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Nayak V, Patra S, Rout S, Jena AB, Sharma R, Pattanaik KP, Singh J, Pandey SS, Singh RP, Majhi S, Singh KR, Kerry RG. Regulation of neuroinflammation in Alzheimer's disease via nanoparticle-loaded phytocompounds with anti-inflammatory and autophagy-inducing properties. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 122:155150. [PMID: 37944239 DOI: 10.1016/j.phymed.2023.155150] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 09/23/2023] [Accepted: 10/14/2023] [Indexed: 11/12/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is characterized by neuroinflammation linked to amyloid β (Aβ) aggregation and phosphorylated tau (τ) protein in neurofibrillary tangles (NFTs). Key elements in Aβ production and NFT assembly, like γ-secretase and p38 mitogen-activated protein kinase (p38MAPK), contribute to neuroinflammation. In addition, impaired proteosomal and autophagic pathways increase Aβ and τ aggregation, leading to neuronal damage. Conventional neuroinflammation drugs have limitations due to unidirectional therapeutic approaches and challenges in crossing the Blood-Brain Barrier (BBB). Clinical trials for non-steroidal anti-inflammatory drugs (NSAIDs) and other therapeutics remain uncertain. Novel strategies addressing the complex pathogenesis and BBB translocation are needed to effectively tackle AD-related neuroinflammation. PURPOSE The current scenario demands for a much-sophisticated theranostic measures which could be achieved via customized engineering and designing of novel nanotherapeutics. As, these therapeutics functions as a double edge sword, having the efficiency of unambiguous targeting, multiple drug delivery and ability to cross BBB proficiently. METHODS Inclusion criteria involve selecting recent, English-language studies from the past decade (2013-2023) that explore the regulation of neuroinflammation in neuroinflammation, Alzheimer's disease, amyloid β, tau protein, nanoparticles, autophagy, and phytocompounds. Various study types, including clinical trials, experiments, and reviews, were considered. Exclusion criteria comprised non-relevant publication types, studies unrelated to Alzheimer's disease or phytocompounds, those with methodological flaws, duplicates, and studies with inaccessible data. RESULTS In this study, polymeric nanoparticles loaded with specific phytocompounds and coated with an antibody targeting the transferrin receptor (anti-TfR) present on BBB. Thereafter, the engineered nanoparticles with the ability to efficiently traverse the BBB and interact with target molecules within the brain, could induce autophagy, a cellular process crucial for neuronal health, and exhibit potent anti-inflammatory effects. Henceforth, the proposed combination of desired phytocompounds, polymeric nanoparticles, and anti-TfR coating presents a promising approach for targeted drug delivery to the brain, with potential implications in neuroinflammatory conditions such as Alzheimer's disease.
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Affiliation(s)
- Vinayak Nayak
- ICAR- National Institute on Foot and Mouth Disease-International Centre for Foot and Mouth Disease, Arugul, Bhubaneswar, Odisha (752050), India
| | - Sushmita Patra
- Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra (410210), India
| | - Shrushti Rout
- Department of Biotechnology, Utkal University, Vani Vihar, Bhubaneswar, Odisha (751004), India
| | - Atala Bihari Jena
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (02115), United States of America
| | - Rohit Sharma
- Department of Rasa Shastra and Bhaishajya Kalpana, Faculty of Ayurveda, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh (221005), India
| | - Kali Prasad Pattanaik
- School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, Bhubaneswar 751024, India
| | - Jay Singh
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh (221005), India
| | - Shyam S Pandey
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu (8080196), Japan
| | - Ravindra Pratap Singh
- Department of Biotechnology, Faculty of Science, Indira Gandhi National Tribal University, Amarkantak, Madhya Pradesh 484887, India
| | - Sanatan Majhi
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (02115), United States of America
| | - Kshitij Rb Singh
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu (8080196), Japan.
| | - Rout George Kerry
- Department of Biotechnology, Utkal University, Vani Vihar, Bhubaneswar, Odisha (751004), India.
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Fedele E. Anti-Amyloid Therapies for Alzheimer's Disease and the Amyloid Cascade Hypothesis. Int J Mol Sci 2023; 24:14499. [PMID: 37833948 PMCID: PMC10578107 DOI: 10.3390/ijms241914499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 09/22/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Over the past 30 years, the majority of (pre)clinical efforts to find an effective therapy for Alzheimer's disease (AD) focused on clearing the β-amyloid peptide (Aβ) from the brain since, according to the amyloid cascade hypothesis, the peptide was (and it is still considered by many) the pathogenic determinant of this neurodegenerative disorder. However, as reviewed in this article, results from the numerous clinical trials that have tested anti-Aβ therapies to date indicate that this peptide plays a minor role in the pathogenesis of AD. Indeed, even Aducanumab and Lecanemab, the two antibodies recently approved by the FDA for AD therapy, as well as Donanemab showed limited efficacy on cognitive parameters in phase III clinical trials, despite their capability of markedly lowering Aβ brain load. Furthermore, preclinical evidence demonstrates that Aβ possesses several physiological functions, including memory formation, suggesting that AD may in part be due to a loss of function of this peptide. Finally, it is generally accepted that AD could be the result of many molecular dysfunctions, and therefore, if we keep chasing only Aβ, it means that we cannot see the forest for the trees.
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Affiliation(s)
- Ernesto Fedele
- Pharmacology and Toxicology Unit, Department of Pharmacy, School of Medical and Pharmaceutical Sciences, University of Genoa, Viale Cembrano 4, 16148 Genoa, Italy;
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
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Eden A, Zhao J, Xiao Y, Gibson J, Wang C. Covalent fragment inhibits intramembrane proteolysis. Front Mol Biosci 2022; 9:958399. [PMID: 36158579 PMCID: PMC9490316 DOI: 10.3389/fmolb.2022.958399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/01/2022] [Indexed: 01/09/2023] Open
Abstract
Alzheimer's disease (AD) is a serious public health crisis with only one current modifying treatment. The reduction of amyloid load by targeting γ-secretase (GS) has been a leading approach in AD drug discovery and development. Despite the focus on GS inhibition, multiple GS inhibitors (GSIs) have failed in clinical trials as a result of side effects including exacerbated cognitive decline. These side effects are largely attributable to inhibition of normal GS function. Standard enzyme inhibitors target catalytic or allosteric sites of the enzyme, including the active site presenilin, as previous GSIs did. To avoid issues observed from broad-spectrum GSIs we discovered that fragment 6H8 that covalently binds to the substrate of GS, the transmembrane domain of amyloid precursor protein (APPTM). Nuclear Magnetic Resonance (NMR) Spectroscopy combined with MALDI-TOF-MS established 6H8 covalently binds to APPTM. 6H8 acts as a Michael acceptor and covalently links to the side chain amines of lysine residues, specifically targeting a cluster of C-terminal lysines K53-K55. Through this modification, 6H8 can inhibit intramembrane proteolysis of an archaeal homolog of presenilin (the active subunit of GS) via substrate binding with a 2-4 μM IC50, determined by a gel-based cleavage assay. 6H8, while too small to be an effective drug candidate, can be combined with a specific non-covalent partner and function as an effective covalent warhead of a targeted covalent inhibitor (TCI). The future development of the 6H8 fragment into the covalent warhead of a TCI is, to our knowledge, a novel approach to AD drug discovery.
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Affiliation(s)
- Angela Eden
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY, United States
- Department of Chemistry and Chemical Biology, Troy, NY, United States
- Department of Biological Sciences, Troy, NY, United States
| | - Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY, United States
| | - Yuanyuan Xiao
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY, United States
| | - James Gibson
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY, United States
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Troy, NY, United States
- Department of Chemistry and Chemical Biology, Troy, NY, United States
- Department of Biological Sciences, Troy, NY, United States
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Ayodele T, Rogaeva E, Kurup JT, Beecham G, Reitz C. Early-Onset Alzheimer's Disease: What Is Missing in Research? Curr Neurol Neurosci Rep 2021; 21:4. [PMID: 33464407 PMCID: PMC7815616 DOI: 10.1007/s11910-020-01090-y] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE OF REVIEW Early-onset Alzheimer's disease (EOAD), defined as Alzheimer's disease (AD) occurring before age 65, is significantly less well studied than the late-onset form (LOAD) despite EOAD often presenting with a more aggressive disease progression. The aim of this review is to summarize the current understanding of the etiology of EOAD, their translation into clinical practice, and to suggest steps to be taken to move our understanding forward. RECENT FINDINGS EOAD cases make up 5-10% of AD cases but only 10-15% of these cases show known mutations in the APP, PSEN1, and PSEN2, which are linked to EOAD. New data suggests that these unexplained cases following a non-Mendelian pattern of inheritance is potentially caused by a mix of common and newly discovered rare variants. However, only a fraction of this genetic variation has been identified to date leaving the molecular mechanisms underlying this type of AD and their association with clinical, biomarker, and neuropathological changes unclear. While great advancements have been made in characterizing EOAD, much work is needed to disentangle the molecular mechanisms underlying this type of AD and to identify putative targets for more precise disease screening, diagnosis, prevention, and treatment.
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Affiliation(s)
- Temitope Ayodele
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
- The Gertrude H. Sergievsky Center, Columbia University, New York, NY, USA
- Department of Neurology, Columbia University, New York, NY, USA
| | - Ekaterina Rogaeva
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, 60 Leonard Avenue, Toronto, ON, M5T 0S8, Canada
| | - Jiji T Kurup
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA
| | - Gary Beecham
- The John P. Hussman Institute for Human Genomics, University of Miami, Miami, FL, USA
| | - Christiane Reitz
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, USA.
- The Gertrude H. Sergievsky Center, Columbia University, New York, NY, USA.
- Department of Neurology, Columbia University, New York, NY, USA.
- Department of Epidemiology, Sergievsky Center, Taub Institute for Research on the Aging Brain, Columbia University, 630 W 168th Street, New York, NY, 10032, USA.
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Zhao J, Liu X, Xia W, Zhang Y, Wang C. Targeting Amyloidogenic Processing of APP in Alzheimer's Disease. Front Mol Neurosci 2020; 13:137. [PMID: 32848600 PMCID: PMC7418514 DOI: 10.3389/fnmol.2020.00137] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Alzheimer's disease (AD) is the most common type of senile dementia, characterized by neurofibrillary tangle and amyloid plaque in brain pathology. Major efforts in AD drug were devoted to the interference with the production and accumulation of amyloid-β peptide (Aβ), which plays a causal role in the pathogenesis of AD. Aβ is generated from amyloid precursor protein (APP), by consecutive cleavage by β-secretase and γ-secretase. Therefore, β-secretase and γ-secretase inhibition have been the focus for AD drug discovery efforts for amyloid reduction. Here, we review β-secretase inhibitors and γ-secretase inhibitors/modulators, and their efficacies in clinical trials. In addition, we discussed the novel concept of specifically targeting the γ-secretase substrate APP. Targeting amyloidogenic processing of APP is still a fundamentally sound strategy to develop disease-modifying AD therapies and recent advance in γ-secretase/APP complex structure provides new opportunities in designing selective inhibitors/modulators for AD.
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Affiliation(s)
- Jing Zhao
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Xinyue Liu
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Weiming Xia
- Geriatric Research Education Clinical Center, Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, United States
- Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
| | - Yingkai Zhang
- Department of Chemistry, New York University, New York, NY, United States
| | - Chunyu Wang
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, United States
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Kim K, Yu J, Kang JK, Morrow JP, Pajvani UB. Liver-selective γ-secretase inhibition ameliorates diet-induced hepatic steatosis, dyslipidemia and atherosclerosis. Biochem Biophys Res Commun 2020; 527:979-984. [PMID: 32439159 DOI: 10.1016/j.bbrc.2020.04.157] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 04/30/2020] [Indexed: 01/05/2023]
Abstract
Hepatic γ-secretase regulates low-density lipoprotein receptor (LDLR) cleavage and degradation, affecting clearance of plasma triglyceride (TG)-rich lipoproteins (TRLs). In this study, we investigated whether γ-secretase inhibition modulates risk of Western (high-fat/sucrose and high-cholesterol)-type diet (WTD)-induced hepatic steatosis, dyslipidemia and atherosclerosis. We evaluated liver and plasma lipids in WTD-fed mice with hepatocyte-specific ablation of the non-redundant γ-secretase-targeting subunit Nicastrin (L-Ncst). In parallel, we investigated the effect of liver-selective Ncst antisense oligonucleotides (ASO) on lipid metabolism and atherosclerosis in wildtype (WT) and ApoE knockout (ApoE-/-) mice fed normal chow or WTD. WTD-fed L-Ncst and Ncst ASO-treated WT mice showed reduced total cholesterol and LDL-cholesterol (LDL-C), as well as reduced hepatic lipid content as compared to Cre- and control ASO-treated WT mice. Treatment of WTD-fed ApoE-/- mice with Ncst ASO markedly lowered total and LDL cholesterol, hepatic TG and attenuated atherosclerotic lesions in the aorta, as compared to control ASO-treated mice. L-Ncst and Ncst ASO similarly showed reduced plasma glucose as compared to control mice. In conclusion, inhibition of hepatic γ-secretase reduces plasma glucose, and attenuates WTD-induced dyslipidemia, hepatic fat accumulation and atherosclerosis, suggesting potential pleiotropic application for diet-induced metabolic dysfunction.
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Affiliation(s)
- KyeongJin Kim
- Department of Medicine, Columbia University, New York, NY, 10032, USA; Department of Biomedical Sciences, College of Medicine, Inha University, Incheon, 22212, South Korea.
| | - Junjie Yu
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Jin Ku Kang
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - John P Morrow
- Department of Medicine, Columbia University, New York, NY, 10032, USA
| | - Utpal B Pajvani
- Department of Medicine, Columbia University, New York, NY, 10032, USA.
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Sushma, Mondal AC. Role of GPCR signaling and calcium dysregulation in Alzheimer's disease. Mol Cell Neurosci 2019; 101:103414. [PMID: 31655116 DOI: 10.1016/j.mcn.2019.103414] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/17/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD), a late onset neurodegenerative disorder is characterized by the loss of memory, disordered cognitive function, caused by accumulation of amyloid-β (Aβ) peptide and neurofibrillary tangles (NFTs) in the neocortex and hippocampal brain area. Extensive research has been done on the findings of the disease etiology or pathological causes of aggregation of Aβ and hyperphosphorylation of tau protein without much promising results. Recently, calcium dysregulation has been reported to play an important role in the pathophysiology of AD. Calcium ion acts as one of the major secondary messengers, regulates many signaling pathways involved in cell survival, proliferation, differentiation, transcription and apoptosis. Calcium signaling is one of the major signaling pathways involved in the formation of memory, generation of energy and other physiological functions. It also can modulate function of many proteins upon binding. Dysregulation in calcium homeostasis leads to many physiological changes leading to neurodegenerative diseases including AD. In AD, GPCRs generate secondary messengers which regulate calcium homeostasis inside the cell and is reported to be disturbed in the pathological condition. Calcium channels and receptors present on the plasma membrane and intracellular organelle maintain calcium homeostasis through different signaling mechanisms. In this review, we have summarized the different calcium channels and receptors involved in calcium dysregulation which in turn play a critical role in the pathogenesis of AD. Understanding the role of calcium channels and GPCRs to maintain calcium homeostasis is an attempt to develop effective AD treatments.
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Affiliation(s)
- Sushma
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India
| | - Amal Chandra Mondal
- Laboratory of Cellular and Molecular Neurobiology, School of Life Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India.
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Toro CA, Zhang L, Cao J, Cai D. Sex differences in Alzheimer's disease: Understanding the molecular impact. Brain Res 2019; 1719:194-207. [PMID: 31129153 DOI: 10.1016/j.brainres.2019.05.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 04/10/2019] [Accepted: 05/22/2019] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder that presents with cognitive impairment and behavioral disturbance. Approximately 5.5 million people in the United States live with AD, most of whom are over the age of 65 with two-thirds being woman. There have been major advancements over the last decade or so in the understanding of AD neuropathological changes and genetic involvement. However, studies of sex impact in AD have not been adequately integrated into the investigation of disease development and progression. It becomes indispensable to acknowledge in both basic science and clinical research studies the importance of understanding sex-specific differences in AD pathophysiology and pathogenesis, which could guide future effort in the discovery of novel targets for AD. Here, we review the latest and most relevant literature on this topic, highlighting the importance of understanding sex dimorphism from a molecular perspective and its association to clinical trial design and development in AD research field.
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Affiliation(s)
- Carlos A Toro
- National Center for the Medical Consequences of Spinal Cord Injury, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Larry Zhang
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Jiqing Cao
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
| | - Dongming Cai
- Research and Development, James J Peters VA Medical Center, Bronx, NY 10468, United States; Neurology Section, James J Peters VA Medical Center, Bronx, NY 10468, United States; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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Locke GM, Bernhard SSR, Senge MO. Nonconjugated Hydrocarbons as Rigid-Linear Motifs: Isosteres for Material Sciences and Bioorganic and Medicinal Chemistry. Chemistry 2019; 25:4590-4647. [PMID: 30387906 DOI: 10.1002/chem.201804225] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 10/20/2018] [Indexed: 01/02/2023]
Abstract
Nonconjugated hydrocarbons, like bicyclo[1.1.1]pentane, bicyclo[2.2.2]octane, triptycene, and cubane are a unique class of rigid linkers. Due to their similarity in size and shape they are useful mimics of classic benzene moieties in drugs, so-called bioisosteres. Moreover, they also fulfill an important role in material sciences as linear linkers, in order to arrange various functionalities in a defined spatial manner. In this Review article, recent developments and usages of these special, rectilinear systems are discussed. Furthermore, we focus on covalently linked, nonconjugated linear arrangements and discuss the physical and chemical properties and differences of individual linkers, as well as their application in material and medicinal sciences.
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Affiliation(s)
- Gemma M Locke
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland
| | - Stefan S R Bernhard
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland
| | - Mathias O Senge
- School of Chemistry, SFI Tetrapyrrole Laboratory, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, 152-160 Pearse Street, Dublin, 2, Ireland
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10
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The multifaceted role of Notch signal in regulating T cell fate. Immunol Lett 2019; 206:59-64. [PMID: 30629981 DOI: 10.1016/j.imlet.2019.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/28/2018] [Accepted: 01/05/2019] [Indexed: 11/22/2022]
Abstract
Notch signaling pathway facilitates important cellular functions of the host. Notch signal is essential for the development of T cells, and the role of Notch in fine tuning of αβ versus γδ T cell lineage commitment is fundamentally different in mice and human. The Notch family of cell surface receptor likewise plays a critical role in regulating T cell activation, and influences T cell response both intrinsically and through the local environment. In this review, we take an overview of Notch signaling pathway and also emphasize the role of Notch signal in T cell lineage differentiation and activating effector function of peripheral T cells.
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Takatori S, Wang W, Iguchi A, Tomita T. Genetic Risk Factors for Alzheimer Disease: Emerging Roles of Microglia in Disease Pathomechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1118:83-116. [PMID: 30747419 DOI: 10.1007/978-3-030-05542-4_5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The accumulation of aggregated amyloid β (Aβ) peptides in the brain is deeply involved in Alzheimer disease (AD) pathogenesis. Mutations in APP and presenilins play major roles in Aβ pathology in rare autosomal-dominant forms of AD, whereas pathomechanisms of sporadic AD, accounting for the majority of cases, remain unknown. In this chapter, we review current knowledge on genetic risk factors of AD, clarified by recent advances in genome analysis technology. Interestingly, TREM2 and many genes associated with disease risk are predominantly expressed in microglia, suggesting that these risk factors are involved in pathogenicity through common mechanisms involving microglia. Therefore, we focus on factors closely associated with microglia and discuss their possible roles in pathomechanisms of AD. Furthermore, we review current views on the pathological roles of microglia and emphasize the importance of microglial changes in response to Aβ deposition and mechanisms underlying the phenotypic changes. Importantly, functional outcomes of microglial activation can be both protective and deleterious to neurons. We further describe the involvement of microglia in tau pathology and the activation of other glial cells. Through these topics, we shed light on microglia as a promising target for drug development for AD and other neurological disorders.
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Affiliation(s)
- Sho Takatori
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Wenbo Wang
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Akihiro Iguchi
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Tomita
- Laboratory of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
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Wyss JC, Kumar R, Mikulic J, Schneider M, Aebi JD, Juillerat-Jeanneret L, Golshayan D. Targeted γ-secretase inhibition of Notch signaling activation in acute renal injury. Am J Physiol Renal Physiol 2018; 314:F736-F746. [DOI: 10.1152/ajprenal.00414.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Notch pathway has been reported to control tissue damage in acute kidney diseases. To investigate potential beneficial nephroprotective effects of targeting Notch, we developed chemically functionalized γ-secretase inhibitors (GSIs) targeting γ-glutamyltranspeptidase (γ-GT) and/or γ-glutamylcyclotransferase (γ-GCT), two enzymes overexpressed in the injured kidney, and evaluated them in in vivo murine models of acute tubular and glomerular damage. Exposure of the animals to disease-inducing drugs together with the functionalized GSIs improved proteinuria and, to some extent, kidney dysfunction. The expression of genes involved in the Notch pathway, acute inflammatory stress responses, and the renin-angiotensin system was enhanced in injured kidneys, which could be downregulated upon administration of functionalized GSIs. Immunohistochemistry staining and Western blots demonstrated enhanced activation of Notch1 as detected by its cleaved active intracellular domain during acute kidney injury, and this was downregulated by concomitant treatment with the functionalized GSIs. Thus targeted γ-secretase-based prodrugs developed as substrates for γ-GT/γ-GCT have the potential to selectively control Notch activation in kidney diseases with subsequent regulation of the inflammatory stress response and the renin-angiotensin pathways.
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Affiliation(s)
- Jean-Christophe Wyss
- Transplantation Center and Transplantation Immunopathology Laboratory, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Rajesh Kumar
- Transplantation Center and Transplantation Immunopathology Laboratory, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Josip Mikulic
- Transplantation Center and Transplantation Immunopathology Laboratory, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Manfred Schneider
- Medicinal Chemistry, Roche Pharma Research and Early Development, Roche Innovation Center, F. Hoffmann-La Roche, Basel, Switzerland
| | - Johannes D. Aebi
- Medicinal Chemistry, Roche Pharma Research and Early Development, Roche Innovation Center, F. Hoffmann-La Roche, Basel, Switzerland
| | - Lucienne Juillerat-Jeanneret
- Transplantation Center and Transplantation Immunopathology Laboratory, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
- University Institute of Pathology, CHUV and UNIL, Lausanne, Switzerland
| | - Dela Golshayan
- Transplantation Center and Transplantation Immunopathology Laboratory, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
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13
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Kim K, Goldberg IJ, Graham MJ, Sundaram M, Bertaggia E, Lee SX, Qiang L, Haeusler RA, Metzger D, Chambon P, Yao Z, Ginsberg HN, Pajvani UB. γ-Secretase Inhibition Lowers Plasma Triglyceride-Rich Lipoproteins by Stabilizing the LDL Receptor. Cell Metab 2018; 27:816-827.e4. [PMID: 29576536 PMCID: PMC5884729 DOI: 10.1016/j.cmet.2018.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 12/14/2017] [Accepted: 02/14/2018] [Indexed: 12/31/2022]
Abstract
Excess plasma triglycerides (TGs) are a key component of obesity-induced metabolic syndrome. We have shown that γ-secretase inhibitor (GSI) treatment improves glucose tolerance due to inhibition of hepatic Notch signaling but found additional Notch-independent reduction of plasma TG-rich lipoproteins (TRLs) in GSI-treated, as well as hepatocyte-specific, γ-secretase knockout (L-Ncst) mice, which suggested a primary effect on hepatocyte TRL uptake. Indeed, we found increased VLDL and LDL particle uptake in L-Ncst hepatocytes and Ncst-deficient hepatoma cells, in part through reduced γ-secretase-mediated low-density lipoprotein receptor (LDLR) cleavage and degradation. To exploit this novel finding, we generated a liver-selective Nicastrin ASO, which recapitulated glucose and lipid improvements of L-Ncst mice, with increased levels of hepatocyte LDLR. Collectively, these results identify the role of hepatic γ-secretase to regulate LDLR and suggest that liver-specific GSIs may simultaneously improve multiple aspects of the metabolic syndrome.
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Affiliation(s)
- KyeongJin Kim
- Department of Medicine, Columbia University, New York, NY, USA
| | - Ira J Goldberg
- Department of Medicine, New York University, New York, NY, USA
| | | | - Meenakshi Sundaram
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Enrico Bertaggia
- Departments of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Samuel X Lee
- Departments of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Li Qiang
- Departments of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Rebecca A Haeusler
- Departments of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | | | | | - Zemin Yao
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | | | - Utpal B Pajvani
- Department of Medicine, Columbia University, New York, NY, USA.
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14
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Lovell MA, Lynn BC, Fister S, Bradley-Whitman M, Murphy MP, Beckett TL, Norris CM. A Novel Small Molecule Modulator of Amyloid Pathology. J Alzheimers Dis 2018; 53:273-87. [PMID: 27163808 DOI: 10.3233/jad-151160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Because traditional approaches to drug development for Alzheimer's disease are becoming increasingly expensive and in many cases disappointingly unsuccessful, alternative approaches are required to shift the paradigm. Following leads from investigations of dihydropyridine calcium channel blockers, we observed unique properties from a class of functionalized naphthyridines and sought to develop these as novel therapeutics that minimize amyloid pathology without the adverse effects associated with current therapeutics. Our data show methyl 2,4-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine-1-carboxylate (BNC-1) significantly decreases amyloid burden in a well-established mouse model of amyloid pathology through a unique mechanism mediated by Elk-1, a transcriptional repressor of presenilin-1. Additionally, BNC-1 treatment leads to increased levels of synaptophysin and synapsin, markers of synaptic integrity, but does not adversely impact presenilin-2 or processing of Notch-1, thus avoiding negative off target effects associated with pan-gamma secretase inhibition. Overall, our data show BNC-1 significantly decreases amyloid burden and improves markers of synaptic integrity in a well-established mouse model of amyloid deposition by promoting phosphorylation and activation of Elk-1, a transcriptional repressor of presenilin-1 but not presenilin-2. These data suggest BNC-1 might be a novel, disease-modifying therapeutic that will alter the pathogenesis of Alzheimer's disease.
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Affiliation(s)
- Mark A Lovell
- Department of Chemistry, University of Kentucky, Lexington, KY, USA.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Bert C Lynn
- Department of Chemistry, University of Kentucky, Lexington, KY, USA.,Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.,Universisty of Kentucky Mass Spectrometry Center, Lexington, KY, USA
| | - Shuling Fister
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | | | - M Paul Murphy
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.,Department of Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Tina L Beckett
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.,Department of Pharmacology, University of Kentucky, Lexington, KY, USA
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15
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Wang C, Shou Y, Pan J, Du Y, Liu C, Wang H. The relationship between cholesterol level and Alzheimer’s disease-associated APP proteolysis/Aβ metabolism. Nutr Neurosci 2018; 22:453-463. [DOI: 10.1080/1028415x.2017.1416942] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Chaoqun Wang
- School of Medicine, Hangzhou Normal University, Hangzhou, People’s Republic of China
| | - Yikai Shou
- School of Medicine, Hangzhou Normal University, Hangzhou, People’s Republic of China
| | - Jie Pan
- Department of Endocrinology and Metabolism, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
- Institute of Gastroenterology, Zhejiang University, Hangzhou, People’s Republic of China
| | - Yue Du
- School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
| | - Cuiqing Liu
- College of Basic Medicine, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
| | - Huanhuan Wang
- School of Medicine, Hangzhou Normal University, Hangzhou, People’s Republic of China
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16
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Genetic Complexity of Early-Onset Alzheimer’s Disease. NEURODEGENER DIS 2018. [DOI: 10.1007/978-3-319-72938-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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17
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Naveed M, Imran K, Mushtaq A, Mumtaz AS, Janjua HA, Khalid N. In silicofunctional and tumor suppressor role of hypothetical protein PCNXL2 with regulation of the Notch signaling pathway. RSC Adv 2018; 8:21414-21430. [PMID: 35539910 PMCID: PMC9080940 DOI: 10.1039/c8ra00589c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 05/31/2018] [Indexed: 12/21/2022] Open
Abstract
Since the last decade, various genome sequencing projects have led to the accumulation of an enormous set of genomic data; however, numerous protein-coding genes still need to be functionally characterized. These gene products are called “hypothetical proteins”. The hypothetical protein pecanex-like protein 2 Homo sapiens (PCNXL2) is found to be mutated in colorectal carcinoma with microsatellite instability; therefore, annotation of the function of PCNXL2 in tumorigenesis is very important. In the present study, bioinformatics analysis of PCNXL2 was performed at the molecular level to assess its role in the progression of cancer for designing new anti-cancer drugs. The retrieved sequence of PCNXL2 was functionally and structurally characterized through the web tools Pfam, Batch CD (conserved domain) search, ExPASy, COACH and I-TASSER directed for pathway analysis and design to explore the intercellular interactions of PCNXL2 involved in cancer development. The present study has shown that PCNXL2 encodes multi-pass transmembrane proteins whose tumor suppressor function may involve regulating Notch signaling by transporting protons across the membrane to provide suitable membrane potential for γ secretase function, which may liberate the Notch intracellular domain NICD from the receptor to inside the cell. Furthermore, domain A of PCNXL2 may exhibit nuclear transport activity of NICD from the cytoplasm to the nucleus through interaction with a nuclear localization signal that may act as an activator for Notch signaling in the nucleus. Conclusively, the tumor suppressor role of PCNXL2 by regulation of the Notch signaling pathway and its functional and structural characteristics are important findings. However, further studies are required to validate the putative role of PCNXL2 as a cancer biomarker in cancer development. Since the last decade, various genome sequencing projects have led to the accumulation of an enormous set of genomic data; however, numerous protein-coding genes still need to be functionally characterized.![]()
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Affiliation(s)
- Muhammad Naveed
- Department of Biotechnology
- Faculty of Life Sciences
- University of Central Punjab
- Lahore 5400
- Pakistan
| | - Komal Imran
- Department of Biotechnology and Biochemistry
- University of Gujrat
- Gujrat 50700
- Pakistan
| | - Ayesha Mushtaq
- Department of Biotechnology and Biochemistry
- University of Gujrat
- Gujrat 50700
- Pakistan
| | - Abdul Samad Mumtaz
- Department of Plant Sciences
- Quaid-i-Azam University
- Islamabad 44500
- Pakistan
| | - Hussnain A. Janjua
- Department of Industrial Biotechnology
- Att-Ur-Rahman School of Applied Biosciences
- National University of Sciences and Technology
- Islamabad
- Pakistan
| | - Nauman Khalid
- School of Food and Agricultural Sciences
- University of Management and Technology
- Lahore 54000
- Pakistan
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18
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Nasrin A, Hassan M, Ye P. Inhibition of Notch signaling pathway using γ-secretase inhibitor delivered by a low dose of Triton-X100 in cultured oral cancer cells. Biochem Biophys Res Commun 2017; 495:2118-2124. [PMID: 29253571 DOI: 10.1016/j.bbrc.2017.12.082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 12/15/2017] [Indexed: 01/23/2023]
Abstract
How to effectively delivering therapeutic agents, including γ-secretase inhibitors (GSIs), into live cells, remains a significant challenge. This study assessed the effect of Notch signaling inhibition by examining levels of the Notch1 intracellular domain (N1ICD) in cultured oral cancer cells analyzed with random stitched images (2D) and 3D visualizations using confocal microscopy and quantitative gene analysis. Substantially, we have developed a novel method to assist the delivery of γ-secretase inhibitor, DAPT, into live cells in the presence of an effective minimum concentration of Triton-X100 (0.001%) without damaging cell activity and membrane integrity assessed with cell proliferation assays. The images obtained in this study showed that DAPT alone could not block the γ-secretase inhibitor despite inhibiting cell growth. Further analysis of quantitative gene expressions of Notch signaling canonical pathway to verify the effectiveness of the novel method for delivering inhibitor into live cells, displayed deregulation of Notch1, Delta-like ligand 1 (DLL1) and hairy and enhancer of split 1 (Hes1). Our data suggest that Notch1/Hes1 signaling pathway is deactivated using DAPT with a low dose of Triton-X100 in this cancer cells. And the finding also suggests that Notch1 could be engaged by DLL1 to promote differentiation in oral cancer cells. Using this approach, we demonstrate that Triton-X100 is a promising and effective permeabilization agent to deliver γ-secretase inhibitor DAPT into live oral epithelial cells. This strategy has the potential to implicate in the treatment of cancer diseases.
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Affiliation(s)
- Aklima Nasrin
- Faculty of Dentistry, The University of Sydney, Sydney, Australia
| | - Mahbub Hassan
- School of Chemical & Biomolecular Engineering, The University of Sydney, Sydney, Australia
| | - Ping Ye
- Faculty of Dentistry, The University of Sydney, Sydney, Australia; Institute of Dental Research, Centre for Oral Health, Westmead Hospital, Westmead, Australia.
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19
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Anderson DB, Zanella CA, Henley JM, Cimarosti H. Sumoylation: Implications for Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:261-281. [PMID: 28197918 DOI: 10.1007/978-3-319-50044-7_16] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The covalent posttranslational modifications of proteins are critical events in signaling cascades that enable cells to efficiently, rapidly and reversibly respond to extracellular stimuli. This is especially important in the CNS where the processes affecting synaptic communication between neurons are highly complex and very tightly regulated. Sumoylation regulates the function and fate of a diverse array of proteins and participates in the complex cell signaling pathways required for cell survival. One of the most complex signaling pathways is synaptic transmission.Correct synaptic function is critical to the working of the brain and its alteration through synaptic plasticity mediates learning, mental disorders and stroke. The investigation of neuronal sumoylation is a new and exciting field and the functional and pathophysiological implications are far-reaching. Sumoylation has already been implicated in a diverse array of neurological disorders. Here we provide an overview of current literature highlighting recent insights into the role of sumoylation in neurodegeneration. In addition we present a brief assessment of drug discovery in the analogous ubiquitin system and extrapolate on the potential for development of novel therapies that might target SUMO-associated mechanisms of neurodegenerative disease.
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Affiliation(s)
- Dina B Anderson
- Ipsen Bioinnovation Ltd, Units 4-10 The Quadrant, Barton Lane, Abingdon, OX14 3YS, UK
| | - Camila A Zanella
- Department of Pharmacology, Federal University of Santa Catarina, Campus Universitario - Trindade, Florianopolis, CEP, 88040-900, Brazil
| | - Jeremy M Henley
- MRC Centre for Synaptic Plasticity, School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Helena Cimarosti
- Department of Pharmacology, Federal University of Santa Catarina, Campus Universitario - Trindade, Florianopolis, CEP, 88040-900, Brazil.
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20
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Cynis H, Frost JL, Crehan H, Lemere CA. Immunotherapy targeting pyroglutamate-3 Aβ: prospects and challenges. Mol Neurodegener 2016; 11:48. [PMID: 27363697 PMCID: PMC4929720 DOI: 10.1186/s13024-016-0115-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 06/24/2016] [Indexed: 12/17/2022] Open
Abstract
Immunization against amyloid-β (Aβ) peptides deposited in Alzheimer’s disease (AD) has shown considerable therapeutic effect in animal models however, the translation into human Alzheimer’s patients is challenging. In recent years, a number of promising Aβ immunotherapy trials failed to reach primary study endpoints. Aside from uncertainties in the selection of patients and the start and duration of treatment, these results also suggest that the mechanisms underlying AD are still not fully understood. Thorough characterizations of protein aggregates in AD brain have revealed a conspicuous heterogeneity of Aβ peptides enabling the study of the toxic potential of each of the major forms. One such form, amino-terminally truncated and modified pyroglutamate (pGlu)-3 Aβ peptide appears to play a seminal role for disease initiation, qualifying it as novel target for immunotherapy approaches.
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Affiliation(s)
- Holger Cynis
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, NRB636, Boston, MA, 02115, USA.,Fraunhofer Institute for Cell Therapy and Immunology, Weinbergweg 22, 06120, Halle, Germany
| | - Jeffrey L Frost
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, NRB636, Boston, MA, 02115, USA.,University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA, 01605, USA
| | - Helen Crehan
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, NRB636, Boston, MA, 02115, USA
| | - Cynthia A Lemere
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, NRB636, Boston, MA, 02115, USA.
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21
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Kumar R, Juillerat-Jeanneret L, Golshayan D. Notch Antagonists: Potential Modulators of Cancer and Inflammatory Diseases. J Med Chem 2016; 59:7719-37. [DOI: 10.1021/acs.jmedchem.5b01516] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Rajesh Kumar
- Transplantation
Center and Transplantation Immunopathology Laboratory, Department
of Medicine and ‡University Institute of Pathology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
| | - Lucienne Juillerat-Jeanneret
- Transplantation
Center and Transplantation Immunopathology Laboratory, Department
of Medicine and ‡University Institute of Pathology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
| | - Dela Golshayan
- Transplantation
Center and Transplantation Immunopathology Laboratory, Department
of Medicine and ‡University Institute of Pathology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
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22
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Drosophila melanogaster as a Model for Studies on the Early Stages of Alzheimer's Disease. Methods Mol Biol 2016; 1303:227-39. [PMID: 26235070 DOI: 10.1007/978-1-4939-2627-5_13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fruit flies (Drosophila melanogaster) have been widely used to study the cellular and molecular basis of human neurodegenerative disease. The biological similarities between the human and the fly have been explored successfully to further investigate the pathological basis of Alzheimer's disease (AD). Here, we discuss transgenic Drosophila models systems and the methodologies that have been employed in the study of AD.
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23
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Juillerat-Jeanneret L, Flohr A, Schneider M, Walter I, Wyss JC, Kumar R, Golshayan D, Aebi JD. Targeted γ-Secretase Inhibition To Control the Notch Pathway in Renal Diseases. J Med Chem 2015; 58:8097-109. [DOI: 10.1021/acs.jmedchem.5b00912] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lucienne Juillerat-Jeanneret
- Transplantation
Center, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
- University
Institute of Pathology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
| | - Alexander Flohr
- Medicinal
Chemistry, Roche Pharma Research and Early Development (pRED), Roche
Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
| | - Manfred Schneider
- Medicinal
Chemistry, Roche Pharma Research and Early Development (pRED), Roche
Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
| | - Isabelle Walter
- Medicinal
Chemistry, Roche Pharma Research and Early Development (pRED), Roche
Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
| | - Jean-Christophe Wyss
- Transplantation
Center, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
| | - Rajesh Kumar
- Transplantation
Center, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
| | - Dela Golshayan
- Transplantation
Center, Department of Medicine, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), CH-1011 Lausanne, Switzerland
| | - Johannes D. Aebi
- Medicinal
Chemistry, Roche Pharma Research and Early Development (pRED), Roche
Innovation Center Basel, F. Hoffmann-La Roche Ltd., CH-4070 Basel, Switzerland
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24
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Calcium Channel Blockers, Progression to Dementia, and Effects on Amyloid Beta Peptide Production. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015. [PMID: 26221415 PMCID: PMC4499419 DOI: 10.1155/2015/787805] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Previous epidemiologic studies suggest that antihypertensive drugs may be protective against cognitive decline. To determine if subjects enrolled in the University of Kentucky longitudinal aging study who used antihypertensive drugs showed diminished progression to dementia, we used a 3-parameter logistic regression model to compare the rate of progression to dementia for subjects who used any of the five common categories of antihypertensive drugs to those with similar demographic characteristics but who did not use antihypertensives. Regression modeling showed that subjects who used calcium channel blockers (CCBs) but not the other classes of antihypertensives showed a significant decrease in the rate of progression to dementia. Significantly, use of CCBs ameliorated the negative effects of the presence of APOE-4 alleles on cognitive decline. To determine if CCBs could minimize amyloid beta peptide (Aβ1–42) production, H4 neuroglioma cultures transfected to overexpress APP were treated with various CCBs and Aβ1–42 levels and levels of proteins involved in Aβ production were quantified. Results show that treatment with nifedipine led to a significant decrease in levels of Aβ1–42, with no significant decrease in cell viability. Collectively, these data suggest that use of CCBs significantly diminishes the rate of progression to dementia and may minimize formation of Aβ1–42.
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25
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Evans AR, Gu L, Guerrero R, Robinson RAS. Global cPILOT analysis of the APP/PS-1 mouse liver proteome. Proteomics Clin Appl 2015; 9:872-84. [PMID: 25620666 DOI: 10.1002/prca.201400149] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/20/2014] [Accepted: 01/21/2015] [Indexed: 12/19/2022]
Abstract
PURPOSE A quantitative proteomics strategy called combined precursor isotopic labeling and isobaric tagging (cPILOT) was designed to discover alterations in the amyloid precursor protein/presenilin-1 (APP/PS-1) mouse liver proteome. The multiplexing strategy allows simultaneous quantitation of 12 samples in a single experiment. EXPERIMENTAL DESIGN For cPILOT samples, six APP/PS-1 and six heterozygous mouse livers were modified using precursor dimethylation (pH 2.5) followed by isobaric tagging (pH 8.0). Samples were pooled, fractioned with strong cation exchange, and analyzed using RPLC-MS(3) for protein identification and relative quantitation. In order to increase proteome coverage, a two-tiered data collection strategy was employed. Six duplex precursor dimethylation experiments were also performed to verify cPILOT protein quantitation. RESULTS The combination of cPILOT with precursor dimethylation data resulted in 2437 total liver proteins identified and 77 differentially expressed proteins in APP/PS-1 liver. Differentially expressed proteins are involved in metabolic processes such as B-oxidation, pyruvate metabolism, and glucose regulation. CONCLUSIONS AND CLINICAL RELEVANCE cPILOT expands protein quantitation using isobaric tags and can be applied to any clinical laboratory interested in enhanced multiplexing strategies. Differentially expressed proteins in APP/PS-1 mouse liver suggest the potential use of ketone bodies to alleviate metabolic dysregulation in Alzheimer's disease brain. Our work also suggests alterations in the alanine cycle potentially leading to hyperammonia production, may contribute to Alzheimer's disease pathogenesis.
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Affiliation(s)
- Adam R Evans
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Liqing Gu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rodolfo Guerrero
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Renã A S Robinson
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
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26
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Onodera T, Futai E, Kan E, Abe N, Uchida T, Kamio Y, Kaneko J. Phosphatidylethanolamine plasmalogen enhances the inhibiting effect of phosphatidylethanolamine on -secretase activity. J Biochem 2014; 157:301-9. [DOI: 10.1093/jb/mvu074] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 10/11/2014] [Indexed: 11/14/2022] Open
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27
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Itakura S, Hama S, Ohgita T, Kogure K. Development of nanoparticles incorporating a novel liposomal membrane destabilization peptide for efficient release of cargos into cancer cells. PLoS One 2014; 9:e111181. [PMID: 25343714 PMCID: PMC4208851 DOI: 10.1371/journal.pone.0111181] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/26/2014] [Indexed: 01/21/2023] Open
Abstract
In anti-cancer therapy mediated by a nanoparticle-based drug delivery system (DDS), overall efficacy depends on the release efficiency of cargos from the nanoparticles in the cancer cells as well as the specificity of delivery to tumor tissue. However, conventional liposome-based DDS have no mechanism for specifically releasing the encapsulated cargos inside the cancer cells. To overcome this barrier, we developed nanoparticles containing a novel liposomal membrane destabilization peptide (LMDP) that can destabilize membranes by cleavage with intramembranous proteases on/in cancer cells. Calcein encapsulated in liposomes modified with LMDP (LMDP-lipo) was effectively released in the presence of a membrane fraction containing an LMDP-cleavable protease. The release was inhibited by a protease inhibitor, suggesting that LMDP-lipo could effectively release its cargo into cells in response to a cancer-specific protease. Moreover, when LMDP-lipo contained fusogenic lipids, the release of cargo was accelerated, suggesting that the fusion of LMDP-lipo with cellular membranes was the initial step in the intracellular delivery. Time-lapse microscopic observations showed that the release of cargo from LMDP-lipo occurred immediately after association of LMDP-lipo with target cells. Consequently, LMDP-lipo could be a useful nanoparticle capable of effective release of cargos specifically into targeted cancer cells.
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Affiliation(s)
- Shoko Itakura
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Susumu Hama
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Takashi Ohgita
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kentaro Kogure
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
- * E-mail:
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28
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Combined treatment with a BACE inhibitor and anti-Aβ antibody gantenerumab enhances amyloid reduction in APPLondon mice. J Neurosci 2014; 34:11621-30. [PMID: 25164658 DOI: 10.1523/jneurosci.1405-14.2014] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Therapeutic approaches for prevention or reduction of amyloidosis are currently a main objective in basic and clinical research on Alzheimer's disease. Among the agents explored in clinical trials are anti-Aβ peptide antibodies and secretase inhibitors. Most anti-Aβ antibodies are considered to act via inhibition of amyloidosis and enhanced clearance of existing amyloid, although secretase inhibitors reduce the de novo production of Aβ. Limited information is currently available on the efficacy and potential advantages of combinatorial antiamyloid treatment. We performed a chronic study in APPLondon transgenic mice that received treatment with anti-Aβ antibody gantenerumab and BACE inhibitor RO5508887, either as mono- or combination treatment. Treatment aimed to evaluate efficacy on amyloid progression, similar to preexisting amyloidosis as present in Alzheimer's disease patients. Mono-treatments with either compound caused a dose-dependent reduction of total brain Aβ and amyloid burden. Combination treatment with both compounds significantly enhanced the antiamyloid effect. The observed combination effect was most pronounced for lowering of amyloid plaque load and plaque number, which suggests effective inhibition of de novo plaque formation. Moreover, significantly enhanced clearance of pre-existing amyloid plaques was observed when gantenerumab was coadministered with RO5508887. BACE inhibition led to a significant time- and dose-dependent decrease in CSF Aβ, which was not observed for gantenerumab treatment. Our results demonstrate that combining these two antiamyloid agents enhances overall efficacy and suggests that combination treatments may be of clinical relevance.
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Ludtmann MHR, Otto GP, Schilde C, Chen ZH, Allan CY, Brace S, Beesley PW, Kimmel AR, Fisher P, Killick R, Williams RSB. An ancestral non-proteolytic role for presenilin proteins in multicellular development of the social amoeba Dictyostelium discoideum. J Cell Sci 2014; 127:1576-84. [PMID: 24463814 PMCID: PMC3970561 DOI: 10.1242/jcs.140939] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 12/29/2013] [Indexed: 11/20/2022] Open
Abstract
Mutations in either of two presenilin genes can cause familial Alzheimer's disease. Presenilins have both proteolysis-dependent functions, as components of the γ-secretase complex, and proteolysis-independent functions in signalling. In this study, we investigate a conserved function of human presenilins in the development of the simple model organism Dictyostelium discoideum. We show that the block in Dictyostelium development caused by the ablation of both Dictyostelium presenilins is rescued by the expression of human presenilin 1, restoring the terminal differentiation of multiple cell types. This developmental role is independent of proteolytic activity, because the mutation of both catalytic aspartates does not affect presenilin ability to rescue development, and the ablation of nicastrin, a γ-secretase component that is crucial for proteolytic activity, does not block development. The role of presenilins during Dictyostelium development is therefore independent of their proteolytic activity. However, presenilin loss in Dictyostelium results in elevated cyclic AMP (cAMP) levels and enhanced stimulation-induced calcium release, suggesting that presenilins regulate these intracellular signalling pathways. Our data suggest that presenilin proteins perform an ancient non-proteolytic role in regulating intracellular signalling and development, and that Dictyostelium is a useful model for analysing human presenilin function.
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Affiliation(s)
- Marthe H. R. Ludtmann
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London TW20 0EX, UK
| | - Grant P. Otto
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London TW20 0EX, UK
| | | | - Zhi-Hui Chen
- School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Claire Y. Allan
- Faculty of Science, Technology and Engineering, La Trobe University, Bundoora VIC 3086, Australia
| | - Selina Brace
- Centre for Ecology and Evolution, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - Philip W. Beesley
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London TW20 0EX, UK
| | - Alan R. Kimmel
- NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul Fisher
- Faculty of Science, Technology and Engineering, La Trobe University, Bundoora VIC 3086, Australia
| | - Richard Killick
- Institute of Psychiatry, King's College London, London SE5 8AF, UK
| | - Robin S. B. Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London TW20 0EX, UK
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Abstract
Ubiquitin-dependent proteolysis is a major mechanism that downregulates misfolded proteins or those that have finished a programmed task. In the last two decades, neddylation has emerged as a major regulatory pathway for ubiquitination. Central to the neddylation pathway is the amyloid precursor protein (APP)-binding protein APP-BP1, which together with Uba3, plays an analogous role to the ubiquitin-activating enzyme E1 in nedd8 activation. Activated nedd8 covalently modifies and activates a major class of ubiquitin ligases called Cullin-RING ligases (CRLs). New evidence suggests that neddylation also modifies Type-1 transmembrane receptors such as APP. Here we review the functions of neddylation and summarize evidence suggesting that dysfunction of neddylation is involved in Alzheimer's disease.
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Affiliation(s)
- Yuzhi Chen
- Department of Geriatrics and Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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The role of γ-secretase in hippocampal synaptic transmission and activity-dependent synaptic plasticity. Neurosci Lett 2013; 554:16-21. [DOI: 10.1016/j.neulet.2013.08.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/08/2013] [Accepted: 08/27/2013] [Indexed: 11/23/2022]
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Dorval V, Nelson PT, Hébert SS. Circulating microRNAs in Alzheimer's disease: the search for novel biomarkers. Front Mol Neurosci 2013; 6:24. [PMID: 24009553 PMCID: PMC3757537 DOI: 10.3389/fnmol.2013.00024] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/11/2013] [Indexed: 01/28/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common neurodegenerative disease in the elderly. While advancements have been made in understanding the genetic and molecular basis of AD, the clinical diagnosis of AD remains difficult, and post-mortem confirmation is often required. Furthermore, the onset of neurodegeneration precedes clinical symptoms by approximately a decade. Consequently, there is a crucial need for an early and accurate diagnosis of AD, which can potentially lead to strategies that can slow down or stop the progression of neurodegeneration and dementia. Recent advances in the non-coding RNA field have shown that microRNAs (miRNAs) can function as powerful biomarkers in human diseases. Studies are emerging suggesting that circulating miRNAs in the cerebrospinal fluid and blood serum have characteristic changes in AD patients. Whether miRNAs can be used in AD diagnosis, alone or in combination with other AD biomarkers (e.g., amyloid and tau), warrants further investigation.
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Affiliation(s)
- Véronique Dorval
- Axe Neurosciences, Centre de Recherche du Centre Hospitalier Universitaire de Québec (Centre Hospitalier de l'Université Laval), Québec QC, Canada ; Département de Psychiatrie et de Neurosciences, Université Laval, Québec QC, Canada
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Naumann EC, Göring S, Ogorek I, Weggen S, Schmidt B. Membrane anchoring γ-secretase modulators with terpene-derived moieties. Bioorg Med Chem Lett 2013; 23:3852-6. [PMID: 23707256 DOI: 10.1016/j.bmcl.2013.04.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 04/24/2013] [Accepted: 04/27/2013] [Indexed: 02/02/2023]
Abstract
Modulation of γ-secretase activity is a promising therapeutic strategy for the treatment of Alzheimer's disease. Herein we report on the synthesis of carprofen- and tocopherol-derived small-molecule modulators carrying terpene moieties as lipophilic membrane anchors. Additionally, these modulators are equipped with an acidic moiety, which contributes to the desired modulatory effect on the γ-secretase with decreased formation of Aβ42 and increased Aβ38 production.
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Affiliation(s)
- Eva Christine Naumann
- Clemens Schöpf-Institute of Organic Chemistry and Biochemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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35
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Ramachandran PS, Keiser MS, Davidson BL. Recent advances in RNA interference therapeutics for CNS diseases. Neurotherapeutics 2013; 10:473-85. [PMID: 23589092 PMCID: PMC3701762 DOI: 10.1007/s13311-013-0183-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Over the last decade, RNA interference technology has shown therapeutic promise in rodent models of dominantly inherited brain diseases, including those caused by polyglutamine repeat expansions in the coding region of the affected gene. For some of these diseases, proof-of concept studies in model organisms have transitioned to safety testing in larger animal models, such as the nonhuman primate. Here, we review recent progress on RNA interference-based therapies in various model systems. We also highlight outstanding questions or concerns that have emerged as a result of an improved (and ever advancing) understanding of the technologies employed.
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Affiliation(s)
| | - Megan S. Keiser
- />Interdisciplinary program in Neuroscience, University of Iowa, Iowa City, IA USA
| | - Beverly L. Davidson
- />Interdisciplinary program in Genetics, University of Iowa, Iowa City, IA 52242 USA
- />Interdisciplinary program in Neuroscience, University of Iowa, Iowa City, IA USA
- />Department of Internal Medicine, University of Iowa, Iowa City, USA
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Abstract
Curcumin is a component of turmeric, a spice used in many types of cooking. Epidemiological evidence suggesting that populations that eat food with a substantial amount of curcumin were at lower risk of Alzheimer’s disease (AD) led to the idea that this compound might have a neuroprotective effect. Curcumin has substantial antioxidant and anti-inflammatory effects, and is being used as a potential preventative agent or treatment for many types of cancer. There is evidence to suggest that the addition of curcumin to cultured neuronal cells decreases brain inflammation and protects against β-amyloid-induced neurotoxicity. Curcumin also protects against toxicity when β-amyloid is administered to produce animal models of AD. Curcumin decreases β-amyloid formation from amyloid precursor protein, and also inhibits aggregation of β-amyloid into pleated sheets. Studies in transgenic mice with overproduction of β-amyloid demonstrate a neuroprotective effect of curcumin as well. Cognitive function was also improved in these animal models. Clinical trials of curcumin in AD have not been very promising. It is possible that this is due to poor oral bioavailability of curcumin in humans, and thus several approaches are being developed to improve delivery systems or to create analogs that will mimic the neuroprotective effects and easily reach the brain. The lack of efficacy of curcumin in humans with AD may also result from treating for too short a time or starting treatment too late in the course of the disease, where substantial neuronal death has already occurred and cannot be reversed. Curcumin may be beneficial in protecting against development or progression of AD if taken over the long term and started before symptoms of AD become apparent.
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Affiliation(s)
- Pamela E Potter
- Department of Pharmacology, Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ, USA
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Genome-wide reprogramming of the chromatin landscape underlies endocrine therapy resistance in breast cancer. Proc Natl Acad Sci U S A 2013; 110:E1490-9. [PMID: 23576735 DOI: 10.1073/pnas.1219992110] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The estrogen receptor (ER)α drives growth in two-thirds of all breast cancers. Several targeted therapies, collectively termed endocrine therapy, impinge on estrogen-induced ERα activation to block tumor growth. However, half of ERα-positive breast cancers are tolerant or acquire resistance to endocrine therapy. We demonstrate that genome-wide reprogramming of the chromatin landscape, defined by epigenomic maps for regulatory elements or transcriptional activation and chromatin openness, underlies resistance to endocrine therapy. This annotation reveals endocrine therapy-response specific regulatory networks where NOTCH pathway is overactivated in resistant breast cancer cells, whereas classical ERα signaling is epigenetically disengaged. Blocking NOTCH signaling abrogates growth of resistant breast cancer cells. Its activation state in primary breast tumors is a prognostic factor of resistance in endocrine treated patients. Overall, our work demonstrates that chromatin landscape reprogramming underlies changes in regulatory networks driving endocrine therapy resistance in breast cancer.
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Chun YS, Oh HG, Park MK, Kim TW, Chung S. Increasing Membrane Cholesterol Level Increases the Amyloidogenic Peptide by Enhancing the Expression of Phospholipase C. JOURNAL OF NEURODEGENERATIVE DISEASES 2013; 2013:407903. [PMID: 26316988 PMCID: PMC4437359 DOI: 10.1155/2013/407903] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 12/09/2012] [Indexed: 11/24/2022]
Abstract
Cerebral elevation of 42-residue amyloid β-peptide (Aβ42) triggers neuronal dysfunction in Alzheimer's disease (AD). Even though a number of cholesterol modulating agents have been shown to affect Aβ generation, the role of cholesterol in the pathogenesis of AD is not clear yet. Recently, we have shown that increased membrane cholesterol levels downregulates phosphatidylinositol 4,5-bisphosphate (PIP2) via activation of phospholipase C (PLC). In this study, we tested whether membrane cholesterol levels may affect the Aβ42 production via changing PIP2 levels. Increasing membrane cholesterol levels decreased PIP2 and increased secreted Aβ42. Supplying PIP2, by using a PIP2-carrier system, blocked the effect of cholesterol on Aβ42. We also found that cholesterol increased the expressions of β1 and β3 PLC isoforms (PLCβ1, PLCβ3). Silencing the expression of PLCβ1 prevented the effects of cholesterol on PIP2 levels as well as on Aβ42 production, suggesting that increased membrane cholesterol levels increased secreted Aβ42 by downregulating PIP2 via enhancing the expression of PLCβ1. Thus, cholesterol metabolism may be linked to Aβ42 levels via PLCβ1 expression and subsequent changes in PIP2 metabolism.
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Affiliation(s)
- Yoon Sun Chun
- Department of Physiology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Hyun Geun Oh
- Department of Physiology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Myoung Kyu Park
- Department of Physiology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
| | - Tae-Wan Kim
- Department of Pathology, Columbia University Medical Center, New York, NY 10032, USA
| | - Sungkwon Chung
- Department of Physiology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, Republic of Korea
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Piscopo P, Canterini S, Carletti V, Rosa P, Crestini A, Fiorenza MT, Confaloni A. Sex effect on presenilins expression in post-natal rat brain. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/abb.2013.412145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Drug pipeline in neurodegeneration based on transgenic mice models of Alzheimer's disease. Ageing Res Rev 2013; 12:116-40. [PMID: 22982398 DOI: 10.1016/j.arr.2012.09.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 08/31/2012] [Accepted: 09/04/2012] [Indexed: 11/21/2022]
Abstract
Alzheimer's disease (AD) is one of the most important neurodegenerative disorders, bringing about huge medical and social burden in the elderly worldwide. Many aspects of its pathogenesis have remained unclear and no effective treatment exists for it. Within the past 20 years, various mice models harboring AD-related human mutations have been produced. These models imitate diverse AD-related pathologies and have been used for basic and therapeutic investigations in AD. In this regard, there are a wide variety of preclinical trials of potential therapeutic modalities using AD mice models which are of paramount importance for future clinical trials and applications. This review summarizes more than 140 substances and treatment modalities being used in transgenic AD mice models from 2001 to 2011. We also discuss advantages and disadvantages of each model to be used in therapeutic development for AD.
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Wolfe MS. The role of tau in neurodegenerative diseases and its potential as a therapeutic target. SCIENTIFICA 2012; 2012:796024. [PMID: 24278740 PMCID: PMC3820460 DOI: 10.6064/2012/796024] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/05/2012] [Indexed: 06/01/2023]
Abstract
The abnormal deposition of proteins in and around neurons is a common pathological feature of many neurodegenerative diseases. Among these pathological proteins, the microtubule-associated protein tau forms intraneuronal filaments in a spectrum of neurological disorders. The discovery that dominant mutations in the MAPT gene encoding tau are associated with familial frontotemporal dementia strongly supports abnormal tau protein as directly involved in disease pathogenesis. This and other evidence suggest that tau is a worthwhile target for the prevention or treatment of tau-associated neurodegenerative diseases, collectively called tauopathies. However, it is critical to understand the normal biological roles of tau, the specific molecular events that induce tau to become neurotoxic, the biochemical nature of pathogenic tau, the means by which pathogenic tau exerts neurotoxicity, and how tau pathology propagates. Based on known differences between normal and abnormal tau, a number of approaches have been taken toward the discovery of potential therapeutics. Key questions still remain open, such as the nature of the connection between the amyloid- β protein of Alzheimer's disease and tau pathology. Answers to these questions should help better understand the nature of tauopathies and may also reveal new therapeutic targets and strategies.
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Affiliation(s)
- Michael S. Wolfe
- Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, H.I.M. 754, Boston, MA 02115, USA
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42
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Abdul-Hay SO, Sahara T, McBride M, Kang D, Leissring MA. Identification of BACE2 as an avid ß-amyloid-degrading protease. Mol Neurodegener 2012; 7:46. [PMID: 22986058 PMCID: PMC3470943 DOI: 10.1186/1750-1326-7-46] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 08/16/2012] [Indexed: 11/10/2022] Open
Abstract
Background Proteases that degrade the amyloid ß-protein (Aß) have emerged as key players in the etiology and potential treatment of Alzheimer’s disease (AD), but it is unlikely that all such proteases have been identified. To discover new Aß-degrading proteases (AßDPs), we conducted an unbiased, genome-scale, functional cDNA screen designed to identify proteases capable of lowering net Aß levels produced by cells, which were subsequently characterized for Aß-degrading activity using an array of downstream assays. Results The top hit emerging from the screen was ß-site amyloid precursor protein-cleaving enzyme 2 (BACE2), a rather unexpected finding given the well-established role of its close homolog, BACE1, in the production of Aß. BACE2 is known to be capable of lowering Aß levels via non-amyloidogenic processing of APP. However, in vitro, BACE2 was also found to be a particularly avid AßDP, with a catalytic efficiency exceeding all known AßDPs except insulin-degrading enzyme (IDE). BACE1 was also found to degrade Aß, albeit ~150-fold less efficiently than BACE2. Aß is cleaved by BACE2 at three peptide bonds—Phe19-Phe20, Phe20-Ala21, and Leu34-Met35—with the latter cleavage site being the initial and principal one. BACE2 overexpression in cultured cells was found to lower net Aß levels to a greater extent than multiple, well-established AßDPs, including neprilysin (NEP) and endothelin-converting enzyme-1 (ECE1), while showing comparable effectiveness to IDE. Conclusions This study identifies a new functional role for BACE2 as a potent AßDP. Based on its high catalytic efficiency, its ability to degrade Aß intracellularly, and other characteristics, BACE2 represents a particulary strong therapeutic candidate for the treatment or prevention of AD.
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Affiliation(s)
- Samer O Abdul-Hay
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Birdsall Bldg,, Rm, 117, Jacksonville, FL 32224, USA
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Bulic B, Ness J, Hahn S, Rennhack A, Jumpertz T, Weggen S. Chemical Biology, Molecular Mechanism and Clinical Perspective of γ-Secretase Modulators in Alzheimer's Disease. Curr Neuropharmacol 2012; 9:598-622. [PMID: 22798753 PMCID: PMC3391656 DOI: 10.2174/157015911798376352] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 10/25/2010] [Accepted: 11/01/2010] [Indexed: 12/25/2022] Open
Abstract
Comprehensive evidence supports that oligomerization and accumulation of amyloidogenic Aβ42 peptides in brain is crucial in the pathogenesis of both familial and sporadic forms of Alzheimer's disease. Imaging studies indicate that the buildup of Aβ begins many years before the onset of clinical symptoms, and that subsequent neurodegeneration and cognitive decline may proceed independently of Aβ. This implies the necessity for early intervention in cognitively normal individuals with therapeutic strategies that prioritize safety. The aspartyl protease γ-secretase catalyses the last step in the cellular generation of Aβ42 peptides, and is a principal target for anti-amyloidogenic intervention strategies. Due to the essential role of γ-secretase in the NOTCH signaling pathway, overt mechanism-based toxicity has been observed with the first generation of γ-secretase inhibitors, and safety of this approach has been questioned. However, two new classes of small molecules, γ-secretase modulators (GSMs) and NOTCH-sparing γ-secretase inhibitors, have revitalized γ-secretase as a drug target in AD. GSMs are small molecules that cause a product shift from Aβ42 towards shorter and less toxic Ab peptides. Importantly, GSMs spare other physiologically important substrates of the γ-secretase complex like NOTCH. Recently, GSMs with nanomolar potency and favorable in vivo properties have been described. In this review, we summarize the knowledge about the unusual proteolytic activity of γ-secretase, and the chemical biology, molecular mechanisms and clinical perspective of compounds that target the γ-secretase complex, with a particular focus on GSMs.
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Affiliation(s)
- Bruno Bulic
- Research Group Chemical Biology of Neurodegenerative Diseases, Center of Advanced European Studies and Research, D-53175 Bonn, Germany
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Vidal R, Ghetti B. Generation of a novel murine model of Aβ deposition based on the expression of human wild-type amyloid precursor protein gene. Prion 2012; 6:346-9. [PMID: 22874668 PMCID: PMC3609061 DOI: 10.4161/pri.21023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Mouse models of Alzheimer disease (AD) have been generated based on Amyloid-β Precursor Protein (AβPP) and the Presenilin (PSEN) gene mutations associated with familial AD (FAD). Such models have provided valuable insights into AD pathogenesis and represent an important research tool for the discovery of potential treatments. To model amyloid deposition in AD, we generated a new mouse line based on the presence of two copies of the genomic region encoding human wild-type AβPP as well as a mutation (L166P) in the murine Psen1. By ~6 months of age, these mice have begun to develop cerebral Aβ pathology with a significant increase in the levels of AβPP C-terminal fragments and Aβ42, as well as increase Aβ42/Aβ40 ratio. Since in the brain and other tissues of these mice, wild-type human AβPP mRNA and protein levels are comparable to those of endogenous AβPP, this model may allow studies about the role of AβPP isoforms in the pathogenesis of AD. This animal model may be suitable to test drugs aimed at inhibiting expression or altering splicing and processing of AβPP, without artifacts associated with the presence of mutations in AβPP or overexpression due to the use of exogenous promoters. These features of the new model are of critical importance in assessing the success of therapeutic interventions.
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Affiliation(s)
- Rubén Vidal
- Department of Pathology and Laboratory Medicine and Indiana Alzheimer Disease Center, Indianapolis, IN, USA.
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45
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Efremov IV, Vajdos FF, Borzilleri KA, Capetta S, Chen H, Dorff PH, Dutra JK, Goldstein SW, Mansour M, McColl A, Noell S, Oborski CE, O’Connell TN, O’Sullivan TJ, Pandit J, Wang H, Wei B, Withka JM. Discovery and Optimization of a Novel Spiropyrrolidine Inhibitor of β-Secretase (BACE1) through Fragment-Based Drug Design. J Med Chem 2012; 55:9069-88. [DOI: 10.1021/jm201715d] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ivan V. Efremov
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Felix F. Vajdos
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Kris A. Borzilleri
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Steven Capetta
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Hou Chen
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Peter H. Dorff
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Jason K. Dutra
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Steven W. Goldstein
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Mahmoud Mansour
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Alexander McColl
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Stephen Noell
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Christine E. Oborski
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Thomas N. O’Connell
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Theresa J. O’Sullivan
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Jayvardhan Pandit
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Hong Wang
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - BinQing Wei
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
| | - Jane M. Withka
- Pfizer Worldwide Research, Groton Laboratories, Eastern Point Road,
Groton, Connecticut 06340, United States
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46
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Vidal R, Sammeta N, Garringer HJ, Sambamurti K, Miravalle L, Lamb BT, Ghetti B. The Psen1-L166P-knock-in mutation leads to amyloid deposition in human wild-type amyloid precursor protein YAC transgenic mice. FASEB J 2012; 26:2899-910. [PMID: 22459153 DOI: 10.1096/fj.12-205542] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Genetically engineered mice have been generated to model cerebral β-amyloidosis, one of the hallmarks of Alzheimer disease (AD) pathology, based on the overexpression of a mutated cDNA of the amyloid-β precursor protein (AβPP) or by knock-in of the murine Aβpp gene alone or with presenilin1 mutations. Here we describe the generation and initial characterization of a new mouse line based on the presence of 2 copies of the human genomic region encoding the wild-type AβPP and the L166P presenilin 1 mutation. At ∼6 mo of age, double-mutant mice develop amyloid pathology, with signs of neuritic dystrophy, intracellular Aβ accumulation, and glial inflammation, an increase in AβPP C-terminal fragments, and an 8 times increase in Aβ42 levels with a 40% decrease in Aβ40 levels, leading to a significant increase (14 times) of Aβ42/Aβ40 ratios, with minimal effects on presenilin or the Notch1 pathway in the brain. We conclude that in mice, neither mutations in AβPP nor overexpression of an AβPP isoform are a prerequisite for Aβ pathology. This model will allow the study of AD pathogenesis and testing of therapeutic strategies in a more relevant environment without experimental artifacts due to the overexpression of a single-mutant AβPP isoform using exogenous promoters.
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Affiliation(s)
- Ruben Vidal
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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Stepan AF, Subramanyam C, Efremov IV, Dutra JK, O'Sullivan TJ, DiRico KJ, McDonald WS, Won A, Dorff PH, Nolan CE, Becker SL, Pustilnik LR, Riddell DR, Kauffman GW, Kormos BL, Zhang L, Lu Y, Capetta SH, Green ME, Karki K, Sibley E, Atchison KP, Hallgren AJ, Oborski CE, Robshaw AE, Sneed B, O'Donnell CJ. Application of the bicyclo[1.1.1]pentane motif as a nonclassical phenyl ring bioisostere in the design of a potent and orally active γ-secretase inhibitor. J Med Chem 2012; 55:3414-24. [PMID: 22420884 DOI: 10.1021/jm300094u] [Citation(s) in RCA: 212] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Replacement of the central, para-substituted fluorophenyl ring in the γ-secretase inhibitor 1 (BMS-708,163) with the bicyclo[1.1.1]pentane motif led to the discovery of compound 3, an equipotent enzyme inhibitor with significant improvements in passive permeability and aqueous solubility. The modified biopharmaceutical properties of 3 translated into excellent oral absorption characteristics (~4-fold ↑ C(max) and AUC values relative to 1) in a mouse model of γ-secretase inhibition. In addition, SAR studies into other fluorophenyl replacements indicate the intrinsic advantages of the bicyclo[1.1.1]pentane moiety over conventional phenyl ring replacements with respect to achieving an optimal balance of properties (e.g., γ-secretase inhibition, aqueous solubility/permeability, in vitro metabolic stability). Overall, this work enhances the scope of the [1.1.1]-bicycle beyond that of a mere "spacer" unit and presents a compelling case for its broader application as a phenyl group replacement in scenarios where the aromatic ring count impacts physicochemical parameters and overall drug-likeness.
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Affiliation(s)
- Antonia F Stepan
- Pfizer Worldwide Research & Development, Eastern Point Road, Groton, Connecticut 06340, USA.
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Sulfonimidamides as Sulfonamides Bioisosteres: Rational Evaluation through Synthetic, in Vitro, and in Vivo Studies with γ-Secretase Inhibitors. ChemMedChem 2012; 7:396-9. [DOI: 10.1002/cmdc.201200014] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Indexed: 12/12/2022]
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Qi X, Cai J, Ruan Q, Liu L, Boye SL, Chen Z, Hauswirth WW, Ryals RC, Shaw L, Caballero S, Grant MB, Boulton ME. γ-Secretase inhibition of murine choroidal neovascularization is associated with reduction of superoxide and proinflammatory cytokines. Invest Ophthalmol Vis Sci 2012; 53:574-85. [PMID: 22205609 DOI: 10.1167/iovs.11-8728] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
PURPOSE This study aimed to determine whether upregulation of γ-secretase could inhibit laser-induced choroidal neovascularization (CNV) and if this was associated with a reduction in both oxidative stress and proinflammatory cytokines. METHODS γ-Secretase, or its catalytic subunit presenilin 1 (PS1), were upregulated by exposure to either pigment epithelial derived factor (PEDF) or an AAV2 vector containing a PS1 gene driven by a vascular endothelial-cadherin promoter. Retinal endothelial cells were infected with AAV2 or exposed to PEDF in the presence or absence of VEGF and in vitro angiogenesis determined. Mouse eyes either received intravitreal injection of PEDF, DAPT (a γ-secretase inhibitor) or PEDF + DAPT at the time of laser injury, or AAV2 infection 3 weeks before receiving laser burns. Lesion volume was determined 14 days post laser injury. Superoxide generation, antioxidant activity and the production of proinflammatory mediators were assessed. Knockdown of γ-secretase was achieved using siRNA. RESULTS γ-Secretase upregulation and PS1 overexpression suppressed VEGF-induced in vitro angiogenesis and in vivo laser-induced CNV. This was associated with a reduction in the expression of VEGF and angiogenin 1 together with reduced superoxide anion generation and an increase in MnSOD compared with untreated CNV eyes. PS1 overexpression reduced proinflammatory factors and microglial activation in eyes with CNV compared with control. siRNA inhibition of γ-secretase resulted in increased angiogenesis. CONCLUSIONS γ-Secretase, and in particular PS1 alone, are potent regulators of angiogenesis and this is due in part to stabilizing endogenous superoxide generation and reducing proinflammatory cytokine expression during CNV.
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Affiliation(s)
- Xiaoping Qi
- Departments of Anatomy and Cell Biology, University of Florida, Gainesville, Florida 32610-0235, USA
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Wolfe MS. γ-Secretase as a target for Alzheimer's disease. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2012; 64:127-53. [PMID: 22840746 DOI: 10.1016/b978-0-12-394816-8.00004-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
γ-Secretase is a protease complex responsible for cutting the transmembrane domain of the amyloid β-protein precursor (APP) to form the amyloid β-protein (Aβ), an aggregation-prone product that accumulates in the brain in Alzheimer's disease. As evidence suggests that Aβ is critical to Alzheimer pathogenesis, γ-secretase is considered a key target for the development of disease-modifying therapeutics. The protease complex cuts many other substrates, and some of these proteolytic events are part of signaling pathways or other important cellular functions. Among these, proteolysis of the Notch receptor is essential for signaling that is involved in a number of cell-fate determinations. Many inhibitors of γ-secretase have been identified, but it is clear that drug candidates for Alzheimer's disease should have minimal effects on the Notch signaling pathway, as serious safety issues have arisen with nonselective inhibitors. Two types of promising candidates that target this protease complex have emerged: the so-called "Notch-sparing" γ-secretase inhibitors, which block cleavage of APP selectively over that of Notch, and γ-secretase modulators, which shift the proportion of Aβ peptides produced in favor of shorter, less aggregation-prone species. The current status and prospects for these two general types of candidates will be discussed.
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Affiliation(s)
- Michael S Wolfe
- Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
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