months prior to hospitalization-noticeable slowing of speech and reactivity, impaired occupational functioning and irritability, followed by aphasic symptoms and transient episodes of disorientation. He was followed up for 2 years and manifested rapidly progressing cognitive decline with further deterioration of speech, apraxia, acalculia, ataxia, and subsequently bradykinesia and tremor. Based on the clinical and neuroimaging findings (severe cortical atrophy), familial EOAD was suspected and a whole exome sequence (WES) analysis was performed. It identified a heterozygous missense variant Leu424Val (g.71074C > G) in PSEN-1 gene considered to be pathogenic, and only reported once until now in a Spanish patient in 2009. Despite genotype identity however, distinct phenotypic presentations were observed in the two affected subjects, with different neuroimaging findings, and the presence and absence of seizures in the Spanish and Bulgarian case, respectively. Besides, myoclonus and spastic paraparesis considered "typical" EOAD clinical features were absent. Age of symptom onset was consistent with two of the reported mutations affecting 424 codon of PSEN-1 gene and significantly earlier than the other two implying that factors influencing activity of PSEN-1 pathological forms are yet to be clarified. Furthermore, our patient had co-occurring lupus erythematosus (LE) and we suggest that this condition might be etiologically linked to the PSEN-1 mutation. In addition to illustrating the symptomatic heterogeneity of PSEN-1 caused EOAD, our study confirms that in patients presenting with early cognitive deterioration and family history for dementia, WES can be especially informative and should be considered as a first-line examination.
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Affiliation(s)
| | | | | | - Lilia Ilieva
- Department of Neurology, Sveti Panteleimon Hospital, Pleven, Bulgaria
| | - Mohamed Swamad
- Department of Health and Aging Unit, King's College Hospital, London, United Kingdom
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158
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Sharma P, Srivastava P, Seth A, Tripathi PN, Banerjee AG, Shrivastava SK. Comprehensive review of mechanisms of pathogenesis involved in Alzheimer's disease and potential therapeutic strategies. Prog Neurobiol 2018; 174:53-89. [PMID: 30599179 DOI: 10.1016/j.pneurobio.2018.12.006] [Citation(s) in RCA: 207] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 12/04/2018] [Accepted: 12/28/2018] [Indexed: 12/14/2022]
Abstract
AD is a progressive neurodegenerative disorder and a leading cause of dementia in an aging population worldwide. The enormous challenge which AD possesses to global healthcare makes it as urgent as ever for the researchers to develop innovative treatment strategies to fight this disease. An in-depth analysis of the extensive available data associated with the AD is needed for a more comprehensive understanding of underlying molecular mechanisms and pathophysiological pathways associated with the onset and progression of the AD. The currently understood pathological and biochemical manifestations include cholinergic, Aβ, tau, excitotoxicity, oxidative stress, ApoE, CREB signaling pathways, insulin resistance, etc. However, these hypotheses have been criticized with several conflicting reports for their involvement in the disease progression. Several issues need to be addressed such as benefits to cost ratio with cholinesterase therapy, the dilemma of AChE selectivity over BChE, BBB permeability of peptidic BACE-1 inhibitors, hurdles related to the implementation of vaccination and immunization therapy, and clinical failure of candidates related to newly available targets. The present review provides an insight to the different molecular mechanisms involved in the development and progression of the AD and potential therapeutic strategies, enlightening perceptions into structural information of conventional and novel targets along with the successful applications of computational approaches for the design of target-specific inhibitors.
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Affiliation(s)
- Piyoosh Sharma
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Pavan Srivastava
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Ankit Seth
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Prabhash Nath Tripathi
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Anupam G Banerjee
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Sushant K Shrivastava
- Pharmaceutical Chemistry Research Laboratory, Department of Pharmaceutical Engineering & Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, India.
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159
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Abstract
β-amyloid is regarded by some scientists to be the cause of Alzheimer’s disease (AD). One of the strongest arguments against this hypothesis is the presence of hundreds of AD-causing mutations in presenilin, but none in the other three components of γ-secretase. This observation implies a γ-secretase–independent function of presenilin. To understand such a putative function, discovery of presenilin-binding proteins represents an important first step. In this study, we report the identification of Bax-inhibitor 1 (BI1) as a stable interacting partner of presenilin 1 (PS1), but not the intact γ-secretase. Our results link PS1 to BI1, a protein thought to play a role in apoptosis and calcium channel regulation. This finding opens a range of possibilities for the investigation of PS1 function and AD genesis. Presenilin is the catalytic subunit of γ-secretase, a four-component intramembrane protease responsible for the generation of β-amyloid (Aβ) peptides. Over 200 Alzheimer’s disease-related mutations have been identified in presenilin 1 (PS1) and PS2. Here, we report that Bax-inhibitor 1 (BI1), an evolutionarily conserved transmembrane protein, stably associates with PS1. BI1 specifically interacts with PS1 in isolation, but not with PS1 in the context of an assembled γ-secretase. The PS1–BI1 complex exhibits no apparent proteolytic activity, as judged by the inability to produce Aβ40 and Aβ42 from the substrate APP-C99. At an equimolar concentration, BI1 has no impact on the proteolytic activity of γ-secretase; at a 200-fold molar excess, BI1 reduces γ-secretase activity nearly by half. Our biochemical study identified BI1 as a PS1-interacting protein, suggesting additional functions of PS1 beyond its involvement in γ-secretase.
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160
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Lopez-Font I, Iborra-Lazaro G, Sánchez-Valle R, Molinuevo JL, Cuchillo-Ibañez I, Sáez-Valero J. CSF-ApoER2 fragments as a read-out of reelin signaling: Distinct patterns in sporadic and autosomal-dominant Alzheimer disease. Clin Chim Acta 2018; 490:6-11. [PMID: 30552869 DOI: 10.1016/j.cca.2018.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/11/2018] [Indexed: 01/06/2023]
Abstract
Reelin is a glycoprotein associated with synaptic plasticity and neurotransmission. The malfunctioning of reelin signaling in the brain is likely to contribute to the pathogenesis of Alzheimer's disease (AD). Reelin binding to Apolipoprotein E receptor 2 (ApoER2) activates downstream signaling and induces the proteolytic cleavage of ApoER2, resulting in the generation of soluble fragments. To evaluate the efficiency of reelin signaling in AD, we have quantified the levels of reelin and soluble ectodomain fragments of ApoER2 (ectoApoER2) in the cerebrospinal fluid (CSF). CSF from sporadic AD patients (sAD; n = 14, age 54-83 years) had lower levels of ecto-ApoER2 (~31% reduction; p = .005) compared to those in the age-matched controls (n = 10, age 61-80), and a higher reelin/ecto-ApoER2 ratio. In contrast, autosomal dominant AD patients, carriers of PSEN1 mutations (ADAD; n = 7, age 31-49 years) had higher ecto-ApoER2 levels (~109% increment; p = .001) and a lower reelin/ecto-ApoER2 ratio than the non-mutation carriers from the same families (n = 7, age 25-47 years). Our data suggest that the levels of ecto-ApoER2 in CSF could be a suitable read-out of an impaired reelin signaling in AD, but also indicate differences between sAD and ADAD.
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Affiliation(s)
- Inmaculada Lopez-Font
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 Sant Joan d'Alacant, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Guillermo Iborra-Lazaro
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 Sant Joan d'Alacant, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Raquel Sánchez-Valle
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, 08036 Barcelona, Spain
| | - José-Luis Molinuevo
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, 08036 Barcelona, Spain
| | - Inmaculada Cuchillo-Ibañez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 Sant Joan d'Alacant, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain.
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, 03550 Sant Joan d'Alacant, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain.
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161
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Cao J, Hou J, Ping J, Cai D. Advances in developing novel therapeutic strategies for Alzheimer's disease. Mol Neurodegener 2018; 13:64. [PMID: 30541602 PMCID: PMC6291983 DOI: 10.1186/s13024-018-0299-8] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's Disease (AD), the most prevalent neurodegenerative disease of aging, affects one in eight older Americans. Nearly all drug treatments tested for AD today have failed to show any efficacy. There is a great need for therapies to prevent and/or slow the progression of AD. The major challenge in AD drug development is lack of clarity about the mechanisms underlying AD pathogenesis and pathophysiology. Several studies support the notion that AD is a multifactorial disease. While there is abundant evidence that amyloid plays a role in AD pathogenesis, other mechanisms have been implicated in AD such as tangle formation and spread, dysregulated protein degradation pathways, neuroinflammation, and loss of support by neurotrophic factors. Therefore, current paradigms of AD drug design have been shifted from single target approach (primarily amyloid-centric) to developing drugs targeted at multiple disease aspects, and from treating AD at later stages of disease progression to focusing on preventive strategies at early stages of disease development. Here, we summarize current strategies and new trends of AD drug development, including pre-clinical and clinical trials that target different aspects of disease (mechanism-based versus non-mechanism based, e.g. symptomatic treatments, lifestyle modifications and risk factor management).
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Affiliation(s)
- Jiqing Cao
- James J Peters VA Medical Center, Research & Development, Bronx, NY 10468 USA
- Department of Neurology, Alzheimer Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- The Central Hospital of The Hua Zhong University of Science and Technology, Wuhan, China
| | - Jianwei Hou
- James J Peters VA Medical Center, Research & Development, Bronx, NY 10468 USA
- Department of Neurology, Alzheimer Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Jing Ping
- The Central Hospital of The Hua Zhong University of Science and Technology, Wuhan, China
| | - Dongming Cai
- James J Peters VA Medical Center, Research & Development, Bronx, NY 10468 USA
- Department of Neurology, Alzheimer Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- The Central Hospital of The Hua Zhong University of Science and Technology, Wuhan, China
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162
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Aguayo-Ortiz R, Straub JE, Dominguez L. Influence of membrane lipid composition on the structure and activity of γ-secretase. Phys Chem Chem Phys 2018; 20:27294-27304. [PMID: 30357233 PMCID: PMC11260083 DOI: 10.1039/c8cp04138e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
γ-Secretase (GS) is a multi-subunit membrane-embedded aspartyl protease that cleaves more than 80 integral membrane proteins, including the amyloid precursor protein (APP) to produce the amyloid-β (Aβ) peptide. Oligomerization and aggregation of the 42-amino acid length Aβ isoform in the brain has been associated with the development and progression of Alzheimer's disease (AD). Based on recent experimental structural studies and using multiscale computational modeling approaches, the conformational states and protein-membrane interactions of the GS complex embedded in six homogeneous and six heterogeneous lipid bilayers were characterized. In order to identify potential lipid and cholesterol binding sites, GS regions with high lipid/cholesterol occupancy values were analyzed using atomistic and coarse-grained simulations. Long lipid residence times were observed to be correlated with a large number of hydrogen bonds between the charged headgroups and key GS amino acids. This observation provides a plausible explanation for the inhibition of GS by charged lipids observed in previous experimental studies. Computed lateral pressure profiles suggest that higher transmembrane pressures favor active state conformations of the catalytic subunit. A probable mechanism for the regulation of the local stress response in cholesterol-rich multicomponent lipid bilayers is identified. Finally, it is demonstrated that interactions between the nicastrin extracellular domain and lipid headgroups leads to a compact structural conformation of the GS complex. Overall, this study provides valuable insight into the effect of bilayer lipid composition on the GS structural ensemble and its function.
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Affiliation(s)
- Rodrigo Aguayo-Ortiz
- Facultad de Química, Departamento de Fisicoquímica, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico.
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163
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Steiner H, Fukumori A, Tagami S, Okochi M. Making the final cut: pathogenic amyloid-β peptide generation by γ-secretase. Cell Stress 2018; 2:292-310. [PMID: 31225454 PMCID: PMC6551803 DOI: 10.15698/cst2018.11.162] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alzheimer´s disease (AD) is a devastating neurodegenerative disease of the elderly population. Genetic evidence strongly suggests that aberrant generation and/or clearance of the neurotoxic amyloid-β peptide (Aβ) is triggering the disease. Aβ is generated from the amyloid precursor protein (APP) by the sequential cleavages of β- and γ-secretase. The latter cleavage by γ-secretase, a unique and fascinating four-component protease complex, occurs in the APP transmembrane domain thereby releasing Aβ species of 37-43 amino acids in length including the longer, highly pathogenic peptides Aβ42 and Aβ43. The lack of a precise understanding of Aβ generation as well as of the functions of other γ-secretase substrates has been one factor underlying the disappointing failure of γ-secretase inhibitors in clinical trials, but on the other side also been a major driving force for structural and in depth mechanistic studies on this key AD drug target in the past few years. Here we review recent breakthroughs in our understanding of how the γ-secretase complex recognizes substrates, of how it binds and processes β-secretase cleaved APP into different Aβ species, as well as the progress made on a question of outstanding interest, namely how clinical AD mutations in the catalytic subunit presenilin and the γ-secretase cleavage region of APP lead to relative increases of Aβ42/43. Finally, we discuss how the knowledge emerging from these studies could be used to therapeutically target this enzyme in a safe way.
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Affiliation(s)
- Harald Steiner
- Biomedical Center (BMC), Metabolic Biochemistry, Ludwig-Maximilians-University Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Akio Fukumori
- Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu & Department of Mental Health Promotion, Osaka University Graduate School of Medicine, Toyonaka, Japan
| | - Shinji Tagami
- Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Masayasu Okochi
- Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
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164
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Moir RD, Lathe R, Tanzi RE. The antimicrobial protection hypothesis of Alzheimer's disease. Alzheimers Dement 2018; 14:1602-1614. [DOI: 10.1016/j.jalz.2018.06.3040] [Citation(s) in RCA: 222] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 06/22/2018] [Indexed: 12/31/2022]
Affiliation(s)
- 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 USA
| | - Richard Lathe
- Division of Infection and Pathway Medicine; University of Edinburgh; Little France Edinburgh UK
| | - 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 USA
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165
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Podder A, Pandit M, Narayanan L. Drug Target Prioritization for Alzheimer's Disease Using Protein Interaction Network Analysis. ACTA ACUST UNITED AC 2018; 22:665-677. [DOI: 10.1089/omi.2018.0131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Avijit Podder
- Bioinformatics Infrastructure Facility, Sri Venkateswara College (University of Delhi), Delhi, India
| | - Mansi Pandit
- Bioinformatics Infrastructure Facility, Sri Venkateswara College (University of Delhi), Delhi, India
| | - Latha Narayanan
- Bioinformatics Infrastructure Facility, Sri Venkateswara College (University of Delhi), Delhi, India
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166
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Kael MA, Weber DK, Separovic F, Sani MA. Aggregation kinetics in the presence of brain lipids of Aβ(1–40) cleaved from a soluble fusion protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [DOI: 10.1016/j.bbamem.2018.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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167
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Verheijen BM, Stevens JAA, Gentier RJG, van 't Hekke CD, van den Hove DLA, Hermes DJHP, Steinbusch HWM, Ruijter JM, Grimm MOW, Haupenthal VJ, Annaert W, Hartmann T, van Leeuwen FW. Paradoxical effects of mutant ubiquitin on Aβ plaque formation in an Alzheimer mouse model. Neurobiol Aging 2018; 72:62-71. [PMID: 30216939 DOI: 10.1016/j.neurobiolaging.2018.08.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 07/03/2018] [Accepted: 08/10/2018] [Indexed: 01/08/2023]
Abstract
Amyloid-β (Aβ) plaques are a prominent pathological hallmark of Alzheimer's disease (AD). They consist of aggregated Aβ peptides, which are generated through sequential proteolytic processing of the transmembrane protein amyloid precursor protein (APP) and several Aβ-associated factors. Efficient clearance of Aβ from the brain is thought to be important to prevent the development and progression of AD. The ubiquitin-proteasome system (UPS) is one of the major pathways for protein breakdown in cells and it has been suggested that impaired UPS-mediated removal of protein aggregates could play an important role in the pathogenesis of AD. To study the effects of an impaired UPS on Aβ pathology in vivo, transgenic APPSwe/PS1ΔE9 mice (APPPS1) were crossed with transgenic mice expressing mutant ubiquitin (UBB+1), a protein-based inhibitor of the UPS. Surprisingly, the APPPS1/UBB+1 crossbreed showed a remarkable decrease in Aβ plaque load during aging. Further analysis showed that UBB+1 expression transiently restored PS1-NTF expression and γ-secretase activity in APPPS1 mice. Concurrently, UBB+1 decreased levels of β-APP-CTF, which is a γ-secretase substrate. Although UBB+1 reduced Aβ pathology in APPPS1 mice, it did not improve the behavioral deficits in these animals.
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Affiliation(s)
- Bert M Verheijen
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Jo A A Stevens
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Romina J G Gentier
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Christian D van 't Hekke
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Daniel L A van den Hove
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands; Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - Denise J H P Hermes
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Harry W M Steinbusch
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Jan M Ruijter
- Department of Medical Biology, Academic Medical Center, Amsterdam, The Netherlands
| | - Marcus O W Grimm
- Deutsches Institut für Demenzprävention, University of Saarland, Experimental Neurology, Homburg, Germany
| | - Viola J Haupenthal
- Deutsches Institut für Demenzprävention, University of Saarland, Experimental Neurology, Homburg, Germany
| | - Wim Annaert
- VIB Center for Brain and Disease Research and KU Leuven, Gasthuisberg, Belgium
| | - Tobias Hartmann
- Deutsches Institut für Demenzprävention, University of Saarland, Experimental Neurology, Homburg, Germany
| | - Fred W van Leeuwen
- Department of Psychiatry and Neuropsychology, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands.
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168
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Inoue K, Oliveira LMA, Abeliovich A. CRISPR Transcriptional Activation Analysis Unmasks an Occult γ-Secretase Processivity Defect in Familial Alzheimer's Disease Skin Fibroblasts. Cell Rep 2018; 21:1727-1736. [PMID: 29141208 DOI: 10.1016/j.celrep.2017.10.075] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/10/2017] [Accepted: 10/17/2017] [Indexed: 12/31/2022] Open
Abstract
Mutations in presenilin (PSEN) 1 and 2, which encode components of the γ-secretase (GS) complex, cause familial Alzheimer's disease (FAD). It is hypothesized that altered GS-mediated processing of the amyloid precursor protein (APP) to the Aβ42 fragment, which is accumulated in diseased brain, may be pathogenic. Here, we describe an in vitro model system that enables the facile analysis of neuronal disease mechanisms in non-neuronal patient cells using CRISPR gene activation of endogenous disease-relevant genes. In FAD patient-derived fibroblast cultures, CRISPR activation of APP or BACE unmasked an occult processivity defect in downstream GS-mediated carboxypeptidase cleavage of APP, ultimately leading to higher Aβ42 levels. These data suggest that, selectively in neurons, relatively high levels of BACE1 activity lead to substrate pressure on FAD-mutant GS complexes, promoting CNS Aβ42 accumulation. Our results introduce an additional platform for analysis of neurological disease.
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Affiliation(s)
- Keiichi Inoue
- Department of Pathology, Cell Biology and Neurology, Taub Institute, Columbia University Medical Center, 650 West 168th St., New York, NY 10032, USA.
| | - Luis M A Oliveira
- Department of Pathology, Cell Biology and Neurology, Taub Institute, Columbia University Medical Center, 650 West 168th St., New York, NY 10032, USA
| | - Asa Abeliovich
- Department of Pathology, Cell Biology and Neurology, Taub Institute, Columbia University Medical Center, 650 West 168th St., New York, NY 10032, USA.
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169
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Watts JC, Prusiner SB. β-Amyloid Prions and the Pathobiology of Alzheimer's Disease. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a023507. [PMID: 28193770 DOI: 10.1101/cshperspect.a023507] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease in humans and will pose a considerable challenge to healthcare systems in the coming years. Aggregation of the β-amyloid (Aβ) peptide within the brain is thought to be an initiating event in AD pathogenesis. Many recent studies in transgenic mice have provided evidence that Aβ aggregates become self-propagating during disease, leading to a cascade of protein aggregation in the brain, which may underlie the progressive nature of AD. The ability to self-propagate and the existence of distinct "strains" reveals that Aβ aggregates exhibit many properties indistinguishable from those of prions composed of PrPSc proteins. Here, we review the evidence that Aβ can become a prion during disease and discuss how Aβ prions may be important for understanding the pathobiology of AD.
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Affiliation(s)
- Joel C Watts
- Tanz Centre for Research in Neurodegenerative Diseases and Department of Biochemistry, University of Toronto, Toronto, Ontario M5T 2S8, Canada
| | - Stanley B Prusiner
- Institute for Neurodegenerative Diseases, Departments of Neurology and of Biochemistry and Biophysics, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California 94143
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170
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Wolfe MS. Dysfunctional γ-Secretase in Familial Alzheimer's Disease. Neurochem Res 2018; 44:5-11. [PMID: 29619615 PMCID: PMC6592691 DOI: 10.1007/s11064-018-2511-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 03/19/2018] [Indexed: 12/24/2022]
Abstract
Genetics strongly implicate the amyloid β-peptide (Aβ) in the pathogenesis of Alzheimer's disease. Dominant missense mutation in the presenilins and the amyloid precursor protein (APP) cause early-onset familial Alzheimer's disease (FAD). As presenilin is the catalytic component of the γ-secretase protease complex that produces Aβ from APP, mutation of the enzyme or substrate that produce Aβ leads to FAD. However, the mechanism by which presenilin mutations cause FAD has been controversial, with gain of function and loss of function offered as binary choices. This overview will instead present the case that presenilins are dysfunctional in FAD. γ-Secretase is a multi-functional enzyme that proteolyzes the APP transmembrane domain in a complex and processive manner. Reduction in a specific function-the carboxypeptidase trimming of initially formed long Aβ peptides containing most of the transmembrane domain to shorter secreted forms-is an emerging common feature of FAD-mutant γ-secretase complexes.
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Affiliation(s)
- Michael S Wolfe
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, 66045, USA.
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171
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Hussain G, Zhang L, Rasul A, Anwar H, Sohail MU, Razzaq A, Aziz N, Shabbir A, Ali M, Sun T. Role of Plant-Derived Flavonoids and Their Mechanism in Attenuation of Alzheimer's and Parkinson's Diseases: An Update of Recent Data. Molecules 2018; 23:E814. [PMID: 29614843 PMCID: PMC6017497 DOI: 10.3390/molecules23040814] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/25/2018] [Accepted: 03/27/2018] [Indexed: 12/13/2022] Open
Abstract
Neurodegeneration is a progressive loss of neuronal cells in certain regions of the brain. Most of the neurodegenerative disorders (NDDs) share the communal characteristic such as damage or reduction of various cell types typically including astrocytes and microglial activity. Several compounds are being trialed to treat NDDs but they possess solitary symptomatic advantages along with copious side effects. The finding of more enthralling and captivating compounds to suspend and standstill the pathology of NDDs will be considered as a hallmark of present times. Phytochemicals possess the potential to alternate the synthetic line of therapy against NDDs. The present review explores the potential efficacy of plant-derived flavonoids against most common NDDs including Alzheimer's disease (AD) and Parkinson's disease (PD). Flavonoids are biologically active phytochemicals which possess potential pharmacological effects, including antiviral, anti-allergic, antiplatelet, anti-inflammatory, anti-tumor, anti-apoptotic and anti-oxidant effects and are able to attenuate the pathology of various NDDs through down-regulating the nitric oxide (NO) production, by reducing the tumor necrosis factor-α (TNF-α), by reducing the excitotoxicity of superoxide as well as acting as tyrosine kinase (TK) and monoamine oxidase (MAO) inhibiting enzyme.
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Affiliation(s)
- Ghulam Hussain
- Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Longbin Zhang
- Center for Precision Medicine, School of Medicine and School of Biomedical Sciences, Huaqiao University, Xiamen 361021, China.
| | - Azhar Rasul
- Department of Zoology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Haseeb Anwar
- Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Muhammad Umar Sohail
- Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Aroona Razzaq
- Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Nimra Aziz
- Department of Physiology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Asghar Shabbir
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad 44000, Pakistan.
| | - Muhammad Ali
- Department of Zoology, Faculty of Life Sciences, Government College University, Faisalabad 38000, Pakistan.
| | - Tao Sun
- Center for Precision Medicine, School of Medicine and School of Biomedical Sciences, Huaqiao University, Xiamen 361021, China.
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172
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Aguayo-Ortiz R, Dominguez L. Simulating the γ-secretase enzyme: Recent advances and future directions. Biochimie 2018; 147:130-135. [DOI: 10.1016/j.biochi.2018.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/27/2018] [Indexed: 11/17/2022]
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173
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Vervliet T. Ryanodine Receptors in Autophagy: Implications for Neurodegenerative Diseases? Front Cell Neurosci 2018; 12:89. [PMID: 29636667 PMCID: PMC5880912 DOI: 10.3389/fncel.2018.00089] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/13/2018] [Indexed: 12/18/2022] Open
Abstract
Intracellular Ca2+ signaling is important in the regulation of several cellular processes including autophagy. The endoplasmic reticulum (ER) is the main and largest intracellular Ca2+ store. At the ER two protein families of Ca2+ release channels, inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs), are expressed. Several studies have reported roles in the regulation of autophagy for the ubiquitously expressed IP3R. For instance, IP3R-mediated Ca2+ release supresses basal autophagic flux by promoting mitochondrial metabolism, while also promoting the rapid initial increase in autophagic flux in response to nutrient starvation. Insights into the contribution of RyRs in autophagy have been lagging significantly compared to the advances made for IP3Rs. This is rather surprising considering that RyRs are predominantly expressed in long-lived cells with specialized metabolic needs, such as neurons and muscle cells, in which autophagy plays important roles. In this review article, recent studies revealing roles for RyRs in the regulation of autophagy will be discussed. Several RyR-interacting proteins that have been established to modulate both RyR function and autophagy will also be highlighted. Finally, the involvement of RyRs in neurodegenerative diseases will be addressed. Inhibition of RyR channels has not only been shown to be beneficial for treating several of these diseases but also regulates autophagy.
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Affiliation(s)
- Tim Vervliet
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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174
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Chang JL, Hinrich AJ, Roman B, Norrbom M, Rigo F, Marr RA, Norstrom EM, Hastings ML. Targeting Amyloid-β Precursor Protein, APP, Splicing with Antisense Oligonucleotides Reduces Toxic Amyloid-β Production. Mol Ther 2018; 26:1539-1551. [PMID: 29628304 DOI: 10.1016/j.ymthe.2018.02.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/21/2018] [Accepted: 02/27/2018] [Indexed: 12/22/2022] Open
Abstract
Alterations in amyloid beta precursor protein (APP) have been implicated in cognitive decline in Alzheimer's disease (AD), which is accelerated in Down syndrome/Trisomy 21 (DS/TS21), likely due to the extra copy of the APP gene, located on chromosome 21. Proteolytic cleavage of APP generates amyloid-β (Aβ) peptide, the primary component of senile plaques associated with AD. Reducing Aβ production is predicted to lower plaque burden and mitigate AD symptoms. Here, we designed a splice-switching antisense oligonucleotide (SSO) that causes skipping of the APP exon that encodes proteolytic cleavage sites required for Aβ peptide production. The SSO induced exon skipping in Down syndrome cell lines, resulting in a reduction of Aβ. Treatment of mice with the SSO resulted in widespread distribution in the brain accompanied by APP exon skipping and a reduction of Aβ. Overall, we show that an alternatively spliced isoform of APP encodes a cleavage-incompetent protein that does not produce Aβ peptide and that promoting the production of this isoform with an SSO can reduce Aβ in vivo. These findings demonstrate the utility of using SSOs to induce a spliced isoform of APP to reduce Aβ as a potential approach for treating AD.
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Affiliation(s)
- Jennifer L Chang
- Department of Cell Biology and Anatomy, Center for Genetic Diseases, Chicago Medical School and School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Anthony J Hinrich
- Department of Cell Biology and Anatomy, Center for Genetic Diseases, Chicago Medical School and School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Brandon Roman
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Robert A Marr
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Eric M Norstrom
- Department of Biological Sciences, DePaul University, Chicago, IL 60614, USA
| | - Michelle L Hastings
- Department of Cell Biology and Anatomy, Center for Genetic Diseases, Chicago Medical School and School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
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175
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Hu C, Xu J, Zeng L, Li T, Cui MZ, Xu X. Pen-2 and Presenilin are Sufficient to Catalyze Notch Processing. J Alzheimers Dis 2018; 56:1263-1269. [PMID: 28234257 DOI: 10.3233/jad-161094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Presenilin-1 (PS1) or presenilin-2 (PS2), nicastrin (NCT), anterior pharynx-defective 1 (Aph-1), and presenilin enhancer-2 (Pen-2) have been considered the minimal essential subunits required to form an active γ-secretase complex. Besides PS, which has been widely believed to function as the catalytic subunit of the complex, the functional roles of the other subunits in the γ-secretase complex remain debatable. In the current study, we set out to determine the role of Pen-2 in γ-secretase activity. To this end, using knockout cells in combination with siRNA and immunoprecipitation approaches, our results revealed that Pen-2 together with presenilin are sufficient to form a functionally active enzyme to process Notch. Specifically, our data demonstrated that Pen-2 plays a crucial role in substrate binding, a mechanism by which Pen-2 contributes directly to the catalytic mechanism of γ-secretase activity. Our data also suggested that there may be different requirements for components to process AβPP and Notch. This information would be important for therapeutic strategy aimed at inhibition or modulation of γ-secretase activity.
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Affiliation(s)
- Chen Hu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
| | - Junjie Xu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.,Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Jilin Medical University, Jilin, China
| | - Linlin Zeng
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.,School of Life Sciences, Jilin University, Changchun, China
| | - Ting Li
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.,Department of Cell Biology, Tianjin Medical University, Tianjin, China
| | - Mei-Zhen Cui
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
| | - Xuemin Xu
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA
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176
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Hu X, Das B, Hou H, He W, Yan R. BACE1 deletion in the adult mouse reverses preformed amyloid deposition and improves cognitive functions. J Exp Med 2018; 215:927-940. [PMID: 29444819 PMCID: PMC5839766 DOI: 10.1084/jem.20171831] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/16/2017] [Accepted: 01/04/2018] [Indexed: 12/21/2022] Open
Abstract
This study uses mouse models to answer how BACE1 inhibitory drugs will be beneficial to Alzheimer’s patients. Hu et al. find that sequentially increased deletion of BACE1 in one adult Alzheimer’s mouse model reverses preexisting amyloid plaques and mitigates synaptic failures. BACE1 initiates the generation of the β-amyloid peptide, which likely causes Alzheimer’s disease (AD) when accumulated abnormally. BACE1 inhibitory drugs are currently being developed to treat AD patients. To mimic BACE1 inhibition in adults, we generated BACE1 conditional knockout (BACE1fl/fl) mice and bred BACE1fl/fl mice with ubiquitin-CreER mice to induce deletion of BACE1 after passing early developmental stages. Strikingly, sequential and increased deletion of BACE1 in an adult AD mouse model (5xFAD) was capable of completely reversing amyloid deposition. This reversal in amyloid deposition also resulted in significant improvement in gliosis and neuritic dystrophy. Moreover, synaptic functions, as determined by long-term potentiation and contextual fear conditioning experiments, were significantly improved, correlating with the reversal of amyloid plaques. Our results demonstrate that sustained and increasing BACE1 inhibition in adults can reverse amyloid deposition in an AD mouse model, and this observation will help to provide guidance for the proper use of BACE1 inhibitors in human patients.
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Affiliation(s)
- Xiangyou Hu
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Brati Das
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Hailong Hou
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Wanxia He
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
| | - Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH
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177
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Styr B, Slutsky I. Imbalance between firing homeostasis and synaptic plasticity drives early-phase Alzheimer's disease. Nat Neurosci 2018; 21:463-473. [PMID: 29403035 DOI: 10.1038/s41593-018-0080-x] [Citation(s) in RCA: 186] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/08/2018] [Indexed: 12/18/2022]
Abstract
During recent years, the preclinical stage of Alzheimer's disease (AD) has become a major focus of research. Continued failures in clinical trials and the realization that early intervention may offer better therapeutic outcome triggered a conceptual shift from late-stage AD pathology to early-stage pathophysiology. While much effort has been directed at understanding the factors initiating AD, little is known about the principle basis underlying the disease progression at its early stages. In this Perspective, we suggest a hypothesis to explain the transition from 'silent' signatures of aberrant neural circuit activity to clinically evident memory impairments. Namely, we propose that failures in firing homeostasis and imbalance between firing stability and synaptic plasticity in cortico-hippocampal circuits represent the driving force of early disease progression. We analyze the main types of possible homeostatic failures and provide the essential conceptual framework for examining the causal link between dysregulation of firing homeostasis, aberrant neural circuit activity and memory-related plasticity impairments associated with early AD.
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Affiliation(s)
- Boaz Styr
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Inna Slutsky
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. .,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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178
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Jakobsen JE, Johansen MG, Schmidt M, Liu Y, Li R, Callesen H, Melnikova M, Habekost M, Matrone C, Bouter Y, Bayer TA, Nielsen AL, Duthie M, Fraser PE, Holm IE, Jørgensen AL. Expression of the Alzheimer's Disease Mutations AβPP695sw and PSEN1M146I in Double-Transgenic Göttingen Minipigs. J Alzheimers Dis 2018; 53:1617-30. [PMID: 27540966 DOI: 10.3233/jad-160408] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Mutations in the amyloid-β protein precursor gene (AβPP), the presenilin 1 gene (PSEN1) or the presenilin 2 gene (PSEN2) that increase production of the AβPP-derived peptide Aβ42 cause early-onset Alzheimer's disease. Rodent models of the disease show that further increase in Aβ42 production and earlier brain pathology can be obtained by coexpressing AβPP and PSEN1 mutations. To generate such elevated Aβ42 level in a large animal model, we produced Göttingen minipigs carrying in their genome one copy of a human PSEN1 cDNA with the Met146Ile (PSEN1M146I) mutation and three copies of a human AβPP695 cDNA with the Lys670Asn/Met671Leu (AβPPsw) double-mutation. Both transgenes were expressed in fibroblasts and in the brain, and their respective proteins were processed normally. Immunohistochemical staining with Aβ42-specific antibodies detected intraneuronal accumulation of Aβ42 in brains from a 10- and an 18-month-old pig. Such accumulation may represent an early event in the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- Jannik E Jakobsen
- Department of Biomedicine (East), Aarhus University, Aarhus C, Denmark
| | | | - Mette Schmidt
- Department of Large Animal Sciences/Reproduction, University of Copenhagen, Frederiksberg C, Denmark
| | - Ying Liu
- Department of Animal Science, Aarhus University, Tjele, Denmark
| | - Rong Li
- Department of Animal Science, Aarhus University, Tjele, Denmark
| | - Henrik Callesen
- Department of Animal Science, Aarhus University, Tjele, Denmark
| | | | - Mette Habekost
- Department of Biomedicine (East), Aarhus University, Aarhus C, Denmark
| | - Carmela Matrone
- Department of Biomedicine (East), Aarhus University, Aarhus C, Denmark
| | - Yvonne Bouter
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Georg-August-University Göttingen, Göttingen, Germany
| | - Thomas A Bayer
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Monika Duthie
- Tanz Centre for Research in Neurodegenerative Diseases, Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Paul E Fraser
- Tanz Centre for Research in Neurodegenerative Diseases, Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Ida E Holm
- Department of Clinical Medicine, Aarhus University, Aarhus C, Denmark.,Department of Pathology, Randers Hospital, Randers, Denmark
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179
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Allosteric Modulation of Intact γ-Secretase Structural Dynamics. Biophys J 2018; 113:2634-2649. [PMID: 29262358 DOI: 10.1016/j.bpj.2017.10.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/26/2017] [Accepted: 10/10/2017] [Indexed: 12/20/2022] Open
Abstract
As a protease complex involved in the cleavage of amyloid precursor proteins that lead to the formation of amyloid β fibrils implicated in Alzheimer's disease, γ-secretase is an important target for developing therapeutics against Alzheimer's disease. γ-secretase is composed of four subunits: nicastrin (NCT) in the extracellular (EC) domain, presenilin-1 (PS1), anterior pharynx defective 1, and presenilin enhancer 2 in the transmembrane (TM) domain. NCT and PS1 play important roles in binding amyloid β precursor proteins and modulating PS1 catalytic activity. Yet, the molecular mechanisms of coupling between substrate/modulator binding and catalytic activity remain to be elucidated. Recent determination of intact human γ-secretase cryo-electron microscopy structure has opened the way for a detailed investigation of the structural dynamics of this complex. Our analysis, based on a membrane-coupled anisotropic network model, reveals two types of NCT motions, bending and twisting, with respect to PS1. These underlie the fluctuations between the "open" and "closed" states of the lid-like NCT with respect to a hydrophilic loop 1 (HL1) on PS1, thus allowing or blocking access of the substrate peptide (EC portion) to HL1 and to the neighboring helix TM2. In addition to this alternating access mechanism, fluctuations in the volume of the PS1 central cavity facilitate the exposure of the catalytic site for substrate cleavage. Druggability simulations show that γ-secretase presents several hot spots for either orthosteric or allosteric inhibition of catalytic activity, consistent with experimental data. In particular, a hinge region at the interface between the EC and TM domains, near the interlobe groove of NCT, emerges as an allo-targeting site that would impact the coupling between HL1/TM2 and the catalytic pocket, opening, to our knowledge, new avenues for structure-based design of novel allosteric modulators of γ-secretase protease activity.
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180
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Sirtuins as Modifiers of Huntington's Disease (HD) Pathology. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 154:105-145. [DOI: 10.1016/bs.pmbts.2017.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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181
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Epigenetic and microenvironmental alterations in bone marrow associated with ROS in experimental aplastic anemia. Eur J Cell Biol 2018; 97:32-43. [DOI: 10.1016/j.ejcb.2017.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/04/2017] [Accepted: 11/20/2017] [Indexed: 12/22/2022] Open
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182
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Campos SK. Subcellular Trafficking of the Papillomavirus Genome during Initial Infection: The Remarkable Abilities of Minor Capsid Protein L2. Viruses 2017; 9:v9120370. [PMID: 29207511 PMCID: PMC5744145 DOI: 10.3390/v9120370] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/01/2017] [Accepted: 12/02/2017] [Indexed: 12/24/2022] Open
Abstract
Since 2012, our understanding of human papillomavirus (HPV) subcellular trafficking has undergone a drastic paradigm shift. Work from multiple laboratories has revealed that HPV has evolved a unique means to deliver its viral genome (vDNA) to the cell nucleus, relying on myriad host cell proteins and processes. The major breakthrough finding from these recent endeavors has been the realization of L2-dependent utilization of cellular sorting factors for the retrograde transport of vDNA away from degradative endo/lysosomal compartments to the Golgi, prior to mitosis-dependent nuclear accumulation of L2/vDNA. An overview of current models of HPV entry, subcellular trafficking, and the role of L2 during initial infection is provided below, highlighting unresolved questions and gaps in knowledge.
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Affiliation(s)
- Samuel K Campos
- The Department of Immunobiology, The University of Arizona, Tucson, AZ 85721-0240, USA.
- The Department of Molecular & Cellular Biology, The University of Arizona, Tucson, AZ 85721-0240, USA.
- The Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, AZ 85721-0240, USA.
- The BIO5 Institute, Tucson, AZ 85721-0240, USA.
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183
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Kusne Y, Wolf AB, Townley K, Conway M, Peyman GA. Visual system manifestations of Alzheimer's disease. Acta Ophthalmol 2017; 95:e668-e676. [PMID: 27864881 DOI: 10.1111/aos.13319] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/07/2016] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is an increasingly common disease with massive personal and economic costs. While it has long been known that AD impacts the visual system, there has recently been an increased focus on understanding both pathophysiological mechanisms that may be shared between the eye and brain and how related biomarkers could be useful for AD diagnosis. Here, were review pertinent cellular and molecular mechanisms of AD pathophysiology, the presence of AD pathology in the visual system, associated functional changes, and potential development of diagnostic tools based on the visual system. Additionally, we discuss links between AD and visual disorders, including possible pathophysiological mechanisms and their relevance for improving our understanding of AD.
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Affiliation(s)
- Yael Kusne
- University of Arizona College of Medicine; Phoenix Arizona USA
| | - Andrew B. Wolf
- University of Colorado School of Medicine; Aurora Colorado USA
| | - Kate Townley
- University of Arizona College of Medicine; Phoenix Arizona USA
| | - Mandi Conway
- University of Arizona College of Medicine; Phoenix Arizona USA
- Arizona Retinal Specialists; Sun City Arizona USA
| | - Gholam A. Peyman
- University of Arizona College of Medicine; Phoenix Arizona USA
- Arizona Retinal Specialists; Sun City Arizona USA
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184
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Guo J, Cheng J, North BJ, Wei W. Functional analyses of major cancer-related signaling pathways in Alzheimer's disease etiology. Biochim Biophys Acta Rev Cancer 2017; 1868:341-358. [PMID: 28694093 PMCID: PMC5675793 DOI: 10.1016/j.bbcan.2017.07.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is an aging-related neurodegenerative disease and accounts for majority of human dementia. The hyper-phosphorylated tau-mediated intracellular neurofibrillary tangle and amyloid β-mediated extracellular senile plaque are characterized as major pathological lesions of AD. Different from the dysregulated growth control and ample genetic mutations associated with human cancers, AD displays damage and death of brain neurons in the absence of genomic alterations. Although various biological processes predominately governing tumorigenesis such as inflammation, metabolic alteration, oxidative stress and insulin resistance have been associated with AD genesis, the mechanistic connection of these biological processes and signaling pathways including mTOR, MAPK, SIRT, HIF, and the FOXO pathway controlling aging and the pathological lesions of AD are not well recapitulated. Hence, we performed a thorough review by summarizing the physiological roles of these key cancer-related signaling pathways in AD pathogenesis, comprising of the crosstalk of these pathways with neurofibrillary tangle and senile plaque formation to impact AD phenotypes. Importantly, the pharmaceutical investigations of anti-aging and AD relevant medications have also been highlighted. In summary, in this review, we discuss the potential role that cancer-related signaling pathways may play in governing the pathogenesis of AD, as well as their potential as future targeted strategies to delay or prevent aging-related diseases and combating AD.
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Affiliation(s)
- Jianping Guo
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Ji Cheng
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Brian J North
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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185
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Williamson RL, Laulagnier K, Miranda AM, Fernandez MA, Wolfe MS, Sadoul R, Di Paolo G. Disruption of amyloid precursor protein ubiquitination selectively increases amyloid β (Aβ) 40 levels via presenilin 2-mediated cleavage. J Biol Chem 2017; 292:19873-19889. [PMID: 29021256 PMCID: PMC5712626 DOI: 10.1074/jbc.m117.818138] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 09/30/2017] [Indexed: 11/06/2022] Open
Abstract
Amyloid plaques, a neuropathological hallmark of Alzheimer's disease, are largely composed of amyloid β (Aβ) peptide, derived from cleavage of amyloid precursor protein (APP) by β- and γ-secretases. The endosome is increasingly recognized as an important crossroad for APP and these secretases, with major implications for APP processing and amyloidogenesis. Among various post-translational modifications affecting APP accumulation, ubiquitination of cytodomain lysines may represent a key signal controlling APP endosomal sorting. Here, we show that substitution of APP C-terminal lysines with arginine disrupts APP ubiquitination and that an increase in the number of substituted lysines tends to increase APP metabolism. An APP mutant lacking all C-terminal lysines underwent the most pronounced increase in processing, leading to accumulation of both secreted and intracellular Aβ40. Artificial APP ubiquitination with rapalog-mediated proximity inducers reduced Aβ40 generation. A lack of APP C-terminal lysines caused APP redistribution from endosomal intraluminal vesicles (ILVs) to the endosomal limiting membrane, with a subsequent decrease in APP C-terminal fragment (CTF) content in secreted exosomes, but had minimal effects on APP lysosomal degradation. Both the increases in secreted and intracellular Aβ40 were abolished by depletion of presenilin 2 (PSEN2), recently shown to be enriched on the endosomal limiting membrane compared with PSEN1. Our findings demonstrate that ubiquitin can act as a signal at five cytodomain-located lysines for endosomal sorting of APP. They further suggest that disruption of APP endosomal sorting reduces its sequestration in ILVs and results in PSEN2-mediated processing of a larger pool of APP-CTF on the endosomal membrane.
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Affiliation(s)
| | - Karine Laulagnier
- the Grenoble Institut des Neurosciences, Inserm, Grenoble 38042, France
| | - André M Miranda
- From the Department of Pathology and Cell Biology and
- the Life and Health Sciences Research Institute, School of Medicine, University of Minho and
- Life and Health Sciences Research Institute/3B's Research Group-Biomaterials, Biodegradables, and Biomimetics Associate Laboratory, 4710-057 Braga/Guimarães, Portugal, and
| | - Marty A Fernandez
- the Center for Neurologic Diseases, Harvard University, Boston, Massachusetts 02115
| | - Michael S Wolfe
- the Center for Neurologic Diseases, Harvard University, Boston, Massachusetts 02115
| | - Rémy Sadoul
- the Grenoble Institut des Neurosciences, Inserm, Grenoble 38042, France
| | - Gilbert Di Paolo
- From the Department of Pathology and Cell Biology and
- the Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, New York 10032
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186
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Somavarapu AK, Kepp KP. Membrane Dynamics of γ-Secretase Provides a Molecular Basis for β-Amyloid Binding and Processing. ACS Chem Neurosci 2017; 8:2424-2436. [PMID: 28841371 DOI: 10.1021/acschemneuro.7b00208] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
γ-Secretase produces β-amyloid (Aβ) within its presenilin (PS1) subunit, mutations in which cause Alzheimer's disease, and current therapies thus seek to modulate its activity. While the general structure is known from recent electron microscopy studies, direct loop and membrane interactions and explicit dynamics relevant to substrate processing remain unknown. We report a modeled structure utilizing the optimal multitemplate information available, including loops and missing side chains, account of maturation cleavage, and explicit all-atom molecular dynamics in the membrane. We observe three distinct conformations of γ-secretase (open, semiopen, and closed) that remarkably differ by tilting of helices 2 and 3 of PS1, directly controlling active site availability. The large hydrophilic loop of PS1 where maturation occurs reveals a new helix segment that parallels the likely helix character of other substrates. The semiopen conformation consistently shows the best fit of Aβ peptides, that is, longer residence before release and by inference more trimming. In contrast, the closed, hydrophobic conformation is largely inactive and the open conformation is active but provides fewer optimal interactions and induces shorter residence time and by inference releases Aβ peptides of longer lengths. Our simulations thus provide a molecular basis for substrate processing and changes in the Aβ42/Aβ40 ratio. Accordingly, selective binding to protect the semiopen "innocent" conformation provides a molecular recipe for effective γ-secretase modulators; we provide the full atomic structures for these states that may play a key role in developing selective γ-secretase modulators for treatment of Alzheimer's disease.
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Affiliation(s)
| | - Kasper P. Kepp
- Technical University of Denmark, DTU Chemistry, DK-2800 Kongens Lyngby, Denmark
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187
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Gazda K, Kuznicki J, Wegierski T. Knockdown of amyloid precursor protein increases calcium levels in the endoplasmic reticulum. Sci Rep 2017; 7:14512. [PMID: 29109429 PMCID: PMC5673940 DOI: 10.1038/s41598-017-15166-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 10/23/2017] [Indexed: 12/15/2022] Open
Abstract
Familial Alzheimer's disease (AD) is caused by mutations in the genes that encode amyloid precursor protein (APP) and presenilins. Disturbances in calcium homeostasis have been observed in various cellular and animal models of AD and are proposed to underlie the pathogenesis of the disease. Furthermore, wildtype presenilins were shown to regulate endoplasmic reticulum (ER) calcium homeostasis, although their precise mechanism of action remains controversial. To investigate whether APP also affects ER calcium levels, we used RNA interference to target the APP gene in cultured T84 cells in combination with two types of ER calcium sensors. Using a genetically encoded calcium indicator, GEM-CEPIA1er, we found that APP-deficient cells exhibited elevated resting calcium levels in the ER and prolonged emptying of ER calcium stores upon the cyclopiazonic acid-induced inhibition of sarco-endoplasmic reticulum calcium-ATPase. These effects could be ascribed to lower ER calcium leakage rates. Consistent with these results, translocation of the endogenous ER calcium sensor STIM1 to its target channel Orai1 was delayed following ER calcium store depletion. Our data suggest a physiological function of APP in the regulation of ER calcium levels.
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Affiliation(s)
- Kinga Gazda
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, 02-109, Warsaw, Poland
| | - Jacek Kuznicki
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, 02-109, Warsaw, Poland
| | - Tomasz Wegierski
- Laboratory of Neurodegeneration, International Institute of Molecular and Cell Biology, 02-109, Warsaw, Poland.
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188
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189
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Wongprayoon P, Govitrapong P. Melatonin as a mitochondrial protector in neurodegenerative diseases. Cell Mol Life Sci 2017; 74:3999-4014. [PMID: 28791420 PMCID: PMC11107580 DOI: 10.1007/s00018-017-2614-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/03/2017] [Indexed: 12/19/2022]
Abstract
Mitochondria are crucial organelles as their role in cellular energy production of eukaryotes. Because the brain cells demand high energy for maintaining their normal activities, disturbances in mitochondrial physiology may lead to neuropathological events underlying neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Melatonin is an endogenous compound with a variety of physiological roles. In addition, it possesses potent antioxidant properties which effectively play protective roles in several pathological conditions. Several lines of evidence also reveal roles of melatonin in mitochondrial protection, which could prevent development and progression of neurodegeneration. Since the mitochondrial dysfunction is a primary event in neurodegeneration, the neuroprotection afforded by melatonin is thereby more effective in early stages of the diseases. This article reviews mechanisms which melatonin exerts its protective roles on mitochondria as a potential therapeutic strategy against neurodegenerative disorders.
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Affiliation(s)
- Pawaris Wongprayoon
- Department of Biopharmacy, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, 73000, Thailand
| | - Piyarat Govitrapong
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand.
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok, 10210, Thailand.
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190
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Walter J, Kemmerling N, Wunderlich P, Glebov K. γ-Secretase in microglia - implications for neurodegeneration and neuroinflammation. J Neurochem 2017; 143:445-454. [PMID: 28940294 DOI: 10.1111/jnc.14224] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/16/2017] [Accepted: 09/18/2017] [Indexed: 12/13/2022]
Abstract
γ-Secretase is an intramembrane cleaving protease involved in the generation of the Alzheimer's disease (AD)-associated amyloid β peptide (Aβ). γ-Secretase is ubiquitously expressed in different organs, and also in different cell types of the human brain. Besides the involvement in the proteolytic generation of Aβ from the amyloid precursor protein, γ-secretase cleaves many additional protein substrates, suggesting pleiotropic functions under physiological and pathophysiological conditions. Microglia exert important functions during brain development and homeostasis in adulthood, and accumulating evidence indicates that microglia and neuroinflammatory processes contribute to the pathogenesis of neurodegenerative diseases. Recent studies demonstrate functional implications of γ-secretase in microglia, suggesting that alterations in γ-secretase activity could contribute to AD pathogenesis by modulation of microglia and related neuroinflammatory processes during neurodegeneration. In this review, we discuss the involvement of γ-secretase in the regulation of microglial functions, and the potential relevance of these processes under physiological and pathophysiological conditions. This article is part of the series "Beyond Amyloid".
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Affiliation(s)
- Jochen Walter
- Department of Neurology, University of Bonn, Bonn, Germany
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191
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Yan Y, Xu TH, Melcher K, Xu HE. Defining the minimum substrate and charge recognition model of gamma-secretase. Acta Pharmacol Sin 2017; 38:1412-1424. [PMID: 28414207 PMCID: PMC5630670 DOI: 10.1038/aps.2017.35] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 03/13/2017] [Indexed: 12/30/2022] Open
Abstract
γ-Secretase is an intramembrane aspartyl protease that cleaves the C99 fragment of amyloid precursor protein to generate extracellular Aβ peptides. These peptides can oligomerize and aggregate to form amyloid plaques, processes that are widely believed to be causal for Alzheimer's disease. In spite of this critical function, it remains unknown how γ-secretase recognizes C99 and its other substrates, including Notch. In this study we determined E22-K55 as the minimal C99 fragment that was sufficient and required for initial cleavage. Within this fragment, we identified four determinants: (i) a transferable extracellular determinant that differed between C99 and Notch, and which included negative charge in the case of C99, (ii) the amino acid sequence of the C-terminal half of the transmembrane helix, (iii) an invariant lysine or arginine at the intracellular membrane border, and (iv) a positive charge cluster that included the invariant lysine/arginine. We demonstrated that the charge clusters of C99 and Notch receptors could directly bind phosphatidylinositol 4,5-bisphosphate (PIP2). The PIP2-binding cluster was required for γ-secretase cleavage, and modulation of membrane PIP2 levels strongly affected γ-secretase cleavage levels and the Aβ40/Aβ42 ratio, providing support for the importance of the PIP2 interaction in cells. Together, these studies provide critically needed insight into substrate recognition by γ-secretase.
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192
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Das B, Yan R. Role of BACE1 in Alzheimer's synaptic function. Transl Neurodegener 2017; 6:23. [PMID: 28855981 PMCID: PMC5575945 DOI: 10.1186/s40035-017-0093-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/15/2017] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease (AD) is the most common age-dependent disease of dementia, and there is currently no cure available. This hallmark pathologies of AD are the presence of amyloid plaques and neurofibrillary tangles. Although the exact etiology of AD remains a mystery, studies over the past 30 have shown that abnormal generation or accumulation of β-amyloid peptides (Aβ) is likely to be a predominant early event in AD pathological development. Aβ is generated from amyloid precursor protein (APP) via proteolytic cleavage by β-site APP cleaving enzyme 1 (BACE1). Chemical inhibition of BACE1 has been shown to reduce Aβ in animal studies and in human trials. While BACE1 inhibitors are currently being tested in clinical trials to treat AD patients, it is highly important to understand whether BACE1 inhibition will significantly impact cognitive functions in AD patients. This review summarizes the recent studies on BACE1 synaptic functions. This knowledge will help to guide the proper use of BACE1 inhibitors in AD therapy.
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Affiliation(s)
- Brati Das
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH 44195 USA
| | - Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC30, Cleveland, OH 44195 USA
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193
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Sogorb-Esteve A, García-Ayllón MS, Llansola M, Felipo V, Blennow K, Sáez-Valero J. Inhibition of γ-Secretase Leads to an Increase in Presenilin-1. Mol Neurobiol 2017; 55:5047-5058. [PMID: 28815510 PMCID: PMC5948247 DOI: 10.1007/s12035-017-0705-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/01/2017] [Indexed: 12/27/2022]
Abstract
γ-Secretase inhibitors (GSIs) are potential therapeutic agents for Alzheimer’s disease (AD); however, trials have proven disappointing. We addressed the possibility that γ-secretase inhibition can provoke a rebound effect, elevating the levels of the catalytic γ-secretase subunit, presenilin-1 (PS1). Acute treatment of SH-SY5Y cells with the GSI LY-374973 (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester, DAPT) augments PS1, in parallel with increases in other γ-secretase subunits nicastrin, presenilin enhancer 2, and anterior pharynx-defective 1, yet with no increase in messenger RNA expression. Over-expression of the C-terminal fragment (CTF) of APP, C99, also triggered an increase in PS1. Similar increases in PS1 were evident in primary neurons treated repeatedly (4 days) with DAPT or with the GSI BMS-708163 (avagacestat). Likewise, rats examined after 21 days administered with avagacestat (40 mg/kg/day) had more brain PS1. Sustained γ-secretase inhibition did not exert a long-term effect on PS1 activity, evident through the decrease in CTFs of APP and ApoER2. Prolonged avagacestat treatment of rats produced a subtle impairment in anxiety-like behavior. The rebound increase in PS1 in response to GSIs must be taken into consideration for future drug development.
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Affiliation(s)
- Aitana Sogorb-Esteve
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Av. Ramón y Cajal s/n, 03550, Sant Joan d'Alacant, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, Spain
| | - María-Salud García-Ayllón
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Av. Ramón y Cajal s/n, 03550, Sant Joan d'Alacant, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, Spain. .,Unidad de Investigación, Hospital General Universitario de Elche, FISABIO, 03203, Elche, Spain.
| | - Marta Llansola
- Laboratory of Neurobiology, Fundación Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Vicente Felipo
- Laboratory of Neurobiology, Fundación Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Institute of Neuroscience and Physiology, University of Gothenburg, Mölndal Campus, Sweden
| | - Javier Sáez-Valero
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Av. Ramón y Cajal s/n, 03550, Sant Joan d'Alacant, Spain. .,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Sant Joan d'Alacant, Spain.
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194
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Li S, Zhang W, Han W. Initial Substrate Binding of γ-Secretase: The Role of Substrate Flexibility. ACS Chem Neurosci 2017; 8:1279-1290. [PMID: 28165225 DOI: 10.1021/acschemneuro.6b00425] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
γ-Secretase cleaves transmembrane domains (TMD) of amyloid precursor protein (APP), producing pathologically relevant amyloid-β proteins. Initial substrate binding represents a key step of the γ-secretase cleavage whose mechanism remains elusive. Through long time scale coarse-grained and atomic simulations, we have found that the APP TMD can bind to the catalytic subunit presenilin 1 (PS1) on an extended surface covering PS1's TMD2/6/9 and PAL motif that are all known to be essential for enzymatic activity. This initial substrate binding could lead to reduction in the vertical gap between APP's ε-cleavage sites and γ-secretase's active center, enhanced flexibility and hydration levels around the ε-sites, and the presentation of these sites to the enzyme. There are heterogeneous substrate binding poses in which the substrate is found to bind to either the N- or C-terminal parts of PS1, or both. Moreover, we also find that the stability of the binding poses can be modulated by the flexibility of substrate TMD. Especially, the APP substrate, when deprived of bending fluctuation, does not bind to TMD9 at PS1's C-terminus. Our simulations have revealed further that another substrate of γ-secretase, namely, notch receptors, though bearing a rigid TMD, can still bind to PS1 TMD9, but by a different mechanism, suggesting that the influence of substrate flexibility is context-dependent. Together, these findings shed light on the mechanism of initial substrate docking of γ-secretase and the role of substrate flexibility in this process.
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Affiliation(s)
- Shu Li
- Key Laboratory of Chemical Genomics, School
of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Wan Zhang
- Key Laboratory of Chemical Genomics, School
of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Wei Han
- Key Laboratory of Chemical Genomics, School
of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
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195
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Liebsch F, Aurousseau MRP, Bethge T, McGuire H, Scolari S, Herrmann A, Blunck R, Bowie D, Multhaup G. Full-length cellular β-secretase has a trimeric subunit stoichiometry, and its sulfur-rich transmembrane interaction site modulates cytosolic copper compartmentalization. J Biol Chem 2017. [PMID: 28637867 DOI: 10.1074/jbc.m117.779165] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The β-secretase (BACE1) initiates processing of the amyloid precursor protein (APP) into Aβ peptides, which have been implicated as central players in the pathology of Alzheimer disease. BACE1 has been described as a copper-binding protein and its oligomeric state as being monomeric, dimeric, and/or multimeric, but the native cellular stoichiometry has remained elusive. Here, by using single-molecule fluorescence and in vitro cross-linking experiments with photo-activatable unnatural amino acids, we show that full-length BACE1, independently of its subcellular localization, exists as trimers in human cells. We found that trimerization requires the BACE1 transmembrane sequences (TMSs) and cytoplasmic domains, with residues Ala463 and Cys466 buried within the trimer interface of the sulfur-rich core of the TMSs. Our 3D model predicts that the sulfur-rich core of the trimeric BACE1 TMS is accessible to metal ions, but copper ions did not trigger trimerization. The results of functional assays of endogenous BACE1 suggest that it has a role in intracellular copper compartmentalization by transferring cytosolic copper to intracellular compartments, while leaving the overall cellular copper concentration unaltered. Adding to existing physiological models, our results provide novel insight into the atypical interactions between copper and BACE1 and into its non-enzymatic activities. In conclusion, therapeutic Alzheimer disease prevention strategies aimed at decreasing BACE1 protein levels should be regarded with caution, because adverse effects in copper homeostasis may occur.
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Affiliation(s)
- Filip Liebsch
- From the Integrated Program in Neuroscience, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Mark R P Aurousseau
- the Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Tobias Bethge
- the Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany
| | - Hugo McGuire
- the Department of Physics, Université de Montréal, Montreal, Quebec H3C 3J7, Canada, and
| | - Silvia Scolari
- the Institut für Biologie, Humboldt Universität zu Berlin, 10115 Berlin, Germany
| | - Andreas Herrmann
- the Institut für Biologie, Humboldt Universität zu Berlin, 10115 Berlin, Germany
| | - Rikard Blunck
- the Department of Physics, Université de Montréal, Montreal, Quebec H3C 3J7, Canada, and
| | - Derek Bowie
- From the Integrated Program in Neuroscience, McGill University, Montreal, Quebec H3G 0B1, Canada.,the Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Gerd Multhaup
- From the Integrated Program in Neuroscience, McGill University, Montreal, Quebec H3G 0B1, Canada, .,the Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
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196
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Abstract
Notch signaling is evolutionarily conserved from Drosophila to human. It plays critical roles in neural stem cell maintenance and neurogenesis in the embryonic brain as well as in the adult brain. Notch functions greatly depend on careful regulation and cross-talk with other regulatory mechanisms. Deregulation of Notch signaling is involved in many neurodegenerative diseases and brain disorders. Here, we summarize the fundamental role of Notch in neuronal development and specification and discuss how epigenetic regulation and pathway cross-talk contribute to Notch function. In addition, we cover aberrant alterations of Notch signaling in the diseased brain. The aim of this review is to provide an insight into how Notch signaling works in different contexts to control neurogenesis and its potential effects in diagnoses and therapies of neurodegeneration, brain tumors and disorders.
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Affiliation(s)
- Runrui Zhang
- Embryology and Stem Cell Biology, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058, Basel, Switzerland
| | - Anna Engler
- Embryology and Stem Cell Biology, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058, Basel, Switzerland
| | - Verdon Taylor
- Embryology and Stem Cell Biology, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058, Basel, Switzerland.
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197
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Pettersson M, Johnson DS, Rankic DA, Kauffman GW, Am Ende CW, Butler TW, Boscoe B, Evrard E, Helal CJ, Humphrey JM, Stepan AF, Stiff CM, Yang E, Xie L, Bales KR, Hajos-Korcsok E, Jenkinson S, Pettersen B, Pustilnik LR, Ramirez DS, Steyn SJ, Wood KM, Verhoest PR. Discovery of cyclopropyl chromane-derived pyridopyrazine-1,6-dione γ-secretase modulators with robust central efficacy. MEDCHEMCOMM 2017; 8:730-743. [PMID: 30108792 PMCID: PMC6071960 DOI: 10.1039/c6md00406g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 10/05/2016] [Indexed: 11/21/2022]
Abstract
Herein we describe the discovery of a novel series of cyclopropyl chromane-derived pyridopyrazine-1,6-dione γ-secretase modulators for the treatment of Alzheimer's disease (AD). Using ligand-based design tactics such as conformational analysis and molecular modeling, a cyclopropyl chromane unit was identified as a suitable heterocyclic replacement for a naphthyl moiety that was present in the preliminary lead 4. The optimized lead molecule 44 achieved good central exposure resulting in robust and sustained reduction of brain amyloid-β42 (Aβ42) when dosed orally at 10 mg kg-1 in a rat time-course study. Application of the unpaced isolated heart Langendorff model enabled efficient differentiation of compounds with respect to cardiovascular safety, highlighting how minor structural changes can greatly impact the safety profile within a series of compounds.
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Affiliation(s)
- Martin Pettersson
- Neuroscience and Pain Medicinal Chemistry , Cambridge , Massachusetts 02139 , USA . ; Tel: +(617) 395 0705
| | - Douglas S Johnson
- Neuroscience and Pain Medicinal Chemistry , Cambridge , Massachusetts 02139 , USA . ; Tel: +(617) 395 0705
| | - Danica A Rankic
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Gregory W Kauffman
- Neuroscience and Pain Medicinal Chemistry , Cambridge , Massachusetts 02139 , USA . ; Tel: +(617) 395 0705
| | - Christopher W Am Ende
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Todd W Butler
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Brian Boscoe
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Edelweiss Evrard
- Neuroscience and Pain Medicinal Chemistry , Cambridge , Massachusetts 02139 , USA . ; Tel: +(617) 395 0705
| | - Christopher J Helal
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - John M Humphrey
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Antonia F Stepan
- Neuroscience and Pain Medicinal Chemistry , Cambridge , Massachusetts 02139 , USA . ; Tel: +(617) 395 0705
| | - Cory M Stiff
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Eddie Yang
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Longfei Xie
- Neuroscience and Pain Medicinal Chemistry , Groton , Connecticut 06340 , USA . ; Tel: +(860) 441 4354
| | - Kelly R Bales
- Neuroscience and Pain Research Unit , Cambridge , Massachusetts 02139 , USA
| | - Eva Hajos-Korcsok
- Neuroscience and Pain Research Unit , Cambridge , Massachusetts 02139 , USA
| | - Stephen Jenkinson
- Global Safety Pharmacology , Pfizer Worldwide Research and Development , La Jolla , California 92121 , USA
| | - Betty Pettersen
- Drug Safety R&D , Pfizer Worldwide Research and Development , Groton , Connecticut 06340 , USA
| | | | - David S Ramirez
- Global Safety Pharmacology , Pfizer Worldwide Research and Development , La Jolla , California 92121 , USA
| | - Stefanus J Steyn
- Pharmacokinetics, Dynamics and Metabolism , Pfizer Worldwide Research and Development , Cambridge , Massachusetts 02139 , USA
| | - Kathleen M Wood
- Neuroscience and Pain Research Unit , Cambridge , Massachusetts 02139 , USA
| | - Patrick R Verhoest
- Neuroscience and Pain Medicinal Chemistry , Cambridge , Massachusetts 02139 , USA . ; Tel: +(617) 395 0705
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198
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Šimić G, Babić Leko M, Wray S, Harrington CR, Delalle I, Jovanov-Milošević N, Bažadona D, Buée L, de Silva R, Di Giovanni G, Wischik CM, Hof PR. Monoaminergic neuropathology in Alzheimer's disease. Prog Neurobiol 2017; 151:101-138. [PMID: 27084356 PMCID: PMC5061605 DOI: 10.1016/j.pneurobio.2016.04.001] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/09/2016] [Accepted: 04/05/2016] [Indexed: 01/02/2023]
Abstract
None of the proposed mechanisms of Alzheimer's disease (AD) fully explains the distribution patterns of the neuropathological changes at the cellular and regional levels, and their clinical correlates. One aspect of this problem lies in the complex genetic, epigenetic, and environmental landscape of AD: early-onset AD is often familial with autosomal dominant inheritance, while the vast majority of AD cases are late-onset, with the ε4 variant of the gene encoding apolipoprotein E (APOE) known to confer a 5-20 fold increased risk with partial penetrance. Mechanisms by which genetic variants and environmental factors influence the development of AD pathological changes, especially neurofibrillary degeneration, are not yet known. Here we review current knowledge of the involvement of the monoaminergic systems in AD. The changes in the serotonergic, noradrenergic, dopaminergic, histaminergic, and melatonergic systems in AD are briefly described. We also summarize the possibilities for monoamine-based treatment in AD. Besides neuropathologic AD criteria that include the noradrenergic locus coeruleus (LC), special emphasis is given to the serotonergic dorsal raphe nucleus (DRN). Both of these brainstem nuclei are among the first to be affected by tau protein abnormalities in the course of sporadic AD, causing behavioral and cognitive symptoms of variable severity. The possibility that most of the tangle-bearing neurons of the LC and DRN may release amyloid β as well as soluble monomeric or oligomeric tau protein trans-synaptically by their diffuse projections to the cerebral cortex emphasizes their selective vulnerability and warrants further investigations of the monoaminergic systems in AD.
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Affiliation(s)
- Goran Šimić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia.
| | - Mirjana Babić Leko
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Selina Wray
- Reta Lila Weston Institute and Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | | | - Ivana Delalle
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Nataša Jovanov-Milošević
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Danira Bažadona
- Department of Neurology, University Hospital Center Zagreb, Zagreb, Croatia
| | - Luc Buée
- University of Lille, Inserm, CHU-Lille, UMR-S 1172, Alzheimer & Tauopathies, Lille, France
| | - Rohan de Silva
- Reta Lila Weston Institute and Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Giuseppe Di Giovanni
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Claude M Wischik
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Patrick R Hof
- Fishberg Department of Neuroscience, Ronald M. Loeb Center for Alzheimer's Disease, and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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199
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New evidence of the relative protective effects of neurodegenerative diseases and cancer against each other. Neurologia 2017; 34:283-290. [PMID: 28325559 DOI: 10.1016/j.nrl.2017.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 01/08/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Cancer and degenerative diseases share some pathogenic mechanisms which act in opposition to one another to produce either uncontrolled cell proliferation or cell death. According to several studies, patients with Alzheimer disease have a lower risk of neoplasia, and vice versa. This study describes the prevalence of tumours (active or successfully treated) in a series of patients with and without a dementing degenerative disease treated at a cognitive neurology unit. PATIENTS AND METHOD We analysed the frequency and topography of tumours and the presence or absence of a neurodegenerative disease in a group of 1,164 patients. Neurodegenerative diseases were classified in 4 groups: Alzheimer disease, synucleinopathies, Pick complex, and polyglutamine complex. We subsequently compared tumour frequency in patients with and without a degenerative disease, and prevalence of neurodegenerative diseases in patients with and without tumours. RESULTS Tumours were detected in 12.1% of the patients with a neurodegenerative disease and in 17.3% of the remaining patients. Around 14.8% of the patients with a history of neoplasia and 20.8% of the patients with no history of neoplasia were diagnosed with a neurodegenerative disease. Except for these differences and the differences between subgroups (type of degenerative disease and tumour location) were not statistically significant, except when comparing neurodegenerative diseases to central nervous system tumours, and synucleinopathies to neoplasms. CONCLUSION Dementing degenerative diseases and neoplastic disorders are not mutually exclusive. Nevertheless, the rate of co-occurrence is lower than would be expected given the prevalence rate for each group.
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200
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Akiyama K, Hizukuri Y, Akiyama Y. Involvement of a conserved GFG motif region in substrate binding by RseP, an E
scherichia coli
S2P protease. Mol Microbiol 2017; 104:737-751. [DOI: 10.1111/mmi.13659] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Koichiro Akiyama
- Institute for Frontier Life and Medical Sciences, Kyoto University; Kyoto 606-8507 Japan
| | - Yohei Hizukuri
- Institute for Frontier Life and Medical Sciences, Kyoto University; Kyoto 606-8507 Japan
| | - Yoshinori Akiyama
- Institute for Frontier Life and Medical Sciences, Kyoto University; Kyoto 606-8507 Japan
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