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Yoon M, Kim H, Shin H, Lee H, Kang MJ, Park SH, Han G, Kim Y, Choi KY. Inhibition of CXXC5 function rescues Alzheimer's disease phenotypes by restoring Wnt/β-catenin signaling pathway. Pharmacol Res 2023; 194:106836. [PMID: 37355147 DOI: 10.1016/j.phrs.2023.106836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 06/26/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent type of dementia and is characterized by cognitive deficits and accumulation of pathological plaques. Owing to the complexity of AD development, paradigms for AD research and drug discovery have shifted to target factors that mediate multiple pathogenesis in AD. Increasing evidence suggests that the suppression of the Wnt/β-catenin signaling pathway plays substantial roles in AD progression. However, the underlying mechanism for the suppression of Wnt/β-catenin pathway associated with AD pathogenesis remains unexplored. In this study, we identified that CXXC5, a negative feedback regulator of the Wnt/β-catenin pathway, was overexpressed in the tissues of AD patients and 5xFAD transgenic mice paired with the suppression of Wnt/β-catenin pathway and its target genes related to AD. The level of CXXC5 was upregulated, upon aging of 5xFAD mice. AD characteristics including cognitive deficits, amyloid-β (Aβ) plaques, neuronal inflammation, and age-dependent increment of AD-related markers were rescued in Cxxc5-/-/5xFAD mice. 5-methoxyindirubin-3'-oxime (KY19334), a small molecule that restores the suppressed Wnt/β-catenin pathway via interference of the CXXC5-Dvl interaction, significantly improved the overall pathogenic phenotypes of 5xFAD mice. Collectively, our findings revealed that CXXC5 plays a key role in AD pathogenesis and suggest inhibition of CXXC5-Dvl interaction as a new therapeutic approach for AD.
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Affiliation(s)
- Minguen Yoon
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Heejene Kim
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Heewon Shin
- Department of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Republic of Korea
| | - HeeYang Lee
- Department of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Republic of Korea
| | | | - Sung-Hye Park
- Department of Pathology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Gyoonhee Han
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - YoungSoo Kim
- Department of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon 21983, Republic of Korea.
| | - Kang-Yell Choi
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Republic of Korea; CK Regeon Inc, Seoul 03722, Republic of Korea.
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2
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Puntambekar SS, Moutinho M, Lin PBC, Jadhav V, Tumbleson-Brink D, Balaji A, Benito MA, Xu G, Oblak A, Lasagna-Reeves CA, Landreth GE, Lamb BT. CX3CR1 deficiency aggravates amyloid driven neuronal pathology and cognitive decline in Alzheimer's disease. Mol Neurodegener 2022; 17:47. [PMID: 35764973 PMCID: PMC9241248 DOI: 10.1186/s13024-022-00545-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 05/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite its identification as a key checkpoint regulator of microglial activation in Alzheimer's disease, the overarching role of CX3CR1 signaling in modulating mechanisms of Aβ driven neurodegeneration, including accumulation of hyperphosphorylated tau is not well understood. METHODOLOGY Accumulation of soluble and insoluble Aβ species, microglial activation, synaptic dysregulation, and neurodegeneration is investigated in 4- and 6-month old 5xFAD;Cx3cr1+/+ and 5xFAD;Cx3cr1-/- mice using immunohistochemistry, western blotting, transcriptomic and quantitative real time PCR analyses of purified microglia. Flow cytometry based, in-vivo Aβ uptake assays are used for characterization of the effects of CX3CR1-signaling on microglial phagocytosis and lysosomal acidification as indicators of clearance of methoxy-X-04+ fibrillar Aβ. Lastly, we use Y-maze testing to analyze the effects of Cx3cr1 deficiency on working memory. RESULTS Disease progression in 5xFAD;Cx3cr1-/- mice is characterized by increased deposition of filamentous plaques that display defective microglial plaque engagement. Microglial Aβ phagocytosis and lysosomal acidification in 5xFAD;Cx3cr1-/- mice is impaired in-vivo. Interestingly, Cx3cr1 deficiency results in heighted accumulation of neurotoxic, oligomeric Aβ, along with severe neuritic dystrophy, preferential loss of post-synaptic densities, exacerbated tau pathology, neuronal loss and cognitive impairment. Transcriptomic analyses using cortical RNA, coupled with qRT-PCR using purified microglia from 6 month-old mice indicate dysregulated TGFβ-signaling and heightened ROS metabolism in 5xFAD;Cx3cr1-/- mice. Lastly, microglia in 6 month-old 5xFAD;Cx3cr1-/- mice express a 'degenerative' phenotype characterized by increased levels of Ccl2, Ccl5, Il-1β, Pten and Cybb along with reduced Tnf, Il-6 and Tgfβ1 mRNA. CONCLUSIONS Cx3cr1 deficiency impairs microglial uptake and degradation of fibrillar Aβ, thereby triggering increased accumulation of neurotoxic Aβ species. Furthermore, loss of Cx3cr1 results in microglial dysfunction typified by dampened TGFβ-signaling, increased oxidative stress responses and dysregulated pro-inflammatory activation. Our results indicate that Aβ-driven microglial dysfunction in Cx3cr1-/- mice aggravates tau hyperphosphorylation, neurodegeneration, synaptic dysregulation and impairs working memory.
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Affiliation(s)
- Shweta S. Puntambekar
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Medical and Molecular Genetics, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Miguel Moutinho
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Anatomy, Cell Biology and Physiology, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Peter Bor-Chian Lin
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Indiana Biomedical Gateway (IBMG) Program, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Vaishnavi Jadhav
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA USA
| | - Danika Tumbleson-Brink
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Medical and Molecular Genetics, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Ananya Balaji
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Indiana Clinical and Translational Institute (CTSI), Summer Research Program (SRP), Indianapolis, IN USA
| | - Martin Alvarado Benito
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Medical and Molecular Genetics, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Guixiang Xu
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Medical and Molecular Genetics, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Adrian Oblak
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Radiology, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Cristian A. Lasagna-Reeves
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Anatomy, Cell Biology and Physiology, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Gary E. Landreth
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Anatomy, Cell Biology and Physiology, Indiana University-School of Medicine, Indianapolis, IN USA
| | - Bruce T. Lamb
- Stark Neurosciences Research Institute, Indiana University-School of Medicine, Indianapolis, IN USA
- Department of Medical and Molecular Genetics, Indiana University-School of Medicine, Indianapolis, IN USA
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3
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Elevated soluble amyloid beta protofibrils in Down syndrome and Alzheimer's disease. Mol Cell Neurosci 2021; 114:103641. [PMID: 34091073 DOI: 10.1016/j.mcn.2021.103641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/27/2021] [Accepted: 05/31/2021] [Indexed: 01/31/2023] Open
Abstract
Down syndrome (DS) is caused by trisomy of chromosome 21, which leads to a propensity to develop amyloid β (Aβ) brain pathology in early adulthood followed later by cognitive and behavioral deterioration. Characterization of the Aβ pathology is important to better understand the clinical deterioration of DS individuals and to identify interventive strategies. Brain samples from people with DS and Alzheimer's disease (AD), as well as non-demented controls (NDC), were analyzed with respect to different Aβ species. Immunohistochemical staining using antibodies towards Aβ was also performed. Elevated levels of soluble Aβ protofibrils and insoluble Aβx-40 and Aβx-42 in formic acid brain extracts, and elevated immunohistochemical staining of Aβ deposits were demonstrated with the antibody BAN2401 (lecanemab) in DS and AD compared with NDC. These data and the promising data in a large phase 2 CE clinical trial with lecanemab suggest that lecanemab may have the potential to preserve cognitive capacity in DS. Lecanemab is currently in a phase 3 CE clinical trial.
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4
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Cao Q, Anderson DH, Liang WY, Chou J, Saelices L. The inhibition of cellular toxicity of amyloid-β by dissociated transthyretin. J Biol Chem 2020; 295:14015-14024. [PMID: 32769117 DOI: 10.1074/jbc.ra120.013440] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 07/31/2020] [Indexed: 01/01/2023] Open
Abstract
The protective effect of transthyretin (TTR) on cellular toxicity of β-amyloid (Aβ) has been previously reported. TTR is a tetrameric carrier of thyroxine in blood and cerebrospinal fluid, the pathogenic aggregation of which causes systemic amyloidosis. However, studies have documented a protective effect of TTR against cellular toxicity of pathogenic Aβ, a protein associated with Alzheimer's disease. TTR binds Aβ, alters its aggregation, and inhibits its toxicity both in vitro and in vivo In this study, we investigate whether the amyloidogenic ability of TTR and its antiamyloid inhibitory effect are associated. Using protein aggregation and cytotoxicity assays, we found that the dissociation of the TTR tetramer, required for its amyloid pathogenesis, is also necessary to prevent cellular toxicity from Aβ oligomers. These findings suggest that the Aβ-binding site of TTR may be hidden in its tetrameric form. Aided by computational docking and peptide screening, we identified a TTR segment that is capable of altering Aβ aggregation and toxicity, mimicking TTR cellular protection. EM, immune detection analysis, and assessment of aggregation and cytotoxicity revealed that the TTR segment inhibits Aβ oligomer formation and also promotes the formation of nontoxic, nonamyloid amorphous aggregates, which are more sensitive to protease digestion. Finally, this segment also inhibits seeding of Aβ catalyzed by Aβ fibrils extracted from the brain of an Alzheimer's patient. Together, these findings suggest that mimicking the inhibitory effect of TTR with peptide-based therapeutics represents an additional avenue to explore for the treatment of Alzheimer's disease.
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Affiliation(s)
- Qin Cao
- Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.,Department of Chemistry and Biochemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Daniel H Anderson
- Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.,Department of Chemistry and Biochemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Wilson Y Liang
- Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.,Department of Chemistry and Biochemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Joshua Chou
- Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.,Department of Chemistry and Biochemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Lorena Saelices
- Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA .,Department of Chemistry and Biochemistry, Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.,Center for Alzheimer's and Neurodegenerative Diseases, Department of Biophysics, O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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5
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Saito T, Hisahara S, Iwahara N, Emoto MC, Yokokawa K, Suzuki H, Manabe T, Matsumura A, Suzuki S, Matsushita T, Kawamata J, Sato-Akaba H, Fujii HG, Shimohama S. Early administration of galantamine from preplaque phase suppresses oxidative stress and improves cognitive behavior in APPswe/PS1dE9 mouse model of Alzheimer's disease. Free Radic Biol Med 2019; 145:20-32. [PMID: 31536772 DOI: 10.1016/j.freeradbiomed.2019.09.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disease that progressively impairs memory and cognition. Deposition of amyloid-β (Aβ) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by generation of reactive oxygen species (ROS) is a prominent phenomenon in AD and known to occur early in the course of AD. Several reports suggest a relationship between change in redox status and AD pathology including progressive Aβ deposition, glial cell activation, and inflammation. Galantamine is an acetylcholinesterase inhibitor and has been reported to have an oxidative stress inhibitory function. In the present study, galantamine was administered orally to AD model mice from before the appearance of Aβ plaques (preplaque phase), and in vivo change in redox status of the brain was measured using electron paramagnetic resonance (EPR) imaging. Administration of galantamine from the preplaque phase ameliorated memory decline in Morris water maze test and novel object recognition test. Monitoring of the redox status of the brain using EPR imaging showed that galantamine treatment improved the unbalanced redox state. Additionally, galantamine administration enhanced microglial function to promote Aβ clearance, reducing the Aβ-positive area in the cortex and amount of insoluble Aβ in the brain. In contrast, galantamine treatment from the preplaque phase suppressed the production of proinflammatory cytokines through neurotoxic microglial activity. Therefore, galantamine administration from the preplaque phase may have the potential of clinical application for the prevention of AD. In addition, our results demonstrate the usefulness of EPR imaging for speedy and quantitative evaluation of the efficacy of disease-modifying drugs for AD.
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Affiliation(s)
- Taro Saito
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Shin Hisahara
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Naotoshi Iwahara
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan; Department of Pharmacology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Miho C Emoto
- Department of Clinical Laboratory Science, School of Medical Technology, Health Sciences University of Hokkaido, Sapporo, Hokkaido, 002-8072, Japan
| | - Kazuki Yokokawa
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Hiromi Suzuki
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Tatsuo Manabe
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Akihiro Matsumura
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Syuuichirou Suzuki
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Takashi Matsushita
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan
| | - Jun Kawamata
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0374, Japan
| | - Hideo Sato-Akaba
- Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
| | - Hirotada G Fujii
- Cancer Preventive Institute, Health Sciences University of Hokkaido, Ishikari, Hokkaido, 061-0293, Japan
| | - Shun Shimohama
- Department of Neurology, School of Medicine, Sapporo Medical University, Sapporo, Hokkaido, 060-8556, Japan.
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6
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Baquero J, Varriano S, Ordonez M, Kuczaj P, Murphy MR, Aruggoda G, Lundine D, Morozova V, Makki AE, Alonso ADC, Kleiman FE. Nuclear Tau, p53 and Pin1 Regulate PARN-Mediated Deadenylation and Gene Expression. Front Mol Neurosci 2019; 12:242. [PMID: 31749682 PMCID: PMC6843027 DOI: 10.3389/fnmol.2019.00242] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/20/2019] [Indexed: 12/17/2022] Open
Abstract
While nuclear tau plays a role in DNA damage response (DDR) and chromosome relaxation, the mechanisms behind these functions are not fully understood. Here, we show that tau forms complex(es) with factors involved in nuclear mRNA processing such as tumor suppressor p53 and poly(A)-specific ribonuclease (PARN) deadenylase. Tau induces PARN activity in different cellular models during DDR, and this activation is further increased by p53 and inhibited by tau phosphorylation at residues implicated in neurological disorders. Tau's binding factor Pin1, a mitotic regulator overexpressed in cancer and depleted in Alzheimer's disease (AD), also plays a role in the activation of nuclear deadenylation. Tau, Pin1 and PARN target the expression of mRNAs deregulated in AD and/or cancer. Our findings identify novel biological roles of tau and toxic effects of hyperphosphorylated-tau. We propose a model in which factors involved in cancer and AD regulate gene expression by interactions with the mRNA processing machinery, affecting the transcriptome and suggesting insights into alternative mechanisms for the initiation and/or developments of these diseases.
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Affiliation(s)
- Jorge Baquero
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Sophia Varriano
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Martha Ordonez
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Pawel Kuczaj
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Michael R. Murphy
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Gamage Aruggoda
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Devon Lundine
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
| | - Viktoriya Morozova
- Department of Biology and Center for Developmental Neuroscience, College of Staten Island, Graduate Center, The City University of New York, Staten Island, NY, United States
| | - Ali Elhadi Makki
- Department of Biology and Center for Developmental Neuroscience, College of Staten Island, Graduate Center, The City University of New York, Staten Island, NY, United States
| | - Alejandra del C. Alonso
- Department of Biology and Center for Developmental Neuroscience, College of Staten Island, Graduate Center, The City University of New York, Staten Island, NY, United States
| | - Frida E. Kleiman
- Chemistry Department, Hunter College and Biochemistry Program, The Graduate Center, The City University of New York, New York, NY, United States
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7
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Zhu BL, Long Y, Luo W, Yan Z, Lai YJ, Zhao LG, Zhou WH, Wang YJ, Shen LL, Liu L, Deng XJ, Wang XF, Sun F, Chen GJ. MMP13 inhibition rescues cognitive decline in Alzheimer transgenic mice via BACE1 regulation. Brain 2019; 142:176-192. [PMID: 30596903 DOI: 10.1093/brain/awy305] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/15/2018] [Indexed: 12/25/2022] Open
Abstract
MMP13 (matrix metallopeptidase 13) plays a key role in bone metabolism and cancer development, but has no known functions in Alzheimer's disease. In this study, we used high-throughput small molecule screening in SH-SY5Y cells that stably expressed a luciferase reporter gene driven by the BACE1 (β-site amyloid precursor protein cleaving enzyme 1) promoter, which included a portion of the 5' untranslated region (5'UTR). We identified that CL82198, a selective inhibitor of MMP13, decreased BACE1 protein levels in cultured neuronal cells. This effect was dependent on PI3K (phosphatidylinositide 3-kinase) signalling, and was unrelated to BACE1 gene transcription and protein degradation. Further, we found that eukaryotic translation initiation factor 4B (eIF4B) played a key role, as the mutation of eIF4B at serine 422 (S422R) or deletion of the BACE1 5'UTR attenuated MMP13-mediated BACE1 regulation. In APPswe/PS1E9 mice, an animal model of Alzheimer's disease, hippocampal Mmp13 knockdown or intraperitoneal CL82198 administration reduced BACE1 protein levels and the related amyloid-β precursor protein processing, amyloid-β load and eIF4B phosphorylation, whereas spatial and associative learning and memory performances were improved. Collectively, MMP13 inhibition/CL82198 treatment exhibited therapeutic potential for Alzheimer's disease, via the translational regulation of BACE1.
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Affiliation(s)
- Bing-Lin Zhu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Yan Long
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Wei Luo
- Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Zhen Yan
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY, USA
| | - Yu-Jie Lai
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Li-Ge Zhao
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Wei-Hui Zhou
- Ministry of Education Key Laboratory of Child Development and Disorders; Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Children's Hospital of Chongqing Medical University, 136 ZhongshanEr Lu, Yuzhong District, Chongqing, China
| | - Yan-Jiang Wang
- Department of Neurology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Lin-Lin Shen
- Department of Neurology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Lu Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Xiao-Juan Deng
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Xue-Feng Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
| | - Fei Sun
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Guo-Jun Chen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing, China
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8
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Congo Red and amyloids: history and relationship. Biosci Rep 2019; 39:BSR20181415. [PMID: 30567726 PMCID: PMC6331669 DOI: 10.1042/bsr20181415] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 12/16/2018] [Accepted: 12/17/2018] [Indexed: 12/17/2022] Open
Abstract
Staining with Congo Red (CR) is a qualitative method used for the identification of amyloids in vitro and in tissue sections. However, the drawbacks and artefacts obtained when using this dye can be found both in vitro and in vivo. Analysis of scientific data from previous studies shows that CR staining alone is not sufficient for confirmation of the amyloid nature of protein aggregates in vitro or for diagnosis of amyloidosis in tissue sections. In the present paper, we describe the characteristics and limitations of other methods used for amyloid studies. Our historical review on the use of CR staining for amyloid studies may provide insight into the pitfalls and caveats related to this technique for researchers considering using this dye.
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9
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Helman AM, Siever M, McCarty KL, Lott IT, Doran E, Abner EL, Schmitt FA, Head E. Microbleeds and Cerebral Amyloid Angiopathy in the Brains of People with Down Syndrome with Alzheimer's Disease. J Alzheimers Dis 2019; 67:103-112. [PMID: 30452414 PMCID: PMC6424116 DOI: 10.3233/jad-180589] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cerebrovascular pathology is a significant mediator in Alzheimer's disease (AD) in the general population. In people with Down syndrome (DS), the contribution of vascular pathology to dementia may play a similar role in age of onset and/or the rate of progression of AD. In the current study, we explored the extent of microbleeds (MBs) and the link between cerebral amyloid angiopathy (CAA) and MBs in the frontal cortex (FCTX) and occipital cortex (OCTX) in an autopsy series from individuals with DS (<40 years), DS with AD pathology (DSAD), sporadic AD, and control cases (2-83 years). Sections were immunostained against Aβ1 - 40 and an adjacent section stained using Prussian blue for MBs. MBs were both counted and averaged in each case and CAA was scored based on previously published methods. MBs were more frequent in DS cases relative to controls but present to a similar extent as sporadic AD. This aligned with CAA scores, with more extensive CAA in DS relative to controls in both brain regions. CAA was also more frequent in DSAD cases relative to sporadic AD. We found CAA to be associated with MBs and that MBs increased with age in DS after 30 years of age in the OCTX and after 40 years of age in the FCTX. MB and CAA appear to be a significant contributors to the development of dementia in people with DS and are important targets for future clinical trials.
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Affiliation(s)
- Alex M Helman
- Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Morgan Siever
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Katie L McCarty
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Ira T Lott
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA
- Department of Neurology, University of California, Irvine, Irvine, CA, USA
| | - Eric Doran
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA
| | - Erin L Abner
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Department of Epidemiology, University of Kentucky, Lexington, KY, USA
| | - Frederick A Schmitt
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Elizabeth Head
- Sanders Brown Center on Aging, University of Kentucky, Lexington, KY, USA
- Department of Pharmacology & Nutritional Sciences, University of Kentucky, Lexington, KY, USA
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10
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Xu X, Cai X, Zhu Y, He W, Wu Q, Shi X, Fang Y, Pei Z. MFG-E8 inhibits Aβ-induced microglial production of cathelicidin-related antimicrobial peptide: A suitable target against Alzheimer’s disease. Cell Immunol 2018; 331:59-66. [DOI: 10.1016/j.cellimm.2018.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 12/18/2022]
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11
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Stravalaci M, Tapella L, Beeg M, Rossi A, Joshi P, Pizzi E, Mazzanti M, Balducci C, Forloni G, Biasini E, Salmona M, Diomede L, Chiesa R, Gobbi M. The Anti-Prion Antibody 15B3 Detects Toxic Amyloid-β Oligomers. J Alzheimers Dis 2018; 53:1485-97. [PMID: 27392850 PMCID: PMC5044783 DOI: 10.3233/jad-150882] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
15B3 is a monoclonal IgM antibody that selectively detects pathological aggregates of the prion protein (PrP). We report the unexpected finding that 15B3 also recognizes oligomeric but not monomeric forms of amyloid-β (Aβ)42, an aggregating peptide implicated in the pathogenesis of Alzheimer's disease (AD). The 15B3 antibody: i) inhibits the binding of synthetic Aβ42 oligomers to recombinant PrP and neuronal membranes; ii) prevents oligomer-induced membrane depolarization; iii) antagonizes the inhibitory effects of oligomers on the physiological pharyngeal contractions of the nematode Caenorhabditis elegans; and iv) counteracts the memory deficits induced by intracerebroventricular injection of Aβ42 oligomers in mice. Thus this antibody binds to pathologically relevant forms of Aβ, and offers a potential research, diagnostic, and therapeutic tool for AD.
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Affiliation(s)
- Matteo Stravalaci
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Laura Tapella
- Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Marten Beeg
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Alessandro Rossi
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Pooja Joshi
- Humanitas Clinical and Research Center, Rozzano (MI), Italy
| | - Erika Pizzi
- Department of Life Science, University of Milan, Milan, Italy
| | | | - Claudia Balducci
- Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Gianluigi Forloni
- Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Emiliano Biasini
- Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Mario Salmona
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Luisa Diomede
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Roberto Chiesa
- Department of Neuroscience, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
| | - Marco Gobbi
- Department of Molecular Biochemistry and Pharmacology, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy
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12
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Head E, Helman AM, Powell D, Schmitt FA. Down syndrome, beta-amyloid and neuroimaging. Free Radic Biol Med 2018; 114:102-109. [PMID: 28935420 PMCID: PMC5748259 DOI: 10.1016/j.freeradbiomed.2017.09.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 12/20/2022]
Abstract
This review focuses on the role of Aβ in AD pathogenesis in Down syndrome and current approaches for imaging Aβ in vivo. We will describe how Aβ deposits with age, the posttranslational modifications that can occur, and detection in biofluids. Three unique case studies describing partial trisomy 21 cases without APP triplication, and the occurrences of low level mosaic trisomy 21 in an early onset AD patient are presented. Brain imaging for Aβ includes those by positron emission tomography and ligands (Pittsburgh Compound B, Florbetapir, and FDDNP) that bind Aβ have been published and are summarized here. In combination, we have learned a great deal about Aβ in DS in terms of characterizing age of onset of this pathology and it is exciting to note that there is a clinical trial in DS targeting Aβ that may lead to clinical benefits.
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Affiliation(s)
- Elizabeth Head
- University of Kentucky, Sanders-Brown Center on Aging, 800 South Limestone Street, Lexington, KY 40536, United States; University of Kentucky, Department of Pharmacology & Nutritional Sciences, Lexington, KY 40536, United States.
| | - Alex M Helman
- University of Kentucky, Sanders-Brown Center on Aging, 800 South Limestone Street, Lexington, KY 40536, United States; University of Kentucky, Department of Pharmacology & Nutritional Sciences, Lexington, KY 40536, United States; University of Kentucky, Magnetic Resonance Imaging and Spectroscopy Center, Lexington, KY 40536, United States; University of Kentucky, Department of Neurology, Lexington, KY 40536, United States
| | - David Powell
- University of Kentucky, Magnetic Resonance Imaging and Spectroscopy Center, Lexington, KY 40536, United States
| | - Frederick A Schmitt
- University of Kentucky, Sanders-Brown Center on Aging, 800 South Limestone Street, Lexington, KY 40536, United States; University of Kentucky, Department of Neurology, Lexington, KY 40536, United States
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13
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MFG-E8 Selectively Inhibited Aβ-Induced Microglial M1 Polarization via NF-κB and PI3K-Akt Pathways. Mol Neurobiol 2016; 54:7777-7788. [PMID: 27844286 DOI: 10.1007/s12035-016-0255-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
Abstract
Activated microglia are classified into two specific states: classically activated (M1) and alternatively activated (M2) subtypes. It is believed that the polarization of M1/M2 phenotype plays an important role in Alzheimer's disease (AD). However, the mechanisms regulating this process remain unclear. Thus, we addressed this question focusing on milk fat globule epidermal growth factor 8 (MFG-E8). MFG-E8 is a unique protein which can bind to microglia and regulate its inflammatory responses. It is speculated that it might play a role in the balance of microglial polarization. In the current study, we used fibril Aβ42 in vitro to stimulate mouse primary microglial cultures and found subsequent M1 marker expression, along with retained M2 marker production. Then, we discovered that MFG-E8 pretreatment reversed the increased trend of M1 markers and the decreased expression of M2 markers, which were induced by Aβ42. Moreover, MFG-E8 effects could be effectively blocked by an MFG-E8 antibody. Further analysis on the signaling pathways showed that NF-κB upregulation and Akt downregulation in microglial cultures were observed after Aβ42 incubation. And the alteration of these pathways could also be reversed by MFG-E8. We then assessed the effects of NF-κB and PI3K-Akt on M1/M2 alteration using their specific inhibitors. Pyrrolidine dithiocarbamate, a NF-κB inhibitor, inhibited M1 marker expression; moreover, LY294002, an Akt inhibitor, enhanced M1 marker expression. Our study indicated the regulatory role of MFG-E8 on microglia M1/M2 alteration for the first time, providing a basis for understanding the potential role of microglia activation in AD.
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14
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Liu J, Yang B, Ke J, Li W, Suen WC. Antibody-Based Drugs and Approaches Against Amyloid-β Species for Alzheimer’s Disease Immunotherapy. Drugs Aging 2016; 33:685-697. [DOI: 10.1007/s40266-016-0406-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Abnormal tau induces cognitive impairment through two different mechanisms: synaptic dysfunction and neuronal loss. Sci Rep 2016; 6:20833. [PMID: 26888634 PMCID: PMC4757872 DOI: 10.1038/srep20833] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 01/08/2016] [Indexed: 01/26/2023] Open
Abstract
The hyperphosphorylated microtubule-associated protein tau is present in several neurodegenerative diseases, although the causal relationship remains elusive. Few mouse models used to study Alzheimer-like dementia target tau phosphorylation. We created an inducible pseudophosphorylated tau (Pathological Human Tau, PH-Tau) mouse model to study the effect of conformationally modified tau in vivo. Leaky expression resulted in two levels of PH-Tau: low basal level and higher upon induction (4% and 14% of the endogenous tau, respectively). Unexpectedly, low PH-Tau resulted in significant cognitive deficits, decrease in the number of synapses (seen by EM in the CA1 region), reduction of synaptic proteins, and localization to the nucleus. Induction of PH-Tau triggered neuronal death (60% in CA3), astrocytosis, and loss of the processes in CA1. These findings suggest, that phosphorylated tau is sufficient to induce neurodegeneration and that two different mechanisms can induce cognitive impairment depending on the levels of PH-Tau expression.
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EPPS rescues hippocampus-dependent cognitive deficits in APP/PS1 mice by disaggregation of amyloid-β oligomers and plaques. Nat Commun 2015; 6:8997. [PMID: 26646366 PMCID: PMC4686862 DOI: 10.1038/ncomms9997] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/23/2015] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by the transition of amyloid-β (Aβ) monomers into toxic oligomers and plaques. Given that Aβ abnormality typically precedes the development of clinical symptoms, an agent capable of disaggregating existing Aβ aggregates may be advantageous. Here we report that a small molecule, 4-(2-hydroxyethyl)-1-piperazinepropanesulphonic acid (EPPS), binds to Aβ aggregates and converts them into monomers. The oral administration of EPPS substantially reduces hippocampus-dependent behavioural deficits, brain Aβ oligomer and plaque deposits, glial γ-aminobutyric acid (GABA) release and brain inflammation in an Aβ-overexpressing, APP/PS1 transgenic mouse model when initiated after the development of severe AD-like phenotypes. The ability of EPPS to rescue Aβ aggregation and behavioural deficits provides strong support for the view that the accumulation of Aβ is an important mechanism underlying AD. Amyloid-beta deposits are a pathological hallmark of Alzheimer's disease, and have previously been targeted in immunisation therapies. Here, the authors show that oral administration of the small molecule EPPS reduces Aß plaque and oligomer load in APP/PS1 mice and improves learning and memory performance.
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Tau immunotherapy modulates both pathological tau and upstream amyloid pathology in an Alzheimer's disease mouse model. J Neurosci 2015; 35:4857-68. [PMID: 25810517 DOI: 10.1523/jneurosci.4989-14.2015] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In Alzheimer's disease (AD), the pathological accumulation of tau appears to be a downstream effect of amyloid β protein (Aβ). However, the relationship between these two proteins and memory loss is unclear. In this study, we evaluated the specific removal of pathological tau oligomers in aged Tg2576 mice by passive immunotherapy using tau oligomer-specific monoclonal antibody. Removal of tau oligomers reversed memory deficits and accelerated plaque deposition in the brain. Surprisingly, Aβ*56 levels decreased, suggesting a link between tau and Aβ oligomers in the promotion of cognitive decline. The results suggest that tau oligomerization is not only a consequence of Aβ pathology but also a critical mediator of the toxic effects observed afterward in AD. Overall, these findings support the potential of tau oligomers as a therapeutic target for AD.
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18
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Down syndrome individuals with Alzheimer's disease have a distinct neuroinflammatory phenotype compared to sporadic Alzheimer's disease. Neurobiol Aging 2015; 36:2468-74. [PMID: 26103884 DOI: 10.1016/j.neurobiolaging.2015.05.016] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/25/2015] [Accepted: 05/26/2015] [Indexed: 01/24/2023]
Abstract
Down syndrome (DS) is the most common genetic cause of intellectual disability and is primarily caused by the triplication of chromosome 21. The overexpression of amyloid precursor protein gene may be sufficient to drive Alzheimer's disease (AD) neuropathology that is observed in virtually all individuals with DS by the age of 40 years. There is relatively little information about inflammation in the DS brain and how the genetics of DS may alter inflammatory responses and modify the course of AD pathogenesis in this disorder. Using the macrophage classification system of M1, M2a, M2b, and M2c inflammatory phenotypes, we have shown that the early stages of AD are associated with a bias toward an M1 or M2a phenotype. In later stages of AD, markers of M1, M2a and M2c are elevated. We now report the inflammatory phenotype in a DS autopsy series to compare this with the progression in sporadic AD. Tissue from young DS cases (under 40 years of age, pre-AD) show a bias toward M1 and M2b states with little M2a or M2c observed. Older DS cases (over 40 with AD pathology) show a distinct bias toward an M2b phenotype. Importantly, this is distinct from sporadic AD where the M2b phenotype has been rarely, if ever observed in postmortem studies. Stimulated by immune complex activation of microglial cells and toll-like receptor activation, the M2b phenotype represents a unique neuroinflammatory state in diseased brain and may have significant implications for therapeutic intervention for persons with DS.
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19
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Murakami K. Conformation-specific antibodies to target amyloid β oligomers and their application to immunotherapy for Alzheimer's disease. Biosci Biotechnol Biochem 2015; 78:1293-305. [PMID: 25130729 DOI: 10.1080/09168451.2014.940275] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Amyloid β-protein (Aβ) oligomers, intermediates of Aβ aggregation, cause cognitive impairment and synaptotoxicity in the pathogenesis of Alzheimer's disease (AD). Immunotherapy using anti-Aβ antibody is one of the most promising approaches for AD treatment. However, most clinical trials using conventional sequence-specific antibodies have proceeded with difficulty. This is probably due to the unintended removal of the non-pathological monomer and fibrils of Aβ as well as the pathological oligomers by these antibodies that recognize Aβ sequence, which is not involved in synaptotoxicity. Several efforts have been made recently to develop conformation-specific antibodies that target the tertiary structure of Aβ oligomers. Here, we review the recent findings of Aβ oligomers and anti-Aβ antibodies including our own, and discuss their potential as therapeutic and diagnostic tools.
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Affiliation(s)
- Kazuma Murakami
- a Division of Food Science and Biotechnology , Graduate School of Agriculture, Kyoto University , Kyoto , Japan
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20
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Weissmiller AM, Natera-Naranjo O, Reyna SM, Pearn ML, Zhao X, Nguyen P, Cheng S, Goldstein LSB, Tanzi RE, Wagner SL, Mobley WC, Wu C. A γ-secretase inhibitor, but not a γ-secretase modulator, induced defects in BDNF axonal trafficking and signaling: evidence for a role for APP. PLoS One 2015; 10:e0118379. [PMID: 25710492 PMCID: PMC4339551 DOI: 10.1371/journal.pone.0118379] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/14/2015] [Indexed: 11/19/2022] Open
Abstract
Clues to Alzheimer disease (AD) pathogenesis come from a variety of different sources including studies of clinical and neuropathological features, biomarkers, genomics and animal and cellular models. An important role for amyloid precursor protein (APP) and its processing has emerged and considerable interest has been directed at the hypothesis that Aβ peptides induce changes central to pathogenesis. Accordingly, molecules that reduce the levels of Aβ peptides have been discovered such as γ-secretase inhibitors (GSIs) and modulators (GSMs). GSIs and GSMs reduce Aβ levels through very different mechanisms. However, GSIs, but not GSMs, markedly increase the levels of APP CTFs that are increasingly viewed as disrupting neuronal function. Here, we evaluated the effects of GSIs and GSMs on a number of neuronal phenotypes possibly relevant to their use in treatment of AD. We report that GSI disrupted retrograde axonal trafficking of brain-derived neurotrophic factor (BDNF), suppressed BDNF-induced downstream signaling pathways and induced changes in the distribution within neuronal processes of mitochondria and synaptic vesicles. In contrast, treatment with a novel class of GSMs had no significant effect on these measures. Since knockdown of APP by specific siRNA prevented GSI-induced changes in BDNF axonal trafficking and signaling, we concluded that GSI effects on APP processing were responsible, at least in part, for BDNF trafficking and signaling deficits. Our findings argue that with respect to anti-amyloid treatments, even an APP-specific GSI may have deleterious effects and GSMs may serve as a better alternative.
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Affiliation(s)
- April M. Weissmiller
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - Orlangie Natera-Naranjo
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - Sol M. Reyna
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, United States of America
| | - Matthew L. Pearn
- Department of Anesthesiology, University of California San Diego, San Diego, California, United States of America
- V.A. San Diego Healthcare System, San Diego, California, United States of America
| | - Xiaobei Zhao
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - Phuong Nguyen
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - Soan Cheng
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - Lawrence S. B. Goldstein
- Department of Cellular and Molecular Medicine, University of California San Diego, San Diego, California, United States of America
| | - Rudolph E. Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Steven L. Wagner
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - William C. Mobley
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
| | - Chengbiao Wu
- Department of Neurosciences, University of California San Diego, San Diego, California, United States of America
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21
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Löffler T, Flunkert S, Havas D, Schweinzer C, Uger M, Windisch M, Steyrer E, Hutter-Paier B. Neuroinflammation and related neuropathologies in APPSL mice: further value of this in vivo model of Alzheimer's disease. J Neuroinflammation 2014; 11:84. [PMID: 24886182 PMCID: PMC4108132 DOI: 10.1186/1742-2094-11-84] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 04/10/2014] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Beyond cognitive decline, Alzheimer's disease (AD) is characterized by numerous neuropathological changes in the brain. Although animal models generally do not fully reflect the broad spectrum of disease-specific alterations, the APPSL mouse model is well known to display early plaque formation and to exhibit spatial learning and memory deficits. However, important neuropathological features, such as neuroinflammation and lipid peroxidation, and their progression over age, have not yet been described in this AD mouse model. METHODS Hippocampal and neocortical tissues of APPSL mice at different ages were evaluated. One hemisphere from each mouse was examined for micro- and astrogliosis as well as concomitant plaque load. The other hemisphere was evaluated for lipid peroxidation (quantified by a thiobarbituric acid reactive substances (TBARS) assay), changes in Aβ abundance (Aβ38, Aβ40 and Aβ42 analyses), as well as determination of aggregated Aβ content (Amorfix A4 assay). Finally, correlation analyses were performed to illustrate the time-dependent correlation between neuroinflammation and Aβ load (soluble, insoluble, fibrils), or lipid peroxidation, respectively. RESULTS As is consistent with previous findings, neuroinflammation starts early and shows strong progression over age in the APPSL mouse model. An analyses of concomitant Aβ load and plaque deposition revealed a similar progression, and high correlations between neuroinflammation markers and soluble or insoluble Aβ or fibrillar amyloid plaque loads were observed. Lipid peroxidation, as measured by TBARS levels, correlates well with neuroinflammation in the neocortex but not the hippocampus. The hippocampal lipid peroxidation correlated strongly with the increase of LOC positive fiber load, whereas neocortical TBARS levels were unrelated to amyloidosis. CONCLUSIONS These data illustrate for the first time the progression of major AD related neuropathological features other than plaque load in the APPSL mouse model. Specifically, we demonstrate that microgliosis and astrocytosis are prominent aspects of this AD mouse model. The strong correlation of neuroinflammation with amyloid burden and lipid peroxidation underlines the importance of these pathological factors for the development of AD. The new finding of a different relation of lipid peroxidation in the hippocampus and neocortical regions show that the model might contribute to the understanding of complex pathological mechanisms and their interplay in AD.
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Affiliation(s)
- Tina Löffler
- QPS-Austria GmbH, Parkring 12, 8074 Grambach, Austria
- Institute of Molecular Biology and Biochemistry, Medical University Graz, Harrachgasse 21, 8010 Graz, Austria
| | | | - Daniel Havas
- QPS-Austria GmbH, Parkring 12, 8074 Grambach, Austria
| | | | - Marni Uger
- Amorfix Life Sciences Ltd, 3403 American Drive, Ontario, Canada L4V 1 T4
| | | | - Ernst Steyrer
- Institute of Molecular Biology and Biochemistry, Medical University Graz, Harrachgasse 21, 8010 Graz, Austria
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Abstract
A hallmark of Alzheimer's disease (AD) brain is the amyloid β (Aβ) plaque, which is comprised of Aβ peptides. Multiple lines of evidence suggest that Aβ oligomers are more toxic than other peptide forms. We sought to develop a robust assay to quantify oligomers from CSF. Antibody 19.3 was compared in one-site and competitive ELISAs for oligomer binding specificity. A two-site ELISA for oligomers was developed using 19.3 coupled to a sensitive, bead-based fluorescent platform able to detect single photons of emitted light. The two-site ELISA was >2500× selective for Aβ oligomers over Aβ monomers with a limit of detection ∼ 0.09 pg/ml in human CSF. The lower limit of reliable quantification of the assay was 0.18 pg/ml and the antibody pairs recognized Aβ multimers comprised of either synthetic standards, or endogenous oligomers isolated from confirmed human AD and healthy control brain. Using the assay, a significant 3- to 5-fold increase in Aβ oligomers in human AD CSF compared with comparably aged controls was demonstrated. The increase was seen in three separate human cohorts, totaling 63 AD and 54 controls. CSF oligomers ranged between 0.1 and 10 pg/ml. Aβ oligomer levels did not strongly associate with age or gender, but had an inverse correlation with MMSE score. The C statistic for the Aβ oligomer ROC curve was 0.86, with 80% sensitivity and 88% specificity to detect AD, suggesting reasonable discriminatory power for the AD state and the potential for utility as a diagnostic marker.
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Yang DT, Joshi G, Cho PY, Johnson JA, Murphy RM. Transthyretin as both a sensor and a scavenger of β-amyloid oligomers. Biochemistry 2013; 52:2849-61. [PMID: 23570378 DOI: 10.1021/bi4001613] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Transthyretin (TTR) is a homotetrameric transport protein, assembled from monomers that each contain two four-stranded β-sheets and a short α-helix and loop. In the tetramer, the "inner" β-sheet forms a hydrophobic pocket while the helix and loop are solvent-exposed. β-Amyloid (Aβ) aggregates bind to TTR, and the level of binding is significantly reduced in mutants L82A (on the loop) and L110A (on the inner β-sheet). Protection against Aβ toxicity was demonstrated for wild-type TTR but not L82A or L110A, providing a direct link between TTR-Aβ binding and TTR-mediated cytoprotection. Protection is afforded at substoichiometric (1:100) TTR:Aβ molar ratios, and the level of binding of Aβ to TTR is highest for partially aggregated materials and decreased for freshly prepared or heavily aggregated Aβ, suggesting that TTR binds selectively to soluble toxic Aβ aggregates. A novel technique, nanoparticle tracking, is used to show that TTR arrests Aβ aggregation by both preventing formation of new aggregates and inhibiting growth of existing aggregates. TTR tetramers are normally quite stable; tetrameric structure is necessary for the protein's transport functions, and mutations that decrease tetramer stability have been linked to TTR amyloid diseases. However, TTR monomers bind more Aβ than do tetramers, presumably because the hydrophobic inner sheet is solvent-exposed upon tetramer disassembly. Wild-type and L110A tetramers, but not L82A, were destabilized upon being co-incubated with Aβ, suggesting that binding of Aβ to L82 triggers tetramer dissociation. Taken together, these results suggest a novel mechanism of action for TTR: the EF helix/loop "senses" the presence of soluble toxic Aβ oligomers, triggering destabilization of TTR tetramers and exposure of the hydrophobic inner sheet, which then "scavenges" these toxic oligomers and prevents them from causing cell death.
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Affiliation(s)
- Dennis T Yang
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI 53706, USA
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24
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Akitake Y, Nakatani Y, Kamei D, Hosokawa M, Akatsu H, Uematsu S, Akira S, Kudo I, Hara S, Takahashi M. Microsomal prostaglandin E synthase-1 is induced in alzheimer's disease and its deletion mitigates alzheimer's disease-like pathology in a mouse model. J Neurosci Res 2013; 91:909-19. [DOI: 10.1002/jnr.23217] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 12/30/2012] [Accepted: 01/30/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Yoshiharu Akitake
- Department of Clinical Pharmacology; Faculty of Pharmaceutical Sciences; Fukuoka University; Fukuoka; Japan
| | - Yoshihito Nakatani
- Department of Health Chemistry; School of Pharmacy; Showa University; Tokyo; Japan
| | | | | | - Hiroyasu Akatsu
- Choju Medical Institute; Fukushimura Hospital; Toyohashi; Aichi; Japan
| | - Satoshi Uematsu
- Department of Host Defense; Research Institute for Microbial Diseases; Osaka University; Osaka; Japan
| | - Shizuo Akira
- Department of Host Defense; Research Institute for Microbial Diseases; Osaka University; Osaka; Japan
| | - Ichiro Kudo
- Department of Health Chemistry; School of Pharmacy; Showa University; Tokyo; Japan
| | - Shuntaro Hara
- Department of Health Chemistry; School of Pharmacy; Showa University; Tokyo; Japan
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25
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Coalier KA, Paranjape GS, Karki S, Nichols MR. Stability of early-stage amyloid-β(1-42) aggregation species. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:65-70. [PMID: 22944394 DOI: 10.1016/j.bbapap.2012.08.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 08/17/2012] [Accepted: 08/20/2012] [Indexed: 11/16/2022]
Abstract
Accumulation of aggregated amyloid-β protein (Aβ) is an important feature of Alzheimer's disease. There is significant interest in understanding the initial steps of Aβ aggregation due to the recent focus on soluble Aβ oligomers. In vitro studies of Aβ aggregation have been aided by the use of conformation-specific antibodies which recognize shape rather than sequence. One of these, OC antiserum, recognizes certain elements of fibrillar Aβ across a broad range of sizes. We have observed the presence of these fibrillar elements at very early stages of Aβ incubation. Using a dot blot assay, OC-reactivity was found in size exclusion chromatography (SEC)-purified Aβ(1-42) monomer fractions immediately after isolation (early-stage). The OC-reactivity was not initially observed in the same fractions for Aβ(1-40) or the aggregation-restricted Aβ(1-42) L34P but was detected within 1-2weeks of incubation. Stability studies demonstrated that early-stage OC-positive Aβ(1-42) aggregates were resistant to 4M urea or guanidine hydrochloride but sensitive to 1% sodium dodecyl sulfate (SDS). Interestingly, the sensitivity to SDS diminished over time upon incubation of the SEC-purified Aβ(1-42) solution at 4°C. Within 6-8days the OC-positive Aβ42 aggregates were resistant to SDS denaturation. The progression to, and development of, SDS resistance for Aβ(1-42) occurred prior to thioflavin T fluorescence. In contrast, Aβ(1-40) aggregates formed after 6days of incubation were sensitive to both urea and SDS. These findings reveal information on some of the earliest events in Aβ aggregation and suggest that it may be possible to target early-stage aggregates before they develop significant stability.
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Affiliation(s)
- Kelley A Coalier
- Department of Chemistry and Biochemistry and Center for Nanoscience, University of Missouri-St. Louis, MO 63121, USA
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Lioudyno MI, Broccio M, Sokolov Y, Rasool S, Wu J, Alkire MT, Liu V, Kozak JA, Dennison PR, Glabe CG, Lösche M, Hall JE. Effect of synthetic aβ peptide oligomers and fluorinated solvents on Kv1.3 channel properties and membrane conductance. PLoS One 2012; 7:e35090. [PMID: 22563377 PMCID: PMC3338507 DOI: 10.1371/journal.pone.0035090] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 03/12/2012] [Indexed: 01/07/2023] Open
Abstract
The impact of synthetic amyloid β (1–42) (Aβ1–42) oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs) was quantified for protocols using hexafluoroisopropanol (HFIP) or sodium hydroxide (NaOH) as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ1–42 samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ1–42 oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect on current amplitude. In contrast to oligomeric samples, freshly prepared, presumably monomeric, Aβ1–42 solutions had no effect on Kv 1.3 channel properties. Aβ1–42 oligomers had no effect on the steady-state current (at −80 mV) recorded from Kv 1.3-expressing cells but increased the conductance of artificial BLMs in a dose-dependent fashion. Formation of amyloid channels, however, was not observed due to conditions of the experiments. To exclude the effects of HFIP (used to dissolve lyophilized Aβ1–42 peptide), and trifluoroacetic acid (TFA) (used during Aβ1–42 synthesis), we determined concentrations of these fluorinated compounds in the stock Aβ1–42 solutions by 19F NMR. After extensive evaporation, the concentration of HFIP in the 100× stock Aβ1–42 solutions was ∼1.7 μM. The concentration of residual TFA in the 70× stock Aβ1–42 solutions was ∼20 μM. Even at the stock concentrations neither HFIP nor TFA alone had any effect on potassium currents or BLMs. The Aβ1–42 oligomers prepared with HFIP as solvent, however, were more potent in the electrophysiological tests, suggesting that fluorinated compounds, such as HFIP or structurally-related inhalational anesthetics, may affect Aβ1–42 aggregation and potentially enhance ability of oligomers to modulate voltage-gated ion channels and biological membrane properties.
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Affiliation(s)
- Maria I. Lioudyno
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
| | - Matteo Broccio
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Yuri Sokolov
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
| | - Suhail Rasool
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Jessica Wu
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Michael T. Alkire
- Department of Anesthesiology and Perioperative Care, University of California Irvine, Irvine, California, United States of America
| | - Virginia Liu
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
- Department of Anesthesiology and Perioperative Care, University of California Irvine, Irvine, California, United States of America
| | - J. Ashot Kozak
- Department of Neuroscience, Cell biology, and Physiology, Wright State University, Dayton, Ohio, United States of America
| | - Philip R. Dennison
- Department of Chemistry, University of California Irvine, Irvine, California, United States of America
| | - Charles G. Glabe
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, United States of America
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - James E. Hall
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
- * E-mail:
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Laganowsky A, Liu C, Sawaya MR, Whitelegge JP, Park J, Zhao M, Pensalfini A, Soriaga A, Landau M, Teng PK, Cascio D, Glabe C, Eisenberg D. Atomic view of a toxic amyloid small oligomer. Science 2012; 335:1228-31. [PMID: 22403391 PMCID: PMC3959867 DOI: 10.1126/science.1213151] [Citation(s) in RCA: 464] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Amyloid diseases, including Alzheimer's, Parkinson's, and the prion conditions, are each associated with a particular protein in fibrillar form. These amyloid fibrils were long suspected to be the disease agents, but evidence suggests that smaller, often transient and polymorphic oligomers are the toxic entities. Here, we identify a segment of the amyloid-forming protein αB crystallin, which forms an oligomeric complex exhibiting properties of other amyloid oligomers: β-sheet-rich structure, cytotoxicity, and recognition by an oligomer-specific antibody. The x-ray-derived atomic structure of the oligomer reveals a cylindrical barrel, formed from six antiparallel protein strands, that we term a cylindrin. The cylindrin structure is compatible with a sequence segment from the β-amyloid protein of Alzheimer's disease. Cylindrins offer models for the hitherto elusive structures of amyloid oligomers.
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Affiliation(s)
- Arthur Laganowsky
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Cong Liu
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Michael R. Sawaya
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Julian P. Whitelegge
- The NPI-Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, USA
| | - Jiyong Park
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Minglei Zhao
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Anna Pensalfini
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California, USA
| | - Angela Soriaga
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Meytal Landau
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Poh K. Teng
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Duilio Cascio
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
| | - Charles Glabe
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California, USA
| | - David Eisenberg
- Howard Hughes Medical Institute, UCLA-DOE, Institute for Genomics and Proteomics, Departments of Biological Chemistry and Chemistry & Biochemistry, Los Angeles, California, USA
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Iwasaki Y, Negishi T, Inoue M, Tashiro T, Tabira T, Kimura N. Sendai virus vector-mediated brain-derived neurotrophic factor expression ameliorates memory deficits and synaptic degeneration in a transgenic mouse model of Alzheimer's disease. J Neurosci Res 2012; 90:981-9. [DOI: 10.1002/jnr.22830] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 10/18/2011] [Accepted: 10/21/2011] [Indexed: 11/11/2022]
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29
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Cenini G, Dowling ALS, Beckett TL, Barone E, Mancuso C, Murphy MP, Levine H, Lott IT, Schmitt FA, Butterfield DA, Head E. Association between frontal cortex oxidative damage and beta-amyloid as a function of age in Down syndrome. Biochim Biophys Acta Mol Basis Dis 2011; 1822:130-8. [PMID: 22009041 DOI: 10.1016/j.bbadis.2011.10.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 09/30/2011] [Accepted: 10/03/2011] [Indexed: 11/17/2022]
Abstract
Down syndrome (DS) is the most common genetic cause of intellectual disability in children, and the number of adults with DS reaching old age is increasing. By the age of 40 years, virtually all people with DS have sufficient neuropathology for a postmortem diagnosis of Alzheimer disease (AD). Trisomy 21 in DS leads to an overexpression of many proteins, of which at least two are involved in oxidative stress and AD: superoxide dismutase 1 (SOD1) and amyloid precursor protein (APP). In this study, we tested the hypothesis that DS brains with neuropathological hallmarks of AD have more oxidative and nitrosative stress than those with DS but without significant AD pathology, as compared with similarly aged-matched non-DS controls. The frontal cortex was examined in 70 autopsy cases (n=29 control and n=41 DS). By ELISA, we quantified soluble and insoluble Aβ40 and Aβ42, as well as oligomers. Oxidative and nitrosative stress levels (protein carbonyls, 4-hydroxy-2-trans-nonenal (HNE)-bound proteins, and 3-nitrotyrosine) were measured by slot-blot. We found that soluble and insoluble amyloid beta peptide (Aβ) and oligomers increase as a function of age in DS frontal cortex. Of the oxidative stress markers, HNE-bound proteins were increased overall in DS. Protein carbonyls were correlated with Aβ40 levels. These results suggest that oxidative damage, but not nitrosative stress, may contribute to the onset and progression of AD pathogenesis in DS. Conceivably, treatment with antioxidants may provide a point of intervention to slow pathological alterations in DS.
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Affiliation(s)
- Giovanna Cenini
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536-0055, USA
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Bruce-Keller AJ, Gupta S, Knight AG, Beckett TL, McMullen JM, Davis PR, Murphy MP, Van Eldik LJ, St Clair D, Keller JN. Cognitive impairment in humanized APP×PS1 mice is linked to Aβ(1-42) and NOX activation. Neurobiol Dis 2011; 44:317-26. [PMID: 21798347 DOI: 10.1016/j.nbd.2011.07.012] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/11/2011] [Accepted: 07/11/2011] [Indexed: 02/08/2023] Open
Abstract
Cognitive impairment in Alzheimer's disease (AD) is strongly associated with both extensive deposition of amyloid β peptides and oxidative stress, but the exact role of these indices in the development of dementia is not clear. This study was designed to determine the relationship between cognitive impairment, activation of the free radical producing enzyme NADPH oxidase (NOX), and progressive changes in Aβ deposition and solubility in humanized APP×PS1 knock-in mice of increasing age. Data show that cognitive performance and expression of key synaptic proteins were progressively decreased in aging APP×PS1 mice. Likewise, NOX activity and expression of the specific NOX subunit NOX4 were significantly increased in APP×PS1 mice in an age-dependent manner, and NOX activity and cognitive impairment shared a significant linear relationship. Data further show that age-dependent increases in Aβ(1-42) had a significant linear relationship with both NOX activity and cognitive performance in APP×PS1 knock-in mice. Collectively, these data show that NOX expression and activity are significantly upregulated with age in this humanized model of Aβ pathogenesis, and suggest that NOX-associated redox pathways are intimately linked to both the loss of cognitive function and the deposition of Aβ(1-42).
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Affiliation(s)
- Annadora J Bruce-Keller
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
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Cai Y, Xiong K, Zhang XM, Cai H, Luo XG, Feng JC, Clough RW, Struble RG, Patrylo PR, Chu Y, Kordower JH, Yan XX. β-Secretase-1 elevation in aged monkey and Alzheimer's disease human cerebral cortex occurs around the vasculature in partnership with multisystem axon terminal pathogenesis and β-amyloid accumulation. Eur J Neurosci 2010; 32:1223-38. [PMID: 20726888 DOI: 10.1111/j.1460-9568.2010.07376.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is the most common dementia-causing disorder in the elderly; it may be related to multiple risk factors, and is characterized pathologically by cerebral hypometabolism, paravascular β-amyloid peptide (Aβ) plaques, neuritic dystrophy, and intra-neuronal aggregation of phosphorylated tau. To explore potential pathogenic links among some of these lesions, we examined β-secretase-1 (BACE1) alterations relative to Aβ deposition, neuritic pathology and vascular organization in aged monkey and AD human cerebral cortex. Western blot analyses detected increased levels of BACE1 protein and β-site-cleavage amyloid precursor protein C-terminal fragments in plaque-bearing human and monkey cortex relative to controls. In immunohistochemistry, locally elevated BACE1 immunoreactivity (IR) occurred in AD but not in control human cortex, with a trend for increased overall density among cases with greater plaque pathology. In double-labeling preparations, BACE1 IR colocalized with immunolabeling for Aβ but not for phosphorylated tau. In perfusion-fixed monkey cortex, locally increased BACE1 IR co-existed with intra-axonal and extracellular Aβ IR among virtually all neuritic plaques, ranging from primitive to typical cored forms. This BACE1 labeling localized to swollen/sprouting axon terminals that might co-express one or another neuronal phenotype markers (GABAergic, glutamatergic, cholinergic, or catecholaminergic). Importantly, these BACE1-labeled dystrophic axons resided near to or in direct contact with blood vessels. These findings suggest that plaque formation in AD or normal aged primates relates to a multisystem axonal pathogenesis that occurs in partnership with a potential vascular or metabolic deficit. The data provide a mechanistic explanation for why senile plaques are present preferentially near the cerebral vasculature.
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Affiliation(s)
- Yan Cai
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, Hunan, China
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Seo H, Isacson O. The hAPP-YAC transgenic model has elevated UPS activity in the frontal cortex similar to Alzheimer's disease and Down's syndrome. J Neurochem 2010; 114:1819-26. [PMID: 20698932 DOI: 10.1111/j.1471-4159.2010.06902.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The ubiquitin-proteasome system (UPS) is critical for handling the intra-cellular load of abnormal and misfolded proteins in several neurodegenerative diseases. First, to determine the effects of the over-expression of human amyloid precursor protein (hAPP) on UPS, we measured proteasome activities using fluorescent substrates in the frontal cortex of hAPP-yeast artificial chromosome (YAC) transgenic (tg) mice (R1.40, hemizygous; Lamb, Nat Genet, 9, 4; 1995). Chymotrypsin and PGPH-like activities of proteasome were increased in frontal cortex of hAPP-YAC tg mice. These proteasome activities (both chymotrypsin and PGPH-like) were further increased by cholinergic stimulation in littermate control mice, but not in hAPP-YAC tg mice. Nerve growth factor (NGF) levels were decreased by hAPP over-expression in the frontal cortex and hippocampus of hAPP-YAC tg mice, and further decreased by M1 agonist treatment in the hippocampus of littermate control and hAPP-YAC tg mice. Interestingly, the frontal cortex (BA9 area) of Alzheimer's disease (AD) patients (Stage 3, n=11) and Down's syndrome (DS) patients (n=9) showed similar up-regulation of the UPS activities to those seen in hAPP-YAC tg mice. M1 agonist stimulation increased the activities of α-secretase, which were down-regulated by hAPP over-expression in the frontal cortex of hAPP-YAC tg mice. These results demonstrate that (i) hAPP-YAC tg mice have an up-regulation in the frontal cortex of the UPS similar to AD and DS patients; (ii) muscarinic stimulation increase UPS activities, increase secreted APP (APPs) levels, and decrease amyloid beta 42/40 ratio only in littermate controls, but not in hAPP-YAC tg mice. Taken together, these results suggest that both the adaptive reactions in the proteostatic network and pathological changes in AD and DS need to be considered in the future potential therapeutics.
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Affiliation(s)
- Hyemyung Seo
- Neuroregeneration Laboratories, Center for Neuroregeneration Research, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA.
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Zhang XM, Xiong K, Cai Y, Cai H, Luo XG, Feng JC, Clough RW, Patrylo PR, Struble RG, Yan XX. Functional deprivation promotes amyloid plaque pathogenesis in Tg2576 mouse olfactory bulb and piriform cortex. Eur J Neurosci 2010; 31:710-21. [PMID: 20384814 DOI: 10.1111/j.1460-9568.2010.07103.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cerebral hypometabolism and amyloid accumulation are principal neuropathological manifestations of Alzheimer's disease (AD). Whether and how brain/neuronal activity might modulate certain pathological processes of AD are interesting topics of recent clinical and basic research in the field, and may be of potential medical relevance in regard to both the disease etiology and intervention. Using the Tg2576 transgenic mouse model of AD, this study characterized a promotive effect of neuronal hypoactivity associated with functional deprivation on amyloid plaque pathogenesis in the olfactory pathway. Unilateral naris-occlusion caused beta-secretase-1 (BACE1) elevation in neuronal terminals in the deprived relative to the non-deprived bulb and piriform cortex in young adult mice. In parallel with the overall age-related plaque development in the forebrain, locally increased BACE1 immunoreactivity co-occurred with amyloid deposition first in the piriform cortex then within the bulb, more prominent on the deprived relative to the non-deprived side. Biochemical analyses confirmed elevated BACE1 protein levels, enzymatic activity and products in the deprived relative to non-deprived bulbs. Plaque-associated BACE1 immunoreactivity in the bulb and piriform cortex was localized preferentially to swollen/sprouting glutamatergic axonal terminals, with Abeta immunoreactivity occurring inside as well as around these terminals. Together, these findings suggest that functional deprivation or neuronal hypoactivity facilitates amyloid plaque formation in the forebrain in a transgenic model of AD, which operates synergistically with age effect. The data also implicate an intrinsic association of amyloid accumulation and plaque formation with progressive axonal pathology.
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Affiliation(s)
- Xue-Mei Zhang
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
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Dodel R, Neff F, Noelker C, Pul R, Du Y, Bacher M, Oertel W. Intravenous Immunoglobulins as a Treatment for Alzheimerʼs Disease. Drugs 2010; 70:513-28. [DOI: 10.2165/11533070-000000000-00000] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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35
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Communication breaks-Down: from neurodevelopment defects to cognitive disabilities in Down syndrome. Prog Neurobiol 2010; 91:1-22. [PMID: 20097253 DOI: 10.1016/j.pneurobio.2010.01.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 12/10/2009] [Accepted: 01/14/2010] [Indexed: 12/31/2022]
Abstract
Down syndrome (DS) is the leading cause of genetically-defined intellectual disability and congenital birth defects. Despite being one of the first genetic diseases identified, only recently, thanks to the phenotypic analysis of DS mouse genetic models, we have begun to understand how trisomy may impact cognitive function. Cognitive disabilities in DS appear to result mainly from two pathological processes: neurogenesis impairment and Alzheimer-like degeneration. In DS brain, suboptimal network architecture and altered synaptic communication arising from neurodevelopmental impairment are key determinants of cognitive defects. Hypocellularity and hypoplasia start at early developmental stages and likely depend upon impaired proliferation of neuronal precursors, resulting in reduction of numbers of neurons and synaptic contacts. The impairment of neuronal precursor proliferation extends to adult neurogenesis and may affect learning and memory. Neurodegenerative mechanisms also contribute to DS cognitive impairment. Early onset Alzheimer disease occurs with extremely high incidence in DS patients and is causally-related to overexpression of beta-amyloid precursor protein (betaAPP), which is one of the triplicated genes in DS. In this review, we will survey the available findings on neurodevelopmental and neurodegenerative changes occurring in DS throughout life. Moreover, we will discuss the potential mechanisms by which defects in neurogenesis and neurodegenerative processes lead to altered formation of neural circuits and impair cognitive function, in connection with findings on pharmacological treatments of potential benefit for DS.
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Jellinger KA. Recent advances in our understanding of neurodegeneration. J Neural Transm (Vienna) 2009; 116:1111-62. [DOI: 10.1007/s00702-009-0240-y] [Citation(s) in RCA: 160] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 05/05/2009] [Indexed: 12/12/2022]
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